Operative versus conservative management for inguinal hernia: a methodology scoping review of randomized controlled trials

Abstract

Introduction: There is a lack of consensus on the management of inguinal hernia with limited symptoms. To address this issue a systematic review of existing randomized clinical trials (RCTs) was performed to critically appraise all existing data on asymptomatic hernia management, focusing on generalizability.

Methods: A scoping review to identify all RCTs comparing surgical and conservative management of patients with inguinal hernias was undertaken. Medline, Embase, Cochrane and ClinicalTrials.gov databases were searched. Data collected included study characteristics and definitions of population, intervention/comparator, and outcomes; and limitations of each study were also extracted. The quality and generalizability of included RCTs were evaluated using Cochrane's ROB-2 and the PRECIS-2 tool, respectively.

Results: Searches returned 661 papers; 14 full-text papers were assessed and three RCTs were identified. All RCTs included only male patients with a mean age above 55 years. All RCTs included asymptomatic patients and two included those with minimal symptoms. Different definitions for 'minimally symptomatic' were used in RCTs and none provided details of what was meant by conservative treatment. Follow-up periods varied between studies (1, 2, 3 years). All RCTs had an overall high risk of bias. According to PRECIS-2, two RCTs were classified as pragmatic, and one was equally pragmatic and explanatory.

Discussion: This systematic review highlights a high risk of bias but a good generalizability of the findings from the RCTs conducted on minimally symptomatic inguinal hernia patients. To improve the guidelines for the management of this group of patients, more generalizable data are needed.

Fig. 1

PRISMA flowchart of included studies This figure shows the identified and selected studies during this review. ICRT, International Clinical Trials Registry Platform; WHO, World Health Organization; RCT, randomized clinical trial.

Fig. 2

Evaluation of each study with PRECIS wheels This figure shows the application of PRECIS-2 wheels to each included study. This also evaluates nine domains that are related to trial design decisions and include: Eligibility criteria, Recruitment, Setting, Organization, Flexibility delivery, Flexibility adherence, Follow-up, Primary outcome, Primary analysis. PRECIS, Pragmatic Explanatory Continuum Indicator Summary. Trials that take an explanatory approach produce wheels nearer the hub; those with a pragmatic approach are closer to the rim.