***TASK***
the task is to simplify the input abstract of a biomedical literature

***INPUT***
the input is the abstract of a biomedical literature

***OUTPUT***
the output is the simplified abstract for the input abstract of a biomedical literature

***DOCUMENTATION***

***EXAMPLES***

Input: We found no RCTs on this topic. We included in this review 12 non-randomised studies that compared laparoscopic versus open distal pancreatectomy (1576 participants: 394 underwent laparoscopic distal pancreatectomy and 1182 underwent open distal pancreatectomy); 11 studies (1506 participants: 353 undergoing laparoscopic distal pancreatectomy and 1153 undergoing open distal pancreatectomy) provided information for one or more outcomes. All of these studies were retrospective cohort-like studies or case-control studies. Most were at unclear or high risk of bias, and the overall quality of evidence was very low for all reported outcomes. Differences in short-term mortality (laparoscopic group: 1/329 (adjusted proportion based on meta-analysis estimate: 0.5%) vs open group: 11/1122 (1%); OR 0.48, 95% CI 0.11 to 2.17; 1451 participants; nine studies; I2 = 0%), long-term mortality (HR 0.96, 95% CI 0.82 to 1.12; 277 participants; three studies; I2 = 0%), proportion of people with serious adverse events (laparoscopic group: 7/89 (adjusted proportion: 8.8%) vs open group: 6/117 (5.1%); OR 1.79, 95% CI 0.53 to 6.06; 206 participants; three studies; I2 = 0%), proportion of people with a clinically significant pancreatic fistula (laparoscopic group: 9/109 (adjusted proportion: 7.7%) vs open group: 9/137 (6.6%); OR 1.19, 95% CI 0.47 to 3.02; 246 participants; four studies; I2 = 61%) were imprecise. Differences in recurrence at maximal follow-up (laparoscopic group: 37/81 (adjusted proportion based on meta-analysis estimate: 36.3%) vs open group: 59/103 (49.5%); OR 0.58, 95% CI 0.32 to 1.05; 184 participants; two studies; I2 = 13%), adverse events of any severity (laparoscopic group: 33/109 (adjusted proportion: 31.7%) vs open group: 45/137 (32.8%); OR 0.95, 95% CI 0.54 to 1.66; 246 participants; four studies; I2 = 18%) and proportion of participants with positive resection margins (laparoscopic group: 49/333 (adjusted proportion based on meta-analysis estimate: 14.3%) vs open group: 208/1133 (18.4%); OR 0.74, 95% CI 0.49 to 1.10; 1466 participants; 10 studies; I2 = 6%) were also imprecise. Mean length of hospital stay was shorter by 2.43 days in the laparoscopic group than in the open group (MD -2.43 days, 95% CI -3.13 to -1.73; 1068 participants; five studies; I2 = 0%). None of the included studies reported quality of life at any point in time, recurrence within six months, time to return to normal activity and time to return to work or blood transfusion requirements. Currently, no randomised controlled trials have compared laparoscopic distal pancreatectomy versus open distal pancreatectomy for patients with pancreatic cancers. In observational studies, laparoscopic distal pancreatectomy has been associated with shorter hospital stay as compared with open distal pancreatectomy. Currently, no information is available to determine a causal association in the differences between laparoscopic versus open distal pancreatectomy. Observed differences may be a result of confounding due to laparoscopic operation on less extensive cancer and open surgery on more extensive cancer. In addition, differences in length of hospital stay are relevant only if laparoscopic and open surgery procedures are equivalent oncologically. This information is not available currently. Thus, randomised controlled trials are needed to compare laparoscopic distal pancreatectomy versus open distal pancreatectomy with at least two to three years of follow-up. Such studies should include patient-oriented outcomes such as short-term mortality and long-term mortality (at least two to three years); health-related quality of life; complications and the sequelae of complications; resection margins; measures of earlier postoperative recovery such as length of hospital stay, time to return to normal activity and time to return to work (in those who are employed); and recurrence of cancer.
Output:

No randomised controlled trials have examined this topic. Randomised controlled trials are the best studies for finding out whether one treatment is better or worse than another because they ensure that similar types of people are receiving the treatments being assessed. In the absence of randomised controlled trials, we sought information from non-randomised studies. We identified 12 non-randomised studies that compared laparoscopic versus open distal pancreatectomy in a total of 1576 patients. One of these studies did not provide results in a useable way. Thus, we included 11 studies in which a total of 1506 patients underwent distal pancreatectomy. Some 353 patients underwent laparoscopic distal pancreatectomy, and 1153 patients underwent open distal pancreatectomy. In all studies, historical information was collected from hospital records (retrospective studies). In general, historical information is less reliable than newly collected (prospective) information and findings of randomised controlled trials. Differences in short-term deaths, long-term deaths, percentage of people with major complications, percentage of people with a pancreatic fistula (abnormal communication between the pancreas and other organs or the skin), recurrence of cancer at final time of follow-up of participants, percentage of people with any complications and percentage of patients in whom cancer was not completely removed were imprecise. Average length of hospital stay was shorter in the laparoscopic group than in the open group by about two days. However, this is not relevant until we can be sure that cancer cures are similar between laparoscopic surgery and open surgery. No studies have reported quality of life at any point in time, short-term recurrence of cancer, time to return to normal activity, time to return to work or blood transfusion requirements. The quality of the evidence was very low, mainly because it was not clear whether similar types of participants received laparoscopic and open distal pancreatectomy. In many studies, people with less extensive cancer received laparoscopic surgery, and those with more extensive cancer received open surgery. This makes study findings unreliable. Well-designed randomised controlled trials are necessary if we are to obtain good quality evidence on this topic.