Penile Strangulation: Analysis of Postextrication Follow-Up, Sequelae, and a Review of Literature.

Numerous case reports exist on penile strangulation injuries and extrication methods; however, the care and long-term consequences of penile strangulation injuries have been under-reported. Our aim is to investigate the long-term outcomes and sequalae following penile strangulation injuries. The PubMed Medline database was searched using the keyword string "penile strangulation," "penis strangulation," and "constriction" for all studies reporting outcomes of published penile strangulation injuries. Articles were evaluated for follow-up after strangulation injury, strangulating agent, extricating agent, and sequelae of injury. Fifty-six studies resulted with reports of 100 cases of penile strangulation and extrication from January 2000 to December 2019. The mean patient age was 41 (range: 3-86) years. Twenty-four (24/100) cases reported sequalae following extrication. Follow-up ranged from 2 weeks to 7 years with median follow-up time in the 7- to 12-month grouping. Metal rings comprised 36% (36/100) of strangulation agents and 50% of reported incidents were attributed to sexual activity. To our knowledge, this is the only study focusing on long-term outcomes after penile strangulation. This review provides a summary of 56 studies that document penile strangulation injuries over the last 20 years. Although a wide array of penile strangulation injuries have been documented in the literature, reports lack secondary management and long-term outcomes after removal of the strangulation device. We recommend that providers report long-term penile strangulation outcomes for future urologic evaluations after extrication.

Sinonasal and Skull Base Metastatic Renal Cell Carcinoma: A Case Series.

Metastatic lesions to the paranasal sinuses and skull base, while rare, carry a poor prognosis. Renal cell carcinoma has been reported in multiple case reports to be one of the most common distant malignancies to spread to the paranasal sinuses; however, it is often unrecognized by physicians, and thus treatment is delayed. To increase awareness of this disease process, we describe three cases of metastatic renal cell carcinoma to the sinonasal cavity, which is the largest case series in the literature to date.

Caution! AI Bot Has Entered the Patient Chat: ChatGPT Has Limitations in Providing Accurate Urologic Healthcare Advice.

OBJECTIVE: To conduct the first study examining the accuracy of ChatGPT, an artificial intelligence (AI) chatbot, derived patient counseling responses based on clinical care guidelines in urology using a validated questionnaire. METHODS: We asked ChatGPT a set of 13 urological guideline-based questions three times. Answers were evaluated for appropriateness and using Brief DISCERN (BD), a validated healthcare information assessment questionnaire. Data analysis included descriptive statistics and Student's t test (SAS Studio). RESULTS: 60% (115/195) of ChatGPT responses were deemed appropriate. Variability existed between responses to the same prompt, with 25% of the 13 question sets having discordant appropriateness designations. The average BD score was 16.8 ± 3.59. Only 7 (54%) of 13 topics and 21 (54%) of 39 responses met the BD cut-off score of ≥16 to denote good-quality content. Appropriateness was associated with higher overall and Relevance domain scores (both P < .01). The lowest BD domain scores were for Source categories, since ChatGPT does not provide references by default. With prompting, 92.3% had ≥1 incorrect, misinterpreted, or nonfunctional citations. CONCLUSION: While ChatGPT provides appropriate responses to urological questions more than half of the time, it misinterprets clinical care guidelines, dismisses important contextual information, conceals its sources, and provides inappropriate references. Chatbot models hold great promise, but users should be cautious when interpreting healthcare-related advice from existing AI models. Additional training and modifications are needed before these AI models will be ready for reliable use by patients and providers.

Comparison of Different Pulse Modulation Modes for Holmium:Yttrium-Aluminum-Garnet Laser Lithotripsy Ablation in a Benchtop Model.

