An Optimal Approach for Laparoscopic D3 Lymphadenectomy Plus Complete Mesocolic Excision (D3+CME) for Right-Sided Colon Cancer.

BACKGROUND: It is common knowledge that high ligation of blood vessels at the D3 level and complete mesocolic excision (CME) are two critical points of right hemicolectomy for right colon cancer (RCC). 1-5 To date, a safe strategy for completing these two procedures under laparoscopic surgery has not been extensively described. The authors provide a video to demonstrate laparoscopic right hemicolectomy (D3 + CME) with an optimal mesentery-defined approach. By identifying three "tri-junctions," this approach facilitates dissection of the entire mesocolon along the embryologic planes as far centrally as possible and enables the high tie of feeding vessels at bifurcation. The authors propose that this approach is safe, decreases blood loss, and is a secure method for right colon cancer intervention. METHODS: Between June 2014 and June 2015, the study recruited 36 patients with informed consent, and these patients underwent laparoscopic D3+CME for right colon cancer by a single surgeon. All the participants provided informed written consent to participate in the study. This study was approved by the Tongji Hospital Ethics Committee. The patients' demographics, oncologic charac- teristics, postoperative outcomes within 30 days, and follow-up data were collected. The perioperative outcomes included blood lost, number of retrieved lymph nodes, postoperative hospital length of stay, and morbidity. The postoperative 30-day morbidity included cardiovascular, pulmonary, and urinary complications, as well as wound infection, anastomotic leakage, and postoperative ileus. The complications were diagnosed and categorized based on relevant clinical manifestations. For this procedure, all patients are placed in the Trendelenburg position, with five trocars inserted. Carbon dioxide (CO2) is inflated through the intraumbilical trocar, maintaining steady intraabdominal pressure. The operating surgeon stands between the patient's legs, with the camera holder on the left and the assistant on the right. The operation table will be rotated left side up to redistribute the small bowels. The standard surgical procedures shown in the video are as follows. First, the surgeon identifies the first "tri-junction" (TJ1) in the ileocolic area (TJ1 is the fusion point of the mesocolon, the visceral peritoneum, and the intestinal mesentery). The surgeon then incises along the fusion fascia and separates the loose connective tissues with an ultrasonically activated device. Mobilization is continued to the origins of the ileocolic vessels, which are clipped and cut. The posterior mesocolic fascia is bluntly separated from the inferior mesentery bed, which is formed by duodenum, Gerota's fascia, and nearby structures. The second part of duodenum and the head of pancreas are exposed. Next, the surgeon mobilizes along the superior mesentery vein (SMV) and superior mesentery artery (SMA), with blunt dissection of the covering fascia and loose connective tissue to preserve the entire mesocolon completely and as far centrally as possible. Careful dissection is continued until the middle colic vessels (middle colic vein and middle colic artery) are reached. Afterward, the superior right colic vein of Henle's trunk is exposed and divided at the root. One pack of gauze is inserted beneath the mobilized mesocolon. Second, the surgeon divides the greater omentum. Entrance to the omental bursa is established after the second "tri-junction" (TJ2) is identified (TJ2 is the fusion point of the transverse mesocolon, the mesogastrium and the greater omentum). The fusion plane is bluntly separated between the transverse mesocolon (TM) and the right gastroepiploic mesentery (RGEM) until the previously placed gauze is exposed. Finally, the third "tri-junction" (TJ3) is identified (TJ3 is the fusion point of the retroperitoneum, the mesocolon, and the lateral peritoneum) at the inferior attachments of cecum. The ascending colon is freed up with mobilization of the lateral retroperitoneal attachments from the cecum to the hepatic flexture. Special attention should be paid to avoid breaking the fascia renalis. The tumor carrying the colon is exteriorized through an abdominal incision with a wound protector. Continuity of the digestive tract is performed extracorporeally with side-to-side ileotransverse colon anastomosis using a linear stapler. All the treatments follow standardized recovery protocols. RESULTS: This study recruited 20 males and 16 females. The median age was 56.5 years, and the median body mass index (BMI) was 22.1 kg/m2. Twelve patients had experienced previous abdominal surgery. No intraoperative complications occurred. The tumor was located in the ileocecus of 14 patients and in the hepatic flexture of 22 patients (Supplemental Table 1). The median number of retrieved lymph nodes was 20 (interquartile range [IQR], 14.8-27 (Supplemental Table 2). The median volume of blood lost was 5 ml (IQR 5-10 ml). The median postoperative hospital stay was 10 days (IQR 9-12.3 days). One patient received treatments from the intensive care unit (ICU). One patient underwent reoperation for incision dehiscence. Seven patients had a postoperative complication diagnosed within 30 days (Supplemental Table 3). The median follow-up period was 12 months (IQR 3-20) months. All the patients received adjuvant chemotherapy, with no case of recurrence (Supplemental Table 4). CONCLUSION: An optimal mesentery-defined approach for laparoscopic D3 + CME allows for ligation of feeding vessels at their bifurcation and for CME to be performed simultaneously with technical efficiency. This procedure is safe and strongly practical for advanced right colon cancer intervention.

Short-term outcomes of laparoscopic D2 lymphadenectomy with complete mesogastrium excision for advanced gastric cancer.

