Login to Access Video or Poster Abstract: MP90-02
Sources of Funding: none

Introduction

Oral dissolution therapy (ODT) for lucent renal calculi is non-invasive effective therapeutic approach however;responders to this approach are not well characterized.

Methods

After obtaining IRB approval, patients with renal stones of less than 600 HU core attenuation value in non contrast computed tomography (NCCT) and without significant hydronephrosis were counseled for 3 months ODT. ODT entails oral potassium citrate 20 mEq three times daily, 3 liters of daily fluid intake and dietary regimen. Patients were followed up at2,4,8 and12weeks,for assessment of ODT compliance and urine analysis.Patients with poor compliance (> one visit) were excluded from final analysis.Study`s end point was change in stone surface area as measured by NCCT at3 months. At 3 months, ODT non-responders were scheduled for secondary intervention and ODT partial responders (reduced stone SA) were asked to choose between ODT extra 3 months vs.immediate secondary intervention. Predictors for 3months ODT-stone free rate and final ODT-success rate were assessed._x000D_

Results

Between February 2015 and January 2016:out of 212 legible patients, 182 patients were compliant for ODT and were included in the final analysis.Figure1 summarizes, ODT responders at3 and 6 months. NCCT depicted 97(45.7%) and 57(31.3%)stone free responders at 3 and 6 months respectively.Table 1,summarizes variables that predict less stone free probability 3 months following start of ODT. On multivariate analysis,only proteinuria at urine dipstick at enrollment(p=0.003), stone density (p=0.01) and uric acid level at 8 weeks after treatment (p=0.03) independently predicts less stone free probability 3 months following start of ODT.Table 2 summarizes variables that predict ODT failure at6months.On multivariate analysis, only higher stone density (p=0.03) and lower urine PH at 12 weeks after treatment (p=0.01) independently predict ODT failure at 6 months.The cut-off point of stone density associated with less probability of successful ODT for is 463.5HU (67.7% Sensitivity, 68.9% Specificity, AUC 0.7,P=0.007).

Conclusions

Regardless stone size, ODT is an effective treatment approach for renal stones. Key factors in determining potential ODT responders are treatment compliance achieving targeted urine PH and low stone density.

Funding

none