Outcomes of Percutaneous Portal Vein Intervention in a Single UK Paediatric Liver Transplantation Programme

Portal vein reconstruction in pediatric liver transplantation using end-to-side jump graft: A case report

Attenuated portal vein (PV) flow is challenging in pediatric liver transplantation (LT) because it is unsuitable for classic end-to-end jump graft reconstruction from a small superior mesenteric vein (SMV). We thus introduce a novel technique of an end-to-side jump graft from SMV during pediatric LT using an adult partial liver graft. We successfully performed two cases of end-to-side retropancreatic jump graft using an iliac vein graft for PV reconstruction. One patient was a 2-year-old boy with hepatoblastoma and a Yerdel grade 3 PV thrombosis who underwent split LT. Another patient was an 8-month-old girl who had biliary atresia and PV hypoplasia with stenosis on the confluence level of the SMV; she underwent retransplantation because of graft failure related to PV thrombosis. After native PV was resected at the SMV confluence level, an end-to-side reconstruction was done from the proximal SMV to an interposition iliac vein. The interposition vein graft through posterior to the pancreas was obliquely anastomosed to the graft PV. There was no PV related complication during the follow-up period. Using a jump vascular graft in an end-to-side manner to connect the small native SMV and the large graft PV is a feasible treatment option in pediatric recipients with inadequate portal flow due to thrombosis or hypoplasia of the PV.

Balloon angioplasty versus stent placement for the treatment of portal vein stenosis in children: a single center experience

PURPOSE

To evaluate the safety and efficacy of percutaneous interventional treatment of portal vein stenosis in children.

MATERIAL AND METHODS

A retrospective analysis of all interventional treatments for portal vein stenosis in pediatric patients at a single institution from 2010 to 2021 was conducted. Platelet count, spleen size and portal vein flow velocity were assessed during the follow-up period. Primary and primary assisted patency time were determined.

RESULTS

A total of ten children (median age 28.5 months, interquartile range (IQR): 2.75-52.5 months) with portal vein stenosis after Mesorex-Shunt (n = 4), liver transplantation (n = 3) and other etiologies (n = 3) underwent 15 interventional procedures. There were five reinterventions and one discontinued intervention. The technical success rate was 93.3% (14/15) and clinical success of treated patients was 100% (14/14). Median follow-up was 18 months (IQR: 13.5-81 months). The median primary patency time for stent placement was 70 months (IQR: 13.5-127.25 months). For balloon angioplasty, the median primary patency time was 9 months (IQR 7.25-11.5 months), while the median assisted primary patency time was 14 months (IQR: 12 to 15 months). Platelet count, spleen size and portal vein flow velocity reliably corresponded to recurrence of portal vein stenosis in asymptomatic patients during follow-up.

CONCLUSION

Interventional treatment is a safe and efficient method to treat portal vein stenosis with long patency times, regardless of etiology. Primary stent placement shows a higher primary patency time than balloon angioplasty. Implementation of stent placement as the primary interventional method may improve patency times and reduce the need for repeat reinterventions in pediatric patients.

Prevalence, management and efficacy of treatment in portal vein obstruction after paediatric liver transplantation: protocol of the retrospective international multicentre PORTAL registry

INTRODUCTION

Portal vein obstruction (PVO) consists of anastomotic stenosis and thrombosis, which occurs due to a progression of the former. The aim of this large-scale international study is to assess the prevalence, current management practices and efficacy of treatment in patients with PVO.

METHODS AND ANALYSIS

The Portal vein Obstruction Revascularisation Therapy After Liver transplantation registry will facilitate an international, retrospective, multicentre, observational study, with 25 centres around the world already actively involved. Paediatric patients (aged <18 years) with a diagnosed PVO between 1 January 2001 and 1 January 2021 after liver transplantation will be eligible for inclusion. The primary endpoints are the prevalence of PVO, primary and secondary patency after PVO intervention and current management practices. Secondary endpoints are patient and graft survival, severe complications of PVO and technical success of revascularisation techniques.

