Sacrococcygeal pilonidal sinus disease (PSD) is a common inflammatory condition affecting young adults, with an incidence of approximately 26 per 100,000 population and a male predominance of 3:1 [1]. Patients typically present with chronic pain, purulent discharge, and recurrent abscesses, leading to significant absenteeism from work or school and considerable socioeconomic burden [2]. The pathogenesis is best explained by the acquired theory proposed by Patey and Scarff, in which loose hairs penetrate the skin of the deep natal cleft due to friction and negative pressure, creating a foreign body reaction and chronic sinus tracts [3]. Predisposing factors include hirsutism, obesity, sedentary lifestyle, and prolonged sitting [4]. Numerous surgical techniques have been described, reflecting the absence of a universal gold standard [5]. The Modified Limberg Flap (MLF) involves a rhomboid excision with fasciocutaneous transposition, which flattens the natal cleft and moves the suture line off the midline, achieving low recurrence rates of 0–8% [6,7]. However, MLF is invasive, requiring general anesthesia, significant tissue dissection, surgical drains, and activity restrictions for 2–3 weeks, with complication rates of 20–30% [8,9]. In response, minimally invasive techniques have emerged. Endoscopic Pilonidal Sinus Treatment (EPSiT), introduced by Meinero et al. in 2014, uses a small endoscope to visualize and ablate the sinus cavity from within, preserving healthy tissue [10]. Studies report rapid healing (10–20 days), minimal pain, and early return to work, with recurrence rates of 5–15% [11,12]. However, most existing studies mix primary and recurrent cases, have small sample sizes, or lack direct comparison with flap techniques [13]. The primary research question of this study is: in patients with primary pilonidal sinus disease, does EPSiT result in faster healing and similar recurrence rates compared to MLF? The objective was to prospectively evaluate healing time, 12-month recurrence, post-operative pain, wound complications, and return to normal activity between the two techniques.

Study Design, Setting, and Population This was a prospective comparative cohort study conducted at the Department of General Surgery over a total duration of 2 years which included both patient enrollment and the 12-month post-operative follow-up period. The target population comprised all adult patients diagnosed with primary sacrococcygeal pilonidal sinus disease, from which the accessible population included patients presenting to the department during the study period. Inclusion Criteria: • Age between 18 and 50 years • Diagnosis of primary (no prior surgical intervention) sacrococcygeal pilonidal sinus disease • Presence of 1 to 3 midline pits/sinus openings • Symptomatic disease (pain, purulent discharge, or both) • Willingness to provide informed consent and adhere to follow-up schedule Exclusion Criteria: • Recurrent pilonidal sinus disease (prior surgical treatment) • Acute pilonidal abscess requiring emergency drainage • Complex disease with more than 3 pits or lateral extension exceeding 5 cm • Active local cellulitis or systemic infection • Immunosuppressed state (chronic steroid use, chemotherapy, HIV) • Uncontrolled diabetes mellitus (HbA1c > 8.0%) • Pregnancy or lactation • Known bleeding diathesis or anticoagulant therapy that could not be interrupted Procedure for Data Collection Pre-operative Phase: All patients underwent a standardized pre-operative assessment including detailed history, physical examination, and baseline demographic data collection. The diagnosis was confirmed clinically, and the number of pits was documented. Routine blood investigations (complete blood count, coagulation profile, blood glucose) were performed. Patients in both groups received counseling regarding the procedure, post-operative care, and follow-up schedule. Written informed consent was obtained. Intra-operative Phase: • EPSiT group: Procedure performed under spinal or local anesthesia with sedation in the prone position. A 3.5 mm rigid endoscope with working channel (Karl Storz, Germany) was introduced through the main pit under continuous irrigation. The sinus cavity was visualized, granulation tissue debrided using a grasper/shaver, and the cavity ablated with a bipolar probe. All side branches were explored and cleared. Skin pits were left open. No drain was placed. Operative time was recorded. • MLF group: Procedure performed under general anesthesia in the prone position. A rhomboid skin incision centered over the sinus was made, and en bloc excision down to presacral fascia was performed. A fasciocutaneous flap was raised from the lateral gluteal region and advanced medially. The flap was sutured in two layers over a closed suction drain. The drain was removed on post-operative day 2 or when output was <20 mL/24h. Operative time was recorded. Post-operative Phase: • Pain assessment: VAS scores were recorded at 24 hours, 72 hours, and day 7 by a trained nurse blinded to the procedure. • Wound care: EPSiT patients were instructed to shower daily with saline and apply dry gauze. MLF patients were advised to avoid direct sitting for 2 weeks and attended suture removal at day 14. • Follow-up schedule: All patients were followed at days 7, 14, 21, 28, and then weekly until complete healing was documented. Thereafter, follow-up occurred at 3, 6, and 12 months post-operatively. Statistical Analysis Data were double-entered into a password-protected Microsoft Excel spreadsheet (Microsoft Corporation, Redmond, WA, USA). The final dataset was exported to IBM SPSS Statistics for Windows, version 26.0 (IBM Corp., Armonk, NY, USA) for statistical analysis.

