Dr.Barin Bose MS, FACRSI .
Surgeon , Coloproctologist and GI Endoscopist.
Jabalpur Hospital and Research Centre.
Email : firstname.lastname@example.org
In Latin pilus means hair and nidus means nest. Pilonidal sinus is
a, minor surgical condition though benign it causes much distress to
the patient. It requires a radical surgical procedure with a long stay
in hospital, discomfort and loss of earning.
It is commonly an infection in the intergluteal (natal) cleft. This
disease consists of a sinus situated a short distance behind the anus
which generally contains hairs. It is a disease of second and third
decades of life. Men are more commonly affected than women. Majority
are dark hairy subjects. Surprisingly the condition is rare in black
Africans. The condition rarely occurs in the blonds. The condition occurs
in dark haired white race persons whose hairs are stiffer than the silky
It occurs in young hairy men who have large buttocks and deep natal
cleft. Patients are less than 40 years of age and have a long sitting
occupation. It was so common among jeep drivers in 1935 to 1945 war
that it was known as "jeep bottom".
It occurs in the sacrococcygeal area in midline about 5 cms behind
the anus . Even if multiple sinus do not extend deep in the sacral fascia,
thus preventing their penetration into the bone . Loose hairs are mostly
found in the sinus hence the inflammation is a combination of an infection
and foreign body reaction. The sinus extend mostly cephaloid and branches
out laterally. Rarely it extends caudally, then it become difficult
to differentiate with anal fistula.
Aetiology : (1) Dermal theory - The pilonidal disease
is either a sequestration dermoid or implantation dermoid. The sinus
which form in the web of fingers can be explained on the basis of implantation
(2) Theory of acquired origin - Patey and Scarff in 1946 suggested
that the sinus was of acquired origin since it - (a) Recurred quite
frequently. (b) It does not contain hair follicle. The hairs are the
secondary invaders as hair is present in only half of the Pilonidal
(3) Rolling theory - Bearly suggested in 1955 that the rolling
movement which takes place between the contiguous surfaces of the buttocks
at the cleft results in hairs being detached from the skin and twisted
into bundles. This bundle of hair lying along the cleft then drills
its way through the skin. Once the skin is punctured further penetration
is helped by the suction mechanism. The separation of buttock during
sitting or bending tends to lift the skin at the base of the natal cleft
away from the underlying sacrococcygeal fascia thus creating a negative
pressure. This negative pressure tends to suck the bundles of hair deep
into the sacrococcygeal fascia.
Presentation - The symptoms are due to inflammation in the sinus.
Pain swelling and pus discharge is the usual symptoms.
¢ Patient present with acute abscess usually single.
¢ Chronic Pilonidal sinus presents with continuous or intermittent
pus discharge or nonhealing midline ulcer with or without pain.
Condition resembles a foreign body granuloma since the tract is lined
by granulation tissue.
Diagnosis - It occurs in young hairy adult male , who have large
buttocks and a deep nalat clift. The affected area is soft oily skin
which is lacking in good hygiene.
Differential Diagnosis - It is to be differentiated from -
¢ Anal fistula.
¢ Hidradenitis suppurate.
Squamous cell carcinoma and basal cell carcinoma have been reported
in the sinus tract.
The sinus extends upwards and forwards but do not reach the bone. It
ends blindly before reaching the bone. It mostly occurs in the midline
in sacrococcygeal area, about 5 cms from anus.
Other sites of the disease are -
¢ Finger web.
¢ Suprapubic region.
¢ Anal canal.
Conservative Treatment: Patients reporting for the first time
with mild symptoms can be cured by conservative treatment. It consists
of cleaning of the tract and removing all hairs from the area. Washing
the area with detergent and water and then applying witch hazel and
alcohol in equal parts. Long sitting and driving is avoided. Depilation
of hair, frequent sitz bath, keeping the area dry. Injection of Phenol
is tried in early sinus with one or two openings or recurrence after
Operative Procedures - It should be performed when inflammation
has been controlled by antibiotics. Patient has been placed in prone
jack knife position. Methylene blue is injected into the sinus to color
all the tracts. Then following can be done -
(1) Lay open the tract, remove all the debris and hairs, then suturing
the edges of the tract with the skin , thus marsupalising the tract.
(2) Excise all the tract as stained by blue dye. Secure good haemostasis
by diathermy and sutures. Then close the subcutaneous tissue and skin
after keeping a Romovac drain for 48 hours.
(3) Excise all the tract as stained by blue dye.Secure good haemostasis
by diathermy and sutures. The wound is packed and dressed ,following
day the whole dressing and pack is removed and then daily dressing is
done till the wound heals by granulation tissue . Ensuring that the
wound heals from below. Epithelialisation can be speeded up by skin
grafting. Cure rate is high if re entry of the hair is prevented. Chronic
Pilonidal sinus is treated keeping in mind the high rate of failure
(4) Excision - Conservative excision - A midline elliptical incision
is made to include all the sinus and whole of the tract is excised.
(5) Wide radical excision - Is done in an assumption that this was the
only way to prevent recurrence, though it was not always necessary.
The wound may be left open for secondary healing.
To accelerate healing the following procedure is done -
¢ Primary closure - Straight midline closure or Z - plasty.
¢ Partial closure or secondary closure.
¢ Skin grafting .
