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15 citation(s) found for "Singer, Andrew".

Overcoming hepatic artery variations: Arterial reconstruction strategies to expand normothermic machine perfusion in liver transplantation
Ohara, Stephanie, Li, Xingjie , Ruch, Brianna , Nunez-Nateras, Raphael, Cosentino, Christopher P., Mirie, Kayla R., Hewitt, Winston R. , Harbell, Jack W. , Singer, Andrew L., Moss, Adyr A. , Reddy, Kunam S. , Mathur, Amit K. , Nunez-Nateras, Raphael, Zhang, Nan , Katariya, Nitin , Jadlowiec, Caroline C. , Nguyen, Michelle

Mayo Clinic

Liver Transplantation | September 26, 2025 | Volume: 32 | Issue: 6 | Pages: 812-822

10.1097/lvt.0000000000000741 | PMID 41002214 Get It

Normothermic machine perfusion (NMP) enables preservation and functional assessment of liver allografts, improving outcomes, particularly in marginal organs. However, the TransMedics Organ Care System (OCS) permits only single hepatic artery (HA) cannulation, limiting its use in grafts with variant arterial anatomy. Arterial reconstruction before NMP may overcome this limitation and expand the pool of grafts eligible for perfusion. We conducted a retrospective single-center cohort study of adult liver transplants utilizing OCS from January 2022 to September 2024. Allografts with variant hepatic artery anatomy requiring arterial reconstruction before NMP initiation were identified. Postoperative outcomes, including vascular and biliary complications, were compared between reconstructed and non-reconstructed grafts. Among 541 OCS-preserved grafts, 74 (13.7%) underwent arterial reconstruction. Compared with non-reconstructed grafts, reconstructed grafts had longer cross-clamp to cannulation time (2.8 vs. 2.4 h, p <0.001), but similar rates of early allograft dysfunction (23.0% vs. 20.8%, p =0.65), ischemic cholangiopathy (4.1% vs. 4.1%, p =1.00), and primary nonfunction (0.0% vs. 0.4%, p =1.00). Early (2.7% vs. 0.2%, p =0.05) and late hepatic artery thrombosis (HAT) (4.1% vs. 2.1%, p =0.40) were infrequent and not significantly different between non-reconstructed and reconstructed groups, respectively. Hepatic artery stenosis occurred more often in reconstructed grafts (12.2% vs. 4.1%, p =0.008), though most cases were managed with interventional radiology or surgical revision. Only one reconstructed graft required retransplantation due to vascular complications. Arterial reconstruction before NMP is safe and feasible, enabling successful perfusion and transplantation of liver allografts with variant HA anatomy. These findings support the broader application of NMP in anatomically complex donor livers.
Improved Outcomes and Resource Use With Normothermic Machine Perfusion in Liver Transplantation
Zhang, Chi , Li, Xingjie , Ohara, Stephanie , Kumm, Kayla , Cosentino, Christopher P., Aqel, Bashar , Frasco, Peter E. , Nunez-Nateras, Raphael, Hewitt, Winston R. , Harbell, Jack W. , Singer, Andrew L., Moss, Adyr A. , Reddy, Kunam S. , Mathur, Amit K. , Kumm, Kayla R, Lizaola-Mayo, Blanca C, Nguyen, Michelle , Chang, Yu‐Hui , Aqel, Bashar A. , Lizaola‐Mayo, Blanca , Nunez-Nateras, Raphael, Katariya, Nitin , Jadlowiec, Caroline C.

