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

Ectopic Variceal Bleeding from the Hepaticojejunostomy due to Extrahepatic Portal Vein Occlusion: How to Treat?

Atypical variceal bleeding, which primarily stems from extrahepatic portal vein obstruction (EHPVO), is a severe complication of pancreatic hepatobiliary surgery. This review provides insights into this condition's incidence, diagnosis, and management strategies. The treatment modalities for atypical variceal bleeding resulting from EHPVO range from endoscopic intervention to surgical procedures, including direct variceal ligation and shunt surgery. Here, we discuss the efficacy and potential limitations of each treatment approach. Additionally, we explored the utility and therapeutic advantages of the meso-Rex shunt, a particularly promising surgical technique for mitigating the hemodynamic and metabolic impacts of EHPVO.

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.

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.

Technical Aspects and Considerations of Meso-Rex Bypass Following Liver Transplantation With Left Lateral Segment Grafts: Case Report and Review of the Literature

In pediatric patients with extrahepatic portal vein obstruction and complications of portal hypertension, but with normal liver function, a meso-Rex bypass (MRB) connecting the superior mesenteric vein to the intrahepatic left portal is the favored surgical management. Pediatric patients with a history of a partial liver transplant (LT), especially living donors, are at greater risk for portal vein complications. Hence, an adequate knowledge of this technique and its additional challenges in the post-LT patient setting is crucial. We provide an overview of the available literature on technical aspects for an MRB post-LT. Preoperative considerations are highlighted, along with intraoperative considerations and postoperative management. Special attention is given to the even-more-demanding aspect of performing an MRB post-liver transplantation with a left lateral segment. Surgical alternatives are also discussed. In addition, we report here a unique case in which this surgical technique was performed on a complex pediatric patient with a history of a living-donor LT with a left lateral segment graft over a decade ago.

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.

Pediatric split liver transplantation for congenital factor X deficiency: first 10-year follow-up of a case with portal vein stenting

Congenital factor X (FX) deficiency is a rare autosomal-recessive disease that induces bleeding disorder. Herein, we present the 10-year posttransplant course of a pediatric patient who underwent liver transplantation (LT) with portal vein (PV) stenting for correction of severe congenital FX deficiency, with focus on long-term maintenance of coagulation function and patency of PV stenting. A 17-month-old infant with recurrent hemorrhagic episodes due to FX deficiency underwent split LT using a left lateral section graft. The graft-recipient weight ratio was 2.2%. The graft implantation procedures were performed by following the standard pediatric split LT procedure. Nevertheless, a wall stent was inserted due to PV anastomotic stenosis on posttransplant day 1. Graft function recovered slowly because of partial parenchyma infarct, and the patient was discharged at 46 days after LT operation. The FX activity started to increase soon after LT and gradually normalized; the coagulation profiles have been maintained well for the past 10 years. The patient has been doing well for the past 10 years after LT without any episodes of abnormal bleeding. Due to the risk of vascular complications owed to PV stenting, life-long follow-up is mandatory with special attention until attainment of complete physical growth to adolescent and adulthood.

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.

Dextroplantation of Left Liver Graft in Infants

The position of the left side liver graft is important, and it could lead to complications of the hepatic vein (HV) and portal vein (PV), especially in a small child using a variant left lateral section (vLLS) graft. The purpose of this study was to evaluate the outcome of a novel technique for the implantation of a vLLS graft to the right side (dextroplantation) in infants. For 3 years, 10 consecutive infants underwent dextroplantation using a vLLS graft (group D). The graft was implanted to the right side of the recipient after 90° counterclockwise rotation; the left HV graft was anastomosed to inferior vena cava using the extended right and middle HV stump, and PV was reconstructed using oblique anastomosis without angulation. Surgical outcomes were compared with the historical control group (n = 17, group C) who underwent conventional liver transplantation using a vLLS during infancy. Group D recipients were smaller than group C (body weight <6 kg: 50.0% versus 11.8%; P = 0.03). The rate of graft-to-recipient weight ratio >4% was higher in group D (60.0%) than C (11.8%; P = 0.01). Surgical drains were removed earlier in group D than in group C (15 versus 18 postoperative days [PODs]; P = 0.048). Each group had 1 PV complication (10.0% versus 5.9%); no HV complication occurred in group D, but 3 HV complications (17.6%) occurred in group C (P > 0.05). Hospital stay was shorter in group D than in group C (20 versus 31 PODs; P = 0.02). Dextroplantation of a vLLS graft, even a large-for-size one, was successful in small infants without compromising venous outcomes, compared with conventional vLLS transplantation. We could remove the surgical drains earlier and reduce hospital stays in cases of dextroplantation.

