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ABSTRACT: The use of homografts for aortic valve replacement (AVR) is an alternative to mechanical or biological valve prostheses, especially in younger patients. This retrospective comparative study evaluated our single-center long-term results, with a focus on the different origins of the homografts.
Since 1992, 366 adult patients have undergone AVR with homografts at our center. We compared 320 homografts of aortic origin and 46 homografts of pulmonary origin. The grafts were implanted via either a subcoronary technique or the root replacement technique. We performed a multivariate analysis to identify independent factors that influence survival. Freedom from reintervention and survival rates were calculated as cumulative events according to the Kaplan-Meier method, and differences were tested with the log-rank test.
Overall mortality within 1 year was 6.5% (21/320) in the aortic graft group and 17.4% (8/46) in the pulmonary graft group. In the pulmonary graft group, 4 patients died from valve-related complications, 1 patient died after additional heterotopic heart transplantation, and 1 patient who entered with a primary higher risk died from a prosthesis infection. Two patients died from non-valve-related causes. During the long-term follow-up, the 15-year survival rate was 79.9% for patients in the aortic graft group and 68.7% for patients in the pulmonary graft group (P = .049). The rate of freedom from reoperation was 77.7% in the aortic graft group and 57.4% in the pulmonary graft group (P < .001). The reasons for homograft explantation were graft infections (aortic graft group, 5.0%; pulmonary graft group, 6.5%) and degeneration (aortic graft group, 7.5%; pulmonary graft group, 32.6%).
Our study demonstrated superior rates of survival and freedom from reintervention after AVR with aortic homografts. Implantation with a pulmonary graft was associated with a higher risk of redo surgery, owing to earlier degenerative alterations.
Heart Surgery Forum 08/2011; 14(4):E237-41. · 0.63 Impact Factor
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ABSTRACT: Studies carried out to date suggest that the interrupted suture technique using U-Clips for anastomoses in coronary surgery may be superior to the standard running polypropylene suture. The purpose of this study was to compare safety and effectiveness of a central T-graft anastomosis constructed with the left internal thoracic artery (LITA) in situ (to the left anterior descending (LAD)) in which the free right internal thoracic artery (to the circumflex branch of the right coronary artery (RCX)) was implanted (RITA-to-LITA) using either self-closing nitinol U-Clips or simple continuous suture. We hypothesized that internal thoracic arteries could adapt their diameter to the blood flow.
Thirty patients underwent total arterial revascularization using a T-graft constructed with free LITA in situ to LAD in which the free RITA to the circumflex artery was implanted (central T-graft anastomosis). In all cases, free RITA was used as a sequential graft with two peripheral anastomoses. Patients were randomly assigned to two groups: in group A (n=15), central T-graft anastomosis was performed using a standard 8/0 polypropylene running suture. In group B (n=15), central T-graft anastomosis was performed using U-Clips. Intra-operative transit time flow measurements were recorded. Patency control was performed in 30 patients 2 weeks and 6 months postoperatively, using 64-slice computed tomography (CT) angiography. The diameter of the LITA was measured proximal and distal and the diameter of the RITA distal to the central T-graft anastomosis.
Perioperative results were similar in the two groups (P=ns). Intra-operative transit time flow measurement showed patent grafts in all patients. There were no hospital deaths. Two weeks postoperatively, all grafts were patent. At 6-month follow-up, one RITA and one LITA (both in group B) were closed distal to the central T-graft anastomosis. There was no death and no re-intervention during follow-up. Statistical analysis showed no significant changes in graft diameters after 2 weeks and 6 months in both groups.
The U-Clip anastomosis technique is in our experience safe but not superior to the standard running suture using polypropylene material. Remodeling of the ITA grafts close to the central T-graft anastomosis was neither observed for the standard running suture nor for the U-Clip anastomoses.
European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 04/2011; 40(2):e93-7. · 2.40 Impact Factor
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ABSTRACT: Minimizing operative risks for the surgical team in infectious patients is crucial. We report on a patient suffering from Hepatitis C undergoing re-operative aortic valve and ascending aorta replacement for aortic aneurysm and paravalvular leakage due to recurrent endocarditis of a Smeloff-Cutter aortic ball prosthesis. Preoperative multi-slice computed tomography and real-time three-dimensional echocardiography proved helpful in changing operative strategy by detecting a previously unknown aortic aneurysm, assessing its extent, and demonstrating the close proximity of the right coronary artery, right ventricle, and the aortic aneurysm to the sternum. Thus, cardiopulmonary bypass was instituted via the femoral vessels, instead of conventionally. Location, morphology, and extent of the paravalvular defect could also be assessed.
Therapeutics and Clinical Risk Management 08/2009; 5(4):409-12.
