Screening for asymptomatic nephrolithiasis in primary hyperparathyroidism patients is warranted.

BACKGROUND: We aimed to investigate the prevalence, characteristics, and management of nephrolithiasis in primary hyperparathyroidism (PHPT) patients. METHODS: Medical records of patients who underwent parathyroidectomy at a tertiary care hospital in British Columbia from January 2016 to April 2023 were retrospectively reviewed. Demographic data, laboratory results, imaging reports, and urologic consultations were examined. Descriptive statistics and relevant statistical tests, including logistic regressions, were utilized for data analysis. RESULT: Of the 413 PHPT patients included in the study population, 41.9% harbored renal stones, and nearly half (48.6%) required urological interventions. Male sex, elevated preoperative serum ionized calcium (iCa) and 24-h urinary calcium (24 â€‹h urine Ca) levels were independent risk factors for stone formation. Additionally, male sex, younger age, and lower preoperative serum 25-hydroxyvitamin D (25(OH)D) level were associated with higher odds of requiring urological intervention for stones. CONCLUSIONS: This study identified significant prevalence of asymptomatic renal calcifications in PHPT patients, with a substantial proportion necessitating urological intervention. These findings emphasize the importance of incorporating screening and treatment of renal stones into the management of PHPT patients.

Pulse modulation with Moses technology improves popcorn laser lithotripsy.

PURPOSE: Moses™ technology has been developed to improve holmium laser fragmentation at 1-2 mm distance from the stone. Because popcorn lithotripsy is a non-contact technique, we compared short pulse (SP) and Moses distance (MD) modes in an in vitro model. METHODS: BegoStones were fragmented using a 120 W Ho:YAG laser (P120 Moses) and a 230 µm core fiber introduced through a ureteroscope. 20 W (1 J × 20 Hz; 0.5 J × 40 Hz) and 40 W (1 J × 40 Hz; 0.5 J × 80 Hz) settings (total energy 4.8 kJ) were tested using SP and MD modes. We assessed fragment size distribution and mass lost in fluid (initial mass-final dry mass of all sievable fragments). High-speed video analysis of fragmentation strike rate and vapor bubble characteristics was conducted for 1 J × 20 Hz and 0.5 J × 80 Hz. Laser strike rate (number of strikes divided by frequency) was categorized as: (1) direct-a visual plume of dust ejected from stone while in contact with fiber tip; (2) indirect-a visual plume of dust ejected with distance between stone and fiber tip. RESULTS: For 1 J × 20 Hz (20 W), MD resulted in more mass lost in fluid and a lower distribution of fragments ≥ 2 mm compared to SP (p < 0.05). 0.5 J × 80 Hz (40 W) produced no fragments ≥ 2 mm, and there were no significant differences in fragment distribution between MD and SP (p = 0.34). When using MD at 1 J × 20 Hz, 96% of strikes were indirect vs 61% for SP (p = 0.059). In contrast to the single bubble of SP, with MD, there was forward movement of the collapsing second bubble, away from the fiber-tip. CONCLUSIONS: For lower frequency and power popcorn settings, pulse modulation results in more fragmentation through true non-contact laser lithotripsy.

Understanding the Popcorn Effect During Holmium Laser Lithotripsy for Dusting.

OBJECTIVE: To assess low and high power settings for the popcorn technique, and relationship of laser fiber-to-stone distance and calyceal size on submillimeter fragmentation. Our in vitro findings may help guide strategies to improve a dusting technique for ureteroscopy. METHODS: BegoStones were fragmented in small (127 mm3) and large (411 mm3) sized bulbs to simulate calyces, using a 120 W Ho:YAG laser. A 242 µm fiber was introduced through a ureteroscope mounted to a 3D positioner with its tip located at 0 or 2 mm distance from the stones. 20 W [1 J × 20 Hz, 0.5 J × 40 Hz] and 40 W [1 J × 40 Hz, 0.5 J × 80 Hz] settings were assessed, including short pulse and long pulse modes. Total energy delivered was constant at 7.2 kJ. Primary outcome was percentage of stone mass converted to fragments <1 mm. High-speed imaging was performed to study stone movement and/or fragmentation. RESULTS: For all settings, popcorn lithotripsy yielded more submillimeter fragments when performed with the fiber positioned on the stone compared to 2 mm from the stone (P <.05). Distribution of submillimeter fragments was higher when utilizing high frequencies regardless of pulse energy. At 2 mm distance, popcorning was more effective in the small model (P <.05). At 2 mm distance, short pulse was superior to long pulse. Video analysis showed fragmentation did not occur when stones collided with each other. At 80 Hz/2 mm distance, only 17.5% of pulses impacted fragments. CONCLUSION: Popcorn technique is more effective when the fiber is directly in contact with stone, and when performed in a small calyceal model. Utilizing settings with higher frequencies may improve dusting outcomes.

