Treatment Options for Pilonidal Sinus

Surgical Techniques

For severe or recurrent pilonidal disease, skin flaps often are required. Several flaps have been developed, including advancement, Bascom cleft lift, Karydakis, and modified Limberg flap. Flaps require a vascular pedicle but allow for closure without tension.²⁶ The cost of a flap procedure, ranging from $10,000 to $30,000, is greater than the cost of excision or other conservative therapy²⁰; however, with a lower recurrence rate of pilonidal disease following flap procedures compared to other treatments, patients may save more on treatment over the long-term.

Advancement Flaps
The most commonly used advancement flaps are the V-Y advancement flap and Z-plasty. The V-Y advancement flap creates a full-thickness V-shaped incision down to gluteal fascia that is closed to form a postrepair suture line in the shape of a Y.⁵ Depending on the size of the defect, the flaps may be utilized unilaterally or bilaterally. A defect as large as 8 to 10 cm can be covered unilaterally; however, defects larger than 10 cm commonly require a bilateral flap.²⁶ The V-Y advancement flap failed to show superiority to primary closure techniques based on complications, recurrence, and patient satisfaction in a large randomized controlled trial.²⁷

Performing a Z-plasty requires excision of diseased tissue with recruitment of lateral flaps incised down to the level of the fascia. The lateral edges are transposed to increase transverse length.²⁶ No statistically significant difference in infection or recurrence rates was noted between excision alone and excision plus Z-plasty; however, wounds were reported to heal faster in patients receiving excision plus Z-plasty (41 vs 15 days).²⁸

Cleft Lift Closure
In 1987, Bascom²⁹ introduced the cleft lift closure for recurrent pilonidal disease. This technique aims to reduce or eliminate lateral gluteal forces on the wounds by filling the gluteal cleft.⁵ The sinus tracts are excised and a full-thickness skin flap is extended across the cleft and closed off-midline. The adipose tissue fills in the previous space of the gluteal cleft. In the initial study, no recurrences were reported in 30 patients who underwent this procedure at 2-year follow-up; similarly, in another case series of 26 patients who underwent the procedure, no recurrences were noted at a median follow-up of 3 years.³⁰ Compared to excision with secondary wound healing and primary closure on the midline, the Bascom cleft lift demonstrated a decrease in wound healing time (62, 52, and 29 days, respectively).³¹

The classic Karydakis flap consists of an oblique elliptical excision of diseased tissue with fixation of the flap base to the sacral fascia (Figures 4 and 5). The flap is closed by suturing the edge off-midline.³² This technique prevents a midline wound and aims to remodel and flatten the natal cleft. Karydakis³³ performed the most important study for treatment of pilonidal disease with the Karydakis flap, which included more than 5000 patients. The results showed a 0.9% recurrence rate and an 8.5% wound complication rate over a 2- to 20-year follow-up.³³ These results have been substantiated by more recent studies, which produced similar results: a 1.8% to 5.3% infection rate and a recurrence rate of 0.9% to 4.4%.^34,35

Figure 4. Anterior view of Karydakis flap. Oblique excision of diseased tissue was performed. Note the flap dimensions.

Figure 5. Cross-section view of Karydakis flap. The base of the flap is sutured to the sacral fascia. The final position is off-midline.

In the modified Karydakis flap, the same excision and closure is performed without tacking the flap to the sacral fascia, aiming to prevent formation of a new vulnerable raphe by flattening the natal cleft. The infection rate was similar to the classic Karydakis flap, and no recurrences were noted during a 20-month follow-up.³⁶

Limberg Flap
The Limberg flap is derived from a rhomboid flap. In the classic Limberg flap, a midline rhomboid incision to the presacral fascia including the sinus is performed. The flap gains mobility by extending the excision laterally to the fascia of the gluteus maximus muscle. A variant of the original flap includes the modified Limberg flap, which lateralizes the midline sutures and flattens the intergluteal sulcus. Compared to the traditional Limberg approach, the modified Limberg flap was associated with a lower failure rate at both early and late time points and a lower rate of infection^37,38; however, based on the data it is unclear when primary closure should be favored over a Limberg flap. Several studies show the recurrence rate to be identical; however, hospital stay and pain were reduced in the Limberg flap group compared to primary closure.^39,40

Results from randomized controlled trials comparing the modified Limberg flap to the Karydakis flap vary. One of the largest prospective, randomized, controlled trials comparing the 2 flaps included 269 patients.Results showed a lower postoperative complication rate, lower pain scores, shorter operation time, and shorter hospital stay with the Karydakis flap compared to the Limberg flap, though no difference in recurrence was noted between the 2 groups.⁴¹

Two randomized controlled trials comprising 145 and 120 patients, respectively, showed no statistically significant difference between the Limberg flap and Karydakis flap with regard to complication rate, length of stay, and recurrence rate^36,42; however, patients in the Karydakis group reported subjectively feeling healed more quickly than patients in the modified Limberg flap group,⁴² and 1 of the 2 studies showed an increase in patient satisfaction with the modified Karydakis flap compared to modified Limberg flap.³⁶ In contrast to earlier studies, a 2009 study showed the Karydakis flap was associated with a higher wound infection rate than the Limberg flap group in a randomized trial of 100 patients (13/50 vs 4/50 patients).⁴³

Overall, larger prospective trials are needed to clarify the differences in outcomes between flap techniques. In our opinion, variations in postoperative complication and recurrence rates likely are due to differences in surgeon comfort and surgical technique. The Table provides a comprehensive list of trials comparing flap techniques.