直肠癌根治术中保留骨盆自主神经的神经解剖学基础及临床意义

目的　探讨直肠癌根治术中保留神经的解剖学基础。　方法　解剖 6例完整尸体标本(男 4例 ,女 2例 )和 4例直肠及盆腔未受破坏的矢状半骨盆标本 ,观察骨盆神经组成及走行。　结果　显露下腹神经干 ,确定其在第 5腰椎处分为左、右下腹神经。其特点是较为粗大 ,位置固定 ,在腹主动脉分叉处易找到 ,呈网状联系 ,质地较实 ,为灰白色 ,与腹主动脉较近。分叉后左右下腹神经还有较粗大分支。骨盆内脏神经在大体标本上较难辨认 ,在矢状半骨盆标本中见到发自骶前孔 2～ 4的骨盆内脏神经 ,该神经较纤细 ,在侧韧带处呈丛状的细小纤维。　结论　保留下腹神经临床上较易完成。保留骨盆内脏神经则须细心操作 ,预保留神经的一侧在侧韧带水平的手术操作应尽量贴近直肠进行。

Anatomical basis of autonomic nerve-preserving radical resection for rectal cancer

Objective To clarify anatomical basis of autonomic nerve preserving radical resection for rectal cancer. Method Of 10 cadavers, 4 were male and 2 female. Four had hemisected pelvis in the mid sagittal plane without damaging the retrorectal anatomy. All stages of each dissection were recorded photographically. Results Hypogastric nerves were identified. The superior hypogastric plexus is the direct extension of the aortic plexus below the aortic bifurcation. It lies immediately behind the peritoneum and descends over the anterior surface of the 5th lumbar vertebra in the retroperitoneal tissue. The superior hypogastric plexus ends by bifurcating into the right and left hypogastric nerves. The two hypogastric nerves diverge from each other at about the level of the sacral promontory and run down and forward along the walls of the pelvis in the lamina of the pelvic fascia closest to the peritoneum.Both of them are strong fibres with white grey and reticular appearance and well located just below and close to the aortic bifurcation. And after bifurcation each of them also gives rise to several branches. But it is difficult to identify the pelvic splanchnic nerves in complete samples. In mid sagitted samples they take origin from the second to fourth sacral ventral rami just after the sacral nerves have emerged from the pelvic sacral foramina. They always form plexus at the lateral ligament and are crossed by middle rectal artery. Conclusions It is not very difficult to preserve the hypogastric nerves to spare functions in resection for rectal cancer to the anatomical knowledge of the pelvic autonomic nerves. When the pelvic splanchnic nerves are to be preserved, dissection must be cautious at the level of the lateral ligment on the side of nerve preservation. The operation should be performed near the rectum as close as possible to achieve functional preservation.