The long-term outcome of hepatic artery thrombosis after liver transplantation in children: role of urgent revascularization

Treatment strategies for hepatic artery complications after pediatric liver transplantation: A systematic review

This study aimed to evaluate the effectiveness of different treatments for hepatic artery thrombosis (HAT) and hepatic artery stenosis (HAS) after pediatric liver transplantation. We systematically reviewed studies published since 2000 that investigated the management of HAT and/or HAS after pediatric liver transplantation. Studies with a minimum of 5 patients in one of the treatment methods were included. The primary outcomes were technical success rate and graft and patient survival. The secondary outcomes were hepatic artery patency, complications, and incidence of HAT and HAS. Of 3570 studies, we included 19 studies with 328 patients. The incidence was 6.2% for HAT and 4.1% for HAS. Patients with an early HAT treated with surgical revascularization had a median graft survival of 45.7% (interquartile range, 30.7%-60%) and a patient survival of 61.3% (interquartile range, 58.7%-66.9%) compared with the other treatments (conservative, endovascular revascularization, or retransplantation). As for HAS, endovascular and surgical revascularization groups had a patient survival of 85.7% and 100% (interquartile range, 85%-100%), respectively. Despite various treatment methods, HAT after pediatric liver transplantation remains a significant issue that has profound effects on the patient and graft survival. Current evidence is insufficient to determine the most effective treatment for preventing graft failure.

European Society of Pediatric Radiology survey of perioperative imaging in pediatric liver transplantation: (3) postoperative imaging

BACKGROUND

Liver transplantation is the state-of-the-art curative treatment for end-stage liver disease. Imaging is a key element in the detection of postoperative complications. So far, limited data is available regarding the best radiologic approach to monitor children after liver transplantation.

OBJECTIVE

To harmonize the imaging of pediatric liver transplantation, the European Society of Pediatric Radiology Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra-, and postoperative phases. This paper reports the responses related to postoperative imaging.

MATERIALS AND METHODS

An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 48 questions about their imaging approach. In total, 26 centers were contacted, and 22 institutions from 11 countries returned the survey.

RESULTS

All sites commence ultrasound (US) monitoring within 24 h after liver transplantation. Monitoring frequency varies across sites, ranging from every 8 h to 72 h in early, and from daily to sporadic use in late postoperative phases. Predefined US protocols are used by 73% of sites. This commonly includes gray scale, color Doppler, and quantitative flow assessment. Alternative flow imaging techniques, contrast-enhanced US, and elastography are applied at 31.8%, 18.2%, and 63.6% of sites, respectively. Computed tomography is performed at 86.4% of sites when clarification is needed. Magnetic resonance imaging is used for selected cases at 36.4% of sites, mainly for assessment of biliary abnormalities or when blood tests are abnormal.

CONCLUSION

Diagnostic imaging is extensively used for postoperative surveillance of children after liver transplantation. While US is generally prioritized, substantial differences were noted in US protocol, timing, and monitoring frequency. The study highlights potential areas for future optimization and standardization of imaging, essential for conducting multicenter studies.

Current Endovascular Management of Arterial Complications After Pediatric Liver Transplantation in a Tertiary Center

PURPOSE

Pediatric liver transplant surgery is burdened by arterial complications whose endovascular treatment is not standardized. We report the outcomes of a cohort of pediatric recipients with hepatic artery complications treated by endoluminal procedures.

MATERIALS AND METHODS

From December 2019 to December 2022, consecutive transplanted pediatric patients who underwent endovascular treatment of hepatic artery complications were reviewed. The analysis included: type of complication (occlusion, stenosis, pseudoaneurysm); onset (acute =  < 15 days, subacute = 15-90 days, late =  > 90 days); endovascular technique (angioplasty, stenting); complications and outcomes. Technical success was defined as the opacification of the hepatic artery at the final angiogram with < 50% residual stenosis and no pseudoaneurysms. Clinical success was defined by graft's and patient's survival.

RESULTS

Seventeen patients (8 males; median age 33 months, IQR 9-103) underwent 21 hepatic arteriography procedures for predominantly acute or subacute occlusions (n = 7) or stenosis (n = 11) with concurrent pseudoaneurysms (n = 4). Primary and secondary technical success was achieved in 13/18 and 3/3 procedures, respectively, with overall technical success of 76%. Angioplasty alone was successful in 5/21 procedures; stent-retriever thrombectomy was performed in one occlusion with thrombosis; stenting was required in 9/17 (53%) patients. Clinical success was obtained in 14/17 (82%) patients with hepatic artery patency after a median of 367 days (IQR 114.5-500). Clinical failure occurred in 3 permanent occlusions, with 2 deaths and 1 re-transplantation. Procedure-related complications included minor events in 3/17 (18%) patients and 1/17 (6%) death.

CONCLUSION

In liver transplanted children with hepatic artery complications, endovascular treatment may provide clinical success, with stenting often required in acute and subacute conditions.

LEVEL OF EVIDENCE

Level 4.

Vascular Complications After Liver Transplantation

OBJECTIVES

Vascular complications after liver transplant can be lethal. High levels of suspicion and aggressive use of diagnostic tools may help with early diagnosis and treatment. Here, we share our experiences regarding this topic.

MATERIALS AND METHODS

Adult and pediatric patients who had liver transplant between February 1997 and June 2018 in our clinic were included in the study. Patients were grouped according to age (pediatric patients were those under 18 years old), male versus female, indication for transplant, type of liver transplant, type of vascular complication, treatment, and survival aftertreatment.We analyzed the statistical incidence of vascular complications according to age, male versus female, and type of liver transplant.

RESULTS

Our analyses included 607 liver transplant procedures, including 7 retransplants, with 349 (57.4%) from living donors and 258 (42.6%) from deceased donors. Of total patients, 539 were adults (89.8%) and 61 were children (10.2%). Vascular complications occurred in 25 patients (4.1%), with hepatic artery complications seen in 13 patients (2.1%) (10 adults [1.8%] and 3 children [4.9%]), portal vein complications seen in 9 patients (1.5%) (6 adults [1.1%] and 3 children [4.9%]), and hepatic vein complications seen in 3 patients (0.5%) (2 adults [0.36%] and 1 child [1.6%]). Rate of vascular complications was statistically higher in pediatric patients (11.4% vs 3.3%; P = .007) and higher but not statistically in recipients of livers from living donors (5.2% vs 2.7%; P = .19). Twelve patients (48.8%) were treated with endovascular approach, and 11 (0.44%)required surgicaltreatment. Two patients underwent immediate retransplant due to hepatic artery thrombosis.

