Vascular Complications After Pediatric Liver Transplantation From the Living Donors

Recanalization of portal vein thrombosis after pediatric liver transplantation: Efficacy and safety of the transsplenic access

BACKGROUND

Endovascular management of portal vein thrombosis (PVT) is challenging. Transsplenic access (TSA) is growing as an access option to the portal system but with higher rates of bleeding complications. The aim of this article is to evaluate the efficacy and safety of transsplenic portal vein recanalization (PVR) using a metallic stent after pediatric liver transplantation.

MATERIALS AND METHODS

This is a retrospective review of 15 patients with chronic PVT who underwent PVR via TSA between February 2016 and December 2020. Two children who had undergone catheterization of a mesenteric vein tributary by minilaparotomy were excluded from the patency analysis but included in the splenic access analysis. The technical and clinical success of PVR and complications related to the procedure via TSA were evaluated.

RESULTS

Thirteen children with PVT were treated primarily using the TSA. The mean age was 4.1 years (range, 1.5-13.7 years), and the most common clinical presentation was hypersplenism (60%). Technically successful PVR was performed in 11/13 (84.6%) children, and clinical success was achieved in 9/11 (81.8%) children. No major complications were observed, and one child presented moderate pain in the TSA (from a total of 17 TSA). The median follow-up was 48.2 months. The median primary patency was 9.9 months. Primary patency in the first 4 years was 75%, and primary assisted patency was 100% in the follow-up period.

CONCLUSIONS

Transsplenic PVR is a safe and effective method for the treatment of PVT after pediatric liver transplantation.

Effect of magnification in pediatric liver transplantation: A systematic review and meta-analysis

BACKGROUND

Hepatic artery thrombosis (HAT) represents a devastating and often fatal complication of liver transplantation. Due to the small vessel caliber in pediatric patients, the use of an operating microscope has largely become the standard for hepatic artery reconstruction to reduce the rate of HAT. Recent evidence, however, suggests that loupe magnification for anastomosis may be equally effective. We aimed to determine the effect of magnification on the rate of hepatic artery thrombosis in pediatric liver transplantation.

METHODS

A systematic search of the literature was conducted. Thousand eighty-eight unique titles were assessed by two independent reviewers. Studies directly comparing rates of HAT from loupe magnification and operating microscope-assisted anastomoses were eligible for meta-analysis.

RESULTS

Among primary transplants, the rate of HAT was 6.0%. Operating microscope anastomosis was associated with a 2.6% decrease in the rate of HAT compared to that of loupe magnification (4.9% and 7.4%, respectively, p < .040). When re-transplants were included, the rate of HAT was 5.8%. Operating microscope anastomosis was associated with a 1.0% decrease in the rate of HAT compared to that of loupe magnification (5.3% and 6.3%, respectively, p < .279). Meta-analysis of eligible studies demonstrated a reduction in the rate of HAT with the use of an operating microscope (p < .03).

CONCLUSIONS

Anastomosis under an operating microscope may be associated with decreased rates of HAT in children undergoing primary liver transplantation. Further high-quality studies comparing the two techniques are needed.

Antithrombotic management and thrombosis rates in children post-liver transplantation: A case series and literature review

Thrombosis is a major postoperative complication in pediatric liver transplantation. There is marked heterogeneity in prophylactic antithrombotic therapies used, without established guidelines. This review summarizes current worldwide incidence of thrombotic events and compares antithrombotic therapies in children post-liver transplant, with comparison to our institution's experience. Of the twenty-three articles with sufficient detail to compare antithrombotic regimens, the overall incidence of thrombosis ranged from 2.4% to 17.3%. Incidence of HAT ranged from 0% to 28.1%, of HVT from 0% to 4.7%, of PVT from 1.5% to 11.2%, and of IVC thrombosis from 0% to 2.8%. Re-transplantation due to thrombosis ranged from 0% to 4.8%. Prophylactic antithrombotic therapies varied between studies, and bleeding complications were infrequently reported. Since 2010, 96 children underwent 100 liver transplants at our institution with thrombosis incidence comparable to international literature (HAT 6%, PVT 5%, IVC 1%, and HVT 0%). Re-transplantation due to thrombosis occurred in 2% and major bleeding occurred in 10%. The prophylactic antithrombotic therapies used post-liver transplantation in children remain varied. Low rates of thrombosis have been reported with antiplatelet use both with and without anticoagulation. Standard definitions and consistent reporting of bleeding complications are required, in addition to thrombosis rates, so that true risk-benefit assessment of reported regimes can be understood.

