Umbilical Hernia RCT-Absorbable vs. Permanent Suture

Not Applicable

Not yet recruiting

• Conditions: Hernia Surgery; Umbilical Hernia Repair

• Registration Number: NCT07156188
• Lead Sponsor: University of British Columbia

Brief Summary

Umbilical hernias can be found in over a quarter of the population and comprise of 15% of hernia repairs performed in Canada. While mesh repair is commonly used for larger hernias, smaller hernia defects are often closed with sutures alone. While non-absorbable sutures may have greater tensile strength, the use of absorbable sutures have been found to reduce the risk for wound infection and improved healing. The objective of this multi-centre, nationwide randomized controlled study is to determine whether there is a difference in hernia recurrence when the repair is completed with absorbable polydioxanone suture versus permanent polypropylene suture. We will also explore post-operative complications and quality of life. Recruitment will take place over 5 years with follow-up at the 30-day, 12-month and 24-month mark following surgery. The results of this trial will be directly applicable to national and international hernia guidelines and will impact the care of thousands of patients.

Detailed Description

Umbilical hernias are defined as a primary hernia with its centre at the umbilicus (Muysoms et al., 2012). In Canada in 2019 there were 66,234 hernia surgeries performed and umbilical hernias comprise about 15% of all abdominal wall hernia repairs such that about 9,900 umbilical hernia repairs are performed in Canada each year (Information, 2023). In America there are around 175,000 umbilical hernia repairs per year (Rutkow, 2003).

Up to 25% of the population have asymptomatic umbilical hernias when examined using ultrasound (Bedewi et al., 2012); and, recent computed tomography studies have identified umbilical hernia in up to 62% of the population (Alvarez-Lozada et al., 2024). The European Hernia Society (EHS) guidelines classify umbilical hernias by size as small (0-1cm), medium (more than 1 cm up to 4cm) and large (over 4 cm) based on diameter (Henriksen et al., 2020). Although many hernias are asymptomatic, intra-abdominal contents (such as fat or bowel) can protrude through the defect and result in a surgical emergency. Up to 20% of patients with asymptomatic umbilical hernia will later require elective surgery and another 4% will require emergency surgery (Holihan et al., 2017).

The EHS guidelines recommend mesh for all hernia repairs to reduce rate of recurrence, but quality of evidence is limited for hernias less than 1cm in size and therefore suture repair can be considered in these situations. Despite EHS guidelines, in many cases umbilical hernias up to 2 cm in size are repaired with suture based on intra-operative assessment, for example, to avoid enlarging the defect necessary to accommodate a pre-peritoneal mesh with overlap of 3cm.

The Americas Hernia Society Quality Collaborative Database found that for mesh repairs were used for 82% of umbilical hernias \>1cm in diameter and 33% of those ≤1cm diameter (Koebe et al., 2021). For the National Health Service in England, 50% of umbilical hernias were repaired with mesh (Pawlak et al., 2020). This has led to controversial reclassification of small hernias to those \<2cm in size. Of small (\<2cm) umbilical hernias captured by Herniamed, a hernia registry in Germany, Austria, and Switzerland, suture repair was performed for 76.5%. (Kockerling et al., 2021)

The double-blind multicentre randomized controlled trial by Kauffmann et al. compared suture to mesh repair of primary umbilical hernias found an 8% recurrence rate following suture repair of umbilical hernias 1-2cm in size (Kaufmann et al., 2018).

Based on clinical experience, there does appear to be higher rates of granuloma formation, sinus tract formation, wound complications following the use of non-absorbable sutures. A systematic review and meta-analysis of techniques for the closure of midline abdominal incisions compared absorbable and non-absorbable suture and identified increased pain and suture sinus formation with the use of non-absorbable suture (van 't Riet et al., 2002). Another systematic review comparing slowly absorbable versus non-absorbable suture for laparotomy fascial closure found no difference in hernia rate, but a higher rate of suture sinus formation after using non-absorbable suture (Sajid et al., 2011). Rat models have also demonstrated that slowly absorbable polydioxanone suture may be preferable to permanent polypropylene suture due to a favourable macrophage response (van Steensel et al., 2020). Two large Danish studies compared non-absorbable, slowly absorbable, and quickly absorbable sutures and found no significant difference in recurrence rates (Christoffersen et al., 2013; Christoffersen et al., 2015)

Common umbilical hernia repair complications include wound infection, pain, or hematoma. Multiple terms exist to describe complications following hernia surgery and the Ventral Hernia Working Group has endeavored to standardize this nomenclature by defining surgical site occurrence (SSO) and surgical site occurrences requiring procedural intervention (SSOPI) (DeBord et al., 2018). The PAPYRUS Trial will utilize these metrics as outcome variables because SSO will capture suture complications.

