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Brent W Snow

Publications and source records attributed to Brent W Snow.

12 recordsLinked to original sources
PubMed2006

Has the growth and development of subspecialization in pediatric urology affected scholarly activity?

PURPOSE: How has academic productivity changed in a decade in the American Academy of Pediatrics Section on Urology? Do academic pursuits slow as section members become older? What is the average number of publications yearly by section members? What percent of research is funded in pediatric urology? Has change occurred with multiple authorships? MATERIALS AND METHODS: American Academy of Pediatrics Urology Section active memberships for 1993 and 2003 were obtained. A PubMed study was performed by reviewing all manuscripts published by American Academy of Pediatrics Section on Urology active members for 1991 to 1993 and 2001 to 2003. The data recorded were author, year, PubMed identification number, the number of authors, financial support and journal. Parametric and nonparametric statistics were used for analysis. RESULTS: In the 1991 to 1993 era there were 245 active members, of whom 145 published a total of 972 manuscripts. There were 604 clinical authorships, 161 basic science articles, 42 reviews and 186 case reports, of which 154 manuscripts received funding. In the 2001 to 2003 era there were 252 members, of whom 177 published a total of 1,152 manuscripts. There were 773 clinical authorships, 140 basic science articles, 107 reviews and 124 case reports, of which 151 manuscripts receiving funding. For members in the 2 periods the mean number of articles decreased by 1.0 from 1 decade to the next (p = 0.002). CONCLUSIONS: Scholarly pursuit of pediatric urology as a subspecialty has remained remarkably steady, averaging about 2 authorships per author yearly in the recent decade. The percent of authorships with funding in pediatric urology has decreased. The number of funded authorships has remained steady. A higher percent of American Academy of Pediatrics members have published manuscripts in the last decade. More manuscripts were published during the last decade study period than during the prior decade. The mix of manuscript types has changed with more reviews, and fewer case reports and basic science authorships in the most recent decade. New members are more likely to publish with a low unpublished percent.

Bibliometrics↗
PubMed2006

New onset of hydroceles in boys over 1 year of age.

AIM: The presentation, and medical and surgical management of all new onset non-congenital hydroceles in boys older than 1 year of age were examined. Of particular interest was the outcome of those patients who presented with a non-communicating hydrocele that developed after the first year of life and was managed conservatively. METHODS: All patients older than 12 months of age who were evaluated as outpatients with the diagnosis of hydrocele from January 1994 to January 2001 were identified. Possible risk factors and predisposing conditions were determined. For the patients who had surgical correction, surgical indications were identified. For non-surgical patients, long-term outcomes were recorded. RESULTS: A total of 302 patients older than 12 months of age with the diagnosis of new onset hydrocele were identified. Of these, 35% were non-communicating, 59% were communicating, and 6% were hydroceles of the spermatic cord. In terms of surgery, 97% of communicating hydroceles, 71% of hydroceles of the spermatic cord, and 34% of non-communicating hydroceles had operative management. Seventy patients with non-communicating hydroceles did not receive surgery and 51 (73%) were contacted for long term follow-up. In these 51 patients, 76% of non-communicating hydroceles resolved completely, 6% decreased in size but were still present, 14% remained the same size, and 4% had an unknown status. The average time to resolution was 5.6 months with a median time of 3 months. The time range to resolution was from 1 day to 24 months. Follow-up averaged 73.7 months with a range of 33 to 120 months. CONCLUSIONS: Approximately 75% of new onset, non-congenital, non-communicating hydroceles resolve spontaneously irrespective of size. An observation period of 6-12 months would be appropriate prior to repair.

Adolescent↗
PubMed2005

Cytogenetics of a pediatric unclassified sex cord-stromal tumor of the testis: a case report.

Unclassified sex cord-stromal tumors account for a small proportion of pediatric testicular tumors and, while most are clinically benign, some have demonstrated malignant potential. Histological findings do not correlate well with clinical behavior and, while cytogenetics may aid in both diagnosis and predicting clinical behavior, these data on sex cord-stromal tumors are scarce. We describe an unclassified sex cord-stromal tumor occurring in the testis of a prepubertal male without evidence of metastasis that had a previously unreported 54,XY,+3,+7,+9,+12,+13,+18,+19,+20 karyotype.

Chromosomes, Human, Pair 12↗
PubMed2005

Endoscopic treatment of vesicoureteral reflux.

