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U Valente

Publications and source records attributed to U Valente.

At least 19 recordsLinked to original sources
PubMed2004

Split liver transplantation in Italy.

The role of split liver transplantation has been well established. The limitation to this technique is the number of potential recipients for a left lateral segment graft. The optimal use of the donor pool is to split the liver to provide 2 grafts suitable for adults obtaining right or left lobe. We explored the potential increase in the number of liver grafts gained from systematically using the technique of splitting on national basis. The crucial factor appeared to be creation of guidelines for the use of optimal livers to optimize organ allocation while minimizing pretransplantation mortality and maximizing post-orthotopic liver transplantation outcome.

Hepatectomy↗
PubMed2004

Preliminary results of an expert-opinion elicitation process to prioritize an informative system funded by Italian Ministry of Health for cadaveric donor management, organ allocation, and transplantation activity.

Expert-opinion elicitation (EOE) is a heuristic process for gathering evidence and data or answering questions on issues/problems of concern. The Delphi method (DM) is the most frequent technique used to obtain structured elicitation of expert opinions. It has been increasingly applied in medicine to produce guidelines and to evaluate the appropriateness of diagnostic procedures. In this study, a DM has been used as structured EOE process to assess the appropriateness and clinical priority of a data set-based informative system in the context of the Liguria-Trento Transplant Network (LTTN) Project, funded by Italian Ministry of Health. The original data set was obtained by using an interdisciplinary pool of regional experts (n = 60). This data set held 1506 items stratified in 21 categories at various surgical phases (preoperative, intraoperative, and postoperative) and transplantation types (liver, kidney, and kidney/pancreas) in adult and pediatric recipients. Some categories included cadaveric donor management, organ allocation, and acute liver failure. In the second DM round, the data set was subjected to a panel of extraregional, independent experts (n = 9) to assess scores ranging from 1 to 9 on each item, based on increasing appropriateness/priority, according to RAND/UCLA Appropriateness Method. The overall agreement between experts was 95.88%, whereas disagreement and uncertainty were 0.13% and 3.98%, respectively. A major uncertainty occurred for the data set concerning the multiorgan cadaveric donor, for liver transplantation, and for kidney transplantation in adult recipients. The use of a structured EOE process may represent an effective strategy to define the appropriateness and prioritization criteria of a large data set in the field of solid organ transplantation.

Health Services Research↗
PubMed2004

First results of Liguria-Trento transplant network project: a model for a macroregional network and real-time registry in Italy.

In Italy, health-care telematic is funded and supported at the level of national government or regional institutions. In 1999, the Italian Ministry of Health started to fund the Liguria-Trento Transplant Network (LTTN) project, a health research project with the aim to build an informative system for donor management and transplantation activity in a macroregional area. At the time of LTTN project proposal, no published Transplant Network Informative System fulfilled Italian rules on telematic management of electronic documentation concerning transplantation activity. Partnership of LTTN project were two Regional Transplant Coordinating Centres, Nord Italia Transplant Interregional Coordinating Centre and the Italian Institute of Health/National Transplant Coordinating Centre. Project Total Quality Management methods were adopted. Technological and case analysis followed ANSI-HL7, CEN-TC251, and Object-Oriented Software Engineering standards. A low-tech prototype powered by a web access relational database is running on a transplant network including web-based clients located in 17 intensive care units, in Nord Italia Transplant Interregional Coordinating Centre, and at the Italian Institute of Health/National Transplant Coordinating Centre. LTTN registry includes pretransplant, surgical, and posttransplant phases regarding liver, kidney, pancreas, and kidney-pancreas transplantation in adult and pediatric recipients. Clinical specifications were prioritized in agreement with the RAND/UCLA appropriateness method. Further implementation will include formal rules for data access and output release, fault tolerance, and a continuous registry evolution plan.

Humans↗
PubMed2004

Preliminary report on impact of pretransplant dialysis on early graft function: peritoneal versus hemodialysis.

Delayed graft function and acute renal failure after kidney transplant negatively influence graft outcome. It has been reported that pretransplantation peritoneal dialysis (PD) instead of hemodialysis (HD) correlated with better short-term graft outcome in adult kidney recipients. In this study the impact of PD versus HD was evaluated among pediatric kidney recipients. This study suggested that different forms of dialysis pretransplantation did not affect early graft function among pediatric kidney recipients.

Adolescent↗
PubMed2004

Severe rhabdomyolysis and acute renal failure in a kidney transplant patient treated with tacrolimus and chimaeric CD25 monoclonal antibody.

Recently observations of rhabdomyolysis in patients treated with tacrolimus have been reported. The authors present a kidney transplant patient who had an epileptic seizures, severe rhabdomyolysis, and acute renal failure. The patient was initially immunosuppressed with tacrolimus and chimeric CD25 monoclonal antibody. After intensive therapy with plasmapheresis, CVVH, and dialysis, the patient completely recovered at 11/2 year his serum creatinine is 1.2 mg/dL.