ETHICS AND DISSEMINATION

Medical Ethics Review Board of the University Medical Center Groningen has approved the study (METc 2021/072). The results of this study will be disseminated via peer-reviewed publications and scientific presentations at national and international conferences.

TRIAL REGISTRATION NUMBER

Netherlands Trial Register (NL9261).

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.

Long-term outcome of primary percutaneous stent angioplasty for pediatric posttransplantation portal vein stenosis

This study aims to evaluate the long-term efficacy and reintervention rate after primary percutaneous portal vein stent angioplasty for portal vein stenosis (PVS) in pediatric liver transplantation (LT) recipients. From 2004 to 2020, a total of 470 pediatric LTs were performed in our center. All cases were screened for interventional PVS treatment and analyzed retrospectively. We identified 44 patients with 46 percutaneous angioplasties for posttransplantation PVS. The median interval from LT to percutaneous catheter intervention was 5 months (16 days-104 months) with a median follow-up (f/u) period after catheter intervention of 5.7 years (2-156 months). In 40 patients, an endovascular stent was placed as primary (n = 38) or secondary (n = 2) intervention. The median age at stent placement was 23 (6-179) months with a median weight of 10 kg (6-46 kg). Technical success and relief of PVS were achieved in all patients irrespective of age or weight. Adverse events occurred peri-interventionally in two patients and were resolved with standard care. All primary portal vein (PV) stents remained patent until the end of f/u. Reinterventions have been successfully performed in 10 patients for suspected or proven restenosis, resulting in a primary patency rate of 75% and an assisted patency rate of 25%. The median time to reintervention was 6.2 years (range 1-10 years). The need for reintervention was independent of age or weight at both transplantation and initial angioplasty as well as of additional risk factors due to portal hypertension. Percutaneous transhepatic PV stent angioplasty in children is safe and effective in all age groups, with excellent long-term patency. Primary stent angioplasty should be considered as first-line treatment for PVS after pediatric LT.

Predictors of portal vein complications after pediatric liver transplantation: A German center experience

BACKGROUND

Portal vein complications (PVCs) after pediatric liver transplantation (LT) are sometimes asymptomatic, especially in the early phase, and can threaten both the graft and patient's survival. Therefore, the purpose of this study is to analyze the risk factors for portal vein thrombosis (PVT) and portal vein stenosis (PVS) after pediatric LT.

METHODS

All pediatric patients (n = 115) who underwent primary LT at Regensburg University Hospital between January 2010 and April 2017 were included in this study. The pre-, intra-, and postoperative parameters of all patients were retrospectively reviewed and risk factors for both PVT and PVS were analyzed.

RESULTS

Of the 115 patients, living donor LT was performed on 57 (49.5%) patients, and biliary atresia was the primary diagnosis in 65 patients (56%). After pediatric LT, 9% of patients developed PVT, and 16.5% developed PVS. Patient weight ≤7 kg [odds ratio (OR) 9.35, 95% confidence interval (CI) 1.03-84.9, p = .04] and GRWR >3% (OR 15.4, 95% CI 1.98-129.5, p = .01) were the independent risk factors for the development of PVT and PVS, respectively upon multivariate analysis. The overall patient survival rates at 1, 3, and 5 years were 91%, 90%, and 89%, respectively, and there was no difference in patient survival among those with and without PVCs.

CONCLUSIONS

Pediatric patients with body weight <7 kg and/or receiving a graft with GRWR >3% may develop PVCs and so require certain surgical modifications, close follow-up, and prophylactic anticoagulant therapy following transplant.

Percutaneous transhepatic interventional therapy of portal vein stenosis in paediatric liver transplantation: A systematic review of efficacy and safety

PURPOSE OF THE SYSTEMATIC REVIEW

To determine the efficacy and safety of percutaneous trans-hepatic balloon and/or stent angioplasty (PTA) in the management of portal vein (PV) stenosis following paediatric liver transplantation.

METHODS

Articles were included from a systematic search of Medline, Embase, Cochrane CENTRAL, ClinicalTrials.gov and International Clinical Trials Registry from inception to the 29th of August 2020.

