Biomedical subjects

Gerhard Wimmer-Greinecker

Publications and source records attributed to Gerhard Wimmer-Greinecker.

At least 19 recordsLinked to original sources

PubMed2006

Minimally invasive transapical beating heart aortic valve implantation--proof of concept.

OBJECTIVE: To evaluate the feasibility of minimally invasive transapical beating heart aortic valve implantation (TAP-AVI) for high-risk patients with aortic stenosis. METHODS: TAP-AVI was performed via a small anterolateral minithoracotomy with or without femoral extracorporeal circulation (ECC) on the beating heart. A pericardial xenograft fixed within a stainless steel, balloon expandable stent (Cribier-Edwards, Edwards Lifesciences, Irvine, CA, USA) was used. Thirty consecutive patients (82 +/- 5.1 years, 21 (70%) female) were operated from 02/06 until 09/06 at one center using fluoroscopic and echocardiographic visualization. Average EuroSCORE predicted risk for mortality was 27 +/- 12%. RESULTS: Valve positioning was successful in 29 patients and one required early conversion to full sternotomy. Implantation (8 mm x 23 mm and 22 mm x 26 mm valves) was performed on the beating heart during brief periods of rapid ventricular pacing. ECC was applied in 13 patients. Neither coronary artery obstruction nor migration of the prosthesis was observed and all valves displayed good hemodynamic function. Echocardiography revealed minor paravalvular leakage in 14 patients (trace in three, mild in nine and moderate in two). Three patients (10%) died, one on postoperative day (POD) three secondary to preoperative global myocardial failure and two on POD 18 and 86 due to abdominal complications. CONCLUSIONS: Minimally invasive beating heart TAP-AVI is feasible. Initial results are encouraging in view of the high-risk profile of the patients. Long-term studies as well as randomized protocols are required.

Aged↗

PubMed2006

Transapical approach for sutureless stent-fixed aortic valve implantation: experimental results.

OBJECTIVE: Percutaneous aortic valve implantation has been performed in patients with severe aortic stenosis judged as nonsurgical candidates. We evaluated a facilitated transapical antegrade approach for potential use in surgical high-risk patients. METHODS: A pericardial xenograft fixed within a 23-mm stent (Cribier-Edwards aortic prosthesis, Edwards Inc., Irvine, CA, USA) was implanted using a transapical approach in fifteen 35-45 kg pigs. A limited or a full sternotomy was used to transapically introduce a crimped valve through a 24-F sheath. Deployments were performed on the beating heart either with ventricular unloading using femoro-femoral cardiopulmonary bypass (CPB) or rapid ventricular pacing (RVP), all under fluoroscopic and echocardiographic visualization. RESULTS: All valves were successfully deployed at the target site with acceptable visualization of the noncalcified annulus. Valve migration occurred in six procedures (three distal and three retrograde) secondary to inadequate reduction of ventricular output, unfavorable annular anatomy, excessive crimping of the valve, and dislodgement by the delivery balloon. Exact positioning of the valve into the target area was confirmed by autopsy at the end of the procedures. Paravalvular leak was noted in five implants. CONCLUSIONS: The transapical approach provides a safe, accurate, and effective route for facilitated antegrade delivery of a stent-fixed valve. Advanced stent design will lead to better stability of the implant and may minimize the risk of paravalvular leakage in future. Identifying the appropriate population for human feasibility trials remains a challenge.

Animals↗

PubMed2006

[Endovascular interventions of the descending thoracic aorta].

Endovascular interventions of the descending thoracic aorta have been established as an alternative to conventional open surgery. Initially, they were limited to elective patients with a high risk profile for open surgery, but soon their use was extended to emergencies as well. In the elective setting, endovascular interventions significantly lowered short-term morbidity and mortality. These excellent perioperative results were reproducible in the emergency setting, thereby leading to superior outcomes for patients treated by endovascular stent grafts when compared to the conventional open surgical approach. However, some questions regarding long-term durability of these devices remain unanswered. Stent-graft failures at mid and long-term follow-up have been reported in the literature. The progressive nature of stent graft-related mid- and long-term complications stresses the need for continued surveillance of these patients.

