Portal vein arterialization in 25 liver transplant recipients:A Latin American single-center experience

BACKGROUND Portal vein arterialization(PVA)has been used in liver transplantation(LT)to maximize oxygen delivery when arterial circulation is compromised or has been used as an alternative reperfusion technique for complex portal vein thrombosis(PVT).The effect of PVA on portal perfusion and primary graft dysfunction(PGD)has not been assessed.All patients receiving PVA and LT at the Fundacion Santa Fe de Bogota between 2011 and 2022 were analyzed.To account for the time-sensitive effects of graft perfusion,patients were classified into two groups:prereperfusion(pre-PVA),if the arterioportal anastomosis was performed before graft revascularization,and postreperfusion(post-PVA),if PVA was performed afterward.The pre-PVA rationale contemplated poor portal hemodynamics,severe vascular steal,or PVT.Post-PVA was considered if graft hypoperfusion became evident.Conservative interventions were attempted before PVA.

Portal venous arterialization resulting in increased portal inflow and portal vein wall thickness in rats

AIM： To explore the influence of portal vein hemodynamic changes after portal venous arterialization （PVA） on peribiliary vascular plexus （PVP） morphological structure and hepatic pathology, and to establish a theoretical basis for the clinical application of PVA. METHODS： Sprague-Dawley rats were randomly divided into control and PVA groups. After PVA, hemodynamic changes of the portal vein and morphological structure of hepatohilar PVP were observed using Doppler ultrasound, liver function tests, ink perfusion transparency management and three-dimensional reconstruction of computer microvisualization, and pathological examination was performed on tissue from the bile duct wall and the liver. RESULTS： After PVA, the cross-sectional area and blood flow of the portal vein were increased, and the increase became more significant over time, in a certain range. If the measure to limit the flow in PVA was not adopted, the high blood flow would lead to dilatation of intrahepatic portal vein and its branches, increase in collagen and fiber degeneration in tunica intima. Except glutamic pyruvic transaminase （GPT）, other liver function tests were normal. CONCLUSION： Blood with a certain flow and oxygen content is important for filling the PVP and meeting the oxygen requirement of the bile duct wall. After PVA, It is the anatomic basis to maintain normal morphology of hepatohilar bile duct wall that the blood with high oxygen content and high flow in arterialized portal vein may fill PVP by collateral vessel reflux. A adequate measure to limit blood flow is necessary in PVA.

Effects of partial portal vein arterialization on the hilar bile duct in a rat model

BACKGROUND: Liver revascularization is frequently required during the enlarged radical operation for hilar cholangio carcinoma involving the hepatic artery. Researchers have carried out a number of experiments applying partial porta vein arterialization (PVA) in clinical practice. In this study we aimed to establish a theoretical basis for clinical application o partial PVA and to investigate the effects of partial PVA on ra hilar bile duct and hepatic functions. METHODS: Thirty rats were randomly and equally assigned into 3 groups: control (group A), hepatic artery ligation+bile duct recanalization (group B), and partial PVA+bile duc recanalization (group C). Proliferation and apoptosis o rat hilar bile duct epithelial cells, arteriolar counts of the peribiliary plexus (PBP) of the bile duct wall, changes in serum biochemistry, and pathologic changes in the bile duc were assessed 1 month after operation. RESULTS: The proliferation of hilar bile duct epithelial cells in group B was greater than in groups A and C (P<0.01). No apoptotic hilar bile duct epithelial cells were detected in any of the groups. The PBP arteriolar counts of the hilar bile duc wall were similar in groups A and C (P>0.05), but the coun was lower in group B than in group A (P<0.01). No statistically significant differences in alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and albumin were found in the 3 groups. The gamma-glutamyltransferase value was higher in group B than in groups A and C (P<0.01) The hepatic tissues of groups A and C showed no significan abnormality. Chronic inflammatory changes in the hilar bile duct walls were observed only in group B. CONCLUSION: Partial PVA can restore the arterial blood supply of the hilar bile duct and significantly extenuate the injury to hilar bile duct epithelial cells resulting from hepatic artery ligation.

Portal vein arterialization technique for liver transplantation patients

Liver transplantations were performed on two patients with hepatic failure caused by liver cirrhosis.Hard obsolete thrombi and portal venous sclerosis were observed in the major portal veins of both patients.The arteria colica media of one recipient and the portal vein of the donor were anastomosed end-to-end.The hepatic artery of the first donor was anastomosed end-to end with the gastroduodenal artery of the first recipient;meanwhile,the portal vein of the second donor was simultaneously anastomosed end-to-end with the common hepatic artery of the second recipient.The blood flow of the portal vein,the perfusion of the donor liver and liver function were satisfactory after surgery.Portal vein arterialization might be an effective treatment for patients whose portal vein reconstruction was difficult.

