Search PubMed⌕ Search

Biomedical subjects

U Valente

Publications and source records attributed to U Valente.

At least 19 recordsLinked to original sources
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↗
PubMed1999

Correlation between angiotensin-converting enzyme gene insertion/deletion polymorphism and kidney graft long-term outcome in pediatric recipients: a single-center analysis.

BACKGROUND: Despite numerous advances in the areas of organ preservation, histocompatibility, and immunosuppression, chronic deterioration of organ allograft function, referred to as "chronic rejection," still remains the main obstacle to long-term graft survival. The common feature of chronic rejection is a concentric generalized graft arteriosclerosis associated with interstitial fibrosis that reflects an allogeneic injury to graft arteries, possibly worsened by other alloantigen-independent risk factors. The presence of the angiotensin I-converting enzyme (ACE) gene-deleted (D) allele has been associated, when in homozygosity, with increased risk of cardiovascular diseases and with an accelerated progression of organ damage in a variety of kidney diseases. In this study, we analyzed whether the insertion/deletion polymorphism of the ACE gene, because of its negative prognostic impact on cardiovascular and renal pathology, could have any influence on kidney graft survival in pediatric recipients. METHODS: DNA was isolated from peripheral blood mononuclear cells from 146 pediatric dialysis patients (mean age: 12.9 years) who received a first kidney graft at our center between December 1985 and July 1997. To rule out any bias due to acute graft losses, only 119 patients who reached a minimum of 12 months of graft survival were considered for statistical analysis. The insertion/deletion polymorphism of the ACE gene was detected using a polymerase chain reaction technique with two flanking primers. RESULTS: The results demonstrated that (i) the distribution of DD and non-DD (ID + II) genotypes was 36.1% (43 patients) and 63.8% (76 patients), respectively; (ii) actuarial graft survival at 7, 8, 9, and 10 years in patients with non-DD genotype was significantly higher than that in patients with DD genotype (7 years: 94.6% vs. 72.4%, P<0.05; 8 years: 94.6% vs. 62%, P<0.025; 9 years: 87.3% vs. 51.4%, P<0.025; 10 years: 76.3% vs. 25.7%, P<0.01). CONCLUSIONS: In conclusion, the above data indicate that DD genotype is associated in pediatric kidney graft recipients with a shorter long-term kidney graft survival and suggest a possible role of this genotype as a cofactor in the progression of nonimmunological injuries leading to chronic kidney graft failure.

Adolescent↗
PubMed1999

Vesico-ureteral reflux in pediatric kidney transplants: clinical relevance to graft and patient outcome.

From June 1985 to December 1998, 173 pediatric renal transplants were carried out in 170 patients at our center. From this pool, 73 patients (34 males and 39 females) with a follow-up of 48 months were examined. In all patients, ureteroneocystostomy was performed according to the Lich-Grégoire procedure. All patients were treated with cyclosporin A (CsA)-based immunosuppression, including prednisone and sometimes azathioprine (AZA). Six months after transplantation, voiding cystography (VCU) was performed in all patients and reflux was classified from Grade I to Grade IV. The patients were divided into two groups: those with reflux (Group A: 25 patients) and those without (Group B: 48 patients). Grade I reflux was found in four patients, Grade II in seven patients, Grade III in seven patients, and Grade IV in seven patients. All the patients with severe reflux (Grade IV) underwent a corrective surgical procedure. Both groups were examined for immunologic and non-immunologic risk factors and no significant differences were found. Analysis of patient and graft survival rates revealed no statistical differences (NS) between Groups A and B. Mean serum creatinine (mg/dL) was 1.06 +/- 0.28 and 1.12 +/- 0.41 at 4 yr in Groups A and B, respectively (NS). Mean calculated creatinine clearance (cCrC; ml/min) was 76.74 +/- 15.92 and 77.96 +/- 15.66 in Groups A and B, respectively (NS). The analysis was further extended by considering the grade of reflux (I to IV). Again, no significant differences in the above parameters emerged between the reflux sub-groups; only in the Grade IV sub-group was a slight decrease in cCrC detected, although this difference was not statistically significant when compared with the other sub-groups. In conclusion, vesico-ureteral reflux (VUR) does not seem to negatively affect graft function. However, as all severe reflux patients (Grade IV) were surgically corrected, no conclusions can be drawn with regard to the influence of Grade IV reflux on long-term graft function.

Adolescent↗
PubMed1999

Can the MEGX test and serum bile acids improve the prognostic ability of Child-Pugh's score in liver cirrhosis?

