Evaluation of thrombus removal by transluminal extraction coronary atherectomy by percutaneous coronary angioscopy

remodeling.4 However, major complications associated with intravascular ultrasound studies are rare.5,6In a recent multicenter registry of intravascular ultrasound, procedural-related major complications were ~0.5%.~ On the other hand, experimental data suggest that the relatively rigid tip of CA may induce intraluminal injuries, namely small flaps.7 In the present report, we demonstrate that CA may deteriorate the angiographic appearance of the dilated lesion. Such angiographic changes required repeat balloon angioplasty to obtain a satisfactory angiographic result. Although a complex lesion morphology may increase the likelihood of spontaneous angiographic worsening after dilatation, we believe that this possibility is unlikely in our patients. In addition, these angiographic findings were not consistent with the elastic recoil phenomenon that sometimes is found early after dilation. The excellent angiographic results obtained after angioplasty and, mainly, the exact temporal relation with CA suggest a causal relation. The intimate mechanisms leading to the angiographic worsening could not be fully elucidated. Nevertheless, dislodgment of intimal flaps or mobilization of residual thrombus may have been operative in our patients.

These data suggest that, although infrequent, angiographic changes requiring repeat dilatation may occur during CA. Special care should be taken to rule out this possibility in patients undergoing intravascular diagnostic techniques to guide coronary interventions. 1. Sherman TC, Litvack F, Grundfest W. Lee M, Hickey A, Chaux A, Kass R, Blanche C, Matloff J, Morgenstem L, Ganz W, Swan HJ, Forrester J. Coronary angioscopy in patients with unstable angina pectoris. N Engl J Med 1986,315: 913-919. 2. Lee G, Garcia JM, Corso PJ, Ghan MC, Rink JL, Pichard A, Lee KK, Reis RL, Mason DT. Correlation of coronary angioscopic to angiographic findings in coronary artery disease. Am J Cardio/ 1986;58:238-241. 3. Ramee SR, White CJ, Collins TJ, Mesa JE, Murgo JP. Percutaneous angioscopy during coronary angioplasty using a steerable microangioscope. .I Am Co// Curdiol 1991;17:10~105. 4. Alfonso F, Macaya C, Goicolea J, Hemandez R, Zamorano J, Zarco P. Angiographic changes (Dotter effect) produced by intravascular ultrasound imaging, J Am Cd Cardiol 1993:21: l92A. 5. The SAFETY and ICUS study group. Safety of intracoronary ultrasound: a multicenter, multicatheter registry in 1837 patients. Circularion 1993:X8(1):1-549. 6. Alfonso F, Macaya C, Goicolea J, Hemandez R, Segovia I, Zamorano J, Zarco P. Acute coronary closure complicating intravascular ultrasound examination. Eur Heart.1 1994;15:71&712. 7. Lee G, Beerline D, Lee MH, Wong W, Argenal AJ, Chang MC, Theis JH, Mason DT. Hazards of angioscopic examination: documentation of damage to the arterial intima. Am Heurt J 19X&l 16:1530-1536.

Evaluation of Thrombus Removal by Transluminal Extraction Coronary Atherectomy by Percutaneous Coronary Angioscopy Brian H. Annex, MD, Timothy

J. Larkin, MD, William W. O’Neill, MD, and Robert D. Safian, MD

T

he transluminal extraction catheter (TEC) is a forward-cutting atherectomy device designed to excise atheroma and aspirate thrombus.’ For this reason, TEC atherectomy may be useful for treating degenerated saphenous vein bypass grafts and other thrombus-containing lesions. l-3 Because coronary angioscopy is superior to contrast angiography in identifying intraluminal thrombus,4-6 this prospective study used angioscopy to determine the efficacy of thrombus removal by TEC. Between August 1992 and June 1993,14 consecutive patients (mean age 61 f 10 years; 13 men and I woman) underwent angioscopy and contrast angiography before and after TEC (Table I). Indications for revascularization included failed thrombolytic therapy for acute myocardial infarction (patients I, 4, and 5) and unstable angina. The mean age of the 10 saphenous vein bypass grafts was 8 + 2 years. Lesions were considered suitable for both TEC and angioscopy if the reference arterial diameter was >2.5 mm and if the lesion was located >I5 mm from the arterial ostium. All patients gave informed consent according to protocols approved by the Human Investigations Committee of William Beaumont Hospital. All patients were pretreated with aspirin, and all (except for patient II) received continuous intravenous

From the Division of Cardiology, William Beaumont Hospital, 3601 West 13 Mile Road, Royal Oak, Michigan 48073-6769. Manuscript received December 16, 1993; revised manuscript received and accepted March 22, 1994.

