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Despite contemporary drug-eluting stent (DES) technology, intracoronary stent restenosis (ISR) occurs in up to 10% of patients, increasing with intervention of complex lesions. The presentation of ISR is still challenging for optimal treatment [1].

Purpose An intraluminal coronary stent is a metal mesh tube deployed in a stenotic artery during percutaneous coronary intervention (PCI), in order to prevent acute vessel occlusion. The identification of struts location and the definition of the stent shape is relevant for PCI planning and for patient follow-up. The authors present a fully automatic framework for computer-aided detection (CAD) of intracoronary stents in intravascular ultrasound (IVUS) image sequences. The CAD system is able to detect stent struts and estimate the stent shape. Methods The proposed CAD uses machine learning to provide a comprehensive interpretation of the local structure of the vessel by means of semantic classification. The output of the classification stage is then used to detect struts and to estimate the stent shape. The proposed approach is validated using a multicentric data-set of 1,015 images from 107 IVUS sequences containing both metallic and bioabsorbable stents. Results The method was able to detect struts in both metallic stents with an overall F-measure of 77.7% and a mean distance of 0.15 mm from manually annotated struts, and in bioabsorbable stents with an overall F-measure of 77.4% and a mean distance of 0.09 mm from manually annotated struts. Conclusions The results are close to the interobserver variability and suggest that the system has the potential of being used as a method for aiding percutaneous interventions.

A 54-year old, hypertensive female patient underwent percutaneous coronary angioplasty (PTCA) followed by stenting of calcified chronic totally occluded right coronary artery. The post dilation balloon catheter got stuck and snapped during manipulations in inflated position within the stent, which could not be retrieved by nonsurgical interventions. Emergency surgery was performed to retrieve the stent along with an inflated balloon, followed by vein patch closure of arteriotomy and reversed saphenous vein graft anastomosis to right coronary artery and left anterior descending artery on cardiopulmonary bypass.

Background and objectives: Cardiovascular implantable electronic devices (CIED) are frequently implanted in patients on anti-thrombotic agents. Pocket hematomas are more likely to occur in these patients. The use of a sterile surgical drain in the pulse generator pocket site could prevent hematomas, but fear of infection precludes its use. The objective of the present study is to study the safety and efficacy of surgical drain in patients on antithrombotics undergoing CIED implantations. Methods: This is a single-centre, retrospective study involving patients undergoing CIED implantations on antithrombotics (antiplatelets and anticoagulants) from August 2013 to July 2016. Patients with high risk of thromboembolism were continued on oral antithrombotics or were bridged with heparin after stopping oral antithrombotics. A sterile close wound suction drain was placed in device pockets following CIED implantations. Post procedure, pressure dressing was applied and removed after 12 h once the drain volume was less than 10 ml in 24 h. Results: Sixty seven patients required surgical drain implantation. Major indications for antithrombotic use were presence of intracoronary stent, atrial fibrillation and mechanical valve replacements. The mean post-procedural hospital stay was 3 ± 0.9 days and mean overall drain was 16.6 ± 8.2 ml. At a mean follow up of 17.6 ± 8.2 months, one patient (1.4%) had pocket hematoma. There were no infections. Conclusion: The use of a surgical drain in CIED implantation significantly reduces the risk of hematoma formation without increasing the risk of infection. Antithrombotic drugs can be safely continued at the time of implantation of cardiac devices. Keywords: Pocket hematoma, Antithrombotic treatment, Device implantation, Anticoagulation, Antiplatelets, Surgical drain

