Supraumbilical, infraumbilical, or transumbilical incisions can be used for SILS. It is generally accepted that a transumbilical incision, rather than a supra- or infraumbilical incision, results in a more cosmetically pleasing scar and an almost normal-looking umbilicus [14]. In the present study, the transumbilical approach was used, and in all 14 patients the Volasertib cancer incision was 2.0�C2.5cm, as previously reported [14]. Tam et al. reported that SILS appendectomy using conventional instruments in children was feasible. They concluded that use of conventional instruments in SILS is technically possible in children undergoing simple to complex procedures and may have the potential to popularize this approach by eliminating the mandatory demand for specially designed instruments [5].

SILS was initially performed by crossing roticulating and articulating laparoscopic instruments. Some researchers suggested using 1 roticulating instrument and 1 straight instrument for dissection [5, 18, 19]. Use of roticulating and articulating devices is complicated due to the difficult hand-eye coordination and limited surgical space, and use of conventional straight instruments may overcome this difficulty; however, use of conventional instruments also has some drawbacks, including instrument collision, limited instrument triangulation, limited range of motion, and often a small number of ports [17]. Tam et al. reported that crossing 2 straight instruments was not significantly different than conventional laparoscopic skills and that the instruments may need to be moved between hands during surgery.

In the present study, we also frequently changed the placement of surgical instruments, which we think may have helped in overcoming the problem of instrument collision [5]. Podolsky and Curcillo II reported their 2-year experience with more than 100 SILS procedures; their major technical refinement was the transition from special roticulating instruments to conventional straight instruments [20]. In the present study, we performed 1 cholecystectomy and 1 appendectomy concomitantly with ovarian cystectomy and unilateral salpingo-oopherectomy, respectively, via the same umbilical incision; the ability to perform multiple procedures via a single incision is an advantage which SILS has over the classical laparoscopic approach. Surico et al.

reported concomitant ovarian cystectomy and cholecystectomy using a multi-instrument access port and concluded that single-port surgery eliminates the problem of multiple site placement of accessory ports [21]. On the other hand, Hart et al. reported concomitant SILS cholecystectomy and hysterectomy for the treatment of a symptomatic fibroid uterus and symptoms of cholelithiasis in a 37-year-old woman. They concluded that complex concomitant procedures could be performed using the SILS Drug_discovery approach [22].