PURPOSE OF REVIEW: The treatment of vesicoureteral reflux in children has seen a shift from invasive surgery to endoscopic management in recent years. Early studies demonstrate favorable outcomes but do not reach the success of surgery. Subspecialization also may play a role in the successful outcomes of all reflux management. This review focuses on the recent literature regarding endoscopic treatment of reflux and the role of subspecialization in treatment of children. RECENT FINDINGS: Dextranomer/hyaluronic acid copolymer has emerged as the favored bulking agent since its Food and Drug Administration approval in the United States. Although success is defined somewhat differently than surgery, overall success rates range from 82-89% with initial injection of dextranomer/hyaluronic acid. The outpatient nature of the procedure and its high success rate have led to a shift in treatment strategies especially in Europe, where endoscopic management is often considered first-line therapy. Extravesical reimplants can be performed on an outpatient basis safely. Subspecialization leads to improved outcomes with no difference in cost. SUMMARY: Endoscopic treatment of reflux is promising, but long-term results are not available to ascertain the efficacy of treatment into adulthood. Open surgery remains the gold standard.

Dextrans↗
PubMed2005

Does surgical subspecialty care come with a higher price?

PURPOSE OF REVIEW: Pediatric surgical specialization has been occurring over the past few decades to improve the outcomes of pediatric surgical care. There is sparse data to support the benefit to children from these educational efforts of these dedicated individuals. This literature review focuses on recent studies and the data documenting improvement in pediatric surgical care. RECENT FINDINGS: Studies from the field of pediatric urology, pediatric general surgery and pediatric neurosurgery are cited. Studies compared outcome data: within a children's hospital between pediatric urology specialists and general urologist performing the same operation; within a healthcare system between pediatric general surgeons and adult general surgeons for appendectomies; population based data for pyloromyotomies performed by general surgeons and pediatric general surgeons; and finally a database study of specialty neurosurgeons and hospital factors affecting outcomes. SUMMARY: Each study documented better pediatric patient surgical outcomes under the care of a pediatric subspecialty trained surgeon regardless of discipline. Those studies that studied costs showed more cost effective care was delivered by pediatric subspecialized surgeons.

Child↗
PubMed2005

Minimally invasive pediatric nephrectomy.

PURPOSE OF REVIEW: Since the first laparoscopic pediatric nephrectomy was performed in 1992, many articles have reported the feasibility of minimally invasive nephrectomy, heminephrectomy, and nephroureterectomy in children. This article reviews the literature related to minimally invasive nephrectomy, including robot-assisted surgery, and its complications published between November 2002 and November 2004. RECENT FINDINGS: The retroperitoneoscopic approach to nephrectomy and nephroureterectomy continues to prove successful in the pediatric population, although the transperitoneal approach is beneficial in combined upper and lower tract procedures. Initial reports on bilateral transperitoneal nephrectomy for nephrotic syndrome and laparoscopic nephrectomy for Wilms tumor are presented. Comparison studies between laparoscopic nephrectomy and open procedures are reviewed. Robot-assisted procedures are possible in children but little information is available on their pediatric use at the present time. Laparoscopy in children appears to have a similar complication rate to that in adults. SUMMARY: More studies are needed to compare the outcomes of minimally invasive procedures with those of open procedures. Robot-assisted surgery offers promise but expense currently limits its use.

Child↗
PubMed2004

Pneumothorax in pediatric patients after urological laparoscopic surgery: experience with 4 patients.

PURPOSE: Pneumothorax is a rare but known complication of adult urological laparoscopic surgery and has been described occasionally in children as well. The etiologies for pneumothorax during such procedures are discussed as is the management of pneumothorax in this setting. We investigate the occurrence of pneumothorax during laparoscopic pediatric urological procedures in children. MATERIALS AND METHODS: Pneumothorax developed during urological laparoscopic procedures in 4 pediatric patients (3 females, 1 male). Patient age ranged from 8 months to 11 years (mean 5.4 years). Laparoscopic surgical procedures performed included right upper pole partial nephrectomy, left upper pole partial nephroureterectomy, removal of left multicystic dysplastic kidney and bilateral Cohen reimplantation of ureters. Procedures were performed with a maximum insufflation pressure of 15 mm Hg. During the same time period as these four cases, a total of 285 laparoscopic urologic procedures were performed at our institution. RESULTS: Pneumothorax was suspected due to decreased oxygen saturations, subcutaneous emphysema, increased respiratory effort and decreased chest lung sounds unilaterally. Pneumothorax was confirmed with chest x-rays. Operative time ranged from 171 to 249 minutes (mean 199.5). Duration of surgery before pneumothorax developed ranged from 75 to 239 minutes (mean 176, median 168). Conservative management of pneumothorax was used in 3 patients and a pigtail chest tube was used in 1. In all cases the estimated blood loss was minimal. CONCLUSIONS: Urologists performing laparoscopy in children should be aware of the possibility of a pneumothorax developing during the procedure. Evaluation for decrease in O2 saturation should include a search for pneumothorax in these patients. Close observation generally suffices for management.

