Chronic Hepatic Artery Occlusion with Collateral Formation: Imaging Findings and Outcomes

Prediction of hepatic artery occlusion after liver transplantation by ultrasound characteristics and clinical risk factors

BACKGROUND

Hepatic artery occlusion (HAO) after liver transplantation (LT) is a devastating complication, resulting in early graft loss and reduced overall survival. Ultrasound is an established assessment method for HAO in patients following LT, especially those with complex hepatic artery reconstruction.

AIM

To investigate the ultrasound characteristics and analyze the risk factors associated with HAO in patients after LT.

METHODS

We retrospectively analyzed the ultrasound characteristics and the clinic risk factors associated with HAO in 400 adult LT patients who were enrolled and treated at the Third People's Hospital of Shenzhen between November 2016 and July 2022. Fourteen patients diagnosed with acute HAO (A-HAO) by surgery and fifteen diagnosed with chronic HAO (C-HAO) were included. A control group of 33 patients without HAO complications during the same period were randomly selected using a random number table. All patients underwent an ultrasonography examination. Parameters including resistance index (RI), peak systolic velocity (PSV), and portal vein velocity (PVV) were compared across the groups. Additionally, basic clinical data were collected for all patients, including gender, age, primary diagnosis, D-dimer concentration, total operation time, cold ischemia time, hot ischemia time, intraoperative blood loss and transfusion, intraoperative urine volume, infusion, model for end-stage liver disease (MELD) score, and whether complex hepatic artery reconstructions were performed. Furthermore, risk factors influencing HAO formation after LT were analyzed.

RESULTS

Compared to the non-HAO group, PVV and RI were higher in the A-HAO group, while PSV was lower. Conversely, both PSV and RI were lower in the C-HAO group compared to the non-HAO group. The proportion of patients undergoing complex hepatic artery reconstructions and the gamma-glutamyltransferase (GGT) level before occlusion were significantly higher in the A-HAO group compared to the non-HAO group. However, there were no distinct differences between the two groups in D-dimer, MELD score, pre-occlusion alanine transaminase and aspartate transaminase levels, or intraoperative conditions.

CONCLUSION

Ultrasound features of the hepatic artery before occlusion are significantly associated with postoperative HAO development. Additionally, complex hepatic artery reconstructions, defined as revascularization of the graft requiring additional anastomosis between donor hepatic arteries, constitute a risk factor for A-HAO. Besides, abnormal pre-occlusion GGT elevation is an important biochemical indicator. Therefore, ultrasound examination serves as an important tool for screening HAO, especially in patients with the identified risk factors.

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.

AIM

To examine the outcomes of patients who required PVA in correlation with their LT procedure.

METHODS

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.

RESULTS

A total of 25 cases were identified: 15 before and 10 after graft reperfusion. Pre-PVA patients were more affected by diabetes, decompensated cirrhosis, impaired portal vein (PV) hemodynamics, and PVT. PGD was less common after pre-PVA (20.0% vs 60.0%) (P = 0.041). Those who developed PGD had a smaller increase in PV velocity (25.00 cm/s vs 73.42 cm/s) (P = 0.036) and flow (1.31 L/min vs 3.34 L/min) (P = 0.136) after arterialization. Nine patients required PVA closure (median time: 62 d). Pre-PVA and non-PGD cases had better survival rates than their counterparts (56.09 months vs 22.77 months and 54.15 months vs 31.91 months, respectively).

CONCLUSION

This is the largest report presenting PVA in LT. Results suggest that pre-PVA provides better graft perfusion than post-PVA. Graft hyperperfusion could play a protective role against PGD.

An Orthotopic Liver Transplantation Patient Survived Without Hepatic Artery Flow Due to Thrombosis: A Case Report

BACKGROUND

Hepatic artery thrombosis (HAT), a serious complication after orthotopic liver transplantation, almost always leads to morbidity and mortality without urgent revascularization or retransplantation, especially if HAT occurs within a few days after transplantation.

CASE PRESENTATION

Herein we describe a case report of an orthotopic liver transplantation patient surviving without hepatic artery flow due to HAT on postoperative day 1. Reanastomosis, thrombectomy, and intra-arterial thrombolysis were performed, but only retrograde arterial flow by Doppler ultrasound, not by angiography, could be demonstrated in the hepatic artery. This case report is in compliance with the Declaration of Helsinki and the Declaration of Istanbul.

CONCLUSION

Based on the evidence from this patient, we believe that patients with failed revascularization can experience a long-term survival with conservative treatment. Retransplantation should be evaluated based on laboratory findings because graft function in individual patients can recover.