CONCLUSIONS

Because vascular complications are the most severe complications afterlivertransplant,there must be close follow-up of vascular anastomoses, particularly early postoperatively, with radiologic methods. In cases of vascular complications, emergent treatment, including endovascular interventions, surgery, and retransplant, must be performed.

The Impact of Hepatic Artery Thrombosis on the Outcome of Pediatric Living Donor Liver Transplantations

The aim of our study was to assess risk factors for hepatic artery thrombosis (HAT) and to evaluate the impact of HAT management on long-term outcomes after pediatric living donor liver transplantation (LDLT). We retrospectively analyzed 400 patients who underwent primary LDLT between 1999 and 2020. We compared preoperative data, surgical factors, complications, and patient and graft survivals in patients with HAT (HAT Group) and without HAT (non-HAT Group). A total of 27 patients (6.75%) developed HAT. Acute liver failure, a hepatic artery (HA) anastomosis diameter below 2 mm, and intraoperative HA flow dysfunction were significantly more common in the HAT Group (p < 0.05, p = 0.02026, and p = 0.0019, respectively). In the HAT Group, 21 patients (77.8%) underwent urgent surgical revision. The incidence of biliary stenosis and retransplantation was significantly higher in the HAT Group (p = 0.00002 and p < 0.0001, respectively). Patient and graft survivals were significantly worse in the HAT Group (p < 0.05). The close monitoring of HA flow with Doppler ultrasound during the critical period of 2 to 3 weeks after LDLT and the immediate attempt of surgical revascularization may attenuate the elevated risk of biliary stenosis, graft loss, and the need for retransplantation due to HAT.

Doppler Ultrasound of Vascular Complications After Pediatric Liver Transplantation: Incidence, Time of Detection, and Positive Predictive Value

Purpose Doppler ultrasound (DUS) is widely used to detect vascular complications after pediatric liver transplantation (LT). This study aimed to assess the moment of first detection of vascular complications with DUS, and to determine the positive predictive value (PPV) of DUS.

Materials and Methods Patients aged 0–18 years who underwent LT between 2015 and 2019 were retrospectively included. 92 LTs in 83 patients were included (median age: 3.9 years, interquartile range: 0.7–10.5). Patients underwent perioperative (intra-operative and immediately postoperative) and daily DUS surveillance during the first postoperative week, and at 1, 3, and 12 months. Vascular complications were categorized for the hepatic artery, portal vein, and hepatic veins. DUS findings were compared to surgical or radiological findings during the 1-year follow-up.

Results 52 vascular complications were diagnosed by DUS in 35/92 LTs (38%). 15 out of 52 (28.8%) were diagnosed perioperatively, 29/52 (55.8%) were diagnosed on postoperative days 1–7, and 8/52 (15.4%) after day 7. The PPV for all vascular complications diagnosed with DUS was 92.3%. During the 1-year follow-up, 18/19 (94.7%) hepatic artery complications, 19/26 (73.1%) portal vein complications, and 7/7 (100%) hepatic vein complications were diagnosed perioperatively or during the first week.

Conclusion The majority of vascular complications during the first year after pediatric LT were diagnosed by DUS perioperatively or during the first week, with a high PPV. Our findings provide important information regarding when to expect different types of vascular complications on DUS, which might improve DUS post-LT surveillance protocols.

Management and outcome of hepatic artery thrombosis with whole-liver transplantation using donors less than one year of age

BACKGROUND/PURPOSE

The incidence of hepatic artery thrombosis (HAT) in recipients is high after pediatric LT using young donors. In this study we investigated the management and outcome of HAT after whole-LT using donors less than one year of age. And evaluate the safety of pediatric donors, and increase the utilization of pediatric donors overall.

METHODS

We retrospectively analyzed the clinical data encompassing children who underwent whole-liver transplantation in our department from January 2014 to December 2019. Recipients receiving a liver from a donor ≥1 month and ≤12 months were included, and a total of 110 patients were included in this study.

RESULTS

The results showed an incidence for HAT of 20% and the median time to HAT diagnosis was 3.0 (2.0, 5.3) days post-operation. Anticoagulant therapy was used for 19 cases and 94.7% of them achieved hepatic artery recanalization or collateral formation. The median time of recanalization was 12 (5, 15) days. Bile leakage and biliary strictures occurring in the HAT group were higher than in the non HAT group (13.6% vs. 1.1% and 31.8% vs. 3.4%). There were no significant differences in the survival rates of recipients or grafts among the two groups (P = 0.474, P = 0.208, respectively).

CONCLUSION

We confirmed that the incidence of HAT in LT recipients use donors less than 1 year is high, but recanalization can be performed using anticoagulant therapy. Although biliary complications increased significantly after HAT, the survival rates of patients and grafts were satisfactory.

LEVEL OF EVIDENCE

Level III.

Antithrombin supplementation for prevention of vascular thrombosis after pediatric liver transplantation

AIMS

After liver transplantation (LT), synthesis of coagulation factors by the graft recovers faster for pro thrombotic than anti thrombotic factors, resulting in a potential pro thrombotic imbalance. We studied the thrombotic and hemorrhagic complications in our pediatric LT series, providing supplementation of fresh frozen plasma (FFP) and/or antithrombin (AT) in the prophylactic antithrombotic regimen.

METHODS

This was a retrospective observational single center study. All isolated pediatric LTs performed between 1/11/2009 and 31/12/2019 (n = 181) were included. Postoperatively, in addition to low molecular weight heparin, 22 patients (12%) received FFP (10 ml/kg twice daily for 10 days), 27 patients (15%) were given FFP (reduced duration) and AT (50-100 IU/kg/day if AT activity remained <70%), and 132 (73%) received AT only. Complications, outcome, and coagulation profiles in postoperative days 0-10 were analyzed.

RESULTS

In all three treatment groups, AT activity normalized by day 4 while prothrombin remained <70% of normal until day 9. Hepatic artery thrombosis (HAT), portal vein thrombosis (PVT), and hemorrhagic complications occurred in 2.8%, 3.3%, and 3.9% of LTs. One- and 5-year patient and graft survival were 88% (±2.4% Standard Error) and 84% (±2.5%), and 86% (±2.6%) and 84% (±2.7%), respectively, without difference between groups. HAT were associated with low AT on days 0 and 1, and PVT with low AT on day 0.

