Article type
Year
Abstract
Background: Surgical expertise is an important outcome predictor in operative treatment of various diseases and conditions. It is also a common argument raised by surgeons against null-differences noted in randomized trials. A famous example is the Cochrane Review of laparoscopic versus open inguinal hernia repair conducted by the EU Hernia Trialists. With regard to relative risks of hernia recurrence, there is a net benefit in the use of synthetic mesh rather than the surgical approach. Many laparoscopic surgeons argued that this result does not reflect clinical practice and neglects potential advantages with minimally-invasive surgery (e.g., improved patient comfort, earlier recovery).
Objectives: Accounting for the significant heterogeneity of trial results, we set out to explore potential confounders contributing to the common effect estimate in the EU Hernia Trialists review.
Methods: We retrieved all publications of randomized trials of laparoscopic versus open inguinal hernia repair included in the EU Hernia Trialists meta-analysis. Two authors independently abstracted information about demographic details and technical issues reported in the original papers. We applied random-effects meta-regression to identify variables that were likely to alter the relative risk of hernia recurrence with either route.
Results: We included 41 randomized trials (7,446 patients), two of which were identified by an extra systematic literature search. Meta-regression was limited because of scarce information provided in the original papers, and small sample sizes. Results varied internationally, with trials from the UK, southern Europe and Australia favoring open hernioplasty (analysis of variance, p=0.0047). Large numbers of surgeons contributing to the open hernioplasty group predicted better results with endoscopic hernia repair (risk ratio 0.99 with any additional surgeon, 95% confidence interval 0.98-1.00, p=0.005). Non-significant trends were observed towards reduced recurrence risks with increasing mesh sizes. Training procedures performed before patient enrolment slightly reduced the relative risk of recurrence with endoscopic hernioplasty.
Conclusion: Because of the diversity in the size of effect, it is questionable whether data from the available hernia trials should be compiled into a single summary measure. Detailed surveys might be necessary if surgeons legitimately complain about the findings of a negative meta-analysis.
Objectives: Accounting for the significant heterogeneity of trial results, we set out to explore potential confounders contributing to the common effect estimate in the EU Hernia Trialists review.
Methods: We retrieved all publications of randomized trials of laparoscopic versus open inguinal hernia repair included in the EU Hernia Trialists meta-analysis. Two authors independently abstracted information about demographic details and technical issues reported in the original papers. We applied random-effects meta-regression to identify variables that were likely to alter the relative risk of hernia recurrence with either route.
Results: We included 41 randomized trials (7,446 patients), two of which were identified by an extra systematic literature search. Meta-regression was limited because of scarce information provided in the original papers, and small sample sizes. Results varied internationally, with trials from the UK, southern Europe and Australia favoring open hernioplasty (analysis of variance, p=0.0047). Large numbers of surgeons contributing to the open hernioplasty group predicted better results with endoscopic hernia repair (risk ratio 0.99 with any additional surgeon, 95% confidence interval 0.98-1.00, p=0.005). Non-significant trends were observed towards reduced recurrence risks with increasing mesh sizes. Training procedures performed before patient enrolment slightly reduced the relative risk of recurrence with endoscopic hernioplasty.
Conclusion: Because of the diversity in the size of effect, it is questionable whether data from the available hernia trials should be compiled into a single summary measure. Detailed surveys might be necessary if surgeons legitimately complain about the findings of a negative meta-analysis.