Excision and Primary Closure Using the Karydakis Flapfor the Treatment of Pilonidal Disease: Outcomes from a SingleInstitution

D. C. Moran • D. O. Kavanagh • I. Adhmed •

M. C. Regan

Published online: 7 May 2011

� Societe Internationale de Chirurgie 2011

Abstract

Background Chronic pilonidal disease is a debilitating

condition that typically affects young adults. There is a

wide variety of available therapeutic strategies reflecting

the inconsistent outcomes attributed to the various opera-

tive approaches. The majority involve excision of the sinus

tract followed by either primary closure or healing by

secondary intention. A variety of closure approaches exist.

There remains uncertainty as to which is more effective.

The aim of the current study was to determine subjective

and objective outcomes following excision and Karydakis

flap closure in a unit where this technique is the standard of

care in the management of chronic pilonidal disease.

Methods This study involving consecutive patients with

chronic pilonidal disease was conducted over a 4-year

period. A tailored patient satisfaction questionnaire was

given to each patient. Postoperative primary and secondary

outcomes were evaluated. The mean follow-up time was

30 months.

Results One hundred six consecutive patients (33 female,

73 male) underwent excision and primary closure using the

Karydakis flap. Ninety-two completed questionnaires were

returned (87% response rate). Patients consulted their

general practitioner 2.8 times (mean) and 46% received

empirical oral antimicrobial therapy prior to referral for a

surgical opinion. The mean time lost to work/school fol-

lowing the Karydakis flap repair was 13 days (range 3–33).

Successful treatment was achieved in 96.3% of cases and

92% of patients were satisfied with their operative result.

Conclusion Excision and primary closure with Karydakis

flap is an effective treatment for chronic pilonidal disease.

It is associated with low morbidity, early return to pre-

morbid functioning, and a high degree of patient satisfac-

tion (92%).

Introduction

A pilonidal sinus arises as a result of inward motion of

hair follicles into the natal cleft overlying the sacrococ-

cygeal bone. It may form a localised abscess which drains

via a sinus tract. It was first described in medical litera-

ture in 1833 by Herbert Mayo [1]. The term was coined

from the Greek words ‘‘pilus’’ meaning hair and ‘‘nidus’’

meaning nest. It is a common disease with an estimated

incidence of 26 per 100,000 [2]. The condition is more

common in men with a 3:1 ratio. The mean age of onset is

21 years in males and 19 in females. It rarely occurs

before puberty or after the third decade. Identified risk

factors for the development of pilonidal disease include

sedentary occupation, positive family history, hirsutism,

obesity, and local irritation or trauma prior to the onset of

symptoms [3, 4].

Pilonidal disease presents as an acute painful abscess

(approximately 20%) or a chronically discharging sinus

tract. Many theories have been advanced regarding why

it affects some individuals and not others and why it

presents acutely in some and as a chronic condition in

others but currently there is no published experimental

work to definitively support one specific hypothesis.

Regardless of the aetiology, pilonidal disease is a

debilitating condition with significant associated pain,

morbidity, and loss of earnings and school absenteeism.

Although symptoms can be controlled nonoperatively

D. C. Moran (&) � D. O. Kavanagh � I. Adhmed � M. C. Regan

Department of General Surgery, University College Hospital

Galway, University Road, Newcastle, Galway, Ireland

e-mail: morandiarmaid@gmail.com

123

World J Surg (2011) 35:1803–1808

DOI 10.1007/s00268-011-1138-z

[5], surgery is required for definitive treatment. There

are a number of operative approaches that can be

broadly classified as those involving primary closure and

those where the wound is left open and allowed to heal

by secondary intention. Primary closure can be further

subdivided into midline or off-midline closure. McCal-

lum et al. [6] analysed 18 trials encompassing 1,573

patients and found that following surgery, closed

wounds primarily healed quicker than those left to heal

by secondary intention. However, primary closure was

shown to be associated with a higher recurrence rate

when compared to open healing [11.7% (primary clo-

sure) vs. 4.5% (secondary healing)]. Furthermore, off-

midlines closure had better outcomes than midline

closures.