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ABSTRACT: Aortic valve replacement (AVR) in younger patients is conventionally performed using a mechanical prosthesis (MP), although homograft (HG) implantation is an accepted alternative. This study compares, retrospectively, the follow up of these two dissimilar prostheses.
Since 1990, a total of 147 Sorin Bicarbon MPs and 285 HGs have been implanted at the authors' institution, and compared statistically for survival, reoperation rate and valve-dependent complications. Only patients aged <70 years were included in the study.
The demographic parameters of both patient groups differed with regards to gender, age at the time of implantation, and duration of follow up. Survival was superior in the HG group (log-rank, p = 0.01). Sixteen of 42 late deaths in the MP group were valve-related due to cerebral infarction (n = 7), ventricular arrhythmias (n = 3), or ventricular failure (n = 6). Six of 24 deaths after HG implantation were valve-related (all prosthesis infections). The choice of valve type and patient age were independent risk factors in the multivariate analysis. Freedom from reoperation was superior after MP implantation (log rank, p = 0.007); in six MP patients the indications for redo surgery were prosthesis infection (n = 2) and paravalvular leak (n = 4). In 20 HG patients, redo surgery was required due to prosthesis infection (n = 12), stenotic degeneration (n = 2), regurgitation > grade II (n = 4), or paravalvular leak (n = 2). Age at the time of implantation and valve type were independent risk factors. Thromboembolic complications were mainly seen in MP patients (log rank, p <0.001): there were five ischemic infarctions and 11 transient ischemic attacks (TIAs) compared to three TIAs among HG patients. Cerebral bleeding was found in only 18 cases after MP implantation, and in no cases after HG implantation. In the multivariate analysis, the type of prosthesis was an independent risk factor.
As expected, these data confirm a longer time period without need for reoperation after MP implantation, but demonstrate a significantly higher survival and fewer complications after AVR with HG.
The Journal of heart valve disease 07/2007; 16(4):404-9. · 0.81 Impact Factor
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ABSTRACT: The DeBakey Surgitool mechanical aortic valve prosthesis was the first mechanical prosthetic valve in which pyrolitic carbon was used. This valve was on the market from 1969 to 1978 and approximately 3300 valves were implanted in this lapse worldwide.
We present a DeBakey Surgitool mechanical aortic valve prosthesis implanted in 1972, which has been functioning for almost 34 years and still presents a good performance.
Spontaneous strut fractures associated with haemodynamic complications and death, even in asymptomatic patients, was the reason to withdraw this prosthetic valve from the market. However, a prophylactic replacement of DeBakey Surgitool valve was not indicated in our patient due to the excellent prosthesis compliance.
Interactive cardiovascular and thoracic surgery 11/2006; 5(5):637-9.
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ABSTRACT: The magnetic vascular positioner (MVP), a device for distal bypass anastomosis in coronary surgery, was developed to allow a simple and rapid procedure and to improve graft patency. We analyze our mid-term results with this device.
Eighteen distal anastomoses were performed by using the MVP, and 18 with a hand-sewn technique were completed in 11 patients. The target arteries for the MVP anastomosis were the left anterior descending in 9 patients, a marginal branch in 4, a diagonal branch in 3, and right coronary artery in 2. The left internal thoracic artery was used as graft in 9 patients, saphenous vein in 6, right internal thoracic artery in 2, and radial artery in 1.
Coronary angiography was performed at discharge and after a complete follow-up of 19 +/- 3.5 months. Patency at follow-up was 83.3% (15/18) for MVP anastomoses and 100% (18/18) for hand-sewn anastomoses. All occluded MVP anastomoses were performed with small-size devices. In one patient, a high-grade left main stenosis was overestimated. Competitive flow may be suspected in this case as a cause of graft occlusion. No deaths occurred during hospital stay or during follow-up. Freedom from reintervention was 100%.
The MVP is the only mechanical connector for distal anastomoses applicable for all kind of grafts, for all coronary artery locations, and with both end-to-side and side-to-side technique. Mid-term patency of MVP anastomoses is acceptable but inferior to the patency of hand-sewn anastomoses. Occlusion of MVP supplied grafts may be produced by small device size.
The Annals of thoracic surgery 11/2006; 82(4):1452-6. · 3.74 Impact Factor
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The Annals of thoracic surgery 02/2006; 81(1):407-8. · 3.74 Impact Factor
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ABSTRACT: Mechanical circulatory support is successfully applied to patients with low cardiac output. The MEDOS/HIA-System provides pulsatile ventricular assistance for pediatric and adult patients. Our experience with 13 consecutive patients with the MEDOS is reported. Perioperative survival was 84.6%, complications occurred in 61% (31% thrombembolism, 23% rethoracotomy, 7% infections). Mean duration of support was 17.6 +/- 14.6 days (1-45 days). Bilirubin decreased from 3.9 +/- 2.3 to 2.7 +/- 1.6 mg/dL; creatinine from 1.6 +/- 1 to 1.4 +/- 0.8 mg/dL; lactate from 5.8 +/- 4.2 to 1.7 +/- 1.5 (P = 0.027; Wilcoxon). All patients who underwent subsequent heart transplantation (6 of 13; 46%) were discharged from hospital. For 38.5% of the patients no organ offer was received. Mechanical circulatory support with the MEDOS/HIA-System can be performed successfully for bridging to transplantation. Secondary organ functions improve under this pulsatile circulatory assistance. Hemorrhage and thromboembolic events are the most frequent complications.
