Biomedical subjects

D Nezić

Publications and source records attributed to D Nezić.

14 recordsLinked to original sources

PubMed2005

Transaortic double valve replacement in difficult mitral valve exposure.

Adequate open exposure of the mitral valve is necessary to accomplish reconstruction or replacement of the diseased mitral valve apparatus. The technique employed by most cardiac surgeons for mitral valve access involves median sternotomy and vertical left atriotomy posterior to the interatrial sulcus. However, certain conditions can somethimes make this approach very difficult. Different approaches are discussed with particular emphasis on our case in which the transaortic double valve replacement have been performed.

Aortic Valve↗

PubMed2004

Foley catheter and deep hypothermic circulatory arrest to control bleeding in redo cardiac surgery.

Two cases with catastrophic hemorrhage in redo cardiac surgery are described. In the first one tearing of right ventricle with uncontrolled bleeding occurred during sternal reentry. In the second one, tearing of the right atria occurred while the patient was on cardiopulmonary bypass. In both cases we were able to control bleeding using Foley catheter, which enabled us to proceed to deep hypothermic circulatory arrest to repair heart chambers (due to dense adhesions it was impossible to manage it in any other way). We have found this combined technique to be extremely useful tool to control catastrophic hemorrhage during redo cardiac surgery.

Blood Loss, Surgical↗

PubMed2003

[Surgical revascularization of the myocardium].

It has been 45 years ago when Longmire (1958.) used internal thoracic artery (ITA) for the first time in coronary artery bypass surgery (CABG). In this review, we are presenting novel surgical approaches in CABG surgery. We have also been summarized the best of knowledge, up to date, regarding histology, pharmacology and pathophysiology of conduits (VSM, ITA and alternative venous and arterial grafts) which have been used in CABG surgery, as well as factors influence on its short and long-term patency.

Coronary Artery Bypass↗

PubMed2003

Postcardiotomy assisted circulation with roller pump--early and late results.

The incidence of postcardiotomy myocardial failure (PMF) requiring mechanical circulatory support beyond IABP is reported to be 0.2% to 1.2%. From Dec. 1989 through Dec. 1995, 18 patients (0.3% of the total pump cases) were supported with roller pump type of LVAD. Assisted flow ranged from 3.5 up to 5 L/min with average support time of 35.5 hours. Six (33.3%) patients died while on LVAD. The causes of additional seven deaths (pts weaned of LVAD) were: myocardial failure (4), stroke (2) and intractable bleeding during removal of the LVAD (1). Overall, five patients (27.8%) were successfully discharged from the hospital. Two out of five long-term survivors died later, 6 months and 4 years postoperatively, both of cardiac causes. The actuarial survival rate of long-term survivors was 60% at 7 years, all of them being in NYHA functional class II. These results have proved efficiency of roller pump driven LVAD for short-term circulatory support in pts with PMF. Results are comparable to so far published data on postcardiotomy support with the same, as well as other types of more versatile and costly devices.

Aged↗

PubMed2002

[Role of the Swan-Ganz pulmonary artery (PA) catheter in evaluation of hemodynamic changes during myocardial revascularization in patients with low left ventricular function].

Coronary artery bypass surgery in patient with bad left ventricular function is a challenge for surgical time. Specially important is monitoring of haemodynamics. We performed this open, prospective, randomized study with the aim to assess haemodynamics and oxygen profile monitoring. 34 pts for coronary surgery (EF < 40%) were divided in two groups. Group A, 17 pts. Received glucose-insulin-potassium (GIK) solution. Group B, 127 pts. Received Ringer solution. Haemodynamic and oxygen metabolism parameters were measured in four time points. I after the induction in anesthesia; II after the operation; III 6 hours post op.; IV 24 hour post op. Data are expressed as mean +/- SD, Anova for repeated measures followed by Newman-Keuls testing were used. In both groups were evident deterioration of cardiac function during first 6 h as well as VO2 and DO2, more prominent in Group B. Significant recovery and improvement of cardiac function were evident in Group A after 24 h. CI during the time in Group A improves significantly (2.14 +/- 0.36 v. 3.05 +/- 0.55; p = 0.0002) and difference during the time between groups was p = 0.005. LVSWI improved significantly during the time him Group A (AIII vs. AIV) p = 0.007. Simultaneously. VO2 improves significantly in Group A (103 +/- 21 vs. 164 +/- 30, p = 0.00001) while difference between groups in DO was p = 0.037. Importance of oxygen metabolism monitoring for both, left ventricular function and haemodynamics assessment was evident in our study.

Cardioplegic Solutions↗

PubMed2001

[Assisted circulation. I. Systems with short-term mechanical circulatory support].

The concept of artificial circulatory support has been established almost 200 years ago. It has only been within the last four decades that physicians and engineers have developed mechanical assist devices that can temporarily support the circulation until the native heart recovers from a reversible injury. If the heart does not recover sufficient function to maintain adequate hemodynamics, long-term circulatory support or permanent replace (biologically--heart transplant or permanent mechanical circulatory support) is needed. In this paper we describe the devices (intraaortic balloon pump, roller, centrifugal and axial pumps), that are in current clinical use for temporary (short-term) mechanical circulatory support.

