Living donor liver transplantation for children in Brazil weighing less than 10 kilograms

Hepatic venous reconstruction of the left lateral segment with emphasis on anomalous hepatic vein in pediatric liver transplantation

Left lateral segment grafts have become a suitable option in pediatric liver transplantation (PLT). The correlation between hepatic vein (HV) reconstruction and outcome is relevant when assessing the safe use of these grafts. We retrospectively reviewed the medical records prospectively collected from a pediatric living donor liver transplantation database and conducted a comparative analysis of the different left lateral segment graft types according to HV reconstruction. Donor, recipient, and intraoperative variables were analyzed. Post-transplant outcomes included vascular complications such as hepatic vein outflow obstruction, early (≤30 d) and late (>30 d) PVT, hepatic artery thrombosis, and graft survival. From February 2017 to August 2021, 303 PLTs were performed. According to venous anatomy, the distribution of the left lateral segment was as follows: single HV (type I) in 174 (57.4%), close HVs, simple venoplasty for reconstruction (type II) in 97 (32.01%), anomalous hepatic vein (AHV) with a distance between the HVs orifices that allowed simple venoplasty (type IIIA) in 25 (8.26%) and AHV with a distance between the HVs orifices requiring homologous venous graft interposition (type IIIB) in 07 (2.31%) grafts. Type IIIB grafts came from male donors ( p =0.04) and had a higher mean donor height ( p =0.008), a higher mean graft weight, and a higher graft-to-recipient weight ratio, both p =0.002. The median follow-up time was 41.4 months. The overall cumulative graft survival was 96.3%, and comparative graft survival showed no difference (log-rank p =0.61). No hepatic vein outflow obstructions were observed in this cohort study. There was no statistically significant difference in the post-transplant outcomes between the graft types. The venous reconstruction of the AHV with homologous venous graft interposition had similar outcomes in the short and long term.

Association of different central venous pressure levels with outcome of living-donor liver transplantation in children under 12 years

BACKGROUND

Pediatric liver transplantation is an important modality for treating biliary atresia. The overall survival (OS) rate of pediatric liver transplantation has significantly improved compared with that of 20 years ago, but it is still unsatisfactory. The anesthesia strategy of maintaining low central venous pressure (CVP) has shown a positive effect on prognosis in adult liver transplantation. However, this relationship remains unclear in pediatric liver transplantation. Thus, this study was conducted to review the data of pediatric living-donor liver transplantation to analyze the associations of different CVP levels with the prognosis of recipients.

METHODS

This was a retrospective study and the patients were divided into two groups according to CVP levels after abdominal closure: low CVP (LCVP) (≤ 10 cmH₂O, n = 470) and high CVP (HCVP) (> 10 cmH₂O, n = 242). The primary outcome measured in the study was the overall survival rate. The secondary outcomes included the duration of mechanical ventilation in the intensive care unit (ICU), length of stay in the ICU, and postoperative stay in the hospital. Patient demographic and perioperative data were collected and compared between the two groups. Kaplan-Meier curves were constructed to determine the associations of different CVP levels with the survival rate.

RESULTS

In the study, 712 patients, including 470 in the LCVP group and 242 in the HCVP group, were enrolled. After propensity score matching, 212 pairs remained in the group. The LCVP group showed a higher overall survival rate than the HCVP group in the Kaplan-Meier curves and multivariate Cox regression analyses (P = 0.018), and the HCVP group had a hazard ratio of 2.445 (95% confidence interval, 1.163-5.140).

CONCLUSION

This study confirmed that a low-CVP level at the end of surgery is associated with improved overall survival and a shorter length of hospital stay.

Thoracic epidural analgesia and immediate extubation for less than 10 kg infants undergoing living donor liver transplantation: A report of two successful cases

BACKGROUND

Perioperative pain management in small infants weighing <10 kg undergoing liver transplantation is challenging. The use of TEA in this setting has not been reported, as well as its potential role to facilitate IE, ie, in the OR.

METHODS

We describe here the use of TEA in two small infants who had IE after a LDLT procedure.

RESULTS

TEA was successfully performed and IE was achieved in both cases. Postoperative analgesia assessment in the OR was satisfactory according to the FLACC pain scale, with scores of 2 and 3 for each patient, respectively. There were no major complications in the postoperative period, and the two children were discharged home uneventfully.

CONCLUSIONS

The use of TEA and its influence on IE rate and other perioperative outcomes should be more explored in small infants undergoing LDLT.

Predictors of patient and graft survival following pediatric liver transplantation: Long-term analysis of more than 300 cases from single centre

BACKGROUND

Pediatric liver transplant (PLT) activity has flourished over time although with limited expansion in the graft pool. The study aims to identify pre-transplant factors that predict post-transplant patient and graft survival in the PLT population.

METHODS

Retrospective review of PLTs at a single tertiary transplant unit from 2000 to 2019. Univariate and multivariate analyses of pre-transplant factors were performed to identify predictors of patient and graft survival.