Indirect Doppler ultrasound abnormalities of significant portal vein stenosis after liver transplantation

PURPOSE

To determine indirect Doppler ultrasound (DUS) abnormalities associated with significant portal vein (PV) stenosis (PVS) in recipients of liver transplantation (LT).

METHODS

This retrospective study was approved by our institutional review board. Between February 2006 and May 2017, 41 LT recipients were diagnosed with significant PVS, defined as having more than 50% narrowing of PV diameter for any reason, including thrombosis or flow disturbance associated with prominent collateral vessels on portal venography. We reviewed the DUS findings of hepatic arteries (HAs) as well as PVs of them, before and after treatment of PVS, and in comparison, with a one-to-one case-matched control. Inter-group comparison of frequency in DUS abnormalities was performed using Chi square (χ²) with Fisher's exact test and McNemar's test. Diagnostic values of each abnormal DUS finding and combinations were also evaluated.

RESULTS

DUS of significant PVS showed "no demonstrable color flow," either at recipient PVs or anastomoses (26.7%), and showed turbulence (66.7%) and hepatofugal portal flow (HFPF; 20.0%) at the graft PVs. HFPF was more frequently observed in those with "no demonstrable color flow" at recipient PVs or anastomoses (p = 0.006). DUS of graft HAs revealed tardus-parvus waveforms (20.9%) and prolonged systolic acceleration times (16.3%), more commonly in the "no demonstrable color flow" group (p = 0.012). These indirect DUS abnormalities disappeared and resolved on follow-up DUS after treatment. In the control group, such Doppler abnormalities were less frequently shown than in the PVS group (p ≤ 0.01, respectively). When one of the portal-blood flow velocity (PFV)-related index abnormalities (such as increased time average velocity [TAV] at anastomosis and TAV ratio between recipient PV and anastomosis) or "no demonstrable color flow" were shown in DUS as well as one of the indirect DUS abnormalities, sensitivity, and specificity was 71.11 and 97.78%, respectively.

CONCLUSION

In addition to PFV-related abnormalities, DUS occasionally shows "no demonstrable color flow" either at recipient PVs or anastomoses, and indirect Doppler abnormalities such as turbulence, HFPF at graft PVs, and abnormal waveforms at graft HAs in LT recipients with significant PVS. The combination of PFV-related abnormalities and indirect DUS abnormalities would be helpful for diagnosis of PVS.

Intra-operative portal hemodynamics in pediatric LDLT: Doppler ultrasound surveillance

Doppler ultrasonography is useful in monitoring intra-operative PV flow in LDLT. A retrospective cohort study included 550 pediatric recipients (<18 years) who underwent LDLT from October 2006 to August 2016 in our hospital. A total of 33 recipients (incidence 6%) were found to have insufficient intra-operative PV flow after PV reperfusion. The treatments included intra-operative stent placement (n=25), anticoagulation (n=3), thrombectomy and re-anastomosis (n=2), graft repositioning (n=1), collateral ligation (n=1), and replaced PV (n=1). The peak PV velocity, HAPSV, HARI, and HV velocity before and after the interventions were significantly improved 0(0,5.5) cm/s vs. 37.36±15.30 cm/s, 38.68±8.92 cm/s vs. 62.30±16.97 cm/s, 0.55±0.08 vs. 0.76±0.10, and 32.37±10.33 cm/s vs. 40.94±15.01 cm/s, respectively (P<.01). Insufficient PV flow and decreased HARI are two significant criteria indicating need for intra-operative PV management. Dramatic changes in the hepatic hemodynamics were detected after proper treatment. Immediate resolution of PV flow is feasible in pediatric LDLT.

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.

Resolution of Hepatic Artery Thrombosis in 2 Pediatric Liver Transplant Patients

Hepatic artery thrombosis (HAT) is a serious complication after liver transplantation. This is the first report of spontaneous resolution of HAT in pediatric liver transplant patients on low molecular weight heparin therapy. A total of 2 patients, a 26-month-old boy who presented with acute liver failure and required emergent liver transplantation and a 15-year-old boy with ulcerative colitis and autoimmune hepatitis-primary sclerosing cholangitis overlap underwent liver transplantation for progressive cirrhosis; both developed HAT during the postoperative period. They were both treated with low molecular weight heparin. Follow-up imaging for both patients showed resolution of HAT without evidence of collateral flow.

