Release of atherosclerotic debris after transluminal angioplasty

Long-term outcomes of endovascular therapy for right subclavian artery occlusive lesions: A multi-center experience

OBJECTIVE

To review our multi-institutional experience with endovascular therapy for right subclavian artery occlusive disease and to evaluate the long-term outcomes.

METHODS

We retrospectively evaluated all patients with right subclavian artery stenosis and occlusive disease who underwent endovascular therapy between March 2014 and September 2022 at two institutions. Patient baseline demographics, lesion characteristics, treatment strategies, and in-hospital and follow-up outcomes were prospectively collected and retrospectively analyzed.

RESULTS

Between March 2014 and September 2022, 73 patients underwent endovascular treatment at the two institutions. The dominant cause of lesions in this cohort was atherosclerosis. Three different types of lesions were summarized, and the corresponding endovascular strategies were performed. 66 patients (90.4%) underwent successful endovascular treatment, and 62 patients (84.9%) underwent balloon-expandable stent deployment. The mean perioperative in-hospital stay was 4.0 days (range, 3-6 days). Two patients died due to myocardial infarction, and one died of cerebral hemorrhage resulting from a traffic accident within 30 days of the intervention. The median follow-up time was 31.6 months (range, 12-96 months). No complications, including death, stroke, stent fractures, or migration, were noted in any patient during the follow-up period. The overall complication rate was 7/73 (9.6%), and 5/7 (6.9%) of the complications required reintervention.

CONCLUSIONS

Endovascular treatment of right subclavian artery lesions is safe, effective, and technically achievable. The reasonable use of balloon-expandable stents can achieve satisfactory outcomes with accurate orientation and promising patency.

The Rescuing Role of Aggressive Thrombosuction in Elective Coronary Angioplasty

Thrombosuction plays a controversial role during primary percutaneous intervention (PCI). Landmark trials have demonstrated no additional role of thrombosuction during primary percutaneous intervention towards improving mortality and outcome during primary percutaneous intervention. We describe a rare elective coronary angioplasty where only aggressive thrombosuction (almost 150-200 mL) of blood from the coronary artery established the antegrade coronary flow and saved an octogenarian from impending sudden cardiac death (SCD). The present case describes the promising role of aggressive thrombosuction even during elective coronary intervention when a large dissection ends in acute total thrombotic occlusion of a coronary artery jeopardizing the antegrade coronary perfusion.

Percutaneous Transluminal Angioplasty of the Subclavian Arteries

Purpose:

To review the feasibility, risks, and long-term results of subclavian artery angioplasty with and without Palmaz stent placement.

Methods:

Over a 9-year period, 113 patients (67 males; mean age 63 ± 13 years) underwent percutaneous balloon angioplasty of subclavian occlusive lesions for a variety of indications: vertebrobasilar insufficiency (n = 70), upper limb ischemia (n = 50), coronary steal syndrome (n = 6), or anticipated coronary artery bypass grafting using the internal mammary artery in 12 asymptomatic patients. There were 94 (83%) stenoses and 19 (17%) occlusions with a mean percent stenosis of 80.1% ± 7.4% (range 70 to 100). Mean lesion length was 24 ± 8 mm (range 10 to 50). Beginning in 1989, stents were implanted for suboptimal dilation; in 1995, stenting became routine.

Results:

Overall, 103 (91%) of 113 lesions were successfully treated; 10 (53%) occlusions could not be recanalized. Fifty-one stents were implanted in 46 patients. There were 3 (2.6%) procedural complications: a transient ischemic attack, one major (fatal) stroke, and an arterial thrombosis 24 hours after the procedure (treated medically) (0.9% major stroke and death rate). During a mean 4.3-year follow-up (range to 10), 16 (15.5%) restenoses were treated with angioplasty (n = 4), stenting (n = 7), or surgery (n = 5). Primary and secondary patencies for all treated lesions (n = 113) at 8 years were 75% and 81%, respectively; in patients without initial stent placement, the rates were 69% and 76%, while in those with stents, the rates rose slightly to 87% and 94% at 2.5 years (NS). Patency rates for all 103 recanalized lesions were 83% and 90% at 8 years (81% and 90% without stent and 87% and 94% with stent at 2.5 years, respectively [NS]).

Conclusions:

Balloon angioplasty with or without stenting is safe and effective for treating subclavian artery occlusive diseases with good long-term patency. Recanalization of occlusions is more difficult to achieve. Stents (implanted only for suboptimal dilation) do not seem to improve long-term patency.

Thrombosuction utilizing an export aspiration catheter during primary percutaneous coronary intervention in acute myocardial infarction

PURPOSE

Effective myocardial reperfusion after primary PCI for an AMI in lesions with a thrombus is limited by distal embolization and the slow/no reflow phenomenon. We evaluated the efficacy of a thrombus reduction technique using an export aspiration catheter for thrombosuction during primary PCI.

MATERIALS AND METHODS

We analyzed 62 patients with AMIs who underwent primary PCI and had a thrombi burden during thrombosuction using an EAC (EAC group; n=31) or without thrombosuction (control group; n=31).

RESULTS

Thrombosuction with an EAC was performed safely in all the patients in EAC group without any complications. After the PCI, restoration to a TIMI flow grade 3 was significantly more frequent in the EAC group (26/31 vs. 20/31, p < 0.05). However, the TIMI perfusion grade did not differ between the two groups. Further, the corrected TIMI frame counts were lower in the EAC group (23.9 +/- 15.1 vs. 34.8 +/- 22.5, p < 0.05). Although there was no statistical significance, a greater incidence of distal embolization was observed in the control group (16.1%, 5/31) as compared to the EAC group (0/31) (p= 0.056). However, the incidence of major adverse cardiac events at 1 and 6 months did not differ between the two groups.