Introduction: Manipulation of Holmium:Yttrium-Aluminum-Garnet laser parameters such as pulse energy (PE), frequency, and duration can impact laser lithotripsy ablation efficiency. In 2017, Lumenis introduced Moses™ Technology, which uses pulse modulation to enhance the delivery of energy from fiber to stone as well as to minimize stone retropulsion. Since the introduction of Moses Technology, other companies have brought additional pulse modulation concepts to market. The purpose of this in vitro study is to compare the pulse characteristics and stone ablation efficiency of Lumenis Moses Technology with Quanta's Vapor Tunnel™. Materials and Methods: Submerged BegoStone phantoms were systematically ablated using either the Lumenis Moses Pulse 120H or the Quanta Litho 100 clinical laser system. Two PEs (0.4 and 1 J), three fiber-stone standoff distances (SDs) (0.5, 1, 2 mm), and all available pulse duration and modulation modes for each laser were tested in combination. Fiber speed was adjusted to scan across the stone surface at either 1 or 10 pulses/mm to form single pulse craters or an ablation trough, respectively. Volumes of single craters and 1 mm trough segments were imaged and quantified using optical coherence tomography. Results: Ablation volumes decreased with decreasing PE and increasing SD. Statistically significant variability was seen between pulse types (PT) at every tested parameter set. Among pulse modulation modes, Moses Distance (MD) was superior at 0.5 mm in all testing and at 2 mm in trough testing. Vapor Tunnel (VT) was superior in 2 mm single crater testing. All modulated pulses performed similarly at 1 mm. Conclusions: In this benchtop model of laser lithotripsy, stone ablation was significantly impacted by PT. MD demonstrated superior or noninferior stone ablation at most tested parameters. VT maintained its efficacy the best as SD increased. Future work should focus on the mechanistic differences of these modes relative to other traditional laser pulse modes.

The Role of Cavitation in Energy Delivery and Stone Damage During Laser Lithotripsy.

Purpose: Although cavitation during laser lithotripsy (LL) contributes to the Moses effect, the impact of cavitation on stone damage is less clear. Using different laser settings, we investigate the role of cavitation bubbles in energy delivery and stone damage. Materials and Methods: The role of cavitation in laser energy delivery was characterized by using photodetector measurements synced with high-speed imaging for laser pulses of varying durations. BegoStone samples were treated with the laser fiber oriented perpendicularly in contact with the stone in water or in air to assess the impact of cavitation on crater formation. Crater volume and geometry were quantified by using optical coherence tomography. Further, the role of cavitation in stone damage was elucidated by treatment in water with the fiber oriented parallel to the stone surface and by photoelastic imaging. Results: Longer pulse durations resulted in higher energy delivery but smaller craters. Stones treated in water resulted in greater volume, wider yet shallower craters compared with those treated in air. Stones treated with the parallel fiber showed crater formation after 15 pulses, confirmed by high-speed imaging of the bubble collapse with the resultant stress field captured by photoelastic imaging. Conclusions: Despite improved energy delivery, the longer pulse mode produced smaller crater volume, suggesting additional processes secondary to photothermal ablation are involved in stone damage. Our critical observations of the difference in stone damage treated in water vs in air, combined with the crater formation by parallel fiber, suggest that cavitation is a contributor to stone damage during LL.

Benchtop Assessment of a New Single-Use Flexible Ureteroscope.

Introduction: Single-use flexible ureteroscopes are an increasingly popular alternative to reusable ureteroscopes. In this study, we performed a benchtop examination of the physical and optical properties of the new Dornier Axis™ (Webling, Germany) single-use ureteroscope. Methods: Ten new, never-used Dornier Axis ureteroscopes were assessed for optical performance, maximal tip deflection, and irrigation flow rate with an empty working channel and with insertion of 200 and 365 µm laser fibers, and a 1.9F nitinol basket. All ureteroscopes were then fully deflected 100 times in each direction, and maximal deflection angles were re-measured with and without instruments in the working channel. All measurements were performed in duplicate. In vitro optical testing for resolution, image distortion, and depth of field was performed and compared vs the LithoVue™ (Boston Scientific, Marlborough, MA) single-use ureteroscope. Statistical analyses using paired Wilcoxon rank-sum tests and Kruskal-Wallis multiple-group comparison tests were performed in R. Results: Median maximal deflection angles exceeded 300° in both directions before and after 100 full deflection cycles for all groups except the 365 µm laser fiber group. After 100 deflection cycles, there was no change in the majority of working instruments, except a decrease in upward flexion with an empty channel and 200 µm Moses™ laser fiber, and downward flexion with 200 µm Flexiva™ laser fiber (all <10°). After excluding the 365 µm fiber, there was no difference in multi-group comparison for upward and downward flexion pre- and post-cycling. Median flow rate through an empty channel was 48.0 mL/min, and it decreased significantly with all used instruments (p < 0.001). Compared with the LithoVue, the Axis demonstrated superior resolution at all tested distances and less distortion. Conclusions: The new Dornier Axis single-use ureteroscope demonstrates excellent tip deflection, which remains unchanged after 100 manual flexions in each direction. The Axis also demonstrates superior optical performance compared with the LithoVue in benchtop testing.

