Percutaneous transluminal angioplasty: a review

Evaluation of coronary stents: A review of types, materials, processing techniques, design, and problems

In the world, one of the leading causes of death is coronary artery disease (CAD). There are several ways to treat this disease, and stenting is currently the most appropriate way in many cases. Nowadays, the use of stents has rapidly increased, and they have been introduced in various models, with different geometries and materials. To select the most appropriate stent required, it is necessary to have an analysis of the mechanical behavior of various types of stents. The purpose of this article is to provide a complete overview of advanced research in the field of stents and to discuss and conclude important studies on different topics in the field of stents. In this review, we introduce the types of coronary stents, materials, stent processing technique, stent design, classification of stents based on the mechanism of expansion, and problems and complications of stents. In this article, by reviewing the biomechanical studies conducted in this field and collecting and classifying their results, a useful set of information has been presented to continue research in the direction of designing and manufacturing more efficient stents, although the clinical-engineering field still needs to continue research to optimize the design and construction. The optimum design of stents in the future is possible by simulation and using numerical methods and adequate knowledge of stent and artery biomechanics.

Balloon Angioplasty - The Legacy of Andreas Grüntzig, M.D. (1939-1985)

In 1974, at the Medical Policlinic of the University of Zürich, German-born physician-scientist Andreas Grüntzig (1939-1985) for the first time applied a balloon-tipped catheter to re-open a severely stenosed femoral artery, a procedure, which he initially called "percutaneous transluminal dilatation". Balloon angioplasty as a therapy of atherosclerotic vascular disease, for which Grüntzig and Charles T. Dotter (1920-1985) received a nomination for the Nobel Prize in Physiology or Medicine in 1978, became one of the most successful examples of translational medicine in the twentieth century. Known today as percutaneous transluminal angioplasty (PTA) in peripheral arteries or percutaneous transluminal coronary angioplasty (PTCA) or percutaneous coronary intervention (PCI) in coronary arteries, balloon angioplasty has become the method of choice to treat patients with acute myocardial infarction or occluded leg arteries. On the occasion of the 40(th) anniversary of balloon angioplasty, we summarize Grüntzig's life and career in Germany, Switzerland, and the United States and also review the developments in vascular medicine from the 1890s to the 1980s, including Dotter's first accidental angioplasty in 1963. The work of pioneers of catheterization, including Pedro L. Fariñas in Cuba, André F. Cournand in France, Werner Forssmann, Werner Porstmann and Eberhard Zeitler in Germany, António Egas Moniz and Reynaldo dos Santos in Portugal, Sven-Ivar Seldinger in Sweden, and Barney Brooks, Thomas J. Fogarty, Melvin P. Judkins, Richard K. Myler, Dickinson W. Richards, and F. Mason Sones in the United States, is discussed. We also present quotes by Grüntzig and excerpts from his unfinished autobiography, statements of Grüntzig's former colleagues and contemporary witnesses, and have included hitherto unpublished historic photographs and links to archive recordings and historic materials. This year, on June 25, 2014, Andreas Grüntzig would have celebrated his 75(th) birthday. This article is dedicated to his memory.

Plasma tissue factor is a predictor for restenosis after femoropopliteal angioplasty

Background

In vitro studies suggest an association between raised levels of tissue factor and restenosis after coronary percutaneous transluminal angioplasty (PTA). This prospective, controlled study examined the association between plasma tissue factor concentrations and restenosis after femoropopliteal PTA.

Methods

Plasma samples from ten healthy controls and 36 patients with unilateral claudication undergoing femoropopliteal PTA were collected at baseline and, in the patients with claudication, at 24 h and 1, 3 and 6 months after PTA. Clinical assessment and arterial duplex imaging were performed before and at the same time points after PTA to identify restenosis. Plasma tissue factor was measured using a specific enzyme-linked immunosorbent assay.

Results

Baseline plasma tissue factor concentrations were significantly higher in patients with claudication (median 3·4 (interquartile range (i.q.r.) 1·3–7·4) ng/ml) than in controls (median 1·2 (i.q.r. 0·5–1·8) ng/ml) (P < 0·050). Baseline tissue factor concentrations were significantly higher in the ten patients with claudication who developed restenosis after PTA (median 7·0 (i.q.r. 3·4–183·5) ng/ml) than in those who did not (median 1·7 (i.q.r. 1·3–7·2) ng/ml) (P < 0·050). In addition, plasma tissue factor levels increased significantly over time in the patients who developed restenosis after PTA.

