Waifro Rigamonti

Selective Decrease in Urinary Aquaporin 2 and Increase in Prostaglandin E2 Excretion Is Associated with Postobstructive Polyuria in Human Congenital Hydronephrosis

This study was undertaken to determine the role of aquaporin 2 (AQP2) in the impaired urinary concentrating capacity observed in patients who underwent pyeloplasty because of congenital unilateral hydronephrosis as a result of pyeloureteral junction disease. Twelve children (mean age, 8 +/- 2 mo) were examined in the study. From day 1 to day 5 after surgery, the urine was collected separately from pyelostomy draining only from the postobstructed kidney and from the bladder catheter draining mostly from the contralateral kidney used as internal control. After pyeloplasty, the postobstructed kidney was characterized by a reduced urinary excretion of AQP2 (approximately 54%) associated with polyuria that persisted from day 1 to day 5 (433 +/- 58 versus 310 +/- 74 ml/24 h at day 1; 326 +/- 44 versus 227 +/- 26 ml/24 h at day 5). In parallel, urine osmolality from the postobstructed kidney was significantly reduced compared with the contralateral kidney (111 +/- 12 versus 206 +/- 49 at day 1; 136 +/- 24 versus 235 +/- 65 mOsm/kg at day 5). Creatinine clearance from the postobstructed kidney was not significantly different compared with the contralateral kidney throughout the 4 d after surgery. However, on day 5, creatinine clearance from the postobstructed kidney became significantly lower. Prostaglandin E2 in the urine from postobstructed kidneys was found to be twofold higher than in the contralateral samples (26.0 +/- 6.7 versus 13.5 +/- 2.5 at day 5). It is concluded that (1) the selective downregulation of AQP2 in postobstructed kidney may account for the higher excretion of hypotonic urine, and (2) the local increase in prostaglandin E2 synthesis in postobstructed kidney may be involved in AQP2 downregulation and in maintaining a GFR similar to that of the contralateral kidney.

Failed hypospadias in paediatric patients

Failed hypospadias refers to any hypospadias repair that leads to complications or causes patient dissatisfaction. The complication rate after hypospadias repairs ranges from 5–70%, but the actual incidence of failed hypospadias is unknown as complications can become apparent many years after surgery and series with lifelong follow-up data do not exist. Moreover, little is known about uncomplicated repairs that fail in terms of patient satisfaction. Risk factors for complications include factors related to the hypospadias (severity of the condition and characteristics of the urethral plate), the patient (age at surgery, endocrine environment, and wound healing impairment), the surgeon (technique selection and surgeon expertise), and the procedure (technical details and postoperative management). The most important factors for preventing complications are surgeon expertise (number of cases treated per year), interposition of a barrier layer between the urethroplasty and the skin, and postoperative urinary drainage. Major complications associated with failed hypospadias include residual curvature, healing complications (preputial dehiscence, glans dehiscence, fistula formation, and urethral breakdown), urethral obstruction (meatal stenosis, urethral stricture, and functional obstruction), urethral diverticula, hairy urethra, and penile skin deficiency.

Bladder urothelial neoplasms in pediatric age: Experience at three tertiary centers

