Pit excision with phenolisation of the sinus tract versus radical excision in sacrococcygeal pilonidal sinus disease: study protocol for a single centre randomized controlled trial

BACKGROUND Excision of the pit of the sinus with phenolisation of the sinus tract and surgical excision are two treatment modalities for patients with sacrococcygeal pilonidal sinus disease. Phenolisation seems to have advantages over local sinus excision as it is performed under local anaesthesia with a relatively small surgical procedure, less postoperative pain, minor risk of surgical site infection (8.7%), and only a few days being unable to perform normal activity (mean of 2.3 days). The disadvantage may be the higher risk of recurrence (13%) and the necessity to perform a second phenolisation in a subgroup of patients. Wide surgical excision of sacrococcygeal pilonidal sinus disease has a recurrence rate of 4 to 11%. The disadvantages, however, are postoperative pain, high risk of surgical site infection, and a longer period being unable to perform normal activity (mean of 10 days). The objective of this study is to show that excision of the pit of the sinus of sacrococcygeal pilonidal sinus disease with phenolisation of the sinus tract is a successful first-time treatment modality for sacrococcygeal pilonidal sinus disease accompanied by a quicker return to normal daily activity compared to local excision of the sinus. METHODS/DESIGN Patients with sacrococcygeal pilonidal sinus disease will be randomly allocated to excision of the pit of the sinus followed by phenol applications of the sinus tract or radical surgical excision of the sinus. Patients are recruited from a single Dutch teaching, non-university hospital. The primary endpoint is loss of days of normal activity/working days. Secondary endpoints are anatomic recurrence rate, symptomatic recurrence rate, quality of life, surgical site infection, time to wound closure, symptoms related to treatment, pain, usage of pain medication and total treatment time. To demonstrate a reduction of return to normal activity from 7.5 days in the excision group to 4 days in the phenolisation group, with 80% power at 5% alpha, a total sample size of 100 is required. DISCUSSION This study is a randomised controlled trial to provide evidence that phenolisation of the sinus tract compared to radical excision reduces the total number of days unable to perform normal activity. TRIAL REGISTRATION Dutch trial register NTR4043 , registered on 24 June 2013.