Metabolic evaluation and medical management of staghorn calculi.

Staghorn renal calculi are large renal calculi that occupy nearly the entirety of the renal collecting system. They may be composed of metabolic or infection stone types. They are often associated with specific metabolic defects. Infection stones are associated with urease-producing bacterial urinary tract infections. The ideal treatment for staghorn calculi is maximal surgical removal. However, some patients are either unwilling or unable to proceed with that modality of treatment, and therefore other management must be used. One such technique is the metabolic evaluation with directed medical management. Based on contemporary evidence that the majority of staghorn stones are metabolic in etiology, and furthermore that even infection stones are usually associated with metabolic abnormalities, metabolic evaluation with directed medical management is recommended for all staghorn stone formers. The scientific basis of this recommendation is reviewed in the present work.

New devices for kidney stone management.

PURPOSE OF REVIEW: The purpose of this review is to summarize recent developments in the array of devices which are commonly used by urologists in the surgical management of kidney stones. To accomplish this goal, an extensive review of recent endourology literature, conference abstracts, and publicly available documents from manufacturers and the United States Food and Drug Administration was collected and reviewed. RECENT FINDINGS: Recent developments in the holmium:yttrium-aluminum-garnet (Ho:YAG) laser lithotripsy include the introduction of pulse modulation. This technique delivers the laser energy in an asymmetric manner such that an initial bubble is created (the 'Moses effect') through which the remainder of the energy can then travel through without being absorbed by surrounding water. Even more novel is the thulium fiber laser, which is produced in a fundamentally different way than traditional Ho:YAG lasers and is not yet available for clinical use. Finally, novel mechanical lithotrites which effectively combine ultrasonic energy, ballistic energy, and suction capability appear to be highly effective for stone clearance in recent benchtop and clinical studies. SUMMARY: With the introduction of both new modifications of time-tested technologies as well as completely novel modalities, the practicing urologist's armamentarium of devices for the surgical management of kidney stones continues to grow. As the popularity of 'mini' procedures continues to grow, the adaptability of these technologies to these procedures will be critical to maintain maximum relevance.

Using Aorta-Lesion-Attenuation Difference on Preoperative Contrast-enhanced Computed Tomography Scan to Differentiate Between Malignant and Benign Renal Tumors.

OBJECTIVE: To evaluate the ability of Aorta-Lesion-Attenuation Difference (ALAD) to differentiate malignant renal tumors from renal oncocytomas. METHODS: A retrospective review of preoperative computed tomography (CT) scans and surgical pathology was performed on patients undergoing partial nephrectomy for small, solid renal masses. ALAD was calculated by measuring the difference in Hounsfield units (HU) between the aorta and the lesion of interest on the same image slice on preoperative CT scan. The discriminative ability of ALAD to differentiate malignant pathology from oncocytoma was evaluated by sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under curve (AUC) using receiver operating characteristic analysis. RESULTS: A total of 227 preoperative CT scans and corresponding pathology reports were reviewed. ALAD values were calculated during the excretory and nephrographic phases. Nephrographic ALAD was able to differentiate malignant pathology from oncocytoma using a HU threshold of 24 with a sensitivity of 84%, specificity of 86%, PPV of 98%, and NPV of 33%. The AUC for malignant pathology vs oncocytoma was 0.86 (95% confidence intervals 0.77-0.96). Nephrographic ALAD was able to differentiate chromophobe renal cell carcinoma (RCC) from oncocytoma using a HU threshold of 24 with a sensitivity of 100%, specificity of 86%, PPV of 75%, and NPV of 100%. The AUC for chromophobe RCC vs oncocytoma was 0.98 (95% confidence intervals 0.91-1.00). CONCLUSION: ALAD discriminates well between chromophobe RCC and oncocytoma, which may aid in the management of patients with indeterminate diagnoses of oncocytic neoplasm on diagnostic needle biopsy. Further validation of ALAD will be necessary prior to routine use in clinical practice.

