ABSITE Personal

Question 1

Breast cancer in pregnancy

Answer 1

1. Sentinel lymph node biopsy (SLNB) should be performed (with radioactive sulfur colloid but NOT isosulfan blue dye), as this may influence whether adjuvant chemotherapy is indicated.
   2.

Question 2

Breast CA staging

Answer 2

Question 3

Hemorrhagic shock classification

Answer 3

I0-750 mL

II750-1500 mL
(15-30%) Anxious

III1500-2000 mL
(30-40%)Confused, combative

IV>2000 mL
(>40%) Lethargic, obtunded

(0-15%)

Question 4

Choledochal cyst types

Answer 4

1-3: extra-hepatic, single.

4 a: extra and intrahepatic

4 b: extrahepatic multiple

5. Solely intrahepatic. Caroli disease if multiple

Type I: Most common variety (80-90%) involving saccular or fusiform dilatation of a portion or entire common bile duct (CBD) with normal intrahepatic duct.

Type IA is singular,

Type IB is segmental.

• Resection and choledochojejunostomy, which is the same reconstruction technique used for a complete transection of the CBD that can occur during cholecystectomy

Type II: isolated diverticulum protruding from the CBD. Simple excision at connecting stalk.

Type III or Choledochocele: Arise from dilatation of intraduodenal portion of CBD or where the pancreatic duct meets.

The CBD is subdivided into supraduodenal, retroduodenal, pancreatic, and intraduodenal portions. Type III cysts are cystic dilations of the intraduodenal portion of the CBD and are also known as choledochoceles. They are further divided into

Group IIIA, where the CBD and main pancreatic duct independently enter the cyst, do not merge, and drain into the duodenum in a separate orifice: Sphincterectomy and epithelium biopsy to rule out malignancy.

Group IIIB, the two ducts merge forming a common channel that enters the cyst. Endoscopic resection or choledochojejunostomy.

Type IVa: Characterized by multiple dilatations of the intrahepatic and extrahepatic biliary tree.

Type IVb: Multiple dilatations involving only the extrahepatic bile ducts.

Type V: Cystic dilatation of intrahepatic biliary ducts without extrahepatic duct disease. The presence of multiple saccular or cystic dilations of the intrahepatic ducts is known as Caroli’s disease.

Both type IVA and V cysts involve the intrahepatic ducts, so liver transplant is an option if hepatic resection is not feasible

Type VI: An isolated cyst of the cystic duct is an extremely rare lesion. Only single case reports are documented in the literature. The most accepted classification system of biliary cysts, the Todani classification, does not include this lesion. Cholecystectomy with cystic duct ligation near the common bile duct is curative.

Question 5

Which breast CA need adjuvant therapy

Answer 5

Adjuvant chemotherapy is recommended in patients with breast cancer who show evidence of :

• nodal disease,
• those with tumors >1 cm,
• and pathologic specimens with evidence of aneuploidy.

Question 6

Chemo cardiotoxicity criteria

Answer 6

• Reduction in >20% of EF is baseline normal
• 10@ if baseline abnormal

Hence TEE needed to establish a baseline prior to beginning

1. Trastuzumab is a monoclonal antibody against humanized epidermal growth factor receptor 2 (HER2). It acts to block HER2-mediated signaling in cardiac myocytes and thereby, impair the stress response of cardiac myocytes leading to decreased myocyte function.

• The incidence of left ventricular dysfunction with trastuzumab is 2%-28%,
• incidence of heart failure is 1.7%-4.1%.

2. Taxanes, such as paclitaxel and docetaxel, act to impair ell division through inhibition of microtubule disassembly during mitosis.
   * The incidence of heart failure with taxanes is approximately 2.3%-8.0%
3. Cyclophosphamide is an alkylating agent that impairs protein synthesis via inhibition of DNA transcription. Left ventricular dysfunction occurs in a dose-dependent manner in patients treated with cyclophosphamide and other alkylating agents, and occurred in 7%-28% of patients.
4. doxorubicin and other anthracyclines act to impair DNA repair (via inhibition of topoisomerase II) and protein synthesis, as well as produces reactive oxygen species leading
   * Left ventricular dysfunction occurs in 1%-5% of patients treated with anthracyclines.

Question 7

Pancreatic trauma grades and management

Answer 7

Question 8

Inguinal hernia repair types

Answer 8

1. Laparoscopic (general anesthesia)
   * Transabdominal preperitoneal (TAPP):
   
   • The peritoneum incised from inside the abdomen
   • mesh placed into the preperitoneal space and sutured to Cooper’s ligament medially.
   • The peritoneum then reapproximated over the mesh
     * Totally extraperitoneal (TEP): The preperitoneal space accessed initially using a dissecting balloon, then a mesh placed in the preperitoneal space
2. Open (local anesthesia with sedation)
   * Bassini tissue repair: The IO and TA and TF secured to the inguinal ligament as a single layer with interrupted sutures. From Pubic Tubercle medially to area of internal inguinal ringh laterally.
   * Shouldice tissue repair: Bassini done in layers with continuous suture to distribute tension evenly
   * Desarda Repair: tissue-reinforcing the floor of the inguinal canal with a medially based strip of the undetached EO aponeurosis.
   * McVay repair, tissue: the conjoined tendon is sutured to the Cooper ligament with interrupted nonabsorbable sutures. For both inguinal and femoral.
   