CONCLUSIONS

Low antithrombin activity after LT was associated with postoperative thromboses. FFP and/or AT supplementation allowed early normalization of AT activity, while thrombotic or hemorrhagic complications were rare, suggesting efficient and safe management of post-LT coagulopathy.

Early hepatic arterial thrombosis in liver transplantation: Systemic intravenous alteplase as a potential rescue treatment after failed surgical revascularization

eHAT is one of the most dreaded post-LT complication. Treatment approaches include retransplantation, revascularization, or observation. Systemic thrombolytic therapy is used in pediatric patients with thromboembolic events. However, there is no previous study reporting on the use of systemic r-tPA to treat eHAT. The treatment strategies used in patients with eHAT are described, focusing on two children who failed SR and were treated with systemic heparinization plus systemic r-tPA infusion. r-tPA-RP consists of intravenous systemic infusion at a dose of 0.3 mg/kg/h during 6 hours, for 5 days. First case (3-year) was transplanted with a whole liver, and second case (6-year) received a LLS from a living donor. HAT was diagnosed by doppler US and confirmed by angioCT scan in both patients in the first day after LT. They underwent SR and were clinically stable. Re-thrombosis occurred in both patients the day after, and r-TPA-RP was started-one patient required two r-TPA-RP for HAT recurrence. They presented minor bleeding, without repercussion. Hepatic artery recanalized after 10 and 3 days in the first and second patient, respectively. Retransplant was avoided, and one developed biliary strictures, successfully managed in the follow-up. r-TPA-RP avoided retransplantation after eHAT in these cases. To our knowledge, this is the first report of the use of systemic r-TPA to treat eHAT in children. This strategy may compose an algorithm to treat eHAT that failed SR in stable patients.

Management and outcome of hepatic artery thrombosis after pediatric liver transplantation

BACKGROUND

Pediatric LT are at particular risk of HAT, and its management still constitutes a matter of debate. Our purpose was to study predisposing factors and outcome of HAT post-LT, including the impact of surgical revisions on survival and biliary complications.

METHODS

Among 882 primary pediatric LT performed between 1993 and 2015, 36 HAT were encountered (4.1%, 35 fully documented). Each HAT case was retrospectively paired with a LT recipient without HAT, according to diagnosis, age at LT, type of graft, and era.

RESULTS

Five-year patient survivals were 77.0% versus 83.9% in HAT and non-HAT paired groups, respectively (P = .321). Corresponding graft survivals were 20.0% versus 80.5% (P < .001), and retransplantation rates 77.7% versus 10.7%, respectively (P < .001). One-year biliary complication-free survivals were 16.6% versus 83.8% in the HAT and non-HAT groups, respectively (P < .001). Regarding chronology of surgical re-exploration, only HAT cases that occurred within 14 days post-LT were re-operated, fourteen of them being explored within 7 days post-LT (revascularization rate: 6/14), versus two beyond 7 days (no revascularization). When revascularization was achieved, graft and biliary complication-free survival rates at 1 year were 33.3% and 22.2%, respectively, both rates being 0.0% in case of failure.

CONCLUSIONS

The pejorative prognosis associated with HAT in terms of graft survival is confirmed, whereas patient survival could be preserved through retransplantation. Results suggest that HAT should be re-operated if occurring within 7 days post-LT, but not beyond.

Time is of the essence: A single-center experience of hepatic arterial supply impairment management in pediatric liver transplant recipients

BACKGROUND

Impairment of hepatic arterial flow including hepatic arterial thrombosis (HAT), hepatic arterial stenosis (HAS), and splenic artery steal syndrome (SASS) is potentially life-threatening complications. The proposed early diagnosis and urgent treatment strategy of graft arterial flow reduction aim to decrease morbidity and mortality.

METHODS

Pediatric patients with known hepatic arterial flow impairment were retrospectively reviewed. Patients were grouped by occlusive (HAT) and non-occlusive (HAS/SASS) arterial flow reduction. Patients with HAT were further divided in two groups based on the estimated maximal hepatic artery occlusion time ≤8 and >8 hours.

RESULTS

Impairment of hepatic arterial flow developed in 32 of 416 pediatric liver transplant recipients. HAT, HAS, and SASS incidences were 4.1% (n = 17), 2.2% (n = 9), and 1.4% (n = 6), respectively. Neither graft loss nor death occurred in the non-occlusive group. The probabilities of sepsis (OR, 1.7; 95% CI, 1.14-2.53; P=.008) and graft loss or death (OR, 1.42; 95% CI, 1.04-1.92; P=.046) were higher in the occlusive group. Patients with estimated maximal duration of hepatic artery occlusion ≤ 8 hours (n = 7; 41.2%) did not have ischemic-type biliary lesions and sepsis (P=.044 and 0.010, respectively) but had excellent 3-year graft survival compared with > 8 hours group (100% vs 40%; P=.037). Multivariate analysis revealed HAT manifestation by fever was associated with increased chances of graft loss or death.

CONCLUSION

Occlusive arterial complications impose higher risks of graft loss and death. Thorough arterial supply monitoring by Doppler ultrasonography and urgent endovascular arterial flow restoration may salvage both graft and the recipient.

Decreased Incidence of Hepatic Artery Thrombosis in Pediatric Liver Transplantation Using Technical Variant Grafts: Report of the Society of Pediatric Liver Transplantation Experience

OBJECTIVE

To evaluate risk factors for hepatic artery thrombosis (HAT) and examine the long-term outcomes of graft and patient survival after HAT in pediatric recipients of liver transplantation.

STUDY DESIGN

Using multicenter data from the Society of Pediatric Liver Transplantation, Kaplan-Meier and Cox regression analyses were performed on first-time pediatric (aged <18 years) liver transplant recipients (n = 3801) in the US and Canada between 1995 and 2016.

RESULTS

Of children undergoing their first liver transplantation, 7.4% developed HAT within the first 90 days of transplantation and, of those who were retransplanted, 20.7% developed recurrent HAT. Prolonged warm ischemia times increased the odds of developing HAT (OR, 1.11; P = .02). Adolescents aged 11-17 years (OR, 0.53; P = .03) and recipients with split, reduced, or living donor grafts had decreased odds of HAT (OR, 0.59; P < .001 compared with whole grafts). Fifty percent of children who developed HAT developed graft failure within the first 90 days of transplantation (adjusted hazard ratio, 11.87; 95% CI, 9.02-15.62) and had a significantly higher post-transplant mortality within the first 90 days after transplantation (adjusted hazard ratio, 6.18; 95% CI, 4.01-9.53).

