Minimally Invasive Approach to Renal Artery Using Different Types of Catheter by Conventional Radiology

Background: Several routes of administration have been used for cell and gene therapy delivery in kidney disease in the last years. Moreover, a more homogenous distribution and a higher response was observed when administered intra-arterially. The main objective of the present study was to describe and to compare the use of Fogarty thru-lumen embolectomy catheter with angiographic catheter through the femoral artery by using conventional radiology as a guide.Materials, Methods & Results: Seven healthy dogs were used in these experiments. First, a Fogarty thru-lumen embolectomy catheter was introduced followed by an angiographic catheter. The primary outcome was the number of attempts for the placement of the introducer and the number of radiographic studies to carry out nephrography. Preceding the surgical procedure, ultrasonographic evaluation was performed in all animals in order to measure the diameter of the left and right femoral arteries, left and right renal and abdominal aorta at the renal level. After trichotomy and antisepsis of the medial face of the two pelvic limbs, the 6F valve introducer was placed based on the modified Seldinger technique. Thereafter, aortography was performed, showing its collateral arteries, with contrast injection, and it was estimated how much of the Fogarty 5,5F catheter had to be introduced. Subsequently, a guidewire was inserted through the catheter followed by the Fogarty catheter. Another x-ray was taken to show the position of the catheter. It was observed whether the catheter was positioned correctly and the cuff was filled, and then another contrasting radiograph was performed. If the contrast was not going to the kidneys, the cuff of the catheter was deflated, the catheter was repositioned and a new contrast radiography was performed. For the angiographic catheters technique, it was estimated how much of the catheter needed to be introduced, and then the curvature of the catheter was directed to the left kidney, followed by placement of the guidewire. The guidewire was then removed and X-rays were taken to confirm the position as many times as necessary for the correct positioning of the catheter. After selective catheterization of the left kidney, the catheter was removed and its tip was repositioned for catheterization of the right kidney, repeating the same procedure. After the radiographic evaluation, the 6F valve introducer was removed followed by the hemostasis of the femoral artery. In five out of seven animals it was possible to place the introducer tube 6F. Angiographic catheter technique needed significantly more radiographic films compared to Fogarty catheter when both arteries were evaluated. No significant difference was observed when compared to only one renal artery. The only complication observed was hematoma in three animals.Discussion: The access of the renal artery for drug delivery and cell therapy is possible using both Fogarty thru-lumen embolectomy catheter and angiographic catheter with conventional radiology as a guide in dogs over 10 kg. However, we considered the Fogarty catheter easier to be applied, since only one procedure is needed to access both renal arteries, thus making it less expensive and faster to run. If access to only one renal artery is required, the angiographic catheter is recommended, since cell therapy would be administered more selectively in the target kidney.