Unusual venous collateral pathways allow for reperfusion of the intrahepatic portal venous system in children with portal vein thrombosis after split liver transplantation: Clinical relevance and management implications

PVT is the most frequent vascular complication after LT in small children, and a higher incidence has been observed in those transplanted for biliary atresia or with a LLSG. Thrombosis of the PV causes extrahepatic portal hypertension and is associated with splenomegaly and the development of venous neo-collaterals, including gastro-oesophageal varices and splenorenal shunts. It has also been incidentally suggested in the literature that patients who have had a Roux-en-Y loop for a biliary reconstruction may present with a cavernomatous transformation of the distal portion of the loop. In this study, 13 children with CEPH caused by thrombosis of the PV after LT were analysed. The study evidenced the development of two types of hepatopetal venous networks: (a) a large cavernoma along the Roux loop and around the biliary anastomosis, and (b) a network of neo-collaterals in the gastro-duodeno-pancreatic area that connected to the intrahepatic portal branches directly through the liver capsule. These hepatopetal venous networks between the venous system of the surrounding organs or the omentum and the intrahepatic portal branches can be identified by radiologists. The relevance for the transplanting physician and the transplant surgeon is discussed.

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.

Long-term outcomes of transmesenteric portal vein recanalization for the treatment of chronic portal vein thrombosis after pediatric liver transplantation

Portal vein thrombosis (PVT) may occur at any time following liver transplantation. We describe our experience with portal vein recanalization in cases of thrombosis after liver transplantation. Twenty-eight children (5%) out of 566 liver transplant recipients underwent portal vein recanalization using a transmesenteric approach. All children received left hepatic segments, developed PVT, and had symptoms or signs of portal hypertension. Portal vein recanalization was performed via the transmesenteric route in all cases. Twenty-two (78.6%) patients underwent successful recanalization and stent placement. They received oral anticoagulants after the procedure, and clinical symptoms subsided. Symptoms recurred due to portal vein restenosis/thrombosis in seven patients. On an intention-to-treat basis, the success rate of the proposed treatment was 60.7%. Only 17 out of 28 children with posttransplant chronic PVT retained stent patency (primary + assisted) at the end of the study period. In cases of portal vein obstruction, the transmesenteric approach via minilaparotomy is technically feasible with good clinical and hemodynamic results. It is an alternative procedure to reestablish the portal flow to the liver graft that can be performed in selected cases and a therapeutic addition to other treatment strategies currently used to treat chronic PVT.

Enlarging vascular stents after pediatric liver transplantation

BACKGROUND

Endovascular intervention with stent placement to treat portal vein (PV) and hepatic vein (HV) stenosis after pediatric liver transplantation (LT) is still controversial in small children owing to the potential risk of functional stenosis after growth. The aim of this study is to evaluate the safety and efficacy of stent placement in this population.

METHODS

Between 2004 and 2016, 6 children (all <3 years) received HV (n = 2) and PV (n = 4) stents placement among 46 pediatric LT patients at our institution. The clinical outcome and patency rate were followed. Morphologic changes of stents were assessed from plain films by a new index: the stent diameter ratio (SDR).

RESULTS

The median age of the patients at LT was 8.9 months. The patency rate was 100% without functional stenosis during a median follow-up period of 65.5 months. The "stent growth" phenomenon was demonstrated by SDR with significant resolution of hourglass deformity 2 years after stent placement (p for trend <.001).

CONCLUSION

Vascular stent placement is a safe and effective method for the management of PV and HV stenosis following pediatric LT because these stents will enlarge as children grow.

TYPE OF STUDY

Case Series with no Comparison Group LEVEL OF EVIDENCE: Level IV.

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

Introduction

Percutaneous transluminal angioplasty (PTA), with or without stent placement, has become the treatment of choice for portal vein complications (PVC) following liver transplantation. We aimed to assess long-term outcomes of intervention in paediatric transplant recipients, in a single institution.

Materials and Methods

227 children received 255 transplants between November 2000 and September 2016. 30 patients developed PVC of whom 21 had percutaneous intervention. Retrospective clinical and procedural outcome data on these 21 patients were collected.

