[Value of the continuous guide in endoscopic operations on the upper urinary tract]

Endoscopic operations on the upper urinary tract, whether they are performed from below upwards from the bladder or from above downwards from the kidney, are faced by a common difficulty: the risk of a false passage. This has led to the idea of using a flexible metal guide, as in vascular radiology. However, such a non-tense guide is not really a guide, as nothing prevents it from twisting around the end of the instrument which it is intended to guide, resulting in false passages. In contrast, a guide which is brought out through the urethral meatus and at the lumbar fossa can be placed under tension, preventing any deviation of the instrument or its covering catheter. The continuous guide is essentially used in three situations: 1. percutaneous nephrolithotomy: when a second phase is not excluded, the continuous guide will make it much easier; 2. descending ureteroscopy; 3. ascending ureteroscopy.