For patients with primarily functional stenoses or mild mid- to low-anatomic stenoses, symptom relief may be achieved with internal sphincterotomy alone. This may be accomplished by single [24] or multiple internal anal sphincterotomies [18], to include bilateral internal anal sphincterotomy [26] in some cases. Good results have been reported with sphincterotomy in the case of mild- to moderate-low anal stenoses, as well as some mid- or high stenoses, with most patients being able to be managed in this way [18]. If the patient does not have sufficient normal anoderm, however, initial relief of symptoms may occur, but post-procedural scarring may lead to recurrent anatomic stenosis. To help diminish this issue, the wound is left open to heal by secondary intention and patients are maintained on an aggressive post-procedural regimen of stool bulking agents, laxatives, and increased hydration [20]. An important consideration when considering sphincterotomy is the possibility of postoperative fecal incontinence. This issue generally resolves with time and is worse with flatus than stool, but can be devastating if it persists. Depending on the individual case, it may be prudent to obtain preoperative anal manometry to determine the patients’ sphincter function prior to considering this approach. It is a rare circumstance where the authors would favor this approach to stenosis after hemorrhoidectomy.

The most common procedure used for proximal anatomic anal stenosis is a lateral mucosal or endorectal advancement flap (Fig. 44.3) [27]. This procedure is initiated by making a lateral incision in the perianal skin and transition zone such that the scar is completely divided (and a lateral internal sphincterotomy may also be performed simultaneously, if favored by the surgeon). Following scar division, the rectal mucosa is then mobilized proximally in a triangular or tongue-like formation proximally into the distant rectum in the muscular plane for 4–6 cm, ensuring that the flap can easily reach to interpose across the scar/stenosis with little to no tension. While this flap is referred to as a mucosal flap, it is vitally important to include mucosa, submucosa, and a portion of the circular muscle of the rectal wall, as flaps including only the mucosa and submucosa are prone to developing recurrent stricture due to ischemia. Additionally, the width of the flap base (proximal) should be approximately twice the width of the apex (distal) as another method to ensure adequate blood supply. The flap is then sutured to the anoderm distal to the stenosis using absorbable sutures in an interrupted, full-thickness fashion (the authors favor 3-0 vicryl, or more rarely, 3-0 chromic for smaller flaps). It is important that the mucosal flap is not fixed distal to this point, as this may lead to ectropion formation. Any portion of the excision of the stricture external to the intersphincteric groove should be left open to heal by secondary intent to avoid ectropion formation and minimize the risk of recurrent stricture. This procedure is generally well tolerated by patients in terms of postoperative pain with good long-term outcomes, and the procedure may be able to be performed with sedation and local anesthesia [21, 27, 28]. While this method is useful for proximal stenoses, perianal skin advancement flaps are better techniques for more distal anatomic stenoses.

One widely performed procedure is the Y-V advancement flap, especially for low and mid-stenoses. The Y-V advancement flap is accomplished by making a wide-based V-shaped incision with the apex just distal to the stenosis and the base of the flap laterally on the anoderm and perianal skin at least 2–3-cm wide, after which the “Y” extension is made from the apex of the “V” through the entire length of the area of stenosis (Fig. 44.3). The flap is then mobilized by dividing the deeper subcutaneous attachments perpendicular to the skin while taking care to ensure both preservation of the subdermal blood supply and a tension-free repair, commonly requiring mobilization to the level of the underlying fascia depending on flap location. The apex of the V is then sutured to the distal corner created by the Y extension at the level of the internal-most aspect of the stenosis using interrupted longer term absorbable sutures (for example, 4-0 or 3-0 Monocryl or PDS), which creates the final “V” configuration of the repair. This technique has been described as very effective for relieving patients’ symptoms [29–31]. The procedure can be performed in the posterior or lateral positions, and bilaterally, if necessary [20].