Portal vein arterialization as a salvage procedure in hepatopancreatobiliary surgery: a systematic review

Background

Portal vein arterialization (PVA) is a possible option when hepatic artery reconstruction is impossible during liver resection. The aim of this study was to review the literature on the clinical application of PVA in hepatopancreatobiliary (HPB) surgery.

Methods

We performed a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We systematically searched the PubMed, Embase and Web of Science databases until December 2019. Experimental (animal) studies, review articles and letters were excluded.

Results

Twenty studies involving 57 patients were included. Cholangiocarcinoma was the most common indication for surgery (40 patients [74%]). An end-to-side anastomosis between a celiac trunk branch and the portal vein was the main PVA technique (35 patients [59%]). Portal hypertension was the most common long-term complication (12 patients [21%] after a mean of 4.1 mo). The median follow-up period was 12 (range 1–87) months. The 1-, 3- and 5-year survival rates were 64%, 27% and 20%, respectively.

Conclusion

Portal vein arterialization can be considered as a rescue option to improve the outcome in patients with acute liver de-arterialization when arterial reconstruction is not possible. To prevent portal hypertension and liver injuries due to thrombosis or overarterialization, vessel calibre adjustment and timely closure of the anastomosis should be considered. Further prospective experimental and clinical studies are needed to investigate the potential of this procedure in patients whose liver is suddenly de-arterialized during HPB procedures.

Diagnosis and outcomes of collateral arterial formation after irreversible early hepatic artery thrombosis in pediatric liver recipients

BACKGROUND

Early hepatic artery thrombosis (eHAT) has been recognized as an important cause of graft loss and mortality. However, the incidence, etiology and outcome are not clear, especially for children. The present study was to investigate the formation of collateral artery flow after irreversible eHAT and its impact on patient's prognosis.

METHODS

We analyzed eHAT after liver transplantation in children from October 2006 to April 2015 in our center, illustrated the formation of collateral hepatic artery flow after irreversible eHAT and explored the diagnosis, complications, treatment and prognosis. The basic and follow-up ultrasonographic images were also compared.

RESULTS

Of the 330 pediatric liver recipients, 22 (6.67%) developed eHAT within 1 month. Revascularization attempts including surgical thrombectomy, interventional radiology and conservational treatment (thrombolysis) were successful in 5 patients. Among the 17 patients who had irreversible eHAT, follow-up ultrasonography revealed that collateral artery flow was developed as early as 2 weeks after eHAT. Liver abscess and bile duct complication occurred secondary to eHAT in variable time.

CONCLUSIONS

Collateral arterial formation is a compensatory adaptation to eHAT to supply blood to liver grafts. However, the severe bile duct damage secondary to eHAT is irreversible and retransplantation is unavoidable.

Formation of Collateral Veins in a Graft Pancreas After a Simultaneous Pancreas and Kidney Transplantation: A Case Report

A graft vein thrombosis is the main cause of early graft failure after pancreas transplantation. We report a case of formation of collateral veins in a graft pancreas after transplant. A 30-year-old woman underwent simultaneous pancreas and kidney transplantation. She was discharged 16 days after the operation with good pancreas and kidney function. A total occlusion of the portal vein was discovered on computed tomography (CT) performed at an outpatient clinic. She had no symptoms or signs of hyperglycemia. Venography was attempted for vein thrombectomy but failed. After 2 weeks of heparinization therapy, the edema disappeared and perfusion of the graft pancreas improved. However, the thrombotic occlusion was not resolved on CT. Arteriography of the Y-graft revealed collateral veins. She was discharged with warfarin. She is currently doing well without any symptoms or signs. This is the first reported case of collateral vein formation in a grafted pancreas after pancreas transplantation.

Evaluation of extrahepatic collateral arteries in hepatocellular carcinoma in three independent groups in a single center

To improve the efficacy of transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC), this study evaluated the prevalence and causes of extrahepatic arteries (EHAs) and identified feeding arteries in HCCs in three independent clinical groups in a single inverventional radiology center. Between November 2011 and September 2012, 942 cases of HCC were included in this retrospective study. The patients were treated in three independent groups of 285, 301 and 356 patients, respectively. Enhanced computed tomography, enhanced magnetic resonance imaging and digital subtraction angiography were reviewed retrospectively and correlations between the presence of tumor-feeding EHAs and tumor number, size and location in the liver, number of repeat TACE procedures and complications were assessed. There were 698 EHAs in the 942 cases of HCC, with 182, 233 and 283 EHAs in the three independent groups, respectively. Tumor size was associated with EHA formation; the percentages of patients with EHAs were 2.7±3.0, 5.5±0.5, 43.2±4.0, 61.8±5.2 and 93.4±1.8% with tumor sizes of 2-3, 3-5, 5-7, 7-9 and >9 cm, respectively. There were 159±19 EHAs in each group feeding tumors in peripheral locations in the liver, but only 48.7±6.8 in the central zone. The most common EHA was the right inferior phrenic artery, with a mean of 101.0±14.1 per group. The number of EHAs increased proportionally with the number of TACE sessions. The number of EHAs was positively associated with tumor size, peripheral location of the tumor and number of TACE sessions.

