Mesopancreas in pancreatic cancer: where do we stand - review of literature. Indian J Surg Oncol. 2015;6:69-74. [PMID: 25937767 DOI: 10.1007/s13193-014-0294-7]

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.

Prognosis and survival analysis of patients with pancreatic cancer: retrospective experience of a single institution

Background

The overall survival of patients  with pancreatic cancer is extremely low. Despite multiple large-scale studies, identification of predictors of patient survival remains challenging. This study aimed to investigate the prognostic factors for pancreatic cancer.

Methods

The clinical data of 625 patients with pancreatic cancer treated at Shengjing Hospital of China Medical University from January 2013 to December 2017 were collected.

Results

Of 625 patients, 569 were followed from 1 to 75 months. The median overall survival was 9.3 months. The overall 1-, 3-, and 5-year survival rates were 37.8%, 15.1%, and 10.5%, respectively. Cox proportional hazards model indicated that baseline carbohydrate antigen 199 level, neutrophil-lymphocyte ratio, operative procedure, lymph node metastasis, number of distant organ metastasis, and postoperative adjuvant chemotherapy were independent prognostic factors of patients with pancreatic cancer. Baseline carbohydrate antigen 199 level, degree of weight loss, operative procedure, lymph node metastasis, number of distant organ metastasis, and postoperative adjuvant chemotherapy were independent prognostic factors of pancreatic head cancer subgroup. Baseline carbohydrate antigen 199 level, carcinoembryonic antigen level, total bilirubin level, neutrophil-lymphocyte ratio, peripancreatic invasion, number of distant organ metastasis, and postoperative adjuvant chemotherapy were independent prognostic factors of the pancreatic body/tail cancer subgroup.

Conclusions

Higher carbohydrate antigen 199 levels, neutrophil-lymphocyte ratio, lymph node metastasis and distant organ metastasis predict a poor prognosis in patients with pancreatic cancer. Early detection, early radical surgery and adjuvant chemotherapy are needed to improve prognosis for this deadly disease.

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.

Can Elderly Patients With Pancreatic Cancer Gain Survival Advantages Through More Radical Surgeries? A SEER-Based Analysis

Background and Aims

In recent years, the best treatment method for pancreatic cancer in elderly patients has remained controversial. Surgery is the main treatment modality for pancreatic cancer. This study aimed to determine whether elderly patients with pancreatic cancer can gain survival advantages through more active and radical surgical treatment and evaluate the best treatment method and potential prognostic factors.

Methods

From the Surveillance, Epidemiology, and End Results program (SEER) database, 10,557 elderly patients (aged ≥65 years) with pancreatic cancer were included as Cohort 1, and Propensity Score Matching (PSM) evaluation was performed to generate Cohort 2 (424 pairs). Overall Survival (OS) and Cause-Specific Survival (CSS) were determined using Kaplan-Meier survival curves, and differences were assessed using the Log-rank test. Multivariate logistic regression analysis and the forest plot of hazard ratio (HR) was made to assess the association between potential prognostic factors, including surgery and different surgical methods, and survival in elderly patients.

Results

We identified 10,557 eligible patients with pancreatic cancer, who formed Cohort 1. The total OS and CSS in the surgery group were significantly higher than those in the non-surgery group (P < 0.001). Age, stage (AJCC 8th), grade, lymph node metastasis, radiation, chemotherapy, and surgical methods were independent factors affecting the prognosis of elderly patients. In Cohort 2, Total pancreatectomy (Total PT) had the lowest risk ratio (HR = 0.31, P < 0.001) and longest median CSS (18.000 months), while Extension Total pancreatectomy (Ex-Total PT, HR = 0.34, P < 0.001) showed the lower median CSS (17.000 months) and median OS (14.000 months). Partial pancreatectomy (Partial PT, HR = 0.46, P < 0.001) showed the lowest median CSS (13.000 months) and median OS (12.000 months), although they were still higher than the median CSS (6.000 months) and median OS (5.000 months) in the non-surgery group.

Conclusions

Based on the SEER database, surgical treatment is an independent prognostic factor in elderly patients with pancreatic cancer. Compared with other surgical methods, Total PT can offer elderly patients the best survival advantages. However, Ex-Total PT, a more radical method, does not seem to be the best treatment option for the survival and benefit of elderly patients.

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.

Modified Heidelberg technique of pancreatic anastomosis postpancreaticoduodenectomy - 10 years of experience

Context

Pancreatic fistula has forever been a dreaded complication after pancreatic anastomosis (PA). We present a retrospective analysis of 10 years of experience with the Modified Heidelberg technique (MHT) that has been recently described.

Aim

The aim of the study is to establish postoperative pancreatic fistula (POPF) rates after MHT.

Settings and Design

This is a retrospective observational study carried out at a tertiary cancer center in South India in the Department of Surgical Oncology.

