Fluid dynamics within renal cavities during endoscopic stone surgery: does the position of the flexible ureteroscope and ureteral access sheath affect the outflow rate?

PURPOSE: To evaluate the impact of ureteroscope position within renal cavities as well as different locations of the tip of the ureteral access sheath (UAS) on fluid dynamics during retrograde intrarenal surgery (RIRS). MATERIALS AND METHODS: A prospective observational clinical study was performed. Measurements with a flexible ureteroscope placed in the upper, middle and lower calyces were obtained with the tip of the UAS placed either 2 cm below the pyelo-ureteric junction (PUJ), or at the level of the iliac crest. RESULTS: 74 patients were included. The outflow rates from the middle and upper calyxes were statistically significantly higher compared to the lower calyx, both with the UAS close to the pyelo-ureteric junction and at the iliac crest. When the UAS was withdrawn and positioned at the level of the iliac crest, a significant decrease in outflow rates from the upper (40.1 ± 4.3 ml/min vs 35.8 ± 4.1 ml/min) and middle calyces (40.6 ± 4.0 ml/min vs 36.8 ± 4.6 ml/min) and an increase in the outflow from the lower calyx (28.5 ± 3.3 ml/min vs 33.7 ± 5.7 ml/min) were noted. CONCLUSIONS: Our study showed that higher fluid outflow rates are observed from upper and middle calyces compared to lower calyx. This was true when the UAS was positioned 2 cm below the PUJ and at the iliac crest. Significant worsening of fluid dynamics from upper and middle calyces was observed when the UAS was placed distally at the level of the iliac crest. While the difference was statistically significant, the absolute change was not significant. In contrast, for lower calyces, a statistically significant improvement was documented.

Nonpapillary prone endoscopic combined intrarenal surgery: effectiveness, safety and tips, and tricks.

PURPOSE: To evaluate the effectiveness and safety of nonpapillary prone endoscopic combined intrarenal surgery (ECIRS) and provide practical tips and tricks for the successful accomplishment of the procedure respecting the anatomical particularities. MATERIAL AND METHODS: This study is an analysis of a prospectively collected database including all cases of ECIRS performed between January 2019 and December 2021 in a high-volume tertiary center. All patients underwent the procedure in prone-split leg position. A nonpapillary renal puncture was performed. The used access sheaths were 22Fr or 30Fr. Lithotripsy was performed anterogradely with a dual-energy lithotripter with incorporated suction and retrogradely with holmium Yttrium-Aluminum-Garnet laser. RESULTS: A total of 33 patients were included. The initial stone-free rate (SFR) was 84.8% and the final SFR was 90.9%. The median stone size was 35 mm and 60% of patients had staghorn calculi. The prevalence of renal abnormalities was 21.3%, including 3 cases of horseshoe kidney, 2 cases of malrotation and 2 cases with complete duplicated systems. The median operative time was 47 min. The median hospital stay was 3 days and median hemoglobin loss was 1.2 gr/dL. Overall, the complication rate was 9.1%, all being Grade II complications (n = 2 fever and n = 1 transient bleeding). CONCLUSIONS: Nonpapillary prone ECIRS is an effective and safe procedure. Standardization of the procedure is critical to achieve good outcomes. Patients who benefit the most are probably the ones where additional punctures can be avoided using this technique, namely patients with renal abnormalities, incrusted ureteral stents and staghorn stones.

What is the impact of pulse modulation technology, laser settings and intraoperative irrigation conditions on the irrigation fluid temperature during flexible ureteroscopy? An in vivo experiment using artificial stones.

PURPOSE: To investigate the effect of different combinations of laser power settings and irrigation conditions using the pulse modulation technology of Quanta™ on irrigation fluid temperature (IFT) during FURS (flexible ureteroscopy) on an in-vivo porcine model with artificial stones. MATERIALS AND METHODS: A female pig was used. Following the insertion of artificial stones (Begostone™, BEGO USA, Lincoln, RI), a K-type thermocouple was fixed to the created percutaneous access tract. Real-time recordings of IFT during FURS were performed without UAS (ureteral access sheath), with 10/12 UAS, 12/14 UAS and 14/16 UAS. Stone fragmentation was achieved using Quanta Litho Cyber Ho 150 W™ (Samarate, Italy). The IFT was recorded for 30 s, during laser activation, with power settings of 20, 40, 60, 75 and 100 W under both manual pump and gravity irrigation. RESULTS: The IFT rise above 54 °C was recorded above a power of 40 W when gravity irrigation was used. The use of UAS prolonged the time for IFT to reach high values, although high power settings increase IFT within seconds from the laser activation. Under pump irrigation, only the 100 W power setting without the use of UAS resulted in dangerous IFT after approximately 10 s. CONCLUSION: The high-power Ho:YAG laser can cause a damaging thermal effect to the kidney exceeding the threshold of 54 °C, under gravity irrigation. Lower power settings (up to 40 W) can be used with safety. According to our experiment, when using high power settings, the use of UAS and manual pump irrigation, is the safest combination regarding renal thermal damage.

