Effect of graft size matching on pediatric living-donor liver transplantation at a single center

Chinese clinical practice guidelines for pediatric split liver transplantation

Liver transplantation is an effective treatment for end-stage liver disease in children, and its clinical efficacy has been validated. Split liver transplantation (SLT) can effectively expand the donor liver pool for children. SLT for children has unique clinical characteristics and principles. Establishing technical operation specifications for pediatric SLT plays a significant role in improving clinical efficacy. In this paper, clinical practice guidelines on pediatric SLT were established in the aspect of donor and donor liver evaluation, donor-recipient matching, and ductal segmentation and reconstruction of donor liver, aiming to standardize the technical process, optimize surgical operational details, minimize the risk of complications of SLT for children, further promoting the rapid development of pediatric SLT in China.

From large-for-size to large-for-flow: A paradigm shift in liver transplantation

Liver graft-recipient matching remains challenging, and both morphologic and hemodynamic characteristics have been shown to be relevant indicators of post-transplant outcomes. However, no combined analysis is available to date. To study the impact of both morphologic and hemodynamic characteristics of liver grafts on transplantation outcomes, we retrospectively evaluated all consecutive 257 liver transplantations with prospective hemodynamic measurements from 2017 to 2020 in a single-center perspective. First, a morphologic analysis compared recipients with or without large-for-size (LFS), defined by a graft/recipient weight ratio >2.5% and excluding extreme LFS. Second, a hemodynamic analysis compared recipients with or without low portal flow (LPF; <80 mL/min per 100 g of liver tissue). Third, an outcome analysis combining LPF and LFS was performed, focusing on liver graft-related morbidity (LGRM), graft and patient survival. LGRM was a composite endpoint, including primary nonfunction, high-risk L-Graft7 category, and portal vein thrombosis. Morphologic analysis showed that LFS (n=33; 12.9%) was not associated with an increased LGRM (12.1% vs 9.4%; p =0.61) or impaired graft and patient survival. However, the hemodynamic analysis showed that LPF (n=43; 16.8%) was associated with a higher LGRM (20.9% vs 7.5%, p = 0.007) and a significantly impaired 90-day graft and patient survival. Multivariable analysis identified LPF but not LFS as an independent risk factor for LGRM (OR: 2.8%; CI:1.088-7.413; and p = 0.03), 90-day (HR: 4%; CI: 1.411-11.551; and p = 0 .01), and 1-year patient survival. LPF is a significant predictor of post-liver transplantation morbi-mortality, independent of LFS when defined as a morphologic metric alone. Consequently, we propose the novel concept of large-for-flow, which may guide graft selection and improve perioperative management of LPF.

Three-dimensional Liver Model Application for Liver Transplantation

BACKGROUND

Children are removed from the liver transplant waitlist because of death or progressive illness. Size mismatch accounts for 30% of organ refusal. This study aimed to demonstrate that 3-dimensional (3D) technology is a feasible and accurate adjunct to organ allocation and living donor selection process.

METHODS

This prospective multicenter study included pediatric liver transplant candidates and living donors from January 2020 to February 2023. Patient-specific, 3D-printed liver models were used for anatomic planning, real-time evaluation during organ procurement, and surgical navigation. The primary outcome was to determine model accuracy. The secondary outcome was to determine the impact of outcomes in living donor hepatectomy. Study groups were analyzed using propensity score matching with a retrospective cohort.

RESULTS

Twenty-eight recipients were included. The median percentage error was -0.6% for 3D models and had the highest correlation to the actual liver explant (Pearson's R = 0.96, P < 0.001) compared with other volume calculation methods. Patient and graft survival were comparable. From 41 living donors, the median percentage error of the allograft was 12.4%. The donor-matched study group had lower central line utilization (21.4% versus 75%, P = 0.045), shorter length of stay (4 versus 7 d, P = 0.003), and lower mean comprehensive complication index (3 versus 21, P = 0.014).

CONCLUSIONS

Three-dimensional volume is highly correlated with actual liver explant volume and may vary across different allografts for living donation. The addition of 3D-printed liver models during the transplant evaluation and organ procurement process is a feasible and safe adjunct to the perioperative decision-making process.

Preoperative Computed Tomography Volumetry and Graft Weight Estimation of Left Lateral Segment in Pediatric Living Donor Liver Transplant

OBJECTIVES

Liver volumetry based on a computed tomography scan is widely used to estimate liver volume before any liver resection, especially before living donorliver donation. The 1-to-1 conversion rule for liver volume to liver weight has been widely adopted; however, debate continues regarding this approach. Therefore, we analyzed the relationship between the left-lateral lobe liver graft volume and actual graft weight.

