Pilonidal sinus

Dr. Zeeshan

Definition: Infection of the skin and subcutaneous tissue at or near the upper part of the natal cleft of the buttocks.

NOT a true cyst

History 1833- hair containing cyst located just below the coccyx Mayo

1880- Hodge coined the term “pilonidal” Nest of hair

In 19th and 20th century – considered to be congenital

In WW II

Patey and Scarf – hypothesised origin of pilonidal sinus acquired by penetration of hair into subcutaneous tissue.

What causes pilonidal sinus??? Midline holes – Hair follicles that have enlarged Pulling forces between sacrum and skin Force concentrate on 1mm2 area where the narrow

gluteal crease comes in close contact with the sharp angle of sacrum

Weakest point of skin gives way first– Skin at the bottom of the follicle.

Primary cause – “Pit” Secondary casue – “ Hair follicles”

Cause of pilonidal sinus (1) Invader hair

(2) Force causing hair penetration

(3) Vulnerability of skin

Anatomy Intergluteal cleft: A groove between the buttocks that

extends from just below the sacrum to the perineum.

Anchoring of the deep layers of skin overlying the coccyx to the anococcygeal raphe

Epidemiology Incidence : 26 per 100,000

Mean age: 19 years for women and 21 years for men

Sex: M/F ratio – 2:1 to 4:1

Equal incidence of acute:chronic

Risk factors Overweight/ obesity

Local trauma or irritation

Sedentary lifestyle/prolonged sitting

Deep natal cleft

Family history

Theory Acquired vs Congenital

Tendency to recur following complete excision.

Tendency to occur in places other than natal cleft.

Pathogenesis Hair and inflammation – inciting factors

On sitting/bending natal cleft stretches- breakage of follicles- opening of a pore/pit- collection of debris - pilonidal sinus - abscess

Proof?? Pilonidal tract extends cephalad. Cavity contains hair, debris or granulation tissue.

Clinical manifestations Patient presentation:- Acute onset mild to severe pain (sitting/bending)

- Intermittent mucoid/purulent/bloody discharge

- Recurrent / persisting pain

- Fever / malaise

Physical examination One/more pits in the natal cleft +/- painless sinus opening

cephalad and lateral to cleft

Tender mass or sinus draining mucoid/bloody or purulent fluid

Diagnosis Clinical - Finding a pore/sinus in the natal cleft- No imaging required

Differential diagnosis Perianal abscess/ fistula

Hidradenitis suppurativa

Perianal complications of Crohn’s disease

Skin abscess/ furuncle/ carbuncle

Folliculitis

Surgical treatment Drainage with/ without excision

Marsupialisation

Excision with primary closure

Excision with grafting

Sinus extraction

Sclerosing injections

ACUTE ABSCESS

-- Incision is performed lateral to midline midline over area of maximum

fluctuance

- Packing of the wound

- Marsupialisation

Problems Recurrence rates are from 20 – 55 %

During a 3 year period, 73 patients treated with I & D for first episode of pilonidal abscess

Healed : 42 patients (58%; 95% CI) within 10 weeks Recurrence : 9 patients (21%;95% CI) Follow up period : median of 60 months

Constant cure rate : 76% (CI 95%) after 18 months Prognosis after simple incision and drainage for a first-episode acute pilonidal abscess. Jensen SL, Harling H Br J Surg. 1988;75(1):60.

Chronic pilonidal sinus

Surgical approaches:- Excision- Wound closure

(1)Primary closure in midline/ off midline > Z plasty > V-Y advancement flap > Rhomboid flap (limberg)

(2) Reconstruction using flaps

Karydakis surgery Karydakis believed that hair insertion is the cause for

pilonidal sinus Low recurrence rates due to:- Wound placed away from midline- Resulting new natal cleft was shallower

Problems- Sutured taken over the presacral fascia causing pain- Patients requiring GA- Prolonged hospital stay

Modified Karydakis/Basscom II/Cleft lip Use of shallow cleft Under LA Causes less pain as presacral fascia not included

Z- plasty

Z-plasty for pilonidal sinus

V-Y Plasty

Limberg flap

Primary versus delayed closure Time to wound healing: - Total of 13 trials done (n= 1421) included data for time

for wound healing (not aggregrated due to high heterogeneity)

- 9 trials reported a faster time to wound healing following primary closure.

