A percutaneous subcostal approach for intercostal stones.

Purpose: Percutaneous upper pole access may be obtained via the supracostal or subcostal approach. The more cranial the location of the percutaneous nephrostomy tract, the greater the risk of incurring intrathoracic complications. We describe a technique for safely accessing the upper pole calix via a subcostal approach, even when the stone is located well above the 12th rib. In our patient the stone was located between the 11th and 12th ribs, and the upper pole extended to above the 10th rib.

Methods: A 78-year-old man with multiple medical problems had a symptomatic upper right pole stone located between 11th and 12th ribs. Due to its size (3 x 2.2 cm), neither a ureteroscopic nor shockwave approach was thought feasible. We elected to angle the access tract both laterally and cranially in order to course below the 12th rib, but still enter the upper pole calix.

Results: Although this tract entered the calix obliquely, instruments were readily passed after sheath placement and the stone was completely removed. An ultrasonic lithotripsy device and suction was used to fragment and evacuate the stone. Postoperatively there were no intrathoracic or pulmonary complications.

Conclusions: The direct percutaneous approach to the upper pole of the kidney requires careful methodology based on a clear understanding of the anatomy of the kidney and surrounding structures. For upper-pole renal calculi located above the 12th rib that are not amenable to shockwave lithotripsy or ureteroscopy, a subcostal angled percutaneous approach can be safely made in selected cases. With this method, the risk of intrathoracic complications may be reduced.