APR

Described by Miles in 1925

Anatomy: Denonvilliers fascia:The consensus is that this fascia represents the fusion of the walls of the peritoneal cul-de-sac that extends down to the pelvic floor in the fetus. This fascia forms the glistening white surface of the anterior aspect of the mesorectum and is removed as an integral component of the resected package in total mesorectal excision

Waldeyers fascia:The rectosacral fascia, often referred to as Waldeyer's fascia (although Waldeyer did not describe it as such in his anatomic report published in 1899), was characterized by Crapp and Cuthbertson. The thickness of this fascia varies from a thin transparent membrane to a thick, tough, opaque fascia. In the latter instance, unless the rectosacral fascia is deliberately divided, the surgical plane of dissection may erroneously extend anteriorly into the mesorectum, resulting in its incomplete excision, or stray posteriorly through the presacral fascia with consequent troublesome bleeding from presacral veins. We do not believe that the depiction of this ligament on MRI has been previously described.

The inferior hypogastric plexus also provides branches to the rectum, which may be accompanied by a middle rectal artery, but this artery is often absent or very small. Traction on this neurovascular bundle produces the so-called lateral ligament, the size of which depends on the presence or absence of the middle rectal vessels. Previous studies have shown that the middle rectal vessels are not consistently shown either in cadaveric dissections or on angiography

Indications:
Sphincter involvement by tumour
Crohns proctitis
Ulcerative colitis with poor sphincter function

Preop stomal therapist
Accurate Staging

1.The abdominal phase of this operation is conducted as described above down to the levators.
Midline laparotomy
Lateral mobilisation along line of Toldt including splenic flexure
First tubular structures will be gonadal vessels, ureter will be medial to these below IMA
Then create window underneath superior haemorrhoidal vessels at level of sacrum. Open peritoneum distally to enlarge window. Continuing superiorly will lead to IMA origin
Then divide IMV and continue dividing sigmoid mesentery and divide proximal limit of resection with linear cutting stapler

Then mobilise rectum in embryonic avascular fusion plane, beginning posteriorly and preserving hypogastric nerves. St Marks retractor in surgeons hand will help get lift and define areolar plane

Mobilise laterally, the plane of dissection anteriorly will depend on whether the tumour is posterior, if it is, then can dissect on the rectal side of Denonvilliers fascia to preserve nerves. If tumour is adherent to posterior vaginal wall, then a posterior vaginectomy should be performed.

2.Divide the sigmoid colon at a point that allows it to be brought out of the abdomen as an end colostomy without tension.
3.Tie a betadine soaked gauze to the clamp at the end of the specimen and move to the perineal dissecting table.
4.Close the anus with a 1-ethibond suture and make an elliptical incision beginning 3-4cm anterior to the anal orifice and ending at the tip of the coccyx. In females with anterior lesions, leave a patch of anterior vagina attached to the specimen along with the posterior portion of the introitus.
5.Incise down to the perirectal fat and grasp the ellipse in Allis tissue forceps. The anterior plane of dissection should be posterior to the superficial transverse perineal muscles. Dissect down to the level of the levators. You may encounter branches of the inferior rectal vessels and the internal pudendal nerve just superficial to the levators. These can usually be controlled with diathermy.
6.Divide the anococcygeal ligament and Waldeyers fascia using diathermy. This should lead to the pelvic cavity superiorly. It is easier to find the right plane if Waldeyers fascia is divided from the abdomen.
7.Place your left index finger around the left levator and divide. Similarly, place your right index finger around the right levator and divide this muscle. Continue this division around to the puborectalis sling anteriorly. Delay this step to last.
8.Deliver the transected recto-sigmoid specimen through the levators into the perineal wound.
9.Palpate the prostate anteriorly and divide the recto-urethralis muscle attaching it to the front of the rectum. Divide any remaining attachments to the prostate.
10.Irrigate and close in layers leaving the vaginal mucosa open to heal by secondary intent.
11.Close the abdominal wound following lavage and placement of a pelvic drain. Mature the end colostomy with 3/0 chromic gut.

Complications
Perineal wound breakdown 10% (30% if NAXRT)
Urinary
Sexual
Recurrence 5-10%