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Featured researches published by Thomas Blanc.


European Urology | 2013

Retroperitoneal laparoscopic pyeloplasty in children: long-term outcome and critical analysis of 10-year experience in a teaching center.

Thomas Blanc; C. Muller; Hendy Abdoul; Stoyen Peev; A. Paye-Jaouen; Matthieu Peycelon; Elisabeth Carricaburu; Alaa El-Ghoneimi

BACKGROUND Laparoscopic pyeloplasty in children remains controversial and is not included in most pediatric urology centers because of technical difficulties and lack of long-term results. OBJECTIVE To critically analyze our 10-yr experience with the retroperitoneal approach (RA), with a particular interest on the impact of the learning curve in a teaching center. DESIGN, SETTING, AND PARTICIPANTS Patients who underwent pyeloplasty between 1999 and 2010 at our institution were reviewed (n=390). The diagnosis of ureteropelvic junction obstruction was confirmed by ultrasound and technetium Tc 99m mercaptoacetyltriglycine-3 renal scan or magnetic resonance imaging; the same criteria were used to evaluate the outcome. The lateral RA was selected in children >1 yr of age without abnormal migration or fusion of the kidney (n=104). SURGICAL PROCEDURE Dismembered pyeloplasty and anastomosis were performed using running monofilament 5-0 or 6-0 absorbable suture. All were drained by double-J stent except 20 cases drained by external transanastomotic stent. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS We assessed intra- and postoperative morbidity and analyzed the teaching of technique and learning curve. Data are expressed as medians and interquartile range (25th, 75th percentiles) for quantitative variables. RESULTS AND LIMITATIONS Median age was 6.2 yr (2.2-10.3). Thirty-three patients had crossing vessels. Median operative time was 185 min (160-235). Median hospital stay was 2 d (1-2). Redo pyeloplasty was needed in only two children (2%). Median follow-up was 2.1 yr (1.4-4.1). Operative time was <3 h after 35 cases. After 30 cases performed by the same surgeon, standardization of the technique was feasible, which helped in the teaching process because 50% of the final 30 cases were done by trainees. CONCLUSIONS Retroperitoneal dismembered laparoscopic pyeloplasty is a safe, reliable, and efficient procedure with an excellent outcome in selected children according to their indications and age, and the experience of the surgical team. Even if the transmission to trainees is successful, it is still a long learning process and remains a challenging task for a teaching center.


European Journal of Endocrinology | 2011

Testicular function and physical outcome in young adult males diagnosed with idiopathic 46 XY disorders of sex development during childhood

Thomas Blanc; Ahmed Ayedi; Alaa El-Ghoneimi; Hendy Abdoul; Yves Aigrain; Françoise Paris; Charles Sultan; Jean-Claude Carel; Juliane Léger

OBJECTIVE There are few studies of outcome in male patients with undefined 46 XY disorder of sex development (DSD). We aimed to assess testicular function and clinical characteristics after puberty in men with idiopathic 46 XY DSD. Design We conducted a University Hospital-based observational follow-up study. METHODS Nineteen patients with severe hypospadias associated with other signs of defective virilization, such as microphallus, cryptorchidism, and/or bifid scrotum, who were initially managed during childhood between 1988 and 1994, were evaluated at a median age of 17.6 (16.3; 17.8) years. Outcome measures included clinical findings and serum testosterone, FSH, LH, and inhibin B concentrations. RESULTS Testicular function was normal in only five (26%) patients. Impaired testicular function was observed in 14 (74%) patients and was partial (n=6; 32%) or total (n=8; 42%), requiring testosterone treatment for the initial (n=2) or secondary (n=6) induction of puberty. Undescended testis (unilateral n=3, bilateral n=2) was found and surgically managed only in the 14 patients with testicular impairment. Testosterone treatment in early childhood greatly increased penis length in all patients, but persistent microphallus following surgical treatment was observed at the end of puberty in most patients, with no difference between patients with and without testicular dysfunction (penis length of 68 (60; 75) vs 65 (60; 65) mm; P=0.42). Half the patients presented an adult height more than 5 cm below their target height. CONCLUSION Men diagnosed with idiopathic 46 XY DSD during childhood are at high risk of testicular insufficiency and persistent micropenis, and this should be taken into account during the follow-up.


The Journal of Urology | 2011

Preliminary experience with external ureteropelvic stent: alternative to double-j stent in laparoscopic pyeloplasty in children.

