Overview
Definition:
Sphincteroplasty is a surgical procedure to repair damage to the anal sphincter muscles, typically following obstetric trauma that results in anal incontinence.
Epidemiology:
Obstetric anal sphincter injuries (OASIS) affect 3-5% of vaginal births, with severe (3rd and 4th degree) tears occurring in approximately 1-3%
These injuries can lead to significant long-term anal incontinence and reduced quality of life.
Clinical Significance:
Untreated or poorly repaired OASIS can result in chronic fecal incontinence, flatus incontinence, pain, and psychological distress, impacting patient well-being and necessitating surgical intervention to restore sphincter function and improve quality of life
Understanding surgical repair is crucial for obstetric and colorectal surgeons preparing for DNB and NEET SS examinations.
Clinical Presentation
Symptoms:
Inability to control gas and/or stool
Urgency to defecate
Sensation of incomplete evacuation
Leakage of feces or mucus
Pain during defecation
Reduced quality of life.
Signs:
Visible evidence of sphincter disruption during digital rectal examination (if acute)
Poor anal tone
Scarring or retraction of the anal canal
Rectovaginal fistula may be present in severe cases.
Diagnostic Criteria:
Diagnosis is primarily clinical, based on history of obstetric trauma and physical examination
Endoscopy (anoscopy/proctoscopy) and manometry can assess sphincter integrity and function
Imaging like endoanal ultrasound or MRI may be used to evaluate the extent of muscle damage.
Indications For Surgery
Indications:
Persistent symptoms of fecal or flatus incontinence following OASIS, typically at least 6 months post-partum
Documented significant disruption of the anal sphincter complex on examination or imaging
Failure of conservative management (e.g., dietary modifications, pelvic floor exercises).
Contraindications:
Active perianal infection
Uncontrolled inflammatory bowel disease
Significant rectal prolapse requiring different surgical approach
Patient refusal or poor surgical risk.
Timing Of Surgery:
Elective repair is usually performed at least 6-12 months after the initial injury to allow for complete healing and scar maturation, optimizing surgical outcomes and reducing the risk of dehiscence.
Surgical Management
Preoperative Preparation:
Bowel preparation with laxatives and enemas
Antibiotic prophylaxis (e.g., parenteral cephalosporin or metronidazole)
Review of anesthetic and surgical risks
Informed consent.
Procedure Steps:
The surgeon identifies the torn ends of the external and/or internal anal sphincters
The muscle ends are mobilized
The damaged tissue is debrided
The sphincter ends are then approximated and sutured using absorbable or non-absorbable sutures, creating a continuous muscular ring
Overlapping sphincteroplasty (e.g., Delorme procedure for rectal prolapse with sphincter deficiency) or direct end-to-end repair may be performed depending on the injury pattern
Primary repair aims to restore continence by reconstructing the sphincter mechanism.
Anesthesia:
General anesthesia or spinal anesthesia is typically used
Epidural anesthesia may also be an option.
Postoperative Care
Immediate Postop:
Pain management with analgesics
Intravenous fluids
Monitoring of vital signs and urine output
Wound care
Stool softeners to prevent straining
Antibiotics may be continued.
Long Term Care:
Gradual diet advancement
Pelvic floor physical therapy to aid in sphincter re-education and strengthening
Regular follow-up to assess continence and healing
Avoidance of constipation is paramount.
Dietary Recommendations:
High-fiber diet, adequate hydration, and regular use of stool softeners (e.g., docusate sodium) to maintain soft stools and prevent constipation and straining, which can compromise the repair.
Complications
Early Complications:
Wound infection
Dehiscence of the repair
Anal stenosis
Fecal impaction
Urinary retention.
Late Complications:
Recurrent anal incontinence
Persistent anal pain
Rectovaginal fistula formation
Poor functional outcome despite successful anatomical repair.
Prevention Strategies:
Meticulous surgical technique with adequate mobilization and secure suturing of sphincter ends
Aggressive pain control
Prophylactic stool softeners
Prompt management of any wound complications
Patient education on bowel care.
Prognosis
Factors Affecting Prognosis:
Severity of initial injury
Quality of surgical repair
Patient adherence to postoperative care and rehabilitation
Presence of comorbidities
Skill of the surgeon.
Outcomes:
Successful sphincteroplasty can significantly improve symptoms of fecal incontinence, with reported success rates varying widely (e.g., 60-80% symptom improvement), but complete continence may not always be achievable
Patient satisfaction is often high when symptoms are substantially reduced.
Follow Up:
Regular follow-up appointments are crucial at 2 weeks, 1 month, 3 months, 6 months, and 1 year post-surgery to monitor healing, assess functional outcomes, and adjust rehabilitation strategies as needed.
Key Points
Exam Focus:
Understanding the grading of OASIS (3rd and 4th degree tears)
Indications for surgical repair are persistent incontinence symptoms
Sphincteroplasty involves direct repair or overlapping of sphincter ends
Postoperative stool softeners are critical.
Clinical Pearls:
Always assess for OASIS in any patient presenting with new-onset fecal incontinence following vaginal delivery
Early diagnosis and appropriate primary repair can minimize long-term sequelae
Conservative management should be attempted first for minor tears, but surgical repair is necessary for significant sphincter defects.
Common Mistakes:
Delaying surgical repair beyond the optimal window
Inadequate debridement of scar tissue
Insufficient mobilization of sphincter ends
Poor postoperative bowel regimen leading to straining and repair dehiscence
Failure to address associated rectovaginal fistulas.