Canal-U

Percutaneous nephrolothotomy: the easy puncture

Correct puncture of the tip of the chosen calyx is a prerequisite for proper ppercutaneous surgery. Bidimensionnal X-Ray is undoubtedly the best equipment but very few institutions can afford it. In fact, a simple C-Arm poortable X-Ray unit is quite sufficient for proper needle guidance : With a patient in the prone position, and a ureteral catheter inserted, a vertical beam gives very good information on calyx geography. However, when the needle is super-imposed to the calyx on the screen if the needle in not in the calyx, it can be either too deep or too superficial. Instead of using a horizontal beam, very difficult to read we advocate to rotate the beam 30 degrees towards the head of the patient : the image of needle and callyx will be modified in the following fashion : the needle in displaced towards the renal lower pole if the needle in too superficial, and towards the renal upper pole if the needle in too deep.