Joseph G. Borer

Pediatric Robot Assisted Laparoscopic Dismembered Pyeloplasty: Comparison With a Cohort of Open Surgery

PURPOSE We assessed the usefulness of RALP in children and compared an age matched cohort undergoing OPN to RALP for safety, efficacy, operative time, blood loss, in-hospital narcotic use and LOS. MATERIALS AND METHODS We performed a retrospective case-control study from 2000 to 2004 of 33 patients undergoing RALP and 33 undergoing OPN. Average age of each group was not significantly different (RALP 7.8 years vs OPN 7.6 years, p = 0.75). Mean followup of RALP and OPN groups was 10 and 21 months, respectively. RESULTS Etiology of the obstruction was not significantly different. Mean operative time was significantly less for OPN (181 minutes vs 219 minutes for RALP, p = 0.031). As RALP experience increased, operative times improved and approached the OPN experience. RALP complications included 1 patient requiring reoperative surgery vs no complications in the OPN group (p = 0.15). Patients undergoing RALP had a mean LOS of 2.3 days compared to 3.5 days for OPN (p <0.001). Total narcotic requirements were significantly less in the RALP group (p = 0.001). All patients in the OPN and 31 in the RALP group had either resolution of hydronephrosis, improvement in drainage or relief of symptoms. CONCLUSIONS We documented the safety and efficacy of RALP in children. RALP showed advantages of decreased hospital stay, decreased narcotic use and operative times approaching those of open surgery. RALP is an option for pyeloplasty, and as robotic technology improves, this method of repair may become the minimally invasive treatment of choice.

TUBULARIZED INCISED PLATE URETHROPLASTY:: EXPANDED USE IN PRIMARY AND REPEAT SURGERY FOR HYPOSPADIAS

PURPOSE We evaluated the impact of tubularized incised plate urethroplasty on primary and repeat hypospadias repair. MATERIALS AND METHODS We retrospectively reviewed the medical records of all boys who underwent hypospadias repair at our institution during a recent 3-year period. The level of the hypospadias defect, technique of repair, primary repair versus reoperation, age at surgery and complications were recorded. RESULTS A total of 520 hypospadias repairs were done from May 1996 through June 1999. We began to perform tubularized incised plate urethroplasty in November 1996. During the ensuing consecutive 32 months 181 primary and 25 repeat hypospadias repairs were done using this technique. Mean patient age at surgery was 22 months (range 3 months to 30 years). During the 6 months immediately before we began to use this method the Mathieu flip-flap procedure was the most commonly performed technique, accounting for 38% of all hypospadias repairs. In contrast, during the last 6 months reviewed tubularized incised plate urethroplasty accounted for 63% of all repairs, including 41 of 65 primary operations (63%) and 4 of 6 reoperations (67%), while no Mathieu procedures were performed. Postoperative followup was 6 to 38 months for tubularized incised plate repair. Overall meatal stenosis and a urethrocutaneous fistula developed in 1 and 14 boys, respectively (7% complication rate). CONCLUSIONS Tubularized incised plate urethroplasty has become the preferred technique of primary and repeat hypospadias repair at our institution. The technique has few complications as well as proved success and versatility that continues to expand its applicability and popularity.

RATE AND PREDICTORS OF SPONTANEOUS RESOLUTION OF PRENATALLY DIAGNOSED PRIMARY NONREFLUXING MEGAURETER

PURPOSE We assessed clinical and ultrasound predictors of the spontaneous resolution of prenatally diagnosed, primary nonrefluxing megaureter. MATERIALS AND METHODS Primary nonrefluxing megaureter was prenatally diagnosed in 54 neonates from 1993 to 1998, including 15 in whom it was bilateral (69 megaureters). Median followup period from birth to the last radiology examination was 25.8 months (range 2.3 to 72). RESULTS Of the patients 10 underwent surgical repair for severe hydroureteronephrosis, including decreasing renal function on diuretic renography in 1, and an episode of bilateral obstruction and acute renal failure in 1. Hydroureteronephrosis resolved in 39 cases (72%) and persisted in 5 at 30 to 72 months of followup. Laterality, gender and retrovesical ureteral diameter had no significant effect on the resolution rate (p >0.05). Mean initial ureteral diameter in patients with resolution was less than in those without resolution and in those who underwent surgery (0.8 versus 1.15 and 1.32 cm., respectively). Presenting hydronephrosis grade was a significant predictor of the resolution rate (p = 0.03). Grades 1 to 3 hydronephrosis resolved at a median age of 12.9, 23.9 and 34.6 months, respectively (range 4.1 to 66). In patients in whom grades 4 and 5 hydronephrosis resolved the median age at resolution was 48.5 months. CONCLUSIONS Most cases of prenatally diagnosed, primary nonrefluxing megaureter resolve spontaneously. Grades 1 to 3 hydronephrosis tend to resolve between ages 12 and 36 months. For these grades followup intervals may be progressively elongated after a pattern of improving hydronephrosis has been established. In children with grade 4 or 5 hydronephrosis, or a retrovesical ureteral diameter of greater than 1 cm. the condition may resolve slowly and require surgery.

