Pavle Kovacevic

Evaluation of results in coronary surgery using EuroSCORE

INTRODUCTION The European System for Cardiac Operative Risk Evaluation (EuroSCORE) was developed in order to predict operative risk in cardiac surgery and to assess the quality of the cardio-surgical care. Introduction of the uniform terminology in result evaluation process leads to the significant improvement in measuring and evaluation of surgical treatment quality. OBJECTIVE The aim of the study was to evaluate our results in isolated coronary surgery using the EuroSCORE. METHODS The study was done respectively by analysing predicted mortality according to the EuroSCORE model and observed operative risk in 4,675 coronary patients operated at our Clinic during the period 2001-2008. For statistical analyses, the Pearson, Chi-square and ANOVA tests were used. RESULTS The total postoperative mortality predicted by the EuroSCORE was 2.9 +/- 2.25, while the observed one was 2.2%. When the scoring system and observed results were compared over the years, a considerably lower observed mortality was found during the last 4 years. Overall average number of distal anastomoses was 2.62 +/- 0.84. During the period 2004-2008, the average number of coronary anastomoses increased over the years reaching the value of 2.77 +/- 0.88. The difference is at the level of statistical significance with the trend of further increase. Percentage of the patients with single or double graft myocardial revascularization decreases, while the number of the patients with triple or more bypasses increases. CONCLUSION During the last years, the results in isolated coronary surgery have considerably improved. The EuroSCORE overestimates operative risk. In order to improve its predictive value, the model should be recalibrated.

Surgical Treatment of Coronary Artery-Pulmonary Artery Fistula with Coronary Artery Disease

Abstract  Coronary arteriovenous fistulae present rare clinical finding with the incidence of about 0.002% in the general population. Usually they are asymptomatic, but sometimes they can mimic other cardiac diseases, most commonly heart failure, myocardial ischemia, and endocarditis. Coronary arteriovenous fistulae have been reported to arise more commonly from the right coronary artery. Most of these fistulae are congenital, and only a small fraction acquired. In this report we present successful surgical treatment of coronary artery to pulmonary artery fistula combined with myocardial revascularization.

Computer simulation of thromboexclusion of the complete aorta in the treatment of chronic type B aneurysm.

The purpose of this computational study was to examine the hemodynamic parameters of the velocity fields, shear stress, pressure and drag force field in the complex aorta system, based on a case of type B aortic dissection. The extra-anatomic reconstruction of the complete aorta and bipolar exclusion of the aneurysm was investigated by computational fluid dynamics. Three different cases of the same patient were analyzed: the existing preoperative condition and two alternative surgical treatment options, cases A and B, involving different distal aorto-aortic anastomosis sites. The three-dimensional Navier-Stokes equations and the continuity equation were solved with an unsteady stabilized finite element method. The aorta and large tube graft geometries were reconstructed based on CT angiography images to generate a patient-specific 3D finite element mesh. The computed results showed velocity profiles with smaller intensity in the aorta than in the graft tube in the postoperative case. The shear stress distribution showed low zones around 0.5 Pa in the aneurysm part of the aorta for all three cases. Pressure distribution and, particularly, drag force had much higher values in the preoperative aneurysm zones (7.37 N) than postoperatively (2.45 N), which provides strong evidence of the hemodynamic and biomechanical benefits of this type of intervention in this specific patient. After assessing the outcome obtained with each of the two alternatives A and B, for which we found no significant difference, it was decided to use option A to treat the patient. In summary, computational studies could complement surgical preoperative risk assessment and provide significant insight into the benefits of different treatment alternatives.

Postpartal Right Ventricular Thrombosis

The discovery of an intracardial mass in patients presents a serious diagnostic dilemma. The differential diagnosis of this condition may seem abundant, but myxomas and intracardial thrombosis are the most frequent diagnoses. A connection between pregnancy and the presence of thrombosis has been documented frequently. Normal pregnancy leads to changes of the coagulative and fibrinolytic status toward a hypercoagulable condition which has its own physiological justification (the risk of blood loss decreases during labor). The case of a patient suffering from postpartal right ventriculare thrombosis, which was successfully resolved by surgery as described in this contribution, demonstrates the value of a multidisciplinary approach.ZusammenfassungDer Nachweis einer intrakardialen Masse bei einem symptomatischen Patienten erfordert die Erwägung verschiedener Differentialdiagnosen. Myxome und Thromben finden sich am häufigsten. Bei einer Schwangerschaft sind Thrombosen nicht selten, denn eine normale Schwangerschaft führt zu einer Änderung des koagulativen und fibrinolytischen Status hin zu einem hyperkoagulabilen Zustand mit dem physiologisch sinnvollen Ziel, das Risikos eines Blutverlusts während der Geburt zu reduzieren. Der hier dargestellte Fall einer Patientin mit postpartaler Thrombose der rechten Herzkammer stellt ein gutes Beispiel einer multidisziplinären Versorgung dar.

Carotid-Carotid Bypass as an Option in the Treatment of Infected Pseudoaneurysm After Prosthetic Carotid Replacement

Development of pseudoaneurysm from an infected carotid prosthetic patch after carotid endarterectomy is extremely rare and is very challenging from the perspective of surgical and medical treatment. This article describes the case of a 65-year-old patient presenting with the signs of wound infection and recurrent bleeding in the region of the right carotid artery. Three years earlier the patient underwent coronary artery bypass grafting and bilateral replacement of carotid arteries with prosthetic tube grafts. Magnetic resonance imaging confirmed the presence of an infected pseudoaneurysm in the region of prosthetic carotid replacement graft. A decision was made to perform retroesophageal carotid-carotid bypass with an autologous venous conduit.

