Transvenous variceal embolization during or after living-donor liver transplantation to improve portal venous flow

Short-Term Results of Plug-Assisted Retrograde Transvenous Obliteration for Portal Steal from Complicated Portosystemic Shunts in Living-Donor Liver Transplantation

PURPOSE

To investigate the effectiveness of plug-assisted retrograde transvenous obliteration (PARTO) for portal steal from complicated portosystemic shunts (PSSs) in living-donor liver transplantation (LDLT).

MATERIALS AND METHODS

This retrospective study included consecutive patients who underwent LDLT and intraoperative or postoperative PARTO for complicated PSS between January 2020 and December 2021. PARTO was performed when hepatofugal portal flow steal was identified during intraoperative cineportography, and afferent vein embolization was difficult because of multiple afferent veins or incomplete afferent vein embolization. Liver volume, complete obliteration of PSS, technical success, adverse events, and follow-up clinical and laboratory data were evaluated.

RESULTS

Thirty-seven patients were included, and the technical success rate was 100% with no major adverse events. During the median follow-up of 20.0 months, all patients recovered well with suitable regeneration of the liver without graft dysfunction related to a portal steal. The liver volume significantly increased within 1 month (median, 956 vs 1,198 mL; P < .001). Complete obliteration of a PSS occurred in 36 of 37 (97.3%) patients, and there was no recurrence during follow-up. The Child-Pugh score, serum albumin and total bilirubin levels, and prothrombin time showed significant improvement over serial follow-up. Compared with preprocedural values (14.9 cm/s), follow-up portal flow (median) peaked on the first day (71.2 cm/s, P < .001) and then remained significantly high at 1 week (60.3 cm/s, P < .001) and 1 month (53.1 cm/s, P < .001), in accordance with the graft regeneration.

CONCLUSIONS

PARTO is an effective procedure for the treatment of complicated PSS in LDLT.

The Role of Imaging in Portal Vein Thrombosis: From the Diagnosis to the Interventional Radiological Management

PURPOSE

To illustrate diagnostic and interventional imaging for the characterization and treatment of portal vein thrombosis (PVT).

INTRODUCTION

The broad spectrum of congenital and acquired PVT manifestations is illustrated, with a focus on the pediatric population; diagnostic and interventional imaging techniques are described.

DESCRIPTION

PVT frequently presents as an incidental finding at imaging in the screening for liver diseases or for other unrelated reasons. PVT can be classified based on: extension (intrahepatic, extrahepatic, involving the spleno-mesenteric tract, etc.); degree (partial or complete); onset (acute or chronic); and with or without cavernomatous transformation. This comprehensive review relies on the experience gained from a large series of congenital and acquired PVT in a referral center for pediatric and adult liver transplantation. Diagnostic and interventional imaging techniques are described, including: color-Doppler and contrast-enhanced Ultrasound; CT and MR angiography; retrograde portography; percutaneous transhepatic, transplenic, and transmesenteric portography; transjugular intrahepatic portosystemic shunt creation. Pre- and post-operative imaging assessment of the surgical meso-rex bypass is discussed. The description is enriched with an original series of pictorial imaging findings.

CONCLUSION

PVT is a clinical condition associated with significant morbidity and mortality. Diagnostic and interventional imaging plays a crucial role in both conservative and operative management.

Clinical Impact of Spontaneous Portosystemic Shunts in Liver Transplantation: A Comprehensive Assessment Through Total Shunt Area Measurement

BACKGROUND

The impact of spontaneous portosystemic shunts (SPSSs) on natural history of cirrhotic patients was recently evaluated through the measurement of total shunt area (TSA), a novel tool that allows a comprehensive assessment of SPSSs extension, identifying a direct correlation of higher TSA with lower patient survival. The role of SPSSs in liver transplant (LT) is still debated: we sought to investigate the clinical impact of TSA on the development of early allograft dysfunction (EAD), acute kidney injury (AKI), postoperative complications, and graft and patient survival following LT.

METHODS

Preoperative imaging of 346 cirrhotic patients undergoing primary LT between 2015 and 2020 were retrospectively revised, recording the size and anatomy of each SPSS to calculate TSA. The impact of TSA and selected patient and donor characteristics on the development of EAD, AKI, and clinically relevant complications was evaluated through univariate and multivariate logistic regression, whereas their effect on graft and patient survival was investigated through Cox regression analysis.