RESULTS

Two hundred and seventy-six patients received 320 PLTs. The most common cause of graft loss was hepatic artery thrombosis (n = 13, 29.6%). The most common cause of mortality was sepsis (n = 11, 29.7%). Univariate analysis showed that the following variables had a significant (p < .05) impact on patient survival: recipient age, weight, height, graft type (technical variant graft), transplant category (acute liver failure), the era of transplant, and invasive ventilation. The following variables had a significant (p < .05) impact on graft survival: recipient age, weight, height, transplant category (acute liver failure), and the era of transplant. Multivariate analysis precluded the era of transplant as the only significant factor for patient survival; patients transplanted after 2005 had significantly higher patient survival. No independent factor predicting graft survival was identified. For children transplanted after 2005, the only factor that predicted patient survival was pre-transplant invasive ventilation.

CONCLUSIONS

Our study suggests that the learning curve and pre-transplant invasive ventilation in the recipient have a significant impact on patient survival. The traditional view of worse outcomes of smaller PLT candidates should be changed.

Impact of hypoxemia on pediatric liver transplantation for hepatopulmonary syndrome

BACKGROUND

The treatment of choice for patients with cirrhosis and HPS is LT. The clinical manifestations associated with hypoxemia result in limitations and a poor health-related quality of life of affected patients. The present report aims to study the differences in outcomes between patients with PaO₂  < 50 mm Hg and those with PaO₂  ≥ 50 mm Hg.

METHODS

This was a retrospective study of 21 patients under 18 years of age conducted from 2001 to 2018; the patients were divided into 2 groups: G1-PaO₂  ≥ 50 mm Hg, 11 patients, and G2-PaO₂  < 50 mm Hg, 10 patients. Demographic, clinical, laboratory, and perioperative data; outcome variables; and post-transplant survival were compared between the groups.

RESULTS

In total, 2/11 (18.2%) patients in G1 and 8/10 (80%) patients in G2 required supplemental oxygen therapy at home (P = .005). Patients in G2 required prolonged MV (median 8.5 days in G2 vs 1 day in G1, P = .015) and prolonged ICU and hospital stays (P = .002 and P = .001, respectively). Oxygen weaning time was longer in G2 (median 127.5 days) than in G1 (median 3 days; P = .004). One (9.1%) patient in G1 and three (30%) patients in G2 died (P = .22). The survival at 90 months was 90.9% in G1 and 70% in G2 (P = .22).

CONCLUSION

The survival between groups was similar. Patients with very severe HPS required a longer MV time, longer ICU and hospital stays, and a longer O₂ weaning time than those with mild, moderate, or severe HPS.

Risk Factors Affecting Outcomes in Pediatric Liver Transplantation: A Real-World Single-Center Experience

Background

Despite liver transplantation (LT) being the standard treatment for pediatric end-stage liver disease, complications often persist and can adversely affect the post-transplant outcomes. This study aimed to identify the risk factors affecting the outcomes in pediatric LT patients.

Material/Methods

Data from pediatric patients who underwent primary LT from March 1988 to December 2018 were retrospectively analyzed. Chronic liver disease was defined as an explanted liver showing fibrosis regardless of grade, cirrhosis, or any other underlying disease that may cause progressive liver injury leading to fibrosis or cirrhosis.

Results

A total of 255 pediatric patients underwent LT during the study period. Their 1-, 5-, and 10-year overall survival rates were 90.5%, 88.4%, and 87.8%, respectively. According to multivariate analysis, while liver disease without underlying chronic liver disease (P=0.024) and a pediatric end-stage liver disease (PELD) score ≥30 (P=0.036) were the only factors associated with worse survival, body weight <6 kg (P=0.050), whole-liver DDLT compared to LDLT (P=0.001), fulminant liver failure (P=0.008), and postoperative hepatic artery complications (P<0.001) were associated with worse graft survival. Liver disease without underlying chronic liver disease was the only factor independently associated with hepatic artery complications (P=0.003).

Conclusions

Greater caution is recommended in pediatric patients with liver disease unaccompanied by underlying chronic liver disease, high PELD score, or low body weight to improve survival after LT. Hepatic artery complication was the only surgical complication affecting the graft survival outcome, especially in patients having liver disease without underlying chronic liver disease.

The "W" Technique: A Safe and Reproducible Technique for Hepatic Artery Reconstruction in Living Donor Liver Transplantation

Background

Reconstruction of the hepatic arterial inflow can be technically demanding in living donor liver transplantation, and thrombosis can result in graft loss and mortality. We describe the safe and reproducible “W” technique to reconstruct the hepatic artery and outcomes before and after adoption of the technique in a consecutive series of liver transplants at 2 high-volume living donor liver transplant centers.

Material/Methods

Prospectively collected data were analyzed to compare the outcomes before and after introduction of a standardized “W” technique for reconstruction of the hepatic artery in 2 high-volume living donor liver transplant programs.

Results

In a consecutive series of 675 liver transplants, of which 27 were deceased donor transplants and 648 were living donor transplants, 443 transplants were performed with a standard interrupted reconstruction of the hepatic artery under loupes. These transplants were performed by a single surgeon, with an incidence of hepatic artery thrombosis of 2%. After introduction of the “W” technique, despite the arterial reconstruction being done by several surgeons in the early part of their learning curve, the incidence of hepatic artery thrombosis decreased to 0.86% in the next 232 transplants.

