A Retrospective Study of Pilonidal Sinus Healing by Secondary Intention Using Negative Pressure Wound Therapy Versus Alginate or Gauze Dressings.

Pilonidal sinus (PS) disease is an inflammatory skin and subcutaneous tissue condition that presents with infection, acute abscess, chronic discharging wounds, and/or pain. Surgery with open healing by secondary intention typically is used to achieve the fastest healing time with minimal recurrence rates. A retrospective analysis was conducted of data extracted from the medical records of 73 consecutive patients who had symptomatic natal cleft PS over a 10-year period to compare use of NPWT to alginate-based/gauze daily dressing (DD) changes in terms of healing time and recurrence. Variables extracted included age, gender, PS wound diameter (small <1 cm, medium 1 cm to 3 cm, large >3 cm), and time in weeks to achieving the endpoint (epithelialization). Risk factors examined that can affect healing or recurrence of previously operated PS disease included initial drainage before excision and risk factors for impaired healing (morbid obesity as determined by body mass index [BMI] ≥35, chronic infective skin conditions, and ongoing therapy with immuno-modulating drugs or chemotherapy), and loss to follow-up. Data were collected and analyzed using the chi-squared statistic, Kaplan-Meier curves, and Cox regression models. The total time of follow-up was 390 weeks for the DD group and 311 weeks for NPWT group. Patient mean age was 26.5 ± 10.7 years, most (53, 72.6%) were male, and 12 (16.4%) had comorbidities potentially affecting healing. Nine (9) were treated with primary closure and 62 patients were treated with open healing by secondary intention (2 additional patients receiving DD were excluded from the analysis because they had small sinuses that made NPWT unfeasible). Among participants, 30 (48%) received DD and 32 had NPWT. The median time to healing was 10 weeks (95% CI: 7-17) in the DD group and 8 weeks (95% CI: 7-9) in the NPWT group (not significantly different). In patients who healed, the average time to healing was 15.0 ± 18.1 and 9.8 ± 6.3 weeks in the DD and NPWT groups, respectively (not significantly different). The PS wound recurred in 5 patients - 4 (12.5%) in the DD group and 1 (3.1%) in the NPWT group (P = .355). In univariate analysis, only the presence of comorbidities was found to significantly affect time to healing (HR 95%, CI: 0.40 [0.17-0.93]; P = .033]. Prospective, randomized controlled clinical studies are warranted.