INTRODUCTIONnUrothelial bladder neoplasms (UBN) typically occur in patients in their sixth or seventh decade of life while they are infrequent in children and young adults. They occur in 0.1-0.4% of the population in the first two decades of life. Their management is controversial and paediatric guidelines are currently unavailable.nnnOBJECTIVEnTo further expound the available data on the outcome of patients younger than 18 year old diagnosed with UBN.nnnSTUDY DESIGNnWe retrospectively reviewed the files of all the consecutive paediatric patients with UBN treated in three tertiary paediatric urology units from January 1999 to July 2013. Lesions were classified according to the 2004 WHO/ISUP criteria as urothelial papillomas (UP), papillary urothelial neoplasm of low malignant potential (PUNLMP), low-grade urothelial carcinoma (LGUC), and high-grade urothelial carcinoma (HGUC).nnnRESULTSnThe table shows the results. Management after TURB varied among centres. One centre recommended only follow-up US at increasing intervals whereas another follow-up US plus urine cytologies and endoscopies, every three months in the first year, and at increasing intervals thereafter. After a median follow-up of 5 years (range 9 months-14.5 years), none of the patients showed disease recurrence or progression.nnnDISCUSSIONnUBN is an uncommon condition in children and adolescents and, unlike in adults, its incidence, follow-up and outcome still controversial. Paediatric guidelines are currently lacking and management varies among centres. Gross painless haematuria is the most common presenting symptom. Therefore, this symptom should never be underestimated. US is generally the first investigation and additional imaging seems unnecessary. TURB often allows for complete resection. Lesions are generally solitary, non-muscle invasive, and low-grade (mainly UP and PUNLMP). Ideal follow-up protocol is the most controversial point. Reportedly, recurrence or progression during follow-up is uncommon in patients under 20 years, recurrence rate 7% and a single case of progression reported so far. Accordingly, a follow-up mainly based on serial US might be considered in this age group compared to adults where also serial endoscopies and urine cytologies are recommended. In the selection of the follow-up investigations, it should also be taken into consideration that urine cytology has a low sensibility in the detection of low-grade lesions while cystoscopy in young patients requires a general anaesthesia and hospitalization, and carries an increased risk of urethral manipulation.nnnCONCLUSIONnUBN is a rare condition in children. Ultrasound is generally accurate in order to visualize the lesion, and TURB can treat the condition. Lesions are generally low-grade and non-muscle invasive, but high-grade lesions can also be detected. In present series, after TURB, follow-up US monitoring at increasing intervals was used at all centres, follow-up cystoscopies were added in two centres, but with different schedules. Urine cytologies were considered only at one centre. After a median follow-up of 5 years (range 9 months-14.5 years), none of the patients showed recurrence or progression of the disease.

Upper Urinary Tract Infections Are Associated with RANTES Promoter Polymorphism

We evaluated the association between MCP-1, CCR2, RANTES, and CCR5 gene polymorphisms and upper urinary tract infection in 273 children recruited in Northeast Italy. Statistical analysis of RANTES-403 G>A genotype frequencies showed that children carrying the RANTES-403 G allele are at higher risk for urinary tract infection, irrespective of vesicoureteral reflux.

Antibiotic prophylaxis in antenatal nonrefluxing hydronephrosis, megaureter and ureterocele

Observation is a conservative management option in infants with nonrefluxing hydronephrosis, primary nonrefluxing megaureter and ureterocele diagnosed postnatally following antenatal detection of hydronephrosis. Antibiotic prophylaxis might be a sensible regimen under these circumstances to prevent UTI in this population who are potentially at increased risk. However, studies examining the efficacy of prophylactic antibiotics are sparse in this setting. For each condition, prophylactic policies seem extremely variable, and UTI rates vary widely with comparable rates reported between patients followed on and off antibiotics. Overall, antibiotic prophylaxis seems unnecessary in patients with isolated low-grade hydronephrosis. Patients with high-grade nonrefluxing hydronephrosis seem at increased risk of UTI, with risk further increasing in patients with associated ureteral dilatation (hydroureteronephrosis) irrespective of the presence of a ureterocele. Obstruction might be an additional independent risk factor, but the diagnosis of obstruction is often possible only in retrospect. The data available suggest that infants are the most at risk of UTI during the first 6 months of life, particularly if they undergo catheterization during workup examinations. Thus, antibiotic prophylaxis might be prudent during the first 6–12 months of life in patients with high-grade hydronephrosis and hydroureteronephrosis with or without ureterocele, and particularly before completion of the diagnostic workup. Paediatric urologists are urged to embark on controlled trials to compare patients followed with and without antibiotic prophylaxis.

