Background
About 10% to 15% of the adult Western population have gallstones. Between 1% and 4% become symptomatic each year. Removal of the gallbladder (cholecystectomy) is the main stay treatment for symptomatic gallstones. More than half a million cholecystectomies are performed per year in the United States alone. Laparoscopic cholecystectomy (removal of gallbladder through a key-hole-sized incision, also known as port) is now the preferred method of cholecystectomy. In conventional or standard laparoscopic cholecystectomy (key hole removal of gallbladder), four ports (two of 10-mm diameter and two of 5-mm diameter) are usually used. The use of fewer ports has been reported (fewer-than-four-ports laparoscopic cholecystectomy). However, the safety of fewer-than-four-ports laparoscopic cholecystectomy and whether it offers any advantages over four-port laparoscopic cholecystectomy is not known. We sought to answer this question by reviewing the medical literature and obtaining information from randomised clinical trials commonly called randomised controlled trials. When conducted well, such studies provide the most accurate information. Two review authors searched the literature to September 2013 and obtained information from the trials, thereby minimising errors.
Study characteristics
We identified nine trials that compared fewer-than-four-ports laparoscopic cholecystectomy with four-port laparoscopic cholecystectomy. In these nine studies, 855 participants were included. Four hundred and twenty seven participants underwent fewer-than-four-ports laparoscopic cholecystectomy while the remaining 428 participants underwent four-port laparoscopic cholecystectomy. The choice of the treatment that the participants received was determined by a method similar to toss of a coin so that the two treatments were given to participants with similar characteristics. Most of these studies included low anaesthetic risk patients undergoing planned laparoscopic cholecystectomy.
Key results
Fewer-than-four-ports laparoscopic cholecystectomy could be completed successfully in more than 90% of participants in most of the trials. The remaining participants were mostly converted to four-port laparoscopic cholecystectomy but some participants had to undergo open cholecystectomy (through a large incision in the abdomen). There was no mortality in either group in the seven trials that reported mortality (634 participants in the two groups). There was no significant difference in the proportion of participants who developed serious complications, quality of life between 10 and 30 days after operation, proportion of participants in whom the laparoscopic operation had to be converted to open cholecystectomy, or in the length of hospital stay between the groups. Fewer-than-four-ports laparoscopic cholecystectomy took about 15 minutes longer to complete than four-port laparoscopic cholecystectomy. The time taken to return to normal activity was one day shorter and time taken to return to work two days shorter in the fewer-than-four-ports group compared with four-port laparoscopic cholecystectomy. There was no significant difference in the cosmetic appearance between the two groups at 6 to 12 months after surgery. There appears to be no advantage of fewer-than-four-ports laparoscopic cholecystectomy in terms of decreasing surgical complications, hospital stay, or in improving quality of life and cosmetic appearance. In contrast, the safety of fewer-than-four port laparoscopic cholecystectomy is yet to be established. Fewer-than-four-ports laparoscopic cholecystectomy cannot be recommended routinely outside well-designed clinical trials.
Quality of evidence
Most of the trials were of high risk of bias, that is, there is possibility of arriving at wrong conclusions because of the way that the trial was conducted. The overall quality of evidence was very low.
Future research
Further well-designed randomised clinical trials (which have low probability to arrive at wrong conclusions because of chance and because of participant or researcher prejudice) are necessary to determine whether fewer-than-four-ports laparoscopic cholecystectomy is safe and whether there is any advantage of fewer-than-four-ports laparoscopic cholecystectomy over four-port laparoscopic cholecystectomy.
There is very low quality evidence that is insufficient to determine whether there is any significant clinical benefit in using fewer-than-four-ports laparoscopic cholecystectomy compared with four-port laparoscopic cholecystectomy. The safety profile of using fewer-than-four ports is yet to be established and fewer-than-four-ports laparoscopic cholecystectomy should be reserved for well-designed randomised clinical trials.
Traditionally, laparoscopic cholecystectomy is performed using two 10-mm ports and two 5-mm ports. Recently, a reduction in the number of ports has been suggested as a modification of the standard technique with a view to decreasing pain and improving cosmesis. The safety and effectiveness of using fewer-than-four ports has not yet been established.
