Transpulmonary closing of left internal mammary artery to pulmonary artery fistula with polytetrafluoroethylene covered stent: A case report and review of literature

Internal mammary artery (IMA) to pulmonary vasculature fistula is a rare condition that can be congenital or associated with coronary artery bypass grafting surgery (CABG), trauma, inflammation, or neoplasia. This complication may cause myocardial ischemia. CABG with an IMA conduit accounts for most iatrogenic cases, thus this problem may be encountered more in the future as the number of patients undergoing CABG and redo-CABG increases. The natural history of IMA-to-pulmonary artery (PA) fistulas is unknown and therefore optimal treatment remains controversial. We describe a case of left IMA-to-PA fistula treated with balloon expandable covered stent with a transpulmonary approach, and we review previously reported cases

Technique of minimally invasive transverse aortic constriction in mice for induction of left ventricular hypertrophy

Transverse aortic constriction (TAC) in mice is one of the most commonly used surgical techniques for experimental investigation of pressure overload-induced left ventricular hypertrophy (LVH) and its progression to heart failure. In the majority of the reported investigations, this procedure is performed with intubation and ventilation of the animal which renders it demanding and time-consuming and adds to the surgical burden to the animal. The aim of this protocol is to describe a simplified technique of minimally invasive TAC without intubation and ventilation of mice. Critical steps of the technique are emphasized in order to achieve low mortality and high efficiency in inducing LVH. Male C57BL/6 mice (10-week-old, 25-30 g, n=60) were anesthetized with a single intraperitoneal injection of a mixture of ketamine and xylazine. In a spontaneously breathing animal following a 3-4 mm upper partial sternotomy, a segment of 6/0 silk suture threaded through the eye of a ligation aid was passed under the aortic arch and tied over a blunted 27-gauge needle. Sham-operated animals underwent the same surgical preparation but without aortic constriction. The efficacy of the procedure in inducing LVH is attested by a significant increase in the heart/body weight ratio. This ratio is obtained at days 3, 7, 14 and 28 after surgery (n = 6 - 10 in each group and each time point). Using our technique, LVH is observed in TAC compared to sham animals from day 7 through day 28. Operative and late (over 28 days) mortalities are both very low at 1.7%. In conclusion, our cost-effective technique of minimally invasive TAC in mice carries very low operative and post-operative mortalities and is highly efficient in inducing LVH. It simplifies the operative procedure and reduces the strain put on the animal. It can be easily performed by following the critical steps described in this protocol

Optical coherence tomography findings in bioresorbable vascular scaffolds thrombosis

Background—Everolimus-eluting bioresorbable vascular scaffolds have been developed to improve late outcomes after coronary interventions. However, recent registries raised concerns regarding an increased incidence of scaffold thrombosis (ScT). The mechanism of ScT remains unknown.Methods and Results—The present study investigated angiographic and optical coherence tomography findings in patients experiencing ScT. Fifteen ScT (14 patients, 79% male, age 59±10 years) occurred at a median of 16 days (25%–75% interquartile range: 1–263 days) after implantation. Early ScT (1 month) and very late (>1 year) ScT (respectively, 5 and 2 cases), 5 scaffolds showed intimal neovessels or marked peristrut low-intensity areas. Scaffold fractures were additionally found in 2 patients, and scaffold collapse was found in 1 patient with very late ScT. Extensive strut malapposition was the presumed cause for ScT in 1 case. One scaffold did not show any morphological abnormality. Thrombectomy specimens were analyzed in 3 patients and did not demonstrate increased numbers of inflammatory cells.Conclusions—The mechanisms of early ScT seem to be similar to metallic stents (mechanical and inadequate antiplatelet therapy). The predominant finding in late and very late ScT is peristrut low-intensity area

Bioresorbable coronary scaffold thrombosis: multicenter comprehensive analysis of clinical presentation, mechanisms, and predictors

Background Recent reports suggest an elevated incidence of bioresorbable vascular scaffold (BVS) thrombosis (scaffold thrombosis [ScT]).Objectives This study investigated occurrence rates, clinical and angiographic characteristics, and possible mechanisms of ScT in all-comer patients undergoing BVS implantation at 2 German and 2 Swiss hospitals.Methods A total of 1,305 consecutive patients (mean age 64 years, 78% male) who received 1,870 BVS (mean 1.4 ± 0.8 BVS/patient) were enrolled. Clinical/procedural characteristics, mortality, and ScT data at 485 days (range 312 to 652 days) were examined.Results ScT occurred in 42 patients. The incidence of probable and definite ScT was 1.8% at 30 days and 3.0% at 12 months, without differences among centers (p = 0.60). A total of 22 (52%) ScTs presented as ST-segment elevation myocardial infarction and 6 (17%) as sudden cardiac death. In multivariable analysis, ostial lesions (p = 0.049) and impaired left ventricular ejection fraction (p = 0.019) were independently associated with ScT. Nine (21%) of the ScTs occurred in patients who had suspended dual antiplatelet therapy, in 6 cases prematurely. Lower post-procedural minimum lumen and reference vessel diameters were hallmarks of ScT (all p < 0.0001). The risk of ScT appeared to rapidly increase for post-procedural minimum lumen diameters below 2.4 mm (for the 2.5- to 3.0-mm BVS) and 2.8 mm (for the 3.5-mm BVS). When a BVS-specific implantation strategy was implemented, 12-month ScT rates fell from 3.3% to 1.0%, an effect that remained significant when adjusted for multivariable propensity score (p = 0.012; hazard ratio: 0.19; 95% confidence interval: 0.05 to 0.70).Conclusions The 12-month incidence of ScT reached 3% and could be significantly reduced when an optimized implantation strategy was employed. (retrospective multicentric registry and Mainz Intracoronary Database. The Coronary Slow-flow and Microvascular Diseases Registry [MICAT]; NCT02180178

