The mesopancreas is the primary site for R1 resection in pancreatic head cancer: relevance for clinical trials

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.

Pancreaticoduodenectomy with superior mesenteric artery first-approach combined total meso-pancreas excision for periampullary malignancies: A high-volume single-center experience with short-term outcomes

Backgrounds/Aims

Pancreaticoduodenectomy (PD) is the only radical treatment for periampullary malignancies. Superior mesenteric artery (SMA) first approach combined with total meso-pancreas (MP) excision was conducted to improve the oncological results. There has not been any previous research of a technique that combines the SMA first approach and total MP excision with a detailed description of the MP macroscopical shape.

Methods

We prospectively assessed 77 patients with periampullary malignancies between October 2020 and March 2022 (18 months). All patients had undergone PD with SMA first approach combined total MP excision. The perioperative indications, clinical data, intra-operative index, R0 resection rate of postoperative pathological specimens (especially mesopancreatic margin), postoperative complications, and follow-up results were evaluated.

Results

The median operative time was 289.6 min (178-540 min), the median intraoperative blood loss was 209 mL (30-1,600 mL). Microscopically, there were 19 (24.7%) cases with metastatic MP, and five cases (6.5%) with R1-resection of the MP. The number of lymph nodes (LNs) harvested and metastatic LNs were 27.2 (maximum was 74) and 1.8 (maximum was 16), respectively. Some (46.8%) patients had pancreatic fistula, but mostly in grade A, with 7 patients (9.1%) who required re-operations. Some 18.2% of cases developed postoperative refractory diarrhea. The rate of in-hospital mortality was 1.3%.

Conclusions

The PD with SMA first approach combined TMpE for periampullary malignancies was effective in achieving superior oncological statistics (rate of MP R0-resection and number of total resected LNs) with non-inferior short-term outcomes. It is necessary to evaluate survival outcomes with long-term follow-up.

Prognostic value of margin clearance in total and distal pancreatectomy specimens with pancreatic ductal adenocarcinoma in a Danish population-based nationwide study

BACKGROUND

The prognostic role of resection margin status following total (TP) and distal (DP) pancreatectomy for pancreatic ductal adenocarcinoma (PDAC) is insufficiently evaluated. In Denmark, pancreatic surgery, including the postoperative pathological examination of the resection specimens, is confined to four centres, all reporting to the Danish Pancreatic Cancer Database (DPCD). In this Danish population-based nationwide study on TP and DP for PDAC from 2015-2019, based on data from DPCD, we evaluated whether there is a prognostically relevant minimum margin clearance definition and whether certain margins hold independent prognostic information.

METHODS

Clinical and pathological data were retrieved from DPCD and supplemented by review of pathology reports and re-microscopy, if needed. One of the study pathologists performed all re-microscopy. The prognostic significance of margin status was evaluated by dichotomisation of the TP cohort (n = 101) and the DP cohort (n = 90) into involved and uninvolved groups, using different clearance definitions (0.5 - ≥3.0 mm).

RESULTS

Following TP, direct involvement of the superior mesenteric artery (SMA) margin had independent prognostic value. When using a clearance definition of ≥ 0.5 or ≥ 1.5 mm for SMA, median survival for R0 versus R1 was 19 (95% CI 14-26) versus 10 (95% CI 5-20) months (p = 0.010), and 21 (95% CI 15-30) versus 10 (95% CI 8-19) months (p = 0.011), respectively. Overall margin status was not of significant prognostic importance following neither DP nor TP.

CONCLUSION

In this Danish population-based nationwide study, SMA margin involvement was a significant isolated prognostic factor following TP, whereas combined assessment of all circumferential margins did not hold statistically significant prognostic information. Following DP, resection margin status did not affect survival.

The Presence of an Aberrant Right Hepatic Artery Did Not Influence Surgical and Oncological Outcomes After Pancreaticoduodenectomy: A Comprehensive Systematic Review and Meta-Analysis

BACKGROUND

The presence of an aberrant right hepatic artery (a-RHA) could influence the oncological and postoperative results after pancreaticoduodenectomy (PD).

METHODS

A systematic review and metanalysis were conducted, including all comparative studies having patients who underwent PD without (na-RHA) or with a-RHA. The results were reported as risk ratios (RRs), mean differences (MDs), or hazard ratios (HRs) with 95% confidence intervals (95 CI). The random effects model was used to calculate the effect sizes. The endpoints were distinguished as critical and important. Critical endpoints were: R1 resection, overall survival (OS), morbidity, mortality, and biliary fistula (BL). Important endpoints were: postoperative pancreatic fistula (POPF), delayed gastric emptying (DGE), post pancreatectomy hemorrhage (PPH), length of stay (LOS), and operative time (OT).

RESULTS

Considering the R1 rate no significant differences were observed between the two groups (RR 1.06; 0.89 to 1.27). The two groups have a similar OS (HR 0.95; 0.85 to 1.06). Postoperative morbidity and mortality were similar between the two groups, with a RR of 0.97 (0.88 to 1.06) and 0.81 (0.54 to 1.20), respectively. The biliary fistula rate was similar between the two groups (RR of 1.09; 0.72 to 1.66). No differences were observed for non-critical endpoints.

CONCLUSION

The presence of a-RHA does not affect negatively the short-term and long-term clinical outcomes of PD.

New approach of circumferential lymph node dissection around the superior mesenteric artery for pancreatic cancer during pancreaticoduodenectomy (with video)

PURPOSE

Various approaches have been reported for the resection of the nervous and lymphatic tissues around the superior mesenteric artery (SMA) during pancreaticoduodenectomy (PD) for pancreatic cancer. We developed a new procedure for circumferential lymph node dissection around the SMA to minimize local recurrence.