Nomograms for Predicting Annual Resolution Rate of Primary Vesicoureteral Reflux: Results From 2,462 Children

PURPOSE We determined the resolution rate of vesicoureteral reflux and the factors that influence it to formulate nomograms to predict the probability of annual resolution for individual cases of reflux. MATERIALS AND METHODS We studied 2,462 children with primary vesicoureteral reflux diagnosed between 1998 and 2006. Cox proportional hazards regression was used to model time to resolution as a function of statistically significant demographic and clinical variables. The resulting model was used to construct nomograms predicting the annual cumulative probability of reflux resolution. RESULTS Multivariate analysis showed that all cases of unilateral reflux resolved earlier than female bilateral reflux (HR 1.42, p <0.001). Additionally age less than 1 year at presentation (HR 1.31, p <0.001), lower reflux grade (2.96, p <0.001 for grade I; 2.28, p <0.001 for grade II; 1.63, p <0.001 for grade III), reflux diagnosed on postnatal evaluation for prenatal hydronephrosis or sibling screening (1.24, p = 0.002) and single ureter (1.55, p <0.001) were associated with significantly earlier resolution of reflux. Specific predicted cumulative probabilities of reflux resolution at annual intervals from diagnosis (1 to 5 years) were calculated for every possible combination of the significant variables. CONCLUSIONS Our analyses demonstrate that resolution of vesicoureteral reflux is dependent on age at presentation, gender, grade, laterality, mode of clinical presentation and ureteral anatomy. We constructed nomogram tables containing estimates of annual reflux resolution rate as a function of these variables. This information is valuable for clinical counseling and management decisions.

Stretch activates heparin-binding EGF-like growth factor expression in bladder smooth muscle cells

Cultured rat bladder smooth muscle cells (SMC) were grown on collagen-coated silicone membranes and subjected to continuous cycles of stretch-relaxation. Semiquantitative RT-PCR analysis revealed a time-dependent increase in heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) mRNA levels after stretch, with maximal levels appearing after 4 h. Immunostaining for proHB-EGF revealed higher levels of HB-EGF protein in the stretched than in the nonstretched SMC. The ANG II receptor type 1 antagonist losartan markedly suppressed stretch-activated HB-EGF expression. ANG II levels were 3.3-fold higher in the stretch- than in the non-stretch-conditioned media. Stretch stimulation of bladder SMC that had been transiently transfected with an HB-EGF promoter-luciferase expression construct resulted in an 11-fold increase in reporter activity. Mechanical stretch induced a 4.7-fold increase in tritiated thymidine incorporation rate, and this was reduced by 25% in the presence of losartan. We conclude that mechanical stretch activates HB-EGF gene expression in bladder SMC and that this is mediated in part by autocrine ANG II secretion.

Long-term experience and outcomes of robotic assisted laparoscopic pyeloplasty in children and young adults.

PURPOSE Laparoscopic pyeloplasty is one of the more common robotic assisted procedures performed in children. However, data regarding long-term experience and clinical outcomes for this procedure are limited. We evaluated the long-term outcomes in a large series of patients undergoing robotic assisted laparoscopic pyeloplasty at a teaching institution, and the effect of a collaborative program between the robotic surgeons, surgical nurses and anesthesiologists on overall operative time. MATERIALS AND METHODS We retrospectively reviewed 155 patients who underwent robotic assisted laparoscopic pyeloplasty between 2002 and 2009. Operative data, including surgical approach, type of procedure, total and specific operative times and placement of ureteral stents, were determined. Postoperative outcome measurements, including duration of hospital stay, duration of Foley catheter drainage, radiological findings and any subsequent complications, were assessed. RESULTS Mean operative time and length of hospitalization decreased significantly by the end of the study. At a mean followup of 31.7 months the primary success rate was 96% (hydronephrosis was improved in 85% of patients and stable in 11%). The complication rate was 11%, and recurrent obstruction requiring redo robotic assisted laparoscopic pyeloplasty or open pyeloplasty developed in 3% of patients. Success rate and complication rate were unchanged during the study period. CONCLUSIONS This study confirms that even within the confines of a pediatric urology training program successful collaboration between robotic surgeons, surgical nurses and anesthesiologists can lead to shorter operative times and hospital stays. Long-term surgical success and complication rates were comparable to open surgery.

Autologous cell seeded biodegradable scaffold for augmentation cystoplasty: phase II study in children and adolescents with spina bifida.