CONCLUSIONS

These data from an international registry demonstrate poorer long-term graft and patient survival in pediatric recipients whose post-transplant course is complicated by HAT. Notably, recipients of technical variant grafts had lower odds of HAT compared with whole liver grafts.

Adult liver transplantation using pediatric donor livers after cardiac or brain death: A report of three cases

The present study reports on the experience at Jiangxi Provincial People's Hospital (Nanchang, China) with liver transplantation in adults using pediatric donor livers, including indications, technique and results. A total of three cases of liver transplantation performed between April 2008 and May 2016 were retrospectively reviewed. Liver procurement and trimming, recipient selection, surgical tips, prevention and treatment of small-for-size syndrome, selection of immunosuppressive regimens, prevention and treatment of vascular complications and anticoagulant therapy were discussed. The three pediatric donors were 8, 8 and 10 years old. The three recipients were confirmed to have primary liver cancer. In recipient 1 (female; age, 39 years), jaundice persisted in the recipient after the liver transplantation. A reduced dose of FK506 was then given to gradually decrease the total bilirubin level to the normal range. Recipient 1 recovered and was discharged from hospital; however, the patient died of liver cancer recurrence and bone metastasis 6 years post-transplantation. In recipient 2 (male; age, 56 years), the recipient experienced sudden abdominal distension on postoperative day 7. The patient's clotting time was prolonged and the transaminase level was sharply increased, peaking on day 9. The patient was suspected of having small-for-size syndrome and was treated symptomatically. The patient experienced a significant improvement in symptoms on postoperative day 13 and regular postoperative follow-ups were performed until now and the patient is now in remission. In recipient 3 (male; age, 48 years), the recipient recovered well and the liver function returned to normal on postoperative day 3. The patient was discharged from hospital and has been in remission thus far. Adult liver transplantations from pediatric donors are feasible treatments. Systematic donor and recipient assessments, sound surgical skills and optimal postoperative treatments are essential for success in the transplantation of livers from pediatric donors into adult recipients. Considering the condition of the donor liver, the selection of recipients and appropriate surgical methods are particularly important in these cases.

Liver Transplantation for Propionic Acidemia: Evidence from A Systematic Review and Meta-analysis

BACKGROUND

The worldwide experience of liver transplantation (LT) in the treatment of propionic acidemia (PA) remains limited and fragmented. This review aims to provide a comprehensive and quantitative understanding of post-transplant clinical outcomes in PA patients.

METHODS

MEDLINE, Embase and the Cochrane Library databases were searched for studies focusing on PA patients who underwent LT. The pooled estimate rates and 95% confidence intervals (CIs) were calculated using a random-effects model with Freeman-Tukey double arcsine transformation.

RESULTS

Twenty-one studies involving 70 individuals were included. The pooled estimate rates were 0.95 (95% CI, 0.80-1.00) for patient survival and 0.91 (95% CI, 0.72-1.00) for allograft survival. The pooled estimate rates were 0.20 (95% CI, 0.05-0.39) for rejection, 0.08 (95% CI, 0.00-0.21) for hepatic artery thrombosis, 0.14 (95% CI, 0.00-0.37) for cytomegalovirus/Epstein-Barr virus infection and 0.03 (95% CI, 0.00-0.15) for biliary complications. The pooled estimate rates were 0.98 (95% CI, 0.88-1.00) for metabolic stability, 1.00 (95% CI, 0.79-1.00) for reversal of pre-existing cardiomyopathy and 0.97 (95% CI, 0.78-1.00) for improvement of neurodevelopmental delay. A large proportion of patients achieved liberalization of protein intake posttransplant [pooled estimate rate 0.66 (95% CI, 0.35-0.93)].

CONCLUSIONS

Despite the risk of transplant-related complications, LT is a viable therapeutic option in PA patients, with satisfactory survival rates and clinical outcomes. Given the diversity in neurological assessment methods and the inconsistency in achievement of dietary protein liberalization across different studies, consensus on neurological evaluation methods and post-transplant protein intake is necessary. Longer-term clinical outcomes of LT for PA warrants further investigation.

Hepatic artery reconstruction in pediatric liver transplantation: Experience from a single group

BACKGROUND

The reconstruction of hepatic artery is a challenging part of the pediatric liver transplantation procedure. Hepatic artery thrombosis (HAT) and stenosis are complications which may result in ischemic biliary injury, causing early graft lost and even death.

METHODS

Two hundred and fifty-nine patients underwent liver transplantation in 2017 in a single liver transplantation group. Among them, 225 patients were living donor liver transplantation (LDLT) and 34 deceased donor liver transplantation (DDLT).

RESULTS

In LDLT all reconstructions of hepatic artery were microsurgical, while in DDLT either microsurgical reconstruction or traditional continuous suture technique was done depending on different conditions. There were five (1.9%) HATs: four (4/34, 11.8%) in DDLT (all whole liver grafts) and one (1/225, 0.4%) in LDLT (P = 0.001). Four HATs were managed conservatively using anticoagulation, and 1 accepted salvage surgery with re-anastomosis. Until now, 3 HAT patients remain in good condition, whereas two developed biliary complications. One of them needed to be re-transplanted, and the other patient died due to biliary complications.

CONCLUSIONS

Microsurgical technique significantly improves the reconstruction of hepatic artery in pediatric liver transplantation. The risk for arterial complications is higher in DDLT. Conservative therapy can achieve good outcome in selected HAT cases.

Application of pediatric donors in split liver transplantation: Is there an age limit?

The experience of using pediatric donors in split liver transplant is exceedingly rare. We aim to investigate the outcomes of recipients receiving split pediatric grafts. Sixteen pediatric recipients receiving split liver grafts from 8 pediatric donors < 7 years were enrolled. The donor and recipient characteristics, perioperative course, postoperative complications, and graft and recipient survival rates were evaluated. The mean follow-up time was 8.0 ± 2.3 months. The graft and recipient survival rates were 100%. The liver function remained in the normal range at the end of the follow-up time in all recipients. No life-threatening complications were seen in these recipients, and the only surgery-related complication was portal vein stenosis in 1 recipient. Cytomegalovirus infection was the most common complication (62.5%). The transaminase level was significant higher in extended right lobe recipients in the early postoperative days, but the difference vanished at the end of first week; postoperative complications and graft and recipient survival rates did not differ between left and right graft recipients. Notably, the youngest split donor graft (2.7 years old) was associated with ideal recipient outcomes. Split liver transplant using well-selected pediatric donors is a promising strategy to expand pediatric donor source in well-matched recipients.

