Cath Lab Digest

Introduction
Iatrogenic renal artery perforation is a rare, but well-described complication of percutaneous renal artery intervention.^1-3 Treatment has traditionally involved surgical intervention including renal artery reconstruction, bypass grafting, and even nephrectomy.^4,5 More recently, several non-surgical techniques have been described, including balloon tamponade, custom-made stent graft deployment, and use of an autologous vein-covered stent.^6,7 The JoStent® (JoMed, Rancho Cordova, California) has been approved by the FDA under humanitarian device exemption for the treatment of coronary artery perforations. Although experience in a variety of clinical settings has been described,⁸ use of the Jostent for renal artery perforations has not been reported. We describe a case in which we successfully treated a renal artery perforation with balloon tamponade and deployment of the Jostent, with subsequent rheolytic thrombectomy using the AngioJet thrombectomy catheter (Possis Medical, Minneapolis, Minnesota).

Case Report
The patient is a 73-year-old female with a past medical history significant for coronary artery disease, hypertension, diabetes mellitus type II, chronic renal insufficiency, and morbid obesity. In addition, she had known right renal artery stenosis (documented by angiography) that was managed medically. The left renal artery was very small and supplied an atrophic left kidney. Over the past year, her hypertension became increasingly resilient to medications and the decision was made to perform percutaneous right renal artery intervention.

An 8 Fr sheath was inserted in the right femoral artery and and the right renal artery was engaged with an 8 Fr RDC catheter (Cordis Corporation, Miami Lakes, FL). Selective angiography revealed an 80% lesion involving the ostium of the right renal artery (Figure 1). The patient received 5,000 units of heparin, and a 190 cm .014 inch S'port™ wire (Guidant Corporation, Santa Clara, CA) was advanced across the lesion into the distal renal artery. The lesion was directly stented with a 6.0 mm x 24 mm Genesis™ stent (Cordis Corp.) to 12 atmospheres, and subsequently post-dilated with a 7.0 mm x 15 mm Viatrac® balloon (Guidant Corp.) to 8 atmospheres. Final angiography revealed a 0% residual lesion (Figure 2). The patient's activated clotting time at the end of the procedure was 285 seconds.

Approximately 2 hours after the intervention, the patient developed severe right flank and back pain. She was emergently returned to the angiography suite. The right renal artery was again engaged with an 8 Fr RDC catheter. The artery was widely patent with normal flow but there was an area of dye extravasation distal to the previously placed stent (Figure 3). Protamine was not administered given the concern of anaphylaxis in this patient who previously received protamine-containing insulin.

Consideration was given to placing a large (> 5 mm) perfusion balloon or covered stent; however, attempts at engaging the right renal artery with multiple larger guides were unsuccessful. We re-engaged the artery with the 8 Fr RDC catheter. A 190 cm .014 inch Marker wire (Cordis Corp.) was advanced into the distal renal artery. A 4.5 mm x 19 mm Jostent (the largest such covered stent in our supply) was advanced across the area of extravasation and inflated to 16 atmospheres. The Jostent was post-dilated with a 6.0 mm x 15 mm Viatrac balloon to 12 atmospheres. The post-deployment angiogram showed significant improvement in the perforation but a small leak persisted. A 4.0 mm x 20 mm ACS Esprit™ perfusion balloon (Guidant Corp.; the largest in our supply) was then advanced across the stented area and inflated to 8 atmospheres. Given that the right kidney was most likey the sole functioning kidney, the patient was sent for a CT scan of the abdomen and pelvis to rule out any significant organ compression that may require surgical intervention. The scan revealed the presence of a moderate-sized retroperitoneal bleed which did not compress the renal artery or kidney.

The patient was returned to the angiography suite, and the perfusion balloon was deflated. Repeat angiography confirmed that the perforation had been sealed. Unfortunately, there was now a large, mobile filling defect within the artery consistent with thrombus (Figure 4). A 300 cm 0.014 inch S'port wire was advanced into the distal artery. A 4 Fr AngioJet catheter was passed through the area of thrombus and there was complete resolution of the filling defect with excellent antegrade flow in the renal artery (Figure 5). A total of 325 ml of contrast was utilized, and over the next few days, her creatinine increased from a baseline of 1.9 to 3.2. This subsequently improved to 2.1 prior to discharge. Her hypertension was well-controlled with beta blockers, hydralazine, and clonidine. The patient was discharged home in good condition 6 days after the initial procedure.

Discussion
Percutaneous intervention has now become a common practice in the treatment of renal artery stenosis, with efficacy and safety similar to or better than surgery.⁹ Advances in both interventional equipment and operator technique have lowered complication rates over the past decade.³ Despite these advances, the risk of renal artery perforation still exists. Perforation can occur from the guidewire (especially hydrophilic wires), angioplasty balloon, stent, and even from the guiding catheter itself. In our case, the perforation was most likely secondary to direct placement of the stent, as this was the site of dye extravasation and there was minimal difficulty with initial wiring of the vessel. Quantitative measurements of the vessel, or pre-dilatation prior to stent placement, may have helped to avoid this complication.