TrueLearn Flashcards
longterm outcomes after congenital diaphragmatic hernia repair
chronic pulmonary disease (emphysematous changes, bronchopulmonary dysplasia, reactive airway disease, pulmonary hypertension, pneumonia); usually imporves over the first two years but hypoplastic lungs never reach normal function
developmental delay (lung disease/hypoxemia, postnatal growth failure, prolonged hospitalization)
congenital diaphragmatic hernia repair associated with higher recurrence
patch repair or laparoscopic repair of congenital diaphragmatic hernia
congenital diaphragmatic hernias on which side (left or right) are associated with better outcomes?
left sided CDH are associated with better outcomes
right sided CDH are more difficult to expose surgically (liver) and require a patch repair more frequently
what is the anatomical landmark of the resection plane when performing right and left hepatectomy?
middle hepatic vein; extends from the gallbladder fossa to the IVC
plane between the right and left lobe of the liver is called the midplane of the liver or Cantlie line
what is the anatomical landmark between the anterior and posterior segments of the right lobe of the liver?
right portal vein
what is the anatomical landmark for the plane between the medial and lateral segment of the left lobe of the liver?
round ligament at the umbilical fissure
what is the most common benign neoplasm of the spleen?
hemangioma
most commonly present as an incidental finding
may be solitary or multiple
bluish purple colored lesion
MRI is very sensitive/specific
biopsy is not recommended due to bleeding risk
typically asymptomatic but massive hemangiomas may rupture
splenectomy or partial splenectomy is indicated in cases of massive hemangioma with capsular distention and pain
management of pancreatic serous cystic neoplasms
very low risk of malignancy, should be resected if clearly symptomatic or if they cannot be distinguished from malignant cystic neoplasms
management of pancreatic mucinous cystic neoplasms
high risk of malignancy, should be resected regardless of size
management of main duct or mixed type intraductal papillary mucinous neoplasms (IPMN)
resection is indicated because of high risk of associated malignancy
management of branched duct intraductal papillary mucinous neoplasms (IPMN)
determined by size, symptoms, radiographic, and cytological findings
the following should be resected:
- branched duct IPMN >/= 3.0cm
- any symptomatic branched duct IPMN
- any branched duct IPMN associated with radiographic (mural nodules) or cytological findings concerning for malignancy
asymptomatic branch duct IPMN < 3.0cm without radiographic or cytologic findings concerning for malignancy should be followed by cross sectional imaging
nodular lymphoid hyperplasia (numerous polyps in the small and large intestine, rarely in the stomach)
enlarged submucosal lymphoid follicles associated with immunosupression (immunocompetent patients usually asymptomatic)
is colorectal or small intestine nodular lymphoid hyperplasia associated with increased malignancy?
colorectal nodular lymphoid hyperplasia is not associated with increased malignancy but small intestine nodular lymphoid hyperplasia is associated with increased incidence of lymphoma
what is the lymphatic drainage of the cervical esophagus?
internal jugular and upper tracheal lymph nodes
what is the lymphatic drainage of the dorsal esophagus?
posterior mediastinal lymph nodes
what is the lymphatic drainage of the anterior portion of the thoracic esophagus
tracheal lymph nodes superiorly and subcarinal/paraesophageal lymph nodes inferiorly
what is the lymphatic drainage of the abdominal esophagus?
cardiac and celiac lymph nodes which eventually drain into the cisterna chyli or the thoracic duct
lymphatic drainage from the upper 2/3 of the esophagus goes in what direction?
cephalad
lymphatic drainage from the lower 1/3 of the esophagus goes in what direction?
cephalad and caudad
where are insulinomas found?
over 99% are found in the pancreas, rare cases are found in ectopic pancreatic tissue
5% are associated with tumors of the parathyroid glands and pituitary (MEN1)
most insulinomas are <2cm
insulinomas are uniformly distributed throughout the pancreas
how is chylothorax diagnosed?
high triglyceride levels in pleural fluid (>110mg/dL)
what is the treatment of chylothorax?
depends on cause and severity
postoperative chylothorax: initially conservative; drainage of >500mL/day predicts failure of conservative treatment
thorascopic thoracic duct ligation is the surgical treatment of choice
lymphoma related chylothorax should initially be managed with thoracentesis, conservative measures, and treatment of the underlying cause
other treatment options include thoracoscopic talc pleurodesis, thoracic duct ligation or pleuroperitoneal shunting
transabdominal percutaneous embolization of the thoracic duct is an alternative to surgical ligation (not widely available)
what is the most common subtype of melanoma?
superficial spreading melanoma; initially grows in a radial fashion but has the potential for a vertical growth phase if untreated
what type of melanoma is most commonly seen in sun-exposed elderly patients?
lentigo maligna melanoma; associated with slow growth and the best overall prognosis
what type of melanoma is most commonly seen in the hands and feet of African Americans
acral lentiginous melanoma; associated with delayed diagnosis and poor prognosis
what type of melanoma has an early vertical growth phase and has the worst overall prognosis of any subtype?
nodular melanoma
what are symptoms of sarcoidosis? how is it diagnosed and treated?
in sarcoidosis abnormal collections of chronic inflammatory cells (noncaseating granulomas) form in multiple organs
dyspnea, dry cough
erythema nodosum, uveitis
hilar adenopathy
diagnosed with biopsy via bronchoscopy or open lung biopsy
treated with steroids
where is cholecystokinin produced?
I cells of the duodenum and jejunum
what causes release of cholecystokinin?
ingestion of fat, protein and amino acids (enteroendocrine cells)
what does cholecystokinin cause?
inhibition of proximal gastric motility
increased antral and pyloric contraction
relaxation of the sphincter of Oddi
stimulation of gallbladder contraction and pancreatic secretion
clinical presentation concerning for scaphoid fracture
fall on outstretched hand
pain worse with palpation over the snuffbox
diagnosis of scaphoid fractures
immediate post injury XR may not show the fracture
CT or MRI may assist with diagnosis or a thumb spica cast can be applied and XR repeated in 2 weeks
management of scaphoid fractures
nondisplaced fractures of distal, midbody, or proximal (but not proximal pole) scaphoid fractures are treated with immobilization for 6, 10, 12 weeks respectively
thumb spica cast (hand to elbow) is required. there is increased incidence of nonunion with short arm splints or wrist casts
serial XR are performed every 2 weeks until radiographic healing has occurred
indications for referral to a hand surgeon for scaphoid fracture
fractures of the proximal pole, displacement >1mm, delayed prsentation of acute fractures (>3 weeks), scapholunate ligament rupture, carpal instability
management of pancreatic injury without ductal involvement (grade I or II)
external closed-suction drainage
(penrose of sump drains are associated with high rates of intra-abdominal abscess formation and skin breakdown at the exit site)
management of proximal pancreatic stump injury
ligation of the duct and oversewing of the parenchyma
management of pancreatic injury involving the duct and left of the superior mesenteric vessels
distal pancreatectomy with or without splenectomy with staple or suture ligation of the proximal pancreatic duct
management of pancreatic injury to the right of the superior mesenteric vessels in the head of the pancreas with intact duodenum
debridement with wide drainage of the pancreatic head
management of massive destruction of the head of the pancreas or combined injury to the pancreas and duodenum
pancreaticoduodenectomy (in stable patients)
damage control operations for pancreatic injury
hemorrhage control, external drainage, temporary abdominal closure
what is phimosis and how is it treated?
abnormal constriction of the opening in the foreskin that precludes retraction over the glans penis resulting from chronic inflammation, infection (balanitis), and edema of the prepuce
treatment: dilation, dorsal slit circumcision, complete circumcision
forcible retraction of the prepuce can cause paraphimosis (trapping of the prepuce behind the glans penis) which limits the venous and lymphatic outflow while allowing continued arterial inflow (urologic emergency)
phimosis complicates sexual function, voiding, hygiene but is not an emergency; physiologic in neonates
what is the goal of treatment of any branchial cleft remnant?
complete surgical resection
dissection of second branchial cleft remnant
dissection penetrates platysma and cervical fascia
ascend along carotid sheath to hyoid bone, turn medially between branches of the carotid, continue behind posterior belly of digastric muscle and stylohyoid muscle, in front of hypoglossal nerve, ends before pharynx in tonsillar fossa (identified by putting finger in the mouth and pressing down in the tonsillar fossa
a second stepladder incision may be required to complete the dissection in older patients with a long tract
what is included with excision of the third and fourth branchial remnant
thyroid lobectomy or resection of the superior pole as indicated by the extent of the cyst
what optimizes the cosmetic result of branchial cleft cyst excision?
transverse cervical incision in a skin crease directly over the cyst
excision of first branchial cleft remnant
superficial lobe of the parotid gland may need to be reflected upward to expose the tract or may require excision in cases of chronic infection
surgical management of brachial cleft remnants when there is infection
antibiotics and delayed surgery (several weeks) while inflammation resolves
abscesses - limited I&D
if excision is pursued in the presence of inflammation/infection there is a higher risk of recurrence, incomplete excision, nerve injury (facial, hypoglossal)
atherosclerotic renal artery lesions - location and management
proximal renal artery
angioplasty and stenting
fibromuscular dysplasia of the renal artery - location and management
distal renal artery
angioplasty without stenting
indications for renal artery revascualrization
difficult to control hypertension (3+ medications)
decreased renal function
hemodynamically significant stenoses
diagnosis of renal artery stenosis
Ultrasound, CTA, MRA
no longer use serologic renin measurement (venous sampling) because it is invasive and has low specificity unless diagnosis is otherwise difficult
renal artery stenosis and ratio of the flow velocity in the renal artery and aorta
ratio velocity in renal artery to aorta > 3.5 = stenosis > 60%
renal artery velocity >180cm/sec is abnormal
renal artery resistive index (RRI)
RRI = 1 - [(end diastolic velocity/maximal systolic velocity) x100]
renal artery resistive index (RRI) > 0.8 identifies patients in whom the renal angioplasty/stenting did not improve renal function or blood pressure
characteristics of the posterior vagal trunk
posterior trunk is larger, normally separated from the posterior esophageal wall (1-2cm) and localized between the 6 and 8 o’clock positions of the esophageal circumference
characteristics of the anterior vagal trunk
anterior trunk is normally buried within the fibers of the anterior aspect of the esophageal wall between the 12 and 2 o’clock positions
where does the criminal nerve of Grassi originate and where does it run?
the criminal nerve of Grassi originates from the posterior vagus nerve and runs toward the left side of the distal esophagus
what is the most common case of recurrent ulceration after truncal vagotomy?
incomplete vagotomy due to failure to identify and divide the posterior vagus nerve
treatment of hypocalcemia
patients with clinical, biochemical, or EKG evidence of hypocalcemia should be treated
symptomatic patients with ionized Ca < 3: IV replacement of calcium gluconate or calcium chloride (provides more elemental calcium than calcium gluconate)
oral calcium supplementation for less severe hypocalcemia
what is familial hypercalcemic hypocalciuria?
autosomal dominant disease caused by increased calcium resorption in the kidney due to a defective PTH receptor leading to mild hypercalcemia with normal levels of parathyroid hormone; no treatment is required
common causes of exudative effusion
pneumonia, malignancy, infection, chylothorax
common causes of transudative effusion
congestive heart failure, liver cirrhosis, nephrotic syndrome, renal failure
Light’s Criteria
- pleural fluid to serum protein ratio > 0/5
- pleural fluid to serum LDH ratio > 0.6
- pleural fluid LDH concentration > 2/3 the upper limit of the serum reference range
presentation of Hirschsprung disease
50 to 90% of children with Hirschsprung disease present during the neonatal period with abdominal distention, bilious vomiting, and feeding intolerance suggestive of distal intestinal obstruction
90% have delayed passage of meconium
delayed presentation in childhood or adulthood with chronic constipation (constipation after weaning in breastfed infants)
presentation of jejunal atresia
infants with bilious emesis, abdominal distention, failure to pass meconium
air fluid levels on KUB with absent distal gas
barium enema with small unused colon, useful to exclude multiple atresias (present in 10-15% of caseS)
presentation of intestinal malrotation
symptoms related to midgut volvulus, duodenal obstruction, or intermittent/chronic abdominal pain
most develop symptoms in the first month of life
chronic abdominal pain, intermittent episodes of emesis (may be nonbilious), early satiety, weight loss, failure to thrive, malabsorption, diarrhea
presentation of duodenal atresia
generally first detected during a prenatal ultrasound evaluation
immediately after birth, KUB shows double bubble sign if obtained before OGT decompression of swallowed air
if distal air is present an upper GI contrast study should be obtained rapidly to confirm diagnosis and exclude midgut volvulus
what types of cancers are most likely to metastasize to the adrenals?
lung (most common), GI tract, breast, kidney, pancreas, and skin (melanoma)
where does thyroid cancer metastasize?
lung, liver, bones
where does ovarian cancer metastasize?
adrenals
what is the standard initial operation for treatment of infants with biliary atresia?