CONCLUSION

For AMIs, thrombosuction with an EAC before or during PCI is a safe and potentially effective method for restoration of the coronary flow.

Thrombus aspiration before primary angioplasty improves myocardial reperfusion in acute myocardial infarction: the DEAR-MI (Dethrombosis to Enhance Acute Reperfusion in Myocardial Infarction) study

OBJECTIVES

This study sought to test the hypothesis that thrombus removal, with a new manual thrombus-aspirating device, before primary percutaneous coronary intervention (PPCI) may improve myocardial reperfusion compared with standard PPCI in patients with ST-segment elevation acute myocardial infarction (STEMI).

BACKGROUND

In STEMI patients, PPCI may cause thrombus dislodgment and impaired microcirculatory reperfusion. Controversial results have been reported with different systems of distal protection or thrombus removal.

METHODS

One-hundred forty-eight consecutive STEMI patients, admitted within 12 h of symptom onset and scheduled for PPCI, were randomly assigned to PPCI (group 1) or manual thrombus aspiration before standard PPCI (group 2). Patients with cardiogenic shock, previous infarction, or thrombolytic therapy were excluded. Primary end points were complete (>70%) ST-segment resolution (STR) and myocardial blush grade (MBG) 3.

RESULTS

Baseline clinical and angiographic characteristics were similar in the 2 groups. Comparing groups 1 and 2: complete STR 50% versus 68% (p < 0.05); MBG-3 44% versus 88% (p < 0.0001); coronary Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 78% versus 89% (p = NS); corrected TIMI frame count 21.5 +/- 12 versus 17.3 +/- 6 (p < 0.01); no reflow 15% versus 3% (p < 0.05); angiographic embolization 19% versus 5% (p < 0.05); direct stenting 24% versus 70% (p < 0.0001); and peak creatine kinase-mass band fraction 910 +/- 128 mug/l versus 790 +/- 132 mug/l (p < 0001). In-hospital clinical events were similar in the 2 groups. After adjusting for confounding factors, multivariate analysis showed thrombus aspiration to be an independent predictor of complete STR and MBG-3.

CONCLUSIONS

Manual thrombus aspiration before PPCI leads to better myocardial reperfusion and is associated with lower creatine kinase mass band fraction release, lower risk of distal embolization, and no reflow compared with standard PPCI. (Thrombus Aspiration Before Standard Primary Angioplasty Improves Myocardial Reperfusion in Acute Myocardial Infarction; http://clinicaltrials.gov/ct/show/NCT00257153).

Cholesterol crystal embolization (CCE) after cardiac catheterization: a case report and a review of 36 cases in the Japanese literature

Cholesterol crystal embolization (CCE) is a complication of atherosclerosis. A 67-year-old Japanese man underwent coronary artery bypass grafting. After the surgery, he underwent coronary angiography via the right femoral artery. Twelve days later, he suddenly developed acalculous cholecystitis and was treated with antibiotics. Gradual deterioration in renal function, purplish discoloration of the distal portion of his toes, and eosinophilia were noted. We performed a skin biopsy and made a diagnosis of CCE. Cilostazol and intravenous heparin improved the symptoms and decreased the creatinine level. We retrospectively studied the clinical features of 36 cases registered with a diagnosis of CCE in the Japanese literature.

Distal protection in native coronary arteries during primary angioplasty in acute myocardial infarction: Single-center experience

Distal embolization of plaque or thrombotic debris is one of the mechanisms involved in the ischemia/reperfusion injury during primary percutaneous intervention for acute occlusion of a native coronary artery. We tested the clinical application of maximal antiplatelet therapy with abciximab combined with one of two different systems of mechanical distal protection: balloon occlusion and aspiration (PercuSurge) in 24 cases and a distal filter (FilterWire Ex) in 10 cases. Feasibility, technical limitations, and pitfalls are described.

Adjunctive thrombus aspiration and mechanical protection from distal embolization in primary percutaneous intervention for acute myocardial infarction

Primary percutaneous intervention for acute occlusion of a native coronary artery may be complicated by distal embolization of plaque or thrombotic debris, with infarct extension. We tested the clinical application of a new therapeutic strategy combining maximal antiplatelet therapy, with glycoprotein IIb/IIIa inhibition, and adjunctive mechanical protection from distal embolization and direct aspiration of thrombus with a new balloon and catheter system (PercuSurgetrade mark). Successful aspiration of thrombus could be obtained in 7 out of 8 attempted procedures, with inability to negotiate the angulated take-off of the circumflex coronary artery in one patient. The current mechanical characteristics of the device, primarily developed for use in larger saphenous vein grafts, and certain caveats and limitations are discussed. New dedicated systems should be available in the near future for the native coronary circulation. Excellent immediate angiographic results were obtained in all treated patients, without evidence of loss of distal branches and no intraprocedural complications.

Embolic risk of the different stages of carotid bifurcation balloon angioplasty: an experimental study

PURPOSE

Embolic events during carotid angioplasty are a challenging problem. This experimental study was undertaken to determine the embolic risk after each stage of carotid angioplasty procedure.

METHODS

Five ex vivo carotid artery balloon angioplasties were performed on fresh carotid specimens. The carotid specimens were obtained from five patients who underwent an internal carotid artery bypass for stenosis >75%. Before the endovascular maneuvers and after each stage of the procedures, the specimens were flushed with 20 mL of saline solution. Small particulate emboli (diameter, <60 microm) were searched in all the effluents according to the Coulter technique. After this procedure, each effluent was also submitted to scanning electron microscopy.

