Aortic Root Bioprosthesis Research Articles

TCT-420 Clinical Outcomes of TAVR in Patients With Degenerative Aortic Root Bioprosthesis

TCT-420 Clinical Outcomes of TAVR in Patients With Degenerative Aortic Root Bioprosthesis

Long Term Outcomes of Freestyle Stentless Aortic Bioprosthesis: A Single Center Experience.

The study is presenting our long-term clinical results after freestyle stentless aortic root bioprosthesis replacement in patients with severe aortic insufficiency with ascending aortic aneurysm. Seventy-seven patients with ascending aortic aneurysms and aortic valve insufficiency underwent a total root replacement procedure using a stentless "Freestyle" valve (Medtronic Inc., Minneapolis, Minnesota). There were 50 (64.9%) men and 27 (35.1%) women. Mean age was 68.7 ± 11.1 years. The surgical procedure used a complete root replacement. Concomitant procedures included coronary artery bypass grafting in 15 (19.5%) patients. The mean cardiopulmonary bypass time was 130.3 ± 26.4 minutes and total aortic cross clamp time was 99.5 ± 23.6 minutes. Hospital mortality was 2.6%. The median follow-up time was 11.2 years. The 5- and 10-years freedom from aortic valve reoperation were 97.4 ± 1.2% and 93.4 ± 4.9%, respectively. During 10 years follow up, there were 14 late deaths; 4 deaths were cardiac, and 10 deaths were noncardiac. Valve-related deaths were attributable to thromboembolism in 1 patient, endocarditis in 2 patients, and congestive heart failure in 1 patient. The freestyle stentless aortic root bioprosthesis offered good clinical outcomes, in terms of survival and structural valve deterioration. The Freestyle valve is a viable option for use in patients undergoing bioprosthetic aortic valve replacement and expected desire for long-term durability.

Morphometrical and biomechanical analyses of a stentless bioprosthetic valve: an implication to avoid potential primary tissue failure.

Stentless bioprosthetic valves provide hemodynamic advantages over stented valves as well as excellent durability. However, some primary tissue failures in bioprostheses have been reported. This study was conducted to evaluate the morphometrical and biomechanical properties of the stentless Medtronic Freestyle™ aortic root bioprosthesis, to identify any arising problem areas, and to speculate on a potential solution. The three-dimensional heterogeneity of the stentless bioprosthesis wall was investigated using computed tomography. The ascending aorta and the right, left, and non-coronary sinuses of Valsalva were resected and examined by an indentation test to evaluate their biomechanical properties. The non-coronary sinus of Valsalva was significantly thinner than the right sinus of Valsalva (p < 0.01). Young's modulus, calculated as an indicator of elasticity, was significantly greater at the non-coronary sinus of Valsalva (430.7 ± 374.2kPa) than at either the left (190.6 ± 70.6kPa, p < 0.01) or right sinuses of Valsalva (240.0 ± 56.5kPa, p < 0.05). Based on the morphometrical and biomechanical analyses of the stentless bioprosthesis, we demonstrated that there are differences in wall thickness and elasticity between each sinus of Valsalva. These differences suggest that the non-coronary sinus of Valsalva is the most vulnerable and at greater risk of tissue failure. The exclusion of the non-coronary sinus of Valsalva may be beneficial to mitigate the long-term risks of tissue failure in the stentless bioprosthesis.

Successful Management of Refractory Prosthetic Vessel Infection, Prosthetic Valve Endocarditis and Mediastinitis: Report of a Case-Late Timing Caused Repeated Surgery

The patient was diagnosed with anuloaortic ectasia with localized dissection in the right Valsalva sinus. He underwent aortic root replacement with mechanical valve. But, he was re-admitted for mediastinitis. Although his serum (CRP) level was normalized for one month, his body temperature suddenly rose to 40°C. An emergency operation was performed including re-sternotomy, drainage, and irrigation. However, a proximal anastomotic site ruptured and he went into shock. Following cardiopulmonary bypass, we performed a second aortic root replacement. Therefore, the patient was operated for sternum debridement and to wrap the prosthetic vessel into an omental pedicle. Nine days after the last intervention, bleeding from the chest wound suddenly appeared and he went into shock. He was transported to the operating room to initiate cardiopulmonary bypass. During circulatory arrest, laceration was detected at the same annular position. Deep into the left ventricle, we made interrupted sutures in the left cardiac muscle. Next, we implanted a Freestyle aortic root bioprosthesis using the full root technique. After removing all former implants, another prosthetic vessel was anastomosed between the Freestyle conduit and the distal aorta, and wrapped with omental pedicle. After three weeks, his serum CRP level was normal. He remained free of infection for at least three years.