Roux-en-Y hepatic portoenterostomy (Kasai Procedure)
1. excision of the entire extrahepatic biliary tree with transection of the fibrous portal plate near the hilum of the liver
2. bilioenteric continuity is reestablished with Roux-en-Y limb
goal is to allow drainage of bile from the liver into the Roux limb via microscopic ductules in the portal plate
liver transplant is used in delayed diagnosis with severe liver failure where a Kasai procedure would be risky and have high failure rate
the use of the appendix as a conduit between the liver and small intestine has been proposed but its use has been limited with some reports of inferior surgical outcome
management of neuroblastomas
neuroblastomas are the second most frequent pediatric solid tumor
staging with the International Neuroblastoma Staging System is based on location, extension of the primary tumor, lymph nodes, distant metastases
International Neuroblastoma Risk Group Classification System (low, intermediate, high) based on age, imaging, histology, MYCN amplification, chromosome 11 q aberration, DNA ploidy
low risk (INSS I or II) - surgery alone, goal complete resection higher stages involve surgery, chemo, radiation
where are motilin receptors located?
smooth muscle cells of the GI tract
what does motilin do?
initiates the MMC to enhance GI motility
where is motilin released from?
small intestine
how does erythromycin affect GI motility?
binds to motilin receptors to promote GI motility
what do parietal cells secrete?
HCl and intrinsic factor
how do enterochromaffin-like cells aid in gastric acid secretion?
histamine release
silver sulfadiazine for burn therapy
most common topical burn therapy
low cost, wide range of antimicrobial activity
side effect: transient neutropenia (no treatment required)
contraindicated on areas of new skin grafting and lesions near the eye
silver nitrate for burn therapy
comes in soak form
hypotonic solution which has been related to hyponatremia and methemoglobinemia
bacitracin with or without neomycin and polymyxin B for burn therapy
superficial partial thickness facial burns
may cause nephrotoxicity
mafenide acetate for burn therapy
usually used for small full-thickness injuries
carbonic anhydrase inhibitor, may cause metabolic acidosis
borders of the inguinal canal
inferior: inguinal ligament
posterior: conjoint tendon
anterior: aponeurosis of the external oblique
superior: external oblique aponeurosis and musculoaponeurotic extensions of internal oblique and transversalis muscle
Lichtenstein repair of an inguinal hernia
the inguinal floor is reconstructed with mesh
the inferior edge of this mesh is sewn to the shelving edge of the inguinal ligament
the medial edge is sewn to the conjoint tendon medially and the internal oblique and transversalis fascia superiorly
do not sew inferior to the shelving edge because of proximity to the external iliac vessels
what is Cooper’s ligament?
the extension of the lacunar ligament that extends along the pectineal line of the pubis
inferior to the inguinal ligament
fat necrosis of the breast
most common secondary to trauma, average time from trauma to palpable breast mass is 70 weeks
polyarteritis nodosa is a rare cause of fat necrosis
pathology: anucleated adipocytes, lipid laden histiocytes, and multinucleated giant cells, no evidence of malignancy
causes of zinc deficiency
reduced absorption or increased gastrointestinal losses (gastric bypass, Crohn disease, chronic liver/renal disease, prolonged TPN)
effects of zinc deficiency
failure to thrive, skin rash, impaired wound healing
effects of selenium deficiency
cardiomyopathy, hypothyroidism, neurological changes
effects of chromium deficiency
hyperglycemia, confusion, peripheral neuropathy
effects of copper deficiency
pancytopenia and myelopathy (neuropathy with ataxia)
effects of vitamin B12 deficiency
megaloblastic anemia, peripheral neuropathy, beefy tongue, myelopathy
type 1 hypersensitivity
anaphylaxis/immediate hypersensitivity reaction
binding of antigens to IgE adn subsequent mast cell and basophil degranulation
systemic vasodilation, itching, urticaria, angioedema, bronchoconstriction, GI symptoms, shock
peanuts, bee stings, medications, C1 esterase deficiency, blood transfusions with IgA deficiency
type 2 hypersensitivity
cytotoxic mediated
immunoglobulins attached to a surface antigen with subsequent complement fixation or autoantibodies attached to cell surface receptors
not immediate after exposure to the antigen
Hashimoto thyroiditis, Grave disease
type 3 hypersensitivity
circulating antigen-antibody reactions with subsequent complement fixation
deposition of immune complexes into vessels, joints, and kidneys
serum sickness
type 4 hypersensitivity
cell mediated immunity
local injury to the area when antigen is present
contact dermatitis
what is the most common metastatic tumor to the small bowel via hematogenous spread?
melanoma
tumors that metastasize to the small bowel via hematogenous spread
melanoma (most common), lymphoma, breast, lung
tumors that metastasize to the small bowl by direct invasion
pancreas, colon cancer
tumors that metastasize to the small bowel via peritoneal implants
ovarian, liver, stomach, appendix, colon
in which patients is overwhelming post-splenectomy infection most likely?
children undergoing splenectomy for malignancy or hematologic illnesses such as beta thalessemia or sickle cell disease
symptoms and diagnosis of condyloma acuminatum
HPV 6 and 11
perianal growth, puritis, discharge, bleeding, odor, anal pain
cauliflower like lesion in radial rows out from the anus
anoscopy and proctosigmoidoscopy because the disease extends internally in >3/4
most common location of VIPoma
distal pancreas
most common location of gastrinoma
gastrinoma triangle
- junction of cystic duct and common bile duct
- junction of second and third parts of duodenum
- junction of the head and neck of pancreas
most common location of somatostatinoma
head of the pancreas
VIPoma presentation
intermittent severe watery diarrhea, hypokalemia (lethargy, muscle weakness, nausea), metabolic acidosis (loss of bicarbonate), half have hyperglycemia/hypercalcemia, less than half with cutaneous flushing
electrolyte derangement in recurrent vomiting
metabolic alkalosis
hypokalemic, hypochloremic with low urine chloride
conditions associated with chloride responsive alkalosis
gastric fluid loss, chloride wasting diarrhea, diuretics
low urine chloride (Cl <10)
conditions associated with chloride resistant alkalosis
Conn syndrome, secondary hyperaldosteronism, Cushing syndrome, Liddle syndrome, Bartter syndrome, exogenous corticoids, ongoing diuretics
high urine chloride (Cl >20)
Vitamin C deficiency (scurvy)
prevents proline hydroxylation resulting in formation of unstable triple helices secondary to the synthesis of defective pro-alpha chains
gradual loss of preexisting normal collagen leading to fragile blood vessels and loose teeth
inflammatory stage of wound healing
characterized by increased vascular permeability, migration of cells into the wound by chemotaxis, secretion of cytokines and growth factors into the wound, and activation of the migrating cells
scaffolding stage of wound healing
angiogenesis, fibroplasia, epithelialization
proliferative stage of wound healing
formation of granulation tissue
what is the most important factor in healing wounds?
tensile strength which depends on collagen deposition and subsequent cross-linking
after primary repair of a thoracic esophageal perforation what has been shown to have value in primary healing of the perforation?
pedicled intercostal muscle flap
the parietal pleura is thin and does not make a suitable buttress
what molecule leads to the development of cachexia?
tumor necrosis factor alpha
cytokine synthesized by macrophages, monocytes, T cells in response to injury and infection
leads to cachexia by increasing catabolism and insulin resistance
what is the effect of granulocyte-macrophage stimulating factor?
stimulates granulocyte and monocyte production from bone marrow stem cells
where is interleukin 1 released from and what does it cause?
interleukin 1 is released from the hypothalamus and causes fever
what does interleukin 2 promote?
interleukin 2 promotes T cell proliferation and immunoglobulin production
what does interleukin 4 stimulate?
Interleukin 4 stimulates T cell differentiation and B cell activation
what is the 4:2:1 rule for maintenance fluids?
4mL for the first 10kg
2mL for the second 10kg
1mL for the remaining weight
postoperative fluid replacement should also include the intraoperative fluid deficit and the ongoing loss
indication for intervention on asymptomatic carotid disease
> 70% CA stenosis
indication for CEA or carotid stenting with symptomatic coronary artery disease
> 90% CA stenosis or contralateral carotid occlusion (theoretical risk for low flow ischemia while on pump for CABG)
characteristics and treatment of chronic autoimmune pancreatitis
densely mononuclear cell infiltrate, significant fibrosis, increased autoantibody titer
treated with systemic steroid therapy
indications for operative treatment of penetrating facial injury
if the injury is medial to the lateral canthus of the eye then the facial nerve’s ability to recover non-operatively is successful due to arborization
if the injury is lateral to the lateral canthus of the eye then surgical intervention is warranted
- exploration is necessary to repair transected nerve if patient demonstrates facial nerve paraplysis
- if injury is near parotid duct then the parotid duct and gland should be explored
repair should be done within 72 hours of injury before wallerian degeneration prevents identification of the nerve endings of the transected facial nerve
what is dermatofibrosarcoma?
low grade sarcoma that is characterized by microscopic lateral extension of tumor cells and high risk of local recurrence
soft tissue tumor that arises from fibroblasts - spindle like CD34 immunohistochemical stain positive
Moh’s procedure is cometimes used to ensure negative margins
predictors of prognosis: grade, size, depth in relation to the fascia, distant or regional metastasis
what is the standard treatment of choice for a low simple fistula and some mid-rectovaginal fistulas?
endorectal advancement of an anorectal flap
what is the treatment for high fistulas and some mid-rectovaginal fistulas
transabdominal repair
what is the management of small and simple rectovaginal fistulas secondary to obstetric trauma?
spontaneous healing occurs in about half of cases; wait 3-6 months until inflammation has subsided before considering surgical repair
what is the treatment for popliteal aneurysm >2cm in healthy patients?
bypass and ligation (prevents further embolization in the future as may occur with bypass alone)
popliteal aneurysms < 2.0cm can be observed
what branches of the aorta are most commonly injured?
innominate and subclavian
what is the most appropriate incision to gain arterial control for an injury to the ascending aorta, aortic arch, innominate, right subclavian, left common carotid?
median sternotomy
where is the incision of an emergency room thoracotomy made?
left anterolateral incision in the 5th intercostal space
allows access to the heart
can be extended to a clam shell incision if needed
what incision should be made to obtain left subclavian proximal control?
high third interspace anterior thoracotomy
what incision should be made to gain control of the descending aorta?
posterolateral thoracotomy
what arteries can be accessed via supraclavicular and infraclavicular incisions?
axillary or subclavian arteries
will not allow for control of the innominate artery coming off the aorta
what is the most common benign tumor of the lung?
hamartomas
men > women
solitary pulmonary nodule with a slow growth pattern
well circumscribed nodule that may contain popcorn calcification
needle aspiration is frequently diagnostic
indications for resection are proximal location, presence of symptoms caused by endobronchial obstruction or inability to rule out carcinoma
management of arrhythmia caused by placing a swan-ganz catheter
- pull back the catheter into the right atrium
2. lidocaine or other antiarrhythmic
which maneuver is indicated for air embolus during swan-ganz catherterization?
left lateral decubitus
traps air in the right atrium
appearance of blunt thoracic aortia injury most often secondary to acute deceleration on CXR
widened mediastinum, apical cap, displacement of the trachea/left main bronchus/NGT
where is blunt thoracic aorta rupture most likely to occur?
at the level of the ligamentum arteriosum secondary to it being relatively fixed at that location
what is the imaging of choice to rule our blunt thoracic aortic injury and to make surgical plans for this injury?
