Ultrasound guided ureteroscopy for the definitive management of ureteral stones: a randomized, controlled trial.

PURPOSE: Ureteroscopy is central to the surgical management of ureteral stones. Fluoroscopy is conventionally used for intraoperative guidance, although there is growing effort to decrease the exposure of patients and staff to ionizing radiation. We developed a radiation-free approach to ureteroscopy using ultrasound guidance to manage ureteral stones. To our knowledge we present the first randomized trial to study its safety and efficacy. MATERIALS AND METHODS: This single center, randomized clinical trial from 2011 to 2013 enlisted patients who presented with symptomatic ureteral stones 8 mm or less without a significant ipsilateral stone burden. Patients were randomly assigned to ultrasound or fluoroscopic guided ureteroscopy after temporizing ureteral stent placement. Intraoperative ultrasound guidance was performed using real-time imaging with the transducer placed at the patient flank to visualize the collecting system of the ipsilateral kidney. We compared operative time, stone size, stone-free status and complication rates between the 2 groups. RESULTS: A total of 50 patients were enrolled in study with 25 per arm. There was no difference in stone size (5.9 vs 5.7 mm), patient age (56 vs 52 years) or body mass index (31 vs 30 kg/m(2)) in the test group compared to controls. The ultrasound guidance cohort showed no significant difference in the stone-free rate (86% vs 86%) or the complication rate (8% vs 16%) compared to controls. Operative time was no longer in the ultrasound guidance cohort. CONCLUSIONS: In this feasibility study we found that ureteral stones may be definitively managed in a timely, effective and safe fashion without ionizing radiation in the general population using this novel technique of ultrasound guided ureteroscopy.

Difference in operative time according to stone location for endoscopic management of ureteral and renal stones.

OBJECTIVE: To study the difference in operative time for endoscopic management of ureteral and renal stones according to the stone location. MATERIALS AND METHODS: We hypothesized that these cases are not equivalent in terms of the surgeon's work as measured by the operating time, and we assessed whether significant variations exist within the umbrella of the Common Procedural Terminology code 52353: "ureterorenoscopic lithotripsy." We retrospectively reviewed the records of all patients undergoing unilateral ureteroscopic laser lithotripsy or retrograde intrarenal surgery under the care of 1 fellowship-trained endourologist from 2008 to 2010. The patients who underwent simultaneous additional endoscopic procedures, including bilateral ureteropyeloscopy, were excluded. The demographics, stone size and location, presence of a previously placed stent, and operative time were assessed and compared. The cohorts were designated according to the stone location--ureteral or renal. RESULTS: Of the total 213 ureteroscopic laser lithotripsy and retrograde intrarenal surgery cases reviewed, 115 were ureteral stones and 98 were renal stones. The renal stones required a significantly increased mean operative time (112 minutes) than did the ureteral stones (70 minutes; P <.001). The renal stone size was significantly larger (11.3 vs 7.7 mm, P <.001), and these cases had a greater preoperative stent rate (55% vs 37%, P = .014). CONCLUSION: Despite bundling within a single Current Procedural Terminology code, endoscopic management of renal stones and ureteral stones were markedly different, with a significant increase in the operative time for renal stones. The renal stone size was significantly larger, as expected. Current Procedural Terminology differentiation should be considered to appreciate the difference between ureteral and renal ureterorenoscopic lithotripsy in terms of resource requirements.

Ultrasound guided ureteroscopy in pregnancy.

INTRODUCTION: Management of renal colic and suspected urolithiasis in pregnancy remains a controversial topic. Competing concerns of operative fluoroscopy and prolonged duration of ureteral stent or nephrostomy tube fuel arguments for expectant management versus early surgical intervention. To address these concerns, we have offered ultrasound guided ureteroscopy for definitive management of suspected urolithiasis during pregnancy. We herein review our experience with this approach. METHODS: We performed a multi-center retrospective review of all pregnant patients undergoing ureteroscopy for suspected urolithiasis between 2008 and 2010. All pregnant patients who had undergone ultrasound guided ureteroscopy were included in this study. We evaluated presence of stone, stone size, operative time, stent duration, and post-operative course. RESULTS: Seven pregnant patients underwent ultrasound guided ureteroscopy. The mean age was 28 years, mean gestation 24 weeks, with stone sizes ranging from 5 to 22 mm. All patients had undergone preoperative stenting. Ureteral stones were identified and removed in four patients. Post-operative imaging confirmed that there was no residual hydronephrosis or significant ipsilateral renal stone burden. Average stent duration was 7.3 days. Preterm labor occurred in one case. DISCUSSION: In our experience, ultrasound guided ureteroscopy is a viable option in pregnancy to manage patients with suspected urolithiasis after failed expectant therapy. This method avoids fetal exposure to ionizing radiation, yet allows intraoperative radiographic monitoring. With this approach it is possible to render the patient stone free, obviating the need for ureteral stents for the duration of the pregnancy.

Effect of stone composition on operative time during ureteroscopic holmium:yttrium-aluminum-garnet laser lithotripsy with active fragment retrieval.

OBJECTIVE: To assess whether the stone composition affects the operative time of ureteroscopic holmium:yttrium-aluminum-garnet laser lithotripsy (ULL) with active fragment retrieval. The chemical composition of a calculus is known to affect the efficacy with which it is fragmented by a device, such as pneumatic, laser, or shock wave lithotripter. Previous studies examining the efficacy of holmium:yttrium-aluminum-garnet laser lithotripsy have been performed in vitro, but it is not known whether the operative time is significantly affected by the chemical composition of a patient's stone. METHODS: We selected all patients who had undergone ULL for stone disease from July 2008 to January 2011 for a retrospective chart review. We used a standardized operative technique of fragmentation and active retrieval of all fragments identified on full inspection of the entire collecting system using rigid and flexible endoscopes. The stone composition was defined as the presence of a single predominant (>51%) component. Statistical analysis was performed on a per-procedure basis relative to the stone burden, as measured in minutes of operative time per gram of stone. RESULTS: A total of 187 cases of unilateral ULL with active retrieval of stone fragments confirmed to have a single predominant chemical composition met the inclusion criteria. When accounting for the weight of the recovered stone, no difference was found in the operative time among the apatite, brushite, cystine, calcium oxalate monohydrate, calcium oxalate dihydrate, and uric acid stones. CONCLUSION: Although stone composition is widely recognized as an important procedural variable, especially for shock wave lithotripsy, it appears to have little effect on the overall operative time for holmium:yttrium-aluminum-garnet lithotripsy when using active fragment retrieval.

Differential diagnosis of solitary lung nodules with gene expression ratios.

OBJECTIVE: We have developed a new technique that uses the ratios of select gene expression levels to translate complex genomic data into simple clinically relevant tests for the diagnosis and prognosis of cancer. We determined whether select gene pair ratio combinations can be used to detect and diagnose lung cancer with high accuracy and sensitivity. METHODS: We used gene expression profiling data to train a ratio-based predictor model to discriminate among a set of samples (n = 145 total) composed of normal lung, small cell lung cancer, adenocarcinoma, squamous cell carcinoma, and pulmonary carcinoid (the training set). We then examined the optimal test in an independent set of samples (the test set, n = 122). Finally, we used one aspect of the test to determine whether the gene ratio technique was capable of detecting cancer in specimens from fine-needle aspirations performed ex vivo with normal lung (n = 14) and suspected tumor nodules (n = 15) acquired at our institution. RESULTS: We found that a ratio-based test with 23 genes could be used to classify training set samples with 90% accuracy. This same test was similarly accurate (88%) when applied to the test set of samples. We also found that this test was 87% and 100% accurate at detecting cancer in normal and tumorous fine-needle aspiration specimens, respectively. CONCLUSION: The gene expression ratio diagnostic technique is likely to aid in the differential diagnosis of solitary lung nodules in patients with suspected cancer and may also prove useful in developing lung cancer screening strategies that incorporate analysis of fine-needle aspiration specimens.