Tamer E. Helmy; Thomas Blanc; A. Paye-Jaouen; Alaa El-Ghoneimi

PURPOSE We assessed whether an external ureteropelvic stent was a feasible and safe alternative to Double-J® stent after laparoscopic pyeloplasty in children, thus avoiding a second general anesthesia. MATERIALS AND METHODS Our study included 22 concurrent age matched children who underwent retroperitoneal laparoscopic pyeloplasty between 2000 and 2008. In group 1 an external ureteropelvic stent was inserted through the renal pelvis, then clamped on postoperative day 2. In group 2 a Double-J stent was antegradely inserted. The ureteropelvic stent was removed at the outpatient clinic on day 10, while the Double-J stent was removed under general anesthesia at 1 month. We retrospectively compared operative time, hospital stay, intraoperative and postoperative complications, and followup. RESULTS Mean±SD age at surgery was 31±9 months in group 1 and 37±12 months in group 2. Mean±SD operative time was slightly shorter in group 1 (190±40 minutes) than in group 2 (205±23 minutes). No intraoperative complications were encountered during placement of stent. Mean±SD hospital stay was 2.18±1.20 days in group 1 and 2.45±0.54 days in group 2. No postoperative complications were reported in group 1. The Double-J stent was noted in the posterior urethra in 1 patient in group 2, requiring cystoscopic repositioning. No patient had urinary tract infection. Median followup was 34 months (range 22 to 56) in group 1 and 35 months (16 to 72) in group 2. CONCLUSIONS The feasibility of external ureteropelvic stenting after laparoscopic pyeloplasty will pave the way to minimizing the use of Double-J stenting and eliminating a second general anesthesia for catheter removal.


Hormone Research in Paediatrics | 2017

Efficacy and Safety of Continuous Subcutaneous Infusion of Recombinant Human Gonadotropins for Congenital Micropenis during Early Infancy

Athanasia Stoupa; Dinane Samara-Boustani; Isabelle Flechtner; Graziella Pinto; Isabelle Jourdon; Laura González-Briceño; Maud Bidet; Kathleen Laborde; Didier Chevenne; Anne-Elodie Millischer; Henri Lottmann; Thomas Blanc; Yves Aigrain; Michel Polak; Jacques Beltrand

Background: Early postnatal administration of gonadotropins to infants with congenital hypogonadotropic hypogonadism (CHH) can mimic minipuberty, thereby increasing penile growth. We assessed the effects of gonadotropin infusion on stretched penile length (SPL) and hormone levels in infants with congenital micropenis. Methods: Single-center study including 6 males with micropenis in case of isolated CHH (n = 4), panhypopituitarism (n = 1), and partial androgen insensitivity syndrome (PAIS; n = 1). Patients were evaluated at baseline, monthly and at the end of the study through a clinical examination (SPL, testicular position and size), serum hormone assays (testosterone, luteinizing hormone, follicle-stimulating hormone, inhibin B, anti-Müllerian hormone [AMH]), and ultrasound of penis/testes. Results: In CHH, significant increases occurred in serum testosterone (from undetectable level to 3.5 ± 4.06 ng/mL [12.15 ± 14.09 nmol/L]), SPL (from 13.8 ± 4.5 to 42.6 ± 5 mm; p < 0.0001), inhibin B (from 94.8 ± 74.9 to 469.4 ± 282.5 pg/mL, p = 0.04), and AMH (from 49.6 ± 30.6 to 142 ± 76.5 ng/mL, p = 0.03). Micropenis was corrected in all patients, except one. On treatment, in the patient with PAIS, SPL was increased from 13 to 38 mm. Conclusions: Early gonadotropin infusion is a safe, well-tolerated and effective treatment. The effect in PAIS has not been reported previously. Long-term follow-up is needed to assess the impact, if any, on future fertility and reproduction.



Journal of Pediatric Urology | 2015

Laparoscopic Mitrofanoff procedure in children: Critical analysis of difficulties and benefits

Thomas Blanc; C. Muller; Maguelonne Pons; Pourya Pashootan; A. Paye-Jaouen; Alaa El Ghoneimi

