Multicenter validation of the liver graft assessment following transplantation (L-GrAFT) score for assessment of early allograft dysfunction.

BACKGROUND & AIMS: Early allograft dysfunction (EAD) following liver transplantation (LT) negatively impacts graft and patient outcomes. Previously we reported that the liver graft assessment following transplantation (L-GrAFT7) risk score was superior to binary EAD or the model for early allograft function (MEAF) score for estimating 3-month graft failure-free survival in a single-center derivation cohort. Herein, we sought to externally validate L-GrAFT7, and compare its prognostic performance to EAD and MEAF. METHODS: Accuracies of L-GrAFT7, EAD, and MEAF were compared in a 3-center US validation cohort (n = 3,201), and a Consortium for Organ Preservation in Europe (COPE) normothermic machine perfusion (NMP) trial cohort (n = 222); characteristics were compared to assess generalizability. RESULTS: Compared to the derivation cohort, patients in the validation and NMP trial cohort had lower recipient median MELD scores; were less likely to require pretransplant hospitalization, renal replacement therapy or mechanical ventilation; and had superior 1-year overall (90% and 95% vs. 84%) and graft failure-free (88% and 93% vs. 81%) survival, with a lower incidence of 3-month graft failure (7.4% and 4.0% vs. 11.1%; p <0.001 for all comparisons). Despite significant differences in cohort characteristics, L-GrAFT7 maintained an excellent validation AUROC of 0.78, significantly superior to binary EAD (AUROC 0.68, p = 0.001) and MEAF scores (AUROC 0.72, p <0.001). In post hoc analysis of the COPE NMP trial, the highest tertile of L-GrAFT7 was significantly associated with time to liver allograft (hazard ratio [HR] 2.17, p = 0.016), Clavien ≥IIIB (HR 2.60, p = 0.034) and ≥IVa (HR 4.99, p = 0.011) complications; post-LT length of hospitalization (p = 0.002); and renal replacement therapy (odds ratio 3.62, p = 0.016). CONCLUSIONS: We have validated the L-GrAFT7 risk score as a generalizable, highly accurate, individualized risk assessment of 3-month liver allograft failure that is superior to existing scores. L-GrAFT7 may standardize grading of early hepatic allograft function and serve as a clinical endpoint in translational studies (www.lgraft.com). LAY SUMMARY: Early allograft dysfunction negatively affects outcomes following liver transplantation. In independent multicenter US and European cohorts totaling 3,423 patients undergoing liver transplantation, the liver graft assessment following transplantation (L-GrAFT) risk score is validated as a superior measure of early allograft function that accurately discriminates 3-month graft failure-free survival and post-liver transplantation complications.

Assessment of Anastomotic Biliary Complications in Adult Patients Undergoing High-Acuity Liver Transplant.

Importance: Anastomotic biliary complications (ABCs) constitute the most common technical complications in liver transplant (LT). Given the ever-increasing acuity of LT, identification of factors contributing to ABCs is essential to minimize morbidity and optimize outcomes. A detailed analysis in a patient population undergoing high-acuity LT is lacking. Objective: To evaluate the rate of, risk factors for, and outcomes of ABCs and acuity level in LT recipients. Design, Setting, and Participants: This retrospective cohort study included adult LT recipients from January 1, 2013, through June 30, 2016, at a single large urban transplant center. Patients were followed up for at least 12 months after LT until June 30, 2017. Of 520 consecutive adult patients undergoing LT, 509 LTs in 503 patients were included. Data were analyzed from May 1 through September 13, 2017. Exposure: Liver transplant. Main Outcomes and Measures: Any complications occurring at the level of the biliary reconstruction. Results: Among the 503 transplant recipients undergoing 509 LTs included in the analysis (62.3% male; median age, 58 years [interquartile range {IQR}, 50-63 years), median follow-up was 24 months (IQR, 16-34 months). Overall patient and graft survival at 1 year were 91.1% and 90.3%, respectively. The median Model for End-stage Liver Disease (MELD) score was 35 (IQR, 15-40) for the entire cohort. T tubes were used in 199 LTs (39.1%) during initial bile duct reconstruction. Overall incidence of ABCs included 103 LTs (20.2%). Anastomotic leak occurred in 25 LTs (4.9%) and stricture, 77 (15.1%). Exit-site leak in T tubes occurred in 36 (7.1%) and T tube obstruction in 16 (3.1%). Seventeen patients with ABCs required surgical revision of bile duct reconstruction. Multivariate analysis revealed the following 7 independent risk factors for ABCs: recipient hepatic artery thrombosis (odds ratio [OR], 12.41; 95% CI, 2.37-64.87; P = .003), second LT (OR, 4.05; 95% CI, 1.13-14.50; P = .03), recipient hepatic artery stenosis (OR, 3.81; 95% CI, 1.30-11.17; P = .02), donor hypertension (OR, 2.79; 95% CI, 1.27-6.11; P = .01), recipients with hepatocellular carcinoma (OR, 2.66; 95% CI, 1.23-5.74; P = .01), donor death due to anoxia (OR, 2.61; 95% CI, 1.13-6.03; P = .03), and use of nonabsorbable suture material for biliary reconstruction (OR, 2.45; 95% CI, 1.09-5.54; P = .03). Conclusions and Relevance: This large, single-center series identified physiologic and anatomical independent risk factors contributing to ABCs after high-acuity LT. Careful consideration of these factors could guide perioperative management and mitigate potentially preventable ABCs.

