CT of complex ventral hernias: a guide to reporting.

Complex ventral hernias (CVHs) represent a subset of incisional hernias so large that they can not be reduced by standard operative techniques without an unacceptable risk of recurrence or potentially dangerous complications. They are debilitating to patients, causing pain, sores and immobility and their incidence is increasing worldwide due to rising operation numbers, an ageing population and increased obesity levels. The field of CVH repair has become its own surgical subspeciality, with the development of CVH multidisciplinary team meetings and tertiary hernia repair centres being established across the world. Preoperative computed tomography (CT) has become one of the most important aspects of CVH repair planning, providing information which cannot be clinically assessed. This includes defect measurements, muscle quality evaluation, evidence of previous hernia repair, and metrics such as domain loss calculations and the rectus defect ratio. Together, this information can be combined with the clinical examination to determine the best surgical course. Unfortunately, there is evidence that when confronted with a CVH on CT radiologists provide reports missing important metrics and reporting information of limited value. This imaging review provides a comprehensive summary of all of the features which should be included in a CT report for CVH assessment, together with the methods used to generate metrics, where appropriate. An illustrative overview of the surgical techniques used to approach CVH repair is provided as well as an up-to-date summary of mesh plane position nomenclature.