Comparison between Endoloop ligature and Hem-o-lok clip (Polymer ligation) for appendiceal stump closure during laparoscopic appendicectomy

A best evidence topic has been constructed using a described protocol. The three-part question addressed was: In patients undergoing laparoscopic appendicectomy is Hem-o-lok clip safer than Endoloop ligature for closure of appendiceal stump? The search has been devised and 6 studies were deemed to be suitable to answer the question. The outcome assessed was the safety and cost effectiveness of Hem-o-lok clip (Polymer ligation) versus Endoloop ligature for appendiceal stump closure during laparoscopic appendicectomy. We concluded that Hem-o-lok clip is a safe and feasible tool for appendiceal stump closure. It's also a cost-effective way and could be a cheaper option compared to other measures.


Introduction
This BET was constructed using a framework outlined by the International Journal of Surgery [1]. A BET provides evidence-based answers to common clinical questions, using a systematic approach of reviewing the literature.

Clinical scenario
In performing laparoscopic appendicectomy, which technique is the best for appendiceal stump closure? Is it Endoloop ligature or Hem-o-lok clip? Are there any downsides for using either one of them? Therefore, we decided to conduct a systematic review to look for an evidence-based answer to these questions. The search was limited to English language and human studies.

Search outcome
250 articles were found. Out of these 6 deemed to be suitable and met the criteria of our search after removing the duplicate and excluding the irrelevant articles. We only included articles which compared these two methods for appendiceal stump closure and excluded studies which compared other methods.
Exclusion criteria: 1 Conference abstracts 2 Studies not comparing both techniques

Discussion
During laparoscopic appendicectomy, the base of the appendix is usually secured by an Endoloop ligature [8] or stapler [9]. A non-absorbable Hem-o-lok clip (Weck Closure Systems, Research Triangle Park, Durham, NC, USA) was shown as an alternative technique which can be cheaper and quicker [10].
In 2012, Delibegovic'et al. [2] devised a prospective randomized clinical trial to compare safety, intraoperative timing and cost effectiveness between different methods. 90 patients with acute appendicitis were randomly divided into three groups: In the first group, the base of the appendix was secured using one Endoloop ligature, in the second group using a 45-mm stapler, and in the third group using only one nonabsorbable Hem-o-lok clip. They concluded that the use of one Hem-o-lok clip is as safe as an Endoloop and/or stapler; however, the time of the laparoscopic procedure using the Hem-o-lok was shorter in comparison with the use of an Endoloop, with the cost of the procedure being the lowest.
Hue et al. [3] conducted a prospective randomized clinical trial in the period between May 2010 to August 2011. 105 patients who underwent laparoscopic appendicectomy were included. Endoloop was used in 66 patients and Hem-o-lok in 39. The aim of the study was to investigate the safety and usefulness of the Hem-o-lok clip for the closure of appendicular stump and its limitations. They concluded that the use of Hem-o-lok clips for the closure of appendicular stumps in laparoscopic appendicectomy is a feasible, safe, fast and cost-effective procedure in patients with a mildly to moderately inflamed appendix base of less than 10 mm in diameter.
In 2013, Colak et al. [4] devised another prospective randomized clinical trial where they randomly allocated 53 patients into either Hem-o-lok or Endoloop groups. 26 patients were in the Hem-o-lok group and 27 in the Endoloop group. The aim of the study was to evaluate the clinical outcomes of Hem-o-lok ligation system in laparoscopic appendiceal stump closure by comparing it to the Endoloop ligature. They concluded that the mean operation time was shorter in the Hem-o-lok group than the Endoloop group; however, the difference was not significant. Other surgical findings were similar. The closure of the appendicular stump with polymeric nonabsorbable clips in laparoscopic appendectomy may be a cheaper and simpler alternative to other widely used methods.
In 2016, Soll et al. [5] looked at the results of 813 patients who underwent laparoscopic appendicectomy in their retrospective observational study. In 435 patients Hem-o-lok was used to close the appendiceal stump while Endoloop suture was used in 378. The aim of the study was to identify the incidence of intra-abdominal abscesses after the application of Hem-o-lok clips and compare them with Endoloop ligatures. They concluded that the closure of the appendiceal stump using the non-absorbable Hem-o-lok ligation system did result in a reduced rate of intra-abdominal surgical abscesses as compared to the application of Endoloop.
In the same year, Sadat-Safavi et al. [6] conducted a randomized clinical trial which compared the two methods of closing the appendiceal stump in terms of the length of operating time, postsurgical complications, and the duration of hospitalization. They included 76 patients who were randomly classified into two groups. 38 patients in Hem-o-lok appendiceal stump closure group and 38 patients in Endoloop group. They concluded that the effect of stump closure with Endoloop versus endoclips is not different for complications, but the duration of surgery was shorter in the endoclip method. Lastly, Lucchi et al. [7] toward the end of 2016 published a retrospective observational study which included 259 patients. The aim of the study was to investigate the safety and usefulness of the Hem-o-lok clip for the closure of appendicular stump, comparing these data with those concerning the Endoloop. Endoloop suture appendiceal stump closure was used in 121 patients while Hem-o-lok was used in 138. They concluded that both the Endoloop and Hem-o-lok are safe for the closure of the appendicular stump. However, Hem-o-lok appears to be superior to Endoloop in terms of ease of use and cheapness while maintaining the same safety.
The observed limitation to all of the abovementioned studies is the risk of bias. Moreover, in cases where the appendicular base is inflamed, friable or too wide most of the articles have either excluded them or have not used Hem-o-lok (have used either endoloop or stapler).

Clinical bottom line
Four randomized clinical trials and two retrospective studies proved that Hem-o-lock is safe and feasible tool for appendiceal stump closure. It's also a cost-effective way and could be a cheaper option compared to other measures.

Ethical approval
Not applicable.

Sources of funding
None.

Author contributions
SA: devised the idea of the study, conducted literature search and wrote the paper.
TS: assisted in literature search and collecting the data. MO: assisted in literature search and writing the paper.