Abrupt vessel closure after directional coronary atherectomy. The U.S. Directional Atherectomy Investigator Group.

From October 1, 1986 to December 31, 1989 directional coronary atherectomy was performed during 1,020 procedures (1,140 lesions) at 14 clinical centers. Abrupt vessel closure, defined as a total coronary occlusion or subtotal occlusion associated with clinical evidence of myocardial ischemia, occurred in 43 procedures (4.2%). It developed in the catheterization laboratory in 34 patients, but was delayed 1 to 96 h after directional atherectomy in 9 patients. By univariate analysis the incidence of abrupt closure was higher in directional atherectomy of de novo lesions (p less than 0.001), lesions in the right coronary artery (p = 0.001) and diffuse lesions (p = 0.04). The incidence of abrupt closure tended to be lower in directional atherectomy of saphenous vein grafts as opposed to native coronary arteries (1.6% vs. 4.4%; p = 0.08). Clinical findings during abrupt closure included severe angina in 26 patients, myocardial infarction in 17 patients, hypotension in 5 patients and death in 2 patients. Balloon angioplasty was attempted in 32 patients after abrupt vessel closure. In 16 patients balloon angioplasty resulted in initial resolution of the closure episode, although 1 patient died 96 h after the procedure. Fifteen of 16 patients without initial improvement after balloon angioplasty underwent coronary bypass operation; 9 additional patients with abrupt closure were referred directly for bypass operation. It is concluded that abrupt vessel closure develops relatively infrequently after directional coronary atherectomy. In the absence of severe coronary dissection, abrupt closure after directional atherectomy may be effectively managed with balloon angioplasty in some cases, although coronary bypass operation is often required.     

Magnum wire for balloon recanalization of chronic total coronary occlusions

A new guidewire (Magnum wire, Schneider) was developed for balloon recanalization of chronic total coronary occlusions. This 0.021-inch solid-steel wire with a floppy tip equipped with a 1-mm diameter "olive" is used like an ordinary guidewire, fits conventional balloon catheters and provides excellent steerability. Magnum wires were used in 50 consecutive chronic total coronary occlusions (mean +/- standard deviation duration 8 +/- 21 months, range 1 day to 10 years; mean length 1.1 +/- 0.8 cm, range 0.2 to 4.0). All occlusions were reached (in 23 right, 18 left anterior descending, 8 left circumflex coronary arteries and 1 diagonal branch) and 30 (60%) were recanalized (1 reoccluded during the procedure, and in 3 patients the Magnum wire did not completely cross the occlusion but enabled the previously impossible passage of a conventional wire). The mean age of the occlusion was 3 +/- 4 months in successful and 17 +/- 33 months in unsuccessful procedures (p = 0.04) and the mean length was 1.1 +/- 0.9 and 1.3 +/- 0.6 cm, respectively (p = 0.4). In 17 patients, conventional techniques had been exhausted before the Magnum wire attempt, which was successful in 8 (47%). In 33 patients the Magnum wire was tried first, with success in 22 (67%). Conventional techniques were subsequently tried in 9 of the 11 failures (none was successful). Of the 38 procedures carried out with a second, improved version of the Magnum wire, 26 (68%) were successful.(ABSTRACT TRUNCATED AT 250 WORDS)     

Outcome after major dissection during coronary angioplasty using the perfusion balloon catheter

Coronary artery dissection is an infrequent but serious complication of coronary angioplasty that can lead to periprocedural vessel occlusion, emergency bypass surgery, myocardial infarction or death. Recently, a perfusion balloon catheter was developed that permits passive perfusion of blood through the central lumen of the catheter. It enables prolonged balloon inflations to be performed and has been used to provide distal blood flow after coronary occlusion. To evaluate the effectiveness of the perfusion balloon catheter in patients with major coronary dissections, 36 consecutive patients treated with the perfusion balloon catheter were compared with 46 consecutive patients treated before its availability. The 2 groups were similar in terms of clinical, angiographic and initial procedural characteristics. Use of the perfusion balloon catheter permitted a significantly longer inflation than standard balloon inflation (average 18 +/- 5 min). Angiographic success was significantly greater with the perfusion balloon catheter (84 vs 62% for conventional therapy), whereas complications were markedly reduced (48 vs 78%). With the perfusion balloon catheter there were fewer deaths (2 vs 6%), myocardial infarctions (14 vs 40%) and emergency bypass operations (11 vs 25%). The findings of this retrospective comparison demonstrate that the perfusion balloon catheter is effective for the management of major dissections after coronary angioplasty. The use of the perfusion balloon catheter should be considered when a major coronary dissection occurs and when emergency bypass surgery is contemplated.     

