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 mainstay treatment for symptomatic gallstones. More than half a million cholecystectomies are performed per year in the US alone. Laparoscopic cholecystectomy (removal of gallbladder through a keyhole, also known as port) is now the preferred method of cholecystectomy. Pain is one the major reasons for delayed hospital discharge after laparoscopic cholecystectomy. Administration of local anaesthetics (drugs that numb part of the body, similar to the ones used by the dentist to prevent the people from feeling pain) into the tummy (abdomen) is considered to be an effective way of decreasing the pain after laparoscopic cholecystectomy. However, the best method of administration of local anaesthetics is not known. The controversies include which drug to use, when to administer it, whether it should be administered in the form of liquid or in the form of misty spray, and to which part of the tummy it should be administered. We sought to answer these questions by reviewing the medical literature and obtaining information from randomised clinical trials for assessment of benefit. When conducted well, such studies provide the most accurate information on the best treatment. We included comparative non-randomised studies for the assessment of treatment-related harms. Two authors searched the literature and obtained information from the studies thereby minimising errors.

Study characteristics

We identified 12 randomised clinical trials involving 798 people undergoing planned laparoscopic cholecystectomy. The trials compared different methods addressing the various controversies mentioned above. The choice of the method of administration of the local anaesthetic was determined by a method similar to the toss of a coin so that the treatments compared were conducted in participants who were as similar as possible.

Key results

There were no deaths or serious complications in either group in the comparisons that reported these. None of the trials reported quality of life, the time taken to return to normal activity, or the time taken to return to work. The differences in hospital stay between the methods being compared was imprecise in all the comparisons that reported hospital stay. Although there were some differences in the pain scores on the visual analogue scale (a chart that rates the amount of pain on a scale of 1 to 10 cm), these differences were neither consistent nor robust to different methods of statistical analysis. The evidence currently available is inadequate to determine the effects of one method of local anaesthetic intraperitoneal instillation compared with any other method of local anaesthetic intraperitoneal instillation in low anaesthetic risk individuals undergoing elective laparoscopic cholecystectomy.

Quality of evidence

Most of the trials were of high risk of bias, that is, there is possibility of arriving at wrong conclusions overestimating benefits or underestimating harms of one method or the other because of the way that the study was conducted. The overall quality of evidence was very low.

Future research

Further trials are necessary. Such trials should include outcomes such as quality of life, the time taken to return to normal activity, and the time taken to return to work, which are important for the person undergoing the procedure and the people who provide funds for the treatment.