PurposeAn intraluminal coronary stent is a metal scaffold deployed in a stenotic artery during percutaneous coronary intervention (PCI). In order to have an effective deployment, a stent should be optimally placed with regard to anatomical structures such as bifurcations and stenoses. Intravascular ultrasound (IVUS) is a catheter-based imaging technique generally used for PCI guiding and assessing the correct placement of the stent. A novel approach that automatically detects the boundaries and the position of the stent along the IVUS pullback is presented. Such a technique aims at optimizing the stent deployment. MethodsThe method requires the identification of the stable frames of the sequence and the reliable detection of stent struts. Using these data, a measure of likelihood for a frame to contain a stent is computed. Then, a robust binary representation of the presence of the stent in the pullback is obtained applying an iterative and multiscale quantization of the signal to symbols using the Symbolic Aggregate approXimation algorithm. ResultsThe technique was extensively validated on a set of 103 IVUS of sequences of invivo coronary arteries containing metallic and bioabsorbable stents acquired through an international multicentric collaboration across five clinical centers. The method was able to detect the stent position with an overall F-measure of 86.4%, a Jaccard index score of 75% and a mean distance of 2.5mm from manually annotated stent boundaries, and in bioabsorbable stents with an overall F-measure of 88.6%, a Jaccard score of 77.7 and a mean distance of 1.5mm from manually annotated stent boundaries. Additionally, a map indicating the distance between the lumen and the stent along the pullback is created in order to show the angular sectors of the sequence in which the malapposition is present. ConclusionsResults obtained comparing the automatic results vs the manual annotation of two observers shows that the method approaches the interobserver variability. Similar performances are obtained on both metallic and bioabsorbable stents, showing the flexibility and robustness of the method.

We report here the longest follow-up of a patient treated with intracoronary stent placement for acute vessel closure following conventional balloon angioplasty. The patient is a 52-year-old lady who developed abrupt left anterior descending coronary artery (LAD) closure shortly after double vessel percutaneous coronary intervention (PCI) for symptomatic stenoses to the right coronary artery (RCA) and LAD on 13 June …

Intracoronary stents have markedly improved the outcomes of catheter-based coronary interventions. Intracoronary stent implantation rates of over 90% during coronary angioplasty are common. Stent implantations are associated with a small but statistically significant number of adverse outcomes including restenosis, thrombosis, strut malapposition, incomplete strut endothelialization, and various types of stenting failure. Better matching of biomechanical properties of stents and lesions could further improve the clinical outcome of intracoronary stenting. Thus, in this article, we assess the need for advanced intracoronary stent–lesion matching. We reviewed the data on biomechanics of coronary stents and lesions to develop knowledge-based rationale for optimum intracoronary stent selection. The available technical information on marketed intracoronary stents and the current understanding of the biomechanical properties of coronary lesions at rest and under stress are limited, preventing the development of knowledge-based rationale for optimum intracoronary stent selection at present. Development of knowledge-based selection of intracoronary stents requires standardization of mechanical stent testing, communication of the nonproprietary technical data on stents by the industry and dedicated research into procedural stent–lesion interactions. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 101B: 1560–1570, 2013.

The minimum in-stent lumen diameter is a predictor of restenosis. Stent dimensions provided by manufacturers are derived from in vitro tests. The aim of this study was to compare actual stent dimensions obtained by angiography and intracoronary ultrasound with dimensions that would be expected theoretically for a given inflation pressure in a cohort of 100 non-complex lesions suitable for direct stenting. Significant differences were found between the theoretical diameters and those observed by angiography and ultrasound. The actual-to-theoretical diameter ratio was 0.83 (0.09) when measured using angiography and 0.78 (0.10), using intravascular ultrasound. In lesions without severe calcification, stent dimensions were significantly smaller than indicated by the manufacturer. Nominal figures should not be used as reference values for stent implantation.