Aortic Dissection↗

PubMed2006

[Indication, technique, and results of aortic valve and ascending aorta reconstruction].

Aortic valve replacement is the standard procedure in patients with aortic valve regurgitation (AR). Although long-term results for both biological and mechanical heart valves could be improved, a valve-sparing operation has several advantages especially in young patients. Alterations in the geometry of the aortic root, especially dilatation of the sinutubular junction, are the primary cause of AR in patients with aneurysms of the ascending aorta. In patients with a bicuspid aortic valve, AR is usually caused by a prolapse; with appropriate surgical experience, the prolapse can be corrected and the valve reconstructed. Isolated reconstruction of a tricuspid aortic valve such as decalcification, commissurotomy or plication of ring or leaflets are seldom indicated. The recontstructive techniques for aortic root aneurysms or type A dissection described by David and Yacoub have become routine procedures over the last decade. The long-term clinical results are excellent, and revision and thromboembolism rates are very low. A maximal diameter of the aortic root > 5 cm is indicative for performing the above procedures. This technique has been used in the own clinic since 1996 with excellent clinical and echocardiographic results. Only four of 101 patients operated had a moderate AR during the follow-up period. The reconstruction of a prolapse in a bicuspid aortic valve is possible by using an autologous, fixed pericardial patch, with very good long-term results. By using this surgical technique, two geometrically correct pockets with a broad coaptation zone can be constructed. In 36 of the patients operated in the own clinic, only four patients showed grade I AR. No patient had to undergo reoperation. An aortic valve reconstruction for an isolated leaflet perforation following a healed endocarditis is seldom indicated.In the authors' opinion, valve-sparing reconstruction in cases of aneurysms of the ascending aorta, and for bicuspid valves, represents a promising alternative to prosthetic valve replacement. With low surgical mortality and morbidity, excellent clinical and functional long-term results can be achieved. Furthermore, the lack of the necessity of anticoagulation as well as positive hemodynamic factors argue for a valve-sparing surgical technique. A final evaluation of the method is not possible, however, until long-term follow-up of up to 20 years is available and the positive results have been confirmed.

Adult↗

PubMed2006

Left ventricular remodeling impacts the function of the Quattro stentless mitral valve bioprosthesis (a 4-year experience).

OBJECTIVE: The St Jude Quattro stentless mitral valve prosthesis (QMV) is sutured to the mitral annulus and the papillary muscle heads, thereby preserving the subvalvular apparatus. After mitral valve replacement, remodeling of the left ventricle is often observed, causing a dilated ventricle to shrink in diameter. It was our objective to assess these changes in left ventricular (LV) geometry and evaluate its effects on the function of the QMV. METHODS: From September 1997 to October 2000, 24 patients received QMV at our institution. The patients were followed up at yearly intervals (mean 4.1 +/- 2.2 years). All pre- and postoperative echocardiograms were evaluated, with attention focused on the subvalvular apparatus, leaflet morphology, and occurrence of late mitral regurgitation. In addition, all clinical outcomes and valve-related complications were recorded. RESULTS: Forty-one percent of patients (10/24) developed late mitral regurgitation (mild, n = 5; moderate, n = 5). The site of regurgitation was located at the 2 commissures in all cases. In 8 patients, changes in LV diameter had occurred. The point of leaflet coaptation had shifted away from the annulus in 4 patients. The overall mortality was 12.3%, and the postoperative stroke rate was 12.3%. CONCLUSIONS: Midterm changes in LV geometry seem to affect the competence of the QMV. Predicting these changes and subsequently adapting the sizing procedure remain a challenging task. The high rate of late valve incompetence and poor clinical outcomes has prompted us to discontinue recruitment of patients for this trial.

