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Dive into the research topics where R. J. Ploeg is active.

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Featured researches published by R. J. Ploeg.


Transplantation | 1993

Risk factors for primary dysfunction after liver transplantation - A multivariate analysis

R. J. Ploeg; Anthony M. D'Alessandro; Stuart J. Knechtle; Mark D. Stegall; John D. Pirsch; Robert M. Hoffmann; T. Sasaki; Hans W. Sollinger; Folkert O. Belzer; Munci Kalayoglu; Miller; Emond; Katz; Otte

In a retrospective analysis on 323 orthotopic liver transplant procedures performed between July 1984 and October 1991 the incidence of two forms of primary dysfunction (PDF) of the liver: primary nonfunction (PNF), and initial poor function (IPF) were studied. The incidence of PDF was 22% (73/323) with 6% PNF (20/323) and 16% IPF (53/323), while 78% (250/323) had immediate function (IF). Occurrence of both IPF and PNF resulted in a higher graft failure rate (P < 0.001), retransplantation rate (P < 0.001), and patient mortality (P < 0.003) within the first three months after OLTx. Univariate analyses of donor and recipient factors and their influence on PDF demonstrated that longer donor hospitalization (> 3 days), older donor age (> 49 years), extended preservation times (> 18 hr), and fatty changes in the donor liver biopsy, as well as reduced-size livers, younger recipient age, and renal insufficiency prior to OLTx, significantly affected the incidence of IPF and PNF. Multivariate analysis of potential risk factors showed that reduced-size liver (P = 0.0001), fatty changes on donor liver biopsy (P = 0.001), older donor age (P = 0.009), retransplantation (P = 0.01), renal insufficiency (P = 0.02), and prolonged cold ischemia times (P = 0.02) were independently associated with a higher incidence of IPF and PNF. No statistical correlation was found between PDF and etiology of ESLD, nutritional status of the recipient, UNOS status, and Child-Pugh classification in this study. We conclude that PNF and IPF are both separate clinical entities that have a significant effect on outcome after OLTx. Routine donor liver biopsies are recommended to decrease the rate of IPF and PNF. The combination of risk factors shown to be significant for PDF should be avoided--and, if that is not possible, the only variable that can be controlled, the preservation time, should be kept as short as possible.


Transplantation | 1996

Determinants of graft survival after renal transplantation

John D. Pirsch; R. J. Ploeg; Stephen J. Gange; Anthony M. D'Alessandro; Stuart J. Knechtle; Hans W. Sollinger; Munci Kalayoglu; Folkert O. Belzer

We studied multiple determinants of graft survival at a single center and the effects of nonimmunologic graft loss on transplant survival. This retrospective study examined the results of 589 cadaver donor transplants performed between 1986 and 1992. Graft survival rates were calculated using Kaplan-Meier estimates for both overall graft survival (all causes of graft loss) and immunologic graft survival (function lost due to acute or chronic rejection and noncompliance). Cadaver graft survival was significantly poorer with an increasing degree of DR mismatch (P=0.02). An analysis of pretransplant variables showed graft loss risk was highest with greater DR mismatches, two B-antigen mismatch, higher donor serum creatinine, and younger recipient age. After transplantation, acute rejection was the most significant factor associated with long-term graft survival. Our data demonstrate a significant advantage for zero DR and one DR mismatch cadaver donor transplants, with excellent immunologic graft survival. This study suggests that a combination of immediate graft function, prevention of acute rejection by appropriate early immunosuppressive therapy, and acceptable DR match enhances cadaveric graft survival.


Transplantation | 1993

Retransplantation of the liver - A seven-year experience

Anthony M. D'Alessandro; R. J. Ploeg; Stuart J. Knechtle; John D. Pirsch; Mark D. Stegall; Robert M. Hoffmann; Hans W. Sollinger; Folkert O. Belzer; Munci Kalayoglu

Three hundred and four patients underwent 362 liver transplants between July 1984 and April 1992. Fifty-eight retransplants were performed in 44 patients (14.5%). Thirty-four patients underwent two (77.3%), seven patients three (15.9%), two patients four (4.5%), and one patient five (2.3%) transplants. Poor function accounted for 23 retransplants (6.4%), technical problems for 19 retransplants (5.2%), and rejection for 15 retransplants (4.1%). One-month patient survivals after retransplantation for poor function, technical problems, or rejection were similar (79.0%, 73.4%, and 80.0%, respectively). No difference in retransplantation rates were seen between adults and children receiving whole liver transplants (WLT) (11.6% versus 19.1%). However, retransplantation for poor function was more common in pediatric recipients receiving reduced-size liver transplants (RLT) (20.0% versus 0.0%, P<0.01), while retransplantation for hepatic artery thrombosis (HAT) was more common in pediatric recipients receiving WLT (16.7% versus 2.8%, P<0.05). The presence of multiorgan system failure of greater than four was associated with a high mortality (90%), whereas patients undergoing emergent retransplantation who had less than four systems fail had a survival of 73.9% and patients who underwent elective retransplantation had a survival rate of 81.8%. Length of stay and cost of liver transplantation was higher in patients undergoing retransplantation when compared with primary transplants (29.7±14.9 days versus 58.4±38.9 days and ±122,358± 59,782 versus ±289, 302±126, 907, P<0.01). The overall actuarial one-year patient survival in primary transplants was 86.6% and in retransplants 74.8%, and at five years these were 71.4% versus 62.5%, respectively (P<0.05). Our results support continued retransplantation of the liver unless the patients medical condition dictates otherwise.


