strong evidence shows that pilonidal disease originates in the epidermis , in a midline stretched hair follicle .
early pilonidal changes are amplified due to deep tissue disruption from moisture , anaerobic conditions , hairs , and bacteria . on the basis of these observations ,
a new paradigm of origin emerges that pilonidal disease is exclusively an epidermal problem , rather than a deep tissue problem , which is the theory behind current recommendations for wide excision [ 2 , 3 ] .
therefore , the focus of treatment should be actions to change the conditions that attack epidermis , rather than wide excision which attacks deep and healable tissue .
the most difficult complication that may follow surgery for pilonidal disease is a persistent unhealed midline wound , most commonly seen after laying open or excision of primary disease .
although the authors are familiar with all procedures , karydakis and z - plasty procedures are among the common procedures done currently , so they were chosen in the study .
karydakis procedure is basically a gluteal advancement flap . unlike other flap procedures ( i.e. , rhomboid flap , z - plasty , and gluteal rotation flap ) which are fasciocutaneous ,
karydakis flap is adipocutaneous flap ; it is , therefore , technically easier , less bloody , and less time consuming ; it obviously has a better cosmetic outcome as it leaves a single , lateral , longitudinal scar ; and it requires significantly shorter hospital stay .
the present study was done to study karydakis flap reconstruction as a treatment of symptomatic pilonidal sinus disease and to compare karydakis flap reconstruction and double z - plasty as a treatment of symptomatic pilonidal sinus disease .
with proper ethical permission , a prospective randomized trial was conducted on 50 cases of symptomatic or recurrent pilonidal sinuses reported in outpatient department of j.l.n .
the sample size is decided according to the past experience of cases of pilonidal sinuses and local guidelines .
the cases are randomized on the basis of hospital registration number by the initial screening personnel who did not get involved in operative part .
after proper preoperative workup and antibiotic prophylaxis , first group ( gp 1 ) undergoes wide excision with karydakis flap reconstruction and the second group undergoes wide excision with double z - plasty .
karydakis technique consisted of a vertical eccentric elliptical incision extended down to the postsacral fascia ; complete removal of unhealthy tissue , including a rim of normal tissue around the cyst and sinus tract ; mobilization of the medial wound edge by undercutting the adipose tissue at a depth of 1  cm ; advancement of flap across the midline to the postsacral fascia ; and suturing of its edges to the lateral wound edges .
close attention was paid to ensure adequate mobilization and tension free fixation of flap , which was lateralized 1  cm from midline ( figures 1(a)1(d ) ) . in group 2 ( gp 2 ) ,
z - plasty was performed by a vertical elliptical incision extended down to the postsacral fascia ; complete removal of unhealthy tissue with a rim of normal healthy tissue ; two oblique incisions given by making an angle of 60 degrees with the vertical line ( figures 2(a ) and 2(b ) ) .
the flaps are suitably interdigitated and sutured in three layers according to depth of wound so as to avoid negative spacing .
all patients were asked to pay attention to hygiene rules , to not sit or use a semisitting position for 15 days , and to depilate hairs around their gluteal region as necessary for every 3 months beginning after hospital discharge .
data obtained during hospital admission and at 10 , 21 , and 30 days after discharge included complications , duration of hospitalization healing , work off period , and degree of satisfaction .
the surgical procedure was considered  unsuccessful  ( early failure ) if a given patient experienced purulent discharge , abscess , or complete wound dehiscence for which further treatment was required within 30 days of the operation .
all similar events that occurred following an uneventful recovery period were considered  recurrent disease . 
the data was analysed using unpaired student 's t - test and the proportions were analysed using fisher exact test .
the most common age of presentation in both groups was 2130 years ( mean age : 28 years ) . in both groups , the incidence in male patients was 9 times more than that in females . in both groups ,
the incidence was more common in patients with coarse body hair density ( 8084% ) and among the patients with a deep natal cleft ( 88% ) . grossly , primary disease was present in 82% of the patients among which 87.8% were males .
recurrent disease was present in 20% of patients and all of them are males and all these patients have deep natal cleft .
in both groups , the common clinical presentations were small pus discharging sinus ( 56% ) , multiple discharging sinus ( 28% ) , and swelling with pus discharging sinus ( 16% ) .
the duration of hospitalization for karydakis procedure was significantly lesser than that for double z - plasty ( mean : 4 versus 11 days , resp .
similar observations are obtained for duration of wound healing ( mean : 13 versus 30 days , resp .