Pediatric transplantation: preventing thrombosis

Due to progressive advances in surgical techniques, immunosuppressive therapies, and supportive care, outcomes from both solid organ transplantation and hematopoietic stem cell transplantation continue to improve. Thrombosis remains a challenging management issue in this context, with implications for both graft survival and long-term quality of life. Unfortunately, there remains a general paucity of pediatric-specific data regarding thrombosis incidence, risk stratification, and the safety or efficacy of preventative strategies with which to guide treatment algorithms. This review summarizes the available evidence and rationale underlying the spectrum of current practices aimed at preventing thrombosis in the transplant recipient, with a particular focus on risk factors, pathophysiology, and described antithrombotic regimens.

Do postliver transplant patients need thromboprophylactic anticoagulation?

Postoperative thromboprophylactic anticoagulation against Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE) is standard of care with current evidence-based guidelines. However, majority of liver transplant (LT) patients have thrombocytopenia and/or prolonged INR before surgery. Studies or guidelines regarding role of prophylactic anticoagulation after LT are lacking. There is a need to balance the risk of thrombosis with significant hemorrhage, implying those needing transfusion or return to OR due to bleeding. We conclude that after LT, anticoagulation is not required routinely for DVT/PE prophylaxis. Rather, it is indicated in specific circumstances, chiefly for prophylaxis of hepatic artery thrombosis or portal vein thrombosis in cases with use of grafts, pediatric cases, small size vessels, Budd Chiari syndrome, amongst others.

Frequency of and factors associated with vascular complications after pediatric liver transplantation

OBJECTIVE

to evaluate the frequency and factors associated with vascular complications after pediatric liver transplantation.

METHOD

risk factors were evaluated in 99 patients under 18 years of age with chronic liver disease who underwent deceased donor liver transplantation (DDLT) between March of 1995 and November of 2009 at the Hospital de Clínicas de Porto Alegre, Brazil. The variables analyzed included donor and recipient age, gender, and weight; indication for transplant; PELD/MELD scores; technical aspects; postoperative vascular complications; and survival.

RESULTS

vascular complications occurred in 19 patients (19%). Arterial events were most common, occurred earlier in the postoperative period, and were associated with high graft loss and mortality rates. In the multivariate analysis, the following factors were identified: portal vein diameter ≤ 3mm, donor-to-recipient body weight ratio (DRWR), prolonged ischemic time, and use of arterial grafts.

CONCLUSION

the choice of treatment depends on the timing of diagnosis; however, in this study, surgical revision or correction produced worse outcomes than percutaneous angioplasty. The reduction of risk factors and early detection of vascular complications are key elements to a successful transplantation.

Management of portal hypertension in children with portal vein thrombosis

Portal vein thrombosis (PVT) is a common cause of portal hypertension in children. Predisposing conditions for PVT are obscure in more than half of the cases. Variceal bleeding and splenomegaly are the most frequent initial manifestations. Radiologic imaging studies are the mainstay for diagnosis. Treatment includes pharmacologic, endoscopic, and surgical modalities. β-Adrenergic blockers are not routinely used in children because of unproven efficacy and significant adverse effects. Endoscopic methods, such as sclerotherapy and endoscopic variceal ligation (EVL), are highly effective in the treatment of acute variceal bleeding and eradication of varices. EVL is the treatment of choice because of minimal complications and the need for few endoscopic sessions. EVL facilitates portal decompression either by the formation of collateral vessels or by surgical portosystemic shunting, when vessels grow to the proper diameter for anastomosis. Surgical portosystemic shunts are reserved for refractory cases because of significant complications and technical difficulties. Transjugular portosystemic shunts have an emerging role in the management of portal hypertension caused by PVT. PVT may occur in the posttransplant setting, but optimal management is not defined yet.

Interventional treatment of lumen-reconstruction-related complications after pediatric living-donor liver transplantation

BACKGROUND

Interventional radiology has recently been reported as an effective means of treating complications after liver transplantation. In children, however, the number of such reports is relatively small. In addition, there is ongoing discussion regarding the best interventional devices and methods for specific complications.

OBJECTIVE

The aim of this study was to determine the value of interventional treatment for vessel and bile duct complications after pediatric living-donor liver transplantation.

MATERIALS AND METHODS

Six cases with lumen-reconstruction-related complications after liver transplantation received intervention. Three cases had hepatic artery thrombosis, one had portal vein stenosis, and two had bilioenteric anastomotic stenosis. Catheter-directed thrombolysis was used to treat cases with hepatic artery thrombosis; balloon dilation and stent placement were used for portal vein stenosis; balloon dilation and drainage were used for bilioenteric anastomotic stenosis.

