Background Laparoscopy is a common procedure in many surgical specialities. Complications arising from laparoscopy are often related to initial entry into the abdomen. Life-threatening complications include injury to viscera e.g. the bowel or bladder, or to vasculature e.g. major abdominal and anterior abdominal wall vessels. Minor complications can also occur, such as postoperative wound infection, subcutaneous emphysema, and extraperitoneal insufflation. There is no clear consensus as to the optimal method of laparoscopic entry into the peritoneal cavity. Objectives To evaluate the benefits and risks of different laparoscopic entry techniques in gynaecological and non-gynaecological surgery. Search methods This updated review has drawn on the search strategy developed by the Cochrane Menstrual Disorders and Subfertility Group. In addition, MEDLINE, EMBASE, CENTRAL and PsycINFO were searched through to September 2014. Selection criteria We included randomised controlled trials (RCTs) in which one laparoscopic entry technique was compared with another. Data collection and analysis Two authors independently selected studies, assessed risk of bias, and extracted data. We expressed findings as Peto odds ratios (Peto ORs) with 95% confidence intervals (CIs). We assessed statistical heterogeneity using the I-2 statistic. We assessed the overall quality of evidence for the main comparisons using GRADE methods. Main results The review included 46 RCTs including three multi-arm trials (7389 participants) and evaluated 13 laparoscopic entry techniques. Overall there was no evidence of advantage using any single technique for preventing major vascular or visceral complications. The evidence was generally of very low quality; the main limitations were imprecision and poor reporting of study methods. There was no evidence of a difference between the groups for vascular (Peto OR 0.14, 95% CI 0.00 to 6.82, three RCTs, n = 795, I-2 = n/a; very low quality evidence) or visceral injury (Peto OR 0.61, 95% CI 0.06 to 6.08, three RCTs, n = 795, I-2 = 0%; very low quality evidence). There was a lower risk of failed entry in the open-entry group (Peto OR 0.16, 95% CI 0.04 to 0.63, n = 665, two RCTs, I 2 = 0%; very low quality evidence). This suggests that for every 1000 patients operated on, 31 patients in the closed-entry group will have failed entry compared to between 1 to 20 patients in the open-entry group. No events were reported in any of the studies for mortality, gas embolism or solid organ injury. Direct trocar versus Veress needle entry There was a lower risk of vascular injury in the direct trocar group (Peto OR 0.13, 95% CI 0.03 to 0.66, five RCTs, n = 1522, I-2 = 0%; low quality evidence) and failed entry (Peto OR 0.21, 95% CI 0.14 to 0.30, seven RCTs, n = 3104; I-2 = 0%; moderate quality evidence). This suggests that for every 1000 patients operated on, 8 patients in the Veress needle group will experience vascular injury compared to between 0 to 5 patients in the direct trocar group; and that 64 patients in the Veress needle group will experience failed entry compared to between 10 to 20 patients in the direct trocar group. The vascular injury significance is sensitive to choice of statistical analysis and may be unreliable. There was no evidence of a difference between the groups for visceral (Peto OR 1.02, 95% CI 0.06 to 16.24, four RCTs, n = 1438, I-2 = 49%; very low quality evidence) or solid organ injury (Peto OR 0.16, 95% CI 0.01 to 2.53, two RCTs, n = 998, I-2 = n/a; very low quality evidence). No events were recorded for mortality or gas embolism. Direct vision entry versus Veress needle entry There was no evidence of a difference between the groups in the rates of visceral injury (Peto OR 0.15, 95% CI 0.01 to 2.34, one RCT, n = 194; very low quality evidence). Other primary outcomes were not reported. Direct vision entry versus open-entry There was no evidence of a difference between the groups in the rates of visceral injury (Peto OR 0.13, 95% CI 0.00 to 6.50, two RCTs, n = 392; low quality evidence), solid organ injury (Peto OR 6.16, 95% CI 0.12 to 316.67, one RCT, n = 60, I-2 = n/a; very low quality evidence), or failed entry (Peto OR 0.40, 95% CI 0.04 to 4.09, one RCT, n = 60; low quality evidence). Vascular injury was reported, however no events occurred. Our other primary outcomes were not reported. Radially expanding (STEP) trocars versus non-expanding trocars There was no evidence of a difference between the groups for vascular injury (Peto OR 0.24, 95% CI 0.05 to 1.21, two RCTs, n = 331, I-2 = 0%; low quality evidence), visceral injury (Peto OR 0.13, 95% CI 0.00 to 6.37, two RCTs, n = 331, I-2 = n/a; low quality evidence), or solid organ injury (Peto OR 1.05, 95% CI 0.07 to 16.91, one RCT, n = 244; very low quality evidence). Other primary outcomes were not reported. Comparisons of other laparoscopic entry techniques There was a higher risk of failed entry in the group in which the abdominal wall was lifted before Veress needle insertion than in the not-lifted group (Peto OR 4.44, 95% CI 2.16 to 9.13, one RCT, n = 150; very low quality evidence). There was no evidence of a difference between the groups in rates of visceral injury or extraperitoneal insufflation. The studies had small numbers and excluded many patients with previous abdominal surgery, and women with a raised body mass index. These patients may have unusually high complication rates. Authors' conclusions Overall, there is insufficient evidence to recommend one laparoscopic entry technique over another. An open-entry technique is associated with a reduction in failed entry when compared to a closed-entry technique, with no evidence of a difference in the incidence of visceral or vascular injury. An advantage of direct trocar entry over Veress needle entry was noted for failed entry and vascular injury. The evidence was generally of very low quality with small numbers of participants in most studies; our findings should be interpreted with caution.
