A 10 cm incision is made starting at the posterior anal verge and carried to the right or left of the coccyx (paracoccygeal) (Fig. 15.3).

The incision is deepened in subcutaneous fat to reach the lower border of the gluteus maximus. The fascia and lower fibers (3–4 cm) of this muscle is divided to achieve exposure to the retrorectal space. The external sphincters, levator ani, puberictalis muscle, and internal sphincter are sharply divided and marked by different colored paired sutures to facilitate identification of each muscle during closure. The posterior rectal wall is then incised longitudinally to open the rectum “like a book” and gain access to low and mid rectum (Fig. 15.4).

To repair the RUF, the fistula is cored out, the urethra repaired with 3/0 monofilament absorbable sutures over a silastic Foley catheter used as a stent. The rectal wall is mobilized 2–3 cm and repaired in vest over pants fashion using absorbable sutures (Figs. 15.5 and 15.6).

The rectal wall is closed and the individual layers of sphincter mechanism are identified using the colored paired sutures and approximated with absorbable sutures (Fig. 15.7).

The wound is irrigated and a suction drain is placed deep or superficial to the gluteus, and its fascia reapproximated. The subcutaneous tissue is irrigated and the skin closed with interrupted sutures after careful approximation of the anoderm and the anal verge [6, 7]. If the York Mason procedure is done to remove a large rectal villous adenoma, submucosal infiltration of dilute (1:200,000) epinephrine solution will elevate the lesion, assist in dissection and decrease bleeding.

The York Mason procedure was expanded in later years to include repair of suprasphincteric or extrasphincteric fistulas and approach to retrorectal (presacral) cyst. In case of an extrasphincteric or high suprasphincteric fistulas, after opening the rectum posteriorally the primary opening of the fistula is cored out the rectal wall closed with vest over pants technique and the external fistula tract is drained with a #12 or #14 mushroom or Mallicot catheter and the incision is closed. A modification of the York Mason procedure, without division of the sphincter mechanism has been used to gain access to retrorectal space for removal of presacral developmental cysts. In such cases, after division of fibers of gluteus maximus, the sphincter mechanism is retraced caudad and the presacral cyst is visualized. Infiltration of dilute epinephrine solution between the cyst and the rectal wall facilitated dissection and prevents injury to the posterior rectal wall. After placement of suction drain within the dead space, the wound is closed per perineum [8, 9].

Results of the York Mason procedure are difficult to assess due to the paucity of reports of large series in the literature. Mason reported recurrence rate of 13% in his original series of rectal cancers treated with this procedure [2]. Allogower and associates reported 36 patients treated for rectal cancer through sphincter splitting transsphincteric approach [10]. There were no operative deaths and nine recurrences (25%). He recommended frozen section examination of margins and depth of invasion in “superficial” cancers. Allogower and colleagues reported a larger series of parasacral approach to the rectum. These included 116 patients with various indications, with nearly 50% done for malignancies [11]. There is little information available on the outcomes of the patients. The same authors subsequently published on the anatomy of the pelvic floor for translevator-transsphincter operations [12].

Huber reported on 106 cases of sphincter splitting parasacral approach performed between 1974 and 1985. The procedure was done in deep lithotomy position and “very good results” were obtained when the technique was applied for benign rectal tumors (villous adenomas), fistulas and traumatic lesions [13]. Radical resection of the bowel wall could be accomplished and the prolapsed rectosigmoid could be resected and the lax pelvic floor tightened through this approach. He concluded that “transsphincteric” approach is a highly desirable technique in the treatment of high fistulas and traumatic lesions. “Severe complications are rare among accurate preliminaries and surgical skills [13].”

Arnaud and colleagues reported on 35 patients (20 ♂, 15 ♀) who had posterior transsphincter approach for villous adenoma, rectal prolapse, rectal stricture, or high fistula [14]. No complications were seen in 20 patients, but delayed fistula occurred in seven patients, four of whom healed spontaneously, and three needed colostomy and surgical repair. Pathology of villous tumors showed invasive malignant changes in three patients requiring proctectomy and end-to-end coloanal anastomosis. Two patients had mild incontinence and were treated with biofeedback. Two patients developed sacrococcygeal hernia and delayed recto-perineal pain was reported in another two patients [14].

Recently, Qui and colleagues reported their experience of 102 patients with mid to low lying rectal neoplasms treated between 1990 and 2006, (40 ♂, 62 ♀ average age 55.5) [15]. Surgical indications were: rectal villous adenoma 36, early rectal cancer 43, advanced rectal cancer 10, and submucosal rectal wall neoplasm 13. Operating time was 75 min, blood loss average 60 ml, and hospital stay was 8 days. All 102 rectal neoplasms were resected completely with partial proctectomy in 96 and segmental proctectomy in 6 all with clear resected margins. Three patients (2.5%) had postoperative infection and 4 (3.9%) had fecal fistula. The authors used Williams incontinence score and reported 33 patients (32.4%) with postoperative incontinence to flatus (26) and liquid stool (7) within 1 week. Three months postoperatively 94 patients (92.2%) achieved grade 1 continence and only eight had occasional episodes of flatus incontinence (grade 2). There were no operative deaths and no incidence of rectal stricture. Three patients (2.9%) developed local recurrence during median follow-up of 76.8 months [15].