冠動脈疾患のステント留置の効果はすでに実証されているが,血栓症併発や再狭窄が多く,問題がある。この研究はこれらに対するシロスタゾールの予防効果を明らかにするため,現在使用中のチクロピジンを比較対照とし,前向き無作為試験を単一施設で行った。目標はステント留置後の急性,亜急性血栓性合併症,および遠隔期再狭窄に対するシロスタゾールの予防効果を6ヶ月追跡しチクロピジンと比較することである。対象は待機的ステント留置を行った130人にチクロピジン(T群 ; n = 65)かシロスタゾール(C群 ; n = 65) を無作為に投与し,両群間で患者経過,冠動脈造影所見について6ヶ月間追跡し比較検討した。結果はステント留置後早期の血栓性合併症はC群では0例,T群では2例に認めた。6ヶ月後の冠動脈造影時にはC群はT群に比べ晩期血管径損失(Late loss ; 0.28±0.40 vs. 0.69±0.79mm,P, Cilostazol is a newly developed anti-platelet drug that has been applied in a wide variety of clinical situations. Its anti-platelet action appears to be mainly due to its inhibition of intracellular phosphodiesterase (PDE) activity. Recently, cilostazol has been used for anti-platelet therapy after the implantation of coronary stents, but this practice has not been fully evaluated and approved yet. The prospective randomized trial was designed to investigate the efficacy of cilostazol as used in the prevention of late restenosis, as well as its usefulness in the treatment of acute or subacute stent thrombosis, incomparison with ticlopidine. One hundred thirty consecutive patients, scheduled for elective coronary stenting, were randomly assigned to receive orally either aspirin (81 mg/day) plus ticlopidine (200 mg/day) (Group T) or aspirin plus cilostazol (200 mg/day) (Group C). The medications were started at least 2 days before coronary intervention and continued until follow-up coronary angiography was performed 6 months later. While subacute stent thrombosis was observed in 2 Group T patients, no patients in Group C were observed with it. Major cardiac events were observed at similar rates in both groups. Elevated transaminase was observed more frequently in Group T than in Group C (P < 0.05). Every Quantitative Coronary Angiography (QCA) variable, both before and immediately after coronary stenting, showed similar tendencies in both groups, but during the follow-up angiography, the late lumen loss (0.69 ± 0.79 vs 0.28 ± 0.40 mm, P < 0.01) and loss index (0.42 ± 0.56 vs 0.16 ± 0.27, P < 0.01) were smaller in Group C than in Group T. Restenosis rate (13% vs 31%, P < 0.05) and target lesion revascularization rate (7% vs 21% P < 0.05) were both lower in Group C than in Group T. In conclusion, it was found that a combination of aspirin and cilostazol may be an effective regimen for prevention of not only stent thrombosis but also restenosis.

Intracoronary stenting is an established modality of treatment to relieve narrowing of coronary arteries. Increasing use of stenting is bringing to light new complications. Here we present our experience with a newly emerging indication for surgical intervention for cardiac surgeons. This new indication is complications arising from intracoronary stents. Very little is available in the existing literature to guide the surgeon. We explain our rationale in doing things with two of our cases. DOI: http://dx.doi.org/10.3329/uhj.v7i1.10213 UHJ 2011; 7(1): 56-58

OBJECTIVES The aim of this study was to evaluate the immediate and long-term outcome of intracoronary stent implantation for the treatment of coronary artery bifurcation lesions. BACKGROUND Balloon angioplasty of true coronary bifurcation lesions is associated with a lower success and higher complication rate than most other lesion types. METHODS We treated 131 patients with bifurcation lesions with ≥1 stent. Patients were divided into two groups; Group (Gp) 1 included 77 patients treated with a stent in one branch and percutaneous transluminal coronary angioplasty (PTCA) (with or without atherectomy) in the side branch, and Gp 2 included 54 patients who underwent stent deployment in both branches. The Gp 2 patients were subsequently divided into two subgroups depending on the technique of stent deployment. The Gp 2a included 19 patients who underwent Y-stenting, and Gp 2b included 33 patients who underwent T-stenting. RESULTS There were no significant differences between the groups in terms of age, gender, frequency of prior myocardial infarction (MI) or coronary artery bypass grafting (CABG), or vessels treated. Procedural success rates were excellent (89.5 to 97.4%). After one-year follow-up, no significant differences were seen in the frequency of major adverse events (death, MI, or repeat revascularization) between Gp 1 and Gp 2. Adverse cardiac events were higher with Y-stenting compared with T-stenting (86.3% vs. 30.4%, p = 0.004). CONCLUSIONS Stenting of bifurcation lesions can be achieved with a high success rate. However, stenting of both branches offers no advantage over stenting one branch and performing balloon angioplasty of the other branch.

