Papers by Santiago Weller
The Journal of urology/The journal of urology, May 1, 2024
International braz j urol
Introduction: Dismembered open pyeloplasty described by Anderson and Hynes is the "gold standard"... more Introduction: Dismembered open pyeloplasty described by Anderson and Hynes is the "gold standard" for the treatment of ureteropelvic junction obstruction. The aim of our study was to compare the results of open (OP) vs laparoscopic (LP) vs robotic (RALP) pyeloplasty. Material and Methods: A multicenter prospective review was conducted of pyeloplasty surgeries performed at five high-volume centers between 2014 and 2018. Demographic data, history of prenatal hydronephrosis, access type, MAG3 renogram and differential renal function, surgery time, length of hospital stay, and complication rate (Clavien-Dindo) were recorded. Access type was compared using the Kruskal-Wallis, Chi-square, or Fisher's exact tests. Results: A total of 322 patients were included: 62 OP, 86 LP, and 174 RALP. The mean age was 8.13 (r: 1-16) years, with a statistically significant lower age (mean 5 years) in OP (p < 0.001). There were no significant differences in the distribution of the side affected. Operative time was 110.5 min for OP, 140 min for LP, and 179 min for RALP (p < 0.0001). Hospital stay was significantly shorter in the RALP group than in the other groups (p < 0.0001). There were no differences in postoperative complications and reoperations between the three groups. Conclusions: Minimally invasive surgery for the management of UPJO in children is gaining more acceptance, even in patients younger than 1-year-old. Operative time continues to be significantly shorter in OP than in LP and RALP. Hospital stay was shorter in RALP compared to the other techniques. No differences were found in complication rates, type of complications, and reoperation rate.
Journal of Pediatric Urology
The proactive management of spina bifida (SB), especially of its severe form, myelomeningocele (M... more The proactive management of spina bifida (SB), especially of its severe form, myelomeningocele (MMC), has contributed to decreasing chronic kidney disease (CKD). The objective of this study is to present the evolution of 5-year-old patient with MMC followed from birth with a proactive approach. This retrospective study included 55 cases with MMC of up to 5 years of age. All of them were admitted at birth and followed by a multidisciplinary group, with a proactive approach: CIC and anticholinergics. In the same group, the variables were compared within the first year and the within the fifth year of life. Chronic kidney disease (CKD) was defined by: alterations on renal DMSA scintigraphy; alterations in microalbuminuria/creatininuria ratio, proteinuria 24 hs and decrease in glomerular filtration rate (GFR) calculated with Schwartz bedside equation. Although overactivity, UTI and VUR decreased throughout the first 5 years (49, 9 and 12%), reduced cystometric capacity, DLPP >40 cm of water and end-filling pressure (Pdet) >20 cm of water increased (41, 27 and 61%). All patients at 5 years of age required CIC. Reduced cystometric capacity and VUR were more significant with abnormal DMSA (36%) at 5 years old ( p: 0.03). Proteinuria and CKD increased to 25% and 49%. Similarly, the need for enalapril increased from 10% to 27%. The microalbuminuria/creatininuria ratio was pathological in 27.3%. 48 patients (87%) remained unchanged on DMSA scan and the other 7 underwent modifications (4 new cases with altered DMSA) over time. Of the 32 normal DMSA cases without changes, 81% did not present proteinuria and 88% continued to respond favorably to oxybutynin. GFR <90 ml/min/1.72m 2 was found in only 3 cases with abnormal DMSA. There was a RR 1.91 (IC95% 1.15-3.16) greater of renal compromise in cases that were anticholinergic-resistant compared to non-refractory cases. Over time, some patients suffered loss of bladder wall compliance, despite the proactive approach. There is an association between abnormal renal DMSA, reduced bladder capacity, and VUR at 5 years of age. Although proteinuria, CKD and enalapril requirement increased over 5 years, almost 90% did not show changes in renal DMSA status. Over time, some patients suffered loss of bladder wall compliance. Hence, even if a proactive approach is followed since birth, it is essential to continue with the ongoing monitoring of the renal status and thus avoid greater renal deterioration.
