Ultrasonography-guided punctures-with and without puncture guide.

The key requisite of any percutaneous nephrolithotomy technique is access to the collecting system. The kidney has a high degree of vascular network and is liable for vascular injury. Therefore, for an ideal puncture, a percutaneous tract would be developed that leads straight from the skin through a papilla and the target calix into the renal pelvis. Percutaneous renal access can be achieved under fluoroscopic control or using an ultrasonography (US)-guided puncture. The shortcomings and side effects of extensive radiation during therapeutic procedures are well known. The choice of method for the type of access depends on training and personal preference. The advantages of US-guided puncture are avoidance of radiation, avoiding adjacent and visceral injury and, most importantly, intrarenal vascular injury. US offers the shortest and straight access to the collecting system with minimal morbidity. US-guided access is of particular importance in the pediatric population and in special situations in which the procedure is performed with the patient in the supine position. I believe US-guided puncture has a significant reduction in complications. The available ultrasound probes come with a puncture attachment and, on US scanning, the puncture pathway is represented by an electronic dotted line on the scanner screen, which facilitates exact placement of the needle. US-guided access is optimal with a needle guide, because the electronic dotted line helps in assessing the depth and plane of the puncture needle. This helps in reaching the desired calix in the most accurate way. US access without a needle guide is useful in bedside procedures, in grossly hydronephrotic systems, and nonavailability of an electronic guide. We think the punctures with this technique are suboptimal. Both methods need a certain degree of training and orientation. The training in US should be structured.