Key principles
• Oncological resection principles apply o Adequate margins o TME o Avoidance of coning of perineal specimen • Patient selection important
An APR is a morbid operation that involves en bloc resection of the rectum and perineum encompassing the anus with primary closure or reconstruction of the pelvic floor and formation of an end colostomy. This is most commonly done in the setting of anal or low rectal malignancy.
Specific preoperative preparation
• Confirmation of diagnosis and adequate staging • Completion of neoadjuvant CRT if required • Enema on morning of operation • Stoma marking • Full informed consent • Confirmation of liaison with plastic surgery etc if perineal reconstruction required
Operation Details
• Time out comp, prophylactic IV abs, TEDS + SCDs, IDC inserted • GA in modified Llyod Davies position • Legs are initially started in low positon as operation begins with abdominal part 1st o Can be done synchronous if 2 surgeons • Key steps o Close the anus with a strong purse-string suture o Abdominal operation to proceed as per an ultra-low anterior resection - Ligation of IMA and dissection of L) colon and rectum in oncological fashion with TME o Choose site of sigmoid ligation and transect o Ensure adequate sigmoid length to safely allow formation of stoma in pre-op marked site. This may require further dissection to get mobility. o Form stoma trephine and pull through end of sigmoid colon o Perineal approach (some do this in prone jack-knife position also) - Elliptical incision around the anus from the coccyx posterior to a point anterior, usually to include the perineal body - Dissect down into Ischioanal Fossa and expose coccyx posteriorly -Dissect down and incise the levator muscles posterior and go through Waldeyer’s fascia - Continue excision up laterally and join up with abdominal operation - All dissection should be kept close to the external sphincter unless there is involvement of this - Anterior dissection differs in males and females but overall: • Care to identify prostate/seminal vesicles in men and vagina in women and avoid injury to urethra • Anterior dissection may take place after specimen delivery - Once peritoneal cavity entered and dissection complete the specimen can be delivered through the pelvic floor defect - Closure of the perineal defect then occurs and can be done in various ways • Primary closure of levator muscles • Mesh-assisted closure • Muscle flap reconstruction (eg VRAM) o Washout o Drains left insitu o Abdominal incision closed in standard mass closure fashion o Stoma matured in usual fashion
Relative Anatomy
• Pelvic floor • Perianal and anal sphincter complex • Anatomy as per Anterior resection especially ureter, TME and pelvic organs
Intraoperative complications & challenges
• Colon length to stoma o Ensure dissection of splenic flexure, ligation IMV higher, score peritoneum etc • Major pelvic vascular bleeding o Pack to control, tell anaesthetist, ensure cross match o Standard vascular control principles • Ureteric injury o Early identification important o Seek urology opinion o Principles are aim for primary repair with debridement of injured ends, avoidance of significant dissection to preserve vascularity and closure in spatulated fashion over a JJ stent
Post-operative complications
• Immediate o Intra-op - Bleeding - Visceral injury - Ureteric or urethral injury § Anaesthetic complications • Early o Infection - Perineal wound >>>Abdominal wound - Pelvic collection o Haematoma o Wound dehiscence (perineal >>>abdominal) o Flap complication eg) Ischaemia/necrosis o Urinary retention - Medications, surgical dissection, autonomic nerve injury o Pain • Late o Autonomic nerve dysfunction - 50% risk impotence in men with APR o Herniae - Perineal and abdominal o Tumour local recurrence o Chronic pain