Can infundibular height predict the clearance of lower pole calyceal stone after extracorporeal shockwave lithotripsy?

Abstract

PURPOSE: To evaluate the efficacy of extracorporeal shock wave lithotripsy (SWL) on lower calyceal calculi in relation to the renal anatomical factors and determine which of these factors can be used to select patients who will benefit from SWL. MATERIAL AND METHODS: We analyzed retrospectively 78 patients with single radiopaque lower calyceal stones treated with SWL. The patients were evaluated 3 months after lithotripsy with a simple abdominal X-ray and a kidney ultrasound scan. The success of the treatment, removal of all fragments, was correlated with renal anatomical factors measured in the pre-treatment intravenous urography: infundibulopelvic angle, lower infundibulum width, lower infundibulum length, ratio length/width, infundibulum height, and number of minor calyces in the lower calyceal group. RESULTS: Three months after SWL treatment, 39 patients were stone-free (NR group) and 39 had residual fragments (R group). Both groups presented no differences in relation to infundibulopelvic angle, width and length of the lower calyceal infundibulum, length/width ratio of the lower infundibulum or number of lower calyces. Height of the infundibulum, described as the distance between the line passing through the lowest part of the calyx containing the calculus and the highest point of the lower lip of renal pelvis, was the only parameter in which significant differences (p = 0.002) were found between the NR and R groups. CONCLUSIONS: Lower Infundibular height could be a good measurement tool for deciding which patients with lower calyceal lithiasis would benefit from SWL treatment. Height of less than 22 mm suggests a good outcome from lithotripsy

Revisiting the morphology of pelvicalyceal system in human cadaveric kidneys with a systematic review of literature

“…The congenital anomalies of upper urinary tract occur in almost 10% of all urinary system malformations. Calculi in lower calyceal group represent more cases in almost 24%–44% of all calculi requiring treatment because of longer stasis of urine in lower infundibulum [6] , [9] .…”

“…In present study, we found more percentage of extra-renal pelvis (21.9%) in comparison to previous authors ( Table 1 ). Clinically, the extra-renal pelvis is roomier and more convenient to explore during nephron sparing surgery and partial nephrectomy than the intra-renal pelvis because it provides larger surface area away from the renal vasculature for safe surgery but the drawback is that the larger pelvic space aggravates accumulation and stasis of urine predisposing formation of renal calculi [9] . A distended renal pelvis and collecting system facilitate the puncture, placement, and maneuvering of the endourologic instruments and by providing a larger fluid chamber around a stone, enhance the efficacy of ESWL [11] , [12] , [13] , [14] .…”

Lower Pole Midsize (1–2 cm) Calyceal Stones: Outcome Analysis of 56 Cases

“…This finding might explain the variability of the results in different reports. Arzoz-Fabregas et al [11] reported that lower infundibular height was the only anatomical factor that could be a good measurement tool for deciding which patients with lower calyceal lithiasis would benefit from SWL treatment. They suggested that patients with a lower infundibular height <22 mm have a good outcome from lithotripsy.…”

Shock wave lithotripsy outcomes for lower pole and non-lower pole stones from a university teaching hospital: Parallel group comparison during the same time period

“…[ 9 ] Other studies have shown that a shorter infundibular length (<22 mm) as well as larger stone size (>10 mm) and burden can decrease stone free rates. [ 3 4 5 8 9 10 11 ]…”

“…Several studies have shown that treatment of lower pole stones (LP) stones has a lower stone free rate (SFR) than other renal or ureteral stones due to the LP anatomy. [ 3 4 5 ]…”