Value and limits of balloon laser-assisted angioplasty in the treatment of acute obstruction during percutaneous transluminal coronary angioplasty]

One of the problems of percutaneous transluminal coronary angioplasty is acute occlusion during the procedure, the main cause of serious complications and emergency coronary bypass surgery. Acute occlusion is generally related to severe intimal dissection and/or thrombosis. In animal experiments, it is possible to treat intimal dissection and dessicate thrombi by balloon laser angioplasty. Using this method, a programmed laser energy may be delivered to the arterial wall via a fiber optic system linked to a Nd:Yag laser during classical balloon inflation. This has been proposed for the treatment of acute coronary occlusion. Between September 1989 and August 1990, 923 patients underwent coronary angioplasty at the Centre Cardiologique du Nord. Peroperative acute occlusions occurred 52 times (3.9%) in 52 patients. Sixteen patients who were "candidates" for emergency coronary bypass surgery (residual stenosis > or = 75%; delayed flow; myocardial ischaemia) were treated by laser balloon angioplasty, 14 with success (87%). Two patients had to be operated as an emergency. There were no hospital deaths. The average follow-up was 4.7 months for the 14 non-operated patients. Systematic control coronary angiography was refused by 2 asymptomatic patients. In the other 12 patients investigated 1 to 17 months after the procedure, there were 10 restenoses (76%), 6 of which were treated by repeat angioplasty and 3 by coronary bypass surgery. These results show that balloon laser angioplasty is very effective in the treatment of peroperative acute occlusions, enabling emergency coronary bypass surgery to be avoided in 87% of cases, but it is associated with a very high restenosis rate which is difficult to accept.     

Open-ended guidewire: new technique for balloon angioplasty of chronically occluded coronary arteries

Chronic total coronary occlusion is a growing indication to percutaneous transluminal coronary angioplasty. Since primary success of balloon angioplasty in this condition is usually limited by the difficulty of crossing the occlusion, different techniques have been described for this purpose, such as use of stiff guidewires, coronary infusion catheters, guidewires with an olive-shaped tip, or new developing methods (atherectomy, laser), in association with balloon dilatation. Here, we describe our initial experience with a thick (0.035 in) and relatively stiff open-ended guidewire, which has an inner (0.018 in diameter) lumen provided with a core wire. Several advantages are considered. The core wire yields a perfect means of steerability of the whole system, while pushability of a thicker guidewire is much greater. Moreover, the core wire can be removed, and contrast injections beyond the occlusion through the inner lumen can assure proper intraluminal location. Finally, position across the occlusion can be kept easily, since an exchange wire for conventional balloon catheters can be inserted in the inner lumen of the open-ended guidewire.     

Initial report of the National Registry of Elective Cardiopulmonary Bypass Supported Coronary Angioplasty

Relative contraindications to coronary angioplasty have been large amounts of jeopardized myocardium and poor left ventricular function. To prevent possible hemodynamic collapse after balloon occlusion or acute vessel closure in such high risk patients, a cardiopulmonary bypass system capable of providing up to 6 liters/min output was employed prophylactically. This technique, termed supported angioplasty, results in reductions of preload and afterload and allows prolonged balloon inflations in critical coronary vessels. A National Registry of 14 centers performing elective supported angioplasty was formed to collate the initial experience with high risk patients. Suggested indications were ejection fraction less than 25% or a target vessel supplying more than half the myocardium, or both. During 1988, the data from 105 patients (mean age 62 years) undergoing supported angioplasty were entered into the Registry. This group included 20 patients whose disease was deemed too severe to permit bypass surgery and 30 patients who had dilation of their only patent coronary vessel. Seventeen patients had stenosis of the left main coronary artery and 15 underwent dilation of that vessel. Chest pain and electrocardiographic changes occurred uncommonly despite prolonged balloon inflations. During the trial, there was a progressive change from cutdown insertion to percutaneous insertion of the circulatory support cannulas. The angioplasty success rate was 95% for the 105 patients, who underwent an average of 1.7 dilations per patient. Morbidity was frequent (41 patients), in most cases due to arterial, venous or nerve injury associated with cannula insertion or removal, or both.(ABSTRACT TRUNCATED AT 250 WORDS)     

