Midline and off-midline wound closure methods after surgical treatment for pilonidal sinus

Pilonidal sinus disease is a common and debilitating condition. Surgical treatment remains the mainstay for managing chronic disease, with options including midline and off-midline wound closure methods. However, the optimal approach remains uncertain. Recent developments in tension-free midline techniques require further exploration.

To assess the effects of midline and off-midline wound closure methods for pilonidal sinus, and to determine the optimal off-midline flap procedures.

In June 2022, we searched the Cochrane Wounds Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL Plus EBSCO, and clinical trials registries. We also scanned the reference lists of included studies, as well as reviews, meta-analyses, and health technology reports. We applied no language, publication date, or study setting restrictions.

We included parallel RCTs involving participants undergoing midline closure without flap techniques and off-midline closure for pilonidal sinus treatment. We excluded quasi-experimental studies and studies that enroled participants presenting with an abscess.

We followed standard Cochrane methodology. The critical outcomes included wound healing (time to wound healing, proportion of wounds healed), recurrence rate, wound infection, wound dehiscence, time to return to work, and quality of life. We assessed biases in these outcomes utilising the Cochrane risk of bias 2 tool and appraised evidence certainty via the GRADE approach.

We included 33 studies with 3667 analysed participants. The median or average age of the participants across the included studies ranged from 21.0 to 34.2 years, with a predominant male representation. Geographically, the trials were primarily conducted in the Middle East. We identified nine intervention comparisons. In this abstract, we focus on and present the summarised findings for the three primary comparisons. Off-midline closure versus conventional midline closure Off-midline closure probably reduces the time to wound healing (mean difference (MD) -5.23 days, 95% confidence interval (CI) -7.55 to -2.92 days; 3 studies, 300 participants; moderate-certainty evidence). However, there may be little to no difference between the two methods in the proportion of wounds healed (100% versus 88.5%, risk ratio (RR) 1.13, 95% CI 0.92 to 1.39; 2 studies, 207 participants; very low-certainty evidence). Off-midline closure probably results in lower rates of recurrence (1.5% versus 6.8%, RR 0.22, 95% CI 0.11 to 0.45; 13 studies, 1492 participants; moderate-certainty evidence) and wound infection (3.8% versus 11.7%, RR 0.32, 95% CI 0.22 to 0.49; 13 studies, 1568 participants; moderate-certainty evidence), and may lower rates of wound dehiscence (3.9% versus 8.9%, RR 0.44, 95% CI 0.27 to 0.71; 11 studies, 1389 participants; low-certainty evidence). Furthermore, off-midline closure may result in a reduced time to return to work (MD -3.72 days, 95% CI -6.11 to -1.33 days; 6 studies, 820 participants; low-certainty evidence). There were no data available for quality of life. Off-midline closure versus tension-free midline closure Off-midline closure may reduce the time to wound healing (median 14 days in off-midline closure versus 51 days in tension-free midline closure; 1 study, 116 participants; low-certainty evidence) and increase wound healing rates at three months (94.7% versus 76.4%, RR 1.24, 95% CI 1.06 to 1.46; 1 study, 115 participants; low-certainty evidence), but may result in little to no difference in rates of recurrence (5.4% versus 7.8%, RR 0.69, 95% CI 0.30 to 1.61; 6 studies, 551 participants; very low-certainty evidence), wound infection (2.8% versus 6.4%, RR 0.44, 95% CI 0.16 to 1.17; 6 studies, 559 participants; very low-certainty evidence), and wound dehiscence (2.5% versus 3.0%, RR 0.82, 95% CI 0.17 to 3.84; 3 studies, 250 participants; very low-certainty evidence) compared to tension-free midline closure. Furthermore, off-midline closure may result in longer time to return to work compared to tension-free midline closure (MD 3.00 days, 95% CI 1.52 to 4.48 days; 1 study, 60 participants; low-certainty evidence). There were no data available for quality of life. Karydakis flap versus Limberg flap Karydakis flap probably results in little to no difference in time to wound healing compared to Limberg flap (MD 0.36 days, 95% CI -1.49 to 2.22; 6 studies, 526 participants; moderate-certainty evidence). Compared to Limberg flap, Karydakis flap may result in little to no difference in the proportion of wounds healed (80.0% versus 66.7%, RR 1.20, 95% CI 0.77 to 1.86; 1 study, 30 participants; low-certainty evidence), recurrence rate (5.1% versus 4.5%, RR 1.14, 95% CI 0.61 to 2.14; 9 studies, 890 participants; low-certainty evidence), wound infection (7.9% versus 5.1%, RR 1.55, 95% CI 0.90 to 2.68; 8 studies, 869 participants; low-certainty evidence), wound dehiscence (7.4% versus 6.2%, RR 1.20, 95% CI 0.41 to 3.50; 7 studies, 776 participants; low-certainty evidence), and time to return to work (MD -0.23 days, 95% CI -5.53 to 5.08 days; 6 studies, 541 participants; low-certainty evidence). There were no data available for quality of life.

This Cochrane review examines the midline and off-midline wound closure options for pilonidal sinus, predominantly based on young adult studies. Off-midline flap procedures demonstrate there may be benefits over conventional midline closure for pilonidal sinus, with various off-midline flap techniques. When off-midline flap closures were compared to tension-free midline closure, low-certainty evidence indicated there may be improved wound healing and increased time to return to work for off-midline closure, whilst very low-certainty evidence indicated there may be no evidence of a difference in other outcomes. There may be no evidence of an advantage found amongst the off-midline techniques evaluated. The choice of either procedure is likely to be based on a clinician's preference, experience, patient characteristics, and the patients' preferences. To more accurately determine the benefits and potential harms of these closure techniques, further large-scale and meticulously-designed trials are essential. Specifically, there is a pressing need for more studies addressing the paediatric population, in addition to adult studies.