Check according to your internal hospital procedures the identity of the patient, the kind of procedure, and the side to be operated (that has to be correctly marked).

Check that the operating table is radiolucent, can be sufficiently translated leaving the abdomen free of radiopaque obstacles and easily host the C-arm of the fluoroscopy for radiological control during the procedure in the areas of interest, and can be arranged with the leg stirrups for lithotomic position.

If the OR is too narrow, incline the operating table, leaving more space on that side to be operated; the floor may be prepared with absorbing materials, in order to avoid inadvertent spilling of irrigation fluids all around.

The first landmark is the posterior axillary line (Fig. 11.3) that has to be drawn with an undeletable pen possibly with the patient standing, arm up, or in any case with the patient pure supine before starting the positioning maneuvers.

The patient is then positioned supine on the operating table, near to the border of the side with the stone to be operated (this is important to increase free mobility of the nephroscope), then prepared and anaesthetized.

The arm contralateral to the side to be operated lies abducted of less than 90° and slightly flexed on a padded support, or along the body, for anesthesiological management (Fig. 11.4).

The ipsilateral arm of the patient crosses the chest lying on it or supported, further elevating the posterior axillary line (Fig. 11.5). It is preferable not to use metallic arm support, because this interferes with the X-ray beam, should the C-arm be tilted cephalad, during fluoroscopic-controlled access creation. A padded support maintains the arm with an angle less than 90° with that of the operating table.

The lumbar region is lifted approximately 20° and exposed. There are several ways to tilt the patient. Valdivia Urìa in his original description used an emptied 3 l saline irrigation bag for transurethral resection, inflating it with air and closing the outflow tube with a Kocher forceps, allowing volume control until the best position is found (Fig. 11.6a, courtesy of Dr. Gaspar Ibarluzea). Others use two silicone gel pads or two “plum cake”-shaped jelly pillows, one under the shoulder and another under the gluteal region, leaving the lumbar region free and creating a space preventing instruments collision (Fig. 11.6b). There is also an inflatable device called “Pelvic-Tilt” (OR comfort LLC, Glen Ridge, NJ, USA) (Fig. 11.6c). This device has a non-inflated flap extending from one side. The flap is placed under the lumbar region opposite to the stone, while the inflatable portion is placed under the stone side. The weight of the patient on the flap prevents the lateral shifting of the pillow.

The further landmarks can now be drawn: the lower margin of the 12th rib and the upper margin of the iliac crest (Fig. 11.7).

Then the patient is put in a modified lithotomy position, very similar to that used during a semirigid retrograde ureteroscopy, with both glutei on the inferior border of the operating table. The ipsilateral leg is slightly abducted and extended, and the contralateral leg is lifted and partially flexed (Fig. 11.8). Both leg stirrups should be adequately padded, possibly with gelatins as well.

After positioning maneuvers, check again for possible corrections (especially of the upper and lower limbs) and fix everything with the aid of Peha-haft or similar.