Journal of Pediatric Urology, 2021
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
In 1954 Murray performed the first truly successful pediatric kidney transplant from one homozygo... more In 1954 Murray performed the first truly successful pediatric kidney transplant from one homozygous twin to another (Murray et al., 1958). In 1966 Kelly reported a kidney transplantation in a patient with dysfunctional bladder who had undergone ileal segment urinary diversion (Kelly et al., 1966). Until that time, patients with ESRD and untreatable dysfunctional urinary tract were excluded from renal transplant programs. At that time, it was believed that the renal allograft connected to a dysfunctional bladder would run the same risk as the native kidneys, that is, the result would be again renal insufficiency (Sheldon et al., 1994).
Videoscopy, 2020
Introduction: Minimally invasive urologic surgery has a challenging learning curve. The developme... more Introduction: Minimally invasive urologic surgery has a challenging learning curve. The development of a simulation surgical training program has become an essential tool in the pediatric urology fellowship program. The aim of this video is to present our initial experience with specific pediatric urology low cost models introduced in the ''Gruyere'' trainer. 1 Materials and Methods: We developed four different models: laparoscopic pyeloplasty, extravesical ureteral reimplantation, Mitrofanoff apendicovesicostomy, and ureteroureteral anastomosis. 2,3 All the models are created using three-dimensional (3D) printed organs, inner mesh, and synthetic gel. They are all introduced and fixed in the same training box. A covering transparent film is used to resemble the peritoneum. Results: This trainer allows the practice of all the main steps in each procedure specially refining delicate suturing in small spaces. All these models are portable and easy to carry. A detailed tutorial of material, steps of each procedure, and evaluation sheet has been designed to facilitate its use.
Urology, 2021
OBJECTIVE To analyze the outcomes of patients undergoing upper-pole heminephrectomy surgery and t... more OBJECTIVE To analyze the outcomes of patients undergoing upper-pole heminephrectomy surgery and to assess the different variables that may have an impact on outcome, specifically regarding morbidity and the need for further surgeries. METHODS A retrospective study of patients who underwent laparoscopic upper-pole heminephrectomy for a non-functional moiety between August 2007 to December 2019 was conducted at three centers. 130 patients met the inclusion criteria. A transperitoneal approach was used. The following variables were evaluated: a) preoperative: presentation, presence of ureterocele and history of ureterocele incision, hydronephrosis grade, presence of VUR, and DRF on renal scintigraphy; and b) postoperative outcomes: Doppler ultrasound, renal scintigraphy, complications, fUTI, LUTS, and need for further surgery. Findings were considered statistically significant at p <0.05. RESULTS Postoperative complications were observed in five patients (3.8%). Six patients (4.6 %) needed further surgeries after heminephrectomy. The presence of ureterocele and VUR was related with the need for further surgeries (OR 4.91 - p 0.0415) and the occurrence of postoperative fUTI (OR 2.81 -p 0.0376). A 13.9% incidence of LUTS was found with no difference between patients with ureterocele and those with an ectopic ureter. Renal scintigraphy showed a median decrease in DRF of 2.7%. No patient had complete loss of function. CONCLUSION Laparoscopic upper-pole heminephrectomy showed to be a feasible and safe procedure. In most patients this surgery will be the definitive procedure. Patients with both VUR and ureterocele will need special consideration. No significant loss of function in the remaining lower moiety was found.