Bioprosthesis↗

PubMed2006

Two hundred forty minimally invasive mitral operations through right minithoracotomy.

BACKGROUND: This study reports of our 7-year experience with minimally invasive mitral valve operations using the transthoracic clamp technique, reviewing morbidity and mortality as well as echocardiographic follow-up results. METHODS: Between 1997 and 2004, 241 patients (121 male; aged 56 +/- 14 years) underwent minimally invasive mitral valve surgery through right thoracotomy using the transthoracic clamp technique. Reconstructions were done in 199 patients, and 42 valves were replaced. Mean length of incision was 7.0 +/- 1.2 cm. Mean preoperative New York Heart Association functional class was 2.6 +/- 0.9. RESULTS: Thirty-day mortality was 3.3% (n = 8). Operating, bypass, and cross-clamp times averaged 241 +/- 52, 142 +/- 40, and 84 +/- 26 minutes, respectively. Seven patients (2.9%) had conversion to sternotomy. Nine patients (3.7%) underwent reexploration for bleeding. Mean intensive care unit and hospital stay were 18 hours and 8.1 days, respectively. Mean follow-up was 30 +/- 18 months (range, 3 to 76). Echocardiographic follow-up documented persistently competent valve function in all but 6 patients who had grade III regurgitation. Five of them underwent mitral valve re-reconstruction and 1 underwent transplantation. At 76 months, freedom from nontrivial recurrent mitral regurgitation and reoperation were 92.3% and 96.2%, respectively. Actuarial survival at 76 months, including early mortality, was 90.7%. Thoracic wounds were free from infection in all patients. CONCLUSIONS: This study demonstrates that the direct vision, transthoracic clamp technique for minimally invasive mitral valve surgery is reproducible with low mortality and morbidity rates. It results in excellent cosmesis and abolished the risk of thoracic wound infection. Results are comparable to midterm outcomes of conventional operations.

Adolescent↗

PubMed2006

Transapical aortic valve implantation: an animal feasibility study.

BACKGROUND: Percutaneous aortic valve implantation has recently been performed in nonsurgical patients with severe aortic stenosis. Retrograde valve delivery has been problematic because of the size of the delivery system and concomitant peripheral vascular disease. We investigated a minimally invasive approach through the left ventricular apex for antegrade placement of a device-deliverable valve. METHODS: Transapical aortic valve implantation was performed using a 23-mm equine valve mounted on a stainless steel stent in 24 swine (weight range, 35 to 45 kg). A limited or full sternotomy approach was used to access the apex of the heart. The crimped valve was introduced through a sheath in the left ventricular apex. Fluoroscopy and echocardiography were used for guidance. Deployments were performed on the beating heart either with ventricular unloading using femoral extracorporeal circulation or rapid ventricular pacing. RESULTS: All valves were successfully delivered at the selected target site with acceptable visualization of the noncalcified aortic annulus. Valve migration occurred during eight deployments (two distal and six retrograde) secondary to persistent cardiac output, unfavorable annular anatomy, and dislodgement by the delivery catheter. Exact positioning of the nonmigrated valves at the aortic annulus was examined by necropsy of all animals at the end of the procedures. Paravalvular leak was noted in 14 of 18 (77.8%) valves remaining in situ. CONCLUSIONS: The transapical approach was used for the successful antegrade placement of a stented valve, obviating the technical problems associated with a large delivery system transiting the peripheral vascular system. Stent design contributing to paravalvular leak remains problematic.

Animals↗

PubMed2006

Navigation-based needle puncture of a cadaver using a hybrid tracking navigational system.

