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Featured researches published by Igor Dvorchik.


Journal of The American College of Surgeons | 1999

Hepatic Resection for Metastatic Colorectal Adenocarcinoma: A Proposal of a Prognostic Scoring System

Shunzaburo Iwatsuki; Igor Dvorchik; Juan Madariaga; J. Wallis Marsh; Forrest Dodson; Andrew Bonham; David A. Geller; Timothy Gayowski; John J. Fung; Thomas E. Starzl

BACKGROUND Hepatic resection for metastatic colorectal cancer provides excellent longterm results in a substantial proportion of patients. Although various prognostic risk factors have been identified, there has been no dependable staging or prognostic scoring system for metastatic hepatic tumors. STUDY DESIGN Various clinical and pathologic risk factors were examined in 305 consecutive patients who underwent primary hepatic resections for metastatic colorectal cancer. Survival rates were estimated by the Cox proportional hazards model using the equation: S(t) = [So(t)]exp(R-Ro), where So(t) is the survival rate of patients with none of the identified risk factors and Ro = 0. RESULTS Preliminary multivariate analysis revealed that independently significant negative prognosticators were: (1) positive surgical margins, (2) extrahepatic tumor involvement including the lymph node(s), (3) tumor number of three or more, (4) bilobar tumors, and (5) time from treatment of the primary tumor to hepatic recurrence of 30 months or less. Because the survival rates of the 62 patients with positive margins or extrahepatic tumor were uniformly very poor, multivariate analysis was repeated in the remaining 243 patients who did not have these lethal risk factors. The reanalysis revealed that independently significant poor prognosticators were: (1) tumor number of three or more, (2) tumor size greater than 8 cm, (3) time to hepatic recurrence of 30 months or less, and (4) bilobar tumors. Risk scores (R) for tumor recurrence of the culled cohort (n = 243) were calculated by summation of coefficients from the multivariate analysis and were divided into five groups: grade 1, no risk factors (R = 0); grade 2, one risk factor (R = 0.3 to 0.7); grade 3, two risk factors (R = 0.7 to 1.1); grade 4, three risk factors (R= 1.2 to 1.6); and grade 5, four risk factors (R > 1.6). Grade 6 consisted of the 62 culled patients with positive margins or extrahepatic tumor. Kaplan-Meier and Cox proportional hazards estimated 5-year survival rates of grade 1 to 6 patients were 48.3% and 48.3%, 36.6% and 33.7%, 19.9% and 17.9%, 11.9% and 6.4%, 0% and 1.1%, and 0% and 0%, respectively (p < 0.0001). CONCLUSIONS The proposed risk-score grading predicted the survival differences extremely well. Estimated survival as determined by the Cox proportional hazards model was similar to that determined by the Kaplan-Meier method. Verification and further improvements of the proposed system are awaited by other centers or international collaborative studies.


Annals of Surgery | 2001

Clinical Intestinal Transplantation: A Decade of Experience at a Single Center

Kareem Abu-Elmagd; Jorge Reyes; Geoffrey Bond; George V. Mazariegos; Tong Wu; Noriko Murase; Rakesh Sindhi; Dolly Martin; Joanne Colangelo; Marsha Zak; Douglas Janson; Mohamed Ezzelarab; Igor Dvorchik; Maria Parizhskaya; Melvin Deutsch; Anthony J. Demetris; John J. Fung; Thomas E. Starzl

ObjectiveTo assess the long-term efficacy of intestinal transplantation under tacrolimus-based immunosuppression and the therapeutic benefit of newly developed adjunct immunosuppressants and management strategies. Summary Background DataWith the advent of tacrolimus in 1990, transplantation of the intestine began to emerge as therapy for intestinal failure. However, a high risk of rejection, with the consequent need for acute and chronic high-dose immunosuppression, has inhibited its widespread application. MethodsDuring an 11-year period, divided into two segments by a 1-year moratorium in 1994, 155 patients received 165 intestinal allografts under immunosuppression based on tacrolimus and prednisone: 65 intestine alone, 75 liver and intestine, and 25 multivisceral. For the transplantations since the moratorium (n = 99), an adjunct immunosuppressant (cyclophos-phamide or daclizumab) was used for 74 transplantations, adjunct donor bone marrow was given in 39, and the intestine of 11 allografts was irradiated with a single dose of 750 cGy. ResultsThe actuarial survival rate for the total population was 75% at 1 year, 54% at 5 years, and 42% at 10 years. Recipients of liver plus intestine had the best long-term prognosis and the lowest risk of graft loss from rejection (P = .001). Since 1994, survival rates have improved. Techniques for early detection of Epstein-Barr and cytomegaloviral infections, bone marrow augmentation, the adjunct use of the interleukin-2 antagonist daclizumab, and most recently allograft irradiation may have contributed to the better results. ConclusionThe survival rates after intestinal transplantation have cumulatively improved during the past decade. With the management strategies currently under evaluation, intestinal transplant procedures have the potential to become the standard of care for patients with end-stage intestinal failure.