Journal of Pediatric Surgery | 1994

100 consecutive liver transplants in infants and children: an 8-year experience.

Devin E. Eckhoff; Anthony M. D'Alessandro; Stuart J. Knechtle; John D. Pirsch; R. J. Ploeg; Robert H. Judd; Folkert O. Belzer; Munci Kalayoglu

Orthotopic liver transplantation has become the treatment of choice for most children and infants with end-stage liver disease. The purpose of this retrospective study was to examine the results of 100 consecutive liver transplants performed in infants and children at a single institution. During an 8-year study period (July 1984 to December 1992), 100 pediatric liver transplants were performed in 76 patients. Thirty-four patients (44.7%) were infants (mean age, 7.0 months; mean weight, 6.1 kg), and 42 (55.3%) were children (mean age, 8.2 years; mean weight, 30.6 kg). There were 36 reduced-size liver transplants (RLT) and 64 whole-size transplants (WLT). Eight infants (23.5%) and 10 children (20.7%) required retransplantation. After transplantation, 71% of the patients had one or more rejection episodes, 66% had one or more infections, 17.1% had biliary complications, and 39.4% required one or more reoperations. There were 17 deaths. The actuarial 8-year survival rate for the patients with biliary atresia was 82.3%; for all infants in this series, it was 77.6%. No difference in patient survival was noted when RLT was compared with WLT. The overall 8-year actuarial patient survival rate for infants and children was 77.3%.


Surgery | 1993

Two hundred consecutive simultaneous pancreas-kidney transplants with bladder drainage

Hans W. Sollinger; R. J. Ploeg; Devin E. Eckhoff; Mark D. Stegall; R. Isaacs; John D. Pirsch; Anthony M. D'Alessandro; Stuart J. Knechtle; Munci Kalayoglu; Folkert O. Belzer; Robert J. Stratta; R. M. Ferguson; J. A. Schulak


Society for Organ Sharing. International Congress | 1993

Impact of donor factors and preservation on function and survival after liver transplantation

R. J. Ploeg; Anthony M. D'Alessandro; Robert M. Hoffmann; Devin E. Eckhoff; R. Isaacs; S. J. Knetchtle; John D. Pirsch; Mark D. Stegall; Munci Kalayoglu; Folkert O. Belzer


International Liver Transplantation Society. Congress | 1993

Effect of surgical and spontaneous portasystemic shunts on liver transplantation.

R. J. Ploeg; Anthony M. D'Alessandro; Mark D. Stegall; Wojtowycz Mm; Ian A. Sproat; Stuart J. Knechtle; John D. Pirsch; Hans W. Sollinger; Folkert O. Belzer; Munci Kalayoglu


Transplantation Society. International congress | 1993

Living unrelated kidney donation: an underutilized resource?

R. J. Ploeg; John D. Pirsch; Mark D. Stegall; Michael J. Armbrust; David Lorentzen; Anthony M. D'Alessandro; Stuart J. Knechtle; Hans W. Sollinger; Munci Kalayoglu; Folkert O. Belzer


Transplantation Society. International congress | 1993

Malfunction of the liver after transplantation : an analysis of potential risk factors

R. J. Ploeg; Anthony M. D'Alessandro; Stuart J. Knechtle; Mark D. Stegall; John D. Pirsch; Robert M. Hoffmann; T. Sasaki; Hans W. Sollinger; Folkert O. Belzer; Munci Kalayoglu


Transplantation Society. International congress | 1993

Effects of DR mismatch on long-term graft survival in simultaneous kidney-pancreas transplantation.

T. Sasaki; John D. Pirsch; R. J. Ploeg; Mark D. Stegall; Anthony M. D'Alessandro; Stuart J. Knechtle; Folkert O. Belzer; Hans W. Sollinger

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Anthony M. D'Alessandro

University of Wisconsin-Madison

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Folkert O. Belzer

University of Wisconsin-Madison

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John D. Pirsch

University of Wisconsin-Madison

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Hans W. Sollinger

University of Wisconsin-Madison

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Munci Kalayoglu

University of Wisconsin-Madison

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Robert M. Hoffmann

University of Wisconsin-Madison

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T. Sasaki

University of Wisconsin-Madison

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Devin E. Eckhoff

University of Wisconsin-Madison

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