To determine the safety and feasibility of solo laparoscopic cholecystectomy, which is defined as the application of solo surgery to laparoscopic cholecystectomy, by comparing consecutive non-solo procedures conducted by a surgeon in the presence or absence of human assistant(s).

Laporoscopic cholecystectomy usually requires three surgeons, including an operator, a camera assistant, and other instrument assistant. Recent advancement of technology made it possible to develop the conveniently adjustable holders for camera and other laparoscopic instruments. The application of these instruments enables "solo-surgery" wherein an operation is driven by single surgeon. During surgery, human assistant(s) are helpful because of their instant assistance according to the operation's need. Therefore, the utilization of instruments instead of human assistants would be cumbersome. However, the utilization of instruments would be helpful by enabling operation-driven repositioning of the camera and instrument(s). Currently, no attempt has been made to objectively compare the merits and demerits of these two procedures. Therefore, this study was conducted to determine the safety and feasibility of solo laparoscopic cholecystectomy, which is defined as the application of solo surgery to laparoscopic cholecystectomy, by comparing consecutive non-solo procedures conducted by a surgeon in the presence or absence of human assistant(s).

Inclusion Criteria:

1. The patients planed to undergo elective laparoscopic cholecystectomy
2. Benign gallbladder diseases requiring surgery
3. The patients who are indicated for single-port laparoscopic cholecystectomy.

Exclusion Criteria:

1. the patients with complicated cholecystitis
2. the patients with the gallbladder with a thickness more than 4mm.
3. the patients who are expected to have severe peritoneal adhesion.
4. the patients with malignant gallbladder diseases.
5. the patients whose operation appears to need human assistant(s)