Pediatric sacral nerve stimulator explanation due to complications or cure: a survival analysis.

INTRODUCTION: Historically, there have been few treatment options for children with severe refractory bladder and bowel dysfunction (BBD). Sacral neuromodulation (SNM) continues to show promising results in this challenging pediatric population with recalcitrant lower urinary tract symptoms. At the authors institution, they have begun offering explantation to those with persistent improvement after >6 months of having device turned off. The authors hypothesized that (1) SNM explantation for cure increases with extended follow-up and (2) those explanted for cure would have improved symptoms and quality of life when compared to those explanted for complication. MATERIALS & METHODS: The authors retrospectively reviewed all consecutive patients aged <18 years who underwent SNM placements at their institution (2012-2017). They excluded those without the second stage procedure. Reasons for device explantation were categorized as cure (resolution of symptoms with the device turned off for at least 6 months) or a complication (e.g. infection, need for magnetic resonance imaging, or pain). Non-parametric tests and survival analysis were used for analysis to account for differential follow-up time. Of those explanted, surveys were electronically sent to assess BBD severity and overall quality of life. RESULTS: Of 67 children who underwent a first stage procedure, 62 (92.5%) underwent a second stage procedure. 61 met inclusion criteria (68.9% female, 29.5% with previous filum section, median age at implantation 10.3 years). During follow-up (median 2.3 years), 12 patients (19.7%) had the SNM exchanged/revised because of lead fracture/breakage and return of urinary symptoms. To date, 50 patients remain with their SNM implanted, and 11 have been explanted. Adjusting for follow-up time, the risk of explantation was 6.5% at 2 years (2.2% for cure, 4.3% for complications) (Figure 1). Explantation increased to 24.5% at 3 years (16.5% for cure, 8.0% for complications) and 40.4% at 4 years (32.4% for cure, 8.0% for complications). Questionnaires were collected on patients after explant (median 2.2 years), with improvement in those explanted for cure compared to complication (Figure 2). DISCUSSION: Sacral neuromodulation explantation for cure is a novel concept previously not described in the literature. Limitations of this study include the relatively small numbers and lack of objective data in the cohort that remains with SNM device implanted. CONCLUSION: Sacral neuromodulation is a safe, viable option for the pediatric patient with refractory bladder dysfunction. Furthermore, SNM explantation for cure is an option with increasing likelihood after 2 years.

Initial collection of an inadequate 24-hour urine sample in children does not predict subsequent inadequate collections.

INTRODUCTION: Approximately half of adult stone formers submit specimens that are either under or over collections as determined by 24-h creatinine/kg. Previously identified predictors of inadequate collection in adults include female sex, older age, higher body mass index (BMI), vitamin D supplementation, and weekday collection. OBJECTIVE: The objective of this study is to determine risk factors for inadequate 24-h urinary specimen collection in the pediatric population. STUDY DESIGN: A retrospective analysis of all children (<18 years of age) with renal and/or ureteral calculi evaluated at the study tertiary care pediatric center from 2005 to 2015 was performed. Those who had at least one 24-h urinary metabolic profile after a clinical visit for kidney and/or ureteral stones were included; children with bladder stones were excluded. Adequate collections had a urine creatinine of 10-15 mg/kg/24 h. A bivariate analysis of potential factors associated with inadequate collection of the initial urinary metabolic profile, including child demographics, parental socio-economic factors, history of stone surgery, and weekday vs. weekend urine collection, was performed. A mixed-effects logistic regression, controlling for correlation of specimens from the same patient, was also performed to determine whether an initial inadequate collection predicted a subsequent inadequate collection. RESULTS: Of 367 patients, 80 had an adequate collection (21.9%): median age, 13 years (interquartile range, 8-16); 61.1% female; 93.5% white; 19.5% obese; and 13.0% overweight. No parental or child factors were associated with inadequate collection (Summary Table). Of inadequate collections, more than 80% were over collections. In the 175 patients with more than one 24-h urinary specimen collection, the effect of an initial inadequate collection on subsequent inadequate collections was not significant after controlling for the correlation of samples from the same patient (p = 0.8). DISCUSSION: Any parental or child factors associated with the collection of inadequate 24-h urine specimens in children were not found. An initial inadequate collection does not predict subsequent inadequate collections. It was surprising that >80% of the inadequate collections were over collections rather than under collections. Possible explanations are that children collected urine samples for longer than the 24-h period or that stone-forming children produce more creatinine per 24-h period than healthy children due to hyperfiltration. CONCLUSION: Inadequate collections are very common, and the risk factors for them are unclear. A repeat collection would be suggested if the first is inadequate. Further studies must be planned to explore barriers to accurate specimen collection using qualitative research methodology.