PURPOSE: The purpose of this study was to determine the puncture accuracy of a navigational system, Medarpa, in a soft tissue environment using augmented overlay imaging. MATERIALS AND METHODS: Medarpa is an optical electromagnetic tracking system, which allows tracking of instruments, the radiologist's head position, and the transparent display. The display superimposes a computed tomography scan of a cadaver chest on a human cadaver in real time. In group A, needle puncture was performed using the Medarpa system. Three targets located inside the cadaver chest were selected. In group B, the same targets were used to perform standard computed tomography-guided puncture using a single-slice technique. A total of 42 punctures were performed in each group. Postpuncture computed tomography scans were made to verify needle tip positions. RESULTS: Mean deviation from targets was 8.42 mm +/- 1.78 mm for group A and 8.90 mm +/- 1.71 mm for group B. No significant difference was found between group A and B in any target (P > 0.05). No significant difference was found between the targets of the same group (P > 0.05). Procedural time for 42 punctures was 160 minutes in group A versus 289 minutes in group B (P < 0.05). CONCLUSION: Needle puncture in a soft tissue environment using the navigational system Medarpa can be reliably performed and matches the accuracy achieved by a computed tomography-guided puncture technique.

Biopsy, Needle↗

PubMed2006

The use of minimized extracorporeal circulation system has a beneficial effect on hemostasis--a randomized clinical study.

BACKGROUND: Conventional cardiopulmonary bypass (CPB) is associated with increased coagulation and fibrinolytic activity. A closed miniaturized bypass circuit (CorX) features a significantly reduced tubing set, an integrated pump, and an air removal system without a cardiotomy reservoir. In a prospective randomized trial, the effects on hemostasis were investigated while comparing CorX with conventional CPB in patients undergoing coronary artery bypass grafting. METHODS: Over a period of 1 year, 81 patients were randomly assigned either to the CorX system (n = 39, group A) or standard CPB system (n = 42, group B). Primary endpoints were platelet count, plasmin-antiplasmin complex (PAP), prothrombin fragments 1+2 (F1+F2), D-dimers, and fibrinogen. Secondary end-points were hematocrit, blood loss in the first 12 hours postoperatively, transfused packed red blood cells, and fresh frozen plasma in the first 24 hours postoperatively. In addition, we analyzed partial thromboplastin time, prothrombin time, and antithrombin III. RESULTS: After aortic declamping, PAP complex and prothrombin F1+F2 were significantly lower in group A than in group B. The difference in D-dimers between groups reached significance at 1 hour post-CPB. Hematocrit values at the end of CPB measured 26 +/- 6% in group A versus 22 +/- 4% in group B (P = .01). The rest of the observed parameters did not significantly differ between groups. CONCLUSION: Postoperative blood loss was not reduced in the present study. However, the use of the CorX system leads to a significant suppression of activation of coagulation and fibrinolytic cascades compared to conventional CPB, suggesting that miniaturized extracorporeal circuits are a step forward toward reduced imbalance of hemostasis in cardiac surgery.

Aged↗

PubMed2005

Disseminated Aspergillus fumigatus infection with consecutive mitral valve endocarditis in a lung transplant recipient.

Aspergillus infection is a known complication of lung transplantation and remains associated with high mortality rates. The manifestation of the infection varies from simple colonization of the lung to disseminated complicated infections. Early Aspergillus infection has been rarely observed in a small number of lung transplant recipients; most cases occur during the late post-operative period. The pulmonary involvement has often been described as the first clinical localization of the disease. Although other various forms of Aspergillus infection are not uncommonly encountered after lung transplantation, Aspergillus mitral valve endocarditis is rare. We present a case of disseminated Aspergillus fumigatus infection with consecutive mitral valve endocarditis having developed 78 days after double-lung transplantation for cystic fibrosis.

Adult↗

PubMed2005

Degradation of microvascular brain endothelial cell beta-catenin after co-culture with activated neutrophils from patients undergoing cardiac surgery with prolonged cardiopulmonary bypass.