   • Joining the anterior (inguinal ligament) and posterior (pectineal ligament) boundaries of the femoral canal create a transverse plane through which tissue cannot pass in a superior to inferior direction. Basis of McVay repair.
     * Femoral : Mesh (or TF if performing tissue repair) sutured to the conjoined tendon (IO&TA) and sutured below Cooper’s ligament medial to the femoral vein and to the inguinal ligament lateral to the femoral vein
     * Plug and patch (?Rutkow): Plug inserted into the defect, only mesh covers the inguinal floor
     * Lichtenstein: Flat mesh sutured to the conjoined tendon, pubic tubercle, and inguinal ligament. Mesh split laterally to create a new internal ring
     * Kugel preperitoneal: Large piece of flat mesh used to cover the entire inguinal floor in the preperitoneal space
     * Two-layer mesh (Gilbert): Two sheets of mesh with an intervening connector. Underlay in the preperitoneal space with overlay along the floor of the inguinal canal. Allows prosthetic reinforcement both posterior and anterior to the transversal fascia

Question 9

Boundaries of inguinal and femoral canals

Answer 9

Pectineus muscle is covered with pectineus ligament aka cooper. See table

Side notes: The pectineus muscle is the most anterior adductor of the hip. The muscle does adduct and internally rotate the thigh but its primary function is hip flexion. It can be classified in the medial compartment of thigh (when the function is emphasized) or the anterior compartment of thigh (when the nerve is emphasized).

Question 10

Divided branches for left vs right colectomy and their extended colectomy versions

Answer 10

1. For right colonic tumors including some of the hepatic flexure tumors a
   * right hemicolectomy: dividing of the ileocolic vessels, right colic artery and the hepatic/right branch of the middle colic artery.
2. For transverse colonic tumors - transverse colectomy is rarely performed.

• If right of the midline
  
  • Extended right hemicolectomy (also referred as a subtotal colectomy by some), resects the terminal ileum, right transverse colon, and proximal descending colon. The ileocolic, right colic, middle colic, and left colic arteries are ligated.
• If left of the midline
  
  • extended left hemicolectomy (below)

1. For splenic flexure cancer - the treatment could be managed in a different way:

• Left hemicolectomy, extended left hemicolectomy or even extended right hemicolectomy.
  
  • Left hemicolectomy involves division of the left branch of the middle colic artery and the left colic artery.
  • Extended left colectomy ligates the left branch of the middle colic and the origin of the IMA with resection of the distal transverse colon, splenic flexure colon, descending colon, and sigmoid colon.

Question 11

Diabetic gastropathy treatment Gastroparesis

Answer 11

Metoclopramide, a dopamine antagonist, and erythromycin, a motilin agonist, are first-line medical therapeutic agents for diabetic gastropathy. Other 2 in tables with too serious risks.

• Of note:*
  1. Opioid-induced constipation:
• methylnaltrexone (relistor) or naloxegol
• selectively antagonizing peripheral mu opioid receptors.

1. Alvimopan (ENTEREG), which is also a peripheral mu-opioid receptor antagonist, is the first and only FDA-approved drug indicated to accelerate time to gastrointestinal recovery after partial bowel resection with primary anastomosis.

Question 12

Whipple procedure steps

Answer 12

After exploring the peritoneal wall for evidence of disease which would be contra-indication to resection

1. Right colon is then fully mobilized and reflected medially (Cattell-Braasch maneuver), exposing the infrapancreatic SMV.
2. A Kocher maneuver is performed to the level of the left lateral border of the aorta, with attention to clearance of the lymphatic tissue overlying the great vessels.
3. The transverse mesocolon is separated off the head of the pancreas.
4. The lesser sac is entered through the gastrocolic ligament, sparing the gastroepiploic vessels.
5. The right gastroepiploic vein is ligated at its confluence with the SMV, allowing the SMV to be dissected from the inferior border and posterior neck of the pancreas.
6. Once the infrapancreatic SMV is dissected and the head of the pancreas is fully mobilized, the gallbladder is removed and the common hepatic duct is circumferentially dissected. Division of the common hepatic duct allows visualization of the suprapancreatic SMV.
7. The duodenum is divided at least 2 cm distal to the pylorus using electrocautery or a blue load stapler.
8. The hepatic artery is exposed proximally and distally and assessed for replacement or aberrant anatomy.
9. Before division of the GDA, the vessel is temporarily occluded, and blood flow through the distal common hepatic artery is ensured using a Doppler device. This maneuver is vital in patients with atherosclerosis of celiac origin to ensure that the hepatic blood supply is not dependent on collateral retrograde arterial flow from the SMA through the GDA.
10. Once the hepatic arterial flow is confirmed, the right gastric artery and GDA are ligated and divided.
    
