Complication Rate of Onlay vs Sublay Mesh Repair in Incisional Hernia

February 6, 2026 updated by: Gohar Ali, Hayat Abad Medical Complex, Peshawar

Comparison of Complication Rates of Onlay vs Sublay Mesh Repair of Incisional Hernia

This randomized controlled trial was conducted at the Department of Surgery, Hayatabad Medical Complex, Peshawar. Eligible patients with incisional hernia were randomized into two parallel groups: sublay mesh repair and onlay mesh repair. Procedures were performed by a single experienced general surgeon. Postoperative complications were assessed by an independent surgeon blinded to the type of procedure. Patients were followed for a period of three months to evaluate safety and recurrence outcomes.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Incisional hernia is a frequent postoperative complication following abdominal surgery and represents a significant source of morbidity due to discomfort, impaired quality of life, and risk of recurrence. Mesh reinforcement has become the standard approach for incisional hernia repair; however, the optimal anatomical position of mesh placement remains debated. Among the commonly used techniques, onlay mesh repair involves placement of mesh over the anterior rectus sheath, while sublay mesh repair places the mesh in the retromuscular preperitoneal plane. Each technique differs in operative dissection, tissue handling, and potential risk of postoperative complications.

This randomized controlled trial was conducted at the Department of Surgery, Hayatabad Medical Complex, Peshawar, to compare postoperative outcomes of onlay versus sublay mesh repair in patients undergoing elective incisional hernia repair. Adult patients aged 18 to 60 years presenting with incisional hernia and meeting predefined eligibility criteria were enrolled after providing written informed consent. Patients with recurrent, strangulated, or obstructed hernias, severe comorbid conditions, high anesthetic risk, or morbid obesity were excluded to minimize confounding factors.

Eligible participants were randomly allocated into two parallel groups using a lottery method. Patients assigned to Group A underwent sublay mesh repair, while those in Group B received onlay mesh repair. All surgical procedures were performed by a single experienced general surgeon to ensure procedural consistency. Standardized perioperative care protocols were followed for all patients.

Postoperatively, patients were monitored during hospital admission and followed in outpatient clinics for a period of three months. Assessment of postoperative complications, including wound infection, seroma, hematoma, and hernia recurrence, was carried out by an independent surgeon who was blinded to the surgical technique used. This masking approach was adopted to reduce assessment bias.

The primary objective of the study was to compare the overall postoperative complication rates between the two mesh placement techniques. Secondary objectives included evaluation of individual complication rates and recurrence during the follow-up period. Data were collected using a structured proforma and analyzed using standard statistical methods to determine differences between groups.

The findings of this study aim to provide evidence-based guidance regarding the safety and effectiveness of mesh placement techniques in incisional hernia repair and to assist surgeons in selecting an optimal approach that minimizes postoperative complications and recurrence.

Study Type

Interventional

Enrollment (Actual)

350

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Pakistan
    • KPK
      • Peshawar, KPK, Pakistan, 25000
        • Hayatabad Medical Complex

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults aged 18-60 years.
  • Patients diagnosed with primary incisional hernia on clinical examination.
  • Hernia suitable for open surgical repair with mesh.
  • Both male and female patients.
  • Patients able and willing to provide written informed consent.

Exclusion Criteria:

  • Obstructed or strangulated hernia on presentation.
  • Recurrent incisional hernia.
  • Patients with BMI > 40.
  • Patients with debilitating chronic diseases, including:
  • Chronic liver disease
  • Chronic renal impairment
  • Chronic cardiac disease
  • Chronic pulmonary disease
  • Patients with American Society of Anesthesiologists (ASA) physical status ≥ 3.
  • Patients unfit for general anesthesia.
  • Patients unable or unwilling to follow up for postoperative assessment.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Sublay Mesh Repair
Patients underwent open incisional hernia repair with placement of polypropylene mesh in the retromuscular preperitoneal (sublay) plane.
Procedure: Sublay Mesh Repair
Patients underwent open incisional hernia repair with placement of polypropylene mesh in the retromuscular preperitoneal (sublay) plane.
Active Comparator: Onlay Mesh Repair
Patients underwent open incisional hernia repair with placement of polypropylene mesh over the anterior rectus sheath (onlay technique).
Procedure: Onlay Mesh Repair
Placement of polypropylene mesh over the anterior rectus sheath during open incisional hernia repair.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative Complication Rate
Time Frame: 30 days after surgery
Incidence of complications within 30 days after surgery, including wound infection, seroma, hematoma, and hernia recurrence, in patients undergoing onlay versus sublay mesh repair of incisional hernia.
30 days after surgery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Length of Hospital Stay
Time Frame: Number of days From enrollment up to the hospital discharge
Duration of hospitalization following surgery in both study groups for this single disease.
Number of days From enrollment up to the hospital discharge
Hernia Recurrence Rate
Time Frame: Assessed at 6 months and 12 months after surgery
Number of patients with hernia recurrence within 6 months and 12 months postoperatively.
Assessed at 6 months and 12 months after surgery
Operative Time
Time Frame: During the index surgical procedure (from skin incision to skin closure)
Total duration of surgery from incision to closure for onlay and sublay procedures.
During the index surgical procedure (from skin incision to skin closure)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hayat Abad Medical Complex, Peshawar

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 1, 2020

Primary Completion (Actual)

August 31, 2025

Study Completion (Actual)

September 15, 2025

Study Registration Dates

First Submitted

January 16, 2026

First Submitted That Met QC Criteria

February 6, 2026

First Posted (Actual)

February 10, 2026

Study Record Updates

Last Update Posted (Actual)

February 10, 2026

Last Update Submitted That Met QC Criteria

February 6, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • HMC-QAD-F No. IREB-1221

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

The decision to share individual participant data (IPD) from this study has not yet been finalized. Considerations regarding patient privacy, data de-identification, and institutional policies on data sharing are still under review. Once these factors are addressed, a detailed plan for data sharing may be developed in compliance with ethical guidelines and institutional requirements.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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