Conclusion

High baseline and progressive increases in the plasma tissue factor concentration were useful predictors of restenosis after femoropopliteal angioplasty.

Subintimal versus intraluminal laser-assisted recanalization of occluded femoropopliteal arteries: one-year clinical and angiographic follow-up

PURPOSE

To compare the prolonged effect of subintimal versus intraluminal recanalization of occluded femoropopliteal arteries.

PATIENTS AND METHODS

Recanalization of an occluded femoropopliteal artery was attempted in 63 patients (51 men, 12 women; mean age, 63 years) with lifestyle-limiting claudication and at least one patent distal artery. After assessment of baseline clinical and angiographic variables, mechanical passage was first attempted with use of a laser catheter with a 2.2-mm- diameter hemispherical contact probe that was connected to a neodymium: yttrium-aluminum-garnet laser. In case of failure, the laser was activated at 1-second pulses of 15 W. In some cases additional guide-wire and catheter manipulations were used. Successful recanalization was followed by standard balloon dilation. An intense antithrombotic regimen was used.

RESULTS

The occluded artery could be entered in 62 of 63 patients. The catheter was assumed to have followed a subintimal course in 20 patients (group A) and an intraluminal course in 42 patients (group B). Successful recanalization was achieved in 17 patients (85%) of group A and in 36 (86%) of group B. No significant differences were found in clinical and angiographic follow-up measurements between the two groups. The angiographic cumulative primary patency rate (open vs closed) at 1 year was 93% +/- 6 in group A and 93% +/- 4 in group B. The cumulative restenosis/reocclusion-free patency rate was 63% +/- 13 and 65% +/- 9 for groups A and B, respectively. Median length of the original occlusion (8.0 cm in group A vs 4.5 cm in group B) was the only distinguishing baseline variable between the groups (P < .02) and was also the single independent predictor of recurrent flow limitation (P = .0017). Significant complications were distal embolization in three patients, followed by death in one patient and puncture site bleeding in two patients.

CONCLUSION

The 1-year clinical and angiographic results of assumed subintimal and intraluminal recanalization are comparable. Thus, a subintimal course per se should not be regarded as a failure of the procedure.

Trends in vascular surgery since the introduction of percutaneous transluminal angioplasty

Lower-limb percutaneous transluminal angioplasty (PTA) has been used increasingly over the past decade, either alone or in conjunction with arterial reconstructive surgery. However, its impact on operation rates has not been evaluated properly. Rates of vascular operations and PTAs performed per referral for peripheral arterial disease to the regional vascular service at The Royal Infirmary, Edinburgh, were calculated for the years 1986-1992. The overall rate of PTA for peripheral arterial disease increased ninefold over this period; that for critical ischaemia increased fivefold. Rates of aortic and femoral reconstruction for all peripheral arterial disease increased by 40 and 100 per cent respectively, but rates for critical ischaemia remained static. The major amputation rate rose by 47 per cent between 1986 and 1990, and thereafter reached a plateau. Increased use of PTA was not associated with a reduction in the number of vascular operations.

Transcervical tubal cannulation, past, present, and future

OBJECTIVE

To evaluate publications that introduced novel diagnostic and therapeutic transcervical procedures on the fallopian tubes.

DESIGN

Major studies that conceptually changed the therapeutic approach to the fallopian tubes were reviewed. Minor publications were also included if they introduced a new concept or contributed to the topic. Clinical publications were selected if they involved transcervical diagnosis and treatment of fallopian tubes.

RESULTS

Transcervical tubal catheterization procedures for diagnosis of tubal disease, tubal obliteration, tubal recanalization, and tubal medication are minimally invasive procedures that can improve our understanding and diagnostic accuracy of tubal disease. These procedures allow transcervical treatment of proximal tubal occlusion. Further improvements in equipment and methodology are promising. Transcervical tubal occlusion, gamete and embryo deposition, and treatment of ectopic pregnancy may all be performed using the transcervical approach.