The clinical outcome after successful conventional coronary balloon angioplasty is compared with that of stent implantation after 30 days and 12 months. The study took place at the Divisions of Cardiology and Thoracic Radiology, Norrland University Hospital, Umea, a referral centre for northern Sweden. The first 100 consecutive patients with stable or unstable angina undergoing successful percutaneous transluminal coronary angioplasty (PTCA) in 1994 and the first 100 consecutive patients undergoing successful coronary stent implantation in 1995 were included. The cardiac endpoints studied were death, myocardial infarction, need for repeat PTCA or coronary artery bypass grafting (CABG). Significantly more adverse cardiac events were observed in the PTCA group compared with the stent group. Event-free 12 months' follow-up (no deaths, myocardial infarction or re-intervention) was 64% in the PTCA group and 86% in the stent group (p < 0.005). The main explanation for the observed difference was a reduction in the need for a repeat PTCA (7 vs 18, p < 0.05) or CABG (4 vs 12, p < 0.05) in the stent group. Patients with stable or unstable angina who can be treated with a stent have a better clinical outcome than those treated with coronary balloon angioplasty only.

We studied the ECGs of patients with single vessel disease before and after (long term) coronary stent implantation. The interlead variability of the QT interval, known as QT dispersion (QTd), is believed to reflect the regional variations in ventricular repolarization and, thus, may provide an indirect marker of arrhythmogenicity. There are no reliable noninvasive markers of significant restenosis after stent implantation. The effect of coronary revascularization on QTd in patients who underwent coronary stenting has not been investigated extensively. The aim of this study was to evaluate the value of QTd in predicting restenosis after intracoronary stent implantation. QTd with 12 lead surface ECG was measured in 48 patients (21 with restenosis and 27 without restenosis; 33 male; mean age, 58 +/- 10.8 years) before the procedure and after long-term follow-up (mean, 6.8 +/- 3.2 months). All patients had coronary angiographic control at the end of the follow-up period. QTd (as the difference between the maximum and minimum QT interval measured from 12 lead EGG) and rate-corrected QT (QTcd) were evaluated at rest. In 27 patients without restenosis, QTd and QTcd decreased from 58 +/- 14.4 and 62.8 +/- 20.4 ms to 26.3 +/- 9.2 and 29.6 +/- 10.6 ms in the long term follow-up, respectively (P < 0.001). However, in 21 patients with restenosis, there was no significant change in QTd and QTcd intervals and they were still increased at the end of the long-term follow-up (P > 0.05). In conclusion, increased QT interval dispersion may be an inexpensive and simple marker of restenosis after intracoronary stent implantation. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.

The intracoronary stent placement in a lesion proximal to a myocardial bridge is of special importance and is considered to be a challenge for the interventional cardiologist. In this study 4 cases of stent implantation proximal to a coronary bridged segment are described. In all cases complications were observed after the procedure. The patients remained free of symptoms and the exercise Tl201 test was negative for ischemia 8.5 ± 2.6 months later. Although there is skepticism because of the abnormal coronary flow pattern, the endothelial dysfunction and the subsequent thrombogenicity, the stent placement proximal to a myocardial bridge was safe and with favorable long term results in all 4 cases. However, further studies in large populations are necessary. Cathet. Cardiovasc. Intervent. 46:363–367, 1999. © 1999 Wiley-Liss, Inc.

Patients who undergo intracoronary stent placement during percutaneous coronary intervention (PCI) have reduced rates of restenosis and acute vessel closure compared with patients who undergo balloon angioplasty.[1][1] Drug-eluting stents (DESs), such as Cypher (Cordis Corp., Miami Lakes, FL) (

