A 21-year-old boy with LT kidney lower pole stones was referred to my hospital.

The ureter was inserted into the high level of the renal pelvis and RIRS was not appropriate to remove the stones. And a pyeloplasty would be needed.

LT PCN was established but it seemed to go though the renal medulla between the midpole and lower pole calices.

During PCNL, I wanted to use the established PCN tract which was established by a radiologist in another hospital. But I should stop the surgery when I see massive bleeding through the MIP M sheath. I think that it was related to the torque from midpole to lower pole calyx to retrieve the stones. Now you can see the immediate postoperative CT angiography. Fortunately, it was venous bleeding.

We need to use another straightforward puncture or a flexible nephroscope when the pre-established PCN was located in a wrong position.