Small Bowel Miscellaneous Topics
Intestinal Obstruction
- Sensitivity of Plain X-ray in intestinal obstruction: 60%
- Sensitivity of CECT abdomen: 80%
Non-invasive Detection
- Superconducting quantum interference device (SQUID) magnetometer can be used to detect mesenteric ischemia noninvasively.
Standard Care
- Nasogastric decompression: Still considered the standard of care.
- Cantor / Baker tube: Long intestinal tubes.
Non-Operative Management
- Successful in 85% of patients.
- If intestinal viability is questionable, the bowel is placed in a warm, saline-moistened sponge for 15 to 20 minutes and then reexamined.
- Second-look laparotomy: Performed 18 to 24 hours after the initial procedure.
Laparoscopic Management Criteria for Obstruction
- Mild abdominal distention allowing adequate visualization.
- Proximal obstruction.
- Partial obstruction.
- Anticipation of single-band obstruction.
Contraindications for Laparoscopic Surgery
- Advanced small bowel obstructions.
- Complete small bowel obstructions.
- Distal small bowel obstructions.
Adhesion Prevention
- Good surgical technique is the most effective way of limiting adhesions:
- Gentle handling of the bowel to reduce serosal trauma.
- Avoidance of unnecessary dissection.
- Exclusion of foreign bodies (e.g., avoid non-absorbable sutures, excessive gauze sponges, powdered gloves).
- Adequate irrigation and removal of debris.
- Preservation and use of the omentum around the site of surgery or in the denuded pelvis.
- >90% of early postoperative obstructions are partial and will resolve spontaneously.
Bouveret Syndrome
- Most common cause: Gastric outlet obstruction by a gallbladder stone.
Question: Bouveret Syndrome is seen in?
- A) Gallstone ileus
- B) Cholecystocolonic fistula
- C) Gastric outlet obstruction by gallbladder stone (Correct Answer)
- D) Crohn's disease
Ileus
- Definition:
- Intestinal distention with slowing or absence of passage of luminal contents without mechanical obstruction.
- Causes of Ileus:
- After laparotomy
- Metabolic and electrolyte derangements:
- Hypokalemia
- Hyponatremia
- Hypomagnesemia
- Uremia
- Diabetic coma
- Drugs:
- Opiates
- Psychotropic agents
- Anticholinergic agents
- Intra-abdominal inflammation
- Retroperitoneal hemorrhage or inflammation
- Intestinal ischemia
- Systemic sepsis
- Clinical Presentation:
- Similar to mechanical obstruction.
- Abdominal distention but no colicky abdominal pain.
- Patients may continue to pass flatus and experience diarrhea.
- Management:
- Supportive treatment:
- Fluids and electrolyte balance.
- Most effective treatment: Correct the underlying condition.
- Aggressive treatment of sepsis.
- Correction of metabolic or electrolyte abnormalities.
- Discontinuation of medications that may induce ileus.
- Supportive treatment:
- Drugs Attempted in Treating Ileus:
- Guanethidine
- Bethanechol
- Neostigmine
- Cholecystokinin
- Motilin
- Erythromycin
- Chewing gum: Not found to be useful in treating ileus.
Typhoid Enteritis
- Caused by Salmonella typhi.
- Peyer's patches: Become hyperplastic, can ulcerate, leading to hemorrhage or perforation.
Diagnosis:
- Widal test: No longer acceptable.
- Blood & urine assay:
- Sensitivity: 83%
- Specificity: 100%
Treatment for Uncomplicated Typhoid Enteritis:
- Fluoroquinolones and third-generation cephalosporins.
Complications:
- Hemorrhage: Occurs in 20% of cases.
- Intestinal perforation:
- Occurs in 2% of cases.
- Typically a single perforation in the terminal ileum.
- prognosis is better with perforations occuring within the first week of acute episode.
- Simple closure of the perforation is the treatment of choice.
- Multiple perforations: Seen in 25% of patients.
- Requires resection anastomosis or stoma.
