PURPOSE: Some recent neurophysiological studies have suggested cross-innervation of pelvic genitourinary organs by extrinsic left-right communicating nerves. However, no definite course for these nerves has been clearly determined macroanatomically in humans. In the present study we extensively investigated the adult human pelvis to elucidate their courses by the whole-mount staining method. MATERIALS AND METHODS: A total of 6 male human specimens that had been subjected to pathological dissection were examined by means of an acetylcholinesterase whole-mount staining method. A map of nerve pathways was made by composite photomicrography. Histologically, nerves dissected accurately under a dissecting microscope were stained with both Klüver-Barrera stain and the Bodian method. RESULTS: The communicating nerves between bilateral pelvic plexuses were observed at the back of the rectum and in the rectoprostatic space. The former were composed of nothing but myelinated fibers in the same way as the pelvic splanchnic nerve. By contrast, the latter were composed of unmyelinated fibers with a few myelinated fibers. The pelvic plexus could be divided into three portions, anterosuperior, anteroposterior and inferior areas, by ganglion type. Morphologically, fiber components differed among those three portions. CONCLUSION: The communicating nerves at the back of the rectum seemed to be predominantly parasympathetic communicantes between bilateral pelvic splanchnic nerves rather than pelvic plexuses. These nerves may be involved in postoperative voiding function in the case of pelvic surgery with hemilateral nerve preservation. The function of the pelvic plexus seemed to be heterogeneous in each portion according to our morphological results.
PURPOSE: Some recent neurophysiological studies have suggested cross-innervation of pelvic genitourinary organs by extrinsic left-right communicating nerves. However, no definite course for these nerves has been clearly determined macroanatomically in humans. In the present study we extensively investigated the adult human pelvis to elucidate their courses by the whole-mount staining method. MATERIALS AND METHODS: A total of 6 male human specimens that had been subjected to pathological dissection were examined by means of an acetylcholinesterase whole-mount staining method. A map of nerve pathways was made by composite photomicrography. Histologically, nerves dissected accurately under a dissecting microscope were stained with both Klüver-Barrera stain and the Bodian method. RESULTS: The communicating nerves between bilateral pelvic plexuses were observed at the back of the rectum and in the rectoprostatic space. The former were composed of nothing but myelinated fibers in the same way as the pelvic splanchnic nerve. By contrast, the latter were composed of unmyelinated fibers with a few myelinated fibers. The pelvic plexus could be divided into three portions, anterosuperior, anteroposterior and inferior areas, by ganglion type. Morphologically, fiber components differed among those three portions. CONCLUSION: The communicating nerves at the back of the rectum seemed to be predominantly parasympathetic communicantes between bilateral pelvic splanchnic nerves rather than pelvic plexuses. These nerves may be involved in postoperative voiding function in the case of pelvic surgery with hemilateral nerve preservation. The function of the pelvic plexus seemed to be heterogeneous in each portion according to our morphological results.