No single treatment of chronic pilonidal disease is

completely satisfactory. This is reflected in the large vari-

ety of techniques and approaches that are currently avail-

able. Ideally, a procedure to definitively treat chronic

pilonidal sinus should be easy to perform, involve a short

inpatient stay, have a low recurrence rate, and have mini-

mal pain and wound care. It should also be cost effective.

No technique fulfils all of these criteria. Many different

types of approaches exist, ranging from marsupialisation of

the wound edges to the use of rotational flaps to cover the

wound defect as well as less widely used interventions

such as phenol injections to obliterate the sinus tracts.

Intuitively, leaving a wound open minimises the need for

reintervention and antimicrobial therapy but these positive

features must be offset against the inconvenience and cost

of daily dressings as well as time spent at daily dressing

clinics for a prolonged period of time.

The Karydakis flap was first described by George

Karydakis [7]. It involves an eccentric excision of vul-

nerable midline tissue and then lateral displacement of the

wound out of the natal cleft. In a series of 7,471 patients

over a 21-year period, a recurrence rate of 1% and a

morbidity rate of 8.5% were reported [8]. In the current

series we document our experience with consecutive

patients who underwent a Karydakis flap for the treatment

of chronic pilonidal disease. Apart from data relating to

inpatient stay and work/school absenteeism, there is a

deficit of information relating to the impact of therapies on

patient satisfaction and perception of post-treatment well-

being. While Armstrong et al. [5] showed significantly

better outcomes with depilation compared to surgical

intervention, they did not examine patient quality of life.

We examined patient satisfaction following Karydakis flap

closure of chronic pilonidal disease.

The aim of our study was to examine subjective and

objective outcomes following Karydakis flap formation in

a unit where this technique is the preferred treatment for

chronic pilonidal disease.

Materials and methods

Operative technique

All patients included in this study were admitted electively

on the morning of their surgery. The procedure is carried

out in the prone, jack-knife position under general anaes-

thesia with the buttocks taped apart to expose the natal

cleft. Intravenous co-amoxiclav (1.2 g) is administered at

induction of anaesthesia. Meticulous depilation of the

affected area and surrounding normal tissue is undertaken.

Using a variety of probes, the anatomy of the sinus cavity

and tracts are delineated. A curve-linear incision is made

and expanded in an elliptical fashion in order to excise the

sinus tracts and cavity as identified (Fig. 1a). Meticulous

haemostasis is essential. A flap is then created by under-

mining the contralateral side and advancing this across the

midline (Fig. 1b). Tension sutures are put in place before

an off-midline multilayer closure (therefore obliterating the

natal cleft) with interrupted 3/0 polypropylene sutures.

The flap is completed with 3/0 nylon interrupted vertical

mattress sutures. A simple adhesive dressing is applied

(Mepore�, Molnlycke Health Care) which the patient can

change. Drains are not routinely employed. Patients are

usually discharged within 24 h of surgery with simple oral

analgesia. A 5-day course of broad-spectrum oral antibi-

otics is prescribed (co-amoxiclav). Daily showering is

recommended from 48 h postoperatively. Patients are

advised to sit in a reclined position and to avoid lying

supine (on their buttocks) as much as possible. All patients

are reviewed in the surgical outpatient clinic within

Fig. 1 a Schematic illustration of the technique of excision and

raising of the flap. b Schematic illustration of the off-midline closure

of the defect

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2 weeks of discharge where the wound is inspected and

sutures removed if appropriate.

Patients

A prospective consecutive series was followed over a

4-year period. It encompassed 106 consecutive patients

with chronic pilonidal disease who underwent excision and

primary closure using the Karydakis flap. Mean follow-up

time was 30 months (range 12–60). Sixty-five patients

were referred to the surgical outpatient clinic by their

general practitioner with symptoms and signs of a chronic

discharging sinus. Twenty-six patients had been treated

(incision and drainage) for a pilonidal abscess by the sur-

gical team with the decision to excise the sinus tract made

at follow-up outpatient visits. Fifteen patients with a

chronic sinus were referred from other sources.

