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Hewitt, Winston R.

https://orcid.org/0000-0001-8221-9521

Mayo Clinic

Mayo Clinic in Arizona

Citations 14

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

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

10.1097/lvt.0000000000000741 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.

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

10.1001/jamasurg.2024.6520 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.
Outcomes of a Large Series of Laparoscopic Ventral Hernia Repairs after Liver Transplantation
Han, Ga-ram , Johnson, Eleanor R., Calderon, Esteban , Hewitt, Winston R. , Harold, Kristi L., Jogerst, Kristen M, Pearson, David G, Jogerst, Kristen M. , Pearson, David G.

The American Surgeon™ | February 24, 2023 | Volume: 89 | Issue: 12 | Pages: 5520-5526

10.1177/00031348231156762 Get It

Background The hernia defects that develop in liver transplant recipients tend to be complex. Unfortunately, there is a paucity of data to guide post-transplant hernia management. Our goal was to evaluate the outcomes following laparoscopic ventral hernia repair (LVHR) in liver transplant recipients. Methods A retrospective review of a prospectively kept database of liver transplant patients at a single tertiary healthcare facility was completed. All patients between 2007 and 2020 who underwent LVHR for a hernia at their transplant incision site were included. The primary outcome studied was hernia recurrence. Secondary outcomes included time-to-hernia repair, complications, and length of stay (LOS). Results There were 89 patients who met inclusion criteria. 82% were male, mean age was 60 years, and mean body mass index was 30.2 kg/m 2 . 94.4% were on tacrolimus and 36% on mycophenolate mofetil. Median time-to-hernia repair was 16 months with a mean mesh size of 743 cm 2 and length of stay of 3.7 days. None required conversion to an open operation. Postoperative complications included ileus (20.2%), acute kidney injury (11.2%), pneumonia (6.7%), and bleeding requiring re-operation (1.1%). Hernia-related complications included chronic suture site pain (1.1%), seroma requiring intervention (3.3%), surgical site infection (3.3%), nonoperative mesh infection (1.1%), and mesh infection requiring explantation (1.1%). Median follow-up was 23 months. Hernia recurrence occurred in 4.5% and no predictive variables for recurrence were identified. Conclusions Although the hernia defects that develop in liver transplant recipients are complex and their comorbidities significant, LVHR can safely and effectively repair these defects with low rates of recurrence and complications.
Outcomes of endoscopic retrograde cholangiography and percutaneous transhepatic biliary drainage in liver transplant recipients with a Roux-en-Y biliary-enteric anastomosis
Kohli, Divyanshoo R., Aqel, Bashar , Segaran, Nicole , Harrison, M. Edwyn , Fukami, Norio , Faigel, Douglas O. , Moss, Adyr A. , Mathur, Amit K. , Hewitt, Winston R. , Katariya, Nitin , Pannala, Rahul , Kohli, Divyanshoo Rai , Aqel, Bashar A. , Segaran, Nicole L , Moss, Adyr , Mathur, Amit , Hewitt, Winston , Harrison, M Edwyn , Faigel, Douglas O , Fukami, Norio , Katariya, Nitin N

Annals of Hepato-Biliary-Pancreatic Surgery | October 17, 2022 | Volume: 27 | Issue: 1 | Pages: 49-55

10.14701/ahbps.22-037 Get It

Donation after circulatory death transplant outcomes using livers recovered by local surgeons
Macdonough, Elizabeth , Pont, Kylie , Valenti, Kristi , Lizaola‐Mayo, Blanca , Brooks, Abigail , Das, Devika , Heilman, Raymond L. , Mathur, Amit K. , Hewitt, Winston R. , Moss, Adyr A. , Aqel, Bashar , Reddy, Kunam S. , Jadlowiec, Caroline , Macdonough, Elizabeth , Pont, Kylie , Valenti, Kristi , Lizaola-Mayo, Blanca , Brooks, Abigail , Das, Devika , Heilman, Raymond , Mathur, Amit , Hewitt, Winston , Moss, Adyr , Aqel, Bashar A. , Reddy, Kunam S , Jadlowiec, Caroline C.

Liver Transplantation | March 25, 2022 | Volume: 28 | Issue: 11 | Pages: 1726-1734