CONCLUSION

Transcervical tubal catheterization can replace microsurgery and IVF in selected patients with proximal tubal occlusion, improve the diagnostic accuracy of tubal disease, and deliver medications to the fallopian tubes. Cumulative knowledge suggests that transcervical tubal catheterization should become a universally accepted, taught, and practiced approach in the diagnosis and treatment of the fallopian tubes.

Intraoperative peripheral rotary atherectomy: early and late clinical results

Early and late clinical results of intraoperative peripheral atherectomy using the Auth Rotablator are analyzed. Twenty patients (15 males and 5 females age 39-89 years, mean 70 years) underwent 25 atherectomy procedures for peripheral arterial occlusive disease from August 1987 to October 1989. All patients underwent serial history, physical exam, and Doppler pressure measurements preoperatively and then postoperatively at 24 hours, one week, one month, and six months during a follow-up period of 15 to 41 months, mean 27 months. Preoperative and intraoperative completion follow-up arteriography was done in all cases and follow-up arteriography in 19 of 25 cases. Initial arteriographic success was achieved in 23/25 (92%) cases and in 39/41 (93%) arterial segments (superficial femoral artery 12/13, popliteal 14/15, tibial 12/13, profunda-femoral 1/1). Complications included intimal dissection (1), equipment breakage (2), minor emboli (3), major emboli with thigh skin loss (1), transient hemoglobinuria (4), wound hematoma (1), wound infection (1), and limb loss (1). Early thrombosis occurred in five cases to give an in-hospital success rate of 18/25 (72%). Primary patency was 66% at six months but only 12% at two years. Rotary atherectomy effectively recanalizes femoral, popliteal and tibial arteries. However, early thromboembolic complications occurred frequently, and the two year patency was dismal. Rotary atherectomy is not recommended for general use until problems of thromboemboli and intimal hyperplasia are solved.

Angioplasty of the iliac and femoral arteries. Initial and long-term results in short stenotic lesions

This retrospective study presents the initial and long-term results of 212 iliac and femoral angioplasties in a selected group of 175 patients with one to three short stenotic lesions (less than 3 cm each). Patients who had iliac (n = 157) and femoral (n = 55) angioplasties were followed for 6-101 months. Claudication was the principal indication for intervention. Success or failure was defined by using a combination of clinical and objective vascular laboratory criteria. Long-term success was estimated by the Kaplan-Meier method. Differences between survival curves for factors such as site of angioplasty and status of run-off were analysed with the log-rank test. For all 212 angioplasties, the initial technical success rate was 93%. The immediate failure rate was 7% (15/212). The cumulative patency rate after 5 years of all technical successful angioplasties was 82% (SE 4%). Five-year patency rates were 84% (SE 4%) for iliac and 73% (SE 11%) for femoral angioplasty. Only one variable in this selected group of patients was associated with success: the site of the lesion.

Percutaneous transluminal atherectomy: preliminary results

Percutaneous transluminal atherectomy with the Simpson atherectomy catheter was performed in 10 patients with 14 severe atheromatous stenoses of the femoropopliteal arteries. Removal of plaque material with restoration of vessel patency was successful in all patients without complication. Further clinical follow-up will have to determine whether the recurrence rate of stenoses will be lower with this method than with conventional balloon angioplasty.

Percutaneous transluminal angioplasty of the distal abdominal aorta

Percutaneous Transluminal Angioplasty (PTA) has become widely practised and is a significant advance in the treatment of arterial disease. Its use in the treatment of atheromatous abdominal aortic stenoses in thirteen patients is described. Technical success was achieved in all with no complications. In a follow-up period from 7 to 70 months all patients have benefitted and 85% remain symptom free.

Percutaneous atherectomy--early experience in Sheffield

Percutaneous transluminal angioplasty (PTA) of arterial stenoses is a well-established and relatively safe technique in the treatment of peripheral and coronary vascular disease. Recurrence, however, remains a problem. The 'atherectomy' catheter is a new device to provide lumen enlargement by the mechanical removal of atheroma. In Sheffield, 14 lesions in the femoral arteries have been treated by atherectomy, with a reduction in mean diameter stenosis from 88% to 15%. There were no complications. Follow-up ranges from 3 to 15 months, with a mean of 9 months. There has been only one recurrence. It can be used in calcified lesions and may prove to be most useful in the treatment of tough lesions. Further experience and follow-up is necessary, however, to determine whether it has any advantage over balloon dilatation.

