Pilonidal Cystectomy Technique

The goal of surgery for a pilonidal cyst is to remove all cystic tissue and allow healing of healthy tissue. Surgical approaches to pilonidal cystectomy may be divided into the following two broad categories:

• Open healing
• Wound closure

The various specific techniques include the following:

• Simple cystectomy
• Cystectomy with primary closure ^[9]
• Karydakis flap
• Bascom procedure
• Limberg flap
• Z-plasty
• Y-V plasty
• Myofascial flap closure

Other techniques have been used and are variations of these techniques, including an elliptical flap and an oblique excision. ^{[10, 11]}  Simple cystectomy with primary closure is reserved for small cysts.

Endoscopic pilonidal sinus treatment (EPSiT) has been described. ^{[12, 13]}  A number of studies have found EPSiT to be a safe alternative with a low short-term complication rate. ^{[14, 15, 16]}  This technique has been applied to pediatric patients as well (PEPSiT). ^{[17, 18]} Additional data from randomized controlled trials are needed for a fuller determination of the therapeutic role of EPSiT.

Laser therapy appears to be a promising approach, but again, more data are needed. ^{[19, 20, 21, 22, 23]}  A study (N = 73) comparing sinus laser therapy (SiLaT; n = 37) with EPSiT (n = 36) found that the two methods were similar in terms of early and late complications but that SiLaT was associated with a longer duration of need for analgesic usage. ^[24]

The primary treatment for any infected pilonidal cyst with an underlying abscess consists of antibiotic therapy with incision and drainage. Antibiotics should cover skin flora; some recommend anaerobic coverage with metronidazole. Surgical referral for definitive pilonidal cystectomy should be made after the infection has cleared.

Practice parameters for the management of pilonidal disease were published in 2019 by the American Society of Colon and Rectal Surgeons (ASCRS). ^[25]  The updated German National Guideline for the management of pilonidal disease was published in 2021. ^[26]

The patient is prepared by clipping any hair around the affected area. (See the image below.) The natal cleft is exposed by applying tape to the gluteals, gently stretching the tissue to the lateral sides, and securing the tape to the table. Iodine-based solution is generally used for prepping unless the patient has an allergy.

Begin by identifying all sinus tracts (see the image below) and gently probing them with a lacrimal duct probe. Care must be taken not to create false tracts in the surrounding tissue. Injection of methylene blue has been used to identify tracts as well. A local anesthetic is injected around the area.

For simple cystectomy, electrocautery is used to dissect the tissues toward the sacrum around the cyst and sinus tracts. Dissection is performed in healthy tissue approximately 0.2 cm lateral to the identified sinus tracts. For small cysts, dissection can continue ventral to the cyst from both sides. In larger cysts, dissection is continued until the fascia overlying the sacrum is encountered, but the fascia is left intact. Occasionally, the walls of the wound are debrided further with curettage. Hemostasis is maintained with electrocautery.

Traditionally, wounds are left open, covered with gauze, and allowed to heal secondarily. Compared with other methods, this technique takes a shorter time in the operating room ^[27] ; however, healing times are long, daily dressing changes are required, and the recurrence rate is about 10%.

After removal of large cysts or actively infected tissue, a negative-pressure wound therapy (NPWT) device can be placed over the wound. These dressings are changed every third day. The NPWT device reduces the bacterial load, shortens healing times, and provides local débridement with each dressing change. ^[6]  Another option for large wound defects is to marsupialize the wound edges by sewing the wound edges to the postsacral fascia. This decreases the amount of exposed tissue.

After a small simple cystectomy with no tension on the skin edges, the wound may be closed primarily with interrupted nylon vertical mattress sutures. Deeper wounds may be closed in layers. Absorbable sutures can be used to close the deeper space by incorporating the postsacral fascia.

