Anatomical and histological investigation of the area anterior to the anorectum passing through the levator hiatus / 中华胃肠外科杂志

Objective: To document the anatomical structure of the area anterior to the anorectum passing through the levator hiatus between the levator ani slings bilaterally. Methods: Three male hemipelvises were examined at the Laboratory of Clinical Applied Anatomy, Fujian Medical University. (1) The anatomical assessment was performed in three ways; namely, by abdominal followed by perineal dissection, by examining serial cross-sections, and by examining median sagittal sections. (2) The series was stained with hematoxylin and eosin to enable identification of nerves, vessels, and smooth and striated muscles. Results: (1) It was found that the rectourethralis muscle is closest to the deep transverse perineal muscle where the longitudinal muscle of the rectum extends into the posteroinferior area of the membranous urethra. The communicating branches of the neurovascular bundle (NVB) were identified at the posterior edge of the rectourethralis muscle on both sides. The rectum was found to be fixed to the membranous urethra through the rectourethral muscle, contributing to the anorectal angle of the anterior rectal wall. (2) Serial cross-sections from the anal to the oral side were examined. At the level of the external anal sphincter, the longitudinal muscle of the rectum was found to extend caudally and divide into two muscle bundles on the oral side of the external anal sphincter. One of these muscle bundles angled dorsally and caudally, forming the conjoined longitudinal muscle, which was found to insert into the intersphincteric space (between the internal and external anal sphincters). The other muscle bundle angled ventrally and caudally, filling the gap between the external anal sphincter and the bulbocavernosus muscle, forming the perineal body. At the level of the superficial transverse perineal muscle, this small muscle bundle headed laterally and intertwined with the longitudinal muscle in the region of the perineal body. At the level of the rectourethralis and deep transverse perineal muscle, the external urethral sphincter was found to occupy an almost completely circular space along the membranous part of the urethra. The dorsal part of the external urethral sphincter was found to be thin at the point of attachment of the rectourethralis muscle, the ventral part of the longitudinal muscle of the rectum. We identified a venous plexus from the NVB located close to the oral and ventral side of the deep transverse perineal muscle. Many vascular branches from the NVB were found to be penetrating the longitudinal muscle and the ventral part of rectourethralis muscle at the level of the apex of the prostate. The rectourethral muscle was wrapped ventrally around the membranous urethra and apex of the prostate. The boundary between the longitudinal muscle and prostate gradually became more distinct, being located at the anterior end of the transabdominal dissection plane. (3) Histological examination showed that the dorsal part of the external urethral sphincter (striated muscle) is thin adjacent to the striated muscle fibers from the deep transverse perineal muscle and the NVB dorsally and close by. The rectourethral muscle was found to fill the space created by the internal anal sphincter, deep transverse perineal muscle, and both levator ani muscles. Many tortuous vessels and tiny nerve fibers from the NVB were identified penetrating the muscle fibers of the deep transverse perineal and rectourethral muscles. The structure of the superficial transverse perineal muscle was typical of striated muscle. These findings were reconstructed three-dimensionally. Conclusions: In intersphincteric resection or abdominoperineal resection for very low rectal cancer, the anterior dissection plane behind Denonvilliers' fascia disappears at the level of the apex of the prostate. The prostate and both NVBs should be used as landmarks during transanal dissection of the non-surgical plane. The rectourethralis muscle should be divided near the rectum side unless tumor involvement is suspected. The superficial and deep transverse perineal muscles, as well as their supplied vessels and nerve fibers from the NVB. In addition, the cutting direction should be adjusted according to the anorectal angle to minimize urethral injury.