Assisted Circulation↗

PubMed2001

[Assisted circulation II--systems for intermediate and long-term mechanical circulatory support].

The concept of artificial circulatory support has been established almost 200 years ago. It has only been within the last four decades that physicians and engineers have developed mechanical assist devices that can temporarily support the circulation until the native heart recovers from a reversible injury. In patients who do not regain native heart function, long-term circulatory support or permanent replace (biologically--heart transplant or permanent mechanical circulatory support) is indicated. In this paper we describe the devices (ABIOMED BSV 5000, Thoratec, HeartMate, Novacor and CardioWest TAH), that are in current clinical use for intermediate and long-term mechanical circulatory support.

Assisted Circulation↗

PubMed2000

[History of surgical treatment of atherosclerosis of the coronary arteries--the first 100 years].

Atherosclerotic coronary artery disease is the most common cause of morbidity and mortality. The incidence of cardiovascular morbidity and mortality has been doubled in our country during the period 1980 through 1996. Surgical treatment of the atherosclerotic coronary artery disease is already a century old, ever since Francois-Franck (in 1899) tried to achieve sympathetic denervation of the cervical ganglion. After the interim period of indirect myocardial revascularization, during the last 30 years, direct surgical revascularization has reached excellent early and long-term results, and became one of the most frequently performed procedures in the surgical practice. Use of arterial grafts and, introduced recently, procedures on the beating heart, minimally invasive procedures and, so called, port-access procedures became a daily routine in many centers. Surgical revascularization of the ischaemic cardiac muscle is the rapidly changing entity, along with diagnostic, technical and other improvements. We present a brief historical overview of the efforts of cardiac surgeons to combat the "disease of the century" atherosclerotic coronary artery disease.

Coronary Artery Disease↗

PubMed2000

[Occlusion of a calcified ascending aorta with a Foley catheter in aortocoronary bypass--case report].

Heavily calcified ascending aorta predisposes to aortic injury and distal embolization during total or partial cross-clamping, during the performance of open-heart procedures. Placement of the arterial cannula may be particularly difficult, occasionally virtually impossible using the standard technique, while placing the clamp on such aorta may be extremely risky. We present a case where we have used a Foley-balloon catheter to occlude the densely calcified ascending aorta, during a aorta-coronary bypass procedure, thus completely avoiding the use of the total aortic clamp.

Aorta↗

PubMed2000

[Myocardial revascularization using the internal thoracic artery: pro and con].

Internal thoracic artery (ITA) has superior histological, physiological and pharmacological properties over the venous grafts, and it is considered to be the graft of choice for myocardial revascularization. It has low incidence of late atherosclerotic lesions, and excellent long-term patency. Usage of ITA yields improved clinical results in all subgroups of patients with coronary artery disease, including patients with poor left ventricular function (EF%), left main stenosis, diffuse coronary artery disease and octogenarians. Since superior long-term results (to be expected only 10-15 years after the operation) may be outweighed with slightly higher incidence of early morbidity and mortality, many cardiac surgeons are reluctant to use it routinely. However, this attitude is difficult to justify, since early operative results in patients that have received ITA graft are superior as well, compared to patients that have received vein grafts only.

Humans↗

PubMed1998

Combined carotid and coronary artery surgery: what have we learned after 15 years?

UNLABELLED: Optimal surgical strategy in patients with concomitant coronary and carotid artery disease is debatable. We have analysed 15-years of experience (January 1981-August 1996) with 195 consecutive patients in whom we have used two different surgical approaches. Group A consisted of 48 patients who underwent a single-stage surgical procedure, and group B (147 patents) underwent a two-stage procedure, either as carotid endarterectomy followed by coronary artery bypass surgery (group B1, 97 patients), or as coronary artery bypass surgery followed by carotid endarterectomy (group B2, 50 patients). Overall, there were 40 (20.5%) patients with left main coronary artery disease, 49 (25.1%) with poor left ventricular function, 128 (65.6%) with previous myocardial infarction, 134 (68.7%) were in New York Health Authority (NYHA) functional class III or IV, and bilateral carotid involvement was present in 57 patients (29.2%). Unstable angina was more frequent in groups A and B2 (P < 0.0001), NYHA class III-IV was more frequent in group A (versus B1, P = 0.001 and versus B2, P = 0.02), low ejection fraction (EF) was more frequent in groups A and B2 (P < 0.0001 for both), bilateral carotid stenosis in groups A and B1 (P = 0.02 and P = 0.0001, respectively) and ulcerated plaque in group B1 (versus A, P = 0.0001). These differences dictated the surgical strategy, which resulted in different protocols for clinical and operative management. RESULTS: Early mortality for the entire group was 4.6% (9/195-6.2% in group A, 6.2% in group B1 and 0% in group B2, respectively P > 0.05). Serious morbidity occurred in 7.3% of patients (14/195-8.3% in group A, 7.2% in group B1 and 6% in group B, respectively P > 0.05). Univariate analysis revealed only bilateral carotid stenosis as a predictor of outcome (P = 0.04). Follow-up was completed for 156 patients (80.0%) and averaged 84.1 +/- 13.3 months (range 1-180 months). Kaplan-Meier survival estimate for the entire group was 81% and event-free survival was 76% at 5 years. Actuarial and event-free survivals were similar for all groups. Early and late outcome in these patients were influenced more by their preoperative clinical status than by the surgical strategy itself. It is therefore concluded that surgical approach should be individualized for the majority of patients.