RESULTS

All interventions were performed successfully, and treatment efficacy was 100 %. Except for one death from multiple organ failure, all other cases survived through follow-up, which lasted up to 18 months. No case had intervention-related complication.

CONCLUSION

Interventional treatment is safe and effective, and can be the first choice for the treatment of complications associated with pediatric living-donor liver transplantation.

The pre-Kasai procedure in living donor liver transplantation for children with biliary atresia

BACKGROUND

Biliary atresia (BA) is a major cause of chronic cholestasis, a fatal disorder in infants. This study was undertaken to evaluate the safety and effectiveness of primary living donor liver transplantation (LDLT) in comparison with the traditional first-line treatment, the Kasai procedure.

METHODS

We assessed 28 children with BA at age of less than two years (3-21.3 months) who had undergone LDLT in two hospitals in Southwest China during the period of 2008-2011. Eighteen children who had had primary LDLT were included in a primary LDLT group, and ten children who had undergone the Kasai operation in a pre-Kasai group. All patients were followed up after discharge from the hospital. The records of the BA patients and donors were reviewed.

RESULTS

The time of follow-up ranged 12-44.5 months with a median of 31 months. The 30-day and 1-year survival rates were 85.7% and 78.6%, respectively. There was no significant difference in the 30-day or 1-year survival between the two groups (83.3% vs 90% and 77.8% vs 80%, P>0.05). The main cause of death was hepatic artery thrombosis. There were more patients with complications who required intensive medical care or re-operation in the pre-Kasai group (8, 80%) than in the primary LDLT group (9, 50%) (P=0.226). But no significant differences were observed in operating time (9.3 vs 8.9 hours, P=0.77), intraoperative blood loss (208.6 vs 197.0 mL, P=0.84) and blood transfusion (105.6 vs 100.0 mL, P=0.91) between the two groups. The durations of ICU and hospital stay in the primary LDLT group and pre-Kasai group were 180.4 vs 157.7 hours (P=0.18) and 27 vs 29 days (P=0.29), respectively.

CONCLUSIONS

Primary LDLT is a safe and efficient management for young pediatric patients with BA. Compared with the outcome of LDLT for patients receiving a previous Kasai operation, a similar survival rate and a low rate of re-operation and intensive medical care for patients with BA can be obtained.

Hepatic artery thrombosis and liver malignancy in pediatric liver transplantation

BACKGROUND

Hepatic artery thrombosis (HAT) remains a significant cause of graft failure and mortality after pediatric liver transplantation. Conditions not associated with hepatic failure, such as liver tumors, may be more prone to thrombotic problems after transplant. We hypothesized that liver transplant for hepatic malignancies may be associated with increased rates of HAT in the posttransplant period.

METHODS

We conducted a retrospective review of pediatric patients (age, 0-21 years) who underwent primary liver transplantation at a free-standing children's hospital from 1990 to 2009. We reviewed cause of underlying liver disease, age, sex, weight, occurrence of HAT, use of antiplatelets and anticoagulants perioperatively, as well as reintervention, retransplant, and death.

RESULTS

A total of 129 children underwent 146 liver transplants, and 15 (12%) patients developed HAT. Nine liver transplants were performed for hepatic malignancy, and 4 (44%) of these patients developed HAT (relative risk, 4.85; 95% confidence interval, 1.9-12.2; P = .0015). All 4 children with hepatic malignancy and HAT required reintervention, including 3 retransplants (75%). One of these patients died.

CONCLUSIONS

Hepatic artery thrombosis occurs approximately 5 times more often and appears to be more morbid in children with hepatic malignancy after transplantation. Prospective evaluation of prophylactic anticoagulation regimens in the setting of hepatic malignancy requiring transplantation is warranted.

Differentiation of liver transplantation complications by quantitative analysis of dynamic hepatobiliary scintigraphy

OBJECTIVE

We retrospectively investigated the value of dynamic Tc-diisopropyl-iminodiacetic acid hepatobiliary scintigraphy (HBS) in discriminating postsurgical complications following liver transplantation (LT).

METHODS

Dynamic HBS was performed for suspected post-LT complications in 201 cases. Hepatic uptake and excretion was visually graded. The portal perfusion index (PPI) and kinetic parameters were quantitatively analyzed.