Evaluation of Early Allograft Function Using the Liver Graft Assessment Following Transplantation Risk Score Model.

Importance: Early allograft dysfunction (EAD) following a liver transplant (LT) unequivocally portends adverse graft and patient outcomes, but a widely accepted classification or grading system is lacking. Objective: To develop a model for individualized risk estimation of graft failure after LT and then compare the model's prognostic performance with the existing binary EAD definition (bilirubin level of ≥10 mg/dL on postoperative day 7, international normalized ratio of ≥1.6 on postoperative day 7, or aspartate aminotransferase or alanine aminotransferase level of >2000 U/L within the first 7 days) and the Model for Early Allograft Function (MEAF) score. Design, Setting, and Participants: This retrospective single-center analysis used a transplant database to identify all adult patients who underwent a primary LT and had data on 10 days of post-LT laboratory variables at the Dumont-UCLA Transplant Center of the David Geffen School of Medicine at UCLA between February 1, 2002, and June 30, 2015. Data collection took place from January 4, 2016, to June 30, 2016. Data analysis was conducted from July 1, 2016, to August 30, 2017. Main Outcomes and Measures: Three-month graft failure-free survival. Results: Of 2021 patients who underwent primary LT over the study period, 2008 (99.4%) had available perioperative data and were included in the analysis. The median (interquartile range [IQR]) age of recipients was 56 (49-62) years, and 1294 recipients (64.4%) were men. Overall survival and graft-failure-free survival rates were 83% and 81% at year 1, 74% and 71% at year 3, and 69% and 65% at year 5, with an 11.1% (222 recipients) incidence of 3-month graft failure or death. Multivariate factors associated with 3-month graft failure-free survival included post-LT aspartate aminotransferase level, international normalized ratio, bilirubin level, and platelet count, measures of which were used to calculate the Liver Graft Assessment Following Transplantation (L-GrAFT) risk score. The L-GrAFT model had an excellent C statistic of 0.85, with a significantly superior discrimination of 3-month graft failure-free survival compared with the existing EAD definition (C statistic, 0.68; P < .001) and the MEAF score (C statistic, 0.70; P < .001). Compared with patients with lower L-GrAFT risk, LT recipients in the highest 10th percentile of L-GrAFT scores had higher Model for End-Stage Liver Disease scores (median [IQR], 34 [26-40] vs 31 [25-38]; P = .005); greater need for pretransplant hospitalization (56.8% vs 44.8%; P = .003), renal replacement therapy (42.9% vs 30.5%; P < .001), mechanical ventilation (35.8% vs 18.1%; P < .001), and vasopressors (22.9% vs 11.0%; P < .001); longer cold ischemia times (median [IQR], 436 [311-539] vs 401 [302-506] minutes; P = .04); greater intraoperative blood transfusions (median [IQR], 17 [10-26] vs 10 [6-17] units of packed red blood cells; P < .001); and older donors (median [IQR] age, 47 [28-56] vs 41 [25-52] years; P < .001). Conclusions and Relevance: The L-GrAFT risk score allows a highly accurate, individualized risk estimation of 3-month graft failure following LT that is more accurate than existing EAD and MEAF scores. Multicenter validation may allow for the adoption of the L-GrAFT as a tool for evaluating the need for a retransplant, for establishing standardized grading of early allograft function across transplant centers, and as a highly accurate clinical end point in translational studies aiming to mitigate ischemia or reperfusion injury by modulating donor quality and recipient factors.

