Body surface area index predicts outcome in orthotopic liver transplantation. J Hepatobiliary Pancreat Sci. 2011;18:216-225. [PMID: 20936303 DOI: 10.1007/s00534-010-0334-9]

A retrospective cohort study of socioeconomic deprivation and post-liver transplant survival in adults

The Area Deprivation Index is a granular measure of neighborhood socioeconomic deprivation. The relationship between neighborhood socioeconomic deprivation and recipient survival following liver transplantation (LT) is unclear. To investigate this, the authors performed a retrospective cohort study of adults who underwent LT at the University of Washington Medical Center from January 1, 2004, to December 31, 2020. The primary exposure was a degree of neighborhood socioeconomic deprivation as determined by the Area Deprivation Index score. The primary outcome was posttransplant recipient mortality. In a multivariable Cox proportional analysis, LT recipients from high-deprivation areas had a higher risk of mortality than those from low-deprivation areas (HR: 1.81; 95% CI: 1.03-3.18, p =0.04). Notably, the difference in mortality between area deprivation groups did not become statistically significant until 6 years after transplantation. In summary, LT recipients experiencing high socioeconomic deprivation tended to have worse posttransplant survival. Further research is needed to elucidate the extent to which neighborhood socioeconomic deprivation contributes to mortality risk and identify effective measures to improve survival in more socioeconomically disadvantaged LT recipients.

A convenient calf proportion index calculator for survival prediction in overweight and obese patients with cancer

OBJECTIVE

This study aimed to define the calf proportion index (CPI) and investigate its association with malnutrition and survival in overweight and obese patients with cancer.

METHODS

This multicenter observational cohort study included 3499 patients diagnosed with cancer, including 3145 overweight and 354 obese individuals. The CPI was defined as the ratio of the cross-sectional area of the calf circumference (CC) to the body surface area (BSA). A CPI calculator that automatically calculated the CPI and survival probability based on the patient's sex, height, weight, and CC was developed.

RESULTS

During a median follow-up of 44.1 months, 935 deaths were recorded. Receiver operating characteristic curves revealed that the CPI was better than CC and BSA as a predictor of survival, with AUCs for the 3-year mortality rate were 0.574, 0.553 and 0.529, respectively. In overweight and obese patients with cancer, the optimal CPI cut-off value was 0.65 % for men and 0.57 % for women. The Kaplan-Meier curve revealed that patients with a low CPI had lower survival. After adjusting confounding factors, a low CPI was an independent risk factor for overweight (hazard ratio [HR]: 1.29, 95 % confidence interval [CI]: 1.11-1.51, P < 0.001) and obesity (HR: 1.92, 95 % CI: 1.20-3.09, P = 0.007) in patients with cancer. The CPI exhibited significant prognostic value in patients with lung and digestive system cancers. The risk of malnutrition was significantly higher in patients with a low CPI (HR: 1.25, 95 % CI: 1.04-1.50, P = 0.019).

CONCLUSIONS

The CPI is a useful prognostic indicator in overweight and obese patients with cancer, especially in obese patients.

Anthropometric measures of obesity in patients with knee joint pathology: Body surface area versus body mass index

BACKGROUND

Obesity is quantified using body mass index. Body surface area may provide a superior and more anthropometric method of quantifying obesity in patients with musculoskeletal knee disease. This study compares the effect of weight, height, age and gender on body mass index and body surface area in a population with orthopaedic knee disease.

METHODS

An observational cohort study was conducted of patients presenting with musculoskeletal knee disease. Associations between body mass index, body surface area, age, gender, height, weight and operative versus non-operative management were analysed.

RESULTS

A total of 151 patients were included. Body surface area was more strongly correlated to weight than body mass index (r = 0.98, p < 0.001 versus r = 0.84, p < 0.001). Body surface area also reflects height which body mass index under presents (r = 0.65, p < 0.001 versus r = -0.08, p = 0.35). Body mass index and body surface area were correlated with one another (r = 0.70, p < 0.001). Age was inversely correlated with body surface area (r = -0.20, p = 0.013) but not body mass index (r = 0.05, p = 0.585). Body mass index did not differ between males and females (30.1 versus 30.9, p = 0.37); however, BSA scores were significantly higher in males than females (2.11 versus 1.91, p < 0.001). Neither body surface area nor body mass index scores influenced operative versus non-operative treatment.

CONCLUSION

Body surface area could be a useful alternative to body mass index when considering obesity in patients with musculoskeletal knee pathology. Body surface area better reflects the effects of height, weight, age and gender than body mass index.

Postreperfusion Syndrome in Patients Receiving Vasoactive Drugs During Liver Graft Reperfusion

OBJECTIVES

The most widely used definition of postreperfusion syndrome in liver transplant is a 30% decrease in mean arterial pressure during the first 5 minutes after vascular unclamping. With these criteria, increased postoperative morbidity has been reported. Vasoactivedrugs couldpreventthis syndrome.Themain objective of our study was to determine the incidence and complications associated with postreperfusion syndrome inpatientswho receivedvasoactive support.

MATERIALS AND METHODS

We studied 246 patients who received norepinephrine infusions to maintain mean arterial pressure ≥60 mm Hg and who were monitored with a Swan-Ganz catheter. Patients received a bolus of adrenaline after vascular unclamping in cases of insufficient response to norepinephrine.

RESULTS

Among the study patients, 57 (23.17%) developed postreperfusion syndrome. Patients who developed postreperfusion syndrome did not present with morepostoperative complications interms ofrenal dysfunction (P = .69), repeat surgery (P = .15), graft rejection (P = .69), transplant replacement surgery (P = .76), hospital stay (P = .70), or survival (P = .17) compared with patients without postreperfusion syndrome.