, p < 0.001 ) , work off period ( mean : 11 versus 36 days , resp . , p
< 0.001 ) , and the duration of presence of significant pain postoperatively ( mean : 11 versus 38 days , resp . ,
the complications observed in double z - plasty were infection of wound ( 60% ) , seroma ( 56% ) , hematoma ( 52% ) , necrosis ( 48% ) , wound dehiscence ( 48% ) , and loss of sensation ( 40% ) .
the complications in karydakis procedure were infection ( 16% ) , seroma ( 12% ) , and loss of sensation ( 4% )
. there was absence of hematoma , necrosis , and wound dehiscence in karydakis procedure .
recurrence developed in 32% of the cases in double z - plasty group comparable to no recurrence seen in karydakis procedure , but the patients were followed up until 6 months .
recurrence information was based on the voluntary information by the patients after that in the outpatient department .
all these complications were more common among patients with primary disease , deep natal cleft , and coarse body hair density ( table 1 ) .
pilonidal sinus disease is an acquired condition usually seen in young adults and carries high postoperative morbidity and patient 's discomfort . through this study
, we compare the two modern methods of treatment , namely , karydakis procedure and double z - plasty.(1)epidemiology : in present study , pilonidal sinus disease is an acquired condition usually seen in young adults of 21 to 30 years of age .
keighley ( peak age incidence is 15 to 24 years ) [ 5 , 6 ] .
this higher occurrence in the 3rd decade of life is because pilonidal disease starts at the onset of puberty , when sex hormones start acting on pilosebaceous glands in the natal cleft .
a hair follicle becomes distended with keratin and subsequently infected , leading to a folliculitis and an abscess which extends into the subcutaneous fat .
awad and saad reported that 56.3% of pilonidal disease patients had coarse hair density and deep natal cleft .
we fully agree with this , as we found that patients with recurrent disease were all males having a coarse body hair density and deeper natal cleft.(2)postoperative comparison : hospitalization , wound healing , and work off periods are relative measures of outcome .
they are strongly related to personal , sociocultural , and socioeconomic levels , type of job , social assurance , and behavioral patterns .
we observed shorter hospitalization period with karydakis flap technique ( 4.08 + 0.91 days ) in comparison to double z - plasty ( 10.92 + 2.29 days ) . in the present study ,
the mean duration of wound healing was 12.84 + 1.70 days , the number of days in which pain lasted postoperatively was 11.52 + 1.50 days , and work off periods were 10.56 + 1.29 days in karydakis flap procedure , while in double z - plasty technique the mean days of wound healing were 30.16  8.97 days , the number of days in which pain lasted postoperatively was 37.92  8.31 days , and work off periods were 35.72  8.59 days .
fazeli et al . ( 2006 ) in a clinical trial of 216 cases divided into three arms of 72 cases each have concluded that wounds healed much faster in the z - plasty group , 15.4 days , and the work off periods were 17.5 days .
taubanakis in 1986 produced a study in which he found that mean time of healing in z - plasty was < 14 days .(3)complications : in present study , the overall complication rates were maximum for the double z - plasty group ( 45.07% ) and the commonest complications were loss of local sensation ( 68% ) , tip necrosis ( 44% ) , infection ( 8% ) , seroma formation ( 4% ) , and wound dehiscence ( 4% ) .
similarly , sayed , in his experience of 30 cases with z - plasty , reported among early complications loss of local sensation in 58% , tip necrosis in 20% , wound infection in 6.7% , and wound dehiscence in 3.3% .
loss of local sensation is a known complication following z - plasty because in this technique flaps are transposed in such a way to avoid suture line in midline . to achieve this
mansoory and dickson , in their experience of 127 cases with z - plasty , suggested that more than 50% of patients develop loss of local sensation and over 30% of patients develop tip necrosis .
tip necrosis was also more with our technique of double z - plasty ( 44% ) ; it was because of sharp triangles .
however , it was only superficial necrosis , thereby increasing morbidity , but it does not affect overall results . in our experience , hematoma occurred in cases having deep natal cleft and coarse body hair density .
this may be attributed to more dissection in deep natal cleft cases and minimal use of cautery in order not to compromise the blood supply of the flaps , resulting in inadequate hemostasis and hematoma formation .
this is mainly because of occurrence of compromised blood supply in making flaps . in double z - plasty , to minimize the tip necrosis , we have observed and advise to do the following:(i)the incision to achieve transposition of flaps should be in full depth
having deeper tissues along with the skin;(ii)approximation of soft tissue ( subcutaneous and deeper ) should be meticulous by vicryl suture;(iii)the cautery should be minimally used .
epidemiology : in present study , pilonidal sinus disease is an acquired condition usually seen in young adults of 21 to 30 years of age .
keighley ( peak age incidence is 15 to 24 years ) [ 5 , 6 ] .
this higher occurrence in the 3rd decade of life is because pilonidal disease starts at the onset of puberty , when sex hormones start acting on pilosebaceous glands in the natal cleft .
a hair follicle becomes distended with keratin and subsequently infected , leading to a folliculitis and an abscess which extends into the subcutaneous fat .
awad and saad reported that 56.3% of pilonidal disease patients had coarse hair density and deep natal cleft .
we fully agree with this , as we found that patients with recurrent disease were all males having a coarse body hair density and deeper natal cleft .
postoperative comparison : hospitalization , wound healing , and work off periods are relative measures of outcome .
they are strongly related to personal , sociocultural , and socioeconomic levels , type of job , social assurance , and behavioral patterns .
we observed shorter hospitalization period with karydakis flap technique ( 4.08 + 0.91 days ) in comparison to double z - plasty ( 10.92 + 2.29 days ) .
