Surgery (Austin & Northern Health) - Research Publications

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    The Hidden Epidemic: The Prevalence and Impact of Concurrent Liver Diseases in Patients Undergoing Liver Transplantation in Australia and New Zealand
    Howell, J ; Majumdar, A ; Fink, M ; Byrne, M ; McCaughan, G ; Strasser, SI ; Crawford, M ; Hodgkinson, P ; Stuart, KA ; Tallis, C ; Chen, J ; Wigg, A ; Jones, R ; Jaques, B ; Jeffrey, G ; Adams, L ; Wallace, MC ; Gane, E ; Thompson, A ; Gow, P (LIPPINCOTT WILLIAMS & WILKINS, 2022-08)
    UNLABELLED: Prevalence of concurrent liver diseases among liver transplant recipients and impact on posttransplant outcomes are unknown. METHODS: This retrospective study included adult liver transplants between January 1' 1985' and December 31' 2019' from the Australian and New Zealand Liver and Intestinal Transplant Registry. Up to 4 liver disease causes were recorded for each transplant; concurrent liver diseases were defined as >1 liver disease indication for transplantation, excluding hepatocellular carcinoma. Impact on posttransplant survival was determined using Cox regression. RESULTS: A total of 840 (15%) of 5101 adult liver transplant recipients had concurrent liver diseases. Recipients with concurrent liver diseases were more likely male (78% versus 64%) and older (mean age 52 versus 50 y). A higher proportion of liver transplants for hepatitis B (12% versus 6%), hepatitis C (33% versus 20%), alcohol liver disease (23% versus 13%), and metabolic-associated fatty liver disease (11% versus 8%, all P < 0.001) were identified when all indications were included than with primary diagnosis only. The number and proportion of liver transplants performed for concurrent liver diseases have increased from 8 (6%) during Era 1 (1985-1989) to 302 (20%) during Era 7 (2015-2019; P < 0.001). Concurrent liver diseases were not associated with increased posttransplant mortality (adjusted hazard ratio, 0.98, 95% confidence interval, 0.84-1.14). CONCLUSIONS: Concurrent liver diseases are increasing among adult liver transplant recipients in Australia and New Zealand; however, they do not appear to impact posttransplant survival. Reporting all liver disease causes in the transplant registry reports provides more accurate estimates of liver disease burden.
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    Epidemiology and Prognostic Significance of Rapid Response System Activation in Patients Undergoing Liver Transplantation
    Robertson, M ; Lim, AKH ; Bloom, A ; Chung, W ; Tsoi, A ; Cannan, E ; Johnstone, B ; Huynh, A ; O'Halloran, T ; Gow, P ; Angus, P ; Jones, D (MDPI, 2021-12)
    Patients undergoing liver transplantation have a high risk of perioperative clinical deterioration. The Rapid Response System is an intensive care unit-based approach for the early recognition and management of hospitalized patients identified as high-risk for clinical deterioration by a medical emergency team (MET). The etiology and prognostic significance of clinical deterioration events is poorly understood in liver transplant patients. We conducted a cohort study of 381 consecutive adult liver transplant recipients from a prospectively collected transplant database (2011-2017). Medical records identified patients who received MET activation pre- and post-transplantation. MET activation was recorded in 131 (34%) patients, with 266 MET activations in total. The commonest triggers for MET activation were tachypnea and hypotension pre-transplantation, and tachycardia post-transplantation. In multivariable analysis, female sex, increasing Model for End-Stage Liver Disease score and hepatorenal syndrome were independently associated with MET activation. The unplanned intensive care unit admission rate following MET activation was 24.1%. Inpatient mortality was 4.2% and did not differ by MET activation status; however, patients requiring MET activation had significantly longer intensive care unit and hospital length of stay and were more likely to require inpatient rehabilitation. In conclusion, liver transplant patients with perioperative complications requiring MET activation represent a high-risk group with increased morbidity and length of stay.
