Overview
Definition:
Small bowel resection is a surgical procedure involving the removal of a segment of the small intestine, followed by the rejoining of the remaining ends (anastomosis)
Primary anastomosis refers to the direct connection of the two cut ends of the bowel without an intervening stoma
This is performed to treat various pathological conditions affecting the small intestine.
Epidemiology:
The incidence of small bowel resection varies based on geographic location and common etiologies
In India, conditions like tuberculosis, intestinal obstruction due to adhesions, and malignancy contribute significantly to the need for bowel resection
The prevalence of Crohn's disease, a common indication in Western countries, is also increasing.
Clinical Significance:
Small bowel resection with primary anastomosis is a cornerstone of surgical management for life-threatening conditions of the small intestine
Successful execution is critical for restoring gastrointestinal continuity, preventing complications like leakage, and improving patient outcomes
Mastering this procedure is essential for surgical residents preparing for DNB and NEET SS examinations.
Indications
Common Indications:
Intestinal obstruction secondary to adhesions
Strangulated hernias
Malignant tumors of the small bowel
Inflammatory bowel disease (e.g., Crohn's disease, especially with strictures or fistulas)
Small bowel perforation
Ischemic bowel disease
Benign strictures or tumors
Trauma leading to bowel injury.
Emergent Indications:
Acute mesenteric ischemia leading to bowel infarction
Perforation with peritonitis
Complete, irreducible intestinal obstruction with signs of ischemia
Severe trauma to the small bowel.
Elective Indications:
Symptomatic strictures from Crohn's disease
Benign tumors causing obstruction or bleeding
Incidental findings of early malignancy
Management of recurrent adhesive obstruction
Palliation of symptoms in advanced malignancy.
Preoperative Preparation
History And Physical:
Thorough assessment of symptoms (pain, vomiting, obstipation, distension)
Detailed surgical history (previous abdominal surgeries)
Physical examination to assess for peritonitis, masses, hernias, and vital signs.
Laboratory Investigations:
Complete blood count (anemia, leukocytosis)
Serum electrolytes and renal function tests (dehydration, electrolyte imbalance)
Liver function tests
Coagulation profile
Blood grouping and cross-matching
Lactate levels to assess for ischemia.
Imaging:
Plain abdominal X-rays (dilated loops, air-fluid levels, free air)
Contrast studies (e.g., small bowel follow-through, CT enterography) to delineate the extent and cause of pathology
CT abdomen with intravenous contrast is often definitive for ischemia, obstruction, and malignancy.
Medical Optimization:
Aggressive intravenous fluid resuscitation
Nasogastric tube decompression
Broad-spectrum intravenous antibiotics, especially if perforation or sepsis is suspected
Correction of electrolyte imbalances
Optimization of comorbidities (cardiac, pulmonary, renal)
Nutritional support if prolonged fasting is anticipated.
Surgical Management
Approach:
Laparotomy (midline, paramedian, or transverse incision) or laparoscopy
Laparoscopic approach is preferred when feasible for less invasive surgery, faster recovery, and reduced adhesion formation, but it depends on surgeon expertise and patient factors.
Resection Technique:
Careful mobilization of the involved segment of the small bowel
Identification of healthy bowel proximal and distal to the pathological segment
Ligation of mesenteric vessels supplying the resected segment
Division of the bowel using a scalpel or stapling device (linear stapler)
Care must be taken to preserve adequate blood supply to the remaining bowel ends.
Anastomosis Technique:
Primary anastomosis is typically performed using either hand-sewn or stapled techniques
Hand-sewn anastomosis can be end-to-end, end-to-side, or side-to-side, often using two layers
Stapled anastomosis (circular or linear staplers) is faster, provides secure closure, and is associated with lower leak rates in many studies
End-to-end stapled anastomosis is most common.
Mesenteric Defect Closure:
After anastomosis, the defect in the mesentery created by the resection must be closed to prevent internal hernias
This is typically done with sutures, carefully avoiding compromise of vascular supply to the bowel.
Postoperative Care
Monitoring:
Close monitoring of vital signs, urine output, and abdominal examination for signs of distension, tenderness, or peritonitis
Assessment for return of bowel sounds and passage of flatus/stool indicates recovery of bowel function.
Pain Management:
Adequate analgesia, often using patient-controlled analgesia (PCA) or epidural anesthesia in the early postoperative period
Transition to oral analgesics as tolerated.
Fluid And Nutrition:
Continued intravenous fluids until adequate oral intake is established
Gradual reintroduction of oral diet, starting with clear liquids and progressing as tolerated
Parenteral nutrition may be necessary in cases of prolonged ileus or malabsorption.
Antibiotics:
Continuation of prophylactic or therapeutic antibiotics as indicated, particularly if there was contamination or high risk of infection.
Complications
Early Complications:
Anastomotic leak (most feared complication, presenting with peritonitis, sepsis)
Intra-abdominal abscess
Ileus (prolonged paralysis of bowel)
Wound infection or dehiscence
Hemorrhage
Deep vein thrombosis (DVT) and pulmonary embolism (PE).
Late Complications:
Stricture formation at the anastomosis site leading to obstruction
Adhesions causing bowel obstruction
Internal hernias through mesenteric defects
Malabsorption (especially with extensive resections)
Nutritional deficiencies.
Prevention Strategies:
Meticulous surgical technique with adequate bowel preparation and safe resection margins
Secure and tension-free anastomosis
Proper closure of mesenteric defects
Judicious use of antibiotics
Early mobilization and ambulation
Prophylaxis against DVT
Careful monitoring for early signs of complications.
Prognosis
Factors Affecting Prognosis:
The underlying etiology of the resection (e.g., malignancy vs
benign disease)
Extent of resection (longer resections carry higher risk of malabsorption)
Presence and severity of complications, particularly anastomotic leak
Patient's overall health status and comorbidities
Surgeon's experience.
Outcomes:
For benign conditions or early malignancy, prognosis is generally good with complete recovery
Patients with malignancy have a prognosis dependent on the stage of cancer and adjuvant therapy
Extensive resections may lead to short bowel syndrome requiring long-term nutritional support.
Follow Up:
Regular follow-up appointments to monitor for recurrence of disease, complications like strictures or adhesions, and nutritional status
Imaging studies may be required depending on the original pathology
Patients with short bowel syndrome require lifelong monitoring and management.
Key Points
Exam Focus:
Indications for resection and anastomosis
Techniques of anastomosis (stapled vs
hand-sewn)
Most common and feared complication (anastomotic leak)
Management of short bowel syndrome
Differential diagnosis of bowel obstruction
Management of mesenteric ischemia.
Clinical Pearls:
Always ensure good vascularity of both bowel ends before anastomosis
Close mesenteric defects to prevent internal hernias
Consider a defunctioning stoma in high-risk cases (e.g., gross contamination, Jehovah's Witnesses, frail patients)
Early recognition and management of anastomotic leak is crucial.
Common Mistakes:
Inadequate resection margins for malignancy
Tension on the anastomosis
Failure to close mesenteric defects
Overly aggressive reintroduction of diet
Delay in diagnosing anastomotic leak or intra-abdominal abscess.