Frequency of Obliteration of the Dorsal and Ventral Ducts of the Pancreas in Islet Transplantation.

BACKGROUND: Islet isolation is an essential process in every human islet transplantation protocol. Intraductal enzyme delivery followed by adequate distention of the pancreas is the most critical step in islet isolation. Anomalies of the pancreatic duct system can significantly affect this process. Thus, identification and characterization of ductal patency is of paramount importance to achieve optimal islet isolation. AIMS: To investigate the frequency of duct obliteration in the human pancreas and explore donor/patient characteristics associated with specific ductal variations. METHODS: We examined ductal patency of pancreata allocated for islet allotransplantation (n = 597) and autotransplantation (n = 21) after removal of the duodenum during islet isolation procedure. Donor/patient factors were reviewed from the batch files. RESULTS: Among 559 deceased donor pancreata without pancreas divisum (n = 38, 6.4%), both ducts were patent in 50.1%, only ventral duct was patent in 46.7%, and only dorsal duct was patent in 3.2%. Donor age was not associated with the frequency of obliterated dorsal duct. Black race tended to have the higher frequency of patent dorsal duct. As expected, pancreas divisum was more frequent in chronic pancreatitis cases (n = 6, 28.6%). Within 7 cases of chronic pancreatitis with unknown etiology, we encountered one case of ventral duct obliteration. CONCLUSIONS: The minor duodenal papilla and aging do not likely play an important role in the occurrence of dorsal duct obliteration. Although frequency of obliterated ventral duct was low in our population, physicians, including gastroenterologists and endoscopists, as well as islet transplantation researchers should be aware of this possibility.

Morphogenesis of the ventral pancreas anlagen is influenced by the SMA branching pattern.

Developmentally, the uncinate process of the pancreas is derived from the ventral pancreatic anlagen, supplied by the superior mesenteric artery (SMA), and contains pancreatic polypeptide (PP)-rich islets of Langerhans. In contrast, the other parts of the pancreas originate from the dorsal anlagen supplied by the celiac system and contain PP-poor islets. This study was performed to investigate whether morphogenesis of the ventral pancreas anlagen is associated with the pattern of SMA branching. SMA branches to the pancreatic body were dissected in 44 cadavers. The cadavers were divided into two groups: the SMA group in which the SMA gave off branches to the pancreatic body and the General group in which it did not. In the SMA group, the ratio of the diameter of the SMA branch supplying the pancreatic body (SMA branch) to that of the SMA itself was calculated. After dissection was completed, tissues were collected from all pancreatic specimens for HE staining and for immunohistochemistry with PP and insulin antibodies. There were 25 cadavers in the General group and 19 in the SMA group. In 10/19 cadavers from the SMA group, PP-rich islets were confirmed in the pancreatic body. The SMA branch diameter ratio was significantly smaller in the SMA group cadavers with PP-poor islets (n = 9) than in cadavers with PP-rich islets (n = 10) (P < 0.001). These findings suggest a relation between the SMA branching pattern and the distribution of PP cells.

Embryological etiology of pancreaticobiliary system predicted from pancreaticobiliary maljunction with incomplete pancreatic divisum: a case report.

BACKGROUND: The genesis of the "complex type" classification of pancreaticobiliary maljunction (PBM) is unclear, and the pancreaticobiliary anatomy is also varied according to each case. We encountered a patient with PBM and incomplete pancreatic divisum (PD). We herein discussed about the embryological etiology of pancreaticobiliary system predicted from PBM with incomplete PD. CASE PRESENTATION: A 67-year-old man was found to have a dilatation of the common bile duct (CBD) during a medical examination at 62 years of age. The dilatation of the CBD subsequently progressed, and he was admitted to our hospital for surgical treatment. Magnetic resonance cholangiopancreatography revealed a dilatation from the common hepatic duct to the middle bile duct with PBM. Endoscopic retrograde cholangiopancreatography from the papilla of Vater revealed the pancreatic main duct via the pancreatic branch duct, and PBM with dilatation of the CBD and incomplete PD were revealed. We performed an extrahepatic bile duct resection and hepaticojejunostomy because of high risk of malignant transformation. Taping and transection of the bile duct without dilatation on the pancreatic side were performed, and thereafter, two orifices of the common channel and ventral pancreatic duct were ligated. The level of amylase in the bile was 7217 IU/L, and a histological examination of the CBD showed an inflammatory change of CBD, not a malignant transformation. CONCLUSION: It is somewhat easy to identify the pancreatobiliary anatomy when the cause of embryology of both PBM and PD is thought to be an abnormal embryology of the ventral pancreas.