Risk factors of hepatic artery thrombosis in pediatric deceased donor liver transplantation

PURPOSE

Hepatic artery thrombosis (HAT) remains a life-threatening complication in liver transplantation. We aim to investigate the risk factors of HAT in deceased donor pediatric liver transplantation.

METHODS

104 recipients from 2014 to 2016 were enrolled; donor and recipient characteristics, surgical variables, graft and recipient survival rate were compared between recipients with or without HAT. Univariate and multivariate analysis were applied to identify the risk factors of HAT.

RESULTS

The recipient survival rate was 87.0% and 96.3% at 1 year, and 87.0% and 96.3% at 3 years in HAT and non-HAT groups without significant difference. The graft survival rate was 73.9% and 96.3% at 1 year, and 73.9% and 95.1% at 3 years in HAT and non-HAT groups; significant difference was observed between two groups at both 1 and 3 years. Donor age less than 8.5 months, graft weight less than 190 g and GRWR less than 2.2% were identified as independent risk factors for HAT. Recipients with HAT were associated with higher incidence of post-operative biliary complications.

CONCLUSIONS

Young donor age and small liver graft are risk factors for HAT in deceased donor pediatric liver transplantation.

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.

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.

Aggressive prevention and preemptive management of vascular complications after pediatric liver transplantation: A major impact on graft survival and long-term outcome

Vascular complications are a major cause of patient and graft loss after LTs. The aim of this study was to evaluate the effect of a multimodal perioperative strategy aimed at reducing the incidence of vascular complications. A total of 126 first isolated LTs-performed between November 2008 and December 2015-were retrospectively analyzed. A minimum follow-up period of 24 months was analyzable for 124/126 patients (98.4%). The aggressive preemptive strategy consisted of identifying and immediately managing any problem and any abnormality in the vascular flow, in any of the hepatic vessels, and at any time after the liver graft revascularization. As a result, with a median follow-up of 57 months (3-112 months), not a single graft has been lost from vascular or biliary problems. The actuarial 8-year graft survival is 96.5%. These results have shown that a combination of technical attention, medical prevention, an early diagnosis, and rapid interventions reduced the negative impact of vascular problems on the outcome of both grafts and patients.

Outcomes of Pediatric Liver Transplantation: Deceased Donor Liver Transplantation vs Living Donor Liver Transplantation

BACKGROUND

The use of pediatric donor liver for pediatric liver transplantation (LT) remains controversial and few studies have focused on pediatric deceased donors. To address this issue, we decided to perform a retrospective research, trying to compare the clinical effects between deceased donor LTs (DDLTs) and living donor LTs (LDLTs).

METHODS

A retrospective review of pediatric LTs using grafts from deceased donors and living donors from June 2013 to August 2016 was performed. The children were divided into a DDLT group and a LDLT group based on their donor styles. The incidence of early vascular complications (VC), biliary complications, and graft and patient survival rates were observed between the 2 groups.

RESULTS

There were 217 cases of pediatric LTs performed in our hospital from June 2013 to August 2016 (83 DDLTs and 134 LDLTs). The 1-year cumulative survival rates of grafts and recipients were 89.16% and 91.57% in DDLTs, and 95.47% and 95.52% in LDLTs, respectively (P > .05). The incidence of early VC was lower in LDLTs than that in DDLTs (3.7% vs 19.3%, P < .001). The incidence of HAT in children aged less than 1 year was significantly higher in the DDLT group (P < .001) and can be up to 31.82%. The incidence of biliary complications was similar in the 2 groups (8.4% vs 13.5%, P = .285).

CONCLUSIONS

Pediatric DDLTs have similar graft and patient survival rates with LDLT. The incidence of early VC was higher in DDLTs, and children aged less than 1 year are at a higher risk of developing HAT.

Pediatric Liver Transplant: Techniques and Complications

Liver transplant is considered to be the last-resort treatment approach for pediatric patients with end-stage liver disease. Despite the remarkable advance in survival rates, liver transplant remains an intricate surgery with significant morbidity and mortality. Early diagnosis of complications is crucial for patient survival but is challenging given the lack of specificity in clinical presentation. Knowledge of the liver and vascular anatomy of the donor and the recipient or recipients before surgery is also important to avoid complications. In this framework, radiologists play a pivotal role on the multidisciplinary team in both pre- and postoperative scenarios by providing a road map to guide the surgery and by assisting in diagnosis of complications. The most common complications after liver transplant are (a) vascular, including the hepatic artery, portal vein, hepatic veins, and inferior vena cava; (b) biliary; (c) parenchymal; (d) perihepatic; and (e) neoplastic. The authors review surgical techniques, the role of each imaging modality, normal posttransplant imaging features, types of complications after liver transplant, and information required in the radiology report that is critical to patient care. They present an algorithm for an imaging approach for pediatric patients after liver transplant and describe key points that should be included in radiologic reports in the pre- and postoperative settings. Online supplemental material is available for this article. ^©RSNA, 2017.

Intraoperative Doppler sonogram in pediatric liver transplants: a pictorial review of intraoperative and early postoperative complications

A spectrum of vascular complications can be seen in pediatric liver transplant patients, including occlusion and hemodynamically significant narrowing of the vessels that provide inflow to or outflow from the graft. Intraoperative Doppler ultrasound (US) has the potential benefit of identifying vascular complications in pediatric liver transplant patients prior to abdominal closure. Importantly, intraoperative Doppler US can be used as a problem-solving tool in situations such as position-dependent kinking of the portal or hepatic veins, or in suspected vasospasm of the hepatic artery. Furthermore, this technique can be used for real-time reassessment after surgical correction of vascular complications. This pictorial review of intraoperative Doppler US in pediatric liver transplant patients illustrates normal findings and common vascular complications, including examples after surgical correction, in the perioperative period.

