Light-based Epilation as an Adjunct to Surgery in the Management of Pilonidal Disease: A Meta-analysis

Abstract

Background:

There is currently no widely accepted treatment protocol for pilonidal disease. Although surgery is often the first line of treatment, it is associated with a high recurrence rate. Noninvasive approaches to treating pilonidal disease, such as light-based epilation, have shown promise in small studies. Systematic reviews on this subject have been limited by small sample sizes, lack of comparative groups, and substantial heterogeneity. The purpose of this systematic review and meta-analysis was to address these limitations and evaluate the effectiveness of light-based epilation as an adjunct to surgery in the treatment of pilonidal disease.

Methods:

A PubMed search was performed of all studies that evaluated the rate of pilonidal disease recurrence when light-based epilation was used. Only English-language comparative studies with more than 10 subjects and a follow-up longer than 6 months were included. Data from all studies were compiled, and a systematic review and meta-analysis were conducted to evaluate the effectiveness of light-based epilation in reducing pilonidal disease recurrence.

Results:

Eleven comparative studies comprising 804 patients were included, including 3 randomized controlled trials, 4 prospective studies, and 4 retrospective studies. Light-based epilation used as an adjunct to surgery was found to significantly reduce pilonidal disease recurrence compared with surgery alone (P = 0.02). No statistically significant differences were observed when light-based epilation alone was compared with conventional treatment (P = 0.9) or surgery alone (P = 0.5).

Conclusions:

This study demonstrated that light-based epilation as an adjunct to surgery results in significantly lower pilonidal recurrence rates than surgery alone.

Takeaways.

Question: Does light-based epilation improve outcomes in the management of pilonidal disease?

Findings: In this meta-analysis of 11 studies, we found that light-based epilation in combination with surgery decreases pilonidal disease recurrence rates compared with surgery alone.

Meaning: Surgeons treating pilonidal disease should consider using light-based epilation in addition to surgery.

INTRODUCTION

Pilonidal disease (PD) is a chronic inflammatory condition, punctuated by acute exacerbations. It consists of abscesses or chronic draining sinuses in the gluteal cleft.^1–6 PD affects an estimated 26 per 100,000 individuals.^1,2,4,6,7 Known risk factors for PD include sedentary lifestyle, obesity, poor hygiene, male sex, and excessive body hair.^8,9 PD can significantly impact quality of life and daily activities,^1,5,6 highlighting the need for effective treatment strategies.

Debate continues regarding the etiology of PD. The role of loose, coarse hair in the initiation of PD is now accepted. Several authors in the mid-20th century found that barbers were at increased risk of developing wounds in their hands similar to pilonidal sinuses.^10,11 The frequent presence of broken, coarse hairs in pilonidal sinuses also supports this theory.¹²

Currently, there is no universally accepted treatment protocol for PD, resulting in substantial variability in clinical management.^13,14 Recurrence rates following surgery alone have been reported to be as high as 44%.^15–17 This underscores the need for alternative strategies, either as standalone therapies or as adjuncts to surgery.

Hair reduction has been proposed as a strategy to reduce PD recurrence by targeting hair density in the gluteal cleft.^1,7 The American Society of Colon and Rectal Surgeons recommends mechanical or chemical depilation, along with proper hygiene, for individuals with PD.³ However, adherence to these mechanical and chemical methods is often poor, as accessing the gluteal cleft for consistent hair removal can be difficult.¹⁵ This highlights the importance of more durable approaches to hair reduction that do not depend on patient compliance,^4,18 such as light-based epilation.^2,6,15,17,19

Light-based epilation operates through selective photothermolysis, in which light energy emitted by the device is absorbed by melanin in the hair shaft. This light energy is then converted into heat, destroying the hair follicle.¹⁸ Multiple treatments across several months are usually needed, as only hair follicles in the anagen phase are affected.

Most prior systematic reviews on the use of light-based epilation in PD have been limited by small sample sizes, the inclusion of noncomparative studies, and substantial heterogeneity across studies.^2,7,17,20 The objective of this meta-analysis and systematic review is to synthesize the available literature on light-based epilation in the management of PD and to provide evidence-based recommendations for its use.

METHODS

A database search in PubMed was performed by 2 independent investigators for all articles containing the terms “pilonidal” AND (“laser” OR “epilation” OR “hair removal”). We excluded studies without an available English full text, studies without a comparison group, case reports, case series with fewer than 10 subjects, and studies with a follow-up shorter than 6 months.