RESULTS

HBS findings were normal in all 119 (59%) cases without complications. Complications were confirmed in 82 cases: 24 had graft rejection, 48 had biliary obstruction, and 10 had hepatitis. Visual grades of uptake and excretion were abnormal for all three types of complications and showed no discriminative value. The PPI level was significantly higher for grafts with rejection (0.83 ± 0.07) compared with no complication (0.57 ± 0.08), biliary obstruction (0.69 ± 0.06), and hepatitis (0.65 ± 0.07; all P<0.0001). Receiver operating characteristic curve analysis confirmed PPI to be highly accurate for discerning rejection from no rejection (area under the curve, 0.97; sensitivity, 95.8%; specificity, 91.7%) or biliary obstruction (area under the curve, 0.93; sensitivity, 95.8%; specificity, 79.2%).

CONCLUSION

PPI measured from dynamic HBS offers a highly accurate method for identifying post-LT rejection and distinguishing it from biliary obstruction or hepatitis.

Prediction of early hepatic artery thrombosis by intraoperative color Doppler ultrasound in pediatric segmental liver transplantation

Early hepatic artery thrombosis (eHAT) after transplantation is associated with a high incidence of graft failure and mortality in pediatric segmental liver transplantation (LT). The evaluation of intraoperative color Doppler ultrasound (CD-US) parameters and their sensitivity and specificity for the prediction of eHAT were important. Pediatric segmental LTs were performed in 49 consecutive patients from October 2006 to December 2010 in our hospital. A total of seven patients (14.3%) experienced eHAT (within one month) after LT. The intraoperative hepatic artery (HA) diameter (p = 0.026), hepatic arterial peak systolic velocity (HAPSV) (p = 0.006), and hepatic artery resistance index (HARI) (p = 0.000) had significant difference between eHAT group and non-eHAT group. Taking a HA diameter <2 mm, a HAPSV of <40 cm/s and a HARI of <0.6 as threshold to predict eHAT, the sensitivity and specificity were 85.7%, 85.7%, 85.7%, and 61.9%, 76.2%, 88.1%, respectively. A HARI of <0.6 was shown to be the most sensitive and specific single parameter for predicting eHAT.

Donor safety in live-related liver transplantation

Living donor liver transplantation (LDLT), since its advent in late 1980's and early 1990's, has rapidly increased especially in countries like Japan, Korea and India where cadaveric programmes are not as well established as in the western world. The main advantage of LDLT is the availability of an organ in the elective setting in the course of a progressive liver disease. This is most applicable in patients with Cirrhosis and Hepatocellular carcinoma. LDLT, from the donor's perspective does carry a risk of not only morbidity but mortality. To date the surgical mortality risk is estimated at 0.1% for left lateral donation and 0.5% for right liver donation. Donor mortality has been reported from various centres in India. There are reports of complications like Hepatic artery thrombosis, portal vein thrombosis and especially biliary leaks and strictures occurring at a significantly increased frequency after living as compared to deceased donor liver transplantation. The key to reduce donor morbidity and mortality is meticulous donor selection and thorough donor work up. In the present study we will analyse the factors that contributed to donor mortality and morbidity and prepare a detailed work up plan, intraoperative and post-operative strategy to reduce donor morbidity and mortality.

Factors predicting persistent thrombocytopenia after living donor liver transplantation in pediatric patients

Thrombocytopenia is common after LT for pediatric end-stage liver diseases. Seventy-six pediatric patients (≤15 yr old) who underwent LDLT were evaluated for the incidence and predictive factors of post-transplant thrombocytopenia (PLT <100, 000/mm(3) ). The prevalence of thrombocytopenia at two wk and at 12 months post-transplant was 22/76 (28.9%) and 11/62 (17.7%), respectively. Thrombocytopenia at two wk after LDLT was significantly associated with age at transplant, preoperative PLT, GRWR, acute rejection, and CMV infection in univariate analysis. Moreover, preoperative PLT, GRWR, and acute rejection had a strong correlation in multivariate analysis. Thrombocytopenia at 12 months after LDLT was associated only with preoperative PLT. We also demonstrated that vascular complications caused thrombocytopenia and that successful treatment recovered the PLT. These results showed that, in addition to considering the preoperative PLT, post-operative monitoring of platelets is very helpful for the early detection of adverse events related to the graft liver in pediatric liver transplant patients.