Conclusions

The “W” technique is a simple, easy to learn and teach technique for reconstruction of the hepatic artery without the use of the operating microscope in living donor liver transplantation.

Technical Choices in Pediatric Living Donor Liver Transplantation: The Path to Reduce Vascular Complications and Improve Survival

Pediatric living donor liver transplantation (PLDLT) is a successful therapeutic option for children with chronic and acute liver disease. After early transplant results, many technical advancements were introduced in the field to reduce the rate of complications and improve survival. The aim of this study is to present the outcomes of 975 primary PLDLTs in 3 periods: initial practice (period 1, 29 patients, January 1995 to December 1999), second period (period 2, 331 patients, January 2000 to December 2009), and third period (period 3 [P3], 615 patients, January 2010 to September 2019). Among the technical refinements introduced in P3 are the use of hyperreduced left lateral segment grafts, abdominal wall prosthetic mesh closure, double hepatic artery anastomosis, and increased use of vascular grafts for portal vein reconstruction. The outcomes included significant reductions of hepatic artery thrombosis (HAT), early portal vein thrombosis (EPVT), and retransplantation, with better patient and graft survival in P3. Additional analyses showed that the factors independently associated with worse 90-day patient survival were HAT, EPVT, and increasing Pediatric End-Stage Liver Disease score. In conclusion, the introduction of technical refinements in P3, in addition to improvements in patient care, determined a reduction in EPVT, HAT, and retransplantation. Consequently, patient and graft survival rates increased in all time points studied.

Outcomes of Pediatric Liver Transplantation in Korea Using Two National Registries

Background: This retrospective study aimed to evaluate overall survival and the risk factors for mortality among Korean pediatric liver transplantation (LT) patients using data from two national registries: the Korean Network Organ Sharing (KONOS) of the Korea Centers for Disease Control and Prevention and the Korean Organ Transplantation Registry (KOTRY). Methods: Prospectively collected data of 755 pediatric patients who underwent primary LT (KONOS, February 2000 to December 2015; KOTRY, May 2014 to December 2017) were retrospectively reviewed. Results: The 1-, 5-, 10-, and 15-year survival rates were 90.6%, 86.7%, 85.8%, and 85.5%, respectively, in KONOS, and the 1-month, 3-month, 1-year, and 2-year survival rates were 92.1%, 89.4%, 89.4%, and 87.2%, respectively, in KOTRY. There was no significant difference in survival between the two registries. Multivariate analysis identified that body weight ≥6 kg (p <0.001), biliary atresia as underlying liver disease (p = 0.001), and high-volume center (p < 0.001) were associated with better survival according to the KONOS database, while hepatic artery complication (p < 0.001) was associated with poorer overall survival rates according to the KOTRY database. Conclusion: Long-term pediatric patient survival after LT was satisfactory in this Korean national registry analysis. However, children with risk factors for poor outcomes should be carefully managed after LT.

Outcome after pediatric liver transplantation for staged abdominal wall closure with use of biological mesh-Study with long-term follow-up

Abdominal wall closure after pediatric liver transplantation (pLT) in infants may be hampered by graft-to-recipient size discrepancy. Herein, we describe the use of a porcine dermal collagen acellular graft (PDCG) as a biological mesh (BM) for abdominal wall closure in pLT recipients. Patients <2 years of age, who underwent pLT from 2011 to 2014, were analyzed, divided into definite abdominal wall closure with and without implantation of a BM. Primary end-point was the occurrence of postoperative abdominal wall infection. Secondary end-points included 1- and 5-year patient and graft survival and the development of abdominal wall hernia. In five out of 21 pLT recipients (23.8%), direct abdominal wall closure was achieved, whereas 16 recipients (76.2%) received a BM. BM removal was necessary in one patient (6.3%) due to abdominal wall infection, whereas no abdominal wall infection occurred in the no-BM group. No significant differences between the two groups were observed for 1- and 5-year patient and graft survival. Two late abdominal wall hernias were observed in the BM group vs none in the no-BM group. Definite abdominal wall closure with a BM after pLT is feasible and safe when direct closure cannot be achieved with comparable postoperative patient and graft survival rates.

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.

Graft reduction using a powered stapler in pediatric living donor liver transplantation

Large-for-size syndrome is defined by inadequate tissue oxygenation, which results in vascular complications and graft compression after abdominal closure in living donor liver transplantation recipients. An accurate graft reduction that matches the optimal liver volume for the recipient is essential. We herein initially present the feasibility and safety of graft reduction using a powered stapler to obtain an optimal graft size. From October 1996 to October 2015, a total of eight graft reductions were performed using a powered stapler (group A; n=4) or by the conventional method using a cavitron ultrasonic surgical aspirator and portal triad suturing (group B; n=4). The background, intraoperative findings and the post-operative outcomes of these eight patients were retrospectively investigated. There were no statistically significant differences in the background of the patients in the two groups. Graft reduction was successfully achieved without any intraoperative complications in group A, whereas intraoperative complications, such as bleeding and bile leakage, occurred in two patients of group B. No post-operative surgical complications were detected on computed tomography; moreover, the serum aspartate aminotransferase level normalized significantly earlier in group A (P<.05). In summary, graft reduction using a powered stapler was feasible and safe in comparison with the conventional method.

