NIHR Signal Mesh repair rather than stitches reduces risk of recurrence of abdominal hernias in adults

Published on 23 March 2016

Artificial mesh is often used to repair hernias in the abdominal wall, but evidence on how this compares with repair using stitches has been lacking. This review found evidence that mesh repair reduces risk of recurrence compared with stitches. There were some quality issues with the included trials, which mean that the impact on recurrence rates might be less in practice. Findings for other outcomes, such as persistent pain, were inconsistent. There was no reported difference in complication rates.

These findings support current practice and may also help healthcare professionals provide patients with more information on the effectiveness of the different approaches. The review authors are planning further research to establish how best to position and fix the mesh.

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Why was this study needed?

This review aimed to look at the best method of repair for abdominal (ventral) hernias. This is where internal organs or tissues bulge out through an area of weakness in the abdominal muscle. Sometimes this can be a scar from past surgery, in which case they are called incisional hernias. If the tissues inside the hernia get stuck their blood supply may be cut off: this is called strangulation. Mesh is a common way to repair ventral hernias (see Definitions), but the benefits over stitching have been assumed rather than proven by evidence. The review aimed to gather evidence on the effects on hernia recurrence, in addition to other outcomes that matter to patients, such as pain persisting in the long term after surgery.

Information is not available on the exact number of ventral hernia repairs that take place in the UK each year. In a study of 1,379 hernia repairs between 2005-8 at a single UK hospital trust, a third (455) were repairs for ventral hernias, including incisional. Almost all of the remaining repairs were carried out for inguinal hernias – around the top of the thigh – the most common type of hernia repair performed.

This was the first review to draw solely on randomised controlled trials, rather than observational studies, which are more likely to give biased results.

What did this study do?

The review included 10 randomised controlled trials comparing ventral hernia repair with mesh or stitches in 1,215 adult participants. Results were pooled only for hernia recurrence, as the included trials used different criteria for complications and length of follow up.

The main outcomes were recurrence of ventral hernia between six months and five years after surgical repair. Other outcomes were post-operative complications, quality of life and pain.

The review was carried out to a high standard, but the 10 included trials had mixed findings, and carried moderate to high risk of bias. These included the way in which participants were allocated to repair method, and whether researchers were aware of the treatment given when assessing outcomes. There was also some indication of publication bias towards studies favouring mesh repair. The geographical location of the trials was not stated, so the applicability to the UK is unclear. Together these limitations reduce the confidence that we can have in precise estimates of risk, but it is likely that with biases taken into account the direction of effect is clear.

What did it find?

  • The pooled results of all 10 trials showed that hernia recurrence within six months to five years after surgery was 64% less likely after mesh repair than after stitching (relative risk [RR] 0.36, 95% confidence interval [CI] 0.27 to 0.49).
  • Five trials analysed differences in pain after surgery, but using different definitions and length of time after surgery, therefore the results of these trials was not pooled. However, three out of five trials reported more pain after mesh repair compared with stitching. There was some indication that the method of fixation used for the mesh may have an effect on persistent pain so this important patient outcome may need further study.
  • Complications such as wound infections were uncommon and did not significantly differ between treatments.

What does current guidance say on this issue?

There is a lack of current UK guidance specifically on repair of ventral hernias in adults. NICE work on a new guideline, the Diagnosis and Management of Hernia, was deferred in 2015 and the future publication date is unknown.

Guidelines from the Society of American Gastrointestinal and Endoscopic Surgeons from 2014 state that evidence is lacking on types of mesh, mesh positioning or how best to fix the mesh.

What are the implications?

The review’s findings lend support to existing practice – to use mesh rather than sutures for ventral hernia repair – as being most effective for preventing hernia recurrence. The included studies were randomised but were subject to some biases. These might have influenced the estimate of recurrence rates but are unlikely to have had an important impact on the finding that recurrences were reduced. Other outcomes, for example post-operative pain, were variably examined and the findings inconsistent across trials.

The findings provide information on the current state of the evidence comparing ventral hernia repair with mesh or sutures, which healthcare professionals could share with prospective adult patients.

Citation and Funding

Mathes T, Walgenbach M, Siegel R. Suture versus mesh repair in primary and incisional ventral hernias: a systematic review and meta-analysis. World J Surg. 2015. [Epub ahead of print].

No funding information was provided for this study.