METHODS

We included 24 patients who underwent PD with circumferential lymph node dissection around the SMA (circumferential dissection) and 94 patients who underwent classical mesopancreatic dissection (classical dissection) between 2019 and 2021. The technical details of this new method are described in the figures and videos, and the clinical characteristics and outcomes of this technique were compared with those of classical dissection.

RESULTS

The median follow-up durations in the circumferential and classical dissection groups were 39 and 36 months, respectively. The patients' characteristics, including tumor resectability, preoperative and adjuvant chemotherapy rates, postoperative complication rates, and tumor stage, were similar between the two groups. No differences were observed in recurrence-free survival and overall survival between the two groups; however, the classical dissection group tended to have more local recurrences than the circumferential dissection group (8.3% vs. 33.3%, P = 0.168). Although no case of nodular-type recurrence after circumferential dissection was observed, 61.1% of local recurrences after classical dissection were of the nodular-type, and 36.4% were located on the left side of the SMA.

CONCLUSIONS

Performing circumferential lymph node dissection around the SMA during PD can be conducted safely with minimal risks of local recurrence and may enhance the completeness of local resection.

Perioperative Outcomes of Systematic Mesopancreas Dissection for Pancreatic and Periampullary Carcinoma at a Tertiary Referral Center From a Low Middle-Income Country

Introduction Systematic mesopancreas dissection (SMD) is an emerging surgical approach in pancreatic cancer surgery. There is still debate about early postoperative and pathological outcomes using SMD in pancreatic cancer surgery. This study has been conducted to compare the perioperative outcomes, the lymph node yield, and the margin status in patients who underwent standard pancreaticoduodenectomy (ST-PD) and SMD-PD for pancreatic and periampullary carcinoma. Methods A retrospective comparative study was conducted in patients who underwent PD for pancreatic and periampullary carcinoma in a single unit of gastrointestinal and hepatopancreatobiliary surgery at Tribhuvan University Teaching Hospital, Nepal. Early perioperative and pathological outcomes were compared between the SMD-PD and ST-PD. Results The demographic data of 30 patients who underwent SMD-PD was comparable with the historical data of 40 patients who underwent ST-PD. The intraoperative blood loss and postoperative complications were found to be comparable between ST-PD and SMD-PD. However, the median operative time for SMD-PD was longer than ST-PD (360 minutes [IQR: 90 minutes] vs. 360 minutes [IQR: 60 minutes]). The rate of margin negative resection was similar between both groups. The median lymph node yield was significantly high in patients who underwent SMD-PD (17.5 (IQR: 6.5) vs. 11 [IQR-10.75]; p < 0.05). Conclusion SMD is safe and feasible for treating periampullary carcinoma and is particularly helpful in increasing lymph node yield.

Pancreatoduodenectomy En Bloc With Superior Mesenteric Artery Resection for Borderline Resectable Pancreatic Cancer - A Case Report and Literature Review

BACKGROUND/AIM

Pancreatic head adenocarcinoma represents the most aggressive digestive malignancy, which affects patients worldwide and is associated with poor outcomes especially due to the fact that most cases are diagnosed when local vascular invasion is already present.

CASE REPORT

This is a case report of a 44-year-old patient diagnosed with a borderline resectable pancreatic head adenocarcinoma invading the superior mesenteric artery. The patient was submitted to surgery, and intraoperatively the mesenteric artery invasion was found. A pancreatoduodenectomy en bloc with superior mesenteric artery resection was performed while the continuity of the arterial structure was re-established by placing a cadaveric graft.

CONCLUSION

In selected cases, extended arterial resections might be needed in order to achieve negative resection margins and therefore, to improve the chances of long-term survival.

The Story Retold: The Kocher Manoeuvre

The Kocher manoeuvre is used for mobilization of the duodenum and head of the pancreas and bears the name of Theodor Kocher, who published it in 1903. We describe the embryology of the duodenum and pancreas, relating it to surgical anatomy applied during the procedure. Finally, we present the key points of the procedure, providing more insights into the anatomical structures that are mainly involved.

Para-aortic lymph node involvement should not be a contraindication to resection of pancreatic ductal adenocarcinoma

BACKGROUND

Para-aortic lymph nodes (PALN) are found in the aortocaval groove and they are staged as metastatic disease if involved by pancreatic ductal adenocarcinoma (PDAC). The data in the literature is conflicting with some studies having associated PALN involvement with poor prognosis, while others not sharing the same results. PALN resection is not included in the standard lymphadenectomy during pancreatic resections as per the International Study Group for Pancreatic Surgery and there is no consensus on the management of these cases.

AIM

To investigate the prognostic significance of PALN metastases on the oncological outcomes after resection for PDAC.

METHODS

This is a retrospective cohort study of data retrieved from a prospectively maintained database on consecutive patients undergoing pancreatectomies for PDAC where PALN was sampled between 2011 and 2020. Statistical comparison of the data between PALN+ and PALN- subgroups, survival analysis with the Kaplan-Meier method and risk analysis with univariable and multivariable time to event Cox regression analysis were performed, specifically assessing oncological outcomes such as median overall survival (OS) and disease-free survival (DFS).

RESULTS

81 cases had PALN sampling and 17 (21%) were positive. Pathological N stage was significantly different between PALN+ and PALN- patients (P = 0.005), while no difference was observed in any of the other characteristics. Preoperative imaging diagnosed PALN positivity in one case. OS and DFS were comparable between PALN+ and PALN- patients with lymph node positive disease (OS: 13.2 mo vs 18.8 mo, P = 0.161; DFS: 13 mo vs 16.4 mo, P = 0.179). No difference in OS or DFS was identified between PALN positive and negative patients when they received chemotherapy either in the neoadjuvant or in the adjuvant setting (OS: 23.4 mo vs 20.6 mo, P = 0.192; DFS: 23.9 mo vs 20.5 mo, P = 0.718). On the contrary, when patients did not receive chemotherapy, PALN disease had substantially shorter OS (5.5 mo vs 14.2 mo; P = 0.015) and DFS (4.4 mo vs 9.8 mo; P < 0.001). PALN involvement was not identified as an independent predictor for OS after multivariable analysis, while it was for DFS doubling the risk of recurrence.