Results

21 patients, with median age 1.7 years (range 0.4–16.2), underwent 42 procedures with PTA with or without stenting. 36 procedures were for PV stenosis and 6 for PV thrombosis. Treatment was with primary PTA, with stenting reserved for suboptimal PTA result or restenosis within 3 months. 28 procedures were performed with PTA and 13 with stenting. Technical success (>50% reduction in mean pressure gradient, absolute pressure gradient ≤4 mmHg or venographic stenosis <30%) was achieved in 41 procedures. Failure to recanalise a thrombosed PV occurred in 1 procedure. There were no major procedural complications. Patients were followed-up with serial Doppler ultrasound surveillance. Kaplan–Meier estimated median primary patency was 9.9 months, with primary-assisted patency of 95% after median follow-up of 45.5 months (range 11.1–171.6).

Conclusion

With regular surveillance, excellent patency rates can be achieved following percutaneous intervention for PVC post-paediatric liver transplantation.

Safety and efficacy of transhepatic and transsplenic access for endovascular management of portal vein complications after liver transplantation

The purpose of this article is to evaluate and compare the safety and efficacy of endovascular management of the portal vein (PV) via percutaneous transsplenic access versus percutaneous transhepatic access in liver transplantation (LT) recipients. A total of 18 patients who underwent endovascular management of PV via percutaneous transhepatic (n = 8) and transsplenic (n = 10) access were enrolled. Transsplenic access was chosen if the spleen was located in a normal position, the splenic vein (SpV) was preserved, and the target lesion did not involve confluence of the superior mesenteric and SpVs. Accessibility of the percutaneous transsplenic puncture was confirmed via ultrasound (US) in the angiography suite. All procedures were performed under local anesthesia. Percutaneous transhepatic or transsplenic access was performed using a 21-gauge Chiba needle under US and fluoroscopic guidance, followed by balloon angioplasty, stent placement, or variceal embolization. The access tract was embolized using coils and a mixture (1:2) of glue and ethiodized oil. Transhepatic or transsplenic access was successfully achieved in all patients. A total of 12 patients underwent stent placement; 3 had balloon angioplasty only; 2 had variceal embolization only; and 1 had variceal embolization followed by successful stent placement. Regarding major complications, 1 patient experienced a SpV tear with extravasation during transsplenic balloon angioplasty, which was successfully managed using temporary balloon inflation, followed by transfusion. Clinical success was achieved in 9 of 11 (82%) patients who exhibited clinical manifestations. The remaining 7 patients who underwent prophylactic endovascular management were healthy. In conclusion, endovascular management of PV via percutaneous transsplenic access is a relatively safe and effective alternative that does not damage the liver grafts of LT recipients. Liver Transplantation 23 1133-1142 2017 AASLD.

Trans-splenic Access for Portal Venous Interventions in Children: Do Benefits Outweigh Risks?

BACKGROUND

The primary concern of trans-splenic access for portal interventions is the risk of life-threatening intraperitoneal bleeding.

OBJECTIVE

To review the clinical indications and efficacy and evaluate the risk factors for intraperitoneal bleeding during trans-splenic portal interventions in children.

MATERIALS AND METHODS

A retrospective review of consecutive patients who underwent trans-splenic portal interventions at a tertiary care pediatric institution between March 2011 and April 2017 was performed. Forty-four procedures were performed in 30 children with a median age of 5 (0.3-18) years. Clinical indications, technical success, procedural success, and incidence of complications were recorded. Potential risk factors for intraperitoneal bleeding were evaluated using Wilcoxon rank and Fisher's exact tests.

RESULTS

Trans-splenic access was 100% successful. In 35/44 (79%) procedures, the subsequent intervention was successful including recanalization of post-transplant portal vein occlusion in 10/13, embolization of bleeding Roux limb varices in 8/8, recanalization of chronic portal vein thrombosis in native liver in 7/13, splenoportography and manometry in 6/6, and occlusion of portosystemic shunts in 4/4 procedures. Intraperitoneal bleeding occurred during 12/44 (27%) procedures and was managed with analgesics, blood transfusion, and peritoneal drainage without the need for splenectomy or splenic artery embolization. Statistically significant correlation of bleeding was found with intraprocedural anticoagulation, but not with patient age, weight, platelet count, INR, ascites, splenic length, splenic venous pressure, vascular sheath size, or tract embolization technique.

