Intraoperative Cone-beam CT for Percutaneous Nephrolithotomy

Not Applicable

Completed

Brief Summary: Percutaneous nephrolithotomy (PCNL) is a first-line treatment for kidney stones \>2cm. Frequently, patients require multiple procedures to address their stone burden. The decision to proceed with a second-look procedure is based on follow-up CT imaging, which is obtained postoperatively. In this study, we propose the use of a portable CT scan technology to obtain follow-up imaging while the patient is still under anesthesia for the initial procedure. The goal of this study is to determine whether this allows the surgeon to identify residual fragments and render the patient stone-free within a single anesthetic event.

Detailed Description: Percutaneous nephrolithotomy (PCNL) is considered a first-line management option for kidney stones larger than two centimeters. Unfortunately, because of the large stone burden, up to 70% of these patients are left with residual stone fragments after their initial PCNL. Additionally, an estimated 20% to 60% of such patients ultimately require further interventions due to residual stone fragments. The need for a subsequent procedure is determined by postoperative abdominal computed tomography (CT) imaging, which is routinely performed on the first postoperative day at this institution. The decision to proceed with a second procedure is based on findings from this postoperative CT scan.

Cone-beam CT (CBCT) is a novel portable imaging technique that can allow cross-sectional imaging to be obtained intraoperatively, rather than post-operatively. Incorporating this modality would allow the surgeon to determine whether the procedure should be continued, in the event of residual fragments, or if it can be safely concluded. This would obviate the need for dedicated postoperative CT scans and, more importantly, reduce the need for subsequent procedures and consequently decrease the patient's length of stay.

Recruitment & Eligibility

Inclusion Criteria

Patients >18 years old
Scheduled for percutaneous nephrolithotomy with stone fragmentation (laser/ultrasonic/mechanical)
For the prospective intervention arm, willingness to consent to participate in the study

Exclusion Criteria

Patients whose habitus does not allow for the use of the cone beam CT machine
Patients whose stones only reside within the mid or distal ureter(s) and thus would not be easily imaged with cone beam CT
Patients who have had lithotripsy on their renal unit within the prior 90 days
Pregnant patients

Arm && Interventions

Group	Intervention	Description
Intervention arm	Cone beam CT	This arm will receive cone beam CT to perform an abdomen-pelvis CT scan immediately following initial percutaneous nephrolithotomy, before the patient emerges from general anesthesia, to allow the surgeon to determine whether additional work is needed or whether the procedure can be concluded without requiring further imaging or future interventions.

Primary Outcome Measures

Name	Time	Method
"Second Look" Rate	90 days	The percentage of patients requiring subsequent surgical intervention to remove residual stones

Secondary Outcome Measures

Name	Time	Method
Surgical Complication Rate	90 days	The percentage of patients experiencing Clavien-Dindo Grade III-V complications (major) related to the patients' surgery.
"Stone Free" Rate	90 days	The percentage of patients who are rendered without residual kidney stone burden after their surgery based on CT scan
Reobstruction Rate	90 days	The percentage of patients who presented with symptoms of renal obstruction following their surgery
Hospital Length of Stay	90 days	The average length of inpatient hospital stay in days