Acute Kidney Injury↗
PubMed2004

Potential predictive value of the MELD score for short-term mortality after liver transplantation.

In the last years, a model for end-stage liver disease (MELD) was suggested as a disease severity score for patients with end-stage liver disease awaiting liver transplantation. In the early 2002, United Network for Organ Sharing (UNOS) has proposed to replace the current status 2A, 2B, and 3 by a modified version of the original MELD score based upon patient risk for 3-month mortality on the waiting list. In this study UNOS status and MELD score were evaluated retrospectively for postoperative 3-month mortality in patients who underwent liver transplantation from 2000 to 2001. Liver recipients were stratified for UNOS status 2A, 2B, and 3, and the corresponding MELD score was calculated for each patient. A receiver operating characteristic (ROC) analysis was performed for both conventional UNOS status and MELD score by fitting patient deaths within 3 months after liver transplantation. The MELD score revealed a better prediction rate for 3-month mortality after the first LT than conventional UNOS status, although no statistical significance was evident by ROC curve comparison. This preliminary study seems to suggest a potentially better predictive rate for the MELD score than conventional UNOS status concerning short-term mortality after liver transplantation.

Humans↗
PubMed2003

Portal vein pressure and graft oxygen consumption monitoring during liver transplantation.

UNLABELLED: Abnormal splanchnic circulation (ASC) is often detected too late, when hepatic circulation is already irreversibly compromised. If we could detect surgical or metabolic problems early after graft reperfusion, we might be able to correct them immediately before the damage becomes irreversible. The aim of this study was to determine if ASC can be predicted early after liver transplantation (LT) using portal vein pressure measurements and graft oxygen consumption monitoring. PATIENTS AND METHODS: Twenty-patients (13 men, 7 women of mean age 46 years) undergoing LT with the piggyback technique for hepatitis C virus (HCV)/hepatitis B virus (HBV)-related cirrhosis were retrospectively divided in two groups. Group A (16 patients), in which LT was successful, and group B (4 patients) in which LT was unsuccessful because of primary nonfunction (2 patients), infrahepatic portal vein thrombosis (1 patient), or hepatic vein kinking (1 patient). We then compared the portal blood pressure values and the prehepatic and posthepatic oxygen content difference (p-pDO(2)) before portal clamping; at the end of anhepatic phase; 5, 15, and 25 minutes after portal vein (PV) reperfusion; and 5, 20, 40, and 100 minutes after hepatic artery anastomosis. RESULTS: Early after graft reperfusion; portal pressure decreased to levels lower than that at baseline in group A, but remained high until the end of surgery in group B. At the end of surgery, p-pDO(2) increased more among group B than group A. CONCLUSION: ASC, specifically an increased PV resistance, can be predicted early after LT by portal vein pressure measurements and graft oxygen consumption monitoring.

Adult↗
PubMed2002

Laparoscopic physiological hiatoplasty for hiatal hernia: new composite "A"-shaped mesh. Physical and geometrical analysis and preliminary clinical results.

BACKGROUND: We analyzed, using a theoretical model, the modality of recurrence after a simple cruroplasty for large hiatal hernias, and on the basis of physical and geometrical principles, we conceived a new shaped mesh for a "tension-free" repair. METHODS: We performed a physical and geometrical analysis of the hiatal region on a theoretical model. We also performed an anatomic study on 20 fresh cadavers to verify the reproducibility of the theoretical model and to study the most suitable shape for mesh and its adaptability to the hiatal region. Between September 2000 and October 2001, eight patients received laparoscopic reparation of large (type II or III) hiatal hernias by means of a composite "A"-shaped polytetrafluoroethylene (PTFE)-polypropylene mesh. There were two men and six women; mean age was 65 years (range, 35-78 years). Concomitant esophagitis was found in five patients and impaired esophageal peristalsis in two patients. A total or a partial fundoplication was associated in these cases. RESULTS: The physical and geometrical analysis of the hiatal region explained the reasons for the recurrence after hiatoplasty. The anatomical study on fresh cadavers resulted in a mesh tailored in an "A" shape and permitted to verify the adaptability of such a shaped mesh composed of two layers, polypropylene and PTFE. In the clinical series no conversions occurred; the mortality rate was null. Persistent dysphagia was present in two patients and disappeared after 3 months of treatment. No recurrence was observed at an 8-month average follow-up. CONCLUSION: The preliminary clinical study confirms the feasibility of this tension-free repair and the effectiveness of this composite A-shaped mesh.

Adult↗
PubMed2002

Laparoscopic splenectomy for hematological diseases.

