ORIGINAL ARTICLE Karydakis procedure can be effectively performed in the lateral position Marie S. De Robles,* Doruk Seyfi,* Assad Zahid* and Christopher J. Young *† *Department of Colorectal Surgery, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia and †Discipline of Surgery, The University of Sydney, Sydney, New South Wales, Australia Key words flap repair, Karydakis, lateral position, pilonidal disease. Correspondence Associate Professor Christopher J. Young, RPAH Medical Centre, Suite 415/100, Carillon Avenue, Newtown, NSW 2042, Australia. Email: cyoungnsw@aol.com M. S. De Robles BSc (PH), MD, DPBS; D. Seyfi BAppSc (Diag Rad), MBBS, MS; A. Zahid MBBS, BSc (Med), MS, FRACS; C. J. Young MS, FRACS, FACS, FASCRS. Accepted for publication 6 August 2018. doi: 10.1111/ans.14844 Abstract Background: Karydakis published a large pilonidal series in 1992, reporting a recurrence rate of less than 1% and complication rate of 8.5%. The aim of this study was to compare the outcomes of Karydakis procedure (KP) performed in the lateral versus the prone posi- tion in a consecutive series. Methods: Ninety-seven consecutive patients undergoing a KP between March 2000 and February 2018 were retrospectively assessed. Patients with disease sinuses or fistulas extending from the midline to either left or right sides only were considered for KP in the contralateral side position. Results: Surgery was carried out for primary pilonidal disease in 71 patients (73%) and for recurrent disease in 26 patients (27%). The majority (62%) of pilonidal tracts veered off from the midline to either the left or right side only. Wound complications, mostly minor skin separation, occurred in 37 patients (38%). Disease recurrence occurred in eight patients (8%). There was no difference between patients who had KP in a lateral position compared with those operated in a prone position regarding wound complica- tions (41% versus 35%, P = 0.675), disease recurrence (9% versus 7%, P = 1.000), mean operating time (64.6 min versus 66.6 min, P = 0.259) and mean length of hospital stay (1 day for both groups). Conclusions: Pilonidal surgery in the lateral position has potential benefits for patient safety, patient comfort and theatre efficiency. The clinical results of this series show that the KP can be performed safely and effectively with the patient in the lateral position for most cases of pilonidal disease. Introduction Pilonidal disease (PD) is common in the young male population, with a peak incidence encountered between 15 and 24 years of age. 1–3 It was described in the 1800s as a chronic inflammatory disease affect- ing the natal cleft. 4,5 A pilonidal sinus is formed when a granulation- lined pilonidal cavity drains via a sinus tract, which may open away from the midline as a fistula onto the skin. Sinus tracts commonly tunnel under the skin often with more than one tract and direction. 1,5 There is a wide range of surgical procedures recommended for the treatment of PD. 6,7 Karydakis described the utilization of an asymmetric advancement flap with excision of the sinus tract, 2,8 and it remains the most common PD procedure in Australia and New Zealand. 7 This technique has consistently demonstrated faster healing times, lower rates of wound morbidity and lower recurrence rates. 9 This procedure can be performed in either the prone, left or right lateral positions. 5,9,10 The aim of this study was to assess the results of the Karydakis procedure (KP) in the management of PD, and specifically to deter- mine whether it can be safely and effectively performed with the patient in the lateral position. Methods The KP was performed on 97 consecutive patients with PD from March 2000 to February 2018 by a single surgeon. The technique used was an asymmetric advanced repair using an off-midline elliptical incision in the long axis on the most affected side. 2,8 The procedures were carried out with the patients in either prone, left or right lateral position. © 2018 Royal Australasian College of Surgeons ANZ J Surg (2018) ANZJSurg.com