OBJECTIVES The Mitrofanoff principle is an accepted continent urinary diversion. We studied the feasibility and the possible benefits of using a laparoscopic approach in children with significant bladder dysfunction associated with difficulty doing efficient urethral catheterization. PATIENTS AND METHODS A fully laparoscopic Mitrofanoff continent cystostomy was attempted in 15 children with a median age of 9 years (IQR 6), between 2003 and 2013. Before the Mitrofanoff procedure was considered, urodynamic evaluation was done for each patient, to study bladder compliance, detrusor activity, and bladder capacity. The procedure was performed using a transperitoneal four-port approach. A 30-degree down camera angle was optimal for viewing the appendix and the posterior wall of the bladder. The operative steps of the open procedure were replicated laparoscopically. The proximal end of the appendix was spatulated and anastomosed to the posterior wall of the bladder, providing an antireflux mechanism by an extramucosal tunnel. The distal end of the appendix was brought out as the cutaneous umbilical stoma. Some modifications were done because of the high rate of conversion due to early opening of the mucosa (harmonic hook) or difficult anastomosis: (a) use of 5-mm trocars to change the laparoscope position from the left to right subcostal area to better visualize the anastomosis, (b) the anastomosis was suspended at its two ends during suturing; a trans-abdominal traction suture of the bladder was inserted for better exposure of the anastomosis (hitch stitch) and to stabilize the anastomotic line during suturing, (c) use of a monopolar hook to cut the detrusor muscle fibers, to avoid incidental opening of the mucosa, and (d) the window between the appendix and the peritoneum was closed to avoid internal hernia. RESULTS The procedure was totally completed by laparoscopy in 12 cases. Three were converted to an open procedure due to tearing of bladder mucosa (n = 2) or appendix ischemia (n = 1). Median operative time for fully laparoscopic Mitrofanoff was 255 min (IQR 52). Median follow-up was 18 months (IQR 35). No patient required stomal revision. Seven patients were continent, five experienced urinary leakage from urethra n = 1 and/or stoma n = 5. Three patients with stomal urinary leakage were successfully managed by Deflux (dextranomer-based implants) injection in the catheterizable channel. Two patients required an open revision of the appendicovesical anastomosis. The patient with both stomal and urethral urinary leakage also required the implantation of an artificial urinary sphincter 1.5 years after Mitrofanoff. One patient had bladder augmentation. CONCLUSION Although our results of laparoscopic Mitrofanoff procedure in children are unsatisfying in cases of high-pressure bladders in terms of incontinent stoma, we still believe that it is justified to develop this challenging technique with more refinement and improvement, to provide a minimal invasive procedure that may postpone or even avoid bladder augmentation in pediatric age.


Archives De Pediatrie | 2010

CL138 - Ectopie urétérale bilatérale sur système simple : un défi thérapeutique

Alaa Cheikhelard; Thomas Blanc; Henri Lottmann; Alaa El-Ghoneimi; Stephen Lortat-Jacob; Yves Aigrain

Objectifs L’ectopie ureterale bilaterale (EUB) sur systeme simple s’associe a une dysplasie du col avec hypoplasie vesicale, responsables d’incontinence urinaire ± insuffisance renale. Le traitement ideal est conservateur (reimplantation ureterovesicale avec uretrocervicoplastie ou injections uretrocervicales), permettant la croissance vesicale sans recourir a l’enterocystoplastie (ECP). Nous rapportons notre experience d’une cohorte de 11 filles avec EUB. Materiels et Methodes Etude retrospective (suivi prospectif) de 1988 a 2009. Resultats Age moyen: 11ans (2-21). Les modes de presentation etaient: diagnostic prenatal [4], incontinence et/ou infections urinaires [5], anomalie perineale a la naissance [2]. Toutes avaient des anomalies associees urinaires (hypoplasie vesicale-reflux-bifidite [19]) ou non (pole caudal-mulleriennes-autres [21]). 4 patientes avaient une insuffisance renale et 7 des anomalies scintigraphiques. Toutes ont ete operees [mediane 4 fois [1-6]), avec un recul moyen de 4,5ans (0,5-15). Seulement 3 ont eu un traitement conservateur (2 continentes). 7 ont eu une ECP (5 continentes en sondages intermittents). 1 attend une chirurgie. 1 a ete transplantee. Conclusion Le traitement conservateur des EUB est rarement suffisant pour acquerir la continence sans ECP.


Journal of Pediatric Urology | 2010

Alternative to Double-J Stent in Laparoscopic Pyeloplasty in Children

Tamer E. Helmy; Thomas Blanc; A. Paye-Jaouen; Alaa El Ghoneimi


55th Annual ESPE | 2016

Clinical History and High Prevalence of Gonadal Tumor in 14 Patients with 46 XY Pure Gonadal Dysgenesis

Claire Sechter-Mavel; Maryse Cartigny; Graziella Pinto; Maud Bidet; Sophie Catteau-Jonard; Geoffroy Robin; Yves Aigrain; Thomas Blanc; Yves Morel; Jacques Weill; Michel Polak; Dinane Samara-Boustani


The Journal of Urology | 2010

1260 HIGH RISK OF TESTICULAR INSUFFICIENCY IN YOUNG ADULT MALES WITH IDIOPATHIC 46 XY DSD TREATED FOR HYPOSPADIAS DURING EARLY CHILDHOOD

Thomas Blanc; Ayadi Ahmed; Alaa El-Ghoneimi; Yves Aigrain; Jean-Claude Carel; Juliane Léger


Journal of Pediatric Urology | 2010

Bilateral Single Ectopic Ureters: A Challenging Entity to Achieve Continence and Preserve Renal Function

Alaa Cheikhelard; Thomas Blanc; Henri Lottmann; Alaa El-Ghoneimi; Stephen Lortat-Jacob; Yves Aigrain

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Yves Aigrain

Paris Descartes University

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Henri Lottmann

Necker-Enfants Malades Hospital

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Alaa Cheikhelard

Necker-Enfants Malades Hospital

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Stephen Lortat-Jacob

Necker-Enfants Malades Hospital

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