Marc Irqsusi

In-vivo deformation measurements of the human heart by 3D Digital Image Correlation

Fast and accurate measurements of the kinetics and deformation of the heart during cardiac surgery can be useful for assessing the best strategies for the protection of the myocardium. While measurements based on ultrasonic technology such as the transesophageal echocardiography are rapidly developing in this direction, also other analysis methods based on optical imaging have been developed within the recent decade. The improved quality of digital cameras and increased computational power of personal computers have led to the development of deformation analysis method known as Digital Image Correlation (DIC). This paper presents preliminary results on the application of the DIC technique on analysing of the movement and deformation of the myocardial movement during a cardiopulmonary bypass surgery. The results show that the natural pattern of the heart should be sufficient for DIC, but better and more accurate results could be obtained with improved contrast conditions. DIC has a potential to be used as a sensitive tool for the surgeon to monitor the cardiac function.

Ischemic Preconditioning Results in an Atp-dependent Inhibition of Cytochrome C Oxidase

Purpose This study addresses the effect of short myocardial ischemia on inhibitory effect of ATP for mitochondrial cytochrome c oxidase (CytOx) activity in myocardium and subsequent hemodynamic alterations. The activity of CytOx is inhibited by ATP (primary substrate control). This additional mechanism was proposed to be switched off at higher mitochondrial membrane potential values in case of stress. The ATP-dependent allosteric enzyme inhibition (second respiratory control) is suggested to reduce the formation of reactive oxygen species and thus is pivotal for cytoprotection. This report addresses the possible involvement of this mechanism in case of myocardial preconditioning. Methods Rat hearts were perfused in a Langendorff system (n = 5 each group). The first two groups underwent short recurrent ischemic periods (three times 5 min) and subsequent high or low reperfusion for 40 min. Besides four control groups, hearts were exposed to an ischemia of 15 min and high flow reperfused for 30 min, in addition. Hemodynamic data were evaluated in parallel. Mitochondria were separated for the polarographic respiration measurements in the presence of ADP or ATP, respectively. Phosphorylation patterns of the CytOx subunits were studied by immunoblotting with P-Ser, P-Thr, and P-Tyr antibodies. Results Short recurrent episodes of ischemia result in an ATP-dependent inhibition of CytOx. Electrophoretic analysis and blotting techniques reveal different phosphorylation patterns of the enzyme. Frequent short-lasting ischemic impacts and subsequent increased coronary flow seem to be essential for this effect. Conclusion The procedure of preconditioning is likely to be dependent on the mechanism of ATP-dependent inhibition of CytOx activity.

Epicardial left atrial appendage closure—comparison of surgical techniques in an ex vivo model

BACKGROUND Formation of clots in the left atrial appendage (LAA) may lead to embolism and consecutive cerebral stroke. This risk is reduced by closure and resection. To address the efficacy of surgical LAA closure, resilience to pneumatic pressure was studied. Different surgical techniques were compared in an experimental model. METHODS From freshly slaughtered pigs cardiopulmonary preparations were taken. The left atrium was clamped airtight and the LAA was cannulated. Via a manually operated pump pressure was applied and a digital pressure gauge was connected. Four groups (each n=12) with different epicardial closures were studied: (I) purse string; (II) single layered continuous suture; (III) double layered suture; (IV) surgical stapler. A nonparametric test was used for group comparisons of mean burst pressures (mmHg). Statistical significance was defined at P<0.05. RESULTS Mean burst pressures in group 1 amounted to 97.1±13.0 mmHg, in group 2 to 105.5±13.3 mmHg, in group 3 to 124.6±14.2 mmHg and in group 4 to 136.6±12.5 mmHg. Excepting differences between groups 1 and 2 comparisons between groups were significantly different. CONCLUSIONS In an ex vivo model surgical staplers and double layered hand crafted sutures proved well suitable for closure of the LAA. They were significantly superior to single layered sutures in terms of resilience to pneumatic pressure. This may be relevant to durability and should be discussed with regard to clinical choice.

