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Dive into the research topics where Michael Wachs is active.

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Featured researches published by Michael Wachs.


Transplantation | 1995

The risk of transmission of hepatitis B from HBsAg(-), HBcAb(+), HBIgM(-) organ donors.

Michael Wachs; William Amend; Nancy L. Ascher; Peter N. Bretan; Jean C. Emond; John R. Lake; Juliet S. Melzer; John P. Roberts; S. Tomlanovich; Flavio Vincenti; Peter G. Stock

Liver allografts from HBcAb(+), IgM(-), HBsAg(-) donors can transmit HBV to uninfected recipients. We currently no longer accept these livers for transplantation while continuing to accept the kidneys. The purpose of this study is to determine the risk of donor-transmitted HBV infections from HBcAb(+), HBIgM(-), HBsAg(-) organ donors and determine if the risk of donor-transmitted HBV infections and their severity is dependent on the organ being transplanted. This study consists of a retrospective review of the posttransplant course of recipients of HBcAb(+), HBIgM(-), HBsAg(-) donors accepted at UCSF from 6/85 to 12/93. Transmitted HBV infection was defined as one in which the recipient changed from HBsAg(-) prior to transplantation to HBsAg(+) posttransplant, with no other source. There were 25 of 1190 donors who were HBcAb(+), HBIgM(-), HBsAg(-); 1/42 kidney, 3/6 liver, and 0/7 heart HBsAg(-) transplant recipients of organs from these donors became HBsAg(+) after transplantation. This difference in infection rate (liver vs. kidney and heart) is statistically significant. The clinical course of the liver recipients was also more severe. All of the patients who became infected were HBsAb(-) and HBcAb(-) prior to transplant. We conclude that (1) HBV can be transmitted from HBcAb(+), HBIgM(-), HBsAg(-) organ donors, (2) the rate of transmission is highest and severity of infection is worst in the liver recipients; and (3) we will continue to transplant kidneys from these donors, preferably into immunized recipients.


Transplantation | 1998

Adult living donor liver transplantation using a right hepatic lobe

Michael Wachs; Tom Bak; Frederick M. Karrer; G T Everson; Roshan Shrestha; T Trouillot; Mercedes Susan Mandell; Tracy Steinberg; Igal Kam

BACKGROUND Living donor liver transplantation has gained wide acceptance as an alternative for children with end-stage liver disease. The standard left lateral segment used in this operation does not provide adequate parenchymal mass to broaden its application to larger children or adults. METHODS We report two cases of adult to adult living donor liver transplantation using a right hepatic lobe in patients with chronic liver disease. RESULTS Both recipients experienced excellent initial graft function and have normal liver function 4 and 9 months postoperatively. Both donors are alive and well and returned to normal life 4 weeks postoperatively. CONCLUSIONS Our initial experience suggests that this technique is a safe and reliable option for adults with chronic end-stage liver disease. A conservative application of this procedure in the adult population could significantly reduce the mortality on the adult waiting list.


Transplantation | 2000

Randomized Trial Of Tacrolimus (prograf) In Combination With Azathioprine Or Mychophenolate Mofetil Versus Cyclosporine (neoral) With Mycophenolate Mofetil After Cadaveric Kidney Transplantation1, 2

Christopher P. Johnson; Nasimul Ahsan; Thomas A. Gonwa; Philip F. Halloran; Mark D. Stegall; Mark A. Hardy; Robert A. Metzger; Charles F. Shield; Leslie L. Rocher; John D. Scandling; John Sorensen; Laura L. Mulloy; Jimmy A. Light; Claudia Corwin; Gabriel M. Danovitch; Michael Wachs; Paul VanVeldhuisen; Kim Salm; Diane Tolzman; William E. Fitzsimmons