    • If the flow in the hepatic artery is interrupted by occlusion of the GDA, resection may proceed only with the preservation of the GDA or arterial resection and bypass, typically as an aortohepatic conduit.
11. The pancreas is then divided after four-point ligation of the inferior and superior pancreaticoduodenal arteries. Blunt dissection is used to separate the portal vein from the uncinate process. This dissection often includes ligation of a superior and inferior branch from the portal vein and SMV to the uncinate process.
12. The jejunum is divided approximately 10 cm distal to the ligament of Treitz, and the short mesenteric vessels are divided to allow retro-mesenteric rotation of the jejunum and third and fourth portions of the duodenum. The head of the pancreas and attached small bowel are then retracted to the patient’s right, and the remaining portal vein and uncinate dissection are completed.

The picture below shows a pylorus-preserving pancreaticoduodenectomy (left) and classical pancreaticoduodenectomy (right).

Question 13

CKD dialysis analgesia choice

Answer 13

Reasonable choices include

• acetaminophen (Tylenol),
• hydromorphone (Dilaudid),
• fentanyl or sufentanil

Question 14

Bismuth-Corlette classification for perihilar cholangiocarcinoma

Answer 14

Type IV is unresectable

Question 15

Anal SCC Tx

Answer 15

• Nigro protocol (chemo and rafiotherapy)
  
  • Chemo: Mitocyni + 5FU
  • For 6 months (stll responsive); seen in office 8 weeks for DRE and then 8-12 weeks to assess progression or regression
  • • Local excision if < 1cm and not involving sphincter (whether initially or after 6 months of Nigro)
• If fails to resolve or progress > 6 months
  
  • Salvage APR
  • or repeat radiation
• PET CT
  
  • in pretreatment, if inguinal nodes are suspected and need to be included in radiation

Question 16

Respiratory Quotient

Answer 16

Calculated from the ratio of carbon dioxide production to oxygen consumed.

Determined by indirect calorimetry

The RQ ranges

• from 0.6, in the case of starvation,
• to 1.1, in the case of overfeeding and lipogenesis.
• 1.0 represents pure carbohydrate metabolism.
• 0.8 is consistent with mostly protein metabolism or a mixed diet,
• 0.7 is typically seen in the case of fat metabolism, starvation, and diabetics.

Question 17

Causes of Milky Pleural Effusions

&TX

Answer 17

Tx for chylothorax depends on the CT output

• < 1L/day: Conservative
  
  • NPO, TPN and/or Octreotide administration
  • OR if fails
• >1L/day:
  
  • OR: thoracic duct ligation (open or lap) through the right chest
    
    • mass suture ligation of the soft tissue located between the patient’s spine and azygos vein at the level of the esophageal hiatus in the diaphragm
  • Chemical pleurodesis or lymphangiography with possible embolization of the duct: similar outcomes
    
    • Lymphangiography: cannulation of the thoracic duct either transabdominally or via access of the lymphatics between a patient’s toes. The thoracic duct is located by injecting sunflower oil (which is naturally radiopaque) in addition, this aids in finding the leak, which is addressed by injecting coils to close the defect
• The use of tPA and DNase is reserved for the early management of empyemas. This allows thinning of the purulent fluid and obliteration of loculations to effectively drain the empyema. Studies have shown this to be an effective alternative to operative decortication when performed within the first 7-10 days of presentation of an empyema.

Question 18

Starvation response: Source of energy during fasting hours to day 10

Answer 18

Hours-1 day: Glycogen breakdown mediated by drop in insulin and increase in glucagon. Glucose is the primary fuel source.

1-3 days: Switch from glucose to fatty acids. Glycogen is depleted, and fatty acids are produced as a result of lipolysis. Fatty acids travel to the liver, where they are transformed into ketone bodies through the process of beta-oxidation. Fatty acids are the primary fuel; however, the brain still needs glucose to function, which is supplied via gluconeogenesis.

3-7 days: Ketosis continues, and ketones are produced in greater quantities by the liver, beginning from precursors obtained from fatty acid breakdown. The brain starts to use ketone bodies as fuel.

>7 days: Cells in the body begin to break down protein. This releases amino acids into the bloodstream, which can be converted into glucose by the liver. Ketones become the primary fuel source for the brain. The brain also uses glucose to a limited extent, but most of the body’s glucose is allocated to the red blood cells (RBCs), which cannot use ketones.