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

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.

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.

The Application of Interventional Radiology in Living-Donor Liver Transplantation

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

Utility of neonatal donors in pediatric liver transplantation: A single-center experience

BACKGROUND

The lack of age- and size-matched organs result in higher waiting list mortality in pediatric recipients than adults. Organs from deceased newborns and infants are a valuable source to increase donor pool in pediatric liver transplantation. However, the feasibility and safety of using neonatal donors have not been well evaluated.

METHODS

From 2014 to 2016, 48 deceased donor pediatric liver transplantations with donor age younger than 1 year old in our center were enrolled in this study. The recipients were divided into three groups based on the donor age (<1 month, 1 month ≤ to <3 months, and 3 months ≤ to <1 year). Recipient's characteristics, perioperative data, and postoperative complications were compared.

RESULTS

Two-year patient survival rates were 87.5%, 94.4%, and 95.5%, and 2-year graft survival rates were 75%, 94.4%, and 95.5%, respectively, without significant difference. The liver grafts from donors younger than 3 months were more advantageous in terms of acute rejection and virus infection, while the young grafts were related to slight higher incidence of hepatic artery thrombosis and SFSS. Those complications could be effectively prevented or treated by our perioperative care strategies. In addition, eight recipients who received neonatal livers achieved comparable outcomes with recipients with older livers.

CONCLUSION

Our data revealed that the application of liver grafts from donors younger than 1 year old could achieve excellent outcome. In particular, neonatal donors could be safely used in well-selected patients.

Early Hepatic Artery Thrombosis After Pediatric Living Donor Liver Transplantation

AIM

Hepatic artery thrombosis is one of the major complications affecting patient and graft survival after liver transplantation. In this study, we analyzed the factors affecting the development of early hepatic artery thrombosis (eHAT) and its outcomes in pediatric liver transplantation.

METHODS

A total of 175 pediatric patients underwent living donor liver transplantation between January 2013 and November 2018. Factors affecting eHAT and its outcomes were examined.

RESULTS

Nine patients (5.1%) developed eHAT. In multivariate analysis, intraoperative hepatic artery revision and Roux-en-Y hepaticojejunostomy biliary reconstruction type were statistically significant (all, P < .05). Thrombectomy and reanastomosis was performed in 5 patients. Two of them were successful. In total, 3 retransplantations were performed and all of those patients are still alive.

CONCLUSION

The factors affecting eHAT are still a matter of debate. Intraoperative hepatic artery anastomosis revision and Roux-en-Y hepaticojejunostomy reconstruction were independent risk factors for development of eHAT. In the present study, the confidence interval of the variables is high, therefore exact determination of the risk factors may not be possible. Early detection and thrombectomy and reanastomosis may be the first treatment of choice to rescue the patient and graft. When it fails, retransplantation must be an alternative. The results of the present study state that at least once a day the vascular anastomosis must be examined by Doppler ultrasonography in the post-transplant first week. It must be repeated when liver enzymes increase. The patients under high risk for eHAT may be followed up closer.

Tardus parvus waveforms in Doppler ultrasonography for hepatic artery stenosis after liver transplantation: can a new cut-off value guide the next step?

PURPOSE

Considering the high false-positive diagnosis of the tardus parvus waveform (TPW) in Doppler ultrasonography (DUS) for hepatic artery stenosis (HAS) after liver transplantation (LT), this study aimed to determine clinical features and new cut-off values to help guide treatment.

MATERIALS AND METHODS

This retrospective study was approved by an Institutional Review Board. A total of 171 LT recipients were included and underwent DUS and either computed tomography angiography or digital subtraction angiography with an interval < 4 weeks at least 1 month post-LT. The DUS of 69 patients exhibited TPW [defined as resistive index (RI) < 0.5 and systolic acceleration time (SAT) > 0.08 s]. A multilevel likelihood ratio (LR) analysis was used to explore new cut-off values for DUS. In addition, abnormal liver function was considered additional evidence (defined as any liver enzyme > 3-fold of the upper limit of normal level or 2-fold increased). The results were stratified into three categories, category 1 (subjects with traditional TPW), category 2 (subjects with traditional TPW and abnormal liver function), and category 3 (subjects with traditional TPW and abnormal liver function, or with new cut-off values), and the diagnostic performance of each category was analyzed.