The ability of a limited metabolic assessment to identify pediatric stone formers with metabolic abnormalities.

INTRODUCTION: American Urological Association guidelines recommend a urinary metabolic evaluation after the first stone event in all pediatric stone patients. Prior studies identified hypercalciuria and urine hypovolemia as the most common abnormalities in children with urolithiasis. Recent data suggest that hypocitraturia is most prevalent. It was hypothesized that a limited evaluation would detect the majority of clinically significant metabolic abnormalities in pediatric stone formers. MATERIAL AND METHODS: A retrospective analysis of all children (<18 years of age) with renal/ureteral calculi evaluated at the study institution from 2005 to 2015 was performed. Children with ≥ one 24-h urinary metabolic profile after a clinical visit for renal/ureteral calculi were included. Those with bladder stones and those with undercollection or overcollection or missing urinary creatinine were excluded. Demographics and data from the first urinary metabolic profile and stone analyses were collected. The sensitivity, specificity, and positive and negative predictive value (NPV) of a limited urinary metabolic evaluation consisting of four parameters (24-h calcium, citrate, and oxalate and low urinary volume) were compared to a complete urinary metabolic profile. The number and type of metabolic abnormalities that would have been missed with this limited evaluation weredetermined. RESULTS: Of 410 patients, 21 were excluded for age ≥18 years, 13 for bladder stones, 248 for overcollections, 38 for undercollections, and 10 for missing creatinine. This left 80 patients for inclusion: median age 11.4 years, 60% female, and 96.3% white. Of the entire cohort, 69.6% had hypocitraturia, 52.5% had low urine volume, and 22.5% had hypercalciuria. Sensitivity was 87.5%. Specificity could not be calculated because no patients had a normal complete metabolic evaluation. The NPV was zero, and the positive predictive value was 100%, but these are artifacts resulting from the absence of patients with a normal complete metabolic evaluation. Of the 80 patients, 10 had at least one abnormality missed by a limited metabolic evaluation (Table 1). The missed abnormalities were high pH (n = 6), abnormal 24-h phosphorus (low in 1 patient and high in 1 patient), low 24-h magnesium (n = 3), low 24-h potassium (n = 3), and high 24-h sodium (n = 4). DISCUSSION: A limited urinary metabolic evaluation would have detected the vast majority of clinically significant metabolic abnormalities in the study sample. Approximately two-thirds of the study patients submitted inadequate 24-h urine specimens. CONCLUSIONS: A simplified approach to metabolic evaluation in first-time stone formers with a stone analysis available was proposed. This streamlined approach could simplify the metabolic evaluation and reduce health care costs.

Incidence of pathologic postobstructive diuresis after resolution of ureteropelvic junction obstruction with a normal contralateral kidney.