CONCLUSION

PALN involvement does not affect OS when patients complete the indicated treatment pathway for PDAC, surgery and chemotherapy, and should not be considered as a contraindication to resection.

[Pathological processing in pancreatic ductal adenocarcinoma-What is new?]

The macroscopic and microscopic assessments of pancreatic cancer resection specimens belong to the standard repertoire of any department of pathology. In recent years standards have been developed regarding both macroscopic and microscopic assessments, which are laid down in international and national guidelines and classifications and are regularly updated. In this way the reporting of results and interdisciplinary communication are facilitated. These classifications and guidelines are influenced by current studies and the data from them provide information on which histopathological factors are particularly relevant for the prognosis and treatment. Due to the increasing use of neoadjuvant therapy the assessment of tumor regression in histopathological specimens is also gaining in importance. Finally, individual targeted treatments are also now available for pancreatic cancer, which require extended molecular pathological diagnostics.

Anatomical Study of the Duodenojejunal Uncinate Process Vein: A Key Landmark for Mesopancreatoduodenal Resection During Pancreaticoduodenectomy

Background

The mesopancreas or mesopancreatoduodenum is an important anatomical concept during pancreaticoduodenectomy (PD) in patients with periampullary carcinoma. This study investigated whether the duodenojejunal uncinate process vein (DJUV), which is defined as the vein draining from the upper jejunum to the superior mesenteric vein adjacent to the uncinate process, is a useful anatomical landmark for the caudal border of mesopancreatoduodenum resection during PD.

Methods

This study enrolled 100 adult patients with hepatobiliary pancreatic disease who underwent preoperative multidetector-computed tomography (CT). The anatomy of the key blood vessels involved during PD, and the relationship between these vessels and the DJUV, were analyzed by preoperative CT.

Results

The first jejunal vein was the DJUV in 85 cases, whereas the second jejunal vein was the DJUV in 15 cases. Furthermore, the DJUV was classified into two subtypes depending on its positional relationship with the superior mesenteric artery (SMA). The inferior pancreaticoduodenal artery and vein were located on the cranial side of the DJUV in all cases. The distance between the middle colonic artery, used as a guide for regional lymph nodes, and the point where the DJUV intersected the SMA was within 10 mm in 80% of cases. These results imply that using the DJUV as a landmark for the caudal border of the mesopancreatoduodenum provides a safe approach and enables sufficient dissection of regional lymph nodes and tissues around the SMA.

Conclusion

The DJUV may be a useful anatomical landmark for the caudal border of the mesopancreatoduodenum resection during PD.

The role of mesopancreas excision for ampullary carcinomas: a single center propensity-score matched analysis

BACKGROUND

Few evidences are available on the prognostic role of mesopancreas excision(MPe) for ampullary cancers(ACs). Aim of this study was to compare the long-term outcomes between pancreaticoduodenectomy(PD) with(PD-MPe group) and without(sPD group) MP.

METHODS

Thirty-seven sPDs were matched and compared to 37 PD-MPes for perioperative outcomes, recurrence rate, disease-free(DFS) and overall survival(OS).

RESULTS

The PD-MPe technique related to a significantly higher number of harvested lymph nodes[16 (±6)] as compared to the sPD [10 (±5); p < 0.0001]. Tumor recurrence was more frequent in the sPD cohort[21 (56.8%) vs 12 (32.4%) in the PD-MPe population; p = 0.03]. Although not statistically different, PD-MPe was associated with a better DFS(40% vs 35.7% for sPD; p = 0.08) and OS(59.3% vs 39.1% for sPD; p = 0.07). At the multivariate analysis, a higher number of lymph nodes retrieved and a more extensive lymphovascular clearance reached with the MPe technique, together with lymph nodes metastases, were recognized as independent prognostic factors for a worse OS and DFS.

CONCLUSION

The PD-MPe technique is associated with a better oncological radicality thanks to the higher number of retrieved lymph nodes and to the more appropriate tumor clearance. This reflects in a lower incidence of tumor relapse and in improved outcomes in terms of OS and DFS.

"Mesopancreas-first" radical resection of pancreatic head cancer following the Cattell-Braasch-Valdoni maneuver: Appreciating the legacy of pioneers in visceral surgery

The “artery-first” approach pancreaticoduodenectomy, with maximal mesopancreas excision and central vascular ligation, represents the current principal determinants of radicality in pancreatic head cancer resection. However, these modifications at the resection stage of pancreaticoduodenectomy constitute extremely demanding and technically complicated procedures. Among the most critical contributing factors in the difficulty of artery-first approaches is the spiral configuration of the mesoduodenum and proximal mesojejunum around the superior mesenteric artery axis. This creates complicated tridimensional anatomy, making surgical dissection in the inferior peripancreatic anatomic area extremely challenging and demanding. The Cattell–Braasch–Valdoni maneuver (right-sided medial visceral mobilization and intestinal derotation maneuver) restores the embryological twist of the duodenojejunal junction, which demystifies the distorted peripancreatic vascular anatomy and facilitates a safe and radical “mesopancreas-first” pancreatic head cancer resection. The aim of this paper was to present the advantages, efficacy, and safety of the Cattell–Braasch–Valdoni maneuver in artery-first approach radical pancreaticoduodenectomy and provide a detailed description of its surgical technique.

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.