The Bard XT stent is a new generation balloon expandable intracoronary stent. It has several unique design advantages. Between October 1996 and November 1997, 127 Bard XT stents of various length were deployed in 93 patients with 109 lesions. According to the American College of Cardiology (ACC) and American Heart Association (AHA) classifications 7 lesions were type A, 38 were type B1, 43 were type B2 and 21 were type C [Ellis et al.: Circulation 82:1193–1202, 1990]. Stent delivery was successful in 98% of attempts. Angiographic success was achieved in 98% of 109 lesions. Procedural success was achieved in 94% of 93 patients. Minimal luminal diameter (MLD) increased from 0.91 ± 0.34 mm to 3.03 ± 0.44 mm and percentage diameter stenosis reduced from 69.1 ± 11.07 to 9.96 ± 6.81. Complications occurred in four patients. One patient had intracranial hemorrhage, one patient had subacute thrombosis and two patients died postprocedure. Patients were followed for a period of 1 to 14 months (average 7 ± 4 months) for major cardiac events and clinical restenosis. The Bard XT stent is a user-friendly device which provided excellent angiographic results and short-term clinical outcome in selected cases. Further study is required to evaluate effects on restenosis.Cathet. Cardiovasc. Diagn. 45:462–470, 1998. © 1998 Wiley-Liss, Inc.

Primary stent implantation in acute myocardial infarction (AMI) is defined as the intentional (not rescue) implantation of intracoronary stent(s) to the culprit lesion of AMI during emergency catheterization. All available data showed that this strategy has favorable short- and long-term clinical effects compared to primary balloon angioplasty.

Intracoronary stenting improves the acute and long-term safety and efficacy of percutaneous coronary interventions by minimizing the risks of abrupt closure and late restenosis. Enhanced designs of new coronary stents will continue to expand the spectrum of coronary anatomy and clinical settings amenable to nonsurgical revascularization. Improvements in deliverability, application to complex lesions, and durability of results are direct effects of improved design characteristics. Future design features may also include incorporating adjunctive therapies such as antithrombotic or antiproliferative agents with stent-based delivery systems. Results of new stent registries and randomized clinical trials are reviewed.

Appropriate animal models for intracoronary stenting are most important for improving understanding of the pathophysiology of acute occlusion and long-term re-stenosis, which currently limits the safety and efficacy of percutaneous transluminal coronary angioplasty in humans. Since the anatomy and physiology of swine coronary arteries closely resemble those of humans, the procine model should be ideal for testing of stents. This is a comprehensive report on an experimental set-up in pigs, communicating in detail the necessary techniques as well as some modifications facilitating safe intra coronary stent placement and successful follow-up studies for weeks or months. Stent procedure is performed in mechanically ventilated and haemodynamically monitored animals under balanced anaesthesia. Intracoronary application of flow wires allows the assessment of local flow conditions, flow properties and coronary flow reserve. Real-time intravascular ultrasonography (IVUS) provides detailed information on coronary morphology and enables the appropriate sizing of the coronary lumen. From our own experience, we like to propose that the use of the porcine model has the potential to gain new insights into the pathophysiology of intracoronary stent placement-associated complications and allows for the study of modifications in techniques and materials, and the development of novel pharmacological therapeutic strategies.

BACKGROUND: Care of patients after stent placement has evolved with the goal of reducing thrombosis and bleeding. Initially, all patients received full antithrombotic therapy; now most receive antiplatelet therapy only. Despite this evolution, no description of the differences in complications and nursing care with these two treatments has been published. OBJECTIVES: To determine the differences in complications and nursing care for patients receiving different pharmacological therapies after placement of an intracoronary stent. METHODS: A nonrandomized, noncontrolled, retrospective, comparative design was used with 176 sequential patients assigned to treatment groups on the basis of the adjunctive pharmacological therapy the patient received after placement of a stent. The equivalency of baseline characteristics and risk of complications, as well as the differences in length of stay, intensity of nursing care, and frequencies of bleeding and ischemic or thrombotic events were determined for the two groups: 65 patients who received anticoagulant therapy and 111 patients who received antiplatelet therapy. RESULTS: The two groups were equivalent with respect to baseline characteristics of sex, concomitant illness, and cardiac condition before stent placement. The two groups differed with respect to predisposing risks for bleeding and ischemic or thrombotic events. Patients receiving antiplatelet therapy alone had significantly shorter lengths of stay, less use of intensive care, fewer requirements for nursing care, and fewer bleeding complications, with no increase in ischemic or thrombotic events. CONCLUSIONS: Patients receiving anticoagulant therapy had more complications and required a higher intensity of nursing care than did patients who received antiplatelet therapy alone.

