J C Imperial

Stanford University, Palo Alto, CA, United States

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Publications (14)62.66 Total impact

  • Transplantation Proceedings 01/2001; 33(1-2):1535-6. · 0.95 Impact Factor
  • Journal of Clinical Gastroenterology 10/1999; 29(2):212-3. · 3.20 Impact Factor
  • A Ahmed, E B Keeffe, J C Imperial
    Gastrointestinal Endoscopy 09/1999; 50(2):279-81. · 5.21 Impact Factor
  • J C Imperial
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    ABSTRACT: Hepatitis B virus (HBV) affects more than 300 million individuals worldwide and in the United States approximately 1.25 million individuals are chronic carriers of HBV. The risk of becoming a chronic hepatitis B virus surface antigen carrier is dependent upon the mode of acquisition of infection as well as the age of the individual at the time of infection. For those individuals with high levels of viral replication, chronic active hepatitis with progression to cirrhosis, liver failure and hepatocellular carcinoma (HCC) is common and liver transplantation is an excellent treatment option for patients with end-stage liver disease from HBV. Patients with chronic HBV infection should be screened periodically for hepatoma, although screening strategies have not been proven to prolong survival. Newer antiviral agents for the treatment of HBV are potent inhibitors of HBV-DNA and their long-term effect on the natural history of HBV is yet to be proven. The natural history of hepatitis C virus (HCV) infection is less well defined than that of chronic HBV. Certain patients who are chronic carriers of HCV may never develop extensive fibrosis, whereas others will progress to chronic active hepatitis with cirrhosis, HCC and end-stage liver disease. Factors that influence the progression of HCV are those related to the host, including the age at acquisition of infection, gender and immune status, and the disease process is accelerated in patients who consume regular amounts of alcohol. Hepatocellular carcinoma develops frequently in patients with HCV infection and its overall incidence is increasing due to this chronic viral disease. Patients with HCV cirrhosis should be screened regularly for hepatoma and liver transplantation is an effective treatment option for those with end-stage disease. The impact of antiviral therapy on the natural history of HCV is still to be determined and should be the focus of large clinical trials.
    Journal of Gastroenterology and Hepatology 06/1999; 14 Suppl:S1-5. · 3.33 Impact Factor
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    ABSTRACT: Hepatocellular carcinoma is responsible for more than 1 million deaths per year worldwide and thus remains a challenging medical problem. It causes few or no symptoms and the tumour frequently reaches an enormous size by the time of diagnosis in countries where screening is seldom used. It is generally resistant to commercially available anti-neoplastic agents and radiation therapy. The principal treatment continues to be resection, either partial or complete, with liver transplantation. However, less than one-third of patients are surgical candidates for either resection or transplantation at the time of clinical presentation. This review will address the results observed following resection or transplantation for hepatocellular carcinoma.
    Journal of Gastroenterology and Hepatology 06/1999; 14 Suppl:S37-41. · 3.33 Impact Factor
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    ABSTRACT: To assess whether Asian race is an independent variable affecting survival and hepatitis B virus (HBV) recurrence after liver transplantation, the results of 27 consecutive liver transplants performed between June 1994 and April 1997 for HBV cirrhosis were analysed. In the group of 13 Asians, 38% had associated hepatocellular carcinoma and 62% had positive hepatitis B virus early antigen (HBeAg) or elevated HBV-DNA before transplant. Prophylactic hepatitis B immunoglobulin (HBIG) was administered perioperatively and long term at 4-6 weekly interval. Four patients with elevated HBV-DNA received lamivudine before transplantation. The 3 year actuarial patient survival rate was 100% in both Asian and non-Asian patients. Twenty-six patients remained seronegative for hepatitis B virus surface antigen after transplantation. The incidence of post-transplant HBV recurrence was similar: 0% in Asians compared with 7% in non-Asians. There was no recurrence in the group of 12 patients who were HBV-DNA or HBeAg negative pretransplant.
    Journal of Gastroenterology and Hepatology 06/1999; 14 Suppl:S48-52. · 3.33 Impact Factor
