Time and rate of sinus formation in pilonidal sinus disease.

BACKGROUND: and aims To elicit mechanisms and timing of sinus development, the role of age at onset of symptoms, symptomatic disease duration, and consecutive number of sinuses were investigated. MATERIALS AND METHODS: Analysis of 1,962 medical records of patients admitted for primary surgical pilonidal sinus treatment. RESULTS: Sinus number ranged from 1 to 16 (median 2), with chronic pilonidal disease showing more sinuses than acute disease (mean 2.6 vs 2.1 sinuses; p < 0.0001; Kolmogorov-Smirnov). Disease duration in chronic pilonidal disease was not linked to sinus formation (p = 0.98; Spearman). In acute pilonidal disease, duration was linked to the development of six sinuses per 1,000 symptomatic disease years (p = 0.0001; Spearman). A larger sinus number correlated with earlier onset of symptoms (p = 0.009; Spearman). CONCLUSION: Long-standing chronic disease does not produce sinus per se. As sinus does not substantially arise during the course of symptomatic disease, there must be a time before the start of symptomatic disease when the sinus originates. These findings suggest that sinus can only be acquired up to a certain age, even if occupational exposure continues.

Timeline of recurrence after primary and secondary pilonidal sinus surgery.

PURPOSE: This study was designed to evaluate the timeline of recurrence of pilonidal sinus disease after primary vs. multiple surgery. Data of medical military service in Germany were reviewed. METHODS: Telephone interview of 205 patients after pilonidal sinus disease surgery after median interval of 14.8 (standard deviation +/-3.9) years was conducted. A total of 345 patient charts with pilonidal sinus disease recurrence and fully documented previous surgery history were analyzed. RESULTS: Pilonidal sinus disease recurred in 41 of 205 patients (20 percent; actuarial survival 22 percent) after first surgery. Median recurrence-free-interval was 1.8 (range, 0.1-16.5) years. Twenty-nine of 41 of all recurrences (71 percent) were observed within four years after primary surgery. Fifteen of 50 patients (30 percent) treated by primary closure had recurrent disease after a median recurrence-free interval of 2.7 (range, 0.2-13.5) years compared with 24 of 144 patients (17 percent), who experienced recurrence after rhomboid excision and open wound treatment after a median of 1.8 (range 0.1-16.5) years (P = 0.081, long-rank-test). Analysis of 345 recurrent disease charts revealed that recurrence time decreased for multiple recurrences compared with first recurrence (R1 vs. R2: P = 0.07; R2 vs. R3: P = 0.03, Mann-Whitney U test). CONCLUSIONS: Long-term recurrence rate was 22 percent and thus higher than previously reported. This may be attributed to the long follow-up interval. Recurrences up to 20 years after surgery were seen. Our data provide evidence that follow-up after first to the third pilonidal sinus surgery should complete or exceed five years, because the majority of recurrences occur during this postoperative interval. Nevertheless, even a five-year follow-up will still miss 25 percent of recurrences.