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.

Is size the only determinant of delayed abdominal closure in pediatric liver transplant?

The aim was to determine the factors associated with the use of delayed abdominal closure in pediatric liver transplantation (LT) and whether this affected outcome. From a prospectively maintained database, transplants performed in children (≤18 years) were identified (October 2010 to March 2015). Primary abdominal closure was defined as mass closure performed at time of transplant. Delayed abdominal closure was defined as mass closure not initially performed at the same time as transplant; 230 children underwent LT. Of these, 176 (76.5%) had primary closure. Age was similar between the primary and delayed groups (5.0 ± 4.9 versus 3.9 ± 5.0 years; P = 0.13). There was no difference in the graft-to-recipient weight ratio (GRWR) in the primary and delayed groups (3.4 ± 2.8 versus 4.1 ± 2.1; P = 0.12). Children with acute liver failure (ALF) were more likely to experience delayed closure then those with chronic liver disease (CLD; P < 0.001). GRWR was similar between the ALF and CLD (3.4 ± 2.4 versus 3.6 ± 2.7; P = 0.68). Primary closure children had a shorter hospital stay (P < 0.001), spent fewer days in pediatric intensive care unit (PICU; P = 0.001), and required a shorter duration of ventilation (P < 0.001). Vascular complications (arterial and venous) were similar (primary 8.2% versus delayed 5.6%; P = 0.52). Graft (P = 0.42) and child survival (P = 0.65) in the primary and delayed groups were similar. Considering timing of mass closure after transplant, patients in the early delayed closure group (<6 weeks) were found to experience a shorter time of ventilation (P = 0.03) and in PICU (P = 0.003). In conclusion, ALF was the main determinant of delayed abdominal closure rather than GRWR. The optimal time for delayed closure is within 6 weeks. The use of delayed abdominal closure does not adversely affect graft/child survival. Liver Transplantation 23 352-360 2017 AASLD.

Alternatives for vascular reconstruction in pediatric living donor liver transplantation

Many publications discuss the various strategies for vascular reconstruction (VR) in pediatric LDLT. Having knowledge of alternative techniques is helpful in planning transplants. This article presents three case reports that illustrate some of the alternative techniques for HV, PV, and HA reconstruction in pediatric LDLT. It also reviews the available alternative strategies reported for VR in pediatric LDLT. In the first case, a 13-month-old girl presented a PRETEXT III HB with invasion of the retrohepatic vena cava. An LLS graft HV was anastomosed to a DD iliac vein graft and subsequently implanted in a "standard" fashion in the recipient. In the second case, a 44-month-old boy presented with multifocal HB and portomesenteric thrombosis and the portal inflow was done through a renoportal anastomosis. In the third case, a 22-month-old child with a failed Kasai procedure had extensive HA thrombosis. The HA reconstruction was performed with an interposition of the recipient's IMV graft. The use of alternative techniques for VR in pediatric LDLT is paramount to the success of such a complex procedure. Imaging studies can help transplant surgeons outline surgical strategies and define the best technique to be used in each case.

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.

Analysis of factors associated with portal vein thrombosis in pediatric living donor liver transplant recipients

The technique of vascular reconstruction plays a major role in the outcome of living donor liver transplantation (LDLT). An increased use of vascular grafts (VGs) as replacements for sclerotic portal veins has become a standard technique for our group. The aim of this study was to analyze the factors associated with portal vein thrombosis (PVT) in pediatric LDLT. We performed a retrospective analysis of 486 primary pediatric LDLT procedures performed between October 1995 and May 2013. VGs used for portal reconstruction included living donor inferior mesenteric veins, living donor ovarian veins, recipient internal jugular veins, deceased donor iliac arteries, and deceased donor iliac veins. Thirty-four patients (7.0%) developed PVT. The incidence of PVT dropped from 10.1% to 2%; the overall utilization of VGs increased from 3.5% to 37.1%. In a multivariate analysis, only the use of VGs remained an independent risk factor for the occurrence of PVT (hazard ratio = 7.2, 95% confidence interval = 2.8-18.7, P < 0.001). There was no difference in survival rates between patients with PVT and patients without PVT. No patient with PVT underwent retransplantation. In conclusion, the use of VGs was independently associated with the development of PVT. Over time, there was a reduction in the incidence of early PVT in this cohort, and there was a trend toward a reduction in total PVT. The occurrence of isolated PVT in this study was not associated with decreased patient or graft survival.

Liver transplantation in children weighing less than 10 kg: Chilean experience

BACKGROUND

Orthotopic liver transplantation is the treatment of choice for most terminal liver diseases in children. In small children (≤ 10 kg), this procedure is challenging and has special considerations. The aim of this study is to describe the experience of a Chilean liver transplantation program in this subgroup of patients.