RESULTS

A TSA exceeding 78.54 mm 2 resulted as an independent risk factor for the development of EAD (odds ratio [OR]: 2.327; P = 0.003), grade 3 AKI (OR: 2.093; P = 0.041), and clinically relevant complications (OR: 1.962; P = 0.015). Moreover, higher TSA was significantly related to early graft and patient survivals, emerging as an independent risk factor for 12-mo graft loss (hazard ratio: 3.877; P = 0.007) and patient death (hazard ratio: 2.682; P = 0.018).

CONCLUSIONS

Higher TSA emerged as a significant risk factor for worse postoperative outcomes following LT, supporting the need for careful hemodynamic assessment and management of patients presenting multiple/larger shunts.

Management of spontaneous portosystemic shunts at the time of liver transplantation: treatment or observation? Results of a systematic review

BACKGROUND

Optimal treatment of spontaneous portosystemic shunts (SPSS) during liver transplantation (LT) remains debated. We systematically reviewed the literature on definitions, treatment and outcomes of patients presenting SPSS undergoing LT.

METHODS

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we used PubMed to retrieve all studies dealing with SPSS and LT between January 1987 and January 2020. The primary endpoints were definitions and outcomes according to the management of SPSS (treatment vs observation).

RESULTS

Thirteen studies detailing the management of 962 SPSS were retrieved. Hemodynamically significant SPSS were defined as those having diameter ≥ 10 mm in 41% (n = 395) of patients. SPSS were splenorenal (42%), cavo-gastric (15.2%), umbilical (7.4%), mesenterico-caval (n = 31; 3.2%), mesenterico-renal (0.1%) and unreported (31.9%), respectively. At the time of LT 372 shunts (38.7%) were treated while 590 were observed (61.3%). During a follow-up time ranging from 4 months to 5 years, the reported overall survival (OS) at 1 year was not significantly different except for one study. Portal vein anastomosis complications (i.e. reduced flow, stenosis or thrombosis) were similarly reported in observed [n = 26 (4%)] and ligated SPSS [n = 10 (2%)] (p = 0.22) but the rate of relaparotomy was significantly higher in observed SPPS (16 vs 2; p = 0.01) to rescue post LT portal vein thrombosis (n = 6) and reduced portal flow and graft dysfunction (n = 10).

CONCLUSIONS

There was a heterogeneous management of SPSS during LT in the literature. Ligation of SPPS did not reduce vascular complications neither improved survival. A randomized prospective study might contribute to identify best management of SPSS at time of LT.

Portal Steal Syndrome From a Large Linton's Splenorenal Shunt after Liver Transplantation: Successful Endovascular Management Through Off-Label Application of a 30 mm Amplatzer Cardiac Plug

A 34-year-old patient underwent liver transplantation for progressive hepatic failure in the setting of congenital hepatic fibrosis. In past medical history, the patient had undergone splenectomy with proximal Linton's splenorenal surgical shunt creation for symptomatic portal hypertension with hypersplenism. The patient developed an early allograft dysfunction, with radiologic evidence of a reduced portal flow associated to portal steal from the patent surgical shunt. The patient was successfully treated through endovascular placement of a 30 mm Amplatzer cardiac plug at the origin of the splenic vein.

Pediatric deceased donor liver transplantation with in situ size reduction for recipient-graft size matching

We present a case of pediatric deceased donor liver transplantation using a reduced whole liver graft in a 25-month-old boy weighing 12.7 kg. After he had undergone Kasai portoenterostomy for biliary atresia, his general condition deteriorated progressively. He was enrolled on the waiting list for liver transplantation with Pediatric End-stage Liver Disease score of 15. The donor was a 51-monthold boy with body weight of 20 kg. The donor-to-recipient body weight ratio was 158%. The liver graft appeared to be larger than the recipient's abdominal cavity. Thus, we planned to do in situ size reduction. Recipient surgery was performed following standard procedures. We performed graft outflow vein reconstruction using a modified piggyback technique like the double inferior vena cava method. Since the portal vein was hypoplastic, a side-to-side anastomosis technique was used. We also performed intraoperative portogram to embolize venous collaterals. After completing the graft implantation, we found that the liver graft was too large to be accommodated within the abdomen. After in situ resection of the left lateral section parenchyma, we successfully performed primary closure of the abdominal wound. This patient experienced episodes of acute rejection. He has been doing well for four years after the transplantation.