Comparison of flexible ureteroscopy damage rates for lower pole renal stones by laser fiber type.

OBJECTIVES: Laser lithotripsy, often used during ureteronephroscopy (URNS), requires the Ho:YAG optical fiber transmit energy via total internal reflection (TIR). In critical lower pole deflections, energy may refract into the cladding causing fiber failure and scope damage. New optical fiber technology aims to have increased tolerance for high degrees of flexion. We compared two brands of laser fibers with sub-300 micron cores (Sureflex, Boston Flexiva) to determine failure rates and scope repair costs. METHODS: A retrospective cohort study comparing these two fibers for patients at a single academic institution who underwent flexible URNS with laser lithotripsy was performed from September 2013 to October 2015. Preoperative imaging was evaluated for stone burden and location. Intraoperative variables were collected, including energy use, lower pole lasering, laser fiber malfunction, and scope damage. The primary outcome was scope damage caused by laser fiber malfunction. Secondary outcome was scope repair costs. Fisher's exact test and two tailed t-tests were used. RESULTS: Of 223 subjects, 143 met inclusion criteria, and 8 had laser fiber failure. All failures occurred with the Sureflex fiber (8 of 63, 13%) vs the Boston Flexiva fiber (0 of 80, 0%) (P < 0.01). Malfunctions occurred in 8 of 79 lower pole stone applications versus 0 of 64 non-lower pole stone laser applications (P < 0.01). No other risk factor was different between fiber cohorts, except energy setting. Scope repair cost averaged $9155 CDN, yielding an average repair cost per case of $1144 CDN for the Sureflex versus $0 for the Boston fiber (P < 0.01). CONCLUSIONS: Both optical fibers perform well in non-lower pole locations. However, the challenge for laser fibers in lower pole URNS is to maintain TIR. Fiber failure reflects an inability to maintain reflection and is not based on energy used or stone burden. The Boston Flexiva laser fiber has fewer failures, resulting in $0 repair cost per case, compared to the Sureflex fiber in URNS with an average repair cost of $1144 CDN per case. Lasers Surg. Med. 50:798-801, 2018. © 2018 Wiley Periodicals, Inc.

Noninfectious Penile Lesions.

Noninfectious penile lesions are classified by clinical presentation as papulosquamous (e.g., psoriasis), inflammatory (e.g., lichen sclerosus, lichen nitidus, lichen planus), vascular (e.g., angiokeratomas), or neoplastic (e.g., carcinoma in situ, invasive squamous cell carcinoma). Psoriasis presents as red or salmon-colored plaques with overlying silvery scales, often with extragenital cutaneous lesions. Lichen sclerosus presents as a phimotic, hypopigmented prepuce or glans penis with a cellophane-like texture. Lichen nitidus usually produces asymptomatic pinhead-sized, hypopigmented papules. The lesions of lichen planus are pruritic, violaceous, polygonal papules that are typically systemic. Angiokeratomas are typically asymptomatic, well-circumscribed, red or blue papules, often with annular or figurate configurations. Carcinoma in situ should be suspected if there are velvety red or keratotic plaques on the glans penis or prepuce, whereas invasive squamous cell carcinoma presents as a painless lump, ulcer, or fungating mass. Some benign lesions, such as psoriasis and lichen planus, may mimic carcinoma in situ or invasive squamous cell carcinoma. Biopsy is indicated if the diagnosis is in doubt or neoplasm cannot be excluded. The management of benign noninfectious penile lesions usually involves observation, topical corticosteroids, or topical calcineurin inhibitors. Neoplastic lesions generally warrant organ-sparing surgery.