RESULTS

There were 213 paediatric liver recipients who underwent PTA for PV stenosis in 19 included studies published between 1991 and 2019. Balloon angioplasty was the initial treatment in the majority (n = 153). Primary stent placement (n = 34) was performed for elastic recoil, intimal tears and PV kinks and rescue stent placement (n = 14) for recurrent PV stenosis following primary balloon angioplasty. The technical success was 97.6%-100% overall, 97.6%-100% for balloon-angioplasty-only and 100% for primary stenting. The clinical success was 50%-100% overall, 50%-100% for balloon-angioplasty-only and 100% for primary stenting. Long-term PV patency was 50%-100% overall, 37.5%-100% for balloon-angioplasty-only and 100% for primary stenting. Primary balloon angioplasty was successful in 78% of the cases. Of the recurrent PV stenoses, 9% resolved with stent placement and one required a meso-Rex shunt. There was one re-transplantation without stenting. The complication rate was 2.6% for balloon-angioplasty-only (bleeding, liver abscess, 2 PV thromboses) and 5.9% for primary stenting (bleeding, stent-fracture). There was no procedure-related mortality.

CONCLUSION

Percutaneous transhepatic balloon angioplasty may be the initial management of portal vein stenosis in paediatric liver recipients. Stent placement may be a primary option in selected cases and a reliable rescue option for recurrent portal vein stenosis following balloon-angioplasty-only.

Portal Vein Complications After Adult Living Donor Liver Transplantation: Time of Onset and Deformity Patterns Affect Long-Term Outcomes

Portal vein complications (PVCs) after adult living donor liver transplantation (LDLT) are potentially lethal. We categorized PVCs by the time of onset (early versus late, <1 month versus ≥1 month, respectively) and deformity patterns (portal vein stenosis [PVS], portal vein thrombosis [PVT], and portal vein occlusion [PVO]) to establish optimal treatment strategies. Overall, 35/322 (10.9%) recipients developed PVCs between 2000 and 2019. Pretransplant PVT (odds ratio [OR], 15.20; 95% confidence interval [CI], 3.70-62.40; P < 0.001) was the only independent risk factor for PVS. In contrast, male sex (OR, 5.57; 95% CI, 1.71-18.20; P = 0.004), pretransplant PVT (OR, 4.79; 95% CI, 1.64-14.00; P = 0.004), and splenectomy (OR, 3.24; 95% CI, 1.23-8.57; P = 0.018) were independent risk factors for PVT. PVS was successfully treated with interventional radiology regardless of its time of onset. On the other hand, late PVT and PVO had significantly lower treatment success rates (2/15, 13%) compared with those that occurred in the early period (10/11, 91%) despite aggressive intervention (P < 0.001). Deformity patterns had a significant impact on the 5-year cumulative incidence of graft loss as a result of PVC (PVO + Yerdel grades 2-4 PVT group [n = 16], 41% versus PVS + Yerdel grade 1 PVT group [n = 19], 0%; P = 0.02). In conclusion, late grades 2 to 4 PVT and PVO are refractory to treatment and associated with poor prognoses, whereas PVS has a good prognosis regardless of time of onset. A tailored approach according to the time of onset and deformity patterns of PVC is essential.

Portal vein obstruction after pediatric liver transplantation: A systematic review of current treatment strategies

INTRODUCTION

Portal vein obstruction (PVO) is a significant vascular complication after liver transplantation (LT) in pediatric patients. Current treatment strategies include percutaneous transluminal angioplasty (PTA), with or without stent placement, mesorex bypass (MRB), splenorenal shunt, mesocaval shunt, endovascular recanalization (EVR), splenic artery embolization and splenectomy. However, specific characteristics of patients undergoing intervention and selection of individual treatment and its efficacy have remained unclear. This review systematically analyzed biochemical and clinical characteristics, selection of treatment, efficacy, and post-procedural complications.

