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Dive into the research topics where João Alexandre Barbosa is active.

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Featured researches published by João Alexandre Barbosa.


The Journal of Urology | 2013

Parent and Patient Perceptions of Robotic vs Open Urological Surgery Scars in Children

João Alexandre Barbosa; Ghassan Barayan; Chad M. Gridley; Daniela C.J. Sanchez; Carlo C. Passerotti; Constance S. Houck; Hiep T. Nguyen

PURPOSE Cumulative evidence shows that robot-assisted laparoscopic surgery is safe and at least as efficacious as open surgery for several pediatric urological procedures. Scars resulting from robotic surgery are often assumed to have a cosmetic advantage. However, no study has clearly demonstrated that parents and patients consistently prefer such scars. MATERIALS AND METHODS We developed 3 distinct surveys consisting of photographs and diagrams of scars resulting from open and robot-assisted laparoscopic surgery for ureteral reimplantation, pyeloplasty and bladder augmentation. Surveys were distributed to parents of patients being evaluated for 1 of the 3 procedures. The surveys evaluated information such as scar preference, reason for preference and demographics. Patients older than 7 years also completed surveys. RESULTS Robot-assisted laparoscopic surgical scars were preferred by parents for all procedures studied (85% for ureteral reimplant, 63% for pyeloplasty and 93% for bladder augmentation). Patients also preferred the robotic scars (76%, 62% and 91%, respectively). Patients and parents did not differ significantly in scar preference or in rating of factors affecting decision. Scar size was important or very important to 80% of parents for reimplant, 83% for pyeloplasty and 86% for bladder augmentation. However, the majority of parents would ultimately base their choice of surgical approach on clinical efficacy rather than scar preference. CONCLUSIONS Parents and patients prefer robot-assisted laparoscopic surgical scars to open surgical scars for pediatric ureteral reimplantation, pyeloplasty and bladder augmentation. Scar appearance is an important influence on the decisions of parents and patients, and should be discussed when surgical treatment is presented.


Prenatal Diagnosis | 2012

Postnatal longitudinal evaluation of children diagnosed with prenatal hydronephrosis: insights in natural history and referral pattern

João Alexandre Barbosa; Jeanne S. Chow; Carol B. Benson; Marco A. Yorioka; Alexandre S. Bull; Alan B. Retik; Hiep T. Nguyen

Clinical significance and management of prenatal hydronephrosis (PNH) are sources of debate. Existing studies are flawed with biased cohorts or inconsistent follow‐up. We aimed to evaluate the incidence of pathology in a large cohort of PNH and assess the biases and outcomes of this population.


The Journal of Urology | 2013

Development and Initial Validation of a Scoring System to Diagnose Testicular Torsion in Children

João Alexandre Barbosa; Bruno Camargo Tiseo; Ghassan Barayan; Brian M. Rosman; Fábio César Miranda Torricelli; Carlo C. Passerotti; Miguel Srougi; Alan B. Retik; Hiep T. Nguyen

PURPOSE Testicular torsion is a surgical emergency requiring prompt intervention. Although clinical diagnosis is recommended, scrotal ultrasound is frequently ordered, delaying treatment. We created a scoring system to diagnose testicular torsion, decreasing the indication for ultrasound. MATERIALS AND METHODS We prospectively evaluated 338 patients with acute scrotum, of whom 51 had testicular torsion. Physical examination was performed by a urologist, and all patients underwent scrotal ultrasound. Univariate analysis and logistic regression were performed, and a scoring system for risk stratification of torsion was created. Retrospective validation was performed with 2 independent data sets. RESULTS The scoring system consisted of testicular swelling (2 points), hard testicle (2), absent cremasteric reflex (1), nausea/vomiting (1) and high riding testis (1). Cutoffs for low and high risk were 2 and 5 points, respectively. Ultrasound would be indicated only for the intermediate risk group. In the prospective data set 69% of patients had low, 19% intermediate and 11.5% high risk. Negative and positive predictive values were 100% for cutoffs of 2 and 5, respectively (specificity 81%, sensitivity 76%). Retrospective validation in 1 data set showed 66% of patients at low, 16% intermediate and 17% high risk. Negative and positive predictive values for cutoffs of 2 and 5 were 100% (specificity 97%, sensitivity 54%). The second retrospective data set included only torsion cases, none of which was misdiagnosed by the scoring system. CONCLUSIONS This scoring system can potentially diagnose or rule out testicular torsion in 80% of cases, with high positive and negative predictive values for selected cutoffs. Ultrasound orders would be decreased to 20% of acute scrotum cases. Prospective validation of this scoring system is necessary.