Common Questions About Chronic Prostatitis.

Chronic prostatitis is relatively common, with a lifetime prevalence of 1.8% to 8.2%. Risk factors include conditions that facilitate introduction of bacteria into the urethra and prostate (which also predispose the patient to urinary tract infections) and conditions that can lead to chronic neuropathic pain. Chronic prostatitis must be differentiated from other causes of chronic pelvic pain, such as interstitial cystitis/bladder pain syndrome and pelvic floor dysfunction; prostate and bladder cancers; benign prostatic hyperplasia; urolithiasis; and other causes of dysuria, urinary frequency, and nocturia. The National Institutes of Health divides prostatitis into four syndromes: acute bacterial prostatitis, chronic bacterial prostatitis (CBP), chronic nonbacterial prostatitis (CNP)/chronic pelvic pain syndrome (CPPS), and asymptomatic inflammatory prostatitis. CBP and CNP/CPPS both lead to pelvic pain and lower urinary tract symptoms. CBP presents as recurrent urinary tract infections with the same organism identified on repeated cultures; it responds to a prolonged course of an antibiotic that adequately penetrates the prostate, if the urine culture suggests sensitivity. If four to six weeks of antibiotic therapy is effective but symptoms recur, another course may be prescribed, perhaps in combination with alpha blockers or nonopioid analgesics. CNP/CPPS, accounting for more than 90% of chronic prostatitis cases, presents as prostatic pain lasting at least three months without consistent culture results. Weak evidence supports the use of alpha blockers, pain medications, and a four- to six-week course of antibiotics for the treatment of CNP/CPPS. Patients may also be referred to a psychologist experienced in managing chronic pain. Experts on this condition recommend a combination of treatments tailored to the patient's phenotypic presentation. Urology referral should be considered when appropriate treatment is ineffective. Additional treatments include pelvic floor physical therapy, phytotherapy, and pain management techniques. The UPOINT (urinary, psychosocial, organ-specific, infection, neurologic/systemic, tenderness) approach summarizes the various factors that may contribute to presentation and can guide treatment.

A multicenter comparison of the safety and effectiveness of ureteroscopic laser lithotripsy in obese and normal weight patients.

OBJECTIVE: Surgical treatment of kidney stones in an obese patient (body mass index [BMI] >30 kg/m(2)) remains challenging as shockwave lithotripsy may not be an option due to weight limitations. We sought to determine the effectiveness of ureteroscopic laser lithotripsy in obese patients compared to nonobese controls. MATERIALS AND METHODS: Patients from 2004 to 2007 were retrospectively analyzed providing a group of 292 patients (163 obese, 76 overweight, 53 normal) who underwent ureteroscopic procedures for urolithiasis at four centers in the United States and Canada. RESULTS: The percentage of obese patients requiring flexible ureteroscopy (URS) (79%) was higher than in the other groups (P<0.0001). Flexible URS was associated with a lower stone-free rate (SFR) on multivariate analysis (P=0.034). There was no difference in SFRs of patients who required a ureteral access sheath, basket extraction, or received a postoperative stent. Complication rates did not differ between groups. CONCLUSION: SFRs using ureteroscopic lithotripsy in obese and overweight populations are the same as in the normal weight patients. A flexible ureteroscope was associated with a decreased SFR, but this likely due to a more proximal stone location in these patients. Ureteroscopic laser lithotripsy is an effective and safe technique to treat urolithiasis in the overweight/obese patient.

Evaluation of a new 240-µm single-use holmium:YAG optical fiber for flexible ureteroscopy.