Use of Entrustable Professional Activities in the Assessment of Surgical Resident Competency.

Importance: Competency-based assessments of surgical resident performance require metrics of entrustable autonomy. Objectives: To designate entrustable professional activities (EPAs) in global performance and in specific operations, and to identify differences in perceived capability, autonomy, and expectations between surgical faculty and residents. Design, Setting, and Participants: This survey study was conducted from August 9, 2016, through August 24, 2016, in the Department of Surgery at the UCLA David Geffen School of Medicine. The survey instrument consisted of 5-point Likert scales for assessing perceptions of entrustability for 5 global and 5 operative EPAs. Faculty members were surveyed regarding resident capabilities and expected capabilities by postgraduate year. Residents were surveyed regarding their own capabilities, actual autonomy entrusted in the last EPA performed, and expected capabilities. Main Outcomes and Measures: Differences in mean ratings were assessed across 7 comparison domains. Results: Among 78 total faculty members, 31 (40%) participated in the survey. Among 49 residents, 39 (80%) participated in the survey. Residents generally rated their global EPA performance higher than the faculty did (mean, 3.7 vs 2.8; P < .01), but operative EPA performance ratings were equivalent (mean, 2.7 vs 2.4; P < .12). Faculty members perceived senior residents as underperforming expectations in operative EPAs. Most faculty members (80%) expected residents not to be independently capable of performing complex operations by graduation. Faculty members perceived residents in postgraduate years 4 and 5 to have greater operative capability than the level of autonomy entrusted to those residents (95% CI, 3.3-3.5 vs 1.9-2.2). Conclusions and Relevance: Global and operative EPAs are practical for developing competency-based curricula. Graduated autonomy should be granted to improve the operative experience for residents.

Damage Control as a Strategy to Manage Postreperfusion Hemodynamic Instability and Coagulopathy in Liver Transplant.

IMPORTANCE: Damage control (DC) with intra-abdominal packing and delayed reconstruction is an accepted strategy in trauma and acute care surgery but has not been evaluated in liver transplant. OBJECTIVE: To evaluate the incidence, effect on survival, and predictors of the need for DC using intra-abdominal packing and delayed biliary reconstruction in patients with coagulopathy or hemodynamic instability after liver allograft reperfusion. DESIGN, SETTING, AND PARTICIPANTS: We performed a retrospective analysis of adults undergoing liver transplant at a large transplant center from February 1, 2002, through July 31, 2012. MAIN OUTCOMES AND MEASURES: Predictors of DC, effects on graft, and patient survival. RESULTS: Of 1813 patients, 150 (8.3%) underwent DC during liver transplant, with 84 (56.0%) requiring a single additional operation for biliary reconstruction and abdominal closure and 57 (38.0%) requiring multiple additional operations. Compared with recipients without DC, patients requiring DC had greater Model for End-stage Liver Disease scores (33 vs 27; P < .001); more frequent pretransplant hospitalization (72.0% vs 47.9%; P < .001), intubation (33.3% vs 19.9%; P < .001), vasopressors (23.2% vs 10.9%; P < .001), renal replacement therapy (49.6% vs 30.3%; P < .001), and prior major abdominal operations (48.3% vs 21.9%; P < .001), including prior liver transplant (29.3% vs 8.9%; P < .001); greater operative transfusion requirements (37 vs 13 units of packed red blood cells; P < .001); worse intraoperative base deficit (10.3 vs 8.4; P = .03); more frequent postreperfusion syndrome (56.2% vs 27.3%; P < .001); and longer cold (430 vs 404 minutes; P = .04) and warm (46 vs 41 minutes; P < .001) ischemia times. Patients who underwent DC followed by a single additional operation for biliary reconstruction and abdominal closure had similar 1-, 3-, and 5-year graft survival (71%, 62%, and 62% vs 81%, 71%, and 67%; P = .26) and patient survival (72%, 64%, and 64% vs 84%, 75%, and 70%; P = .15) compared with recipients not requiring DC. Multivariate predictors of DC included prior liver transplant or major abdominal operation, longer pretransplant recipient and donor length of stay, greater Model for End-stage Liver Disease score, and longer warm and cold ischemia times (C statistic, 0.75). CONCLUSIONS AND RELEVANCE: To our knowledge, this study represents the first large report of DC as a viable strategy for liver transplant recipients with coagulopathy or hemodynamic instability after allograft reperfusion. In DC recipients not requiring additional operations, outcomes are excellent and comparable to 1-stage liver transplant.