Reconsideration of the Appropriate Dissection Range Based on Japanese Anatomical Classification for Resectable Pancreatic Head Cancer in the Era of Multimodal Treatment

Patients with resectable pancreatic cancer are considered to already have micro-distant metastasis, because most of the recurrence patterns postoperatively are distant metastases. Multimodal treatment dramatically improves prognosis; thus, micro-distant metastasis is considered to be controlled by chemotherapy. The survival benefit of "regional lymph node dissection" for pancreatic head cancer remains unclear. We reviewed the literature that could be helpful in determining the appropriate resection range. Regional lymph nodes with no suspected metastases on preoperative imaging may become areas treated with preoperative and postoperative adjuvant chemotherapy. Many studies have reported that the R0 resection rate is associated with prognosis. Thus, "dissection to achieve R0 resection" is required. The recent development of high-quality computed tomography has made it possible to evaluate the extent of cancer infiltration. Therefore, it is possible to simulate the dissection range to achieve R0 resection preoperatively. However, it is often difficult to distinguish between areas of inflammatory changes and cancer infiltration during resection. Even if the "dissection to achieve R0 resection" range is simulated based on the computed tomography evaluation, it is difficult to identify the range intraoperatively. It is necessary to be aware of anatomical landmarks to determine the appropriate dissection range during surgery.

Mesopancreas Excision and Triangle Operation During Robotic Pancreatoduodenectomy

BACKGROUND

The retropancreatic space between the superior mesenteric artery, celiac axis, and portal vein is called the mesopancreas. Total mesopancreas excision and skeletonization of both celiac axis and superior mesenteric artery are used to reduce R1 resection in high-risk patients and in those with locally advanced disease. The aim of this study was to present a series of video clips from several patients showing the mesopancreas excision and the triangle operation with a detailed technical description of both techniques with different approaches.

METHODS

Video clips were compiled from several robotic pancreatoduodenectomies to demonstrate the total mesopancreas excision and triangle operation technique, as follows: (1) main steps for mesopancreas excision and triangle operation, (2) anterior approach for mesopancreas excision, and (3) triangle operation.

RESULTS

A total of 87 patients underwent robotic PD at our center between March 2018 and March 2021. Of these, 22 patients underwent robotic mesopancreas excision. This technique was used for patients at high risk for R1 resection in 18 patients and triangle operation in four patients. Partial portal vein resection was necessary in 6 cases. One patient had R1 resection and was treated with adjuvant therapy. The remaining patients presented free surgical margins. The mean number of harvested lymph nodes was 40 (range: 27-77). The median interval between the operation and chemotherapy was 23 days.

CONCLUSIONS

The robotic total mesopancreas excision and the triangle operation are feasible and safe for selected patients. The indication for this radical operation is the presence of a high risk for R1 resection and for those with locally advanced disease. The presented video may help oncological surgeons to perform these techniques.

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.

Morphological speculation of the MHPD and related clinical projections

OBJECTIVE

The concept of mesopancreas has been brought into focus nowadays. Studies on membrane morphology of pancreas are clinically significant in determining an ideal surgical route for a "holy plane". In this paper, we aimed to observe the structure of the peripancreatic membranes and its interactions with adjacent tissues; tentatively put forward the proposition of mesohepatopancreaticoduodenum (MHPD) and explore in depth in surgical local resection.

METHODS

33 cadavers were examined in the experiment, including 30 for gross anatomy and 3 for histological observation after transection. The histological characteristics of the membrane covering the pancreas were proved by Masson and Bielschowsky silver staining and further explored in clinical application and testified in a surgical scenario. All above were carried out through traditional procedures.

RESULTS

The anterior surface membrane of the pancreas was intact and the posterior portion expanding to the pancreaticoduodenum enclosed the surface of the duodenum and the pancreatic head, which could be easily isolated from the posterior abdominal wall. The posterior surface membrane around the body and tail wrapped the pancreatic parenchyma, which created a soft-tissue window for the posterior abdominal wall. Then, dense connective tissue adhesions were detected between the celiac artery and the superior mesenteric artery.

CONCLUSIONS

The embryonic origin of the mesopancreas and the surgical procedures were reviewed and inspected based on the proposition of MHPD and above results. We hope that this study could stir up our interest in the advancement of imaging diagnoses and minimally invasive surgical treatment of pancreas.

Vascular Anatomy of Mesopancreas in Pancreatoduodenectomy Using an Intestinal Derotation Procedure

BACKGROUND

Mesopancreas excision in pancreatoduodenectomy is technically complicated because of the anatomical complexity of the mesopancreas with the inferior peripancreatic blood vessels which is caused by intestinal rotation in fetal life. We have developed a novel artery-first approach (the intestinal derotation procedure) for facilitating mesopancreas excision. The aim of this study was to clarify the vascular anatomy of the mesopancreas after derotation.

METHODS

The right-sided colon and small intestine are mobilized from the retroperitoneum, and the intestinal loop is then derotated. In 136 cases of pancreatoduodenectomy employing the derotation procedure, we analyzed the vascular anatomy of the mesopancreas.

RESULTS

After derotation, the anatomy was simplified. The mesopancreas extended from the right aspect of the superior mesenteric artery (SMA), forming a horizontal plane. The first jejunal trunk (FJT) was situated in parallel with the second jejunal artery and was anterior (91%) or posterior (9%) to the SMA. The inferior pancreaticoduodenal vein (IPDV) entered the right side of the FJT (83%) or the superior mesenteric vein (17%). Besides the IPDV, 1-4 tributaries entered the right wall of the FJT, in 89% of cases. The inferior pancreaticoduodenal artery was observed to originate from the right wall of the SMA, sharing a common stem with the first jejunal artery (70%) or branching directly from the SMA (29%).

CONCLUSIONS

Intestinal derotation simplifies the mesopancreas anatomy and reveals the anatomical details of the inferior peripancreatic blood vessels in pancreatoduodenectomy.

