Research Article: Supine Percutaneous Nephrolithotripsy in Double-S Position

Date Published: March 11, 2018

Publisher: Hindawi

Author(s): Giuseppe Giusti, Antonello De Lisa.


At present, the percutaneous nephrolithotripsy (PCNL) is performed both in supine and in prone position. The aim of this paper is to describe an innovative position during PCNL.

We describe a supine position. The patient’s legs are slightly abducted at the hips. The thorax is laterally tilted (inclination 30°–35°) and kept in the right position by one or two gel pads placed between the scapula and the vertebrae. External genitalia can be accessed at any time, so that it is always possible to use flexible instruments in the upper urinary tract. We used this position for a period of 12 months to treat with PCNL 45 patients with renal lithiasis.

All the procedures were successfully completed without complications, using the position we are describing. The following are some of its benefits: an easier positioning of the patient; a better exposure of the flank for an easier access to the posterior renal calyces of the kidney; a lower risk of pressure injuries compared to positions foreseeing the use of knee crutches; the possibility of combined procedures (ECIRS) through the use of flexible instruments; and a good fluoroscopic visualization of the kidney not overlapped by the vertebrae.

This position is effective, safe, easy, and quick to prepare and allows for combined anterograde/retrograde operations.

Partial Text

Percutaneous access to the kidney was first used in 1954 when radiologists dared to puncture the pelvis of hydronephrotic kidneys to perform anterograde pyelography [1]. The techniques to place nephrostomy drainages have been developed over the years, as well as the technique to extract stones from the kidney’s cavities (percutaneous nephrolithotripsy (PCNL)) [2].

This is a preliminary study, carried out by the Department of Urology at the University of Cagliari (Cagliari, Italy) with the purpose to first describe the innovative position we developed.

All the procedures performed in the described position were successfully completed. The mean operating time was 43.5 minutes.

Besides the well-known anesthesiological advantages of the supine position, the double-S position presents other benefits. It indeed combines all the advantages of the several variations of the supine position already described in the scientific literature [15–17]:A smaller number of nurses in the operating room, who have an easier position to prepare and lighter loads to shift.A better exposure of the flank and an increased distance between the last rib and the iliac crest (as reported by Desoky), providing a wider space for puncture, dilatation, and maneuverability of the nephroscope. This is feasible thanks to the fact that a single support is placed under the shoulder, and not under the lumbar region as in the Valdivia position (Figure 1).A lower risk of pressure injuries to vascular and nervous structures compared to positions foreseeing the use of knee crutches (e.g., Galdakao position).The absence of flank support, which prevents the cephalad sliding of the kidney, making upper-pole puncture more feasible.A lower degree of thorax rotation, allowing for a better fluoroscopic view of the kidney, which is not overlapped by the vertebrae, as it may happen in semi-supine (more tilted) positions.The possibility to always have a retrograde access to the high urinary tract.

The supine double-S position we describe turned out to be efficient, safe, easy, and quick to prepare. It allows for an easy access to the upper urinary tract and therefore for the performance of combined anterograde/retrograde operations. In our clinical practice, it has become the standard position for PCNL procedures in a supine position. In the age of flexible endoscopy, we believe that this position could be a new valid option and we recommend it both to those with a good experience in percutaneous kidney operations as well as to those who are approaching this technique.




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