Laparoscopic cholecystectomy has been established as the first choice treatment of benign gall bladder disease needing removal of gall bladder (GB) in general surgery [1]. It shortened the operation time and duration of hospital stay, reduced post operative pain [2] and made better recovery compared with conventional open cholecystectomy [3,4]. At first laparoscopic cholecystectomy began with four-port surgery [5]. But now, many centers do three-port laparoscopic cholecystectomy. The concept of single port laparoscopic cholecystectomy (SPLC) arose from the idea of the "fewer-port" cholecystectomy [6].

Multiple ports were good for surgeons to handle laparoscopic instruments and to imagine and understand intra-abdominal structure anatomically [7]. The more ports that were used, however, the higher rate of complications that occurred; bleeding on port insertion site, post operative pain, decrease of cosmetic effect, organ injury that might be caused by inserting the trocar, and incisional hernia [8].

Single-port access surgery was the natural evolution of this reduced port concept for cholecystectomy [9,10]. The more surgical skills became sophisticated, the less patients wanted anatomical changes [11]. SPLC reflects the trend of minimally invasive surgery. Safety is the most important concern of all in new operative techniques [12].

The transumbilical cholecystectomy was first described in 1999 [13,14]. However, SPLC is still in its early days with little data having been accumulated and published, formally [15]. At our center, single port laparoscopic surgery has just reached the 100th surgery mark in December, 2010. The first operation was done in May, 2009. This article reports on the achievement of 100 cases of SPLC in the hopes it will encourage laparoscopic surgery centers that are beginning SPLC.

From May 2009 to December 2010, 100 patients who had GB stone with or without cholecystitis, or GB polyp had undergone elective SPLC by a single surgeon. The diagnosis of GB stone or GB polyp was based on abdominal ultrasonography (US) or computed tomography (CT). Only one case used magnetic resonance imaging and positron emission tomography CT to rule out malignancy. Some patients had subjective symptoms such as right upper quadrant abdominal pain, dyspepsia, or abdominal discomfort. SPLC was done under the patients' informed consent: information about the surgical procedure, the difference in cost between SPLC and conventional laparoscopic cholecystectomy was provided.

From May 2009 to December 2010, 100 cases of SPLC were performed by a single surgeon. Table 1 shows us patient characteristics including age, gender, BMI, previous history of abdominal surgery, diagnostic tools, patients' symptom and diagnoses. Forty-two men and 58 women aged an average of 45.8 years (range, 27 to 68 years) received SPLC. Their mean BMI was 23.85 kg/m² (range, 18.4 to 33.7 kg/m²). The BMI of 22 patients were over than 25 kg/m². Mean operating time took 76.75 minutes (range, 45 to 125 minutes). However, operating time decreased according to the increase of experience of single port surgery cases. Fig. 1 explains operating time saved according to the surgeon's experiences [17]. Twenty-one patients had had a history of previous surgery. Nine underwent appendectomy, 13 had obstetric and gynecologic surgery, and 2 had urology surgery. Sixty-seven patients had no symptom, 27 patients had abdominal pain and 6 had gastric discomfort. Forty-nine patients were diagnosed with GB stone, 32 of them were symptomatic cholecystitis with GB stone. Fifty patients were diagnosed with GB polyp, and 1 was GB empyema. Twenty-four of the 50 patients diagnosed with GB polyp, were pathologically diagnosed with cholesterol polyp and the other 26 were tubular adenoma. CT and US were used for the diagnoses. Eighteen cases had intra-operative bile leakage because GB were injured when dissected from the liver bed; 10 cases were cholecystitis and 8 were GB polyp. No postoperative bile leakage occurred. Eighty-four patients were discharged two days after operation.

There were 6 patients with complications after surgery described in Table 2. One patient experienced liver enzyme elevation; it resolved spontaneously. Three had wound infection with fever. Wound dressing and antibiotics resolved these, and their wounds were found clean at out patient clinic. One patient suffered continuous abdominal pain after surgery. Sludges in the common bile duct were found on abdominal US and he received endoscopic sphincterotomy. No incisional hernia was observed.

Of the one hundred cases of SPLC, 21 cases were converted to multi-port surgery. Seven cases were converted to three-port surgery, and 14 cases were converted to two-port surgery. The main reason for conversion to multi-port surgery was poor visualization of Calot's triangle [18]. Three cases were converted because of bleeding. We tried to understand the reason of conversion to multi-port surgery and compared variable parameters of the pure single port surgery and converted to multi-port surgery. In Table 3, we compared age, gender, BMI and previous abdominal surgery history. Interestingly, each parameter did not have significant statistical meaning. No conversions were performed due to complications, and no conversions resulted in complications. There was no case of conversion to open surgery.

Even though the first transumbilical cholecystectomy was described in 1999 [14], SPLC is still in its early days [19]. SPLC is challenging to laparoscopic surgeons [20], however, there are a few reports of laparoscopic single port surgery. When a new technique is accepted, many factors should be considered. Who is a likely candidate for SPLC? Is it a safe method without severe complications? Is it a difficult method for a surgeon to become accustomed to? Does it increase operation time? Does the new technique need new surgical instruments and will it increase the cost of equipment? This review of 100 cases of SPLC aims to answer those questions.

For the 10 cases at the very beginning of our study, we restricted indication on only simple GB stone without any symptom or any evidence of inflammatory change on image study. After the 10 cases, the strict criteria were reduced as the surgeon became accustomed to the new method. For the first 20 cases, BMI over 25 kg/m² were excluded. However, BMI did not have much influence on conversion to multi-port laparoscopic cholecystectomy. Twenty-one cases were converted to multi-port surgery. We compared data of the single port laparoscopic surgery with converted multi-port laparoscopic cholecystectomy. Mean BMI didn't seem to have statistically significant meaning (P = 0.381).

SPLC did not incur severe complications. Liver enzyme elevation and delayed bleeding resolved spontaneously. Wound infection was controlled by wound dressing and antibiotics. Song et al. [21] stated the risks associated with SPLC were not greater than multi-port laparoscopic cholecystectomy.

Han et al. [22] demonstrated that SPLC could be applied effectively and performed as quickly as conventional cholecystectomy with a learning curve of approximately 8 cases. We found that mean operation time dropped dramatically after thirty cases. Youn et al. [17] suggested the learning curve for SPLC for a surgeon with prior conventional laparoscopic cholecystectomy experience and for a self taught single port technique should be around 30 cases. The time decreasing slope was rigid for the first 30 cases. After that the slope remained flat. The more expert to the surgical skill, the more difficult cases were enrolled. Thus, operation time does not sharply decrease.

At first, flexible laparoscopic instruments were used. After 10 cases, all the conventional rigid laparoscopic instruments were used for SPLC. A hook Bovie was the only flexible instrument. If any laparoscopic center is considering trying SPLC, little extra cost of equipment is needed because conventional equipment would suffice in SPLC as well.