Child↗
PubMed2004

Serum potassium and creatinine changes following unstented bilateral ureteral reimplantation in children.

PURPOSE: We assess the incidence of electrolyte and creatinine changes following unstented bilateral ureteral reimplantation and attempt to identify associated risk factors. MATERIALS AND METHODS: A total of 107 consecutive children with bilateral vesicoureteral reflux underwent bilateral unstented ureteral reimplantation. Study exclusion criteria were plication or tapering of any ureter, age less than 1 year and/or baseline serum creatinine greater than twice normal for age. Postoperatively serum electrolytes and creatinine were assessed by venous puncture until values normalized. The presence of nausea, vomiting, urinary retention and oliguria were recorded. RESULTS: Of the patients 46 females and 10 males 1.0 to 10.9 years old met the study criteria and had complete data available. Four patients (7.1%) had postoperative potassium greater than or equal to 5.0 mmol/l (range 5.0 to 5.3), including 3 (75%, p = 0.0238) who received potassium supplemented intravenous fluid postoperatively. Eight (14.3%) patients had postoperative creatinine greater than 1 mg/dl (range 1.3 to 2.3) and concurrent hyperkalemia with increased creatinine occurred in 2 (25%, p = 0.0295). Nausea and vomiting beyond postoperative day 1 were noted in 6 patients (75%, p = 0.0122). Neither oliguria nor urinary retention reached statistical significance in correlation with increased potassium and/or creatinine. However, urine retention approached statistical significance in patients with increased creatinine (p = 0.0747). No adverse effects from hyperkalemia were noted. CONCLUSIONS: Adverse effects from hyperkalemia following unstented bilateral ureteral reimplantation are uncommon. Potassium containing intravenous fluids should be avoided in the early postoperative period. Routine serum electrolyte determination may be helpful in patients undergoing unstented bilateral ureteral reimplantation when persistent nausea, emesis or urinary retention is present.

Child↗
PubMed2003

Comparison of laparoscopic versus open partial nephrectomy in a pediatric series.

PURPOSE: Recent advances in laparoscopic surgery as well as increasing experience with these techniques have led to the selection of laparoscopic surgery for many urological procedures. A lesser number of pediatric laparoscopic surgical studies have been reported. Few pediatric comparative laparoscopic versus open surgical procedure studies have been published. We compared 2 groups of similar pediatric patients who underwent partial nephrectomy via the laparoscopic or open technique. MATERIALS AND METHODS: A total of 22 consecutive partial nephrectomies were performed in pediatric patients 3 months to 15 years old. Of these procedures 11 chosen according to surgeon preference were performed laparoscopically and 11 were done by the open technique. Clinical data were obtained by chart review and compared retrospectively in the 2 groups. Demographic data, operative time and blood loss, the perioperative complication rate, hospital stay and costs, postoperative analgesic use and followup findings were compared. RESULTS: Mean operative time in the laparoscopic and open groups was 200.4 and 113.5 minutes, respectively (p <0.0005). Blood loss was less than 50 cc in all patients. In the laparoscopic and open groups mean hospital stay was 25.5 and 32.6 hours (p = 0.068), and mean cost was $6,125 and $4,244 (p = 0.016), respectively. Patients in the laparoscopic group required fewer doses of analgesics than those who underwent open surgery (mean 10.9 versus 21, p = 0.041). CONCLUSIONS: Our findings show that increased operative time and costs are disadvantages of pediatric laparoscopic nephrectomy compared with open techniques. Conversely decreased hospital stay, lower analgesic requirements and cosmesis support the use of laparoscopy for pediatric partial nephrectomy. These differences must be considered when deciding which technique is best for overall patient care.

Adolescent↗
PubMed2002

Bladder augmentation in dogs using the tissue capsule formed around a perivesical tissue expander.