Valve-in-valve transcatheter aortic valve implantation for failing surgical aortic stentless bioprosthetic valves: A single-center experience

BackgroundValve-in-valve (ViV) transcatheter aortic implantation (TAVI) is an alternative to redo surgery for patients with a failing aortic bioprosthesis. A lack of anatomic markers may complicate the procedure. This study reports procedural and midterm outcomes of patients undergoing ViV-TAVI for failing stentless bioprostheses, at a single institution. MethodsA total of 22 consecutive patients with failing homograft (n = 17), stented porcine valve (n = 3), aortic root bioprosthesis (n = 1), or native resuspended aortic valve (n = 1) (aged 74 ± 12 years; Society of Thoracic Surgeons 30-day predicted risk of mortality score: 14% ± 8%) were treated with ViV-TAVI, between 2007 and 2014. All had severe aortic regurgitation and were highly symptomatic before TAVI: 41% had chronic kidney disease; 32% had undergone previous coronary bypass grafts; 27% had previous percutaneous coronary intervention; 14% had severe pulmonary disease; 14% had had a stroke. All underwent TAVI with a self-expanding device. ResultsThe 30-day mortality was 0%. No cases occurred of myocardial infarction, tamponade, stroke, severe bleeding, acute kidney injury, or major vascular complications. Three instances of device migration, and 1 of device embolization, occurred. Permanent pacing was required in 14%. Paravalvular aortic regurgitation was absent or mild in 19, and mild to moderate in 3. Average hospital stay was 8 ± 3 days; all patients were discharged home. Six-month and 1-year mortality was 4.8% and 14.3%, respectively. Aortic valve area and paravalvular aortic regurgitation were unchanged at 1 year. ConclusionsThe ViV-TAVI procedure may be performed in high-risk patients with a degenerate stentless bioprosthesis with low 30-day mortality, and 1-year mortality of 14.3%. Although technically challenging, owing to a lack of anatomic markers, satisfactory positioning is possible in most cases, with excellent clinical and echocardiographic outcomes.

Aortic valve repair versus replacement for aortic regurgitation: effects on left ventricular remodeling.

Left ventricular (LV) reverse remodeling after aortic valve replacement (AVR) for aortic regurgitation (AR) is associated with superior prognosis. The outcomes of valve-sparing aortic root replacement techniques on LV performance have not been compared with LV reverse remodeling in AVR. The present evaluation compared the extent of long-term LV reverse remodeling in patients with aortic root pathology and/or AR who underwent aortic valve repair (AVr) with patients who underwent AVR. A total of 226 patients (54.7 ± 14.3 years, 63% male) with AR or aortic root pathology who underwent AVr (n = 135) or AVR with the Freestyle® stentless aortic root bioprosthesis [Medtronic, Inc.; Minneapolis, Minnesota] (n = 91) were included in the present retrospective evaluation. LV volumes and ejection fraction were assessed preoperatively, postoperatively (before hospital discharge) and during follow-up. Baseline characteristics were comparable between patient groups, except for higher prevalence of bicuspid aortic valve anatomy among AVR patients (38% vs. 16%, p < 0.001). In addition, patients undergoing AVR had significantly larger LV end-diastolic and end-systolic volumes than their counterparts. After a median follow-up of 46 months (interquartile range: 17 to 78 months), both groups of patients showed a significant and sustained reduction in LV end-diastolic and end-systolic volumes, with significantly larger reduction in patients undergoing AVR. Ejection fraction decreased significantly postoperatively and improved later during follow-up similarly in both groups. The incidence of significant AR at long-term follow-up was comparable among groups (AVr: 8% vs. AVR: 7%). LV reverse remodeling occurs after AVR and AVr, reaching comparable LV volumes and function after a median of four years of follow-up.