Stone ablation rates using innovative pulse modulation technology: Vapor tunnel, virtual basket, and bubble blast. An in vitro experimental study.

INTRODUCTION AND OBJECTIVES: Virtual BasketTM , Bubble BlastTM , and Vapor TunnelTM are three laser pulse modulation technologies that modify the holmium: yttrium-aluminum-garnet (Ho:YAG) laser pulse transmission through the creation of bubbles emerging from the fiber tip with different effects on the target stone. The primary outcome of the current study was to test the stone ablation rates for the different pulse modulation modes, Virtual Basket, Bubble Blast, and Vapor Tunnel, using different power, energy, and frequency settings. MATERIALS AND METHODS: Quanta Cyber: Ho 150 WTM , a 365 µm PrecisionTM fiber, and hard and soft phantom BegoStonesTM were used in an in vitro experimental configuration in a saline bath. In the Virtual Basket mode, the combinations of power, energy and frequency were tested; 10 W = 0.5 J × 20 Hz, 10 W = 0.5 J × 20 Hz, 60 W = 1 J × 60 Hz and 60 W = 2 J × 30 Hz. In the Bubble Blast mode, the combinations, 12 W = 1.2J × 10 Hz, 60 W = 1.2J × 50 Hz and 60 W = 2 J × 30 Hz, were tested. Similarly, the combination of 10 W = 0.5 J × 20 Hz was tested with Vapor Tunnel mode. High-speed camera captures of the bubble formation and regular photographs of the fragmentation pattern were also taken for each mode. RESULTS: High power lithotripsy was faster and related to higher ablation rates. The Virtual Basket, Bubble Blast, and Vapor Tunnel modalities showed different ablation rates for the same energy and frequency settings. For hard stones, there was an improvement in the ablation rate using 60 W = 2 J × 30 Hz compared with 60 W = 1 J × 60 Hz and 60 W = 1.2 J × 50 Hz. The highest ablation rates were recorded using the Virtual Basket mode with the high-power settings of 2 J of energy and 30 Hz of frequency. CONCLUSIONS: The Virtual BasketTM pulse-modulation technology was related to the highest ablation rates for both hard and soft stones, compared to the Bubble BlastTM and the Vapor TunnelTM technologies in high-power and low-power lithotripsy respectively. For the same high power settings, higher energy seems to provide higher ablation rates.

Parasitic Hematuria: Six Cases in a Row in a Single Centre in Spain.

Most cases of urogenital parasitosis are registered in Africa. However, migration movements and travellers moving from developed to developing countries are responsible for leading to an increased incidence of genitourinary infections caused by parasites in the western world including Spain having serious economic and health implications. The importance of its early detection and treatment also results from its potential risk for infertility, susceptibility for HIV infection and the development of bladder cancer. The most common presentation symptom is terminal haematuria, and when diagnosed, praziquantel is the treatment of choice. We report a series of 6 cases of urinary schistosomiasis that happened in a single centre in Spain and reminds the importance of having the infection in mind in certain cases of haematuria study.

Deep Vein Thrombosis: A Rare Cause of Acute Testicular Pain. Case Report: Literature Review.

INTRODUCTION: Thrombosis is defined as the formation of a clot in a blood vessel that obstructs the flow of blood to the peripheral tissues. The incidence of thromboembolic disease ranges from 0.7 to 1.2% within urology. CASE REPORT: A 40-year-old warehouse worker male presented to the emergency department with worsening of a month's lasting scrotal pain. Physical examination showed the presence of an enlarged and painful left testicle with no other findings. Right testicle, penis and abdominal examination showed no abnormalities whatsoever. Bilateral varicocele with a partial thrombosis of the left one associated with left inguinal hernia was diagnosed by performing an urgent testicular ultrasound test. Conservative treatment was first given. However, since pain was not relieved, surgery was indicated with left varicocelectomy and a left inguinal hernia repair procedure leading to complete symptoms control and normal testicular flow in the control Doppler ultrasound study 2 months after the surgery. CONCLUSION: Spontaneous thrombosis of the pampiniform plexus is a rare entity where the management remains controversial. The clinical case we report here shows that surgery may be considered an effective option.

