PubMed Health⌕ Search

Biomedical subjects

Y Révillon

Publications and source records attributed to Y Révillon.

At least 19 recordsLinked to original sources
PubMed2003

Vascular ring abnormalities: a retrospective study of 62 cases.

BACKGROUND: The authors analyzed clinical signs of vascular ring anomalies together with appropriate complementary examinations and factors predictive of outcome after surgical treatment. METHODS: The authors reviewed the files of 62 patients with vascular ring abnormalities treated at Necker-Enfants Malades Hospital between January 1990 and January 2000, to analyze age at symptom onset, results of paraclinical examinations, the type of vascular ring abnormality, the surgical indications and type of surgery, and postoperative outcome. Outcomes were divided into 3 categories: cure, partial improvement, and no improvement. The chi2 test corrected with Fischer's Exact test was used for statistical analysis. RESULTS: Vascular ring abnormalities were diagnosed at birth in 28% of cases and during the first year of life in 68%. Sixteen percent of patients had associated abnormalities. Recurrent pulmonary and bronchial infections occurred after one year of age. An esophagogram was done in 76% of cases and showed impression images. Endoscopy was done in 63% of cases and showed malacia in 41% of patients and stenosis in 51%. Fifty-eight children were treated surgically. The average hospital stay was 7.4 days. The average follow-up was 37.4 months (12 to 159 months). Complete improvement was obtained in 68% of cases, partial improvement in 17%, and no improvement in 15%. Preoperative malacia was more frequent in patients with partial improvement or no improvement. CONCLUSIONS: Surgical treatment of congenital vascular ring abnormalities is effective and safe. Complications are rare. Prognostic factors include the quality of preoperative preparation of respiratory function, the type of abnormality, and the degree of malacia.

Abnormalities, Multiple↗
PubMed2001

Urological complications after renal transplantation using ureteroureteral anastomosis in children.

PURPOSE: Ureterovesical reimplantation is most often performed for renal transplantation in children. We reviewed our experience to evaluate the safety and efficacy of ureteroureteral reimplantation in pediatric renal transplantation. MATERIALS AND METHODS: We retrospectively evaluated the charts of 92 boys and 72 girls who underwent a total of 166 ureteroureteral anastomoses for renal transplantation from January 1990 to December 1999. Spatulated end-to-end anastomosis was performed between recipient and graft ureters without stenting and with a bladder catheter for at least 10 days. RESULTS: Mean patient age at transplantation was 11.2 years (range 1 to 21.5). There were 22 living related donor and 144 cadaveric grafts. Urological anomalies and nephropathy were the cause of end stage renal disease in 146 and 20 patients, respectively. Urological complications were noted in 14 of the 166 transplantations (8.4%) in 10 boys and 4 girls, including 12 initial and 2 repeat grafts from 2 living related and 12 cadaveric donors. Five of these patients had undergone previous urological surgery. The 2 children (1.2%) with acute ureteral obstruction underwent repeat intervention after stent failure. Anastomotic leakage in 7 cases (4.2%) was treated conservatively in 1 and with a Double-J stent (Medical Engineering Corp., New York, New York) only required in 3. Reoperation was required in 3 cases. One patient (0.6%) with late ureteral stenosis underwent repeat anastomosis, 1 (0.6%) required reimplantation for recurrent pyelonephritis due to vesicoureteral reflux in the graft, 1 (0.6%) with a valve bladder required bladder augmentation and ureteral reimplantation, and 1 (0.6%) with lymphocele and 1 (0.6%) with lithiasis were successfully treated conservatively. Complications were associated with acute rejection in 6 cases. Mean followup without graft loss in patients who presented with versus without complications was 58.3 months (range 1 to 112) versus 75 (range 1 to 118). In the former patients with a mean age of 16 years 9 months versus those without urological complications mean serum creatinine was 116 and 108 mol./l., respectively. Two grafts were lost in patients with urological complications, including 1 who died of pulmonary embolism and 1 with refractory chronic rejection. Seven patients were lost to followup after 54 months (range 12 to 113) of adequate graft function. CONCLUSIONS: Ureteroureteral anastomosis is a safe and effective technique for pediatric renal transplantation with a low complication rate, which may be due to better vascularization of the shorter ureteral end of the graft. Our results should encourage the use of this technique in pediatric renal transplantation. Efforts to preserve the recipient ureters should be made at nephrectomy.

