Technical aspects of portal vein arterialization for acute liver failure: from rat lab to man

A modified kidney-sparing portal vein arterialization model of heterotopic auxiliary liver transplantation increases liver IL-6, TNF-α, and HGF levels and enhances liver regeneration: an animal model

BACKGROUND AND AIM

The success of partial donor liver transplantation is affected by the implantation site of the donor liver and the vascular reconstruction approach. We investigated the effects of different donor liver implantation sites and vascular reconstruction approaches on liver regeneration using a rat kidney-sparing heterotopic auxiliary liver transplantation model, with portal vein arterialization (PVA).

METHODS

Sixty male Sprague-Dawley rats underwent end-to-end anastomosis of the donor liver portal vein and the right renal artery stent (control group), or end-to-side anastomosis of the donor liver portal vein and the left common iliac artery (experimental group).

RESULTS

The experimental group had significantly lower plasma levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, and cholinesterase than the control group (all, P < 0.05). The levels of tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and hepatocyte growth factor (HGF) in the liver were significantly higher in the experimental group than that in the control group (all, P < 0.05). Hematoxylin and eosin (HE) staining of the liver tissue specimens indicated that the experimental group had greater hepatocyte regeneration compared to the control group.

CONCLUSIONS

The modified kidney-sparing PVA model of heterotopic auxiliary liver transplantation is more conducive to liver regeneration with quicker return of liver function.

Does Arterialization of Portal Vein Have Any Effects in Large-for-Size Liver Transplantation? Hemodynamic, Histological, and Biomolecular Experimental Studies

BACKGROUND

In pediatric liver transplantation, the optimal size of the transplanted liver ranges between 0.8% and 4.0% of the recipient's weight. Sometimes, the graft weight exceeds this upper limit, characterizing the large-for-size condition potentially associated with reduced blood flow and worsening of ischemia-reperfusion injury. Therefore, it would be beneficial to increase the portal flow through arterialization of the portal vein. Materials and methods: Fifteen pigs underwent large-for-size liver transplants. They were divided into two groups: control (CTRL 6 animals - conventional technique) and arterialization - a shunt was established between the portal vein and the splenic artery (ART 9 animals). Hemodynamic, biochemical, histological, and molecular variables were compared. Results: Arterialization resulted in a significant increase in portal vein pressure but no changes in other hemodynamic variables, as shown in the analysis of variance. It was observed lower ALT values (p = 0.007), with no differences regarding the values of blood pH and lactate (p = 0.54 and p = 0.699 respectively) or histological variables (edema, steatosis, inflammation, necrosis, and IRI - p = 1.0, p = 0.943, p = 0.174, p = 0.832, p = 0.662, respectively). The molecular studies showed significantly increased expression of IL6 after 3 hours of reperfusion (p = 0.048) and decreased expression of ICAM immediately after reperfusion (p = 0.03). The regression analysis suggested a positive influence of portal flow and pressure on biochemical parameters. Conclusion: Arterialization of the portal vein showed no histological, biochemical, or molecular benefits in large-for-size transplantation.

Pancreaticoduodenectomy assisted by 3-D visualization reconstruction and portal vein arterialization: A case report (a CARE-compliant article)

BACKGROUND

Three-dimensional visualization reconstruction, the 3-D visualization model reconstructed by software using 2-D CT images, has been widely applied in medicine; but it has rarely been applied in pancreaticoduodenectomy. Although the hepatic artery is very important for the liver, it has to be removed when tumor invades it. Therefore, portal vein arterialization has been used in clinic as a remedial measure, but there still is professional debate on portal vein arterialization.

METHODS

Here, we report 1 case that was diagnosed with poorly differentiated adenocarcinoma of the duodenum. The tumor had large size and invaded surrounding organs and vessels.

RESULTS

Preliminary diagnoses were poorly differentiated adenocarcinoma of the duodenum and viral hepatitis B. Pancreaticoduodenectomy assisted by 3-D visualization reconstruction and portal vein arterialization were performed in this case. The tumor was removed. Liver function returned to normal limits 1 week after operation. Digital subtraction arteriography showed compensatory artery branches within the liver 1 month after operation.

CONCLUSION

3-D visualization reconstruction can provide a reliable assistance for the accurate assessment and surgical design before pancreatoduodenectomy, and it is certainly worth adopting portal vein arterialization when retention of hepatic artery is impossible or conventional arterial anastomosis is required during pancreatoduodenectomy.