Complications of trans-anastomotic externalised stents in open pyeloplasty: influence of the method of placement, the duration of stenting, and the associated bladder drainage

PurposeTo assess the influence of the method for stent placement, the duration of stenting, and the presence of bladder drainage on the complication rate of open pyeloplasty.Patients and methodsComplications were, retrospectively, compared in 228 consecutive open pyeloplasties performed at institution A using a trans-pyelostomic 6-Fr splint/stent for 5xa0days and no bladder drainage, and 150 consecutive open pyeloplasties performed at institution B using a trans-nephrostomic 6-Fr splint/stent for 9xa0days plus bladder drainage.ResultsMedian age at surgery was comparable between groups. The overall complication rate was 13% and was comparable at the two institutions, but for the presence of perioperative bleeding that was more common when the stent was placed trans-nephrostomically (institution B) and the rate of stent dislodgements, which was lower at institution A, perhaps due to some technical details aiming to prevent any inadvertent traction on the stent. Additional procedures, such as double J internal stent insertion, were required in <2% of cases.ConclusionsA 5-day period of stenting after open pyeloplasty is generally enough. Trans-nephrostomic and trans-pyelostomic stent placement is equally effective. However, the former can be associated with a slightly higher bleeding rate. Details during stent placement are keys to avoid postoperative dislodgement and malfunctioning. Systematic bladder drainage seems unnecessary.

Dismembered extravesical reimplantation of dilated upper pole ectopic ureters in duplex systems.

PURPOSEnWe report the results in patients with obstructed upper pole ectopic ureters in duplex systems undergoing dismembered extravesical reimplantation of the upper pole ureter alone.nnnMETHODSnBetween 01/2007 and 03/2012, 11 patients with an upper pole ectopic ureter (1 bilateral) diagnosed following the antenatal detection of hydronephrosis and showing preserved function on renal scintigraphy in a dilated upper moiety, underwent a dismembered reimplantation of the ectopic upper pole ureter as follows. The ureter was identified, separated from the lower pole ureter, and divided just above the bladder. The distal stump was suture closed, while the proximal segment was mobilized, tapered as necessary, and reimplanted using an extravesical technique.nnnRESULTSnTwelve ectopic ureters were reimplanted. Median (range) patient age at surgery was 8 (3-48)months. Ureteral tapering was performed in 11 ureters, by infolding in 9 and using an excisional tailoring in the single case undergoing bilateral reimplantation. After a median (range) follow-up of 17 (6-50)months, all patients were asymptomatic. Eleven reimplanted ureters showed improving hydroureteronephrosis, no obstruction on diuretic scintigraphy, and no evidence of reflux on indirect radionuclide cystography. One reimplanted ureter developed worsening hydroureteronephrosis after excisional tailoring of the ureter and partial nephrectomy was performed.nnnCONCLUSIONSnExtravesical reimplantation of the upper pole ureter is an option in dilated upper pole ectopic ureters with good function. Separating the upper and lower pole ureters proximally to the bladder does not jeopardize the ureteral blood supply and allows leaving the lower pole ureter undisturbed. Excisional ureteral tailoring should be avoided.

Preputial reconstruction in hypospadias repair

OBJECTIVEnIn principle, the prepuce can be reconstructed during hypospadias repair, but the procedure has not gained wide acceptance and preputial reconstruction (PR) is surrounded by several controversies.nnnMATERIAL AND METHODSnA review is provided of the technique for PR, how PR combines with the other steps of hypospadias repair, the risks of complications related to the urethroplasty and specific to PR, and the results of PR with particular regard to the relevance for the patient and his family.nnnRESULTSnPR can be important for patients requiring hypospadias repair and their parents. It can be performed in almost all patients with distal hypospadias except perhaps those with the most asymmetrical prepuces or severe ventral skin deficiency. PR does not seem to increase urethroplasty complications, but combination of PR with tubularisation of the urethral plate urethroplasty seems to offer the best chance of success. Specific complications occur in around 8% of patients and include partial or complete dehiscence of the prepuce and secondary phimosis. To prevent the latter, the reconstructed prepuce should be easily retractile at the end of surgery. Technical modifications can help to achieve this goal. Cosmetically, reconstructed prepuces are not fully normal, but the abnormality could be less important for a patient and his parents that the complete absence of the prepuce.nnnCONCLUSIONnOn the basis of the evidence summarised above, an algorithm for PR in patients with distal hypospadias is proposed. PR can be offered to the vast majority of distal hypospadias patients, although some modification of the technique for hypospadias repair can be required. Retractility of the reconstructed prepuce at the end of surgery seems paramount for final success.