CTA
how do acute paraesophageal hernias present?
sudden onset of retching, vomiting, chest pain
can progress rapidly to strangulation and gastric ischemia
management of acute paraesophgeal hernias
NGT placement to relieve pressure followed by surgical intervention approached via urgent laparotomy or laparoscopy
repair may require mesh
in what patients is pneumocystis carinii seen? what do they present with? how is it treated?
immunocompromised patients
weeks of dry cough, fever, sweats, difficulty taking a deep breath, tachypnea, tachycardia, cyanosis, fine crackles on auscultation
CXR reveals diffuse bilateral infiltrates
may be disseminated via lymphatics and hematogenous spread to thyroid, liver, bone marrow, lymph nodes, spleen
prophylaxis with bactrim in transplant patients
what is seen on CXR in mycobacterium tuberculosis?
cavitating lesion
in what region is histoplasmosis most common?
Ohio River Valley
caves
in what region is coccidiomycosis most common?
southwestern US
how is a DeMeester score calculated?
DeMeester score is calculated based on percent total time pH<4 while upright, supine, and overall
number and duration of each episode is monitored
what is an abnormal DeMeester score?
> 14.72 (95th percentile)
what is esophageal impedance?
an adjunct to traditional pH testing using electrical current
low voltage current is applied to multiple electrodes within the probe to determine the presence of liquid, food, or esophageal tissue; the direction of a bolus may also be determined (this allows for detection of nonacid reflux and may be used to determine reflux even with PPIs)
where is the pH probe placed in esophageal pH monitoring?
5cm above the LES
what electrolyte abnormalities are seen in refeeding syndrome?
hypokalemia, hypophosphatemia, hypomagnesemia
decreased Mg and K lead to arrhythmia and sometimes cardiac arrest
decreased phos leads to decreased ATP generation (weakness, encephalopathy, congestive heart failure, ventilator dependence)
what is the management approach of acute diaphragm injury?
acute injuries of the diaphragm are repaired through an abdominal incision via laparotomy or laparoscopy
what is the management approach of chronic diaphragm injury?
thoracoscopic
blunt trauma is more likely to result in diaphragm injury on which side?
left more common than right because liver diffuses some of the energy on the right side
(75% on the left)
what are the characteristics of diaphragmatic injury secondary to blunt trauma?
linear tear in the central tendon
what is the most common indication for parotidectomy?
neoplasm
genetic abnormality in which electrolyte leads to malignant hyperthermia with certain inhalational anesthetic agents?
calcium
mutation results in altered calcium regulation in skeletal muscle
enhanced efflux of calcium from endoplasmic reticulum
what is the mechanism of inheritance in malignant hyperthermia?
autosomal dominant with variable penetrance
what is seen in malignant hyperthermia?
rigidity and hypermetabolism
uncontrolled glycolysis, aerobic metabolism, cellular hypoxia, progressive lactic acidosis, hypercapnia, heat, hyperkalemia, myoglobinuria, DIC, CHF, bowel ischemia, compartment syndrome
What is seen in vitamin D deficiency?
osteomalacia, pathologic bone fractures, proximal myopathy
what is seen in Vitamin E deficiency?
neuronal degeneration, neuropathy, spinocerebellar ataxia
seen in prolonged steatorrhea
what are the vitamin K dependent coagulation factors?
II VII IX X
what is seen in vitamin A deficiency?
visual disturbances, night blindness, ocular keratitis
what are the causes of vitamin K deficiency?
inadequate dietary intake (including TPN without fat emulsions), insufficient adsorption (biliary tract obstruction), loss of storage (hepatic disease)
how does fat necrosis of the breast present?
firm, irregular, often nontender mass that may be associated with skin retraction and thickening
on mammography appears as soft tissue with calcified rim, may have spiculated calcifications (often not distinguishable from cancer)
what is the presentation of a phyllodes tumor?
rapidly growing smooth, round, breast mass
what type of acid base disturbance is seen with high ileostomy output?
nonanion gap metabolic acidosis
what are the indications for emergency thoracotomy for hemothorax?
initial chest tube output of 1500mL of blood or persistent drainage of 200-300mL/hr
indications for emergency room thoracotomy
- cardiac arrest (resuscitative thoracotomy)
- massive hemothorax
- penetrating injuries of the anterior aspect of the chest with cardiac tamponade
- large open wounds of the thoracic cage
- major thoracic vascular injuries in the presence of hemodynamic instability
- major tracheobronchial injuries
- evidence of esophageal perforation
what medical therapy is used for Crohn disease persistent perianal fistula?
infliximab, a monoclonal chimeric antibody to tumor necrosis factor
how do azathioprine and 6MP work?
inhibition of DNA synthesis leads to immunosuppression by suppressing cytotoxic T cell and natural killer cells
how does sulfasalazine suppress inflammation?
5-ASA derivative that inhibits cyclooxygenase and lipooxygenase pathways
used in moderately active and quiescent Crohn’s
what liver tumors are appropriate for laparoscopic resection?
LLRs are ideal for tumors <5cm located in segments 2, 3, 4, 5, 6
what surveillance is indicated following surgery for stage III colorectal cancer?
CEA levels every 3-6 months for 2 years and then every 6 months for 3 years
CT of pelvis annually for 5 years and colonoscopy within 1 year
what is the treatment for stage III rectal cancer?
neoadjuvant chemoradiation followed by resection followed by adjuvant chemotherapy
which nerve becomes the posterior vagus?
the right vagus
which nerve becomes the anterior vagus?
the left vagus
where does the criminal nerve of Grassi originate and what does it innervate?
the posterior vagus gives rise to a high branching nerve, the criminal nerve of Grassi, which innervates the cardia of the stomach and continues down the remainder of the stomach to join the celiac plexus
if the vagotomy is performed below the level of the criminal nerve of Grassi, the patient may continues to remain symptomatic
where does the hepatic branch of the vagus originate and what does it innervate?
the anterior vagus gives rise to the hepatic branch which innervates the stomach and near the pylorus it branches to the nerve of Latarejet which innervates the pylorus
how is a truncal vagotomy performed?
both the anteiror and posterior vagus nerves are transected at the level of the distal esophagus 4cm proximal to the GE junction
what is a selective vagotomy?
division of the two vagus nerves just below the posterior celiac branches that innervate the pancreas, small intestine, and hepatic branches
what is a highly selective vagotomy?
dissection of the nerves near their terminal ends where the nerves splay out into a characteristic crow’s foot appearance with preservation of the Latarjet’s nerves
a drainage procedure is not necessary
why are the excised nerves sent to pathology in vagotomy?
a 1-2cm area of each nerve is sent to pathology to confirm the vagus was excised as intended prior to ending the procedure
what is the maximum amount of air a person can expel from the lungs after a maximal inhalation called?
vital capacity
it is equal to the inspiratory reserve volume + tidal volume + expiratory reserve volume
amount of air moved in a normal breath
tidal volume
amount of air left after maximal exhalation
residual volume
amount of air left after exhaling a normal breath
expiratory reserve volume
expiratory reserve volume + residual volume
functional residual capacity
where is the most likely site for a traction diverticulum to occur in the esophagus?
mid-esophagus
what is a traction diverticula of the esophagus?
true diverticula that occurs as a result of inflammatory processes in the nearby lymph nodes that pull on the esophageal wall
what is a Zenker diverticulum and where does it occur?
pulsion diverticulum which occurs above the cricopharyngeus muscle
false diverticulum which only contains mucosa and submucosa that herniated through muscular wall
what is an epiphrenic diverticulum and where does it occur?
pulsion diverticula which occurs in the distal esophagus
false diverticulum which only contains mucosa and submucosa that herniated through muscular wall
what is the most common site for melanoma recurrence?
skin > subcutaneous tissue, distant lymph nodes > visceral sites
what are the common visceral sites of metastasis of melanoma?
lung, liver, brain, bone, GI tract
what are two common causes of death in metastatic melanoma?
respiratory failure, cerebral complications
what is the larges risk factor for postoperative cardiac complications?
active congestive heart failure
what is the predominant cellular source of tumor necrosis factor?
macrophages
what is the operative treatment of type II choledochal cysts?
excision of the cyst and primary closure of the choledochotomy
what is the operative treatment of type III choledochal cysts?
transduodenal approach with either marsupialization or excision of the cyst
what is the operative treatment of type I choledochal cysts?
primary cyst excision with Roux-en-Y hepaticojejunostomy reconstruction
why are internal drainage procedures not used for choledochal cyst treatment?
higher rates of stricture, stone formation, pancreatitis, and cholangitis
when is intramural cyst dissection and removal of the cyst wall epithelium (leaving the posteromedial outer cyst wall adjacent to the portal vein and hepatic artery intact) used for management of choledochal cysts?
severe inflammation and fibrosis resulting in adhesion of the cyst wall to the hepatoduodenal ligament
MAP - ICP =
mean arterial pressure minus intracranial pressure
CPP (central perfusion pressure)
what is central perfusion pressure?
net pressure gradient causing brain perfusion, should be a minimum of 60mmHg
GCS eye criteria/scoring
- open spontaneously
- open in response to speech
- open in response to pain
- do not open
GCS verbal criteria/scoring
- oriented, appropriate
- confused speech
- inappropriate speech
- incomprehensible speech
- no speech
GCS motor criteria/scoring
- obeys commands
- localizes painful stimulus (cross midline)
- withdraws from painful stimuli
- flexor response (decorticate)
- extensor response (decerebrate)
- no response
what are absolute contraindications for liver transplantation?
inability to withstand the operative procedure, recent intracranial hemorrhage, untreated extrahepatic malignancy
which type of thyroid cancer results from proliferation of cells derived from neural crest cells?
medullary thyroid cancer
parafollicular C cells produce calcitonin and are derived from neural crest cells
what is the primary fuel of neoplastic cells?
glutamine
what are the stages of skin graft healing?
imbibition: diffusion of nutrients into the graft without direct blood supply
inosculation: donor and recipient capillary beds align
revascularization: arterial inflow and venous outflow detected
what are the precursors of glucose in gluconeogenesis?
lactate, pyruvate, glycerol
what is the Cori cycle?
lactate produced from glycolysis in the skeletal muscles and peripheral tissues are shifted to the liver and transformed into glucose
Cori cycle uses 4 ATP molecules to produce a single amino acid, inefficient
what is the most common indication for liver transplantation?
end stage liver disease - minimal function and no potential for recovery
what is fulminant hepatic failure?
the progression from good health to liver failure with hepatic encephalopathy within 8 weeks
the mortality rate is 75% without transplantation
indication for emergent liver transplantation
weakness in the conjoint tendon that forms the posterior wall of the inguinal canal leads to what type of hernia?
direct inguinal hernia (medial to the inferior epigastric vessels)
what forms the anterior and medial boundaries of the femoral canal?
iliopubic tract
what is diastasis recti?
separation of the rectus muscles at the linea alba resulting in cosmetic defect that generally does not demand surgical attention
a sac that resides lateral to the inferior epigastric vessels and is primarily the result of a patent processus vaginalis describes what type of hernia?
indirect inguinal hernia
what is Petersen’s space?
the space between the Roux limb and transverse colon mesentery
what is the jejunojejunostomy mesenteric space?
the space between the Roux limb and biliopancreatic limb mesenteries
what is a Petersen hernia?
an internal hernia which occurs in the potential space posterior to a gastrojejunostomy caused by the herniation of intestinal loops through the defect between the small bowel limbs , the transverse mesocolon and the retroperitoneum
which maneuver is completed to allow for proper supraceliac aortic exposure?