Subjects and Methods

Two hundred and eight consecutive patients who underwent pancreaticoduodenectomy (PD) and PA with MHT for a variety of proximal pancreatic lesions from January 2008 to February 2018 were included in this study. The incidence of POPF was recorded by the International Study Group on Pancreatic Fistula 2005 and 2016 definitions.

Statistical Analysis Used

Epidemiological and clinical data are expressed in ratios and percentage and presented in table format.

Results

Between January 2008 and March 2016, 186 patients underwent PD, and MHT was used for PA. Five (2.7%) patients developed Grade A POPF whereas Grades B and C were seen in three (1.6%) patients each with one death. Between April 2016 and February 2018, 22 patients underwent PD. Two patients (9%) had biochemical leak whereas none of them developed clinically relevant POPF. No deaths were recorded in this period. Overall, Grade B and Grade C POPF rates were 1.4% each, whereas 30-day mortality was 0.4%.

Conclusions

Results of this study indicate that MHT is a safe, reliable, easy to learn, and adopt technique of pancreatic reconstruction after PD.

Correlation between appearance of the retroportal fat plane at preoperative CT and pathology findings in resected adenocarcinoma of the pancreatic head

AIM

To correlate the appearance of the retroportal fat plane at preoperative computed tomography (CT) and the pathology findings in resected adenocarcinoma of the pancreatic head (PDAC).

MATERIAL AND METHODS

Forty-eight patients with resected PDAC of the pancreatic head were included (24 men, 24 women, mean age 63 years, median BMI 24.1). All patients underwent CT <30 days before surgery. The state of the retroperitoneal resection margin and the presence of lymphatic or perineural invasion were obtained from pathology reports. CT images were reviewed independently by two radiologists for assessment of the retroportal fat plane and graded in two categories (clear/effaced). Inter-reader discrepancies were solved in consensus. Interobserver agreement was calculated and Fisher's test was used to assess the correlation between CT and pathology findings. Visceral fat areas were measured and correlated with CT findings.

RESULTS

A clear retroportal fat plane was significantly associated with a negative retroperitoneal margin at pathology with 100% specificity and PPV (p=0.0001). No association was observed between the appearance of the fat plane at CT and the presence of lymphatic or perineural invasion (p=ns). Interobserver agreement for retroportal fat plane evaluation was good (0.741). False-positive cases had a significantly lower visceral fat area than the correctly classified patients (p=0.0480).

CONCLUSIONS

A clear retroportal fat plane is significantly associated with negative retroperitoneal resection margins at pathology. The lack of visceral adipose tissue can lead to overestimation of retroportal fat plane involvement at preoperative CT.

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.

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.

Laparoscopic uncinate process first pancreatoduodenectomy-feasibility study of a modified 'artery first' approach to pancreatic head cancer

PURPOSE

The aim of this study was to discuss the feasibility of laparoscopic 'uncinate first' pancreatoduodenectomy.

METHODS

The analysis included prospectively collected data from 12 consecutive patients undergoing elective pure laparoscopic 'uncinate process first' pancreatoduodenectomy (Group 1). They were compared with patients previously operated on with a classical laparoscopic approach (Group 2). The primary outcome was the quality of the resected specimen (lymph node (LN) yield, R0 rate, involved resection margins). Secondary outcomes were perioperative parameters.

RESULTS

The LN yield in Group 1 was 19.3 and in Group 2 it was 13.9 (p = 0.03). R0 resection rates did not vary (66.7 vs. 63.2%, p = 0.84). Although the involvement of the superior mesenteric artery margin and uncinate process margin seemed lower in Group 1, the difference was not significant. Total operative time (467 vs. 425 min, p = 0.13) and resection time (221 vs. 232 min, p = 0.34) were similar in both groups. The estimated blood loss in Group 1 was 408 ml, whereas in Group 2 it was 392 ml (p = 0.33). Complication rates were 66.7% in Group 1 and 63.2% in Group 2 (p = 0.84). Median length of stay was 9 days in both groups (p = 0.36). Postoperative complication rates did not differ between groups.

CONCLUSIONS

Laparoscopic uncinate first approach is a feasible method for pancreatic head neoplasms. Achieved quality of the specimen is comparable with the traditional laparoscopic approach, whereas intra- and postoperative course is not inferior. However, further studies on larger cohorts are required to fully establish whether the novel approach has potential advantages over classical access in pancreatic head cancer.

Superior mesenteric artery first approach versus standard pancreaticoduodenectomy: a systematic review and meta-analysis

BACKGROUND

The superior mesenteric artery (SMA) first approach was proposed recently as a new modification of the standard pancreaticoduodenectomy. Increasing evidence showed that a periadventiceal dissection of the SMA with early transection of the inflow during pancreaticoduodenectomy associates better early perioperative results, and setup the scene for long-term oncological benefits. The objectives of the current study are to compare the operative results and long-term oncological outcomes of SMA first approach pancreaticoduodenectomy (SMA-PD) with standard pancreaticoduodenectomy (S-PD).

