Superficial peroneal neuromodulation of persistent bladder underactivity induced by prolonged pudendal afferent nerve stimulation in cats.

The purpose of this study is to determine whether superficial peroneal nerve stimulation (SPNS) can reverse persistent bladder underactivity induced by prolonged pudendal nerve stimulation (PNS). In 16 α-chloralose-anesthetized cats, PNS and SPNS were applied by nerve cuff electrodes. Skin surface electrodes were also used for SPNS. Bladder underactivity consisting of a significant increase in bladder capacity to 157.8 ± 10.9% of control and a significant reduction in bladder contraction amplitude to 56.0 ± 5.0% of control was induced by repetitive (4-16 times) application of 30-min PNS. SPNS (1 Hz, 0.2 ms) at 1.5-2 times threshold intensity (T) for inducing posterior thigh muscle contractions was applied either continuously (SPNSc) or intermittently (SPNSi) during a cystometrogram (CMG) to determine whether the stimulation can reverse the PNS-induced bladder underactivity. SPNSc or SPNSi applied by nerve cuff electrodes during the prolonged PNS inhibition significantly reduced bladder capacity to 124.4 ± 10.7% and 132.4 ± 14.2% of control, respectively, and increased contraction amplitude to 85.3 ± 6.2% and 75.8 ± 4.7%, respectively. Transcutaneous SPNSc and SPNSi also significantly reduced bladder capacity and increased contraction amplitude. Additional PNS applied during the bladder underactivity further increased bladder capacity, whereas SPNSc applied simultaneously with the PNS reversed the increase in bladder capacity. This study indicates that a noninvasive superficial peroneal neuromodulation therapy might be developed to treat bladder underactivity caused by abnormal pudendal nerve somatic afferent activation that is hypothesized to occur in patients with Fowler's syndrome.

Bladder underactivity induced by prolonged pudendal afferent activity in cats.

The purpose of this study was to determine the effects of pudendal nerve stimulation (PNS) on reflex bladder activity and develop an animal model of underactive bladder (UAB). In six anesthetized cats, a bladder catheter was inserted via the urethra to infuse saline and measure pressure. A cuff electrode was implanted on the pudendal nerve. After determination of the threshold intensity (T) for PNS to induce an anal twitch, PNS (5 Hz, 0.2 ms, 2 T or 4 T) was applied during cystometrograms (CMGs). PNS (4-6 T) of 30-min duration was then applied repeatedly until bladder underactivity was produced. Following stimulation, control CMGs were performed over 1.5-2 h to determine the duration of bladder underactivity. When applied during CMGs, PNS (2 T and 4 T) significantly (P < 0.05) increased bladder capacity while PNS at 4 T also significantly (P < 0.05) reduced bladder contraction amplitude, duration, and area under contraction curve. Repeated application of 30-min PNS for a cumulative period of 3-8 h produced bladder underactivity exhibiting a significantly (P < 0.05) increased bladder capacity (173 ± 14% of control) and a significantly (P < 0.05) reduced contraction amplitude (50 ± 7% of control). The bladder underactivity lasted more than 1.5-2 h after termination of the prolonged PNS. These results provide basic science evidence supporting the proposal that abnormal afferent activity from external urethral/anal sphincter could produce central inhibition that underlies nonobstructive urinary retention (NOUR) in Fowler's syndrome. This cat model of UAB may be useful to investigate the mechanism by which sacral neuromodulation reverses NOUR in Fowler's syndrome.

Superficial peroneal neuromodulation of nonobstructive urinary retention in cats.