We investigated the safety and efficacy of the recently introduced intracoronary beStent(TM). High flexibility, zero shortening after expansion and delineating gold markers at either end of the stent are favorable features of this device. Between July 1996 and February 1997, 117 patients received a total of 126 stents, measuring 15, 25 and 35 mm in length. The majority of lesions were located in the LAD (n = 48; 38%), followed by lesions in the RCA (n = 41; 33%) and the circumflex artery (n = 28; 22%). Nine additional stents were delivered into vein grafts (7%). Successful stent deployment was achieved in 94% (n = 118), even in cases with complex lesion morphology and angulated segments. The markers proved to be helpful in placing the stent close to side-branches and whenever serial stents were used. Complications during hospitalization were as follows: one cardiac death unrelated to stenting, one subacute stent thrombosis after 30 min of effective anticoagulation and one Q-wave myocardial infarction due to peripheral thrombus embolization after stent placement in a vein graft. One patient was sent for elective CABG after an unsatisfactory procedural result. Stent loss occurred in four patients, and all stents could be retrieved successfully; in another four patients stent placement at the target site was impossible. We conclude that the investigated stent demonstrates several favorable stent characteristics which have proved to be useful in treating complex lesions by providing favorable acute results with a low complication rate.

With the release of intracoronary artery stents, the role of the critical care nurse is vital in decreasing complications in the stented patient as well as optimizing patient outcomes. The importance of understanding and adhering to anticoagulation and activity protocols is a must for successful patient management.

To date, accurate quantification and localization of malapposed and uncovered struts needs manual and time consuming analysis of large datasets. To develop an algorithm for automated detection and quantification of clusters of malapposed and uncovered struts in optical coherence tomography (OCT) pullbacks, including comprehensive information about their three-dimensional spatial distribution. 64 lesions in 64 patients treated with drug-eluting stent underwent assessment with OCT immediately after implantation and at 9-month follow-up (55 patients). An automated algorithm was used to detect and quantify stent strut malapposition at baseline and coverage at follow-up on an individual strut level. We subsequently applied an algorithm for the automated clustering of malapposed and uncovered struts and for the quantification of clusters’ properties. In the 64 baseline examinations, a total of 24,013 struts were analyzed, of which 1,519 (6 %) were malapposed. Most malapposed struts (78 %) occurred in clusters and more than half of patients had malapposition clusters. The mean number of struts per cluster was 19.7 ± 11.8 with a mean malapposition distance of 213 ± 66 μm. In the 55 follow-up pullbacks, a total of 20,484 struts were analyzed, of which 1,320 (6 %) were uncovered. Again, most uncovered struts (85 %) occurred in clusters. The mean number of struts per cluster was 21.1 ± 14.7. We developed an automated algorithm for studying clustering of malapposed or uncovered struts. This algorithm might facilitate future investigations of the prognostic impact of clusters of malapposed or uncovered struts.

A case of dextran induced adult respiratory distress syndrome is used to illustrate the most serious complication of dextran usage during intracoronary stent placement. This reaction occurred despite premedication with the hapten dextran 1. Mechanisms of dextran induced complications are discussed. A mechanism for hapten resistant dextran reactions is postulated. Suggestions to prevent such reactions are made.

Recently, the Palmaz-Schatz coronary stent was approved by the FDA as an alternative to coronary angioplasty in the treatment of de novo native coronary stenosis. Developed by Dr. Julio Palmaz and Dr. Richard Schatz, the Palmaz-Schatz intracoronary stent design was implanted in 1987 at Brooke Army Medical Center. During the past 7 years, The University of Texas Health Science Center-San Antonio (clinical sites include University Hospital, Brooke Army Medical Center, and Audie Murphy Veterans Administration Hospital) has used this intracoronary stent to treat more than 300 patients. Nursing care for this patient population is both distinct and challenging. Successful patient outcomes require a knowledgeable staff and a team approach. This article will emphasize the nursing care and patient education required both before and after the stent procedure, as well as considerations for long-term follow-up.