DATA SOURCES

Electronic search of the PubMed/MEDLINE, EMBASE, Web of Science and Cochrane Library was performed until July 2015. We considered randomized controlled trials (RCTs) and non-randomized comparative studies (NRCSs) comparing SMA-PD with S-PD to be eligible if they included patients with periampullary cancers.

RESULTS

A total of one RCT and thirteen NRCSs met the inclusion criteria, involving 640 patients with SMA-PD and 514 patients with S-PD. The SMA-PD was associated with less intraoperative bleeding, less blood transfusions and higher rate of associated venous resections. The pancreatic fistula and delayed gastric emptying had a significantly lower rate in the SMA-PD group. There were no differences between the two approaches regarding overall complications, major complication rates and in-hospital mortality. There was no difference regarding R0 resection rate, and one-, two- or three-year overall survival. The SMA-PD was associated with a lower local, hepatic and extrahepatic metastatic rate.

CONCLUSIONS

The SMA-PD is associated with better perioperative outcomes, such as blood loss, transfusion requirements, pancreatic fistula, and delayed gastric emptying. Although the one-, two- or three-year overall survival rate is not superior, the SMA-PD has a lower local and metastatic recurrence rate.

Mesopancreas is a misnomer: time to correct the nomenclature

Focused pathological attention to tumor invasion of the retroperitoneal resection margin after pancreaticoduodenectomy for cancer of head of the pancreas led to the knowledge of strong tendency of cancer cells to infiltrate into the retropancreatic tissue and to spread along the peripancreatic neural plexuses as the cause of local recurrence. The term 'mesopancreas' was coined to describe perineural lymphatic layer located dorsally to the pancreas and it was suggested that its complete resection will minimize loco-regional recurrence and improve outcome. This catchy title and concept attracted the attention of surgeons and "total meso-pancreas excision" was introduced by 'artery first' or 'posterior first' surgical techniques to ensure 'en-bloc' extended resection of retropancreatic lymphatics. However, mesopancreas is a misnomer and cannot be called a 'true' mesentery as it does not have a fascial envelope attaching the pancreas to the posterior wall of the abdomen and does not contain 'all' its blood vessels and 'all' its primary draining lymphatics and lymph nodes. Japan Pancreas Society's description of pancreatic head plexus II is anatomically consistent with 'mesopancreas' and it should be renamed as such. This nomenclature clearly illustrates its exact anatomical location and surgical relevance; and stands up to necessary rigorous scientific scrutiny.

R0 resection of pancreatic head carcinoma: Definition of surgical margins and influencing factors

Early diagnosis of pancreatic head carcinoma is difficult. Once diagnosed, it often has been in the advanced stage, the prognosis is poor, and five-year survival does not exceed 6%. R0 resection is the only way to obtain long-term survival in patients with pancreatic head cancer. Numerous clinical studies have shown that lack of retroperitoneal tissue dissection is the important reason for being unable to achieve R0 resection in pancreatic cancer patients. The proposed mesopancreas and total mesopancreas excision (TMpE) concept provides a better definition of retroperitoneal dissection, thereby increasing the rate of R0 resection effectively.

Progress in treatment of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a malignant tumor of the digestive system with a high degree of malignancy, accounting for about 90% of cases of pancreatic cancer. It has an occult onset and progresses rapidly, with a poor treatment effect and prognosis. It is one of malignant tumors with the worst prognosis. Surgical resection, as the only effective treatment, can be performed in only 20%-30% of patients, and the average period of survival after surgery is still less than 2 years. The main treatment strategy for PDAC are surgery-based individualized treatment modalities under comprehensive multidisciplinary collaboration. Currently, the therapeutic effect on pancreatic cancer is still not satisfactory. In recent years, various treatments for PDAC is becoming a hot spot of research. This article reviews the progress in the treatment of PDAC in terms of radical surgery, palliative surgery, adjuvant therapy, and other treatment opinions.

The concept and controversy of retroperitoneal nerve dissection in pancreatic head carcinoma (Review)

Pancreatic head cancer is a common but the most lethal cancer of the human digestive system. It is invasive, resulting in early infiltration of adjacent structures and lymph node and distant metastases. Its biological characteristics of neurotropic growth lead to early neural invasion (NI) which is an independent prognostic factor of survival for pancreatic cancer. Radical surgical resection remains the only form of curative treatment. The extent of surgical resection and whether extended resection results in better long-term survival have been controversial. Studies have reported that peripancreatic plexus invasion is a frequent cause of pancreatic cancer recurrence and death. The relationship between cancer microenvironment and nerve cells, and whether the peripancreatic nerve plexus nearby needs to be resected require further studies. The present review aims to discuss the role of peripancreatic nerve and its implications in pancreatic head cancer resection.