Drug-induced urinary calculi

Urinary calculi may be induced by a number of medications used to treat a variety of conditions. These medications may lead to metabolic abnormalities that facilitate the formation of stones. Drugs that induce metabolic calculi include loop diuretics; carbonic anhydrase inhibitors; and laxatives, when abused. Correcting the metabolic abnormality may eliminate or dramatically attenuate stone activity. Urinary calculi can also be induced by medications when the drugs crystallize and become the primary component of the stones. In this case, urinary supersaturation of the agent may promote formation of the calculi. Drugs that induce calculi via this process include magnesium trisilicate; ciprofloxacin; sulfa medications; triamterene; indinavir; and ephedrine, alone or in combination with guaifenesin. When this situation occurs, discontinuation of the medication is usually necessary.     

The modulus of toughness of urinary calculi

To improve the efficacy of extracorporeal shock wave lithotripsy (ESWL) treatment, it is desirable to identify the physical properties of urinary calculi could offer direct correlation with their fragilities during ESWL and thus could be used to guide treatment procedures for more effective stone fragmentation. Thirty stone specimens removed surgically were compressed by an axial testing system to measure the compressive strength and trace the stress-strain curve. Image analysis software SigmaScan (Jandel Co.) was used to calculate the area under the stress-strain curve, the modulus of toughness, for each stone. The values of compressive strength measured were similar to those reported by other researchers. The modulus of toughness of urinary calculi correlates with clinical representation of the stone fragility during ESWL. The modulus of toughness could be an index to evaluate the physical property of urinary calculi that could be used to guide treatment procedures for more effective stone fragmentation.     

微创经皮肾镜取石术治疗上尿路结石

目的:探讨微创经皮肾取石术(MPCNL)治疗上尿路结石的效果.方法:分别应用激光碎石术和气压弹道超声碎石术通过经皮肾镜通道治疗76例、82例上尿路结石,分析比较其结石清除率、出血量、手术时间等指标.结果:①微创经皮肾镜气压弹道超声碎石术Ⅰ期结石清除率为95.12%,高于激光碎石术的88.16%Ⅰ期结石清除率,差异具有显著性(P＜0.05).②气压弹道超声碎石术平均手术时间(74 min)和平均出血量(35 ml),显著少于激光碎石术的平均手术时间(92 min)和平均出血量(65 ml),差异具有显著性(P＜0.05).③两种治疗方法在造瘘管置留时间、平均住院时间、积水好转率、术后复发率上差异无统计学意义(P＞0.05).结论:微创经皮肾镜气压弹道超声碎石术相较于微创经激光碎石术在上尿路结石治疗中更为安全有效.     

Influence of succinimide on experimental rat urinary calculi]

An experimental study made on rat shows an inhibitrice activity of succinimide on formation of others kinds of urinary stones than those constituted with Ca oxalate and suggests the existence of a non specific anticrystallizing effect.