The adhesion of highly activated neutrophils to cerebral microvascular endothelial cells (MVECs) may contribute to disruption and hyperpermeability of the blood-brain barrier (BBB) after cardiac surgery with prolonged cardiopulmonary bypass (CPB). A correlation between CPB duration and neutrophil-mediated BBB damage has not been investigated on the cellular level yet. Therefore, we studied the effects of neutrophils from cardiac surgery patients with CPB time <80 min (group I; n=8) and >80 min (group II; n=8) on the integrity of cultured porcine MVEC. Ex vivo, neutrophils of group II but not of group I significantly degraded the zonula adherens molecule beta-catenin whereas VE-cadherin and occludin were not modified. The transendothelial electric resistance as a measure for the integrity of the endothelial monolayers was reduced over time in both groups. In conclusion, prolonged CPB time entails neutrophil-mediated decrease in MVEC beta-catenin expression, and thus may be an important trigger for BBB disruption.

Animals↗

PubMed2005

Aortic leaflet replacement with the new 3F stentless aortic bioprosthesis.

PURPOSE: Clinical trials with the new 3F stentless aortic bioprosthesis began October 2001, and as one of the first centers to implant this prosthesis in humans, we would like to present our experiences with this new device. DESCRIPTION: The 3F aortic bioprosthesis is a stentless biological heart valve fabricated from three equal leaflets of equine pericardium, assembled in a tubular shape, and implanted in the native aortic root to replace the patient's diseased aortic leaflets. Between January 2002 and August 2002, 24 3F aortic bioprostheses were implanted at our institution. Effective orifice area, mean gradients, and ejection fraction were evaluated by echocardiography at discharge and at 12-month follow-ups after surgery. EVALUATION: At 12-month follow-ups, the 3F bioprosthesis showed a good hemodynamic performance with a significant drop of mean gradients to 10.3 mm Hg, a mean effective orifice area of 1.7 cm2, and a mean ejection fraction of 61.5%. CONCLUSIONS: The clinical performance of the new 3F aortic bioprosthesis is comparable with regular stentless aortic valves. However its unique design facilitates implantation.

Adult↗

PubMed2005

Minimally invasive port access versus conventional mitral valve surgery: prospective randomized study.

BACKGROUND: We compared the port access mitral valve surgery with the conventional procedure through median sternotomy in a prospective randomized study. METHODS: Forty elective patients with mitral valve disease were prospectively randomized to undergo minimally invasive (group I) or conventional (group II) mitral valve operation. The patients of group I had limited access through right small anterior thoracotomy and a femorofemoral cardiopulmonary bypass system using the endoclamp technique. To assess the efficiency and safety of the procedure, intraoperative and postoperative clinical data and markers of myocardial, cerebral, and lower limb ischemia were collected. Pulmonary function tests were performed to compare the preservation of pulmonary function. Neuropsychological tests were conducted for quantification of neurological and cognitive disorders. RESULTS: Mitral valve reconstructions were performed in 28 patients (70%) in both groups. Intraoperative procedure-associated problems were experienced in 9 patients (45%) in group I, and 6 of them (30%) had to be converted to direct transthoracic aortic clamping. Markers of myocardial and cerebral damage as well as pulmonary and neuropsychological tests did not show statistically significant difference between groups. CONCLUSIONS: The minimally invasive port access technique for mitral valve surgery can be done with similar clinical safety as procedures through median sternotomy. The problems with endoclamping have forced us to change our practice to the more simple and economic transthoracic aortic clamping technique.

Cardiopulmonary Bypass↗

PubMed2005

Initial experience with a minimized extracorporeal bypass system: is there a clinical benefit?

