Pilonidal sinus excision--healing by open granulation.

A prospective study is reported of 100 pilonidal sinus excisions healing by open granulation. Delays in healing appeared to be due to infection, particularly by anaerobic bacteria. Comparisons are made between three groups studied consecutively - 30 wounds not treated with antibiotics, 20 given a fixed two-week course of metronidazole and 50 managed flexibly. In this last group, wound management was determined by clinical appearance; 24 wounds were clinically healthy throughout and received no antibiotic while 26 looked unhealthy initially or after an interval and were treated with metronidazole, supplemented in some cases with erythromycin. The best results were obtained in the group managed flexibly. It is considered that the problems of delayed healing are due to excisions which leave a wound of a shape ill-designed to maintain good drainage. Unhealthy wounds should be re-shaped if possible and treated early with a combination of metronidazole and erythromycin.