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. 2014 Jun;12(2):155-61.
doi: 10.1016/j.aju.2014.01.002. Epub 2014 Feb 16.

The success of extracorporeal shock-wave lithotripsy based on the stone-attenuation value from non-contrast computed tomography

Amr M Massoud  1 , Ahmed M Abdelbary  1 , Ahmad A Al-Dessoukey  1 , Ayman S Moussa  1 , Ahmed S Zayed  2 , Osama Mahmmoud  1
Affiliations

The success of extracorporeal shock-wave lithotripsy based on the stone-attenuation value from non-contrast computed tomography

Amr M Massoud et al. Arab J Urol. 2014 Jun.

Abstract

Objective: To determine the utility of the urinary stone-attenuation value (SAV, in Hounsfield units, HU) from non-contrast computed tomography (NCCT) for predicting the success of extracorporeal shock-wave lithotripsy (ESWL).

Patients and methods: The study included 305 patients with renal calculi of ⩽30 mm and upper ureteric calculi of ⩽20 mm. The SAV was measured using NCCT. Numerical variables were compared using a one-way analysis of variance with posthoc multiple two-group comparisons. Univariate and multivariate regression analysis models were used to test the preferential effect of the independent variable(s) on the success of ESWL.

Results: Patients were grouped according to the SAV as group 1 (⩽500 HU, 81 patients), group 2 (501-1000 HU, 141 patients) and group 3 (>1000 HU, 83 patients). ESWL was successful in 253 patients (83%). The rate of stone clearance was 100% in group 1, 95.7% (135/141) in group 2 and 44.6% (37/83) in group 3 (P = 0.001).

Conclusions: The SAV value is an independent predictor of the success of ESWL and a useful tool for planning stone treatment. Patients with a SAV ⩾956 HU are not ideal candidates for ESWL. The inclusion criteria for ESWL of stones with a SAV <500 HU can be expanded with regard to stone size, site, age, renal function and coagulation profile. In patients with a SAV of 500-1000 HU, factors like a body mass index of >30 kg/m(2) and a lower calyceal location make them less ideal for ESWL.

Keywords: BMI; BMI, body mass index; ESWL; HU, Hounsfield unit; Lower calyceal stone; NCCT, non-contrast computed tomography; ROC, receiver operating characteristic (curve); SAV, stone-attenuation value; Stone attenuation value; US, ultrasonography; Urinary calculi.

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Figures

Figure 1
Figure 1
The ROC curve for HU to determine which SAV threshold predicts the success or failure of ESWL.
None
See this image and copyright information in PMC

References

    1. Wolf J.S., Clayman R.V. Percutaneous nephrostolithotomy. What is its role in 1997. Urol Clin N Am. 1997;24:43–58. - PubMed
    1. Lingeman J.E., Newman D., Mertz J.H., Mosbaugh P.G., Steele R.E., Kahnoski R.J. Extracorporeal shock wave lithotripsy: the Methodist Indiana experience. J Urol. 1996;135:1134–1137. - PubMed
    1. Rassweiler J.J., Renner C., Chaussy C., Thüroff S. Treatment of renal stones by extracorporeal shockwave lithotripsy: an update. Eur Urol. 2001;39:187–199. - PubMed
    1. Pareek G., Armenakas N.A., Panagopoulos G., Bruno J.J., Fracchia J.A. Extracorporeal shock wave lithotripsy success based on body mass index and Hounsfield units. Urology. 2005;65:33–36. - PubMed
    1. Choi J.W., Song P.H., Kim H.T. Predictive factors of the outcome of extracorporeal shockwave lithotripsy for ureteral stones. Korean J Urol. 2012;53:424–430. - PMC - PubMed

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