Transplant artery thrombosis and outcomes

Post-transplantation allograft arterial thrombosis is a well-recognized complication associated with solid organ transplantation. Much of the literature is centered on liver and kidney transplantation, which will therefore serve as the principle basis for this review, with a brief discussion on pancreas transplantation and associated arterial complications. The number of solid organ transplants has been steadily increasing over the past decade in parallel with growing demand for organs and expansion of the transplantation criteria for both donors and recipients. This increase has been accompanied by a number of innovative medical advances and surgical techniques, as well as improved imaging that has allowed for thoughtful exploration of vascular anatomic variants and the possibilities for transplant with which they are associated. It has also been accompanied by a growing field of behavioral research, as potential recipients must weigh the risk of accepting certain organs based on perceived outcomes that may differ according to the quality of the underlying organ. Improvements in imaging technology have brought greater sensitivity to detecting arterial complications in post-operative surveillance examinations and have allowed for further development of tailored endovascular and surgical interventions for transplant-associated vascular complications. This review will focus on post-transplantation solid organ allograft artery thrombosis, including discussion of risk factors, diagnostic imaging, natural history, and therapeutic options.

Twenty Years of Experience in Pediatric Living Donor Liver Transplantation: Focus on Hepatic Artery Reconstruction, Complications, and Outcomes

BACKGROUND

Hepatic artery thrombosis (HAT) increases morbidity and mortality after liver transplantation (LT). The identification of risk factors for HAT may aid transplant teams in the development of strategies aimed at reducing HAT. This article describes the risk factors for HAT and outcomes after LT.

METHODS

This report describes a retrospective study (1995 to 2015) of primary pediatric living donor LT (LDLT). Pretransplant and technical variables were included in the study. Binary logistic regression was used for data analysis.

RESULTS

This study included 656 primary LDLT. The median age, body weight, and pediatric end-stage liver disease score at the time of transplant were 13 months, 8.4 kg and 15, respectively. Twenty-one (3.2%) patients developed HAT. Intraoperative HAT (odds ratio, 62.63; 95% confidence interval, 12.64-310.19; P < 0.001) and the use of liver grafts with a graft-to-recipient weight ratio less than 1.1% (odds ratio, 24.46; 95% confidence interval, 4.55-131.56; P < 0.001) retained statistical significance in the multivariate model. Patient and graft survivals were significantly worse in cases with HAT. The overtime trend analysis revealed a decrease in the incidence of HAT (P = 0.008) and an increase in the use of 2-arterial anastomosis (P < 0.001).

CONCLUSIONS

A graft-to-recipient weight ratio of 1.1% or less and intraoperative HAT were independently associated with HAT. Trend analysis further revealed a significant reduction in the incidence of HAT over time, as well as the increased use of 2 hepatic arteries for anastomosis during graft implantation. The double artery anastomosis may represent an extra protection to pediatric recipients undergoing LDLT.

Abdominal Arterial Anomalies in Children With Alagille Syndrome: Surgical Aspects and Outcomes of Liver Transplantation

OBJECTIVES

Angiogenic defects secondary to gene mutations of JAG1 and NOTCH2, causing arterial anomalies in Alagille syndrome (AGS), are well described in the literature. The study analyzes the frequency of abdominal arterial anomalies in children with AGS with an emphasis on outcomes following liver transplantation (LT).

METHODS

Between 1988 and 2013, 242 children with AGS were treated at our institution. We performed a retrospective analysis of 55 who underwent LT during the study period. Preoperative abdominal arterial findings, operative reports, arterial reconstruction technique, and early as well as late complications following LT were reviewed specifically focusing on arterial thrombosis.

RESULTS

Twenty-five patients had preoperative imaging available for analysis. Twelve of these patients showed celiac trunk stenosis (48.0%), 2, a superior mesenteric artery stenosis (8.0%) and one a stenosis of both renal arteries. Twenty patients (36.3%) underwent standard hepatic reconstruction using the native recipient hepatic artery. Thirty-five patients (63.7%) underwent aortic conduit reconstruction (ACR) from the infrarenal aorta using donor arterial conduits. Hepatic artery thrombosis occurred in 9 patients (16.3%). This number was higher in the standard arterial anastomosis group 7/20 (35.0%) than in those with ACR 2/35 (5.7%, P = 0.0079).

CONCLUSIONS

In this series, children with AGS pretransplant have a high prevalence of abdominal arterial anomalies. Preoperative abdominal vascular imaging makes it possible to anticipate whether or not a classical arterial revascularization can be performed or whether an ACR is required.

Reducing the incidence of hepatic artery thrombosis in pediatric liver transplantation: Effect of microvascular techniques and a customized anticoagulation protocol

We aimed to assess the incidence of HAT over three eras following implementation of microvascular techniques and a customized anticoagulation protocol in a predominantly cadaveric split liver transplant program. We retrospectively reviewed pediatric liver transplants performed between April 1986 and 2016 and analyzed the incidence HAT over three eras. In E1, 1986-2008, each patient received a standard dose of 5 U/kg/h of heparin and coagulation profiles normalized passively. In E2, 2008-2012, microvascular techniques were introduced. In E3, 2012-2016, in addition, a customized anticoagulation protocol was introduced which included replacement of antithrombin 3, protein C and S, and early heparinization. A total of 317 liver transplants were completed during the study period, with a median age of 31.7 months. In E1, 22% of grafts were cadaveric in situ split grafts, while the second and third eras used split grafts in 59.0% and 64.9% of cases, respectively. HAT occurred in 9.5% in the first era, 11.5% (P=.661) in the second, and dropped to 1.8% in the third era (P=.043). A routine anticoagulation protocol has significantly reduced the incidence of HAT post-liver transplantation in children in a predominantly cadaveric in situ split liver transplant program.

Rescue Arterial Revascularization Using Cryopreserved Iliac Artery Allograft in Liver Transplant Patients

OBJECTIVES

Management of hepatic arterial complications after liver transplant remains challenging. The aim of our study was to assess the efficacy of rescue arterial revascularization using cryopreserved iliac artery allografts in this setting.

MATERIALS AND METHODS

Medical records of patients with liver transplants who underwent rescue arterial revascularization using cryopreserved iliac artery allografts at a single institution were reviewed.

RESULTS

From 1992 to 2015, 7 patients underwent rescue arterial revascularization using cryopreserved iliac artery allografts for hepatic artery pseudoaneurysm (3 patients), thrombosis (2 patients), aneurysm (1 patient), or stenosis (1 patient). Two patients developed severe complications, comprising one biliary leakage treated percutaneously, and one acute necrotizing pancreatitis causing death on postoperative day 29. After a median follow-up of 75 months (range, 1-269 mo), 2 patients had an uneventful long-term course, whereas 4 patients developed graft thrombosis after a median period of 120 days (range, 2-488 d). Among the 4 patients who developed graft thrombosis, 1 patient developed ischemic cholangitis, 1 developed acute ischemic hepatic necrosis and was retransplanted, and 2 patients did not develop any further complications.