Journal of Pediatric Urology | 2013

Comparative evaluation of the resolution of hydronephrosis in children who underwent open and robotic-assisted laparoscopic pyeloplasty.

João Alexandre Barbosa; Alexander Kowal; Bulent Onal; Éder Maxwell Gouveia; Michele Walters; Justin Newcomer; Jeanne S. Chow; Hiep T. Nguyen

OBJECTIVES To assess long-term postoperative ultrasonographic outcomes of robotic-assisted laparoscopic pyeloplasty (RALP) and of conventional open pyeloplasty (COP) in pediatric patients with ureteropelvic junction obstruction. METHODS Retrospective review of 312 patients who underwent RALP or COP in a single institution. Preoperative and postoperative ultrasounds were used to determine the grade of hydronephrosis. Postoperative assessment included 3 ultrasounds at 0-6, 6-12 and >12 months intervals. Patients were matched by age, etiology of obstruction, grade of preoperative hydronephrosis and gender for case-matched analysis. RESULTS We identified 212 pyeloplasties that met inclusion criteria, being 58 RALP and 154 COP. Groups were different in age, gender and etiology, but similar in severity of hydronephrosis and follow-up time. At the end of follow-up, complete resolution and success rates were 62% and 74% in RALP and 45% and 70% in COP, respectively. Matching included 105 patients. Complete resolution was higher in RALP (p = 0.004), while median time before improvement was lower (12.3 months RALP vs 29.9 months COP). There was no difference in success rate at the end of follow-up between the groups. CONCLUSION RALP shows satisfactory long-term outcomes, comparable to COP. In our cohort, patients who underwent robotic pyeloplasty showed faster resolution of hydronephrosis on ultrasound.


World Journal of Gastrointestinal Surgery | 2016

Impact of laparoscopic surgery training laboratory on surgeon's performance

Fábio César Miranda Torricelli; João Alexandre Barbosa; Giovanni Marchini

Minimally invasive surgery has been replacing the open standard technique in several procedures. Similar or even better postoperative outcomes have been described in laparoscopic or robot-assisted procedures when compared to open surgery. Moreover, minimally invasive surgery has been providing less postoperative pain, shorter hospitalization, and thus a faster return to daily activities. However, the learning curve required to obtain laparoscopic expertise has been a barrier in laparoscopic spreading. Laparoscopic surgery training laboratory has been developed to aid surgeons to overcome the challenging learning curve. It may include tutorials, inanimate model skills training (box models and virtual reality simulators), animal laboratory, and operating room observation. Several different laparoscopic courses are available with specific characteristics and goals. Herein, we aim to describe the activities performed in a dry and animal-model training laboratory and to evaluate the impact of different kinds of laparoscopic surgery training courses on surgeon’s performance. Several tasks are performed in dry and animal laboratory to reproduce a real surgery. A short period of training can improve laparoscopic surgical skills, although most of times it is not enough to confer laparoscopic expertise for participants. Nevertheless, this short period of training is able to increase the laparoscopic practice of surgeons in their communities. Full laparoscopic training in medical residence or fellowship programs is the best way of stimulating laparoscopic dissemination.


The Journal of Urology | 2013

Interactions between Lower Urinary Tract Symptoms and Cardiovascular Risk Factors Determine Distinct Patterns of Erectile Dysfunction: A Latent Class Analysis

João Alexandre Barbosa; Eduardo Muracca; Elcio Nakano; Adriana Rochetto Assalin; Paulo Cordeiro; Mario Paranhos; José Cury; Miguel Srougi; Alberto A. Antunes

PURPOSE An epidemiological association between lower urinary tract symptoms and erectile dysfunction is well established. However, interactions among multiple risk factors and the role of each in pathological mechanisms are not fully elucidated MATERIALS AND METHODS We enrolled 898 men undergoing prostate cancer screening for evaluation with the International Prostate Symptom Score (I-PSS) and simplified International Index of Erectile Function-5 (IIEF-5) questionnaires. Age, race, hypertension, diabetes, dyslipidemia, metabolic syndrome, cardiovascular disease, serum hormones and anthropometric parameters were also evaluated. Risk factors for erectile dysfunction were identified by logistic regression. The 333 men with at least mild to moderate erectile dysfunction (IIEF 16 or less) were included in a latent class model to identify relationships across erectile dysfunction risk factors. RESULTS Age, hypertension, diabetes, lower urinary tract symptoms and cardiovascular event were independent predictors of erectile dysfunction (p<0.05). We identified 3 latent classes of patients with erectile dysfunction (R2 entropy=0.82). Latent class 1 had younger men at low cardiovascular risk and a moderate/high prevalence of lower urinary tract symptoms. Latent class 2 had the oldest patients at moderate cardiovascular risk with an increased prevalence of lower urinary tract symptoms. Latent class 3 had men of intermediate age with the highest prevalence of cardiovascular risk factors and lower urinary tract symptoms. Erectile dysfunction severity and lower urinary tract symptoms increased from latent class 1 to 3. CONCLUSIONS Risk factor interactions determined different severities of lower urinary tract symptoms and erectile dysfunction. The effect of lower urinary tract symptoms and cardiovascular risk outweighed that of age. While in the youngest patients lower urinary tract symptoms acted as a single risk factor for erectile dysfunction, the contribution of vascular disease resulted in significantly more severe dysfunction. Applying a risk factor interaction model to prospective trials could reveal distinct classes of drug responses and help define optimal treatment strategies for specific groups.