MATERIALS AND METHODS

This study retrospectively included consecutive donors who underwent left lateral hepatectomy for pediatric living donor liver transplant from December 2008 to September 2020. All donors were healthy adults who met the evaluation criteria for pediatric living donor liver transplant and underwent a preoperative contrast-enhanced computed tomography scan. Manual segmentation of the leftlateral liverlobe for graft volume estimation and intraoperative measurement of an actual graft weight were performed. The relationship between estimated graft volume and actual graft weight was analyzed.

RESULTS

Ninety-four living liver donors were included in the study. The mean actual graft weight was ~283.4 ± 68.5 g, and the mean graft volume was 244.9 ± 63.86 mL. A strong correlation was shown between graft volume and actual graft weight (r = 0.804; P < .001). Bland-Altman analysis revealed an interobserver agreement of 38.0 ± 97.25, and intraclass correlation coefficient showed almost perfect agreement(r = 0.840; P < .001). The conversion formula for calculating graft weight based on computed tomography volumetry was determined based on regression analysis: 0.88 × graft volume + 41.63.

CONCLUSIONS

The estimation of left liver graft weight using only the 1-to-1 rule is subject to measurable variability in calculated graft weights and tends to underestimate the true graft weight. Instead, a different, improved conversion formula should be used to calculate graft weight to more accurately determine donor graft weight-to-recipient body weightratio and reduce the risk of underestimation of liver graft weightin the donor selection process before pediatric living donor liver transplant.

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.

Factors associated with immediate and early extubation in pediatric living-donor liver transplant recipients

BACKGROUND

The practice of prompt extubation after adult liver transplantation has increasingly been applied in the pediatric population. Therefore, the factors contributing to this intervention should be identified in order to minimize failures.

AIMS

We sought to determine the factors associated with immediate and early extubation in pediatric living-donor liver transplant recipients.

METHODS

The medical records of pediatric liver transplant recipients at our center from January 2013 to December 2021, a 9-year period, were retrospectively collected and divided into early or delayed extubation groups. Factors associated with early extubation were determined using univariate and multivariate analyses, as the primary outcome. Comparisons of the postoperative management and outcomes between groups were evaluated as secondary outcomes.

RESULTS

Seventy-nine patients were included in the analysis, of whom 19 (24%) were immediately extubated in the operating room while 12 patients (15%) were extubated early, within 24 h postoperatively. These 31 patients (39%) were assigned to the early extubation group, whereas the others were assigned to the delayed extubation group. Shorter anhepatic time was the only factor associated with early extubation (adjusted odds ratio = 0.52; 95% confidence interval: 0.30, 0.89 per 30-min increment; p-value = .018) in patients with the same characteristics, including diagnosis, total operative time, and intraoperative volume of albumin and packed red blood cells. The length of intensive care unit stay was shorter in the early extubation group than in the delayed extubation group (p = .001). The rates of total and early medical complications and total reintubation in 30 days were significantly higher in the delayed extubation group than in the early extubation group (p-value = .002, .044, and .006 respectively). There were no significant differences in the length of hospital stay between the groups.

CONCLUSION

Our findings indicated that 39% of the pediatric living donor-liver transplantation patients tolerated early extubation and that the only associated factor was anhepatic time. Early extubation significantly reduces the number of days of intensive care unit stay but may not change the length of hospital stay.

Meta-analysis of donor-recipient gender profile in paediatric living donor liver transplantation

OBJECTIVE

Paediatric living donor liver transplantation (LDLT) has gained popularity due to limited deceased donor organ supply. Some studies report inequalities in donor and recipient gender profiles, but data are sparse. We evaluated LDLT donor-recipient gender profiles, comparing country income categories and gender disparity level.

DESIGN

We performed a systematic review, searching PubMed, Embase and Cochrane databases for publications dated January 2006-September 2021. We included full-text English articles reporting gender in ≥40 universally sampled donor-recipient pairs. Search terms were permutations of 'liver transplant', 'living donor' and 'paediatric'. Countries were grouped as high/middle/low-income economies based on World Bank criteria and into groups based on deviation from gender parity in Gender Development Index (GDI) values (group 1 indicating closest to gender parity, group 5 indicating furthest). Proportions analysis with corresponding 95% CI were used for analysis of dichotomous variables, with significance when 95% CI did not cross 0.5. Data are reported as female proportion (%) and 95% CI.