Primary outcomes measured included complete wound

healing without recurrence and the rate of surgical site

infection (SSI). A SSI is defined as a wound with clinical

features of infection (erythema, wound breakdown, mac-

eration, and discharge) with a positive bacteriological swab

that required prolonged (over 5 days) antimicrobial treat-

ment or removal of sutures to drain the underlying infec-

tion. Secondary outcomes included length of hospital stay,

requirement for dressings, postoperative pain, and any

other postoperative morbidity. Postoperative pain was

measured the morning after the surgery before the patient

was discharged. This measurement was based on a visual

pain scale where 0 reflects absence of pain and 10 refers to

the maximum pain that one could imagine. In order to

address postoperative satisfaction, a tailored patient ques-

tionnaire (Fig. 2) was given to each patient at the 2-week

outpatient follow-up and again at the 3-month follow-up.

This questionnaire focused on presenting symptoms,

medical treatments sought, antibiotic treatments taken, and

previous surgical interventions. Data regarding time to

resumption of normal activity and overall patient satis-

faction were also recorded. If a patient delayed/failed to

return the questionnaire, a telephone call was made by the

authors to the patient after 6 weeks. During this time period

there were no patients attending the outpatient clinic who

pursued a nonoperative approach.

Results

Demographics

One hundred six consecutive patients were included in the

study. The mean follow-up was 30 months (range 12–60).

There were 73 males and 33 females. The mean age was

25 years (range 17–53) for males and 21 years (range

18–27) for females. Of the 106 patient questionnaires

administered, 92 (87%) were returned.

Primary-care management

Twenty-six patients presented acutely with an abscess

requiring emergent incision and drainage with subsequent

referral to our service for definitive management. Of those

patients who did not present acutely, the major presenting

features included pain, pruritus, serosanguinous discharge,

limitation of movement, and difficulty sitting down.

Patients visited their primary-care physician an average of

2.8 times (range 1–7) before being referred for surgical

evaluation. Of those who visited their primary-care phy-

sician, 46% received empirical antimicrobial treatment.

In this group the mean number of antibiotic courses pre-

scribed was three (range = 1–5). The mean duration of

each course of antimicrobial treatment was 7 days (range

4–12). The mean time from first medical consultation

(primary-care physician) to surgical review was 188 days

(median 194, range 48–552). The mean time from surgical

referral to being assessed by the surgical team was 53 days

(median 41, range 16–332).

Primary outcomes

In 89% of the cases, excision and primary closure with a

Karydakis flap carried out by the authors represented the

first definitive surgical intervention after incision and

drainage. Twelve patients had previous surgical interven-

tion at other institutions before referral to our institute

following disease recurrence. These patients previously

underwent laying open (n = 8) or excision/marsupialisa-

tion (n = 4). Postoperatively, all patients in the study were

discharged within 24 h of having their surgery.

Primary operative success (complete wound healing

without recurrence) was achieved in 96.3%. Four (3.7%)

patients had a recurrence. Two of the recurrences presented

as an acute abscess. One presented at day 37 and the other

at day 45 postoperatively. Both of these were treated ini-

tially with incision and drainage and subsequently had

excision of the sinus tract and marsupialisation of the

wound edges. The two remaining recurrences presented

with recurrent chronic draining sinuses. One presented at

day 98 and the other at day 121 postoperatively. Both cases

were laid open and allowed to heal by secondary intention.

All four recurrences healed and remain asymptomatic.

There were no features specific to these cases which pre-

dicted a less favourable outcome.

Postoperative drains were not used and there were no

recorded instances of postoperative bleeding. Postoperative

pain was measured the morning after surgery before the

patient was discharged. The mean pain score prior to

World J Surg (2011) 35:1803–1808 1805

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discharge was 4.5 (range 1–10). This pain was treated with

oral analgesia and on average took 5.6 days (range 1–28) to

be relieved. Postoperatively, there were six SSIs, which

were identified at an outpatient setting and all occurred

within 2 weeks of surgery. These were not the four cases

that ultimately recurred. All were successfully treated with

oral antimicrobial therapy and in no case was further sur-

gical intervention or hospital admission required.

Postoperatively, the mean time (days) to resumption of

normal activity (return to school/work) was 13.6 days

(range 3–33). Other than simple dressings that could be

applied by the patient him/herself, no other dressings or

outpatient wound care was required in the postoperative

period. Overall patient satisfaction with the procedure was

92% as outlined in Table 1.