The main outcome variable was recurrence of PD. A systematic review was performed to evaluate the rate of PD recurrence with various interventions. These interventions included conventional management (hygiene, mechanical epilation, chemical epilation), light-based epilation (using laser and intense pulsed light [IPL]), and surgery. A meta-analysis was performed using the Grading of Recommendations Assessment, Development and Evaluation working group methodology.^20–23 This was used to assess heterogeneity, quality of evidence, and strength of recommendation for each intervention.

Heterogeneity (I²) was considered low when less than 50%, moderate when between 50% and 75%, and high when greater than 75%.²⁴

The quality of evidence (high, moderate, low, and very low) was assessed based on the type of study, the presence of study design limitations, indirectness, heterogeneity and imprecision, and the probability of bias.^21,22

The strength of recommendation (strong, weak) depended on 4 factors: risk-to-benefit ratio of the intervention, strength of evidence for or against the intervention, values/preferences of patients and physicians toward the intervention and the outcome, and cost of intervention and outcome.²⁵

The meta-analysis was performed using a Bayesian random effects model. All analyses were performed using JASP Version 0.19.3 (Amsterdam, the Netherlands). A P value of 0.05 or less was considered statistically significant.

RESULTS

Articles Included

The initial database search identified 201 articles. A manual search of the references yielded an additional 15 studies. After manually screening abstracts, studies that were not relevant to the research question were excluded, resulting in 62 eligible articles. After applying all exclusion criteria, 11 studies comprising 804 subjects were included in the meta-analysis (Fig. 1). (See table, Supplemental Digital Content 1, which displays the studies included in the meta-analysis, https://links.lww.com/PRSGO/E558.) All included studies were comparative and included 3 randomized controlled trials (RCTs), 4 prospective studies, and 4 retrospective studies. Table 1 shows the methodology for the quantification of the strength of recommendation for each analysis, based on the GRADE guidelines discussed earlier.²⁵

Fig. 1.

Study selection for the meta-analysis.

Table 1.

Summary of Comparative Studies Included in the Meta-analysis

First Author	Year of Publication	Type of Study	Institution	Subjects	Male Subjects	Mean Age, y	Follow-up, mo	Groups and PD Recurrence				Note
								Light-based Epilation	Surgery	Light-based Epilation + Surgery	Conventional Treatment
Minneci6	2024	RCT	Nationwide Children’s Hospital, Columbus, OH	230	—	—	12	Subjects: 96 Recurred: 10 (10.4%)			Subjects: 134 Recurred: 45 (33.6%)	Laser: diode or Nd:YAG every 4–6 wk for 5 treatments Conventional treatment: improved hygiene and mechanical/chemical epilation
Badawy13	2009	Prospective	Alexandria University, Egypt, and International Clinic, Kuwait	25	25	21.6	23		Subjects: 10 Recurred: 7 (70%)	Subjects: 15 Recurred: 0 (0%)		Surgery: excision with primary closure or healing by secondary intention Laser: Nd:YAG starting 2 wk after wound healing, every 6–8 wk for at least 3 treatments
Bütter15	2015	Prospective	Western University, East London, ON, Canada	99	—	—	20.5	Subjects: 18 Recurred: 10 (55.5%)	Subjects: 47 Recurred: 16 (34%)		Subjects: 34 Recurred: 9 (26.5%)	Surgery: unknown Laser: unknown
Demircan16	2015	RCT	Diyarbakir Education and Research Hospital, Turkey	60	45	23	12		Subjects: 30 Recurred: 1 (3.3%)	Subjects: 30 Recurred: 6 (20%)		Surgery: excision and Karydakis flap Laser: Alexandrite 2 wk before and 3 wk after surgery
El-Ramah4	2013	Retrospective	Al-Azhar University, Egypt	18	16	22.3	18		Subjects: 9 Recurred: 4 (44.4%)	Subjects: 9 Recurred: 0 (0%)		Surgery: excision and healing by secondary intention Laser: Alexandrite after wound healing, every 4–6 wk for 3–5 sessions
Ghnnam18	2011	RCT	Mansoura University, Egypt	86	75	23.3	24		Subjects: 41 Recurred: 2 (4.9%)	Subjects: 45 Recurred: 0 (0%)		Surgery: excision and healing by secondary intention Laser: Alexandrite starting after wound healing, every 4 wk for 4 sessions
Kelati17	2018	Retrospective	University Hospital of Nice, France	41	24	17.6	28.1		Subjects: 29 Recurred: 15 (51.7%)	Subjects: 12 Recurred: 1 (8.3%)		Surgery: unknown Laser: Alexandrite or Nd:YAG every 6–8 wk for an average of 4.2 sessions
Mutus26	2018	Retrospective	Istanbul Medeniyet University, Istanbul, Turkey	114	—	16	25		Subjects: 82 Recurred: 21 (25.6%)	Subjects: 32 Recurred: 0 (0%)		Surgery: excision and primary closure Laser: unknown laser, starting 6 wk after surgery
Emengo5	2024	Prospective	Stanford University, Palo Alto, CA	34	23	20	13.5	Subjects: 20 Recurred: 3 (15%)		Subjects: 14 Recurred: 2 (14.3%)		Surgery: various procedures Laser: diode every 6–8 wk for at least 6 sessions
Braungart27	2016	Retrospective	Leeds Teaching Hospitals, Leeds, UK	19	9	15	13		Subjects: 12 Recurred: 4 (33.3%)	Subjects: 7 Recurred: 0 (0%)		Surgery: excision with flap closure Laser: unknown
Check28	2022	Prospective	Boston Children’s Hospital, Boston, MA	78	–	16.3	7.5	Subjects: 9 Recurred: 0 (0%)	Subjects: 4 Recurred: 0 (0%)	Subjects: 64 Recurred: 1 (1.6%)		Surgery: pit excision Laser: unknown laser every 6–8 wk for an average of 3 sessions