Self-expanding stents for emergency treatment of acute vessel closure following coronary angioplasty: immediate and long-term results

Intracoronary stents may be used to treat acute coronary occlusion following balloon angioplasty. We report the immediate and long-term results of emergency implantation of the self-expanding stent (Wallstent) in 39 patients with acute vessel closure. Stents were successfully deployed in 38 patients (97%). Procedural complications occurred in 14 patients (36%); one patient died, two required emergency coronary artery bypass graft surgery, nine sustained myocardial infarcts (one Q wave), and two had acute stent thrombosis successfully treated by intracoronary thrombolysis and repeat angioplasty. Four patients (10%) had femoral artery bleeding, two required surgery. Angiographic follow-up was performed after 6 months in all 34 eligible patients, or earlier for symptoms. Two patients died prior to follow-up angiography. The stented segment was widely patent in 27 of the 34 patients (79%); restenosis within the stent was detected in 4 (12%) and thrombotic stent occlusion occurred in three (9%). Twenty-six of the 39 patients (67%) were free from major cardiac events and symptoms at 1 year. These results suggest that the self-expanding stent provides an attractive alternative to emergency surgery for the treatment of acute coronary occlusion following coronary angioplasty.     

Acute and long-term outcome of narrowed saphenous venous grafts treated by endoluminal stenting and directional atherectomy.

Angioplasty of the narrowed saphenous vein bypass grafts remains a difficult challenge. Over a 37-month period at this institution, 119 of 176 interventions (68%) on saphenous vein grafts (average age 8.3 years from bypass surgery to graft intervention) were performed using either directional coronary atherectomy (n = 35) or Palmaz-Schatz intracoronary stents (n = 84), representing 37% of all stents and 15% of all atherectomies during the study period, respectively. Of the 57 saphenous vein graft lesions treated with conventional balloon angioplasty during this period, 49 (86%) had 1 or more contraindications to stenting or directional atherectomy (thrombus, total occlusion, reference vessel less than 3 mm in diameter). The acute success rate was 99% for stents (1 failure to dilate) and 94% for directional atherectomy (2 failures to cross the lesion with the atherectomy device). Lumen diameter increased from 0.9 to 3.6 mm (reference vessel 3.6) for stents, and from 0.9 to 3.5 mm (reference 3.8) for atherectomy (for all comparisons, p = not significant), with no major complications (abrupt or subabrupt closure, emergent coronary bypass surgery, death, or Q-wave myocardial infarctions). During the same time period 50 of 57 vein grafts (88%) rejected for stenting or atherectomy were dilated successfully by conventional balloon angioplasty, with 3 patients (5%) requiring emergent coronary bypass surgery. Angiographic follow-up was available for 50 of 64 eligible patients (78%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Coronary vessel stent implantation in patients with symptomatic dissections following balloon dilatation

Dissections after coronary balloon angioplasty are risk factors for acute or subacute vessel closure. Intracoronary stenting was developed to avoid this complication by wrapping the intimal and medial flaps against the vessel wall, which reduces the risk of acute thrombosis. A total of 17 stents were implanted into the coronary arteries of 10 patients with angiographically documented dissections after balloon angioplasty, who presented angina and ischemic ECG changes. Mean minimal stenosis diameter was 1.11 +/- 0.35 mm (65.1%) before, and 1.48 +/- 0.56 mm (53.9%, n.s.) and 2.45 +/- 0.62 mm (23.5%, p less than 0.005), respectively, after balloon angioplasty with and without taking the dissection membrane into account. All patients reported an immediate recovery of their anginal complaints after stent delivery, and ischemic ECG changes disappeared. The mean residual stenosis after coronary stenting was measured as 3.33 +/- 0.23 mm (0%, p less than 0.001). The immediate control angiograms and these after 24 h depicted smooth vessel walls without any irregulations at the site of implantation, and the mean residual stenosis diameter remained unchanged after 24 h (3.3 +/- 0.23 mm; 1.2%, p less than 0.001). No patient suffered acute myocardial infarction, one patient underwent coronary bypass surgery because of persisting episodes of angina pectoris. Thus, intracoronary stenting seems to be a secure and effective method to handle dissections after balloon angioplasty, and perhaps reduces the rate of acute complications and the need for emergency bypass surgery after coronary balloon angioplasty.     

