The ratio between anterior abdominal wall surface/wall defect surface: a new parameter to classify abdominal incisional hernias

Current classifications of incisional hernias are often not suitable. The aim of our study was to demonstrate that it is important to consider not only the wall defect surface (WDS) but also the total surface of the anterior abdominal wall (SAW) and the ratio between SAW/WDS). Twenty-three patients affected by >10 cm size incisional hernias were examined for anthropometric analyses. The SAW, the WDS and the ratio SAW/WDS were calculated. All of the 23 patients were operated on 13 patients were treated with the Rives technique using a polypropylene mesh while the remaning ten patients had an intraperitoneal Parietex Composite mesh (PC). The two groups were compared for post-operative pain (with VAS) and intra-abdominal pressure (IAP) 48 h after the operation: bladder pressure, length of the procedure, average hospital stay and return to work were calculated. In the Rives group, WDS being equal, the higher IAP values were, the lower was the ratio SAW/WDS; furthermore, SAW/WDS ratio being equal, IAP values were low in cases where intraperitoneal mesh was used. Post-operative pain, measured with VAS, was critical when there was a low SAW/WDS ratio and a high IAP. In our experience, it is possible to predict a strong abdominal wall tension if the SAW/WDA ratio is below 15 mmHg. In these cases it is advisable to use a technique requiring the use of an intraperitoneal mesh. Our experience with PC was so positive that it is used in our department for all cases where an intraperitoneal mesh is required. At present, our proposal is that the SAW/WDS ratio is to be considered as a new parameter in current classifications of incisional hernias.