INTRODUCTION: Postobstructive diuresis (POD) after unilateral pyeloplasty or percutaneous nephrostomy (PCN) tube insertion for ureteropelvic junction obstruction (UPJO) in patients with a normal contralateral kidney is not well described. OBJECTIVE: The objective of this study was to determine the incidence and characteristics of POD after relief of unilateral UPJO in patients with a normal contralateral kidney. STUDY DESIGN: Children who underwent a unilateral pyeloplasty or PCN for UPJO from 2010 to 2017 with a normal contralateral kidney were retrospectively reviewed. Postobstructive diuresis was defined as urine output (UO) of >300% of expected UO. Patients with a solitary kidney or those who underwent bilateral pyeloplasty or bilateral PCN tube placement were excluded. RESULTS: Out of 396 children meeting inclusion criteria, seven (1.8%) developed POD (4 after pyeloplasty and 3 after PCN tube placement). Median age at intervention was 1.7 years (range 11 days-18 years); median weight was 11.4 kg (range 3.7-54.2 kg). Postobstructive diuresis was more likely to occur in patients with grade 4 hydronephrosis (3.0%) and larger kidneys and if a PCN tube was placed before pyeloplasty. There was no significant difference in age, gender, kidney laterality, or function between those who developed POD and those who did not. Postobstructive diuresis was managed with additional intravenous fluids and electrolyte monitoring. Median initial postprocedure UO was 5.9 mg/kg/hr (range 3.2-10.0 mg/kg/hr). In five children who underwent PCN in whom UO could be differentiated between kidneys, median initial postprocedure UO was 6.1 mg/kg/hr (range 2.5-9.1 mg/kg/hr) from the affected side and 0.8 mg/kg/hr (range 0.4-0.9 mg/kg/hr) from the unaffected side. The median length of time to resolution of POD was 3 days (range 2-4 days). One patient developed significant acidosis and lethargy that improved with intravenous fluid management. Mild hyponatremia developed in two, hypokalemia in one, hypophosphatemia in one, acidosis in one, and hypoglycemia in 1 patient. DISCUSSION: A low but clinically significant risk of POD occurring after relief of unilateral UPJO in children with a normal contralateral kidney is described. Limitations include retrospective analysis and small sample size due to the rarity of the condition. CONCLUSION: Postobstructive diuresis after decompression of UPJO in patients with a normal contralateral kidney is a rare event (1.8%). However, POD does occur, and patients should be carefully monitored after these procedures given the potential for significant dehydration and electrolyte disturbances.

Early readmission and reoperation characteristics of ambulatory hypospadias repair.

INTRODUCTION AND BACKGROUND: Hypospadias is a common birth defect. It is present in about 34.2 in 10,000 live births in North America. However, few studies have evaluated the immediate reoperation and readmission rates following elective repair. OBJECTIVE: This study aimed to define the rates of readmission and reoperation following elective hypospadias repair, to improve pre-operative counseling on risks of the procedure. STUDY DESIGN: The Pediatric Health Information System (PHIS) was interrogated from 2004 to 2015 for all elective hypospadias repairs (ICD-9-CM code 58.45) performed in the ambulatory surgical setting. The following were then determined: age at initial operation, insurance status, race, presence or absence of readmission or reoperation within 30 days, presence of repeat hypospadias repair (same ICD-9 code), and presence or absence of another urethral operation (ICD-9 CM code 58.XX, excluding 58.45). Mixed effects logistic regression were then performed with dependent variables of 30-day repeat encounter, 30-day emergency department (ED) visit, 30-day readmission, or 30-day reoperation; and independent variables of age, race, ethnicity, and insurance status. RESULTS: The study identified 45,264 hypospadias repairs during 2004-2015 performed in 43 hospitals. Within 30 days of the procedures, 2826 (6.2%) had additional encounters in the ED at the same facilities, and 546 (1.2%) had readmissions. A total of 105 (0.2%) underwent second anesthetic within the first 30 days. With regards to a 30-day repeat encounter, odds of repeat encounter were significantly increased in patients aged <5 years, Black and Asian patients, and those with Medicaid. Of the 4882 repeat encounters, 954 (19.5%) had discharge ICD-9 codes related to the penis, or to postoperative complications in general. DISCUSSION: This study described the epidemiology of clinical events occurring at the same tertiary children's hospital within the first 30 days following more than 45,000 hypospadias repairs. Limitations included a cohort generated from a single set of ICD-9 codes. CONCLUSIONS: Elective hypospadias repair had a low rate of readmission (1.2%) and reoperation (0.2%) within the first 30 days. Patients aged <5 years, of non-white race, Hispanic ethnicity, and on Medicaid had significantly higher odds of 30-day repeat encounters.