RESULTS

When the stenosis was crossed with the guidewire or the balloon catheter, the number and the mean diameter of embolic particles did not change with three plaques (CP1, CP2, and CP3) and were increased with two plaques (CP4 and CP5). The maximal size of particles was 220 microm (CP5). After balloon angioplasty, the number and the mean diameter of particles increased with CP1, CP2, and CP3. With CP4 and CP5, the number of particles decreased, but their size increased. The maximal size of particles was 1100 microm (CP4).

CONCLUSION

Carotid balloon angioplasty generates embolic particles after each stage of the procedure. Techniques of prevention should then be effective from the initial step of the angioplasty procedure, and the selection of patients for carotid angioplasty remains crucial.

Atherosclerotic renal artery stenosis: from diagnosis to treatment

Renovascular hypertension represents a form of correctable hypertension and preventable renal failure. Such patients need to be identified early so that specific therapy can be instigated. Patient identification requires a high index of suspicion in patients with certain clinical features. Subsequent non-invasive imaging may result in angiography which is required for diagnostic purposes and for planning intervention. Correctable therapy takes one of two forms, namely percutaneous transluminal renal angioplasty, with or without stenting, or surgical revascularisation, together with modification of underlying risk factors.

Percutaneous transluminal angioplasty of the subclavian arteries

PURPOSE

To review the feasibility, risks, and long-term results of subclavian artery angioplasty with and without Palmaz stent placement.

METHODS

Over a 9-year period, 113 patients (67 males; mean age 63 +/- 13 years) underwent percutaneous balloon angioplasty of subclavian occlusive lesions for a variety of indications: vertebrobasilar insufficiency (n = 70), upper limb ischemia (n = 50), coronary steal syndrome (n = 6), or anticipated coronary artery bypass grafting using the internal mammary artery in 12 asymptomatic patients. There were 94 (83%) stenoses and 19 (17%) occlusions with a mean percent stenosis of 80.1% +/- 7.4% (range 70 to 100). Mean lesion length was 24 +/- 8 mm (range 10 to 50). Beginning in 1989, stents were implanted for suboptimal dilation; in 1995, stenting became routine.

RESULTS

Overall, 103 (91%) of 113 lesions were successfully treated; 10 (53%) occlusions could not be recanalized. Fifty-one stents were implanted in 46 patients. There were 3 (2.6%) procedural complications: a transient ischemic attack, one major (fatal) stroke, and an arterial thrombosis 24 hours after the procedure (treated medically) (0.9% major stroke and death rate). During a mean 4.3-year follow-up (range to 10), 16 (15.5%) restenoses were treated with angioplasty (n = 4), stenting (n = 7), or surgery (n = 5). Primary and secondary patencies for all treated lesions (n = 113) at 8 years were 75% and 81%, respectively; in patients without initial stent placement, the rates were 69% and 76%, while in those with stents, the rates rose slightly to 87% and 94% at 2.5 years (NS). Patency rates for all 103 recanalized lesions were 83% and 90% at 8 years (81% and 90% without stent and 87% and 94% with stent at 2.5 years, respectively [NS]).

CONCLUSIONS

Balloon angioplasty with or without stenting is safe and effective for treating subclavian artery occlusive diseases with good long-term patency. Recanalization of occlusions is more difficult to achieve. Stents (implanted only for suboptimal dilation) do not seem to improve long-term patency.

Role of coronary artery lumen enlargement in improving coronary blood flow after balloon angioplasty and stenting: a combined intravascular ultrasound Doppler flow and imaging study

OBJECTIVES

This study sought to examine the mechanism of increasing coronary flow reserve after balloon angioplasty and stenting.

BACKGROUND

Coronary vasodilatory reserve (CVR) does not improve after percutaneous transluminal coronary angioplasty in > or = 50% of patients, postulated to be due to impaired microvascular circulation or inadequate lumen expansion despite adequate angiographic results.

METHODS

To demonstrate the role of coronary lumen expansion, serial coronary flow velocity (0.014-in. Doppler guide wire) was measured in 42 patients before and after balloon angioplasty and again after stent placement. A subset (n = 17) also underwent intravascular ultrasound (IVUS) imaging of the target sites after angioplasty and stenting. CVR (velocity) was computed as the ratio of adenosine-induced maximal hyperemic to basal average peak velocity.

RESULTS

The percent diameter stenosis decreased from (mean +/- SD) 84 +/- 13% to 37 +/- 18% after angioplasty and to 8 +/- 8% after stenting (both p < 0.05). CVR was minimally changed from 1.70 +/- 0.79 at baseline to 1.89 +/- 0.56 (p = NS) after angioplasty but increased to 2.49 +/- 0.68 after stent placement (p < 0.01 vs. before and after angioplasty). IVUS lumen cross-sectional area was significantly larger after stenting than after angioplasty (8.39 +/- 2.09 vs. 5.10 +/- 2.03 mm2, p < 0.05). Anatomic variables were related to increasing coronary flow velocity reserve (CVR vs. IVUS lumen area: r = 0.47, p < 0.005; CVR vs. quantitative coronary angiographic percent area stenosis: r = 0.58, p < 0.0001).

CONCLUSIONS

In most cases, increases in CVR were associated with increases in coronary lumen cross-sectional area. These data suggest that impaired CVR after angioplasty is often related to the degree of residual narrowing, which at times may not be appreciated by angiography. A physiologically complemented approach to balloon angioplasty may improve procedural outcome.

