**2. Laparoscopic vs. small-incision cholecystectomy**

A review in 1993 (Olsen, 1993) concluded that there are no good studies comparing conventional cholecystectomy by minilaparotomy or by laparoscopy. However, it was apparent that the small incision was better than the big one and that the length of the incision appears to be associated with hospital stay and return to the workplace. The ultimate goal is to achieve a safe surgery with the maximum benefit for the patient, and the keys are: knowledge of anatomy, good surgical view and a proper exposure. This last key to safety, exposure, is a limiting factor for minilaparotomy, which leads the question of how small an incision can still provide a exposure to perform the cholecystectomy safely. For Olsen, the answer is the laparoscopy, which allows for smaller incision, but it is noteworthy that the sum of the incisones made for the insertion of four trocars is about 4 cm and twodimensional view. An incision of this size can provide adequate exposure for cholecystectomy under direct three-dimensional vision.

An overview of the Cochrane Hepato-Biliary Group reviews in January 2010 (Keus et al., 2010) revealed the evidence to date of the revisions that assess the effect of differents techniques of cholecystectomy: open, small-incision, or laparoscopic. A total of 5246 patients in 56 randomized trials are included. Total complications of laparoscopic cholecystectomy and small-incision were similar (17%), hospital stay and convalescence were not significantly different, small-incision cholecystectomy operative time was shortest (16.4 minutes) and is less costly. In our study of 1998 (Grau-Talens et al., 1998) small-incision cholecystectomy was \$ 1003 U.S less costly than laparoscopic. The effects of anesthesia and surgery on lung function have been well studied (Lindell & Hendenstierna 1976). There is a reduction in FVC (Forced Vital Capacity) and FEV1 (Forced Expiratory Volume in one second) to 75% of baseline for a separate incision without cutting the muscles, while reducing down to 40-55% in the subcostal incisions and midline laparotomy. An incision that spares the muscular section can prevent postoperative pulmonary complications. The restrictive pattern of lung dysfunction in postoperative abdominal surgery is influenced by several factors and is not well understood. The size, location and direction of the incision are responsible for the alteration of mechanical ventilation, by themselves and the pain. Kind of anesthetic agent and diaphragmatic dysfunction are also involved (Craig 1981).

In some studies, laparoscopic cholecystectomy has shown lower spirometric reductions when compared to open cholecystectomy (Frazee et al., 1991) and to mini-lap (McMahon et al., 1994) although the latter with incisions between 5 and 10 cm. Presumably, a reduction in the length of the incision could be rewarded by a smaller reduction in the impairment of lung physiology, ie, an incision of 4.5 cm, uniform to all layers of the abdominal wall could improve postoperative spirometric results as happened in our study (Grau-Talens et al.,1998) wich shows that the reduction of spirometrics values were similar in laparoscopic and small-incision cholecystectomy, ie over 20% of preoperative value for FVC and 25% for FEV1. The results obtained by keus et al. are similar to ours (Keus et al 2008).
