男性泌尿生殖层的层面解剖及其临床意义研究

Stratified anatomy of male Urogenital stratum and its clinical significance

目的观察并描述男性泌尿生殖层的层面解剖学形态,探讨该层面在结直肠手术中的临床意义。方法采用层面解剖学方法解剖10具男性尸体躯干与20具盆腔标本,系统地描述泌尿生殖层的解剖形态,并与相应腹腔镜下解剖结构相比较。结果男性泌尿生殖层为泌尿生殖筋膜包被,整体结构可分3段——腹段、盆段和精索段。泌尿生殖层腹段头侧由泌尿生殖筋膜紧密愈着于膈下筋膜,外侧与腹横筋膜间形成侧锥筋膜,其腹侧为原始体腔膜形成的后腹膜以及后腹膜与腹内脏器固有筋膜形成的融合筋膜,背侧为腰肌筋膜;腹段在肠系膜下动脉以下,形成位于腹主动脉与下腔静脉前方的独立层面,在盆腔入口处延续为位于中央的盆段和位于两侧的精索段。精索段外侧界为精索血管,内侧界为输尿管,前界为输精管,外被泌尿生殖筋膜,形似三角,经由内环外出至腹股沟管,延伸至睾丸。盆段入盆后包绕在直肠周围下行,直肠后方的泌尿生殖层约在骶4椎体前方融汇于直肠固有筋膜,其内走行腹下神经;直肠侧方泌尿生殖层内为下腹下神经丛以及输尿管、输精管走行,泌尿生殖筋膜脏层覆盖其内侧表面,行向直肠前方,终于精囊腺—前列腺交界,泌尿生殖筋膜壁层覆盖于下腹下神经、输尿管背侧及外侧,下行与膀胱固有筋膜融汇。结论泌尿生殖层各段构成结肠、直肠周围毗邻层面,该解剖结构对于结直肠手术具有重要的指导意义。

Objective To investigate the anatomical morphology of the human male urogenital stratum(UGS),and to explore its clinical significance in colorectal surgery.Methods Ten male cadavers and 20 male pelvic specimens were dissected using stratified anatomical methods.The anatomical morphology of the UGS was described systematically and compared to corresponding laparoscopic anatomical structure.Results The UGS,which is derived from the embryonic intermediate mesoderm and located in the retroperitoneal space,is surrounded by the urogenital fascia(UGF).In males,it includes the adrenal glands,kidneys,ureters,vas deferens,and seminal vesicles,together with corresponding blood vessels,nerves,lymphoid tissues,and integrated connective tissues.The UGS can be divided into 3 segments:abdominal segment,spermatic segment,and pelvic segment.Cranially,the abdominal segment adheres closely to the subphrenic fascia;bilaterally,it adheres to the transversalis fascia through the lateroconal fascia.The ventral side of abdominal segment is the retroperitoneum derived from the primitive coelomal membrane(the retroperitoneum and the fascia propria of the abdominal viscera fuse together forming Toldt’s fascia),and the dorsal side of abdominal segment is delineated by psoas fascia.Caudal to the inferior mesenteric artery,the abdominal segment of the UGS becomes a separate layer in front of the abdominal aorta and inferior vena cava.At the pelvic brim,the medial UGS descends into the pelvis,where it constitutes the pelvic segment of the UGS.The bilateral portions of the UGS join the internal ring,forming the spermatic segment.The lateral boundary of the spermatic segment is the spermatic vessel,the medial boundary is the ureter,and the anterior boundary is the vas deferens;these structures are covered by UGF,thus forming the spermatic cord and extending to the testis through the inguinal canal.The pelvic segment of UGS descends around the rectum and fuses with the fascia propria of the rectum in front of the forth sacral vertebrea.The hypogastric nerves run inside the UGS bilaterally and connect with the inferior hypogastric plexus on both sides of the rectum.In the pelvis,the visceral urogenital fascia(vUGF)covers the internal surface of UGS,extending inferiorly and anteriorly until it reaches the seminal vesicle-prostate junction.Denonvilliers fascia inserts between the vUGF and the rectum.The parietal urogenital fascia(pUGF),which covers the ureter and hypogastric nerve dorsally and laterally,extends inferiorly and anteriorly and fuses with the fascia propria of bladder.The pelvic segment of UGS constitutes a stratum surrounding the middle part of the rectum.Conclusion Each segment of the UGS constitutes the anatomic stratum adjacent to the colon and rectum,which has important significance for colorectal surgery.