Structural Valve Deterioration After Aortic Valve Replacement with Medtronic Freestyle Stentless Porcine Aortic Root Bioprostheses

The Medtronic freestyle aortic root bioprosthesis (Medtronic, Inc., Minneapolis, MN, USA) is a stentless valve with an effective orifice area that is larger than that observed on other bioprostheses. However, there have been sporadic reports of structural valve deterioration (SVD), such as aortic root wall rupture, leaflet tearing, and pseudoaneurysm formation. We report five cases of SVD of freestyle aortic root bioprostheses. doi: 10.1111/jocs.12235 (J Card Surg 2014;29:22-25)

Long-Term Clinical Outcomes 15 Years After Aortic Valve Replacement With the Freestyle Stentless Aortic Bioprosthesis

The Freestyle stentless aortic root bioprosthesis has excellent hemodynamics and durability through 10 years. The purpose of this report is to present clinical outcomes in a large multicenter cohort through 15 years. The multicenter evaluation of the Freestyle valve began in 1992 at 21 centers in North America and Europe. In 1997, a long-term study continued, including 725 patients from 8 of the original centers; clinical outcomes data after 10 years have continued to be collected at 6 of 8 centers. Patient age was 71.7±7.9 years. There were 402 (55.4%) men and 323 (44.6%) women. Total follow-up was 5,491.2 patient-years. There were 52 late reoperations, with explant of the bioprosthesis in 47 cases. Respective 10- and 15-year survival was 46.2%±2.3% and 25.9%±3.2%; freedom from valve-related death was 94.9%±1.5% and 92.7%±3.5%; freedom from reoperation was 92.3%±1.8% and 80.7%±5.0%; and freedom from explant owing to structural valve deterioration was 96.5%±1.3% and 83.3%±4.8%. Increased age was associated with higher risks of all-cause mortality and valve-related mortality and lower risks of reoperation and explant caused by structural valve deterioration. In this long-term, multicenter, observational study, the Freestyle stentless aortic root bioprosthesis offered good clinical outcomes in terms of survival, freedom from valve-related mortality, freedom from reoperation, and freedom from structural valve deterioration. The Freestyle valve is a viable option for use in patients undergoing bioprosthetic aortic valve replacement and for anticipated desire for long-term durability.

Transcatheter implantation of self-expanding valve for failed stentless aortic root bioprosthesis

Although repeat aortic valve replacement (AVR) remains the standard treatment for failed bioprostheses, the feasibility of transcatheter aortic valve implantation (TAVI) has also been demonstrated. We report the successful implantation of a CoreValveTM self expanding aortic prosthesis (Medtronic, Inc) in a patient with a degenerated BioConduitTM stentless valve conduit (Shelhigh, Inc). A 63 year-old man was admitted due to NYHA class IV heart failure symptoms. He had a history of triple percutaneous coronary intervention followed by AVR plus LIMA to LAD grafting. Two years after the first surgery, acute dissection of the ascending aorta occurred and the mechanical valve along with the proximal ascending aorta were replaced by a stentless 25 mm valve conduit. Postoperative mediastinitis and atrio-ventricular block warranted sternum refixation and pacemaker implantation. Another year later, the patient underwent conservative treatment for prosthetic valve endocarditis. On current admission, transthoracic and transoesophageal echocardiography (TTE, TEE) revealed left ventricle (LV) end-diastolic diameter (EDD) of 62 mm and ejection fraction (EF) of 25%. Bioprosthetic cusps were opening well but seemed perforated and had attached two additional structures of ultrasound intensity, irregular shape and high mobility corresponding to organised bacterial vegetations. Consequently, severe aortic regurgitation (AR) was present. On coronary angiography, the arterial graft was occluded and no revascularisation within native coronaries was required. The unfavourable anatomical environment expected after mediastinitis accompanied by high STS scoring (16%) and wide peripheral arteries contributed to a decision to reject reoperation in favour of the transcatheter approach. On multi-detector computed tomography (MDCT), the prosthesis length was 45 mm with significant angulation of neighbouring ascending aorta and coronaries reimplanted 12 mm and 17 mm above the valve (Fig. 1). Laboratory findings excluded active infective endocarditis. After induction of general anaesthesia, a Prostar XL (Abbott) device was introduced into the right common femoral artery. Next, a 26 mm CoreValve prosthesis (the size had been selected according to the inner BioConduit diameter of 22 mm by TEE, standard delivery system) was positioned and deployed in a retrograde manner. Lack of fluoroscopy markers such as calcifications or rigid ring rendered the procedure more TEE-dependent. After completion, no transprosthetic gradient was measured and residual paravalvular AR was trivial. Nevertheless, deficient expansion of the stent frame distal part within the non-pliable BioConduit was noted. The time from arterial puncture to closure was 65 min with 22 min of fluoroscopy, and 180 mL of contrast agent was used. The post-procedural course was uneventful and the patient remained asymptomatic at 12-month follow-up. A remarkable improvement in LV performance was noted, with EDD of 54 mm and EF of 56% by TTE. Repeated MDCT visualised uncompromised coronaries ostia and persistent distal stent frame deformation. Proximal circularity remained however unaffected, which corresponded to the valve’s excellent function (Figs. 2, 3). Initial balloon valvuloplasty may optimise transcatheter valve stent alignment at the expense of degenerated bioprosthesis fragmentation and peripheral embolisation. The anticipated fragility of the thin-walled bioprosthetic cuff further added to our refraining from the manoeuvre. Lack of natural aorta sinus widening in patients with full root prostheses renders coronary flow impairment during TAVI more likely. This was avoided by careful positioning of the CoreValve sealing skirt below the coronaries’ ostia.