Mayo Clinic

JAMA Surgery | January 29, 2025 | Volume: 160 | Issue: 3 | Pages: 322

10.1001/jamasurg.2024.6520 | PMID 39878966 Get It

Importance Normothermic machine perfusion (NMP) has been shown to reduce peritransplant complications. Despite increasing NMP use in liver transplant (LT), there is a scarcity of real-world clinical experience data. Objective To compare LT outcomes between donation after brain death (DBD) and donation after circulatory death (DCD) allografts preserved with NMP or static cold storage (SCS). Design, Setting, and Participants This single-center, retrospective observational cohort study included all consecutive adult LTs performed between January 2019 and December 2023 at the Mayo Clinic in Arizona. Data analysis was performed between February 2024 and June 2024. Outcomes of DBD-SCS, DBD-NMP, DCD-SCS, and DCD-NMP transplants were compared. Exposure DBD and DCD livers preserved on NMP or SCS. Main Outcomes and Measures The primary outcomes were early allograft dysfunction (EAD), intraoperative transfusion, and post-LT hospital resource use, including length of stay (LOS) and readmissions. Secondary outcomes included acute kidney injury (AKI) and 1-year graft and patient survival. Results A total of 1086 LTs were included in the following 4 groups: DBD-SCS (n = 480), DBD-NMP (n = 63), DCD-SCS (n = 264), and DCD-NMP (n = 279). Among LT recipients, median (IQR) age was 60.0 years (52.0-66.0); 399 LT recipients (36.7%) were female. DCD-NMP had the lowest EAD rate (17.5%), followed by DCD-SCS (50.0%), DBD-NMP (36.8%), and DBD-SCS (27.3%) ( P &amp;lt; .001). DCD-NMP had the lowest intraoperative transfusion requirement compared to all other groups. Hospital and intensive care unit (ICU) LOS were shortest in DCD-NMP (median [IQR] hospital LOS, 5.0 days [4.0-7.0]; P = .01; median [IQR] ICU LOS, 1.5 days [1.2-3.1]; P = .01). One-year cumulative readmission probability was 86% lower for DCD-NMP vs DCD-SCS (95% CI, 0.09-0.22; P &amp;lt; .001) and 53% lower for DBD-NMP vs DBD-SCS (95% CI, 0.26-0.87; P &amp;lt; .001). AKI events were lower in DCD-NMP (31.1%) vs DCD-SCS (47.4%) ( P = .001). Compared to SCS, the NMP group had a 78% overall reduction in graft failure (hazard ratio [HR], 0.22; 95% CI, 0.10-0.49; P &amp;lt; .001). For those receiving DCD allografts, the risk reduction was even more pronounced, with an 87% decrease in graft failure (HR, 0.13; 95% CI, 0.05-0.33; P &amp;lt; .001). NMP was significantly protective from patient mortality vs SCS (HR, 0.31; 95% CI, 0.12-0.80; P = .02). Conclusions and Relevance In this observational high-volume cohort study, NMP significantly improved LT clinical outcomes and reduced hospital resource use, especially in DCD allografts. NMP may enhance access to LT by addressing the challenges historically linked with DCD liver use.
Normothermic Machine Perfusion of Donor Livers for Transplantation in the United States
Chapman, William C. , Barbas, Andrew S. , D’Alessandro, Anthony M. , Vianna, Rodrigo , Abt, Peter L. , Sonnenday, Christopher J. , Barth, Rolf N. , Alvarez-Casas, Josue, Yersiz, Hasan, Genyk, Yuri , Sher, Linda , Singer, Andrew L., Doyle, Maria B. Majella, Sudan, Debra L. , Al‐Adra, David , Khan, Adeel , Subramanian, Vijay , Abraham, Nader , Olthoff, Kim M. , Tekin, Akin , Berg, Lynn, Morris, C.G. , Randle, Lucy V., Friend, Peter J. , Singer, Andrew, Chapman, William C , Sudan, Debra L , Kubal, Chandrashekhar A. , Eckhoff, Devin E. , Cannon, Robert M. , Feng, Sandy , Roll, Garrett Richard , Cohen, Ari J. , Coussios, Constantin C. , Knechtle, Stuart J.

