Abdominal Surgery- Intestines Part B Flashcards
1
Q
Diverticular Disease
A
- encompasses a set of colonic pathologies that result from abnormal outpouchings of the colonic mucosa (diverticula).
2
Q
Diverticula
A
blind pouches that protrude from the gastrointestinal wall and communicate with the lumen
3
Q
Diverticulosis
A
the presence of multiple colonic diverticula without evidence of infection
4
Q
Diverticulitis
A
inflammation or infection of colonic diverticula
5
Q
Diverticular Disease
Epidimeology
A
∼ 50% of individuals > 60 years have diverticulosis
6
Q
Diverticular Disease Etiology
A
Caused mainly by lifestyle and environmental factors
- Diet (low-fiber, rich in fat and red meat)
- Obesity
- Low physical activity
- Increasing age
7
Q
Diverticulitis Pathophysiology
A
Most commonly:
- chronic inflammation and increased intraluminal pressure →
- erosion of diverticula wall →
- inflammation and bacterial translocation
Rarely:
- stool becomes lodged in diverticula →
- obstruction of intestinal lumen → inflammation
8
Q
Diverticulosis Clinical Features
A
- Usually asymptomatic
- may have abdomincal discomfort
- chronic constipation
9
Q
Diverticulitis Clinical Features
A
- Low-grade fever
- Sigmoid colon most commonly affected → left lower quadrant pain
- Possibly tender, palpable mass (pericolonic inflammation)
- Change in bowel habits
- (constipation in ∼ 50% of cases and diarrhea in 25–35% of cases)
- Nausea and vomiting
Elderly or immunocompromised milder symptoms
10
Q
Symptomatic Diverticulosis Diagnosis
A
Colonoscopy- modality of choice
11
Q
Diverticulitis Diagnotics
A
Laboratory studies
- leukocytosis; possible anemia
Imaging
-
CT abdomen and pelvis with IV contrast
- Preferred initial imaging modality
- Bowel wall thickening > 3 mm
- Screening colonoscopy
- 6–8 weeks after acute episode to assess and rule out malignancy
- Contraindicated during an acute episode because of the increased risk of perforation.
12
Q
Diverticulitis Tx Aproach
A
Uncomplicated diverticulitis
- Conservative management
- Consider broad-spectrum oral antibiotics (e.g., ciprofloxacin PLUS metronidazole)
Complicated diverticulitis
- broad-spectrum IV antibiotics
- CT-guided percutaneous drainage for abscesses > 4 cm
- Emergency colectomy in patients with generalized peritonitis
13
Q
Uncomplicated vs Complicated Diverticulitis
A
Uncomplicated diverticulitis: localized inflammation of a colonic diverticulum with no evidence of complications
Complicated diverticulitis: inflammation of a colonic diverticulum associated with
- perforation,
- abscess,
- fecal peritonitis,
- bowel obstruction,
- fistula formation
14
Q
Uncomplicated DIverticulitis Tx
A
Mild diverticulitis is more likely to be an inflammatory process rather than an infectious one. The selective administration of antibiotics is a conditional recommendation.
- MetronidazolePLUS one of the following
- Ciprofloxacin
- Levofloxacin
15
Q
Complicated Diverticulitis Tx
A
Antibiotic therapy: broad-spectrum IV antibiotics
- Metronidazole PLUS one of the following
- Ciprofloxacin
- Levofloxacin
Management of complications
- Abscess Size ≥ 4 cm
- Ultrasound- or CT-guided percutaneous drainage
- Perforation with generalized peritonitis;
- emergency surgery
Elective colectomy
- Routinely recommended 6–8 weeks after resolution of complicated diverticulitis
16
Q
Prevention of Diverticulitis
A
- High-fiber diet
- Fluid hydration
- Vigorous physical activity
17
Q
Complications of Diverticular Disease
A
- GI Bleeding
- Fistulas
- Inflammtions (diverticulitis)
- Abscess
- Perforation
- Intestinal Obstruction
18
Q
Diverticular Disease Fistulas
A
Colovesical (most common)
Symptoms : Pneumaturia and fecaluria
19
Q
Volvulus
A
twisting of a loop of bowel on its mesentery
20
Q
Volvulus Epidimiology
A
Incidence
- Volvulus: 3rd most common cause (∼ 10–15%) of intestinal obstruction in the United States
- Sigmoid volvulus (most common, 80%)
Age and sex
- Sigmoid volvulus: ∼ 70 years
- Cecal volvulus: 40–60 years
- Intestinal malrotation and midgut volvulus: neonates and infants
21
Q
Vovulus Risk Factors
A
- Long mesentery
- Acquired (sigmoid volvulus): chronic constipation
- Congenital (cecal volvulus): abnormally mobile cecum
- Intestinal malrotation
- Megacolon
- Intestinal bands/adhesions
22
Q
Sigmoid Volvulus Clinical Features
A
- abdominal pain, which decreased after explosive passage of stool/gas
- Slowly (most common) or rapidly progressive symptoms of bowel obstruction
- peritonitis
23
Q
Sigmoid Volvulus Tx
A
- IV fluids; NPO; placement of a nasogastric tube
- Evaluation
- No signs of peritonitis: rigid/flexible sigmoidoscopic detorsion of the volvulus