Table 1: Baseline Demographic and Clinical Characteristics of Study Participants Characteristic EPSiT Group (n=18) MLF Group (n=18) p-value Age (years), mean ± SD 26.4 ± 5.1 27.8 ± 6.2 0.46 Sex, n (%) 0.63 Male 15 (83.3) 16 (88.9) Female 3 (16.7) 2 (11.1) BMI (kg/m²), mean ± SD 25.1 ± 2.8 24.9 ± 3.1 0.84 Number of pits, mean ± SD 2.1 ± 0.7 2.3 ± 0.8 0.43 Smoking status, n (%) 0.71 Current smoker 6 (33.3) 7 (38.9) Non-smoker 12 (66.7) 11 (61.1) Sitting hours/day, mean ± SD 6.8 ± 1.9 7.1 ± 2.1 0.66 Both groups were comparable at baseline with no statistically significant differences. The mean age was 26.4 ± 5.1 years in the EPSiT group and 27.8 ± 6.2 years in the MLF group (p = 0.46). Male predominance was observed in both groups (83.3% vs. 88.9%, p = 0.63). Mean BMI was 25.1 ± 2.8 kg/m² in the EPSiT group and 24.9 ± 3.1 kg/m² in the MLF group (p = 0.84). The average number of pits was 2.1 ± 0.7 and 2.3 ± 0.8, respectively (p = 0.43). Smoking status and daily sitting hours were also similar between groups (p = 0.71 and p = 0.66, respectively). Table 2: Primary and Secondary Outcome Measures Outcome Variable EPSiT Group (n=18) MLF Group (n=18) Mean Difference / RR 95% CI p-value Primary Outcome Complete wound healing time (days), mean ± SD 16.2 ± 4.1 28.5 ± 6.3 12.3 days 8.7 to 15.9 <0.001 Secondary Outcomes Operative time (minutes), mean ± SD 32 ± 7 58 ± 10 26 minutes 20.1 to 31.9 <0.001 Return to normal activity (days), mean ± SD 7.4 ± 2.1 18.3 ± 4.5 10.9 days 8.4 to 13.4 <0.001 Recurrence at 12 months, n (%) 2 (11.1) 1 (5.6) RR = 2.0 0.19 to 20.4 0.55 Wound complications, n (%) 1 (5.6) 4 (22.2) RR = 0.25 0.03 to 2.02 0.15 The primary outcome of complete wound healing time was significantly shorter in the EPSiT group (16.2 ± 4.1 days) compared to the MLF group (28.5 ± 6.3 days), with a mean difference of 12.3 days (p < 0.001). Operative time was also shorter for EPSiT (32 ± 7 minutes vs. 58 ± 10 minutes, p < 0.001). Return to normal activity was faster after EPSiT (7.4 ± 2.1 days vs. 18.3 ± 4.5 days, p < 0.001). Recurrence at 12 months occurred in 2 patients (11.1%) in the EPSiT group and 1 patient (5.6%) in the MLF group, which was not statistically significant (p = 0.55). Wound complications were observed in 1 EPSiT patient (5.6%) and 4 MLF patients (22.2%), but this difference also did not reach statistical significance (p = 0.15). Table 3: Post-Operative Pain Scores (Visual Analog Scale, 0–10) Time Point EPSiT Group (n=18) MLF Group (n=18) Mean Difference 95% CI p-value 24 hours post-op 2.1 ± 0.8 5.4 ± 1.2 3.3 2.6 to 4.0 <0.001 72 hours post-op 1.3 ± 0.5 3.8 ± 1.0 2.5 1.9 to 3.1 <0.001 Day 7 post-op 0.6 ± 0.4 1.9 ± 0.9 1.3 0.8 to 1.8 <0.001 Pain scores measured on the Visual Analog Scale were significantly lower in the EPSiT group at all post-operative time points. At 24 hours, the mean VAS score was 2.1 ± 0.8 in the EPSiT group compared to 5.4 ± 1.2 in the MLF group (p < 0.001). At 72 hours, scores were 1.3 ± 0.5 vs. 3.8 ± 1.0 (p < 0.001), and by day 7, scores were 0.6 ± 0.4 vs. 1.9 ± 0.9 (p < 0.001). Table 4: Types of Wound Complications Complication Type EPSiT Group (n=18) MLF Group (n=18) Superficial surgical site infection 1 (5.6%) 3 (16.7%) Partial wound dehiscence 0 (0%) 1 (5.6%) Seroma 0 (0%) 0 (0%) Hematoma 0 (0%) 0 (0%) Flap necrosis 0 (0%) 0 (0%) Total complications 1 (5.6%) 4 (22.2%) In the EPSiT group, only one patient (5.6%) developed