Artificial Organs 11/2005; 29(10):857-60. · 2.00 Impact Factor
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Journal of Thoracic and Cardiovascular Surgery 09/2005; 130(2):605-6. · 3.41 Impact Factor
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ABSTRACT: The main goals in the development of an anastomotic device are to reduce the invasiveness of the procedure and to improve graft patency. We analyze our preliminary clinical experience with the Ventrica magnetic vascular positioner (MVP) series 6000 system.
Eighteen distal anastomoses were performed in 11 patients using the MVP.
The target artery for MVP was left anterior descending in 9 patients, a marginal branch in 4, the first diagonal branch in 3, and the right coronary artery in 2. Graft material was the left internal thoracic artery in 9 patients, saphenous vein in 6, the right internal thoracic artery in 2, and the radial artery in 1 case. Fifteen anastomoses were performed in an end-to-side and 3 in a side-to-side fashion. Predischarge angiography was performed in 10 of 11 patients. There was a patent MVP anastomosis in all patients.
Distal anastomoses using the MVP were performed successfully in all patients. The procedure is simple. Short-term patency is excellent. Further randomized trials are necessary to determine long-term safety and patency.
The Annals of thoracic surgery 06/2005; 79(5):1738-42; discussion 1742-3. · 3.74 Impact Factor
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ABSTRACT: The HEARTSTRING is a device designed to enable the creation of a clampless hand-sewn proximal anastomosis.
Seventy-six patients who underwent myocardial revascularization had 113 proximal anastomoses created by the HEARTSTRING. Fifty-five procedures were performed on cardiopulmonary bypass and 21, off pump.
Of 114 intended proximal anastomoses, 113 (99.1%) were successfully performed using the HEARTSTRING. The conduits anastomosed proximal with support of the HEARTSTRING were in 92 cases saphenous veins and in 21 cases radial arteries. Mean time to perform a HEARTSTRING-supported anastomosis was 6.6 +/- 1.2 minutes. One patient (1.3%) died postoperatively; the death was not device related. In 1 additional patient (1.3%), a stroke most likely due to air embolism occurred. Forty-nine patients (64.5%) underwent a predischarge coronary angiography (n = 20) or a contrast multislice computed tomography (n = 29). Of 76 grafts with a HEARTSTRING-supported proximal anastomosis, 74 (97.4%) were patent in these 49 patients.
Our initial clinical experience with the HEARTSTRING demonstrates safety, reliability, and ease of use. Side clamping of the ascending aorta can be avoided, potentially decreasing the incidence of neurologic complications.
The Annals of thoracic surgery 06/2005; 79(5):1732-7; discussion 1737. · 3.74 Impact Factor
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ABSTRACT: Aortic valve replacement using homografts is an accepted alternative to the use of other replacement devices, and has been established at the authors' institution for more than 10 years.
Since 1992, a total of 389 homografts was implanted, and 332 patients (mean age 54 years, 72% males) were followed up. The initial patients (n = 75) had subcoronary implantation, all subsequent patients had root replacement. Both aortic grafts (AG) and pulmonary grafts (PG) were used. Follow up was conducted with regard to the factors 'graft origin', 'implantation technique' and 'gender', and included clinical examination, ECG and transthoracic echocardiography on an annual basis.
Overall 30-day mortality was 5.4% (AG patients 3.9%, PG patients 13.5%; p = 0.09). Among late deaths (n = 22), six were valve-related (all prosthetic infection). Four minor thrombembolic events were recorded due to amaurosis fugax and transient ischemic attacks (TIA). Freedom from reoperation was 86.5%. Indication for graft replacement was greater after subcoronary implantation than after root implantation (p = 0.04). Reoperation was necessary in 24 patients due to restenosis (n = 4), regurgitation grade >II (n = 5), paravalvular leak (n = 2) and prosthetic infection (n = 13). At the latest echocardiographic follow up, mean peak pressure gradient was 15.60 +/- 11.76 mmHg, homograft regurgitation grade was 0.82 +/- 0.66, left ventricular end-diastolic diameter (EDD) was 49.1 +/- 7.54 mm, and mean aortic root diameter was 30.54 +/- 5.48 mm. When comparing parameters at a mean of five years postoperatively, the pressure gradient increased from 10.26 to 15.02 mmHg, regurgitation grade increased from 0.53 to 0.81, and EDD decreased from 52.3 to 50.4 mm. Other variables showed no significant differences.