CONCLUSIONS

Despite a high rate of allograft thrombosis, rescue arterial revascularization using cryopreserved iliac artery allografts after liver transplant is an effective and readily available approach, with a limited risk of infection and satisfactory long-term graft and patient survival.

Pediatric Liver Transplantation: Our Experiences

OBJECTIVE

The aim of our study was to evaluate our liver transplant pediatric patients and to report our experience in the complications and the long-term follow-up results.

MATERIALS AND METHODS

Patients between the ages of 0 and 18 years, who had liver transplantation in the organ transplantation center of our university hospital between 1997 and 2016, were included in the study. The age, sex, indications for the liver transplantation, complications after the transplantation, and long-term follow-up findings were retrospectively evaluated. The obtained results were analyzed with statistical methods.

RESULTS

In our organ transplantation center, 62 pediatric liver transplantations were carried out since 1997. The mean age of our patients was 7.3 years (6.5 months-17 years). The 4 most common reasons for liver transplantation were: Wilson's disease (n=10; 16.3%), biliary atresia (n=9; 14.5%), progressive familial intrahepatic cholestasis (n=8; 12.9%), and cryptogenic cirrhosis (n=7; 11.3%). The mortality rate after transplantation was 19.6% (12 of the total 62 patients). The observed acute and chronic rejection rates were 34% and 4.9%, respectively. Thrombosis (9.6%) was observed in the hepatic artery (4.8%) and portal vein (4.8%). Bile leakage and biliary stricture rates were 31% and 11%, respectively. 1-year and 5-year survival rates of our patients were 87% and 84%, respectively.

CONCLUSION

The morbidity and mortality rates in our organ transplantation center, regarding pediatric liver transplantations, are consistent with the literature.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evaluation of Pediatric Liver Transplantation-Related Artery Complications Using Intra-Operative Multi-Parameter Ultrasonography

Background

This article discusses the value of using multi-parameter evaluation of intra-operative ultrasonography in evaluating pediatric liver transplantation-related arterial complications.

Material/Methods

Sixty-eight children receiving a liver transplant underwent intraoperative ultrasonography for monitoring of artery hemodynamics. The ultrasonic measurement parameters included the diameters of the hepatic artery (HA) of the donor and anastomotic stoma, peak systolic velocity (PSV), resistance index (RI), acceleration time (SAT), and blood flow volume.

Results

After being treated immediately using surgery or other means, blood flow returned to normal in 8 cases, and did not in 3 cases, of whom 2 experienced postoperative HAT. There was a significant difference in HA diameter of the donor, anastomotic stoma diameter, PSV, RI, SAT, and blood flow volume before and after treatment of the donor in the complications group. Postoperative complications occurred in 7 of 68 recipients, including the 2 cases exhibiting complications during the surgery (complication group) and 5 without complications during the surgery (no complication group). There was a statistically significant difference (P<0.05) between the 2 groups in intraoperative ultrasonography parameters of HA diameter, anastomotic stoma diameter, RI, and blood flow volume.

Conclusions

Through intraoperative multi-parameter ultrasonic measurement, a definite diagnosis of hepatic artery complications can be made in liver transplantation patients. HA diameter of the donor, anastomotic stoma diameter, PSV, RI, SAT, and blood flow volume are important in assessing intraoperative artery complications.

Liver regeneration model in growing rats with hepatic artery ligation: histologic and molecular studies

BACKGROUND

Liver transplantation is an effective treatment for irreversible liver diseases. The incidence of hepatic artery thrombosis remains high. Our objective was to analyze the effect of ligature of the hepatic artery on liver regeneration in a growing animal model.

METHODS

Seventy-five male Wistar rats were divided into the following 3 groups: group 1 (sham, G1): incision without intervention; group 2 (G2): 70% hepatectomy; group 3 (G3): 70% hepatectomy and ligation of the hepatic artery. Preceding the 70% hepatectomy, a hepatic artery ligature was performed with resection of a segment of the artery. The liver specimens were stained with hematoxylin-eosin, and immunohistochemical staining for Ki-67 was performed. The expression of the interleukin (IL) 6 gene was studied by means of reverse-transcription polymerase chain reaction.

RESULTS

G2 and G3 demonstrated similar tendencies toward an increase in the gain weight ratio over time. The mitotic activity was significantly lower at 72 hours in G3 than in G2. There was no difference between Ki-67 staining between G2 and G3. The expression of the IL-6 gene was present in all of the groups, lower in G1, with no difference between G2 and G3.

CONCLUSIONS

The experimental model was feasible and adequate for these investigations. Hepatectomy stimulated hepatocyte proliferation, and the obstruction of the arterial flow did not affect liver regeneration.

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.

Risk factors for early and late biliary complications in pediatric liver transplantation

BC are a common source of morbidity after pediatric LT. Knowledge about risk factors may help to reduce their incidence. Retrospective analysis of BC in 116 pediatric patients (123 LT) (single institution, 05/1990-12/2011, medium follow-up 7.9 yr). One-, five-, and 10-yr survival was 91.1%, no patient died of BC. Prevalence and risk factors for anastomotic and intrahepatic BC were examined. There were 29 BC in 123 LT (23.6%), with three main categories: 10 (8.1%) primary anastomotic strictures, eight (6.5%) anastomotic leaks, and three (2.4%) intrahepatic strictures. Significant risk factors for anastomotic leaks were total operation time (increase 1.26-fold) and early HAT (<30 days post-LT; increase 5.87-fold). Risk factor for primary anastomotic stricture was duct-to-duct choledochal anastomosis (increase 5.96-fold when compared to biliary-enteric anastomosis). Risk factors for intrahepatic strictures were donor age >48 yr (increase 1.09-fold) and MELD score >30 (increase 1.2-fold). To avoid morbidity from anastomotic BC in pediatric LT, the preferred biliary anastomosis appears to be biliary-enteric. Operation time should be kept to a minimum, and HAT must by all means be prevented. Children with a high MELD score or receiving livers from older donors are at increased risk for intrahepatic strictures.