10.1002/lt.26461 Get It

Abstract Donation after circulatory death (DCD) liver transplantation (LT) outcomes have been attributed to multiple variables, including procurement surgeon recovery techniques. Outcomes of 196 DCD LTs at Mayo Clinic Arizona were analyzed based on graft recovery by a surgeon from our center (transplant procurement team [TPT]) versus a local procurement surgeon (non‐TPT [NTPT]). A standard recovery technique was used for all TPT livers. The recovery technique used by the NTPT was left to the discretion of that surgeon. A total of 129 (65.8%) grafts were recovered by our TPT, 67 (34.2%) by the NTPT. Recipient age (p = 0.43), Model for End‐Stage Liver Disease score (median 17 vs. 18; p = 0.22), and donor warm ischemia time (median 21.0 vs. 21.5; p = 0.86) were similar between the TPT and NTPT groups. NTPT livers had longer cold ischemia times (6.5 vs. 5.0 median hours; p < 0.001). Early allograft dysfunction (80.6% vs. 76.1%; p = 0.42) and primary nonfunction (0.8% vs. 0.0%; p = 0.47) were similar. Ischemic cholangiopathy (IC) treated with endoscopy occurred in 18.6% and 11.9% of TPT and NTPT grafts (p = 0.23). At last follow‐up, approximately half of those requiring endoscopy were undergoing a stent‐free trial (58.3% TPT; 50.0% NTPT; p = 0.68). IC requiring re‐LT in the first year occurred in 0.8% (n = 1) of TPT and 3.0% (n = 2) of NTPT grafts (p = 0.23). There were no differences in patient (hazard ratio [HR], 1.95; 95% confidence interval [CI], 0.76–5.03; p = 0.23) or graft (HR, 1.99; 95% CI, 0.98–4.09; p = 0.10) survival rates. Graft survival at 1 year was 91.5% for TPT grafts and 95.5% for NTPT grafts. Excellent outcomes can be achieved using NTPT for the recovery of DCD livers. There may be an opportunity to expand the use of DCD livers in the United States by increasing the use of NTPT.
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

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

10.1093/bjs/znab348 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.
Primary Alveolar Soft-Part Sarcoma of the Liver: Anomalous Presentation of a Rare Disease
Shaddix, Kyle K., Fakhre, G Peter, Nields, William W., Steers, Jeffery L., Hewitt, Winston R. , Menke, David M.

The American Surgeon™ | June 17, 2020 | Volume: 74 | Issue: 1 | Pages: 43-46

10.1177/000313480807400109 Get It

Alveolar soft-part sarcoma is a highly vascular soft-tissue tumor that is uniformly malignant. It comprises less than 1 per cent of all soft-tissue sarcomas. Patients with alveolar soft-part sarcoma most frequently are aged 15 to 35 years, and the soft tissues of the lower extremities typically are affected. In the pediatric population, it most frequently occurs in the head and neck and particularly affects the tongue and orbit. Alveolar soft-part sarcoma has been described as a primary lesion in the trunk, upper extremities, and retroperitoneum; more novel locations include the mediastinum, female genital tract, stomach, bone, and larynx. Numerous case reports describe alveolar soft-part sarcoma in diverse anatomic locations, but this report is, to our knowledge, the first documentation of primary alveolar soft-part sarcoma of the liver. We describe a 47-year-old woman with such a manifestation. Despite surgical resection and numerous chemotherapeutic regimens, this patient had widespread metastasis and died approximately 2 years after the diagnosis was established.
Clinical Outcomes of Portosystemic Shunts on the Outcome of Liver Transplantation
Rodríguez, Eduardo A. , Perez, Rachel , Zhang, Nan , Lim, Elisabeth S. , Schwartz, Michael , McGirr, A., Srinivasan, Ananth, Hewitt, Winston R. , Silva, Alvin C. , Rakela, Jorge , Vargas, Hugo E. , Schwartz, Michael A , McGirr, Aidan J, Hewitt, Winston, Rakela, Jorge , Vargas, Hugo E , Perez, Rachel M , Miller, Christopher, Srinivasan, Ananth

Liver Transplantation | December 24, 2019 | Volume: 26 | Issue: 5 | Pages: 693-701

10.1002/lt.25710 Get It

Spontaneous portosystemic shunts (SPSSs) have been associated with worse clinical outcomes in the pre–liver transplantation (LT) setting, but little is known about their post‐LT impacts. Our aim was to compare LT candidates with and without SPSSs and assess the impact of SPSSs on patient mortality and graft survival in the post‐LT setting. Patients 18 years or older with abdominal imaging done prior to LT were included. Exclusion criteria were the presence of pre‐LT surgical shunts, LT indications other than cirrhosis, and combined solid organ transplantations. SPSSs were classified as absent, small, or large according to their maximum diameter (8 mm). Multiple variables that could influence the post‐LT course were extracted for analysis. Patient and graft survival were estimated using the Kaplan‐Meier method and were compared between groups using a log‐rank test. The project received institutional review board approval. We extracted data from 326 patients. After comparing patients without SPSS or with small or large SPSSs, no statistical difference was found for overall patient survival: no SPSS (n = 8/63), reference; small SPSS (n = 18/150), hazard ratio (HR), 1.05 (95% confidence interval [CI], 0.45‐2.46); and large SPSS (n = 6/113), HR, 0.60 (95% CI, 0.20‐1.78); P = 0.20. Also, no difference was found for graft survival: no SPSS (n = 11/63), reference; small SPSS (n = 21/150), HR, 0.80 (95% CI, 0.38‐1.70); large SPSS (n = 11/113), HR, 0.59 (95% CI, 0.25‐1.40); P = 0.48. Similarly, no statistical significance was found for these variables when comparing if the graft used was procured from a donation after circulatory death donor versus a donation after brain death donor. In conclusion, the previously described association between SPSSs and worse clinical outcomes in pre‐LT patients seems not to persist once patients undergo LT. This study suggests that no steps to correct SPSS intraoperatively are necessary.
Nontraditional Use of TEE to Evaluate Hepatic Vasculature and Guide Surgical Management in Orthotopic Liver Transplantation
Khurmi, Narjeet , Seman, Mitchell T. , Gaitan, Brantley, Rosenfeld, David M. , Giorgakis, Emmanouil , Hewitt, Winston R. , Mathur, Amit K. , Seman, Mitchell, Young, Scott , Rosenfeld, David, Hewitt, Winston, Mathur, Amit , Giorgakis, Emmanouil , Young, Scott W.