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    Relationship between QT interval prolongation and structural abnormalities in cirrhotic cardiomyopathy: A change in the current paradigm
    Koshy, AN ; Gow, PJ ; Testro, A ; Teh, AW ; Ko, J ; Lim, HS ; Han, H-C ; Weinberg, L ; VanWagner, LB ; Farouque, O (WILEY, 2021-06)
    It is postulated that cardiac structural abnormalities observed in cirrhotic cardiomyopathy (CCM) contribute to the electrophysiologic abnormality of QT interval (QTc) prolongation. We sought to evaluate whether QTc prolongation is associated with intrinsic abnormalities in cardiac structure and function that characterize CCM. Consecutive patients undergoing liver transplant work-up between 2010 and 2018 were included. Measures of cardiac function on stress testing including cardiac reserve and chronotropic incompetence were collected prospectively and a corrected QTc ≥ 440 ms was considered prolonged. Overall, 439 patients were included and 65.1% had a prolonged QTc. There were no differences in markers of left ventricular and atrial remodeling, or resting systolic and diastolic function across QTc groups. The proportion of patients that met the criteria for a low cardiac reserve (39.2 vs 36.6%, p = .66) or chronotropic incompetence (18.1 vs 21.3%, p = .52) was not different in those with a QTc ≥ 440 vs <440 ms. Further, there was no association between QTc prolongation and CCM by either the 2005 World College of Gastroenterology or modified 2020 Cirrhotic Cardiomyopathy Consortium criteria. QT interval prolongation was not associated with structural or functional cardiac abnormalities that characterize CCM. These findings suggest that CCM and QT interval prolongation in cirrhosis may be two separate entities with distinct pathophysiological origins.
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    Clinical outcomes of patients with two small hepatocellular carcinomas
    Anh, DP ; Vaz, K ; Ardalan, ZS ; Sinclair, M ; Apostolov, R ; Gardner, S ; Majeed, A ; Mishra, G ; Kam, NM ; Patwala, K ; Kutaiba, N ; Arachchi, N ; Bell, S ; Dev, AT ; Lubel, JS ; Nicoll, AJ ; Sood, S ; Kemp, W ; Roberts, SK ; Fink, M ; Testro, AG ; Angus, PW ; Gow, PJ (BAISHIDENG PUBLISHING GROUP INC, 2021-10-27)
    BACKGROUND: Management of single small hepatocellular carcinoma (HCC) is straightforward with curative outcomes achieved by locoregional therapy or resection. Liver transplantation is often considered for multiple small or single large HCC. Management of two small HCC whether presenting synchronously or sequentially is less clear. AIM: To define the outcomes of patients presenting with two small HCC. METHODS: Retrospective review of HCC databases from multiple institutions of patients with either two synchronous or sequential HCC ≤ 3 cm between January 2000 and March 2018. Primary outcomes were overall survival (OS) and transplant-free survival (TFS). RESULTS: 104 patients were identified (male n = 89). Median age was 63 years (interquartile range 58-67.75) and the most common aetiology of liver disease was hepatitis C (40.4%). 59 (56.7%) had synchronous HCC and 45 (43.3%) had sequential. 36 patients died (34.6%) and 25 were transplanted (24.0%). 1, 3 and 5-year OS was 93.0%, 66.1% and 62.3% and 5-year post-transplant survival was 95.8%. 1, 3 and 5-year TFS was 82.1%, 45.85% and 37.8%. When synchronous and sequential groups were compared, OS (1,3 and 5 year synchronous 91.3%, 63.8%, 61.1%, sequential 95.3%, 69.5%, 64.6%, P = 0.41) was similar but TFS was higher in the sequential group (1,3 and 5 year synchronous 68.5%, 37.3% and 29.7%, sequential 93.2%, 56.6%, 48.5%, P = 0.02) though this difference did not remain during multivariate analysis. CONCLUSION: TFS in patients presenting with two HCC ≤ 3 cm is poor regardless of the timing of the second tumor. All patients presenting with two small HCC should be considered for transplantation.