Coronary artery and saphenous vein graft remodeling: a review of histologic findings after various interventional procedures--Part IV

Catheter balloon angioplasty is a well accepted form of nonsurgical treatment of acutely and chronically obstructed coronary artery vessels. It is also the centerpiece for various new intervention techniques. Their morphologic effects on the site of obstruction has been termed "remodeling." Part IV of this six-part series focuses on morphologic correlates of coronary angiographic patterns of remodeling after balloon angioplasty and discusses effects of angioplasty on adjacent, nondilated vessels.

Isolated splenic infarction following left cardiac catheterization: case report and a review of the literature

A cardiac catheterization was performed in a 57-year-old man for post-infarction angina. A severe left flank pain developed following the angiography. Ultrasonography, computed tomography, and radionuclear scanning of the abdomen showed splenic infarction. An isolated cholesterol atheroembolism of spleen from disrupted atheromatous plaques so far has not been reported.

Percutaneous transluminal angioplasty of an innominate artery occlusion

A middle-aged woman presented with recent-onset left hemiparesis and right subclavian steal syndrome. She was found to have an obstructed innominate artery. We successfully performed balloon angioplasty of the occluded innominate artery and encountered no complications during follow-up of currently 8 months.

Nephrotoxic risks of renal angiography: contrast media-associated nephrotoxicity and atheroembolism--a critical review

Renal angiography remains the "gold standard" procedure for the detection of renal artery stenosis. However, clinicians often avoid renal angiography because of fears of contrast media-associated nephrotoxicity (CM-AN) and atheroembolism. This review focuses on these potential angiographic complications, with particular emphasis, in the case of CM-AN, on clinical features, incidence, risk factors with an emphasis on pre-existing renal insufficiency and diabetes mellitus, volume of contrast media, low osmolar versus high osmolar contrast media, and prophylaxis. For atheroembolism, areas emphasized are pathology, clinical features, precipitating features, and incidence in various settings. Although the literature contains an abundance of information about CM-AN and atheroembolism, this review identified multiple areas of uncertainty regarding features of both of these complications. For example, additional studies are needed to determine the incidence of CM-AN, both asymptomatic and clinically severe, in patients with a wide range of pre-existing renal insufficiency with and without diabetes mellitus, following low volume digital subtraction renal angiography with low osmolar contrast media. In a similar manner, studies are needed with adequate postcontrast observation periods to determine the true incidence of clinically significant atheroembolism following diagnostic renal angiography and angioplasty and techniques that may modify this complication. Until further knowledge in both of these areas is available, it is difficult to precisely determine the risks of renal angiography and/or angioplasty in the azotemic patient suspected of or having renal ischemic disease using modern radiologic techniques.

A new triple-balloon, four-channel vascular catheter for use in renal transplantation

While current surgical techniques of renal transplantation afford excellent results, some steps of the operation are associated with potential morbidity. Application of vascular clamps on an atherosclerotic recipient artery can cause plaque fracture or atheroembolism. atheroembolism. Prolonged revascularization time may aggravate ischemic allograft damage. Based on the premise that arterial occlusion by an intraluminal balloon is less damaging to the vascular endothelium than an external vascular clamp, a new three-balloon, four-channel vascular catheter has been developed for use in renal transplantation. Catheters are inserted by the Seldinger technique, one catheter being positioned in each recipient external iliac artery and external iliac vein. Vascular control of the recipient vessels is obtained by inflation of the balloons. A pilot study in four dogs has confirmed the technical feasibility of using this catheter during renal transplantation. A description of the catheter, technique of surgical placement, advantages and potential uses is presented.

Balloon angioplasty results in increased segmental coronary distensibility: a likely mechanism of percutaneous transluminal coronary angioplasty

OBJECTIVES

The purpose of this study was to evaluate the hypothesis that the increase in lumen area induced by percutaneous transluminal coronary angioplasty is secondary to a change in lesion (segmental) distensibility.

BACKGROUND

Despite the widespread use of coronary angioplasty, the precise mechanism (or mechanisms) of lumen area improvement remains poorly understood.

METHODS

Quantitative coronary angiography was used to measure the minimal (contrast agent filled) balloon diameters at 1 to 5 atm, inclusive, during the first and final balloon inflations in 24 lesions successfully treated with coronary angioplasty. To rule out possible confounding effects due to changes in balloon material distensibility during repeated inflations, five control balloons were studied ex vivo. In parallel, intravascular ultrasound imaging was utilized to compare the segmental distensibility (change in lumen area during the cardiac cycle) of eight disease-free and seven mildly diseased coronary segments and seven segments after successful balloon angioplasty.

RESULTS

Minimal balloon diameters increased significantly between the first and final inflations (46%, 33%, 26%, 14% and 10% at 1, 2, 3, 4 and 5 atm, respectively, all p < 0.0001), demonstrating an increase in arterial distensibility after successful coronary angioplasty. No significant changes in balloon diameters were observed during sequential initial inflations at 1 and 2 atm (n = 5). Minimal increases in balloon diameters were observed during repeated balloon inflations in the ex vivo studies (4.9 +/- 1% [mean +/- SEM]). A distensibility index, derived from the intravascular ultrasound data, was not different between the balloon-dilated and the normal segments but was significantly lower in mildly diseased sites (14.7 +/- 2.2 vs. 12.9 +/- 1.2 vs. 6.9 +/- 1.9, respectively, p < 0.05) despite a smaller plaque area (7.3 +/- 1 vs. 11.3 +/- 1 mm2, proximal/nondilated vs. dilated segments, respectively, p < 0.05).