Impact of pre-transplant liver hemodynamics and portal reconstruction techniques on post-transplant portal vein complications in pediatric liver transplantation: a retrospective analysis in 197 recipients

BACKGROUND AND OBJECTIVE

Portal vein (PV) complications are the most frequent vascular complications in pediatric liver transplant (LT). We hypothesized that pre-LT liver hemodynamic parameters and PV reconstruction technique could predict the risk of PV complications post-LT.

METHODS

Three hundred seventy-three children had a primary LT. A detailed ultrasound study of the pre-LT native liver hemodynamics was available in 198 cases, with details of PV anastomosis available for 197 of these: end-to-end anastomosis (n = 146, 74%), interposition vein graft technique (n = 28, 14%), or portoplasty (latero-lateral anastomosis of vein graft and recipient PV) (n = 23, 12%).

RESULTS

Overall 5-year patient survival rate was 90%. Among the 198 patients with pre-LT hemodynamic data, 79 (40%) had PV hypoplasia (diameter ≤4 mm), 64 (32%) had a pathological portal flow (nonhepatopetal flow), and 47 (24%) had an arterial resistance index (ARI) ≥1. Abnormal hemodynamics were mostly observed in biliary atresia (BA). Among these 3 parameters, only ARI ≥1 was significantly correlated with a higher rate of PV complications post-LT (P = 0.041). PV complication-free survival at 5 years were 91% for end-to-end anastomosis, 91% for portoplasty, and 62% for interposition vein graft technique (P = 0.002). At multivariate analysis, the use of an interposition vein graft was the only factor to be significantly associated with a higher rate of PV complications post-LT (P = 0.003).

CONCLUSIONS

PV hypoplasia with liver hemodynamic disturbances was mainly observed in BA. Hepatic ARI ≥1 might be a good predictor of PV complications post-LT. Latero-lateral portoplasty seemed to provide the best results when end-to-end anastomosis is not feasible.

Long-term results of the percutaneous transhepatic venoplasty of portal vein stenoses after pediatric liver transplantation

  This paper has the objective to evaluate retrospectively the long-term results of transhepatic treatment of PV stenoses after pediatric LT. During an eight-yr period, 15 children with PV stenoses underwent PTA with balloon dilation or stent placement in case of PTA failure after LT. Patients' body weights ranged from 9.3 to 46kg (mean, 15.5kg). PV patency was evaluated in the balloon dilation and in the stent placement groups. Technical and clinical successes were achieved in all cases with no complication. Eleven patients (11/15; 73.3%) were successfully treated by single balloon dilation. Four patients (4/15; 26.7%) needed stent placement. One patient was submitted to stent placement during the same procedure because of PTA failure. The other three developed clinical signs of portal hypertension because of PV restenoses two, eight, and twenty-eight months after the first PTA. They had to be submitted to a new procedure with stent placement. The follow-up time ranged from 3 to 8.1 yr (mean, 6.3 yr). In conclusion, transhepatic treatment of PV stenoses after pediatric LT with balloon dilation or stent placement demonstrated to be a safe and effective treatment that results in long-term patency.

Vascular complications after deceased and living donor liver transplantation: a single-center experience

INTRODUCTION

Vascular complications (VC) after liver transplantation (OLT) are one of the most feared problems that frequently result in graft and patient loss. Herein we have reported our experience with VC after either deceased donor liver transplantation (DDLT) or living donor liver transplantation (LDLT).

PATIENTS AND METHODS

Between April 2001 and September 2009, we performed 224 OLT: 155 DDLT and 69 LDLT. The overall male/female ratio was 136/88 and the adult/pediatric ratio was 208/16. We retrospectively identified and analyzed vascular complications in both groups.

RESULTS

In the DDLT group, 11/155 recipients (7%) suffered vascular complications; hepatic artery thrombosis (HAT; n=5; 3.2%), portal vein thrombosis occurred (n=4; 2.6%); hepatic vein stenosis (n=1; 0.6%), and severe postoperative bleeding due to a slipped splenic artery ligature (n=1, 0.6%). In the DDLT group, 4/11 (36.4%) patients died as a direct result of the vascular complications. In the LDLT group, 9/69 recipients (13%) suffered vascular complications: HAT (n=3; 4.3%), portal vein problems (n=5; 7.2%), and hepatic vein stenosis (n=1; 1.5%). Among LDLT, 3/9 (33.3%) patients died as a direct result of the vascular complications. In both groups vascular complications were associated with poorer patient and graft survival.

CONCLUSIONS

In our experience, the incidence of vascular complications was significantly higher among the LDLT group compared with the DDLT group. Vascular complications were associated with poorer graft and patient survival rates in both groups.

