Surgery for asymptomatic pilonidal sinus disease.

INTRODUCTION: Asymptomatic pilonidal sinus disease (PSD) discovered incidentally is regarded as a precursor of symptomatic disease, which is characterized by intradermal hair eliciting an inflammatory reaction. We aimed to investigate whether asymptomatic PSD already shows inflammation, though clinically inapparent, or represents a 'virgin' sinus.

MATERIALS AND METHODS: One thousand seven hundred and thirty-one medical records of patients presenting with primary PSD, which underwent surgery, were analysed to identify patients with surgically resected incidental PSD.

RESULTS: Acute purulent pilonidal disease was seen in 514 of 1,731, whereas chronic fistulating pilonidal disease was the most common diagnosis group with 1,019 of 1,731 (58.9%). One hundred and forty-three of 1,731 (8.3%) patients had a previous chronic remitting pilonidal sinus. A total of 55 (3.2%) patients with clinically asymptomatic PSD were identified. Histological workup documented hair in 64.6% (1,119/1,731), with comparable rates between 68% and 71% in chronic fistulating disease, chronic remitting disease and incidental PSD (p = 0.80). Inflammation was found in 53 of 55 (96.4%) incidental PSD specimens, with two thirds (37 of 55) showing chronic inflammatory changes and one third (16 of 55) combining acute and chronic inflammation.

CONCLUSION: Our findings support the idea that incidental PSD is a sub-clinically inflamed pilonidal sinus, with hair and chronic infection present. However, the data suggest that a prophylactic surgery for asymptomatic PSD provides no benefit for the patient compared to surgery in chronic PSD; thus, observational treatment is most likely sufficient for asymptomatic PSD.