Kevan Sternberg

Preoperative stenting decreases operative time and reoperative rates of ureteroscopy.

PURPOSE Large stone burden can be treated ureteroscopically, but the treatment often requires more than one procedure. Placement of a preoperative stent may theoretically enhance stone clearance by dilating the ureter to facilitate both access and stone removal. This study determines the impact of stent placement before ureteroscopy on operative time, radiologic stone clearance, and reoperative rates. MATERIALS AND METHODS We retrospectively reviewed the records of patients who underwent ureteroscopic stone intervention at our institution from 2002 to 2008 by a single surgeon. Nonstented matched controls were used for comparison. Demographics, stone characteristics (size, number, density, and location), presence of preprocedural ureteral stent, operative time, and results of postoperative imaging were compared between the two cohorts. Statistical analysis was performed. RESULTS There were 104 patients included in the study (45 prestented and 59 nonstented). Median stone size was 1 cm (range 0.3-4 cm). Overall stone clearance was 95.8%. The median number of procedures was one. Prestenting significantly reduced operative time during first ureteroscopy in patients with large stone requiring multiple ureteroscopies (p = 0.008) and total operative time to stone clearance in patients with stone >1 cm (p = 0.01), but not in patients with stone burdens <1 cm (p = 0.48). Prestenting also significantly reduced reoperative rates in patients with stone burden >1 cm (p = 0.001), especially for stones located in proximal ureter and kidney. Prestenting improves postoperative radiologic clearance, but this was not statistically significant (p = 0.56). CONCLUSIONS Results show that ureteroscopic lithotripsy of large stone burden can be performed with a high success rate. Preureteroscopic stent placement was associated with a decreased operative time and reoperative rates in patients with larger stone burdens of >1 cm.

Ultrasonography Significantly Overestimates Stone Size When Compared to Low-dose, Noncontrast Computed Tomography

OBJECTIVE To evaluate the differences between low-dose noncontrast computed tomography (NCCT) and renal ultrasound (US) in the identification and measurement of urinary calculi. MATERIALS AND METHODS A retrospective review was conducted at 3 institutions of patients evaluated for flank pain with both renal US and NCCT, within 1 day of one another, from 2012 to 2015. Stone presence and size were compared between imaging modalities. Stone size was determined by largest measured diameter. Stones were grouped into size categories (≤5 mm, 5.1-10 mm, and >10 mm) based on NCCT and compared with US. Statistical analysis was performed using 2-sided t tests. RESULTS One hundred fifty-five patients received both a renal US and NCCT within 1 day. In 79 patients (51.0%), both US and NCCT identified a stone for size comparison. Fifty-eight patients (37.4%) had a stone visualized on NCCT but not on US, and 2 patients (1.3%) had a stone documented on US but not seen on NCCT. The average NCCT size of the stones missed on US was 4.5 mm. When comparing the average largest stone diameter for US (9.1 mm) vs NCCT (6.9 mm), US overestimated stone size by 2.2 mm (P < .001). US overestimated stone size by 84.6% for stones ≤5 mm, 27.1% for stones 5.1-10 mm, and 3.0% for stones >10 mm. CONCLUSION US significantly overestimated stone size and this was most pronounced for small (≤5 mm) stones. The potential for systematic overestimation of stone size with standard US techniques should be taken into consideration when evaluating endourologic treatment options.

Compliance with American Urological Association Guidelines for Post-Percutaneous Nephrolithotomy Antibiotics Does Not Appear to Increase Rates of Infection