METHODS

We systematically searched PubMed and Embase between January 1995 and March 2021 for studies on the management of PVO after LT. We analyzed the reports for biochemical and clinical characteristics at the timing of the intervention in different patients, selection of treatment, and reported efficacies.

RESULTS

We found 22 cohort studies with 362 patients who had the following characteristics: biliary atresia (83%), living-donor LT (85%), thrombocytopenia (73%), splenomegaly (40%), ascites (16%), or gastrointestinal bleeding (26%). The 3-year primary patency of PTA without stent placement was similar to that with stent placement (70%-80% and 43%-94%, respectively). MRB was used as an initial treatment with a 3-year patency of 75% to 100%. One study showed that 5-year primary patency of EVR was 80%. Secondary patency was 90% to 100% after 3 years in all studies with PTA alone, PTA/stent placement, and stent placement alone.

CONCLUSION

This is the first review of all treatment protocols in PVO after pediatric LT. We showed that an important group of patients has severe symptoms of portal hypertension. Efficacy of all treatment modalities was high in the included studies which make them important modalities for 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.

Safety and Efficacy of Endovascular Treatment of Portal Vein Stenosis in Liver Transplant Recipients: A Systematic Review

PURPOSE

To evaluate the efficacy of Angioplasty and Stent Placement for the treatment of Portal Vein Stenosis in Liver Transplant Recipients by performing a systematic review.

MATERIALS AND METHODS

The PubMed Database was extensively searched for articles describing Portal Vein Stenosis (PVS) as a complication in Liver Transplant (LT) patients. The initial database search yielded 488 unique records published in the PubMed Database, 19 of which were deemed to meet the inclusion criteria. Outcomes were separated into 2 groups (Group A included patients with primary angioplasty, Group B included patients with primary stent placement), and further subdivided into Adult and Pediatric populations.

RESULTS

Group A included a total of 282 LT patients with portal vein stenosis. The population was predominantly pediatric (n = 243). Group B included a total of 111 LT patients with portal vein stenosis. This population was predominantly adult (n = 66). Technical success was significantly higher in both Group B pediatric (100%) and adults (97%) compared to Group A (69.5%) and (66.7%) respectively. Re-stenosis rates were significantly lower in Group B pediatric group compared to Group A (2.3% vs 29.7%, χ² = 13.9; p < 0.001). Overall major (3.1%) and minor complications rates (1.5%) were low.

CONCLUSION

Primary stent placement appears to have higher technical success in both populations and lower re-stenosis rates for treatment of PVS in pediatric populations.

Portal vein stent placement after hepatobiliary and pancreatic surgery

Purpose

To evaluate the long-term outcomes of percutaneous transhepatic stent placement for portal vein (PV) stenosis after liver transplantation (LT) and hepato-pancreato-biliary (HPB) surgery.

Methods

Retrospective study of 455 patients who underwent LT and 522 patients who underwent resection of the pancreatic head between June 2011 and February 2016. Technical success, clinical success, patency, and complications were evaluated for both groups.

Results

A total of 23 patients were confirmed to have postoperative PV stenosis and were treated with percutaneous transhepatic PV stent placement. The technical success rate was 100%, the clinical success rate was 80%, and the long-term stent patency was 91.3% for the entire study population. Two procedure-related hemorrhages and two early stent thromboses occurred in the HPB group while no complications occurred in the LT group. A literature review of selected studies reporting PV stent placement for the treatment of PV stenosis after HPB surgery and LT showed a technical success rate of 78–100%, a clinical success rate of 72–100%, and a long-term patency of 57–100%, whereas the procedure-related complication rate varied from 0–33.3%.

Conclusions

Percutaneous transhepatic PV stent is a safe and effective treatment for postoperative PV stenosis/occlusion in patients undergoing LT regardless of symptoms. Due to increased risk of complications, the indication for percutaneous PV stent placement after HPB surgery should be limited to patients with clinical symptoms after an individual assessment.

The devil is in the detail: current management of perioperative surgical complications after liver transplantation

PURPOSE OF REVIEW

Despite advances in the field, perioperative morbidity is common after liver transplantation. This review examines the current literature to provide up-to-date management of common surgical complications associated with liver transplantation.

