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_______________________ Three Main Surgical Techniques Transperineal Approach First described by Shafik, this involves a vertical para-anal incision. The ischio rectal fossa is entered and the inferior rectal nerve is identified then traced back to Alcock’s Canal. Alcock’s Canal is then opened with the finger (sometimes the aid of scissors is required) and the wound is then closed with 2 stitches. This technique does not open the “clamp” between the sacro-spinal and sacro-tuberous ligaments, however, it does provide improvement in pain, urinary and anal incontinence. The procedure is limited by its small area of exposure and incomplete access to all the possible areas of entrapment. More recently, using the same incision, it has been demonstrated that it is possible to free the nerve in the so-called “clamp” between the two ligaments. This is accomplished by opening the fascia linking them. This opening (fasciotomy) enables the easy passage of one finger into the abdomen which is largely sufficient to free the nerve. With this modified technique, all areas of entrapment can be addressed with a minimally invasive procedure and without cutting any ligaments.
Transgluteal Approach First described by Robert et al, this involves a gluteal incision overlying the ischial tuberosity. The sacrotuberous ligament is identified and windowed over a 2-3cm segment. The neurovascular bundle is then identified and traced to the entrance to Alcock’s Canal. This overlies the sacrospinous ligament, which is also incised at the level of the ischial spine. The overlying fascial of Alcock’s Canal is also incised as is the remnants of the falciform process if necessary. The nerve is then transposed in front of the ischial spine. The procedure has the advantage of good access and visualization. All areas of possible entrapment are dealt with. The procedure is limited by the necessary sacrificing of both the sacrospinous and sacrotuberous ligament in some patients. There have been reports indicating that the transgluteal approach has been modified in some patients so that the sacrotuberous ligament is not compromised. Particularly for those patients with sacroiliac joint dysfunction, it is imperative that the sacrotuberous ligament is intact. If a patient is considering the transgluteal technique, sacroiliac joint dysfunction should be evaluated as a part of each patients workup with their physician. Also, the surgical manipulation of the nerve might be harmful in and of itself. Trans-ischio Rectal Approach In women, a vertical vaginal incision is made and the pararectal space is entered. In men, a paramedian transverse perineal incision is made and again, the pararectal space is entered. The rectum is retracted medially and the sacrospinous ligament is identified. The pudendal nerve is tested using a stimulating electrode on a fingerstall above the ischial spine. A needle electrode is placed in the external anal sphincter. PNTML and electrical potential surface area is measured. The sacrospinous ligament is divided progressively. Bipolar cautery is employed for hemostasis. If necessary, the falciform extension of the sacrotuberous ligament is partially divided. The operator then can digitally explore the canal caudally to ensure that the nerve is completely free. Nerve testing is repeated several times during the procedure. Once a normal result is returned, the dissection is complete. A drain is placed and the incision is closed. The procedure has the advantage of good access to all of the surgically amenable areas of entrapment. The complication rate is low (1-2.5% for hemorrhage and surgical site infection). The intraoperative nerve testing limits dissection to what is necessary to relieve entrapment. This increases the safety and efficacy of the procedure. The procedure avoids direct manipulation of the nerve, thus, reducing the risk of surgical nerve damage. Finally, complete sectioning of the sacrotuberous ligament is avoided. Disadvantages include a smaller field of vision during the procedure. Operators must be familiar with the approach via the vagina or perineum (in men). Expertise in intraoperative nerve testing is not wide spread. Summary The three main surgical techniques all have advantages and disadvantages. There has never been a head to head randomized trial to determine which is best. Comparing the currently published trials is also difficult because of different modes of evaluation of efficacy, preoperative evaluation, definitions and degree of long-term follow up. Therefore, a meta-analysis is not feasible. Success rates vary in the published literature. In patients who have failed conservative therapy, the TIR approach yielded a 62% pain free and 24% significantly improved rate at one-year post surgery in one study. In one study, the TG approach yielded a 45% cured and 22% improved rate. Also, the transperineal approach yielded a 61% cured and 17% improved rate in one study. It is difficult to compare these results because of the different sample sizes, methodologies, etc. Therefore, great care must be exercised in evaluating which approach has the best results. Ultimately, the decision to have surgery to treat this condition should not be taken lightly. Every patient should discuss these surgical options with their physician and determine which approach is best for them. Remember, the information we provide here is based upon our research and experience and is provided for informational purposes only. It is not and should not be considered a substitute for a visit and assessment by your physician. _______________________ |