Anatomical classification of and laparoscopic surgery for left-sided colorectal cancer with persistent descending mesocolon / 中华胃肠外科杂志

Objective: To investigate anatomical morphology and classification of persistent descending mesocolon (PDM) in patients with left-sided colorectal cancer, as well as the safety of laparoscopic radical surgery for these patients. Methods: This is a descriptive study of case series. Relevant clinical data of 995 patients with left colon and rectal cancer who had undergone radical surgery in Fujian Medical University Union Hospital from July 2021 to September 2022 were extracted from the colorectal surgery database of our institution and retrospectively analyzed. Twenty-four (2.4%) were identified as PDM and their imaging data and intra-operative videos were reviewed. We determined the distribution and morphology of the descending colon and mesocolon, and evaluated the feasibility and complications of laparoscopic surgery. We classified PDM according to its anatomical characteristics as follows: Type 0: PDM combined with malrotation of the midgut or persistent ascending mesocolon; Type 1: unfixed mesocolon at the junction between transverse and descending colon; Type 2: PDM with descending colon shifted medially (Type 2A) or to the right side (Type 2B) of the abdominal aorta at the level of the origin of the inferior mesentery artery (IMA); and Type 3: the mesocolon of the descending-sigmoid junction unfixed and the descending colon shifted medially and caudally to the origin of IMA. Results: The diagnosis of PDM was determined based on preoperative imaging findings in 9 of the 24 patients (37.5%) with left-sided colorectal cancer, while the remaining diagnoses were made during intraoperative assessment. Among 24 patients, 22 were male and 2 were female. The mean age was (63±9) years. We classified PDM as follows: Type 0 accounted for 4.2% (1/24); Type 1 for 8.3% (2/24); Types 2A and 2B for 37.5% (9/24) and 25.0% (6/24), respectively; and Type 3 accounted for 25.0% (6/24). All patients with PDM had adhesions of the mesocolon that required adhesiolysis. Additionally, 20 (83.3%) of them had adhesions between the mesentery of the ileum and colon. Twelve patients (50.0%) required mobilization of the splenic flexure. The inferior mesenteric artery branches had a common trunk in 14 patients (58.3%). Twenty-four patients underwent D3 surgery without conversion to laparotomy; the origin of the IMA being preserved in 22 (91.7%) of them. Proximal colon ischemia occurred intraoperatively in two patients (8.3%) who had undergone high ligation at the origin of the IMA. One of these patients had a juxta-anal low rectal cancer and underwent intersphincteric abdominoperineal resection because of poor preoperative anal function. Laparoscopic subtotal colectomy was considered necessary for the other patient. The duration of surgery was (260±100) minutes and the median estimated blood loss was 50 (20-200) mL. The median number of No. 253 lymph nodes harvested was 3 (0-20), and one patient (4.2%) had No.253 nodal metastases. The median postoperative hospital stay was 8 (4-23) days, and the incidence of complications 16.7% (4/24). There were no instances of postoperative colon ischemia or necrosis observed. One patient (4.2%) with stage IIA rectal cancer developed Grade B (Clavien-Dindo III) anastomotic leak and underwent elective ileostomy. The other complications were Grade I-II. Conclusions: PDM is frequently associated with mesenteric adhesions. Our proposed classification can assist surgeons in identifying the descending colon and mesocolon during adhesion lysis in laparoscopic surgery. It is crucial to protect the colorectal blood supply at the resection margin to minimize the need for unplanned extended colectomy, the Hartmann procedure, or permanent stomas.

Delayed gastric emptying after surgery for transverse colon cancer: diagnosis, management and prevention / 中华胃肠外科杂志