CONCLUSION

Trans-splenic access is a useful technique for successful pediatric portal interventions. Although it entails a substantial risk of intraperitoneal bleeding, this can be managed conservatively.

Jejunal varices diagnosed by capsule endoscopy in patients with post-liver transplant portal hypertension

Portal hypertension secondary to portal vein obstruction following liver transplant occurs in 5%-10% of children. Jejunal varices are uncommon in this group. We present a case series of children with significant GI blood loss, negative upper endoscopy, and jejunal varices detected by CE. Case series of patients who had CE for chronic GI blood loss following liver transplantation. Three patients who had their initial transplants at a median age of 7 months were identified at our institution presenting at a median age of 8 years (range 7-16 years) with a median Hgb of 2.8 g/dL (range 1.8-6.8 g/dL). Upper endoscopy was negative for significant esophageal varices, gastric varices, and bleeding portal gastropathy in all three children. All three patients had significant jejunal varices noted on CE in mid-jejunum. Jejunal varices were described as large prominent bluish vessels underneath visualized mucosa, one with evidence of recent bleeding. The results led to venoplasty of the portal vein in two patients and a decompressive shunt in one patient with resolution of GI bleed and anemia. CE is useful to diagnose intestinal varices in children with portal hypertension and GI bleeding following liver transplant.

Living Donor Liver Transplantation in Children: Surgical and Immunological Results in 250 Recipients at Université Catholique de Louvain

OBJECTIVES

To evaluate the outcome of pediatric living donor liver transplantation (LDLT) regarding portal vein (PV) reconstruction, ABO compatibility, and impact of maternal donation on graft acceptance.

BACKGROUND

LDLT and ABO-mismatched transplantation constitute feasible options to alleviate organ shortage in children. Vascular complications of portal hypoplasia in biliary atresia (BA) and acute rejection (AR) are still major concerns in this field.

METHODS

Data from 250 pediatric LDLT recipients, performed at Cliniques Universitaires Saint-Luc between July 1993 and June 2012, were collected retrospectively. Results were analyzed according to ABO matching and PV complications. Uni- and multivariate analyses were performed to study the impact of immunosuppression, sex matching, and maternal donation on AR rate.

RESULTS

Overall, the 10-year patient survival rate was 93.2%. Neither patient or graft loss nor vascular rejection, nor hemolysis, was encountered in the ABO nonidentical patients (n = 58), provided pretransplant levels of relevant isoagglutinins were below 1/16. In BA recipients, the rate of PV complications was lower after portoplasty (4.6%) than after truncal PV anastomosis (9.8%) and to jump graft interposition (26.9%; P = 0.027). In parental donation, maternal grafts were associated with higher 1-year AR-free survival (55.2%) than paternal grafts (39.8%; P = 0.041), but only in BA patients.

CONCLUSIONS

LDLT, including ABO-mismatched transplantation, constitutes a safe and efficient therapy for liver failure in children. In BA patients with PV hypoplasia, portoplasty seems to constitute the best technique for PV reconstruction. Maternal donation might be a protective factor for AR.

Portal Vein Thrombosis and Arterioportal Shunting Due To Chronic Cholangitis: A Rare Complication of Living-Donor Liver Transplant

OBJECTIVES

We present a patient with portal vein thrombosis due to chronic cholangitis after undergoing a living-donor liver transplant.

CASE PRESENTATION

A 52-year-old woman with a history of hepatitis B virus-related liver cirrhosis underwent a living-donor liver transplant. After the surgery, the patient had recurrent episodes of cholangitis because of common and intrahepatic bile duct stricture. Biliary stricture because of cholangitis eventually resulted in acute portal vein thrombosis. A stent was inserted by percutaneous transluminal portography. Blood flow through the portal vein progressively improved from the third through the 10th day after stent placement. The anticoagulation regimen was change to acetylsalicylic acid and clopidogrel hydrogen sulfate (Plavix). On poststenting day 10, a follow-up computed tomographic scan showed good patency of the main portal vein and no evidence of arterioportal shunting.

CONCLUSIONS

Cholangitis after living-donor liver transplant is a rare cause of portal vein thrombosis. Regular follow-up examinations with color Doppler ultrasound are required to monitor portal vein flow in patients with biliary complications after living-donor liver transplant.