American Journal of Transplantation | 2009

Liver Transplantation Using Donation After Cardiac Death Donors: Long-Term Follow-Up from a Single Center

M. E. De Vera; R. Lopez‐Solis; Igor Dvorchik; S. Campos; W. Morris; Anthony J. Demetris; Paulo Fontes; Jane W. Marsh

There is a lack of universally accepted clinical parameters to guide the utilization of donation after cardiac death (DCD) donor livers and it is unclear as to which patients would benefit most from these organs. We reviewed our experience in 141 patients who underwent liver transplantation using DCD allografts from 1993 to 2007. Patient outcomes were analyzed in comparison to a matched cohort of 282 patients who received livers from donation after brain death (DBD) donors. Patient survival was similar, but 1‐, 5‐ and 10‐year graft survival was significantly lower in DCD (69%, 56%, 44%) versus DBD (82%, 73%, 63%) subjects (p < 0.0001). Primary nonfunction and biliary complications were more common in DCD patients, accounting for 67% of early graft failures. A donor warm ischemia time >20 min, cold ischemia time >8 h and donor age >60 were associated with poorer DCD outcomes. There was a lack of survival benefit in DCD livers utilized in patients with model for end‐stage liver disease (MELD) ≤30 or those not on organ‐perfusion support, as graft survival was significantly lower compared to DBD patients. However, DCD and DBD subjects transplanted with MELD >30 or on organ‐perfusion support had similar graft survival, suggesting a potentially greater benefit of DCD livers in critically ill patients.


Journal of The American College of Surgeons | 1998

Treatment of hilar cholangiocarcinoma (Klatskin tumors) with hepatic resection or transplantation

Shunzaburo Iwatsuki; Satoru Todo; J. Wallis Marsh; Juan Madariaga; Randall G. Lee; Igor Dvorchik; John J. Fung; Thomas E. Starzl

BACKGROUND Because of the rarity of hilar cholangiocarcinoma, its prognostic risk factors have not been sufficiently analyzed. This retrospective study was undertaken to evaluate various pathologic risk factors which influenced survival after curative hepatic resection or transplantation. METHODS Between 1981 and 1996, 72 patients (43 males and 29 females) with hilar cholangiocarcinoma underwent hepatic resection (34 patients) or transplantation (38 patients) with curative intent. Medical records and pathologic specimens were reviewed to examine the various prognostic risk factors. Survival was calculated by the method of Kaplan-Meier using the log rank test with adjustment for the type of operation. Survival statistics were calculated first for each kind of treatment separately, and then combined for the calculation of the final significance value. RESULTS Survival rates for 1, 3, and 5 years after hepatic resection were 74%, 34%, and 9%, respectively, and those after transplantation were 60%, 32%, and 25%, respectively. Univariate analysis revealed that T-3, positive lymph nodes, positive surgical margins, and pTNM stage III and IV were statistically significant poor prognostic factors. Multivariate analysis revealed that pTNM stage 0, I, and II, negative lymph node, and negative surgical margins were statistically significant good prognostic factors. For the patients in pTNM stage 0-II with negative surgical margins, 1-, 3-, and 5-year survivals were 80%, 73%, and 73%, respectively. For patients in pTNM stage IV-A with negative lymph nodes and surgical margins, 1-, 3-, and 5-year survivals were 66%, 37%, and 37%, respectively. CONCLUSIONS Satisfactory longterm survivals can be obtained by curative surgery for hilar cholangiocarcinoma either with hepatic resection or liver transplantation. Redefining pTNM stage III and IV-A is proposed to better define prognosis.


