Retroperitoneal fasciae as barriers for nerve and arterial passages connecting the retroperitoneal region to the peritoneal organs.

The fascia of the pancreatic head is referred to as the retropancreatic fascia of Treitz, and that of the body and tail of the pancreas is named the retropancreatic fascia of Toldt. However, the spatial relationship between the nerves, fascia, and the distribution of the fascia on the dorsal side of the pancreas remains unclear. Therefore, this study aimed to explore the distribution of these fasciae and elucidate the spatial relationship between the nerves and arteries connecting the retroperitoneal space and the peritoneal organs by studying eight cadavers using macroscopic anatomical examination, wide-range serial sectioning, and three-dimensional reconstruction. The fasciae of Treitz and Toldt converge caudally to the root of the superior mesenteric artery (SMA), forming a narrower gap around the roots of the celiac trunk and SMA than in the celiac plexus. The fasciae eventually get closer to each other, and the boundary between them becomes obscured, providing coverage to the anterior surface of the aorta between the SMA and the inferior mesenteric artery. The celiac plexus does not penetrate the fascia but converges before spreading into the pancreas. Similarly, the arteries pass through this gap in the fasciae. Our findings suggest that the retroperitoneal space and peritoneal organs are connected through a narrow no-fascia area, with the distribution of the fascia relating to nervous and vascular pathways. Our findings reveal that the distribution of the avascular plane may provide a crucial anatomical foundation for abdominal digestive organ surgery by reducing bleeding volume and determining the dissection region.

Surgical anatomy of the dorsal pancreatic artery: Considering embryonic development.

OBJECTIVES: The dorsal pancreatic artery (DPA) is a pancreatic branch with various anatomical variations. Previous studies mostly focused on the origin of the DPA, and its pathways and branching patterns have rarely been examined. The purpose of this study was to investigate the branching patterns and pathways of the DPA. METHODS: This study included 110 patients who underwent computed tomography scans. We examined the pathways and branching patterns of the DPA. RESULTS: The DPA was identified in 101 patients (92%), and originated from the splenic artery in 30 patients (31%), the common hepatic artery in 17 patients (17%), the celiac trunk in 10 patients (10%), the superior mesenteric artery in 27 patients (27%), the replaced right hepatic artery in 7 patients (7%), the inferior pancreaticoduodenal artery in 5 patients (5%), and other arteries in 3 patients (3%). Four distinct types of branches were identified as follows: the superior branch (32%), the inferior branch (86%), the right branch (80%), and the accessory middle colic artery (12%). Additionally, the arcs of Buhler and Riolan were observed in two patients each and their anastomotic vessels followed almost the same pathway as the DPA. CONCLUSION: A number of variations of the DPA were observed with regard to its origin and branching pattern; however, the DPA and its branches always ran along the same pathway, as summarized in Fig. 4. The anatomical information gained from this study may contribute to performing safe pancreatic resections.