Influence of Parks' anal retractor on anal sphincter pressures.

PURPOSE The effects of the Parks' anal retractor on anal sphincter function were studied in a prospective, randomized trial. A closed hemorrhoidectomy was performed intra-anally in 20 patients using the Parks' anal retractor; in 20 other patients, the procedure was done perineally without the use of a retractor. METHODS Anal manometry was performed before and at 6 and 12 weeks after hemorrhoidectomy. RESULTS Mean squeeze pressure decreased by 4 percent whether or not a retractor was used. Mean resting pressure decreased by 23 percent after use of Parks' anal retractor (P = 0.01) compared with 8 percent when it was not used (P > 0,05). CONCLUSIONS The internal anal sphincter is easily damaged with the use of the Parks' anal retractor. When possible, its use should be avoided to obtain better manometric and functional results.