Adolescent↗
PubMed2000

Blockade of the integrin alphaLbeta2 but not of integrins alpha4 and/or beta7 significantly prolongs intestinal allograft survival in mice.

BACKGROUND: Small bowel transplantation remains a difficult therapeutic option endangered by a high rate of rejection and infectious complications. To improve these clinical results, it is mandatory to set up animal models to test alternative immunosuppressive regimens which may lead to immunotolerance. AIMS: To determine the value of blockade of alphaLbeta2 (LFA-1) and alpha4 and beta7 integrins (alpha4beta1, alpha4beta7, and alphaEbeta7) in the prevention of rejection of fetal small bowel grafts in mice and the effect of the association of calcineurin dependent drugs in anti-LFA-1 treated mice. METHODS: Adult recipient mice engrafted with allogeneic fetal small bowel received a short course of anti-alpha4 and/or anti-LFA-1 monoclonal antibodies (mAb) with or without FK506 or cyclosporin A. In addition, in a set of experiment, beta7-/- mice were used as recipients. Graft biopsies were performed and processed for standard histology. RESULTS: Blockade of the pathways of the integrins alpha4 and beta7 had a modest or no effect on intestinal graft survival. In contrast, transitory, short administration of anti-LFA-1 monoclonal antibody alone, when started before engraftment (day -1), allowed long term survival of intestinal grafts, even when associated with calcineurin dependent drugs. However, early withdrawal of FK506 reversed the immunosuppressive effect of anti-LFA-1 treatment. CONCLUSION: These results suggest that firstly, anti-LFA-1, but not anti-alpha4 mAb treatment, may be useful in improving the results of intestinal transplantation, and secondly, that this treatment is not incompatible with long term administration of tacrolimus currently used in the prevention of small bowel graft rejection in humans.

Animals↗
PubMed1999

[Role of calcineurin-dependent drugs on the immunosuppressive effect induced by the anti-LFA-1 antibody in a fetal intestinal transplantation model in mice].

STUDY AIM: We have previously demonstrated that anti-LFA-1 monoclonal antibody (mAb) can efficiently protect against rejection of small bowel allograft in a mouse model. The aim of the present work was to determine, in the same model, the optimum conditions for utilisation of anti-LFA-1 mAb and the effects of calcineurin-dependent drugs on the immunosuppression induced by anti-LFA-1 mAb treatment. MATERIALS AND METHODS: Foetal small intestines of C57Bl/6 (H-2b) mice were transplanted into adult C3H/He (H-2k) mice. Recipients were treated with anti-LFA-1 mAb alone (with or without day-1 injection), or combined to cyclosporin (20 mg.kg-1.j-1 for 14 days), or to tacrolimus (1 mg.kg-1.j-1 from day 0 to day 7). Biopsies were performed after engraftment from day 5 to day 30. RESULTS: Administration of anti-LFA-1 mAb alone is sufficient to induce significant prolongation of intestinal allograft survival, provided that the treatment starts one day before engraftment. This tolerogenic effect is reversed by the transitory administration of tacrolimus (p = 0.008). CONCLUSION: Treatment with anti-LFA-1 mAb has to be started before the allogeneic response has begun. Calcineurin-dependent drugs can modulate the tolerogenic effect induced by anti-LFA-1. A transgenic mice model should give precise details about underlying mechanisms of these interactions, before a possible utilisation of anti-LFA-1 mAb in intestinal transplantation in humans.

Animals↗
PubMed1999

Up-to-date evolution of small bowel transplantation in children with intestinal failure.