AIMS: To determine if superficial peroneal nerve stimulation (SPNS) can improve nonobstructive urinary retention (NOUR). METHODS: In α-chloralose anesthetized cats, NOUR was induced by repetitive application (4-16 times) of 30-minute tibial nerve stimulation (TNS: 5 Hz frequency, 0.2 ms pulse width) at 4 to 6 times threshold intensity (T) for inducing toe twitches. SPNS (1 Hz, 0.2 ms) at 2 to 4 times threshold intensity (T) for inducing posterior thigh muscle contractions was applied either continuously (SPNSc) during a cystometrogram (CMG) or during voiding (SPNSv) by a surgically implanted cuff electrode or by skin surface electrodes to determine if the stimulation reduced NOUR induced by prolonged TNS. RESULTS: During control CMGs, efficient (86.4% ± 5.5%) voiding occurred with a postvoid residual (PVR) volume equal to 14.9% ± 6.2% of control bladder capacity. NOUR elicited by prolonged TNS significantly (P < .05) increased bladder capacity to 168.6% ± 15.5% of control, reduced voiding efficiency to 30.4% ± 4.8%, and increased PVR to 109% ± 9.2% of control. Using the implanted cuff electrode, SPNSc and SPNSv significantly (P < .05) increased voiding efficiency to 66.7% ± 7.4% and 65.0% ± 5.9%, respectively, and reduced PVR to 52.2% ± 11.4% and 64.3% ± 11.6%, respectively. SPNSc but not SPNSv significantly (P < .05) reduced bladder capacity to 133.4% ± 15% of control. Transcutaneous SPNSv but not SPNSc also significantly (P < .05) reversed the TNS-induced NOUR responses. CONCLUSIONS: This study shows that SPNS is effective in reversing NOUR induced by prolonged TNS. Transcutaneous SPNS provides the opportunity to develop a noninvasive neuromodulation therapy for NOUR to treat more patients than current sacral neuromodulation therapy.

Importance of long-term follow-up after endoscopic management for upper tract urothelial carcinoma and factors leading to surgical management.

PURPOSE: Patients undergoing endoscopic management for upper tract urothelial carcinoma often progress to definitive therapy with radical nephroureterectomy. This study examined the rate of progression as well as risk factors for transitions in treatment over time. METHODS: Retrospective review at two institutions identified patients undergoing endoscopic management for upper tract urothelial carcinoma. Patients were assessed for progression to radical nephroureterectomy. Baseline characteristics were compared using Chi square analysis. Kaplan-Meier method analyzed the probability of patients not progressing to radical nephroureterectomy. Cox proportional hazards identified factors associated with progression to radical nephroureterectomy. RESULTS: Eighty-one patients had endoscopic management alone and 89 progressed to radical nephroureterectomy. The two groups had similar age, histories of bladder cancer, and Charlson comorbidity index. Positive urinary cytology, ureteroscopic visualization, and biopsy grade were higher in those progressing to RNU (p < 0.001). Hazard modeling demonstrated higher rates of progression to radical nephroureterectomy with positive biopsy (HR 11.8, 95% CI 2.4-59.5, p = 0.003) or visible lesion on ureteroscopy (HR 8.4, 95% CI 3.0-23.9, p < 0.001). Patients with a higher Charlson comorbidity index were less likely to have radical nephroureterectomy. On Kaplan-Meier modeling, the probability of not undergoing radical nephroureterectomy at 2 years and 5 years was 50% and 20%, respectively. CONCLUSIONS: Patients who progress to radical nephroureterectomy after endoscopic management have fewer comorbid conditions and changes in disease status including visible lesions on ureteroscopy and positive biopsies. The high rate of progression to radical nephroureterectomy reinforces the need for long-term follow-up of these patients.

Trends in the Usage of Contrast Allergy Prophylaxis for Endourologic Procedures.