CONCLUSIONS

In patients who underwent orthotopic liver transplant, in whom vasoactive drugs were administered, a diagnosis of self-limited postreperfusion syndrome during the first 5 minutes after unclamping may not be associated with postoperative complications. The administration of vasoconstrictors may have a preventive effect on the postoperative complications associated with postreperfusion syndrome or they may mask the real incidence of postreperfusion syndrome. A broader definition of postreperfusion syndrome should be accepted.

Role of intelligent/interactive qualitative and quantitative analysis-three-dimensional estimated model in donor-recipient size mismatch following deceased donor liver transplantation

BACKGROUND

Donor-recipient size mismatch (DRSM) is considered a crucial factor for poor outcomes in liver transplantation (LT) because of complications, such as massive intraoperative blood loss (IBL) and early allograft dysfunction (EAD). Liver volumetry is performed routinely in living donor LT, but rarely in deceased donor LT (DDLT), which amplifies the adverse effects of DRSM in DDLT. Due to the various shortcomings of traditional manual liver volumetry and formula methods, a feasible model based on intelligent/interactive qualitative and quantitative analysis-three-dimensional (IQQA-3D) for estimating the degree of DRSM is needed.

AIM

To identify benefits of IQQA-3D liver volumetry in DDLT and establish an estimation model to guide perioperative management.

METHODS

We retrospectively determined the accuracy of IQQA-3D liver volumetry for standard total liver volume (TLV) (sTLV) and established an estimation TLV (eTLV) index (eTLVi) model. Receiver operating characteristic (ROC) curves were drawn to detect the optimal cut-off values for predicting massive IBL and EAD in DDLT using donor sTLV to recipient sTLV (called sTLVi). The factors influencing the occurrence of massive IBL and EAD were explored through logistic regression analysis. Finally, the eTLVi model was compared with the sTLVi model through the ROC curve for verification.

RESULTS

A total of 133 patients were included in the analysis. The Changzheng formula was accurate for calculating donor sTLV (P = 0.083) but not for recipient sTLV (P = 0.036). Recipient eTLV calculated using IQQA-3D highly matched with recipient sTLV (P = 0.221). Alcoholic liver disease, gastrointestinal bleeding, and sTLVi > 1.24 were independent risk factors for massive IBL, and drug-induced liver failure was an independent protective factor for massive IBL. Male donor-female recipient combination, model for end-stage liver disease score, sTLVi ≤ 0.85, and sTLVi ≥ 1.32 were independent risk factors for EAD, and viral hepatitis was an independent protective factor for EAD. The overall survival of patients in the 0.85 < sTLVi < 1.32 group was better compared to the sTLVi ≤ 0.85 group and sTLVi ≥ 1.32 group (P < 0.001). There was no statistically significant difference in the area under the curve of the sTLVi model and IQQA-3D eTLVi model in the detection of massive IBL and EAD (all P > 0.05).

CONCLUSION

IQQA-3D eTLVi model has high accuracy in predicting massive IBL and EAD in DDLT. We should follow the guidance of the IQQA-3D eTLVi model in perioperative management.

Maximizing utility of nondirected living liver donor grafts using machine learning

Objective

There is an unmet need for optimizing hepatic allograft allocation from nondirected living liver donors (ND-LLD).

Materials and method

Using OPTN living donor liver transplant (LDLT) data (1/1/2000-12/31/2019), we identified 6328 LDLTs (4621 right, 644 left, 1063 left-lateral grafts). Random forest survival models were constructed to predict 10-year graft survival for each of the 3 graft types.

Results

Donor-to-recipient body surface area ratio was an important predictor in all 3 models. Other predictors in all 3 models were: malignant diagnosis, medical location at LDLT (inpatient/ICU), and moderate ascites. Biliary atresia was important in left and left-lateral graft models. Re-transplant was important in right graft models. C-index for 10-year graft survival predictions for the 3 models were: 0.70 (left-lateral); 0.63 (left); 0.61 (right). Similar C-indices were found for 1-, 3-, and 5-year graft survivals. Comparison of model predictions to actual 10-year graft survivals demonstrated that the predicted upper quartile survival group in each model had significantly better actual 10-year graft survival compared to the lower quartiles (p<0.005).

Conclusion

When applied in clinical context, our models assist with the identification and stratification of potential recipients for hepatic grafts from ND-LLD based on predicted graft survivals, while accounting for complex donor-recipient interactions. These analyses highlight the unmet need for granular data collection and machine learning modeling to identify potential recipients who have the best predicted transplant outcomes with ND-LLD grafts.

Donor-Recipient Body Surface Area Mismatch and the Outcome of Liver Transplantation in the UK

Introduction: Too small or too big liver grafts for recipient's size has detrimental effects on transplant outcomes. Research Questions: The purpose was to correlate donor-recipient body surface area ratio or body surface area index with recipient survival, graft survival, hepatic artery or portal vein, or vena cava thrombosis. High and low body surface area index cut-off points were determined. Design: There were 11,245 adult recipients of first deceased donor whole liver-only grafts performed in the UK from January 2000 until June 2020. The transplants were grouped according to the body surface area index and compared to complications, graft and recipient survival. Results: The body surface area index ranged from 0.491 to 1.691 with a median of 0.988. The body surface area index > 1.3 was associated with a higher rate of portal vein thrombosis within the first 3 months (5.5%). This risk was higher than size-matched transplants (OR: 2.878, 95% CI: 1.292-6.409, P = 0.01). Overall graft survival was worse in transplants with body surface area index ≤ 0.85 (HR: 1.254, 95% CI: 1.051-1.497, P = 0.012) or body surface area index > 1.4 (HR: 3.704, 95% CI: 2.029-6.762, P < 0.001) than those with intermediate values. The graft survival rates were reduced by 2% for cases with body surface area index ≤ 0.85 but were decreased by 20% for cases with body surface area index > 1.4. These findings were confirmed by bootstrap internal validation. No statistically significant differences were detected for hepatic artery thrombosis, occlusion of hepatic veins/inferior vena cava or recipient survival. Conclusions: Donor-recipient size mismatch affects the rates of portal vein thrombosis within the first 3 months and overall graft survival in deceased-donor liver transplants.

