Successful treatment of in-stent restenosis of a covered stent graft with a paclitaxel-eluting stent

Summary

We present the case of a 58-year-old male with coronary artery disease and a significant stenosis of the left circumflex artery that was preceded by a coronary aneurysm. The stenosis and aneurysm were treated successfully with a coronary stent graft. The patient subsequently developed in-stent restenosis (ISR). The ISR was then successfully treated with a paclitaxel-eluting stent (PES). The patient has been followed clinically for 4–6 years without recurrence of his anginal symptoms. This is the first description in the literature of which we are aware of the successful treatment of an ISR of a coronary stent graft with a PES with persistent long-term clinical effectiveness.

Case Report

The patient is a 58-year-old male with a long history of coronary artery disease. He had undergone multiple percutaneous coronary interventions in both the right coronary artery (RCA) and proximal left anterior descending artery (LAD) with bare metal stents. In December 2003 during follow up for angina-type chest discomfort, a perfusion study demonstrated inferior wall reversibility. The patient underwent cardiac catheterization which demonstrated total occlusion of the proximal RCA which was previously stented from the ostium to the distal vessel and now filled from left-to-right and right-to-right collaterals. The left-to-right collaterals are well developed from the LAD and the left circumflex artery (LCA) all the way up to the RCA distal stents. However, there were also extensive bridging collaterals with very small caliber side-branches at the occlusion cap. Eventually, the bridging collaterals form a very thin column of faint contrast filling all the way down to the distal stents. A new 1 cm aneurysmal segment in the midportion of the LCA with a 50% stenosis just before the aneurysmal segment followed by an 80% stenotic hazy lesion at the distal portion of the aneurysm “wrap-around-aneurysmal-candy” (Fig. 1A), followed by a trifurcating obtuse marginal branch (Fig. 1A).

Figure 1.

(A) Aneurysmal dilatation [arrow] of the left circumflex coronary artery which is immediately followed by a tight stenosis [arrow head]. (B) The immediate angiographic results following JOSTENT^®GraftMaster coronary stent graft placement. (C) Severe in-stent restenosis of the JOSTENT^®GraftMaster coronary stent graft. (D) The result following paclitaxel-eluting stent.

The patient was seen in the clinic two weeks after his diagnostic angiogram. Options included percutaneous intervention to re-canalize the RCA or treatment of the aneurysm with both the proximal and distal portion lesions with a covered stent. Alternatively, bypass surgery was an option, but his LAD was patent and his left ventricular function was normal. The RCA total occlusion was unfavorable to percutaneous approach in view of the presence of side branches at the occlusion cap and bridging collaterals. Furthermore, the posterior descending artery and the posterolateral branch were filled by well-developed collaterals from the left coronary system up to the distal RCA segment. The patient preferred the percutaneous approach. Therefore, we elected to treat the left circumflex lesion and not to intervene on the RCA. The covered stent approach was proposed in view of the lesion complexity and morphology. The provisional stenting approach probably would require either two short stents leaving a sticking stent in the aneurysmal segment or a long stent with an exposed and unopposed stent struts in the mid portion of the aneurysm and would be at risk for stent thrombosis.

The patient proceeded to intervention in March 2004. The mid LCA lesion distal to the aneurysm was predilated with a 2.75 × 18 mm Power Sail balloon (Guidant Corporation, Santa Clara, CA, USA) to 10 atmospheres. A 3.0 × 19 mm JOSTENT^®GraftMaster coronary stent graft (Abbott, Redwood City, CA, USA) was then delivered to the lesion covering the aneurysmal segment, which was deployed at 16 atmospheres. Final angiography revealed no dissection or dye staining with resolution of the aneurysmal segment (Fig. 1B).

Nine months subsequent to the covered stent implantation he began to have anginal symptoms on exercise. He underwent repeated coronary angiography revealing a 99% area of in-stent restenosis (ISR) in the LCA JOSTENT^®GraftMaster coronary stent graft (Fig. 1C). Therefore, the lesion was predilated with a 2.5 × 9 mm Maverick Balloon (Boston Scientific, Natick, MA, USA) at 20 atmospheres. A 3.0 × 20 mm Taxus stent (Boston Scientific, Natick, MA, USA) was then deployed to 14 atmospheres covering the previously placed JOSTENT^®GraftMaster coronary stent graft (Fig. 1D).

Since his last stenting procedure, the patient has remained asymptomatic and active. He continues to undergo routine annual stress testing. His last study was completed in November 2008 demonstrating no wall motion abnormalities on stress echocardiography. Therefore, no follow-up angiography was performed.

Discussion

We present a patient who has an extensive history of significant coronary artery disease who developed a coronary aneurysm followed by a tight stenosis and was successfully treated with a JOSTENT^®GraftMaster coronary stent graft. He subsequently developed ISR within the covered stent and was treated with placement of a paclitaxel-eluting stent (PES). The patient has remained symptom-free for the intervening 4–6 years while able to maintain a high exercise capacity.

Coronary artery aneurysms are defined as localized dilatation of a coronary artery greater than 1.5 times the normal adjacent reference vessel. They may occur in response to occlusive coronary artery disease in up to 50% of cases. In addition, balloon angioplasty, atherectomy, and excimer laser angioplasty have been implicated in their formation at the sites of previous intervention. Sluggish or turbulent coronary blood flow with resultant ischemic symptoms can occur regardless of the severity of the associated stenotic lesion. Potential complications that could happen include rupture, tamponade, arterial occlusion, and sudden cardiac death [1].

There have been multiple reports in the literature showing successful treatment of coronary artery aneurysms with covered stents 2, 3, 4. The use of covered stents to treat coronary aneurysms is off label and its use in our patient was pursued only after detailed discussion with the patient. While the treatment of the aneurysm was successful, our patient developed significant ISR within the covered stent. This is the first description in the literature of which we are aware of the successful treatment of an ISR of a coronary stent graft with a PES with persistent long-term clinical effectiveness.

The JOSTENT^®GraftMaster coronary stent graft is composed of a polytetrafluoroethylene membrane sandwiched between two bare metal stents. Previous studies evaluating covered stent restenosis (>50% diameter stenosis) have shown rates similar to bare metal stents with 30% restenosis at 6-month follow up [5]. The pattern of ISR most commonly seen in covered stents has been at the stent margins [6]. A recent study utilizing optical coherence tomography and angioscopy reported that ISR in the proximal edge of the stent was organized white-thrombus with non-endothelialized areas in the mid stent. The authors concluded that neointimal hyperplasia which is the most common process in typical stent restenosis has a limited role in covered stent restenosis [7].

At the time the patient presented, we elected to treat the ISR with a PES. This approach is supported by Taxus V ISR trial which demonstrated the superiority of PES when compared to vascular brachytherapy in bare metal stents by showing a lower incidence of ischemia-driven target vessel revascularization at 24 months of follow up [8]. However, recent studies have suggested that “limus-” eluting stents, particularly the newer generation versions, are superior to PES and may be better alternatives in future cases 9, 10.

Conclusion

In conclusion, we demonstrate the successful treatment of covered stent ISR. Even though stent grafts are not frequently used and are mainly utilized in coronary perforations, they do have a high restenosis rate once implanted. This case suggests that drug-eluting stents can be used if ISR develops, which adds another potential treatment to the DES armamentarium as a revascularization strategy in these patients.