Surgical and endovascular treatment of hepatic arterial complications following liver transplant

Vascular complications after liver transplantation increase post-operative morbidity and contribute to the incidence of retransplantation. Vascular complications comprise arterial, caval, and portal venous pathology, with the majority of complications being arterial in etiology, including anastomotic stricture, pseudoaneurysm, and thrombosis. There are two major therapeutic options for the treatment of these arterial complications: endovascular intervention and surgery. The former includes intra-arterial thrombolysis, embolization, percutaneous transluminal angioplasty, and stent placement. The latter includes thrombectomy, reanastomosis, and retransplantation. Although surgical treatment has been considered the first choice for management in the past, advances in endovascular intervention have increased and make it a viable therapeutic option following orthotopic liver transplantation. This review focuses on the role of surgical and endovascular therapy in the management of hepatic arterial complications after liver transplantation.

Bile duct strictures after liver transplantation

PURPOSE OF REVIEW

Biliary complications account for relevant morbidity and mortality after liver transplantation. Advances have taken place in understanding their aetiology, in preventive operative techniques, imaging procedures, as well as interventional and endoscopic management. However, progress in living donation, donation after cardiac death as well as paediatric transplant procedures have changed the incidence and causes of biliary complications. This review summarizes recent progress in the field, particularly related to biliary strictures after liver transplantation.

RECENT FINDINGS

Significant findings in the period of interest for this review focussed on improvements of endoscopic treatment of postliver transplant biliary complications, including novel stenting devices, the routine analysis of bacterial and fungal flora, and the use of steroids to prevent postendoscopic retrograde cholangiopancreaticography pancreatitis. The importance of cytomegalovirus and hepatitis C in the aetiology of biliary complications was highlighted. Under certain circumstances, biliary complications after liver transplantation of organs secondary to donation after cardiac death may be reduced to a level known from liver transplantation after brain death. Further evidence was added to support the risk-adapted use of biliary drainage during liver transplantation.

SUMMARY

The ongoing research in the aetiology, prevention, and treatment of biliary strictures after liver transplantation highlights the significance of biliary complications for patient and graft outcome.

Minimally invasive endovascular and biliary treatments of children with acute hepatic artery thrombosis following liver transplantation

Hepatic artery thrombosis is a major problem after pediatric liver transplantation. Ischemia caused by hepatic artery thrombosis results in severe biliary and parenchymal damage and is associated with high rates of graft loss and mortality. We present a case-based pictorial essay to illustrate the role of minimally invasive treatment in the prompt management of acute hepatic artery thrombosis, and the associated biliary complications.

Reconstructing single hepatic artery with two arterial stumps: biliary complications in pediatric living donor liver transplantation

INTRODUCTION

Liver grafts can at times have two hepatic arterial stumps. This can result in a dilemma whether to reconstruct single or both the arteries. Hepatic artery (HA) thrombosis is the most dreaded complication in pediatric living donor liver transplantation (LDLT) as it can result in biliary complications and subsequent graft loss. We herein report the feasibility of reconstructing single hepatic artery in pediatric living donor liver transplantation having two arterial stumps in the liver graft.

MATERIALS AND METHODS

From 2008 to 2010, 87 pediatric patients undergoing LDLT were divided into three groups. Group 1 (n = 20): two HA stumps with two HA reconstruction, Group 2 (n = 22): two HA stumps with one HA reconstruction and Group 3 (n = 45): one HA stump with one HA reconstruction. The decision regarding the reconstruction of single or multiple HAs was made depending on the pre-operative radiological and intraoperative assessments.

RESULTS

The incidence of HA thrombosis (p = 0.126) and biliary complications (p = 0.617), was similar in the three groups.

CONCLUSION

Single HA reconstruction does not increase the risk of biliary strictures in pediatric LDLT recipients having dual hepatic arterial stumps in the liver graft.

Risk factors and treatments for hepatic arterial complications in pediatric living donor liver transplantation

BACKGROUND

Hepatic artery complications (HAC) are a serious complication in pediatric liver transplant recipients because its incidence is high and it can occasionally lead to graft liver failure. We herein present a retrospective analysis of our 10-year experience with pediatric living donor liver transplantation (LDLT) focusing on the risk factors and treatments for HAC.

METHODS

Between May 2001 and November 2011, 209 LDLTs were performed for 203 pediatric recipients. We performed the multivariate analyses to identify the factors associated with HAC and showed the therapeutic strategy and outcome for HAC.

RESULTS

The overall incidence of HAC was 7.2%, and the graft survival of recipients with HAC was 73.3%. The multivariate analysis showed that the pediatric end-stage liver disease score (≥20), post-transplant laparotomy except for HAC treatment and extra-anatomical hepatic artery reconstruction were independent risk factors for HAC (P = 0.020, P = 0.015 and P = 0.002, respectively). Eleven surgical interventions and 13 endovascular interventions were performed for 15 recipients with HAC. The serum aspartate aminotransferase levels pre- and post-treatment for HAC were significantly higher in the surgical group than in the endovascular group (P = 0.016 and P = 0.022, respectively).

CONCLUSIONS

It is important for recipients with risk factors to maintain strict post-transplant management to help prevent HAC and detect it in earlier stages. Endovascular intervention can be a less invasive method for treating HAC than surgical intervention, and can be performed as an early treatment.

Clinical experience with microdialysis catheters in pediatric liver transplants

Ischemic vascular complications and rejection occur more frequently with pediatric liver transplants versus adult liver transplants. Using intrahepatic microdialysis catheters, we measured lactate, pyruvate, glucose, and glycerol values at the bedside for a median of 10 days in 20 pediatric liver grafts. Ischemia (n = 6), which was defined as a lactate level > 3.0 mM and a lactate/pyruvate ratio > 20, was detected without a measurable time delay with 100% sensitivity and 86% specificity. Rejection (n = 8), which was defined as a lactate level > 2.0 mM and a lactate/pyruvate ratio < 20 lasting for 6 or more hours, was detected with 88% sensitivity and 45% specificity. With additional clinical criteria, the specificity was 83% without a decrease in the sensitivity. Rejection was detected at a median of 4 days (range = 1-7 days) before alanine aminotransferase increased (n = 5, P = 0.11), at a median of 4 days (range = 2-9 days) before total bilirubin increased 25% or more (n = 7, P = 0.04), and at a median of 6 days (range = 4-11 days) before biopsy was performed (n = 8, P = 0.05). In conclusion, microdialysis catheters can be used to detect episodes of ischemia and rejection before current standard methods in pediatric liver transplants with clinically acceptable levels of sensitivity and specificity. The catheters were well tolerated by the children, and no major complications related to the catheters were observed.