Original article

The rhomboid flap for pilonidal disease

P. J. Arumugam, T. V. Chandrasekaran, A. R. Morgan, J. Beynon and N. D. Carr

Colorectal Unit, Singleton Hospital, Swansea, UK

Received 11 March 2002; accepted 22 July 2002

Abstract

Introduction There have been many surgical tech-

niques described for the treatment of pilonidal sinuses.

Recurrent disease causes significant morbidity particularly

with time from work.

Aim To assess the rhomboid flap’s role in promoting

one-stage primary healing in pilonidal disease and to

evaluate the morbidity and recurrence.

Methods Fifty-three patients were prospectively recrui-

ted of which 27 had previous multiple abscess formation

requiring surgical drainage from their pilonidal disease,

although none had acute disease at the time of surgery.

By using the transposition flap, we were able to obliterate

the natal cleft and therefore the rolling action of the

buttocks between the cleft in these patients and thereby

remove one of the factors involved in pilonidal disease.

Hospital stay, healing time, wound infection, wound

breakdown and recurrence were noted.

Results There were 47 males and 6 females with a

median age of 28 years (range 16–64 years). Median

follow-up was 24 months (range 3–36 months). Post-

operative morbidity involved superficial wound infection

in 7 (13%) which settled with out-patient dressings.

There were four recurrences (7%), two occurred

between the flap and the anal canal, and the other

two in the flap margin needing intervention. All the

patients healed their wounds and the median healing

time was 14 days.

Conclusion As this condition affects a predominantly

young population causing significant time off from work,

we feel that the Rhomboid Flap is useful for difficult cases

in that it allows early return to full activity and does not

necessitate prolonged postoperative care.

Keywords Rhomboid flap, pilonidal sinus, recurrence,

natal cleft

Introduction

Pilonidal sinus is a common condition affecting males

predominantly and can lead to considerable discomfort

and morbidity. Various surgical techniques have been

described but none of them are considered as gold

standard. The deep natal crease is prone to the collection

of loose hairs, sweaty and sebaceous maceration, bacterial

contamination and internal friction. Recurrence is a major

problem in 60% of patients treated with conventional

techniques like incision and drainage, excision, marsupi-

alization and primary skin grafting.

Anderson (1847) and Mason (1854) originally repor-

ted this condition while Hodges (1880) suggested the

term pilonidal sinus. Little progress has been made since

then to treat this condition effectively.

At present surgery aims to obliterate the natal cleft and

thereby the rolling action of the buttocks. Karydakis [1]

described a technique of asymmetric closure with excel-

lent results. Recently ambulatory surgical treatments have

come into vogue including Bascom’s operation per-

formed under local anaesthesia. Transposition flaps

have been described which effectively obliterate the

crease and thereby neutralize the causal factors, which

lead on to a vicious cycle of infection and recurrence.

The purpose of the present study is two fold: first to

assess the effectiveness of a rhomboid transposition flap in

the promotion of one stage primary healing after excision

of pilonidal sinus and second to assess associated

morbidity and recurrence.

Patients and methods

Fifty-three consecutive patients were prospectively

recruited. Of these, 50% had undergone prior incision

and drainage and 50% had been treated with antibiotics.

None had acute sepsis at the time of rhomboidal flap

Presented as a poster in European tissue repair society annual conference,

Cardiff September 2001.

Correspondence to: Mr N. D. Carr, Consultant Surgeon, Singleton Hospital,

Sketty, Swansea SA2 8QA, UK.

E-mail: ndcarr@hotmail.com

218 � 2003 Blackwell Publishing Ltd. Colorectal Disease, 5, 218–221

surgery. Patients were counselled about the size and

shape of the scar and the healing rates.

Technique

With the patient under general anaesthetic and in the

prone position, the operative field was draped. All

patients received cefuroxime 1 g IV and metronidazole

500 mg at induction and orally for the next three days.

The area to be excised (ABCD) is marked on the skin

(Fig. 1) with the axis AC being along the natal cleft, with

the anus below C. Lines CD and BD are then extended

and the angle thus formed, is bisected by lines having the

same length as any one side of the rhomboid (thus

AB ¼ BC ¼ CD ¼ AD ¼ DE). Line EF is then drawn

parallel to the long axis, AC.

The sinus ABCD, (Fig. 2) is excised down to the

sacrococcygeal fascia centrally and the gluteal fascia later-

ally with haemostasis secured with diathermy. The rhom-

boid flap (CDEF, Fig. 3) is mobilized from the gluteal

fascia and sutured without tension, with interrupted

mattress sutures (Fig. 4). A suction drain is inserted.