Long-term results of urgent revascularization for hepatic artery thrombosis after pediatric liver transplantation

Hepatic artery thrombosis (HAT) after pediatric orthotopic liver transplantation (OLT) is a serious complication resulting in bile duct necrosis and often requiring retransplantation. Immediate surgical thrombectomy/thrombolysis has been reported to be a potentially successful treatment for restoring blood flow and avoiding urgent retransplantation. The long-term results of this strategy remain to be determined. In 232 pediatric liver transplants, we analyzed long-term outcomes after urgent revascularization for early HAT. HAT developed in 32 patients (13.7%). In 16 children (50%), immediate surgical thrombectomy was performed in an attempt to salvage the graft. Fourteen patients (44%) underwent urgent retransplantation, and 2 (6%) died before further intervention. Immediate thrombectomy resulted in long-term restoration of the hepatic artery flow in 6 of 16 patients (38%) and in 1- and 5-year graft and patient survival rates of 83% and 67%, respectively. In 10 patients, revascularization was unsuccessful, and retransplantation was inevitable. The 1- and 5-year patient survival rates in this group decreased to 50% and 40%, respectively. After immediate retransplantation, the 5-year patient survival rate was 71%. In conclusion, immediate surgical thrombectomy for HAT after pediatric OLT results in long-term graft salvage in about one-third of patients. However, when thrombectomy is unsuccessful, long-term patient survival is lower than the survival of patients who underwent immediate retransplantation.

Living donor liver transplantation: usefulness of hemostatic and prothrombotic screening in potential donors

Bleeding and thrombosis are serious complications of living donor liver transplantation (LDLT). The aim of this paper was to describe the results of a screening for coagulation disorders, including for thrombophilic factors, in potential living liver graft donors and to evaluate thrombotic and bleeding events in donors and recipients, during and after the procedure. From January 2001 to January 2007, 41 LDLTs were performed at our institution. We performed systematic screening for bleeding or prothrombotic states among 188 potential donors, 38 (20.2%) of whom showed at least one abnormality. We rejected potential donors with factor V Leiden, prothrombin mutation G20210A, and deficiencies in anticoagulant proteins (protein C, protein S, and antithrombin) or coagulation factors. Bleeding and thrombotic events in donors and recipients of the 41 LDLTs were evaluated during 7 days to 70 months follow-up. No major bleeding events were detected in the donors. Neither donor nor recipient experienced venous thrombosis or pulmonary embolism. Among all recipients, six suffered hepatic artery thrombosis including five in the first month probably related to surgery. Deep venous thrombosis and pulmonary embolism are well-known complications of hepatic surgery; Prothrombotic abnormalities in the donor can be transmitted to the recipient, leading to increased risk of serious postoperative events. Although the cost-effectiveness is not definitely established, we recommend systematic screening for hemostatic and prothrombotic disorders to prevent more morbidity of a procedure that already has high risks of bleeding and thrombosis.

Twenty years' follow-up of portal vein conduits in liver transplantation

Portal vein problems remain a formidable challenge in liver transplantation. In select situations, a portal vein conduit can provide a solution. No long-term results have been reported. This study was designed to assess the impact of portal vein conduits on graft survival after liver transplantation and the safety of portal vein conduits and to establish the long-term results (up to 20 years) of portal vein conduits. Data from 2370 adult liver transplants were prospectively collected into a computerized research database and analyzed. All portal vein conduits were constructed from the donor iliac vein obtained at the liver retrieval. Portal vein conduits were required in 35 (1.5%) first transplants. The long-term (up to 20 years of follow-up) graft survival after liver transplantation using portal vein conduits was excellent and comparable to that of the control group. The graft survival was 65% with the conduit versus 66% without the conduit at 5 years of follow-up, 58% versus 51% at 10 years, and 48% versus 35% at 15 years. There was a higher rate (8.6% versus 1.4%) of portal vein thrombosis after the portal vein conduit, and the majority occurred in the first 3 months after transplantation. For the same time period, there was no statistically significant difference in graft survival or patient survival for the retransplants with and without portal vein conduits. There was no statistically significant difference in graft survival or patient survival for the transplants with portal vein conduits and with portal vein thrombendvenectomy. In conclusion, portal vein conduits can be used safely for liver transplantation with no negative impact on long-term graft survival or patient survival. Despite the higher rate of portal vein thrombosis in the immediate postoperative period, excellent long-term results can be obtained.