CONCLUSIONS

Coronary distensibility is significantly impaired in atherosclerotically diseased coronary segments and increases significantly after balloon angioplasty. This increase in segmental coronary compliance after coronary angioplasty may create a larger lumen area by allowing the vessel to distend in response to normal intraarterial pressure.

High frequency rotational ablation: an alternative in treating coronary artery stenoses and occlusions

OBJECTIVE

To prove the safety and effectiveness of high frequency rotational ablation of coronary artery stenoses and occlusion in humans.

SUBJECTS

106 patients with symptoms (91 men, 15 women) who had 67 significant stenoses, mainly types B and C, and 46-chronic occlusions.

MAIN OUTCOME MEASURES

Mean change in diameter stenosis after rotational angioplasty alone and in combination with percutaneous transluminal coronary angioplasty immediately after treatment and 24 hours and six months later; restenosis rates at six months; complication of treatment.

RESULTS

Rotational ablation could not be used in five stenoses and 16 chronic occlusions because of inability to reach or cross the lesion with the Rotablator guide wire. In four cases rotational ablation failed. Initial angiographic and clinical success by rotational ablation was achieved in 40 of the 67 stenoses (60%) and in 18 of the 46 chronic occlusions (39%). Additional balloon angioplasty was performed in 45 patients, increasing the success rates to 79% and 54%, respectively. In the 62 stenoses treated by rotational ablation the angiographic diameter stenoses were reduced from 76% (SD 14%) to 32% (14%) after Rotablator treatment alone and from 75% (11%) to 33% (17%) with additional balloon angioplasty. In the 30 chronic occlusions treated by rotational ablation the angiographic diameter stenoses were reduced to 38% (18%). At six months angiographic restenosis was evident in nine of the 25 (36%) stenoses treated with rotational ablation alone, in seven of the 22 (32%) stenoses treated with rotational and balloon angioplasty, and in 14 of the 24 (58%) chronic occlusions. There were no procedural deaths and two patients (2%) underwent emergency coronary artery bypass grafting. Although no transmural infarction occurred, there were five (6%) non-Q wave infarctions (two embolic side branch occlusions, two subacute occlusions, and one acute occlusion). Clinically insignificant slight increases in creatine kinase activity were seen in five patients (6%). Severe coronary artery spasm unresponsive to medical treatment was provoked in seven cases (8%).

CONCLUSIONS

High frequency rotational ablation is a safe and effective method for treating type B and C coronary artery lesions with results comparable to percutaneous transluminal coronary balloon angioplasty. The combined use of rotational ablation and balloon angioplasty is feasible and is necessary in about half of all procedures, in most cases because the lumen created by the biggest burr is too small.

Angiographic predictors of a rise in serum creatine kinase (distal embolization) after balloon angioplasty of saphenous vein coronary artery bypass grafts

Distal coronary embolization is thought to be increased in the balloon angioplasty of coronary by-pass vein grafts. One hundred fifty-five procedures of balloon angioplasty involving single vein graft dilatation were successfully performed. Distal coronary embolization was defined as an elevation of creatine phosphokinase greater than twice the preangioplasty value and positive MB fraction. Twenty procedures were found to have embolism by this definition. Forty preangioplasty angiograms were randomly selected from the remaining procedures and analyzed as a control group. Eight angiographic features were evaluated as possible risk factors for distal coronary embolization, i.e., diffusely diseased vein graft, presence of thrombus, ulcerated lesion surface, marked eccentricity, large plaque volume, lesion angulation, abrupt proximal face and ectasia. A diffusely diseased vein graft (p = 0.002), presence of thrombus (p = 0.006), irregular or ulcerated lesion surface (p = 0.007), large plaque volume (p = 0.02) and marked eccentricity (p = 0.03) were found to be important predictors by univariate analysis. A diffusely diseased vein graft and a large plaque volume were found to be important independent predictors by multivariate analysis. The presence of thrombus and an irregular or ulcerated lesion surface frequently coexist with a diffusely diseased vein graft. It is concluded that a diffusely diseased vein graft and a large plaque volume are important independent predictors of distal embolization, and thrombus and an ulcerated lesion surface are also important.

Influence of balloon size and stenosis morphology on immediate and delayed elastic recoil after percutaneous transluminal coronary angioplasty

After successful coronary angioplasty, the minimal luminal diameter of the dilated coronary artery segment is generally smaller than the diameter of the largest balloon catheter at the maximal inflation pressure. The determinants of this phenomenon were studied in 28 patients. Biplane angiograms were obtained after intracoronary administration of isosorbide dinitrate (1 mg) before, immediately and 24 h after coronary angioplasty. Balloon and coronary luminal diameters were measured by automated contour detection. Immediately after the procedure, the difference between inflated balloon diameter and minimal luminal diameter averaged 0.93 +/- 0.43 mm for the entire group and was greater both in eccentric stenoses (1.13 +/- 0.39 vs. 0.70 +/- 0.36 mm; p less than 0.01) and after angioplasty with an oversized balloon (1.20 +/- 0.37 vs. 0.71 +/- 0.33 mm; p less than 0.005). At 24 h, the balloon - minimal luminal diameter difference was unchanged at the group level (0.86 +/- 0.38 mm, but the minimal luminal diameter increased significantly in the subgroup of coronary segments dilated with an oversized balloon (1.97 +/- 0.37 vs. 1.81 +/- 0.28 mm; p less than 0.05). Thus, the difference between the minimal diameter of a dilated coronary segment immediately after a successful coronary balloon angioplasty procedure and the maximal diameter of the inflated balloon catheter is dependent both on eccentricity of the stenosis and on the balloon/artery diameter ratio. Moreover, the increase in minimal luminal diameter 24 h after angioplasty performed with an oversized balloon suggest that in addition to elastic recoil partly reversible factors related to vessel barotrauma are involved.

