[Mesh shrinkage in hernia surgery: data from a prospective randomized double-blinded clinical study].
According to an estimated mesh shrinkage following hernia repair of up to 40% a current dogma in hernia surgery requires a mesh overlap of 5 cm around the hernia. However, no valid data addressing this problem of mesh shrinkage are available at present. Within the framework of a prospective randomized double-blinded clinical trial, 50 patients were operated on for a ventral abdominal hernia with the open sublay technique using specially prepared radio-opaque polypropylene (PP) meshes. Of the patients 27 received a conventional heavyweight mesh (P group) and 23 a new lightweight mesh construction (NK group). Follow-up for at least 2 years after mesh repair included conventional abdominal x-rays after 7 days, 3 weeks and 4, 12 and 24 months, as well as computed tomography after 7 days and 4 and 12 months. Main criteria were mesh shrinkage, recurrence and complication rates and quality of life comparing groups P and NK. In 46 cases (92%) no mesh shrinkage could be detected and only 4 meshes (8%) showed a moderate shrinkage (1 of 22.2%, 2 of 8% and 1 of 3%) all from the P group. While no hernia recurrences were found, 2 surgical complications occurred with 1 seroma in the P group and 1 hematoma in the NK group. Quality of life showed a linear improvement over time up to the 2 year time point following mesh repair with advantages for the NK group. Pain and mobility scores reached standard values 12 months postoperatively without significant differences between the two groups. In principle PP meshes following an uncomplicated ventral hernia repair do not shrink at all. A moderate shrinkage in isolated cases might occur following heavyweight mesh implantation. Under controlled conditions recurrence as well as complication rates are equal for heavyweight and lightweight PP meshes. Quality of life improves up to 2 years following mesh repair with a trend to a better outcome for lightweight meshes. Pain and mobility scores reached standard values 12 months postoperatively without significant differences between the lightweight and heavyweight meshes.