Selection of Safe Donors for Living Donor Liver Transplant Using Extended Right Lobe Graft

Extended right lobectomy (ERL) for living donor liver transplant (LDLT) is selectively performed in many transplant centers and has shown excellent recipient outcomes as reported in previous studies. Yet, there is no universally accepted indication for ERL in respect to donor safety. Current study was designed to stratify risk factors of adverse donor outcome after ERL. A total of 79 living donors who underwent ERL for LDLT were included in analysis. Donors were classified as safety and hazard donor groups according to postoperative findings relevant to posthepatectomy liver failure classification by the International Study Group for Liver Surgery. On multivariable analysis, left lateral section volume <20% of total liver volume and nonpreservation of segment 4a venous drainage were the independent risk factors impairing postoperative outcomes. Despite the short-term impairment of liver function in hazard donor groups, all donors recovered and showed satisfactory remnant liver regeneration. However, these findings have implications in establishing selection criteria of donors eligible for ERL donation. In conclusion, LDLT using ERL graft can be safely performed provided so that left lateral section volume/total donor liver is ≥20% besides conventional donor selection criteria. Also, efforts to preserve segment 4a vein must be made in performing ERL graft procurement in LDLT donors.

Rescue venovenous extracorporeal membrane oxygenation for the deterioration of acute respiratory distress syndrome in pediatric liver transplantation

BACKGROUND

Twenty percent of pediatric patients with BA develop ACLF with increased mortality while awaiting LT. Respiratory complications are common in pediatric ACLF and are associated with increased morbidity and mortality. ARDS is the most severe manifestation of acute respiratory failure with considerable risk of mortality.

METHODS

A 5-month-old girl with post-Kasai BA preoperatively experienced ARDS from RSV infection while awaiting LT. She developed decompensated liver failure with shock, acute kidney injury, coagulopathy, and pulmonary hemorrhage after several episodes of sepsis over the course of 1 month in the PICU. At this stage, RSV was not detected in the patient's tracheal aspirate by real-time polymerase chain reaction. She underwent living donor LT to manage her pre-existing critical state. Following reperfusion during LT, her pre-existing ARDS rapidly deteriorated, which was alleviated by intraoperative VV ECMO.

RESULTS

Severe respiratory acidosis improved rapidly following ECMO, and LT was completed uneventfully. The patient was successfully weaned off ECMO on POD 3.

CONCLUSIONS

This is the first pediatric case rescued by the intraoperative application of ECMO during LT. Our case and cumulative evidence suggest that VV ECMO can serve as rescue therapy for perioperative refractory respiratory failure in pediatric LT.

Understanding Local Hemodynamic Changes After Liver Transplant: Different Entities or Simply Different Sides to the Same Coin?

Liver transplantation is an extremely complex procedure performed in an extremely complex patient. With a successful technique and acceptable long-term survival, a new challenge arose: overcoming donor shortage. Thus, living donor liver transplant and other techniques were developed. Aiming for donor safety, many liver transplant units attempted to push the viable limits in terms of size, retrieving smaller and smaller grafts for adult recipients. With these smaller grafts came numerous problems, concepts, and definitions. The spotlight is now aimed at the mirage of hemodynamic changes derived from the recipients prior alterations. This article focuses on the numerous hemodynamic syndromes, their definitions, causes, and management and interconnection with each other. The aim is to aid the physician in their recognition and treatment to improve liver transplantation success.

Factors Associated With Postreperfusion Syndrome in Living Donor Liver Transplantation: A Retrospective Study

BACKGROUND

Postreperfusion syndrome (PRS) after portal vein reperfusion during liver transplantation (LT) has been reported to cause rapid hemodynamic changes and is associated with a prolonged postoperative hospital stay, renal failure, and increased mortality. Although there are some reports on risk factors for PRS in brain-dead donor LT, there are a few reports on those in living donor LT. Therefore, we retrospectively reviewed the factors associated with PRS to contribute to the anesthetic management so as to reduce PRS during living donor LT.

METHODS

After approval by the ethics committee of our institution, 250 patients aged ≥20 years who underwent living donor LT at our institution between January 2013 and September 2018 were included in the study. A decrease in mean arterial pressure of ≥30% within 5 minutes after portal vein reperfusion was defined as PRS, and estimates and odds ratio (OR) for PRS were calculated using logistic regression. The backward method was used for variable selection in the multivariable analysis.

RESULTS

Serum calcium ion concentration before reperfusion (per 0.1 mmol/L increase; OR, 0.74; 95% confidence interval (CI), 0.60-0.95; P < .001), preoperative echocardiographic left ventricular end-diastolic diameter (per 1-mm increase: OR, 0.90; 95% CI, 0.85-0.95; P < .001, men [versus women: OR, 2.45; 95% CI, 1.26-4.75; P = .008]), mean pulmonary artery pressure before reperfusion (restricted cubic spline, P = .003), anhepatic period (restricted cubic spline, P = .02), and graft volume to standard liver volume ratio (restricted cubic spline, P = .03) were significantly associated with PRS.