BACKGROUND: We reviewed retrospectively the records of all patients who underwent laparoscopic splenectomy (LS) at our institution for a wide range of hematological disorders. We compared our experience to those reported in the literature and analyzed various aspects of the treatment that are still under discussion and in need of confirmation, such as the treatment of malignant blood diseases, the indication in case of splenomegaly, and the adequacy of the detection of accessory spleens. METHODS: Between June 1997 and June 2001, we performed 43 LS. The patients were classified into three groups according to clinical diagnosis: idiopathic thrombocytopenic purpura (ITP) (n = 23), hemolytic anemia (HA) (n = 5), and hematological malignancy (HM) (n = 15). Statistical analyses were done to compare the three groups. RESULTS: LS was completed in 41 patients, with a conversion rate of 5%. Splenomegaly was present in 37% of all patients (73% of HM). Mean operative time was 128 min. The incidence of accessory spleens was 20%. A concomitant laparoscopic procedure was done in three cases (cholecystectomy). Postoperative complications occurred in eight patients (18%). Duration of surgery, length of hospital stay, transfusions rate, and some demographics features, such as age and spleen weight and length, were significantly different in each group. No deaths were attributed to the procedure. CONCLUSIONS: The statistical analysis of our series shows that, the laparoscopic approach reliable even in the management of malignant and nonmalignant blood diseases.

Adolescent↗
PubMed2001

Successful renal transplantation in children under 6 years of age.

To evaluate the efficacy of renal transplantation in small pediatric patients, we have reviewed 41 allografts performed in 39 children (28 M/11 F) less than 6 years of age between 1987 and 1998 in the North Italy Transplant Program. Of these patients, 39 had a cadaver donor and 2 a living-related donor, with ages ranging from 20 days to 35 years. The mean follow-up was 56 months. Graft survival was 74.5% and 70.5% at 1 and 5 years, respectively. The causes of graft lost were acute rejection (4), graft vascular thrombosis (4), and hemolytic uremic syndrome recurrence (1). Only 1 patient has died due to chickenpox. Double and triple immunosuppressive therapies were used in 63% and 37% of patients, respectively, on the basis of different center protocols, without differences in graft survival. Steroids were successfully administered on alternate days in 37% of patients, 6-12 months after transplantation. Thrombosis was reported in 2 of 6 kidneys from donors less than 1 year of age and in 2 of 35 donors older than 1 year (P < 0.05). Thirty rejections occurred in 23 patients: 7 episodes were steroid resistant and were treated with ATG/OKT3. Thirty-four infections were reported in 16 of 41 patients; of these 17 were viral, 14 bacterial, and 3 due to Mycoplasma. Four surgical complications were reported: 1 graft artery stenosis, 1 ureteral stenosis, 1 urinary leak, and 1 lymphocele. Mean height standard deviation score improved from -2.0 +/- 1.3 pre transplantation to -1.8 +/- 1.4, -1.5 +/- 1.3, and -1.5 +/- 1.5 at 1, 2, and 5 years post transplantation. Linear growth was significantly better in infants treated with alternate-day steroids. Hypertension was a frequent complication, since 19 of the 30 patients with a 5-year follow-up were still being treated with antihypertensive drugs. In conclusion, graft survival in patients less than 6 years old is satisfactory and similar to that obtained in children aged from 6 to 18 years (70.5% vs. 78.9% at 5 years, P = NS). Consequently, since there are many difficulties in managing infants on maintenance dialysis, an early transplant should be considered. Donors older than 24 months carry a low risk of vascular thrombosis and may be successfully grafted in infants.

Child Development↗
PubMed2001

In situ splitting of a liver with middle hepatic vein anomaly.

In situ liver splitting provides a way to expand the graft pool, minimize cold ischemia time, and improve hemostasis at the cut surface of the graft. Vascular anomalies of the liver may make the splitting procedure very difficult or even impossible to perform. The in situ splitting procedure, performed on a liver with a middle hepatic vein (MHV) anomaly, is described here. The MHV drained directly into the segment III vein within the hepatic parenchyma instead of draining into the left hepatic vein to form the common trunk. In situ splitting was performed during multiorgan procurement from a 33-year-old man who died of isolated cerebral trauma. The MHV was reconstructed on the back table to secure right graft venous drainage using an iliac vein graft. The resultant right graft, segments I and IV to VIII, and left graft, segments II and III, were transplanted successfully into an adult and a child, respectively. The 2 transplant recipients are currently alive with normal hepatic function 20 months after transplantation.

Adult↗
PubMed2000

De novo cancers in paediatric renal transplant recipients: a multicentre analysis within the North Italy Transplant programme (NITp), Italy.