heparin therapy; 3 patients received thrombolytic therapy within 6 hours of the procedure. After insertion of the arterial sheath, 10,000 U of heparin was administered and additional heparin was given to maintain the activated clotting time of >300 seconds. Baseline angiography was performed with 1OFr guiding catheters (InterVentional Technologies, San Diego, California) and the lesion was crossed with a special 0.014-inch TEC guidewire (InterVentional Technologies). Coronary angioscopy was then performed with a 4SFr angioscope (Coronary Image Cath Angioscope, Baxter Healthcare Corp., Edwards LIS Division, Santa Ana, California), similar to methods previously described.j Pre-TEC angioscopic imaging was performed until either the thrombus was visualized or the entire lesion was crossed. Imaging time was generally 60 to 120 seconds. Images were recorded on videotape for immediate review and archiving. TEC was then performed as described previ0us1y.~ Angiography after TEC was petformed and angioscopic images after this procedure were recorded over the entire lesion length. Angioscopic thrombus was dejined as laminated thrombus, with red or purple material adherent to the vessel wall, or globular thrombus with a red mass protruding into the lumen. Thrombus removal was considered complete when no thrombus was present on postTEC angioscopy. Thrombus removal was incomplete when some residual thrombus was still present on the post-TEC angioscopic images. Dissections were defined as white or yellow flaps of tissue hanging from the vessel wall into the lumen. All data were collected prospec-

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I TABLE

I Results of Angiography and Angioscopy Before and After Transluminal Extraction Atherectomy J

Patient 2 3 4

5 6 7

6 9 10 11 12 13 14

Vessel SVG SVG SVG SVG LCX SVG RCA RCA LCX SVG SVG SVG SVG SVG

Before TEC Angiography/Angioscopy + I G,L +/o +I0 0 I G,L OIL + I G,L O/G +/L O/L +lG +lL +/L 0 i G,L 0 I G,L

After TEC Angiography/Angioscopy + I G,L c/o +/o O/L O/L 0 I G,L o/o +I0 o/o o/o OIL O/L +/o o/o

1

Thrombus Removal N N/A N/A N C C C C N C C

C = complete thrombus removal; G = globular thrombus; I = incomplete thrombus removal; L = laminated thrombus; LCX = left cmxmflex coronary artery; N = no thrombus removal; N/A = not applicable; RCA = right coronary artery; SVG = saphenous vein graft; TEC = transluminal extraction catheter; + = thrombus present; 0 = thrombus absent.

1

FIGURE 1. Angiogram of the right coronary artery before and after transluminai extraction catheter atherectomy (patient 7). Baseline angiography revealed a severe stenosis in the proximal vessel (left panel). Although there was no angiographic evidence for thrombus, a large globular thrombus was identiied by angioscopy. After transiuminai extraction catheter atherectomy (m&k//e panel), there was a moderate residual stenosis with intraiuminal haziness (r&M panel). Although multiple intimai flaps were identified by an@oscopy, there was no residual thrombus.

tively and the angioscopy videotapes were reviewed by ing (n = 1). Patients 9 and IO were treated with TEC alone. Final angiographic success (Figure I) was the consensusof 3 observers (BHA, TJL, and RDS). Procedural success was defined as final diameter achieved in 13 of 14 patients (93%), but patient 1 had stenosis ~50% (after TEC alone or after TEC and ad- a persistent total occlusion after TEC. Some patients junctive therapy) in the absenceof a major complication experienced transient and reversible chestpain or elec(death, emergency bypass, or acute myocardial infarc- trocardiographic ischemia, or both, during angioscopic tion). All diameter stenoseswere measuredusing digital imaging. Angiographic and angioscopic findings before and calipers as previously described.3Angiographic thrombus was de$ned as the presence of intraluminal filling after TEC are listed in Table 1. Angioscopy identified defectsin or adjacent to the culprit lesion. thrombus in 12 of 14 lesions (86%) before TEC (Figures Sensitivity, specificity, accuracy, and positive predic- 2 and 3), including laminated thrombus in 10 lesions tive value were calculated by standard formulas: sensi- and globular thrombus in 2 lesions. Both laminated and tivity = true positiveltrue positive + false negative; speci- globular thrombi were present in 5 lesions. Although ficity = true negativelfalse positive + true negative; angiography identified thrombus in 8 of 14 lesions accuracy = true positive + true negativeltotal; positive (57%), no thrombus was identified in 2 lesions by predictive value = true positiveltrue positive + false pos- angioscopy. Angiography failed to identify thrombus in itive. 6 lesions in which thrombuswas identified by angioscopy Post-TECadjunctive therapy included balloon angio- (Figure 3). Assuming that angioscopy is 100% accurate plasty (n = S), directional atherectomy(n = 3), and stent- in detecting thrombus,the sensitivity of angiography was BRIEF REPORTS