Preliminary experience with transcervical balloon tuboplasty

We developed a new technique, transcervical balloon tuboplasty, an adaptation of established balloon angioplasty techniques that facilitates recanalization of proximally occluded oviducts. Sixteen patients with obstruction of the proximal portion of one or two fallopian tubes (based on at least two hysterosalpingograms and one laparoscopic examination) were selected for the procedure. Four patients (25%) were found to have patent oviducts on intraoperative third tubal patency evaluation and were therefore excluded from study. Of the remaining 12 patients, tubal patency was achieved in at least one fallopian tube in 7 patients (58%), as demonstrated by hysterosalpingogram immediately after the transcervical balloon tuboplasty procedure. On follow-up 2 months to 1 year afterward, two pregnancies and one delivery occurred. We conclude that transcervical balloon tuboplasty appears to represent a useful and safe technique to achieve patency in selected cases of tubal interstitial obstruction. Reocclusion rates, long-term complication rates, and pregnancy rates after transcervical balloon tuboplasty remain to be established before the procedure should be considered a recommended alternative for either surgical tuboplasty or in vitro fertilization.

Intraoperative transluminal balloon dilatation permits simpler safer reconstructive surgery

The clinical and radiological features of seven patients in whom intraoperative transluminal balloon dilatation was used, are described. Indications and advantages of the technique are discussed.

Renovascular hypertension following radiotherapy and chemotherapy treated by transluminal angioplasty

A man aged 33 with poorly controlled hypertension who had been treated with radiotherapy and combination chemotherapy for testicular teratoma 8 years earlier was found on arteriography to have 75% stenosis of the left renal artery and occlusion of the right renal artery. The stenosis was dilated by transluminal angioplasty and the hypertension adequately controlled. Patients who develop high blood pressure after abdominal radiotherapy with or without chemotherapy should be investigated for renal artery stenosis.

Percutaneous transluminal angioplasty for severe lower extremity ischaemia

Percutaneous transluminal angioplasty (PTA) was attempted on 70 occasions in 63 consecutive patients presenting with advanced ischaemia. The procedure was technically successful in 64 (91%) with haemodynamic improvement in 39 (56%) and clinical improvement maintained at 6 months in 51 (73%). Follow-up ranged from 6 months to 4 years and life-table analysis showed 60% success at 1 year and 58% success at 2 years. Overall limb salvage was 76%. Complications occurred in 6 (9%) and in one case this lead to amputation. The relationship of a number of associated factors to outcome was assessed. The presence of cardiac disease requiring treatment for failure or angina was a highly significant adverse factor (P less than 0.001). Decreasing age and greater extent of disease were also significant adverse factors (P less than 0.05). Therefore, because of its low morbidity and cost, PTA can be seen as a useful procedure in patients presenting with advanced peripheral vascular disease.

The impact of percutaneous transluminal angioplasty on the management of peripheral vascular disease

Percutaneous transluminal angioplasty is a well established technique with wide application, but its place in the overall management of peripheral vascular disease is not well defined. This study compares similar groups of patients with peripheral vascular disease in 1981 and 1984, before and after the introduction of the technique to a district general hospital. More patients are now being investigated and treated and this is almost entirely due to the availability of angioplasty. The rates for surgery have not changed. Percutaneous transluminal angioplasty should therefore be seen as a new and separate form of treatment for peripheral vascular disease, not necessarily influencing or replacing surgery, and requiring its own allocation of resources in accordance with the increase in the level of care afforded by the technique.

Peripheral angioplasty: emphasising the need for complete visualisation in lower limb angiography

The importance of optimal visualisation by the use of multiple projections in lower limb angiography is stressed. This is particularly relevant to the safe and effective performance of percutaneous angioplasty; illustrative examples are presented.

Percutaneous transluminal angioplasty. The radiologist's contribution to the treatment of vascular disease

Percutaneous transluminal angioplasty is a nonsurgical treatment for vascular disease. It is relatively safe and economical and may be an alternative, or an adjunct, to surgery, or may be helpful where no surgical alternative exists. Percutaneous transluminal angioplasty is applicable to nearly every system, except the carotid bifurcation plaque.