OBJECTIVE: To characterize current practice patterns of urologists in the management of intravenous (IV) contrast allergy in the setting of endourologic procedures. METHODS: A survey was administered to all members of the Endourological Society to assess management of IV contrast allergy prior to ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL). Treatment regimens, reports of adverse outcomes, and demographics of respondents were also collected. Data were analyzed using chi-square tests. RESULTS: The response rate was 15% (325/2100). A total of 21% and 28% of respondents reported giving prophylaxis prior to URS and PCNL, respectively. Nearly 3% of respondents reported having observed a severe adverse reaction to intraluminal contrast in the past. Approximately half reported giving prophylaxis only 1 hour prior to the procedure. Most respondents (77%) completed a fellowship, the most common being endourology. Chi-square analysis revealed a significant difference between giving prophylaxis for URS or PCNL and the respective case volumes (for URS, X2 = 8.3, P= .004; for PCNL, X2 = 8.5, P= .003) where urologists with the lowest and highest case volumes were more likely to give prophylaxis (Fig. 1). There was no significant difference between giving prophylaxis for URS or PCNL and recency of residency, fellowship training, practice setting, or practice type. CONCLUSION: Most urologists do not give prophylaxis for patients with IV contrast allergy prior to URS and PCNL. Further studies are needed to evaluate the necessity of prophylaxis as well as to establish clear guidelines.

Outcomes of Endourologic Interventions in Patients with Preoperative Funguria.

Introduction: Funguria is encountered in 1% to 5% of cultured urine specimens and may be a result of specimen contamination, colonization, or invasive infection. The characteristics and outcomes of patients with funguria undergoing endourologic intervention have not been evaluated. Materials and Methods: Patients with preoperative funguria undergoing endourologic intervention were retrospectively identified. Preoperative funguria was defined as a urine culture containing >10,000 colony forming units of fungus within 30 days of the operative intervention. Univariable and multivariable regression was performed to identify predictors of postoperative systemic inflammatory response syndrome (SIRS). Results: A total of 65 patients with preoperative funguria were identified, of whom 49 (75.4%) underwent ureteroscopy and 16 (24.6%) underwent percutaneous nephrolithotomy. Average patient age was 55.1 ± 18.3 years, body mass index was 31.8 ± 11.0, and Charlson comorbidity index was 2.52 ± 2.0. Twenty-three patients (35.4%) carried a diagnosis of neurogenic bladder, of whom 18 (27.7%) required indwelling or intermittent catheterization. In total 57 patients (87.7%) had been exposed to antibiotics in the 3 months before intervention. Eighteen (27.7%) patients met SIRS criteria postoperatively, of whom 11 (16.9%) required intensive care unit (ICU) admission. Three (4.6%) and two (3.1%) patients developed postoperative fungemia and bacteremia, respectively. All cases of fungemia were caused by Candida glabrata. On univariable analysis, presence of an indwelling catheter (p = 0.009), presence of a known neurological diagnosis (p = 0.02), presence of C. glabrata on preoperative culture (p = 0.04), and longer operative time (p = 0.04) were predictive of development of postoperative SIRS. No significant predictors were identified on multivariable analysis. Conclusions: Patients with preoperative funguria have high rates of comorbid illness, urinary catheterization, and recent exposure to antibiotics. This patient population is at high risk of perioperative infectious complications after endourologic intervention.

A Rare Case of Uterine Torsion With Juvenile Granulosa Cell Tumor in the Pediatric Patient.

Juvenile granulosa cell tumors of the ovary are rare sex cord-stromal ovarian tumors that are typically diagnosed during the first 2 decades of life. Most patients present with precocious puberty in the early stages of disease. We present a rare case of asymptomatic uterine torsion from a 15-cm juvenile granulosa cell tumors in a 5-year-old girl with elevated inhibin B, breast development, vaginal bleeding, and a palpable right-sided abdominal mass.

Transition by head-on collision: mechanically mediated manoeuvres in cockroaches and small robots.

