Which mesh for hernia repair?

Abstract

Introduction: The concept of using a mesh to repair hernias was introduced over 50 years ago. Mesh repair is now standard in most countries and widely accepted as superior to primary suture repair. As a result, there has been a rapid growth in the variety of meshes available and choosing the appropriate one can be difficult. This article outlines the general properties of meshes and factors to be considered when selecting one.

Materials and methods: We performed a search of the medical literature from 1950 to 1 May 2009, as indexed by Medline, using the PubMed search engine (www.pubmed.gov). To capture all potentially relevant articles with the highest degree of sensitivity, the search terms were intentionally broad. We used the following terms: 'mesh, pore size, strength, recurrence, complications, lightweight, properties'. We also hand-searched the bibliographies of relevant articles and product literature to identify additional pertinent reports.

Results and conclusions: The most important properties of meshes were found to be the type of filament, tensile strength and porosity. These determine the weight of the mesh and its biocompatibility. The tensile strength required is much less than originally presumed and light-weight meshes are thought to be superior due to their increased flexibility and reduction in discomfort. Large pores are also associated with a reduced risk of infection and shrinkage. For meshes placed in the peritoneal cavity, consideration should also be given to the risk of adhesion formation. A variety of composite meshes have been promoted to address this, but none appears superior to the others. Finally, biomaterials such as acellular dermis have a place for use in infected fields but have yet to prove their worth in routine hernia repair.

Figure 2

Comparison of mesh strength with abdominal wall pressures.

Figure 1

The tension placed on the abdominal wall as calculated by the law of Laplace.

Figure 3

Granulomas forming around individual mesh fibres and bridging where individual granulomas become confluent with each other and encapsulate the entire mesh.

Figure 4

Shrinkage properties of different meshes. Prolene shrinks 75–94%, PTFE shrinks 40–50%, Vypro II shrinks 29%, Ultrapro shrinks < 5%, and Sofradim shrinks < 5%.