Freestyle Aortic Root Bioprosthesis Is a Suitable Alternative for Aortic Root Replacement in Elderly Patients: A Propensity Score Study

The aim of this retrospective study was to compare the early and midterm clinical outcomes of aortic root replacement in elderly patients receiving the Freestyle stentless bioprosthesis (FSB) (Medtronic Inc, Minneapolis, MN) with younger patients receiving a mechanical valve conduit. From January 2001 to December 2010, 185 consecutive patients underwent aortic root replacement. Of these, 79 (43%) patients received the Freestyle bioroot (Medtronic Inc, Minneapolis, MN) (group F) and 106 (57%) patients received a mechanical valve conduit (group M). Target endpoints were 30-day mortality, 5-year survival, 5-year freedom from cardiac death, and 5-year freedom from major adverse valve-related and cardiovascular events (MAVCE) (cardiac death, cerebrovascular accident, myocardial infarction, heart failure, valve prosthesis dysfunction requiring reoperation, and thromboembolic and hemorrhagic events). A propensity score model was built to adjust the results according to preoperative and operative characteristics of both groups. Thirty-day mortality was similar in both groups (F group, 2.5% versus M group, 5.7%; p=0.407). Unadjusted analysis showed no differences between groups, whereas adjusted analysis showed a significantly higher 5-year freedom from cardiac death and MAVCE in group F (group F, 98.6±1.9 versus group M, 88.0%±3.0%; p=0.038; group F, 97.4%±2.6% versus group M, 81.2%±3.6%; p=0.010). Multivariate analysis confirmed a significantly higher risk for 5-year MAVCE in patients who did not undergo implantation with the Freestyle bioprosthesis (hazard ratio [HR], 6.87; 95% confidence limit [CL], 1.43-15.09; p=0.016). In elderly patients, the FSB seems to be as safe as mechanical composite grafts in the perioperative period but results in superior freedom from MAVCE at 5 years postoperatively.

An Unusual Left Ventricular Outflow Pseudoaneurysm: Usefulness of Echocardiography and Multidetector Computed Tomography for Surgical Repair

Left ventricular outflow tract (LVOT) pseudoaneurysm is a rare but potentially lethal complication, mainly after aortic root endocarditis or surgery. Usually it originates from a dehiscence in the mitral-aortic intervalvular fibrosa and it arises posteriorly to the aortic root. Due to these anatomical features, its imaging assessment is challenging and surgical repair requires complex procedures. An unusual case of LVOT pseudoaneurysm is described. It was detected by transthoracic ecocardiography 7 months after aortic root replacement for acute endocarditis. Multidetector computed tomography (MDCT) confirmed the presence of a pouch located between the aortic root and the right atrium. Computed tomography also detected the origin of the pseudoaneurysm from the muscular interventricular septum of the LVOT, rather below the aortic valve plane. It was repaired with an extracardiac surgical approach, sparing the aortic root bioprosthesis previously implanted. The high-resolution three-dimensional details provided by the preoperative MDCT allowed us to plan a simple and effective surgical strategy.