Other Operative Techniques - (1) Excision of coccyx to reduce suture
(2) Skin flap advancement to obliterate the natal cleft
(3) Excision of sinus with Z plasty.
(4)Gluteus maximum myocutaneous flap.
(5)Karydakis Technique- The sinus is excised by an eccentric
elliptical incision. A flap is mobilized from the medial side of the
wound. Sound closure is to one side of the midline.
(6) Bascom's Technique- An incision 2-3cms lateral and parallel to the
midline is made and the chronic abscess cavity is drained, freed of
the hairs, granulation tissue is curetted. Removal of small midline
pits is carried out by a small elliptical incision. The lateral wounds
are kept open but the midline wound is closed.
(7)Excision and direct closure- the complete tract with its extension
is excised and the cavity is closed with primary sutures. Primary closure
with midline scar is associated with recurrence rate of 18%. Where as
it is less than 10% when the scar is displaced from the midline.
(8) Bascom's cleft closure Technique- this is used for open midline
wounds after failure of surgery. After debridement of the abscess cavity.
A full thickness skin flap is excised and advanced (rotated) across
the midline to obliterate the natal cleft .
(9) Rhomboid flap Technique- The Pilonidal sinus is excised and a rhomboid
flap of skin taken from the adjoining gluteal area is rotated into the
resultant defect and completed with primary closure. Disadvantage of
this technique is -- (a) blood loss
(b) Flap necrosis (c) Numbness over the flap.
(10) Excision and Saucerisation Technique- The sinus is excised widely
and the raw area is left to granulate from the depth and to obliterate
the cavity with long healing process.
(a) Long healing process
(b) Long hospital stay of patient.
(c) Persistent nonhealing midline wound.
(d) Wide excision of all the tissue till the sacrum and leaving the
wound open to granulate can never be justified.
(11) Marsupialisation- The wound is partially closed by suturing the
skin edges to the sacral fascia.
(12) D- Excision Technique - The sinus is excised enblock up to the
sacral fascia through a D shaped incision. The flaps are undermined
and approximated without any tension.
(13) Using Gluteal muscle myocutaneous flap - It is a complex produce
and is used rarely. It produces reliable healing with low recurrence,
but requires prolonged hospital stay and is more technically demanding.
Loss of such a flap can be a serious complication.
(14) Multiple Z-Plasty Technique - By Dr. Predeep P Sharma . Pune (vide
Indian Journel of Coloproctology Vol. 19, 2004 , P.3 to 8 ) Under local
anaesthesia and sedation with Medazolam. The patient is kept prone in
a Jack knife position with a pillow under the belly to raise the hips.The
buttock were strapped with sticking plaster to keep them apart and expose
the operative area. The operative area was shaved just before the surgery
and suitably painted and drapped. Methylene blue was injected through
the mouth of the sinus to stain the entire tract, to enable complete
excision of the tract. The area was infiltrated with 2% xylocaine and
adrenaline. The mouth of the sinus or the sinuses along with all the
congenital pits are encircled with an elliptical incision and the tract
is cored out .The congenital pits are encircled and cored out as these
pit are the precursor of the sinus. The sinuses are cored out completely,
taking care not to enter the tract at any time. A complete excision
of the diseased tissue is the key to the success of the operation .Haemostasis
is achieved by a bipolar cautry. Skin hooks are applied at either end
of the wound and traction is applied, cuts are marked on the skin. The
number of cuts depend on the length of the wound from 1 to 5 cuts are
deepened till the subcutaneous fat. The flaps are undermined and mobilized.
Extensive undermining is avoided to prevent devascularising of the flaps,
the flaps are suitably interdigited and sutured. Subcutaneous sutures
are applied with Vicryl 4-0 and skin sutures are applied with 5-0 Nylon,
interrupted sutures. Drain is avoided if the haemostasis is good. But
a Redivac drain is used if the situation demands . A haematoma in the
absence of the drain would lead to breakdown of the wound causing relapse.
Healex spray is applied to prevent contamination.
Post Operative Care - The patient is put on liquid diet for
3 to 4 days bowel movement is discouraged till then patient is nursed
in a prone position for first few days , then gradually moved out of
bed. Sitting on the bed is discouraged for 15 days. Patient is discharged
on 5th day. Sutures are removed on the 10th day. Followup is done on
7th and 15th day. Then monthly for three months and three monthly for
Advantages of Multiple Z-Plasty over single Z-Plasty -
¢ It requires less undermining.
¢ It is done under local anaesthesia.
¢ Blood loss is less.
¢ No necrosis of the flaps.
¢ Absence of numbness of flap which is common with single Z-plasty.
¢ Cosmetic effect is better as the scar does not extend to the
¢ The side tracts are easily excised as one of the limbs of Multiple
Z-plasty. In single Z-plasty it would require a wider ellipse to encompass
the side tracts, which would later cause tension on the wound closure.
After Care - The operative area need regular cleaning with soap
and water even after the wound has healed, the area should be regularly
scrubbed with soap and washed with water to wash away loose hairs. The
surroundings should be kept free of hairs by regular shaving.
Cause of Recurrent Pilonidal Sinus -
(1) A diverticulum of the main channel which has been overlooked at
the time of primary operation.
(2) New hairs enter the sinus or scar.
(3) When the natal cleft is deformed by scarring. A least trauma causes
tearing of the scar. The ulcer thus formed become contaminated with