- Signs of peritonitis→ broad-spectrum IV antibiotics and emergency surgery
- Surgery
24
Q
Sigmoid Vovlus Surgery
A
Sigmoid colectomy and primary anastomosis :
- indicated in hemodynamically stable patients with viable bowel
Hartmann procedure:
- resection of the rectosigmoid colon followed by creation of an end colostomy with closure of the rectal stump
- indicated in hemodynamically unstable patients (faster)
- those with ischemic/gangrenous bowel (risk of anastomosis leak)
25
Cecal Volvus Clinical Features
* Acute presentation: features of small bowel obstruction
* Insidious onset: recurrent episodes of right lower abdominal pain
26
Cecal Volvus Tx
1. IV fluids; NPO; placement of a nasogastric tube
2. Surgery
* Stable patients: ileocecal resection or right colectomy with ileocolic anastomosis
* Hemodynamically unstable patients
* Cecostomy
* Detorsion with cecopexy
27
Midgut Volvulus
torsion of a malrotated midgut causing mechanical bowel obstruction, mostly in neonates and infants
28
Midgut Volvulous Clinical Presentation
* Bilious vomiting with abdominal distension in a neonate/infant
* Signs of bowel ischemia: hematochezia
* older children/adults: recurrent episodes of abdominal pain and vomiting; failure to gain weight; malabsorption
29
MIdgut Volvulus Tx
* Initial resuscitation: **NPO; nasogastric tube insertion**; IV fluids
* **broad-spectrum IV antibiotics**
* Emergency surgery- Ladd Proceddure
Incidentally detected/asymptomatic intestinal malrotation: elective surgery
30
Volvulus Diagnostics
Abdominal x-ray (erect and supine)
* Sigmoid volvulus: coffee bean sign
* Cecal volvulus: kidney bean sign
* Bowel perforation: air under diaphragm
CT scan
* Whirl sign/ Whrilpool sign: pathognomonic for volvulus
Barium enema
* bird's beak sign
31
Whril Sign
* characterized by a whorled appearance created by the twisting of one structure around another
* Twisted loops of bowel are seen on the axial plane of the CT scan.
* Twisted mesentry and vascular pedicle lies at the center of the whirl.
32
Megacolon
Loss of intestinal peristalsis and subsequent dilation of the colon in the abscence of a mechanical obstruction
* Acute megacolon
* Chronic megacolon
* Toxic megacolon
33
Acute Mega Colon
(Acute Colonic Pseudo-Obstruction/Olgivie's Syndrome)
Acute dilation of the colon in the absence of a mechanical obstruction; characteristically seen in severely ill or postoperative patients
34
Acute Mega Colon
Etiology
* Occurs in **seriously ill patients** or those who have undergone a **major surgical procedure**
* Idiopathic; possible factors include:
* Electrolyte imbalance
* Drugs (anticholinergic drugs, opioid analgesics, antipsychotics, calcium channel blockers)
35
Acute Mega Colon
Pathophysiology
1. Etiological factors →
2. impairment/destruction of the autonomic nervous system →
3. imbalance between sympathetic and parasympathetic control of intestinal motility
36
Acute Mega Colon
Clinical Features
* Gradual abdominal distention
* Abdominal pain
* Constipation/diarrhea
* Tympanitic abdominal percussion
* Decreased frequency of bowel sounds
* Signs of colonic ischemia or impending perforation: Fever, tachycardia, and peritoneal signs
37
Acute Megacolon
Treatment
Conservative management
* IV fluids and bowel rest (NPO)
* Bowel decompression
* Nasogastric tube
* Rectal tube
* Pharmacologic management: NeostigmineIndications
* No improvement \> 24–48 hours
Surgery
* Signs of impending or actual colonic ischemia/perforation or peritonitis
* Failure of conservative therapy
38
Acute Megacolon
Diagnostics
* **Abdominal x-ray:** dilation of the cecum and right colon (occasionally up to the rectum) with/without multiple air-fluid levels; haustrae are preserved
* Contrast enhanced CT scan (oral and IV contrast)
* Confirms x-ray findings
39
Chronic Megacolon
Chronic colonic pseudo-obstruction
Permanent dilation of the colon caused by congenital/acquired colonic dysmotility in the absence of a mechanical obstruction
40
Chronic Megacolon
Etiology
* Congenital
* Hirschsprung disease
* Acquired
* Neuropathies (diabetic)
* Myopathies (Duchenne's muscular dystrophy)
* Chronic Chagas disease
41
Chronic Megacolon
Clinical Features
Recurrent episodes of:
* **Constipation**
* Abdominal pain and distention
* Anorexia, early satiety, and nausea
Examination findings:
* Abdominal distention; mild abdominal tenderness
42
Chronic Megacolon
Diagnostics
* Abdominal x-ray: dilation of the cecum and right colon (occasionally up to the rectum) with/without multiple air-fluid levels; haustrae are preserved
* The cecum, ascending, and transverse colonare the first to dilate, followed by the splenic flexure, descending, and sigmoid colon.
