Surgical anatomy of the inguinal region: implications during inguinal laparoscopic herniorrhaphy.

INTRODUCTION: In laparoscopic inguinal hernia repair the inguinal region is approached and hernia repair performed from the interior side instead of the classical open external access. Exploration and placement of staplers in the internal inguinal region during laparoscopic hernia repair may sever different anatomical structures, or induce specific complications such as nerve entrapment, neuralgia, hematomas or osteitis. The incidence of these complications may be reduced by careful dissection of the preperitoneal tissues and by placing a prosthetic mesh without the use of stapling. As laparoscopic techniques evolved, different sizes of meshes have been used. An exact determination of mesh size was hitherto not investigated. AIM: Cadaver studies of the topography of blood vessels and nerves in the preperitoneal tissue in this region were carried out in order to assess a safe position and adequate size of the prosthetic mesh. METHODS: Dissection in 6 preserved human female cadavers was performed to define the actual surface of the internal inguinal region. A physical model was developed to formulate the ideal size of the prosthesis. Specific measurements were used to define the maximal size of the meshes, so as to place them without stapling, and without inducing neurovascular complications. RESULTS: The designed physical formula defines the size of the mesh as a function of the maximum intra-abdominal pressure, the size of the abdominal wall defect and the abdominal wall tension. CONCLUSION: On mathematical and physical grounds our study points out that the size of the currently used prosthetic mesh (10 x 15 cm) is large enough to be placed without stapling so that with proper placement no recurrences should occur.

Phase-dependent modulation of cutaneous reflexes of tibialis anterior muscle during hopping.

During human gait, the amplitude of cutaneous reflexes in the leg is modulated as a function of the phase of the step cycle. In tibialis anterior (TA) the responses to sural nerve stimulation are facilitatory at end stance while they are suppressive at end swing. To investigate in how far this modulation is specifically related to alternating locomotion, the modulation of such reflexes was studied during a symmetric rhythmic movement, namely hopping (as equivalent of galloping). The end-stance facilitation was present during hopping while the end-swing suppression was absent. It is concluded that the end-stance facilitation is not specific for alternating gait. The absence of the end-swing suppressive reflexes may be related to the absence of heel strike in hopping.