Mayo Clinic

Annals of Surgery | June 30, 2023 | Volume: 278 | Issue: 5 | Pages: e912-e921

10.1097/sla.0000000000005934 | PMID 37389552 Get It

Objective: To compare conventional low-temperature storage of transplant donor livers [static cold storage (SCS)] with storage of the organs at physiological body temperature [normothermic machine perfusion (NMP)]. Background: The high success rate of liver transplantation is constrained by the shortage of transplantable organs (eg, waiting list mortality >20% in many centers). NMP maintains the liver in a functioning state to improve preservation quality and enable testing of the organ before transplantation. This is of greatest potential value with organs from brain-dead donor organs (DBD) with risk factors (age and comorbidities), and those from donors declared dead by cardiovascular criteria (donation after circulatory death). Methods: Three hundred eighty-three donor organs were randomized by 15 US liver transplant centers to undergo NMP (n = 192) or SCS (n = 191). Two hundred sixty-six donor livers proceeded to transplantation (NMP: n = 136; SCS: n = 130). The primary endpoint of the study was “early allograft dysfunction” (EAD), a marker of early posttransplant liver injury and function. Results: The difference in the incidence of EAD did not achieve significance, with 20.6% (NMP) versus 23.7% (SCS). Using exploratory, “as-treated” rather than “intent-to-treat,” subgroup analyses, there was a greater effect size in donation after circulatory death donor livers (22.8% NMP vs 44.6% SCS) and in organs in the highest risk quartile by donor risk (19.2% NMP vs 33.3% SCS). The incidence of acute cardiovascular decompensation at organ reperfusion, “postreperfusion syndrome,” as a secondary outcome was reduced in the NMP arm (5.9% vs 14.6%). Conclusions: NMP did not lower EAD, perhaps related to the inclusion of lower-risk liver donors, as higher-risk donor livers seemed to benefit more. The technology is safe in standard organ recovery and seems to have the greatest benefit for marginal donors.
Cover Image, Volume 6, Issue 2
Giorgakis, Emmanouil , Wells, Allison, Balogh, Julius , Krinock, Derek , Burdine, Lyle , Singer, Andrew L., Mathur, Amit K. , Giorgakis, Emmanouil , Balogh, Julius , Ivanics, Tommy , Wallace, David , Hardgrave, Hailey , Klutts, Garrett N.

Mayo Clinic

Health Science Reports | February 15, 2023 | Volume: 6 | Issue: 2 | Pages: No page available

10.1002/hsr2.1125 Get It

Acuity circles allocation policy impact on waitlist mortality and donation after circulatory death liver transplantation: A nationwide retrospective analysis
Giorgakis, Emmanouil , Wallace, David , Wells, Allison, Balogh, Julius , Hardgrave, Hailey , Krinock, Derek , Burdine, Lyle , Singer, Andrew L., Mathur, Amit K. , Balogh, Julius , Singer, Andrew, Giorgakis, Emmanouil , Ivanics, Tommy , Klutts, Garrett N.

Mayo Clinic

Health Science Reports | February 2, 2023 | Volume: 6 | Issue: 2 | Pages: No page available

10.1002/hsr2.1066 | PMID 36751274 Get It

413.1: The Impact of UNOS Acuity Circles-Based Organ Allocation on DCD Liver Transplant Rates and Waitlist Mortality in the United States
Wallace, David , Burdine, Lyle , Patel, Raj , Rude, Mary K., Balong, Julius, Wells, Allison Childs, Krinock, Derek , Singer, Andrew L., Mathur, Amit K. , Giorgakis, Emmanouil , Ivanics, Tommy , Wells, Allison, Hardgrave, Hailey

Mayo Clinic

Transplantation | September 19, 2022 | Volume: 106 | Issue: 9S | Pages: S409-S409

10.1097/01.tp.0000887652.80903.2e Get It

A Randomized Double-Blinded Placebo Controlled Trial of Clazakizumab for the Treatment of COVID-19 Pneumonia With Hyperinflammation*
Spiegler, Peter, Wesson, Russell , Weldon, Elaina , Dieter, Rebecca A., Quinn, Max M., Mattoo, Aprajita , Soomro, Irfana, Leung, Sherry , Deterville, Cecilia L., Landrum, B. Mark, Ali, Muhammad Imran, Cohen, David J. , Singer, Andrew L., Sen, Ayan , Lonze, Bonnie E. , Alachkar, Nada , Petkova, Eva , Dieter, Rebecca A. , Li, Yi , Cohen, Steven M. , Ali, Muhammad Imran, Chong, Edward, Hochman, Judith S. , Troxel, Andrea B. , Montgomery, Robert A.

