Radicality and safety of total mesopancreatic excision in pancreatoduodenectomy: a systematic review and meta-analysis.

BACKGROUND: Pancreatic head cancer patients who undergo pancreatoduodenectomy (PD) often experience disease recurrence, frequently associated with a positive margin status (R1). Total mesopancreas excision (TMpE) has emerged as a potential approach to increase surgical radicality and minimize locoregional recurrence. However, its effectiveness and safety remain under evaluation. METHODS: We conducted a systematic review and meta-analysis to synthesize current evidence on TMpE outcomes. A systematic search of MEDLINE, EMBASE, Cochrane, and Web of Science databases was conducted up to March 2024 to identify studies comparing TMpE with standard pancreatoduodenectomy (sPD). The risk ratio (RR) or mean difference (MD) was pooled using a random effects model. RESULTS: From 452 studies identified, 9 studies with a total of 738 patients were included, with 361 (49%) undergoing TMpE. TMpE significantly improved the R0 resection rate (RR 1.24; 95% CI 1.11-1.38; P < 0.05), reduced blood loss (MD -143.70 ml; 95% CI -247.92, -39.49; P < 0.05), and increased lymph node harvest (MD 7.27 nodes; 95% CI 4.81, 9.73; P < 0.05). No significant differences were observed in hospital stay, postoperative complications, or mortality between TMpE and sPD. TMpE also significantly reduced overall recurrence (RR 0.53; 95% CI 0.35-0.81; P < 0.05) and local recurrence (RR 0.39; 95% CI 0.24-0.63; P < 0.05). Additionally, the risk of pancreatic fistula was lower in the TMpE group (RR 0.66; 95% CI 0.52-0.85; P < 0.05). CONCLUSION: Total mesopancreas excision significantly increases the R0 resection rate and reduces locoregional recurrence while maintaining an acceptable safety profile when compared with standard pancreatoduodenectomy. Further prospective randomized studies are warranted to determine the optimal surgical approach for total mesopancreatic resection.

What do surgeons need to know about the mesopancreas.

BACKGROUND: Pancreatoduodenectomy is the only treatment with a promise of cure for patients with pancreatic head adenocarcinoma, and a negative resection margin is an important factor related to overall survival. Complete clearance of the medial margin with removal of the so-called mesopancreas may decrease the recurrence rate after pancreatic resection. Here, we present some important information about the mesopancreas, total mesopancreas excision, and technical aspects to achieve negative resection margins. The area named mesopancreas is defined as the tissue located between the head of the pancreas and the superior mesenteric vessels and the celiac axis and consists of the nerve plexus, lymphatic tissue, and connective tissue. The superior mesenteric and celiac arteries define the border of the mesopancreas. En bloc resection of anterior and posterior pancreatoduodenal nodes, hepatoduodenal nodes, along the superior mesenteric artery nodes, pyloric nodes, and nodes along the common hepatic artery is necessary. CONCLUSIONS: Improved knowledge of the surgical anatomy of the region and technical refinements of excision of the mesopancreas along with standardized pathological examination are important to increase and to determine radical resection of pancreatic head cancer.

Total mesopancreas excision for pancreatic head cancer: analysis of 120 cases.

OBJECTIVE: To evaluate the feasibility and safety of total mesopancreas excision (TMpE) in the treatment of pancreatic head cancer. METHODS: The clinical and pathological data of 120 patients with pancreatic head cancer who had undergone TMpE in our center from May 2010 to January 2014 were retrospectively analyzed. RESULTS: The mean operative time was (275.0±50.2) min and the average intra-operative blood loss was (390.0±160.5) mL. Post-operative complications were reported in 45 patients, while no peri-operative death was noted. The specimen margins were measured in three dimensions, and 86 patients (71.6%) achieved R0 resection. CONCLUSIONS: TMpE is safe and feasible for pancreatic head cancer and is particularly helpful to increase the R0 resection rate.

Comparative study of pancreatic vessels and mesopancreas of rhesus monkeys and humans.

