Abdominoperineal Resection: A Surgeon’s Perspective on Patient Outcomes

Abdominoperineal resection (APR) is a surgical procedure primarily performed to treat rectal cancer located in the distal rectum, typically within 5 cm of the anal verge. It involves the removal of the rectum, anus, and surrounding tissues, followed by the creation of a permanent colostomy. This procedure is considered when sphincter-preserving surgeries, such as low anterior resection, are not feasible due to the tumor's location or involvement of the anal sphincter.

This article will delve into all aspects of APR, including its indications, preoperative evaluation, contraindications, surgical techniques, postoperative care, potential complications, different approaches, prognosis, alternative treatments, cost considerations, and recent advances in the field.

Indications for Abdominoperineal Resection

APR is indicated primarily for the treatment of rectal cancer, particularly when the tumor is:

• Located in the distal third of the rectum, especially within 5 cm of the anal verge.
• Infiltrating or involving the anal sphincter complex, making sphincter-sparing surgeries unfeasible.
• Associated with extensive local disease where negative margins cannot be achieved through less radical surgery.
• Present with locally advanced rectal cancer where neoadjuvant therapy has not reduced the tumor size sufficiently to allow for sphincter preservation.
• Recurrent rectal cancer after previous treatment where more conservative surgery is not an option.

APR is also occasionally performed for other conditions, such as:

• High-grade anal intraepithelial neoplasia not amenable to local excision.
• Perianal fistula associated with Crohn’s disease, though this is rare and typically considered only after exhausting other surgical options.

Preoperative Evaluation

The preoperative evaluation for a patient undergoing APR involves a thorough assessment to ensure the patient is a suitable candidate for surgery and to plan the procedure effectively. Key components of this evaluation include:

1. Detailed History and Physical Examination:
   • Assessing the extent of the disease, symptoms, and any prior treatments.
   • Physical examination, including a digital rectal exam, to evaluate the tumor's location, size, and fixity.
2. Imaging Studies:
   • MRI of the Pelvis: The gold standard for assessing the local extent of rectal cancer, including involvement of the mesorectum, sphincters, and surrounding structures.
   • CT Scan: Often used for staging and detecting distant metastases, particularly in the liver and lungs.
   • Endorectal Ultrasound (ERUS): Helpful in evaluating the depth of tumor invasion in the rectal wall and regional lymph node involvement.
3. Colonoscopy:
   • To confirm the diagnosis, assess the entire colon, and obtain biopsies. It also helps to rule out synchronous tumors.
4. Laboratory Tests:
   • Complete blood count (CBC), liver function tests, renal function tests, and carcinoembryonic antigen (CEA) levels are standard. CEA is particularly useful for monitoring during follow-up.
5. Neoadjuvant Therapy:
   • For patients with locally advanced rectal cancer (T3, T4, or node-positive disease), neoadjuvant chemoradiation is typically administered to downstage the tumor and increase the chances of obtaining clear margins during surgery.
6. Multidisciplinary Team (MDT) Review:
   • A thorough discussion involving surgeons, oncologists, radiologists, and pathologists to finalize the treatment plan.
7. Patient Counseling:
   • Detailed discussion with the patient regarding the nature of the surgery, the need for a permanent colostomy, potential risks, and postoperative recovery. Psychological support and stoma education are crucial at this stage.

Contraindications

While APR is a standard procedure for low rectal cancer, certain conditions may contraindicate the surgery or necessitate alternative approaches:

1. Poor General Health:
   • Patients with significant comorbidities may not tolerate the extensive nature of APR, particularly those with severe cardiac, pulmonary, or renal disease.
2. Metastatic Disease:
   • Widespread metastatic disease, where local control would not significantly impact overall survival, may contraindicate aggressive surgical intervention.
3. Inability to Create a Colostomy:
   • Some patients may have abdominal conditions (e.g., previous extensive surgeries, obesity) that make the creation of a functional colostomy challenging or risky.
4. Patient Refusal:
   • After understanding the implications of a permanent colostomy, some patients may opt against surgery, preferring non-operative management or less radical procedures.

Surgical Techniques and Steps

Abdominoperineal resection is a complex procedure involving both abdominal and perineal components. The surgical steps include:

1. Patient Positioning:
   • The patient is typically placed in a modified lithotomy position, allowing simultaneous access to the abdomen and perineum.
2. Abdominal Phase:
   • Midline Laparotomy: An incision is made from the pubic symphysis to just above the umbilicus. Laparoscopic and robotic approaches are increasingly used.
   • Mobilization of the Rectum: The sigmoid colon and rectum are mobilized, with attention to preserving the autonomic nerves to avoid postoperative sexual and urinary dysfunction.
   • Ligation of Blood Vessels: The superior rectal artery is ligated, and the mesorectum is dissected.
   • Total Mesorectal Excision (TME): The rectum is circumferentially dissected within the mesorectal fascia to ensure a clear margin.
3. Perineal Phase:
   • Perineal Incision: A circumferential incision is made around the anus, and the rectum is carefully dissected from surrounding structures.
   • Excision: The entire rectum, anus, and surrounding tissues are removed en bloc.
   • Wound Closure: The perineal wound is often closed primarily, but in some cases, a flap (e.g., gluteal or gracilis) may be used to aid in healing, especially if radiation therapy was administered.
4. Colostomy Creation:
   • A permanent colostomy is created, usually in the left lower quadrant of the abdomen. The stoma should be well-constructed with adequate protrusion to minimize complications like retraction or herniation.