The Journal of Urology | 2012

A Novel Method of Evaluating Ureteropelvic Junction Obstruction: Dynamic Near Infrared Fluorescence Imaging Compared to Standard Modalities to Assess Urinary Obstruction in a Swine Model

Courtney K. Rowe; Felipe Franco; João Alexandre Barbosa; Brian J. Minnillo; Jeanne S. Chow; Ted Treves; Alan B. Retik; Hiep T. Nguyen

PURPOSE Dynamic near infrared fluorescence imaging of the urinary tract provides a promising way to diagnose ureteropelvic junction obstruction. Initial studies demonstrated the ability to visualize urine flow and peristalsis in great detail. We analyzed the efficacy of near infrared imaging in evaluating ureteropelvic junction obstruction, renal involvement and the anatomical detail provided compared to conventional imaging modalities. MATERIALS AND METHODS Ten swine underwent partial or complete unilateral ureteral obstruction. Groups were survived for the short or the long term. Imaging was performed with mercaptoacetyltriglycine diuretic renogram, magnetic resonance urogram, excretory urogram, ultrasound and near infrared imaging. Scoring systems for ureteropelvic junction obstruction were developed for magnetic resonance urogram and near infrared imaging. Physicians and medical students graded ureteropelvic junction obstruction based on magnetic resonance urogram and near infrared imaging results. RESULTS Markers of vascular and urinary dynamics were quantitatively consistent among control renal units. The same markers were abnormal in obstructed renal units with significantly different times of renal phase peak, start of pelvic phase and start of renal uptake. Such parameters were consistent with those obtained with mercaptoacetyltriglycine diuretic renography. Near infrared imaging provided live imaging of urinary flow, which was helpful in identifying the area of obstruction for surgical planning. Physicians and medical students categorized the degree of obstruction appropriately for fluorescence imaging and magnetic resonance urogram. CONCLUSIONS Near infrared imaging offers a feasible way to obtain live, dynamic images of urine flow and ureteral peristalsis. Qualitative and quantitative parameters were comparable to those of conventional imaging. Findings support fluorescence imaging as an accurate, easy to use method of diagnosing ureteropelvic junction obstruction.


Revista Da Associacao Medica Brasileira | 2017

Low serum testosterone is a predictor of high-grade disease in patients with prostate cancer.

George A. M. Lins de Albuquerque; Giuliano Guglielmetti; João Alexandre Barbosa; José Fernandes Pontes; Arnaldo Fazoli; Mauricio Cordeiro; Rafael F. Coelho; Paulo Afonso de Carvalho; Fabio Gallucci; Guilherme Philomeno Padovani; Rubens Park; José Cury; Henrique Nonemacher; Miguel Srougi; William Carlos Nahas

OBJECTIVE To evaluate the relation between serum total testosterone (TT) and prostate cancer (PCa) grade and the effect of race and demographic characteristics on such association. METHOD We analyzed 695 patients undergoing radical prostatectomy (RP), of whom 423 had serum TT collected. Patients were classified as having hypogonadism or eugonadism based on two thresholds of testosterone: threshold 1 (300 ng/dL) and threshold 2 (250 ng/dL). We evaluated the relation between TT levels and a Gleason score (GS) ≥ 7 in RP specimens. Outcomes were evaluated using univariate and multivariate analyses, accounting for race and other demographic predictors. RESULTS Out of 423 patients, 37.8% had hypogonadism based on the threshold 1 and 23.9% based on the threshold 2. Patients with hypogonadism, in both thresholds, had a higher chance of GS ≥ 7 (OR 1.79, p=0.02 and OR 2.08, p=0.012, respectively). In the multivariate analysis, adjusted for age, TT, body mass index (BMI) and race, low TT (p=0.023) and age (p=0.002) were found to be independent risk factors for GS ≥ 7. Among Black individuals, low serum TT was a stronger predictor of high-grade disease compared to White men (p=0.02). CONCLUSION Hypogonadism is independently associated to higher GS in localized PCa. The effect of this association is significantly more pronounced among Black men and could partly explain aggressive characteristics of PCa found in this race.


