Treatment of Complex Stenoses Involving Renal Artery Bifurcations with Use of Drug-eluting Stents

Simultaneous Kissing Balloon Stenting Technique in Management of Two Branches of Right Renal Artery Bifurcation: A Case Report

Atherosclerosis and fibromuscular dysplasia are the commonest types of diseases associated with renovascular hypertension, with atherosclerosis accounting for 70%-80% of all cases and the latter accounting for 10% of cases. We report a case of a 65-year-old asian male with stenosis of the right renal artery with early bifurcation treated by percutaneous balloon dilation and simultaneous kissing balloon stenting technique.

Revascularization for Renovascular Disease: A Scientific Statement From the American Heart Association

Renovascular disease is a major causal factor for secondary hypertension and renal ischemic disease. However, several prospective, randomized trials for atherosclerotic disease failed to demonstrate that renal revascularization is more effective than medical therapy for most patients. These results have greatly reduced the generalized diagnostic workup and use of renal revascularization. Most guidelines and review articles emphasize the limited average improvement and fail to identify those clinical populations that do benefit from revascularization. On the basis of the clinical experience of hypertension centers, specialists have continued selective revascularization, albeit without a summary statement by a major, multidisciplinary, national organization that identifies specific populations that may benefit. In this scientific statement for health care professionals and the public-at-large, we review the strengths and weaknesses of randomized trials in revascularization and highlight (1) when referral for consideration of diagnostic workup and therapy may be warranted, (2) the evidence/rationale for these selective scenarios, (3) interventional and surgical techniques for effective revascularization, and (4) areas of research with unmet need.

An Original Bailout Solution for Renal Artery Dissection after Fenestrated/Branched EVAR

BACKGROUND

Renal artery (RA) dissection may occur during endovascular treatment of thoracoabdominal aneurysms. The aim of this paper is to report the use of kissing coronary stents in the renal bifurcation as a bailout solution for dissection after fenestraded/branched endovascular aortic repair (F/B-EVAR).

METHODS/RESULTS

A 73-year-old male with an asymptomatic Crawford type 4 thoracoabdominal aneurysm and a concomitant right common iliac artery aneurysm was proposed for endovascular repair, consisting of thoracic endovascular aortic repair plus custom-made device F/B-EVAR, followed by staged bifurcated EVAR plus right-sided IBD. In the control angiogram of the first procedure, a distal occlusion of the left renal artery was observed and attributed to iatrogenic dissection. The 6F sheath was reintroduced and the two main branches of the RA were catheterized with 0.014 wires. Then, two coronary drug-eluting stents were used for a kissing stenting technique with good angiographic and clinical results. As planned, one week later the patient underwent an uneventful second stage procedure. Follow-up CTA at 1 year showed normal patency of the renal stents as well as aneurysm shrinking and no signs of endoleak.

CONCLUSIONS

In the reported case, the use of coronary stents was a safe and long-lasting solution to rescue an iatrogenic renal artery dissection during F/B-EVAR.

Restenosis Rates After Drug-Eluting Stent Treatment for Stenotic Small-Diameter Renal Arteries

PURPOSE

To determine primary rates in small-diameter renal arteries, including complex bifurcation lesions, treated with drug-eluting stents (DES) in patients with atherosclerotic renal artery stenosis.

MATERIALS AND METHODS

This is a retrospective single-institution study. A total of 37 patients with 39 stented renal arteries were included. Patient and procedural data were obtained from the electronic medical record. Survival free from restenosis was estimated using the Kaplan-Meier method with patients stratified into two groups based on renal artery diameters (≤ 3.5 mm or > 3.5 mm). Univariate Cox proportional models were used to estimate hazard ratios associated with clinical and angiographic variables.

RESULTS

Average renal artery diameter at time of treatment was 3.4 mm ± 0.4 mm. The median survival free from restenosis was 992 days, with 11 out of 37 (29.7%) developing an in-stent restenosis. Renal arteries < 3.5 mm in diameter had similar patency rates as renal arteries > 3.5 mm (P = 0.33). The 1-, 2-, and 5-year patency rates were 71%, 63%, and 38%, respectively. History of stroke was the only comorbidity to portend a significantly greater rate of restenosis (hazard ratio 3.77; 95%CI, 1.05-13.6; P = 0.04). Medications did not statistically alter the risk of restenosis.

CONCLUSION

Revascularization of renal arteries with DES achieved similar primary patency rates irrespective of renal artery diameter. Stent configuration was not associated with time to renal replacement therapy or all-cause mortality.

LEVEL OF EVIDENCE

Level 3, Cohort Study.

Kissing stenting of aorto-ostial lesions in juxtaposed renal arteries

Percutaneous angioplasty with or without stenting has become an established procedure for treatment of renal artery stenosis for control of hypertension or progressive renal dysfunction. Anatomic variation of renal arteries is common with dual blood supply of unilateral kidney noted in almost 25% of the general population. Renal angioplasty of these anatomic variants of renal arteries is challenging. We present an unusual case of juxtaposed renal arteries with aorto-ostial lesion where direct kissing stenting was done with excellent technical and clinical outcome.