Postoperative Care

Postoperative care following APR is extensive and includes:

1. Pain Management:
   • Adequate pain control is essential, often using epidural analgesia initially, followed by oral analgesics.
2. Monitoring for Complications:
   • Immediate Complications: These include bleeding, infection, anastomotic leakage (if any anastomosis was performed), and urinary retention.
   • Long-term Complications: These include stoma-related issues, perineal wound dehiscence, sexual dysfunction, and urinary incontinence.
3. Stoma Care:
   • Stoma care education is critical for patients, and stoma nurses play a vital role in patient education and support.
4. Early Mobilization:
   • Early mobilization is encouraged to reduce the risk of deep vein thrombosis (DVT) and pulmonary complications.
5. Dietary Management:
   • Gradual reintroduction of diet is recommended, starting with clear fluids and progressing to a normal diet as tolerated.
6. Follow-up:
   • Regular follow-up is essential, including surveillance for cancer recurrence, stoma evaluation, and management of any complications.

Possible Complications

Like any major surgery, APR carries risks, including:

1. Intraoperative Complications:
   • Hemorrhage: Significant bleeding may occur during dissection, especially near the pelvic sidewalls.
   • Injury to Adjacent Structures: Bladder, ureters, or sexual organs can be injured during surgery.
2. Postoperative Complications:
   • Perineal Wound Complications: Wound infection, dehiscence, or delayed healing, particularly in irradiated patients.
   • Stoma Complications: Retraction, prolapse, hernia, or parastomal skin irritation.
   • Sexual Dysfunction: Due to nerve damage, affecting both erectile function in men and vaginal lubrication in women.
   • Urinary Dysfunction: Risk of urinary retention or incontinence due to autonomic nerve damage.
   • Recurrence: Local recurrence in the pelvis or distant metastases may occur despite surgery.

Prognosis and Outcome

The prognosis following APR depends on several factors, including:

• Stage of Cancer: Earlier stages (T1-T2) have a better prognosis compared to more advanced stages (T3-T4).
• Clear Margins: Achieving clear surgical margins is crucial for reducing the risk of local recurrence.
• Response to Neoadjuvant Therapy: Patients who respond well to preoperative chemoradiation tend to have better outcomes.
• Patient Factors: Age, overall health, and presence of comorbidities influence recovery and long-term survival.

The 5-year survival rate for patients undergoing APR varies widely depending on these factors, ranging from 60% to 80% for those with early-stage disease. However, local recurrence remains a significant concern, particularly in patients with advanced disease or those with positive circumferential resection margins.

Alternative Options

While APR is the standard treatment for low rectal cancers involving the anal sphincter, alternative options may be considered in specific cases:

1. Low Anterior Resection (LAR):
   • If the tumor is sufficiently high in the rectum and does not involve the sphincter, LAR with a coloanal anastomosis may be possible, preserving the anal sphincter and avoiding a permanent colostomy.
2. Local Excision:
   • For small, early-stage tumors, particularly in high-risk surgical candidates, local excision with or without adjuvant therapy may be considered, though the risk of recurrence is higher.
3. Non-operative Management:
   • In select patients with a complete clinical response to neoadjuvant therapy, a "watch and wait" approach may be considered, avoiding surgery altogether. This approach remains controversial and is best suited for clinical trials or in highly selected patients.

Cost Considerations

The cost of APR varies depending on the healthcare system and geographical location. Key cost factors include:

• Surgery: The cost of the surgical procedure, including surgeon fees, anesthesia, and hospital stay.
• Stoma Supplies: Long-term costs associated with stoma care, including appliances and accessories.
• Follow-up: Ongoing costs related to surveillance, imaging, and management of complications.
• Adjuvant Therapy: Costs related to chemotherapy or radiation therapy, if required.

In general, APR is a costly procedure, particularly when factoring in the long-term costs of stoma care and potential complications.

Recent Advances

Recent advances in APR aim to improve outcomes, reduce complications, and enhance the quality of life for patients. These include:

1. Minimally Invasive Techniques:
   • Laparoscopic and robotic approaches to APR have been increasingly adopted, offering reduced blood loss, shorter hospital stays, and faster recovery, though long-term outcomes are comparable to open surgery.
2. Enhanced Recovery After Surgery (ERAS) Protocols:
   • ERAS protocols have been implemented to reduce postoperative complications and speed up recovery, including early feeding, multimodal analgesia, and early mobilization.
3. Pelvic Floor Reconstruction:
   • Advances in reconstructive techniques, including the use of biological meshes and muscle flaps, have improved perineal wound healing and reduced the incidence of perineal hernias.
4. Targeted Therapies:
   • The integration of targeted therapies and immunotherapy in the neoadjuvant or adjuvant setting is an area of active research, potentially improving outcomes in patients with advanced rectal cancer.

Conclusion

Abdominoperineal resection remains a critical surgical procedure for the treatment of low rectal cancers, particularly those involving the anal sphincter. While the procedure is associated with significant morbidity and a permanent change in lifestyle due to the colostomy, it offers the potential for cure in patients with locally advanced disease. The decision to proceed with APR must be made in a multidisciplinary setting, with careful consideration of the patient's overall health, tumor characteristics, and personal preferences. Advances in surgical techniques and perioperative care continue to improve outcomes for patients undergoing this challenging surgery.