PURPOSE: The aim of the authors was to report an up-to-date review of their experience with 26 intestinal transplantations in children since 1987. METHODS: A retrospective study was conducted of 26 patients with a mean age of 5 years (range, 0.3 to 14 years). Three groups were isolated. In group A (1987 to 1990), seven patients received nine isolated intestinal transplants for short bowel syndrome. Immunosuppression therapy consisted of cyclosporine, aziathioprine, and corticosteroids. In group B (1994-current), nine patients received nine isolated intestinal transplants for short bowel syndrom (n = 2), intestinal pseudoobstruction (n = 2), neonatal intractable diarrhea (n = 3), and Hirschsprung' disease (n = 1); hepatic biopsy results showed weak cholestasis or fibrosis. In group C (1994-current), 10 patients received 10 combined liver-small bowel transplants for short bowel syndrome (n = 3), neonatal intractable diarrhea (n = 4), and Hirschsprung' disease (n = 3); hepatic cirrhosis related to total parenteral nutrition (TPN) was shown in all cases. Groups B and C received immunosupressive treatment consisting of tacrolimus, aziathioprine, and corticosteroids. Posttransplant follow-up included intestinal biopsies of the small bowel twice a week and more frequently or combined with liver biopsy if rejection was suspected. RESULTS: Overall patient survival (PS) and graft survival (GS) are 61% (16 of 26) and 50% (13 of 26), respectively. In group A, severe intestinal allograft rejection occurred in six patients leading to graft removal (GS, 11%). Five patients died of TPN complications after graft removal (PS, 28%). One survivor is off TPN, and one currently is waiting for a second graft. In group B, six patients survived (PS, 66%). Causes of death include hepatic failure (n = 1), renal and liver failure (n = 1), and systemic infection (n = 1). Severe intestinal allograft rejection occurred in five patients, which neccessitated aggressive immunosuppression (antilymphocyte serum) leading to an incomplete functional recovery of the graft. Only two patients currently are off TPN. In group C, eight patients survived (PS, 80%) all of which are currently off TPN. One patient died during the procedure, and one died of severe systemic infection. Intestinal graft rejection occurred in six patients; rejection of the liver allograft occurred in five patients, yet all rejections were weak and successfully treated by corticosteroids (GS, 80%). CONCLUSIONS: Intestinal transplantation is a valid therapeutic option for children with definitive intestinal failure and not only for short bowel syndrome. Tacrolimus improves graft and patient survival (group A v group B). The lower severity of graft rejection in combined liver-small bowel transplantation improves functional results of intestinal transplantation in children without additional mortality or morbidity (group B vgroup C).

Adolescent↗
PubMed1999

Living-related liver transplantation in children: the 'Parisian' strategy to safely increase organ availability.

PURPOSE: The aim of the authors was to report their experience with living related liver transplantation (LRLT) in children, particularly focusing on the safety of the two-center "Parisian" strategy. METHODS: The records of donors and recipients of 26 pediatric living-related donor liver transplantations performed between November 1994 and March 1998 were reviewed retrospectively. Donors were assessed 1 year after transplantation for medical and overall status. RESULTS: Indications for LRLT included biliary atresia (n = 18), Byler's disease (n = 5), alpha-1-antitrypsin deficiency (n = 1), Alagille syndrome (n = 1), and undefined cirrhosis (n = 1). Liver harvesting consisted of either a complete left hepatectomy (n = 14) or left lateral hepatectomy (n = 12) without vascular clamping. The recipient procedure essentially was the same as in split liver transplantation. Mean overall cold ischemia time averaged 140 minutes (range, 90 to 230 minutes). Twenty-four of 26 patients had end-to-end vascular anastomoses without interposition. Biliary reconstruction consisted of a Roux-en-Y choledochojejunostomy in all patients. All recipients except one received cyclosporine A (CSA). Mean donor hospitalization was 8 days (range, 6 to 13) with normalization of all liver function assays by the time of discharge. There were no donor deaths and two postoperative complications (perihepatic fluid collection and bleeding from the wound). One year after donation, the initial 19 donors had resumed their pretransplant status. Two of the children who underwent transplant died. Thirteen of the recipients required reoperation for hepatic artery thrombosis (n = 2), portal vein thrombosis (n = 2), biliary complications (n = 6), fluid collection (n = 3), small bowel perforation (n = 1), and plication for diaphragmatic eventration (n = 1). With mean follow-up of 2 years, 24 of 26 patients are alive and well (patient and graft survival rate, 92%). CONCLUSIONS: LRLT is still controversial, even with minimal and decreasing donor risk. The "Parisian" strategy consists of harvesting the liver in an adult unit by an adult hepatic surgery team. The transplantation is then performed in a pediatric hospital by the pediatric liver transplantation team. The two steps of the procedure allow units specialized in adult surgery, on one hand, and pediatric liver transplantation, on the other hand, to dedicate themselves completely to their respective procedures, improving the safety of the harvest, and alleviating stress for both the medical staff and the families.

