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Procedure created 2026-08-19 · updated 2026-08-27
colorectalrectal-cancerAPRMiles-procedure

Abdominoperineal Resection (APR)

Also known as the Miles procedure. See Total Mesorectal Excision (TME) & Sphincter-Sparing Resection for the sphincter-preserving alternative. Content below is from a textbook reference chapter (Sabiston Ch52 - Rectal Cancer Surgery), not primary literature.

Indications

If the sphincters are infiltrated by tumor, complete excision of both the rectum and the anus, along with the sphincter apparatus, must be performed, together with creation of a permanent colostomy. Also an option for elderly patients with distal rectal cancer and poor sphincter function, since an end colostomy can offer a better quality of life than an ultradistal coloanal anastomosis that would further compromise continence.

Per ASCRS Ch29 - Proctectomy for Rectal Cancer: the subset of rectal cancer patients undergoing APR is decreasing over time, most likely because many patients with ultralow tumors that don't invade the external sphincter or pelvic floor now undergo restorative proctectomy with a low colorectal/coloanal anastomosis rather than APR. Patients with a tumor invading the external sphincter muscle or pelvic floor are most appropriately treated with APR. Incontinence alone is not an indication for APR — there's no need to subject a patient to excision of their pelvic floor unless it's invaded by tumor; incontinent patients with rectal cancer may instead be best served by a Hartmann resection or intersphincteric proctectomy with preservation of the pelvic floor musculature, if blowout of a short rectal stump is a concern.

Technique

The IMA is divided, the descending colon is mobilized and divided above the rectosigmoid junction, and the rectum is dissected according to TME principles down to the level of the levator ani (see Total Mesorectal Excision (TME) & Sphincter-Sparing Resection for the TME technique itself). The colostomy aperture is created. The perineal part of the operation then begins: a purse-string suture is placed around the anus, and an elliptical incision made around the anus, which is then excised en bloc with the sphincter. Dissection continues cephalad until the abdominal plane of dissection is reached, and the specimen is removed through the pelvic incision. The perineum is closed in layers. The empty pelvis can often be filled with an omental pedicle; wider perineal resections (especially in irradiated pelvises, which have more healing difficulty) may need the perineal defect closed with a rectus abdominis flap or gracilis muscle flap.

The specimen includes the origin of the IMA, the mesorectum, the hemorrhoidal vessels, and the "naked" portion of the ultradistal rectum and anal sphincters.

Prone perineal dissection technique, per ASCRS Ch29 - Proctectomy for Rectal Cancer: after completing the abdominal portion (extending dissection to the pelvic floor, creating the colostomy, closing the abdomen), the patient is repositioned prone, with a large cylindrical bump/pillow placed to elevate the pelvis/buttocks and create hip flexion. Buttocks are taped widely apart and the anus sewn shut to prevent fecal soilage. Key landmarks (tip of coccyx, ischial tuberosities, midpoint of perineum) are marked before an elliptical incision is made from the coccyx to the perineal midpoint, outside the anal sphincter muscle. Dissection starts posteriorly at the coccyx level, deepened through the anococcygeal ligament and onto the coccyx's anterior surface — the safest, easiest place to enter the pelvis from the perineum — then proceeds posterolaterally through the levators and laterally from ischial tuberosity to ischial tuberosity. Once the posterior two-thirds of the anus and rectum (including the levators) are freed, the specimen can be everted through the perineum, leaving only the distal anterior rectum/anus attached; the anterior dissection is performed last, as it's typically the most technically challenging (risks include membranous urethra/prostate injury, inadvertent vaginotomy, specimen perforation).

Recurrence rate and the case for a wider (cylindrical) excision

APR carries an intrinsic risk of higher recurrence rates than low anterior resection — up to 33%. This is partly explained by APR being performed for more aggressive cancers, but there's also an intrinsic higher risk of specimen perforation and a higher rate of positive circumferential margins (up to 40%) in patients undergoing APR — a technical, not just biological, contributor.

For this reason, a wider excision has been proposed, allowing a more cylindrical resection and avoiding the risk of "coning" toward the rectum (the conventional dissection plane tends to narrow toward the rectum, increasing the risk of a positive margin at the level of the tumor). After the abdominal part of the operation is completed, the patient is rotated to a prone jackknife position; a wider elliptical incision is made up to the tip of the coccyx (removed with the specimen), and the sphincter apparatus is removed en bloc with the levator ani in a cylindrical manner. The wide perineal defect, if needed, can be closed with a biologic mesh or a muscle flap.

Outcome data, per ASCRS Ch29 - Proctectomy for Rectal Cancer: this extralevator APR (ELAPE), or cylindrical APR, is meant to be a much wider excision of the pelvic floor to avoid the specimen "waisting" that typically occurs when dissecting the distal rectum to the pelvic floor during the abdominal portion — the abdominal dissection stops at a higher point, and the cylindrical APR is completed from the perineal portion to create a more uniform specimen with less narrowing at the pelvic floor. However, in one of the largest nationwide database studies examining short-term oncologic outcomes of ELAPE vs. traditional APR (954 patients), there was found to be no benefit to ELAPE. In patients with non-circumferential tumors specifically, there would seem to be no obvious benefit to the wide resection of the pelvic floor contralateral to the tumor — this should be considered during operative planning, since pelvic floor defects after ELAPE can be substantial, most requiring tissue-transfer closure.