BACKGROUND: Drawbacks of conventional cardiopulmonary bypass (CPB) are increased inflammatory response, deteriorated coagulation and systemic organ dysfunction. A closed extracorporeal circuit (CorX) features reduced foreign surface area and priming volume. Potential benefits were studied in comparing the CorX system with conventional CPB in arrested heart coronary artery bypass grafting (CABG). METHODS: Two hundred and four patients were randomly assigned either to CorX system (n = 101, group A) or a standard CPB with cardiotomy reservoir (n = 103, group B). Besides evaluation of perioperative data and routine blood samples, we focused on lung function and perioperative bleeding. Polymorphonuclear elastase (PMNE) and terminal complement complex (TCC) served to assess inflammatory response. RESULTS: Patient demographics and operative data did not differ between groups. Postoperative lung function was not significantly impaired comparing groups A and B. Intraoperative blood loss was significantly higher in group A compared with group B (1245 +/- 947 mL vs 313 +/- 282 mL, p < 0.0001) as well as the need of fresh frozen plasma. Postoperative chest drainage did not differ significantly between groups. Two patients in each group required re-exploration due to bleeding. One hour after CPB, PMNE as well as TCC were significantly lower in group A compared with group B (PMNE: 76 +/- 44 ng/mL vs 438 +/- 230 ng/mL, p < 0.0001; TCC: 16 +/- 8 IU/mL vs 29 +/- 19 IU/mL, p < 0.0001). CONCLUSIONS: The CorX system is safe and feasible in patients undergoing CABG. Despite of markedly reduced inflammatory reaction, no clinical benefit was observed.

Aged↗

PubMed2005

Do pulmonary autografts provide better outcomes than mechanical valves? A prospective randomized trial.

BACKGROUND: The objective of this study was to compare the performance of pulmonary autografts with mechanical aortic valves, in the treatment of aortic valve stenosis. METHODS: Forty patients with aortic valve stenoses, and below the age of 55 years, were randomly assigned to receive either pulmonary autografts (n = 20) or mechanical valve (Edwards MIRA; Edwards Lifesciences, Irvine, CA) prostheses (n = 20). Clinical outcomes, left ventricular mass regression, effective orifice area, ejection fraction, and mean gradients were evaluated at discharge, 6 months, and one year after surgery. Follow-up was complete for all patients. RESULTS: Hemodynamic performance was significantly better in the Ross group (mean gradient 2.6 mm Hg vs 10.9 mm Hg, p = 0.0005). Overall, a significant decrease in left ventricular mass was found one year postoperatively. However, there was no significant difference in the rate and extent of regression between the groups. There was one stroke in the Ross group and one major bleeding complication in the mechanical valve group. Both patients recovered fully. CONCLUSIONS: In our randomized cohort of young patients with aortic valve stenoses, the Ross procedure was superior to the mechanical prostheses with regard to hemodynamic performance. However, this did not result in an accelerated left ventricular mass regression. Clinical advantages like reduced valve-related complications and lesser myocardial strain will have to be proven in the long term.

Aortic Valve Stenosis↗

PubMed2005

Decreased intermediate term patency of automated proximal anastomoses evaluated by sequential ultrafast CT.

OBJECTIVE: The Symmetrytrade mark aortic connector creates proximal anastomoses of saphenous vein grafts using a nitinol implant. The device avoids partial clamping and thus possibly reduces neurologic complications. To evaluate graft patency, a single surgeon randomised study was performed in our institution. METHODS: Seventy-seven patients were randomised either to automated proximal anastomoses (group I, n=39, 61 vein grafts connected using the aortic connector, 47 as single, 15 as sequential bypasses) or controls (group II, n=38, 62 proximal anastomoses handsewn, 46 as single, 16 as sequential bypasses). Ultrafast CT-scans were performed on postoperative day 5 in 34 patients of group I and 16 patients of group II to evaluate early graft patency. Intermediate term patency was evaluated with ultrafast CT-scan in 30 patients of group I (46 grafts) and 25 patients of group II (39 grafts) 1 year after the operation. RESULTS: Two early graft occlusions were detected in group I (3.8%). In group II all evaluated grafts were patent 5 days after surgery. 11.4 months after surgery, seven out of 46 grafts were found occluded (15.2%) in group I. In the control group, only one occlusion was detected (2.6%). CONCLUSIONS: We observed a trend towards an increased occlusion rate 1 year after surgery with automated connector devices. For evaluation of long-term patency larger patient groups have to be evaluated. Other benefits of these devices have to be proven to promote their clinical application.