Endovascular management of portal steal syndrome due to portosystemic shunts after living donor liver transplantation

Background and Aim

After liver transplant, pre‐existent porto‐systemic shunts (PSS) may persist, causing “portal steal,” leading to graft dysfunction, hepatic encephalopathy (HE), and eventual rejection. In recipients of small‐for‐size transplant liver grafts, shunts may be created intraoperatively, facilitating diversion of portal flow to systemic circulation to avoid ill‐effects of portal overperfusion. These iatrogenic shunts may also subsequently lead to portal steal. We aim to evaluate safety and efficacy of endovascular techniques in management of portal steal due to PSSs in living donor liver transplantation (LDLT) recipients.

Methods

Between 2013 and 2020, we encountered five LDLT recipients with large PSS, who presented with graft dysfunction and/or HE. One patient had a surgically created shunt and four had spontaneous shunts, not surgically ligated during transplant. Endovascular techniques including plug‐assisted or balloon‐occluded retrograde transvenous obliteration (PARTO/BRTO) or covered inferior vena cava (IVC) stent grafts were to occlude these PSS and counter the portal steal in all patients. Technical success and clinical outcomes at 1‐year‐follow‐up were assessed.

Results

Imaging showed large PSS causing portal steal syndrome in all five patients. IVC stent graft was used to isolate the shunt in two patients and PARTO/BARTO was performed in three patients. One patient had guarded prognosis due to multiple organ dysfunction and died 5 days after endovascular procedure. At 1‐year follow up, graft functions normalized in four patients with no recurrence of HE. No procedure‐related complications were seen.

Conclusion

Endovascular techniques can be safely and effectively used to counter portal steal syndrome in LDLT recipients, thus avoiding surgical re‐exploration in these patients.

The Application of Interventional Radiology in Living-Donor Liver Transplantation

Owing to improvements in surgical techniques and medical care, living-donor liver transplantation has become an established treatment modality in patients with end-stage liver disease. However, various vascular or non-vascular complications may occur during or after transplantation. Herein, we review how interventional radiologic techniques can be used to treat these complications.

Pediatric split liver transplantation in a patient with biliary atresia polysplenia syndrome and agenesis of inferior vena cava

Biliary atresia (BA)-polysplenia syndrome (PS) is diagnosed in a small proportion of BA patients. We present a case of split liver transplantation (LT) successfully performed in a pediatric recipient with BA-PS. The recipient was 29-month-old boy who underwent Kasai procedure. The coexisting malformations included agenesis of the inferior vena cava with azygos vein continuation, polysplenia, intestinal malrotation, truncated pancreas, and preduodenal portal vein and annular pancreas. With pediatric end-stage liver disease score of 33, the patient was allocated for split LT. Under this condition, the left lateral section graft was equivalent to a graft-recipient weight ratio of 2.6%. The recipient surgery was performed according to the standard procedures of pediatric LT. The graft hepatic vein was directly anastomosed with the suprahepatic confluence of the recipient hepatic veins. An external iliac vein homograft was interposed for portal vein reconstruction. Portal collateral veins were embolized intraoperatively to secure portal vein inflow. No surgical complications were developed. Currently, the patient has been doing well for 4 years after transplantation. Our pediatric patient with BA-PS had various anatomical malformations. Thorough preoperative and intraoperative assessment of these anomalies, adoption of customized reconstruction techniques of LT, and careful posttransplant monitoring are necessary for successful LT.

Endovascular transsplenic recanalization with angioplasty and stenting of an occluded main portal vein in an adult liver transplant recipient

Endovascular transshepatic access has limitations that can be exacerbated in the posttransplantation setting. Although several techniques are available for portal venous system catheterization, the transsplenic approach offers a direct pathway for accessing the portal venous system, as well as associated varices or shunts, while avoiding potential injury to the liver transplant. The purpose of this report is to present the diagnostic and interventional management of main portal vein occlusion in a 56-year-old female after liver transplantation. Endovascular transsplenic recanalization with stenting and shunt embolization is a viable method for treatment of main portal vein thrombosis in an adult liver transplant recipient.