Stentless Aortic Bioprosthesis for Disease of the Aortic Valve, Root and Ascending Aorta

Disease of the aortic valve is frequently associated with morphologic abnormalities of the ascending aorta and the aortic arch. Ectasia of the ascending aorta is commonly associated with bicuspid aortic valve. Degenerative aortic valve disease is often associated with atherosclerotic deposits or aneurysm in the ascending aorta and the aortic arch. Aortic valve disease causing hemodynamic burden sufficient to affect left ventricular structure or function is indication for operation to replace the aortic valve. Current practice dictates replacement of the ascending aorta and/or arch in combination with replacement of the aortic valve because the aortic disease usually does not stabilize and, in fact, progresses despite resolution of disease of the aortic valve. Similarly, aortic disease requiring primary operative intervention in the presence of morphologic abnormalities of the aortic valve is best treated by combined replacement operation because of the frequency of early reoperation on the aortic valve. More aggressive treatment of combined aortic valve and aortic disease has been prompted by the frequent necessity of reoperation for progression of associated morphologic abnormalities, availability of improved aortic valve bioprostheses, and improved ability of surgeons to treat associated disease in a single operation. This article demonstrates use of a stentless aortic root bioprosthesis to replace the aortic valve and aortic root for aortic valve disease associated with (1) aneurysm of ascending aorta; (2) extensive atherosclerotic ulcerated plaque disease of aorta; and (3) coarctation of aorta. These operations are applied in adults and in all cases used the Medtronic Freestyle® aortic root bioprosthesis (Medtronic, Inc., Minneapolis, MN). This device was chosen because of proven efficacy and durability, excellent hemodynamic performance, and no requirement for anticoagulant therapy. 1

Stenosis of the grafted portion of the coronary artery after aortic root replacement with a Freestyle prosthesis

We report a case of stenosis at the grafted portion of the coronary artery after aortic root replacement with a Freestyle prosthesis (Freestyle Aortic Root Bioprosthesis; Medtronic, Inc, Minneapolis, Minn). The coronary artery was reconstructed with the full root technique. There was no displacement or flexion of the coronary artery graft as a result of the surgical procedure. Aspirin was used as a postoperative anticoagulant. A coronary angiogram obtained 18 months after the surgery showed 90% stenosis at the left coronary ostium (Figure 1) and 75% stenosis at the right coronary ostium.

Ten-Year Outcome After Aortic Valve Replacement with the Freestyle Stentless Bioprosthesis

Stentless aortic bioprostheses offer excellent hemodynamics and potentially improved durability compared with other bioprostheses. The present report describes the clinical and hemodynamic outcomes for the Freestyle aortic root bioprosthesis in a large, multicenter cohort prospectively followed up for 10 years. A total of 725 patients at 8 centers in North America (668 [92%] aged more than 60 years) were followed up prospectively after aortic valve replacement with the Freestyle stentless bioprosthesis. Implant technique was subcoronary in 509, total root in 178, and root inclusion in 38. Follow-up was 4,488 patient-years (mean 6.2 years/patient). For subcoronary, full root, and root inclusion groups, 10-year actuarial freedom from structural valve deterioration was 97.0% +/- 2.2%, 96.0% +/- 4.5%, and 90.9% +/- 11.2%, respectively; and actuarial freedom from reoperation was 91.7% +/- 3.5%, 92.3% +/- 6.0%, and 92.0% +/- 10.7%, respectively. Mean pressure gradient at 10 years was 8.9 +/- 7.9 mm Hg for subcoronary, 7.0 +/- 4.1 mm Hg for full root, and 10.0 +/- 11.1 mm Hg for root inclusion groups; effective orifice area was 1.6 +/- 0.5 cm2, 1.6 +/- 0.6 cm2, and 1.7 +/- 0.5 cm2, respectively. Fredom from moderate or more aortic regurgitation at 10 years was good for all three implant groups, but slightly higher for full root (97.7% +/- 1.6%) compared with subcoronary (87.2% +/- 2.8%) patients (p < 0.005). The Freestyle stentless aortic root bioprosthesis is a versatile option for aortic valve replacement. Measures of clinical outcomes and prosthesis durability remain excellent through 10 years.