Percutaneous transluminal angioplasty of the lower extremities by the vascular surgeon

As vascular surgeons, we performed 376 percutaneous transluminal angioplasties as follows: aorta and iliac arteries (148), infrainguinal arteries (191), and bypass grafts (21). Sixteen procedures were attempted but not completed. Neodymium-yttrium-aluminum-garnet laser thermoprobe was successfully used prior to balloon dilatations in 49 procedures. In contrast to our experience with operative intervention, percutaneous transluminal angioplasty was performed more frequently for claudication (75%), nondiabetics (72%), and women (45%). Median age was 71 years. Percutaneous transluminal angioplasty either preceded or followed proximal or distal open reconstruction in 58 extremities. Primary patency rates for iliac percutaneous transluminal angioplasties were: 94% at one month, 93% at six months, and 88% at one year. For infrainguinal percutaneous transluminal angioplasties they were 95%, 82%, and 70% at 1, 6, and 12 months, respectively. Repeat percutaneous transluminal angioplasty increased the one-year patency rates to 92% and 86% for iliac and infrainguinal percutaneous transluminal angioplasties, respectively. Preliminary data indicate that the six-month secondary patency rates were 82% for laser-assisted percutaneous transluminal angioplasty and 65% for percutaneous transluminal angioplasty of distal bypass grafts. The implementation of balloon angioplasty was facilitated by our 21 years of experience with arteriography. Percutaneous transluminal angioplasty has become a valuable adjunct to the practice of vascular surgery by expanding the therapeutic options for managing peripheral vascular occlusive disease.

Stenting of coronary arteries: has a modern Pandora's box been opened?

Interventional cardiology has recently witnessed the growth of several alternatives to percutaneous transluminal angioplasty, including coronary stenting. Although stenting appears to be useful in treating abrupt closure after coronary angioplasty, its effectiveness in limiting the complex processes responsible for late restenosis is much less certain. Pathologic examination of stented human saphenous bypass grafts shows extensive deposits of platelets, fibrin and leukocytes along the stent wires within the 1st week and formation of a neointima of variable thickness after 3 months without evidence of foreign body reaction. The long-term effects of continuous barotrauma induced by the expanded stent remain unknown. It is difficult to assess the relative merits of the new devices, but stenting has several theoretic advantages. It seems less disruptive to the underlying architecture of the vessel wall and enjoys favorable theoretic and effective expansion ratios. Wide-spread clinical acceptance for stenting will depend on demonstrating that its safety, efficacy and cost efficiency are superior to those of balloon angioplasty.

Cholesterol atheroembolism: an increasingly frequent complication of cardiac catheterisation

Cholesterol atheroembolisation is increasingly encountered as a complication of cardiac catheterisation. We report three cases seen recently in our unit. Autopsy and histological evidence confirmed cholesterol atheroembolism in one case, while the other two patients presented with classical clinical features of this condition. All three patients were elderly with extensive atheromatous disease. No excessive difficulty was encountered at catheterisation. Embolisation involved the gastrointestinal tract, the skin and extremities, and the kidneys. Despite anticoagulation, dialysis and surgical intervention all our patients died. With investigative and therapeutic catheterisation being increasingly performed in the setting of severe atherosclerosis, the need for continued scrutiny for catheter-induced complications is emphasised.

Restenosis following coronary angioplasty

The last decade has witnessed an enormous increase in the use and success of percutaneous transluminal coronary angioplasty. During this time, our knowledge of the mechanisms of angioplasty and of how it relates to the pathophysiology of restenosis has also grown. Despite our better understanding of the mechanisms responsible for it, restenosis remains a significant problem in coronary angioplasty, affecting approximately one third of patients. A variety of factors can affect the measured rate of restenosis, such as the symptomatic status of the patient and the timing of restenosis studies. Certain clinical, anatomic, and procedural factors are associated with increased rates of restenosis. Pharmacologic interventions are ineffective in preventing restenosis. A variety of new mechanical devices are being developed, but their efficacy at this time does not appear to be superior to angioplasty alone. While attempts at preventing restenosis have thus far been unsuccessful, the information gained through the various studies has added tremendously to our knowledge base of angioplasty. Through this better understanding of the mechanisms of angioplasty and restenosis, it is likely that the problem of restenosis will be improved, either through existing technology or by methods yet to be discovered.

Histopathologic examination of material from angioplasty balloon catheters used in vivo in human coronary arteries

Reports on vascular pathology post-PTCA in both human and animal coronary vessels have revealed medial and intimal cracks and tears, thrombus formation, platelet accumulation, and loss of endothelial cells. The extent and type of damage can currently be assessed in vivo at the macro level by means of coronary artery angiography. However, this technique cannot define vessel wall characteristics at the cellular level. Our hypothesis is that vessel wall material may adhere to the balloon and thus provide a source for coronary artery cytological investigation in vivo. Ten balloon catheters were evaluated to discern any material which was dislodged from the coronary artery and which remained attached to the balloon catheter or guide wire. Our results indicate that angioplasty catheter balloons frequently have adherent collagen, endothelial cells, organized thrombus, and plaque with obvious cholesterol clefts, that can be retrieved and examined histologically. We conclude that material is often dislodged from the plaque during PTCA. In addition, plaque material removed by the balloon catheter offers an unusual opportunity to analyze the morphologic characteristics of cells from the human coronary artery in vivo.