Chronic Coronary Occlusion Ñ Treatment Options and Results

Indications for chronic coronary occlusion angioplasty are based on the projected benefit and technical difficulties. With current indications, primary success is around 60% and complications are rare. In successful cases, the main benefits are improvement of symptoms and obviation of the need for bypass surgery. Late improvement of left ventricular function can also occur. Recurrences are frequent, but reocclusions occur only in about 20% of cases. Several techniques have been advocated to improve the success rate. It is obvious that the stiffer the instrument used the higher the crossing rate, but also the risk for perforation. While the laser wire aims at high crossing success, the Magnum wire aims at high safety. In about 800 cases using the Magnum wire, the success rate was 64% before, and 66% after crossover to another technique. Complications were comparable to those of routine coronary angioplasty. Chronic total occlusions are a major reason for selecting bypass surgery over angioplasty. The technical success with angioplasty leaves room for improvement. However, safety should not be compromised and there are limits to the investment in terms of time and material because the clinical yield is relatively small, albeit uncontested.     

Changing incidence and management of abrupt closure following coronary intervention in the new device era

Abrupt closure of the dilated segment occurs in approximately 4 to 7% of cases following conventional percutaneous coronary angioplasty. Additional balloon angioplasty reverses roughly 40% of these closures, to yield an overall 1.6 to 3.4% rate of emergent surgery. The impact of new devices on the incidence and reversal rate of abrupt closure has not been examined. Abrupt closure occurred in 80 (4.2%) of 1,919 consecutive coronary angioplasties performed in our single center, 389 (20%) of which were performed using newer interventions (208 Palmaz-Schatz stents, 170 directional coronary atherectomies, and 11 elective laser balloon angioplasties). Abrupt closure was less frequent following newer coronary interventions (1.8%) compared to standard balloon angioplasty (4.9%, P < 0.01), possibly reflecting case selection. When abrupt closure did occur, percutaneous rescue was successful in 53 (66%) patients, including 42 (53%) who were rescued using standard or perfusion balloon angioplasty, and 11 (13%) who were rescued using laser balloon balloon angioplasty after failure of additional angioplasty attempts. Medical therapy alone was used in 8 (10%), while emergent coronary bypass surgery was performed in 18 (23%), yielding an overall emergent surgery rate of 0.9%. Q-wave myocardial infarction was significantly less frequent (0.2%) following percutaneous rescue, compared to either medical therapy (25%) or emergent surgery (33%, P < 0.001). In our catheterization laboratory, use of these 3 new coronary interventional devices coincides with a trend towards a lower incidence of abrupt closure, a higher percutaneous rescue rate with reduced incidence of myocardial infarction, and a lower emergent bypass surgery rate.     

Changing incidence and management of abrupt closure following coronary intervention in the new device era.

Abrupt closure of the dilated segment occurs in approximately 4 to 7% of cases following conventional percutaneous coronary angioplasty. Additional balloon angioplasty reverses roughly 40% of these closures, to yield an overall 1.6 to 3.4% rate of emergent surgery. The impact of new devices on the incidence and reversal rate of abrupt closure has not been examined. Abrupt closure occurred in 80 (4.2%) of 1,919 consecutive coronary angioplasties performed in our single center, 389 (20%) of which were performed using newer interventions (208 Palmaz-Schatz stents, 170 directional coronary atherectomies, and 11 elective laser balloon angioplasties). Abrupt closure was less frequent following newer coronary interventions (1.8%) compared to standard balloon angioplasty (4.9%, P < 0.01), possibly reflecting case selection. When abrupt closure did occur, percutaneous rescue was successful in 53 (66%) patients, including 42 (53%) who were rescued using standard or perfusion balloon angioplasty, and 11 (13%) who were rescued using laser balloon balloon angioplasty after failure of additional angioplasty attempts. Medical therapy alone was used in 8 (10%), while emergent coronary bypass surgery was performed in 18 (23%), yielding an overall emergent surgery rate of 0.9%. Q-wave myocardial infarction was significantly less frequent (0.2%) following percutaneous rescue, compared to either medical therapy (25%) or emergent surgery (33%, P < 0.001). In our catheterization laboratory, use of these 3 new coronary interventional devices coincides with a trend towards a lower incidence of abrupt closure, a higher percutaneous rescue rate with reduced incidence of myocardial infarction, and a lower emergent bypass surgery rate.     