Effects of dual arterial blood supply on liver regeneration in the graft and the host following heterotopic auxiliary liver transplantation

This study aimed to investigate the effect of the dual arterial blood supply method used in auxiliary liver transplantation on the regeneration of grafted and host liver. A total of 72 male Sprague-Dawley rats were randomly assigned to three experimental groups, namely the 68% hepatectomy group (group A), the 68% hepatectomy with dual arterial blood supply group (group B) and the auxiliary liver transplantation with dual arterial blood supply group (group C). Group C was further divided into the host liver subgroup (group Ca) and the transplanted liver subgroup (group Cb). Six animals from each group were sacrificed at 1, 2 and 7 days after surgery. The calculation of the liver regeneration rate (LRR) was based on measuring liver weight. Liver function was assessed by measuring serum alanine aminotransferase (ALT) levels. Immunohistochemistry was employed to detect the expression of proliferating cell nuclear antigen (PCNA). Apoptotic changes in the grafts and host livers were evaluated using TUNEL staining. The LRR in each group exhibited a tendency to increase over time. At each time point, the LRR of transplanted livers in group C exhibited no significant difference from that of host livers in group C (P>0.05). The ALT levels for each group exhibited a time-dependent decreasing tendency. The ALT level in group C was significantly higher compared to that in groups A and B at each time point (P<0.05). The expression of PCNA in transplanted and host livers in group C was significantly lower compared to that in groups A and B at the same time point (P<0.001). Although the number of apoptotic cells in each group varied at different time points, there was no statistically significant difference (P>0.05). In auxiliary liver transplantation with the dual arterial blood supply method, the capacity of the liver regeneration in the grafts was similar to that of the host livers. Therefore, this technique may reduce the potential risk of graft liver atrophy caused by functional competition.

Portal Vein Arterialization as a Bridge Procedure Against Acute Liver Failure After Extended Hepatectomy for Hilar Cholangiocarcinoma

Background. Acute liver failure (ALF) is a severe and highly fatal complication arising after extended hepatobiliary surgery. The aim of this study was to investigate the primary management experience of portal vein arterialization (PVA) as a bridge procedure to reduce the risk of ALF for hilar cholangiocarcinoma (HCCA) after extended hepatectomy. Method. Between January 2010 and January 2012, 4 patients with HCCA with possible involvement of the right and/or left hepatic artery underwent resectional surgery with reconstruction of the right or left artery blood flow by arterializations of portal vein. Results. The arteries used for this surgical procedure included gastroduodenal artery (n = 2), common hepatic artery (n = 1), and right gastroepiploic artery (n = 1). PVA was verified as a key point during the course of the disorder between surgery and postoperative recovery. During follow-up, 1 patient suffered secondary portal hypertension and was subsequently cured by interventional artery coil embolization. Conclusion. PVA can be indicated where there is arterial involvement in HCCA patients who have undergone extended hepatectomy or trisectionectomy.

Portal vein arterialization in liver transplantation: an option to restore arterial flow: a case report

We report a 66-year-old woman who underwent emergency orthotopic liver transplantation due to acute liver failure. The donor's liver graft displayed extensive arteriosclerosis, involving the celiac trunk and hepatic artery. Arterial revascularization of the graft could not be achieved, requiring an arterioportal shunt between the gastroduodenal artery and the portal vein of the recipient. During the early postoperative period, the patient's clinical condition and liver function tests improved rapidly; the patient was discharged on postoperative day 30. Two months later, she developed acute cholangitis. Ischemic-type stenosis of the intrahepatic biliary tree was present, so successful elective retransplantation was undertaken at the ninth postoperative month. In our experience, portal vein arterialization may be useful as a bridging therapy in extreme situations.

Two-year follow-up of splenic radiofrequency ablation in patients with cirrhotic hypersplenism: does increased hepatic arterial flow induce liver regeneration?

BACKGROUND

Hepatocyte hypoxia may be a mechanism determining abnormal tissue oxygenation and dysfunction of the cirrhotic liver. Since the introduction of radiofrequency ablation (RFA) for patients with cirrhotic hypersplenism, we observed a phenomenon of visible hepatic regeneration. This study aims to investigate the potential mechanism of RFA-induced liver regeneration, and the 2-year outcomes of splenic RFA.

METHODS

Forty patients who underwent splenic RFA for cirrhotic hypersplenism were followed for 24 months. Before and after RFA procedures, portal hemodynamics and liver and spleen volumes were measured by Doppler ultrasonography and computed tomography volumetry. Liver function tests and blood counts were also determined.

RESULTS

The splenic and portal venous flows decreased, but hepatic arterial flow (HAF) increased dramatically after the RFA procedure. Liver volumes at 3 month post-RFA increased compared to the baseline volumes (872 +/- 107 vs. 821 +/- 99 cm(3), P = .031). A correlation was found between maximum absolute values of liver volumes (triangle upliver volumes) and that of HAF (triangle upHAF) in Child-Pugh class A/B patients (r = 0.60; P < .001). Leukocyte and platelet counts, as well as liver function, improved substantially during the 2-year follow-up. Patients with > or = 40% of spleen volume ablated had better improvement of thrombocytopenia. No death or severe complications occurred.

CONCLUSIONS

RFA for cirrhotic hypersplenism is safe and efficacious. The increase in HAF as a result of splenic RFA may improve liver function and induce liver regeneration in cirrhotics, but further studies are necessary to clarify the underlying mechanisms.