Adult↗

PubMed2005

Closure of atrial and ventricular septal defects should be performed by the surgeon.

Surgeons look back on 57 years of experience in the closure of atrial septal defects (ASDs) and 46 years in the closure of ventricular septal defects (VSDs). The transcatheter approaches to repair ASDs started first in the 1980s and for VSDs 8 years later. This study sought to reveal the surgical features only given by the surgical therapy and the limitation of interventional ASD and VSD closure. A variety of surgical techniques including the minimal invasive techniques for ASD or VSD closure are well described in recent publication with good results. The surgical trend is to improve the cosmetic outcome by minimizing the size of skin incision. The latest robotically assisted technique requires only four stab wound incisions. New techniques and devices have revolutionized the transcatheter technique but could not achieve the surgical ability to close all types of ASD or VSD, control arrhythmias, and correct additional valve disease or malformation. The mortality for interventional and surgical procedures approaches zero in recent publication. The residual shunting after surgical closure of ASD varies from 2% to 7.8% versus 5% to 33% after interventional closure. General complications caused by the surgical procedure are negligible; however, the shortness of hospital stay and the cosmetic appeal is an advantage of interventional ASD closure. There is no scientific comparison of surgical vs. interventional VSD closure yet.

Cardiac Catheterization↗

PubMed2005

Valve opening and closing dynamics after different aortic valve-sparing operations.

BACKGROUND AND AIM OF THE STUDY: Aortic valve resuspension for ascending aortic aneurysm repair is associated with removal of the sinus of Valsalva. This may cause changes in leaflet motion and thus impact on long-term durability. The opening and closing characteristics of the aortic valve leaflets after reimplantation were studied using a published technique and a modification to create a 'neosinus', and the results compared to those of an age-matched control group. METHODS: Between September 1995 and March 2002, 25 patients underwent normal aortic root reconstruction (group A), while in a further 21 patients the modified neosinus technique was used (group B). In both groups, the native valve was preserved and suspended inside a tubular prosthesis, with reimplantation of the coronary arteries. Transthoracic and transesophageal studies of aortic valve dynamics were performed intraoperatively, before hospital discharge, and at one year after surgery in all patients; the data were compared with those from a separate group of 25 matched control individuals (group C). RESULTS: The valve opening velocity was 61.3+/-20.1, 46.3+/-8 and 29.2+/-9.8 cm/s in groups A, B and C, respectively (group A versus B, p = 0.003; A versus C, p <0.0001; B versus C, p <0.0001). Closing velocity was increased to 57.5+/-23 and 43.8+/-7 cm/s in groups A and B, compared to 23.6+/-7 cm/s in group C (A versus B, p = 0.012; A versus C, p <0.0001; B versus C, p = 0.0002). In seven group A patients, the leaflets touched the prosthetic wall during systole. Slow systolic closing displacement (SCD) amounted to 7.3+/-6 % of maximal opening in group A and 12.6+/-5 % in group B (p = 0.05), compared to 21.1+/-8.3% in group C (group A versus group C, p <0.0001; B versus C, p = 0.002). CONCLUSION: Reimplantation of the natural aortic valve in a prosthetic graft causes abnormally high opening and closing speeds, with possibly increased stress. The study results showed lower valve opening and closure dynamics after the creation of a sinus bulge compared to the conventional reimplantation technique. However, mid-term clinical observations showed favorable valve competence for both types of repair. Further long-term follow up is necessary to prove whether more physiological leaflet dynamics lead to improved durability.

Adolescent↗