Concealed arch incision: a cosmetic incision for pelvic surgery in girls.

INTRODUCTION: The concealed arch incision is a new cosmetic incision used in pediatric urology to access the lower urinary tract. This study explores the varieties of procedures that can be performed through this new incision on girls. MATERIALS AND METHODS: The varieties of lower urinary tract operations performed in 27 girls were evaluated. RESULTS: Ureteral reimplantation procedures performed in the Cohen technique, Glenn-Anderson and Lich as well as ureteral tapering and ureteroureterostomy were performed through this new incision without difficulty. CONCLUSIONS: Many lower urinary tract procedures can be performed through this new concealed arch incision with excellent cosmetic results.

Design and optimization of an ultra wideband and compact microwave antenna for radiometric monitoring of brain temperature.

We present the modeling efforts on antenna design and frequency selection to monitor brain temperature during prolonged surgery using noninvasive microwave radiometry. A tapered log-spiral antenna design is chosen for its wideband characteristics that allow higher power collection from deep brain. Parametric analysis with the software HFSS is used to optimize antenna performance for deep brain temperature sensing. Radiometric antenna efficiency (η) is evaluated in terms of the ratio of power collected from brain to total power received by the antenna. Anatomical information extracted from several adult computed tomography scans is used to establish design parameters for constructing an accurate layered 3-D tissue phantom. This head phantom includes separate brain and scalp regions, with tissue equivalent liquids circulating at independent temperatures on either side of an intact skull. The optimized frequency band is 1.1-1.6 GHz producing an average antenna efficiency of 50.3% from a two turn log-spiral antenna. The entire sensor package is contained in a lightweight and low-profile 2.8 cm diameter by 1.5 cm high assembly that can be held in place over the skin with an electromagnetic interference shielding adhesive patch. The calculated radiometric equivalent brain temperature tracks within 0.4 °C of the measured brain phantom temperature when the brain phantom is lowered 10 °C and then returned to the original temperature (37 °C) over a 4.6-h experiment. The numerical and experimental results demonstrate that the optimized 2.5-cm log-spiral antenna is well suited for the noninvasive radiometric sensing of deep brain temperature.

Non-invasive measurement of brain temperature with microwave radiometry: demonstration in a head phantom and clinical case.

This study characterizes the sensitivity and accuracy of a non-invasive microwave radiometric thermometer intended for monitoring body core temperature directly in brain to assist rapid recovery from hypothermia such as occurs during surgical procedures. To study this approach, a human head model was constructed with separate brain and scalp regions consisting of tissue equivalent liquids circulating at independent temperatures on either side of intact skull. This test setup provided differential surface/deep tissue temperatures for quantifying sensitivity to change in brain temperature independent of scalp and surrounding environment. A single band radiometer was calibrated and tested in a multilayer model of the human head with differential scalp and brain temperature. Following calibration of a 500MHz bandwidth microwave radiometer in the head model, feasibility of clinical monitoring was assessed in a pediatric patient during a 2-hour surgery. The results of phantom testing showed that calculated radiometric equivalent brain temperature agreed within 0.4°C of measured temperature when the brain phantom was lowered 10°C and returned to original temperature (37°C), while scalp was maintained constant over a 4.6-hour experiment. The intended clinical use of this system was demonstrated by monitoring brain temperature during surgery of a pediatric patient. Over the 2-hour surgery, the radiometrically measured brain temperature tracked within 1-2°C of rectal and nasopharynx temperatures, except during rapid cooldown and heatup periods when brain temperature deviated 2-4°C from slower responding core temperature surrogates. In summary, the radiometer demonstrated long term stability, accuracy and sensitivity sufficient for clinical monitoring of deep brain temperature during surgery.

Stable Microwave Radiometry System for Long Term Monitoring of Deep Tissue Temperature.