Early hepatic artery thrombosis after liver transplantation: a systematic review of the incidence, outcome and risk factors

To clarify inconsistencies in the literature we performed a systematic review to identify the incidence, risk factors and outcome of early hepatic artery thrombosis (eHAT) after liver transplantation. We searched studies identified from databases (MEDLINE, EMBASE, Science Citation Index) and references of identified studies. Seventy-one studies out of 999 screened abstracts were eligible for this systematic review. The incidence of eHAT was 4.4% (843/21, 822); in children 8.3% and 2.9% in adults (p < 0.001). Doppler ultrasound screening (DUS) protocols varied from 'no routine' to 'three times a day.' The median time to detection was at day seven. The overall retransplantation rate was 53.1% and was higher in children (61.9%) than in adults (50%, p < 0.03). The overall mortality rate of patients with eHAT was 33.3% (range: 0-80%). Mortality in adults (34.3%) was higher than in children (25%, p < 0.03). The reported risk factors for eHAT were, cytomegalovirus mismatch (seropositive donor liver in seronegative recipient), retransplantation, arterial conduits, prolonged operation time, low recipient weight, variant arterial anatomy, and low volume transplantation centers. eHAT is associated with significant graft loss and mortality. Uniform definitions of eHAT and uniform treatment modalities are obligatory to confirm these results and to obtain a better understanding of this disastrous complication.

Severe thrombocytopenia before liver transplantation is associated with delayed recovery of thrombocytopenia regardless of donor type

AIM: To compare the recovery of thrombocytopenia and splenomegaly during long-term follow-up after liver transplantation in patients receiving a living donor transplant or a cadaveric donor transplant.

METHODS: This was a retrospective cohort study of 216 consecutive liver transplant patients who survived for > 6 mo after transplantation; 169 received a liver transplant from a living donor and 47 from a cadaveric donor. The platelet counts or spleen volumes were examined before transplant, 1, 6, and 12 mo after transplant, and then annually until 5 years after transplant.

RESULTS: The mean follow-up period was 49 mo (range, 21-66). Platelet counts increased continuously for 5 years after orthotopic liver transplant. The restoration of platelet counts after transplant was significantly slower in patients with severe pretransplant thrombocytopenia (< 50 000/μL) until 4 years after transplant (P = 0.005). Donor type did not significantly affect the recovery of platelet count and spleen volume in either patient group. In multivariate analysis, pretransplant severe thrombocytopenia (< 50 000/μL) was an independent factor associated with sustained thrombocytopenia (P < 0.001, odds ratio 6.314; confidence interval, 2.828-14.095). Thrombocytopenia reappeared after transplant in seven patients with portal flow disturbance near the anastomosis site.

CONCLUSION: Our study suggests that severe thrombocytopenia before transplant is closely associated with delayed recovery of platelet count after transplant and donor type did not affect the recovery of thrombocytopenia. The reappearance of thrombocytopenia after transplant should be considered a possible indicator of flow disturbance in the portal vein.

Portal vein complications after adult-to-adult living donor liver transplantation

Successful management of portal vein (PV) complications after liver transplantation is crucial to long-term success. Little information is available, however, regarding the incidence and treatment of PV complications after adult-to-adult living donor liver transplantation (LDLT). Between January 1996 and October 2006, 310 adult LDLTs were performed at our institution. PV thrombus was present in 54 patients at the time of LDLT. The incidence of PV complications, choice of therapeutic intervention, and outcomes were retrospectively analyzed. Among the 310 recipients, PV complications were identified in 28 (9%). Risk factors included smaller graft size, presence of PV thrombus at the time of LDLT, and use of jump or interposition cryo-preserved vein grafts for PV reconstruction. When divided into early (within 3 months, n = 11) and late (after 3 months, n = 17) complications, the use of vein grafts for PV reconstruction predisposed to the occurrence of late, but not early, PV complications. Portal vein thrombosis occurred more frequently in the early period (eight out of 11, 73%), whereas stenosis occurred more frequently in the later period (14 out of 17, 82%). Surgical interventions were favored in the earlier period, whereas interventional radiologic approaches were selected for later events. Overall 3- and 5-year survival rates were 81% and 77%, respectively, in patients with PV complications and 88% and 84%, respectively, in those without PV complications (P = 0.21, log-rank test). PV complications are a significant problem following LDLT with both early and late manifestations. Acceptable long-term results, however, are achievable with periodic ultrasonographic surveillance and timely conventional therapeutic interventions. The use of cryo-preserved vein grafts for reconstructing portal flow should be discouraged.