Page 198 - Prevention and Treatment of Incisional Hernia- New Techniques and Materials

Chapter 9
distinguishing parameter between groups: W1 (< 4 cm), W2 (≥ 4 - 10 cm) and W3 (≥ 10 cm). If descriptive terminology like “large, giant, huge” are used, a clear description of the de nition should be given. However, the use of such adjectives to de ne the hernia size is discouraged.
Operative techniques and mesh variables
Surgical technique and their outcome is an important issue in surgical studies. A detailed description of the surgical techniques used is important for the readers to understand the procedure(s) used in the patients studied. It should allow to reproduce the technique in future patients. Authors should be encouraged to use clear terminology like those proposed by the EuraHS working group(1). For prosthetic materials, xation devices and other equipment, we recommend using not only the generic name of the material but also providing the product and company name. When comparing di erent meshes the classi cation of meshes proposed by Klinge and Klosterhalfen is recommended(23). A complete description of the size of implanted mesh, the overlap of the hernia defect and the detailed technique used for xation will help the reader to understand the procedure used.
Assessment of outcome: recurrences, complications and quality of life
Recurrences
The outcome parameter recurrence is the primary endpoint in most studies of abdominal wall hernia surgery. A hernia recurrence is de ned as: “A protrusion of the contents of the abdominal cavity or preperitoneal fat through a defect in the abdominal wall at the site of a previous repair of an abdominal wall hernia.”(1). Recurrence is a categorical dichotomous variable, which means the outcome cannot be quanti ed, but is a yes or no response. The de nition used in the study of what constitutes a recurrence should be given as well as the method of follow-up that is used to look for possible recurrence. If the primary endpoint of the study is recurrence, the consensus is that only clinical follow- up will be considered adequate. In an interventional study, blinding of the evaluator to the treatment arm will minimize investigator bias and improve the quality of the data and is to be strongly encouraged.
Basically, there are two options to describe the primary endpoint recurrence in a cohort of patients. The “recurrence rate” can be measured at a speci c time point (Tx) during follow-up, as the number of patients of the
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