*5.1.1 Open lateral internal sphincterotomy*

The open technique involves a radial incision made on the intersphincteric groove and the dissection and division of the internal sphincter muscle to the level of the dentate line. The incision is usually left open for drainage (**Figure 5**).

In a prospective randomized study, delayed healing and higher postoperative pain scores have been found in the open technique group [48]. Similar results have been obtained by Pernkoft and Kortbeek et al., who have reported lower complication rates with the closed technique [49, 50].