Adolescent↗
PubMed1998

[Prevention of intestinal allograft rejection by anti-adhesion molecule antibodies in a mouse model].

STUDY AIM: Small bowel transplantation is still hampered by a high morbidity and mortality linked to the heavy non specific immunosuppression which is required by the transplantation of this lymphoid organ. Adhesion molecules appear to be potential targets for specific immunosuppression. The aim of the study was to investigate the effect of a transitory administration of anti-LFA-1 or anti-alpha 4 monoclonal antibodies (mAb) in the prevention of rejection in a model of fetal small-bowel transplantation in mice. MATERIALS AND METHODS: The small bowel of C57BL/6 (H-2b) fetus (16 to 20 days of gestation) was transplanted into adult C3H/He mice (H-2k) or C57BL/6 recipient mice. Recipients were treated with a short course of either anti-LFA-1 mAb alone, either with anti-alpha 4 mAb alone, or with both mAb. Biopsies with histological study of the grafts were performed between post-operative day 5 and 60. A score of development and rejection was assigned to each sample. RESULTS: Normal intestinal development with no sign of rejection was observed in 24/28 syngenic grafts till post-operative day 45. In the absence of treatment, intense rejection was observed as soon as day 5 and all allogenic grafts were rejected (n = 22). In contrast, in anti-LFA-1 mAb treated mice, 18/20 allogenic grafts developed normally with minimal signs of rejection. In anti-alpha 4 treated mice, a transient protective effect on small bowel allograft survival was observed on day 7 but thereafter, all grafts were massively rejected within a few days (n = 18). The combination of both mAb didn't improve the survival of the grafts when compared to anti-LFA-1 mAb treated grafts (n = 10). CONCLUSION: These results demonstrate that a transitory administration of anti-LFA-1 mAb, but not of anti-alpha 4 mAb, is able to prolong significantly the survival of non vascularized small bowel fetal grafts in mice. Our results are promising for the possible use of the anti-LFA-1 mAb in clinical intestinal transplantation.

Animals↗
PubMed1998

Decreased expression of the interleukin 2 receptor on CD8 recipient lymphocytes in intestinal grafts rendered tolerant by liver transplantation in rats.

BACKGROUND: In a previous study, it was shown that a spontaneously tolerated DA (RT1a) liver allograft in a PVG (RT1c) recipient was able to induce tolerance of a DA small bowel graft performed 17 days later in spite of infiltration of the intestinal grafts by mononuclear cells. AIMS: To compare the phenotype of graft infiltrating cells in rejecting and tolerated small bowel grafts in order to elucidate the mechanism(s) which block the graft infiltrating cells from mediating rejection. METHODS: Multiparameter immunofluorescence was used to compare the phenotype and state of activation of donor and recipient cells isolated from intestinal grafts rejected or tolerated after liver transplantation. RESULTS: Three differences were found. Firstly, there was a more rapid replacement of lamina propria (LP) cells by recipient lymphocytes in tolerated than in rejected grafts. Secondly, the proportion of LP recipient CD8alphabeta+ lymphocytes bearing the high affinity receptor for interleukin 2 was significantly less in tolerated grafts (1.1%, range 0-2%) than in rejected grafts (21.3%, range 9-26%). Finally, tolerated grafts contained significantly less NK lymphocytes (NKR-P1+) and macrophages than rejected intestinal allografts. CONCLUSIONS: These observations make it possible to delineate clear cut differences in the phenotype of cells infiltrating rejecting versus tolerated grafts. Furthermore, the data suggest that liver transplantation induces tolerance of intestinal grafts by hampering the activation of recipient TcRalphabeta+ CD8alphabeta+ T cells and subsequently the recruitment of non-specific effector cells.

