Reviews & Research

/Reviews & Research
Reviews & Research2018-11-17T21:15:04+00:00

Comparing surgical groin hernia repair performed with or without mesh

https://www.cochrane.org/CD011517/COLOCA_comparing-surgical-groin-hernia-repair-performed-or-without-mesh

September 2018

Review question

This review assessed the difference in outcomes between surgical hernia repair with and without mesh.

Background

Hernias are out-pouchings of an organ through the body wall that normally contains it; in this review, we refer to the bowel or its surrounding fatty tissues protruding through the abdominal wall in the groin region. This is a very common medical problem, affecting 27 out of every 100 men. These hernias can cause significant discomfort, and can occasionally become so tightly stuck that the blood supply can be cut off (strangulation), requiring emergency surgery. The curative treatment of hernias is surgical repair, which can be closed with sutured techniques (non-mesh repair) or with a fine mesh to promote tissue growth to strengthen the previously weak area (mesh repair). Mesh repair is becoming increasingly popular in many countries, particularly in conjunction with laparoscopic (key-hole) surgery.

Search date

We searched a number of databases for studies; this search was last updated on 9 May 2018.

Study characteristics

In this update of a review originally published in 2001, we included a total of 25 studies (with a total of 6293 people) undertaken in a number of different countries. A variety of outcomes were assessed, including return of the hernia after initial repair (hernia recurrence), a variety of complications including pain, duration of surgery, hospital stay and time before going back to normal activities.

Key results

One hernia recurrence is prevented for every 46 mesh repairs performed rather than non-mesh repairs. Compared to non-mesh repairs, mesh repairs are more likely to develop collections of fluid next to the surgical wound, but are less likely to result in difficulty urinating following the operation, or injury to nerves, blood vessels or other organs. Postoperative pain could not be clearly compared between studies due to differences in measurement methods and time frames, but overall the studies appeared to indicate that participants who had mesh repairs had less pain. The length of the surgical operation was slightly shorter for mesh repairs. Participants who had a mesh repair were more likely to have a shorter hospital stay and had a shorter average recovery time before returning to their normal activities.

Quality of the evidence

The studies included in this review used good-quality methods, considered potential factors which could affect the results, and addressed their proposed outcomes clearly. In our assessment of the quality of evidence, we marked down some outcomes to ‘moderate’ quality, particularly due to variability within results.

Conclusions

Overall, hernia repairs with and without mesh both proved effective in the treatment of hernias, although mesh repairs demonstrated fewer hernia recurrences, a shorter operation time and faster return to normal activities. Non-mesh repairs are still widely used, often due to the cost and poor availability of the mesh product itself.

Authors’ conclusions:

Mesh and non-mesh repairs are effective surgical approaches in treating hernias, each demonstrating benefits in different areas. Compared to non-mesh repairs, mesh repairs probably reduce the rate of hernia recurrence, and reduce visceral or neurovascular injuries, making mesh repair a common repair approach. Mesh repairs may result in a reduced length of hospital stay and time to return to activities of daily living, but these results are uncertain due to variation in the results of the studies. Non-mesh repair is less likely to cause seroma formation and has been favoured in low-income countries due to low cost and reduced availability of mesh materials. Risk of bias in the included studies was low to moderate and generally handled well by study authors, with attention to details of allocation, blinding, attrition and reporting.

Transvaginal mesh or grafts compared with native tissue repair for vaginal prolapse

https://www.cochrane.org/CD012079/MENSTR_transvaginal-mesh-or-grafts-compared-native-tissue-repair-vaginal-prolapse

2016

Review question

Should transvaginal mesh or biological grafts or native tissue be utilised to repair vaginal prolapse?

Background

Pelvic organ prolapse is common, affecting as many as 50% of women who have had children. The traditional method of repairing vaginal prolapse using native tissue is associated with high rates of recurrence. It is thought that transvaginal grafts made of absorbable or permanent mesh or biological material may improve the outcomes of prolapse surgery.

Study characteristics

We evaluated 37 randomised controlled trials (4023 women) comparing transvaginal grafts versus traditional native tissue repair for repairing vaginal prolapse. The evidence is current to July 2015.

Key results

Low to moderate quality evidence suggests that there are advantages to using transvaginal permanent mesh compared to native tissue repair, including lower rates of awareness of prolapse, repeat surgery for prolapse, and recurrent prolapse on examination. The evidence suggests that if 19% of women are aware of prolapse after native tissue repair, between 10% and 15% will be aware of prolapse after permanent mesh repair. If the rate of recurrent prolapse on examination after a native tissue repair is assumed to be 38%, the risk would be between 11% and 20% after a repair with transvaginal permanent mesh. However, there are also problems associated with permanent transvaginal mesh. If we assume that 5% of women require repeat surgery for prolapse or urinary incontinence or mesh exposure (any of the three) after native tissue repair, the risk would be between 7% and 18% after permanent mesh repair. Eight per cent of women in the mesh groups required repeat surgery for mesh exposure.

Low quality evidence suggests that absorbable mesh may reduce the risk of recurrent prolapse on examination compared to native tissue repair, but there is insufficient evidence on absorbable mesh for us to draw any conclusions for other outcomes.

Low quality evidence suggests there is no difference between biological grafts and native tissue repair on rates of awareness of prolapse or reoperation for prolapse. Due to the very low quality of evidence, the impact of the interventions on prolapse on examination was uncertain.

While permanent mesh has some advantages over native tissue, there are also disadvantages in its routine use. Many transvaginal permanent meshes were withdrawn from use in 2011, and the newer, lightweight transvaginal permanent meshes still available have not been evaluated within a randomised study.

Quality of the evidence

Overall, the quality of the evidence ranged from very low to moderate. The main limitations were poor reporting of study methods, inconsistency, and imprecision.

Authors’ conclusions:

While transvaginal permanent mesh is associated with lower rates of awareness of prolapse, repeat surgery for prolapse, and prolapse on examination than native tissue repair, it is also associated with higher rates of repeat surgery for prolapse or stress urinary incontinence or mesh exposure (as a composite outcome), and with higher rates of bladder injury at surgery and de novo stress urinary incontinence. The risk-benefit profile means that transvaginal mesh has limited utility in primary surgery. While it is possible that in women with higher risk of recurrence the benefits may outweigh the risks, there is currently no evidence to support this position.

Limited evidence suggests that absorbable mesh may reduce rates of recurrent prolapse on examination compared to native tissue repair, but there was insufficient evidence on absorbable mesh for us to draw any conclusions for other outcomes. There was also insufficient evidence for us to draw any conclusions regarding biological grafts compared to native tissue repair.

In 2011, many transvaginal permanent meshes were voluntarily withdrawn from the market, and the newer, lightweight transvaginal permanent meshes still available have not been evaluated within a RCT. In the meantime, these newer transvaginal meshes should be utilised under the discretion of the ethics committee.