Allogeneic Venous Grafts of Different Origin Used for Portal Vein Reconstruction After Pancreaticoduodenectomy – Experimental Study

Abstract

Background: In clinical medicine, little is known about the use of allografts for portal vein (PV) reconstruction after pancreaticoduodenectomy (PD). Portal and caval systems are physiologically different, therefore the properties of allografts from caval and portal systems were studied here in a pig model. Materials and Methods: PD with PV reconstruction with allogeneic venous graft from PV or inferior vena cava (IVC) was performed in 26 pigs. Biochemical analysis and ultrasonography measurements were performed during a 4-week monitoring period. Computer simulations were used to evaluate haemodynamics in reconstructed PV and explanted allografts were histologically examined. Results: The native PV and IVC grafts varied in histological structure but were able to adapt morphologically after transplantation. Computer simulation suggested PV grafts to be more susceptible to thrombosis development. Thrombosis of reconstructed PV occurred in four out of five cases in PV group. Conclusion: This study supports the use of allografts from caval system for PV reconstruction in clinical medicine when needed.Pancreatic cancer is one of the leading causes of cancer mortality in developed countries; its incidence has been rising over last decades and without a breakthrough in therapy this trend is expected to continue (1, 2). The incidence of pancreatic cancer is almost equal to its mortality rate and the estimated 5-year survival rate is only 5% (1, 3).Nowadays the only potential curative therapy of this disease is radical surgical resection, which can help to increase the 5year survival rate up to 25% (4). The standard surgical method for curative resection of tumours arising in the head of the pancreas is pylorus-preserving pancreaticoduodenectomy (PPPD) (5). However, the resectability of pancreatic cancer is limited by vessel infiltration. In the presence of tumour ingrowth into adjacent arteries, surgical resection is not generally recommended due to high postoperative morbidity and mortality (4, 6). However, tumours infiltrating venous structures [such as the superior mesenteric vein (SMV), and portal vein (PV)] can be safely resected together with involved part of the vein, resulting in morbidity and mortality comparable with standard PPPD (4, 7).Resection of either PV or SMV during PPPD requires a suitable reconstruction of the involved vessel. In cases when only a tangential resection or short segmental resection is performed, the vein can be reconstructed by venorrhaphy, patch plasty or primary anastomosis. When a longer venous 6603

Microdialysis for the Assessment of Intervertebral Disc and Vertebral Cancellous Bone Metabolism in a Large Porcine Model

“…The present study demonstrates that microdialysis may be a suitable tool to dynamically evaluate the biochemical properties in spine tissue with the potential to generate a larger understanding of the metabolism and pathogenesis of degenerative back disorders. As seen in other experimental setups (23,24), large porcine models may prove to be significantly important, since it may be problematic to identify certain applicable clinical setups. For future studies, and in terms of clinical relevance, study designs evaluating the effect of puncture of the intervertebral disc, infection, surgical intervention, instrumentation, etc.…”

Decellularized porcine vena cava grafts are fully repopulated after orthotopic implantaiton

“…The limited graft patency in our study could be attributed to the omission of anticoagulation or anti-aggregation in the postoperative period. In our previous study focused on portal vein reconstruction with cold-stored venous allografts, we noted portal vein thrombosis in 19.2% when using the same breed of domestic pig and also no postoperative anticoagulation [57]. Decellularized veins implanted in arterial system usually show good patency.…”

Borderline Resectable and Locally Advanced Pancreatic Cancers

“…22 Endoscopic ultrasound has been showed to have an accuracy of around 85% in diagnosing stages of pancreatic cancers. 23 It has also been found to be a low-risk, reliable method to provide tissue diagnosis of pancreatic lesions and assess vascular involvement. 24 On the other hand, CT scans produce high-resolution images of pancreatic lesions, along with the surrounding vasculature, and provide evidence of possible metastases.…”

“…The main tools used in the diagnosis of BRPC and LAPC are endoscopic ultrasound, computed tomography (CT), magnetic resonance imaging, and diagnostic laparoscopy 22 . Endoscopic ultrasound has been showed to have an accuracy of around 85% in diagnosing stages of pancreatic cancers 23 . It has also been found to be a low-risk, reliable method to provide tissue diagnosis of pancreatic lesions and assess vascular involvement 24 .…”