Kaya C. et al., 2020: The Predictive Role of Abdominal Fat Parameters and Stone Density on SWL Outcomes
Kaya C, Kaynak Y, Karabag A, Aykaç A.
Department of Urology, Eskisehir City Hospital, Eskisehir, Turkey.
Department of Urology, Eskisehir Ümit Visnelik Hospital, Eskisehir, Turkey.
Department of Radiology, Eskisehir City Hospital, Eskisehir, Turkey.
Department of Urology, Medical School, Karabuk University, Karabuk, Turkey.
BACKGROUND: Our aim was to detect the role of radiological abdominal fat parameters by tomography and stone density by plain X-ray on extracorporeal Shock Wave Lithotripsy (SWL) stone-free rate.
METHODS: The patients who had undergone SWL for a single opaque renal stone < 2 cm in diameter and proximal ureteric stone < 1 cm in diameter were collected retrospectively. The characteristics of patients and stones were recorded. The stone attitude, HU, abdominal fat parameters, paraperirenal fat area, perirenal infiltration and severity of hydronephrosis with pre-treatment Non- Contrast Computed Tomography (NCCT) and stone density with radiography were evaluated by a radiologist. Four weeks after the last SWL; all patients were evaluated by plain X-ray and categorized as Stone Free (SF) and Residual Fragment (RF) group.
RESULTS: 51 patients with renal stones and 88 patients with proximal ureteral stones were included in the study. 24 (47%) and 63 (71%) patients were classified as SFfor renal and ureteral stones respectively. Only stone size was an independent predictor for stone-free rates after SWL for renal and proximal ureteral stones on multivariate analysis. The Receiver Operating Characteristic (ROC) curves for renal calculi revealed that creatinine level, stone size, stone attitude, Houns-Field Unit (HU) and Skin-to-Stone Distance (SSD) were the predictive factors for the SWL outcome (p< 0.05). The ROC curve for ureteral calculi demonstrated that HU, stone size and attitude were the predictive factors (p< 0.05).
CONCLUSION: All abdominal fat parameters and the stone density were not related to SWL failure. A large follow-up with more patients is essential to confirm the role of radiological parameters on the outcome of SWL.
Curr Med Imaging Rev. 2020;16(1):80-87. doi: 10.2174/1573405614666180927112127.
The fat business is going on and may be over. I remember the impressive colour coded pictures in a publication from 2012 (1) demonstrating the relation between ESWL success and fat.
A typical example of mixing random statistical relations with causal relations
1 Juan HC, Lin HY, Chou YH, et al. Abdominal fat distribution on computed tomography predicts ureteric calculus fragmentation by shock wave lithotripsy. Eur Radiol. 2012;22(8):1624–1630. doi:10.1007/s00330-012-2413-6