The late angiographic outcome of the Gianturco-Roubin intracoronary stent has not been well defined. To investigate serial changes within the stent, we studied 23 patients (15 men and 8 women, median age 63) who had late angiographic follow-up (>1 year) after undergoing Gianturco-Roubin stenting for angioplasty-associated acute or threatened native coronary artery closure. Coronary angiography before and after stenting, at 6-month follow-up, and at late return was analyzed with quantitative coronary angiography. The median time from stent deployment to late angiographic follow-up was 27 months. As expected, stenting significantly increased the median minimal lumen diameter (MLD) acutely from 1.0 to 2.46 mm. Median percent diameter stenosis decreased from 66% to 18%. Although at 6 months there was a significant loss of the acute gain (median MLD decreased from 2.46 to 1.9 mm), with a corresponding increase in percent stenosis from 18% to 31%, late angiography demonstrated lesion regression, median MLD increasing from 1.9 to 2.15 mm (p = 0.004), and percent stenosis decreasing from 31% to 21% (p = 0.0026). No patient had a significant decline in minimal lesion diameter, and 5 patients had a >50% increase in MID at late follow-up. Linear regression analysis of 6-month MLD and late lumen gain suggested that lesions with the greatest regression were those with the lowest lumen diameters at 6-month angiography. Late angiographic analysis demonstrated significant lesion regression within the Gianturco-Roubin stent, which was sometimes dramatic. In suggesting that coronary arteriography at 6 months may underestimate the late angiographic benefit of intracoronary stenting, these data have important clinical implications, and imply that patients with a stable clinical course and angiographic stent restenosis may often be followed rather than routinely redilated.

Coronary artery stenting is currently treatment of choice for management of coronary artery disease. Stent restenosis is the most important problem during follow up. Conventional coronary angiography is the gold standart for assessment of intracoronary stent patency. It is an invasive method and even though rare, has some significant risks. For this reason, noninvasive imaging methods are necessary to evaluate stent patency. Noninvasive methods such as the exercise test, myocardial perfusion scintigraphy and stress echocardiography could not reach enough diagnostic accuracy. Multislice computed tomography (MSCT) has been under investigation for stent restenosis detection. Aim of this study is to investigate usefulness of the 16-slice CT for evaluation of stent patency in patients with suspicion of stent restenosis. Thirty six patients were included in the study and 16-slice CT and conventional coronary angiographies were performed in all patients. The results of 16-slice CT and conventional coronary angiography were compared. Sufficient or good quality imaging with 16-slice CT angiography was obtained in 69% of all patients. Sixteen-slice CT angiography detected 42/49 (86%) stents and gave the correct localization for all of the detected stents. Stent lumen could be assessed in 30 (61%) stents and according to the results of luminal assessment, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of 16-slice MSCT were calculated as 33%, 95%, 75%, 77% and 77%, respectively. According to these results, the diagnostic performance of 16-slice CT angiography for detection of stent restenosis was relatively low. However, the assessment of relatively small number of stents because of insufficient heart rate control did not allow reliable and precise evaluation. Our results showed that diagnostic capacity of 16-slice CT angiography for detection of coronary stent restenosis is limited. © 2013 OMU.

In the area of increasing interventional techniques there is a need for noninvasive imaging modalities to provide postinterventional follow-up. We were able to visualize the apparent patency and measure the dimensions of an intracoronary Palmaz-Schatz stent in the left circumflex coronary artery using transesophageal two-dimensional echocardiography. This report indicates the potential of echocardiography to directly assess coronary stents.

Intracoronary stenting has largely improved the safety and acute efficacy of coronary interventions. However, the long-term results did not yet quite fulfill the expectation. It can be hypothesized that acute benefits of stenting may be partly set off by current gaps in knowledge of interactions between stents and coronary walls and suboptimal stent implantation techniques resulting in long-term complications. In this chapter, current concept of intracoronary stent implantations, related complications, and resulting limitations are reviewed.