Enteritis in Immunocompromised Hosts
- Most common GI symptom in AIDS: Diarrhea
- Most common organisms causing diarrhea in AIDS: Protozoa
- Most common site of infection: Small bowel
Bacterial Causes
- Salmonella, Shigella, and Campylobacter are the most common bacteria.
- Campylobacter:
- Best diagnosed by PCR.
- Rifabutin prophylaxis is given.
Tuberculosis (M. tuberculosis)
- Most common intestinal site: Distal ileum and cecum (90%).
- Lesions can be ulcerative, hypertrophic, or ulcer hypertrophic.
Cytomegalovirus (CMV)
- Most common viral cause of diarrhea in immunocompromised patients.
- Causes mucosal ischemic ulcerations with a high rate of perforations.
- Characteristic intranuclear inclusions: Owl's eye appearance.
- Treated with Ganciclovir or Foscarnet.
Fungal Infections
- GI Histoplasmosis: Treated with Amphotericin B.
Pneumatosis Intestinalis
- Benign cause of pneumoperitoneum.
- Characterized by multiple gas-filled cysts in the GI tract.
- Cysts are located in the subserosa, submucosa, and rarely in the muscularis layer.
Most Common Locations
- Jejunum > Ileocecal region > Colon.
Epidemiology
- M:F ratio: 1:1.
- Most common in the 4th to 7th decades.
Associations
- Most cases are associated with COPD or AIDS.
Histology
- Honeycomb appearance.
Complications
- Occur in 3% of cases.
Diagnosis
- If free abdominal air is present but no evidence of peritonitis:
- Use Barium or CT to confirm the diagnosis.
Treatment
- Treat the underlying cause.
Blind Loop Syndrome
Symptoms:
- Diarrhea
- Steatorrhea
- Megaloblastic anemia
- Weight loss
- Abdominal pain
- Deficiencies of fat-soluble vitamins
- Neurologic disorders
Underlying Cause:
- Bacterial overgrowth in areas of:
- Stricture
- Stenosis
- Fistulas
- Diverticula
Diagnostic Tests:
- 14C-xylose or 14C-cholylglycine breath tests
- Schilling test: 57Co-labeled vitamin B12 absorption
Treatment:
- Parenteral vitamin B12 therapy
- Broad-spectrum antibiotics:
- Tetracycline
- Metronidazole
- Rifaximin
Wilkie's Syndrome (SMA Syndrome/Cast Syndrome)
- Pathophysiology: D3 (third part of the duodenum) compression by the Superior Mesenteric Artery (SMA).
- Weight loss often occurs before the onset of symptoms.
Epidemiology
- Most commonly seen in young asthenic individuals.
- F>M (female > male).
Predisposing Factors:
- Weight loss
- Supine immobilization
- Scoliosis
- Placement of a body cast (Cast syndrome).
Associations:
- Anorexia nervosa
- After proctocolectomy and J-pouch anal anastomosis.
- Resection of an arteriovenous malformation of the cervical cord.
- Abdominal aortic aneurysm repair.
- Orthopaedic procedures, especially spinal surgery.
Diagnosis:
- Barium upper gastrointestinal series.
Treatment:
- Operative treatment of choice: Duodenojejunostomy.
Question: Hayes maneuver is seen in?
- A) SMA syndrome (Correct Answer)
- B) Crohn's disease
- C) Paralytic ileus
- D) Mesenteric injury
Explanation of Hayes Maneuver
The Hayes maneuver is a diagnostic technique specifically associated with Superior Mesenteric Artery (SMA) syndrome, also known as Wilkie's syndrome or Cast syndrome.
Superior Mesenteric Artery (SMA) Syndrome
- SMA syndrome occurs when the third part of the duodenum (D3) is compressed between the abdominal aorta and the superior mesenteric artery (SMA). This results in symptoms like nausea, vomiting, and postprandial pain due to intestinal obstruction.
Hayes Maneuver
- The Hayes maneuver involves placing the patient in a knee-chest position or left lateral decubitus position to alleviate compression of the duodenum by the SMA.
- In this position, the angle between the SMA and the aorta widens, thereby relieving the compression of the duodenum.