The present results confirmed good midterm-results for aortic valve replacement with homografts. These prostheses are vulnerable to infection, and root replacement was superior to the subcoronary implantation technique.
The Journal of heart valve disease 08/2004; 13(4):554-9. · 0.81 Impact Factor
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ABSTRACT: Success of surgical therapy for atrial fibrillation (AF) mainly depends on creating a complete set of transmural atrial lesions. The established Cox procedures may be simplified by dropping lesions, but not without the risk of impaired results. We aimed to create a complete set of lesions using bipolar irrigated radiofrequency including ablation of the posterior-inferior left atrium (LA) and coronary sinus. Feasibility and safety were investigated.
Six patients (mean age 63 +/- 14 years) with continuous AF (duration 15 +/- 8 months) underwent elective heart surgery for isolated mitral valve procedures (n = 4), in combination with myocardial revascularization (n = 1) or isolated bypass surgery (n = 1). Ablation of AF was performed using bipolar irrigated radiofrequency to create a modified Cox minimaze pattern.
No major intraoperative or postoperative complication occurred. Two patients left the operating room in sinus rhythm and 4 in junctional rhythm with atrioventricular pacing. AF ablation required 20 +/- 5 minutes.
Bipolar irrigated radiofrequency ablation including ablation of the posterior-inferior LA and coronary sinus is feasible and can be performed safety. Long-term studies in large patient cohorts are necessary to show efficiency of this method.
Heart Surgery Forum 02/2004; 7(6):E535-8. · 0.63 Impact Factor
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Journal of Thoracic and Cardiovascular Surgery 11/2003; 126(4):1192-4. · 3.41 Impact Factor
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ABSTRACT: Skeletal myoblasts have been proven to survive transplantation into myocardial scar tissue. The objective of this study was to evaluate whether these cells can also be transferred into vital myocardium and maintain their ability for cell division after transplantation. In addition, an intravital fluorescence dye for marking these cells was evaluated.
Skeletal myoblasts were harvested from male Lewis rats (n = 6) and then expanded in culture. Before implantation, these cells were trypsinized and labeled using an intravital fluorescence dye (PKH-26). Syngenic myoblast transfer to recipient female Lewis rats (n = 36) was used to simulate autologous transplantation. Under general anesthesia, the rats received injections of 106 myoblasts via a subxyphoidal approach into the apex of the heart. The animals were then divided into 3 groups (n = 10 each). The animals were sacrificed at several time points, and the hearts were harvested for histologic examination: group A, 7 days postoperatively; group B, 14 days postoperatively; and group C, 28 days postoperatively. An additional group, group D (n = 6), served as a control group; these animals were injected with only cell medium. Corresponding to the study groups, 2 animals of this control group were sacrificed at each time point, and the hearts were explanted. At histological examination, 8- m sections were investigated to identify surviving stained cells. For further evaluation, the sections were stained using monoclonal antibodies against n-cam, desmin, and a- actin.
No fluorescing cells were found in any hearts of rats in the control group. Surviving fluorescing myoblasts were found in 9 of 10 hearts of groups A and C and 8 of 10 hearts of group B. Labeled myoblasts were located in the intercellular spaces between the myocardial fibers. Fibrotic or inflammatory reactions could not be identified around the injection site in any hearts of the study groups. Immunohistochemical staining results showed that the labeled cells expressed n-cam, desmin, and a-actin. The myoblasts had regained their physiologic structures and had started to form myofibers. In groups B and C, more n-cam-positive cells than labeled cells were found, indicating further cell division.
Intravital fluorescence staining with PKH- 26 dye proved to be an easy and reliable method for identifying cells after cellular transplantation. Myoblasts survived an intracardiac transfer, regaining their physiologic structures and maintaining their ability for further cell division.
The Heart Surgery Forum 02/2002; 5(4):340-4. · 0.42 Impact Factor
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ABSTRACT: After operative treatment of aortic isthmus stenoses, late complications, such as aneurysm formation or aortic restenosis, might occur, with relevant morbidity and mortality rates during open surgical reintervention. We report on the endovascular repair of a symptomatic suture aneurysm caused by an aortic isthmus restenosis by thoracic aortic stent graft implantation and additional intraoperative balloon dilatation. Based on our experience, endovascular repair of thoracic aortic aneuryms caused by native aortic isthmus stenosis or postcoarctation restenosis is a valuable treatment option, especially in symptomatic patients with an imminent risk of rupture or a difficult immediate transthoracic surgical approach. Long-term follow-up is required to assess the durability of the stent graft treatment.
Vascular 14(3):161-4. · 0.89 Impact Factor