607

5090, the accuracy was 4390, and the positive predictive value was 7590. After TEC, angioscopy detected thrombus in 6 lesions including both globular and laminated thrombus in 2 lesions and laminated thrombus alone in 4 lesions. The post-TEC angiogram correctly identijed the presence or absence of intraluminal thrombus in only 5 of 14 lesions (36%). The angiogram failed to identify thrombus in 5 lesions that had thrombus by angioscopy and incorrectly identified thrombus in 4 lesions that were free of thrombus by angioscopy (Figure 4). After TEC, the sensitivity of angiography compared with angioscopy was 17%, the spectfkity was 50%, the accuracy was 36%, and the positive predictive value when compared with angioscopy was 2090 . After TEC, transient “no-reflow” (patient 6) and severe intraluminal haziness (patients 3, 8, 12, and 13) may have contributed to the poor reliability of angiography in identifying thrombus. Angioscopy also demonstrated multiple residual flaps consistent with dissections (Figure 4B) in all lesions after TEC. Thrombus removal was determined by comparing the pre- and post-TEC angioscopic images. Of the I2 lesions with angioscopic thrombus before TEC, no residual

FIGURE 2. Angkscoplc image before tranduminai extm tion catheter atherectomy corresponding to the angie gram displayed in Figure 1 (patient 7). G = guidewire, R7 q red thrombus.

thrombus was detected after TEC in 6 lesions (Figure 3 and 4). Some residual intraluminal thrombus was detected in 3 lesions, and no evident thrombus removal was observed in 3 lesions. The eficacy of thrombus removal was diflerent for globular and laminated thrombus. In the 7 lesions with globular thrombus, there was complete removal of the globular thrombus in 5, partial removal in 1, and no evident thrombus removal in I after TEC. In the 10 lesions with laminated thrombus, there was complete removal of the laminated thrombus in 4, partial removal in 2, and no evident thrombus removal in 4 after TEC. The major finding of this study was that angioscopy contirmed thrombus removal in 75% of these lesions treated with TEC. Although the number of lesions was small, our study suggests that TEC may be more effective at rembving globular rather than laminated throm-

FIGURE 3. Angiogram (A) and angioscopic image (B) of a saphenous vein graft to the obtuse marginal branch (patient 13) before transluminai extraction catheter atberectomy. ARhoua there was no definRe thrombus by angiogr@Iy (A), a portion of the thrombus can be seen as the ii@t purple region adherent to the vessel wail by angioscopy (6). Bashed whfte lines am used to outline the guidewire (0) and the thrombus (1).

FIGURE 4. Angiogram after transiuminai extraction catheter atherectomy (A) and angioscopic image (B and C) of the lesion shown in Figure 3 (patient 13). After transiuminai extraction catheter atherectomy, there was a complex residual lesion with contrast staining, but it was diicult to distinguish thrombus from dissection by angiography (A). Angloscopy demonstrated multiple itiimai flaps (F) (B and C), but no residual thrombus. A single Paimaz-Gchatz biiiary stent was inserted with excellent results. G = guidewire.

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bus. The reasonfor this difference is unknown, but globular thrombus may be recent and more amenableto aspiration by TEC, whereaslaminated thrombus may be organized and more adherent to the vessel wall. Given the size mismatch between the largest TEC cutter (2.5 mm) and the normal diameter of most saphenousvein grafts, it is not surprising that extraction of laminated thrombus was incomplete using a forward-cutting device. Multiple tissue disruptions consistent with dissections were observed in all 14 lesions after TEC (Figure 4B). Theseobservationsare similar to the superficial intima1disruptions described by intravascular ultrasound in all lesions after TEC2 These flaps could explain the frequent finding of in&alumina1 haziness after TEC in our study, and could contribute to the high restenosis rates after TEC in vein grafts.3 In general, contrast angiography was of limited value before and after TEC in correctly identifying intraluminal thrombus. After TEC, the presenceof no-reflow, intraluminal haziness, and dissections may impair the angiographic interpretation of thrombus. These observations support the findings of White et al7regarding the value of coronary angioscopy in evaluating the “hazy” or high-risk lesion after balloon angioplasty. These data may also have implications for other studies that rely solely on angiography to evaluate in&alumina1thrombus before and after percutaneousinterventions. There are severallimitations in this study. First, many patients had unstable clinical syndromes and lesions in saphenousvein grafts, and these results may not apply to other patient subsets.Second, angioscopy cannot be used to evaluate aorto-ostial lesions becauseof the need to position the occlusion cuff proximal to the stenosis. Third, angioscopy is not a quantitative technique and