BACKGROUND Our clinical trial was designed to investigate the optimal combination of immunosuppressants for renal transplantation. METHODS A randomized three-arm, parallel group, open label, prospective study was performed at 15 North American centers to compare three immunosuppressive regimens: tacrolimus + azathioprine (AZA) versus cyclosporine (Neoral) + mycophenolate mofetil (MMF) versus tacrolimus + MMF. All patients were first cadaveric kidney transplants receiving the same maintenance corticosteroid regimen. Only patients with delayed graft function (32%) received antilymphocyte induction. A total of 223 patients were randomized, transplanted, and followed for 1 year. RESULTS There were no significant differences in baseline demography between the three treatment groups. At 1 year the results are as follows: acute rejection 17% (95% confidence interval 9%, 26%) in tacrolimus + AZA; 20% (confidence interval 11%, 29%) in cyclosporine + MMF; and 15% (confidence interval 7%, 24%) in tacrolimus + MMF. The incidence of steroid resistant rejection requiring antilymphocyte therapy was 12% in the tacrolimus + AZA group, 11% in the cyclosporine + MMF group, and 4% in the tacrolimus + MMF group. There were no significant differences in overall patient or graft survival. Tacrolimus-treated patients had a lower incidence of hyperlipidemia through 6 months posttransplant. The incidence of posttransplant diabetes mellitus requiring insulin was 14% in the tacrolimus + AZA group, 7% in the cyclosporine + MMF and 7% in the tacrolimus + MMF groups. CONCLUSIONS All regimens yielded similar acute rejection rates and graft survival, but the tacrolimus + MMF regimen was associated with the lowest rate of steroid resistant rejection requiring antilymphocyte therapy.


Liver Transplantation | 2008

Sirolimus-based immunosuppression following liver transplantation for hepatocellular carcinoma.

Michael A. Zimmerman; James F. Trotter; Michael Wachs; Tom Bak; Jeffrey Campsen; Afshin Skibba; Igal Kam

Experience with sirolimus (SRL)‐based immunosuppression following orthotopic liver transplantation (OLT) is rapidly accumulating. In combination with calcineurin inhibitors (CNIs), SRL may reduce the incidence of acute rejection and lower overall required drug levels. This study sought to quantify long‐term outcome following OLT in patients with cirrhosis and concomitant hepatocellular carcinoma (HCC) who were treated with an SRL‐based regimen as a primary therapy. From January 2000 to June 2007, 97 patients underwent OLT for end‐stage liver disease and HCC at the University of Colorado Health Sciences Center. Of those, 45 patients received SRL, in addition to CNIs, as a component of their primary immunosuppression regimen post‐OLT. Conversely, 52 patients received the standard immunosuppression regimen including CNIs, mycophenolate mofetil, and corticosteroids. The 2 treatment groups were compared with respect to the following variables: age, gender, tumor stage by explant, grade, size, presence of vascular invasion, focality, Childs class, baseline creatinine, and warm and cold ischemic times. The 2 groups were comparable by all factors save for cold ischemic time, which was significantly longer in the CNI‐treated group. Overall survival at 1 and 5 years post‐OLT for patients treated with SRL was 95.5% and 78.8%, respectively. Conversely, survival in patients treated with CNIs exclusively at the same time intervals was 83% and 62%. Although there was no difference in the incidence of major complications, the SRL group experienced a modest improvement in renal function. Cumulatively, these data suggest a potential survival benefit with SRL‐based therapy in patients undergoing OLT for end‐stage liver disease and concomitant malignancy. Liver Transpl 2008.


Transplantation | 2001

Randomized trial of tacrolimus plus mycophenolate mofetil or azathioprine versus cyclosporine oral solution (modified) plus mycophenolate mofetil after cadaveric kidney transplantation: results at 2 years.