Mattox maneuver
left medial visceral rotation
the left colon, left kidney, spleen, tail of the pancreas, and fundus of the stomach are moved to the midline to provide extensive exposure to the entire abdominal aorta from the diaphragmatic hiatus to the bifurcation
which maneuver allows for access to the retrohepatic inferior vena cava and involves medialization of the right sided abdominal organs?
Cattell-Braasch maneuver
right medial visceral rotation
which maneuver is used to mobilize the duodenum?
Kocher maneuver
which maneuver involves clamping the portal triad and provides inflow occlusion to the liver?
Pringle maneuver
what is the most common secondary cause of death for a patient diagnosed with familial adenomatous polyposis after treatment with an appropriate surgical resection?
duodenal tumor
diligent upper endoscopy screening is recommended in all FAP patients beginning at ager 20-25 or when colonic polyps first appear
brain cancer is also seen with FAP but is rarer
what landmarks are used for subclavian vein central line access?
- deltopectoral groove
- sternal notch
- medical third of the clavicle
with the introducer needle angled toward the sternal notch, horizontal to the chest wall, and about 1cm inferior to the bend in the clavicle or medial third of the clavicle the subclavian vein may be aspirated
once attained the Seldinger technique is employed with the assistance of fluoroscopy
what is the maximum size of a bleeding vessel that can be safely sealed with minimal thermal spread using bipolar electrosurgery?
7mm
benefits of bipolar electrosurgery
- bipolar electrosurgery uses coagulating mode for hemostasis and division of unsupported vascular tissues =7mm
- the laparoscopic tool is versatile resulting in fewer instrument exchanges
- less thermal injury occurs compared to monopolar electrosurgery
- no capacitive coupling occurs and inadvertent direct coupling is unlikely
- fewer accessories such as grounding electrodes are required eliminating the possibility of alternate site burns
- safety of the technology for use in laparoscopy has been established
posterior dislocation of the hip (flexed, shortened, internally rotated, adducted LE) may be associated with concomitant injury to which nerve?
sciatic nerve (peroneal division)
supracondylar humerus fracture is associated with what other injury?
brachial artery injury (may lead to Volkmann’s ischemic contracture)
distal radius fracture is associated with what other injury?
median nerve compression
anterior dislocation of the shoulder is associated with what other injury?
axillary nerve injury
posterior dislocation of the knee is associated with what other injury?
popliteal artery injury
pelvic fractures are associated with what other injuries?
bladder injuries
obturator artery injuries
femoral vein injury is associated with what?
penetrating trauma or femur fractures
what is the Strasberg classification?
the most commonly used system to classify bile duct injuries following CCY
Strasberg type A injury
leakage from the cystic duct stump or duct of Luschka
should be oversewn and a drain should be left in place if discovered intraoperatively
if discovered postoperatively, management depends on the severity of the presentation and amount of output
Strasberg type B injury
ligation of an aberrant right hepatic duct
Strasberg type C injury
transection of an aberrant right hepatic duct
Strasberg type D injury
lateral injury to a major duct
Strasberg type E injury
complex injuries often accompanied by a vascular component, occur higher on the biliary system
complications of acute pancreatitis
pancreatic abscesses, infected necrosis, acute fluid collections and pseudocysts, pancreatic ascites and fistulas, splenic vein thrombosis, and arterial pseudoaneurysms
what is the most common cause of benign bile duct strictures?
iatrogenic injury to the bile ducts during CCY
incidence of stricture is higher after laparoscopic versus open CCY
less common causes include malignancy, chronic pancreatitis, Mirrizi syndrome, choledocholithiasis
What is Mirrizi syndrome?
results from chronic inflammation associated with gallstones in either the gallbladder or common bile duct
associated with narrowing at the level of the common hepatic duct caused by a stone impacted in the infundibulum
management of inguinal hernias in children
all inguinal hernias in children need to be repaired
if the hernia can be reduced then surgery can be delayed for 24-48 hours to allow edema to resolve, if the hernia cannot be reduced then the hernia is repaired urgently
observation beyond 48 hours increases risk of incarceration/strangulation
operative repair is high ligation of the hernia sac
what is a phyllodes tumor?
fibroepithelial tumors composed of an epithelial and cellular stromal component; may be considered benign, boarderline, or malignant depending on histologic features (stromal cellularity, infiltration at tumor’s edge, mitotic activity)
10% are malignant and metastasize hematogenously
management is wide local excision or simple mastectomy
incision type for colostomy reversal
peristomal circumferential incision has the lowest morbidity
what is used for a sentinel lymph node biopsy in pregnant women?
Tc-99m is safe in pregnancy.
blue dye should not be used for sentinel lymph node biopsy in pregnancy due to limited data on teratogenic effect and low risk of anaphylactic maternal reaction
what is the most common complication following pancreatic injury?
postoperative pancreatic fistula
which bacteria are commonly isolated from biliary cultures?
E. coli, klebsiella, enterobacter, bacteroides
what is the natural history of acute cholecystitis?
the impacted stone initially causes a sterile inflammatory response leading to inflammation of the gallbladder mucosa, distention and eventually ischemia. if untreated, this leads to secondary infection, abscess formation, and occasionally sepsis or perforation.
what are the steps that lead to formation of ascites?
- sinusoidal portal hypertension
- splanchnic vasodilation results in decreased effective arterial blood volume
- activation of RAAS, vasopressin, SNS to increased circulating volume
- renal retention of sodium and water, renal vasoconstriction
- excess fluid is compartmentalized into the peritoneal space because of portal hypertension
- further splanchnic vasodilation and renal vasoconstriction
- refractory ascites and hyponatremia
what is a galactocele?
a milk retention cyst of the breast that sometimes occurs in postpartum females when breast feeding is slowed or stopped and milk becomes stagnant in ducts
they are composed of water, protein, fat, lactose
protein debris plugs the duct creating obstruction
usually does not becomes infected because milk within the cyst is sterile
initial treatment is supportive
what is the most common cause of iatrogenic splenic injury during abdominal surgery?
forceful retraction of the omentum for exposure causing tearing of the splenic capsule
what is the pathophysiology of anorectal abscesses?
small mucin secreting crypts (anal glands at the dentate line) get blocked causing localized inflammation that eventually leads to abscess formation
because these glands are located at the intersphincteric space, that is where abscesses start
what is the most common site of perforation during colonoscopy?
sigmoid colon (70% of all perforations) mechanical perforation by endoscope tip, barotrauma from overinsufflation, and therapeutic procedures
in an infant with profound cyanosis, what is the best first step in management?
IV PGE 1
maintain patent ductus arteriosus and provide left to right shunting and improved pulmonary blood flow
in rectal prolapse repair, are recurrence rates higher for perineal or abdominal approaches?
recurrence rates are higher in the perineal repair (16-30%)
are internal or external rectal prolapses easier to surgically treat?
external rectal prolapse is more amenable to surgical repair
is the abdominal or perineal approach to rectal prolapse associated with less postoperative pain, fewer complications and shorter hospital stay?
the perineal approach is associated with less pain, fewer complications, and shorter hospital stay
After a TIA, what is the risk of stroke within the first 48 hours?
the risk of stroke in the first 48 hours after TIA is 4-10%. This risk increases with time.
vertebrobasilar symptoms
ataxia, dizziness, bilateral weakness and numbness
what is a TIA
stoke-like symptoms that last for less than 24 hours but can be a predictor of actual stroke
What is Barrett’s esophagus, where does it occur, how does it appear on EGD, and what is the cancer risk?
Barrett’s esophagus occurs in the distal esophagus proximal to the GE junction seconary to chronic reflux.
Cells undergo conformational change from squamous to columnar with Goblet cells.
EGD: salmon colored mucosa with inflammation and erosion
Barrett’s esophagus increases the risk of adenocarcinoma but the overall risk is < 1% per year. Because the mortality of esophageal cancer is high, Barrett’s mandates aggressive treatment.
what is the most common site of esophageal perforation during endoscopy?
at the level of the cricopharyngeus muscle- narrow opening leading into the esophagus
risk of perforation increases with the presence of Zenker diverticulum and cervical osteophytes
second most common location of perforation after EGD is proximal to the lower esophageal sphincter
what percentage of esophageal perforations are iatrogenic secondary to EGD?
30-75% of esophageal perforations are secondary to EGD
where does esophageal perforation due to caustic injury typically occur?
at the sites of anatomical compression of the esophagus near the left mainstem bronchus
where do esophageal tears secondary to Boerhaave syndrome occur?
in the distal esophagus on the left side after spontaneous vomiting
what are contraindications to the use of ketamine?
elevated intracranial pressure (ketamine increases cerebral blood flow)
open eye injuries (ketamine may cause increased intraocular pressure)
ischemic heart disease (ketamine causes hypertension and tachycardia, should not be used as the sole anesthetic in this case)
can ketamine be used intrathecally or in an epidural?
no, chlorobutanol is a preservative used with ketamine and is neurotoxic
Name pull-through procedures used to treat Hirschsprung’s disease
Swenson, Duhamel, Soave
what are the advantages of the Duhamel procedure over the Swenson or Soave procedures for Hirschsprung’s?
Duhamel is believed to be easier and safer with less pelvic dissection; it has a large anastomosis between the rectal stump and normal colon which decreases the risk of anastomotic stricture; the presence of a reservoir makes it appealing for children with longer aganglionic segments
describe the Duhamel procedure (type of pull-through for Hirschsprung’s)
the aganglionic rectal stump is left in place and the ganglionated normal colon is pulled behind the stump
a stapler is inserted through the anus with one arm within the normal ganglionated bowel posteriorly and the other in the aganglionic rectum anteriorly
firing of the stapler results in the formation of a neorectum that empties normally because of the posterior patch of ganglionated bowel
what mechanisms contribute to hepatorenal syndrome?
- activation of the RAAS in response to systemic hypotension
- activation of the SNS in response to systemic hypotension and increased intrahepatic sinusoidal pressure
- increased release of arginine vasopressin in response to systemic hypotension
- reduced hepatic clearance of vascular mediators (endothelin, prostaglandins, endotoxin)
what is hepatorenal syndrome?
a life-threatening medical condition that consists of rapid deterioration in kidney function in individuals with cirrhosis or fulminant liver failure due to underlying mechanisms that cause renal vasoconstriction in the setting of systemic vasodilation
how is cancer metastatic to the colon treated?
it is treated based on the primary malignancy
breast, ovary, melanoma, stomach, esophagus, renal cancers, prostate
what is actinic keratosis and how is it treated?
actinic keratosis is a precursor to squamous cell carcinoma
surgical destruction of the epidermis with cautery, cautery and curettage, and cryotherapy are acceptable approaches to the treatment of AK
AK lesions do not require a margin
nonsurgical management includes topical chemo such as 5FU (no role for systemic chemo), photodynamic therapy, topical immune modulators (Imiquimod), fluorescence
what skin layer must be removed when performing excision of perianal condylomas?
epidermis
what is condyloma acuminata, how is it transmitted, and how is it treated?
caused by HPV and is transmitted by sexual contact
the virus lives and replicates in the epidermis
treated with fulgration and excision, it is essential to excise the epidermal layer and leave dermis. despite this there is a high recurrence rate (the most common complication)
squamous cell carcinoma of the anal skin is a possible sequelae of untreated disease
which gene is responsible for the most common genetic alteration in pancreatic cancer?
K-ras
which genes are involved in the pathogenesis of pancreatic cancer?
tumor suppressor genes: p53, p16, DPC4, BRCA2
oncogenes: K-ras
mis-match repair genes
what are the antibiotics of choice in spontaneous bacterial peritonitis?