BACKGROUND: There are numerous clinical applications for non-invasive monitoring of deep tissue temperature. We present the design and experimental performance of a miniature radiometric thermometry system for measuring volume average temperature of tissue regions located up to 5cm deep in the body. METHODS: We constructed a miniature sensor consisting of EMI-shielded log spiral microstrip antenna with high gain on-axis and integrated high-sensitivity 1.35GHz total power radiometer with 500 MHz bandwidth. We tested performance of the radiometry system in both simulated and experimental multilayer phantom models of several intended clinical measurement sites: i) brown adipose tissue (BAT) depots within 2cm of the skin surface, ii) 3-5cm deep kidney, and iii) human brain underlying intact scalp and skull. The physical models included layers of circulating tissue-mimicking liquids controlled at different temperatures to characterize our ability to quantify small changes in target temperature at depth under normothermic surface tissues. RESULTS: We report SAR patterns that characterize the sense region of a 2.6cm diameter receive antenna, and radiometric power measurements as a function of deep tissue temperature that quantify radiometer sensitivity. The data demonstrate: i) our ability to accurately track temperature rise in realistic tissue targets such as urine refluxed from prewarmed bladder into kidney, and 10°C drop in brain temperature underlying normothermic scalp and skull, and ii) long term accuracy and stability of ∓0.4°C over 4.5 hours as needed for monitoring core body temperature over extended surgery or monitoring effects of brown fat metabolism over an extended sleep/wake cycle. CONCLUSIONS: A non-invasive sensor consisting of 2.6cm diameter receive antenna and integral 1.35GHz total power radiometer has demonstrated sufficient sensitivity to track clinically significant changes in temperature of deep tissue targets underlying normothermic surface tissues for clinical applications like the detection of vesicoureteral reflux, and long term monitoring of brown fat metabolism or brain core temperature during extended surgery.

Padded self-adhesive strap immobilization following newborn bladder exstrophy closure: the Utah straps.

PURPOSE: Several methods have been described for immobilization of the pelvis following bladder exstrophy closure, which can be challenging to manage. We hypothesized that immobilization can be significantly simplified using a modified mermaid wrap with padded Velcro® straps around the thigh and lower leg. MATERIALS AND METHODS: We retrospectively reviewed all patients who underwent bladder exstrophy closure in the newborn period at our institution from 1990 through 2010. Patients with cloacal exstrophy and those who underwent delayed closure due to other medical conditions were excluded. We collected data on closure technique, length of stay and complications of the primary closure as outcomes. RESULTS: A total of 20 boys and 7 girls underwent closure of classic bladder exstrophy. Followup ranged from 2 to 22 years. Seven boys underwent complete primary repair and 13 underwent staged repair. All patients had the legs stabilized with a modified wrap technique using 2 lengths of Velcro straps lined with self-adhering open cell foam pads for 3 weeks. Complications of exstrophy closure included bladder dehiscence in 1 patient (4%) and incisional hernia in 2 (7%). Following complete primary repair urethrocutaneous fistula developed in 2 patients and urethral stricture in 2. Average length of stay for patients without significant prematurity was 15 days. CONCLUSIONS: Padded Velcro strap immobilization simplifies postoperative care, provides secure fixation, decreases length of stay, and enables parents to hold and bond with the child shortly after repair. We advocate this simplified technique, which can be applied with a rate of complications that is comparable to other procedures.

New noninvasive methods to diagnose vesicoureteral reflux.

PURPOSE OF REVIEW: The undesirable nature of bladder imaging in children for vesicoureteral reflux detection makes the search for noninvasive bladder imaging methods and devices an urgent concern. RECENT FINDINGS: Ultrasound imaging of the bladder aided by contrast agents can be performed without ionizing radiation. However, urethral catheterization and contrast instillation is still necessary. The accuracy and reliability are still significant problems with this method. A new method of 'hiding' gadolinium in lysosomes followed by external energy application to rupture the lysosomes releasing the gadolinium for MRI holds future hope, but this research is in its infancy. A novel method to apply external microwave energy to warm the bladder urine with microwave kidney temperature monitoring is being developed. Temperature changes noted in the kidney after bladder warming would indicate vesicoureteral reflux. Further studies are ongoing. SUMMARY: Ultrasonography imaging of the bladder to find vesicoureteral reflux has yet to be refined enough to be accurate and reliable for clinical use. MRI studies are in their infancy but may hold future benefit. Noninvasive bladder heating and kidney temperature monitoring is showing promise in animal studies to be a completely noninvasive reflux detection device.

Parameatal urethral cysts in prepubertal males.