There is currently insufficient evidence base to recommend suture type or technique for the suture repair of small umbilical hernias (Dias Rasador et al., 2024). The PAPYRUS Trial will help guide surgical management and suture decisions for thousands of patients annually in North America.

Suture type may play a role in reducing risk of recurrence and post-operative complications following primary suture repair of umbilical hernia. There have been no recent systematic reviews or meta-analyses comparing suture type for umbilical hernia. In the systematic review comparing mesh versus suture for elective repair of umbilical hernia, the studies using slowly absorbable suture may favour suture repair whereas those using permanent suture may favour mesh repair (Dias Rasador et al., 2024).The European Hernia Society Guidelines states that there is insufficient clinical literature to determine whether permanent or absorbable suture should be used for the primary open repair of small umbilical hernias (Henriksen et al., 2020). This trial is needed to guide the best practices on the use of suture type when performing suture repair of primary umbilical hernia.

The results of this trial will add to the limited evidence base of the surgical management of umbilical hernias ≤2 cm in size and inform treatment guidelines for suture selection in the management of suture repair for primary umbilical hernia. This trial will guide surgical decision on preferred suture material for primary umbilical hernia repair based on differences or lack difference in recurrence, SSO, SSOPI, and patient reported QoL.

Thus, the research question for this trial is: Does slowly absorbable polydioxanone suture compared to permanent polypropylene suture for primary open repair of small \<2 cm umbilical hernias result in non-inferior recurrence, SSO, SSOPI, or QoL at 24 months following surgery?

The primary hypothesis is that slowly absorbable polydioxanone suture will be non-inferior (at a non-inferiority margin of 5%) to permanent polypropylene suture for primary repair of small (≤2cm) umbilical hernias for recurrence at 24 months.

Secondary hypotheses are:

1. Slowly absorbable polydioxanone suture is non-inferior to permanent polypropylene suture for primary repair of small (≤2cm) umbilical hernias for SSO and SSOPI at 24 months post-operatively.

Slowly absorbable polydioxanone suture is non-inferior to permanent polypropylene suture for primary repair of small (≤2cm) umbilical hernias in patient reported QoL as measured by the HerQLes and the SF-12 surveys at 24 months.

All analyses will be conducted on the intention-to-treat (ITT) population. Continuous data will be expressed as means and standard deviations and analyzed using two-sample t-test. Categorical data will be expressed as contingency tables using counts and percentages and analyzed using Chi-squared test or Fisher's exact test.

Recurrence, SSO, and SSOPI will be analyzed as follows:

* Descriptive statistics using Chi-squared test at 30 days, 12 months and 2 years

* Kaplan-Meier survival analysis at 30 days, 12 months and 2 years

* Log-rank test to compare differences in survival distributions

* Cox proportional hazards model to adjust for covariates and obtain estimates for hazard ratio and 95% confidence interval

HerQLes and SF-12 scores:

• Differences between preoperative and postoperative HerQLes and SF-12 scores at 30 days, 12 months, and 2 years will be first evaluated using repeated measures ANOVA. If significant overall event is detected, then pairwise comparisons using paired t-test at 30 days, 12 months, and 2 years with Bonferroni correction will be conducted.

Subgroup analyses will be conducted to evaluate differences in hernia risk factors and sites. All analyses will be conducted using R Statistical Software (v4.5.0; Vienna, Austria).