Urology, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of Pediatric Urology, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of Pediatric Surgery, 2020
Preserving renal function and achieving urinary continence are the most important urological goal... more Preserving renal function and achieving urinary continence are the most important urological goals in the management of cloaca patients. Many prognostic factors have been described, such as the length of the common channel (CC) and urethra, the presence of spinal dysraphism, and associated urological anomalies. The aim of this study was to analyze urinary continence status and need for reconstructive procedures and their correlation with urological risk factors in a series with a long-term follow-up. Material and methods: The institutional database of patients with anorectal malformations was reviewed. Patients with cloaca who underwent cloacal reconstructive surgery at our institution between January 1995 and May 2015 and who had a minimum postoperative follow-up of 5 years with complete urological care were included. Urologic and spinal anomalies, length of the CC, renal function, urodynamic study patterns, continence status, and urologic reconstructive surgeries were assessed. A CC was defined as long CC when its measure was longer than 3 cm in the cloacogram and then confirmed by cystoscopy. Descriptive statistical analysis was performed. Results: Fifty-five cloaca patients with a mean follow-up of 12 years (5-20) were included. A long CC was documented in 38 patients (69%). The sacral ratio (SR) was b0.4 in the AP projection in 30 (54.5%). Urodynamic evaluation revealed an inadequate detrusor contraction pattern in 65.4% of the cases. A CC N3 cm and SR b 0.4 were significantly correlated with this urodynamic finding. A total of 50 patients (91%) achieved urinary continence, but only 30.9% had volitional voiding and 56% needed major urological reconstructive surgeries. Eighteen patients (32.7%) were in stage 2 or more of chronic kidney disease (b 90 ml/min/1.73 m2) at the last follow-up visit. Conclusion: Cloacal management requires a multidisciplinary and long-term follow-up. Early assessment of prognostic urological factors and accurate stratification of each patient are essential to avoid renal impairment and achieve urinary continence in the future. The length of the common channel and the presence of spinal dysraphism were correlated with the presence of neurovesical dysfunction specifically an abnormal bladder contraction efficiency. A significant number of these patients will need catheterization and reconstructive urinary tract surgeries to attain urinary continence. Type of study: Retrospective study. Level of evidence: Level 3. Retrospective comparative study.
Urology, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of Pediatric Urology, 2017
Discussion: Almost all the children in this sample population showed urinary dysfunction, and app... more Discussion: Almost all the children in this sample population showed urinary dysfunction, and approximately half of them had high-risk videourodynamic findings. Although many cases showed reflex urinary contractions, almost the entire sample had inefficient bladder voiding. An important limitation of this work was the lack of simultaneity in obtaining each of the requested studies. In the initial urological evaluation of patients with myelomeningocele, almost all the urodynamic studies showed abnormalities and one-third showed abnormal DMSA, which led to therapeutic actions being initiated, although imaging studies were normal in a great number of patients. CIC alone, starting immediately after birth, is not sufficient. To eliminate or decrease upper tract damage, oxybutynin should be started in addition.
Frontiers in Pediatrics, 2017
We compare open pyeloplasty (OP) versus laparoscopic pyeloplasty (LP) in children in a multicente... more We compare open pyeloplasty (OP) versus laparoscopic pyeloplasty (LP) in children in a multicenter, prospective, case-control study. Materials and methods: From May 2007 to March 2009, a program was established at Hospital Garrahan, the reference center, to perform LP with a mentoring surgeon that would attend the institution once a month. Every new case of ureteropelvic junction obstruction (UPJO) diagnosed in the reference institution was offered to participate in the study. If the patient was enrolled, it was scheduled for LP. The following patient diagnosed with UPJO was operated on with open technique and served as a case-control. In three other facilities, patients were only offered LP and had a matched control open case at the reference institution. The first end point of the study was patient recovery: analgesia requirement and length of hospitalization (LOH). The second end point of the study was resolution of UPJO in long-term follow-up for the two techniques. Demographic data, surgical time, perioperative complications, analgesia requirement, analgesia score during hospitalization, LOH, and outcome were recorded. Both groups received the same postoperative indications for pain control. Parents were asked to assess pain in their children every 4 h postoperatively and to complete a pain scale chart to which the nurses were blinded. results: Fifteen OP and 15 LP were compared. Groups were similar with regard to sex, age, weight, and laterality. Mean surgical time was longer in LP than in OP group (mean 188 versus 65 min) (p < 0.01). Hospitalization was shorter for LP group with a mean of 1.9 versus 2.5 days for OP group (p < 0.05). Postoperative analgesia requirement was significantly higher in the OP group with a mean use of morphine of 1.7 versus 0.06 mg/ kg in the LP group (p < 0.05). Pain scores were similar in both the groups. At a mean follow-up of 58 months there were no failures.
