Overview
Definition:
Open sigmoid colectomy is a surgical procedure involving the removal of a segment of the sigmoid colon through an abdominal incision
It is typically performed for diseases affecting this part of the large intestine
The remaining ends of the colon are then reconnected (anastomosis) or brought out as a stoma
This approach is often chosen when minimally invasive techniques are not feasible or have failed.
Epidemiology:
Sigmoid colectomy is a common procedure performed for various colonic pathologies, including diverticular disease, colorectal cancer, and inflammatory bowel disease
The incidence varies geographically and is influenced by the prevalence of these underlying conditions
Age is a significant factor, with older populations more frequently undergoing this surgery.
Clinical Significance:
This procedure is crucial for treating serious sigmoid colon pathology that cannot be managed conservatively or endoscopically
It offers a definitive treatment for conditions like complicated diverticulitis, malignant tumors, and severe ulcerative colitis or Crohn's disease affecting the sigmoid
Successful execution improves patient outcomes by removing diseased tissue and restoring bowel continuity or function.
Indications
Absolute Indications:
Sigmoid volvulus with ischemia or perforation
Sigmoid colon cancer requiring resection
Complicated sigmoid diverticulitis (e.g., abscess, fistula, obstruction, perforation)..
Relative Indications:
Recurrent or chronic sigmoid diverticulitis unresponsive to medical management
Severe sigmoid ischemia without frank perforation
Benign strictures of the sigmoid colon
Suspected malignancy not amenable to endoscopic evaluation or treatment.
Contraindications:
Uncorrected coagulopathy
Severe systemic illness with prohibitive anesthetic risk
Widespread intra-abdominal malignancy with unresectable metastases
Active infection at the operative site (relative contraindication).
Preoperative Preparation
Patient Evaluation:
Thorough medical history and physical examination
Assessment of comorbidities (cardiac, pulmonary, renal)
Nutritional status assessment.
Laboratory Investigations:
Complete blood count (CBC) to assess for anemia and infection
Coagulation profile (PT/INR, aPTT)
Electrolytes and renal function tests (creatinine, urea)
Liver function tests (LFTs)
Blood group and cross-matching for potential transfusion.
Imaging:
Contrast-enhanced CT scan of the abdomen and pelvis to delineate the extent of disease, assess for complications like abscess or fistula, and evaluate for metastatic disease (in malignancy)
Colonoscopy may be performed preoperatively for cancer staging or to rule out synchronous lesions, if not contraindicated.
Bowel Preparation:
Mechanical bowel preparation using polyethylene glycol (PEG) or other osmotic laxatives is typically performed to clear the colon
Antibiotic prophylaxis (e.g., cefazolin with metronidazole or ciprofloxacin with metronidazole) is administered intravenously to reduce the risk of surgical site infection
Oral antibiotics may also be used as part of the bowel preparation regimen in elective cases.
Anesthesia Considerations:
General anesthesia with endotracheal intubation is standard
Epidural analgesia may be considered for postoperative pain control
Fluid management and hemodynamic monitoring are critical throughout the procedure.
Procedure Steps
Surgical Approach:
A midline or left paramedian incision is the most common approach for open sigmoid colectomy
The incision length is determined by the surgeon's preference and the extent of the pathology
The abdominal cavity is explored to assess for gross pathology, adhesions, and metastatic disease (if indicated).
Sigmoid Mobilization:
The sigmoid colon is identified and carefully mobilized
This involves dividing the sigmoid mesentery, starting from the peritoneal reflection of the sigmoid and moving towards the superior rectal artery origin
Care is taken to ligate and divide the mesenteric vessels to control bleeding
The dissection proceeds laterally and anteriorly to free the colon from surrounding structures.
Division And Anastomosis:
The colon is divided proximally and distally to the diseased segment
The distal margin is typically placed just proximal to the peritoneal reflection of the rectum, or lower if rectal involvement necessitates it
Staples or sutures are used to divide the bowel and control the lumina
The freed sigmoid segment is then removed
The proximal and distal ends are then prepared for anastomosis
Hand-sewn or stapled techniques can be employed to create the anastomosis, ensuring adequate blood supply to both ends and a leak-free closure
A double-stapled technique is common for colorectal or colo-anal anastomoses.
Diversion Or Ostomy:
In cases of high risk for anastomotic leak (e.g., emergency surgery, distal anastomosis, poor patient condition), a temporary diversionary stoma (e.g., loop ileostomy or colostomy) may be created to protect the anastomosis
This stoma is typically reversed in a subsequent procedure after the anastomosis has healed.