Postoperative care

Patients are advised to lie on the lateral side until the

wound is healed. The dressing is changed on the first

postoperative day and the patients are usually discharged

on the fourth day, with advice on the importance of

regular shaving of the buttocks and hygienic measures.

The sutures were removed on the tenth postoperative

day.

Results

There were 47 males and 6 females with a median age of

28 years (range 16–64). The duration of hospital stay was

A

B

C

D

E

F

Figure 1 Configuration of the rhomboid flap (see text).

Figure 2 Flap marked on the skin and wide excision of the

sinuses.

Figure 3 Flap being transposed to flatten the natal cleft.

Figure 4 Completed flap with sutures in place.

P. J. Arumugam et al. Rhomboid flap for pilonidal disease

� 2003 Blackwell Publishing Ltd. Colorectal Disease, 5, 218–221 219

3 to 10 days (median 4 days) and the median follow up

was 24 months (range 3–36 months). Primary healing

occurred in 37 patients when reviewed at the time of

suture removal on the tenth day. Seven (13%) patients

developed superficial separation of the wound that settled

with subsequent dressings. A further 5 (10%) patients had

a breakdown of the wound, of these two needed

resuturing under local anaesthetic and the rest settled

with dressings. All the patients who had minor wound

problems healed within 18 days from the time of surgery.

The median healing time overall, excluding recurrence,

was14 days. There was no flap necrosis.

Of 53 patients, 4 (7%) developed a recurrence, two

between the flap and the anal canal and two in the flap

margin. Three patients who developed recurrence were

managed by further excision and primary suturing and

another patient needed incision and drainage with

packing for the wound. All the patients in our study

eventually healed their wounds. The median time off

work was 28 days.

Discussion

Pilonidal sinus predominantly affects the 20–30 years age

group. The average amount of time lost from work is

some 13 weeks of which 6–7 weeks are spent recovering

from an operation designed to cure the condition [2].

There is a high recurrence rate in most published

series irrespective of the procedure. Edwards [3] has

reported a 46% recurrence rate for excision and healing by

secondary intention and a 38% recurrence rate is quoted

for excision and primary closure [2]. Reported healing

time is in the range of 4–12 weeks [4].

Bose and Candy [5] suggested that the predisposing

factors for pilonidal sinus are the deep natal cleft and

the rolling action of the buttocks. Flattening the natal

cleft was proposed to prevent the macerating action

induced by rolling the buttocks while walking. Hence

techniques which involved the obliteration of the deep

natal cleft, such as Z-plasty, rhomboid flaps and

primary skin grafting [6], have been developed.

Z-Plasty involves transposing two triangular flaps with

narrow apices but flap tip necrosis was reported in 20%

of cases [5] and primary skin grafting has not stood the

test of time.

The rhomboid flap technique is easy to reproduce [7].

Published series have been promising with some authors

quoting recurrence rates of less than 5% [7,8], such low

rates may have been due to inadequate follow up but

similar results have been obtained in the present series in

which patients have been followed for up to two years. Of

these, 50% had furthermore had a previous incision and

drainage, some more than twice. Some patients were

referred for further management since previous proce-

dures had failed. This may explain the marginally higher

rate of recurrence (7%) noted in our series.

Akinci et al. [9] have reported infection and recur-

rence rates of 5% and 1% after asymmetric excision

and primary closure. There were, however, few patients

who had previous operative procedures in this series. A

randomised trial [10] comparing the rhomboid flap and

the deep suturing techniques showed higher healing rates

and a lower recurrence rate for the former. Our rates of

healing and superficial wound infections are comparable

with this study.

The Bascom procedure [11] has been advocated with

the advantage that it can be done as a day-case procedure.

A recurrence rate of 10% and a mean healing time of

4 weeks has been reported. Although a more extensive

procedure, the rhomboid flap technique would appear to

have the advantage of earlier healing.

Conclusion

The surgeon should be familiar with the various options

available and should be prepared to use the one with

which he or she is comfortable, since none of the

procedures is perfect. Rhomboid flap heals cleanly and

rapidly by primary healing, and it should be the operation

of choice for recurrences. It may be used primarily in new

non-infected cases. It is easily learnt and reproducible and

is a valuable asset in a general ⁄ colorectal surgeon’s

armamentarium for management of this difficult condi-

tion.

Acknowledgement

We acknowledge Mr S. Kurrimbaccous’ contribution to

this study.

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� 2003 Blackwell Publishing Ltd. Colorectal Disease, 5, 218–221 221