Introduction: With the introduction of the concept of mesopancreas defining the perineural structures that includes neurovascular bundle and lymph nodes extending from the posterior surface of the pancreatic head to behind the mesenteric vessels,Total Mesopancreas Excision (TMpE) based on this theory has facilitated the development of pancreatic cancer surgery in clinical practice in recent years. However, the existence of so called mesopancreas in the human body is still in debate and the comparative study of mesopancreas of rhesus monkey and human have not been well investigated. Purpose: The aim of our study is to compare the pancreatic vessels and fascia of human and rhesus monkeys in anatomical and embryological perspectives and to support the utilization of rhesus monkey as animal model. Methods: In this study, 20 rhesus monkey cadavers were dissected and their mesopancreas location, relationships and arterial distribution were analyzed. We compared the location and developmental patterns of mesopancreas in macaques and humans. Results: The results showed that the distribution of pancreatic arteries in rhesus monkeys was the same as that in humans, which is consistent with phylogenetic similarities. However, the morphological features of the mesopancreas and greater omentum is anatomically different from that of humans, including (1) the greater omentum is not connected to the transverse colon in monkeys. (2) The presence of the dorsal mesopancreas of the rhesus monkey suggests that it be an intraperitoneal organ. Comparative anatomical studies of mesopancreas and arteries in macaques and humans showed characteristic patterns of mesopancreas and similarities in pancreatic artery development in nonhuman primates, consistent with phylogenetic differentiation.

Total mesopancreas excision is the better staging tool of the mesopancreas in pancreatic head carcinoma.

Preoperative imaging staging based on tumor, node, metastasis classification cannot be effective to avoid R1 resection because only further improvements in imaging technologies will allow the precise assessment of perineural and lymphatic invasion and the occurrence of microscopic tumour deposits in the mesopancreas. However, waiting for further improvements in imaging technologies, total mesopancreas excision remains the only tool able to precisely assess mesopancreatic resection margin status, maximize the guarantee of radicality in cases of negative (R0) mesopancreatic resection margins, and stage the mesopancreas.

Paraaortic dissection in "total mesopancreas excision" and "mesopancreas-first resection" pancreaticoduodenectomies for pancreatic cancer: Useless, optional, or necessary?A systematic review.

The mesopancreas does not have well-defined boundaries but is continuous and connected through its components with the paraaortic area. The mesopancreatic resection margin has been indicated as the primary site for R1 resection after PD in pancreatic head cancer and total mesopancreas excision has been proposed to achieve adequate retropancreatic margin clearance and to minimize the likelihood of R1 resection. However, the anatomy of the mesopancreas requires extended dissection of the paraaortic area to maximize posterior clearance. The artery-first surgical approach has been developed to increase local radicality at the mesopancreatic resection margin. During PD, the artery-first approach begins with dissection of the connective tissues around the SMA. However, the concept of the mesopancreas as a boundless structure that includes circumferential tissues around the SMA, SMV, and paraaortic tissue highlights the need to shift from artery-first PD to mesopancreas-first PD to reduce the risk of R1 resection. From this perspective the "artery-first" approach, which allows for the avoidance of R2 resection risk, should be integrated into the "mesopancreas-first" approach to improve the R0 resection rate. In total mesopancreas excision and mesopancreas-first pancreaticoduodenectomies, the inclusion of the paraaortic area and circumferential area around the SMA in the resection field is necessary to control the tumour spread along the mesopancreatic resection margin rather than to control or stage the spread in the nodal basin.

Application and progress of medical imaging in total mesopancreas excision for pancreatic head carcinoma.

Pancreatic head carcinoma (PHC) is one of the common gastrointestinal malignancies with a high morbidity and poor prognosis. At present, radical surgery is still the curative treatment for PHC. However, in clinical practice, the actual R0 resection rate, the local recurrence rate, and the prognosis of PHC are unsatisfactory. Therefore, the concept of total mesopancreas excision (TMpE) is proposed to achieve R0 resection. Although there have various controversies and discussions on the definition, the range of excision, and clinical prognosis of TMpE, the concept of TMpE can effectively increase the R0 resection rate, reduce the local recurrence rate, and improve the prognosis of PHC. Imaging is of importance in preoperative examination for PHC; however, traditional imaging assessment of PHC does not focus on mesopancreas. This review discusses the application of medical imaging in TMpE for PHC, to provide more accurate preoperative evaluation, range of excision, and more valuable postoperative follow-up evaluation for TMpE through imaging. It is believed that with further extensive research and exploratory application of TMpE for PHC, large-sample and multicenter studies will be realized, thus providing reliable evidence for imaging evaluation.

Real robotic total mesopancreas excision (TMpE) assisted by hanging manoeuver (HM): Standardised technique.