PURPOSE: Parameatal urethral cyst in boys is an uncommon and often poorly understood condition. We describe the largest known series of 18 prepubertal boys with parameatal cysts. MATERIALS AND METHODS: We retrospectively reviewed the charts of all pediatric patients at our institution diagnosed with a penile cyst according to our office database between 1992 and 2010. Charts were reviewed to determine patient demographics, symptomatology, pathology, cyst characteristics and treatment. RESULTS: We identified 18 patients during the last 18 years who were diagnosed with a parameatal cyst. Most patients (66%) were asymptomatic. All cysts were less than 1 cm in diameter. Of the patients 50% were circumcised before presentation and 78% underwent surgical excision. There have been no recurrences in patients who underwent excision. One patient had spontaneous resolution of the cyst during the first few weeks of life. Pathology results were available for 6 patients. Three specimens contained a single type of epithelium and 3 contained a combination of transitional, cuboidal and/or columnar epithelia. The transitional and cuboidal epithelia were the most common components. There was no evidence of malignancy in any of the specimens and only 1 specimen contained an inflammatory infiltrate. CONCLUSIONS: Parameatal cysts are a benign, usually asymptomatic condition that may contain a variety of epithelial types. The cysts may resolve spontaneously in neonates but are also easily excised with minimal risk of recurrence.

Modeling the detectability of vesicoureteral reflux using microwave radiometry.

We present the modeling efforts on antenna design, frequency selection and receiver sensitivity estimation to detect vesicoureteral reflux (VUR) using microwave (MW) radiometry as warm urine from the bladder maintained at fever range temperature using a MW hyperthermia device reflows into the kidneys. The radiometer center frequency (f(c)), frequency band (Deltaf) and aperture radius (r(a)) of the physical antenna for kidney temperature monitoring are determined using a simplified universal antenna model with a circular aperture. Anatomical information extracted from the computed tomography (CT) images of children aged 4-6 years is used to construct a layered 3D tissue model. Radiometric antenna efficiency is evaluated in terms of the ratio of the power collected from the target at depth to the total power received by the antenna (eta). The power ratio of the theoretical antenna is used to design a microstrip log spiral antenna with directional radiation pattern over f(c) +/- Deltaf/2. Power received by the log spiral from the deep target is enhanced using a thin low-loss dielectric matching layer. A cylindrical metal cup is proposed to shield the antenna from electromagnetic interference (EMI). Transient thermal simulations are carried out to determine the minimum detectable change in the antenna brightness temperature (deltaT(B)) for 15-25 mL urine refluxes at 40-42 degrees C located 35 mm from the skin surface. Theoretical antenna simulations indicate maximum eta over 1.1-1.6 GHz for r(a) = 30-40 mm. Simulations of the 35 mm radius tapered log spiral yielded a higher power ratio over f(c) +/- Deltaf/2 for the 35-40 mm deep targets in the presence of an optimal matching layer. Radiometric temperature calculations indicate deltaT(B) 0.1 K for the 15 mL urine at 40 degrees C and 35 mm depth. Higher eta and deltaT(B) were observed for the antenna and matching layer inside the metal cup. Reflection measurements of the log spiral in a saline phantom are in agreement with the simulation data. The numerical study suggests that a radiometer with f(c) = 1.35 GHz, Deltaf = 500 MHz and detector sensitivity better than 0.1 K would be the appropriate tool to noninvasively detect VUR using the log spiral antenna.

250 consecutive unilateral extravesical ureteral reimplantations in an outpatient setting.

PURPOSE: Unilateral extravesical ureteral reimplantation is comparable to intravesical procedures and more effective than subureteral injection to resolve vesicoureteral reflux. Initial reports showed that the procedure could be feasibly done on an outpatient basis. We present further data on a large series of consecutive, planned, outpatient unilateral extravesical ureteral reimplantations. MATERIALS AND METHODS: A total of 250 consecutive patients underwent scheduled outpatient unilateral extravesical ureteral reimplantation. We retrospectively reviewed their records. Patient data were collected on reflux laterality and grade, operative time, hospital stay, complications, need for rehospitalization and resolution rate on radiography 1 month postoperatively. RESULTS: A total of 209 females (84%) and 41 males (16%) underwent planned outpatient extravesical ureteral reimplantation, including on the left side in 158 (63%) and on the right side in 92 (37%). Mean reflux grade was 3.2 with grades II to V in 64 (26%), 96 (38%), 74 (30%) and 16 cases (7%), respectively. Average operative time was 63 minutes and average length of stay, defined as time from initial admission in to discharge home, was 6.2 hours (range 3 to 10 hours). Short-term and late complications occurred in 9 (3.6%) and 8 patients (3.2%), respectively. CONCLUSIONS: Extravesical ureteral reimplantation for unilateral vesicoureteral reflux may be consistently done on an outpatient basis with a reasonable complication rate and a low postoperative hospital admission rate.

Non-invasive vesicoureteral reflux imaging.