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    ABSTRACT: Autoimmune liver diseases (AILD) may progress to liver failure, requiring liver transplantation as definitive therapy, and these immune-mediated disorders may predispose the patient to more frequent graft rejection. The objective of this study was to determine the effect of preexisting AILD on the incidence of allograft rejection after liver transplantation. Sixty-three patients who underwent liver transplantation between March 1988 and December 1994 for AILDs that included autoimmune hepatitis (AIH; n = 33) and primary biliary cirrhosis (PBC; n = 30) were retrospectively compared with 47 patients who underwent liver transplantation for alcoholic cirrhosis during the same time period. There was a lower incidence of acute allograft rejection in patients with AILD who received tacrolimus-based compared with cyclosporine-based immunosuppression (50% v 85.5%; P = .02). However, patients with AILDs overall had a higher incidence of acute rejection than patients with alcoholic cirrhosis (81% v 46.8%; P < .001), regardless of the type of immunosuppression. In addition, steroid-resistant rejection occurred more frequently in patients with AILDs than in patients with alcoholic cirrhosis (38.1% v 12.8%; P = .003). There was also a trend toward a higher incidence of chronic rejection in patients with AILDs compared with patients with alcoholic cirrhosis (11.1% v 2.1%), but this difference did not reach statistical significance. Patient and graft survivals at 1 and 3 years were similar between patients with AILDs and alcoholic liver disease. Compared with alcoholic cirrhosis, preexisting AILDs are associated with a higher incidence of acute allograft rejection and a trend toward more frequent chronic rejection.
    Liver transplantation and surgery: official publication of the American Association for the Study of Liver Diseases and the International Liver Transplantation Society 05/1998; 4(3):208-14.
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    ABSTRACT: Because of the unique demographics of our patient population, we have had the opportunity to dedicate further studies of the management of hepatitis B and hepatitis C. We have experienced a very low HBV recurrence rate with the use of HBIG in patients transplanted for hepatitis B. Investigations, including the use of new antiviral agents, and the development of approaches to minimize or abrogate disease recurrence such as lower levels of immunosuppression are ongoing. Using a standardized approach to the proper evaluation and selection of patients for liver transplantation with alcoholic liver disease or other liver diseases with coexistent alcohol abuse, we report favorable long-term results in these patients. We have reviewed our results and our approach to the management of EBV and posttransplant lymphoproliferative disorder. There is a firm commitment in our laboratories and outpatient clinics to the investigation of disease prevention, reliable detection and screening methods, and treatment modalities for EBV-related disease. We have addressed specific technical considerations to pediatric liver transplant and have discussed unique aspects of postoperative management in these patients. One-third of the transplants performed at Stanford are in children, 42% of whom are less than one year old. Results with our pediatric transplant recipients compare favorably with those of our adult recipients with patient and graft survival rates approaching 90% at one year and exceeding 80% at 46 months for both groups. As a response to the limited organ supply, we have extended our criteria for suitable donors. Most notably, we have utilized older donors and grafts with significant microsteatosis and have observed good results with these grafts as long as ischemia time is minimized. We have also successfully used reduced size grafts for our pediatric patients with good results and are continuing to expand the use of living-related partial grafts and split allografts.
    Clinical transplants 02/1998;
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    ABSTRACT: To determine the influence of several clinicopathologic factors on the 3-year actuarial survival of patients with nonfibrolamellar hepatocellular carcinoma (HCC) following orthotopic liver transplantation (OLT). A case series of 26 consecutive patients with HCC treated with OLT, with a maximum follow-up of 90 months. A tertiary care center. Between March 1988 and December 1993, 521 OLTs were performed in 480 patients, 27 of whom had HCC. One patient was excluded because of donor-transmitted melanoma. Of the remaining 26 patients, there were 18 adults and 8 children, with a mean age of 41 years (range, 0.2-67.4 years). Fourteen patients (54%) had either hepatitis B (n = 6) or hepatitis C (n = 8), while 15 (58%) had coincidental tumor. OLT was performed using standard techniques. The effect of several clinicopathologic factors on 3-year actuarial patient survival. The overall actuarial survival rates for the 26 patients with HCC were 73%, 65.4%, and 65.4%, at 1, 2, and 3 years, respectively. Sixteen patients (62%) were alive at the time of this report, with 14 (54%) free of disease. None of the clinicopathologic factors significantly affected the 3-year patient survival rate. However, the rate of recurrent HCC was significantly higher in nonincidental vs coincidental tumors and in solitary vs multiple tumors. Our results suggest that HCC should not contraindicate OLT, as long-term patient survival and cure can be achieved. While patient selection is important, survival in patients with HCC after OLT is not always predictable using the usual clinicopathologic prognostic factors.
    Archives of Surgery 10/1996; 131(9):935-9; discussion 939-41. · 4.10 Impact Factor
