Abdominoperineal resection

Abdominoperineal resection aka Miles procedure

Pre-op

• Mark colostomy site

Prep

• GA, IV Abx, IDC, TEDS/SCDS
• Lloyd-Davies position
• DRE to confirm distance of cancer from AV

Technique:

Abdominal resection - supine - laparoscopic

• • IMA divided
  • Descending colon mobilised and divided above the rectosigmoid junction, but with enough length to reach pubis (enough length for stoma)
  • Rectum dissected according to TME principles to the level of levator ani.
  • Colostomy created and abdomen closed.

Perineal resection - change to prone

• • Close anus with purse-string suture to prevent leakage
  • Mark landmarks: ischial tuberosities, coccyx, perineal body
  • Elliptical or circular incision made around anus, which is then resected an bloc with the sphincter, and aiming to excise up to ischial tuberosities/coccyx/perineal body. Careful not to cone the dissection.
  • Continue circumferential dissection, but posterior is easiest - less important structures
    • Lateral: deepen to expose ischiorectal fossa and coccyx, with self-retainer for help. Ischiorectal fossa tissue should be areolar and avascular, except for branches of inferior rectal artery crossing to anus.
    • Posterior: through the anococcygeal ligament in front of presacral fascia, until the abdominal plane of dissection is reached
    • Anterior: deepen incision anteriorly through perineal body. Stay behind the line of transverse perineal muscles, and aim towards the sacral promontory.. If bulbospongiosus is seen, you are too far anterior. Dissecting between anus and urethra/anus and prostate in men, or anus and vagina in women. Constantly feeling for position of IDC.
  • Take a rim of levator muscle and join abdominal dissection
• Specimen removed through the pelvic incision
• Fill empty space of pelvis with omentum
• Close pelvic floor and skin
• Perineal defect can also be closed with rectus abdominis flap or gracilis muscle flap or IGAM flap (inferior gluteal artery myocutaneous flap)