Nd:YAG, neodymium-doped yttrium aluminum garnet laser.

Light-based Epilation Versus Conventional Treatment

Two comparative studies (1 prospective, 1 RCT) were included, comprising 329 subjects.^6,15 Light-based epilation was performed in 114 subjects, and conventional treatment was undertaken in 168 subjects. The recurrence rate of PD was 17.5% with light-based epilation and 32.1% with conventional treatment. Meta-analysis found no significant difference between the 2 treatments (Bayesian μ = −0.086, 95% confidence interval [CI] [−1.017, 0.912], P = 0.9), with considerable heterogeneity (I² = 92.9%) (Fig. 2).

Fig. 2.

Forest plot for light-based epilation vs conventional treatment.

Recommendation

There is no significant difference in PD recurrence rates between light-based epilation alone and conventional therapy (quality of evidence: low; strength of recommendation: weak).

Light-based Epilation and Surgery Versus Surgery Alone

Eight comparative studies (2 prospective, 2 RCTs, 4 retrospective), comprising 441 subjects, were included.^{4,13,16–18,26–28} Light-based epilation and surgery were performed in 214 subjects, and surgery alone was performed in 217 subjects. Overall, the recurrence rate of PD was 3.7% with surgery and light-based epilation and 24.9% with surgery alone. Meta-analysis demonstrated a significant difference between the 2 treatments (Bayesian μ = −0.826, 95% CI [−1.531, −0.139], P = 0.02), with moderate heterogeneity (I² = 54.2%) (Fig. 3).

Fig. 3.

Forest plot for light-based epilation and surgery vs surgery alone.

Recommendation

Surgery combined with light-based epilation is superior to surgery alone in the treatment of PD (quality of evidence: high; strength of recommendation: strong).

Light-based Epilation Versus Surgery

Two comparative studies (both prospective), comprising 138 subjects, were included.^15,28 Light-based epilation was performed in 27 subjects, and surgery was performed in 111 subjects. Overall, the recurrence rate of PD was 37% with light-based epilation and 31.4% with surgery. Meta-analysis demonstrated no significant difference between the 2 treatments (Bayesian μ = 0.293, 95% CI [−0.444, 0.990], P = 0.5), with minimal heterogeneity (I² = 0%) (Fig. 4).

Fig. 4.

Forest plot for light-based epilation vs surgery.

Recommendation

There is no significant difference in PD recurrence rates between light-based epilation alone and surgery (quality of evidence: low; strength of recommendation: weak).

Light-based Epilation and Surgery Versus Light-Based Epilation

Two comparative studies (both prospective), comprising 107 subjects, were included.^5,28 Light-based epilation and surgery were performed in 78 subjects, and light-based epilation alone was performed in 29 subjects. Overall, the recurrence rate of PD was 3.8% with light-based epilation and surgery, and 10.3% with light-based epilation alone. Meta-analysis demonstrated no significant difference between the 2 treatments (Bayesian μ = −0.080, 95% CI [−0.926, 0.759], P = 0.5), with minimal heterogeneity (I² = 0%) (Fig. 5).

Fig. 5.

Forest plot for light-based epilation and surgery vs light-based epilation.

