This review concluded that the LigaSure vessel-sealing system for thyroidectomy could be a safe, useful and fast alternative to conventional thyroidectomy. However, in light of high levels of heterogeneity, the possibility of publication bias and the unknown quality of included trials, these conclusions should be viewed with caution.

To investigate the haemostatic effects and safety of thyroidectomy performed using the LigaSure vessel-sealing device compared with conventional vessel ligation.

MEDLINE, EMBASE, Scopus, SpringerLink, and the Cochrane Library databases were searched (from 1996 to 2008) for published or unpublished articles in any language. Search terms were reported. The LigaSure manufacturer's website was also searched. In addition, the "related articles" function was used and reference lists were handsearched.

For inclusion in the meta-analyses, studies had to be either randomised controlled trials (RCTs) or non randomised controlled trials that compared the LigaSure vessel sealing system with conventional vessel ligation in patients undergoing thyroidectomy. Eligible trials were required to allow four counts of a standard 2x2 table to be extracted or calculated from published data for postoperative complication rates.

Primary outcomes of interest were operative duration and amount of intraoperative blood loss. Secondary outcomes of interest were length of hospital stay and postoperative complications.

The included trials were of patients that underwent total or subtotal thyroidectomy; two trials had no restrictions on what type of thyroidectomy was performed. The proportion of male participants ranged from 10 to 22% in the LigaSure group and 11 to 35% in the conventional group. Mean ages of participants ranged from 44 to 52 years in the LigaSure group and 44 to 54 years in the conventional group. The percentage of malignant tumours ranged from 0 to 26% in the LigaSure group and 0 to 24% in the conventional group. The thyroidectomy procedures used were generally consistent between trials and were described in details in the review

Two reviewers independently assessed the eligibility of studies, with disagreements resolved by a third reviewer; decisions to include or exclude studies were made by two reviewers.

Methodological quality was assessed independently by two reviewers using published guidelines (CRD, Verhagen et al, Downs and Black) and the generic appraisal tool for epidemiological studies.

Two reviewers independently extracted continuous outcomes and means and medians (with standard deviations; SDs) for operative duration, intraoperative blood loss and length of hospital stay. Odds ratios (ORs) were extracted for complication incidence. Authors of primary trials were contacted for further information if necessary. Disagreements were resolved by a third reviewer.

Odds ratios and mean differences were pooled to produce weighted mean differences (WMDs) using the random-effects model in the presence of high heterogeneity (I² over 50%); if heterogeneity was not high, a fixed-effect model was used. Heterogeneity was assessed using χ² and I² tests. Publication bias was assessed using the Begg funnel plot and Egger regression test.

Nine clinical trials were included (n=927 patients, range 40 to 200); four were randomised (n=474 patients) and five were non randomised (n=453 patients).

Operative duration was significantly decreased with LigaSure compared with conventional treatment (WMD -11.97 minutes, 95% CI -16.42 to -7.53; eight studies). Similar results were seen in subgroup analyses of those undergoing total thyroidectomy and subtotal thyroidectomy.

There was no significant difference between LigaSure and conventional treatment for the outcomes intraoperative blood loss, length of hospital stay and postoperative complication rates.

All analyses excluding complication rates were associated with significant heterogeneity (I² ranged from 78.6 to 98.9%).

There was evidence of publication bias.

This review showed that the LigaSure vessel-sealing system for thyroidectomy could be a safe, useful and fast alternative to conventional thyroidectomy.

The review question was defined in terms of study design, intervention, comparator, participants and outcomes. Although unpublished studies were eligible for inclusion, no attempts to uncover unpublished studies were reported and publication bias was suggested. Searching for studies in all languages reduced the possibility of language bias. The review process was performed in duplicate, reducing the possibility of reviewer error and bias.

The quality of the studies was assessed, but it was unclear how this was performed and how this was incorporated into the analysis. The results of the validity assessment were not reported. The meta-analyses were associated with high levels of heterogeneity, so the results of these may not be reliable.

In light of high levels of heterogeneity, the possibility of publication bias and the unknown quality of included trials, the authors' conclusions should be viewed with caution.

Practice: The authors did not state any implications for practice.

Research: The authors stated that further prospective RCTs are required to assess routine use of LigaSure during thyroidectomy.

Not reported.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.