BACKGROUND AND PURPOSE: Numerous holmium:yttrium-aluminum-garnet laser fibers are available for flexible ureteroscopy. Performance and durability of fibers can vary widely among different manufacturers and their product lines with differences within a single product line have been reported. We sought to evaluate a newly developed nontapered, single-use 240-µm fiber, Flexiva™ 200 (Boston Scientific, Natick, MA), during clinical use and in a bench-testing model. MATERIALS AND METHODS: A total of 100 new fibers were tested after their use in 100 consecutive flexible ureteroscopic lithotripsy procedures by a single surgeon (B.K.). Prospectively recorded clinical parameters were laser pulse energy and frequency settings, total energy delivered and fibers failure. Subsequently, each fiber was bench-tested using an established protocol. Parameters evaluated for were fibers true diameter, flexibility, tip degradation, energy transmission in straight and 180° bend configuration and fibers failure threshold with stress testing. RESULTS: The mean total energy delivered was 2.20 kJ (range 0-18.24 kJ) and most common laser settings used were 0.8 J at 8 Hz, 0.2 J at 50 Hz, and 1.0 J at 10 Hz, respectively. No fiber fractured during clinical procedures. The true fiber diameter was 450 µm. Fiber tips burnt back an average of 1.664 mm, but were highly variable. With laser setting of 400 mJ at 5 Hz, the mean energy transmitted was 451 and 441 mJ in straight and 180° bend configuration, respectively. Thirteen percent of fibers fractured at the bend radius of 0.5 cm with a positive correlation to the total energy transmitted during clinical use identified. CONCLUSION: Fiber performance was consistent in terms of energy transmission and resistance to fracture when activated in bent configuration. Fiber failure during stress testing showed significant correlation with the total energy delivered during the clinical procedure. The lack of fiber fracture during clinical use may reduce the risk of flexible endoscope damage due to fiber failure.

Multi-institutional assessment of ureteroscopic laser papillotomy for chronic flank pain associated with papillary calcifications.

PURPOSE: We evaluated the long-term safety, efficacy and durability of ureteroscopic laser papillotomy for chronic flank pain associated with renal papillary calcifications. MATERIALS AND METHODS: We reviewed the medical records of all patients who underwent ureteroscopic laser papillotomy in the absence of free urinary calculi at our institutions from 1998 through 2008. Success was defined as patient report of significant pain relief. The duration of response was considered the time from papillotomy to repeat papillotomy in the same renal unit, patient report of recurrent pain or final followup. RESULTS: Ureteroscopic Ho:YAG laser papillotomy was done a total of 176 times in 65 patients, including 147 unilateral and 29 bilateral procedures. Of the patients 39 underwent multiple procedures (2 to 12). Symptomatic followup was available in 50 patients (146 procedures) during a mean of 38 months. Significantly less pain was reported after 121 procedures (83%). The mean duration of response per procedure was 26 months and 30 patients (60%) had a mean remission duration of greater than 1 year. Postoperatively hospital admission was required after 14 procedures (8%). There was no significant change in the mean estimated glomerular filtration rate during a mean 41.3-month followup. Seven of the 65 patients (11%) had hypertension before papillotomy. In 3 of the 49 patients (6.1%) with adequate followup new hypertension developed during a mean of 38 months. CONCLUSIONS: Ureteroscopic laser papillotomy is safe and effective. In patients with papillary calcifications and characteristic chronic, noncolicky pain this procedure provides significant, moderately durable symptom relief.

Femtosecond laser lithotripsy: feasibility and ablation mechanism.

Light emitted from a femtosecond laser is capable of plasma-induced ablation of various materials. We tested the feasibility of utilizing femtosecond-pulsed laser radiation (lambda=800 nm, 140 fs, 0.9 mJ/pulse) for ablation of urinary calculi. Ablation craters were observed in human calculi of greater than 90% calcium oxalate monohydrate (COM), cystine (CYST), or magnesium ammonium phosphate hexahydrate (MAPH). Largest crater volumes were achieved on CYST stones, among the most difficult stones to fragment using Holmium:YAG (Ho:YAG) lithotripsy. Diameter of debris was characterized using optical microscopy and found to be less than 20 microm, substantially smaller than that produced by long-pulsed Ho:YAG ablation. Stone retropulsion, monitored by a high-speed camera system with a spatial resolution of 15 microm, was negligible for stones with mass as small as 0.06 g. Peak shock wave pressures were less than 2 bars, measured by a polyvinylidene fluoride (PVDF) needle hydrophone. Ablation dynamics were visualized and characterized with pump-probe imaging and fast flash photography and correlated to shock wave pressures. Because femtosecond-pulsed laser ablates urinary calculi of soft and hard compositions, with micron-sized debris, negligible stone retropulsion, and small shock wave pressures, we conclude that the approach is a promising candidate technique for lithotripsy.

