CLINICAL DECISION MAKING

Tissue Shearing with Distal Translocation Complicating Cutting Balloon Angioplasty During Treatment of In-stent Restenosis

Christopher H. Smith, Michael B. Erwin, Efthymios N. Deliargyris
Christopher H. Smith, Michael B. Erwin, Efthymios N. Deliargyris
Case report. A 49-year-old white female presented with recurrent angina. Six months prior, she was successfully treated for a similar anginal syndrome with a 5.0 x 43 Magic Wallstent in the proximal and mid-RCA. Coronary angiography showed a focal 90% narrowing in the proximal segment of the Magic Wallstent; no other lesions were noted (Figure 1A). Due to the focal character of the restenotic lesion, angioplasty as primary treatment was considered acceptable and intracoronary brachytherapy was not contemplated.5 The patient was treated with 3,500 units of heparin and weight-based abciximab bolus and infusion. The lesion was treated with a 5.0 x 18 mm High-Sail balloon to 4 atm, but significant residual narrowing was present. The lesion was then treated with a 4.0 x 15 mm cutting balloon inflated up to 11 atm. Following treatment with the cutting balloon, a filling defect was noted distal to the site of the balloon inflation, but still within the stented segment (Figure 1B). Activated clotting time was 273 seconds. Intracoronary ultrasound (Endodonics) showed a hypoechogenic mass more consistent with tissue rather than thrombus. Repeat dilatation was attempted with a 5.0 x 22 mm NC Big Raptor to 6 atm, however, the severity and location of the lesion was unchanged. An attempt at tissue removal utilizing a 2.33 mm TEC catheter was unsuccessful (Figure 1C). A Multilink Ultra 5.0 x 28 mm stent was positioned covering the mass and deployed inside the existing stent at 13 atm (Figure 1D). The narrowing from the mass was still not completely relieved and the stent was further expanded to 18 atm with the 5.0 x 18 mm High-Sail balloon, but the mass proved resistant and a residual 15% narrowing was still evident (Figure 1E). The patient recovered well and reported resolution of her angina. References (see below) How Would You Treat This Patient? David R. Ramsdale, MD The Cardiothoracic Centre Liverpool, United Kingdom This case deals with the management of focal in-stent restenosis in a large right coronary artery previously stented with a 5.0 x 43 mm Magic Wallstent. Neointimal tissue that causes in-stent restenosis is often relatively soft and responds well to balloon angioplasty. I would agree with the authors that the best treatment would be to use balloon angioplasty. If the lesion is resistant and the angioplasty results are suboptimal, then cutting balloon angioplasty could be used next. Some operators prefer to use cutting balloon as the initial treatment in focal cases of in-stent restensosis, as this is thought to be more effective in disrupting the neointimal hyperplasia that causes in-stent restenosis. However, there is a possibility of damaging the stent struts with the blades of the cutting balloon, thus, I would reserve its use for resistant lesions. The operators noticed a new filling defect distal to the site of cutting balloon inflation which could be due to thrombus or tissue displacement. Thrombus formation within the stent is unlikely with a therapeutic activated clotting time and good distal flow. The fact that the lesion proved resistant to further balloon angioplasty confirmed that it was tissue. Placing a stent within the previous stent is often used in such cases to try to compress the tissue between the two layers of metal. Due to the large size of the vessel, drug-eluting stents are not an option, as they are only available up to a maximum nominal diameter of 3.5 mm. A Multilink Ultra 5.0 x 28 mm with a high metal-to-artery ratio was deployed within the previous stent, with a 15% residual narrowing. Nicolas W. Shammas, MS, MD, FSCAI Midwest Cardiovascular Research Foundation Genesis Heart Institute Affiliate Cardiovascular Medicine, PC Davenport, Iowa Although the culprit segment of the lesion illustrated in this case appears to be focal at the proximal edge of the Magic Wallstent, the proximal and mid-portion of the stent also shows a lesser degree of restenosis. In our experience, we find it that treating only a short segment of a restenotic lesion, without addressing the remaining restenotic segments of that same lesion (though less severe), quite often leads to suboptimal angiographic results. My approach to this lesion will be to initially use a long 4.0 x 30 mm FX Minirail balloon (Guidant) and to dilate the entire restenotic segment at the same time. The advantages of this approach are: 1) less “watermelon seeding” with the Minirail as compared to the use of a regular balloon; 2) an adequate coverage of the entire restenotic lesion is likely to be achieved; 3) the 4.0 mm balloon at 10 to 12 atmospheres leads to a theoretical minimal luminal diameter of 4.5 to 4.57 mm, which should be adequate for this large vessel size; and 4) coverage for the entire lesion will likely avoid tissue shifting and prolapse. If results remain suboptimal despite this approach, (proximal dissection, plaque shifting, continued significant residual stenosis or intraluminal tissue prolapse), then I will use adjunctive stenting. Generally, restenting the vessel leads to optimal angiographic results as in this type of case. If tissue shifting was the reason for adjunctive stenting, it is important to have a long stent to adequately cover several millimeters proximal and distal to the affected area to avoid further shifting of the tissue beyond the restented segment. Drug-eluting stents (DES) in this case are not ideal, given the large vessel size. The current 3.5 mm DES on the market in the United States can be expanded to 4.0 mm. Larger expansion might lead to polymer delamination and loss of effectiveness of the stent. Larger DES stents might become available in the near future.
References
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