Renal Transplantation - Updates and Advances, 2012
Journal of Pediatric Surgery, 2015
Background/purpose: It is still under discussion which is the best tissue augmenting substance fo... more Background/purpose: It is still under discussion which is the best tissue augmenting substance for the endoscopic treatment of children with vesicoureteral reflux (VUR). We describe our preliminary experience (September 2009-November 2011) with polyacrylate-polyalcohol copolymer hydrogel (PPCH). Methods: This is an observational, descriptive, prospective study which included 81 female and male patients (age 1-14 years) diagnosed with unilateral (n = 45) and bilateral (n = 36) primary VUR comprising a total of 117 refluxing renal units (RRU). Complex cases were excluded from the study. All patients were clinically and radiologically evaluated and those who met the inclusion criteria were treated endoscopically with a single subureteral injection of PPCH by a single surgeon. 11 patients (13.5%) had a pathological 99mTc-DMSA before treatment. The volume of injected product was measured in all cases. Results were considered successful if 6 months postinjection, conventional voiding cystourethrogram (VCUG) revealed VUR was cured (Grade 0). Follow-up ranged from 7 to 32 months. Results: The overall resolution rate based on the number of RRUs studied was 92.3% (108/117). The mean injected volume of PPCH per patient was 0.6 ml. One patient with obstructive anuria required vesicoureteral reimplantation. Other complications were persistent, self-limiting hematuria (n = 2); lumbar pain (n = 4) and urinary tract infection with normal VCUG (n = 4). Conclusions: Our short term data show PPCH provides a high level of reflux resolution in selected patients. Long term follow-up is required.
ISRN Urology, 2012
When the neurogenic bladder is refractory to anticholinergics, botulinum toxin type A is used as ... more When the neurogenic bladder is refractory to anticholinergics, botulinum toxin type A is used as an alternative. The neurotoxin type A reduces bladder pressure and increases its capacity and wall compliance. Additionally, it contributes to improving urinary continence and quality of life. This novel therapy is ambulatory with a low incidence of adverse effects. Due to its transitory effect, it is necessary to repeat the injections in order to sustain its therapeutic effect. In these review article we talk about Mechanism of Action, Indications, effects, administration and presentations of the Botulinum Neurotoxin Type A in pediatric patients. Also, we make references to controversial issues surrounding its use. A bibliographic search was done selecting articles and revisions from Pubmed. The key words used were botulinum toxin A, neurogenic bladder, and children. The search was limited to patients younger than 18 years of age and reports written in English in the past ten years.
Pediatric Surgery International, 2010
To determine whether surgical procedures of the lower urinary tract in patients with uropathies a... more To determine whether surgical procedures of the lower urinary tract in patients with uropathies affect evolution of the graft in renal transplantation. 156 kidney transplantations were performed in 150 patients with end-stage renal failure due to urologic disorders. The patients were classified into three groups: A, patients who did not require surgery in the lower urinary tract; B, required surgery and preserved adequate bladder function, and C, required surgery due to vesical dysfunction. Graft survival rates at 1 year were 93.38% in group A, 95.45% in group B and 93% in group C. Rates at 5 years post-transplantation were 82.45, 79.85 and 86.58% for each group, respectively (not significant). Complications were vesicoureteral stenosis: 2 in group A, 3 in B and 1 in C; vesicoureteral reflux: 1 in group A, 1 in B and 10 in C; distal ureteral necrosis: 2 cases in group A, 2 in B and 1 in C; upper urinary tract infection: 12, 23.1 and 42.2% in each group, respectively. Children with reconstructed urinary tract may be good candidates for kidney transplantation despite the higher frequency of urinary infections. Thus, careful and strict post-surgical urologic follow-up is mandatory.
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Papers by Santiago Weller