Recommendation

There is no significant difference in PD recurrence rates between light-based epilation combined with surgery and light-based epilation alone (quality of evidence: low; strength of recommendation: weak).

DISCUSSION

This study examined the use of light-based epilation as an alternative or an adjunct treatment in PD. The main finding of this study is that light-based epilation as an adjunct to surgery is superior to surgery alone. This was a strong recommendation with high-quality evidence. These findings are in line with prior studies and systematic reviews.^29–33 For example, in a systematic review of 14 studies, Pronk et al³⁴ previously found that subjects with PD who had surgery without epilation had a recurrence rate of 19.7%. In those who had mechanical or chemical epilation after surgery, the recurrence rate was 23.4%. In those who had light-based epilation after surgery, the recurrence rate was 9.3%.³⁴

Our findings are consistent with the most likely underlying pathophysiology of PD. As previously described, PD is characterized by the formation of abscesses and sinus tracts within the deep layers of the skin in the gluteal cleft. These cavities arise due to a combination of genetic and environmental factors that contribute to follicular rupture within the subcutaneous tissue. Loose hairs may then be drawn into these spaces, triggering a foreign body reaction and subsequent infection.^4,18 The primary goal of most surgical interventions is to incise or excise these pathological tracts.¹ By also ablating hair follicles in the surrounding area, the risk of future follicular rupture and the formation of abscesses and tracts may be further reduced.

Light-based devices that are commonly used for epilation include Alexandrite laser (755nm), diode laser (810 nm), neodymium-doped yttrium aluminum garnet laser (1064 nm), and IPL.³⁵ These devices target melanin in the hair shaft, causing photothermal destruction of the hair follicle. Alexandrite and IPL devices are ideal for light-skinned individuals (Fitzpatrick I–III), whereas the diode and neodymium-doped yttrium aluminum garnet laser devices are safer for dark-skinned individuals (Fitzpatrick IV–VI), with a lower risk of dyspigmentation. The studies included in this systematic review used various combinations of these devices, without a clear superiority of 1 device over another. Because light-based therapy affects only hair follicles in the anagen phase, multiple treatments are needed to achieve sufficient hair reduction to produce a clinical benefit.¹⁸ Indeed, in studies where fewer than 3 treatments were performed, results were suboptimal, and PD recurrence rates remained high.^16,30 Most authors who found a benefit with the use of light-based epilation performed 4–6 sessions, separated by 4–6 weeks. In addition, some studies found that starting epilation before surgical wound healing can be deleterious.^16,31 Most authors who found benefit with light-based epilation started epilation after surgical wound healing.^4,13,18

There are various surgical procedures used for the treatment of PD.¹ These include minimally invasive endoscopic treatment,³⁶ trephination,³⁷ excision with healing by secondary intention,³⁸ excision with primary midline closure,³⁹ and excision with off-midline closure (eg, Limberg flap, Karydakis flap,⁴⁰ and Bascom cleft lift⁴¹). The studies included in this meta-analysis used a variety of these surgical techniques. Our study design was unable to elucidate whether 1 approach was superior to others. It should be noted, however, that recent literature seems to signal a shift toward less invasive surgical treatment, which may be possible due to the use of light-based epilation as an adjunct.^28,42 Most notably, the risk of PD recurrence decreases in subjects who achieve a greater degree of hair reduction.⁴² Based on the evidence elucidated in this study, a treatment timeline is suggested in Figure 6.

Fig. 6.

Suggested evidence-based timeline for the treatment of PD.

Our study comprised a large number of subjects and included only high-quality, comparative studies. Limitations include heterogeneity among the underlying studies and inherent variability in treatment protocols. This made it impossible to study the potential superiority of 1 laser-based device or 1 surgical technique over others. There were no consistent analyses of complications (other than recurrence), recovery time, or healthcare/societal costs in the studies included in our review, and therefore, we were unable to analyze those factors. In addition, the majority of the studies included were not randomized, introducing the possibility of baseline differences between the different subject groups in those studies, as well as selection bias.

CONCLUSIONS

Our meta-analysis demonstrated that light-based epilation used as an adjunct to surgery is superior at reducing PD recurrence than surgery alone. This treatment approach holds promise for decreasing the morbidity associated with PD and may offer patients meaningful benefits in recovery time, healthcare costs, and psychosocial well-being.

DISCLOSURES

Dr. Khansa receives book royalties from Amazon Kindle Direct Publishing. Mr. Kutkut has no financial interest to declare in relation to the content of this article.