Nasimul Ahsan; Christopher P. Johnson; Thomas A. Gonwa; Philip F. Halloran; Mark D. Stegall; Mark A. Hardy; Robert A. Metzger; Charles F. Shield; Leslie Rocher; John D. Scandling; John Sorensen; Laura L. Mulloy; Jimmy A. Light; Claudia Corwin; Gabriel M. Danovitch; Michael Wachs; Paul VanVeldhuisen; Kim Salm; Diane Tolzman; William E. Fitzsimmons

Background. A previous report described the 1-year results of a prospective, randomized trial designed to investigate the optimal combination of immunosuppressants in kidney transplantation. Recipients of first cadaveric kidney allografts were treated with tacrolimus+mycophenolate mofetil (MMF), cyclosporine oral solution (modified) (CsA)+MMF, or tacrolimus+azathioprine (AZA). Results at 1 year revealed that optimal efficacy and safety were achieved with a regimen containing tacrolimus+MMF. The present report describes results at 2 years. Methods. Two hundred twenty-three recipients of first cadaveric kidney allografts were randomized to receive tacrolimus+MMF, CsA+MMF, or tacrolimus+AZA. All regimens contained corticosteroids, and antibody induction was used only in patients who experienced delayed graft function. Patients were followed up for 2 years. Results. The results at 2 years corroborate and extend the findings of the previous report. Patients randomized to either treatment arm containing tacrolimus experienced improved kidney function. New-onset insulin dependence remained in four, three, and four patients in the tacrolimus+MMF, CsA+MMF, and tacrolimus+AZA treatment arms, respectively. Furthermore, patients with delayed graft function/acute tubular necrosis who were treated with tacrolimus+MMF experienced a 23% increase in allograft survival compared with patients receiving CsA+MMF (P =0.06). Patients randomized to tacrolimus+MMF received significantly lower doses of MMF compared with those administered CsA+MMF. Conclusions. All three immunosuppressive regi-mens provided excellent safety and efficacy. How-ever, the best results overall were achieved with tacrolimus+MMF. The combination may provide particular benefit to kidney allograft recipients who develop delayed graft function/acute tubular necrosis. Renal function at 2 years was better in the tacrolimus treatment groups compared with the CsA group.


Transplantation | 1997

Prednisone withdrawal 14 days after liver transplantation with mycophenolate: a prospective trial of cyclosporine and tacrolimus.

Mark D. Stegall; Michael Wachs; Gregory T. Everson; Tracy Steinberg; Bahri M. Bilir; Roshan Shrestha; Frederick M. Karrer; Igal Kam

BACKGROUND The long-term complications of immunosuppressive therapy such as diabetes, hypercholesterolemia, and hypertension are a major source of morbidity in liver transplant recipients. In this prospective, randomized, open-label study we completely withdrew prednisone (PRED) 14 days after liver transplantation in an effort to decrease these metabolic complications. Patients were maintained on mycophenolate mofetil (MMF) in combination with either cyclosporine (CsA; Neoral formulation) or tacrolimus (TAC). Thus, we also were able to compare CsA to TAC in patients not receiving PRED with respect to efficacy, toxicity, and effect on posttransplant metabolic complications. METHODS A total of 71 patients were randomized to receive either TAC-MMF (n=35) or CsA-MMF (n=36) after liver transplantation and were analyzed for patient and graft survival. Fifty-eight patients continued the immunosuppressive protocol for at least 6 months after transplantation and were analyzed for the incidence of acute rejection and the prevalence of diabetes, hypertension, and hypercholesterolemia. RESULTS The 6-month patient survival rates were 94.4% for CsA-MMF and 88.6% for TAC-MMF. Corresponding 6-month graft survival rates were 88.7% and 85.71% with no immunologic graft losses in either group. The incidence of biopsy-proven acute rejection was 46% for CsA-MMF and 42.3% for TAC-MMF. Six patients were converted from CsA to TAC (four for recurrent rejection) and seven patients were converted from TAC to CsA (four for neurotoxicity). Only one patient (in the TAC-MMF group) developed new-onset posttransplant diabetes. In contrast, four of eight patients in the CsA-MMF group who were diabetic before transplant became nondiabetic in the first 3 months after transplant. The mean serum cholesterol level was significantly lower in the TAC-MMF group than in the CsA-MMF group (145.2+/-41.8 mg/dl and 190.3+/-62.2, respectively; P<0.001) and the incidence of hypertension was lower in the TAC-MMF group (12% vs. 30.3% in the CsA-MMF group, P<0.01). Both groups had a lower incidence of metabolic complications compared with a historical group (n=100) maintained on CsA and PRED (10 mg/day at 6 months). CONCLUSIONS MMF in combination with either TAC or CsA allows withdrawal of PRED 14 days after liver transplantation with a moderate rejection rate and no immunologic graft losses. Early PRED withdrawal decreases posttransplant diabetes, hypercholesterolemia, and hypertension, but patients maintained on TAC have lower serum cholesterol levels and a lower incidence of hypertension than CsA-treated patients.