Animals↗
PubMed1997

Congenital adenomatoid malformation of the lung: when is active fetal therapy indicated?

OBJECTIVE: Although aggressive fetal therapies such as thoracoamniotic shunting can be applied to cystic adenomatoid malformations of the lung diagnosed in utero, there is no clear consensus regarding their indications. Our purpose was to evaluate a management policy in which aggressive fetal therapy was restricted to those cases complicated by major polyhydramnios or hydrops; all other cases were managed conservatively. STUDY DESIGN: A prospective cohort study of 33 cases with a prenatal diagnosis of cystic adenomatoid malformations of the lung was performed. Thoracoamniotic shunting was offered only in nine macrocystic cases with acute polyhydramnios or hydrops. RESULTS: Four cases were diagnosed postnatally as sequestrations. Of 12 cases complicated by acute polyhydramnios or hydrops, 5 survived (1 type III with spontaneous incomplete resolution in utero, 4 type I with substantial volume reduction after shunting). The 17 cases without acute polyhydramnios or hydrops were managed conservatively and survived. CONCLUSION: Conservative management is indicated in cases of cystic adenomatoid malformations of the lung without acute polyhydramnios or hydrops.

Cohort Studies↗
PubMed1995

Small bowel transplantation in children: an immunohistochemical study of intestinal grafts.

Seven children with short bowel syndrome underwent small bowel allografting. Episodes of early rejection were observed in five patients who received a graft from paediatric or adult donors but not in two patients who received a neonatal graft. This study aimed, firstly, to define immunohistochemical parameters accompanying rejection and, secondly, to compare immunohistochemical parameters in neonatal grafts with those in grafts from older donors. An immunohistochemical analysis was performed on 85 intestinal biopsy specimens taken for monitoring the transplant. Acute histological rejection was associated with pericryptic infiltrates of CD3+TcR alpha beta + T cells containing clusters of CD8+ cells, numerous CD25+ cells, and increased numbers of CD68+ macrophages. These changes were associated with the appearance of major histocompatibility (MHC) class II antigens on crypt enterocytes and with an appreciable increase in the expression of E-selectin on mucosal endothelial cells. Immunohistochemistry was useful in predicting rejection by showing the appearance of pericryptic CD25+ T cells 48 hours before the first histological lesions of crypt necrosis. Comparison of neonatal grafts with grafts from older donors did not show any significant difference in the density of CD68+ macrophages or in the endothelial expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, or E-selectin. In contrast to grafts from older donors, however, neonatal grafts did not express MHC class II antigens on epithelial cells and contained very low numbers of intraepithelial lymphocytes. These data indicate, firstly, that immunohistochemistry is useful for monitoring intestinal transplants and, secondly, that the better clinical tolerance of neonatal allografts may be related to the lower immunogenicity of the neonatal epithelium.

CD3 Complex↗
PubMed1993

Prenatal management of congenital cystic adenomatoid malformation of the lung.

In utero evolution and postnatal outcome were studied for 18 cases of congenital adenomatoid malformation (CAM) diagnosed by prenatal ultrasound. Five were macrocystic CAM, 9 were microcystic, and 4 were homogeneously hyperechogenic. Three fetuses presented with hydrops. Pulmonary amniotic shunting was performed in 3 patients. Outcome was the following: 4 were aborted, 1 died neonatally, and 13 survived. Four of these infants required no surgery in the neonatal or postneonatal period. In three of these, the size of the mass had decreased spontaneously in utero. Outcome did not appear to be related to the anatomic type of CAM nor to the presence of moderate polyhydramnios, but was related to the degree of mediastinal compression and to the existence of hydrops. A clearer understanding of the natural evolution of CAM is useful to determine the indications for in utero therapy.

Cystic Adenomatoid Malformation of Lung, Congenita↗