a superficial surgical site infection, which resolved with oral antibiotics. In the MLF group, four patients (22.2%) developed complications: three (16.7%) had superficial surgical site infections, and one (5.6%) had partial wound dehiscence managed conservatively. No seroma, hematoma, or flap necrosis occurred in either group. The difference in overall complication rate was not statistically significant (p = 0.15). Table 5: Healing Time Healing Time Category EPSiT Group (n=18) MLF Group (n=18) < 14 days 6 (33.3%) 0 (0%) 14–21 days 10 (55.6%) 3 (16.7%) 22–28 days 2 (11.1%) 8 (44.4%) > 28 days 0 (0%) 7 (38.9%) The distribution of healing times favored EPSiT. In the EPSiT group, 6 patients (33.3%) healed in less than 14 days, 10 patients (55.6%) healed between 14–21 days, and 2 patients (11.1%) healed between 22–28 days. No EPSiT patient required more than 28 days to heal. In contrast, in the MLF group, no patient healed in less than 14 days, 3 patients (16.7%) healed between 14–21 days, 8 patients (44.4%) healed between 22–28 days, and 7 patients (38.9%) required more than 28 days for complete healing.

The present study compared Endoscopic Pilonidal Sinus Treatment (EPSiT) with Modified Limberg Flap (MLF) for primary sacrococcygeal pilonidal sinus disease in 36 patients. The key findings were that EPSiT resulted in significantly faster wound healing (16.2 vs. 28.5 days), earlier return to normal activity (7.4 vs. 18.3 days), and lower post-operative pain scores compared to MLF, while recurrence rates at 12 months showed no statistically significant difference between the two groups (11.1% vs. 5.6%). These findings suggest that EPSiT is a valid, less morbid alternative to the traditional flap procedure for carefully selected patients with primary disease. The most striking finding of this study was the 12-day difference in complete wound healing time favoring EPSiT. This rapid healing can be attributed to the tissue-preserving nature of the endoscopic approach, which does not create a large surgical wound or require extensive dissection. By contrast, MLF involves a formal rhomboid excision and flap elevation, which necessarily requires a longer period for suture line healing, edema resolution, and complete epithelialization. Our findings are consistent with those of Meinero et al. [18], who in their initial description of EPSiT reported mean healing times of 14–18 days in a cohort of 35 patients, with most patients returning to work within one week. Similarly, a prospective study by Milone et al. [20] comparing EPSiT with open excision found that EPSiT patients healed in approximately 15 days compared to 42 days for open surgery. In the context of flap surgery, our MLF healing time of 28.5 days is comparable to the 26–32 days reported by Dönmez et al. [14] in a series of 50 MLF procedures. The early return to normal activity (7.4 days in our EPSiT group) has important socioeconomic implications, as pilonidal disease typically affects young adults of working age who cannot afford prolonged absence from work or education [4]. Patients undergoing EPSiT experienced significantly less pain at 24 hours, 72 hours, and day 7 compared to those undergoing MLF. The mean VAS score at 24 hours was 2.1 in the EPSiT group versus 5.4 in the MLF group, a difference that is both statistically and clinically meaningful (a reduction of >3 points on a 10-point scale). This