RESULTS

Of 12 525 studies identified, 14 retrospective studies (12 countries; 6152 recipients and 6138 donors) fulfilled study inclusion criteria. Male recipient preponderance was seen in lower middle-income countries (all were also GDI group 5) (39.3 (95% CI 34.7 to 44.0)) and female recipient preponderance in GDI groups 1 and 3. Female donor preponderance was seen overall (57.4% (95% CI 55.1 to 59.6)), in middle income countries and in three of four GDI groups represented.

CONCLUSION

There are significant imbalances in recipient-donor gender profiles in paediatric LDLT that are not well explained. The reasons for overall female donor preponderance across income tiers must be scrutinised.

Pediatric living donor liver transplantation (LDLT): Short- and long-term outcomes during sixteen years period at a single centre- A retrospective cohort study

BACKGROUND AND OBJECTIVES

Pediatric living donor liver transplantation (LDLT) is an effective tool for managing pediatric patients with end-stage liver disease (ESLD) with good long-term graft and patient survival, especially after improvement in peri-operative care, surgical tools and techniques; however, the morbidity and mortality after such a procedure are still a challenging matter. The study aimed to analyze short-and long-term outcomes after pediatric LDLT in a single centre.

METHODS

We retrospectively analyzed 67 pediatric patients who underwent LDLT in the period from April 2003 to July 2018. The overall male/female ratio was 40/27.

RESULTS

Forty-one (61.2%) of patients had ≥1 early and/or late morbidities; the early (less than 3months) and late (≥3months) ones affected 36(53.7%) and 12(17.9%) of them respectively. The 16-year graft and patient survivals were 35(52.2%) while early and late mortalities were 23(34.3%) and 9(13.4%) respectively. Sepsis and chronic rejection were the most frequent causes of early and late mortalities respectively. Moreover, more packed RBCs transfusion units, bacterial infections, and pulmonary complications were independent predictors of poor patient survival.

CONCLUSIONS

More packed RBCs transfusion units intra-operatively, and post-liver transplant (LT) bacterial infection, sepsis, chronic rejection, as well as pulmonary complications had a negative insult on our patients' outcomes, so proper management of them is mandatory for improving outcomes after pediatric LDLT.

Advanced preoperative three-dimensional planning decreases the surgical complications of using large-for-size grafts in pediatric living donor liver transplantation

BACKGROUND

Using "large-for-size" liver graft, graft-to-recipient weight ratio (GRWR) ≥4%, has been debated in pediatric liver transplantation due to possible graft compartment after abdomen closure. Meticulous preoperative evaluation with three-dimensional (3D) techniques may prevent these problems. This study compared the safety of large-for-size grafts in pediatric living donor liver transplantation (PLDLT) during the eras with or without 3D planning.

METHODS

We defined the 3D era was after November 2017 due to our first implication of 3D printing for surgical planning and subsequently developing a 3D simulation implanting model. From November 2004 to July 2021, we enrolled 30 PLDLT patients with body weight (BW) < 10 kg and categorized them into conventional group: GRWR ≥4% before the 3D era (n = 9), 3D group: GRWR ≥4% in the 3D era (n = 8), and control group: GRWR <4% (n = 13). We followed and compared their clinical outcomes.

RESULTS

The 3D group had the lowest BW and the highest graft volume reduction rate, with all receiving modified left lateral segments (LLS), such as reduced LLS (n = 2), hyperreduced LLS (n = 5), and segment 2 monosegment (n = 1). Overall postoperative complications were similar in conventional and control groups but significantly lower in the 3D group (OR 0.06, 95% CI 0.006-0.70, p = 0.025). However, all groups had similar graft and patient survival at 1, 2, and 4 years.

CONCLUSION

Advanced preoperative 3D planning can decrease post-transplant complications and increase the safety of large-for-size grafts in PLDLT.

LEVEL OF EVIDENCE

Type of study: Retrospective comparative study; Evidence level: Level III.

Impact of Monosegment Graft Use for Infants in Pediatric Living Donor Liver Transplantation

BACKGROUND

Left lateral segment grafts are generally used for very young pediatric patients undergoing living donor liver transplantation (LDLT). Recently, graft reduction techniques were developed for LDLT. Monosegment grafting has been used in newborns. The aim of this study was to determine the usefulness of monosegment grafting for infants.