En bloc proximal peri-mesenteric clearance for pancreatic head cancer surgery

The superior mesenteric artery (SMA) first approach and meso-pancreas excision (MPE) during pancreatoduodenectomy (PD) for pancreatic head cancer have been suggested for complete local tumor control, less operative blood loss, and early determination of resectability. However, SMA-first approach is merely a mode of approach and the concept of MPE has been challenged due to its anatomical obscurity. Dissection around proximal mesenteric vessels, superior mesenteric vein and SMA, is a critical procedure point for local tumor control as tumor infiltration is frequently observed both at the time of initial diagnosis and recurrence. The meso-pancreas, which encompasses the soft tissue between the uncinated process and SMA, does not include all the aforementioned points of proximal mesenteric areas. Therefore, the authors propose a new terminology named, “en bloc proximal peri-mesenteric clearance (PPMC)”, to describe the removal of all the lymph nodes including soft tissue around proximal mesenteric vessels, especially the SMA, to ensure complete local tumor control of pancreatic head cancer. The SMA-first approach applied either by the mesenteric approach or supra-colic approach can make this procedure more feasible. The extent of the circumferential dissection of the peri-SMA nerve plexus can be adjusted according to the primary disease. PPMC including the removal of all lymph nodes around the proximal SMA may be considered as a standard extent of PD for pancreatic head cancer.

Prognostic relevance of the posterior resection margin for predicting disease free survival in ampullary adenocarcinoma

BACKGROUND

Pancreaticoduodenectomy is the only curative treatment option for patients with resectable ampullary adenocarcinoma (AA). Excellent disease free survival (DFS) can be achieved in patients with clear resection margins but it is poorly understood which patients are at increased risk of recurrence and hence would benefit from adjuvant chemotherapy. There is evolving evidence that the anatomical location of incomplete resection margins influences DFS in pancreatic adenocarcinoma. It is unknown if this also pertains to AA and therefore this study aimed to assess individual resection margin status and other predictors of DFS in AA.

MATERIAL & METHODS

Consecutive patients undergoing pancreaticoduodenectomy for AA at our institution from 1996 to 2017 were analysed. Pancreas neck, posterior and superior mesenteric vein margins were assessed individually. Cox proportional hazards modelling was used to identify predictors of 5-year DFS. Factors with p < 0.1 on univariate analysis were included for multivariate analysis.

RESULTS

Analysis of 104 patients revealed median OS and DFS of 56 and 34 months, respectively. Predictors associated with worse DFS on multivariate analysis were T3-stage (HR 3.6, p = 0.048), N1 (HR 2.9, p = 0.01) and N2 -stage (HR 3.6, p = 0.006), R1 status at the posterior margin (HR 3.0, p = 0.009) and a visible mass on CT (HR 2.0, p = 0.039).

CONCLUSION

Routine histopathological assessment of individual resection margins may aid in predicting recurrence of AA. Future studies to assess if routine mesopancreas excision during pancreaticoduodenectomy can reduce the incidence of R1 status at the posterior margin are warranted.

A phase II study of liposomal irinotecan with 5-fluorouracil, leucovorin and oxaliplatin in patients with resectable pancreatic cancer: the nITRO trial

Background:

Up-front surgery followed by postoperative chemotherapy remains the standard paradigm for the treatment of patients with resectable pancreatic cancer. However, the risk for positive surgical margins, the poor recovery after surgery that often impairs postoperative treatment, and the common metastatic relapse limit the overall clinical outcomes achieved with this strategy. Polychemotherapeutic combinations are valid options for postoperative treatment in patients with good performance status. liposomal irinotecan (Nal-IRI) is a novel nanoliposome formulation of irinotecan that accumulates in tumor-associated macrophages improving the therapeutic index of irinotecan and has been approved for the treatment of patients with metastatic pancreatic cancer after progression under gemcitabine-based therapy. Thus, it remains of the outmost urgency to investigate introduction of the most novel agents, such as nal-IRI, in perioperative approaches aimed at increasing the long-term effectiveness of surgery.

Methods:

The nITRO trial is a phase II, single-arm, open-label study to assess the safety and the activity of nal-IRI with fluorouracil/leucovorin (5-FU/LV) and oxaliplatin in the perioperative treatment of patients with resectable pancreatic cancer. The primary tumor must be resectable with no involvement of the major arteries and no involvement or <180° interface between tumor and vessel wall of the major veins. A total of 72 patients will be enrolled to receive a perioperative treatment of three cycles before and three cycles after surgical resection with nal-IRI 50 mg/m², oxaliplatin 60 mg/m², leucovorin 200 mg/m², and 5-fluorouracil 2400 mg/m2, days 1 and 15 of a 28-day cycle. The primary objective is to improve from 40% to 55% the proportion of patients achieving R0 resection after preoperative treatment.

Discussion:

The nITRO trial will contribute to strengthen the clinical evidence supporting perioperative strategies in resectable pancreatic cancer patients. Moreover, this study represents a unique opportunity for translational analyses aimed to identify novel immune-related prognostic and predictive factors in this setting.

Trial registration

Clinicaltrial.gov: NCT03528785. Trial registration data: 1 January 2018

Protocol number: CRC 2017_01

EudraCT Number: 2017-000345-46

The mesopancreas and pancreatic head plexus: morphological, developmental, and clinical perspectives

PURPOSE

Total mesopancreas excision has been found to be helpful for increasing no residual tumor resection rate and improving the prognosis of pancreatic cancer. This study analyzed the relationships among the mesopancreas and pancreatic head plexus from the morphological, developmental, and clinical perspectives.