METHODS

The liver transplant database of Hospital Luis Calvo Mackenna and Clinica Las Condes was reviewed. All children less than 10 kg undergoing liver transplantation between January 1994 and July 2011 were included. Patient and graft outcomes and main complications were analyzed.

RESULTS

We have performed 230 pediatric liver transplantations, 49 of them in 41 patients weighing less than 10 kg. The first indication for transplantation was biliary atresia in 25 patients (61%). A living related donor was used in 23 cases (51%). Actuarial survival was 75.7% at 1 year and 67.1% at 5 years. The main cause of death was infection, and the leading cause of graft loss was vascular complication.

DISCUSSION

Our transplant program includes 2 centers that perform more than 90% of pediatric liver transplantations in Chile, including public health pediatric patients from all around the country. Patients weighing less than 10 kg represent the most challenging group in pediatric liver transplantation due to higher rates of vascular and biliary complications and postoperative infections.

Transplantation with hyper-reduced liver grafts in children under 10 kg of weight

BACKGROUND

We had previously described a left lateral segment hyper-reduction technique capable of sizing the graft according to the volume of the abdominal cavity of the recipient.

AIM

The purpose of our study was to evaluate our 14-year live-donor liver transplantation experience with in situ graft hyper-reduction in children under 10 kg of weight.

PATIENTS AND METHODS

Between January 1997 and May 2011, we performed 881 liver transplants. Two hundred and seventy-seven (n = 277) involved pediatric recipients, of which 102 (37 %) were from live donors. Thirty-five (n = 35) patients under 10 kg of weight underwent hyper-reduced living donor liver transplants. There were 21 females (60 %) and 14 males (40 %), with a median age of 12 months (range 3-23) and a median weight of 7.7 kg (range 5.6-10).

RESULTS

Median operative time was 350 min (range 180-510). Median cold ischemia time was 180 min (range 60-300). Twenty-six (n = 26) patients required intraoperative transfusion of blood products. There were 49 postoperative complications involving 26 patients (74 % morbidity rate). One-, 3-, and 5-year survival rates were 87, 79, and 74 %, respectively. Twenty-eight patients are currently alive.

CONCLUSIONS

Hyper-reduced grafts provide an alternative approach for low-weight pediatric recipients. The relatively high immediate postoperative morbidity could be related to the complexity of these patients.

Living donor liver transplantation in 43 children with biliary atresia: a single-center experience from the mainland of China

BACKGROUND

There is no large-cohort report on living donor liver transplantation (LDLT) for biliary atresia (BA) patients from the mainland of China. This single-center study describes our initial experience with 43 LDLTs for BA patients aged two years or younger.

METHODS

In this study, the eligibility criteria were BA as the primary diagnosis and two years of age or younger. From October 2006 to December 2010, the clinical data of 43 LDLTs, including pre-operative evaluations, surgical techniques, postoperative complications and outcomes of donors and recipients, were retrospectively analyzed.

RESULTS

Donor graft type was the left lateral segment with compatible ABO blood groups. Forty-three recipients were selected in this study. The median patient age at operation was 9 months (range 6-24), and the median body weight was 8 kg (range 5.7-12.5). Fourteen (32.6%) recipients received Kasai operations before liver transplantation. The overall one- and two-year cumulative survival rates for grafts and recipients were 81%, 81% and 76%, 76%, respectively. No donor mortality was encountered, with a minimal morbidity and no long-term sequelae. Nine out of 43 recipients died. Postoperative complications of recipients were biliary leakage and refluxing cholangitis (11/43, 25.6%), hepatic artery thrombosis (4, 9.3%), pulmonary infections (4, 9.3%), portal vein thrombosis (3, 7.0%), wound disruption (3, 7.0%), acute rejection (3, 7.0%), cytomegalovirus infection (2, 4.7%), and intra-abdominal bleeding (1, 2.3%).

CONCLUSION

Despite the relatively low survival rates due to lack of experience initially, LDLT still provides encouraging outcomes for pediatric recipients with BA, even small children under two years old.

Four hundred thirty consecutive pediatric living donor liver transplants: variables associated with posttransplant patient and graft survival

The availability of living donors allows transplant teams to indicate living donor liver transplantation (LDLT) early in the course of liver disease before the occurrence of life-threatening complications. Late referral to transplant centers is still a problem and can compromise the success of the procedure. The aim of this study was to examine the perioperative factors associated with patient and graft survival for 430 consecutive pediatric LDLT procedures at Sirio-Libanes Hospital/A. C. Camargo Hospital (São Paulo, Brazil) between October 1995 and April 2011. The studied pretransplant variables included the following: recipient age and body weight, Pediatric End-Stage Liver Disease score, z score for height/age, bilirubin, albumin, international normalized ratio, hemoglobin, sodium, presence of ascites, and previous surgery. The analyzed technical aspects included the graft-to-recipient weight ratio and the use of vascular grafts for portal vein reconstruction. In addition, the occurrence of hepatic artery thrombosis (HAT), portal vein thrombosis (PVT), and biliary complications was also analyzed. The liver grafts included 348 left lateral segments, 5 monosegments, 51 left lobes, and 9 right lobes. In a univariate analysis, an age < 12 months, a low body weight (≤10 kg), malnutrition, hyperbilirubinemia, and HAT were associated with decreased patient and graft survival after LDLT. In a multivariate analysis, a body weight ≤ 10 kg and HAT were significantly associated with decreased patient and graft survival. The use of vascular grafts significantly increased the occurrence of PVT. In conclusion, a low body weight (≤10 kg) and the occurrence of HAT independently determined worse patient and graft survival in this large cohort of pediatric LDLT patients.