BACKGROUND: Liver transplantation is nowadays the therapeutic option for end-stage liver disease. Correct disease staging is the main step towards improving the timing of listing for liver transplantation so as to avoid premature or late entry. The need for correct prognostic evaluation is due to the limited number of donors and to the increasing number of patients awaiting transplantation. Our aim was to verify whether Child-Pugh's score might be improved by adding the monoethylglycinexylidide (MEGX) formation test and/or serum bile acid determination. METHODS: We evaluated 182 cirrhotic patients (44 Child-Pugh class A, 97 class B, and 41 class C) of mixed aetiology referring to a tertiary care centre for functional staging of liver disease. These patients were prospectively followed-up for 12-72 months. During this period, 45 patients died, 46 received a transplant, and 91 survived without transplantation. The end-point of analysis was either survival or liver disease-related death at the 6th, 12th, 18th and 24th months of follow-up. The 46 transplanted patients were excluded from the study upon transplantation. RESULTS: In our study, a cut-off for Child-Pugh's score < 8 confirmed its usefulness, especially in short-term prognostic prediction, while mid- and long-term prediction improved by almost 10% by using the combination of a Child- Pugh's score > 8 and an MEGX value < 15 mg/l. Cox's multi-variate regression analysis indicated that MEGX values either with Child-Pugh's score or with prothrombin activity and ascites were independent prognostic variables. CONCLUSIONS: Besides confirming that Child-Pugh's score as the basis of prognostic evaluation of cirrhotic patients, these results suggest that the MEGX test might be a complement to the original score when a patient is being evaluated for a liver transplantation programme.

Adult↗
PubMed1998

Pattern and management of recurrent hepatocellular carcinoma after liver transplantation.

A series of 132 patients who underwent liver transplantation for primary liver cancer was collected from three different Italian hospitals and studied for recurrence of hepatocellular carcinoma after liver replacement. Twenty-one patients (15.9%) had a neoplastic recurrence after an average follow-up period of 7.8 months after transplantation (range, 1-25 months); 15 (71%) occurred within the first 18 months after transplant and only two recurred later than 2 years. The sites of recurrence were grafted liver (19%), lung (19%), bone (14%), and other (5%). Eight patients (38%) had multiple organ involvement at the onset. After 1, 2, 3, and 4 years the overall survival rates were 62%, 43%, 29%, and 23%, respectively. The tumor factors related to early cancer recurrence after transplantation were diameter of nodules more than 3 cm (P < 0.05), tumor stage not meeting the "Milan criteria" (P < 0.03), and presence of peri-tumoral capsule (P < 0.05); the number of nodules, TNM stage, presence of vascular invasion, alpha-fetoprotein level more than 150 UI/l, pre-transplant chemoembolization and resectability of cancer deposits did not seem to be related to early recurrence. The prognosis differed in the 7 patients with resectable recurrences (57% 4-year survival) and the 14 patients with unresectable disease (14% 4-year survival) (P < 0.02). Better patient selection and new combined medical strategies could reduce the incidence of and mortality from liver cancer recurrence after transplantation. The role of surgical resection of recurrence should be further investigated.

Adolescent↗
PubMed1998

Acyclovir plus CMV immunoglobulin prophylaxis and early therapy with ganciclovir are effective and safe in CMV high-risk renal transplant pediatric recipients.

Cytomegalovirus (CMV) infection is still a major cause of morbidity in high-risk renal transplant recipients. In the present report, we have reviewed our records of renal transplant pediatric recipients (RTPR; mean age 14.1 +/- 4.9 years) since 1991, when we started a policy of CMV prophylaxis constituting high-dose oral acyclovir plus CMV hyperimmune immunoglobulins (HIg) followed by early i.v. ganciclovir therapy in high-risk patients (i.e., CMV donor+/recipient-). Four patients received a kidney from a living relative (LR), 2 patients had one previous transplant, and 1 had a combined liver-kidney transplant. Thirty-three patients who were negative for CMV antibodies (ab) before transplantation received a kidney from CMV ab positive donors. The immunosuppressive regimen included cyclosporine A and steroids, with the addition of azathioprine in the 4 patients who received an LR kidney. Serial assessments for CMV antigenemia (pp 65) were routinely performed for 6 months after transplantation to define CMV infection. Among the 33 CMV seronegative recipients (R-) who received the graft from a CMV seropositive donor (D+), 18 (54.5%) experienced CMV infection, whereas among the 28 CMV R+, who received a graft from a CMV D+, 11 (39.3%) experienced CMV infection. With regard to CMV- related symptoms, only 2 patients suffered from a CMV syndrome (fever and leukopenia in 1 patient, fever and arthralgia in the other). In no case did the spectrum of CMV disease occur; only minor symptoms were present in 7 of the remaining CMV-infected patients (fever in 6 and leukopenia in 1). Rejection episodes and renal function did not differ between CMV-infected and non-CMV-infected patients. Our experiences support the use of prophylactic acyclovir plus CMV HIg followed by early therapy with i.v. ganciclovir to combat the risk of increased morbidity in high risk RTPR.

Acyclovir↗