Contrast-Enhanced Sonography for Diagnosing Collateral Transformation of the Hepatic Artery After Liver Transplantation

OBJECTIVES

To determine the contrast-enhanced sonographic features of hepatic artery collateral transformation in patients with hepatic artery complications after liver transplantation.

METHODS

Ninety-nine liver transplant recipients who underwent contrast-enhanced sonography were recruited from April 2004 to May 2014. The reference standards were conventional angiography and computed tomographic angiography. The contrast-enhanced sonographic features of the hepatic artery in patients with and without collateral arteries were retrospectively analyzed.

RESULTS

All 15 patients with hepatic artery collateral transformation had hepatic artery thrombosis (10 of 15) or hepatic artery stenosis (5 of 15). The collateral artery detection rate on contrast-enhanced sonography was 100%. The peripheral hepatic artery could not be visualized by contrast-enhanced sonography in most of the patients with hepatic artery collateral transformation (14 of 15). Additionally, many small tortuous collateral arteries in the porta hepatis region were visualized during the arterial and early portal phases, showing reticulated/patchy (15 of 15) and striped (3 of 15) enhancement patterns on contrast-enhanced sonography.

CONCLUSIONS

Collateral transformation of the hepatic artery in patients with hepatic artery complications after liver transplantation appears to have characteristic features on contrast-enhanced sonography, especially a reticulated or patchy enhancement pattern in the porta hepatis region during the arterial and early portal phases combined with the absence of the peripheral hepatic artery. Contrast-enhanced sonography may be a novel method for diagnosing hepatic artery collateral transformation, which may be a highly specific sign of hepatic artery thrombosis or stenosis.

The features of extrahepatic collateral arteries related to hepatic artery occlusion and benefits in the transarterial management of liver tumors

Purpose. To investigate the extrahepatic collateral arteries related to hepatic artery occlusion (HAO) and to determine its benefits in the transarterial management of liver tumors. Methods and Findings. Eleven patients (7 hepatocellular carcinomas, 3 liver metastases, and 1 with hemangioma) with HAO confirmed with digital subtraction angiography (DSA) were admitted to our hospital. Of the 11 patients, 7 were men and 4 were women, with an average age of 41.5 ± 15.5 years (range: 29 to 70 years). DSA was performed to evaluate the collateral routes to the liver. In the 11 patients with HAO, DSA showed complete occlusion of the common hepatic artery in 9 patients and the proper hepatic artery (PHA) in 2 patients. Extrahepatic collateral arteries supplying the liver were readily evident. The collateral arteries originated from the superior mesenteric artery (SMA) in 8 patients, from the gastroduodenal artery in 2 patients, and from the left gastric artery (LGA) in 1 patient. Transcatheter treatment was successfully performed via the collateral artery in all patients except the one who had hemangioma. Conclusions. DSA is an effective method for detecting collateral circulation related to HAO and may provide information to guide transcatheter management decisions.

Hepatic artery thrombosis after orthotopic liver transplantation: 3 patients with collateral formation and conservative treatment

Hepatic artery thrombosis (HAT), a serious complication after orthotopic liver transplantation (OLT), can lead to patient death in the absence of revascularization or retransplantation. Herein we have presented clinical characteristics, imaging findings, and long-term outcomes of 3 OLT patients with HAT who were treated conservatively and developed hepatic arterial collaterals. These patients underwent transplantation due to hepatitis B cirrhosis, cryptogenic cirrhosis, or hepatitis C infection and alcoholic disease. They presented with bile duct stenosis and/or a bile leak at 1, 3, and 36 months after transplantation, respectively, and were treated with percutaneous drainage and stent placement, endoscopic retrograde cholangio-pancreatography (ERCP), or reanastomosis of the bile duct over a T tube. HAT was confirmed using multidetector computed tomography (MDCT) 3-dimensional (3D) angiography and Doppler sonography. They survive in good condition with normal liver function at 30, 50, and 42 months after OLT, respectively. Development of collateral arterial circulation to the liver graft was detected with MDCT 3D angiography and Doppler sonography. From our experience with 3 patients and a literature review, we believe that there are a number of patients who experience long-term survival after the diagnosis of irreversible HAT and the development of collaterals. Although this group is at high risk for sepsis and biliary complications, these are usually self-limiting complications due to improved treatment regimens. The development of collateral arterial flow may also be beneficial.