Actuarial Analysis↗

PubMed1997

Cardiac events after combined surgery for coronary and carotid artery disease.

OBJECTIVE: To evaluate serious cardiac events after combined (either single or two stage) coronary artery surgery (CAS) and carotid endarterectomy (CEA) for concomitant coronary and carotid artery disease. METHODS: We have analyzed our 15 year experience (January 1981-September 1996) with 201 consecutive patients operated on using both approaches. Group A consisted of 48 patients with the single-stage procedure, while in group B (153 patients), two stage procedure was carried out, either as carotid endarterectomy (CEA), followed by coronary artery bypass surgery (CAS) (group B1- 103 patients), or as CAS followed by CEA (group B2- 50 patients). Five patients from B1 group died after the CEA procedure, but were included, despite the fact they never reached the second stage. Left main coronary artery disease was found in 41 patients (20.4%), poor left ventricular function in 49 (24.4%) previous MI in 133 (66.2%), while 136 (67.7%) were in NYHA functional class III or IV. Bilateral carotid involvement was present in 61 patients (30.3%). Unstable angina was more prevalent in groups A and B2 (P < 0.0001). NYHA class III/IV in group A (versus B1, P = 0.001 and versus B2, P = 0.02), low ejection fraction in groups A and B2 (P < 0.0001), bilateral carotid stenosis in group B1 (versus A, P = 0.003 and versus B2, P < 0.0001), and ulcerated plaque in group B1 (P < 0.0001). These differences dictated the surgical strategy, which resulted in different protocols for clinical and operative management. RESULTS: Early mortality for the entire group was 5.5% (11/201) 6.2% in group A, 7.8% in group B1 and 0% in group B2, respectively; (P > 0.05). Serious morbidity occurred in 7.5% of patients (8.3% in group A, 7.8% in group B1 and 6% in group B2, respectively; P > 0.05). Univariate analysis revealed only bilateral carotid stenosis to influence early outcome (P = 0.04). CONCLUSION: Patients with concomitant coronary and carotid artery disease have relatively good immediate operative results, providing all existing lesions are corrected. Despite it did not reach the statistical significance, cardiac events were less frequent in groups A and B2 indicating possible protective effect of prior CAS in patients with concomitant disease.

Aged↗

PubMed1985

A new efficient method of topical cooling and rewarming of the myocardium.

Profound myocardial hypothermia (below 17 degrees C, and more often around 12 degrees C) is imperative in myocardial protection while the aorta is cross-clamped. Based on our experience in more than 800 open-heart operations, profound myocardial hypothermia can be achieved by very efficient topical cooling despite mild systemic hypothermia (30 to 33 degrees C) and a small, single dose of crystaloid K + cardioplegia. Very efficient topical cooling is achieved by a high flow (1 to 1(1/2) L/min) of continuously cooled fluid (+ 0.5 to + 2 degrees C). The great temperature-reducing capacity of the cooling system is due to a 10 to 15 meter long metal coil tube that is immersed in an ice-salt cold bath. The water pump placed in the bath makes heat exchange even more efficient. The described method of myocardial protection with stable profound myocardial hypothermia safely prolongs the ischemic time during operation to more than 2 hours. By repositioning the coil into the warm bath (39 to 40 degrees C), the whole system can be used for topical rewarming of the heart.

Journal Article↗

PubMed1984

A technique of myocardial protection during aorto-coronary bypass in high-risk patients.

In the authors' opinion, profound myocardial hypothermia is imperative in myocardial protection while the aorta is cross-clamped. They based their own protection method, beside using a single dose of crystalloid cardioplegic solution, on very efficient topical cooling, by which myocardial temperature is reduced to below 15 degrees C. Very efficient topical cooling is achieved by a high flow (2 l/min) of continuously cooled fluid (0 degrees C- +2 degrees C). The great temperature-reducing capacity of the cooling system is due to 10-15 metres long metal coil tubing which is immersed in an ice-salt cold bath. The water pump placed in the bath makes heat exchange even more efficient. The described method of myocardial protection with stable profound myocardial hypothermia safely prolongs the ischaemic time during operation to more than two hours.

Coronary Artery Bypass↗