PURPOSE We compared infection rates after percutaneous nephrolithotomy in a group of patients without a history of infection or struvite calculi who received 24 hours or less of antibiotics postoperatively (ie compliance with AUA guidelines) vs a group that received 5 to 7 days of antibiotics postoperatively. MATERIALS AND METHODS We retrospectively reviewed the records of consecutive percutaneous nephrolithotomy procedures in patients without a history of urinary tract infection. Group 1 received 24 hours or less of antibiotics postoperatively and group 2 received a mean of 6 days of antibiotics postoperatively. RESULTS A total of 52 patients in group 1 (24 hours or less of antibiotics) and 30 in group 2 (mean 6 days of antibiotics) met study inclusion criteria. In 5 group 1 patients (9.6%) fever developed within 72 hours of percutaneous nephrolithotomy but none demonstrated bacteriuria or bacteremia on cultures. No patient in group 1 was treated for urinary tract infection on postoperative days 3 to 14. In 4 group 2 patients (13.3%) fever developed within 72 hours of percutaneous nephrolithotomy. A single patient showed bacteriuria (less than 10,000 cfu mixed gram-positive bacteria) on culture while no patient demonstrated bacteremia. No patient in group 2 was treated for urinary tract infection on postoperative days 3 to 14. There was no difference in stone-free rates or the need for additional procedures between the 2 groups. CONCLUSIONS In this pilot series compliance with AUA guidelines for antibiotic prophylaxis did not result in higher rates of infection than in a comparable group of 30 patients who received approximately 6 days of antibiotics postoperatively.

Is Hydronephrosis on Ultrasound Predictive of Ureterolithiasis in Patients with Renal Colic

PURPOSE Renal ultrasound accurately identifies hydronephrosis but it is less sensitive than computerized tomography for the detection of ureterolithiasis. We investigated whether the presence of hydronephrosis on ultrasound was associated with a ureteral stone in patients who underwent both ultrasound and computerized tomography during the evaluation of acute renal colic. MATERIALS AND METHODS We retrospectively reviewed the records of patients from 3 institutions who were evaluated for acute renal colic by both ultrasound and computerized tomography between 2012 and 2015. Patients were included in analysis if ultrasound and computerized tomography were performed on the same day. The presence of ureterolithiasis, stone location and hydronephrosis was reviewed and compared between imaging modalities. RESULTS Ureteral stones were present in 85 of 144 patients. Ultrasound identified hydronephrosis in 89.8% of patients and a ureteral stone in 25.9%. Computerized tomography identified hydronephrosis in 91.8% of patients and a ureteral stone in 98.8%. In 75.0% of cases the presence or absence of hydronephrosis on ultrasound correctly predicted the presence or absence of a ureteral stone on computerized tomography. Hydronephrosis on ultrasound had a positive predictive value of 0.77 for the presence of a ureteral stone and a negative predictive value of 0.71 for the absence of a ureteral stone. CONCLUSIONS Hydronephrosis on ultrasound did not accurately predict the presence or absence of a ureteral stone on computerized tomography in 25.0% of the patients in this study. Ultrasound is an important tool for evaluating hydronephrosis associated with renal colic but patients may benefit from other studies to confirm the presence or absence of ureteral stones.

A Retrospective Review Demonstrating the Feasibility of Discharging Patients Without Opioids After Ureteroscopy and Ureteral Stent Placement

PURPOSE Efforts have begun to implement nonopioid protocols for outpatient urologic surgery. In this study, we report a retrospective review of the feasibility of implementing a nonopioid protocol to manage postoperative pain after ureteroscopy with stent placement. METHODS Between November 2016 and March 2018, 210 patients underwent ureteroscopy with stent placement by a single surgeon at an academic medical center. A treatment algorithm was used to determine the eligibility and appropriately select patients for the nonopioid pathway. Frequency of postoperative events was reviewed and included visits to the emergency department (ED), telephone calls to the clinic, and requests for prescription refills. RESULTS Two hundred six of 210 patients met the inclusion criteria. Of these 206 patients, 151 were discharged without opioid medications (73%) and 55 received opioids (27%). Both patients receiving opioids and nonopioids had a low number of postoperative visits to the ED for genitourinary-related concerns (7 patients receiving opioids [13%] and 15 patients without opioids [10%]). Telephone calls made to the urology clinic for concerning symptoms were made by 25 patients receiving opioids (45%) and 32 patients without opioids (21%). The number of pain medication refill requests was low for both groups: 13 patients receiving opioids (24%) and 11 patients without opioids (7%). CONCLUSIONS Our experience using a nonopioid pathway after ureteroscopy and stent placement reveals that approximately three-fourths of patients can be discharged without opioids. Patients had a low number of visits to the ED for postoperative genitourinary symptoms, a low number of telephone calls to the clinic, and requested few prescription pain medication refills regardless of whether or not they received opioids on discharge.