CONCLUSIONS

In living donor LT, male sex and presence of small left ventricular end-diastolic diameter, large graft volume, and long anhepatic period are associated with PRS, and a high calcium ion concentration and low pulmonary artery pressure before reperfusion are negatively associated with PRS.

A Novel Strategy for Preventing Posttransplant Large-For-Size Syndrome in Adult Liver Transplant Recipients: A Pilot Study

There are two causes of graft compression in the large-for-size syndrome (LFSS). One is a shortage of intra-abdominal space for the liver graft, and the other is the size discrepancy between the anteroposterior dimensions of the liver graft and the lower right hemithorax of the recipient. The former could be treated using delayed fascial closure or mesh closure, but the latter may only be treated by reduction of the right liver graft to increase space. Given that split liver transplantation has strict requirements regarding donor and recipient selections, reduced-size liver transplantation, in most cases, may be the only solution. However, surgical strategies for the reduction of the right liver graft for adult liver transplantations are relatively unfamiliar. Herein, we introduce a novel strategy of HuaXi-ex vivo right posterior sectionectomy while preserving the right hepatic vein in the graft to prevent LFSS and propose its initial indications.

Predicting the available space for liver transplantation in cirrhotic patients: a computed tomography-based volumetric study

BACKGROUND

Anthropometric parameters (weight, height) are usually used for quick matching between two individuals (donor and recipient) in liver transplantation (LT). This study aimed to evaluate clinical factors influencing the overall available space for implanting a liver graft in cirrhotic patients.

METHODS

In a cohort of 275 cirrhotic patients undergoing LT, we calculated the liver volume (LV), cavity volume (CV), which is considered the additional space between the liver and the right hypocondrium, and the overall volume (OV = LV + CV) using a computed tomography (CT)-based volumetric system. We then chose the formula based on anthropometric parameters that showed the best predictive value for LV. This formula was used to predict the OV in the same population. Factors influencing OV variations were identified by multivariable logistic analysis.

RESULTS

The Hashimoto formula (961.3 × BSA_D-404.8) yielded the lowest median absolute percentage error (21.7%) in predicting the LV. The median LV was 1531 ml. One-hundred eighty-five patients (67.2%) had a median CV of 1156 ml (range: 70-7006), and the median OV was 2240 ml (range: 592-8537). Forty-nine patients (17%) had an OV lower than that predicted by the Hashimoto formula. Independent factors influencing the OV included the number of portosystemic shunts, right anteroposterior abdominal diameter, model for end-stage liver disease (MELD) score > 25, high albumin value, and BMI > 30.

CONCLUSIONS

Additional anthropometric characteristics (right anteroposterior diameter, body mass index) clinical (number of portosystemic shunts), and biological (MELD, albumin) factors might influence the overall volume available for liver graft implantation. Knowledge of these factors might be helpful during the donor-recipient matching.

Early outcomes of implanting larger-sized grafts in deceased donor liver transplantation

BACKGROUND

The outcomes of large-sized graft mismatch in deceased donor liver transplantation (LT) have been rarely studied. The aim of this study was to determine whether a large-sized graft for recipient influenced the post-transplant outcomes.

METHODS

A total of 273 patients undergoing LT were enrolled and divided into a large and a normal-sized graft group by graft weight to recipient weight (GWRW) >2.5% (n = 76) or GWRW ≤2.5% (n = 197). Post-operative complications and outcomes were retrospectively analysed.

RESULTS

The two groups were comparable in demographic characteristics. The rate of complications was significantly higher in the large-sized graft group including early allograft dysfunction (36.8% versus 17.8%, P = 0.001), hepatic necrosis (26.3% versus 13.7%, P = 0.01) and massive hydrothorax (25% versus 14.7%, P = 0.04). The large-sized graft group suffered higher early mortality compared with the normal-sized graft group (30 days: 14.5% versus 5.6%, P = 0.02, 90 days: 21.1% versus 9.6%, P = 0.01). The primary causes of early death were multiple organ failure (10.5% versus 2%, P = 0.002) and sepsis (2.6% versus 1.5%, P = 0.54). Four parameters including donor alanine transaminase, GWRW, estimated blood loss and model for end-stage liver disease score were significant on multivariate analysis, and indicated significant risk factors for the early mortality of recipients.

CONCLUSION

In deceased donor LT, GWRW >2.5% is associated with increased liver injury, risk of early mortality and other adverse outcomes. Thus, donor livers should be allocated to recipients with GWRW ≤2.5%.

Large-for-Size Orthotopic Liver Transplantation: a Systematic Review of Definitions, Outcomes, and Solutions

BACKGROUND

We systematically reviewed the literature on definitions and outcomes of large-for-size (LFS) syndrome in orthotopic liver transplantation (LT).

METHODS

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The Cochrane Library, PubMed, and Embase were searched (January 1990-January 2019) for studies reporting LFS in LT. Primary outcomes were definitions and mortality of LFS LT.

RESULTS

Eleven studies reporting patients with LFS LT were identified. Four different formulas (graft-to-recipient weight ratio (GRWR), body surface area index (BSAi), donor standardized total liver volume (sTLV)-to-recipient sTLV ratio, and graft weight/right anteroposterior distance (RAP) ratio) with their critical thresholds were found. There were 81 patients (54% women) with a median weight and height of 62.5 kg (range, 40-105 kg) and 165 cm (range, 145-180 cm). The median graft weight was 1772 g (range, 1290-2400 g), and the median GWRW was 2.77% (range, 2.1-4.00%). Graft venous outflow obstruction was described in seven patients (8.6%). At the time of LT, fascial closure was not achieved in 24 patients (29.6%) and the graft size was reduced by a liver resection in three patients (3.7%). Thirteen deaths (16%) were reported in the first 90 postoperative days with two patients undergoing re-transplant.