43
Chronic Megacolon
Tx
Conservative management
* Dietary modifications
* Osmotic laxatives and enemas
* Prokinetic drugs
Surgery:
* patients who do not improve/worsen on conservative therapy
* colectomy with ileorectal anastomosis
* partia colectomy high chance of recurrance
44
Toxic Megacolon
A life-threatening, acute dilation of the colon associated with systemic toxicity
45
Toxic Megacolon
Etiology
Infectious colitis
* Bacterial: **C. difficile (pseudomembranous colitis)**, Salmonella, Shigella, Campylobacterinfections
Inflammatory colitis:
* Ulcerative colitis, Crohn's disease
46
Toxic Megacolon
Clinical Features
* (Bloody) **diarrhea and vomiting**
* Abdominal **distention and pain**
* Signs of sepsis (fever, tachycardia, hypotension) and dehydration
47
Toxic Megacolon
Diagnostics
Labs:
* neutrophilic leukocytosis, anemia, ↑ ESR/CRP, hypokalemia
Abdominal x-ray findings
* Dilation of the colon (transverse colon diameter \> 6 cm)
* **Loss of haustration**
* **Multiple air-fluid levels**
48
Toxic Megacolon
Treatment
Conservative treatment
* Admission to intensive care unit
* Complete bowel rest: NPO
* Nasogastric tube insertion
* IV fluids
* Correction of fluid and electrolyte imbalances
Surgery
* No response to medical management within 24–72 hours; development of complications
* Subtotal colectomy and end ileostomy
* anastamosis contraindicated due to inflamed and friable bowel wall
49
Colonic Polyps
Abnormal colonic mucosal overgrowths.
* Pendunculated
* Sessile
50
Colonic Polyps
Epidemiology
∼ 30% of individuals \> 50 years
Male\> female
∼ 70% are adenomatous polyps
51
Colonic Polyp
Highest Malignancy Potential
Adenomatous polyps. Villous adenoma Histology: finger-like projections lined by dysplastic epithelium. Risk of malignancy: ∼ 50%. Frequency: 5–15%
52
Colonic Polyps
Clinical Features
Mostly asymptomatic
If symptomatic
* Blood in stool (hematochezia) is the most common symptom
* Change in bowel habits (constipation/diarrhea)
* Mucus in stool
53
Hereditary Polyposis Syndrome
1. Adenomatous Polyposis Syndromes (Familial Adenomatous Polyposis)
2. Hamartomatous Polyposis Syndromes
54
Familial Adenomatous Polyposis
Inheritance
* Mutation of the tumor suppressor gene **APC** (adenomatous polyposis coli)
* **Autosomal dominant**;
* positive family history
55
Familial Adenomatous Polyposis
Epidemiology
Develops during 3rd dacade of life
56
FAP
Clinical Features
* initially asymptomatic until progressing to colon cancer
* Altered bowel habits (constipation/diarrhea), blood in stool, and abdominal pain
* Congenital hypertrophy of the retinal pigment epithelium
57
FAP
Diagnosis
Colonoscopy: \>100 polyps
gentic testing: APC mutations
58
FAP
Treatment
* Screening beginning at **10 years of age**
* **Prophylactic proctocolectomy + ileoanal anastomosis**; diagnosis
* Screening upper endoscopy beginning at 25 years of age
* **Celecoxib; sulindac**
59
Gardner Syndrome
* FAP + **extracolonic bony and/or soft tissue tumors** (e.g., osteomas, desmoid tumors, sebaceous cysts, lipomas, fibromas)
60
Turcot Syndrome
Adenomatous colonic polyps + brain tumors
61
Hamartomatous Polyposis Syndromes
* Peutz-Jeghers Syndrome
* Juvenile Polyposis Syndrome
* Cowden Syndrome
* Cronkhite- Canada Syndrome
62
Peutz-Jeghers Syndrome
* 95% of patients have mucocutaneous hyperpigmentation
* Autosomal Dominant
* **Enteroscopy:** hamartomatous polyps throughout the gastrointerstinal tract
* **Prognosis**
* The lifetime risk of colorectal cancer is ∼40%.
* Increased risk of ovarian, breast, and pancreatic cancer
63
Juvenile Polyposis Syndrome
Etiology: autosomal dominant with incomplete penetrance
Clinical features: Onset is within the first decade of life, often with gastrointestinal bleedingand anemia
64
Cronkhite- Canada Syndrome
* Etiology: probably immune-mediated (rare, **nonfamilial** disorder)
* Clinical features: GI polyposis with alopecia and cutaneous hyperpigmentation
65
Colorectal Rectal