Cancer | 2000

Is the pathologic TNM staging system for patients with hepatoma predictive of outcome

J. Wallis Marsh; Igor Dvorchik; C. Andrew Bonham; Shunzaburo Iwatsuki

The pathologic TNM (pTNM) staging system was designed to aid in determining the prognosis of cancer patients and in planning and evaluating their treatment. The current pTNM classification system was not found to be predictive for patients undergoing orthotopic liver transplantation (OLTx) in the presence of hepatocellular carcinoma (HCC). Therefore, the authors examined the current system to determine whether improvements would allow the development of a more predictive system.


Journal of The American College of Surgeons | 2000

Liver Transplantation for Hepatocellular Carcinoma: A Proposal of a Prognostic Scoring System

Shunzaburo Iwatsuki; Igor Dvorchik; J. Wallis Marsh; Juan Madariaga; Brian I. Carr; John J. Fung; Thomas E. Starzl

BACKGROUND The current staging system of hepatocellular carcinoma established by the International Union Against Cancer and the American Joint Committee on Cancer does not necessarily predict the outcomes after hepatic resection or transplantation. STUDY DESIGN Various clinical and pathologic risk factors for tumor recurrence were examined on 344 consecutive patients who received hepatic transplantation in the presence of nonfibrolamellar hepatocellular carcinoma to establish a reliable risk scoring system. RESULTS Multivariate analysis identified three factors as independently significant poor prognosticators: 1) bilobarly distributed tumors, 2) size of the greatest tumor (2 to 5 cm and > 5 cm), and 3) vascular invasion (microscopic and macroscopic). Prognostic risk score (PRS) of each patient was calculated from the relative risks of multivariate analysis. The patients were grouped into five grades of tumor recurrence risk: grade 1: PRS = 0 to < 7.5; grade 2: PRS = 7.5 to < or = 11.0; grade 3: PRS > 11.0 to 15.0; grade 4: PRS > or = 15.0; and grade 5: positive node, metastasis, or margin. The proposed PRS system correlated extremely well with tumor-free survival after liver transplantation (100%, 61%, 40%, 5%, and 0%, from grades 1 to 5, respectively, at 5 years), but current pTNM staging did not. CONCLUSIONS 1) Patients with grades 1 and 2 are effectively treated with liver transplantation, 2) patients with grades 4 and 5 are poor candidates for liver transplantation, and 3) patients with grade 1 do not benefit from adjuvant chemotherapy.


Liver Transplantation | 2006

MELD and prediction of post–liver transplantation survival

Shahid Habib; Brian S. Berk; Chung Chou H Chang; Anthony J. Demetris; Paulo Fontes; Igor Dvorchik; Bijan Eghtesad; Amadeo Marcos; A. Obaid Shakil

The model for end‐stage liver disease (MELD) was developed to predict short‐term mortality in patients with cirrhosis. It has since become the standard tool to prioritize patients for liver transplantation. We assessed the value of pretransplant MELD in the prediction of posttransplant survival. We identified adult patients who underwent liver transplantation at our institution during 1991–2002. Among 2,009 recipients, 1,472 met the inclusion criteria. Based on pretransplant MELD scores, recipients were stratified as low risk (≤15), medium risk (16–25), and high risk (>25). The primary endpoints were patient and graft survival. Mean posttransplant follow‐up was 5.5 years. One‐, 5‐ and 10‐year patient survival was 83%, 72%, and 58%, respectively, and graft survival was 76%, 65%, and 53%, respectively. In univariable analysis, patient and donor age, patient sex, MELD score, disease etiology, and retransplantation were associated with posttransplantation patient and graft survival. In multivariable analysis adjusted for year of transplantation, patient age >65 years, donor age >50 years, male sex, and retransplantation and pretransplant MELD scores >25 were associated with poor patient and graft survival. The impact of MELD score >25 was maximal during the first year posttransplant. In conclusion, older patient and donor age, male sex of recipient, retransplantation, and high pretransplant MELD score are associated with poor posttransplant outcome. Pretransplant MELD scores correlate inversely with posttransplant survival. However, better prognostic models are needed that would provide an overall assessment of transplant benefit relative to the severity of hepatic dysfunction. Liver Transpl 12:440–447, 2006.