3rd generation cephalosporin (cefotaxime) or fluoroquinolone
gram negative coverage, penetrate ascitic fluid
what is the mortality rate associated with spontaneous bacterial peritonitis?
20-40%
which cirrhotic patients get prophylactic antibiotic therapy for spontaneous bacterial peritonitis?
- cirrhotic patients who have a gastrointestinal hemorrhage
- cirrhotic patients with low protein ascites (under 15g/L)
- cirrhotic patients with history of spontaneous bacterial peritonitis
what bacteria are the most common cause of spontaneous bacterial peritonitis?
gram negative enteric bacteria (single organism)
how does spontaneous bacterial peritonitis present?
abdominal pain and fever in cirrhotic patients
what leads to perirectal abscess formation?
the majority have a cryptoglandular etiology- blockage of the anal glands leads to an acute infection
other causes include Crohn’s and trauma
how do patients with perirectal abscess present?
severely tender, fluctuant mass in the perirectal space
where may a perirectal abscess in the ischiorectal space track?
to the rectum to form what is known as a horseshoe abscess
what is the most common location of an anal fissure?
posterior midline
how do anal fistulas track to the anal canal?
According to Goodsall’s rule where anterior locations track in a linear fashion
what is the most common cause of anal incontinence?
obstetric trauma during spontaneous vaginal delivery
what is the most common surgical procedure for anal incontinence?
wrap around sphincteroplasty
how is a wrap around sphincteroplasty for anal incontinence performed?
identify the sphincter, mobilize it and reapproximate without tension
what is the gracilis muscle transposition with constant low frequency stimulation and what is it used for?
the gracilis is identified and tunneled to the perineum to create a neosphincter
this is used for complex and recurrent cases of anal incontinence
what is Phalen sign and what does it indicate?
provocative testing with the wrists firmly pressed in full flexion, positive test indicate carpal tunnel syndrome
what is carpal tunnel syndrome?
results from compression of the median nerve at the wrist
symptoms include pain, paresis, paresthesia involving the palmar side of the thumb, second finger, third finger and radial side of the fourth finger
symptoms are usually worse at night
physical findings include hypesthesia and decreased two point discrimination
EMG and nerve conduction studies may be performed
what is Tinel sign and what does it indicate?
Tinel sign produces paresthesias in the involved digit with tapping over the carpal tunnel
indicative of carpal tunnel syndrome
what is the treatment of carpal tunnel syndrome?
initial treatment is conservative (splinting, antiinflammatory medications, steroid injections, etc.)
if conservative management fails after 2-7 weeks then surgery may be considered
avoidance of repetitive motion is important and may result in symptom resolution
surgical decompression is by section of the transverse carpal ligament
what is a GIST and where do they originate?
GISTs are mesenchymal neoplasms of the GI tract and are thought to originate from the interstitial cells of Cajal
what mutation is seen in 90% of GISTs?
c-KIT (CD117)
what is the most important factor indicating malignant potential and poor prognosis for a GIST?
high mitotic index (>5 per 10 high power field)
other less important prognostic indicators include size of tumor >5cm, presence of necrosis, presence of atypia, and location in the small bowel when compared to gastric GISTs
what is the tumor marker for epithelial subtype of ovarian cancer?
CA 125
lacks sensitivity and specificity for ovarian cancer and levels may be elevated in endometriosis, uterine myoma, acute/chronic salpingitis, inflammatory disease
what is the tumor marker for embryonal cell carcinomas, ovarian choriocarcinomas, mixed germ cell tumors, and some dysgerminomas
beta-hCG
what is the tumor marker for yolk sac tumors, embryonal cell carcinomas, and polyembryoma carcinomas, mixed germ cell tumors, and some immature teratomas
alpha-FP
most dysgerminomas are associated with normal alpha-FP
what is the tumor marker for dysgerminoma?
lactate dehydrogenase
what is the tumor marker for epithelial stromal tumors such as mucinous and endometroid carcinoma and sex cord stromal tumors like granulosa cell tumors and Sertoli-Leydig cell tumors
Inhibin A
what is the tumor marker for colon adenocarcinoma?
carcinoembryonic antigen (CEA)
what is the recommended post operative surveillance of patients with FAP who opt for a total abdominal colectomy and ileorectal anastomosis?
annual endoscopy (12-29% risk of cancer developing in the rectal stump within 20-25 years; patients with mutation in codon 1309 are at higher risk for developing rectal stump cancer)
how is a laparoscopic adjustable gastric band placed?
placement utilizes the pars flaccida technique
the band is placed along a space created posterior to the proximal stomach through the avascular portion of the gastrohepatic ligament; this reduces slippage
complications of laparoscopic adjustable gastric bands
gastric herniation, band slippage, band erosion
how is erosion of a laparoscopic adjustable gastric band diagnosed and treated?
diagnosis is confirmed by endoscopy visualizing the band within the gastric lumen; treatment is removal of the band and repair of the stomach defect
how is herniation of a laparoscopic adjustable band managed?
urgent reoperation to manually reduce and resecure the stomach
how does LCIS present?
no palpable lesion or calcifications on mammography, incidental finding on final pathology following core needle biopsy done for other reasons
what is lobular carcinoma in situ and how is it managed?
LCIS is a tumor marker for breast cancer but it is not a premalignant lesion
prophylactic bilateral mastectomy is an option however negative margins are not required for excisional biopsies
what is the risk of subsequent malignancy in LCIS?
0.5-1.0% per year
approximately 10-20% of patients may have ductal carcinoma in situ or invasive cancer in the surrounding tissue of the biopsy specimen showing LCIS
what are risk factors for pseudoaneurysm development after an endovascular procedure?
anticoagulation, obesity, use of a large sheath, poor technique, hypertension, dialysis and heavily calcified vessels
what is the presentation of a pseudoaneurysm after endovascular procedure and how is it diagnosed?
pain, tenderness at the puncture site with a pulsatile mass which usually occurs within the first 24-48 hours
bruit may be auscultated
diagnosis is confirmed with arterial duplex
what is the treatment of a pseudoaneurysm after endovascular procedure?
initial treatment consists of ultrasound guided compression for 10-20 minutes (success is as high as 88%)
thrombin injection into the sac under ultrasound guidance (successful in 95%, complications include anaphylaxis and thrombosis of the main artery)
surgical intervention
what are the indications for surgical intervention on pseudoaneurysm after endovascular procedure?
infection, hemodynamic instability, expanding pulsatile mass (especially with skin necrosis or cellulitis), distal ischemia, neurologic deficit (from femoral nerve compression, size >5cm or wide neck), failure of ultrasound techniques
if a pseudoaneurysm following endovascular procedure requires surgical repair, how is it done?
technique involves obtaining proximal and distal control and direct repair of the arteriotomy
if the fascia is closed alone there will likely be recurrence so the artery wall must be included
the hematoma may then be evacuated and wound closed
which condition is most commonly implicated in Budd-Chiari syndrome?
myeloproliferative disorders
which test should be done if a patient has an elevated 24hr urine free cortisol level and elevated serum ACTH?
high dose dexamethasone suppression test
cortisol will be suppressed with pituitary adenomas and will not be suppressed in patients with ectopic tumors
what is bilateral inferior petrosal sinus sampling used for?
a patient who meets biochemical criteria for Cushing’s disease (elevated 24 hr urine free cortisol, elevated ACTH) and suppressed cortisol on dexamethasone suppression test but no evidence of pituitary mass on MRI
demonstration of a central to peripheral ACTH gradient on inferior petrosal sinus sampling is sufficient to diagnose Cushing’s disease
how does an intrahepatic carcinoma usually present?
liver mass seen on axial imaging
what is a Klatskin tumor?
hilar cholangiocarcinoma
affects the upper part of the bile duct
how does extrahepatic lower duct cholangiocarcinoma present?
painless jaundice, obstructive labs, high C19-9
axial imaging reveals dilation of the intrahepatic bile ducts, gallbladder, and extrahepatic bile ducts down to the level of the pancreatic head where the dilation terminates abruptly
MRCP/ERCP shows a focal stricture
how do patients with pancreatic endocrine neoplasms present?
- incidental discovery of a mass on cross sectional imaging
- symptoms secondary to the mass effect of a lesion in the pancreas
- as a consequence of associated symptoms of a functional tumor
clinical findings in glucagonoma
severe dermatitis, mild diabetes, stomatitis, anemia, weight loss
how are glucagonomas diagnosed?
clinical presentation, biopsy of the skin lesions and documentation of high fasting levels of serum glucagon
what is secretin stimulation testing used for?
to differentiate between gastrinoma, antral G-cell hyperplasia, or hyperfunction
serum gastrin levels of 200 or more suggest gastrinoma, gastrin levels higher than 1000 in the setting of hyperacidity and ulcer disease are virtually pathognomonic for gastrinoma
what is post transplant lymphoproliferative disorder?
B-cell proliferation due to therapeutic immunosuppression after organ transplantation
patients develop infectious mono-like lesions or polycloncal polymorphic B cell hyperplasia
some B cells may undergo mutations which will render them malignant giving rise to lymphoma
where are the ports placed in a laparoscopic cholecystectomy?
periumbilical, subxiphoid, and two lateral ports
how is an intraoperative cholangiogram performed?
injection of contrast into the infundibulum of the gallbladder
what is a contraindication to using meperidine (Demerol)?
significant hepatic or renal impairment
a toxic metabolite (normeperidine) has a longer halflife than meperidine and can accumulate to toxic levels in patients with hepatic or renal dysfunction and cause seizures
which rectal cancers are candidates for primary surgical therapy?
most rectal cancers are treated with neoadjuvant chemo
tumors that invade the submucosa or muscularis propria (T1 or T2) lesions without lymphadenopathy (N0) are candidates
T1 lesions can undergo transanal excision or abdominoperineal resection, T2 undergo APR
which tumors get APR vs LAR?
tumors located in the superior or mid rectum can undergo LAR and avoid colostomy
tumors in the lower third of the rectum less than 2cm from the anal verge are not candidates for LAR and require APR
any tumors at the dentate line with extramural spread to involve the sphincter complex or direct extension into pelvic structures require APR
which enzyme is cleared the fastest in the course of pancreatitis?
amylase is cleared first, in less than 48 hours
lipase and elastase remain elevated for > 96 hours
where can the splenic artery be identified for quick ligation?
superior to the pancreas in the lesser sac
what is oncologic resection of colon cancer?
margin of at least 2-5 cm with at least 12 negative lymph nodes
what operation should be done for a type IV ulcer located on the proximal lesser curvature?
Pauchet gastrectomy
if the ulcer is not amenable to this more limited procedure a subtotal gastrectomy would be appropriate
what is the ideal oreation for type III gastric ulcers?
antrectomy, vagotomy, and Billroth I reconstruction
Billroth II and Roux-en-Y reconstruction are also appropriate
what is the evolution of a hemangioma and how is it treated?
rapid proliferative phase, quiescence phase, and an involution phase
observation is the treatment of choice however surgical excision is required if they involve a critical structure
medical treatment includes systemic steroids and beta blockers
hemangioma interfering with the visual axis should be excised to avoid visual field obstruction, astigmatism, and amlyopia
where are clotting factors produced?
all factors are produced in the liver except for factor VIII which is produced by the endothelium
what are the vitamin K dependent factors?
II, VII, IX, X, protein C and S
what is a Breslow tape and what needs to be taken into account when using it?
The Breslow tape is used to determine height, weight, and resuscitative equipment sizes for children up to 12 years old and 80lb
the Breslow tape may not be accurate for overweight children
what is the most common noniatrogenic cause of esophageal perforation?
