Percutaneous nephrostomy for complex renal stones: Percutaneous renal access behind the stone versus renal calyx dilation

Abstract

Objective: To evaluate the technical success rate and complications associated with percutaneous nephrostomy (PCN) via percutaneous renal access behind the stone and renal calyx dilation in patients with complex renal stones.

Materials and methods: From January 2010 to February 2021, we identified 69 patients with 70 complex renal stones who underwent PCN. Complex renal stones were classified as simple (renal pelvis only) (27.1%, 19/70), borderline staghorn (8.6%, 6/70), partial staghorn (51.4%, 36/70), or complete staghorn (12.9%, 9/70). All PCNs were performed under ultrasound and fluoroscopic guidance using one of two renal-entry techniques: puncture behind the stone (56%, 39/70) or renal calyx dilation (44%, 31/70). Then, we retrospectively evaluated the technical success rates and complications associated with each renal entry access technique.

Results: The overall technical success rate was 100%, and the complication rate was 20.0% (14/70). For those who underwent renal access behind the stone, the complication rate was 15.4% (6/39), and six patients (six PCNs) had transient gross hematuria. For those who underwent dilated renal calyx entry, the complication rate was 25.8% (8/31), and one patient had significant bleeding complications requiring transfusion. Furthermore, seven patients (seven PCNs) had transient gross hematuria. Overall, the complication rates did not differ between the technique groups (p = 0.279).

Conclusion: PCN for complex renal stones has a high technical success rate and an acceptable complication rate regardless of the specific technique. Renal entry behind the stone is as safe and feasible as approaching via a dilated renal calyx.

Fig 1. Renal access for dilated renal calyx with hydronephrosis under ultrasound guidance.

(A) A grayscale ultrasonography image showed a dilated middle and superior renal calyces and replaced inferior renal calyx with renal stone in the right kidney. (B) A 21-G Chiba needle (arrowhead) was advanced to the center of the renal pyramid at middle pole. (C)The Chiba needle (arrowhead) was introduced into the dilated renal calyx. (D) Finally an 8.5Fr drainage catheter was successfully inserted after renal access via dilated renal calyx.

Fig 2. A representative case of a 61-year-old man with a right, partial staghorn stone.

(A) A kidney, ureter, and bladder imaging exam identified a right, partial staghorn stone. (B) A grayscale ultrasonography image showed a staghorn stone in the right kidney with marked posterior acoustic shadowing. (C) A 21-G Chiba needle (arrowhead) was introduced into the periphery of the complex stone through the center line of the renal pyramid. (D) A radiograph image showed that the 21-G Chiba needle was introduced behind the stone. (E) A few millilters of contrast medium was injected, then the renal calyx was opacified by contrast medium (arrowhead). (F) A 0.018-inch guide wire (arrow) was introduced with rotating movements to minimize resistance at the tip as the wire advanced. (G) A 0.035-inch hydrophilic guidewire was introduced, and track dilatation was performed under fluoroscopic guidance. (H) An 8.5-Fr pigtail catheter was placed after sequential tract dilatation.