Ureteroscopic ultrasound technology to size kidney stone fragments: proof of principle using a miniaturized probe in a porcine model.

PURPOSE: A prototype ultrasound-based probe for use in ureteroscopy was used for in vitro measurements of stone fragments in a porcine kidney. METHODS: Fifteen human stones consisting of three different compositions were placed deep in the collecting system of a porcine kidney. A 2 MHz, 1.2 mm (3.6F) needle hydrophone was used to send and receive ultrasound pulses for stone sizing. Calculated stone thicknesses were compared with caliper measurements. RESULTS: Correlation between ultrasound-determined thickness and caliper measurements was excellent in all three stone types (r(2) = 0.90, p < 0.0001). All 15 ultrasound measurements were accurate to within 1 mm, and 10 measurements were accurate within 0.5 mm. CONCLUSION: A 3.6F ultrasound probe can be used to accurately size stone fragments to within 1 mm in a porcine kidney.

Noninfectious penile lesions.

Family physicians commonly diagnose and manage penile cutaneous lesions. Noninfectious lesions may be classified as inflammatory and papulosquamous (e.g., psoriasis, lichen sclerosus, angiokeratomas, lichen nitidus, lichen planus), or as neoplastic (e.g., carcinoma in situ, invasive squamous cell carcinoma). The clinical presentation and appearance of the lesions guide the diagnosis. Psoriasis presents as red or salmon-colored plaques with overlying scales, often with systemic lesions. Lichen sclerosus presents as a phimotic, hypopigmented prepuce or glans penis with a cellophane-like texture. Angiokeratomas are typically asymptomatic, well-circumscribed, red or blue papules, whereas lichen nitidus usually produces asymptomatic pinhead-sized, hypopigmented papules. The lesions of lichen planus are pruritic, violaceous, polygonal papules that are typically systemic. Carcinoma in situ should be suspected if the patient has velvety red or keratotic plaques of the glans penis or prepuce, whereas invasive squamous cell carcinoma presents as a painless lump, ulcer, or fungating irregular mass. Some benign lesions, such as psoriasis and lichen planus, can mimic carcinoma in situ or squamous cell carcinoma. Biopsy is indicated if the diagnosis is in doubt or neoplasm cannot be excluded. The management of benign penile lesions usually involves observation or topical corticosteroids; however, neoplastic lesions generally require surgery.

The relationship between sexual abuse and interstitial cystitis/painful bladder syndrome.

Interstitial cystitis/painful bladder syndrome (IC/PBS) is a chronic syndrome characterized by irritative voiding symptoms and pelvic pain or discomfort. IC/PBS represents localized bladder pathophysiologic changes and central nervous system upregulation. Patients exhibit bladder hyperalgesia and allodynia. Childhood sexual abuse occurs in up to 27% of females in the United States. Adults with a prior history of abuse or traumatization demonstrate hypothalamic-pituitary-adrenal (HPA) axis abnormalities, similar to IC/PBS patients. Childhood sexual abuse and physical traumatization are associated with subsequent lifelong risks of chronic pain syndromes. IC/PBS patients have increased rates of sexual abuse or physical traumatization histories compared with controls. IC/PBS patients with abuse histories tend to have greater pain intensity and lesser irritative voiding symptoms compared with nonabused IC/PBS patients. This article reviews the relationship between sexual abuse, HPA axis abnormalities, IC/PBS pathophysiology, and the role of sexual abuse on subsequent IC/PBS.

Quantification of holmium:yttrium aluminum garnet optical tip degradation.