Discussion

Pilonidal disease is a common condition that predomi-

nantly affects young adults. It is a debilitating disorder

which carries significant morbidity. It often disrupts normal

activity and may result in lost school/work time. Treatment

of chronic pilonidal disease is highly variable and often

unsatisfactory. Treatment options range from excision/

laying open/marsupialisation to excision and primary

PPOOSSTTOOPPEERRAATTIIVVEE PPAATTIIEENNTT SSAATTIISSFFAACCTTIIOONN QQUUEESSTTIIOONNNNAAIIRREEName:........................... Hospital Number: ...... Date of completion:.............

1. Prior to surgery, how long did you have the pilonidal sinus?

2. When was your pilonidal sinus first diagnosed? (approx date)

3. How often did you have to seek medical advice and who did you seek advice from?• GP• A&E• Hospital Clinic

4. Did you ever have antibiotic treatment of your pilonidal sinus? Yes / NoIf yes, who prescribed these and how many courses and for all long did you take these antibiotics?

5. Can you describe the sort of problems that you were having from your pilonidal sinus prior to having surgery?

6. When did you have your pilonidal sinus repair? Approximately what date?

7. Was this your first surgical repair or had you previous operations? If so please give details of the hospital, type of surgery and the approximate date of that operation.

8. Please tick one of the following regarding your opinion on the following statement “I am currently pleased with the outcome of my operation”

Strongly agreeAgreeNeither agree nor disagreeDisagreeStrongly disagree

9. How much time did you loose from work/school/college prior to having your operation?

10. After how long following your operation did you return to normal activities (i.e return to work/school or college)?

11. How long (days) did it take for your pain to settle after your operation?

12. Were dressings required post operatively? If so, for how long?

13. Did you have any post-operative ‘wound healing problems?

14. Do you have any residual problems / issues regarding your surgery?

Fig. 2 Postoperative patient

satisfaction questionnaire

1806 World J Surg (2011) 35:1803–1808

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closure, which may be midline or off-midline. Currently

there is no ‘‘ideal’’ treatment available. The ‘‘ideal’’ treat-

ment should satisfy the criteria of providing a quick cure,

allowing a rapid return to normal activity, and result in a

low recurrence and morbidity rate. With these issues in

mind, we examined our data on patients who underwent

excision and primary closure with a Karydakis flap.

We evaluated defined primary and secondary outcomes and

assessed postoperative satisfaction in 106 consecutive

patients.

Data published by McCallum et al. [6], which examined

18 trials and more than 1,500 patients, suggested that exci-

sion and laying open of the surgical wound is associated

with a recurrence rate of 4.5%. However, wound healing

(full epithelialisation of the wound) in this group was pro-

longed and the process took from 41 to 91 days [9, 10].

Primary closure has been shown to have a recurrence rate

ranging from 1.4 to 100% [11]. Wound-healing time is

unsurprisingly reduced in these patients to between 10 and

30 days. Analysis of our data regarding the treatment of

chronic pilonidal disease by excision and an off-midline

closure with the Karydakis flap reveals a complete cure rate

of 96.7%. There were four recurrences, all of which needed

a second surgical intervention. Surgical site infection

occurred in 6 (5.6%) patients, none of whom required fur-

ther surgical intervention. These results compare favourably

with other published series. All patients were discharged

from hospital within 24 h of their operation and required no

outpatient wound care other than simple adhesive dressings

which could be applied by the patient. The procedure pos-

sibly can be performed as a day case, with patients in one

study discharged within 4 h of surgery [12]. However,

operational restrictions and demands on our surgical work-

load as well as optimal postoperative patient comfort means

that in our institution it is preferable that patients stay

overnight after their procedure. The mean postoperative pain

score (as evaluated using a visual pain score) prior to dis-

charge was 4.5 (range 1–10). Resolution of pain was

observed at a mean of 5.6 days (range 1–28) following

treatment with oral analgesia. Postoperatively all patients

receive a 5-day course of broad-spectrum oral antibiotics.

This practice has been shown to significantly reduce the rate

of surgical site infection [13], though it has been disputed in

other published studies [14].