Laser balloon angioplasty: clinical, angiographic and histologic results

Laser balloon angioplasty combines conventional coronary angioplasty with laser energy to transiently heat vascular tissue. Laser balloon angioplasty, was performed in 21 patients (aged 56 +/- 13 years), including 10 patients treated urgently after acute failure of conventional angioplasty and 11 patients treated with elective laser balloon angioplasty. Immediately after conventional angioplasty, laser doses (1 to 10 doses of 205 to 380 J each) were delivered during inflation of the laser balloon to a pressure of 4 atm. Seven (70%) of 10 patients with acute failure of conventional angioplasty were successfully treated with laser balloon angioplasty, but 3 (30%) were unsuccessfully treated with the laser procedure and required emergency coronary artery bypass surgery. In all three failures, the 3 mm laser balloon angioplasty catheter was not the optimal size for the vessel. In the 11 patients treated with elective laser balloon angioplasty (reference diameter 2.94 +/- 0.22 mm), the minimal luminal diameter increased from 0.45 +/- 0.25 to 1.85 +/- 0.46 mm after conventional angioplasty and to 2.44 +/- 0.29 mm after laser balloon angioplasty (p less than 0.001). This corresponded to a decrease in diameter stenosis from 84 +/- 9% before to 35 +/- 16% after conventional angioplasty and to 15 +/- 10% after laser balloon angioplasty (p less than 0.001). There were no instances of myocardial infarction, emergency coronary artery bypass surgery or death and no acute complications related to delivery of laser energy in this group. Follow-up coronary angiography was performed 5.5 +/- 1.1 months after laser balloon angioplasty in 18 patients discharged from the hospital after a successful procedure. Ten patients (56%) had angiographic restenosis, defined as recurrent diameter stenosis greater than 50%. Six patients were subsequently treated by directional coronary atherectomy, which revealed intimal proliferation indistinguishable from that in patients with restenosis after conventional angioplasty. In conclusion, laser balloon angioplasty may be effective in sealing severe coronary dissections and reversing abrupt closure associated with failed conventional angioplasty. After uncomplicated conventional angioplasty, laser balloon angioplasty improves immediate luminal dimensions, but restenosis appears to be mediated by intimal hyperplasia, similar to that seen after conventional angioplasty.     

Acute coronary artery occlusion during percutaneous transluminal coronary angioplasty treated by redilation of the occluded segment

Acute occlusion of a coronary artery during percutaneous coronary angioplasty usually results in unremitting ischemia requiring emergency surgical intervention. Seven patients are described, in whom complete occlusion occurred during coronary angioplasty as a result of coronary artery dissection. Despite this, it was possible to reintroduce the balloon catheter immediately and redilate the vessel with abrupt reversal of clinical and electrocardiographic manifestations of ischemia. Six patients had no subsequent evidence of myocardial infarction. The seventh had a slight elevation of serum creatine kinase and transient electrocardiographic changes. All patients were discharged from the hospital without further intervention. Four patients had elective coronary artery bypass surgery (greater than 4 weeks after angioplasty) and three have remained asymptomatic or in improved condition since the coronary angioplasty. It is concluded that sudden occlusion of a coronary artery during coronary angioplasty can be safely treated by redilation in the acute stage.     

Clinical experience with the Wiktor stent in native coronary arteries and coronary bypass grafts.