The purpose of this study was to determine the frequency and the outcome of de novo malignancies in a cohort of renal transplant paediatric patients. The records of 493 kidney transplants, carried out in 454 paediatric recipients at the three paediatric transplant centres of the North Italy Transplant programme (NITp, Italy) were reviewed. 10 cases of malignancies (2.2%) comprising both PTLD (post-transplant lymphoproliferative disorders) (6 cases, 1.3%) and non-PTLD malignancies (4 cases, 0.88%) were reported. Non-PTLD included one urothelial carcinoma and one Wilms' tumour of the recipient's left native kidney, one abdominal dysgerminoma and one optic nerve glioma of the left eye. The PTLD consisted of localised or disseminated Epstein-Barr virus (EBV)--associated B-lymphocyte monoclonal (5 cases) and polyclonal (1 case) proliferations. All patients suffering from PTLD had been EBV-negative at the time of transplantation, but developed EBV primary infection after transplantation. All PTLD patient donors were EBV-positive. In addition, all but 1 patient received, before and/or after transplantation, a range of immunosuppressive drugs in addition to the baseline prophylactic immunosuppressive regimen. Moreover, 3 patients suffered from syndromes associated with a genetic predisposition to cancer. Finally, the malignancies reported here were associated with 20% graft failure and 20% mortality rates.

Adolescent↗
PubMed2000

Effects of ischemia-reperfusion on hepatic glutathione and plasmatic markers of graft function during in situ split-liver transplantation in adult recipients.

In situ split-liver transplantation is a new surgical technique where the bipartition of a single liver allows procurement of a right graft (segments I, IV, V-VIII) for an adult recipient (75% of the total liver volume), and a left graft (segments II and III) for a child recipient. The present study was designed to assess the effects of ischemia-reperfusion on right grafts obtained by in situ split-liver transplantation. To this aim, hepatic glutathione and conventional plasmatic markers of allograft function (alanine and aspartate aminotransferase, total bilirubin, prothrombin time, lactate dehydrogenase, gamma-glutamyltranspeptidase, and alkaline phosphatase) were evaluated in four adult recipients. At the time of reperfusion, a marked glutathione decrease was found in the segment VI in three cases, whereas the amount of glutathione in segment IV was related to the duration of cold ischemia in all cases. Upon reperfusion, a marked increase in plasmatic alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase was found. A recovery in prothrombin time was observed from the first day in three cases. An increasing trend in total bilirubin, gamma-glutamyltranspeptidase, and alkaline phosphatase was noted from the second day after transplant. This preliminary study suggests a possible relationship between the duration of cold ischemia, amount of glutathione in segment IV of the right graft, and the trend in plasmatic markers of allograft damage during in situ split-liver transplantation in adult recipients.

Adult↗
PubMed2000

Late Epstein-Barr virus infection of a hepatosplenic gamma delta T-cell lymphoma arising in a kidney transplant recipient.

BACKGROUND AND OBJECTIVE: gd T-cell lymphomas are only exceptionally observed in transplanted patients. Aim of this study was the detailed characterization of one such case. DESIGN AND METHODS: The patient developed spontaneous splenic rupture six years after kidney transplantation. The splenic red pulp was infiltrated by medium-sized and large lymphoid cells with two or more nucleoli. At autopsy, similar lymphoid cells infiltrated the hepatic sinusoids. Histologic, immunologic and molecular studies were carried out. RESULTS: By immunohistochemistry, the atypical lymphoid cells were found to express CD3, CD45 and CD43, indicating their T-lineage origin. Approximately 99% of spleen mononuclear cells (MNC) were CD3(+), gammadelta TcR+, CD4-, CD8-, alphabeta TcR-. A clonal gammadelta TcR rearrangement (Vgamma1-Jgamma1.3/2.3-Cgamma2; Vdelta1-Ddelta2-Jdelta1) was detected. The final diagnosis was peripheral T-cell lymphoma, hepato-splenic gammadelta-type. EBV infection of spleen MNC was documented by molecular studies. However, in situ hybridization for EBER-1 (EBV-RNA) showed that only a minority of malignant lymphoid cells (5-7%) were EBV-infected. INTERPRETATION AND CONCLUSIONS: It is concluded that EBV infection was as a late event involving an already transformed gd T-cell clone.

Adult↗
PubMed2000

[The national program of pediatric transplantation].

The national programme for paediatric transplants currently implemented at the Istituto Superiore di Sanità is one of the first results of the efforts devoted to the definition of an efficient co-ordination policy of the transplantation activity in Italy. Since 1997 the programme has allowed all transplant centres throughout Italy to share unified waiting lists for kidney, heart, lung and liver, which gives paediatric patients a much better possibility than with local waiting lists. We present the regulations, criteria and operative solutions adopted to make the programme work, and the analysis of the data collected in these three years. The analysis gives statistical information on the composition and evolution of waiting lists and transplants done, which may be useful in the continuous process of revision and improvement of the criteria for recipient selection.

Adult↗