Boerhaave syndrome
what is the blood supply to the cervical esophagus?
inferior thyroid artery
branch of the subclavian
what is the blood supply to the abdominal esophagus?
left gastric artery
what is the blood supply to the thoracic esophagus?
branches directly off the thoracic aorta
management of Barrett’s esophagus
low or moderate grade dysplasia - repeat endoscopies every 3-6 months
high grade dysplasia - endoscopic ablation (previously esophagectomy)
describe laparoscopic esophagomyotomy (Heller myotomy)
standard surgical treatment of achalasia
dissection of the gastroesophageal junction with preservation of the anterior vagus nerve
myotomy should extend 5-6cm on the esophagus and 2cm on the stomach below the gastroesophageal junction
a partial fundal wrap should be performed to avoid reflux associated with Heller alone (not Nissen, higher rate of post operative dysphagia)
how are anal melanomas diagnosed and managed?
women > men, average age 63
suspect in a deeply pigmented hemorrhoid causing symptoms, may not be pigmented
EUA and excisional biopsy for diagnosis
anal canal melanomas do not respond to chemo, radiation, immunotherapy
surgery is rarely curative but is the best option. abdominoperineal resection confers no survival benefit over wide local excision (if involves destroying anal sphincter then needs diverting colostomy)
how do anal canal melanomas spread?
submucosally into the rectum, rarely invade adjacent organs
lymphatic spread to mesenteric nodes is seen in 1/3 at the time of diagnosis, spread to inguinal nodes is less common
wide hematogenous spread especially to the liver and lung is common accounting for most deaths
What are the diagnostic criteria for spontaneous bacterial peritonitis?
elevated ascitic fluid absolute PMN count of at least 250 and a positive ascitic fluid bacterial culture without an obvious intra-abdominal source of infection
what adjunctive treatment is recommended to decrease in hospital mortality for SBP?
IV albumin
what is the mechanism for the ionotropic effect of amrinone?
inhibition of the breakdown of cAMP
phosphodiesterase inhibitor that blocks cAMP breakdown and facilitates an increase in calcium uptake by the sarcoplasmic reticulum of the heart increasing contractility
amrinone also acts as a vasodilator by causing relaxation of vascular smooth muscle cells
what is the management of toxic megacolon secondary to C.diff colitis?
total abdominal colectomy with end ileostomy
what is the first step in management of an open pneumothorax?
occlusive dressing on three sides followed by a tube thoracostomy at a site distant rom the wound
what injury should be expected with persistent pneumothorax despite a well-placed chest tube and a continuous air leak throughout the entire respiratory cycle?
tracheobronchial disruption
clinical signs: subcutaneous emphysema, continuous large airleaks, hemoptysis
fallen lung sign on CT (lung falls away from the hilum)
which test is used to confirm carcinoid syndrome in a symptomatic patient?
24 hour urine 5-HIAA measurement
sensitivity 73% specificity 100%
can be falsely elevated with serotonin rich foods and certain medications
what is chromogranin A a marker of?
chromogranin A is a sensitive serum marker but is nonspecific; elevated in multiple types of neuroendocrine tumors
what is somatostatin receptor scintigraphy scan used for?
somatostatin scintigraphy should be used after the diagnosis of carcinoid syndrome has been confirmed to identify occult metastasis in patients being considered for curative resection and to determine if the patient is likely to respond to octreotide
what is the most common cause of ascites in the US?
cirrhosis
what is the most common complication of cirrhosis?
ascites
what is the first step in managing ascites?
dietary sodium restriction
what is the most common adult small bowel lymphoma?
Non-Hodgkin B cell type
is small bowel lymphoma associated with systemic symptoms?
No fevers, night sweats, etc.
what is the most common site of small bowel lymphoma?
terminal ileum
diseases linked to small bowel lymphoma
Wegener disease, lupus, Crohn disease, celiac sprue
what is the most common cause of urinary retention after hemorrhoidectomy?
pelvic floor muscle spasms
what is the first line therapy for T2 anal cancer?
chemoradiation with 5FU and mitomycin C based regimens
abdominoperineal resection is indicated with evidence of disease 6 months after initiation of treatment or with local recurrence
what electrolyte abnormalities are seen in tumor lysis syndrome?
hypocalcemia, hyperuricemia, hyperkalemia, hyperphosphatemia, increased creatinine
during ex-lap for acute mesenteric ischemia what is done after seeing signs of patchy segmental bowel ischemia from jejunum to ascending colon?
palpate the SMA at the level of the ligament of Treitz
if blood supply is compromised a transverse arteriotomy with embolectomy via Fogarty balloon is performed (allows for easy closure without narrowing the lumen)
frankly necrotic bowel is resected at the initial operation while all questionable bowel is left for a second look operation in 24-48 hours
consequences of hypokalemia and the potassium levels at which they occur
hypokalemia = K less than 3.5 fatigue, ileus, arrhythmia EKG changes (U wave, flat/inverted T wave) with K < 3 rhabdomyolysis can occur when K < 2.5 flaccid paralysis when K < 2 weakness K < 2.5
hypokalemia is usually asymptomatic until potassium concentration falls below 3
what is the most common location of GIST?
stomach (60-70%)
small bowel (20-25%)
colorectum (5%)
esophagus (5%)
which GISTs have a better prognosis, those in the small bowel or stomach?
gastric GIST have a better prognosis than small bowel GIST
is preoperative biopsy required for resectable lesions which are consistent with GIST on imaging?
no but biopsy may be considered if treatment with imatinib is considered in the setting of large tumors o there is evidence of metastatic disease
if done biopsy should be endoscopic
what is GIST prognosis based on?
tumor size and mitotic index
how is refeeding syndrome managed?
electrolyte abnormalities should be corrected early
feeding should be started at a lower rate and increased over a week
patients with refeeding symptoms can continue to receive nutrition but the rate should be slowed
what characterizes the proliferative phase of wound healing?
neovascularization and collagen synthesis
begins with formation of a provisional matrix of fibrin and fibronectin as part of initial clot formation
macrophages are present initially but fibroblasts appear by day 3 in the fibronectin-fibrin framework and initiate collagen synthesis
neovascularization is driven in part by tissue hypoxia (hypoxia inducible factor- 1)
what is ferritin?
ferritin is an iron storage protein and acute phase reactant
extracellular serum level correlates with total body iron stores
low in iron deficiency anemia, high in anemia of chronic disease
which pancreatic neuroendocrine tumor is associated with diarrhea and refractory peptic ulcer disease?
gastrinoma
which pancreatic neuroendocrine tumor is associated with fasting hypoglycemia, symptoms of hypoglycemia, and symptom relief with glucose?
insulinoma
which pancreatic neuroendocrine tumor is associated with watery diarrhea, hypokalemia, and achlorihydria?
VIPoma
which pancreatic neuroendocrine tumor is associated with anemia, weight loss, stomatitis, dermatitis, and diabetes?
glucagonoma
which pancreatic neuroendocrine tumor is associated with steatorrhea, diabetes, and cholelithiasis?
somatostatinoma
what is the surgical approach for acute mesenteric ischemia?
xiphoid to pubis midline incision
examine the small bowel, resect gangrenous or perforated bowel
self retaining retractor
lift omentum and transverse colon cephalad to evaluate the SMA
retract small bowel to the right and pack sigmoid to the left
divide ligament of Treitz, mobilize duodenum to the right
palpate the SMA at the base of the transverse colon mesentery
what organ is exposed by opening the lesser sac?
pancreas
what vessel is exposed with the right medial visceral rotation?
IVC
what vessels are exposed with the left medial visceral rotation?
aorta including take off of the celiac trunk and SMA
what organs are exposed with the Kocher maneuver?
first/second portion of the duodenum and the pancreatic head
what are the borders for the posterior triangle of the neck?
sternocleidomastoid
trapezius
clavicle
where is Zone 1 of the neck and what structures may be injured?
clavicle to cricoid
lung apex, trachea, brachiocephalic/subclavian artery and veins, nerve roots, esophagus
where is Zone 2 of the neck and what structures may be injured?
cricoid to angle of the mandible
carotid/vertebral arteries, jugular veins, esophagus, trachea
where is Zone 3 of the neck and what structures may be injured?
angle of the mandible to the skull base
external or internal carotids, jugular veins, cranial nerve, hypopharyneal nerve
indications for operative interventions for neck trauma
hemodynamic instability (regardless of zone)
signs of tracheal injury (subcutaneous air, bubbling from the wound)
hard signs of vascular injury (bruit, thrill, expanding or pulsatile hematoma)
what may be included in work up for neck injury?
CXR to evaluate for hemothorax or pneumothorax, retropharyngeal air, apical capping
four vessel CTA, color flow Doppler to evaluate for vascular injuries
esophagography with barium or esophagoscopy to evaluate for esophageal injury
laryngotracheobronchoscopy may also be performed
what are complications of therapeutic hypothermia following cardiac arrest?
coagulopathy, cardiac dysrrhythmia, increased infection risk, hyperglycemia, cold diuresis
should be stopped immediately if significant bleeding develops
what is afferent loop syndrome following Billroth II gastrojejunostomy and how is it managed?
obstruction of the afferent limb secondary to excessive length of the afferent limb (more common than efferent limb obstruction)
abdominal pain, cramping, vomiting
surgical management is required - conversion to Billroth I or Roux-en-Y or creation of an enteroenterostomy (afferent to efferent; Braun anastomosis)
what is efferent loop syndrome following Billroth II gastrojejunostomy and how is it managed?
gastric outlet obstruction caused by kinking of the efferent jejunal limb often because of herniation of the limb posterior to the anastomosis
nausea, bilious emesis, abdominal pain
uncommon, usually occurs in the first postoperative month
corrected surgically by reducing the efferent loop if it has herniated posterior to the anastomosis, then closing the retroanastomotic space to prevent recurrence
resuscitation in septic shock
IVF to achieve MAP >/= 65
if not achieved with fluids, start pressors starting with norepinephrine and then vasopressin
dopamine is indicated if there is low risk for arrhythmia and absolute or relative bradycardia
dobutamine is an inotrope that can be considered as an adjunct if there are signs of cardiac dysfunction (high cardiac filling pressures or low cardiac output)
when is phenylephrine used in septic shock?
phenylephrine should not be used in septic shock unless 1. norepinephrine is associated with serious arrhythmia 2. cardiac output is high and the blood pressure is persistently low 3. salvage therapy when combined with vasopressors and MAP is not >=/ 65
what is pseudomyxoma peritonei and what treatment has the best outcomes?
chronic progressive mucinous malignancy characterized by copious mucin production
occurs most commonly as a result of a ruptured cystadenocarcinoma, usually appendiceal origin
best outcomes involve surgicla debulking with excision of the entire parietal peritoneum, ovaries, uterus, and fallopian tubes, with administration of hyperthermic intraperitoneal chemotherapy (HIPEC) intra-operatively
what is the most common late postoperative complication of restorative proctocolectomy with ileal-pouch anal anastomosis for ulcerative colitis?
pouchitis, a nonspecific inflammation of the ileal pouch
occurs in up to 50%
presents with increased stool frequency, urgency, incontinence, abdominal pain, bleeding
other complications: SBP, anastomotic leak (leading to sepsis, abscess, fistula), stricture
what are the mechanisms by which radiation therapy causes changes?
direct damage to DNA and production of oxygen free radicals
what cells are most affected by radiation colitis?
rapidly dividing crypt cells are most sensitive to radiation damage
atrophy of the villi causing degeneration of the mucosal lining
when does chronic radiation injury appear and what does it involve?