METHODS

Twenty-four cadavers were employed. The upper abdominal viscera were resected en-bloc with the hepatoduodenal ligament, abdominal aorta, and nerve plexuses, and the innervation of the pancreas was dissected. Ten additional cadavers were used for histological examination of the pancreatic head and neck, part of the duodenum, the superior mesenteric artery (SMA) and its surrounding tissues, and the related arteries and veins.

RESULTS

As results, cross-sections of the SMA revealed 6-9 layers of membranous structures resembling the layers of an onion, and the nerve fibers of the superior mesenteric plexus ran between the layers. Loose areolar tissue, adipose tissue, and lymphatics existed between the SMA and the pancreatic head/uncinate process, along with abundant thin blood vessels and capillaries, but very few nerves were found approaching the pancreas. Several parallel layers of collagen fibers (so-called Treitz's fusion fascia) existed between the dorsal aspect of the pancreatic head and the aortocaval plane.

CONCLUSION

The mesopancreas was continuous and connected with the para-aortic area. It may be better termed the mesopancreatoduodenum than the mesopancreas, as the duodenum-pancreas-SMA forms a complex morphological, developmental, functional, and pathological structure.

Total mesopancreas excision for periampullary malignancy: a single-center propensity score-matched comparison of long-term outcomes

PURPOSE

Few comparative studies are available on the long-term prognostic role of mesopancreas (MP) excision after pancreaticoduodenectomy (PD). We compared the long-term outcomes of patients undergoing standard PD (sPD) and PD with MP excision (PD-MPe).

METHODS

Sixty sPDs were compared to 60 matched PD-MPe patients for intraoperative and postoperative data, histopathological findings, and long-term outcomes.

RESULTS

R0 rate was similar in the two groups (p = 0.17). However, PD-MPe related to a lower rate of MP resection margin positivity (16.7% vs 5%; p = 0.04) and to a higher harvested lymph nodes number (19.8 ± 7.6 vs 10.1 ± 5.1; p < 0.0001). Local tumor recurrence was more frequent in the sPD cohort (55.5% vs 26.8% in the PD-MPe group; p = 0.002), with a consequent worse disease-free survival (DFS) (14.8% vs 22.3%; p = 0.04). An inferior 5-year overall survival (OS) was noted in case of MP margin positivity compared with MP margin negativity (0% vs 29%; p < 0.0001). MP positivity resulted as an independent prognostic factor for both a worse OS and DFS at the multivariate analysis.

CONCLUSION

PD-MPe offers clinical advantages in terms of MP resection margin status, local recurrence, long-term mortality, and DFS. The lower MP positivity rate, achieved with PD-MPe, leads to better outcomes both in terms of OS and DFS.

Total Pancreatectomy: Indications, Advantages and Disadvantages - A Review

Background: Total pancreatectomy is an obligatory surgical procedure in locally advanced or centrally located pancreatic neoplasms to achieve complete tumour clearance. Owing to sound understanding of tumour biology and evolution in intervention technique and improved postoperative care, nowadays the indications of total pancreatectomy have taken a significant change. Aim: To review the indications of total pancreatectomy and its advantages and disadvantages under current perspectives. Method: Major databases, including PubMed, EMBASE, Science Citation Index Expanded, Scopus and the Cochrane Library, were searched for studies of total pancreatectomy and the results reported by various authors were summarized. Results: The indications of total pancreatectomy in subjects diagnosed with chronic pancreatitis were classified into four subgroups, including "Tumour", "Trouble", "Technical difficulties" and "Therapy-refractory pain". Today, total pancreatectomy has more specific and different indications than before. Currently, IPMN (intraductal papillary mucinous neoplasm) seems to have the most essential indication quantitatively. Morbidity and mortality related to total pancreatectomy are more profoundly decreased than before due to improvements in the operative techniques and post-operative managements. Some of the metabolic disorders are reported as major disadvantages of total pancreatectomy. Conclusion: Despite the disadvantages of total pancreatectomy, it remains an inevitable procedure for subjects with chronic pancreatitis, improvements in operative techniques and postoperative management ensuring long-term survival, a better quality of life, and diminished mortality and morbidity rates.

Precise anatomical resection based on structures of nerve and fibrous tissue around the superior mesenteric artery for mesopancreas dissection in pancreaticoduodenectomy for pancreatic cancer

BACKGROUND

The aim of the present study was to investigate the feasibility of resection based on the nerve and fibrous tissue (NFT) structures around the superior mesenteric artery (SMA) for resectable pancreatic adenocarcinoma (R-PDAC) patients.

METHODS

NFTs around the SMA were classified into four "intensive NTFs area" with spreading the NFTs around the SMA and three SMA nerve plexus regions without branching nerves according to autopsy findings. Complete dissection of four "intensive NTFs areas" was performed by pre-exposing three SMA nerve plexus regions without branching nerves as "dissection-guiding points" with SMA nerve plexus preservation (NFT-based resection). Among 157 R-PDAC patients undergoing pancreaticoduodenectomy, surgical outcomes of 78 patients with NFT-based resection were compared with 59 patients with half-SMA nerve plexus dissection and 20 patients without NFTs dissection.

RESULTS

In the NFT-based resection group, 76.5% had tumor involvement and metastasis in each intensive NTFs area. Operative time, blood loss, and postoperative diarrhea rate were significantly lower in NFT-based resection than in half-SMA nerve plexus group (321 vs 390 min; P < .01, 228 vs 550 mL; P < .01, 5.1% vs 15.3%; P = .04, respectively). R0 rate and median overall survival significantly improved in NFT-based resection than in non-NFT dissection group (93.6% vs 65.0%; P < .01, 49.6 vs 23.6 months, P = .01).

CONCLUSION

NFT-based resection may become a novel method for R-PDAC patients.