OBJECTIVE: To evaluate non-invasive and non-ionizing methods of determining the presence of vesicoureteral reflux (VUR) and to preview upcoming ideas that have the potential of finding VUR non-invasively. MATERIALS AND METHODS: We performed a PubMed search using the terms 'vesicoureteral reflux/radiography', 'vesicoureteral reflux/ultrasonography' and 'magnetic resonance imaging/urologic disease'. We also included information from a recent American Academy of Pediatrics meeting and our own research. RESULTS: Voiding ultrasonography is non-radiating and has undergone significant improvements recently. Best results require instillation of contrast through invasive catheter placement, and doubts regarding sensitivity and specificity are significant. Magnetic resonance cystograms are best with catheter-instilled contrast. They are expensive, require anesthesia or sedation, and are impractical. Horizon technologies include magnetic resonance cystogram with gadolinium 'activation' within the bladder. Another promising completely non-invasive method includes warming the bladder with microwaves and measuring kidney temperatures before and after warming. Detection of a rise in kidney temperatures would indicate VUR. CONCLUSIONS: Voiding cystourethrography remains the gold standard in reflux diagnosis but is invasive and submits the child to ionizing radiation. Developing technologies need improvements and further research before they may have a role in significantly decreasing voiding cystourethrography use or replacing it completely.

Is there a learning curve for subureteric injection of dextranomer/hyaluronic acid in the treatment of vesicoureteral reflux?

OBJECTIVE: To answer the question: 'Is there a learning curve associated with a subureteric injection of Deflux(®)?' MATERIALS AND METHODS: We retrospectively reviewed charts of patients who received subureteric injection of dextranomer/hyaluronic acid (Deflux(®){AQ2}) (225 procedures) for treatment of vesicoureteral reflux (VUR) by four surgeons. The study included 55 patients, 82 ureters, who had postoperative follow-up with a voiding cystogram or nuclear medicine cystogram. Exclusion criteria were prior anti-refluxing procedures, duplicated collecting systems, and non-achievement of a negative intraoperative cystogram. Patients were divided into two groups based on whether or not they received an intraoperative cystogram after the injection. The two groups were compared for VUR resolution rates on follow-up imaging. RESULTS: Twenty patients underwent an intraoperative cystogram (Group 1, 33 ureters) and 35 did not (Group 2, 49 ureters). The two groups were similar in age, preoperative reflux grade, amount of Deflux injected into each ureter, and time to postoperative studies. In Group 1, 11 ureters (33.3%) and also, in Group 2, 11 ureters (22.4%) had reflux on follow-up imaging. CONCLUSIONS: There was no improvement in VUR resolution rate following subureteric injection of Deflux(®) when an intraoperative cystogram demonstrated no reflux to be present immediately after injection. Of ureters that did not reflux on intraoperative cystograms, one-third displayed return of reflux on follow-up imaging, which suggests no learning curve and that failures are not likely to be caused by poor surgical technique.

A method to improve patient access in urological practice.

PURPOSE: Studies to improve patient access to care have generally involved office based primary care practices or highly managed systems. Surgical practices differ in their referral nature, the common need for imaging at the first appointment and the need to schedule subsequent surgical procedures. We determined whether new patient access to care can be improved in a surgical practice. MATERIALS AND METHODS: To reduce new patient appointment wait times to a goal of 5 working days (1 week), a 12-week transition period into a new scheduling approach was designed. At the next clinic with open slots (9 weeks away) 10% of the appointments were held open until the week before for new patient visits. For each of the following 4 weeks 10% additional appointments were held open each week until 50% were being reserved. These slots were not available until 1 week before the clinic date and then were only open for new patients calling to make an appointment. RESULTS: Appointment delay times improved significantly and this improvement has been durable for 2 years. Interestingly our no show rate did not change. CONCLUSIONS: A surgical office with long new patient appointment wait times can improve access to clinic consultations by implementing this system.

Penile torsion correction by diagonal corporal plication sutures.

Penile torsion is commonly encountered. It can be caused by skin and dartos adherence or Buck's fascia attachments. The authors suggest a new surgical approach to solve both problems. If Buck's fascia involvement is demonstrated by artificial erection then a new diagonal corporal plication suture is described to effectively solve this problem.

Penile torsion correction by diagonal corporal plication sutures

Penile torsion is commonly encountered. It can be caused by skin and dartos adherence or Buck’s fascia attachments. The authors suggest a new surgical approach to solve both problems. If Buck’s fascia involvement is demonstrated by artificial erection then a new diagonal corporal plication suture is described to effectively solve this problem.