6-12 months after radiation
secondary to progressive fibrosis of the microvasculature causing endothelial thickening which leads to nonhealing ulcers and telangiectasias of the bowel wall, fistulas, and sepsis
what do all types of LeForte fracture have in common?
ptrygoid plate fracture
LeForte type 1
horizontal fracture through the maxilla superior to the maxillary dentition
LeForte type 2
pyramidal type fracture outlining the nose, fracture through the maxilla and orbit
LeForte type 3
complete craniofacial separation, fracture of facial bones from the skull
what are the histologic types of small bowel adenomas and where are they most commonly found?
tubular, tubulovillous, villous
predominantly found in the duodenum, majority in the periampullary region
25% of villous and tubulovillous adenomas harbor malignancy, must be resected
screen for colorectal cancers in patients with duodenal adenomas
what does a soap bubble or paint brush sign on contrast series indicate?
small bowel villous adenoma
what is the most common type of collagen found in a scar?
type I
what is the most common type of collagen in the body?
type I
what is the most common type of collagen in cartilage?
type II
what is the most common type of collagen in blood vessels, fetal skin, and the uterus?
type III
what is the most common type of collagen in the basement membrane?
type IV
what is the most common type of collagen in the cornea?
type V
what are the effects of increasing PEEP?
improved oxygenation (takes hours to have effect) keep alveoli open at the end of expiration reduces venous return and cardiac output
what does increasing tidal volume or respiratory rate do?
increases ventilation
what is the fastest way to increase oxygenation?
increasing the inspired concentration of oxygen
what are the anatomic changes in Tetralogy of Fallot?
pulmonary stenosis
ventricular septal defect, overriding aorta with deviation of the origin to the right side and concentric right ventricular hypertrophy
what type of heart murmur is seen in Tetralogy of Fallot?
crescendo-decrescendo harsh systolic ejection murmur that radiates posteriorly due to right ventricular outflow obstruction (not the VSD)
what structures are preserved in a highly selective vagotomy?
Latarjet’s nerves which provide motor function to the pylorus
posterior branches of the vagus that innervate the pancreas and small intesting
anterior branches of the vagus that innervate the liver and the gallbladder
what is the primary fuel source of the small bowel enterocyte in times of stress?
glutamine
what is the primary course of fuel for colonocytes?
short chain fatty acids
what two structures are connected by the epididymis?
testis and vas deferens
it is responsible for semen transport and is the site of sperm maturation
compare split and full thickness skin grafts
split thickness skin grafts have less primary contraction, more secondary contraction, better graft survival, ability to cover larger surface area
what is pharmacokinetics?
pharmacokinetics = what happens to a drug in the body
dissolution, absorption, distribution, metabolism, excretion
what is pharmacodynamics?
pharmacodynamics = what the drug does to the body
cell membrane disruption, ligand binding, cytotoxicity
what is the most appropriate position for indirect laryngoscopy?
upright with atlanto-occipital extension
what is the optimal position for colonoscopy?
left lateral decubitus
turn to supine or apply pressure to left lower quadrant if there is difficulty advancing the scope to the cecum
what is the bicaval technique for recipient hepatectomy in liver transplantation?
excision of the recipient liver en bloc with the retrohepatic inferior vena cava after caval clamps have been placed in a suprahepatic and infrahepatic position
disadvanage: requires dissection posterior to the vena cava possibly leading to bleeding
what is the piggyback technique for recipient hepatectomy in liver transplantation?
leaving the vena in continuity, the hepatic veins are divided within the substance of the liver
advantage: one single caval anastomosis required limiting warm ischemic time
what is the cavocavostomy technique for recipient hepatectomy in liver transplantation?
side to side caval technique
clamps are placed on the right, left, and middle hepatic veins
the liver is then excised, the venous stumps are oversewn and the clamps are removed
advantages: shorter vena cava clamping time, minimal or no changes in the recipient’s hemodynamics (vena cava clamp is placed longitudinally, only occluding the anterior third of the vena cava), lower incidence of caval stenosis (cavostomy performed), lover risk for hepatic vein outflow complications (longer anastomosis)
where are level 2 mediastinal lymph nodes located?
superior to the innominate artery
where are level 4 mediastinal lymph nodes located?
inferior to the innominate artery
Which mediastinal lymph nodes are visualized with EBUS?
superior and inferior mediastinal lymph nodes at stations 2R/2L, 4R/4L, 7, 10, 11, 12
level 5 subaortic lymph nodes (aortopulmonary window) are lateral to the ligamentum arteriosum and are usually not usually accessible by EBUS
what is a Chamberlain procedure (anterior mediastinostomy)?
incision is made to the left of the sternum on the 2nd or 3rd intercostal space (not to the right)
levels 5 and 6 are sampled
why has VATS largely replaced anterior mediastinostomy (Chamberlain procedure)?
superior visualization
less surgical time
more information about the extent of local disease
how is soft tissue sarcoma of the extremities treated?
surgical resection with 1-2 cm margins
adjuvant radiation decreases the risk of recurrence but does not affect survival and is associated with higher risk of fibrosis ands stiffening joints (reserved for high risk patients, >5cm in size and high grade or recurrent tumors not previously treated with radiation)
adjuvant chemo has not been shown to be beneficial
neoadjuvant chemo is important in patients with rhabdomyosarcoma, Ewing sarcoma, high grade tumors >10cm in size, and tumors 5-10cm with chemosensitive histology
where is pain felt due to appendicitis and why?
early in appendicitis, distension of the lumen causes vague abdominal pain due to visceral nerve fibers that course through the SMA ganglia (periumbilical pain)
inflammation of the parietal peritoneum later produces a localizing effect
somatic pain fibers from T7-T12
thinly myelinated and fast conducting
muscle rigidity is an involuntary spasm of abdominal muscles in response to peritoneal inflammation
what are mesenteric cysts?
rare, benign lesions
seen on US, CT, MRI
typically unilocular without a solid component
presentation ranges from incidental finding to acute abdominal pain. nonspecific complaints of nausea, vomiting, anorexia or weight loss are common
most common location for mesenteric cysts is small bowel mesentery (terminal ileum most common)
treated with enucleation which may require resection of associated bowel if blood supply to the adjacent bowel is compromised
simply unroofing the cysts results in a high rate of recurrence
aggressive thyroid cancer, few survive 6 mo past presentation
most common in patients 60-70 years old
women >men
long standing neck mass that rapidly enlarges and is then associated with pain, dysphonia, dysphagia, dyspnea
large mass fixed to the tracheolaryngeal framework resulting in vocal cord paralysis and tracheal compression
more than 80% have jugular LN involvement and more than 50% have systemic metastases at the time of presentation
most patients die of vena cava syndrome, asphyxiation, or exsanguination
anaplastic thyroid cancer
what is the most important prognostic indicator with colorectal carcinoid tumors?
tumor size
Brooke Formula
Parkland Formula
for burn resuscitation
patients >15% total body surface area
modified Brooke = 2mL/kg/TBSA leads to less over-resuscitation than Parkland = 4mL/kg/TBSA
to calculate the 24 hour fluid requirements with one half given over the first 8 hours and the remainder given over the next 16 hours
common to guide titration according to goal urine output 0.5-1mL/kg/hr
rule of nines for calculating TBSA of burns
second or third degree burns
4.5% for each side of each arm (9% total each arm)
18% front torso, 18% back torso
9% of each side of each leg (18% total each leg)
9% head
1% genitals
what structure is used to guide the dissection of the elevator ani muscles from the perineum into the pelvis?
coccyx
Describe APR
abdominal portion - rectum is dissected into the pelvis including wide mesenteric excision
perineal dissection - close the anus with purse string, vertically oriented elliptical incision around the anus, tip anus upwards to sever attachment to the coccyx
insert finger into presacral space and sweep finger laterally to identify the elevator muscles
expose the levator muscle on one side, divide between the clamps lateral to rectum to avoid compromising the circumferential margin
therapeutic strategy in rectal cancer
surgery - stage I (Tis, T1, T2 and no nodal involvement)
neoadjuvant chemotherapy followed by surgery - stage II and above (>/=T3 +/- nodes)
type of surgery for cancer in the upper rectum
left hemicolectomy
type of surgery for cancer in the middle and lower rectum
low anterior resection
type of surgery for cancer close to the anal sphincters or lower rectum with no oncological clearance possible
abdominoperineal resection
type of surgery for T1 rectal cancers within 8cm of the anal verge, <3 cm in size, well-differentiated, <30% circumference involvement, and mobile, non-fixed
transanal local excision
what structure is used to guide dividing the peritoneum on the right side of the rectosigmoid in APR?
sacral promontory
what level of fibrinogen is associated with increased risk of bleeding?
< 150 mg/dL
normal circulating levels of fibrinogen are 200-400
causes of spontaneous rectus sheath hematomas
vigorous abdominal wall contraction (coughing, sneezing, exercise)
especially in older patients and those on anticoagulation
traumatic rectus sheath hematomas
blunt or penetrating trauma
iatrogenic injury during laparoscopy
management of rectus sheath hematomas
non-expanding: observation
large/expanding, anticoagulation: angiography and/or surgery
abdominal mass that does not cross the midline and does not move with rectus muscle flexion, seen in rectus sheath hematoma
Fothergill’s sign
gold standard surgery for young UC patients with intact sphincter
total proctocoloectomy with ill pouch anal anastomosis
avoids ostomy and creates reserved for improved continence and decreased frequency
technique used to decrease tension at the ileoanal anastomosis
division of the ileum flush with the cecum, complete mobilization of the small bowel mesentery to the third portion of the duodenum and the pancreatic body, full adhesiolysis off necessary and step-ladder relaxing incisions on the front and back of the mesentery over tension lines along the superior mesenteric vessels
location of the right renal artery in relation to the IVC and renal calyx
right renal artery is posterior to the IVC and anterior to the renal calyx
where does the spinal accessory nerve (CN XI) exit the skull?
exits skull at the jugular foramen
what does CN XI innervate?
sternocleidomastoid, trapezius
BI-RADS 0 interpretation and management
incomplete assessment
additional studies needed
BI-RADS 1 interpretation and management
negative
routine screening
BI-RADS 2 interpretation and management
benign
routine screening
BI-RADS 3 interpretation and management
probably benign
6 month follow-up
BI-RADS 4 interpretation and management
suspicious
core needle biopsy
BI-RADS 5 interpretation and management
highly suggestive of malignancy
core needle biopsy
BI-RADS 6 interpretation and management
biopsy-proven malignancy
appropriate care
in which patients are pure fungal abscess most often seen?
hematologic malignancies recovering from chemotherapy induced neutropenia
Candida is most common followed by Aspergillus and Cryptococcus; first line treatment is drainage and caspofungin or micafungin
what are the most common causes of pyogenic liver abscesses?
hepatobiliary malignancy and biliary tree instrumentation
which factors does PT measure?
extrinsic pathway - I, II, V, VII, X
which factors does PTT measure?
intrinsic pathway - I, II, V, VIII, IX, X, XI, XII
describe the Beger procedure
resection of the pancreatic head with Roux-en-Y jejunal loop as side-to-end and side-to-side pancreaticojejunostomy
reserved for patients with a large inflammatory mass in the head of the pancreas with no evidence of distal ductal dilation
describe to Puestos procedure
longitudinal pancreaticojeunostomy
reserved for chronic pancreatitis with dilation of the pancreatic duct > 7mm
describe the Frey procedure
coring out the head of the pancreas with a longitudinal dissection of the pancreatic duct toward the tail
reconstruction with Roux-en-Y pancreaticojejunostomy
reserved for smaller inflammatory masses of the head of the pancreas and dilated pancreatic ducts
describe the Whipple procedure
pancreaticoduodenectomy
resection of the head, duodenum, and distal 1/3 of the stomach
reconstruction with GJ, PJ, HJ
reserved for neoplasms of the head of the pancreas, used in chronic pancreatitis if malignancy cannot be excluded
describe the Bern procedure
modification of the Beger procedure that involves resection of the pancreatic head
pancreas is not transected at the level of the portal vein as in the Beger which is advantageous in extensive inflammation
reconstruction requires a single anastomosis with a Roux-en-Y jejunal loop to the pancreas
no significant difference in outcomes between Beger and Bern
what are bronchopulmonary sequestrations
non-functional pulmonary tissue fed by anomalous systemic arterial supply and have no connection to bronchial tree
intralobar - increased risk of bleeding
extralobar - usually asymptomatic with low risk of infection
describe congenital lobal emphysema
caused by failure in development of bronchus cartilage resulting in air trapping with expiration
90%+ of cases involve either left upper or middle lobes
presents between first few days and first 6 months after birth
CXR with overinflation of the involved lobe
what is a Morgagni hernia?