Impact of resection margins on long-term survival after pancreaticoduodenectomy for pancreatic head carcinoma

BACKGROUND

The impact of resection margin status on long-term survival after pancreaticoduodenectomy (PD) for patients with pancreatic head carcinoma remains controversial and depends on the method used in the histopathological study of the resected specimens. This study aimed to examine the impact of resection margin status on the long-term overall survival of patients with pancreatic head carcinoma after PD using the tumor node metastasis standard.

METHODS

Consecutive patients with pancreatic head carcinoma who underwent PD at the Chinese People's Liberation Army General Hospital between May 2010 and May 2016 were included. The impact of resection margin status on long-term survival was retrospectively analyzed.

RESULTS

Among the 124 patients, R0 resection was achieved in 85 patients (68.5%), R1 resection in 38 patients (30.7%) and R2 resection in 1 patient (0.8%). The 1- and 3-year overall survival (OS) rates were significantly higher for the patients who underwent R0 resection than the rates for those who underwent R1 resection (1-year OS rates: 69.4% vs 53.0%; 3-year OS rates: 26.9% vs 11.7%). Multivariate analysis showed that resection margin status and venous invasion were significant risk factors for OS.

CONCLUSION

Resection margin was an independent risk factor for OS for patients with pancreatic head carcinoma after PD. R0 resection was associated with significantly better OS after surgery.

Positive Resection Margins Detected by Standardized Study of a Pancreaticoduodenectomy Sample: Is There Any Real Impact on Long-term Survival?

INTRODUCTION

The pathological evaluation of pancreaticoduodenectomy (PD) samples and the impact of R1 resections on survival has recently been questioned. This study evaluates the introduction of a standardized pathology study protocol (PSP) and the prognosis of R1 resections after long-term follow-up.

METHODS

We reviewed data from a prospectively maintained database regarding 109 periampullary tumors treated by PD from 2005 to 2013. The results of the introduction of a PSP were analysed, and the recurrence rate (RR), disease-free survival (DFS) and overall survival (OS) of the R1 resections were evaluated for each positive margin.

RESULTS

The PD specimens of periampullary tumors analyzed by PSP showed a higher rate of isolated lymph nodes (17 vs. 8; P=.003), N+ (60% vs. 31%; P<.001), microvascular invasion (67% vs. 34%; P=.001) and R1 resections (42% vs. 18%; P=.010). Pancreatic adenocarcinomas with R1 resection in the PSP group were compared with R0, presenting higher percentages of vascular resections (P=.033), N+ (P=.029), lymphatic and perineural invasion (P=.047; P=.029), higher RR (P=.026), lower DFS (P=.016) and lower OS (P=.025). Invasion of the medial margin correlated with a worse prognosis.

CONCLUSIONS

Our series shows an increase in R1 resection after the introduction of a PSP. Infiltration of the medial margin seems to be associated with a higher RR and a decrease in DFS and OS.

Pancreatic cancer surgical management

Pancreatic ductal adenocarcinoma (PDAC) remains a dismal prognosis and surgery is the only chance for cure. However, only few of the patients have localized tumor eligible for curative complete resection. Preoperative management and well-staging of the disease are the cornerstone for appropriate surgery and major issues to define the best therapeutic strategy. This review focuses on the surgical and optimal perioperative management of PDAC and summarizes updates data on the subject.

Pancreatoduodenectomy with artery-first approach

"Artery-first approach" encompasses different aspects for the surgical treatment of pancreatic cancer. It is a surgical technique or set of techniques which share in common the dissection of the main arterial vasculature involved in pancreatic cancer, before any irreversible surgical step is performed. On the other hand it represents the need for a meticulous dissection of the arterial planes and clearing of the retropancreatic tissue between the superior mesenteric artery, the common hepatic artery and portal vein in an attempt to achieve R0 resections. The recent expansion of this approach is based mainly on three factors: venous involvement should not be considered a contraindication for resection, most of the pancreatic resections performed with a standard procedure may be in fact non-oncological (R1) resections and the postero-medial or vascular margin is the most frequently invaded by the tumor. This review aimed to summarize and update the artery-first approach in pancreaticoduodenectomy.

Systematic review of the mesopancreas: concept and clinical implications

BACKGROUND

In 2007, Gockel et al. coined the term mesopancreas (MP). In the next 10 years, a limited number of publications about MP have been published, but little is known about the oncological benefit of MP resection. We performed a systematic review of the literature on MP.

METHODS

An electronic search was performed in PubMed, EMBASE, Cochrane, Latindex, Scielo, and Koreamed databases until 15 June 2017 to identify all published articles dealing with the subject of MP. Some language restriction was done (Chinese and Rumanian).

RESULTS

The search yielded 51 articles; 28 articles were selected as relevant. All were retrospective studies focused more on describing technical variants, feasibility and safety than on the cancer results. The R0 rate in patients with MP resection ranged between 57 and 96.7%. In all the articles with a control group, the R0 rate was higher in the MP excision group. Survival data were explicitly stated only in five series.

CONCLUSION

MP is a difficult-to-excise retropancreatic area. In theory, it is agreed that MP excision raises the rate of R0 resections, which in turn reflected in an improvement in the oncological results; however, at present there are no randomized studies to prove this. Achieving a worldwide consensus on its concept, landmarks, excision technique and oncological results is essential.

Predictors of long-term survival after pancreaticoduodenectomy for peri-ampullary adenocarcinoma: A retrospective study of 5-year survivors

BACKGROUND

Pancreaticoduodenectomy (PD) is the standard curative treatment for periampullary tumors. The aim of this study is to report the incidence and predictors of long-term survival (≥ 5 years) after PD.

METHODS

This study included patients who underwent PD for pathologically proven periampullary adenocarcinomas. Patients were divided into 2 groups: group (I) patients who survived less than 5 years and group (II) patients who survived ≥ 5 years.