CONCLUSIONS

LFS LT remains heterogeneously defined but characterized by high mortality rates despite the use of tailored surgical solutions (graft reduction and open abdomen). A composite definition is proposed in order to better describe LFS clinical syndrome.

In Situ Left Lateral Sectionectomy in Deceased Donor Liver Transplantation: Could This Be Another Solution for a Large-for-Size Graft? A Case Report

BACKGROUND

Large-for-size (LFS) graft should be avoided when performing an adult deceased donor liver transplantation (DDLT) as it is associated with abdominal compartment syndrome, severe graft injury, and primary graft nonfunction. When inadvertently facing with LFS graft intraoperatively, the most commonly reported approach has been a surgical reduction of the right lobe despite its technical difficulty in addition to ongoing coagulopathy after graft reperfusion. We report a case where we performed a left lateral sectionectomy instead of a right lobe modification.

CASE REPORT

A 44-year-old 58.4 kg female patient was admitted with drug-induced acute hepatic failure and underwent an emergency DDLT. The donor was a 51-year-old 60.0 kg man. At the time of procurement, the liver was noted to be hypertrophic. The estimated graft/recipient weight ratio was 3.49%. After completing the vascular and bile duct anastomosis, the abdomen could not be closed due to its large graft size. Because of the hypertrophic left lateral lobe and ongoing coagulopathy, we decided to perform an in situ left lateral sectionectomy rather than right posterior sectionectomy or right hemihepatectomy. The next day, the liver function failed to improve, and the patient's blood pressure began to decline gradually. Computed tomography showed severe inferior vena cava (IVC) compression by the graft, and the patient underwent transjugular IVC stent placement. Soon after, the patient's blood pressure improved and liver function gradually normalized. The patient was discharged uneventfully on postoperative day 45.

CONCLUSION

Under specific conditions, in situ left lateral sectionectomy is a solution for unexpected LFS graft during DDLT.

Increase in post-reperfusion sensitivity to tissue plasminogen activator-mediated fibrinolysis during liver transplantation is associated with abnormal metabolic changes and increased blood product utilisation

BACKGROUND

Increased systemic fibrinolytic activity can occur in liver transplant recipients after the donor graft is reperfused. However, it remains unclear whether this is related solely to tissue plasminogen activator (t-PA) levels or whether unique metabolic changes can alter t-PA activity and enhance fibrinolytic activity. We hypothesise that an increase in sensitivity to t-PA-mediated fibrinolysis (StF) following liver reperfusion is associated with specific metabolic abnormalities.

MATERIALS AND METHODS

Liver transplant recipients had serial blood samples analysed with a modified thrombelastography assay using exogenous t-PA to measure sensitivity/resistance to fibrinolysis with the lysis 30 min after maximum clot strength (tLY30). Paired plasma samples were analysed with mass spectroscopy-based metabolomics. The tLY30 was correlated to metabolites using Spearman's rho. StF was defined as a tLY30 change of >8.5% from the anhepatic phase to 30 min after reperfusion based on the distribution of tLY30 in a healthy control population.

RESULTS

StF occurred in 53% of patients. Cohorts had similar MELD scores (18 vs 16, p=0.876) and tLY30 at baseline (p=0.867) and anhepatic phase of surgery (p=0.463). Thirty min after reperfusion, the tLY30 was 73% in patient with StF vs 33% in those without StF 33% (p=0.006). StF was associated with increased red blood cell transfusions (p=0.035), during the first 2 hours of reperfusion. Nine metabolites demonstrated a correlation with tLY30 (p<0.05).

DISCUSSION

StF is a transient event that resolves within 2 hours of graft reperfusion and is associated with increased blood product use. This phenomenon correlates with derangements in citric acid cycle, purine and amino acid metabolism. Future research is needed to determine whether these metabolites are biomarkers or mechanistically linked to increased sensitivity to t-PA-mediated fibrinolytic activity following graft reperfusion.

Extreme large-for-size syndrome after adult liver transplantation: A model for predicting a potentially lethal complication

There is currently no tool available to predict extreme large-for-size (LFS) syndrome, a potentially disastrous complication after adult liver transplantation (LT). We aimed to identify the risk factors for extreme LFS and to build a simple predictive model. A cohort of consecutive patients who underwent LT with full grafts in a single institution was studied. The extreme LFS was defined by the impossibility to achieve direct fascial closure, even after delayed management, associated with early allograft dysfunction or nonfunction. Computed tomography scan-based measurements of the recipient were done at the lower extremity of the xiphoid. After 424 LTs for 394 patients, extreme LFS occurred in 10 (2.4%) cases. The 90-day mortality after extreme LFS was 40.0% versus 6.5% in other patients (P = 0.003). In the extreme LFS group, the male donor-female recipient combination was more often observed (80.0% versus 17.4%; P < 0.001). The graft weight (GW)/right anteroposterior (RAP) distance ratio was predictive of extreme LFS with the highest area under the curve (area under the curve, 0.95). The optimal cutoff was 100 (sensitivity, 100%; specificity, 88%). The other ratios based on height, weight, body mass index, body surface area, and standard liver volume exhibited lower predictive performance. The final multivariate model included the male donor-female recipient combination and the GW/RAP. When the GW to RAP ratio increases from 80, 100, to 120, the probability of extreme LFS was 2.6%, 9.6%, and 29.1% in the male donor-female recipient combination, and <1%, 1.2%, and 4.5% in other combinations. In conclusion, the GW/RAP ratio predicts extreme LFS and may be helpful to avoid futile refusal for morphological reasons or to anticipate situation at risk, especially in female recipients. Liver Transplantation 23 1294-1304 2017 AASLD.