BACKGROUND: Pancreaticoduodenectomy (PD) is one of the most demanding interventions for digestive surgeons. R0 resection is a key point for the overall survival and disease-free survival. Total mesopancreas excision (TMpE) has been described by laparotomy but laparoscopy did not provide good results probably because of the technical difficulties of the approach. We propose a standardised total robotic approach. METHODS: In this step-by-step technical description, we propose as example, a case of a 53-year-old man with a pancreatic head adenocarcinoma with doubts about the invasion of the mesopancreas surrounding superior mesenteric artery. The mesopancreas hanging manoeuver allows us to perform a TMpE. RESULTS: The surgery performed was a robotic artery first pancreaticoduodenectomy with TMpE. The pathological result was pancreatic ductal adenocarcinoma pT2, N1 (1/23), M0, V0, L0, Pn0, R0. CONCLUSIONS: Robotic approach is safe, effective and reproductible. Through a standardised technique, it may overcome some of the technical difficulties of laparoscopic PD.

Pancreaticoduodenectomy With Arterial Approach of Total Mesenteric Resection of the Pancreas for Pancreatic Head Cancer.

BACKGROUND: This study aims to observe and analyze the clinical efficacy of the pancreaticoduodenectomy (PD) with total mesopancreas excision (TMpE) via the artery approach for carcinoma of head of the pancreas. METHODS: From October 2015 to October 2016, 60 patients with pancreatic head cancer were enrolled in this study. Twenty-eight patients were treated with PD with TMpE via the artery approach (group A), while 32 patients were treated with PD alone (group B) in our hospital. The clinical data of the patients were retrospectively collected, including intra-operative evaluation index, R0 resection rate of postoperative pathological specimens, postoperative complications, and the tumor recurrence time was observed after operation (at third, sixth, and 12th months). Clinical efficacy of PD with TMpE via the artery approach was evaluated between the two groups. RESULTS: There was no significant difference in the operation time or perioperative death between the two groups (P > 0.05). Postoperative specimen pathology showed that there was a statistically significant difference in the R0 resection rate between the two groups (P < 0.05). There was no significant difference in the incidence of postoperative complications between the two groups (P > 0.05). Tumor recurrence rate at month 3 post operation was 0 (0/28) in group A and 3.13% (1/32) in group B. There was no significant difference in the 6-month recurrence rate (P > 0.05). Postoperative recurrence rate in group A was significantly lower than that in group B at month 12 (P < 0.05). CONCLUSIONS: The PD with TMpE via the artery approach treatment of pancreatic head cancer can reduce the amount of intra-operative bleeding and save the operation time without increasing postoperative complications. It provides effective technical support for combined vascular anastomosis in the treatment of pancreatic head cancer with venous system invasion, and ensures the safety of operation. Moreover, this procedure can improve the R0 resection rate and reduce the recurrence rate in the near future. As a safe, effective and feasible surgical method for the treatment of pancreatic head cancer, it can be widely used in clinical practice.

Total mesopancreas excision for the treatment of pancreatic head cancer.

Mesopancreas is a controversial structure. This study aimed to explore the anatomical characteristics of the mesopancreas, define the range of the total mesopancreas excision (TMpE), and evaluate the feasibility, safety and effectivity of TMpE in the treatment of pancreatic head cancer. The clinical and pathological data of 58 consecutive patients undergoing TMpE for pancreatic head carcinoma from January 2013 to December 2015 were analyzed prospectively. The perioperative morbidity, mortality and clinical outcomes of patients undergoing TMpE were compared with the patients undergoing conventional pancreaticoduodenectomy. The mesopancreas was located in the retropancreatic area, extending from the head, neck, and uncinated process of pancreas to the aorto-caval groove, in which there were loose areolar tissue, adipose tissue, nerve plexus, lymphatic and capillaries. We observed significantly higher R0 rate (94.8% vs. 81.4%, P=0.035), more lymph nodes (16.2 vs. 11.4, P=0.000), lower total and local recurrence rate (half-year local recurrence rate 7.8% vs. 23.7%, P=0.036, one-year 18.2% vs. 39.5%, P=0.018) and longer disease-free survival (16.9 vs. 13.4 months, P=0.044) in TMpE group than in control group. In conclusion, mesopancreas is different from mesorectum because there is no fascial envelop or anatomical boundary in this area. TMpE could be safely and feasibly performed for the treatment of pancreatic head cancer to increase the R0 resection rate and improve the clinical outcomes.