Mayo Clinic

Critical Care Medicine | May 18, 2022 | Volume: 50 | Issue: 9 | Pages: 1348-1359

10.1097/ccm.0000000000005591 | PMID 35583232 Get It

OBJECTIVES: We designed this study to test whether clazakizumab, a direct interleukin-6 inhibitor, benefits patients hospitalized with severe or critical COVID-19 disease accompanied by hyperinflammation. DESIGN: Multicenter, randomized, double-blinded, placebo-controlled, seamless phase II/III trial. SETTING: Five U.S. medical centers. PATIENTS: Adults inpatients with severe COVID-19 disease and hyperinflammation. INTERVENTIONS: Eighty-one patients enrolled in phase II, randomized 1:1:1 to low-dose (12.5 mg) or high-dose (25 mg) clazakizumab or placebo. Ninety-seven patients enrolled in phase III, randomized 1:1 to high-dose clazakizumab or placebo. MEASUREMENTS AND MAIN RESULTS: The primary outcome was 28-day ventilator-free survival. Secondary outcomes included overall survival, frequency and duration of intubation, and frequency and duration of ICU admission. Per Data Safety and Monitoring Board recommendations, additional secondary outcomes describing clinical status and status changes, as measured by an ordinal scale, were added. Bayesian cumulative proportional odds, logistic, and Poisson regression models were used. The low-dose arm was dropped when the phase II study suggested superiority of the high-dose arm. We report on 152 patients, 74 randomized to placebo and 78 to high-dose clazakizumab. Patients receiving clazakizumab had greater odds of 28-day ventilator-free survival (odds ratio [OR] = 3.84; p [OR > 1] 99.9%), as well as overall survival at 28 and 60 days (OR = 1.75; p [OR > 1] 86.5% and OR = 2.53; p [OR > 1] 97.7%). Clazakizumab was associated with lower odds of intubation (OR = 0.2; p [OR] < 1; 99.9%) and ICU admission (OR = 0.26; p [OR < 1] 99.6%); shorter durations of ventilation and ICU stay (risk ratio [RR] < 0.75; p [RR < 1] > 99% for both); and greater odds of improved clinical status at 14, 28, and 60 days (OR = 2.32, p [OR > 1] 98.1%; OR = 3.36, p [OR > 1] 99.6%; and OR = 3.52, p [OR > 1] 99.8%, respectively). CONCLUSIONS: Clazakizumab significantly improved 28-day ventilator-free survival, 28- and 60-day overall survival, as well as clinical outcomes in hospitalized patients with COVID-19 and hyperinflammation.
Solid Organ Transplantation From SARS-CoV-2–infected Donors to Uninfected Recipients: A Single-center Experience
Jayasekera, Channa R., Vikram, Holenarasipur R., Rifat, Zeeshan, Wagler, Josiah, Okubo, Keita, Braaksma, Brandon R., Harbell, Jack W., Jadlowiec, Caroline C., Katariya, Nitin N., Mathur, Amit K., Moss, Adyr, Reddy, K. Sudhakar, Singer, Andrew, Orenstein, Robert, Saling, Christopher F., Seville, Maria T., Mour, Girish K., Vargas, Hugo E., Byrne, Thomas J., Hewitt, Winston R., Aqel, Bashar A., Vargas, Hugo E. , Vikram, Holenarasipur R. , Katariya, Nitin , Vikram, Holenarasipur R. , Vargas, Hugo E , Katariya, Nitin N , Jayasekera, Channa R., Rifat, Zeeshan, Wagler, Josiah, Okubo, Keita, Braaksma, Brandon R., Harbell, Jack W., Jadlowiec, Caroline C., Mathur, Amit K., Moss, Adyr, Reddy, K. Sudhakar, Singer, Andrew, Orenstein, Robert, Saling, Christopher F., Seville, Maria T., Mour, Girish K., Byrne, Thomas J., Hewitt, Winston R., Aqel, Bashar A., Okubo, Keita