Extranodal Richter's syndrome of the urinary bladder.

Lymphomas of the urinary bladder are rare and can be primary or secondary. The latter group includes Richter's Syndrome-which is a transformation of a chronic low-grade lymphoproliferative syndrome into a common type of non-Hodgkin lymphoma, most commonly localized in the lymph nodes. We report a case of an 84-year-old male, former-smoker with a history of low-grade chronic lymphocytic leukemia, treated with chemotherapy, with a recurrence of the disease to retroperitoneal and iliac lymph nodes, splenomegaly, and thickening of the bladder wall. The hematologist consulted us because of hematuria with coexistent bilateral obstructive uropathy. We performed transurethral resection of the bladder which revealed secondary lymphoma in the bladder, probably the result of a high-grade transformation from chronic leukemia, a very rare location of this transformation.

Radiological Density, Atomic Numbers, and Stone Fragmentation of Bego Stones Used for Research in Endourology: Comparison to Real Urinary Stones.

Objective: The aim of the study was to characterize artificial stones used for research in endourology in terms of radiological properties and hardness, based on stone fragmentation, and to compare them with real stones. Materials and Methods: We built artificial stones using BegoStone Plus™ powder (BEGO, Lincoln, RI), with powder (g)-water (mL) ratios ranging from 15:03 to 15:12. The CT Gemstone Spectral Imaging Software® (GE Medical Systems, LLC, Waukesha, WI) was used to evaluate the radiological density in HU and spectral properties. Stone fragmentation was assessed in an in vitro experimental setting. These properties of artificial stones were compared with real urinary calculi. Results: Regarding radiological density in terms of HUs, 15:03 artificial calculi showed similar results when compared with real stones comprising calcium oxalate and calcium phosphate. The 15:03 and 15:04 artificial stones showed similar spectral property results to calcium pyrophosphate stones. The 15:11 artificial stones showed similar stone fragmentation results to real stones comprising uric acid, and 15:03 artificial calculi showed similar results to apatite and cystine stones. Conclusions: Artificial stones are useful for research in endourology. Stones with a powder (g)-water (mL) ratio of 15:03 proved to mimic real hard stones in terms of HUs, atomic number, and stone fragmentation in our study and could be used as artificial hard stones, and 15:11 stones showed similar stone fragmentation to uric acid stones. Our study might suggest that standard Bego stones are useful to investigate different areas in endourology, but not radiological properties because radiological homogeneity is not ensured unless more sophisticated mixing methods are used.

Demonstrating the Efficacy of Dual Energy Computer Tomography with Gemstone Spectral Imaging Software to Determine Mixed and Single Composition ex vivo Urolithiasis.

Objective: To assess the capability of determining the mixed chemical composition of urinary stones using spectral imaging properties of Dual Energy Computed Tomography (DECT) Gemstone Spectral Imaging (GSI) software. Material and Methods: Twenty-six single and 24 mixed composition ex vivo urinary stones with known chemical composition determined by Fourier-transform infrared spectroscopy (FTIR) prior to this project were scanned with DECT imaging and GSI in vitro. The major components of the stones included Uric Acid (UA), Calcium Oxalate (CaOx), Calcium Phosphate (CaP), Magnesium Ammonium Phosphate (MAP), and Cystine (Cys). A histogram to display the distribution of the effective atomic number (Z-eff) of each pixel of the tested area, spectral curve (40-140 keV, with 10 keV interval) and Hounsfield Units (HU) of each stone scanned was provided with analysis of monochromatic images at 140 keV in the axial plane. Results: The overall pooled sensitivity, specificity, and accuracy of DECT for identifying major stone composition were 0.802, 0.831, and 0.807, respectively, with a 95% confidence interval. Accuracy was 100% for identifying UA and Cys stones. Conclusion: DECT is a superior imaging modality when compared to low dose computed tomography kidney ureter bladder scans. It allows for improved characterization of major components of urinary stones, in an accurate, non-invasive approach to pre-treatment. This can translate to urologists having greater confidence in determining patient suitability for medical or surgical management of their renal stones, in clinical practice.

Modified shockwave propulsion lithotripsy improves the lower pole renal stone clearance.

