Faculty Bibliography

Flexible ureteroscopy (fURS) with laser lithotripsy is currently the gold standard surgical treatment for ureteral and kidney stones with a maximum diameter of 2 cm [...].

PURPOSE:Radiation exposure is affected by C-arm fluoroscopy device positioning during percutaneous renal puncture. Our aim was to compare the exposure of surgeon's lens, hand and chest with a fluoroscopy protocol replicated in different C-arm positions. MATERIALS AND METHODS:A standardized fluoroscopy protocol was created using water-equivalent solid phantoms to replicate a surgeon and patient. 111 mGy radiation (360 s) was applied in standard fluoroscopy mode (91 kVp, 2.7 mA/mAs). Dosimeters were placed on lens, chest and hand of surgeon and patient phantom models. 7 different C-arm positions were created: 0°, mediolateral (ML) +90°, ML -90°, ML +30°, ML -15°, craniocaudal (CC) +30°, CC +15°. Measurements were evaluated separately for different positions. RESULTS:The highest radiation exposure was measured on patient dosimeter (2.97 mSv). The highest exposure on surgeon was recorded on finger dosimeter in all C-arm positions; highest dose was recorded in ML +90° position (2.88 mSv). In finger dosimeters, lowest exposure was recorded in 0° position (0.51 mSv). The lowest exposure of all positions was measured in chest dosimeter in ML -90° position (0.24 mSv). CONCLUSIONS:In positions where X-ray generator of the C-arm was facing towards the surgeon, radiation exposure measured in all dosimeters was higher compared to positions where the generator was facing away. The hand radiation exposure in all positions was higher than chest and lens. Special care must be taken to avoid facing the X-ray generator tube and hands should be as well-protected as chest and eyes with special protective gear.

Advances in laser technology and surgical telescopic systems have propelled retrograde intrarenal surgery (RIRS) to the forefront as a viable alternative to percutaneous nephrolithotomy (PCNL). Currently, RIRS is being increasingly utilized as a treatment option, even for kidney stones larger than 2 cm. In this narrative review, we aimed to take a snapshot of current practice in renal stone treatment and the latest technological and technical developments and to evaluate the efficacy of RIRS in larger renal stones. With low complication rates and acceptable stone-free rates, RIRS offers patients a less invasive option with favorable outcomes. There are insufficient data comparing PCNL with RIRS using a new-generation high-power laser and suctioning ureteral access sheath (UAS). Further studies with novel lasers and UAS could provide superiority in terms of RIRS. It is crucial to take into account various patient-specific considerations, such as stone location and burden, when deciding on the appropriate treatment approach.

PURPOSE:We evaluated stone-free rate and complications after flexible ureteroscopy for renal stones, comparing thulium fiber laser and holmium:YAG laser with MOSES technology. MATERIALS AND METHODS:Data from adults who underwent flexible ureteroscopy in 20 centers worldwide were retrospectively reviewed (January 2018-August 2021). Patients with ureteral stones, concomitant bilateral procedures, and combined procedures were excluded. One-to-one propensity score matching for age, gender, and stone characteristics was performed. Stone-free rate was defined as absence of fragments >2 mm on imaging within 3 months after surgery. Multivariable logistic regression analysis was performed to evaluate independent predictors of being stone-free. RESULTS:< .001). At multivariable analysis, the use of thulium fiber laser and ureteral access sheath ≥8F had significantly higher odds of being stone-free. Lasing time, multiple stones, stone diameter, and use of disposable scopes showed significantly lower odds of being stone-free. CONCLUSIONS:This real-world study favors the use of thulium fiber laser over holmium:YAG laser with MOSES technology in flexible ureteroscopy for renal stones by way of its higher single-stage stone-free rate.

PURPOSE OF REVIEW/OBJECTIVE:Urinary pH is an important factor related to renal stone disease, and it plays an essential role in stone prevention. Monitoring of urinary pH by patients at home provides information that can help to assess the treatment needed by each patient. We conducted a systematic review is to assess the available evidence concerning urinary pH monitoring methods along with their accuracy, cost, and usefulness by patients with urolithiasis. RECENT FINDINGS/RESULTS:A total of 9 articles were included (1886 urinary pH measurements). They reported information about urinary dipsticks, portable electronic pH meters and electronic strip readers, amongst other methods. Accuracy was compared with a laboratory pH meter (gold standard). Urinary dipsticks were found to be not accurate enough to guide clinical decision making and portable electronic pH meters showed promising results. Urinary dipsticks are neither precise nor accurate enough. Portable electronic pH meters seem to be more accurate, easy to use, and cost-effective. They are a reliable source for patients to use at home in order to prevent future episodes of nephrolithiasis.

BACKGROUND:Retrograde Intrarenal Surgery (RIRS) is recommended as an alternative to percutaneous nephrolithotomy for stones up to 2 cm. Pre-stenting before RIRS remains controversial with various studies differing in outcomes and recommendations. We aim to understand how pre-stenting influences surgical outcomes. METHODS:A number of 6579 patients from the TOWER group registry were divided into pre-stented (group 1) and non-pre-stented groups (group 2). Patients aged ≥18 years old, with normal calyceal anatomy were enrolled. Patients with ureteric stones, anomalous kidneys, bilateral stones, planned for ECIRS were excluded. RESULTS:Patients are homogeneously distributed in both groups (3112 vs. 3467). The predominant indication for pre-stenting was symptom relief. Overall stone size was comparable, whilst group 1 had a significantly more multiple (1419 vs. 1283, P<0.001) and lower-pole (LP) stones (1503 vs. 1411, P<0.001). The mean operative time for group 2 was significantly longer (68.17 vs. 58.92, P<0.001). Stone size, LP stones, age, recurrence and multiple stones are contributing factors for residual fragments at the multivariable analysis. The incidence of postoperative day 1 fever and sepsis was significantly higher in group 2, indicating that pre-stenting is associated with a lower risk of post-RIRS infection and a lower overall complications rate (13.62% vs. 15.89%) (P<0.001). CONCLUSIONS:RIRS without pre-stenting can be considered safe without significant morbidity. Multiple, lower-pole and large stone is a significant contributor towards residual fragments. Patients who were not pre-stented had significantly higher but low-grade complications, especially for lower pole and large volume stones. While we do not advocate routine pre-stenting, a tailored approach for these patients should include proper counselling regarding pre-stenting.