METHODS

Recipients <2 years of age who underwent LDLT with a monosegment graft between 2010 and 2020 were gathered. Parents comprised all LDLT donors. A segment 2 monosegment graft was resected as a graft from the donor. Standard liver volume (SLV) was estimated using Urata's equation. Graft type, graft weight (GW), and native liver weight were assessed.

RESULTS

Eight patients were included in the study. Original diseases consisted of biliary atresia (n = 6) and fulminant hepatitis (n = 2). Final graft type included monosegment (n = 5) and reduced monosegment (n = 3). Median final GW/body weight after reduction was 3% (range, 2%-3.4%). Median native liver weight/SLV was 134% except in patients with fulminant hepatitis. Median pre-reduction graft volume (GV)/estimated GV was 113% (range, 60%-208%). Median pre-reduction GV/SLV of monosegment grafts that required reduction (n = 3) was 109% (range, 106%-121%). Median final reduced graft GV/SLV was 80% (range, 74%-91%). Complications due to large-for-size grafts were not observed. One case of bile leakage due to graft reduction occurred as a complication. Grafts were functioning well with the exception of one graft loss due to antibody-mediated rejection.

CONCLUSION

Estimated GV in infants varies widely. Monosegment grafting can be useful for infants as well as newborns.

Impact of Graft Size Matching on the Early Post-Transplant Complications and Patients Survival in Children after Living Donor Liver Transplantations

We aimed to assess the impact of the graft-recipient weight ratio (GRWR) on early post-transplant complications and patient survival rates in children after living donor liver transplantation (LDLT). We retrospectively analyzed 321 patients who underwent LDLT from 2004 to 2019. The recipients were categorized into four groups: 37 patients had a GRWR ≤ 1.5% (Group A), 196 patients had a GRWR > 1.5% and ≤3.5% (Group B), 73 patients had a GRWR > 3.5% and <5% (Group C) and 15 patients had a GRWR ≥ 5% (Group D). Incidence of early surgical complications including vascular complications, biliary complications, postoperative bleedings, gastrointestinal perforations and graft loss were comparable among groups with a different GRWR. Delayed abdominal wound closure was more common in patients with a GRWR > 3.5%. Recipients with a GRWR < 5% had a significantly better prognosis concerning patients and graft survival. Using grafts with a GRWR < 5% allows us to expand the donor pool and decrease the risk of mortality while on the waiting list, when patients at the time of transplantation have less advanced liver disease. LDLT with a GRWR ≥ 5% is related to a higher risk of poor outcome, and thus should be an option for treating selected patients when the risk of a delayed transplantation is high and access to deceased donors is limited.

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.

Living Donor Liver Transplantation in Children: Perioperative Risk Factors and a Nomogram for Prediction of Survival

BACKGROUND

Living donor liver transplantation (LDLT) in children has achieved promising outcomes during the past few decades. However, it still poses various challenges. This study aimed to analyze perioperative risk factors for postoperative death in pediatric LDLT.

METHODS

We retrospectively analyzed medical records of pediatric patients who underwent LDLT surgery from January 1, 2014, to December 31, 2016, in our hospital. Predictors of mortality following LDLT were analyzed in 430 children. Cox regression and Kaplan-Meier curve analysis were used for covariates selection. A nomogram was developed to estimate overall survival probability. The performance of the nomogram was assessed using calibration curve, decision curve analysis, and time-dependent receiver operating characteristic curve.

RESULTS

Among the 430 patients in this cohort (median [interquartile range] age, 7 [6.10] mo; 189 [43.9%] female; 391 [90.9%] biliary atresia), the overall survival was 91.4% (95% confidence interval, 89.2-94.4), and most of the death events (36/37) happened within 6 months after the surgery. Multivariate analysis indicated that the Pediatric End-stage Liver Disease score, neutrophil lymphocyte ratio, graft-to-recipient weight ratio, and intraoperative norepinephrine infusion were independent prognostic factors. A novel nomogram was developed based on these prognostic factors. The C index for the final model was 0.764 (95% confidence interval, 0.701-0.819). Decision curve analysis and time-dependent receiver operating characteristic curve suggested that this novel nomogram performed well at predicting mortality of pediatric LDLT.

CONCLUSIONS

We identified several perioperative risk factors for mortality of pediatric LDLT. And the newly developed nomogram can be a convenient individualized tool in estimating the prognosis of pediatric LDLT.

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.