Carotid transluminal angioplasty with evidence of distal embolization. Case report

A 57-year-old woman presented with symptomatic triple tandem stenosis of the left carotid artery. Transluminal angioplasty of an atherosclerotic stenosis at the origin of the common carotid artery was performed retrogradely through a distal arteriotomy after endarterectomy. The postangioplasty effluent was collected and analyzed. Cholesterol crystals and amorphous plaque debris were identified, indicating a source for distal embolization. The clinical significance of this small amount of debris embolizing to the intracranial circulation is uncertain, but should be of concern when considering angioplasty of the cerebral circulation.

Balloon angioplasty of aortocoronary saphenous vein bypass grafts: a histopathologic study of six grafts from five patients, with emphasis on restenosis and embolic complications

Among 103 patients undergoing percutaneous transluminal balloon angioplasty of obstructed aortocoronary saphenous vein bypass grafts at the Mayo Clinic, six grafts from 5 patients were available for histopathologic examination. The interval from graft insertion to angioplasty ranged from 5 to 105 months and that from angioplasty to graft excision ranged from 6 h to 24 months. Angioplasty produced intimal fissures in three grafts initially obstructed by intimal fibromuscular proliferation. Healing and restenosis resulted from filling of lacerations with fibrocellular tissue and apparently also from restitution of muscular tone. In two of three grafts initially narrowed by atherosclerosis, balloon angioplasty cause extensive plaque rupture and restenosis resulted from extrusion of plaque debris and secondary luminal thrombosis. In the third graft, angioplasty produced no distinct lesions and late restenosis was due to progressive atherosclerosis of the vein graft. Atheroembolization was observed in both patients with plaque rupture and was associated with reoperation in one and death in the other. In conclusion, the results derived from six saphenous vein bypass grafts subjected to balloon angioplasty indicate that restenosis may result from intimal fibrocellular proliferation, thrombosis, restitution of muscular tone and progressive atherosclerosis. Symptomatic atheroembolization may occur in grafts greater than 1 year old.

Pathological changes induced by repeated percutaneous transluminal coronary angioplasty

The histopathological appearances of seven coronary arteries obtained from four patients after repeated percutaneous transluminal coronary angioplasty were analysed. A complex picture was found; typically there were ruptured atherosclerotic plaques, plaque dissection, and a fibrous tissue response. The histopathological appearance of older and more recent fibrous lesions was different. Older lesions contained more collagen and elastin fibres, whereas recent ones had more loosely arranged connective tissue containing abundant glycosaminoglycan and readily identifiable cells. The fibrous tissues tended to be damaged at the sites of previous injury and where the vessel wall was thinnest. In five of the seven arteries there was evidence of a repeated fibrous response to injury with partial or total rupture of the original media. In one instance a repair response within a pre-existing atherosclerotic plaque had caused restenosis. The results indicate that restenosis after repeated percutaneous transluminal coronary angioplasty, like restenosis after a first procedure, is mainly the result of fibrocellular tissue response to injury of the wall tissues. Because older (that is more mature) repair tissue contains fewer cells and more connective elements than younger repair tissue (that is the loosely arranged connective tissue found soon after angioplasty), when it is disrupted by a further angioplasty procedure it is less capable of producing tissue that will obstruct the lumen. This may explain why in the majority of patients with restenosis repeated percutaneous transluminal coronary angioplasty is successful. The present study also showed that occasionally plaque haemorrhages may become organised and incorporated into the pre-existing atherosclerotic lesion.

Coronary angioplasty

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Percutaneous transluminal angioplasty of the subclavian artery: early and late results

Percutaneous transluminal angioplasty of 23 subclavian arteries was attempted in 22 patients. Dilatation was successful in 3 of 4 right subclavian artery stenoses and 18 of 19 left subclavian artery stenoses. The primary clinical indication was posterior fossa ischemia in 11 patients, upper limb ischemia in 14 and both symptoms in 6. In 2 patients, dilatation of an asymptomatic high-degree left subclavian artery stenosis was performed before coronary artery bypass surgery using the internal mammary artery. Eighteen patients on follow-up over 6-60 months (mean 25 months) are free of symptoms with equivalent systolic blood pressures in both arms. Three patients showed relapse of the stenosis after 8, 12, and 15 months; one was successfully treated with a second dilatation. Complications consisted of an occlusion at the left axillary artery puncture site and a distal embolus to a finger artery. Percutaneous transluminal angioplasty appears safe and efficient therapy for subclavian artery stenoses with excellent short- and long-term results.

Percutaneous transluminal coronary angioplasty--histopathological analysis of nine necropsy cases

From 1982 to 1984 nine of 300 patients undergoing transluminal coronary angioplasty died. The nine coronary arteries and one saphenous aorto-coronary by-pass graft affected by angioplasty were studied by light microscopy. The following types of lesions were found, frequently in association: rupture of the plaque, circumscribed or reaching to the intimal layer or extending beyond it, dissections (fissures) between arterial layers, intra-plaque haemorrhage, plaque emboli and thrombosis. In two cases the therapeutic approach was considered to be clinically and pathologically successful; the patients survived 24 h (case 6) and forty days (case 4). Case 6 which presented recent lesions indicative of success showed, in contrast with the other non-successful cases, rupture affecting not only the intimal layer but also deeper structures of the arterial wall. There were also more extensive fissures. Case 4 which presented late alterations indicative of success showed a plaque fracture whose borders were kept apart by fibrous tissue. In conclusion, we believe that angioplasty allows the re-establishment of arterial blood flow by provoking deep intimal and medial rupture producing a small fissure between the arterial layers and a widening of the lumen; in cases with good late results these alterations cicatrize leaving a wider arterial lumen.

