Ultrasound an option for heavy patient’s kidney stones

Dear Dr. Roach: My urologist found two big kidney stones in my right kidney, too large to pass naturally. I thought that the option would then be to “crush” them to sand with laser or ultrasound and then flush out the sand by drinking lots of water.

However, my urologist says that I am too big for this to work (I weigh close to 300 pounds), as they would not be able to focus the laser properly. So, his preferred option is to surgically remove the stones when/if they become a painful problem. Right now, we are monitoring them twice a year with CAT scan and ultrasound checks. (The other alternative he suggested, of going up through my penis to crush the stones, sounds completely unappealing to me.)

Wouldn’t a surgical alternative also damage the kidney, if he has to cut into the kidney to take out the stones? It sounds rather risky to me. I would much prefer a laser solution that crushed the stones to sand without cutting into me or my kidney. I appreciate your opinion on this.

P.R. I don’t have enough information to recommend the optimal treatment to remove your particular stones, since knowing the size and location of the stones in the kidney is necessary to make that determination.

I can tell you that laser lithotripsy (from the Greek “lithos,” meaning “stone,” and “tripsis,” meaning “rubbing” or possibly “thryptein,” meaning “crushing”) has been successfully used in people up to 420 pounds, according to a 2009 study, and ultrasound lithotripsy has been used in people over 300 pounds in an earlier study. Complication rates are higher in heavier people, due to difficulty getting the focus correct, as you suggested.

Ten to 20 per cent of all stones still require surgical removal, and this can be done endoscopically in some cases. Surgical stone removal is safe and effective in most cases, but has the potential for complications, like all procedures. I’d recommend a second opinion from someone who has experience in performing the procedure.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu.