A Prospective Evaluation of High-Resolution CT Parameters in Predicting Extracorporeal Shockwave Lithotripsy Success for Upper Urinary Tract Calculi.

OBJECTIVE: To evaluate the ability of noncontrast CT parameters (stone size, stone attenuation, and skin-to-stone distance [SSD]) to predict the outcome of extracorporeal shockwave lithotripsy (SWL) in a prospective cohort of patients with renal and upper ureteric stones. PATIENTS AND METHODS: Patients with stones 5 to 20 mm were prospectively enrolled from 2011 to 2014. Patients had NCCT with recording of stone size, stone mean attenuation, and SSD, as well as various stone and patient parameters. The numbers of needed sessions as well as the final outcome were determined, with SWL failure defined as residual fragments >3 mm. Predictors of SWL failure were assessed by multiple regression analysis. RESULTS: Two hundred twenty patients (mean ± standard deviation [SD] age 41.5 ± 12.4 years) underwent SWL. Mean ± SD stone size was 11.3 ± 4.1 mm, while mean ± SD stone attenuation was 795.1 ± 340.4 HU. Mean ± SD SSD was 9.4 ± 2.1 cm. The average number of sessions was 1.64. SWL was effective in 186 (84.5%) patients (group A), while 34 (15.5%) patients had significant residual fragments (>3 mm). On univariate analysis, predictors of SWL failure included stone attenuation >1000 HU, older age, higher body mass index, higher attenuation value, larger stone size, and longer SSD. Increased SSD and higher stone attenuation retained their significance as independent predictors of SWL failure (p < 0.05) on multiple regression analysis both after first session and as final SWL outcome. A positive correlation was found between number of SWL sessions and mean stone attenuation (r = 0.6, p < 0.001) and SSD (r = 4, p < 0.001). CONCLUSIONS: Stone mean attenuation and SSD on noncontrast CT are significant independent predictors of SWL outcome in patients with renal and ureteric stones. These parameters should be included in clinical decision algorithms for patients with urolithiasis. For patients with stones having mean attenuation of >1000 HU and/or large SSDs, alternatives to SWL should be considered.

A novel antireflux technique for orthotopic ileal bladder substitutes-flat-segment technique: preliminary results.

Objective. Although a large debate exists regarding the need for reflux prevention in ileal orthotopic neobladders, it is our policy to continue performing nonrefluxing ureteroileal anastomoses for our patients. An ideal uretero-ileal anastomosis must be simple, nonrefluxing, as well as non-obstructive. Here, we present a new antireflux mechanism for orthotopic ileal neobladders. Methods. 12 radical cystectomy patients for muscle invasive bladder cancer were candidates for orthotopic urinary diversion and underwent a non-refluxing uretero-ileal anastomosis using the flat-segment technique with a follow up of 6 to 18 months. Results. Preliminary results after the short-term followup showed that the success rate in reflux prevention was 92% and no cases of obstruction. The upper tracts were preserved or improved in all 12 patients. Operative time for neobladder creation ranged between 120-240 minutes, with a mean of 165 minutes (±36 minutes). No diversion-related complications. Conclusions. Based on our early data, we believe that the flat-segment uretero-ileal anastomosis technique for reflux prevention in orthotopic ileal bladder substitutes is simple, easy to learn and carries no additional morbidity to a standard refluxing uretero-ileal anastomosis, but has the advantage of effective reflux prevention. A longer follow-up period study with more patient numbers is ongoing.