Cancer | 1999

Should hepatomas be treated with hepatic resection or transplantation

Junji Yamamoto; Shunzaburo Iwatsuki; Tomoo Kosuge; Igor Dvorchik; Kazuaki Shimada; J. Wallis Marsh; Susumu Yamasaki; Thomas E. Starzl

The aim of this collaborative study was to compare the long term results of hepatic resection (Hx) with those of orthotopic liver transplantation (OLTx) in large numbers of cirrhotic patients with hepatocellular carcinoma (HCC) and to delineate the roles of these two surgical treatments.


American Journal of Transplantation | 2006

Survival of liver transplant patients coinfected with HIV and HCV is adversely impacted by recurrent hepatitis C.

M. E. De Vera; Igor Dvorchik; Kusum Tom; Bijan Eghtesad; Ngoc Thai; Obaid Shakil; Amadeo Marcos; Anthony J. Demetris; A. Jain; John J. Fung; Margaret V. Ragni

Although liver transplantation (LTx) in HIV‐positive patients receiving highly active antiretroviral therapy (HAART) has been successful, some have reported poorer outcomes in patients coinfected with hepatitis C virus (HCV). Here we discuss the impact of recurrent HCV on 27 HIV‐positive patients who underwent LTx. HIV infection was well controlled posttransplantation. Survival in HIV‐positive/HCV‐positive patients was shorter compared to a cohort of HIV‐negative/HCV‐positive patients matched in age, model for end‐stage liver disease (MELD) score, and time of transplant, with cumulative 1‐, 3‐ and 5‐year patient survival of 66.7%, 55.6% and 33.3% versus 75.7%, 71.6% and 71.6%, respectively, although not significantly (p = 0.07), and there was a higher likelihood of developing cirrhosis or dying from an HCV‐related complication in coinfected subjects (RR = 2.6, 95%CI, 1.06–6.35; p = 0.03). Risk factors for poor survival included African‐American race (p = 0.02), MELD score >20 (p = 0.05), HAART intolerance postLTx (p = 0.01), and postLTx HCV RNA >30 000 000 IU/mL (p = 0.00). Recurrent HCV in 18 patients was associated with eight deaths, including three from fibrosing cholestatic hepatitis. Among surviving coinfected recipients, five are alive at least 3 years after LTx, and of 15 patients treated with interferon‐α/ribavirin, six (40%) are HCV RNA negative, including four with sustained virological response. Hepatitis C is a major cause of graft loss and patient mortality in coinfected patients undergoing LTx.


Journal of Pediatric Surgery | 1999

Hepatic hemangioendothelioma: Clinical experience and management strategy

John A Daller; Javier Bueno; Jorge Gutierrez; Igor Dvorchik; Richard B. Towbin; Paul S. Dickman; George V. Mazariegos; Jorge Reyes

PURPOSE This study sought to define management strategies based on clinical experience in treating infantile hepatic hemangioendothelioma. METHODS A retrospective analysis of patients with hemangioendothelioma presenting to a tertiary liver transplantation center between 1989 and 1997 was performed. RESULTS Thirteen patients (median age, 14 days) with hemangioendothelioma were identified. Congestive heart failure (P<.03) and abdominal mass (P<.081) were predictive of 5-month mortality rates. Ultrasonography and computerized axial tomography were the diagnostic modalities most commonly used. Treatment strategies consisted of medical management (steroids and alpha-interferon) and interventional modalities (hepatic artery ligation or embolization, resectional surgery, or orthotopic liver transplantation). Patients who underwent resectional surgery, with or without orthotopic liver transplantation, had a lower 5-month mortality rate (P<.02) and a greater 2-year survival rate (P<.003) than did those who underwent hepatic artery ligation or embolization. Early morbidity and mortality tended to be a consequence of the primary lesion, whereas late morbidity and mortality were reflective of the treatment modality used. CONCLUSIONS In cases of failed medical management, resectional therapy should be used when possible. If partial hepatectomy is not technically achievable, hepatic artery embolization should be used either as definitive therapy or as a temporizing measure until orthotopic liver transplantation is possible.

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