BACKGROUND: D2 lymphadenectomy has been widely accepted as a standard procedure of surgical treatment for local advanced gastric cancer [1, 2]. However, neither the dissection boundary nor the extent of the excision for perigastric soft tissues has been described [3-7]. Our previous researches demonstrate the existence of disseminated cancer cells in the mesogastrium [8, 9] and present an understandable mesogastrium model for gastrectomy [10]. Hence, the D2 lymphadenectomy plus complete mesogastrium excision (D2 + CME) is firstly proposed in this study, aiming to assess the safety, feasibility and corresponding short-term surgical outcomes. METHODS: All of these patients underwent laparoscopy assisted D2 + CME radical gastrectomy with a curative R0 resection, and all the operations were performed by Prof. Jianping Gong, chief of GI surgery of Tongji Hospital, Huazhong University of Science and Technology. All participants provided informed written consent to participate in the study. This study was approved by the Tongji Hospital Ethics Committee. The standard surgical procedures in the video are described as follows. Dissect along the gastrocolic ligament and then toward the left colic flexture with special made gauze. Bluntly separate the adipose tissues to find fascia plane. Expose along the plane toward the splenic inferior polar area. Precede to the origins of left gastroepiploic vessels (LGEVs), clip and cut. All the mobilized adipose tissues in this area are defined as left gastroepiploic mesentery (LGEM) [10]. Next, turn to infra-pyloric area. Dissect the fascia plane between right gastroepiploic mesentery (RGEM) and transverse mesocolon. Turn to the pancreas head, remove the covering adipose tissues, identify the superior mesentery vein and expose the origins of right gastroepiploic vessels (RGEVs). Clip and cut. All the surrounding mobilized adipose tissues are defined as RGEM [10]. Move to the superior boarder of pancreas with the stomach reflected cephalad, incise the serosa and bluntly mobilize through the plane with gauze. Turn to the common hepatic artery (CHA), remove the adherent adipose tissue. Expose the root of left gastric vein, clip and cut. Dissect the thick sheath of left gastric artery, expose at the root, trip clip and cut. All mobilized lateral adipose tissues and dorsal parts are defined as left gastric mesentery (LGM) [10]. Toward right, dissect follow the CHA and hepatic portal vein (HPV). Next, move toward the left side of LGM and dissect along the splenic artery until reaching the posterior gastric wall. Move to the anterior area of stomach and divide the lesser omentum. Clean up the adipose tissue and nerves along the lesser curvature up to the gastroesophageal junction. Expose and cut the right gastric vessels (RGVs) where the mobilized adipose tissues are defined as right gastric mesentery (RGM) [10]. Reconstruction of the alimentary tract was done by extracorporeal anastomosis. Standard recovery protocols were followed in postoperative treatments. RESULTS: Fifty-four patients between September 2014 and March 2015 have been recruited with informed consent and underwent laparoscopic D2 + CME by a single surgeon. The mean number of retrieved regional lymph nodes was 35.04 ± 10.70 (range 14-55). The mean volume of blood loss was 12.44 ± 22.89 ml (range 5-100). The mean laparoscopic surgery time was 127.82 ± 17.63 min (range 110-165). The mean hospitalization time was 11.09 ± 4.28 days (range 8-28). No operative complication was observed during the hospitalization. CONCLUSION: The anatomical boundary of mesogastrium is well described and dissected within D2 + CME surgical process. It proves to be safely feasible and repeatable with less blood lost, qualified lymph nodes retrieval results and other improved short-term surgical outcomes in advanced gastric cancer. Meanwhile, potential disseminated cancer cells fall into the mesogastrium can be eradicated by D2 + CME.

Detection and Characterization of Metastatic Cancer Cells in the Mesogastrium of Gastric Cancer Patients.

Gastric cancer is the second leading cause of cancer death worldwide. Here, we propose a novel type of tumor metastasis designated as Metastasis V in gastric cancer. Metastasis V is defined as the appearance of cancer cells in the mesogastrium with perigastric adipose tissue. To detect its incidence and characterize its clinic pathological features, large cross sectional tissue analysis of mesogastrium from 74 patients were used. Metastasis V was detected in 1 of 40 (2.5%) patients with early gastric cancer, 8 of 34 (24%) patients with advanced gastric cancer. The mean distance of Metastasis V from gastric wall was approximately 2.6 cm. Metastasis V was closely associated with tumor invasion depth, along with a number of positive lymph node metastasis. The prognosis of patients with Metastasis V was significantly (P<0.05) worse than those with tumor cell-free mesogastrium. These findings indicate that by using whole-sectional analysis, Metastasis V can be detected in the mesogastrium of gastric cancer patients, and also suggests that it may be a risk factor for patient survival after radical surgery.

Mesogastrium: a fifth route of metastasis in gastric cancer?

Radical gastrectomy for gastric cancer with D2 lymph node dissection has been widely applied in advanced gastric cancer. It is believed that such surgery should extremely sweep away local-regional tumor tissues and cancer cells and thoroughly prevent tumor recurrence in situ. However, for most patients with advanced gastric cancer, tumor local-regional recurrence has been proven unavoidable. This study has found that isolated cancer cells, separate from the primary lesion and lymph nodes, existed in the mesogastrium of resected gastric cancer specimens, leading to the hypothesis that these cancer cells may have infiltrated the mesogastrium through a fifth metastasis route (here named Metastasis V) which is distinct from the other four classic metastasis routes, and cannot be resected by conventional radical gastrectomy with D2 lymph node dissection. Local-regional recurrence might be closely associated with these cancer cells in the mesogastrium, and therefore, complete mesogastrium excision (CME) should be imperative and become the third radical principle for radical gastrectomy.