RESULTS

There were 47 (20.6%) long-term survivors (≥ 5 years) among 228 patients underwent PD for periampullary adenocarcinoma. Patients with ampullary adenocarcinoma represented 31 (66.0%) of the long-term survivors. Primary analysis showed that favourable factors for long-term survival include age < 60 years old, serum CEA < 5 ng/mL, serum CA 19-9 < 37 U/mL, non-cirrhotic liver, tumor size < 2 cm, site of primary tumor, postoperative pancreatic fistula, R0 resection, postoperative chemotherapy, and no recurrence. Multivariate analysis demonstrated that CA 19-9 < 37 U/mL [OR (95% CI) = 1.712 (1.248-2.348), P = 0.001], smaller tumor size [OR (95% CI )= 1.335 (1.032-1.726), P = 0.028] and Ro resection [OR (95% CI) = 3.098 (2.095-4.582), P < 0.001] were independent factors for survival ≥ 5 years. The prognosis was best for ampullary adenocarcinoma, for which the median survival was 54 months and 5-year survival rate was 39.0%, and the poorest was pancreatic head adenocarcinoma, for which the median survival was 27 months and 5-year survival rate was 7%.

CONCLUSIONS

The majority of long-term survivors after PD for periampullary adenocarcinoma are patients with ampullary tumor. CA 19-9 < 37 U/mL, smaller tumor size, and R0 resection were found to be independent factors for long-term survival ≥ 5 years.

Laparoscopic pancreaticoduodenectomy with major venous resection and reconstruction: anterior superior mesenteric artery first approach

BACKGROUND

The en bloc resection of the superior mesenteric or portal vein with concomitant venous reconstruction may be required in patients with borderline resectable pancreatic cancer. However, performing laparoscopic pancreaticoduodenectomy (LPD) with major venous resection and reconstruction is technically challenging. Herein, we introduced a safe and feasible technique to perform LPD with major venous resection.

METHODS

Over the period of November 2015 to November 2016, 18 patients underwent laparoscopic pancreaticoduodenectomy with major venous resection and reconstruction using the anterior superior mesenteric artery (SMA)-first approach at our institution. Demographic characteristics, intraoperative and postoperative variables, and follow-up outcomes were prospectively collected.

RESULTS

Eighteen male and ten female patients were included in this study. The median age of the patients was 58 years (range 49-76 years). Eight cases of wage resections, six cases of end-to-end anastomosis, and four cases of artificial grafts were performed in our series. Only one patient (5.6%) required conversion because of uncontrolled bleeding from the splenic vein. The average operative time was 448 min (range 420-570 min). The mean time for blood occlusion was 32 min, including 17 min for wage resections, 28 min for end-to-end anastomosis, and 48 min for artificial grafts. Thirty-day mortality was not observed in our series. The median postoperative hospital stay was 13 days (range 9-18 days). Three patients suffered from pancreatic fistula (Grade A), and one suffered from abdominal bleeding after subcutaneous injection with low-molecular heparin. In this case, abdominal bleeding was stopped through conservative therapies.

CONCLUSION

Laparoscopic pancreaticoduodenectomy with major venous resection and reconstruction can be safely and feasibly performed. The anterior SMA-first approach can facilitate this procedure and decrease operative time and blood occlusion duration.

Superior mesenteric artery margin in pancreaticoduodenectomy for pancreatic adenocarcinoma

The aim of this study is trying to describe more details of superior mesenteric artery margin in pancreaticoduodenectomy for pancreatic ductal adenocarcinoma, to evaluate biological and prognostic implications of tumor budding in this margin, and to provide more evidence for evaluation of R0 surgery in pancreaticoduodenectomy. 46 patients in 5-years period are included in this study. Immunochemistry and immunofluorescence are used to analyze tumor budding and epithelial-mesenchymal transition. Superior mesenteric artery margin might be described from four aspects including location, gross appearance, microscopic appearance and tumor budding. We find that 1mm rule for R1 surgery is more appropriate to predict prognosis (P = 0.009) than 0mm rule (P = 0.141). Expression of cytokeratin in tumor budding is significantly lower than primary tumor (P = 0.001), and it suggests that tumor budding may participate the procedure of epithelial-mesenchymal transition. High-grade tumor budding and decreasing cytokeratin of tumor budding correlate with distant metastasis and has negative influence on prognosis. So superior mesenteric artery margin might be not only an area that tumor cells may invade, but also a pathway for distant metastasis. It is necessary to evaluate superior mesenteric artery margin in pancreaticoduodenectomy for pancreatic cancer.

Short-Term Outcomes of Extended Pancreatectomy: A Single-Surgeon Experience

Background/Aims

The International Study Group of Pancreatic Surgery recently published a consensus statement on the definition of extended pancreatectomy (EP). We aimed to determine the safety profile and short-term outcomes of EP compared to standard pancreatectomy (SP). To mitigate surgeon bias, only pancreatectomies performed by a single surgeon were included.

Methods

Ninety consecutive patients who underwent pancreatectomy by a single surgeon over a period of 5 years and who met our study criteria were classified into an SP or an EP group. Sixty-two patients underwent pancreaticoduodenectomy (PD), including total pancreatectomy, and 28 patients underwent distal pancreatectomy.

Results

The 25 patients who underwent EP had significantly increased operation time, estimated blood loss, postoperative intensive care unit (ICU) transfer, and postoperative stay compared to the 65 patients who underwent SP. There was 1 (1.1%) 30-day mortality and 4 (4.4%) in-hospital mortalities. Postoperative morbidity and mortality were similar between both groups. Subgroup analysis of the patients who underwent PD demonstrated that the EP group (n = 22) had significantly increased operation time and postoperative ICU transfers.

Conclusion

Although patients who underwent EP experienced significantly increased operative time, blood loss, and postoperative stay, they did not experience significantly higher postoperative morbidity or mortality compared to patients who underwent SP.

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.