Posterior Mesentery Research Articles

Feasibility analysis on membrane-based right-sided approach of laparoscopic suprapancreatic lymph node dissection for advanced distal gastric cancer

To investigate the feasibility and safety of membrane-based right-sided approach of laparoscopic suprapancreatic lymph node dissection for advanced distal gastric cancer. The clinical data of 41 patients with advanced distal gastric cancer who underwent laparoscopic gastrectomy using membrane-based right-sided approach for laparoscopic suprapancreatic lymph node dissection at the Department of Gastrointestinal Surgery, Zhongshan Hospital of Xiamen University from January 2016 to January 2018 were retrospectively analyzed. There were 24 males and 17 females with a mean age of 56.8 years and a mean body mass index of 22.6 kg/m². Membrane-based right-sided approach of laparoscopic suprapancreatic lymph node dissection contained 4 steps briefly: (1) dissection of mesenteria above the head of pancreas: the tri-junction of pancreas-duodenum was cut to expose and identify the logo of Benz;clearance of the membrane of No.5a was performed towards the left, and then expanded to the posterior layer of No.12a. (2) dissection of the V shape dorsal mesogastrium: membrane bridge at splenic artery trunk root was cut; in suprapancreatic space, clearance was performed towards to the left to the middle of the splenic artery trunk and expanded to the posterior Tolds plane upwards to the posterior phrenic angle and retroperitoneal esophagus, then the surrounding tissue of anterior abdominal aorta. (3) dissection of the U shape mesenteria:membrane bridge at common hepatic artery root was cut; mesentery was separated; the left gastric vein was freed and ligated at its root; in posterior pancreatic space, the mesentery of No.7, No.9 and No.8 was dissected in turns; the left gastric artery was high ligated and cut; the portal vein and posterior dorsal mesogastrium Toldt plane was routinely exposed; clearance was performed to right for No.8a and upward to the hepatic portal meeting at posterior mesentery No.12 plane. (4) dissection of the upper triangular area of pylorus: the trigone mesentery was cut along the upper edge of the pylorus; No.12a was swept upward along the gastric ventral mesentery; the upper boundary(No.8a) on the right side of the U-shaped membrane was joined. Intraoperative and postoperative presentations were analyzed. Laparoscopic gastrectomy for advanced distal gastric cancer with membrane-based right-sided approach of laparoscopic suprapancreatic lymph node dissection was successfully carried out in all the 41 patients. Distal gastric mesenteria en bloc resection was successfully performed. The operation time was (145.2±25.4) minutes and intraoperative blood loss was (53.3±18.3) ml without massive bleeding and severe complication. Number of lymph nodes dissected was 41.1±6.4, and number of suprapancreatic lymph node dissected was 23.3±3.7 without residual cancer at cut margin by pathology. Postoperative drainage volume was (65.8±21.7) ml; time to withdraw of catheter was (7.0±1.7) days; time to fluid intake was (3.5±1.8) days; postoperative hospital stay was (10.4±2.8) days; time to postoperative anal exhaust was (3.3±1.1) days. No complications, such as chyle leakage, postoperative massive bleeding, anastomotic leakage, abdominal cavity infection or gastroplegia occurred within 30 days after surgery. Membrane-based right-sided approach of laparoscopic suprapancreatic lymph node dissection for advanced distal gastric cancer can achieve en bloc resection and conform to the radical principle of oncology, and is safe and feasible.

Mesorectal lymph nodes: their location and distribution within the mesorectum.

Total mesorectal excision is an alternative surgical approach for resectable rectal cancer and is associated with favorable results and a low rate of local recurrence. Despite the popularity of this technique, few data exist regarding the location and distribution of lymph nodes within the rectal mesentery. The purpose of this study was to define the distribution, size, and location of lymph nodes within the mesorectum and on the pelvic side wall. Seven fresh cadavers at our institution's Fresh Tissue Dissection Laboratory were studied. The rectum, its mesentery, and all fatty tissue from both pelvic side walls were removed and placed in a lymph node clearing solution for 24 hours. After appropriate dissection, the distribution, size, and location of lymph nodes within the rectal mesentery and pelvic side wall tissue were documented. A total of 174 lymph nodes were identified (approximately 25 per patient). The majority (>80 percent) of lymph nodes were smaller than 3 mm in diameter. Fifty-six percent of the nodes within the rectal mesentery were located in the posterior mesentery, and most were located in the upper two-thirds of the posterior rectal mesentery. The majority of perirectal lymph nodes are small. There are few lymph nodes within the mesentery of the lower third of the rectum and relatively few in the right and left lateral portions of the mesorectum. We confirm that the majority of nodes are located in the proximal two-thirds of the posterior rectal mesentery. It is possible that removal of these nodes is responsible for the superior oncologic results found with total mesorectal excision in contrast to more traditional surgical techniques.

Mesenteric paraganglioma: a case report and review of the literature.

Approximately 5% to 10% of paragangliomas occur in extra-adrenal sites, which can extend from the upper cervical region to the pelvis, parallel to the autonomic nervous system. This distribution corresponds to the embryologic development of the paraganglia from neural crest cells. Rarely, extra-adrenal paragangliomas can also occur aberrantly outside this distribution. We report such a case of extra-adrenal paraganglioma occurring in the anterior mesentery in a 76-year-old man. Two case reports exist in the literature describing extra-adrenal paragangliomas in the posterior mesentery. Normal paraganglionic tissue has been described at the roots of the superior and inferior mesenteric arteries, theoretically explaining the origin of the posterior mesenteric paragangliomas. Our case can best be attributed to the ventral migration of paraganglionic tissue through these vessels to reach the anterior mesentery, where they could potentially give rise to paragangliomas in this site.