anteriomedial congenital diaphragmatic hernia
5% of CDH
what is a Bochdalek hernia?
posterolateral congenital diaphragmatic hernia
most common type of CDH
proposed cause of congenital diaphragmatic hernia
failure of closure the pleuroperitoneal canal
treatment of inflammatory breast cancer
induction chemotherapy followed by surgical resection once inflammatory skin changes have subsided
radiation to reduce locoregional recurrence
there is no role for breast-conserving therapy in inflammatory breast cancer
which of the following blood products is safe when considering the risk of transmitting hepatitis?
albumin is heat treated prior to packaging, which eradicates any circulating viruses
describe dermatofibrosarcoma
rare (<1%) form of sarcoma that usually presents as a flesh-colored ass over the back and can be mistaken for keloid or hypertrophic scars
microscopic tentacles that extend laterally from the lesion - careful en bloc excision with a wide margin (2cm) to prevent recurrence or Mohs surgery
immune reactivity to CD34
usually low grade
commonly diagnosed between 30 and 50
gut absorption of calcium is decreased in deficiency of which vitamin?
vitamin D
what is a common cause of outflow failure in peritoneal dialysis?
omental wrapping
treated with omentopexy or omentectomy if needed
is prior abdominal surgery a contraindication to peritoneal dialysis?
not id LOA can be safely and effectively performed
how are hernias developed during peritoneal dialysis managed?
repair hernias electively without removal of the peritoneal dialysis catheter
patients with polycystic kidney disease undergoing peritoneal dialysis are at increased risk of what complication?
abdominal wall hernias
what is the most likely reason for non healing anal fissure after sphincterotomy?
inadequate division of the sphincter complex resulting in persistent tension
risk factors for stress gastritis
critical illness, multi-organ system failure ventilator dependency massive resuscitation extensive trauma burns hemorrhage
acid production has a secondary role (prophylactic PPI can aid in prevention)
what mammography finding is pathognomonic for fat necrosis?
oil cyst - circumscribed mass of mixed soft tissue density and fat with a calcified rim
when is short term follow-up and no biopsy ok for management of fat necrosis?
with a clear history of trauma and radiographic findings consistent with fat necrosis
factors associated with increased postoperative morbidity and mortality?
performing = 4 mets
frailty score >/= 2
ASA class >/= 2
created albumin level
management of brown recluse spider bite
initial management with cold compresses and elevation to decrease of spread of venom
frank areas of necrosis will need to be derided but early surgical intervention can result in unnecessary removal of tissue
symptoms of hypophosphatemia
diplopia, dysphagia, confusion, respiratory muscle weakness
symptoms of hypokalemia
constipation, fatigue, arrhythmia
symptoms of hyponatremia
dizziness, lethargy, headache
symptoms of hypernatremia
thirst, altered level of consciousness, tachycardia
where are Delphian lymph nodes found?
within the anterior suspensory ligament, small group of midline prelaryngeal nodes
where are level VI lymph nodes found?
the central compartment
where are level II lymph nodes found?
upper jugular
where are level III lymph nodes found?
mid jugular
where are level IV lymph nodes found?
lower jugular
where are level V lymph nodes found?
posterior triangle
where are level I lymph nodes found?
submental
where are level VII lymph nodes found?
superior mediastinal
which lymph nodes does thyroid cancer tend to involve?
level VI before II, III, IV
I and VII are most common
where are Rotter’s lymph nodes found?
between the pectorals major and minor muscles
what are the most common endoscopic findings in eosinophilic esophagitis?
edema, rings, exudates, furrows, and strictures
what is the mechanism of action of magnesium sulfate when used to treat premature labor?
competitive inhibition of calcium influx
magnesium sulfate causes tocolysis by inhibiting calcium at motor end plates and cell membrane calcium influx
what is the management of periampullary tumors?
standard management is surgical resection with a Whipple but with small tumor, benign path, and patient preference a trans duodenal tumor resection is reasonable
what is the appropriate management of medullary thyroid cancer?
total thyroidectomy with bilateral level VI central lymph node dissection
if there is evidence of metastasis to the lateral lymph nodes, a lateral neck dissection should be done
in MEN IIA and IIB what prophylactic surgery is required?
total thyroidectomy before one year of age for MEN IIB and before age five for MEN IIA
mechanism, metabolism, and side effects of tacrolimus
calcineurin inhibitor that acts by binding FK-binding protein
inhibition of IL2
metabolized by cytochrome P450 system
side effects: headache, seizures, tremors, nephrotoxicity, hypertension, alopecia, hyperkalemia, hypomagnesemia, GI symptoms, increased infections
adverse effects of corticosteroids
adverse effects include acne, increased appetite and associated weight gain, mood changes, diabetes, hypertension, and impaired wound healing.
adverse effects of azathioprine
the most significant and commonly dose-related, is bone marrow suppression. This leukopenia is often reversible with dose reduction or temporary cessation of the drug. Other significant side effects include hepatotoxicity, pancreatitis, neoplasia, anemia, and pulmonary fibrosis.
adverse effects of mycophenolate mofetil
The most common side effects of mycophenolate mofetil are gastrointestinal in nature, most commonly diarrhea, nausea, dyspepsia, and bloating. Other important side effects are leukopenia, anemia, and thrombocytopenia.
adverse effects of sirolimus
Sirolimus is a substrate of CYP3A/4 and has many significant drug interactions. Side effects of sirolimus include hypertriglyceridemia, impaired wound healing, thrombocytopenia, leukopenia, and anemia.
when is surgery indicated for electrical injury?
vascular compromise with progressive neurologic dysfunction
how are renal complications from electrical injury prevented?
fluid resuscitation titrated to 2mL/kg/hr
IV sodium bicarb
mannitol
what medication should be avoided in burn patients 48 hours after injury
succinylcholine due to exaggerated hyperkalemic response which may result in cardiac arrest
for how long should electrical burns patients be on a cardiac monitor if they have indications?
at least 24 hours
indications for monitoring:
arrhythmia on initial EKG
evidence of cardiac ischemia on initial EKG
history of cardiac arrest or loss of consciousness at time of injury
how do bronchopleural fistulas present?
persistent air leaks from chest tubes
what is lobar torsion and how does it present?
occurs when the bronchus and adjacent vascular structures twist upon themselves
typically occurs in the immediate post operative period following right upper lobectomy
mucus plugging of airways can cause white out of the affected lobes on CXR
presents with fevers, tachycardia, decreased breath sounds
if discovered early - detorsion, if not will need lobectomy
what is the calculation for nitrogen balance?
nitrogen balance (grams) = protein intake / 6.25 - (UUN + 4)
UUN = urinary excretion of nitrogen in a 24 hours period
6.25g of protein has 1g of nitrogen
describe discrete data
nominal, binary, or ordinal
no implied order
describe the quality of what is being studied and provide qualitative rather than quantitative observations
chi squared test is used for binary data
describe continuous data
composed of number that can be broken down into many increment such as age, height, weight, blood pressure
measures of central tendency to describe the chief feature of the data set
they are comparable to the population mean using tests of significance such as Student T test
how is catheter associated thrombosis managed?
therapeutic anticoagulation in the absence of contraindication (in which case IVC filter should be placed)
the catheter may be left in place if it remains functional
how much of the liver’s blood supply comes from the hepatic artery and portal vein?
75% from the portal vein
25% from the hepatic artery
however they each supply 50% of the liver’s oxygen
etiologies of chylous ascites
malignant obstruction of lymphatic vessels at the base of the mesentery or the cisterns chyli
congenital lymphangiectasia
thoracic duct obstruction
lymph peritoneal fistula
what does cetuximab work on and which cancers does it treat?
cetuximab works against EGFR and is used in colon and head and neck cancer, not useful in KRAS+
what is trastuzumab used for?
HER2 breast cancer
what is rituximab used against and what cancers does it treat?
rituximab is used against CD20 in the treatment of lymphoma and CLL
what is the mechanism of imatinib, and what is it used against?
imatinib is a tyrosin kinase inhibitor used against c-kit and ABL in the treatment of GIST and CML
Diagnosis:
Cortisol level suppresses with low dose dexamethasone
ACTH level low (ACTH appropriately suppressed)
primary hypercortisolism; adrenal adenoma
Diagnosis:
cortisol level suppresses with high-dose dexamethasone
ACTH normal to slightly high (ACTH inappropriately normal to elevated)
Cushing disease; pituitary adenoma
Diagnosis:
cortisol does not suppress
ACTH very high (in the hundreds); ACTH is responsible
ectopic ACTH syndrome; small cell lung cancer
is NSAID induced mucosal ulceration more common in the stomach or duodenum?
stomach
how many patients with H. pylori develop peptic ulcer disease?
20%
H pylori infection is present in what percentage of patients with duodenal ulcers and gastric ulcers?
H pylori is present in almost all patients with duodenal ulcers and about 70% of patients with gastric ulcers
what are the three different patterns of inflammation associated with H pylori infection?
diffuse, astral, and stomach body related inflammation
what is the most common cause of portal been thrombosis in children?
umbilical vein infection
causes of portal vein thrombosis
umbilical vein infection, hepatic malignancy, myeloproliferative disorders, coagulopathies (protein C and antithrombin III deficiency), inflammatory bowel disease, trauma, pancreatitis, previous splenorenal shunt
most cases in adults are idiopathic
most common cause in children is umbilical vein infection
what is the triad of symptoms seen in pheochromocytoma?
headache
diaphoresis
palpitations
most patients do not present with all three symptoms and they are often paroxysmal in nature
most common symptom is 90%
how is pheochromocytoma diagnosed?
24 hour urine metanephrines and catecholamines
which familial disorders are associated with pheochromocytoma?
von Hippel-Lindau syndrome
MEN2
neurofibromatosis type 1
what is the pheochromocytoma rule of 10s?
10% malignant
10% bilateral
10% extra adrenal
10% familial (likely more)
indications for central venous catheter
chemotherapeutic agents TPN (10 or 20% dextrose preparation) vasopressors 3% hypertonic saline inability to place peripheral venous catheters
causes of abdominal compartment syndrome
post traumatic hemorrhage
intraperitoneal bleeding
retroperitoneal bleeding
aggressive fluid resuscitation causing visceral edema
effects of abdominal compartment syndrome
decreased cardiac output from decreased venous return
increased peak inspiratory pressures and pulmonary failure
decreased portal flow to the liver
decreased urine output from decreased flow to the kidneys
decreased blood flow to the intestines
diagnosis: tense abdomen, ventilator insufficiency (increased peak inspiratory pressure) progressing to oliguria and cardiac collapse
abdominal compartment syndrome
diagnosis of abdominal compartment syndrome
bladder pressure >20mmHg
new onset organ failure
presentation of chronic mesenteric ischemia
severe sharp abdominal pain that develops 30-60 minutes after a meal and is associated with gradual weight loss from developing food fear
treatment of acute mesenteric ischemia
exploratory laparotomy, assessment of bowel integrity, retraction cephalic of the transverse colon and tracing of the middle colic artery to the root of the mesentery to locate the SMA
transverse arrteriotomy, removing clot with Fogarty catheter both proximally and distally, closing the arteriotomy site
treatment of severe class II purulent peritonitis or Hinchey Class IV fecal peritonitis from acute sigmoid diverticulitis
ex-lap, sigmoid resection, rectal stump creation, end colostomy
differential diagnosis for acute onset of severe, sharp and diffuse abdominal pain
biliary colic, ureteral colic, perforated ulcer, ruptured abdominal aortic aneurysm, acute mesenteric ischemia
patient safety events that result in patient death, permanent harm, severe temporary harm, or risk thereof
sentinel events