Study Timeline

• Status Verified: 2025-09
• Study First Submitted: 2025-09-03
• Study First Submitted QC: 2025-09-03
• Last Update Submitted: 2025-09-03
• Study First Posted: 2025-09-05
• Last Update Posted: 2025-09-05
• Study Start: 2026-01-01
• Primary Completion: 2028-12-31
• Study Completion: 2030-12-31

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 914

Inclusion Criteria

1. Elective surgery for primary umbilical hernia with a defect ≤ 2 cm measured clinically or radiographically
2. Age > 18 years
3. Patient able to give oral and written informed consent

Exclusion Criteria

1. Umbilical hernia defect > 2 cm measured clinically, radiologically, or intraoperatively with ruler
2. Multiple defects
3. Incisional hernia: prior hernia in area of operation
4. Recurrent umbilical hernia
5. Epigastric hernia
6. Secondary operation performed simultaneously
7. Pregnancy
8. Infected wounds
9. Acute operation (incarcerated or strangulated hernia)
10. BMI ≥ 35 kg/m^2
11. Ascites or liver cirrhosis
12. Peritoneal dialysis
13. Immunosuppression
14. Connective tissue disorder
15. Patient deemed unfit for primary repair at time of surgery based on surgeon discretion at time of operation (e.g. poor tissue quality or unexpected operative finding)
16. Defect is made in the umbilical skin or skin incision extended beyond paraumbilical incision (e.g. sigma or midline extended incision)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Recurrence	24 months	Recurrence will be diagnosed clinically at the time of follow-up. Clinical diagnosis of hernia recurrence will be determined by a standard medical assessment (ie. physical exam). In the event that clinical recurrence is uncertain, a computed tomography scan or ultrasound will be performed while the patient performs a Valsalva maneuver.

Secondary Outcome Measures

Name	Time	Method
SSO	30 days, 12 months, 24 months	SSO will be diagnosed according to the Ventral Hernia Working Group definition which includes: surgical site infection, seroma, dehiscence, enterocutaneous fistula, surgical site infection, seroma, wound dehiscence, enterocutaneous fistula, wound cellulitis, non-healing incisional wound, fascial disruption, skin or soft tissue ischemia, skin or soft tissue necrosis, wound serous or purulent drainage, stitch abscess, seroma, hematoma, and infected or exposed mesh (Ventral Hernia Working et al., 2010).
SSOPI	30 days, 12 months, 24 months	Surgical Site Occurrences (SSOs) requiring a procedural intervention, defined as wound opening or debridement, suture excision, or percutaneous drainage
Quality of Life - HerQLes	30 days, 12 months, 24 months	The Hernia-Related Quality of Life Survey (HerQLes) is a validated patient reported outcome measure specific to abdominal wall hernias, verified in subgroup analysis of patients with small hernias (Haisley et al., 2021; Krpata et al., 2012). The HerQLes includes 12 statements related to the abdominal wall (Haisley et al., 2021; Krpata et al., 2012; Renshaw et al., 2022). Each of the 12 statements is scored from 1 to 6 (strongly disagree to strongly agree, respectively). Each statement covers a domain relevant to hernia-related QoL and the scores can be compared for each statement and in aggregate. Summary scores are calculated using the following formula: (120-\[(20/12)∗(raw score)\]).
Quality of Life - SF-12	30 days, 12 months, 24 months	The 12-item Short Form Survey from the RAND Medical Outcomes Study (SF-12) is a general health status questionnaire, a truncated and validated version of the extensively used SF-36, used to assess baseline health and postoperative recovery (Antonescu et al., 2014; Brazier et al., 1992; LaGuardia et al., 2024). The SF-12 is a self-reported health related QoL questionnaire comprised of 12 items including 8 domains of health (physical functioning, role functioning physical, bodily pain, general health, vitality, social functioning, role functioning emotional, and mental health) (Ware et al., 1996). In accordance with prior hernia research, the results of test items will be normalized and expressed in terms of 2 meta-scores: Physical Component Summary and Mental Component Summary. (Rosen et al., 2017) A higher SF-12 is indicative of better functioning.
Post-Operative Complications	30 days	Complications will be determined at follow-up 30 days after surgery and will be defined based on Clavien-Dindo criteria (Clavien et al., 2009).

Trial Locations

Locations (5)

Royal Alexandra Hospital/University of Alberta; 🇨🇦 Edmonton, Alberta, Canada

Royal Victoria Hospital; 🇨🇦 Barrie, Ontario, Canada

London Health Sciences Centre; 🇨🇦 London, Ontario, Canada

North York General Hospital; 🇨🇦 North York, Ontario, Canada

Vancouver Coastal Health; 🇨🇦 Vancouver, Canada