Exceptional performance is often considered to be elegant and free of 'errors' or missteps. During the most extreme escape behaviours, neural control can approach or exceed its operating limits in response time and bandwidth. Here we show that small, rapid running cockroaches with robust exoskeletons select head-on collisions with obstacles to maintain the fastest escape speeds possible to transition up a vertical wall. Instead of avoidance, animals use their passive body shape and compliance to negotiate challenging environments. Cockroaches running at over 1 m or 50 body lengths per second transition from the floor to a vertical wall within 75 ms by using their head like an automobile bumper, mechanically mediating the manoeuvre. Inspired by the animal's behaviour, we demonstrate a passive, high-speed, mechanically mediated vertical transitions with a small, palm-sized legged robot. By creating a collision model for animal and human materials, we suggest a size dependence favouring mechanical mediation below 1 kg that we term the 'Haldane limit'. Relying on the mechanical control offered by soft exoskeletons represents a paradigm shift for understanding the control of small animals and the next generation of running, climbing and flying robots where the use of the body can off-load the demand for rapid sensing and actuation.

Trends in the Management of Small Renal Masses: A Survey of Members of the Endourological Society.

Treatment modalities for small renal masses (SRMs) include open or minimally invasive radical or partial nephrectomy, and laparoscopic or percutaneous ablations. Members of the Endourological Society were surveyed to evaluate how practitioner and clinical practice characteristics may be associated with the management of SRMs over time. The survey assessed characteristics of urologists (recency of residency and fellowship training, clinical practice type and location, and treatment modalities available) and their management of SRMs over the past year and over the course of the year 5 years prior. Of the 1495 surveys e-mailed, there were 129 respondents (8.6%). Comparing the past year to 5 years prior, there was increasing utilization of robotic partial nephrectomy (p < 0.001) and robotic radial nephrectomy (p = 0.031). In contrast, there was decreasing utilization of open partial nephrectomy (p < 0.001), open radical nephrectomy (p = 0.039), laparoscopic partial nephrectomy (p = 0.002), and laparoscopic radical nephrectomy (p = 0.041). Employment of laparoscopic ablation decreased (p = 0.001), but that of percutaneous ablation did not change significantly. For masses treated with image-guided therapy, there was increasing utilization of microwave ablation (p = 0.008) and decreasing usage of radiofrequency ablation (p = 0.002). Future studies should focus on the most effective treatment modalities based on provider, patient, and tumor characteristics.

Lymphoepithelioma-like carcinoma of the ureter: a rare presentation, synchronous with conventional urothelial carcinoma.

Lymphoepithelioma-like carcinoma (LELC) is a rare finding in the upper urinary tract. The presenting clinical findings mimic those of other more common upper-tract tumors, such as urothelial carcinoma. Preoperative imaging has not been shown to reliably predict the diagnosis of LELC. This tumor can be misdiagnosed as a reactive inflammatory lesion or lymphoma if the proper immunohistochemical stains for cytokeratin are not used.

Metastatic Granulosa Cell Tumor of the Testis: Clinical Presentation and Management.

Granulosa cell tumors (GCTs) of the testis are rare sex cord-stromal tumors that are present in both juvenile and adult subtypes. While most adult GCTs are benign, those that present with distant metastases manifest a grave prognosis. Treatments for aggressive GCTs are not well established. Options that have been employed in previous cases include retroperitoneal lymph node dissection (RPLND), radiation, chemotherapy, or a combination thereof. We describe the case of a 57-year-old man who presented with a painless left testicular mass and painful gynecomastia. Serum tumor markers (alpha fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase) and computed tomography of the chest and abdomen were negative. The patient underwent left radical orchiectomy. Immunohistochemical staining was consistent with a testicular GCT. He underwent a left-template laparoscopic RPLND which revealed 2/19 positive lymph nodes. Final pathological stage was IIA. He remains free of disease 32 months after surgery.

Granulomatosis with polyangiitis (Wegener's granulomatosis) causing atlantoaxial instability: a case report.