Incidence of postoperative infections in non-immunocompromised pediatric patients with low absolute neutrophil counts preoperatively.

PURPOSE: To discover the incidence of postoperative surgical site infections in non-immunocompromised pediatric patients with an absolute neutrophil count (ANC) < or = 1,000 preoperatively. METHODS: Office and hospital charts of consecutive patients with preoperative ANC < or = 1,000 undergoing elective surgery over a three-year period were reviewed for evidence of postoperative surgical site infection. RESULTS: Six of 200 patients with preoperative ANCs < or = 1,000 developed a postoperative surgical site infection, an infection rate of 3.0%. One of 35 patients with preoperative ANCs < or = 500 developed a surgical site infection. The mean ANC of the study population was 800 (range 200 to 1,000); the mean ANC of the group with postoperative infection likewise was 800 (range 500 to 1,000). CONCLUSIONS: There was a postoperative surgical site infection rate of 3.0% in non-immunocompromised children who had a preoperative ANC < or = 1,000, similar to the overall surgical site infection rate in children. Cancellation of elective procedures in non-immunocompromised children with ANC < or = 1,000 is not warranted on the grounds of concern about postoperative infection.

Variation in diethylenetriamine pentaacetic acid and mercaptoacetyltriglycine renal scans: clinical implications of interobserver and intraobserver differences.

PURPOSE: Diethylenetriamine pentaacetic acid and mercaptoacetyltriglycine renal scans are commonly used to evaluate infants and children with hydronephrosis to assess for changes in kidney function and drainage. We evaluate the certified nuclear medicine technologist intraobserver and interobserver variability of data processing in diuretic renal scan interpretation of the percent differential function of the right kidney so that true physiological changes can be understood by the clinician. MATERIALS AND METHODS: A total of 30 renal scans (diethylenetriamine pentaacetic acid in 20 patients and mercaptoacetyltriglycine in 10) were randomly selected for evaluation by 3 technologists who processed the scan data for each patient on 5 different occasions at least 1 week apart. Regions of interest were drawn and background areas were subtracted, and percent differential function of the right kidney was calculated. Technologists were blinded to patient identification and previous interpretation results. The data were then statistically analyzed. RESULTS: The data focused on percent differential function of the right kidney. Confidence limits for the single scan interpretation at the 95% level showed +/-5.8% differential function variation, although this scan was the same renal scan processed 1 week later. CONCLUSIONS: For differential function determined on diethylenetriamine pentaacetic acid or mercaptoacetyltriglycine diuretic renal scan the single scan 95% confidence limits were +/-5.8% differential function. From one renal scan to the next the differential percent of kidney function must change +/-11.6% differential function for a clinician to be 95% confident that a real change in kidney function has occurred. This uncertainty is substantial and is likely larger than is currently allowed for in clinical practice.

Genitourinary anomalies of pediatric FG syndrome.

PURPOSE: The FG syndrome, also known as Opitz-Kaveggia syndrome, is an X-linked disorder characterized by developmental delay, congenital hypotonia, characteristic facial appearance, relative macrocephaly and anomalies affecting the genitourinary, gastrointestinal and musculoskeletal systems. Genitourinary abnormalities in the FG syndrome include cryptorchidism, hypospadias, inguinal hernia, hydrocele and occasional anomalies of renal or ureteral development. To our knowledge no previous study has systematically evaluated the genitourinary aspects of the disorder. We describe the genitourinary anomalies seen in children with the FG syndrome. This report may help elucidate the pathogenic mechanisms responsible for the disorder. Also, we provide a simple checklist for urologists that will help guide referrals for genetics and other specialty consultations. MATERIALS AND METHODS: We retrospectively reviewed 228 patients with the FG syndrome to identify the frequency of characteristic historical and physical findings. These patients were diagnosed on the basis of a firsthand history and physical examination, or by a careful outside evaluation including detailed records and photographs. RESULTS: Of the patients 90% were male. The overall incidence of any genitourinary anomaly was 48.5% in boys, 13.6% in girls and 44.7% overall. In boys the most common abnormalities were cryptorchidism (24%), hypospadias (14%) and hernia or hydrocele (13%). CONCLUSIONS: The FG syndrome is a disorder with a greater prevalence than previously thought, yet is rarely suspected by urologists. The manifestations may be complex. Identification of patients with syndromal genitourinary anomalies by urologists will enhance the quality of care based on referral of patients for additional evaluation.

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.