- Largest trial (n=380) found that patients undergoing primary repair had a significant faster wound healing rate compared to open wounds(14.5 versus 60 days)

- Excision with or without primary closure for pilonidal sinus disease.- Al-Salamah SM, Hussain MI, Mirza SM; J Pak Med Assoc. 2007 Aug;57(8):388-91.

Time to return to work: - A total of 11 trials done (n=1729)- 9 studies reported a faster return to work following

primary closure- The largest study (n=144) found that patients had a faster

return to work following primary repair compared to delayed closure.(11.9 versus 17.5 days)

Comparison of outcomes in Z-plasty and delayed healing by secondary intention of the wound after excision of the sacral pilonidal sinus: results of a randomized,

clinical trial.Fazeli MS, Adel MG, Lebaschi AH

Dis Colon Rectum. 2006 Dec;49(12):1831-6.

Recurrence rates:- Based on 16 trials including 1666 patients , the overall

recurrence rate was 6.9%.- Primary wound closure was associated with a HIGHER

recurrence rate compared to delayed wound closure. (8.7 versus 5.3 percent, relative risk RR [1.5] CI1.08-2.17

Rate of surgical site infection:- Based on 10 trials including 1231 patients

NO SIGNIFICANT DIFFERENCE between primary and delayed wound closure and risk of SSI

(8 versus 10% , RR 0.76, CI 0.54-1.08)

Off midline versus midline primary sutured closures Sutured off midline wounds – less time to heal (n=100 ,

mean difference 5.4 days, 95% CI 2.3-8.5)

Risk of SSI was significantly lower for off midline wounds (n=541, RR 0.27, CI 0.13-0.54)

Risk of recurrence LOWER for off midline wounds (n=574, RR=0.22, CI 0.11-0.43)

The overall complication rate was LOWER for off midline wounds (n=461, RR=0.23, CI0.08-0.66)

Types of off-midline closure While an off midline approach is superior , optimal off

midline approach has not been identified.

Two trials were perfomed to determine recurrence and complications rates between lateral advancement flaps ( modified Karydakis) and modified Limberg’s flap

N = 120 Karydakis lateral advancment flap

Limberg’s flap

Wound disruption 0 patients 9 patients

Rate of complications

23 % 40 %

Wound infection 3% 5%

Subcutaneous fluid collection

5% 0%

Hypoaesthesia 10% 23%

Recurrence rates 3% 2%

Comparison of short-term results between the modified Karydakis flap and the modified Limberg flap in the management of pilonidal sinus disease: a randomized controlled study.Bessa SSDis Colon Rectum. 2013;56(4):491.

N=295 Karydakis flap Limberg

Seroma formation 19.8% 7.4%

Wound dehiscence 15.4% 3.7%

Flap maceration 11% 3.7%

Which flap method should be preferred for the treatment of pilonidal sinus? A prospective randomized study.Arslan K, Said Kokcam S, Koksal H, Turan E, Atay A, Dogru OTech Coloproctol. 2013 Feb;

In summary Patients with acute pilonidal sinus – I & D

For patients with chronic pilonidal sinus – An excision of the sinus and all tracts

A primary closure is associated with faster wound healing – however a delayed closure is associated with less recurrence

For patients undergoing primary wound closure – off midline closure recommended

Role of Abx Generally limited to clinical setting of cellulitis Indications:- Immunosuppresion- High risk for Endocarditis- MRSA- Concurrent systemic illness