Pediatric liver transplant portal vein anastomotic stenosis: correlation between ultrasound and transhepatic portal venography

The objective of this study was to determine which transabdominal ultrasound parameters correlate with portal vein stenosis (PVS) on percutaneous transhepatic portal venography in pediatric liver transplant patients. A retrospective review was performed of percutaneous transhepatic portal venograms performed between 2005 and 2013. The findings were compared to those from ultrasounds performed before venography and at the baseline. Patients were stratified on the basis of the presence of significant PVS (group 1, >50% stenosis; group 2, ≤50% stenosis) on portal venography. Findings were compared to those for age-matched controls. Twenty portal venograms were performed for 12 pediatric patients. Thirteen of the 20 patients (65%) demonstrated significant PVS (>50%). The mean peak anastomotic velocity (PAV) was 253.6±96 cm/s in group 1, 169.7±48 cm/s in group 2, and 51.3±20 cm/s in the control group. PAV (r=0.672, P=0.002) was the only ultrasound variable that correlated with the presence of significant PVS. A receiver operating characteristic curve was generated from PAV and PVS data (area under the curve=0.75, P=0.08). A threshold velocity of 180 cm/s led to a sensitivity of 83% and a specificity of 71% in predicting significant PVS on portal venography. At the baseline, the mean PAV was 155.8±90 cm/s for group 1 and 69.5±33 cm/s for group 2 (P=0.08); for control subjects, it was 78.9±53 cm/s (P=0.06). PAV is the only measured ultrasound parameter that correlates with significant PVS on portal venography in pediatric liver transplant patients. An elevated baseline PAV may increase the risk of developing PVS.

Successful Portal Vein Stent Placement in a Child with Cavernomatous Replacement of the Portal Vein After Partial Liver Transplantation: The Importance of a Recognizable Portal Vein Remnant

Late portal vein thrombosis with cavernomatous replacement has been reported in 4.5% of pediatric patients who have undergone partial liver transplantation. In such cases, minimally invasive radiological treatments have a high failure rate. We report a successful case of percutaneous recanalization of the portal vein remnant, and subsequent stent placement, in a pediatric patient who underwent left lateral split liver transplantation with cavernomatous replacement of the portal vein.

Current state of the art in management of vascular complications after pediatric liver transplantation

Vascular complications by compromising the blood flow to the allograft can have significant and sometimes life-threatening consequences after pediatric liver transplantation. High level of suspicion and aggressive utilization of diagnostic modalities can lead to early diagnosis and salvage of the allograft. This review will summarize the current trends in management of vascular complications after pediatric liver transplantation.

Long-term outcome of percutaneous transhepatic balloon angioplasty for portal vein stenosis after pediatric living donor liver transplantation: a single institute's experience

PURPOSE

To evaluate retrospectively the long-term outcomes of percutaneous transhepatic balloon angioplasty performed for portal vein stenosis (PVS) after pediatric living donor liver transplantation (LDLT).

MATERIALS AND METHODS

Between October 1997 and December 2013, of 527 pediatric patients (age < 18 y) who underwent LDLT in a single institution, 43 patients (19 boys, 24 girls; mean age, 4.1 y ± 4.1) were confirmed to have PVS at direct portography with or without manometry and underwent percutaneous interventions, including balloon angioplasty with or without stent placement. Technical success, clinical success, laboratory findings, manometry findings, patency rates, and major complications were evaluated. Follow-up periods after initial balloon angioplasty ranged from 5-169 months (mean, 119 mo).

RESULTS

Technical success was achieved in 65 of 66 sessions (98.5%) and in 42 of 43 patients (97.7%), and clinical success was achieved in 37 of 43 patients (86.0%). Platelet counts improved significantly. Of 32 patients undergoing manometry, 19 showed significant improvement of pressure gradient across the stenosis after percutaneous transhepatic balloon angioplasty. At 1, 3, 5, and 10 years after balloon angioplasty, the rates of primary patency were 83%, 78%, 76%, and 70%, and the rates of primary-assisted patency were 100%, 100%, 100%, and 96%. Two major complications subsequent to balloon angioplasty were noted: severe asthma attack and portal vein thrombosis.

CONCLUSIONS

Percutaneous transhepatic balloon angioplasty is a safe and effective treatment with long-term patency for PVS after pediatric LDLT.