INTRODUCTION: Optical laser fibers are utilized to transmit energy to the surface of a stone during holmium:yttrium aluminum garnet (Ho:YAG) laser lithotripsy. During lithotripsy, fiber tip degradation (burn back) can occur. Fiber burn back may diminish fragmentation efficiency, increase operative time, and increase cost because of fiber replacement. We hypothesize that fiber tip degradation (burn back) varies among different commercially available Ho:YAG laser fibers. METHODS: Fibers of varying core diameter sizes for Ho:YAG lithotripsy were evaluated from different manufacturers. Fibers were cleaved, stripped, polished, and inspected for tip uniformity. Fibers were initially tested without contact followed by contact testing using artificial Bego stones. Pre- and postcontact energy outputs were measured by energy detector. Distal tip degradation (burn back) was measured by digital micrometer. Testing was performed on two Ho:YAG lasers (Lumenis VersaPulse 100W and Dornier Medilas H20). All fibers were tested while submerged in water. RESULTS: No burn back was observed in any fiber tested in still water (without contact). Before and after lithotripsy, a trend existed with fibers demonstrating high burn back and high preablation energy outputs. The majority of these fibers were <300 microm diameter. Conversely, fibers with low burn back showed low preablation energy outputs and were >300 microm diameter. CONCLUSION: Fiber burn back and energy transmission varied among the fibers tested. Burn back only occurred during lithotripsy. Burn back may be reduced by fiber selection or using low pulse energy. Fiber burn back may affect the efficiency of fragmentation and contribute to decreased longevity of the fiber.

Proof of principle in vitro study of a prototype ultrasound technology to size stone fragments during ureteroscopy.

PURPOSE: Proof-of-principle in vitro experiments evaluated a prototype ultrasound technology to size kidney stone fragments. MATERIALS AND METHODS: Nineteen human stones were measured using manual calipers. A 10-MHz, 1/8'' (10F) ultrasound transducer probe pinged each stone on a kidney tissue phantom submerged in water using two methods. In Method 1, the instrument was aligned such that the ultrasound pulse traveled through the stone. In Method 2, the instrument was aligned partially over the stone such that the ultrasound pulse traveled through water. RESULTS: For Method 1, the correlation between caliper- and ultrasound-determined stone size was r(2) = 0.71 (P < 0.0001). All but two stone measurements were accurate and precise to within 1 mm. For Method 2, the correlation was r(2) = 0.99 (P < 0.0001), and measurements were accurate and precise to within 0.25 mm. CONCLUSIONS: The prototype technology and either method measured stone size with good accuracy and precision. This technology may be possible to incorporate into ureteroscopy.

Evaluation of 24 holmium:YAG laser optical fibers for flexible ureteroscopy.

PURPOSE: Prior study has shown that holmium:YAG laser fiber performance differs among manufacturers. We determined the performance and threshold for failure of 24 commercially available holmium:YAG laser fibers. MATERIALS AND METHODS: Single use and reusable fibers were tested in small (150 to 300 microm) and medium (300 to 400 microm) core diameter sizes. All fibers were evaluated for flexibility, failure threshold and true fiber diameter. Flexibility was measured by maximally deflecting a Stryker U-500 ureteroscope with the fiber in the working channel. The diameter of each fiber was measured by a digital micrometer. The failure threshold was assessed by bending the fibers to 180 degrees, beginning with a radius of 1.25 cm. A VersaPulse 100 W holmium:YAG laser was operated at 1.2 J and 10 Hz for 1 minute or until fiber fracture. The bend radius was decreased in 0.25 cm increments and testing was repeated until a minimum bend radius of 0.5 cm was attained or until the fiber failed. RESULTS: Of the small core fibers the SureFlex LLF-150 and LLF-273, OptiLite SMH1020F and Dornier LG Super 270 had the highest threshold for failure. The Accuflex 200 had the lowest failure threshold failing at the largest bend radius (1.75 cm). Of the medium core fibers the SureFlex LLF-365, Accuflex 365 and Lumenis SL 365 had the highest failure threshold, while the Dornier LG 400 and Lumenis EZ SL 365 were the lowest. The reusable Lumenis 365 fiber had a higher failure threshold than the single use Lumenis 365 fiber. CONCLUSIONS: Commercially available holmium:YAG laser fibers differ significantly in their performance characteristics.