Initial Experience with the Transapical Access for TEVAR

Background The endovascular approach has become a mainstay in the treatment of aortic aneurysms. While the transfemoral approach is most commonly used, it is often inaccessible due to a vascular pathology, such as occlusion, tortuosity or heavy calcifications. The transapical access provides an alternative approach. The goal of this study is to report the feasibility of the transapical approach for total endovascular repair of thoracic aortic aneurysms (TEVAR). Methods Three patients with thoracic aortic aneurysms with inaccessible femoral arteries underwent TEVAR via the transapical approach. For access, the apex of the left ventricle was exposed by a mini-thoracotomy. After left ventricular puncture, a stiff guidewire was placed through the aortic valve into the descending thoracic aorta. All stent grafts were delivered under fluoroscopic guidance. Results All three procedures were technically successful with complete exclusion of the aneurysm without endoleak. One patient suffered spinal ischemia with subsequent paraplegia on day 4 after the procedure. The same patient died on day 43 after the procedure due to esophageal rupture. The two remaining patients did not present procedure-related problems. Conclusion The transapical access is a feasible and safe alternative to the transfemoral route in selected cases scheduled for TEVAR. Key Points  · Transapical TEVAR is a feasible option if the transfemoral route is not accessible.. · Reversed orientation of the stent graft has to be taken into account for procedure planning and graft deployment.. · Care has to be taken in the case of aortic valve vegetation in order to avoid stroke due to downstream embolism.. Citation Format · Mahnken AH, Irqsusi M, Hundt W et al. Initial Experience with the Transapical Access for TEVAR. Fortschr Röntgenstr 2017; 189: 760 - 764.

A method for stereoscopic strain analysis of the right ventricle by digital image correlation during coronary bypass surgery: short communication.

Abstract Perioperative cardiosurgical management of volume therapy remains one of the challenging tasks in cases of patients with severe heart disease. Early detection of congestive cardiac failure prevents subsequent low output and worse outcome. An effective method for controlling extracorporeal circulation is created by developing a non-invasive intraoperative method for right ventricular strain analysis through digital image contrast correlation.

Paradoxical embolization of brachiocephalic and pulmonary arteries in a case of persistent foramen ovale: a case report.

Paradoxical embolism is the result of systemic arterial embolism and pulmonary embolism. It indicates the presence of an intracardial defect in the area of the atrial or ventricular septum. The most frequent cause of an intracardiac defect associated with paradoxical embolism is a patent foramen ovale (PFO). In the case presented here, the symptoms, diagnostics and surgical therapy are discussed.

Early Results of Surgical Simultaneous Therapy for Significant Carotid Artery Stenosis and Heart Disease

Abstract Background The purpose of this single‐center, retrospective study was to review the early outcome with defined endpoints of myocardial infarction, brain injury, and death after coronary bypass grafting and simultaneous carotid endarterectomy with or without combined valve replacement. Methods During the preoperative investigation 52 (44 males, 8 females) patients were examined by cardiac catheterization within the scope of their coronary status. In addition, all patients underwent echocardiography, CT angiography of the supra‐aortic vessels, and full description of their neurologic status. Included were all patients with the need of coronary revascularization, valve disease, and either symptomatic or asymptomatic carotid artery stenosis with a maximal narrowing of >70%. Results There was one (2%) patient with a perioperative stroke and paresis of the upper limb. One (2%) patient experienced PRIND (2%). Eighteen (35%) patients suffered symptomatic transitory psychotic syndrome that fully recovered in all patients. One (2%) patient incurred a perioperative myocardial infarction that could be cured by percutaneous coronary stent implantation. Overall mortality was 4%. Conclusion Simultaneous coronary bypass grafting as a single procedure or in combination with valve replacement and endarterectomy of severe carotid lesions with or without patients’ history of previous stroke can be performed with a calculated low surgical risk. The complication rate for neurologic and myocardial events is low compared with the hazard of a single surgical repair. The in‐hospital mortality is not significantly different to isolated procedures. The concomitant appearance of coronary stenosis and carotid artery disease is reasonable due to the nature of arteriosclerosis. In our opinion these patients benefit from a combined surgical approach.

Extraadrenal Biatrial Cardiac Paraganglioma: Diagnosis, Histological Criteria and Surgical Management

Fig 2. Pthat originate from the neural crest. We report a case of successful surgical treatment of a noncatecholamineproducing cardiac paraganglioma in a 25-year-old white male patient with dyspnea on exertion and intermittent palpitations. Echocardiography revealed solid 4.64.3-cm tumor mass located in close relation to the left and right atria. A magnetic resonance image of the heart demonstrated the solid tumor mass adjacent mainly to the right atrium and in part to the left atrium with an early and strong arterial uptake of the contrast medium (see arrow in Fig 1). A coronary angiogram revealed a feeding blood supply primarily by the right and also left coronary artery systems. The highly vascularized tumor was located mainly in the epicardium with infiltrative growth. The intraoperative situs showed a large, primary epicardially capsulated tumor between the right and left atria compressing the inferior vena cava and the right upper pulmonary vein. The tumor was removed en bloc after clipping and oversewing the feeding vessels of the proximal right coronary artery and the first marginal