Once the decision has been made to operate on a specific patient, a protective colostomy should be created. We always prefer a right transverse colostomy. The technique corresponds in principle to Pena's procedure for PSARP and redo operations .
The patient is placed in the prone position, as described previously. The electrical stimulator allows the surgeon to make a full evaluation of the available muscles in the perineum. Multiple 5-0 stitches are placed at the mucocutaneous junction of the anus. All of these stitches are used for traction as in a primary PSARP (Fig. 31.3). The incision runs from a point immediately below the coccyx midsagittally and around the mucocutaneous junction in a "racket-like" fashion. Since the rectum is usually anteriorly mislo-cated, the midline incision necessarily cuts through the midline external sphincter and divides it into two halves. The dissection around the rectum must run as close as possible to the serosa of the rectum (colon) to avoid unnecessary damage to the surrounding stri-
Fig. 31.1 Secondary repair of the levator ani muscle following inadequate rectoplasty. Rerouting the rectum from the lateral diaphragmatic to the sphinc-teric parts of the levator ani (From Stephens and Smith , Fig. 21-1). A Perineal incision in the natal cleft and around the anus. B Rectum located in the lateral levator diaphragm. C Levator incised in the line of the raphe. D Rectum then dissected from its tunnel through the le-vator muscle. E Rectum drawn up through the lateral tunnel. F Rectum rerouted through the puborectalis funnel; levator ani sutured in the midline, lateral rent closed, and anus resutured
Fig. 31.2 Posterior sagittal ano-rectoplasty with repair of the levator ani muscle following inadequate rectoplasty. Rerouting the rectum in the sagittally divided levator ani muscle (from Stephens and Smith , Fig. 212). A Rectum emerging from the split diaphragmatic part of the levator ani. B Liberation of the rectum from the adherent levator muscles. C Levator ani incised in the midline behind and around the rectum. D Rectum tucked closely against the urethra and the levator ani muscle, including the remains of the puborectalis, approximated caudal to it. End of the rectum resutured to the skin of the perineum.
ated muscle structures. The midline incision is deepened until the posterior rectal wall is located. The lowest part of the levator muscle, the muscle complex, and the external sphincter usually have to be divided. The rectal dissection is carried out high enough until the posterior urethra is identified. The electrical stimulator allows one to determine whether there is any striated muscle left behind the urethra and in front of the rectum, which could be identified as the "missed puborectalis" .
to the rectal wall. D Finished repair showing tapered rectum, reconstruction of the muscle complex with reestablished anorectal angle including striated muscle of external anal sphincter
Once the dissection is complete, the operative field is evaluated and the strategy of reconstruction is established. Moreover, each case represents a different problem. There have been several basic findings in most of these cases, including:
1. A prolapsed patulous anus was found located anterior to an intact external sphincter.
2. An intact muscle complex had been left behind the rectum, which was pulled down in a rather straight manner.
3. There was a significant piece of mesenteric fat surrounding the rectum (colon) that represented the colon mesentery, which was pulled down to preserve the blood supply of the colon. The mesen-teric fat occupies a significant space and interferes with the muscle function, since it lies in between the bowel wall and the striated muscle.
4. There have been different degrees of lateral mislo-cation of the rectum.
5. There have been a few patients in whom the rectum was pulled down behind the muscle complex and behind the external sphincter, leaving a significant portion of the striated muscle (which represents the lowest part of the levator), which also could be identified as a "missed puborectalis" . In these patients the rectum was pulled straight behind, leaving a good portion of levator muscle in front of the rectum and behind the urethra.
6. There have also been different degrees of leva-tor muscle scarring and destruction, particularly in its lowest portion, as a consequence of a pull-through of a very large rectum or muscle hypoplasia, or just an inappropriate preparation of the muscle complex. In some patients there is a gap between the upper part of the muscle complex being well developed at its posterior coccygeal attachment and hypoplastic close to the external sphincter fibers.
The goal of the operation is to reconstruct the patient's anatomy to make it resemble, as closely as possible, the normal configuration (Fig. 31.3 D). Thus, the rectum (which is not frequently necessary in secondary operations) might be tapered and should be relocated and placed in front of the levator and in the middle of the muscle complex. Then the new anus is created at the center of the contraction of the external sphincter. The entire mesenteric fat should be resected, leaving the blood supply of the rectum through its transmural circulation. During this type of operation, one can gain a very accurate idea of the final prognosis of the patient based on the appearance of the muscles and on their strength of contractions.
The reconstruction is carried out with 5-0 Vicryl or Dexon interrupted sutures. The same principles described for the primary reconstruction of these patients [6,7] are used for the secondary repair.
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