Eight-year results after aortic valve replacement with the freestyle stentless bioprosthesis

Objectives We sought to describe the hemodynamic and clinical outcomes for the Freestyle aortic root bioprosthesis (Medtronic, Inc, Minneapolis, Minn) in a large multicenter cohort prospectively followed for 8 years. Methods A total of 700 patients (651 [93%] >60 years of age) at 8 centers in North America were followed prospectively after aortic valve replacement with the Freestyle stentless bioprosthesis; the implant technique was subcoronary in 500, total root in 162, and root inclusion in 38. Follow-up was 3395 patient-years (4.9 ± 2.3 years per patient). Clinical and echocardiographic follow-up was prospectively obtained at yearly intervals. Results For the subcoronary, total root, and root inclusion groups, actuarial freedom from valve-related death was 96.8% (SE 3.0%), 92.3% (SE 7.7%), and 90.9% (SE 11.2%), respectively, and freedom from structural deterioration was 98.6% (SE 2.0%), 100.0% (SE 0.0%), and 100.0% (SE 0.0%), respectively. Hemodynamics remained excellent at 6 years. Freedom from moderate or more aortic regurgitation was 86.0% (SE 5.1%), 98.7% (SE 3.9%), and 97.3% (SE 6.6%), respectively. Gradients were slightly lower ( P = .0009), and the effective orifice area ( P = .02) and freedom from aortic regurgitation were slightly higher ( P = .03) with total root than subcoronary implantation. Conclusions The Freestyle stentless aortic root bioprosthesis is a versatile option for aortic valve replacement. Measures of clinical outcomes and prosthesis durability remain excellent in multicenter follow-up through 8 years in a population predominantly older than 60 years at the time of the operation.

Treatment of destructive aortic valve endocarditis with the freestyle aortic root bioprosthesis

Background Successful treatment of destructive aortic valve endocarditis with annular abscess formation requires extensive surgical debridement and reconstruction of the left ventricular outflow tract and aortic root. Homograft aortic roots are the conduits of choice, but because they are not available in all cases, alternative conduits are needed. Methods Owing to its features, which are comparable to those of homografts, the Freestyle aortic root xenograft was used in 10 consecutive patients aged between 32 and 77 years. All patients had extensive abscess formation, 5 presented with prosthetic valve endocarditis, 2 had additional mitral valve endocarditis requiring partial leaflet resection and reconstruction, 1 patient had an additional fistula into the right atrium, and 1 required coronary bypass. One patient developed a septic ventricular septal defect and fistula into the right atrium with tricuspid valve endocarditis. Results None of the patients required reoperation for bleeding. Two (20%) patients died in the postoperative period, 1 due to multiorgan failure, and 1 due to preexisting invasive pulmonary aspergillosis. At autopsy, neither had evidence of intrapericardial hematoma or suture dehiscence. One patient died 13 months postoperatively without clinical signs of valve dysfunction or recurrent endocarditis. All other patients are well at 12 to 42 months after surgery. Clinical examination and echocardiography at the most recent follow-up showed no signs of valve dysfunction, recurrent fistulation, or endocarditis. Conclusions The Freestyle aortic root appears to be an acceptable alternative to homografts in the treatment of severe endocarditis. Long-term valve durability in younger patients, however, remains to be determined.

Impact of implant technique following freestyle stentless aortic valve replacement

Background. Stentless aortic bioprostheses have excellent hemodynamics and clinical outcomes. The purpose of the present study was to determine whether implant technique of the Freestyle aortic root bioprosthesis impacts clinical outcomes or hemodynamic performance. Methods. The long-term multicenter study of the Freestyle stentless aortic bioprosthesis includes 500 consecutive patients implanted using the subcoronary and 162 using the full root technique. Clinical outcomes and echocardiographic hemodynamics were compared through 5 years. Results. There were no differences between groups in time to death, valve-related death, or reoperation. The incidence of operative death was higher in the full root than in the subcoronary group (odds ratio 3.97, p = 0.001). Patients in the subcoronary group were more likely to have New York Heart Association functional class III or IV symptoms at 1 year (1.7% versus 0%, p = 0.04) and 5 years postoperatively (4.4% versus 0%, p = 0.02). Mean gradient was lower ( p = 0.0004) and effective orifice area larger ( p = 0.04) in the full root group. Left ventricular mass index decreased in both groups. The preponderance of patients in both groups had no or trivial aortic regurgitation through 5 years. Conclusions. Full root implantation of the Freestyle stentless aortic bioprosthesis was associated with higher operative mortality, but somewhat better hemodynamics, functional class, and freedom from aortic regurgitation. Higher operative mortality argues against the empiric replacement of the ascending aorta in the absence of aortic root pathology. In appropriately selected patients, both implant techniques are viable alternatives for valve implantation.