To assess the benefits (such as improvement in cosmesis and earlier return to activity) and harms (such as increased complications) of using fewer-than-four ports (fewer-than-four-ports laparoscopic cholecystectomy) versus four ports in people undergoing laparoscopic cholecystectomy for any reason (symptomatic gallstones, acalculous cholecystitis, gallbladder polyp, or any other condition).
We searched the Cochrane Central Register of Controlled Trials (CENTRAL; Issue 8, 2013), MEDLINE, EMBASE, Science Citation Index Expanded, and the World Health Organization International Clinical Trials Registry Platform portal to September 2013.
We included all randomised clinical trials comparing fewer-than-four ports versus four ports, that is, with standard laparoscopic cholecystectomy that is performed with two ports of at least 10-mm incision and two ports of at least 5-mm incision.
Two review authors independently identified the trials and extracted the data. We analysed the data using both the fixed-effect and the random-effects models. For each outcome, we calculated the risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CI) based on intention-to-treat analysis, whenever possible.
We found nine trials with 855 participants that randomised participants to fewer-than-four-ports laparoscopic cholecystectomy (n = 427) versus four-port laparoscopic cholecystectomy (n = 428). Most trials included low anaesthetic risk participants undergoing elective laparoscopic cholecystectomy. Seven of the nine trials used a single port laparoscopic cholecystectomy and the remaining two trials used three-port laparoscopic cholecystectomy as the experimental intervention. Only one trial including 70 participants had low risk of bias. Fewer-than-four-ports laparoscopic cholecystectomy could be completed successfully in more than 90% of participants in most trials. The remaining participants were mostly converted to four-port laparoscopic cholecystectomy but some participants had to undergo open cholecystectomy.
There was no mortality in either group in the seven trials that reported mortality (318 participants in fewer-than-four-ports laparoscopic cholecystectomy group and 316 participants in four-port laparoscopic cholecystectomy group). The proportion of participants with serious adverse events was low in both treatment groups and the estimated RR was compatible with a reduction and substantial increased risk with the fewer-than-four-ports group (6/318 (1.9%)) and four-port laparoscopic cholecystectomy group (0/316 (0%)) (RR 3.93; 95% CI 0.86 to 18.04; 7 trials; 634 participants; very low quality evidence). The estimated difference in the quality of life (measured between 10 and 30 days) was imprecise (standardised mean difference (SMD) 0.18; 95% CI -0.05 to 0.42; 4 trials; 510 participants; very low quality evidence), as was the proportion of participants in whom the laparoscopic cholecystectomy had to be converted to open cholecystectomy between the groups (fewer-than-four ports 3/289 (adjusted proportion 1.2%) versus four port: 5/292 (1.7%); RR 0.68; 95% CI 0.19 to 2.35; 5 trials; 581 participants; very low quality evidence). The fewer-than-four-ports laparoscopic cholecystectomy took 14 minutes longer to complete (MD 14.44 minutes; 95% CI 5.95 to 22.93; 9 trials; 855 participants; very low quality evidence). There was no clear difference in hospital stay between the groups (MD -0.01 days; 95% CI -0.28 to 0.26; 6 trials; 731 participants) or in the proportion of participants discharged as day surgery (RR 0.92; 95% CI 0.70 to 1.22; 1 trial; 50 participants; very low quality evidence) between the two groups. The times taken to return to normal activity and work were shorter by two days in the fewer-than-four-ports group compared with four-port laparoscopic cholecystectomy (return to normal activity: MD -1.20 days; 95% CI -1.58 to -0.81; 2 trials; 325 participants; very low quality evidence; return to work: MD -2.00 days; 95% CI -3.31 to -0.69; 1 trial; 150 participants; very low quality evidence). There was no significant difference in cosmesis scores at 6 to 12 months between the two groups (SMD 0.37; 95% CI -0.10 to 0.84; 2 trials; 317 participants; very low quality evidence).