PURPOSE: Enterocystoplasty provides needed improvement in bladder storage parameters in many patients but it also generates significant morbidity. We evaluated the unusual potential alternative of using the capsule that forms around a standard silicone tissue expander placed perivesically to augment the bladder in dogs. MATERIALS AND METHODS: Six mongrel dogs underwent baseline videourodynamics and assessment of serum electrolytes, followed by placement of a 250 to 500 cc perivesical silicone tissue expander. Four months after implantation the tissue expander was removed and the fibrous capsule around the expander was biopsied. The capsule was opened and anastomosed to the bladder to augment storage. Serum electrolytes were determined 2 and 4 weeks after augmentation. Videourodynamics were repeated after 3 to 5 months, that is at sacrifice. The harvested bladders underwent histological evaluation. RESULTS: Five dogs underwent augmentation as described, while in an additional dog that underwent intraperitoneal placement of the tissue expander a fibrous capsule failed to form. Of the 5 augmented dogs 4 underwent repeat urodynamic and electrolyte evaluation with harvesting of the lower urinary tract, while 1 died of undetermined causes 3 weeks after augmentation. A distinct capsule formed in all dogs and augmentation was technically achievable. Anastomosis calcification in 3 dogs limited filling the augmenting capsule for cystography. Bladder capacity and compliance improved in all animals but it varied in degree. Histological examination of the capsule biopsies showed collagen rich connective tissue without epithelium or smooth muscle. After augmentation the capsular segment revealed urothelium in all cases with squamous metaplasia in 1. The subepithelial region had dense fibrosis and a thin band of osseous metaplasia occupied the lamina propria in all cases. Disorganized smooth muscle bundles were noted in all augmented bladders within the collagen of the capsule wall. CONCLUSIONS: Bladder augmentation with the collagenous capsule formed over a perivesical tissue expander is technically feasible. There was evidence of epithelial and smooth muscle ingrowth from the native bladder with improved bladder capacity and compliance in all dogs. Osseous metaplasia of the luminal surface of the collagen based capsule that developed in all animals may have been responsible for anastomotic narrowing and limited filling on cystography.

Animals↗
PubMed2002

Variables in successful repair of urethrocutaneous fistula after hypospadias surgery.

PURPOSE: We evaluate variables affecting the success of repairs of urethrocutaneous fistula after hypospadias surgery. MATERIALS AND METHODS: The records of 123 boys who underwent fistula repair at Primary Children's Medical Center were reviewed. Of these patients 100 underwent initial fistula repair at our center (surgery was performed at our center in 82 and elsewhere in 18) and 23 were referred from elsewhere after unsuccessful fistula repairs. Patient age was 6 months to 34 years (median 3.21 years) and interval between surgeries was 3.7 months to 12 years (median 12.6 months). Several variables potentially affecting the success of fistula closure were retrospectively assessed. RESULTS: Including those patients referred from outside hospitals, fistulas were successfully closed in 71%, 72%, 77%, 100% and 100% of these patients after fistula repairs 1 to 5, respectively. Variables studied yielded stent 67.7% (36 of 54 cases) versus no stent 76.1% (35 of 46) and operating microscope 70.4% (59 of 71) versus loupes 72.4% (21 of 29) in terms of success. Success based on patient age yielded 65.5% for younger than 2 years (n = 29 patients), 71.7% for 2 to 5 (46), 64.7% for 6 to 12 (17) and 87.5% for older than 12 (8). When considering the type of original hypospadias repair and its affect on fistula closure success, a significantly lower success was noted with Yoke and King procedures (p = 0.007 and 0.037, respectively). In patients who underwent hypospadias surgery and all subsequent fistula closure attempts at our center, fistulas were successfully repaired in 72%, 67% and 100% of patients after attempts 1 to 3, respectively. Initial fistula repair was successful in 72% (59 of 82) of patients who underwent original hypospadias surgery at our center and in 67% (12 of 18) of those referred after hypospadias surgery at an outside hospital. CONCLUSIONS: Regarding urethrocutaneous fistula closure, the data from this study suggest that there is no clear difference in stent versus no stent and microscope versus loupes, age at fistula closure does not affect success, type of original hypospadias procedure may influence success (King and Yoke procedures were least successful), success rate is not negatively impacted in recurrent fistula cases, given a diverse group of fistulas, success of fistula repair for attempts 1 to 5 was 71%, 72%, 77%, 100% and 100%, respectively, and success rate in a tertiary pediatric urology setting is not influenced by whether the original hypospadias procedure or initial fistula closure was performed in the pediatric urology setting versus outside hospital.

Adolescent↗