Survival benefit of solid-organ transplant in the United States.

IMPORTANCE: The field of transplantation has made tremendous progress since the first successful kidney transplant in 1954. OBJECTIVE: To determine the survival benefit of solid-organ transplant as recorded during a 25-year study period in the United Network for Organ Sharing (UNOS) database and the Social Security Administration Death Master File. DESIGN, SETTING, AND PARTICIPANTS: In this retrospective analysis of UNOS data for solid-organ transplant during a 25-year period (September 1, 1987, through December 31, 2012), we reviewed the records of 1,112,835 patients: 533,329 recipients who underwent a transplant and 579 506 patients who were placed on the waiting list but did not undergo a transplant. MAIN OUTCOMES AND MEASURES: The primary outcome was patient death while on the waiting list or after transplant. Kaplan-Meier survival functions were used for time-to-event analysis. RESULTS: We found that 2,270,859 life-years (2,150,200 life-years from the matched analysis) were saved to date during the 25 years of solid-organ transplant. A mean of 4.3 life-years were saved (observed to date) per solid-organ transplant recipient. Kidney transplant saved 1,372,969 life-years; liver transplant, 465,296 life-years; heart transplant, 269,715 life-years; lung transplant, 64,575 life-years; pancreas-kidney transplant, 79,198 life-years; pancreas transplant, 14,903 life-years; and intestine transplant, 4402 life-years. CONCLUSIONS AND RELEVANCE: Our analysis demonstrated that more than 2 million life-years were saved to date by solid-organ transplants during a 25-year study period. Transplants should be supported and organ donation encouraged.

Assessment of hepatic steatosis by transplant surgeon and expert pathologist: a prospective, double-blind evaluation of 201 donor livers.

An accurate clinical assessment of hepatic steatosis before transplantation is critical for successful outcomes after liver transplantation, especially if a pathologist is not available at the time of procurement. This prospective study investigated the surgeon's accuracy in predicting hepatic steatosis and organ quality in 201 adult donor livers. A steatosis assessment by a blinded expert pathologist served as the reference gold standard. The surgeon's steatosis estimate correlated more strongly with large-droplet macrovesicular steatosis [ld-MaS; nonparametric Spearman correlation coefficient (rS ) = 0.504] versus small-droplet macrovesicular steatosis (sd-MaS; rS = 0.398). True microvesicular steatosis was present in only 2 donors (1%). Liver texture criteria (yellowness, absence of scratch marks, and round edges) were mainly associated with ld-MaS (variance = 0.619) and were less associated with sd-MaS (variance = 0.264). The prediction of ≥30% ld-MaS versus <30% ld-MaS was excellent when liver texture criteria were used (accuracy = 86.2%), but it was less accurate when the surgeon's direct estimation of the steatosis percentage was used (accuracy = 75.5%). The surgeon's quality grading correlated with the degree of ld-MaS and the surgeon's steatosis estimate as well as the incidence of poor initial function and primary nonfunction. In conclusion, the precise estimation of steatosis remains challenging even in experienced hands. Liver texture characteristics are more helpful in identifying macrosteatotic organs than the surgeon's actual perception of steatosis. These findings are especially important when histological assessment is not available at the donor's hospital.