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    ABSTRACT: To determine the safety and efficacy of ganciclovir treatment of hepatitis B virus (HBV) infection after liver transplantation, nine patients (seven males, two females; mean age, 38 years) with posttransplant HBV infection were treated with ganciclovir for 3 to 10 months. Ganciclovir was administered intravenously at an initial dose of 5 mg/kg/d and then increased to 10 mg/kg/d. Immunosuppressive drug therapy was maintained at low levels. There were no major side effects of ganciclovir therapy. Serum HBV DNA levels decreased by a mean of 90% (range, 42% to 100%), and four of nine patients had no measurable HBV DNA at the completion of therapy. Mean serum alanine aminotransferase levels decreased by 83%. Hepatic expression of HBV antigens and HBV DNA was assessed before and after therapy in six patients and found to be reduced in three patients. The histology activity index was also stabilized or improved in all patients. After discontinuation of therapy, four of nine patients underwent retreatment for 4- to 12-fold elevation of serum HBV DNA and/or biochemical and clinical relapse, that was severe in one patient. This pilot study shows the safety and efficacy of ganciclovir therapy for reducing HBV replication in patients with HBV infection after liver transplantation.
    Hepatology 02/1996; 23(1):1-7. · 12.00 Impact Factor
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    ABSTRACT: Two patients with liver failure secondary to isoniazid hepatotoxicity were successfully treated with orthotopic liver transplantation. A 49-year-old man received isoniazid prophylaxis for a positive tuberculin test, and a 60-year-old woman was treated for active pulmonary tuberculosis with isoniazid, rifampin, and pyrazinamide. Both patients developed hepatic failure 4 and 1.5 months after initiation of antituberculous drug therapy, respectively. Liver transplantation was performed for progressive hepatic failure and was successful in both patients. The patient with active pulmonary tuberculosis was successfully treated with a modified antituberculous drug regimen while taking standard doses of immunosuppressive drugs after transplantation. In conclusion, liver transplantation is feasible and effective therapy for patients with isoniazid-induced hepatic failure, and active pulmonary tuberculosis may represent a relative rather than absolute contraindication to transplantation.
    Digestive Diseases and Sciences 11/1994; 39(10):2255-9. · 2.26 Impact Factor
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    ABSTRACT: Recent preliminary reports suggest a poor outcome of orthotopic liver transplantation for patients with hemochromatosis. We analyzed an institutional experience with orthotopic liver transplantation for hemochromatosis, focusing on factors contributing to increased morbidity and mortality. Between March 1988 and October 1992, nine of 249 adults (3.6%) undergoing orthotopic liver transplantation had hemochromatosis. Mean age was 53 yr (range, 42 to 62 yr), and eight of nine patients were men. The diagnosis of hemochromatosis was based on transferrin saturation > 62% and hepatic iron index > 2.0. Only two patients were known to have hemochromatosis before liver transplantation. All nine patients underwent standard cardiac evaluation before transplantation, and no patient had detectable pre-existing cardiac disease. One patient had a major operative cardiac complication as a result of pulmonary embolism and made a full recovery. Postoperatively, congestive heart failure developed in three patients and four patients had arrhythmias. One patient is undergoing phlebotomy for post-transplant cardiac complications from hemochromatosis. Two patients had primary hepatic tumors in the explant liver. There were four deaths caused by multiorgan failure with congestive heart failure (1), infection (2), and/or malignancy (2). Five patients are alive 3 to 25 mo post-transplant. The actuarial survival of the nine patients was 53% at 25 mo vs. 89% for 18 age- and sex-matched control transplant recipients (p = 0.1) and 81% for all other adult liver transplant recipients (p < 0.01). In five of seven patients, post-transplant liver biopsies revealed hepatic iron accumulation.(ABSTRACT TRUNCATED AT 250 WORDS)
    Hepatology 08/1994; 20(2):404-10. · 12.00 Impact Factor
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    ABSTRACT: Three patients with primary sclerosing cholangitis and Hodgkin's disease, a previously unrecognized association, are reported. All three patients were men, and one patient had Crohn's disease of the colon. Primary sclerosing cholangitis was diagnosed 2, 11 and 17 yr before diagnosis of Hodgkin's disease in the three patients, and all three had advanced biliary cirrhosis prompting referral for liver transplantation. The symptoms of Hodgkin's disease were often masked by similar manifestations of primary sclerosing cholangitis, particularly symptoms of recurrent biliary sepsis. Hodgkin's disease is another disorder that may occur in patients with primary sclerosing cholangitis, particularly in the setting of advanced disease, and may be masked by the underlying hepatobiliary disease.
    Hepatology 12/1993; 18(5):1127-31. · 12.00 Impact Factor
  • Transplantation Proceedings 01/1992; 23(6):3019-20. · 0.95 Impact Factor

Publication Stats

315 Citations
62.66 Total Impact Points

Institutions

  • 1998–1999
    • Stanford University
      • • Division of Gastroenterology
      • • Department of Surgery
      Palo Alto, CA, United States
    • Stanford Medicine
      • Department of Medicine
      Stanford, California, United States
  • 1993–1996
    • California Pacific Medical Center Research Institute
      • • Department of Transplantation
      • • Department of Medicine
      San Francisco, California, United States