Experimental investigation of the role of the splenic vein in gastric venous obstruction after pylorus-preserving pancreatoduodenectomy in the dog

Summary Conclusion   This study showed that the splenic vein (SV) plays a major role in maintaining gastric blood flow after ligature of peripyloric vesels in the dog. Therefore, SV preservation or alternative venous drainage may be recommended to maintain sufficient gastric blood flow in pylorus-preserving pancreatoduodenectomy (PPPD). Background  In PPPD, we often encounter the problem of gastric venous drainage obstruction, if the splenic-portal vein confluence needs to be resected. This study investigated significance of venous drainage via the left gastric and splenic veins in gastric tissue blood flow. Methods  In seven mongrel dogs, gastric tissue blood flow was measured by both laser Doppler flowmetry (LDF) in the antrum and hydrogen gas clearance (HGC) in the antrum and body. Blood flow was measured after the following treatments:

1.	No treatment;
2.	Duodenal transection;
3.	Ligature of the right gastric and gastroepiploic arteries and veins;
4.	Transient obstruction of the left gastric vein (LGV);
5.	Transient obstruction of the SV with the LGV open; and
6.	Obstruction of both the LGV and the SV.

Results  As judged by LDF, treatments 2,3, and 4 did not decrease blood flow, but treatments 5 and 6 significantly decreased it compared with both treatments 1 and 3. By HGC, changes in the antrum and the body were parallel. Duodenal transection did not, but treatments 3 and 4 did decrease blood flow compared with no treatment. Obstruction of the left gastric vein did not, but treatments 5 and 6 did significantly decrease it compared with treatment 3.