Disparities in Waitlist and Posttransplantation Outcomes in Liver Transplant Registrants and Recipients Aged 18 to 24 Years: Analysis of the UNOS Database

BACKGROUND

We evaluated liver transplantation waitlist and posttransplantation outcomes in those aged 18 to 24 years compared with both younger (0-17 years) and older (25-34 years) registrants and recipients.

METHODS

Using national data from the United Network for Organ Sharing, competing risk, Cox regression and Kaplan-Meier analyses were performed on first-time liver transplant registrants (n = 13 979) and recipients (n = 8718) ages 0 to 34 years between 2002 and 2015.

RESULTS

Nonstatus 1A registrants, registrants aged 0 to 17 and 25 to 34 years were less likely to experience dropout from the waiting list compared with those aged 18 to 24 years (adjusted hazard ratio, 0-5 years = 0.36; 6-11 = 0.29; 12-17 = 0.48; 18-24 = 1.00; 25-34 = 0.82). Although there was no difference in risk of graft failure across all age groups, both younger and older age groups had significantly lower risk of posttransplant mortality compared with those aged 18 to 24 years (adjusted hazard ratio, for 0-5 years = 0.53, 6-11 = 0.48, 12-17 = 0.70, 18-24 = 1.00, 25-34 = 0.77). This may be related to lower likelihood of retransplantation after graft failure in those aged 18 to 24 years.

CONCLUSIONS

This national registry study demonstrates for the first time poorer waitlist and postliver transplant outcomes in young adults ages 18 to 24 years at the time of listing and transplantation compared to older and younger age groups. Given the potential survival benefit in transplanting young adults and the shortage of solid organs for transplant, future studies are critical to identify and target modifiable risk factors to improve waitlist and long-term posttransplant outcomes in 18- to 24-year-old registrants and recipients.

Size mismatch in liver transplantation

Size mismatch is an unique and inevitable but critical issue in live donor liver transplantation. Unmatched metabolic demand of recipient as well as physiologic mismatch aggravates the damage to liver graft, inevitably leading to graft failure on recipient. Also, an excessive resection of liver graft for better recipient outcome in live donor liver transplant may jeopardize the healthy donor well-being and even put donor life in danger. There is a fine balance between resected graft volume required to meet the recipient's metabolic demand and residual graft volume required for donor safety. The obvious clinical necessity of finding that balance has prompted a clinical need and promoted the improvement of knowledge and development of management strategies for size-mismatched transplants. The development of the size-matching methodology has significantly improved graft outcome and recipient survival in live donor liver transplants. On the other hand, the effect of size mismatch in cadaveric transplants has never been observed as being so pronounced. The importance of matching of the donor recipient size has been unrecognized in cadaveric liver transplant. In this review, we attempt to summarize the current most updated knowledge on the subject, particularly addressing the definition and complications of size-mismatched cadaveric liver transplant, as well as management strategies.

Post reperfusion syndrome during liver transplantation: From pathophysiology to therapy and preventive strategies

This review aims at evaluating the existing evidence regarding post reperfusion syndrome, providing a description of the pathophysiologic mechanisms involved and possible management and preventive strategies. A PubMed search was conducted using the MeSH database, “Reperfusion” AND “liver transplantation” were the combined MeSH headings; EMBASE and the Cochrane library were also searched using the same terms. 52 relevant studies and one ongoing trial were found. The concept of post reperfusion syndrome has evolved through years to a multisystemic disorder. The implications of the main organ, recipient and procedure related factors in the genesis of this complex syndrome are discussed in the text as the novel pharmacologic and technical approaches to reduce its incidence. However the available evidence about risk factors, physiopathology and preventive measures is still confusing, the presence of two main definitions and the numerosity of possible confounding factors greatly complicates the interpretation of the studies.

Influence of graft size matching on outcomes of infantile living donor liver transplantation

We aimed to assess the impact of size mismatching between grafts and recipients on outcomes of infants or small children after LDLT. Between October 2006 and December 2014, 129 LDLT recipients weighing no more than 8 kg were retrospectively analyzed. The entire cohort was categorized into three groups by GRWR: GRWR < 3.0% (group A, n = 38), 3.0% ≤ GRWR < 4.0% (group B, n = 61), and GRWR ≥ 4.0% (group C, n = 30). Baseline characteristics were similar among groups A, B, and C. Compared with groups A and B, post-transplant alanine aminotransferase and aspartate aminotransferase within seven days were significantly higher in group C; however, differences between total bilirubin and albumin after transplantation were not prominent. Moreover, incidences of surgical complications, perioperative deaths, infections, and acute rejections were all comparable among the three groups. Five-yr patient survival rates for groups A, B, and C were 89.5%, 88.9%, and 81.6%, respectively (p = 0.872), and the graft survival rates were 89.5%, 86.6%, and 81.6%, respectively (p = 0.846). In conclusion, GRWR between 1.9% and 5.8% would not cause noticeable adverse events for infantile LDLT recipients ≤ 8 kg. However, there is still a role for considering reduction in the graft mass as an applicable strategy in selected cases.

Hemodynamic recovery following postreperfusion syndrome in liver transplantation

OBJECTIVES

The authors' current understanding of the phenomenon of significant and sustained decrease in arterial pressure following liver graft reperfusion (postreperfusion syndrome [PRS]), is derived from relatively small observational reports, and no large scale analysis of PRS exists up to date. This study investigated its incidence, risk factors, temporal course of hemodynamic recovery, and its impact on functional graft outcome.