A study by Gabor et al found that NPWT was associated with reductions in length of hospital stay, postoperative pain, and time to healing when used over closed incisions in the intergluteal groove after surgical treatment of pilonidal cysts. ^[28]

Other methods of addressing the surgical wound are chosen in accordance with the amount of tissue removed, the individual surgeon's preference, and the contour and tension of the wound.

Karydakis flap

A Karydakis flap is designed to move the wound away from the midline. In brief, an elliptical incision is made lateral to the midline. Instead of dissection straight down to the fascia, the tissue is dissected at an angle toward the diseased tissue. The deep tissue is sutured to the sacral fascia. The skin is closed primarily lateral to the midline. ^{[29, 30]}  It has been suggested that using intracutaneous absorbable sutures for closure after this procedure may reduce infection and maceration rates. ^[31]

Bascom procedure

A Bascom procedure (cleft lift procedure ^[32] ) is a modification of the Karydakis flap and has been shown to reduce recurrence rates of pilonidal disease. An ellipse of diseased tissue is removed, but the deep tissues are not removed. A wide excision is not preferred. A 7-mm skin flap is created on one side and brought across the midline to approximate the tissues away from the midline. The wound is closed with nylon sutures. This technique also reduces the depth of the natal cleft. Bascom and Bascom reported no recurrences. ^{[33, 34]}

Limberg flap

A Limberg (rhomboid) flap is designed to keep the healing wound away from the midline. A rhomboid-shaped incision is made over the diseased tissue in the midline. A modified version keeps the apices of the incision away from the midline. A rhomboid-shaped flap is dissected from one side, including the gluteal fascia, and rotated into the wound defect. The lateral defect is closed primarily. ^[27]

A meta-analysis comparing the Limberg flap with the Karydakis flap in the treatment of pilonidal sinus disease found that whereas the two procedures were comparable with respect to complication and healing failure rates, length of hospital stay, pain scores, and time to wound healing, KP and LF were followed by similar rates of complications and failure of healing of PND and comparable stay, pain scores, and time to wound healing, the Limberg flap was associated with lower rates of seroma and wound infection, a longer time to return to work, and a lower rate of cosmetic satisfaction. ^[35]

Z-plasty

A Z-plasty is designed to decrease tension on the wound after repair. An elliptical incision is made to remove the cyst, including the deep tissue. The limbs of the Z incision are made at angles of approximately 30º to the midline. Two triangular flaps of tissue are raised and transposed. The wound may be closed in layers. ^[6]

Y-V plasty

A Y-V plasty is designed for large wound defects with significant skin tension. All diseased tissue is removed from the midline with an elliptical incision. A V-shaped incision is then made lateral to the tissue beginning from the apices of the ellipse. The subcutaneous tissue is dissected to allow the healthy tissue to be advanced over the wound defect. This technique also flattens the natal cleft. ^[6]

Myofasciocutaneous gluteal flap

A myofasciocutaneous gluteal flap is reserved for very large wounds when previous methods of pilonidal cystectomy have failed. It is usually performed by very experienced surgeons or plastic surgeons. There are several variants of the procedure, which involve isolating part of the gluteal muscles and the superior gluteal artery blood supply. The flap is rotated into the wound defect. This procedure has a long operating time and is associated with a higher complication rate than other techniques. ^[6]

Complications of pilonidal cystectomy include the following:

• Wound dehiscence
• Infection
• Delayed healing
• Recurrent disease necessitating reoperation
• Pain

The most common complication involves delayed wound healing. In cases where the wound has been closed, the wound may not heal and sutures may have to be removed to allow drainage of excess fluid. Delayed wound healing may also be caused by excessive tension on the wound. ^[6]

The wound may become infected after surgery. Gram-positive cocci are the most common etiologic agents. Antibiotics for skin flora and anaerobic bacteria may be prescribed empirically and cultures obtained for sensitivity testing. If an abscess develops, the fluid should be drained by removing the sutures. ^{[33, 34]}

For extensive wounds that were left open, the patient may feel a significant amount of pain from changing the dressings once or twice daily.