European Urology | 2018

Retrograde Release of the Neurovascular Bundle with Preservation of Dorsal Venous Complex During Robot-assisted Radical Prostatectomy: Optimizing Functional Outcomes

Paulo Afonso de Carvalho; João Alexandre Barbosa; Giuliano Guglielmetti; Mauricio Cordeiro; Bernardo Rocco; William Carlos Nahas; Vipul R. Patel; Rafael F. Coelho

BACKGROUND Robot-assisted laparoscopic radical prostatectomy (RARP) presents consistent oncological outcomes for prostate cancer; yet continence and potency results are not uniform. We present a technical modification for RARP which preserves the nerves and vascular structures anterior to the prostate aiming to optimize functional outcomes. OBJECTIVE To present oncological and functional results of a modified technique for RARP. DESIGN, SETTING, AND PARTICIPANTS Prospective, noncontrolled case series including 128 consecutive patients undergoing RARP performed by a single surgeon (R.F.C). SURGICAL PROCEDURE RARP with retrograde release of the neurovascular bundle and preservation of dorsal venous complex. MEASUREMENTS Potency was defined as a Sexual Health Inventory for Men score of ≥17; continence was defined as use of no pads. Oncological results analyzed were positive surgical margins (PSM) rates and biochemical recurrence (BCR)-free survival. BCR was defined as prostate-specific antigen >0.2ng/ml. Complications were graded according to the Clavien-Dindo classification. RESULTS AND LIMITATIONS Median patient age was 63.5 yr. Median skin-to-skin time was 78min. Median length of hospital stay was 1 d, with seven patients (5.5%) hospitalized for more than 24h. Median intraoperative bleeding was 200ml and two patients required postoperative blood transfusion (1.6%). Four patients (3.1%) had grade ≥3 complications. Biochemical recurrence (BCR) occurred in nine of 128 patients (7%) and median time to BCR was 6 mo. Overall PSM rate was 13.3% (17 of 128 patients). PSM rate was 9% among patients with pT2 disease (8/89) and 27% in patients with pT3 (9/38). Continence was reached immediately in 85.9% of the patients and 98.4% were continent at1 yr. At 1 mo postoperatively, 60 patients were potent (53%), while 98 patients among 113 (86%) were potent 1 yr after surgery. A limitation of this study is that it was a noncomparative study. CONCLUSIONS Retrograde release of the neurovascular bundle with preservation of dorsal venous complex during RARP is safe and associated with excellent oncological and functional outcomes. Future comparative studies are needed. PATIENT SUMMARY Robot-assisted radical prostatectomy (RARP) presents consistent oncological outcomes for prostate cancer; yet continence and potency results are not uniform. We present a technical modification for RARP aiming to preserve the nerves and vascular structures anterior to the prostate. We evaluated 128 consecutive patients with clinically localized or locally advanced prostate cancer undergoing RARP with our modified technique of retrograde release of the neurovascular bundles with dorsal vein sparing. We have shown that this technique is safe, effective and associated with early recovery of continence and sexual function after surgery.


The Journal of Urology | 2017

PD66-01 RENAL CELL CARCINOMA WITH PERIRENAL FAT INVASION: IS PARTIAL NEPHRECTOMY AS GOOD AS RADICAL SURGERY?

Fabio Gallucci; Mauricio Cordeiro; João Alexandre Barbosa; Paulo Afonso de Carvalho; Henrique Nonemacher; Eder Ilario; Arnaldo Fazoli; Daniel Kanda Abe; Valter Cassao; Romulo Loss Mattedi; William Carlos Nahas

e16056Background: Partial nephrectomy (PN) is the standard of care in the management of cT1a tumors, while radical nephrectomy (RN) is indicated in more advanced tumors. Recent studies provided evi...

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Hiep T. Nguyen

Boston Children's Hospital

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Alan B. Retik

Boston Children's Hospital

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Miguel Srougi

University of São Paulo

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Brian M. Rosman

Boston Children's Hospital

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Jeanne S. Chow

Boston Children's Hospital

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Ghassan Barayan

Boston Children's Hospital

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Mario Paranhos

University of São Paulo

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