DESIGN

Retrospective observational study of 1,024 electronic records of orthotopic liver transplant recipients.

SETTING

Major transplant center.

MEASUREMENTS

Out of 1,024, 715 records satisfied the inclusion criteria. Data were analyzed by multivariable Cox's proportional hazard model to identify risk factors for PRS. Hemodynamic recovery patterns and functional graft outcomes were compared between the cohorts of interest (intraoperative PRS) and control (no intraoperative PRS) after propensity score-matching. Association between donor risk index and hemodynamic recovery after hepatic artery reperfusion was analyzed by a multivariable regression model.

RESULTS

The overall incidence of PRS was 31.6% with associated mortality of 0.3%. Independent risk factors for PRS included older donor age, higher donor risk index, and lower central venous pressure at reperfusion. Hemodynamic recovery after PRS following portal vein reperfusion was delayed until hepatic artery reperfusion. The slope of hemodynamic recovery, expressed as %MAP/min, correlated negatively with donor risk index (p=0.014). Immediate and 1-year graft survival rates were similar in both cohorts.

CONCLUSIONS

Host hemodynamic response to graft reperfusion appeared to be phasic: initial abrupt hypotension after portal vein reperfusion was followed by a period of gradual decline of blood pressure until hepatic artery reperfusion, and sustained hemodynamic recovery afterwards. The slope of hemodynamic recovery correlated negatively with the donor risk index. PRS was not associated with deterioration of post-transplant graft survival and function.

Effects of ischemic preconditioning in a pig model of large-for-size liver transplantation

OBJECTIVE

In most cases of pediatric liver transplantation, the clinical scenario of large-for-size transplants can lead to hepatic dysfunction and a decreased blood supply to the liver graft. The objective of the present experimental investigation was to evaluate the effects of ischemic preconditioning on this clinical entity.

METHODS

Eighteen pigs were divided into three groups and underwent liver transplantation: a control group, in which the weights of the donors were similar to those of the recipients, a large-for-size group, and a large-for-size + ischemic preconditioning group. Blood samples were collected from the recipients to evaluate the pH and the sodium, potassium, aspartate aminotransferase and alanine aminotransferase levels. In addition, hepatic tissue was sampled from the recipients for histological evaluation, immunohistochemical analyses to detect hepatocyte apoptosis and proliferation and molecular analyses to evaluate the gene expression of Bax (pro-apoptotic), Bcl-XL (anti-apoptotic), c-Fos and c-Jun (immediate-early genes), ischemia-reperfusion-related inflammatory cytokines (IL-1, TNF-alpha and IL-6, which is also a stimulator of hepatocyte regeneration), intracellular adhesion molecule, endothelial nitric oxide synthase (a mediator of the protective effect of ischemic preconditioning) and TGF-beta (a pro-fibrogenic cytokine).

RESULTS

All animals developed acidosis. At 1 hour and 3 hours after reperfusion, the animals in the large-for-size and large-for-size + ischemic preconditioning groups had decreased serum levels of Na and increased serum levels of K and aspartate aminotransferase compared with the control group. The molecular analysis revealed higher expression of the Bax, TNF-alpha, I-CAM and TGF-beta genes in the large-for-size group compared with the control and large-for-size + ischemic preconditioning groups. Ischemic preconditioning was responsible for an increase in c-Fos, IL-1, IL-6 and e-NOS gene expression.

CONCLUSION

Ischemia-reperfusion injury in this model of large-for-size liver transplantation could be partially attenuated by ischemic preconditioning.

Peak Serum AST Is a Better Predictor of Acute Liver Graft Injury after Liver Transplantation When Adjusted for Donor/Recipient BSA Size Mismatch (ASTi)

Background. Despite the marked advances in the perioperative management of the liver transplant recipient, an assessment of clinically significant graft injury following preservation and reperfusion remains difficult. In this study, we hypothesized that size-adjusted AST could better approximate real AST values and consequently provide a better reflection of the extent of graft damage, with better sensitivity and specificity than current criteria. Methods. We reviewed data on 930 orthotopic liver transplant recipients. Size-adjusted AST (ASTi) was calculated by dividing peak AST by our previously reported index for donor-recipient size mismatch, the BSAi. The predictive value of ASTi of primary nonfunction (PNF) and graft survival was assessed by receiver operating characteristic curve, logistic regression, Kaplan-Meier survival, and Cox proportional hazard model. Results. Size-adjusted peak AST (ASTi) was significantly associated with subsequent occurrence of PNF and graft failure. In our study cohort, the prediction of PNF by the combination of ASTi and PT-INR had a higher sensitivity and specificity compared to current UNOS criteria. Conclusions. We conclude that size-adjusted AST (ASTi) is a simple, reproducible, and sensitive marker of clinically significant graft damage.

Large-for-size liver transplantation: a flowmetry study in pigs

BACKGROUND

Ischemia-reperfusion injury is partly responsible for morbidity in pediatric liver transplantation. Large-for-size (LFS) liver transplantation has not been fully studied in the pediatric population, and the effects of reperfusion injury may be underestimated.

MATERIALS AND METHODS

Thirteen Landrace-Large white pigs weighing 23 kg (range, 17-38 kg) underwent orthotopic liver transplantation. They were divided into two groups according to the size of the donor body: LFS and control (CTRL). After transplantation, the abdominal cavity of the recipient was kept open and portal venous flow (PVF) was measured after 1 h. The ratio of recipient PVF (PVFr) to donor PVF was used to establish correlations with ischemia and reperfusion parameters. Liver biopsies were taken 1 h after transplantation to assess ischemia and reperfusion and to quantify the gene expression of endothelial nitric oxide synthase, interleukin 6, BAX, and BCL.