Livedo reticularis due to multiple cholesterol emboli

Three patients with advanced atherosclerotic vascular disease developed multiple cholesterol emboli. The clinical presentation typically includes livedo reticularis of the lower part of the body and purple toes. Small areas of necrosis and ulceration may be present distally, despite palpable pulses. Muscular and abdominal pain, as well as alterations in renal function, may also occur. Cutaneous biopsy reveals characteristic cholesterol clefts within atheromatous debris filling small, deep arterial lumen. Pathophysiologic mechanisms are discussed.

Transluminal dilatation of the subclavian artery

Transluminal dilatation of seven left subclavian arteries and one right subclavian artery was attempted in seven patients. Dilatation was successful in four left subclavian arteries and the single right subclavian artery treated. Five of the patients suffered from cerebral symptoms as well as ischemia of the upper limb, one had only cerebral symptoms and another had only arm claudication. All patients also had significantly reduced systolic blood pressures in the brachial artery. Standard techniques for percutaneous transluminal angioplasty (PTA) were employed, using the femoral route six times and the axillary route four times. No complications occurred. All patients were permanently given a maintenance dose of antiplatelet treatment with dipyridamole 75 mg tds after PTA. Follow-up of up to 36 months, indicates that angioplasty can be accomplished in the stenosed subclavian artery with relatively little hazard. Patients with hemodynamically significant stenoses should be considered for PTA if their symptoms and signs warrant such therapy.

Vascular recanalizing techniques in interventional neuroradiology

Vascular recanalizing techniques only recently became methods of some clinical importance. Angioplasty of the subclavian artery in cases with subclavian steal syndrome has now been performed in so many instances that it can be judged safe. Angioplasty at the origin of the vertebral artery has not yet been performed in as many cases. However, even there this method is obviously less hazardous than surgery. Local intraarterial fibrinolytic therapy is the only therapy providing some success in progressive stroke from vertebrobasilar thrombosis. In contrast to the vertebrobasilar territory local fibrinolytic therapy within the carotid territory has to be strictly limited to some special indications.

The persistent enigma of percutaneous angioplasty

In summary, while both the short-term and long-term success of PTCA is undeniable in most patients, the basis for this success remains an enigma. Admittedly, simply because "plaque fractures" and "dissection clefts" have been observed to occur as the result of artifact, one cannot exclude the possibility that the success of PTCA may be related to these lesions. Alternatively, the fact that improved vessel patency is frequently observed angiographically and pathologically in the absence of such lesions precludes firm assurance that such lesions are the basis for a successful dilatation. Identification of the mechanism responsible for the success of PTCA is more than a matter of simple curiosity: improved understanding of the basis for successful PTCA might lead to technical refinements in the procedure and allow one to better tailor the technique to individual variations in lesion morphology. Perhaps the combined use of selective, intra-vascular angioscopy at the time of PTCA will enhance our understanding of the fundamental mechanism responsible for this highly effective therapy.

Mechanism of transluminal angioplasty

Experimental studies of transluminal angioplasty in atherosclerotic animal models as well as in human postmortem arteries all have shown that splitting of the atheromatous plaque occurs during angioplasty. Histologic sections of human arteries that were studied after successful angioplasty done in vivo also have shown splitting of the atheromatous plaque. The split may extend down to the internal elastic membrane. As the angioplasty balloon becomes fully inflated, the elastic media and adventitia stretch to conform to the outer diameter of the expanded balloon. Damage to medial cells may occur and may be important in keeping the artery dilated after the balloon is deflated and withdrawn. The "healing" process of the atheromatous plaque after angioplasty is poorly understood. Whether there is metabolic dissolution of atheromatous material or whether there is fibrous retraction of the atheromatous plaque against the dilated arterial wall is not known. Further studies are needed to elucidate the late changes after angioplasty.

Subclavian artery stenosis treated by transluminal angioplasty: six cases

Transluminal angioplasty (TLA) has been used in six patients with subclavian artery stenosis admitted to a large community hospital. Five patients had lesions proximal to the origin of the left vertebral artery, three of whom had angiographic evidence of subclavian steal syndrome. In all six, arteries were successfully dilated with only one complication of a hematoma at an arteriotomy site. In a 10 to 24-month follow-up, all six patients have remained totally asymptomatic without any further complications.

Frequency in nonangioplasty patients of morphologic findings reported in coronary arteries treated with transluminal angioplasty

The coronary arteries from 70 consecutive patients in whom percutaneous transluminal angioplasty (PTA) had not been performed during life were examined at necropsy for findings that have been previously described in patients or animals treated with PTA. In 33 (49%) of the 70 patients, 1 or more findings identical to those observed in necropsy studies of PTA-treated arteries were observed: "plaque fractures" in 31 (44%), "dissection clefts" in 26 (33%), and extensive medial thinning in 40 (57%). Observations in these 70 patients indicate that findings previously described in PTA-treated patients cannot necessarily be assumed to represent the results of PTA. The fact that improved vessel patency may be seen in the absence as well as the presence of such lesions precludes firm assurance that such lesions are the sole basis for successful angioplasty.