Portal vein arterialization promotes liver regeneration after extended partial hepatectomy in a rat model

In the current study, we sought to establish a novel rat model of portal vein artefialization （PVA） and evaluate its impact on liver regeneration after extended partial hepatectomy （PH）. A total of 105 Sprague-Dawley rats were randomly assigned to three groups： 68% hepatectomy （the PH group）, portal arterialization after 68% hepatectomy （the PVA group）, and fight nephrectomy only （the control group）. Liver regeneration rate （LRR）, 5-bromo-2-deoxyuridine （BrdU） labeling index, and liver functions were assessed on postoperative day 2, 7, 14 and 28. The 28-day survival rates were compared among the three groups. The 28-day survival rates were similar in all groups （P = 0.331）, and the anastomotic patency was 100%. The LRR in the PVA group was significantly higher than that of the PH group within postoperative 14 days （P 〈 0.05）. The PVA and PH group had increased serum alanine aminotransferase levels （232 ±61 U/L and 212 ±53 U/L, respectively） compared with the control group （101 ±13 U/L） on postoperative day 2, whereas from postoperative day 7 to day 28 there were no differences among the three groups. Serum albumin values were higher after the PVA procedure within postoperative day 14, which gradually became comparable on postoperative day 28 among the three groups. The peaks of BrdU labeling index appeared on postoperative day 2 in all rats, and the PVA procedure was associated with increased BrdU labeling index from postoperative day 7 to 28. The 28-day survival of the PVA rats was comparable. Our findings demonstrate that the PVA procedure utilizing portal vein trunk-renal artery microvascular reconstruction promotes remnant liver regeneration and confers beneficial effects on maintaining and even optimizing liver function after extended partial hepatectomy in rats.

Partial portal vein arterialization using right gastroepiploic artery:A novel solution for portal hypoperfusion

To the Editor:Establishing dual arterial and portal inflow is essential for liver transplantation[1].Inadequate portal inflow compromises graft function and graft survival[2].Portal hypoperfusion is usually a consequence of spontaneous portosystemic shunt,ligation of which

From portal to splanchnic venous thrombosis:What surgeons should bear in mind

The present study aims to review the evolution of surgical management of portal(PVT) and splanch-nic venous thrombosis(SVT) in the context of liver transplantation over the last 5 decades. PVT is more commonly managed by endovenous thrombectomy, while SVT requires more complex technical expedients. Several surgical techniques have been proposed, such as extensive eversion thrombectomy, anastomosis to collateral veins, reno-portal anastomosis, cavo-portal hemi-transposition, portal arterialization and combined liver-intestinal transplantation. In order to achieve satisfactory outcomes, careful planning of the surgical strategy is mandatory. The excellent results that are ob-tained nowadays confirm that, even extended, splanch-nic thrombosis is no longer an absolute contraindication for liver transplantation. Patients with advanced portal thrombosis may preferentially be referred to specialized centres, in which complex vascular approaches and even multivisceral transplantation are performed.

Effects of partial portal vein arterialization on liver regeneration after hepatectomy in minipigs with obstructive jaundice

Background Hilar cholangiocarcinoma is a malignant tumor that is difficult to cure. The aim of this study was to observe the effects of flow-controlled partial portal vein arterializations （PPVA） on liver regeneration after hepatectomy in minipigs with chronic obstructive jaundice. Methods Eight minipigs were made into chronic obstructive jaundice models. United semi-hepatectomy, which imitates extended radical surgery for treatment of hilar cholangiocarcinoma, was then performed. The eight minipigs were randomly divided into groups A and B （n=4 minipigs each）. PPVA was performed in Group A but not in Group B. The effects of flow-controlled PPVA on live regeneration after hepatectomy were observed for 30 days after hepatectomy. Results The portal vein PO2 at the immediate time point and on postoperative day 30 was higher in Group A （（47.33±2.43） and （48.50±4.44） mmHg） than in Group B （（35.38±4.06） and （35.55±2.55） mmHg respectively, all P 〈0.01）. The mitotic index of liver cells on postoperative days 14 and 21 was higher in Group A （12.55%±2.85% and 15.25%±1.99% respectively） than in Group B （6.85%±2.10% and 11.88%±1.15% respectively, all P 〈0.05）. The regeneration rate of residual liver on postoperative days 14 and 21 was higher in Group A （24.56%±6.15% and 70.63%±9.83% respectively） than in Group B （11.96%±5.43% and 44.92%±7.42% respectively, P 〈0.05 and P 〈0.01 respectively）.Conclusion Flow-controlled PPVA can promote liver regeneration after hepatectomy and prevent liver failure in minipigs with chronic obstructive jaundice.

Effects of portal venous arterialization on acute occlusion of hepatic artery in rats

Background A fatal complication after liver transplantation is anastomotic embolization of the hepatic artery. In order to solve this problem, the portal venous arterialization （PVA） is used to reconstruct the hepatic arterial blood flow. The purpose of this study was to investigate the influence of PVA on rats with acute occlusion of hepatic artery. Methods Rat PVA models were established and then randomly divided into Group 1 （control group）, Group 2 （jaundice group）, Group 3 （bile duct recanalization group）, and Group 4 （portal vein arterilization group）. Recanalization of the common bile duct and PVA were performed 5 days after bile duct ligation in the rats. The influence of the PVA on general conditions, hepatic changes of structure and function, portal vein pressure and hepatic micrangium were observed for one month. Results Five days after common bile duct ligation the serum bilirubin, transaminase and alkaline phosphatase levels were significantly increased. Compared with group 1, there was a statistically significant difference （P 〈0.01）. These rats then underwent bile duct recanalization and PVA. After a month, the liver functions and microscopic structures completely returned to normal and, compared with group 1, there was no statistically significant difference in portal vein pressure （P 〉0.05）. Vascular casting samples showed that hepatic sinusoids were slightly thicker and more filled than normal ones and although they had some deformations, the hepatic sinusoids were still distributed around the central vein in radial form. Conclusion Within a month after operation, bile duct recanalization and PVA do not show obvious adverse effects on liver hemodynamics and hepatic micrangium, and the liver function and microscopic structure can return to normal.