Transplantation | 2003

Randomized trial of tacrolimus + mycophenolate mofetil or azathioprine versus cyclosporine + mycophenolate mofetil after cadaveric kidney transplantation : Results at three years

Thomas A. Gonwa; Christopher P. Johnson; Nasimul Ahsan; Edward J. Alfrey; Philip F. Halloran; Mark D. Stegall; Mark A. Hardy; Robert A. Metzger; Charles F. Shield; Leslie Rocher; John D. Scandling; John Sorensen; Laura L. Mulloy; Jimmy A. Light; Claudia Corwin; Gabriel M. Danovitch; Michael Wachs; Paul VanVeldhuisen; Maryanne Leonhardt; William E. Fitzsimmons

Methods. Two hundred twenty-three recipients of first cadaveric kidney allografts were randomized to receive tacrolimus (TAC) + mycophenolate mofetil (MMF), TAC + azathioprine (AZA), or cyclosporine (Neoral; CsA) + MMF. All regimens contained corticosteroids, and antibody induction was used only in patients who experienced delayed graft function (DGF). Patients were followed-up for 3 years. Results. The results at 3 years corroborate and extend the findings of the 2-year results. Patients with DGF treated with TAC+MMF experienced an increase in 3-year allograft survival compared with patients receiving CsA+MMF (84.1% vs. 49.9%, P =0.02). Patients randomized to either treatment arm containing TAC exhibited numerically superior kidney function when compared with CsA. During the 3 years, new-onset insulin dependence occurred in 6, 3, and 11 patients in the TAC+MMF, CsA+MMF, and TAC+AZA treatment arms, respectively. Furthermore, patients randomized to TAC+MMF received significantly lower doses of MMF as compared with those who received CsA+MMF. Conclusion. All three immunosuppressive regimens provided excellent safety and efficacy. However, the best results overall were achieved with TAC+MMF. The combination may provide particular benefit to kidney allograft recipients with DGF. In patients who experienced DGF, graft survival was better at 3 years in those patients receiving TAC in combination with either MMF or AZA as compared with the patients receiving CsA with MMF.


Liver Transplantation | 2004

Impact of pretransplant diagnosis of hepatocellular carcinoma on cadveric liver allocation in the era of MELD

Paul H. Hayashi; James F. Trotter; Lisa M. Forman; Marcelo Kugelmas; Tracy Steinberg; Paul D. Russ; Michael Wachs; Thomas Bak; Igal Kam; Gregory T. Everson

The allocation system based on the Model for End‐stage Liver Disease (MELD) has led to more patients diagnosed with hepatocellular carcinoma (HCC) being transplanted. We hypothesized that more patients misdiagnosed with HCC are also being transplanted, leading to inappropriate organ allocation. Therefore, we retrospectively analyzed all liver transplants at our center from July 14, 2000, to October 22, 2002 (N = 172; 129 pre‐MELD, 43 post‐MELD), comparing pretransplant HCC diagnosis to explant histology. Thirty patients met the United Network for Organ Sharing (UNOS) diagnostic criteria for pretransplant HCC diagnosis. There were 25 men (median age, 52.5 yr), and 80% had hepatitis C. The proportion of patients transplanted who had an HCC diagnosis increased from 12% (15/129) pre‐MELD to 35% (15/43) post‐MELD implementation (P < 0.01). Three of 15 (20%) transplanted pre‐MELD and 5 of 15 (33%) transplanted post‐MELD lacked HCC in the explant (P = 0.10). Of the three false‐positives pre‐MELD, one was Status 2B already, and two received living‐donor livers. Of the 5 false‐positives post‐MELD, three had score upgrades that led to early transplantation (13 to 29, 20 to 29, and 9 to 24) while two had MELD scores of 35 and 36 already. The percentage of organs that could have gone to patients with more advanced liver disease without HCC increased from 0% (0/129) pre‐MELD to 7% (3/43) post‐MELD (P < 0.01). Since the implementation of MELD, the proportion of patients transplanted who had an HCC diagnosis nearly tripled, and a small but significant proportion of organs are now going to patients misdiagnosed with HCC. More stringent HCC diagnostic criteria will be required to decrease the effect that misdiagnosis has on organ allocation. (Liver Transpl 2004;10:42–48.)


