• April (a month, a date, an event?)
• APR (Annual Percentage Rate?)
• Apr as part of a longer word or question?

Abdominoperineal Resection (APR)

Definition

• Schwartz's Principles of Surgery, 11th ed.
• Bailey and Love's Short Practice of Surgery, 28th ed.

Indications

• Low rectal cancer (lower third, within ~5 cm of the anal verge) that is not amenable to sphincter-preserving surgery
• Tumors involving or too close to the anal sphincter complex
• Poor preoperative anal sphincter function (moderate to poor function is better served by APR than a low anastomosis that will result in incontinence)
• Anal canal cancers - as salvage surgery after failed/incomplete chemoradiotherapy (Nigro protocol); historically APR was the primary treatment but is now reserved for residual/recurrent disease
• Complications of chemoradiotherapy: fistula, incontinence, recurrent disease
• Adenocarcinoma of the anal canal (extension of low rectal cancer)

Key point: Anal canal squamous cell carcinoma is now treated primarily with chemoradiotherapy (mitomycin + 5-FU + radiotherapy 50.5 Gy). APR is a salvage procedure for the 20-25% with incomplete response or recurrence, and achieves cure in ~50% of salvage cases.

• Bailey and Love's Short Practice of Surgery, 28th ed.

Surgical Technique

Patient Positioning

1. Complete the abdominal phase first (patient in Lloyd-Davies position with legs in low supports)
2. Then reposition the patient in prone jack-knife position (or keep in Lloyd-Davies) for the perineal phase

Abdominal Phase

• Lower midline laparotomy or minimally invasive (laparoscopic/robotic) approach
• Explore for metastatic disease
• Medial-to-lateral colon mobilization with early identification of the left ureter and inferior mesenteric artery (IMA)
• Total mesorectal excision (TME): sharp dissection in the avascular embryological plane between the visceral and parietal pelvic fascia, maintaining the "shiny" mesorectal envelope intact
• Abdominal dissection stops before reaching the pelvic floor (at the level of the seminal vesicles in men / the cervix in women) - this avoids "coning down" onto the tumor
• Identify and protect bilateral hypogastric nerves, ureters, and neurovascular bundles
• End sigmoid/descending colostomy is fashioned in the left iliac fossa

Perineal Phase

• Circumanal elliptical incision around the anus
• Deepen into the ischiorectal fossae laterally toward the levator muscle attachments on the pelvic sidewall
• Posteriorly: incise Waldeyer's fascia (thick pelvic fascia between rectum and sacrum); some surgeons remove the coccyx for better access
• Anteriorly: carefully develop the plane between the rectum and the prostate/membranous urethra in males or the posterior vaginal wall in females; a urinary catheter helps identify the urethra
• Division of pubococcygeus and puborectalis muscles
• Specimen retrieved through the perineal wound when perineal dissection connects with the abdominal dissection

Extralevator APR (ELAPE)

• Avoids "coning down" or entering the plane between the tumor and levator ani
• Reduces intraoperative perforation rates
• Improves circumferential resection margin (CRM) clearance
• Reduces local recurrence

• Schwartz's Principles of Surgery, 11th ed.
• Bailey and Love's Short Practice of Surgery, 28th ed.

Neoadjuvant Therapy and Downstaging

• Fischer's Mastery of Surgery, 8th ed.

Preoperative Preparation

• MRI pelvis (locoregional staging), CT chest/abdomen/pelvis (distant staging)
• PET-CT for equivocal inguinal node assessment
• Baseline CEA level
• Mechanical bowel prep + oral antibiotics (metronidazole + neomycin) the day before
• ERAS protocol: preoperative anti-inflammatories, nausea prophylaxis, VTE prophylaxis
• Stoma marking by enterostomal nurse preoperatively
• TAP (transversus abdominis plane) blocks for pain control
• Ureteral catheters in cases with extensive pelvic dissection, reoperation, or prior pelvic radiotherapy
• Informed consent must include the possibility of APR even in planned low anterior resections
• Fischer's Mastery of Surgery, 8th ed.

Complications

Note on sexual dysfunction: Radical pelvic dissection damages pelvic parasympathetic supply needed for erection. This must be specifically counseled preoperatively - it is a significant source of morbidity.

• Gray's Anatomy for Students
• Fischer's Mastery of Surgery, 8th ed.

Oncologic Outcomes

• For rectal cancer: 5-year recurrence rates ~3-5%, comparable to sphincter-preserving surgery when adequate margins are achieved
• For anal canal SCC (salvage APR): ~50% cure rate
• Local recurrence after APR: 6-12% depending on series
• Yamada's Textbook of Gastroenterology, 7th ed.

APR vs. Sphincter-Preserving Surgery

• Tumor level and relation to sphincters
• Preoperative sphincter function
• Response to neoadjuvant therapy
• Surgeon experience
• Patient preference (permanent colostomy vs. risk of low anterior resection syndrome)