Patients resumed normal activities within 2 weeks of

their operation (mean 13.6 days, range 3–33). Time to

resumption of normal activity is an important outcome

parameter as pilonidal disease is a condition that most often

affects young adults. In this patient cohort, time lost from

work/school may pose significant long-term difficulties in

terms of educational opportunities and earning ability.

Direct health-care and indirect economic costs through

absenteeism may be high. Overall patient satisfaction rate

following surgery was favourable at 92%. We acknowl-

edge that the questionnaire used in this study has not been

internationally validated. However, there is little published

evidence regarding postoperative patient satisfaction fol-

lowing other techniques and approaches for the treatment

of chronic pilonidal disease. This questionnaire was care-

fully constructed to address these relevant issues. Simi-

larly, our patients were not compared to a control group

treated by laying open and healing by secondary intention.

Intuitively, the added costs of daily dressings and work

absenteeism for appointments at dressing clinics would far

outweigh the cost related to early enforced absenteeism

from work in the immediate postoperative period.

The Karydakis flap procedure, developed by the Greek

surgeon George Karydakis, first appeared in medical lit-

erature in 1973 [7]. Karydakis published the largest series

in the literature (6,545 patients over 20 years) in 1992 in

which a recurrence rate of 1% was reported [8]. He argued

for a technique that would treat the presenting condition

and prevent recurrence. Since then other authors have

reported their experience with this flap, including Kitchen

[15] who reported on 141 patients (of whom 108 had this

procedure as a primary treatment) with a 4% recurrence

rate. He did not quantify the impact of this on the patients’

lifestyle.

On review of the patient questionnaire data (Table 2),

those patients who did not present with an acute

abscess requiring incision/drainage (n = 66) attended their

Table 1 Patient satisfaction in response to the following statement:

I am currently pleased with the outcome of my operation

Patient satisfaction % of patients

Strongly agree 72

Agree 20

Neither agree or disagree 7

Disagree 1

Strongly disagree 0

Table 2 Outcome of patient questionnaire

N (range)

Mean duration of symptoms prior to referral for

specialist review (days)

22 (2–54)

Mean duration of time from referral to review at a

specialist clinic (days)

53 (16–332)

Mean number of appointments at nonspecialist clinics 2.8 (1–7)

Mean number of antibiotic courses 3 (1–5)

Mean duration of antibiotic course (days) 7 (4–12)

Mean duration of absenteeism prior to surgery (days) 16 (0–45)

Mean duration of absenteeism following surgery (days) 13 (3–33)

Mean duration of pain following surgery (days) 4 (0–28)

World J Surg (2011) 35:1803–1808 1807

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primary-care physician on average 2.8 times before referral

to our surgical service. Thirty patients (46%) received

antibiotic treatment for their symptoms. This suggests

delayed recognition of the condition and delayed referral

by primary-care physicians which may prolong patient

symptoms. As a result of these findings, our department has

undertaken a series of measures to improve understanding

of this condition amongst general practitioners within our

catchment region. This study has also allowed us to iden-

tify those patients who have encountered prolonged wait-

ing times from referral to assessment. As a surgical unit

that has developed a focused interest in the treatment of

pilonidal disease, we now aim to assess these patients who

are referred within a 4-week period.

This study is limited by its small patient cohort. Though

one published study [16] suggested that this technique may

be feasible in the emergency setting, we do not use the

Karydakis flap to treat an acute pilonidal abscess as it

defies surgical common practice [17]. Therefore, in the

setting of an acute abscess two separate surgical interven-

tions are required. We have not examined the incidence of

complete healing that does not require any further surgical

intervention after incision and drainage of an acute abscess.

However, reports from the literature would suggest this

incidence of recurrence is as high as 70% if left untreated.

Healing time is also prolonged in these patients.

Conclusion

Pilonidal disease is a common condition that is associated

with considerable distress to patients. There appears to be a

protracted management algorithm in the primary-care set-

ting which may in part reflect difficulty in accessing sur-

gical services. This delay prolongs symptoms and may

involve futile antimicrobial therapy. Excision of the pilo-

nidal sinus and subsequent off-midline primary closure

with a Karydakis flap is associated with favourable surgical

outcomes (96.7% cure rate), a low recurrence rate, an early

return to normal activity, and a high degree of patient

satisfaction (92%).

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