in the present study , the mean duration of wound healing was 12.84 + 1.70 days , the number of days in which pain lasted postoperatively was 11.52 + 1.50 days , and work off periods were 10.56 + 1.29 days in karydakis flap procedure , while in double z - plasty technique the mean days of wound healing were 30.16  8.97 days , the number of days in which pain lasted postoperatively was 37.92  8.31 days , and work off periods were 35.72  8.59 days .
fazeli et al . ( 2006 ) in a clinical trial of 216 cases divided into three arms of 72 cases each have concluded that wounds healed much faster in the z - plasty group , 15.4 days , and the work off periods were 17.5 days .
taubanakis in 1986 produced a study in which he found that mean time of healing in z - plasty was < 14 days .
complications : in present study , the overall complication rates were maximum for the double z - plasty group ( 45.07% ) and the commonest complications were loss of local sensation ( 68% ) , tip necrosis ( 44% ) , infection ( 8% ) , seroma formation ( 4% ) , and wound dehiscence ( 4% ) .
similarly , sayed , in his experience of 30 cases with z - plasty , reported among early complications loss of local sensation in 58% , tip necrosis in 20% , wound infection in 6.7% , and wound dehiscence in 3.3% .
loss of local sensation is a known complication following z - plasty because in this technique flaps are transposed in such a way to avoid suture line in midline . to achieve this
mansoory and dickson , in their experience of 127 cases with z - plasty , suggested that more than 50% of patients develop loss of local sensation and over 30% of patients develop tip necrosis .
tip necrosis was also more with our technique of double z - plasty ( 44% ) ; it was because of sharp triangles .
however , it was only superficial necrosis , thereby increasing morbidity , but it does not affect overall results . in our experience , hematoma occurred in cases having deep natal cleft and coarse body hair density .
this may be attributed to more dissection in deep natal cleft cases and minimal use of cautery in order not to compromise the blood supply of the flaps , resulting in inadequate hemostasis and hematoma formation .
this is mainly because of occurrence of compromised blood supply in making flaps . in double z - plasty , to minimize the tip necrosis ,
we have observed and advise to do the following : ( i)the incision to achieve transposition of flaps should be in full depth having deeper tissues along with the skin;(ii)approximation of soft tissue ( subcutaneous and deeper ) should be meticulous by vicryl suture;(iii)the cautery should be minimally used .
the incision to achieve transposition of flaps should be in full depth having deeper tissues along with the skin ; approximation of soft tissue ( subcutaneous and deeper ) should be meticulous by vicryl suture ; the cautery should be minimally used . however , in karydakis flap technique , infection , seroma , hematoma , loss of sensation , flap necrosis , and wound dehiscence were very less common . in both groups , wound dehiscence and infection were more common in cases having deep natal cleft and coarse body hair density .
this is because , as we already know the perineum to be the most contaminated area of our body with the mid natal cleft being the bacterial harbor where maximum bacterial colonization occurs , dense body hair adversely affects maintenance of a proper hygiene , thus increasing the infection rate .
so , with our experience , it is obvious that the deep natal cleft and coarse body hair density not only are risk factors for the causation of the disease but also complicate the procedure done , increasing the infection , necrosis , and wound dehiscence rate.(4)recurrences : in present study , no recurrence proves the superiority of the karydakis flap procedure over double z - plasty technique for treatment of pilonidal disease .
recurrences : in present study , no recurrence proves the superiority of the karydakis flap procedure over double z - plasty technique for treatment of pilonidal disease .
on comparison , karydakis flap was found superior to double z - plasty having less seroma formation , no local hematoma , and no flap necrosis . statistically , this comparison was highly significant ( p < 0.001 ) .
karydakis flap has some added advantages over double z - plasty technique like keeping scar away from the midline and flattening of the natal cleft , thus reducing local recurrence rates .
 the most difficult problems that follow surgery for pilonidal disease are persistent unhealed midline wound and recurrence . 
 various innovations were proposed to deal with these problems . 
 the adipocutaneous flap of karydakis was devised to shift the natal cleft , 
 while z - plasty involves fasciocutaneous flap . 
 the present prospective randomized trial was conducted on 50 cases of symptomatic or recurrent pilonidal sinuses divided randomly into two equal groups undergoing karydakis procedure and z - plasty . 
 the duration of hospitalization for karydakis procedure was found significantly lesser than that for double z - plasty ( p < 0.001 ) . 
 similar observations are obtained for duration of wound healing ( p < 0.001 ) , work off period ( p < 0.001 ) , and the duration of presence of significant pain postoperatively ( p < 0.001 ) . 
 the overall complications were more in double z - plasty . 
 recurrence developed in 32% of the cases in double z - plasty group comparable to no recurrence seen in karydakis procedure . 
 thus , karydakis flap was found superior to double z - plasty having less seroma formation , no local hematoma , and no flap necrosis . statistically , this comparison was highly significant ( p < 0.001 ) . 
 karydakis flap has some added advantages over double z - plasty technique like keeping scar away from the midline and flattening of the natal cleft , thus reducing local recurrence rates . 
1. Introduction
2. Methods
3. Results
4. Discussion
5. Conclusion