RESULTS

The LR analysis revealed new cut-off values of RI < 0.4 (LR = 10.58) or SAT > 0.12 s (LR = 16.46). The false-positive rates for categories 2 and 3 were significantly lower (7.6% vs. 18.1%, P = 0.038; 1.9% vs. 18.1%, P < 0.001, respectively) than those for category 1, while the sensitivity for category 2 was significantly lower (41.8% vs. 74.6%, P < 0.001; 41.8% vs. 61.2%, P = 0.038, respectively) than that for categories 1 and 3.

CONCLUSION

Using either (1) RI < 0.4 or SAT > 0.12 s, or (2) traditional TPW (RI < 0.5 and SAT > 0.08 s) in the presence of abnormal liver functions as the DUS criteria for HAS will significantly decrease the false-positive rate compared to traditional TPW without a significant increase in the false-negative rate.

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.

Outcomes of Liver Transplantation Using Pediatric Deceased Donor Livers: A Single-Center Analysis of 102 Donors

BACKGROUND

The outcome of pediatric deceased donor liver transplantation (LT) has not been well studied, especially pediatric deceased donor livers used in adult transplantation. This study aimed to evaluate the efficacy of LT using pediatric deceased donor livers and compare the outcomes between pediatric-to-pediatric LT and pediatric-to-adult LT.

METHODS

A retrospective review of LT using pediatric deceased donor livers from June 2013 to August 2016 was performed. The patients were divided into the pediatric-to-pediatric LT group and pediatric-to-adult LT group based on the ages of the recipients. The survival and incidence of early vascular complications (VCs) were observed between the two groups. We also analyzed the risk factors of early VCs in pediatric LT and the effect of donor hypernatremia on the prognosis of recipients.

RESULTS

There were 102 cases of LT using pediatric deceased donor livers in our hospital from June 2013 to August 2016, 83 pediatric-to-pediatric LT (recipients' age ≤13 years) and 19 pediatric-to-adult LT (recipients' age ≥19 years). The ratio of early VC was similar in the two groups (19.3% vs. 10.6%, P = 0.514). Low body weight of recipient was an independent risk factor of early VC in pediatric LT (odds ratio: 0.856, 95% confidence interval: 0.752-0.975, P = 0.019). The 1-year cumulative survival rates of grafts and patients were 89.16% and 91.57% in pediatric-to-pediatric LT and 89.47% and 94.74% in pediatric-to-adult LT, respectively (all P > 0.05). In all cases, patients using donors with hypernatremia (serum sodium levels ≥150 mmol/L) had worse graft survival (χ2=4.330, P = 0.037).

CONCLUSIONS

Pediatric-to-pediatric LT group has similar graft and patient survival rates with those of pediatric-to-adult LT group. Low body weight of recipients is an independent risk factor of early VC in pediatric LT. Patients using donors with hypernatremia have worse graft survival.

Arterial and biliary complications after living donor liver transplantation: a single-center retrospective study and literature review

AIM

The mortality of patients on the waiting list for deceased donor liver transplantation (DDLT) is high, especially in countries where donation rates are low. Thus, living donor liver transplantation (LDLT) is an attractive option. However, compared with DDLT, LDLT is associated with increased rates of arterial and biliary complications. We examined the rates of complications and risk factors following LDLT.

METHODS

We retrospectively investigated and compared the rates of complications of DDLT and LDLT in our institute. We also performed univariate and multivariate analyses to identify the independent risk factors for these complications. The complications and specific disadvantages of LDLT were reviewed and discussed.

RESULTS

The incidence rate of arterial complications in LDLT was 6.0%, compared with 3.2% (13/441) in DDLT. A multivariate analysis identified low body weight (P = 0.032) as the only independent risk factor for hepatic artery thrombosis. The rate of all biliary complications in LDLT was 17.3%, compared with 18.7% in DDLT. The risk factors for biliary stricture identified by the multivariate analysis were recurrent cholangitis and the number of bile ducts. The durations of hospital stay and overall survival rates were similar between the two groups.

CONCLUSION

Given the shortage of deceased donor organs, we believe that LDLT is acceptable in an attempt to meet demand.

Translational microsurgery. A new platform for transplantation research

PURPOSE

Clinical microsurgery has been introduced in many fields, while experimental microsurgery has the cross-disciplinary features of the sciences and techniques for growth of medicine, pharmacology, veterinary, engineering etc. Training protocol, proposing a new name as Translational Microsurgery, was introduced.