Is surgical antibiotic prophylaxis necessary for pediatric orchiopexy?

INTRODUCTION: Surgeons frequently use surgical antibiotic prophylaxis (SAP), despite limited evidence to support its efficacy. Potential adverse events associated with antibiotic use include allergic reaction (including anaphylaxis), Clostridium difficile infection, and selecting for resistant bacteria. Surgical site infections (SSI) are very rare in patients undergoing clean pediatric urologic procedures. Current guidelines are unclear about the efficacy of surgical antibiotic prophylaxis for prevention of SSI in the pediatric population. OBJECTIVE: It was hypothesized that children who received SAP prior to orchiopexy would have no reduction in surgical site infection (SSI) risk but an increased risk of antibiotic-associated adverse events. METHODS: A retrospective cohort study was conducted of all males aged between 30 days and 18 years who underwent an orchiopexy (ICD-9 CM 62.5) in an ambulatory or observation setting from 2004 to 2015 using the Pediatric Health Information System database. Inpatients and those with concomitant procedures were excluded. Chi-squared or Fisher's exact tests were used to determine the association between SAP and allergic reaction (defined as a charge for epinephrine or ICD-9 diagnosis code for allergic reaction on the date of surgery) and any of the following within 30 days: SSI, hospital readmission or any repeat hospital encounter. Mixed effects logistic regression was performed, controlling for age, race, and insurance, and clustering of similar practice patterns by hospital. RESULTS: A total of 71,767 patients were included: median age was 4.6 years, 61.4% were white, and 49.3% had public insurance; 33.5% received SAP. Of these participants, 996/71,767 (1.4%) had a perioperative allergic reaction and <0.1% were diagnosed with an SSI. On mixed effects logistic regression, those who received SAP had 1.2 times the odds of a perioperative allergic reaction compared with those who did not receive SAP (P = 0.005). Surgical antibiotic prophylaxis was not associated with decreased rates of SSI, lower hospital readmission, nor a lower chance of a repeat encounter within 30 days. CONCLUSIONS: In patients undergoing orchiopexy, it was found that SAP did not reduce the risk of postoperative SSI, readmissions, or hospital visits. Patients who received SAP had significantly increased odds of perioperative allergic reaction. This demonstrated that the risks of SAP outweigh the benefits in children undergoing orchiopexy.

Is renal scintigraphy necessary after heminephrectomy in children?

INTRODUCTION: Heminephrectomy remains an excellent option for a poorly functioning moiety in a duplicated collecting system. A primary concern during heminephrectomy is the potential for a significant functional loss in the remaining ipsilateral moiety. As the gold standard for the assessment of differential renal function, renal scintigraphy is often used in the postoperative evaluation of children undergoing heminephrectomy. However, this imaging modality is costly, invasive, and associated with exposure to radiation. Doppler renal ultrasound (RUS) avoids these concerns and is able to evaluate for structural and functional abnormalities. OBJECTIVE: The present study sought to compare Doppler RUS to renal scintigraphy in determining the viability of the remaining ipsilateral moiety in children who underwent heminephrectomy for a poorly functioning moiety in a duplicated collecting system. MATERIALS AND METHODS: The institutional database of children who underwent open heminephrectomy for a poorly functioning moiety in a duplicated collecting system between 2006 and 2013 was reviewed. Only children who underwent both a postoperative Doppler RUS and renal scan were included. A blinded pediatric radiologist independently reviewed all Doppler RUS. Vascular flow on Doppler RUS was correlated with the preservation of renal function in the remaining ipsilateral moiety on renal scintigraphy. RESULTS: A total of 29 children were identified for inclusion. Demographic and operative data are provided in Table. The average pre-operative and postoperative differential renal function in the ipsilateral kidney was 41.6% and 38% on renal scintigraphy, respectively, for an average decrease of 3.6% (-18% to +12%). Doppler RUS demonstrated the presence of vascular flow to the remaining ipsilateral moieties of all children after heminephrectomy. Renal scintigraphy confirmed the viability of these moieties in all children. DISCUSSION: The first study comparing Doppler RUS to renal scintigraphy was performed to determine the viability of the remaining ipsilateral moiety after heminephrectomy. While no cases of complete functional loss were observed, an average decrease of 3.6% in the ipsilateral renal function favorably compared with other series of children undergoing open heminephrectomy. The limitations of the study included its retrospective design at a single institution. The interpretation of Doppler RUS by an individual pediatric radiologist may also have lead to interobserver variability and impacted the reproducibility of the study, while the absence of any cases of complete functional loss may have impacted its generalizability. CONCLUSIONS: Doppler RUS is an accurate imaging modality for determining the viability of the remaining ipsilateral moiety after heminephrectomy and may obviate the need for renal scintigraphy.