Mayo Clinic

Transplantation Direct | January 13, 2022 | Volume: 8 | Issue: 2 | Pages: e1286

10.1097/txd.0000000000001286 | PMID 35047665 Get It

Background. The risk of donor-derived severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in solid organ (heart, lung, liver, kidney, pancreas, and intestine) transplant recipients is poorly understood. Since hematogenous transmission of SARS-CoV-2 has not been documented to date, nonlung solid organs might be suitable for transplantation since they likely portend a low risk of viral transmission. Methods. Abdominal solid organs from SARS-CoV-2–infected donors were transplanted into uninfected recipients. Results. Between April 18, 2021, and October 30, 2021, we performed transplants of 2 livers, 1 simultaneous liver and kidney, 1 kidney, and 1 simultaneous kidney and pancreas from SARS-CoV-2–infected donors into 5 uninfected recipients. None of the recipients developed SARS-CoV-2 infection or coronavirus disease 2019, and when tested, allograft biopsies showed no evidence of SARS-CoV-2 RNA. Conclusions. Transplanting nonlung organs from SARS-CoV-2–infected donors into uninfected recipients demonstrated no evidence of virus transmission.
Centre volume impact on graft survival and waiting list time in donation after circulatory death liver transplantation in the USA
Giorgakis, Emmanouil , Khorsandi, Shirin Elizabeth , Burdine, Lyle , Singer, Andrew L., Hewitt, Winston R. , Heaton, Nigel, Mathur, Amit K. , Khorsandi, Shirin E , Singer, Andrew, Hewitt, Winston, Giorgakis, Emmanouil

Mayo Clinic

British Journal of Surgery | September 8, 2021 | Volume: 108 | Issue: 12 | Pages: e404-e406

10.1093/bjs/znab348 | PMID 34672324 Get It

During 2001–2015, numbers of donation after circulatory death (DCD) liver transplantations (LTs) remained surprisingly low. Post-transplant outcomes improved overall over time, regardless of centre volume. High-volume centres that promoted DCD LT significantly shortened their waiting list time, therefore limiting waiting list mortality and drop-outs.
Transplant outcomes using kidneys from high KDPI acute kidney injury donors
Hanna, W. A., Ninan, Jacob, Ryan, Margaret , Das, Devika , Khamash, Hasan , Mathur, Amit K. , Singer, Andrew L., Moss, Adyr A. , Reddy, Kunam S. , Heilman, Raymond L. , Jadlowiec, Caroline , Hanna, Wael A, Ryan, Margaret S, Das, Devika M, Mathur, Amit , Singer, Andrew, Das, Devika , Jadlowiec, Caroline C. , Hanna, Wael A., Smith, Maxwell L.

Mayo Clinic

Clinical Transplantation | March 10, 2021 | Volume: 35 | Issue: 5 | Pages: No page available

10.1111/ctr.14279 | PMID 33690907 Get It

AbstractKidney transplant (KT) outcomes from high kidney donor profile index (KDPI ≥85%) donors with acute kidney injury (AKI) remain underreported. KT from 172 high KDPI Acute Kidney Injury Network (AKIN) stage 0‐1 donors and 76 high KDPI AKIN stage 2‐3 donors from a single center were retrospectively assessed. The AKIN 2‐3 cohort had more delayed graft function (71% vs. 37%, p < .001). At one year, there were no differences in the estimated glomerular filtration rate (44 ± 17 vs. 46 ± 18, p = .42) or fibrosis on protocol biopsy (ci, p = .85). Donor terminal creatinine (p = .59) and length of delayed graft function (p = .39) did not impact one‐year eGFR. There were more primary nonfunction (PNF) events in the high KDPI AKIN 2‐3 group (5.3% vs. 0.6%, p = .02). With a median follow‐up of 3.8 years, one‐year death‐censored graft failure was 3.5% for AKIN 0‐1 and 14.5% for AKIN 2‐3 (HR 2.40, 95% CI 1.24‐4.63, p = .01). Although AKIN stage 2‐3 high KDPI kidneys had comparable one‐year eGFR to AKIN stage 0‐1 high KDPI kidneys, there were more PNF occurrences and one‐year death‐censored graft survival was reduced. Given these findings, additional precautions should be undertaken when assessing and utilizing kidneys from severe AKI high KDPI donors.