METHODS

Reconstructive skills of hepatic artery in pediatric living donor liver transplantation were summarized. Ex vivo training protocol using artificial blood vessel for surgeons was proposed.

RESULTS

Clinical microsurgery requires anastomosis with delicate arteries and limited field of view. Our training protocol revealed that the relation between the score and speed was seen, while not all the surgeons with enough experience got high score. This training led to muster clinical skills and to apply excellent experimental works.

CONCLUSIONS

Our microsurgical training protocol has been planned from the points of clinical setting. Training for vascular anastomosis led to rodent transplantation models. These models were used for immunology and immunosuppressant research. Microsurgical techniques led to master catheter technique and to inject various drugs or gene vectors.

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.

Dorsal approach plus branch patch technique is the preferred method for liver transplanting small babies with monosegmental grafts

PURPOSE

When living donor liver transplantation (LDLT) is performed on small infant patients, the incidence of hepatic artery complications (HACs) is high. Here, we present a retrospective analysis that focuses on our surgical procedure for hepatic arterial reconstruction and the outcomes of monosegmental LDLT.

METHODS

Of the 275 patients who underwent LDLT between May 2001 and December 2015, 13 patients (4.7 %) underwent monosegmental LDLT. Hepatic artery reconstruction was performed under a microscope. The size discrepancy between the graft and the recipient's abdominal cavity was defined as the graft to recipient distance ratio (GRDR) between the left hepatic vein and the portal vein (PV) bifurcation on a preoperative computed tomography scan. HACs were defined as hepatic arterial hypoperfusion.

RESULTS

Recipient hepatic arteries were selected for the branch patch technique in five cases (38.5 %), and the diameter was 2.2 ± 0.6 mm. The anastomotic approaches selected were the dorsal position of the PV in seven cases (53.8 %) and the ventral position in six, and the GRDRs were 2.8 ± 0.4 and 1.9 ± 0.5, respectively (p = 0.012). The incidence rate of HACs caused by external factors, such as compression or inflammation around the anastomotic site, was significantly higher in monosegmental than in non-monosegmental graft recipients (15.4 vs. 1.1 %, p < 0.001).

CONCLUSION

Although monosegmental graft recipients experienced HACs caused by external factors around the anastomotic field, hepatic arterial reconstruction could be safely performed. Important components of successful hepatic arterial reconstructions include the employment of the branch patch technique and the selection of the dorsal approach.

Impact of early reoperation following living-donor liver transplantation on graft survival

BACKGROUND

The reoperation rate remains high after liver transplantation and the impact of reoperation on graft and recipient outcome is unclear. The aim of our study is to evaluate the impact of early reoperation following living-donor liver transplantation (LDLT) on graft and recipient survival.

METHODS

Recipients that underwent LDLT (n = 111) at the University of Tokyo Hospital between January 2007 and December 2012 were divided into two groups, a reoperation group (n = 27) and a non-reoperation group (n = 84), and case-control study was conducted.

RESULTS

Early reoperation was performed in 27 recipients (24.3%). Mean time [standard deviation] from LDLT to reoperation was 10 [9.4] days. Female sex, Child-Pugh class C, Non-HCV etiology, fulminant hepatitis, and the amount of intraoperative fresh frozen plasma administered were identified as possibly predictive variables, among which females and the amount of FFP were identified as independent risk factors for early reoperation by multivariable analysis. The 3-, and 6- month graft survival rates were 88.9% (95%confidential intervals [CI], 70.7-96.4), and 85.2% (95%CI, 66.5-94.3), respectively, in the reoperation group (n = 27), and 95.2% (95%CI, 88.0-98.2), and 92.9% (95%CI, 85.0-96.8), respectively, in the non-reoperation group (n = 84) (the log-rank test, p = 0.31). The 12- and 36- month overall survival rates were 96.3% (95%CI, 77.9-99.5), and 88.3% (95%CI, 69.3-96.2), respectively, in the reoperation group, and 89.3% (95%CI, 80.7-94.3) and 88.0% (95%CI, 79.2-93.4), respectively, in the non-reoperation group (the log-rank test, p = 0.59).

CONCLUSIONS

Observed graft survival for the recipients who underwent reoperation was lower compared to those who did not undergo reoperation, though the result was not significantly different. Recipient overall survival with reoperation was comparable to that without reoperation. The present findings enhance the importance of vigilant surveillance for postoperative complication and surgical rescue at an early postoperative stage in the LDLT setting.