Staged stenting of a long aneurysm of a saphenous vein coronary artery bypass graft

A 65-year-old male who underwent coronary artery bypass graft surgery (CABG) 21 years ago and received a mitral valve annuloplasty 5 years ago presented with recurrent angina. Computed tomography showed an aneurysm of the saphenous vein graft (SVG), measuring approximately 43 x 33 mm with mural thrombus. Diagnostic catheterization showed that the SVG to the marginal branch of the left circumflex artery had a large aneurysm with mural thrombus, which measured 32 x 45 mm. The lesion was pretreated with a 5.5 x 47 mm Magic Wallstent (Boston Scientific, Maple Grove, Minnesota) followed by 4.0 x 26, 4. x 26, 4.0 x 19 and 4.0 x 16 mm PTFE-covered stents. Postdilatation was performed using a 5.0 x 20 mm balloon. Because of significant flow from the distal end of the PTFE-covered stents seen at coronary angiography after 6 months, we implanted another 4.0 x 26 mm PTFE-covered stent at the distal edge of the previous stent. Final angiography and intravascular ultrasound showed no significant flow into the aneurysm

Full-root aortic valve replacement by stentless aortic xenografts in patients with small aortic roots

In patients with small aortic roots who need an aortic valve replacement with biological valve substitutes, the implantation of the stented pericardial valve might not meet the functional needs. The implantation of a too-small stented pericardial valve, leading to an effective orifice area indexed to a body surface area less than 0.85 cm2/m2, is regarded as prosthesis-patient mismatch (PPM). A PPM negatively affects the regression of left ventricular hypertrophy and thus the normalization of left ventricular function and the alleviation of symptoms. Persistent left ventricular hypertrophy is associated with an increased risk of arrhythmias and sudden cardiac death. In the case of predictable PPM, there are three options: 1) accept the PPM resulting from the implantation of a stented pericardial valve when comorbidities of the patient forbid the more technically demanding operative technique of implanting a larger prosthesis, 2) enlarge the aortic root to accommodate a larger stented valve substitute, or 3) implant a stentless biological valve or a homograft. Compared to classical aortic valve replacement with stented pericardial valves, the full-root implantation of stentless aortic xenografts offers the possibility of implanting a 3-4 mm larger valve in a given patient, thus allowing significant reduction in transvalvular gradients. However, a number of cardiac surgeons are reluctant to transform a classical aortic valve replacement with stented pericardial valves into the more technically challenging full-root implantation of stentless aortic xenografts. Given the potential hemodynamic advantages of stentless aortic xenografts, we have adopted full-root implantation to avoid PPM in patients with small aortic roots necessitating an aortic valve replacement. Here, we describe in detail a technique for the full-root implantation of stentless aortic xenografts, with emphasis on the management of the proximal suture line and coronary anastomoses. Limitations of this technique and alternative options are discussed

Technique and Patient Selection Criteria of Right Anterior Mini-Thoracotomy for Minimal Access Aortic Valve Replacement

Aortic valve stenosis has become the most prevalent valvular heart disease in developed countries, and is due to the aging of these populations. The incidence of the pathology increases with growing age after 65 years. Conventional surgical aortic valve replacement through median sternotomy has been the gold standard of patient care for symptomatic aortic valve stenosis. However, as the risk profile of patients worsens, other therapeutic strategies have been introduced in an attempt to maintain the excellent results obtained by the established surgical treatment. One of these approaches is represented by transcatheter aortic valve implantation. Although the outcomes of high-risk patients undergoing treatment for symptomatic aortic valve stenosis have improved with transcatheter aortic valve replacement, many patients with this condition remain candidates for surgical aortic valve replacement. In order to reduce the surgical trauma in patients who are candidates for surgical aortic valve replacement, minimally invasive approaches have garnered interest during the past decade. Since the introduction of right anterior thoracotomy for aortic valve replacement in 1993, right anterior mini-thoracotomy and upper hemi-sternotomy have become the predominant incisional approaches among cardiac surgeons performing minimal access aortic valve replacement. Beside the location of the incision, the arterial cannulation site represents the second major landmark of minimal access techniques for aortic valve replacement. The two most frequently used arterial cannulation sites include central aortic and peripheral femoral approaches. With the purpose of reducing surgical trauma in these patients, we have opted for a right anterior mini-thoracotomy approach with a central aortic cannulation site. This protocol describes in detail a technique for minimally invasive aortic valve replacement and provides recommendations for patient selection criteria, including cardiac computer tomography measurements. The indications and limitations of this technique, as well as its alternatives, are discussed

"Apical ballooning" - what is the cause?

The pathophysiology of takotsubo cardiomyopathy remains enigmatic. Here we attempted to define the link between the coronary arteries and the histopathological involvement of the left ventricle. We observed similarities and discrepancies between patients. All patients experienced stress prior to the event. We found a reduced coronary flow reserve in all patients and signs of hibernating myocardium on biopsy specimen. This raises a strong suspicion of stress-induced endothelial dysfunction with hibernating myocardium in the pathogenesis of this cardiomyopathy