ABSTRACT
OBJECTIVES. Several authors hypothesized the usefulness of the non-contrast helical computed tomography (NCHCT) with the determination of stone Hounsfield Unit (HU) values in order to predict urinary stone compositions. Preoperative knowledge of stone composition might be interesting in pre-operative decision-making process. The aim of this study was to evaluate the possible correlation between stone chemical composition and correspondent stone HU value in an in-vivo experience. METHODS. Forty patients with urinary stones were preoperatively studied with abdominal NCHCT, where stone HU values were reported. Stone chemical composition was obtained in each patient, using the colorimetric method. The HU value of each stone was compared with the correspondent chemical analysis. Results. The median HU values of calcium oxalate (n=10), mixed calcium oxalate and phosphate (n=19), calcium phosphate (n=2), uric acid (n=6) and mixed uric acid and calcium oxalate (n=3) stones were 1060 HU [interquartile range (IQR) 743.75-1222.5]; 900 HU (IQR 588.5-1108.5); 774 HU (range 720-828); 371 HU (IQR 361.25-436.25) and 532 HU (range 476-626), respectively. CONCLUSIONS. Our results confirmed a statistically significant difference of the HU values between calcium and pure uric acid calculi, suggesting a correlation between stone chemical composition and CT-density. Hounsfield unit.
ABSTRACT
A 40-year-old lady presented with marked swelling and inability to open her left eye immediately after laparoscopic nephrectomy for a left pyelonephritic kidney. A diagnosis of periorbital emphysema was made and within 7 days the emphysema spontaneously disappeared. Periorbital emphysema is a rare benign condition that may complicate a laparoscopic nephrectomy.
ABSTRACT
Flexible ureterorenoscopy should be routinely used at the Urological Centers that deal with urinary stones. Flexible instruments should be used for both diagnostic and therapeutic purposes, allowing a safe exploration of the whole upper urinary tract. Thanks to their flexibility and to the active and passive deflection of their distal part, these instruments allowed to successfully treat several difficult situations, such as renal caliceal calculi in the lower calices or even in some middle/upper calices or in horseshoe kidneys. The therapeutic potential of this approach is enhanced by the large availability of ancillary instrumentation, such as baskets, grasps, holmium laser fibers, etc, which is continuously growing. On the other side, a steep learning curve of the technique is usually required for the surgeon. Furthermore, the intrinsic fragility of the instrument components and a potentially lower quality, when compared to that of the rigid and semi-rigid ureteroscopes, should be considered.