PURPOSE Augmentation cystoplasty using gastrointestinal segments in children/adolescents with medically refractory neurogenic bladder is associated with significant complications. We evaluated an autologous cell seeded biodegradable scaffold (Tengion®) for bladder augmentation as an alternative to traditional enterocystoplasty in this population. MATERIALS AND METHODS A phase II prospective study was performed in children with neurogenic bladder due to spina bifida requiring enterocystoplasty for detrusor pressure 40 cm H2O or greater despite maximum antimuscarinic medication. Following open bladder biopsy, urothelial and smooth muscle cells were grown ex vivo and seeded onto a biodegradable scaffold to form a regenerative augment as the foundation for bladder tissue regeneration. Bladder neck sling was the only concomitant surgical procedure permitted. Bladders were cycled postoperatively to promote regeneration. Primary and secondary outcomes at 12 months included change in bladder compliance, bladder capacity and safety. Long-term assessment was done with similar outcomes at 36 months. RESULTS Compliance improved in 4 patients at 12 months and in 5 patients at 36 months, although the difference was not clinically or statistically significant. There was no clinical or statistical improvement in bladder capacity at 12 or 36 months in any patient. Adverse events occurred in all patients, and most were easily treated. Two patients had low cell growth following bladder biopsy, of whom 1 withdrew from the study and 1 underwent a second biopsy. Serious adverse events of bowel obstruction and/or bladder rupture occurred in 4 patients. CONCLUSIONS Our autologous cell seeded biodegradable scaffold did not improve bladder compliance or capacity, and our serious adverse events surpassed an acceptable safety standard.

Robot Assisted Laparoscopic Partial Nephrectomy: A Viable and Safe Option in Children

PURPOSE The safety, benefits and usefulness of laparoscopic partial nephrectomy have been demonstrated in the pediatric population. We describe our technique, and determine the safety and feasibility of robot assisted laparoscopic partial nephrectomy based on our initial experience. MATERIALS AND METHODS We retrospectively reviewed robot assisted laparoscopic partial nephrectomy performed at our institution between 2002 and 2005. The technique was conducted via a transperitoneal approach with the da Vinci Surgical System using standard laparoscopic procedural steps. Clinical indicators of outcomes included estimated blood loss, complications, in hospital narcotic use and length of stay. RESULTS Robot assisted laparoscopic partial nephrectomy was completed successfully in 9 cases. Mean patient age was 7.2 years and mean followup was 6 months. Mean operative time was 275 minutes and mean estimated blood loss was 49 ml. Operative times improved significantly with experience. Overall patients had a mean hospitalization of 2.9 days and required 1.3 mg morphine per kg. All patients had a normal remaining renal moiety confirmed on Doppler ultrasound. The only complication was an asymptomatic urinoma discovered on ultrasound, which was treated with percutaneous drainage and ultimately resolved. CONCLUSIONS Our initial experience shows the safety and feasibility of robot assisted laparoscopic partial nephrectomy in children. Operative time decreases with experience. The enhanced visualization and dexterity of a robotic system potentially offer improved efficiency and safety over standard laparoscopy. Robot assisted laparoscopy is an option for partial nephrectomy and may become the minimally invasive treatment of choice.

Relationship between determinants of oxygen delivery and respiratory abnormalities in preterm infants with anemia.

To study the relationship between anemia and breathing abnormalities in preterm infants, we measured oxygen supply and demand in two groups of anemic infants less than or equal to 32 weeks of gestational age. Six-second apnea density was less than 1% in one group and greater than or equal to 5% in the other. There were no differences in hemoglobin concentration, available oxygen, oxygen consumption, or Doppler-determined cardiac output between the two groups of infants. Furthermore, in anemic preterm infants with apnea density greater than or equal to 5%, reductions in 6-second apnea density were similar after erythrocyte transfusion (mean +/- SEM: from 8.6% +/- 1.1% to 4.7% +/- 0.7%) or after an isovolemic infusion of 5% albumin (from 9.0% +/- 1.4% to 4.7% +/- 0.7%). These results show no relationship between measures of oxygen delivery and respiratory irregularities, and indicate that volume expansion may play a role in ameliorating the pneumocardiogram abnormalities.

Ultrasound Versus Computerized Tomography for Evaluating Urolithiasis

PURPOSE We prospectively evaluated the precision of ultrasound and computerized tomography to diagnose urinary stones in children and determined whether these differences in radiological findings have any impact on clinical management. MATERIALS AND METHODS A total of 50 consecutive patients with suspected urolithiasis underwent computerized tomography and ultrasound. Two radiologists reviewed each study independently in blinded fashion. When a difference in findings was detected, 8 pediatric urologists reviewed the case. Clinical management was based on the results of each radiological test independently. Statistical analysis was performed using Fishers exact test. RESULTS Compared to computerized tomography ultrasound had 76% sensitivity and 100% specificity. In 8 patients stone(s) seen on computerized tomography was not seen on ultrasound. The average size of missed stones was 2.3 mm. In 7 patients computerized tomography showed stones bilaterally but stone was seen on only 1 side on ultrasound. When evaluating the clinical impact, the ultrasound/computerized tomography discrepancy did not result in any significant change in clinical management except in 4 cases. In these cases ultrasound findings suggested that additional imaging was required and, thus, stone(s) in the distal ureter would have been identified on subsequent imaging. CONCLUSIONS Although computerized tomography is more sensitive for detecting urolithiasis than ultrasound, the difference in usefulness between the 2 radiological tests may not be clinically significant. Given concerns for the potentially harmful cumulative long-term effect of radiation, ultrasound should be considered the first imaging test in children with suspected urolithiasis.