右原始后腹膜在右半结肠癌完整结肠系膜切除术中的解剖学观察和临床意义

Anatomical observation of the right retroperitoneal fascia and its clinical significance in complete mesocolic excision for right colon cancer

目的对右半结肠癌完整结肠系膜切除术(CME)手术过程中的右原始后腹膜走行进行活体和尸体标本解剖观察,探讨该筋膜的解剖特点和临床意义。方法采用描述性研究的方法。(1)回顾性收集2020年1—10月期间,就诊于福建医科大学附属协和医院结直肠外科的17例行腹腔镜右半(扩大右半)结肠癌根治术的非连续患者的临床病理资料和手术录像,从尾侧背侧入路和尾侧腹侧入路2个方向观察右原始后腹膜结构。(2)前瞻性纳入2020年6月手术的3例腹腔镜下右半结肠癌根治手术的术后标本,进行解剖观察和组织学研究。(3)纳入来源于福建医科大学解剖学教研室的5具腹部尸体标本,其中男性3例,女性2例,从头侧入路和尾侧背侧入路进行解剖观察和组织学研究。组织学研究采用Masson染色进行观察。结果(1)手术录像观察结果:17例患者均可观察到典型的右原始后腹膜结构,该筋膜为升结肠后间隙与横结肠后胰十二指肠前间隙之间的刚性障碍,应锐性切断右原始后腹膜以使两间隙相沟通,以便避免误进入右半结肠系膜内。切断后的右原始后腹膜腹侧断端沿右半结肠系膜背侧面向外侧走行,背侧断端向尾侧覆盖十二指肠水平部,继续向下移行,覆盖Gerota筋膜表面向下走行。(2)解剖观察结果:对3例腹腔镜下右半结肠癌根治手术的术后标本进行观察,见右半结肠系膜背侧面光滑完整,于十二指肠外侧缘对应区域可锚定并观察到右原始后腹膜的腹侧断端,断端呈半环形附着于右结肠系膜背侧面。组织切片并Masson染色观察,可见右原始后腹膜腹侧断端向头侧走行,与右结肠系膜背侧面紧密融合并卷曲,汇合点尾侧右半结肠系膜背侧面呈双叶结构。(3)尸体标本解剖所见:从5具腹部尸体标本观察到右原始后腹膜为薄层筋膜结构,是横结肠后胰十二指肠前间隙和升结肠后间隙之间的刚性障碍。分别选取右原始后腹膜腹侧断端(含右结肠系膜背侧面)、右原始后腹膜背侧断端(含部分十二指肠壁)和右结肠系膜背侧面进行组织学观察,可见右原始后腹膜腹侧断端向头侧与右半结肠系膜背侧面融合,融合水平尾侧的右半结肠系膜背侧面逐渐分开呈双层疏松筋膜结构;右原始后腹膜背侧断端覆盖于十二指肠水平部表面,于其腹侧移行至肾前筋膜表面,继续向尾侧走行。结论右原始后腹膜是横结肠后胰十二指肠前间隙和升结肠后间隙之间的刚性障碍,其与右半结肠背侧叶融合形成的Toldt筋膜走行至十二指肠降部和水平部边缘,再次分开,右原始后腹膜附着于十二指肠边缘,折反走行于肾前筋膜表面,而右半结肠背侧叶走行于胰十二指肠前方移行为胰十二指肠前筋膜。术中识别并切断该筋膜,从而贯通横结肠后胰十二指肠前间隙和升结肠后间隙,有助于保证右半结肠系膜背侧面的完整。

Objective To investigate the anatomic characteristics of the right retroperitoneal fascia and its surgical implementation while performing complete mesocolic excision(CME)for right colon cancer.Methods A descriptive study was carried out.(1)Clinicopathological data and surgical videos of 17 non-consecutive patients undergoing laparoscopic right hemicolectomy(extended right hemicolectomy)with CME for right colon cancer at Department of Colorectal Surgery of Union Hospital,Fujian Medical University between January 2020 and October 2020 were retrospectively collected.The construction of right retroperitoneal fascia was observed from caudal dorsal direction and caudal ventral direction.(2)Three postoperative specimens from 3 cases undergoing laparoscopic right hemicolectomy with CME for right colon cancer in June 2020 were prospectively included to observe anatomy and examine histology.(3)Five abdominal cadaver specimens from the Department of Anatomy of Fujian Medical University were enrolled,including 3 males and 2 females.Anatomical observation and histological studies were performed from the cranial approach and the caudal dorsal approach.Masson staining was used to examine the histology.Results(1)Surgical video observation:The typical structure of right retroperitoneal fascia could be observed in all the 17 patients.The fascia was a rigid barrier between the posterior space of the ascending colon and the anterior pancreaticoduodenal space behind the transverse colon.The right retroperitoneal fascia should be sharply cut to communicate between the two spaces to avoid entering the right mesocolon by mistake.The severed ventral stump of the right retroperitoneal fascia ran along the dorsal side of the right hemicolon to the lateral side,and the dorsal stump covered the level of the duodenum caudally,and continued to move downward,covering the surface of Gerota's fascia.(2)Observation of 3 surgical specimens:The dorsal side of the right mesocolon was smooth and intact,which could be anchored in the corresponding area of the lateral edge of the duodenum.The ventral stump of the right retroperitoneal fascia could be seen,which attached to the dorsal side of the right mesocolon semi-circularly.Masson staining observation:The ventral stump of the right retroperitoneal fascia ran cephalad,fused with the dorsal side of the right mesocolon tightly and curled.The caudal side of confluence and the dorsal side of the right mesocolon presented a bilobed structure.(3)Anatomy of 5 cadaveric specimens:The right retroperitoneal fascia was a thin fascia structure,which was a rigid barrier between the anterior pancreaticoduodenal space behind the transverse colon and the posterior space of the ascending colon.The ventral stump of the right retroperitoneal fascia(including the dorsal side of the right mesocolon),the dorsal stump of the right retroperitoneal fascia(including part of the duodenal wall)and the dorsal side of the right mesocolon were retrieved for histological examination.The ventral stump of the right retroperitoneal fascia fused with the dorsal side of the right mesocolon by the cephalic side,and the dorsal side of the right hemi-mesocolon on the fusion level by caudal side gradually separated into a double-layer loose fascial structure.The dorsal stump of the right retroperitoneal fascia covered the surface of the duodenum level,moved on from the ventral side to the surface of the prerenal fascia,and continued to the caudal side.Conclusions The right retroperitoneal fascia is a rigid barrier between the anterior pancreaticoduodenal space behind the transverse colon and the posterior space of the ascending colon.The Toldt fascia formed by fusion with the dorsal lobe of the right colon travels to the edge of the descending and horizontal part of the duodenum and separates again.The right retroperitoneal fascia is attached to the edge of the duodenum,reversing and running on the surface of the prerenal fascia,while the dorsal lobe of the right colon runs in front of the pancreas and duodenum,and shifts to the pancreaticoduodenal fascia.During the operation,this fascia should be identified and cut to penetrate the anterior pancreaticoduodenal space behind the transverse colon and the posterior ascending colon space,which helps to ensure the integrity of the dorsal side of the right hemi-mesocolon.