Eight-year results of aortic root replacement with the freestyle stentless porcine aortic root bioprosthesis

Background. Stentless porcine aortic valves offer several advantages over traditional valves. Among these are superior hemodynamics, laminar flow patterns, lack of need for anticoagulation, and perhaps improved durability. Methods. One hundred four patients were operated on from September 17, 1992, to October 31, 1997, as part of a multicenter worldwide investigation of the Medtronic Freestyle stentless porcine bioprosthesis. All patients received a total aortic root replacement. The patients were evaluated postoperatively at discharge, at 3 to 6 months, and yearly by clinical examination and color flow Doppler echocardiography. Results. Operative mortality was 3.9%. No patient experienced structural valve deterioration, nonstructural deterioration, perivalvular leak, or unacceptable hemodynamic performance. At 8 years, survival was 59.8%. Freedom from thromboembolic complications was 83.3%. Freedom from postoperative endocarditis was 96.9%. Freedom from reoperation was 100%. Mean systolic gradients did not change over the time period studied. They were 6.4 ± 3.8 mm Hg at 1 year and 6.7 ± 2.6 mm Hg at 8 years. Correspondingly, effective orifice area was 1.9 ± 0.7 cm 2 at 1 year and 1.8 ± 0.8 cm 2 at 8 years. The incidence of any aortic insufficiency also did not change over the length of follow-up. At 1 year, 98% of patients had no or trivial aortic insufficiency and 2% had mild aortic insufficiency. At 8 years, 100% of patients evaluated were free of any aortic insufficiency. Conclusions. The Medtronic Freestyle aortic root bioprosthesis can be used safely to replace the aortic root or aortic valve for aortic valve and aortic root pathology. Total root replacement allows optimal hemodynamic performance with no significant aortic regurgitation. Results up to 8 years show excellent survival and no signs of degeneration. Further follow-up is still needed to determine valve durability.

Aortic root replacement with the freestyle stentless porcine aortic root bioprosthesis

Background. Stentless porcine prosthetic valves offer several advantages over traditional valves. Among these are superior hemodynamics, laminar flow patterns, lack of need for anticoagulation and perhaps improved durability. Methods. One hundred and twelve patients were operated on from September 17, 1992 to April 13, 1998 as part of a multi-center worldwide investigation. All patients received a total aortic root replacement. Patients were evaluated postoperatively at discharge, 3 to 6 months, and yearly by clinical exam and color flow Doppler echocardiography. Results. There were 4 deaths either in the hospital or within 30 days after surgery for an operative mortality of 3.6%. No patients experienced structural valve deterioration, non-structural valve deterioration, paravalvular leak, unacceptable hemodynamic performance, or postoperative endocarditis. The linearized rates for survival and thromboembolic complications at 5 years were 82.8% and 90.5% respectively. Excellent hemodynamic function is demonstrated by very low gradients, large EOA, and an exceedingly low incidence of any aortic regurgitation. Conclusions. The Medtronic Freestyle aortic root bioprosthesis can be used safely to replace the aortic root for aortic valve and aortic root pathology. Root replacement allows optimal hemodynamic performance with no significant aortic regurgitation. Early and intermediate results are encouraging, but further follow-up is needed to determine valve durability.

Clinical and hemodynamic performance of the freestyle aortic root bioprosthesis

Background. The objective of this study is to assess the clinical and hemodynamic performance of a stentless porcine bioprosthesis, the Freestyle aortic root bioprosthesis. Methods. Consenting patients requiring isolated aortic valve or aortic root replacement received the Freestyle bioprosthesis. Clinical follow-up and echocardiographic data were obtained at discharge, 3 to 6 months, 1 year, and annually thereafter. Results. Two hundred seventy-six patients received a Freestyle aortic root bioprosthesis between January 1993 and July 1997. The mean age was 67.7 years. Preoperatively, 86.3% were either New York Heart Association class III or IV. Two hundred thirty-eight patients underwent valve (subcoronary) replacement, 36 underwent aortic root replacement, and 2 underwent valve replacement using the root-inclusion technique. The early mortality was 5.4%, with 3.3% mortality for the subcoronary technique and 19.4% mortality for aortic root replacement. The mean gradient decreased significantly between discharge and the 3- to 6-month follow-up and stabilized thereafter. The effective orifice area increased significantly from discharge to 3 to 6 months’ follow-up. At 3 years, 84.4% of the patients had either no or trivial regurgitation. Conclusions. The Freestyle bioprosthesis has good clinical performance and good short-term hemodynamic performance. The majority of the regurgitation identified is not clinically significant.