Dermatome Mapping: Preoperative and Postoperative Assessment

Abstract

Chronic postoperative inguinal pain (CPIP) has become our main concern in inguinal hernia repair, since recurrence is a less frequent and problematic issue with the advent of tension free techniques. Evaluating the intensity and measuring the occupational impact of this incapacitating entity has now occupied our attention. In order to properly and effectively address the complex problem of inguinodynia, a uniform way of evaluating, describing, and documenting this conglomeration of overlapping etiologies is needed. Many different diagnostic modalities are used in the evaluation of the patient with CPIP; unfortunately, none of these tests provide an objective diagnostic tool: (1) that shows if we are dealing with neuropathic or non-neuropathic pain; (2) that indicates which specific nerve or nerves are involved; (3) that proves if the patient is really feeling pain or is faking findings for secondary gain (workers’ compensation, other psychosocial or legal motivation); and (4) that serves as a reliable test to follow up denervated patients and evaluate whether or not our surgical or nonsurgical approach has been successful. In May 1998, we developed and published the Dermatome Mapping Test (DMT) using a blunt stimulator and color markers to determine which dermatomes were involved, and using this simple system, we have evaluated and followed our patients with postoperative chronic pain. In 2009, we classified these data using the Dermatome Mapping Classification (DMC), which allows us not only to differentiate all possible pain scenarios but also to provide a common language that defines the broad forms of presentation of these data.