- This maneuver helps confirm the diagnosis of SMA syndrome if the symptoms are temporarily relieved by the change in position.
Clinical Significance
- The maneuver is helpful in initial management and diagnosis, allowing temporary relief, but definitive treatment often requires more permanent intervention such as a duodenojejunostomy.
The Hayes maneuver is a crucial step in identifying SMA syndrome and differentiating it from other conditions causing similar obstructive symptoms.
MCQ Explanations
-
Most common cause of intestinal obstruction
- a) Hernia
- b) Crohn's disease
- c) Adhesions (Correct Answer)
- d) Malignancy
Explanation: Adhesions are the most common cause of small bowel obstruction, particularly in patients with a history of abdominal surgery. Adhesions form between loops of intestines and cause obstruction.
-
SQUID is used in:
- a) Diverticulosis
- b) Mesenteric Ischemia (Correct Answer)
- c) GI malignancy
- d) Crohn's disease
Explanation: Superconducting Quantum Interference Device (SQUID) magnetometer is used to detect mesenteric ischemia non-invasively by sensing changes in blood flow in the intestines.
-
All are criteria for laparoscopic management in obstruction except:
- a) Mild abdominal distension allowing adequate visualization
- b) Distal small bowel obstruction (Correct Answer)
- c) Partial obstruction
- d) Anticipated single-band obstruction
Explanation: Distal small bowel obstructions are more difficult to manage laparoscopically due to poor visualization and technical challenges. The other criteria are favorable for laparoscopy.
-
All are true about paralytic ileus except:
- a) Presentation similar to mechanical obstruction
- b) Abdominal distention, with colicky abdominal pain, is the typical and most notable finding (Correct Answer)
- c) Patients with an ileus may continue to pass flatus and diarrhea
- d) The treatment of an ileus is entirely supportive, with nasogastric decompression and IV fluids
Explanation: In paralytic ileus, there is no colicky abdominal pain as seen in mechanical obstruction. The bowel is simply paralyzed, so peristalsis is absent, leading to distension without colicky pain.
-
Most common intestinal site of M. tuberculosis is:
- a) Distal ileum (Correct Answer)
- b) Proximal ileum
- c) Caecum
- d) Jejunum
Explanation: The distal ileum and cecum are the most common sites of intestinal tuberculosis, likely due to the large amount of lymphoid tissue in these regions, which provides a favorable environment for Mycobacterium tuberculosis.
-
Treatment of choice in SMA syndrome:
- a) Duodenojejunostomy (Correct Answer)
- b) Duodenoduodenostomy
- c) Duodenogastrostomy
- d) Ileostomy
Explanation: In Superior Mesenteric Artery (SMA) syndrome, the third part of the duodenum is compressed between the aorta and SMA. The surgical correction, duodenojejunostomy, bypasses the compression.
-
Paralytic ileus first to recover in:
- a) Small intestine (Correct Answer)
- b) Stomach
- c) Colon
- d) Rectum
Explanation: In paralytic ileus, the small intestine is typically the first to recover its peristaltic function, followed by the stomach and colon.
-
Stapfer's classification is used for:
- a) Acute pancreatitis
- b) ERCP-induced duodenal perforation (Correct Answer)
- c) FAP-associated duodenal adenoma
- d) Chronic calcific pancreatitis
Explanation: Stapfer's classification is a system used to grade duodenal perforations caused by ERCP (Endoscopic Retrograde Cholangiopancreatography), which helps guide treatment decisions.
-
Which of the following intestinal staple color corresponds to maximum available staple height:
- a) White
- b) Blue
- c) Golden
- d) Black (Correct Answer)
Explanation: Black staples represent the maximum staple height, typically used in situations where thicker tissue or difficult closure is required.
-
Brooke Ileostomy is the term used for:
- a) Continent Ileostomy
- b) Protruding spigot Ileostomy (Correct Answer)
- c) Loop ileostomy
- d) Permanent Ileostomy
Explanation: The Brooke ileostomy refers to a protruding spigot ileostomy, where the end of the ileum is everted to form a spout, ensuring that stool is diverted away from the skin to prevent irritation.