Laparoscopic and robotic APR

Per ASCRS Ch36 - Colorectal Cancer Minimally Invasive Surgery: APR is still required in ~18% of rectal cancer patients despite sphincter-preservation advances. Data specific to minimally invasive APR are limited — most published RCTs comparing laparoscopic/open rectal resection included APR cases without a dedicated subset analysis. Ng et al. conducted a prospective RCT specifically in low rectal cancer comparing open (n=48) vs. laparoscopic (n=51) APR: earlier return of bowel function (3.1 vs. 4.1 days, p<0.001) and improved time to independent ambulation (4.4 vs. 5.9 days, p=0.005) with laparoscopic APR, but higher cost ($9588 vs. $7517, p<0.001) and longer operative time (213 vs. 163 min, p<0.001); 5-year survival was equivalent (75% vs. 76%, p=0.20), consistent with the CLASICC trial's findings (see Total Mesorectal Excision (TME) & Sphincter-Sparing Resection's Oncologic outcomes section). CRM reporting is inconsistent across the laparoscopic-APR literature — among 19 studies published since 1994 reporting oncologic outcomes, only 6 reported CRM involvement rates (ranging 2-21%); two studies (including the Dutch TME trial) found an association between higher tumor stage and CRM involvement, with the Dutch trial's APR subset showing 30% CRM positivity — raising selection-bias concerns for non-randomized laparoscopic-APR comparisons (patients with more advanced tumors more likely to undergo open surgery). Overall existing data suggest laparoscopic APR, performed by skilled surgeons, is associated with reasonable oncologic outcomes and possibly faster recovery.

Robotic APR/ELAPE is feasible/safe in select patients per the few published studies, with functional outcomes comparable to laparoscopic APR; one study reported lower conversion rates but higher total hospital charges with robotic vs. laparoscopic APR, and faster bowel recovery plus a trend toward reduced CRM+ vs. open APR. Applies the same wide-levator-resection principle described above (avoiding "coning in" and a specimen "waist") extending distally into the ischiorectal fat before the perineal phase begins.

Laparoscopic perineal approach: an alternative retrograde technique (dissection plane created in the pelvis before entering the peritoneal cavity) using a single-port laparoscopic or TEM device positioned within the ischiorectal/extrasphincteric dissection space — still in its infancy, with little feasibility/safety/outcomes data yet published.

Reconstruction after APR

Per ASCRS Ch29 - Proctectomy for Rectal Cancer: the perineal wound is the most common source of morbidity after APR, with wound-complication rates estimated as high as 66% with primary closure. Many perineal wound complications are attributable not just to the wound's location in a weight-bearing area, but also to the fact that the overwhelming majority of these patients have received neoadjuvant pelvic radiotherapy. Reconstructive options include a gracilis flap, vertical rectus abdominis myocutaneous (VRAM) flap, anterolateral thigh flap, and gluteal-based fasciocutaneous flaps — some can be harvested with an associated skin pedicle to reconstruct the posterior vagina after en bloc vaginectomy. Many flaps carry their own donor-site complications/morbidity — a VRAM flap, for example, very often results in an abdominal wall hernia but may provide the greatest tissue mass for the perineal defect. Choice of flap coverage should weigh defect size, use of preoperative external-beam radiotherapy, and the likelihood/impact of donor-site morbidity.

A well-vascularized omental pedicle flap placed into the pelvis can serve as a useful adjunct to primary perineal closure, especially with uncertain radial margins where postoperative boost-dose radiotherapy is being considered — filling the pelvis with omentum may help avoid small-bowel toxicity from radiotherapy, and placement of fiducials can guide radiation delivery in these cases. Closed-suction drainage of the pelvis can also help prevent excessive fluid buildup that could otherwise affect perineal-wound healing.

Open items / gaps

  • ~~No primary trial data yet directly comparing conventional vs. cylindrical APR oncologic outcomes.~~ Resolved by ASCRS Ch29 - Proctectomy for Rectal Cancer: a 954-patient nationwide database study found no benefit to ELAPE/cylindrical APR over traditional APR, particularly for non-circumferential tumors — see the Outcome data note above. Not independently ingested from its primary publication.
  • No detail on APR-specific complications (perineal wound issues, sexual/urinary dysfunction rates) beyond what's covered generally for TME dissection. Partially addressed: General Postoperative Complications (ASCRS Ch8) notes sexual dysfunction may be higher after APR than after low anterior resection, but its quantified figures (71% postop erectile dysfunction, 78% ejaculatory dysfunction) are general proctectomy data, not APR-specific — the APR-vs-LAR comparison itself remains unquantified. The 66% primary-closure perineal-wound- complication rate above is now the wiki's first APR-specific complication figure. Sexual Function After Colorectal Surgery (Ch64) further corroborates APR as highest-risk and names the contributing mechanisms (nerve injury, disrupted pelvic floor anatomy, body-image/stoma impact), but likewise does not quantify APR separately from proctectomy generally.
  • Ng et al.'s laparoscopic-APR RCT, the Dutch TME trial's APR-subset CRM data, and the robotic-APR cost/conversion-rate comparison (all per ASCRS Ch36 - Colorectal Cancer Minimally Invasive Surgery) are not independently ingested from primary publications.
  • The laparoscopic perineal (retrograde) approach is described as still in its infancy — little feasibility/safety/outcomes data yet published, per Ch36.