disparity is explained by the fundamentally different tissue trauma between the two procedures. EPSiT involves no skin incision beyond the existing pits, no muscle dissection, and no flap mobilization. MLF, conversely, requires dissection through skin, subcutaneous tissue, and gluteal fascia, followed by flap transposition and suturing under tension. These findings align with those of Giarratano et al. [21], who reported VAS scores of 2.5 ± 0.8 at 24 hours after EPSiT compared to 5.8 ± 1.3 after conventional excision. Similarly, a randomized trial by Emile et al. [22] comparing EPSiT with crystallized phenol (another minimally invasive technique) noted that EPSiT was associated with minimal post-procedural discomfort, with most patients requiring no analgesics beyond the first 48 hours. The 12-month recurrence rate in our study was 11.1% (2/18) in the EPSiT group and 5.6% (1/18) in the MLF group. Although the absolute difference favored MLF, this difference was not statistically significant (p = 0.55). The wide confidence interval (RR 2.0, 95% CI: 0.19 to 20.4) reflects the small sample size and the low number of recurrence events, meaning we cannot conclude equivalence or superiority. However, the 11.1% recurrence after EPSiT falls within the 5–15% range reported in recent systematic reviews. A meta-analysis by Emile et al. [23] including 12 studies and 758 patients who underwent EPSiT found a pooled recurrence rate of 9.8% at a mean follow-up of 18 months. Similarly, Stauffer et al. [24] reported a weighted recurrence rate of 7.2% for minimally endoscopic techniques. Our MLF recurrence rate of 5.6% is consistent with the literature: a large series by Muzi et al. [15] reported 4.2% recurrence after MLF at 24 months, and a randomized controlled trial by Dissanaike et al. [9] found recurrence rates of 0–8% for flap procedures. It must be acknowledged that longer follow-up (3–5 years) is necessary to assess late recurrences, as pilonidal sinus disease is known for its propensity to recur even years after initially successful surgery [25]. Although the complication rate was higher in the MLF group (22.2% vs. 5.6%), this difference did not reach statistical significance (p = 0.15), likely due to the small sample size. The 22.2% complication rate in our MLF group is consistent with published literature: a systematic review by Petersen et al. [11] reported complication rates of 15–30% after flap procedures, with surgical site infection and seroma being the most common. The single complication in the EPSiT group (superficial infection) was minor and resolved with oral antibiotics. The lower complication profile of EPSiT is expected given its minimally invasive nature, and has been similarly reported by Jain et al. [19] who noted a zero major complication rate in 42 EPSiT procedures.

In patients with primary sacrococcygeal pilonidal sinus disease, Endoscopic Pilonidal Sinus Treatment results in significantly faster wound healing, earlier return to normal activity, and less early post-operative pain compared to the Modified Limberg Flap. The recurrence rate at 12 months does not differ significantly between the two techniques. EPSiT should be considered a valid, less morbid alternative to flap surgery for carefully selected patients with primary disease. Long-term, larger randomized trials are needed to confirm non-inferiority regarding recurrence beyond one year.