Angiographic evidence of thrombus may have important implications during coronary stent deployment procedures. The periprocedural presence of thrombus has been shown to increase the risk of subsequent stent thrombosis. Coronary angioscopy is a new technology that may prove more accurate for the detection of coronary thrombus. Angiographic filling defects suspicious for thrombus were observed in 15 (22%) of 64 patients undergoing coronary angioscopy during stent implantation procedures. Angioscopy confirmed the presence of thrombus in 9 (60%) of these 15 patients. Protruding thrombus was found in four cases and only mural thrombus in five. In six cases (40%) thrombus was not visualized and angioscopy provided an alternative explanation for the angiographic filling defect. Bulky atherosclerotic plaque was seen protruding into the lumen in two cases, disection with protruding fronds of tissue was found in three cases and a ruptured venus valve was found in one final case. Thrombolytic therapy was administered in all four cases containing protruding thrombus, in only two of the five cases containing mural thrombus, and in none of the cases where thrombus was not visualized. Angioscopy was more accurate than angiography for the diagnosis of thrombus and allowed more precise tailoring of the intervention to the underlying anatomical substraight. This resulted in an excellent clinical outcome, with no episodes of stent thrombosis and limitation of the risks associated with thrombolytic therapy to only those patients at increased risk of a thrombotic complication.

With more complex interventional procedures, such as intracoronary stent placement, there is a higher incidence of procedural related peripheral vascular complications including pseudoaneurysm and hemorrhage. In these procedures, the amount of anticoagulation as well as the use of thrombolytic agents intraprocedurally increases the risk of complication. Meticulous care during vascular access, careful use and monitoring of anticoagulation, and patient selection are helpful in reducing the risk. Newer vascular hemostatic devices utilizing biodegradable collagen plugs might be of advantage since they allow early sheath removal without interrupting anticoagulation and, therefore, early ambulation. However, it remains to be determined, whether these devices are effective in reducing complications, duration of bed rest and hospitalization, or improvement of stent patency. Newer designs, e.g., coated or biodegradable stents, or different deployment strategies might reduce the need of anticoagulation and lower the risk of peripheral vascular complications.

A case of symptomatic myocardial bridge requiring intracoronary stent complicated by in-stent restenosis is reported. A stratified approach for the treatment of a symptomatic myocardial bridge is proposed.

A 48-year-old male patient diagnosed with Kawasaki disease in childhood presented with recurrent angina after undergoing coronary artery bypass surgery in 1996. Percutaneous transluminal coronary angioplasty and intracoronary stent placement to a lesion in the proximal ramus intermedius were performed successfully. This case illustrates the complementary nature of percutaneous and surgical myocardial revascularization strategies in appropriately selected patients with Kawasaki disease.

Summary: At present, there is an exponential use of new interventional techniques whose proper role and value have not yet been defined. The intracoronary stent is just one example. There is no doubt that stents can be implanted with a high technical success rate associated with highly predictable immediate angiographic results and that they appear to be superior to all other interventional techniques. However, the intrinsic thrombogenicity of all devices cmntly available for clinical use warrants a vigorous anticoagulation, exposing the patient either to the risk of (sub)acute stent thrombosis or to the risk of hemorrhage and vascular complications. It remains to be determined whether stent implantation will reduce the incidence of restenosis and whether this results in an improved long-term event and symptom-free survival. Experimental studies indicate that the thrombogenic nature of stents may be controlled by coating the struts with endothelial cells or polymers. With respect to restem sis, it is evident that as long as mechanical injury is applied to the vessel wall, the vessel wall will respond with neointimal thickening. The intracoronary stent has the potential to control this tissue response by serving as a carrier for local antiproliferative drug delivery or eventually for genetic manipulation. The intensive research which is now going on in Combination with experimental animal data, human postmortem pathologic observations, and angiographic studies is yielding clear insights and future directions to address these issues.

At present, the product information of intracoronary stents provided by the industry contains only limited technical data restricting judgments on the in vivo performance of individual products. Available experimental and clinical evidence suggests that interventional target sites display highly heterogeneous biomechanical behavior needed to be matched by specific stent and stent delivery system characteristics. To allow individualized stent-lesion matching, both, understanding of biomechanical properties of the atherosclerotic coronary artery lesions and expert knowledge of the intracoronary stent systems, are required. Here, the authors review some of the initial data on mechanical properties of coronary artery lesions potentially relevant to stenting and suggest standards for technical documentation of intracoronary stents.