Afonso C. Piovesan
University of São Paulo
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Featured researches published by Afonso C. Piovesan.
Transplantation | 2006
Eduardo Mazzucchi; Alexandre Danilovic; Ioannis M. Antonopoulos; Afonso C. Piovesan; William Carlos Nahas; Antonio Marmo Lucon; Miguel Srougi
Background. We reviewed our experience with third, fourth, and fifth renal transplants performed by the extraperitoneal access. Methods. The charts of 21 third and subsequent transplants performed extraperitoneally were reviewed. Surgical aspects, the occurrence of rejection episodes, delayed graft function (DGF), graft and patient survival were evaluated and compared with 1560 first transplants in adults with nonmanipulated fossa performed in the same period. Results. Transfusion was necessary in 52% of the retransplants and in 5.7% of the first transplants (P<0.0001). Mean operative time was 327 min for retransplants and 212 min for first transplants (P<0.0001). Surgical complications occurred in 4 patients (19%): two arterial thrombosis and two ureteral obstructions. DGF occurred in 11 patients (52%) among retransplants and in 453 (29%) among first transplants (P=0.028). Acute rejection occurred in 7 (33.3%) retransplants and in 530 first transplant patients (33.9%). The mean serum creatinine among retransplant patients 30 days and one year after transplantation was 2.5 mg/dl and 1.8 mg/dl. One-year graft survival was 57.1% (75% for live and 46% for cadaver donors) for retransplants and 86% for first transplant patients (P<0.0001). Conclusion. Third and subsequent transplants performed extraperitoneally are more time-consuming and require more transfusions in the perioperative period. A higher but acceptable incidence of arterial thrombosis and urinary obstruction were observed. One-year graft survival was better with live donor grafts, but was still lower when compared with first transplants using the same surgical technique.
Nephrology Dialysis Transplantation | 2011
Elias David-Neto; Daisa Silva Ribeiro David; Giordano F. Ginani; Helcio Rodrigues; Patricia Soares Souza; Maria Cristina Ribeiro de Castro; Hideki Kanashiro; Fernando Saito; Renato Falci; Ioannis M. Antonopoulos; Afonso C. Piovesan; William Carlos Nahas
BACKGROUND Sensitized patients (pts) may develop acute antibody-mediated rejection (AMR) due to preformed donor-specific antibodies, undetected by pre-transplant complement-dependent cytotoxicity (CDC) crossmatch (XM). We hypothesized that C4d staining in 1-h post-reperfusion biopsies (1-h Bx) could detect early complement activation in the renal allograft due to preformed donor-specific antibodies. METHODS To test this hypothesis, renal transplants (n = 229) performed between June 2005 and December 2007 were entered into a prospective study of 1-h Bx and stained for C4d by immunofluorescence. Transplants were performed against a negative T-cell CDC-XM with the exception of three cases with a positive B-cell XM. RESULTS All 229 1-h Bx stained negative for C4d. Fourteen pts (6%) developed AMR. None of the 14 protocol 1-h Bx stained positive for C4d in peritubular capillaries (PTC). However, all indication biopsies-that diagnosed AMR-performed at a median of 8 days after transplantation stained for C4d in PTC. CONCLUSIONS These data show that C4d staining in 1-h Bx is, in general, not useful for the early detection of AMR when CDC-XM is negative.