Bibliography

Dabbas N, Adams K, Pearson K, Royle GT. Frequency of abdominal wall hernias: is classical teaching out of date? JRSM Short Reports. 2011;2(1):5.

Earle D, Roth S, Saber A, et al. Guidelines for laparoscopic ventral hernia repair. Los Angeles (CA): Society of American Gastrointestinal and Endoscopic Surgeons;2014.

NHS Choices. Hernia [internet]. NHS Choices; 2014.

NICE. Diagnosis and management of hernia (guidance in development). London: National Institute for Health and Care Excellence; 2015.

Sauerland S, Walgenbach M, Habermalz B, et al; Laparoscopic versus open surgical techniques for ventral or incisional hernia repair. Cochrane Database Syst Rev. 2011. 16;(3):CD007781.

Walgenbach M, Mathes T, Siegel R, Eikermann M. Mesh fixation techniques in primary ventral or incisional hernia repair [protocol]. Cochrane Database Syst Rev. 2015;(3):CD011563.

Why was this study needed?

This review aimed to look at the best method of repair for abdominal (ventral) hernias. This is where internal organs or tissues bulge out through an area of weakness in the abdominal muscle. Sometimes this can be a scar from past surgery, in which case they are called incisional hernias. If the tissues inside the hernia get stuck their blood supply may be cut off: this is called strangulation. Mesh is a common way to repair ventral hernias (see Definitions), but the benefits over stitching have been assumed rather than proven by evidence. The review aimed to gather evidence on the effects on hernia recurrence, in addition to other outcomes that matter to patients, such as pain persisting in the long term after surgery.

Information is not available on the exact number of ventral hernia repairs that take place in the UK each year. In a study of 1,379 hernia repairs between 2005-8 at a single UK hospital trust, a third (455) were repairs for ventral hernias, including incisional. Almost all of the remaining repairs were carried out for inguinal hernias – around the top of the thigh – the most common type of hernia repair performed.

This was the first review to draw solely on randomised controlled trials, rather than observational studies, which are more likely to give biased results.

What did this study do?

The review included 10 randomised controlled trials comparing ventral hernia repair with mesh or stitches in 1,215 adult participants. Results were pooled only for hernia recurrence, as the included trials used different criteria for complications and length of follow up.

The main outcomes were recurrence of ventral hernia between six months and five years after surgical repair. Other outcomes were post-operative complications, quality of life and pain.

The review was carried out to a high standard, but the 10 included trials had mixed findings, and carried moderate to high risk of bias. These included the way in which participants were allocated to repair method, and whether researchers were aware of the treatment given when assessing outcomes. There was also some indication of publication bias towards studies favouring mesh repair. The geographical location of the trials was not stated, so the applicability to the UK is unclear. Together these limitations reduce the confidence that we can have in precise estimates of risk, but it is likely that with biases taken into account the direction of effect is clear.

What did it find?

  • The pooled results of all 10 trials showed that hernia recurrence within six months to five years after surgery was 64% less likely after mesh repair than after stitching (relative risk [RR] 0.36, 95% confidence interval [CI] 0.27 to 0.49).
  • Five trials analysed differences in pain after surgery, but using different definitions and length of time after surgery, therefore the results of these trials was not pooled. However, three out of five trials reported more pain after mesh repair compared with stitching. There was some indication that the method of fixation used for the mesh may have an effect on persistent pain so this important patient outcome may need further study.
  • Complications such as wound infections were uncommon and did not significantly differ between treatments.

What does current guidance say on this issue?

There is a lack of current UK guidance specifically on repair of ventral hernias in adults. NICE work on a new guideline, the Diagnosis and Management of Hernia, was deferred in 2015 and the future publication date is unknown.

Guidelines from the Society of American Gastrointestinal and Endoscopic Surgeons from 2014 state that evidence is lacking on types of mesh, mesh positioning or how best to fix the mesh.

What are the implications?

The review’s findings lend support to existing practice – to use mesh rather than sutures for ventral hernia repair – as being most effective for preventing hernia recurrence. The included studies were randomised but were subject to some biases. These might have influenced the estimate of recurrence rates but are unlikely to have had an important impact on the finding that recurrences were reduced. Other outcomes, for example post-operative pain, were variably examined and the findings inconsistent across trials.

The findings provide information on the current state of the evidence comparing ventral hernia repair with mesh or sutures, which healthcare professionals could share with prospective adult patients.

