Renal Calculus

September 1, 2005

A 30-year-old active-duty sergeant with no history of urinary tract disease presented to a combat support hospital with acute pain in the left lower abdominal quadrant. For 4 months, the pain had been mild and intermittent; it had worsened during the past 24 hours. Before deployment, microscopic hematuria had been detected and the soldier had been informed of the possibility of a urinary stone.

 

A 30-year-old active-duty sergeant with no history of urinary tract disease presented to a combat support hospital with acute pain in the left lower abdominal quadrant. For 4 months, the pain had been mild and intermittent; it had worsened during the past 24 hours. Before deployment, microscopic hematuria had been detected and the soldier had been informed of the possibility of a urinary stone.

The pain was severe (10 on a scale of 1 to 10) and constant. Vital signs were normal. Serum chemistries were unremarkable. His urine was dark yellow; microscopy revealed 20 to 30 red blood cells per high-power field. An abdominal radiograph showed a large (10 mm) left renal pelvic calculus (A). Intravenous morphine sulphate (20 mg), meperidine (50 mg), and promethazine (25 mg) failed to control the pain.

Thomas A. Rozanski, COL, MC, of San Antonio, Tex, and Jeffrey M. Edmondson, COL, MC, of Fairfax, Va, write that the pain had initially appeared to be renal colic secondary to the large left renal calculus. During ureteral stent placement, retrograde ureterography demonstrated a dense left distal ureteral stricture and proximal dilation (B). A floppy-tip guidewire was negotiated beyond the stricture; however, a stent could not be advanced through the stricture, and the endoscopic procedure was terminated.

Large renal calculi rarely cause acute symptoms. Many large staghorn calculi are asymptomatic and do not obstruct the ureter. Although renal colic often radiates from the affected flank to the groin and/or ipsilateral testis in men, this soldier's pain did not radiate.

The cause of this large calculus is probably urinary stasis secondary to obstruction from the ureteral stricture. Explanations for the high rate of urinary stone formation in deployed soldiers include the high ambient temperatures, increased fluid loss from insensible perspiration, decreased fluid intake, and high sodium content in prepackaged meals.

Most renal calculi are small and pass spontaneously after several days of hydration and analgesia. A small percentage of stones require intervention, such as stent placement and removal,1 surgical removal, or extracorporeal shock wave lithotripsy.

This soldier underwent endoscopic correction of the distal obstruction and surgical removal of the renal stone.

References:

REFERENCE:1. Leventhal EK, Rozanski TA, Crain TW, Deshon GE Jr. Indwelling ureteral stents as definitive therapy for distal ureteral calculi. J Urol. 1995;153:34-36.