Case Reports in Transplantation | June 19, 2019 | Volume: 2019 | Issue: No issue available | Pages: 1-6

10.1155/2019/5293069 Get It

Intraoperative Transesophageal Echocardiography (TEE) during orthotopic liver transplant (OLT) is used to gather real-time information on cardiovascular function and intravascular volume status. We report a case where nonstandard TEE views were used to inspect the hepatic vasculature after allograft implantation. A 29-year-old male with secondary biliary cirrhosis with a MELD score of 20 underwent OLT using a liver from a 21-year-old brain-dead donor. Postreperfusion TEE, using the modified hepatic vein views, confirmed the presence of an inferior vena cava (IVC) suprahepatic anastomotic stenosis and hepatic vein and IVC thrombus resulting in hepatic venous outflow obstruction, allograft congestion, and hemodynamic instability. These nonstandard TEE images established the extent of suprahepatic caval outflow obstruction, in which intraoperative ultrasound was unable to definitively demonstrate. This guided real-time surgical decision-making in the postimplantation phase of the operation—ultimately leading to hepatic vein and IVC thrombectomy and revision of suprahepatic caval anastomosis.
Cardiorespiratory Fitness (Peak Oxygen Uptake): Safe and Effective Measure for Cardiovascular Screening Before Kidney Transplant
Chakkera, Harini A. , Angadi, Siddhartha S. , Heilman, Raymond L. , Scott, Robert L. , Bollempalli, Harini, Cha, Stephen S., Khamash, Hasan , Huskey, Janna L. , Nair, S. , Singer, Andrew L., Reddy, Kunam S. , Mathur, Amit K. , Moss, Adyr A. , Hewitt, Winston R. , Qaqish, Ibrahim , Behmen, Senaida, Keddis, Mira T. , Unzek, Samuel , Steidley, D. Eric , Khamash, Hasan A, Mour, Girish K., Sukumaran Nair, Sumi, Kaplan, Bruce , Cha, Stephen S., Mour, Girish , Chakkera, Harini A

Journal of the American Heart Association | May 31, 2018 | Volume: 7 | Issue: 11 | Pages: No page available

10.1161/jaha.118.008662 Get It

Background Significant heterogeneity exists in practice patterns and algorithms used for cardiac screening before kidney transplant. Cardiorespiratory fitness, as measured by peak oxygen uptake (VO 2peak ), is an established validated predictor of future cardiovascular morbidity and mortality in both healthy and diseased populations. The literature supports its use among asymptomatic patients in abrogating the need for further cardiac testing. Methods and Results We outlined a pre–renal transplant screening algorithm to incorporate VO 2peak testing among a population of asymptomatic high‐risk patients (with diabetes mellitus and/or >50 years of age). Only those with VO 2peak <17 mL/kg per minute (equivalent to <5 metabolic equivalents) underwent further noninvasive cardiac screening tests. We conducted a retrospective study of the a priori dichotomization of the VO 2peak <17 versus ≥17 mL/kg per minute to determine negative and positive predictive value of future cardiac events and all‐cause mortality. We report a high (>90%) negative predictive value, indicating that VO 2peak ≥17 mL/kg per minute is effective to rule out future cardiac events and all‐cause mortality. However, lower VO 2peak had low positive predictive value and should not be used as a reliable metric to predict future cardiac events and/or mortality. In addition, a simple mathematical calculation documented a cost savings of ≈$272 600 in the cardiac screening among our study cohort of 637 patients undergoing evaluation for kidney and/or pancreas transplant. Conclusions We conclude that incorporating an objective measure of cardiorespiratory fitness with VO 2peak is safe and allows for a cost savings in the cardiovascular screening protocol among higher‐risk phenotype (with diabetes mellitus and >50 years of age) being evaluated for kidney transplant.