RECENT FINDINGS

Research focuses on problems with anastomoses of the vena cava, portal vein, hepatic artery, and bile ducts. Interventional endoscopic and radiological techniques are used more frequently to avoid reoperation.

SUMMARY

Advances in the management of perioperative surgical complications have focused on minimally invasive measures that successfully treat technical problems with implantation of liver allografts from both living and deceased donors.

Perioperative thrombotic complications associated with pediatric liver transplantation: a UNOS database evaluation

BACKGROUND

This retrospective UNOS database evaluation analyzes the prevalence of preoperative portal vein thromboses (PVT), and postoperative thromboses leading to graft failure in pediatric patients undergoing liver transplantation (LT).

METHODS

The evaluation was performed in three age groups: I (0-5), II (6-11), III (12-18) years old. Factors predictive of pre- and postoperative thromboses were analyzed.

RESULTS

Between 2000 and 2015, 8982 pediatric LT were performed in the US. Of those, 390 patients had preoperative PVT (4.3%), and 396 (4.4%) had postoperative thromboses. The prevalence of both types of thromboses was less in Group III than in the other two groups (3.20% vs 4.65%, p = 0.007 and 1.73% vs. 5.13%, p < 0.001, respectively). The prevalence of postoperative thromboses was significantly higher in Group I than in the other two groups (5.49% vs. 2.51%, p < 0.001). Preoperative PVT was independently associated with postoperative thromboses (OR = 1.7, p = 0.02). Children less than 5 years of age were more likely to develop postoperative thromboses leading to graft failure (OR = 2.9, p < 0.001).

CONCLUSION

Younger children undergoing LT are prone to pre-and postoperative thrombotic complications. Preoperative PVT at the time of transplantation was independently associated with postoperative thromboses. Perioperative antithrombotic therapy should be considered in pediatric patients undergoing LT.

Recanalization of Chronic Portal Vein Occlusion in Pediatric Liver Transplant Patients

PURPOSE

To evaluate technical and clinical success and report long-term outcomes of portal vein (PV) recanalization in pediatric orthotopic liver transplant (OLT) patients with chronic PV occlusion.

MATERIALS AND METHODS

This is a retrospective review of 15 OLT patients (5 males) with chronic PV occlusion who underwent PV recanalization (33 procedures) between October 2011 and February 2018. Median age was 4.5 years (range, 1-16 years); median weight was 16.6 kg (range, 11.5-57.3 kg). Median time interval from OLT to first intervention was 3.25 years (range, 0.6-15.7 years). Clinical presentations included hypersplenism (n = 12), gastrointestinal bleeding (n = 9), and ascites (n = 3). One patient had incidental diagnosis of PV occlusion. Primary, primary-assisted, and secondary patency at 3, 6, 12, and 24 months were evaluated.

RESULTS

Technically successful PV recanalization and reduction of PV pressure gradient to ≤ 5 mm Hg was performed in 13/15 patients (87%). Ten of 15 (67%) patients had successful recanalization with the first attempt. Clinical success, defined as improvement in signs and symptoms of portal hypertension, was achieved in 12/13 (92%) patients. Five of 33 (15%) major complications (Society of Interventional Radiology class C), including perisplenic hematoma (n = 2), hemoperitoneum (n = 2), and hepatic artery pseudo aneurysm (n = 1), were managed with pain medication and blood product replacement. Median follow-up was 22 months (range, 1-77 months). Median primary patency was 5 months. Primary patency at 3, 6, 12, and 24 months was 53.8%, 46.2%, 38.5%, and 30.8%, respectively. Primary-assisted patency was 84.6%, 76.9%, 53.8%, and 46.2%, respectively. Secondary patency was 92.3%, 84.6%, 53.8%, and 46.2%, respectively.

CONCLUSIONS

PV recanalization is a safe and effective minimally invasive option in the management of chronic PV occlusion after pediatric OLT.