Endovascular Treatment of Acute Posttransplant Portal Vein Thrombosis Due to Portal Steal From Mesocaval And Coronary Portosystemic Shunts

The management of portosystemic shunts in liver transplant recipients relies on appropriate perioperative study. There are several strategies for shunt handling, ranging from preoperative interventional procedures to intraoperative surgical interruption or embolization. Appropriate management often results in a successful outcome, although wrong decisions could lead to serious consequences. Here, we report a liver transplant recipient with grade 2 portal vein thrombosis associated with 2 large portosystemic shunts (coronary and mesocaval), which were managed intraoperatively via thrombectomy without shunt ligation. Acute portal vein thrombosis developed early after transplant due to portal steal syndrome. The patient underwent a successful endovascular shunt embolization, with prompt restoration of hepatopetal portal flow and resolution of the portal steal. Use of interventional radiology in perioperative management of transplant patients has recently gained wider importance; our case reported here is particularly suggestive of the good outcomes of a multidisciplinary approach to a threatening complication such as postoperative acute portal vein thrombosis.

N-butyl-2 cyanoacrylate (NBCA) embolus in the graft portal vein after portosystemic collateral embolization in liver transplantation recipient: what is the clinical significance?

Background An N-butyl-2 cyanoacrylate (NBCA) embolus in the graft portal vein was frequently observed after an intraoperative embolization of portosystemic collaterals performed to prevent portal steal in liver transplant (LT) recipients. The radiological and clinical features of NBCA emboli have not yet been described. Purpose To describe radiological and clinical features of NBCA embolus in graft portal vein after portosystemic collateral embolization in LT recipients. Material and Methods A total of 165 consecutive LT recipients who had undergone intraoperative NBCA embolization of varix were found in single institution's computerized databases of a clinical cohort of LT. Patients were evaluated for NBCA emboli (categorized into major and minor emboli according to location) on first postoperative computed tomography (CT). All electronic medical records and radiologic studies including follow-up was evaluated to determine any radiological and clinical abnormality associated with NBCA embolus. Results NBCA emboli were found in 24% (39/165) of recipients. Although most patients had minor emboli (77%, 30/39) without remarkable ultrasonography (US) abnormalities, seven (78%) of nine recipients with major emboli showed intraluminal echogenic lesions in graft portal vein on grayscale US, and five of them (71%) showed partial portal flow obstruction, although none exhibited any abnormality on contrast-enhanced US. Recipients with NBCA portal emboli showed no significant clinical abnormalities and were discharged safely. NBCA embolus eventually disappeared mostly within six months (82%, 32/39). Conclusion NBCA emboli are frequently observed after portosystemic collateral embolization in LT recipients and are not associated with poor clinical outcome. They may mimic ordinary thromboemboli on US.

Interventional radiology in the management of the liver transplant patient

Liver transplantation (LT) is commonly used to treat patients with end-stage liver disease. The evolution of surgical techniques, endovascular methods, and medical care has led to a progressive decrease in posttransplant morbidity and mortality. Despite these improvements, a multidisciplinary approach to each patient remains essential as the early diagnosis and treatment of the complications of transplantation influence graft and patient survival. The critical role of interventional radiology in the collaborative approach to the care of the LT patient will be reviewed. Liver Transplantation 23 1328-1341 2017 AASLD.

Radiologic evaluation of portal steal phenomenon in recipients of liver transplantation

It is important to maintain adequate portal flow and to prevent the detrimental effect of portosystemic shunt in recipients following liver transplantation. The purpose of this article is to present a comprehensive review of portosystemic shunts and to illustrate such phenomenon demonstrated on radiologic studies such as Doppler ultrasound, computed tomography, and portogram. It is important for radiologists to be aware of such phenomenon not only in preoperative evaluation of the recipients but also in postoperative screening to detect recurrence of the phenomenon.

Portal flow steal after liver transplantation

Portal flow steal occasionally persists even after the liver transplantation, which may reduce the portal flow and thus threaten the patients' outcome. Therefore, pre- and peri-operative detection of portal steal phenomenon requiring radiological or surgical interruption is essential for the liver transplantation candidates as well as for the recipients.

Effective balloon-occluded retrograde transvenous obliteration of the superior mesenteric vein-inferior vena cava shunt in a patient with hepatic encephalopathy after living donor liver transplantation

Balloon-occluded retrograde transvenous obliteration (BRTO) has become a common and effective procedure for treating hepatic encephalopathy due to a portosystemic shunt related to cirrhosis of the liver. However, this method of treatment has rarely been reported in patients after liver transplantation. Here, we report the case of a 52-year-old patient who underwent living donor liver transplantation (LDLT) due to hepatitis C virus-infected hepatocellular carcinoma that was complicated with portal vein thrombosis and a large portosystemic shunt between the superior mesenteric vein (SMV) and inferior vena cava (IVC). The SMV-IVC shunt was not obliterated during LDLT because there was sufficient portal flow into the graft after reperfusion. However, the patient was postoperatively complicated with encephalopathy due to the portosystemic shunt. BRTO was performed and was demonstrated to have effectively managed the encephalopathy due to the SMV-IVC shunt, while preserving the hepatic function after LDLT.