BACKGROUND CONTEXT: No previous cases of atlantoaxial instability due to granulomatosis with polyangiitis have been reported. PURPOSE: The aim of this study was to report a case of granulomatosis with polyangiitis causing atlantoaxial instability. STUDY DESIGN: This is a case report. PATIENT SAMPLE: A 45-year-old woman participated in this study. OUTCOME MEASURES: The patient's pain and atlantoaxial instability were resolved. METHODS: A 45-year-old Caucasian woman with a large ulcerative lesion in her oropharynx initially presented with chronic sinusitis, pharyngitis, and severe odynophagia. Years after her original symptoms began, she developed neck pain radiating into her upper trapezial region and shoulders. RESULTS: Atlantoaxial fusion was performed on the patient, resolving her neck, upper trapezial, and shoulder pain. She was diagnosed with granulomatosis with polyangiitis (formerly Wegener's granulomatosis) and treated with cyclophosphamide. CONCLUSIONS: Granulomatosis with polyangiitis should be part of the working differential diagnosis for non-traumatic cervical spine injury. The atlantoaxial instability can be managed with stabilization, and the disease process itself can be treated with cyclophosphamide.

Trends in the utilization of imaging for upper tract urothelial carcinoma.

OBJECTIVES: To evaluate the changes in use of the different imaging modalities for diagnosing upper tract urothelial carcinoma (UTUC) and assess how these changes have affected tumor stage at the time of surgery. MATERIALS AND METHODS: We assessed the Surveillance, Epidemiology, and End Results (SEER) cancer registry and linked Medicare claims data (1992-2009) for 5377 patients who underwent surgery for UTUC. We utilized International Classification of Disease-Oncology 3 codes to identify UTUC. International Classification of Disease, ninth Revision, Clinical Modification and Current Procedure Terminology codes identified surgical treatment and imaging modalities. We assessed for use of intravenous pyelography, retrograde pyelography (RGP), computed tomography urography (CTU), magnetic resonance urography (MRU), and endoscopy. For each modality, patients were categorized as having received the modality at least once or not at all. Patient characteristics were compared using chi-squared tests. Usage of imaging modalities and tumor stage was trended using Cochran-Armitage tests. We stratified our data into 2 multivariate logistic regression models to determine the effect of imaging modalities on tumor stage: 1992 to 1999 with all modalities except MRU, and 2000 to 2009 with all modalities. RESULTS: Our patient population was predominantly White males of more than 70 years old. Intravenous pyelography and RGP declined in use (62% and 72% in 1992 vs. 6% and 58% in 2009, respectively) while computed tomography urography, MRU, and endoscopy increased in use (2%, 0%, and 37% in 1992 vs. 44%, 6%, and 66% in 2009, respectively). In both regression analyses, endoscopy was associated with lower-stage tumors. In the 2000 to 2009 model, RGP was associated with lower-stage tumors, and MRU was associated with higher-stage tumors. Finally, our data showed an increasing number of modalities utilized for each patient (1% receiving 4 modalities in 1992 vs. 20% in 2009). CONCLUSIONS: We found trends toward the utilization of newer imaging modalities to diagnose UTUC and more modalities per patient. Endoscopy and RGP were associated with smaller tumors, whereas MRU was associated with larger tumors. Further studies are needed to evaluate the utility of the different modalities in diagnosing UTUC.

Atlantoaxial subluxation and nasopharyngeal necrosis complicating suspected granulomatosis with polyangiitis.

Granulomatosis polyangiitis (GPA, formerly Wegener granulomatosis) is a vasculitis that typically involves the upper respiratory tract, lungs, and kidneys. The 2 established methods to confirm a suspicion of GPA are the antineutrophil cytoplasmic antibody (ANCA) test and biopsy. However, ANCA-negative cases have been known to occur, and it can be difficult to find biopsy evidence of granulomatous disease.We report a case of suspected granulomatosis with polyangiitis limited to the nasopharynx. With a negative ANCA and no histological evidence, our diagnosis was founded on the exclusion of other diagnoses and the response to cyclophosphamide therapy. This case is unique because the patient's lesion resulted in atlantoaxial instability, which required a posterior spinal fusion at C1-C2. This is the first reported case of suspected GPA producing damage to the cervical spine and threatening the spinal cord.