Single-cell transcriptomic analyses reveal distinct dorsal/ventral pancreatic programs.

The pancreas of vertebrates is separately derived from both the dorsal and ventral endodermal domains. However, the difference between these two programs has been unclear. Here, using a pancreatic determination gene, Pdx1, driven GFP transgenic mouse strain, we identified Pdx1-GFP highly expressing cells (Pdx1high) and Pdx1-GFP lowly expressing cells (Pdx1low) in both embryonic dorsal Pdx1-expressing region (DPR) and ventral Pdx1-expressing region (VPR). We analyzed the transcriptomes of single Pdx1low and Pdx1high cells from the DPR and VPR. In the VPR, Pdx1low cells have an intermediate progenitor identity and can generate hepatoblasts, extrahepatobiliary cells, and Pdx1high pancreatic progenitor cells. In the DPR, Pdx1high cells are directly specified as pancreatic progenitors, whereas Pdx1low cells are precocious endocrine cells. Therefore, our study defines distinct road maps for dorsal and ventral pancreatic progenitor specification. The findings provide guidance for optimization of current ß-cell induction protocols by following the in vivo dorsal pancreatic specification program.

Fusion plane between dorsal and ventral pancreas and it's clinical significance / 中华肝胆外科杂志

Pancreas arises from dorsal and ventral anlagen,and there is an embryological fusion plane between them.The embryological fusion plane can be discriminated by immunohistochemical staining for an anti-pancreatic polypeptide or computed tomography.The embryological fusion plane can not only guide the management of benign or low malignant potential tumors,but also determine the clinicopathological characteristics of pancreatic head cancer and patients'survival,and the embryological fusion plane plays an important role in the management of pancreatic disease.In this review,the research progressions and clinical significance in the embryological fusion plane of dorsal and ventral pancreas are described.

Duodenum and ventral pancreas preserving subtotal pancreatectomy for low-grade malignant neoplasms of the pancreas: An alternative procedure to total pancreatectomy for low-grade pancreatic neoplasms.

AIM: To describe the indications, technique and outcomes of the novel surgical procedure of duodenum and ventral pancreas preserving subtotal pancreatectomy (DVPPSP). METHODS: Data collected retrospectively from 43 patients who underwent DVPPSP and TP between 2009 and 2015 in our single centre were analysed. For enrolment, only patients with low-grade pancreatic neoplasms, such as pancreatic neuroendocrine tumors, intraductal papillary mucinous neoplasms (IPMNs), and solid pseudo-papillary tumors, were included. Ten DVPPSP (group 1) and 13 TP (group 2) patients were selected in this study. RESULTS: There were no significant differences in age, gender, comorbidities, preoperative symptoms, American Society of Anesthesiologists score or indications for surgery between the two groups. The most common indication was IPMN for DVPPSP and TP (60% vs 85%, P = 0.411). Compared with the TP group, the DVPPSP group had comparable postoperative morbidities (P = 0.405) and mortalities (both nil), but significantly shorter operative time (232 ± 19.6 min vs 335 ± 32.3 min, P < 0.001). DVPPSP preserved better long-term pancreatic function with less supplementary therapy (P < 0.001) and better quality of life (QoL) after surgery, including better scores in social (P = 0.042) and global health (P = 0.047) on functional scales and less appetite loss (P = 0.049) on the symptom scale. CONCLUSION: DVPPSP is a feasible and safe procedure that could be an alternative to TP for low-grade neoplasms arising from the body and tail region but across the neck region of the pancreas; DVPPSP had better metabolic function and QoL after surgery.

Research progress of pancreatic head cancer arising from dorsal and ventral pancreas / 中华消化外科杂志

Pancreas arises from dorsal and ventral anlagens on an embryological basis,with a difference in histocytology.Immunohistochemical staining for an anti-pancreatic polypeptide can be performed to discriminate between the dorsal and ventral pancreas because of the difference in the amount of pancreatic polypeptide contained by the dorsal and ventral pancreas.Differences of survival in patients were approved due to the difference in histocytology between the dorsal and ventral pancreas,including the ability of local invasion,lymph node metastases,and nerve plexus invasion.

Research progress of pancreatic head cancer arising from dorsal and ventral pancreas / 中华消化外科杂志

Pancreas arises from dorsal and ventral anlagens on an embryological basis,with a difference in histocytology.Immunohistochemical staining for an anti-pancreatic polypeptide can be performed to discriminate between the dorsal and ventral pancreas because of the difference in the amount of pancreatic polypeptide contained by the dorsal and ventral pancreas.Differences of survival in patients were approved due to the difference in histocytology between the dorsal and ventral pancreas,including the ability of local invasion,lymph node metastases,and nerve plexus invasion.