Transplantation | 1996

The use of the T tube after orthotopic liver transplantation.

Henry B. Randall; Michael Wachs; Kenneth A. Somberg; John R. Lake; Jean C. Emond; Nancy L. Ascher; John P. Roberts

An end-to-end choledochocholedochostomy (CD) over a T tube or a Roux-en-Y choledochojejunostomy (CDJ) have been the standard method of biliary reconstruction following orthotopic liver transplantation (OLTx). The objective of this study was to assess whether or not use of the T tube leads to increased biliary tract complications. Biliary tract complications were categorized as bile leak, stenosis, or obstruction that required therapeutic intervention. OLTx was performed in 161 patients over an 18-month period. Fifty-one patients were excluded from the study leaving a total of 110 patients for evaluation. Fifty-nine had their bile duct reconstructed over a T tube (CD T tube, group I) while the remaining 51 patients underwent bile duct reconstruction without a T tube (CD, group II). No difference was noted between groups I and II in their survival rate, rate of conversion to Roux-en-Y CDJ, or biliary complication rates. Our results indicate that CD (i.e., without a T tube) is both a safe and effective technique to reconstruct the biliary tract following hepatic transplantation. Routine use of a T tube with a CD anastomosis is unnecessary in most liver transplant patients. In addition, the omission of a T tube has reduced the number of radiological procedures performed at our center.


American Journal of Transplantation | 2004

Hepatic Artery Chemoembolization for Hepatocellular Carcinoma in Patients Listed for Liver Transplantation

Paul H. Hayashi; Michael Ludkowski; Lisa M. Forman; Michael J. Osgood; Stephen P. Johnson; Marcelo Kugelmas; James F. Trotter; Thomas Bak; Michael Wachs; Igal Kam; Janette D. Durham; Gregory T. Everson

We retrospectively analyzed all listed patients having hepatic artery chemoembolization (HACE) for hepatocellular carcinoma (HCC) stage T2 or less. Outcomes were transplantation, waiting list removal, death, and HCC recurrence. Twenty patients (mean age 55.7 years; 15 males) were identified. Twelve (60%) were transplanted, seven (35%) were removed from the list and one (5%) remains listed. Fourteen (70%) are alive. All 12 transplanted patients are alive (mean 2.94 years); one of seven removed from the list is alive (mean 1.45 years). Survival was significantly higher for those transplanted or listed vs. removed from the list (100% vs. 14.3%, p = 0.0002). No HCCs recurred. Three patients (15%) were removed from the list after prolonged waiting times before MELD. Hepatic artery chemoembolization induced deterioration and removal from the list of one (5%) patient. Survival for those transplanted was excellent(100%), but overall survival was significantly lower (61.3%) at a mean 5.48 years. Hepatic artery chemoembolization for listed patients with ≤€ T2 stage HCC is beneficial, but must be weighed against decreased waiting times and risk of HACE‐induced deterioration. This balance is influenced greatly by the MELD systems determination of waiting times for HCC patients.

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Igal Kam

University of Colorado Denver

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Thomas Bak

Anschutz Medical Campus

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James F. Trotter

Baylor University Medical Center

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Gregory T. Everson

University of Colorado Denver

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Tracy Steinberg

University of Colorado Denver

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Michael A. Zimmerman

Medical College of Wisconsin

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Roshan Shrestha

University of North Carolina at Chapel Hill

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Tom Bak

Anschutz Medical Campus

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Marcelo Kugelmas

University of Colorado Denver

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