Percutaneous revascularization for ischemic nephropathy: the past, present, and future

Occlusion of the renal arteries can threaten the viability of the kidney when severe, in addition to accelerating hypertension and circulatory congestion. Renal artery stenting procedures have evolved from a treatment mainly for renovascular hypertension to a maneuver capable of recovering threatened renal function in patients with “ischemic nephropathy” and improving management of congestive heart failure. Improved catheter design and techniques have reduced, but not eliminated hazards associated with renovascular stenting. Expanded use of endovascular stent grafts to treat abdominal aortic aneurysms has introduced a new indication for renal artery stenting to protect the renal circulation when grafts cross the origins of the renal arteries. Although controversial, prospective randomized trials to evaluate the added benefit of revascularization to current medical therapy for atherosclerotic renal artery stenosis until now have failed to identify major benefits regarding either renal function or blood pressure control. These studies have been limited by selection bias and have been harshly criticized. While studies of tissue oxygenation using blood oxygen level dependent (BOLD) MR establish that kidneys can adapt to reduced blood flow to some degree, more severe occlusive disease leads to cortical hypoxia associated with microvascular rarefication, inflammatory injury and fibrosis. Current research is directed toward identifying pathways of irreversible kidney injury due to vascular occlusion and to increase the potential for renal repair after restoring renal artery patency. The role of nephrologists likely will focus upon recognizing the limits of renal adaptation to vascular disease and identifying kidneys truly at risk for ischemic injury at a time point when renal revascularization can still be of benefit to recovering kidney function.

Stents in renal artery bifurcation stenosis: a case report

A 39-year-old patient presented with poorly controlled hypertension, and she was referred to renal angiogram and potential renal angioplasty. Renal angiogram showed a bifurcation lesion of the right renal artery. A guide wire was used to cross the upper branch, while the lower branch was protected by another same-type guide wire through the same introducer. Two thin monorail balloons were used to dilate the two branches; however, despite balloon dilatation, the stenosis of the vessels persisted. The “kissing balloon” technique was then attempted by simultaneously inflating both branches using the same balloons, but more than a 70% residual stenosis persisted in each branch. Two stents were finally placed in a “kissing” way through the main renal artery. The imaging and clinical results were good, without any procedure-related complications. Three years clinical followup was also good, without any reason for further interventional approach.

Two-stent strategy for renal artery stenosis with bifurcation lesion

Renal artery stenosis (RAS) with a bifurcation lesion is a challenge for interventional therapy. The aim of this study is to summarize our experience in RAS with a bifurcation lesion. Five patients with RAS involving bifurcation lesion are described. In cases 1 to 3, a single-stent strategy was first adopted. However, these three patients were converted to a two-stent strategy for bailout stent implantation in the side branches. In cases 4 and 5, a simultaneous kissing stent technique was performed. Angiography showed that the reference vascular diameter of the main branch was much larger than those of the side branches. Although obvious residual stenosis existed in cases 1 to 3 after stent implantation, no obvious residual stenosis was seen in cases 4 and 5. Renal artery duplex sonography was performed in cases 1 through 5 at 6, 7, 7, 8, and 6 months, respectively, after the procedures. No evidence of restenosis or occlusion was seen. In conclusion, stent implantation with the simultaneous kissing stent technique may result in more simple and more satisfactory immediate angiographic results.

Use of kissing embolic protection devices in the treatment of early bifurcation renal artery stenosis: a case report

Renal artery stenosis (RAS) is a progressive disease that may cause hypertension and chronic renal insufficiency. Percutaneous renal artery angioplasty with stent placement is a well-recognized treatment for atherosclerotic RAS. It can infrequently involve the bifurcation, and treatment of this stenosis has been described using bare metal and drug-eluting stents deployed simultaneously in a kissing fashion. Atheroembolism is believed to be caused by the release of microscopic plaque fragments and cholesterol crystals from the RAS or atherosclerotic aorta. Herein, the authors describe the use of a kissing embolic protection device technique during renal artery stent placement.

Renal artery stent placement for restoration of renal function in hemodialysis recipients with renal artery stenosis

PURPOSE

Renal artery stent placement to treat renal artery stenosis (RAS) in patients undergoing hemodialysis is not performed commonly. We present our outcomes of discontinuation of hemodialysis after treating patients with RAS by stent placement on acute (< or =30 days of hemodialysis) and chronic hemodialysis (>30 days).

MATERIALS AND METHODS

A retrospective study was conducted in 16 patients (nine men) with an average age of 74.6 years +/- 10.6 (range, 49-86 y) who underwent treatment of 22 RAS for acute renal failure (n = 8) or uncontrolled hypertension with chronic hemodialysis (n = 8). The average follow-up was 448 days +/- 450 (median, 363.5 d; range, 6-1,583 d). The primary outcome consisted of discontinuation of hemodialysis, death, and transplantation. Secondary endpoints included restenosis, changes in blood pressure (and use of medications), and estimated glomerular filtration rate (eGFR).

RESULTS

After the stent procedure, eight patients were able to discontinue hemodialysis and remained free from dialysis over a mean period of 564 days +/- 533. The predictors of discontinuation of hemodialysis were 24-hour proteinuria, eGFR before renal artery stent placement, and size of the kidney on ultrasound studies (P < .05 for all three). There was no difference in patients who were undergoing acute versus chronic hemodialysis. There were three minor complications, and one patient died 6 days after the procedure because of multiple cardiovascular problems.

CONCLUSIONS

Renal artery stent placement for the treatment of RAS in patients receiving hemodialysis can result in discontinuation of hemodialysis in patients with low proteinuria level and adequate kidney size and eGFR.