Pilonidal sinus disease (PSD) is a chronic inflammatory condition of the sacrococcygeal region that frequently affects young adults, often causing pain, drainage, and recurrent infection. Traditional surgical approaches such as wide excision or flap techniques may result in prolonged healing times, relevant postoperative pain, and recurrence rates up to 20-30%.

The SiLaC (Sinus Laser-Assisted Closure) technique is a minimally invasive procedure that uses a 1470-nm diode laser fiber to ablate the sinus epithelium and induce concentric contraction of the tract. International studies have reported promising results with faster recovery, minimal wound care, and low morbidity.

This prospective single-center cohort study aims to evaluate the clinical outcomes and perceived recovery time of adult patients treated with the SiLaC® technique at Hospital Universitario La Paz (Madrid, Spain). The main outcome is the total recovery time perceived by patients after surgery. Secondary outcomes include postoperative complications, recurrence rate, pain intensity, need for wound care, and patient satisfaction. Data will be collected from medical records and structured follow-up interviews.

Pilonidal sinus disease (PSD) represents a chronic, recurrent inflammatory disorder of the natal cleft that primarily affects young males. It is associated with risk factors such as obesity, prolonged sitting, and deep gluteal folds. Although not life-threatening, PSD significantly affects quality of life and healthcare resources due to recurrences and delayed wound healing.

Conventional surgical approaches, including excision with secondary healing or flap reconstruction (Limberg, Karydakis, Bascom), often require prolonged recovery and intensive postoperative care. Minimally invasive alternatives have been developed to improve patient recovery and reduce morbidity. Among them, the SiLaC® (Sinus Laser-Assisted Closure) technique employs a radial 1470-nm diode laser fiber to achieve epithelial destruction and tract contraction after curettage. Early evidence suggests favorable outcomes, but robust prospective data remain scarce, especially in Spain.

This study is an ambispective, descriptive, single-center cohort conducted at Hospital Universitario La Paz, Madrid. It includes all adult patients (≥18 years) who undergo SiLaC® surgery for chronic pilonidal sinus between August 2024 and January 2026. Data will be collected retrospectively from electronic health records and prospectively during follow-up visits and structured interviews.

The primary outcome is the total recovery time perceived by the patient (days from surgery to full return to normal activities).

Secondary outcomes include postoperative complications (minor or major), pain intensity (EVA 0-10), wound infection, recurrence within 6 months, patient satisfaction (0-10 scale), and number of wound care visits.

Data will be anonymized and analyzed descriptively using R software (version 4.3.1). Normality will be assessed with the Kolmogorov-Smirnov test; comparisons will use Student's t-test, Mann-Whitney, ANOVA, or Chi-square as appropriate. A significance level of p < 0.05 will be applied.

The study poses no additional risk, as SiLaC® is part of routine surgical practice. Ethical approval will be obtained from the Institutional Ethics Committee (CEIm of Hospital Universitario La Paz / IdiPAZ). Patient confidentiality will be guaranteed under EU Regulation 2016/679 and Spanish Law 3/2018.

Inclusion Criteria:

• Age ≥ 18 years.
• Clinical diagnosis of chronic pilonidal sinus disease.
• Undergoing surgery using the SiLaC (Sinus Laser-Assisted Closure) technique.
• Signed informed consent for the use of anonymized clinical data for research purposes.

Exclusion Criteria:

• Patients with inflammatory bowel disease or complex anorectal fistulas.
• Severe immunosuppression (active chemotherapy, high-intensity immunosuppressive therapy, uncontrolled HIV).
• Prior pelvic radiotherapy.
• Missing essential clinical data required for outcome assessment

Adult patients (≥18 years) with chronic pilonidal sinus disease who undergo laser-assisted closure (SiLaC®) at the Department of General and Digestive Surgery, Coloproctology Section, Hospital Universitario La Paz (Madrid, Spain). Participants will be included consecutively between August 2024 and January 2026, with a minimum follow-up of 6 months after surgery.

Individual participant data will not be shared. The study uses anonymized clinical data stored in institutional repositories at Hospital Universitario La Paz/IdiPAZ. Data access is restricted to the research team in compliance with EU Regulation 2016/679 (GDPR) and Spanish data protection law.