A formula for determining the standard liver volume in children: a special reference for neonates and infants

Accurately evaluating the ratio of GV to the SLV (GV/SLV) is important in successful pediatric liver transplantation. However, the formula used to calculate the SLV of children, including neonates and infants, has not yet been established. The aim of the current study was to estimate the SLV of children, including neonates, and to establish an accurate formula. The LV of 100 children (including 7 neonates and 15 infants) were measured using thin slice (3-5 mm) helical CT images. Their BSA was calculated from height and weight. A new formula to estimate the SLV was established as follows: SLV (mL) =689.9 × BSA (m(2)) -24.7. The SLV of children was significantly lower than that in previous reports (p < 0.001). A formula for calculating the SLV of children including neonates was established. This new formula will be useful in pediatric liver transplantation.

Liver transplantation in children weighing 5 kg or less: analysis of the UNOS database

LT is a major medical and surgical challenge in very small patients. Aim of the study is to determine the outcomes after LT in infants ≤ 5 kg at transplant in a large cohort of patients.

METHODS

Infants ≤ 5 kg who had LT between 10/1987 and 5/2008 were identified from the UNOS database. Risk factors for death and graft loss were analyzed by multivariate logistic regression.

RESULTS

Of 11,467 children, 570 (5%) were ≤ 5 kg at LT. Mean age and weight at LT were 0.11 ± 0.48 yr, 4.32 ± 0.74 kg, respectively. One- and five-yr patient and graft survival were 77.7%, 72.2% and 66.1%, 57.6%, respectively. The primary cause of death was infection (25.9%). Recipient age was a predictor of graft loss. Patient and graft survival have improved over time. Life support at transplant was identified as a risk factor for both death and graft loss (p < 0.02, p < 0.01, respectively).

CONCLUSION

LT recipients ≤5 kg have high mortality and graft loss. Over time, graft survival has improved, although it is still inferior to the overall reported outcomes of pediatric LT. Being on life support at transplant is a significant risk factor for death and graft loss in very small recipients.

Parenchyma-wise technique for the harvest and implantation of hepatic segment 2-3 grafts: Anatomic basis and surgical steps

We propose a technique for pediatric liver transplantation that does not waste the donor's parenchyma. Organ shortage has extended criteria for donor acceptance, such that even individuals with livers of suboptimal volume can donate their segment 2-3. By incorporating wise use of parenchyma, our proposed technique for harvesting segment 2-3 for implantation in a pediatric recipient benefits these and other donors, and it might increase donations. This is especially important in countries in which procurement of organs from the deceased is not allowed. Our technique also aims to solve the problem of the large-for-size syndrome for neonates and extremely small infants and to allow for primary closure of the abdomen. This technique enables harvest of the following four grafts: (1) complete segment 2-3; (2) reduced segment 2-3; (3) complete segment 3; and (4) reduced segment 3. The surgeon will select the type that has suitable graft-to-recipient weight ratio and that suits the donor's liver anatomy and volume. These four types benefit the donor by preserving the parenchyma of segment 4 and the left part of the caudate lobe. The three graft types other than the complete segment 2-3 graft will also preserve varying fractions of the parenchyma of segment 2-3. The technique for complete segment 2-3 graft can be put into practice immediately; the techniques for the other three grafts need an imaging modality to preoperatively delineate the donor's fourth-order bile ducts. We expect to correct this deficiency in the near future by developing the requisite imaging technique.

Risk factors for portal vein complications in pediatric living donor liver transplantation

BACKGROUND

Portal vein (PV) complications in pediatric living donor liver transplantation (LDLT) are often asymptomatic in the early stages after transplantation and can be serious enough to lead to graft failure. There have been few reports on risk factors for PV complications in LDLT. The aim of this study is to investigate the influence of hepatic inflow upon PV complications and to predict patients at risk for these complications.

MATERIAL/METHOD

From 1997 to 2008, 46 pediatric patients underwent LDLT at our center. Portal venous and hepatic arterial flows and PV diameter were analyzed.

RESULTS

PV complications were identified in seven patients (15.2%) and occurred at a younger age and lower weight. As a result of appropriate treatment, none of the patients suffered graft failure. Analysis of the 46 patients and 27 patients under two yr of age identified smaller PV diameter in recipient and larger discrepancy of PV diameter as risk factors. Portal venous flow tended to be low, in contrast to hepatic arterial flow, which tended to be high.

CONCLUSION

PV size strongly influences PV complications. Other factors such as younger age, low portal venous flow, and high hepatic arterial flow may be risk factors for PV complications.