Thromboexclusion of the Complete Aorta in the Treatment of Chronic Type B Aneurysm

We report a case of a 55-year-old woman who was referred to us with a huge chronic postdissection thoracoabdominal aneurysm of a maximal intrathoracic diameter of 13.5 cm and signs of intrathoracic imminent rupture with subparietal pleural hemorrhagic effusion. Computed tomography examination revealed that the left lung had undergone complete atelectasis and carnification owing to compression of the left principal bronchus. There were also signs of left kidney atrophy because of the left renal artery originating from the thrombosed false lumen. Owing to delicate preoperative condition, we decided to perform thromboexclusion of the complete aorta with reattachment of all the supra-aortic and visceral branches and complete bipolar exclusion of thoracoabdominal aorta. The patient was discharged from the hospital on the 35th postoperative day in a good condition. Following computed tomography scan revealed complete thrombosis of the excluded portion of the aorta.

An unusual origin of proximal coronary bypass anastomosis in a patient with porcelain aorta: how we solved the problem.

Severe calcification of the ascending aorta (porcelain aorta) is a very difficult condition in cardiac surgery because of a high embolization potential during the process of cannulation, aortic cross-clamping and a particular difficulty to suture the proximal anastomosis. We described a case of a 68-year-old female referred to our Institute due to unstable angina. Further diagnostics revealed a severe high grade, multilevel fibrolipid symptomatic carotid stenosis and ostial left main coronary artery stenosis and a highly calcified ascending aorta and aortic arch. We performed simultaneous carotid segment replacement with the Dacron prosthesis and revascularisation of the left anterior descending coronary artery. Proximal venous anastomosis was created in the Dacron prosthesis of the right carotid artery. Perfusion of the patient was achieved via the graft sutured at the right subclavian artery due to impossibility of direct aortic cannulation.

Late complications of transcatheter atrial septal defect closure requiring urgent surgery

A 21-year-old female patient was transferred to our hospital after being diagnosed with massive pulmonary thromboembolism (PTE). Three years prior to admission, she underwent transcatheter closure of the secundum ASD with a 33 mm CardioSEAL-StarFLEX occluder (NMT Medical, Boston, MA, USA). A year ago, she was involved in a car accident and sustained significant blunt chest trauma. Transthoracic echocardiography confirmed the presence of thrombi in the right atrium and the pulmonary artery, with massive dilatation of the right ventricle and the pulmonary artery, along with severe pulmonary hypertension. Also, protrusion or dislodgement of the occluder was suspected. Her deteriorated clinical conditions warranted immediate surgery. The patient was put on a cardiopulmonary bypass (CPB) and the right atrium and the pulmonary artery were opened. Several thrombi were removed, the largest being 2 × 3 cm. The ASD occluder was identified with a thrombus attached to it and evident device-arm fracture (Figure 1). The occluder underwent almost complete healing with full endocardium covering except in the rim area. The device was removed and the ASD was repaired with a patch. Unfortunately, due to right heart failure, the patient could not be successfully weaned from the CPB, not even after an artificially created interatrial shunt, and she expired. Although one cannot say with absolute certainty that massive PTE developed because of device-related thrombosis, it seems intuitive that blood turbulence around the protruded umbrella and device-arm fracture could have acted as a nidus for repeated thrombus formation with subsequent embolization. The occluder malfunction (fracture) was most likely the result of sustained blunt chest trauma a year prior to admission. We hypothesize that the sudden increase in intrathoracic pressure during trauma as well as direct compression on the heart generated a point of high wall stress around the occluder’s septal insertion, which may have led to device fracture and dislodgment.

Numerical simulation of blood flow and plaque progression in carotid–carotid bypass patient specific case

Abstract This study describes computer simulation of blood flow and plaque progression pattern in a patient who underwent surgical treatment for infected carotid prosthetic tube graft using carotid–carotid cross-over bypass. The 3D blood flow is governed by the Navier–Stokes equations, together with the continuity equation. Mass transfer within the blood lumen and through the arterial wall is coupled with the blood flow and is modelled by the convection–diffusion equation. Low-density lipoprotein (LDL) transport in lumen of the vessel is described by Kedem–Katchalsky equations. The inflammatory process is solved using three additional reaction–diffusion partial differential equations. Calculation based on a computer simulation showed that flow distribution in the left carotid artery (CA) was around 40–50% of the total flow in the right common CA. Also, the left CA had higher pressure gradient after surgical intervention. Plaque progression simulation predicted development of the atherosclerotic plaque in the position of the right common CA and the left internal CA. A novel way of atherosclerotic plaque progression modelling using computer simulation shows a potential clinical benefit with significant impact on the treatment strategy optimization.

Delayed closure of postinfarction ventricular septum defect in a patient with single vessel disease

A 65-year-old patient with a systolic murmur that developed five days after acute anteroseptal myocardial infarction was referred to our Institution. He had previously been treated with fibrinolytic therapy. The patient was in a stable hemodynamic condition when admitted, with sustained diuresis. Blood gas analysis revealed normal parameters, whereas a chest X-ray showed signs of pulmonary congestion. Transthoracic echocardiography revealed a 1.5×1.2 cm post-infarction ventricular septum defect (VSD) in the apical part of the septum. Because the patient’s hemodynamic conditions were stable, we decided to postpone the operative treatment to allow scarring of the infarcted area to make VSD repair feasible, thereby increasing the chance for success. Operative treatment was performed three weeks after admission. We performed closure of the VSD with a bovine pericardial patch. The patient was discharged in good condition and remained well three months after the surgery.