Aid to percutaneous renal access by virtual projection of the ultrasound puncture tract onto fluoroscopic images.
OBJECTIVE
Percutaneous renal access in the context of percutaneous nephrolithotomy (PCNL) is a difficult technique, requiring rapid and precise access to a particular calix. We present a computerized system designed to improve percutaneous renal access by projecting the ultrasound puncture tract onto fluoroscopic images.


METHODS
The system consists of a computer and a localizer allowing spatial localization of the position of the various instruments. Without any human intervention, the ultrasound nephrostomy tract is superimposed in real time onto fluoroscopic images acquired in various views.


RESULTS
We tested our approach by laboratory experiments on a phantom. Also, after approval by our institution's Ethics Committee, we validated this technique in the operating room during PCNL in one patient.


CONCLUSIONS
Our system is reliable, and the absence of image-processing procedures makes it robust. We have initiated a prospective study to validate this technique both for PCNL specialists and as a learning tool.
Mozer
Pierre
P
Service d'Urologie, Groupe Hospitalier Pitié-Salpétrière, Paris, France. pierre.mozer@psl.aphp.fr
Conort
Pierre
P
Leroy
Antoine
A
Baumann
Michael
M
Payan
Yohan
Y
Troccaz
Jocelyne
J
Chartier-Kastler
Emmanuel
E
Richard
François
F
D002138:Calibration; D005471:Fluoroscopy / Q000379:methods* / Q000592:standards; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007669:Kidney Calculi / Q000000981:diagnostic imaging / Q000601:surgery; D007670:Kidney Calices / Q000000981:diagnostic imaging / Q000601:surgery; D009403:Nephrostomy, Percutaneous / Q000379:methods*; D019047:Phantoms, Imaging; D010865:Pilot Projects; D015203:Reproducibility of Results; D018084:Ultrasonography, Interventional / Q000379:methods* / Q000592:standards