MCQ - Small intestine - Meckels diverticulum, tuberculosis, typhoid, enterocutaneous fistula

Meckels diverticulum

• • 2% prevalenceQ
• • 2 inch in lengthQ
• • Half of these who are symptomatic are <2 yrsQ of age
• • 2 feet proximal to ileocecal valveQ

Antimesenteric border of the ileum - 45 to 60 cm proximal to the ileocecal valve

Gastric mucosa (50%)Q >Pancreatic mucosa (5%) >colonic mucosa (rarely)

GI bleeding (25-50%)Q

• In children and young adults: BleedingQ
• In adults: Intestinal obstructionQ

• in children: Scintigraphy with sodium 99mTc-pertechnetateQ. The 99mTc-pertechnetate is preferentially taken up by the mucus-secreting cells of gastric mucosa and ectopic gastric tissue in the diverticulumQ.
• It is less accurate in adults because of the reduced prevalence of ectopic gastric mucosaQ.

• Symptomatic - Diverticulectomy or resection of the segment of ileumQ bearing the diverticulum.
• Asymptomatic diverticula found in children during laparotomy should be resectedQ.
• Incidentally found Meckel’s diverticulum should be removed at any age up to 80 years as long as no additional conditions (e.g., peritonitis) made removal hazardousQ.

Meckel’s diverticulum that is broad based should not be amputated at its base and invaginated in the same way as a vermiform appendix, because of risk of stricture. Furthermore, this does not remove hetrotopic epithelium where it is present.

• Colon – MC
• Duodenum – second MC

• Underlying cause: Bacterial overgrowth in stagnant areas of the small bowel produced by stricture, stenosis, fistulas, or diverticulaQ
• Bacterial overgrowth competes for vitamin B12, producing systemic deficiency of vitamin B12 and megaloblastic anemiaQ.
• Fat soluble vitamin deficiency

• Parenteral vitamin B12 therapy + Broad-spectrum antibiotic (tetracycline or amoxicillin-clavulanate)Q.
• For most patients, a single course of therapy (7-10 days) is sufficient, and the patient may remain symptom-free for months.
• Surgical correction of the condition producing stagnation and blind loop syndrome produces a permanent cure and is indicated in those patients who require multiple rounds of antibiotics or are on continuous therapyQ

Secondary – swallowed contaminated sputum

• In submucosaQ
• MC site is terminal ileum and ileocecal junctionQ

• Deep and transversely placedQ in the direction of lymphatics
• Multiple ulcers - most often in terminal ileumQ

Abdominal painQ

• • Earliest feature is spasm and hypermotility with edema of valveQ
• • Thickening of valve lips with narrowing of the terminal ileum (Fleishner or umbrella signQ)
• • Symmetric, annular, napkin ring stenosisQ and obstruction or shortening and pouch formation in advanced disease
• • Pulled up cecumQ
• • Loss of ileocecal angle with dilated terminal ileum imparting goose neck deformityQ
• • Narrowing of terminal ileum due to irritability, along with shortened rigid cecum called as “Sterlein sign”Q
• • Persistent narrow stream of barium in the bowel indicates stenosis known as String signQ
• String sign and Sterlein sign are also seen in Crohn’s disease and are not specific for TBQ

• • Intestinal obstruction secondary to stricture (MC)Q
• • Free perforationQ
• • Severe GI hemorrhageQ
• Intra-abdominal abscessQ
• • Internal or external fistulaQ

Ileocecal regionQ

Peritoneal tuberculosisQ

Vascular compression of third portionQ of the duodenum by the superior mesenteric artery as it passes over this portion of the duodenum.

Acute angle (50-60°)

DuodenojejunostomyQ

• It is an uncommon condition presenting as multiple gas-filled cysts of the gastrointestinal tract.
• Located in the subserosa, submucosa, and, rarely, muscularis layer
• MC site: JejunumQ >ileocecal region >colon

• Bacterial overgrowthQ from the colon → diarrhea and malabsorptionQ
• Decrease in intestinal transit timeQ

Proximal bowel resection is tolerated much better than distal resectionQ, because the ileum can adapt and increase its absorptive capacity more efficiently than the jejunumQ

• Bianchi ProcedureQ: Longitudinal intestinal lengthening and tailoring
• STEP: Serial transverse enteroplasty procedureQ

May be related to reduced hormonal inhibition of acid secretion or increased gastrin levels due to reduced small intestinal catabolism of circulating gastrin.

• Serious late complications are unusual if the total radiation dosage is <4000 cGyQ
• Morbidity risk increases with dosages >5000 cGyQ

• Damage to the small submucosal blood vesselsQ
• Progressive obliterative arteritis and submucosal fibrosisQ
• Thrombosis and vascular insufficiencyQ

AmifostineQ

Bypass or resection with reanastomosis

Typhoid

• Usually during the third weekQ
• Occasionally the first sign of the disease
• Ulcers – are longitudinal

• −−Gentle handlingQ of the bowel
• −−Adequate hemostasisQ
• −−Meticulous approximationQ of well-vascularized bowel
• −−Tension-free anastomosisQ

• Two layer anastomosis - Inner layer absorbable 3-0 or 4-0 running full-thickness stitchQ • Outer layer is an inverting, usually 3-0, seromuscular stitch, which may be running or interrupted nonabsorbableQ
• One layer anastomosis - Full-thickness technique, interrupted or running with nonabsorbable sutureQ

• • High output (>500 mL/day)Q
• • Severe disruption of intestinal continuityQ (>50% of bowel circumference)
• • Active inflammatory bowel diseaseQ of bowel segment
• • CancerQ
• • Radiation enteritisQ
• • Distal obstructionQ
• • Undrained abscess cavityQ
• • Foreign bodyQ in the fistula tract
• • Fistula tract <2.5 cm longQ
• • Epithelialization of fistula tractQ

Iatrogenic (MC)Q

Fistula tract excision and segmental resection of the involved segment of intestine and reanastomosisQ.

DuodenumQ

Duodenal atresiaQ

• Cystic - More common (75%)Q, Do not have communication with the lumenQ of the normal small intestine, Manifested as partial small bowel obstructionQ
• Tubular - Less common (25%), Parallel to the normal bowel lumenQ, Higher incidence of communicationQ with the existing lumen of the small intestine, Significant incidence of ectopic gastric mucosaQ, BleedingQ is a common manifestation