OBJECTIVES--To evaluate the results of implantation of Wiktor tantalum wire coronary stents in stenosed or occluded coronary vessels or in saphenous vein bypass grafts. DESIGN--A retrospective analysis of clinical and angiographic data from patients treated with tantalum wire stents implanted by one operator at two centres. PATIENTS--52 patients undergoing conventional balloon angioplasty had 67 lesions treated by stents after acute or threatened closure of the target vessel, or because the lesions concerned were considered to be at particularly high risk of becoming restenosed, or because the result of primary angioplasty was inadequate. RESULTS--65 of the 67 lesions were successfully stented although in two cases the first attempt failed and a second stent was then implanted successfully. There were no cases of stent occlusion and no myocardial infarctions in hospital or in the follow up period of 1-20 months. Eight patients had haemorrhagic complications that were minor in 4. One patient later had coronary bypass surgery after failure to stent a lesion. Angiographic follow up at a mean of 6 months after stenting showed restenosis associated with 4 of 47 stents studied. All patients with chest pain had had repeat angiography, and 84% of those without symptoms also agreed to reinvestigation after about 6 months. CONCLUSIONS--The Wiktor tantalum wire stent is an effective means of treating acute complications during angioplasty and seems to offer hope of a significant reduction in the rate of late restenosis in both native coronary vessels and saphenous vein bypass grafts. A prospective comparison of balloon angioplasty and stenting is needed.     

Abrupt vessel closure complicating coronary angioplasty: clinical, angiographic and therapeutic profile.

To assess the clinical, angiographic and procedural correlates of outcome after abrupt vessel closure during coronary angioplasty, results were analyzed of 109 patients (8.3%) who had abrupt vessel closure during 1,319 consecutive coronary angioplasty procedures performed between July 1, 1988 and June 30, 1990. These 109 patients had a mean age of 59 +/- 11 years; 63% were male, 57% had had a prior myocardial infarction and 61% had multivessel disease. Coronary angioplasty was performed in the settings of acute myocardial infarction (14%), recent myocardial infarction (36%), unstable angina (34%) and stable ischemia (29%). Abrupt vessel closure occurred at a median of 27 min (range 0 min to 5 days) from the first balloon inflation. By angiographic criteria, thrombus or coronary dissection was identified in 20% and 28% of cases, respectively; both thrombus and dissection were present in 7% of closures, and 45% were due to indeterminate mechanisms. Successful reversal of abrupt vessel closure, defined as restoration of normal Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow without resultant Q wave myocardial infarction, emergency bypass surgery or death, was achieved in 47 patients (43%). By hierarchal analysis, the incidence of death, emergency coronary bypass surgery, Q wave and non-Q wave myocardial infarction was 8%, 20%, 9% and 11%, respectively. Univariate analysis using 23 clinical, morphologic and procedural variables demonstrated that successful outcome after abrupt closure was associated with prolonged balloon inflations (greater than 120 s) (odds ratio = 6.87, p less than 0.001), unstable angina (odds ratio = 2.37, p = 0.034) and placement of an intracoronary stent (odds ratio = 5.33, p = 0.062). By multivariate analysis, independent correlates of successful outcome were prolonged balloon inflations (odds ratio = 5.11, p = 0.001) and intracoronary stenting (odds ratio = 4.37, p = 0.049). Thus, although prolonged balloon inflations and intracoronary stents may improve outcome after abrupt vessel closure, the cumulative risk of morbidity or mortality remains significant and mandates investigation into improved strategies for its prevention and treatment.     

The Magnum wire for percutaneous coronary balloon angioplasty in 723 patients

The experience of the use of the Magnum wire in a single center is reported. Percutaneous balloon coronary angioplasty, using the Magnum 0.021 inch wire, was attempted in 723 patients with 850 lesions; of these, 453 (53%) were chronic total occlusions and 50 (7%) recent occlusions of less than 24 hours (patients presenting with acute myocardial infarction). The overall technical success rate per lesion was 655/850 (77%). It was 255/280 (91%) for non-total lesions, 311/453 (69%) for chronic total occlusions, 53/67 (79%) for functional (TIMI grade I) occlusions, and 36/50 (72%) for recent occlusions. Clinical success was achieved in 196/232 patients (84%) with non-total lesions, in 292/436 (67%) with total chronic occlusions, in 49/65 (75%) with functional occlusions, and in 34/50 (68%) with recent occlusions. Complications (significant creatine kinase rise, new Q-wave infarction, need for coronary bypass surgery or in-hospital death) occurred in 7% (3% if patients presenting with unstable ischemic syndromes were excluded from the analysis). These data confirm that the use of the Magnum wire has success rates competitive with other systems both in setting of chronic total occlusion and in that of routine percutaneous transluminal coronary angioplasty.     