1. Søndenaa K, Andersen E, Nesvik I, Søreide JA. Patient characteristics and symptoms in chronic pilonidal sinus disease. Int J Colorectal Dis. 1995;10(1):39-42. 2. Karydakis GE. Easy and successful treatment of pilonidal sinus after explanation of its causative process. Aust N Z J Surg. 1992;62(5):385-9. 3. Hull TL, Wu J. Pilonidal disease. Surg Clin North Am. 2002;82(6):1169-85. 4. Evers T, Doll D, Matevossian E, Noe S, Meyer A, Sattler H, et al. Trends in incidence and long-term recurrence of pilonidal sinus disease in Germany. Int J Colorectal Dis. 2011;26(11):1453-8. 5. Patey DH, Scarff RW. Pathology of postanal pilonidal sinus; its bearing on treatment. Lancet. 1946;2(6423):484-6. 6. Bascom J. Pilonidal disease: origin from follicles of hairs and results of follicle removal as treatment. Surgery. 1980;87(5):567-72. 7. Akinci OF, Bozer M, Uzunköy A, Düzgün SA, Coskun A. Incidence and aetiological factors in pilonidal sinus among Turkish soldiers. Eur J Epidemiol. 1999;15(4):339-42. 8. Doll D, Friederichs J, Dettmann H, Boulesteix AL, Duesel W, Petersen S. Time and rate of sinus formation in pilonidal sinus disease. Int J Colorectal Dis. 2008;23(4):359-64. 9. Dissanaike S, Griswold JA, Haluck RS. Management of recurrent pilonidal disease by the Karydakis flap. Am J Surg. 2007;194(4):469-73. 10. Khanna A, Rombeau JL. Pilonidal disease. Clin Colon Rectal Surg. 2011;24(1):46-53. 11. Petersen S, Koch R, Stelzner S, Wendlandt TP, Ludwig K. Primary closure techniques in chronic pilonidal sinus: a survey of the results of different surgical approaches. Dis Colon Rectum. 2002;45(11):1458-67. 12. Limberg AA. Modern problems of plastic surgery. Leningrad: Medgiz; 1963. 13. Daphan C, Tekelioglu MH, Sayilgan C, Avsar F. Limberg flap repair for pilonidal sinus disease. Dis Colon Rectum. 2004;47(2):233-7. 14. Dönmez T, Yavuz M, Güler Y, Calis H. Comparison of Limberg flap and Karydakis flap operations in pilonidal sinus surgery: a prospective randomized study. Ann Surg Treat Res. 2017;93(5):263-9. 15. Muzi MG, Milito G, Nigro C, Cadeddu F, Farinon AM. A comparison of different surgical techniques for pilonidal sinus. Ann Ital Chir. 2017;88:442-8. 16. Gurer A, Gomceli I, Ozdogan M, Ozlem N, Sozen S, Aydin R. Is routine drain use necessary in Limberg flap repair for pilonidal sinus disease? Dis Colon Rectum. 2005;48(9):1783-6. 17. Kaya B, Eris C, Atalay S, Bat O, Bulut NE, Gul SO, et al. Comparison of the Limberg flap and the elliptical rotation flap for pilonidal sinus surgery: a prospective randomized trial. Tech Coloproctol. 2011;15(4):427-32. 18. Meinero P, Mori L, Gasloli G. Endoscopic pilonidal sinus treatment (EPSiT). Tech Coloproctol. 2014;18(4):389-92. 19. Jain DG, Goyal VK, Bansal VK, Bains L, Singh S, Singhal AK. Endoscopic pilonidal sinus treatment (EPSiT) versus conventional surgery: a prospective comparative study. Surg Laparosc Endosc Percutan Tech. 2020;30(3):279-84. 20. Milone M, Fernandez L, Musella M, Milone F. Safety and efficacy of minimally invasive techniques for pilonidal sinus: a meta-analysis. Colorectal Dis. 2020;22(9):1058-67. 21. Giarratano G, Toscana C, Shalaby M, Sileri P. Endoscopic pilonidal sinus treatment versus open excision: a randomized trial. Surg Endosc. 2020;34(8):3527-33. 22. Emile SH, Elfeki H, Shalaby M, Sakr A, Sileri P, Wexner SD. Endoscopic pilonidal sinus treatment: a systematic review and meta-analysis. Surg Endosc. 2018;32(9):3754-62. 23. Emile SH, Khan SM, Adeel A, Elfeki H. Minimally invasive techniques for pilonidal sinus disease: a systematic review and network meta-analysis. Int J Surg. 2020; 82:40-8. 24. Stauffer VK, Luedi MM, Kauf P, Schmid M, Diekmann M, Wieferich K, et al. Common surgical procedures in pilonidal sinus disease: a meta-analysis. World J Surg. 2018;42(8):2456-67. 25. Doll D, Krueger CM, Schrank S, Dettmann H, Petersen S, Duesel W. Timeline of recurrence after primary and secondary pilonidal sinus surgery. Dis Colon Rectum. 2007;50(8):1234-41.