Laparoscopic left hemicolectomy has become the gold standard for the treatment of both descending colon and left colonic flexure lesions.14 Currently, totally laparoscopic resection with IA for reestablishing intestinal transit in colorectal surgery has been gradually accepted by clinicians.15 This meta-analysis reviewed the safety and superiority between the two anastomosis techniques.
Compared with EA group, IA group showed no significantly difference on intraoperative outcomes covering operation time, blood loss and number of excised lymph nodes, which suggested that the two surgical techniques have little influence on the progress of surgery and the intraoperative effect. However, IA group demonstrated significant longer operation time in use of laparoscopy through subgroup analysis. Operation time tended to be longer in the group of IA owing to that the IA technique is more challenging during the learning curve and require more hands-on, which had reported in other studies.9,16 The IA technique is rather challenging for surgeons on the learning curve, which perhaps require more hands on time. Nevertheless, patients can obtain a shorter surgical incision through IA technique. The technique of EA requires the removal of the fixed bowel tubes and mesentery outside the abdomen for performing the anastomosis. Especially in obese patients, there is necessary to enlarge the incision for avoiding mesenteric tear and bleeding in the process of traction, as well as affecting the blood supply to the anastomotic stom because of their thickend abdominal wall and mesenteries.6,17,18 However, the adoption of IA only needs a mini-laparotomy to ensure the extraction of the bowel resected, which can be more easily accepted by young patients whoever with high aesthetic requirements. The subgroup analysis of this study showed that the group of IA spended even more time in laparoscopic surgery. we suspect that the reason is that the narrow space makes it difficult for the surgeons to operate and the surgeons themselves is not skilled enough, which may be remedied after mastering the technique ultimately.
Postoperative complication, as one of the most concerned topics for surgeons, is an important indicator to evaluate the satisfactory to the operation.19,20 This meta-analysis showed no obvious difference in postoperative anastomotic leakage, deep space infection and ileus between IA and EA. However, the group IA manifested inferior to the group EA in the occurrence of wound infection. In addition to the longer incision for EA, another reason may be that the infection was created when the enlarged surgical incision was made before the bowel tube was removed for anastomosis.21,22
The group of IA, in the postoperative period, demonstated significantly shorter on time to first flatus, time to first stool and time to first diet. Totally laparoscopic intracorporeal anastomosis take less mobilization and manipulation to the intestine, which cause less damage to the nerves and blood vessels of the intestine, and can be more conducive to the recovery of intestinal function after operation. Moreover, surgical stress may also affect the recovery of intestinal function. EA requires the removal of the intestinal tube and its mesentery outside the body, which will cause stress response to the intestinal tube when get the sutured intestinal tube transported back into the abdominal cavity. In addition, the process of returning to the abdomen may cause temporary ischemia and paralysis due to the location and direction of the intestinal tube, and eventually affect the intestinal peristalsis and nutrient absorption. Studies had reported that IA is beneficial to the recovery of intestinal function in other intestinal resection procedures.23
Above all, IA not only has a smaller incision length, fewer complications, but also has faster recovery of intestinal function. Therefore, patients with IA have superiority in the speed of postoperative recovery. Study showed that the length of hospital stay was significantly shorter than the group of EA. which means that IA has obvious advantages for postoperative recovery of patients.
This meta-analysis still has several limitations. Firstly, all the 8 articles included were retrospective studies, which have a great impact on the selection bias. The research did not collect and analyze the long-term outcomes of patients after surgery, which dose not permit to draw any conclusions regarding many parameters including the rate of strictures in the anastomoses, disease-free survival retes, overval rates and hernia rates in the incision sites.6 Additionally, different surgeons, patients and conditions for surgery also have a great influence on the results of surgery.
In conclusion, this meta-analysis showed that IA had obvious advantages over EA in reducing postoperative complications, promoting postoperative recovery of gastrointestinal function and reducing hospital stay duration. Although the operation time tended to be longer in the IA group of laparoscopic treatment. Furthermore. Additional case studies are required to confirm this systematic review, especially in terms of long-term parameters.