Initial clinical experiences with rescue unipolar radiofrequency thermal balloon angioplasty after abrupt or threatened vessel closure complicating elective conventional balloon coronary angioplasty

Objectives. The purpose of this study was to evaluate the effectiveness of radiofrequency thermal balloon angioplasty and rescue procedure after abrupt or threatened vessel closure complicating elective percutaneous transluminal coronary angioplasty.Background. Coronary angioplasty is an established therapy for ischemic heart disease. However, abrupt closure after successful angioplasty remains a serious problem.Method. We utilized a unipolar radiofrequency balloon in which a radiofrequency potential of 13.56 MHz was transmitted between the coil within the balloon and a plate electrode attached to the patient's body. The temperature within the balloon could be monitored through a thermistor within the balloon. From October 1991 through December 1993, 31 patients who had abrupt or threatened vessel closure during 1,005 consecutive elective coronary angioplasty procedures were randomly assigned to radiofrequency balloon angioplasty or to other procedures as rescue treatment.Results. Fifteen patients were assigned to radiofrequency balloon angioplasty (5 with abrupt vessel closure and 10 with threatened closure). The average balloon temperature and inflation time were 62 ± 9 °C and 129 ± 62 s, respectively. Percent diameter stenosis decreased from 87 ± 14% to 36 ± 25% (p < 0.01). The procedure was successful in 14 patients. The rate of restenosis was 67%, but the success rate of repeat conventional coronary angioplasty for restenosed lesions was 86%.Conclusions. Radiofrequency balloon angioplasty is effective in the treatment of abrupt or threatened vessel closure complicating elective coronary angioplasty even though the procedure is associated with a relatively high rate of restenosis.     

Wiktor stent implantation in patients with restenosis following balloon angioplasty of a native coronary artery.

Intracoronary stenting has been introduced as an adjunct to balloon angioplasty aimed at overcoming its limitations, namely acute vessel closure and late restenosis. This study reports the first experience with the Wiktor stent implanted in the first 50 consecutive patients. All patients had restenosis of a native coronary artery lesion after prior balloon angioplasty. The target coronary artery was the left anterior descending artery in 26 patients, the circumflex artery in 7 patients and the right coronary artery in 17 patients. The implantation success rate was 98% (49 of 50 patients). There were no procedural deaths. Acute or subacute thrombotic stent occlusion occurred in 5 patients (10%). All 5 patients sustained a nonfatal acute myocardial infarction. Four of these patients underwent recanalization by means of balloon angioplasty; the remaining patient was referred for bypass surgery. A major bleeding complication occurred in 11 patients (22%): groin bleeding necessitating blood transfusion in 6, gastrointestinal bleeding in 3 and hematuria in 2. Repeat angiography was performed at a mean of 5.6 +/- 1.1 months in all but 1 patient undergoing implantation. Restenosis, defined by a reduction of greater than or equal to 0.72 mm in the minimal luminal diameter or a change in diameter stenosis from less than to greater than or equal to 50%, occurred in 20 (45%) and 13 (29%) patients, respectively. In this first experience, the easiness and high technical success rate of Wiktor stent implantation are overshadowed by a high incidence of subacute stent occlusion and bleeding complications.(ABSTRACT TRUNCATED AT 250 WORDS)     

Acute and long-term outcome of failed percutaneous transluminal coronary angioplasty treated by directional coronary atherectomy

Since its initial performance, balloon percutaneous transluminal coronary angioplasty (PTCA) has been limited by a small but finite incidence of acute coronary dissection. This can result in abrupt vessel closure, usually managed with urgent coronary artery bypass grafting. Despite improvements in equipment, technique, and operator experience, the need for urgent bypass after PTCA has remained relatively stable at 2% to 5%, due in part to the expanding indications of the procedure and its use in patients with more complicated conditions and lesions.₁ Techniques that have been used to stabilize acute coronary dissections and avoid emergency coronary bypass surgery include repeat FTCA balloon inflations, prolonged balloon inflations with perfusion balloons,^2,3 laser balloons,⁴ and permanent and temporary stenting.^5,6 The recent availability of directional coronary atherectomy (DCA) has made possible an additional technique for the acute treatment of coronary dissection.⁷ The purpose of this report is to assess both the acute and long-term efficacy of directional coronary atherectomy for the treatment of failed PTCA due to refractory abrupt closure.