therefore can only provide a qualitative assessmentof intraluminal thrombus. Fourth, we cannot entirely exclude the possibility that thrombus was embolized by the angioscope before TEC. However, none of the patients in this study had angiogrdphic or clinical evidence of distal embolization immediately after angioscopy. Furthermore, it is not necessaryto advance the angioscope through the lesion before intervention since the imaging focal length is >4 mm. Finally, although patient 6 had angioscopic evidence for thrombus removal, the possibility that the TEC cutter resulted in distal embolization and no-reflow (rather than thrombus removal) cannot be entirely excluded. Coronary angioscopy was superior to angiography for evaluating the efficacy of thrombus removal after TEC. In patients with acute ischemic syndromes, TEC was effective in removing intraluminal thrombus.

1. SketchMH Jr, Philhps HR. Lee M-M. Stack RS. Coronary transluminalextraction-endwerectomy. J Irrvasi\r Cardiol 1YY1;3:13-18.

2. PopmaJJ, Leon MB, Mintz GS, Kent KM, Satler LF, GarrandTJ, PichardAD. Results of coronary angioplasty using the trattsluminal extraction catheter.Am J Curd;<,/ lYY2;70:152~1532.

3. SaftanRD. GrimesCL, May MA, LichenbergA, JuranN, SchreiberTL, Pavlides G, Many TB, SavasV, O’Neill WW. ChIlical and angiographicresults of tmnsluminal extraction coronary atherectomy(TEC) in saphenousvein bypassgrafts. Circxdurion lYY4;89:302-312,

4. RameeSR, White CJ, Collins TJ, Mesa J, Murgo JP. Percutaneousangioscopy during percutaneouscoronary angioplastyusinga steerablemicroa~gioscope.J Am Cdl Curdiol 199 1; 17: lOG105.

5. White CJ, RameeSR, Collins TJ. Mesa JE, Jain A. Percutaneousangioscopyof saphenousvein bypassgrafts.J Am Co// Cmdiol lYY3;21:1181-11x5. 6. Siegel RJ, Ariani M, Fishbein MC, Chae JS, Park JC, Maurer G, ForresterJS. Htatopathologicvalidation of angioscopyand intravascularultrasound.Cixx~ltifiu~ lYYl;84:109-I 17. 7. White CJ, RameeSR, Collins TJ, Mesa JE, Jain A, Ventura HO. Percutaneous coronary angioscopy:applicationsin interventional cardiology. J lnremw Cordial iYY3:6:61-67.

Comparison of the Wallstent, Palmaz-Schatz Stent, and Wiktor Stent Late After Intracoronary Stenting Eric Eeckhout, MD, Jean-Jacques Goy, MD, Jean-Christophe Stauffer, MD, Pierre Vogt, MD, and Lukas Kappenberger, MD isual or qualitative estimation of coronary angioV grams has a poor reproducibility and low accuracy.’ Since 1985, different systems of quantitative coronary angiographic analysis have been developed and have demonstratedprecision and reproducibility in vitro and in vivo.2 In the field of interventional cardiology, this method has become an appropriate tool to assessthe angiographic outcome after coronary intervention. Published reports reveal data for the Wallstent, the PalmazSchatz stent, and Wiktor stent; however, a comparison has never been performed.’ Therefore, we examined the quantitative angiographicanalysisdataof 3 different types of coronary stentsusedat our institution in order to comFrom the Cardiology Division, Centre Hospitalier Universitaire Vaudois, 101 I Lausanne, Lausanne, Switzerland. Dr. Eeckhout is the recipient ot a grant from the Fondation de tirdiologie, Lausanne, Switzerland. Manuscript received Detxtnber 16, 1993; revised manuscript received March 16, IYY4, and accepted March 18.

pare their performancesand to investigate whether late intimal proliferation is a stent type-dependent reaction. Since April 1986, coronary stents have been available for clinical investigation at our hospital. Patients with symptomatic and documented ischemia presenting with a new-onset stenosis, restenosis after coronary angioplasty, threatened closure after coronary angioplasty, and narrowed saphenousvein bypassgrafts were considered for intracoronary stenting. Patients with a contraindication to anticoagulation or antiplatelet therapy, or both, and with a target vessel morphology deemedunsuitable jtir stenting (extreme vessel tortuosity, chronic total occlusion, ostial stenosis, and vessel diameter <3 mm) were not considered. The implantation of coronary stents was approved by the hospital ethical committee before$rst stent application. Three types of stents are being used at our institution. The se&expanding Wallstent was the first device ever uvuiluble und wus used until its temporury withBRIEFREPORTS 609