Overview
Definition:
Abdominoperineal resection (APR) is a major surgical procedure involving the removal of the entire rectum, anus, and surrounding tissues, along with the creation of a permanent colostomy.
Epidemiology:
APR is indicated for certain rectal and anal cancers, particularly those involving the distal rectum or anus, or advanced tumors requiring wide local excision
Its incidence is directly related to the prevalence of these malignancies and the necessity for sphincter preservation in some cases.
Clinical Significance:
APR is a critical life-saving procedure for patients with locally advanced or recurrent rectal and anal cancers, or conditions like severe inflammatory bowel disease unresponsive to medical therapy, where radical excision is necessary
It represents a significant surgical intervention with long-term implications for the patient's quality of life.
Indications
Neoplastic Indications:
Locally advanced squamous cell carcinoma of the anus
Adenocarcinoma of the distal rectum or anal canal where sphincter preservation is not feasible
Recurrent rectal or anal cancer after previous treatment
Tumors invading adjacent structures requiring en bloc resection.
Inflammatory Indications:
Severe, refractory Crohn's disease or ulcerative colitis involving the distal rectum and anus, leading to intractable symptoms or dysplasia/cancer development
Perianal sepsis unresponsive to other measures.
Other Indications:
Radiation-induced proctitis with severe symptoms and complications
Pelvic floor dysfunction with severe constipation requiring diversion
Certain congenital anomalies of the anus and rectum.
Preoperative Preparation
Patient Assessment:
Comprehensive oncological staging (CEA, imaging)
Assessment of cardiopulmonary reserve
Nutritional status evaluation
Rectal examination to assess tumor extent and mobility.
Bowel Preparation:
Mechanical bowel preparation with clear fluids and laxatives
Prophylactic antibiotics (e.g., cephalosporin plus metronidazole) administered 1 hour prior to incision.
Stoma Counseling:
Preoperative stoma nurse consultation
Site selection for the colostomy to ensure ease of appliance management and patient comfort
Patient and family education on stoma care.
Anesthesia Considerations:
General anesthesia with epidural analgesia for postoperative pain control
Positioning of the patient in lithotomy or exaggerated lithotomy position for perineal dissection.
Procedure Steps
Abdominal Phase:
Midline laparotomy or lower midline incision
Mobilization of the rectosigmoid colon
Division of mesenteric vessels supplying the rectosigmoid
Dissection of the mesorectum and lateral pelvic attachments
Ligation of the inferior mesenteric artery and vein
Creation of a proximal end colostomy (typically sigmoid colostomy).
Perineal Phase:
Positioning patient in lithotomy
Incision around the anus, extending superiorly to meet the abdominal dissection
Sharp dissection through the sphincter complex, levator ani muscles, and ischiorectal fossa
Careful dissection to maintain oncologic margins and avoid injury to surrounding nerves and vessels.
Specimen Retrieval:
En bloc removal of the specimen from the abdomen and perineum
The specimen comprises the distal colon, rectum, anal canal, and surrounding perirectal tissues.
Wound Closure:
Perineal wound management: open packing, primary closure with drains, or flap reconstruction depending on the extent of resection and contamination
Abdominal wound closure in layers.
Postoperative Care
Pain Management:
Aggressive multimodal pain control using patient-controlled analgesia (PCA), epidural anesthesia, and oral analgesics
Regular assessment of pain scores.
Stoma Care:
Immediate postoperative stoma care
Monitoring stoma viability, color, and function
Education on pouching, emptying, and skin barrier maintenance
Diet advancement as tolerated.
Wound Care:
Perineal wound care: dressing changes, monitoring for infection or dehiscence
Abdominal wound monitoring for signs of infection or hernia
Pelvic drain management.
Complication Monitoring:
Vigilant monitoring for systemic complications such as sepsis, ileus, pneumonia, and DVT/PE
Close observation for specific surgical complications related to the APR.
Complications
Early Complications:
Wound infection (abdominal and perineal)
Anastomotic leak (if any stapled anastomosis is performed, rare in APR)
Hemorrhage
Pelvic abscess
Ileus
Urinary retention
Stoma ischemia or retraction
Bowel obstruction due to adhesions.
Late Complications:
Stoma-related issues (hernia, prolapse, stenosis)
Chronic perineal pain
Sexual dysfunction
Incisional hernia
Pelvic floor dysfunction
Chronic wound breakdown
Phantom rectal pain.
Prevention Strategies:
Meticulous surgical technique
Adequate bowel preparation and antibiotic prophylaxis
Careful stoma site selection and stoma care
Aggressive pain management
Early mobilization
DVT prophylaxis
Appropriate wound closure techniques.
Prognosis
Factors Affecting Prognosis:
Stage of cancer at diagnosis
Histological grade and type of tumor
Completeness of surgical resection (margin status)
Presence of lymph node metastasis
Patient's overall health status.
Outcomes:
For oncological indications, APR can provide good local control and improve survival rates for advanced rectal and anal cancers when combined with adjuvant therapy
For benign conditions, it resolves intractable symptoms.
Follow Up:
Regular oncological surveillance including physical examination, CEA monitoring, and periodic imaging
Stoma site checks and patient support for long-term stoma management
Management of chronic pain and functional sequelae.
Key Points
Exam Focus:
Indications for APR vs
low anterior resection (LAR)
Key steps of abdominal and perineal dissection
Management of complications like perineal wound infection and stoma issues
Oncologic principles of mesorectal excision.
Clinical Pearls:
Preoperative stoma siting is crucial for patient acceptance and function
Aggressive perineal wound management is essential
Multidisciplinary approach involving oncologists, stoma nurses, and physiotherapists is vital for optimal patient outcomes.
Common Mistakes:
Inadequate oncologic margins
Poor stoma site selection
Underestimating perineal wound complications
Insufficient postoperative pain management leading to delayed mobilization
Failure to consider adjuvant therapy.