Portal vein obstruction after liver transplantation in children treated by simultaneous minilaparotomy and transhepatic approaches: initial experience

Portal vein thrombosis is a complication that occurs anytime after liver transplantation and can compromise the patient and graft survival. We describe a combined technique for PV recanalization in cases of PV obstruction after liver transplantation. Four children (1%), of 367 subjected to liver transplantation from June 1991 to December 2008, underwent PV recanalization through a combined approach (transhepatic and minilaparotomy). All children received left lateral hepatic segments, developed Portal vein thrombosis (n=3) and stenosis (n=1), and presented with symptoms of portal hypertension after transplantation. PV recanalization was tried by transhepatic retrograde access, and a minilaparotomy was performed when percutaneous recanalization was unsuccessful. Three patients underwent a successful portal recanalization and stent placement with the combined technique. In one patient, the recanalization was unsuccessful because of an extensive portomesenteric thrombosis. The other three children had the portal flow reestablished and followed with Doppler US studies. They received oral anticoagulation for three consecutive months after the procedure and the clinical symptoms subsided. In case of PV obstruction, the combined approach is technically feasible with good clinical and hemodynamic results. It' is a minimally invasive procedure and can be tried to avoid or delay surgical treatment or retransplantation.

Predictors of survival following liver transplantation in infants: a single-center analysis of more than 200 cases

BACKGROUND

Infants (<12 months) who require liver transplantation (LTx) represent a particularly challenging and understudied group of patients.

METHODS

This retrospective study aimed to describe a large single-center experience of infants who received isolated LTx, illustrate important differences in infants versus older children, and identify pretransplant factors which influence survival. More than 25 pre-LTx demographic, laboratory, and operative variables were analyzed using the Log-rank test and Cox proportional hazards model.

RESULTS

Between 1984 and 2006, 216 LTx were performed in 186 infants with a mean follow-up time of 62 months. Median age at LTx was 9 months, the majority had cholestatic liver disease, were hospitalized pre-LTx, and received whole grafts. Leading indications for re-LTx (n=30) included vascular complications (43%) and graft nonfunction (40%), whereas leading causes of death were sepsis and multiorgan failure. One-, 5-, and 10-year graft and patient survivals were 75%/72%/68% and 79%/77%/75%, respectively. Relative to older pediatric recipients, infants had worse overall patient survival (P=0.05). The following were significant univariate predictors of graft loss: age less than 6 months and reduced cadaveric grafts; and of patient loss: age less than 6 months, calculated CrCl less than 90, pre-LTx hospitalization, pre-LTx mechanical ventilation, repeat LTx, infants transplanted for reasons other than cholestatic liver disease, and patients transplanted between 1984 and 1994.

CONCLUSIONS

Long-term outcomes for infants undergoing LTx are excellent and have improved over time. As the largest, single-center analysis of LTx in infants, this study elucidates a unique set of predictors that can aid in medical decision making.

Modified pediatric end-stage liver disease scoring system and pediatric liver transplantation in Brazil

The Pediatric End-Stage Liver Disease (PELD) scoring system is a formula developed to provide a continuous numerical assessment of the risk of death in order to allocate livers to children in need of transplantation. The PELD scoring system was introduced in Brazil in July 2006. An important change was made in the system: the final number for listing patients less than 12 years old for transplantation was the calculated PELD score multiplied by 3. The consequences of this allocation policy were analyzed in 2 ways in this research: nationally and in the state of São Paulo (SP State). In the analysis of the national data, a comparison of the pre-PELD era (July 2003 to July 2006) and the post-PELD era (August 2006 to April 2009) showed that the total number of pediatric transplants for children under 12 years of age decreased 7%. Regionally, in SP State, there was a 62% increase in the number of deceased donor liver transplantation procedures for the pediatric population after the introduction of the modified PELD system. There was also a 6.1-fold increase in split liver transplantation as well as a statistically significant decrease in the time on the waiting list (P < 0.001). In conclusion, changing the allocation policy in Brazil in order to benefit pediatric patients on the waiting list had different results according to analyses of national and regional data. A significant increase in deceased donor liver transplantation/split liver transplantation and a shorter time on the waiting list were observed in SP State. The modified PELD scoring system is simple and optimizes the utilization of deceased donor liver grafts in centers performing pediatric transplants.

Progress in surgical techniques in pediatric liver transplantation

Pediatric LT has evolved into an accepted treatment modality for children with end-stage liver disease with excellent long-term graft and patient survival. A number of factors have been critical in the improvement in recipient outcomes including a change in organ donation from donation after cardiac death, to donation after brain death, and more recently live donor LT and a better appreciation of hepatic anatomy allowing for split LT, LDLT, auxiliary partial orthotopic LT, and laparoscopic donor hepatectomy. In this review we summarize the surgical advances that have occurred in pediatric LT that have been important in shaping what is now considered by many to be a routine operation.

Development and validation of a comprehensive new hepatobiliary software. Part II: Segmental liver function

OBJECTIVE

This study was undertaken to develop comprehensive new hepatobiliary software to quantify segmental and lobar liver function and to obtain FDA approval.