The septum transversum mesenchyme induces gall bladder development.

The liver, gall bladder, and ventral pancreas are formed from the posterior region of the ventral foregut. After hepatic induction, Sox17+/Pdx1+ pancreatobiliary common progenitor cells differentiate into Sox17+/Pdx1- gall bladder progenitors and Sox17-/Pdx1+ ventral pancreatic progenitors, but the cell-extrinsic signals that regulate this differentiation process are unknown. This study shows that the septum transversum mesenchyme (STM) grows in the posterior direction after E8.5, becoming adjacent to the presumptive gall bladder region, to induce gall bladder development. In this induction process, STM-derived BMP4 induces differentiation from common progenitor cells adjacent to the STM into gall bladder progenitor cells, by maintaining Sox17 expression and suppressing Pdx1 expression. Furthermore, the STM suppresses ectopic activation of the liver program in the posterior region of the ventral foregut following hepatic induction through an Fgf10/Fgfr2b/Sox9 signaling pathway. Thus, the STM plays pivotal roles in gall bladder development by both inductive and suppressive effects.

Fetal Topographical Anatomy of the Pancreatic Head and Duodenum with Special Reference to Courses of the Pancreaticoduodenal Arteries

PURPOSE: The purpose of this study is to provide better understanding as to how the "double" vascular arcades, in contrast to other intestinal marginal vessels, develop along the right margin of the pancreatic head. MATERIALS AND METHODS: In human fetuses between 8-30 weeks, we described the topographical anatomy of the vessels, bile duct, duodenum as well as the ventral and dorsal primordia of the pancreatic head with an aid of pancreatic polypeptide immunohisto-chemistry. RESULTS: The contents of the hepatoduodenal ligament crossed the superior side of the pylorus. Moreover, the right hepatic artery originating from the superior mesenteric artery ran along the superior aspect of the pancreatic head. An arterial arcade, corresponding to the posterior pancreaticoduodenal arteries, encircled the superior part of the pancreatic head, whereas another arcade, corresponding to the anterior pancreaticoduodenal arteries, surrounded the inferior part. The dorsal promordium of the pancreas surrounded and/or mixed the ventral primordium at 13-16 weeks. Thus, both arterial arcades were likely to attach to the dorsal primordium. CONCLUSION: The fetal anatomy of the pancreaticoduodenal vascular arcades as well as that of the hepatoduodenal ligament were quite different from adults in topographical relations. Thus, in the stage later than 30 weeks, further rotation of the duodenum along a horizontal axis seemed to be required to move the pylorus posterosuperiorly and to reflect the superior surface of the pancreatic head posteriorly. However, to change the topographical anatomy of the superior and inferior arterial arcades into the final position, re-arrangement of the pancreatic parenchyma might be necessary in the head.

Establishment of the Guideline for the Anatomical Resection of the Ventral and Dorsal Portion of the Pancreatic Head

PURPOSE: This study was designed to delineate the anatomical details of the pancreatic head for a ventral or dorsal segmental pancreatic resection along the embryological fusion plane, and to determine the feasibility of both procedures. METHODS: The resected pancreaticoduodenectomy specimens were analyzed (n=8), with the pancreatic and distal common bile ducts visualized by pancreatography (n=8). Immunohistochemical staining, with pancreatic polypeptide (PP), was performed in serially sliced specimens (n=3). The immunohistochemical and H&E staining were performed to evaluate the composition of the anatomical structures of the two differentially stained pancreas. RESULTS: What was presumed to be the embryological fusion plane was discovered between two differentially stained segments. This started just above the anterior inferior pancreaticoduodenal artery, directed to the posterior superior part of the pancreatic head and ended at the anterior surface of the distal common bile duct. The duct of Wirsung and the distal common bile duct were included in the posterior segment of the pancreas (ventral pancreas). There were two types of pancreatic duct arrangement, with the differences between the two types being; (1) the distance between the fusion point of the ventral and dorsal pancreatic ducts and the papilla of Vater, and (2) the stream of the Santorini duct. The branches of the pancreatic ducts were scattered over the entire pancreatic head region in multiple-directions. CONCLUSION: The fusion plane of the ventral and dorsal pancreas seems to initiate just above the anterior inferior pancreaticoduodenal artery, in a posterior-superior direction along the anterior surface of the distal common bile duct. A ventral pancreatectomy seems an impractical procedure with regard to the postoperative morbidity and operative difficulty, while a dorsal pancreatectomy seems to be more practical and feasible in its clinical aspects.