A comparison of the Monti and spiral Monti procedures: A long-term analysis.

INTRODUCTION/BACKGROUND: The Monti ileovesicostomy provides an excellent substitution for an appendicovesicostomy when the appendix is unavailable or suitable for use. The spiral Monti is a useful modification to the traditional Monti as it allows creation of a longer channel when needed. In 2007, the short-term outcomes were reported; they compared traditional and spiral Monti in 188 patients with an average follow-up of 43 months. In the present population, a total of 25 subfasical revisions were performed in 21 patients: nine (8.3%) subfascial revisions in the traditional Monti (TM) patients and 12 (15.2%) subfascial revisions in the spiral Monti (SM) patients. The study found an increased risk of subfascial revisions of either TM or SM when the stoma was located at the umbilicus versus right lower quadrant (16.8% vs 6.3%, P < 0.05). On subgroup analysis, this increased subfascial revision rate appeared to be driven by SM channels to the umbilicus rather than other stomal locations, but this trend was not statistically significant. OBJECTIVE: It was hypothesized that with longer follow-up, the spiral Monti would require more subfascial revisions due to progressive lengthening of the channel. STUDY DESIGN: A retrospective chart review was performed for all patients undergoing a traditional Monti (TM) or spiral Monti (SM) procedure at the present institution (1997-2013). Patient demographics, bowel segment used, stomal location, channel or stomal revisions, number of anesthetic endoscopic procedures performed, and indications for revision were reviewed. Kaplan-Meier analysis and Cox proportional hazards modeling was used for analysis. RESULTS: Of the 296 patients identified, 146 had Monti procedures and 150 had spiral Monti procedures (median follow-up 7.7 years). Median age at surgery was 10.6 years. Myelomeningocele was the most common underlying cause of neuropathic bladder, totaling 169 (57.1%) patients. Stomas were located at the umbilicus (106, 35.8%), right lower quadrant (183, 61.8%) and left lower quadrant (seven, 2.4%). Median follow-up for the entire cohort was 7.7 years (range: 1 month-15.7 years). Stomal stenosis rate was 7.4%, and 96.6% of the channels were continent. A total of 87 revisions were performed in 74 patients (25.0%). Of these, 55 were subfascial revisions in 49 patients (16.6%). The umbilical spiral Monti on univariate and multivariate analysis was found to be over twice as likely to undergo subfascial revision. DISCUSSION: The majority of patients with a Monti channel had durable results and did not require further channel surgery with long-term follow-up. Spiral Monti channels to the umbilicus were more than twice as likely to undergo subfascial revision compared to all other Monti channels. Overall, one in three umbilical SM channels required a subfascial revision at 10 years after the initial surgery, compared to one in six of all other Monti channels. The study was limited by being a retrospective, single-center series; however, it does represent the largest series of pure SM and TM patients. It focused only on surgical interventions, thus was likely to underestimate the overall risk of complications, as some complications were managed conservatively. As in all studies, some patients were lost to follow-up and inevitably some of these may have had complications. Correction for this was attempted through survival analysis. CONCLUSION: The present study reported durable and reliable long-term results with Monti and spiral Monti procedures based on a large patient cohort. Spiral Monti to the umbilicus was more than twice as likely to require a subfascial revision.