Horseshoe abscess drainage requires a thor­ough understanding of the anatomy. To ade­quately drain these abscesses, there must be both bilateral transcutaneous ischiorectal drainage and posterior drainage after division of the anococ­cygeal ligament to access the deep postanal space (Hanley procedure) (Fig.20.3). For those arising from a perianal abscess extending through the postanal space, posterior stulotomy with seton

Incision and drainage of an abscess is pre­ferred when the patient is rst evaluated in the clinic. This reduces any unnecessary delay in time to controlling sepsis. If performed in the clinic, one must ensure that there is an adequate setup and that the patient is amenable to proceed under local anesthesia. Complex abscesses or those associated with tissue necrosis and/or patients who are intolerant of a bedside proce­dure should be managed in the operating room. Packing is not recommended as wounds left unpacked are associated with less pain and faster healing [5]. For large or deep abscess cavities, a catheter (such as a mushroom-type catheter) can be placed in the cavity to promote drainage and minimize the size of the external incision. Antibiotics are recommended for those with extensive cellulitis or signs of sepsis or in immu­nocompromised patients, but routine antibiotics are not recommended [6].