The Effect of Continued Low Dose Aspirin Therapy in Patients Undergoing Percutaneous Nephrolithotomy.

PURPOSE: Aspirin is often stopped prior to percutaneous nephrolithotomy due to concern about the surgical bleeding risk. There is evidence that discontinuing aspirin perioperatively increases thromboembolic events and continuing it may be safe. We assessed the effect of continuing low dose aspirin through percutaneous nephrolithotomy and its effect on surgical and safety outcomes. MATERIALS AND METHODS: We retrospectively reviewed the records of 285 consecutive percutaneous nephrolithotomies performed between 2012 and 2015 at our institution. We compared outcomes and complications in patients who continued 81 mg aspirin daily to those in patients not receiving aspirin. RESULTS: A total of 67 patients (24.5%) were maintained on low dose aspirin and 207 (75.5%) were not on aspirin. The aspirin group was older (66 vs 52 years), included more tobacco users (58.2% vs 31.4%) and had a higher ASA® (American Society of Anesthesiologists®) score (2.9 vs 2.5, all p <0.001). There was no difference in mean S.T.O.N.E. (size, topography [stone location], obstruction, number of stones and evaluation of HU) score (7.6 vs 7.7, p = 0.71) or blood loss (44 vs 54 ml, p = 0.151). There was no difference in residual stone fragment size, including 0 to 2 mm in 65.3% vs 61.4% of aspirin vs no aspirin cases, 3 to 4 mm in 19.4% vs 16.2% and greater than 4 mm in 15.3% vs 22.4% (p = 0.407). Length of stay and the change in hemoglobin, hematocrit and creatinine were similar. There was no difference in the readmission rate (14.9% vs 12.6%, p = 0.618) or the total complication rate (34.4% vs 26.6%, p = 0.221). There was also no difference in the number of major complications (10.4% vs 5.8%, p = 0.193), bleeding complications (3.0% vs 2.9%, p = 0.971) and the transfusion rate (1.5% vs 1.0%, p = 0.57). CONCLUSIONS: Percutaneous nephrolithotomy appears effective and safe in patients who continue low dose aspirin perioperatively.

Postoperative rhabdomyolysis following robotic renal and adrenal surgery: a cautionary tale of compounding risk factors.

This study aimed at reviewing a contemporary series of patients who underwent robotic renal and adrenal surgery by a single surgeon at a tertiary referral academic medical center over a 6-year period, specifically focusing on the unique and serious complication of post-operative rhabdomyolysis of the dependent lower extremity. The cases of 315 consecutive patients who underwent robotic upper tract surgery over a 6-year period from August 2008 to June 2014 using a standardized patient positioning were reviewed and analyzed for patient characteristics and surgical variables that may be associated with the development of post-operative rhabdomyolysis. The incidence of post-operative rhabdomyolysis in our series was 3/315 (0.95%). All three affected patients had undergone robotic nephroureterectomy. Those patients who developed rhabdomyolysis had significantly higher mean Body Mass Index, Charlson Comorbidity Index, and median length of stay than those who did not. The mean OR time in the rhabdomyolysis group was noted to be 52 min longer than the non-rhabdomyolysis group, though this value did not reach statistical significance. Given the trends of increasing obesity in the United States and abroad as well as the continued rise in robotic upper tract urologic surgeries, urologists need to be increasingly vigilant for recognizing the risk factors and early treatment of the unique complication of post-operative rhabdomyolysis.