Management of late-onset portal vein complications in pediatric living-donor liver transplantation

The purpose of this study was to evaluate retrospectively the results of PTA for late-onset PV complications after pediatric LDLT and to assess whether a meso-Rex shunt is a viable option for treating restenosis of the PV after PTA in selected cases. Seventy-five children who underwent adult-to-child LDLT were included in this study, and there were six late-onset PV complications (8.0%). The initial therapeutic approach was PTA, with or without stent: PTA with balloon dilation for three children, PTA with stent placement for one child, and failure to cannulate the occluded PV for two children. A meso-Rex shunt was performed in the two children after failed PTA: One suffered complete obstruction of the main PV, and the other, restenosis with total thrombosis after PTA with stent. The PTA was a technical and clinical success in four with PV stenosis of the six patients (66.7%), and successful application of a meso-Rex shunt in the other two children resulted in restoration of PV flow. In conclusion, PTA is a safe and effective procedure for treating late-onset PV stenosis after pediatric LDLT. However, in growing pediatric recipients with restenosis of the PV after PTA or chronic PV thrombosis, a meso-Rex shunt may be a better choice for late-onset PV complications.

Portal vein complications after pediatric liver transplantation

Relatively few pediatric donors are available in relation to the number of children waiting for a liver transplant. This limited number of pediatric donor livers leads to the use of adult livers, usually requiring more complex portal vein (PV) anastomoses. These anastomoses are complicated by differences in PV caliber between donors and recipients, as well as by limitations of PV length, which may be inadequate to reach the recipient spleno-mesenteric junction. Three types of post-transplant complications result from these complexities: 1) anomalies of the portal flow; 2) stenosis of the PV anastomosis; and 3) PV thrombosis. Abnormal portal flow may rarely need a specific intervention, but persistent stenosis or appearance of signs of portal hypertension need to be corrected. Balloon dilatation and placement of a stent are usually successful to repair stenosis. Portal vein thromboses are in general diagnosed in the immediate post-operative period and frequently lead to re-transplantation; however, thrombolytic therapy should be attempted in children without major signs of liver necrosis. When intra-hepatic portal vein(s) are permeable, despite extrahepatic PV thrombosis, a Meso-Rex shunt may be the indicated therapy.

Balloon-occluded retrograde transvenous obliteration for a portosystemic shunt after pediatric living-donor liver transplantation

Portosystemic shunts may cause steal phenomenon after liver transplantation, which can lead to graft loss without proper management. Portal vein stenosis is one of the causes for the occurrence of portosystemic shunts after liver transplantation. Recently, new interventional radiologic techniques have been developed in the field of liver transplantation. Balloon-occluded retrograde transvenous obliteration (B-RTO) is a novel interventional technique for gastric varices and portosystemic shunts and also is effective for increasing portal vein flow. We herein report a pediatric case of portal vein stenosis with a large shunt successfully treated with a combination of balloon dilatation and B-RTO. If enlarged collateral vessels cause steal phenomenon, then B-RTO should be considered as an additional therapy.

Living donor liver transplantation

PURPOSE OF REVIEW

The widening gap between the growing number of liver transplant candidates and the supply of deceased donor organs became a strong motivation for the development of living donor liver transplantation (LDLT). LDLT has gone through its developmental phase and become an established life-saving procedure.

RECENT FINDINGS

Despite the challenging nature of the technique of LDLT, there have been continuous innovations. A better understanding of complex surgical anatomy and physiologic differences of partial hepatic allografts has helped to avoid graft congestion, small-for-size syndrome, or graft hypoperfusion from portal flow steal. LDLT for patients with high Model for End-Stage Liver Disease score can achieve comparable results with deceased donor liver transplantation (DDLT). Size limitation of partial grafts can be overcome with dual grafts. The extended application of LDLT for hepatocellular carcinoma beyond Milan criteria seems feasible but at the cost of slightly compromised survival. More information has become available for prospective donors about the consequences of living liver donation in terms of psychosocial impact.

SUMMARY

Although LDLT is still evolving, it has become the most effective alternative to DDLT. Proven or potential benefit of LDLT include the superior quality of the allograft despite the smaller size, selection of proper timing for transplantation and a reduced waiting time, which prevents waiting list mortality.