Delayed gastric emptying is a syndrome of gastric motility disorder with slow gastric emptying as the main sign, provided that mechanical factors such as intestinal obstruction and anastomotic stricture are excluded. The incidence of delayed gastric emptying after colon cancer surgery is 1.4%, mainly after transverse colon cancer surgery. Most of the studies on delayed gastric emptying are case reports, lacking systematic studies. The diagnoses and treatments can be draw on the experience of delayed gastric emptying after pancreatic surgery. Our retrospective study indicated that the incidence of delayed gastric emptying after surgery for transverse colon cancer was 4.0%, higher than that for other colon cancer. Patients who underwent gastrocolic ligament lymph node dissection were at higher risk than those who did not (3.6% vs. 0.8%). Gastrocolic ligament lymph node dissection and stress are causative factors for delayed gastric emptying after surgery for transverse colon cancer. We add the gastrografin test upon the diagnostic criteria of the International Study Group for Pancreatic Surgery, which is simple and practical. Nasogastric tube decompression, enteral nutrition combined with parenteral nutrition, glucocorticoids, and prokinetic agents can cure most patients with postoperative delayed gastric emptying. All the patients with postoperative delayed gastric emptying were cured in our studies. Strict indications for gastrocolic ligament lymph node dissection (patients with cT3-4 and cN+) may decrease the occurrence of delayed gastric emptying after surgery for transverse colon cancer.

Research Progress in TCM Promoting the Development of Cerebral Ischemia Angiogenesis / 中国中医药信息杂志

The promotion or inhibition of blood vessels by TCM, active ingredients of TCM, TCM compounds, and Chinese patent drugs is currently a research hotspot, with relatively abundant research. However, the study of the role and profound mechanism of TCM on angiogenesis after cerebral ischemia is relatively rare. Therefore, this article reviewed theories, in vitro studies and in vivo studies on the promotion of cerebral angiogenesis by TCM, and summarized the studies on TCM regulation of angiogenesis through Notch and Wnt signaling pathway mechanisms, with a purpose to provide references for resarch on related mechanisms and development of new deugs.

Risk factors of postoperative chyle leak following complete mesocolic excision for colon cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the incidence, risk factors and preventative methods associated with chyle leak following complete mesocolic excision(CME) for colon cancer.</p><p><b>METHODS</b>Clinical data of 592 patients with colon cancer undergoing CME in the department of Colorectal Surgery in the Fujian Medical University Union Hospital from September 2000 to September 2011 were analyzed retrospectively.</p><p><b>RESULTS</b>Chyle leak occurred in 46 patients(7.7%). The incidence of postoperative chyle leak following right CME hemicolectomy was 13.3%(30/226), significantly higher than that after left CME hemicolectomy (4.4%). On univariate analysis, chyle leak following CME was associated with tumor size(P<0.05), tumor location(P<0.01), and lymph nodes harvested(P<0.01). Multivariate logistic regression revealed that tumor location and lymph nodes harvested were independent risk factors associated with chyle leak following CME(P<0.05).</p><p><b>CONCLUSIONS</b>Tumor location and lymph nodes harvested are independent risk factors for chyle leak following complete mesocolic excision for colon cancer. When the drainage output suddenly increases after oral intake resumption, the chyle test of ascitic fluid should be performed for early diagnosis and prompt management.</p>

Comparison of efficacy between laparoscopic versus open complete mesocolic excision for colon cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the differences in long-term outcomes between laparoscopic and open complete mesocolic excision(CME) for colon cancer.</p><p><b>METHODS</b>A total of 273 patients with colon cancer who underwent CME at the Fujian Medical University Union Hospital from September 2000 to December 2008 were divided into laparoscopic(LP, n=147) and open(OP, n=126) groups in a non-random manner. The oncologic and long-term outcomes were compared.</p><p><b>RESULTS</b>No significant differences were seen in the length of distal and proximal margin, and number of lymph nodes(all P>0.05). Median postoperative follow up was 50 months. Local regional recurrence rates (LP 6.1% vs. OP 7.9%) and distal metastasis rates(LP 23.8% vs. OP 16.7%) were similar between the two groups(all P>0.05). The 5-year overall survival rates (LP 69.4% vs. OP 74.0%, P=0.840) and 5-year disease-free survival rates(LP 68.5% vs. OP 70.9%, P=0.668) between the two groups were not statistically different.</p><p><b>CONCLUSIONS</b>Laparoscopic CME has the same oncologic clearance effects compared with open CME for colon cancer. It might become a new standardized surgery for colon cancer.</p>