RESULTS

Recipient weight, total ischemia time, and warm ischemia time were similar between groups. Among hemodynamic and metabolic analyses, pH, central arteriovenous PCO2 difference, and AST were statistically worse in the LFS group than in the CTRL group. The same was found with endothelial nitric oxide synthase (0.41 ± 0.18 versus 1.56 ± 0.78; P = 0.02) and interleukin 6 (4.66 ± 4.61 versus 16.21 ± 8.25; P = 0.02). In the LFS group, a significant decay in the PVFr was observed in comparison with the CTRL group (0.93 ± 0.08 and 0.52 ± 0.11, respectively; P < 0.001).

CONCLUSIONS

The implantation of a graft was responsible for poor hemodynamic status of the recipient 1 h after transplantation. Furthermore, the LFS group demonstrated markers of ischemia and reperfusion that were worse when compared with the CTRL group and exhibited a more significant decrease in PVF from donor to recipient.

Cardiac arrest during adult liver transplantation: a single institution's experience with 1238 deceased donor transplants

Liver transplantation (LT) is one of the highest risk noncardiac surgeries. We reviewed the incidence, etiologies, and outcomes of intraoperative cardiac arrest (ICA) during LT. Adult cadaveric LT recipients from January 1, 2001 through December 31, 2009 were reviewed. ICA was defined as an event requiring either closed chest compression or open cardiac massage. Cardiac arrest patients who recovered with only pharmacological interventions were excluded. Data included etiologies and outcomes of ICA, intraoperative deaths (IDs) and hospital deaths (HDs), and potential ICA risk factors. ICA occurred in 68 of 1238 LT recipients (5.5%). It occurred most frequently during the neohepatic phase (60 cases or 90%), and 39 of these cases (65.0%) experienced ICA within 5 minutes after graft reperfusion. The causes of ICA included postreperfusion syndrome (PRS; 26 cases or 38.2%) and pulmonary thromboembolism (PTE; 24 cases or 35.3%). A higher Model for End-Stage Liver Disease (MELD) score was found to be the most significant risk factor for ICA. The ID rate after ICA was 29.4% (20 cases), and the HD rate was 50.0% (34 cases). The 30-day patient survival rate after ICA was 55.9%, and the 1-year survival rate was 45.6%: these rates were significantly lower (P < 0.001) than those for non-ICA patients (97.4% and 85.1%, respectively). In conclusion, the incidence of ICA in adult cadaveric LT was 5.5% with an intraoperative mortality rate of 29.4%. ICA most frequently occurred within 5 minutes after reperfusion and resulted mainly from PRS and PTE. A higher MELD score was identified as a risk factor.

Predictors of renal recovery in patients with pre-orthotopic liver transplant (OLT) renal dysfunction

BACKGROUND

Renal dysfunction occurs commonly in patients awaiting orthotopic liver transplantation (OLT) for end-stage liver disease. The use of simultaneous liver-kidney transplantation has increased in the MELD scoring era. As patients may recover renal function after OLT, identifying factors predictive of renal recovery is a critical issue, especially given the scarcity of available organs.

METHODS

Employing the UNOS database, we sought to identify donor- and patient-related predictors of renal recovery among 1720 patients with pre-OLT renal dysfunction and transplanted from 1989 to 2005. Recovery of renal function post-OLT was defined as a composite endpoint of serum creatinine (SCr) ≤1.5 mg/dL at discharge and survival ≥29 days. Pre-OLT renal dysfunction was defined as any of the following: SCr ≥2 mg/dL at any time while awaiting OLT or need for renal replacement therapy (RRT) at the time of registration and/or OLT.

RESULTS

Independent predictors of recovery of renal function post-OLT were absence of hepatic allograft dysfunction, transplantation during MELD era, recipient female sex, decreased donor age, decreased recipient ALT at time of OLT, decreased recipient body mass index at registration, use of anti-thymocyte globulin as induction therapy, and longer wait time from registration. Contrary to popular belief, a requirement for RRT, even for prolonged periods in excess of 8 weeks, was not an independent predictor of failure to recover renal function post-OLT.

CONCLUSION

These data indicate that the duration of renal dysfunction, even among those requiring RRT, is a poor way to discriminate reversible from irreversible renal dysfunction.

Influence of larger graft weight to recipient weight on the post-liver transplantation course

Size matching between recipient and donor livers is an important factor in organ allocation in the context of liver transplantation (LT). The aim of this study was to determine whether a large graft for recipient size influenced the post-transplant course. One hundred and sixty-two successive LT recipients were included and retrospectively divided into two groups: 25 (15%) had a graft-to-recipient weight ratio (GWRW) ≥ 2.5% and 137 (85%) had a GWRW <2.5%. Postoperative complications and outcomes were recorded. In the GWRW >2.5% group, more end-to-end caval replacement (72% vs. 38%, p = 0.003) and veno-venous bypass (48% vs. 23%, p = 0.01) were used. Peak AST/ALT values were higher in the GWRW >2.5% group (AST: 596 [70-5876] vs. 453 [29-5132] IU/l, p = 0.03; ALT: 773 [101-5025] vs. 383 [36-4921] IU/l, p = 0.02). Among postoperative complications, the rate of respiratory failure was higher in the GWRW >2.5% group (32% vs. 14%, p = 0.04). The rates of other complications did not differ between the two groups. Both groups had similar graft and patient survival rates at one yr. Using large grafts for recipient size did not impair liver function and did not modify graft and patient outcomes at one yr. However, a GWRW >2.5% appeared to be a determining factor for respiratory morbidity following LT.