Citation and Funding

Mathes T, Walgenbach M, Siegel R. Suture versus mesh repair in primary and incisional ventral hernias: a systematic review and meta-analysis. World J Surg. 2015. [Epub ahead of print].

No funding information was provided for this study.

Bibliography

Dabbas N, Adams K, Pearson K, Royle GT. Frequency of abdominal wall hernias: is classical teaching out of date? JRSM Short Reports. 2011;2(1):5.

Earle D, Roth S, Saber A, et al. Guidelines for laparoscopic ventral hernia repair. Los Angeles (CA): Society of American Gastrointestinal and Endoscopic Surgeons;2014.

NHS Choices. Hernia [internet]. NHS Choices; 2014.

NICE. Diagnosis and management of hernia (guidance in development). London: National Institute for Health and Care Excellence; 2015.

Sauerland S, Walgenbach M, Habermalz B, et al; Laparoscopic versus open surgical techniques for ventral or incisional hernia repair. Cochrane Database Syst Rev. 2011. 16;(3):CD007781.

Walgenbach M, Mathes T, Siegel R, Eikermann M. Mesh fixation techniques in primary ventral or incisional hernia repair [protocol]. Cochrane Database Syst Rev. 2015;(3):CD011563.

Suture Versus Mesh Repair in Primary and Incisional Ventral Hernias: A Systematic Review and Meta-Analysis

Published on 14 November 2015

Mathes, T.,Walgenbach, M.,Siegel, R.

World J Surg , 2015

BACKGROUND: Today, ventral hernia repair is predominantly performed with meshes. There is no meta-analysis of high quality evidence that compares the results of suture to mesh repair. The objective of this systematic review with meta-analysis is to compare patient centred outcomes of suture versus mesh repair. METHODS: A systematic literature search was performed in EMBASE, MEDLINE and CENTRAL (inception to 06/2014). Furthermore a hand search was performed. RCTs comparing suture versus mesh repair in primary and incisional ventral hernia repair were included. Data on patient characteristics, interventions and results were extracted in standardized tables. Risk of bias was assessed with the cochrane risk of bias tool. Results of studies were pooled with a meta-analysis. All steps were performed by two reviewers. Discrepancies were discussed until a consensus. RESULTS: The search in the databases resulted in 1560 hits. After screening, 10 randomized controlled trials including 1215 patients satisfied all inclusion criteria. Risk of bias was moderate to high. The relative risk for recurrence was 0.36 [95% CI (0.27, 0.49); I 2 = 0; heterogeneity p = 0.70]. Other complications did not differ significantly. Results for chronic pain were heterogeneous across studies. CONCLUSION: Mesh repair reduces the number of recurrences significantly. In patients without recurrence mesh repairs seem to be associated with a risk of chronic pain especially if the mesh is fixed sublay.

The aim of surgery for ventral hernia is to repair the weakness and retain the abdominal tissues inside the abdominal wall, so preventing the risk of the tissues getting stuck in the hernia and strangulating.

Mesh for hernia repairs is typically a patch made from polypropylene, cut and shaped to fit during surgery and acting as a support for the body’s own tissues as they heal.  It is soft and flexible and so can move with the body, spreading the load rather than concentrating the strain at wound stitches. Stitching is now an infrequent method for repair in the UK as almost half of surgical scar hernias recur after using this approach.

Expert commentary

Incisional hernia repair without prosthetic mesh is associated with unsatisfactory recurrence rates varying between 12% and 54 %, while mesh hernia repair results in recurrence rates of 2% to 36%. It is now accepted that only the smallest (less than 3cm) incisional hernia should be repaired via primary tissue approximation with sutures. The difficulty in interpreting the literature comparing various types of mesh and suture repair results from the heterogeneity of studies. Many randomised controlled trials are limited to short term follow up of 12 months or less and there is considerable variability in the methods used for diagnosing recurrence (radiological or clinical) and measuring chronic pain.

Taking these factors into account any meta-analysis is limited by heterogeneity and publication bias of the randomised controlled trials used in the analysis. Nevertheless incisional hernias are a cause of significant morbidity and cost. Getting the repair right first time is important as subsequent repairs after recurrence have significantly worse outcomes.

Mr David Sanders, Consultant Surgeon North Devon District Hospital, Board Member of the British Hernia Society

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