The shockwave lithotripsy is an established modality for the treatment of urinary stone disease. The aim of the study was to present our modified shockwave lithotripsy (SWL) technique, a shockwave propulsion lithotripsy (SWPL) technique, for the treatment of lower pole renal stones and compare its clinical outcomes with the standard SWL technique. An evaluation of a prospectively collected database including 168 patients divided into two groups and treated with ultrasound-guided SWL (n = 80) and SWPL (n = 88) were included in our study. The data were collected between January 2016 and December 2021. Patients older than 18 years old with single lower pole stones sized up to 2 cm were included in the study. SWPL was associated with significant higher SFR compared to standard SWL (85.2 vs. 62.5%, p = 0.001) and required less applied shockwaves (2151 vs. 2502, p = 0.001). Most of the patients in both groups underwent only one SWL session. Overall, a 7.1% complication rate (12 out of 168 patients) was reported, with no difference between groups. In conclusion, our proposed SWPL technique was aimed to overcome difficulties associated with the gravity and anatomic specificities of the lower pole, increased SFR and decreased the need for additional treatment.

Position-related anesthesiologic considerations and surgical outcomes of prone percutaneous nephrolithotomy: a review of the current literature.

The aim of the current study was to perform a critical review of existing literature and report the potential morbidity of patient positioning during urological surgeries as well as evaluate the surgical outcomes and anesthesiologic benefits and risks of prone percutaneous nephrolithotomy (PCNL). A narrative review of the current literature has been performed. Articles related to position-related injuries and complications under general anesthesia in prone positions were selected, studied, and considered for the current review. We found that under general anesthesia, the prone position improved the oxygenation of patients and increased the elimination of carbon dioxide. A potential risk for position-related anesthesiologic side effects was reported for longer spine surgeries in a prone position. The injuries and position-related side effects were extremely rare following prone PCNL since the mean duration of the procedure was significantly shorter than that of spine surgery. In conclusion, the prone PCNL remains the most often utilized and preferred approach globally with well-established success and complication rates. Clinical outcomes of prone PCNL do not demonstrate an increased rate of anesthesiologic complications compared to the supine approach. Standardization of turnover of the position, and reduction of the operative time warrant a faster and complication-free recovery.

Could the High-Power Laser Increase the Efficacy of Stone Lithotripsy During Retrograde Intrarenal Surgery?

Objective: To compare a high-power setting in holmium: yttrium-aluminum-garnet laser lithotripsy with the established low-power setting approach during retrograde intrarenal surgery (RIRS). Materials and Methods: Our study analyzed the data of consecutive patients managed with RIRS. The patients were divided into two groups according to the employed laser settings of power, energy, and frequency; dusting (20 W = 0.5 J × 40 Hz) (group 1) and stone self-popping (60 W = 1.5-2 J × 30-40 Hz) (group 2). Perioperative outcomes, including operative time (OT) and stone disintegration time (SDT), were compared between groups. The stone-free rate (SFR) was evaluated 1 month after the surgery. Results: Overall, 174 patients with 179 renal units were included. The dusting mode was utilized in 98 patients (100 renal units), whereas 76 patients (79 renal units) underwent the stone self-popping technique. The SFR was 82.1% for both groups. The OT and SDT were 60.1 ± 18.6 and 32.6 ± 9.4 minutes, respectively, for group 1 and 44.9 ± 15.5 and 16.5 ± 4.7 minutes, respectively, for group 2. According to the final analysis, laser lithotripsy using the stone self-popping technique was significantly faster compared with the dusting technique with coefficient values of 14.12 minutes (95% confidence interval [CI] = 8.8-19.44) and 15.84 minutes (95% CI = 13.44-18.2) for OT and SDT, respectively. Conclusions: The stone self-popping technique with power at 60 W, frequency at 30 to 40 Hz, and energy at 1.5 to 2.0 J is a safe and effective modality for active treatment of renal stones. In comparison with the dusting mode, it resulted in significantly faster procedures (14.12 minutes) with similar SFRs.

Recurrence of urethral leiomyoma: A case report.

Urethral leiomyoma is an infrequent benign tumor. Much more infrequent is recurrence. It has been described in exceptional cases. We report a rare case of a 46 year old woman who had a surgery for a urethral leiomyoma eight years ago. Now, she presents with nodulation in her vagina with no other symptoms. The patient underwent surgical excision of the tumor, and pathological examination revealed an recurrence of urethral leiomyoma.