Postoperative Care
Immediate Postoperative Management:
Patients are monitored in a post-anesthesia care unit (PACU) initially
Pain management with intravenous analgesics, including patient-controlled analgesia (PCA) or epidural anesthesia, is crucial
Fluid management and electrolyte balance are maintained with intravenous fluids
Nasogastric (NG) tube may be placed for gastric decompression, especially if bowel manipulation was extensive or if ileus is a concern.
Monitoring:
Vital signs are closely monitored for signs of hemodynamic instability, fever, or tachycardia suggestive of infection or complications
Abdominal examination for distension, tenderness, or signs of peritonitis
Output from any drains or stomas is carefully recorded
Serial laboratory tests to monitor for infection and electrolyte imbalances.
Nutrition:
Early enteral feeding is encouraged as tolerated, typically starting with clear liquids and advancing to a regular diet as bowel function returns
This promotes gut healing and reduces the risk of parenteral nutrition-related complications
In cases of prolonged ileus or malabsorption, nutritional support may be required.
Ambulation And Mobilization:
Early ambulation is vital to prevent deep vein thrombosis (DVT), pulmonary complications, and promote bowel function
Patients are encouraged to mobilize as soon as they are stable
Incentive spirometry is used to prevent atelectasis and pneumonia.
Anastomotic Leak Surveillance:
Patients are educated about signs and symptoms of anastomotic leak, including increasing abdominal pain, fever, tachycardia, abdominal distension, and reduced or absent flatus/stool output
Any suspicion warrants prompt investigation with imaging (e.g., CT scan) and clinical assessment.
Complications
Early Complications:
Anastomotic leak: The most serious complication, leading to peritonitis, sepsis, and potential need for reoperation and stoma formation
Wound infection: Superficial or deep surgical site infection
Intra-abdominal abscess: Collection of pus within the abdominal cavity
Bleeding: From mesenteric vessels or at the anastomosis site
Ileus: Delayed return of bowel function
Urinary retention
Pneumonia
Deep vein thrombosis (DVT) and pulmonary embolism (PE).
Late Complications:
Anastomotic stricture: Narrowing of the bowel at the anastomosis site, potentially causing obstruction
Incisional hernia: Protrusion of abdominal contents through a weakened abdominal wall incision
Chronic pain: Persistent abdominal pain after surgery
Adhesions: Scar tissue formation that can lead to bowel obstruction
Stoma-related complications (if a stoma was created): Skin irritation, retraction, prolapse, or stenosis.
Prevention Strategies:
Meticulous surgical technique with careful ligation of vessels and gentle tissue handling
Adequate bowel preparation and antibiotic prophylaxis
Optimal patient selection and preoperative optimization
Careful anastomosis construction with good blood supply and tension-free closure
Early recognition and prompt management of postoperative complications
Prophylaxis against DVT and PE.
Prognosis
Factors Affecting Prognosis:
The underlying pathology (e.g., cancer stage, severity of diverticulitis), patient's overall health and comorbidities, presence and management of complications (especially anastomotic leak), and the surgeon's experience all significantly influence prognosis
For colorectal cancer, stage at diagnosis is the most critical prognostic factor.
Outcomes:
In elective cases for benign conditions, the prognosis is generally excellent, with most patients recovering fully and returning to normal bowel function
For malignant conditions, prognosis depends on the stage and success of oncological resection and adjuvant therapy
Morbidity and mortality rates are higher in emergency procedures or when complications arise.
Follow Up:
Follow-up schedules vary based on the indication for surgery
For benign conditions, routine follow-up may involve clinical assessment and symptomatic monitoring
For colorectal cancer, follow-up includes regular clinical examinations, CEA monitoring, and periodic imaging or colonoscopy as per established guidelines (e.g., by ASCRS or national cancer guidelines) to detect recurrence or metachronous lesions.
Key Points
Exam Focus:
Indications for sigmoid colectomy, particularly for complicated diverticulitis and sigmoid volvulus
Steps of the surgical procedure, including mobilization, division, and anastomosis techniques
Management of anastomotic leak and common postoperative complications
Distinguishing features of sigmoid volvulus on imaging.
Clinical Pearls:
In cases of sigmoid volvulus, untwisting the volvulus laparoscopically or endoscopically (detorsion) can sometimes be attempted prior to resection if there are no signs of ischemia or perforation, but this is an adjunct to surgery
Be vigilant for signs of impending perforation in acute diverticulitis, which mandates urgent surgical intervention
Always assess the entire colon for synchronous lesions when dealing with colorectal cancer
Consider a temporary stoma in high-risk anastomosis patients.
Common Mistakes:
Inadequate bowel preparation leading to increased infection risk
Insufficient mobilization of the sigmoid colon, leading to tension on the anastomosis
Poorly identified or ligated mesenteric vessels causing intraoperative bleeding
Delayed diagnosis and management of anastomotic leak
Failure to consider or adequately investigate for synchronous lesions in cases of malignancy.