METHODS

Hepatobiliary software written on JAVA platform and loaded on to a PC accepts 99mTc-HIDA dicom image data transferred from a gamma camera. Liver boundary was determined by threshold-based auto edge detection and liver height at right midclavicular (RMCL) line. Geometric mean area of the physiologic right lobe, physiologic left lobe and total liver area were measured. Segmental liver function was determined using the 5th minute frame as the default (100%).

RESULTS

In 24 control participants, mean (+/-SD) liver height at RMCL was 14.7+/-0.12 cm. Geometric mean area of the physiologic right lobe was 116+/-3 cm2, left lobe 96+/-4 cm2, and total liver area 212+/-3 cm. Right upper lobe (segments 7 and 8) contributed 31+/-0.7%, right lower lobe (segments 5 and 6) 34+/-0.6%, left medial (segments 4A and 4B) 24+/-1%, left lateral (segments 2 and 3) 10+/-2%, and caudate lobe (segment 1) 1+/-0.02% of total liver function. In 23 patients, contrast three-dimensional computerized tomographic volume of the right lobe was 1194+/-419 ml, left lobe 434+/-221 ml, and total liver volume 1628+/-490 ml. Right lobe area was 120+/-30 cm2, left lobe (plus caudate) 88+/-29 cm2 with total liver area of 208+/-51 cm. Right upper lobe (segments 7 and 8) contributed 33+/-10%, right lower lobe (segments 5 and 6) 34+/-7%, left medial (segments 4A and 4B) 23+/-6%, left lateral (segments 2 and 3) 9+/-3%, and caudate lobe (segment 1) 1+/-0.4% of total liver function. There was good correlation of RMCL height, and area of right lobe and total liver with computerized tomographic liver volume. Correlation of percentage volume with percentage function was excellent.

CONCLUSION

New FDA approved software provides quantitative assessment of segmental, lobar, and total liver size and function from a planar 99mTc-HIDA cholescintigraphy and may enable universal standardization in nuclear hepatology. Quantification may aid surgeons in the determination of the amount of tissue resection during liver surgery.

[Hepatitis C recurrence after living donor and cadaveric liver transplantation]

OBJECTIVE

To determine the recurrence of hepatitis C in patients subjected to living donor liver transplantation compared to those subjected to cadaveric liver transplantation.

METHODS

Of a total of 333 liver transplantations, 279 (83.8%) were cadaveric liver transplantation and 54 (16.2%) living donor liver transplantation. Hepatic cirrhosis due to hepatitis C virus was the most common indication of both cadaveric liver transplantation (82 patients) and living donor liver transplantation (19 patients). The electronic study protocols of all patients with hepatic cirrhosis due to hepatitis C virus were reviewed. All data, including patients' age and sex, laboratory tests, hepatitis C virus recurrence and acute rejection were evaluated statistically.

RESULTS

A total of 55 cadaveric liver transplantation and 10 living donor liver transplantation performed in patients with liver cirrhosis due to hepatitis C virus was included in the study. Clinical and laboratory characteristics of the two groups before the transplantation were similar, except for the prothrombin time that was higher for the cadaveric liver transplantation than the living donor liver transplantation (P = 0.04). Hepatitis C virus recurrence was similar in the cadaveric liver transplantation (n = 37; 69.3%) and living donor liver transplantation (n = 7; 70%) groups (P = 0.8). The incidence of acute rejection was similar in cadaveric liver transplantation (n = 27; 49%) and living donor liver transplantation (n = 2; 20%) groups (P = 0.08). Hepatitis C virus recurrence in patients of the cadaveric liver transplantation group who received bolus doses of corticosteroids (9 of 11 patients) was similar to the remained patients (28 of 44 patients) (P = 0.25). Recurrence was also similar in patients of the living donor liver transplantation group who received bolus doses of corticosteroids (one of one patient) in relation to those who did not receive them (six of nine patients) (P = 0.7).

CONCLUSION

Hepatitis C recurrence is similar in patients who underwent living donor liver transplantation or cadaveric liver transplantation.

The potential impact of using donations after cardiac death on the liver transplantation program and waiting list in the state of Sao Paulo, Brazil

Liver transplantation was first performed at the University of Sao Paulo School of Medicine in 1968. Since then, the patient waiting list for liver transplantation has increased at a rate of 150 new cases per month. Liver transplantation itself rose 1.84-fold (from 160 to 295) from 1988 to 2004. However, the number of patients on the liver waiting list jumped 2.71-fold (from 553 to 1500). Consequently, the number of deaths on the liver waiting list moved to a higher level, from 321 to 671, increasing 2.09-fold. We have applied a mathematical model to analyze the potential impact of using a donation after cardiac death (DCD) policy on our liver transplantation program and on the waiting list. Five thousand one hundred people died because of accidents and other violent causes in our state in 2004; of these, only 295 were donors of liver grafts that were transplanted. The model assumed that 5% of these grafts would have been DCD. We found a relative reduction of 27% in the size of the liver transplantation waiting list if DCD had been used by assuming that 248 additional liver transplants would have been performed annually. In conclusion, the use of DCD in our transplantation program would reduce the pressure on our liver transplantation waiting list, reducing it by at least 27%. On the basis of this model, the projected number of averted deaths is about 41,487 in the next 20 years.