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    Effect of QT interval prolongation on cardiac arrest following liver transplantation and derivation of a risk index
    Koshy, AN ; Ko, J ; Farouque, O ; Cooray, SD ; Han, H-C ; Cailes, B ; Gow, PJ ; Weinberg, L ; Testro, A ; Lim, HS ; Teh, AW (WILEY, 2021-02)
    Liver transplantation (LT) has a 4-fold higher risk of periprocedural cardiac arrest and ventricular arrhythmias (CA/VAs) compared with other noncardiac surgeries. Prolongation of the corrected QT interval (QTc) is common in patients with liver cirrhosis. Whether it is associated with an increased risk of CA/VAs following LT is unclear. Rates of 30-day CA/VAs post-LT were assessed in consecutive adults undergoing LT between 2010 and 2017. Pretransplant QTc was measured by a cardiologist blinded to clinical outcomes. Among 408 patients included, CA/VAs occurred in 26 patients (6.4%). QTc was significantly longer in CA/VA patients (475 ± 34 vs 450 ± 34 ms, P < .001). Optimal QTc cut-off for prediction of CA/VAs was ≥480 ms. After adjustment, QTc ≥480 ms remained the strongest predictor for the occurrence of CA/VAs (odds ratio [OR] 5.2, 95% confidence interval [CI] 2.2-12.6). A point-based cardiac arrest risk index (CARI) was derived with the bootstrap method for yielding optimism-corrected coefficients (2 points: QTc ≥480, 1 point: Model for End-Stage Liver Disease [MELD] ≥30, 1 point: age ≥65, and 1 point: male). CARI score ≥3 demonstrated moderate discrimination (c-statistic 0.79, optimism-corrected c-statistic 0.77) with appropriate calibration. QTc ≥480 ms was associated with a 5-fold increase in the risk of CA/VAs. The CARI score may identify patients at higher risk of these events. Whether heightened perioperative cardiac surveillance, avoidance of QT prolonging medications, or beta blockers could mitigate the risk of CA/VAs in this population merits further study.
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    Turning the Tide on Hepatitis C Virus-Related Liver Transplantation: The Return on Investment in Hepatitis C Virus Treatment in Australia and New Zealand
    Howell, J ; Majumdar, A ; Fink, MA ; Byrne, M ; McCaughan, G ; Strasser, S ; Crawford, M ; Hodgkinson, P ; Stuart, KA ; Tallis, C ; Chen, J ; Wigg, A ; Jones, R ; Jaques, B ; Jeffrey, G ; Adams, L ; Wallace, MC ; Munn, S ; Gane, E ; Thompson, AJ ; Gow, P (WILEY, 2022-02)
    Introduction of universal access to direct-acting antiviral (DAA) therapy for hepatitis C virus (HCV) in Australia and New Zealand on March 1st , 2016, has had a major impact on the number of people with chronic HCV infection, but the impact on liver transplantation rates is unknown. We conducted a retrospective registry study including all adult liver transplantations from the Australia and New Zealand Liver and Intestinal Liver Transplant Registry (ANZLITR) data set. Interrupted time series analysis determined the impact of DAAs in 2016 on the number of HCV liver transplantations per year. Cox regression analysis was used to determine the impact of DAAs on post-liver transplantation survival. Between January 1, 1990, and December 31, 2019 5318 adult liver transplantations were performed, and 29% (1531) were for HCV infection. Prior to the introduction of DAAs, there was a mean increase of 3.5 adult liver transplantations performed for HCV per annum, but between 2016 and 2019 there was a mean decrease of 7.9 adult liver transplantations per annum (P < 0.001). Similarly, the proportion of liver transplantations performed for HCV increased from 9% (1990) to 33% in 2016 and then fell to 23% in 2019 (P < 0.001). The number and proportion of patients with HCV added to the liver transplantation waiting list also fell in 2016 (P < 0.001) when compared with other indications. The introduction of DAAs was associated with a 31% reduction in death after liver transplantation, adjusted for age at transplant and hepatocellular carcinoma (HCC; hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.48-0.99; P = 0.047). The number of adult liver transplantations performed for HCV-related liver cirrhosis and HCC has reduced since the introduction of universal access to DAAs in 2016 in Australia and New Zealand.