Transplantation Proceedings | 2008
Afonso C. Piovesan; Antonio Marmo Lucon; Daisa Silva Ribeiro David; Willian Nahas; Ioannis M. Antonopoulos; Miguel Srougi
OBJECTIVE There are no data to support the suggestion that samples removed from one segment of the transplanted kidney are representative of the whole graft. The aim of this study was to compare the histological differences between biopsies obtained from different portions of the renal allograft and their impact on treatment recommendations. PATIENTS AND METHODS Two hundred percutaneous biopsies were performed on kidney allografts and samples were collected from the upper and lower poles (100 kidneys). All samples were randomized and blindly reviewed. We obtained the discordance rates between the poles for the grading of acute rejection and for the diagnosis of nephrotoxicity due to immunosuppression. We also checked if the differences found were sufficient to call for different clinical recommendations. These values were compared with the intrapathologist variation rates. RESULTS In 70 kidneys adequate sampling was obtained from both poles. The diagnosis of acute rejection were made in 17. The discordance rate between the upper and lower poles was 82.3% (kappa = 0.34), higher than the intrapathologist variation (P = .002). Nephrotoxicity was found in 14 kidneys. The discordance rate between the upper and lower poles was 28.6% (kappa = 0.88), with no difference compared with the intrapathologist variation. In 14 of the 70 kidneys (25.7%), discordances between poles had impact on clinical recommendations, most of these cases due to different gradings of acute rejection (78%). This number was higher than the intrapathologist variation (P = .04). CONCLUSIONS The histopathological changes in the kidney allograft are not always homogeneous. This heterogeneity may affect the therapeutic recommendations.
Transplantation Proceedings | 2015
Kleiton Yamaçake; Ioannis M. Antonopoulos; Afonso C. Piovesan; Hideki Kanashiro; R.B. Kato; Willian Nahas; Daisa Silva Ribeiro David
Tumor transmission is a rare complication of organ transplantation. Despite several improvements in excluding donor malignant disease, there continue to be reports of unknown tumors in the donors. The risk of having a donor with an undetected malignancy ranges between 1.3% and 2%. The cases of two kidney transplant recipients who had intestinal carcinoma transmitted from the same deceased donor are described. The clinical presentation, previous data, and management options are discussed. As a result of the increase in the overall donor pool, using extended criteria donors, donors of extreme ages, donors with prolonged intensive care admission, and donors who may potentially transmit disease to their recipients, the risk of tumor transmission and also infections should be considered.
Transplantation Proceedings | 2012
Renato Falci; Fábio César Miranda Torricelli; Ioannis M. Antonopoulos; Afonso C. Piovesan; Hideki Kanashiro; Fernando Akira Saito; Gustavo Ebaid; Willian Nahas
PURPOSE To report a single center experience with elective surgical patients as living kidney donors. METHODS We retrospectively analyzed a prospective database of 458 living kidney donors from September 2005 to May 2011. Fifteen (3.2%) of them were elective surgical patients simultaneously undergoing living donor nephrectomy. We reviewed age, gender, operative time, intraoperative blood transfusion, intra- and postoperative complications, as well as length of hospital stay. Recipients were evaluated for delayed graft function. Four hundred forty-three patients undergoing living donor nephrectomy alone composed the control group. RESULTS Among the elective surgical patients group, the mean (range) operative time was 155 (90 to 310) minutes and mean (range) length of hospital stay was 3 (2 to 9) days. One (6.7%) recipient displayed delayed graft function. Among the regular living kidney donors group, the mean (range) operative time was 100 (70 to 150) minutes, mean (range) length of hospital stay was 3 (2 to 5) days, and delayed graft function was observed in 5.6% of recipients. Only operative time (P = .03) was significantly different between the groups. CONCLUSIONS Elective surgical patients are potential donors who may be treated at the same time as the living donor nephrectomy.
The Journal of Urology | 2003
Eduardo Mazzucchi; Wiliam C. Nahas; Ioannis M. Antonopoulos; Afonso C. Piovesan; Luis Estevan Ianhez; Sami Arap
Rev. Med. (São Paulo) | 2008
Miguel Srougi; Leopoldo Alves Ribeiro; Afonso C. Piovesan; José Roberto Colombo; Adriano Nesrallah
Transplantation Proceedings | 2003
Willian Nahas; Eduardo Mazzucchi; Marco A. Arap; Ioannis M. Antonopoulos; Afonso C. Piovesan; Elias David Neto; Sami Arap
Transplantation | 2014
Afonso C. Piovesan; H. Andrade; A. Bull; G. Messi; G. Ebaid; H. Kanashiro; R. Falci; Ioannis M. Antonopoulos; Willian Nahas
Transplantation | 2014
Afonso C. Piovesan; H. Andrade; H. Kanashiro; R. Falci; Ioannis M. Antonopoulos; Willian Nahas