Aortic valve replacement with the medtronic freestyle stentless bioprosthesis

During a five-year period from 1996 to 2000, the Medtronic Freestyle stentless bioprosthesis was implanted in 310 patients of advanced age. Age at operation ranged from 60 to 90 years (mean, 76 +/- 4 years). 191 patients were female and 119 male. All implants were done by the modified subcoronary method using our own modification which enabled an improved adaptation of the porcine aortic root to the human anatomy. Two sinuses were scalloped and the third left intact. Additional coronary bypass grafts were necessary in 129 (39%) patients and mitral valve procedures in 23 (7%). Mean perfusion time was 109 +/- 12 minutes and crossclamp time 87 +/- 8 minutes. 16 (5%) patients died perioperatively. Another 17 (5.7%) patients died during a 1 to 5.6 year follow-up (mean, 2.9 years). There was only one valve related death due to infection of the valve. In spite of the advanced age, 95% of the survivors were free from cardiac symptoms and continued to live an active and fruitful life. The biological nature of the valve and the low gradients are perhaps reasons for the good results. The long-term results are expected to be good.     

Bilateral ostial coronary stenosis and rheumatic aortic valve stenosis

A 49-year-old patient presented with angina pectoris and clinical findings of aortic valve stenosis and regurgitation. Rheumatic aortic valve stenosis and regurgitation was diagnosed on echocardiography. Coronary angiography findings showed severe calcification in the aorta root with right coronary ostial occlusion, and were suggestive of left main ostial stenosis and proximal main stem stenosis, which was confirmed on CT angiography. Curvilinear calcification of the aorta was present on CT angiography. The findings suggested syphilitic aortitis. Syphilis serology was positive (RPR titre 1/16). The angina was caused by severe coronary ostial disease likely due to syphilitic aortitis and exacerbated by the rheumatic aortic valve stenosis and regurgitation.     

Bilateral ostial coronary stenosis and rheumatic aortic valve stenosis

A 49‐year‐old patient presented with angina pectoris and clinical findings of aortic valve stenosis and regurgitation. Rheumatic aortic valve stenosis and regurgitation was diagnosed on echocardiography. Coronary angiography findings showed severe calcification in the aorta root with right coronary ostial occlusion, and were suggestive of left main ostial stenosis and proximal main stem stenosis, which was confirmed on CT angiography. Curvilinear calcification of the aorta was present on CT angiography. The findings suggested syphilitic aortitis. Syphilis serology was positive (RPR titre 1/16). The angina was caused by severe coronary ostial disease likely due to syphilitic aortitis and exacerbated by the rheumatic aortic valve stenosis and regurgitation.     

Left ventricular mass regression after aortic valve replacement with CryoLife-O'Brien stentless aortic bioprosthesis

BACKGROUND AND AIM OF THE STUDY: Left ventricular (LV) hypertrophy has been shown adversely to affect LV function and late outcome after aortic valve replacement (AVR). The study aim was to assess the time course of LV mass regression (LVMR) after AVR with a CryoLife-O'Brien stentless bioprosthesis, and to identify factors affecting late reduction of myocardial hypertrophy. METHODS: In total, 113 patients (60 males, 73 females; mean age 70.9+/-6.5 years) were studied by echocardiography preoperatively, at discharge, at six and 12 months postoperatively, and yearly thereafter. LV diameter and thickness were measured using M-mode echocardiography; LV mass was calculated using the Devereux formula and indexed by body surface area (BSA). RESULTS: LV end-systolic diameter, end-diastolic diameter, septal thickness and wall thickness decreased significantly after surgery (p <0.001). LV mass index (LVMI) was reduced by 16.6, 13.6, 10.1, 3.1, 3.3, 1.7, 2.6, and 1.8% at discharge and at 6 months and 1, 2, 3, 4, 5, and 6 years, respectively. Most LVMR occurred within the first year, with further (not significant) reductions at later examinations. Male sex (p = 0.002), arterial blood pressure > or =150 mmHg (p <0.001), LV ejection fraction (LVEF) < or =35% (p = 0.01), NYHA functional class > or = III (p = 0.01), atrial fibrillation (p <0.001), mean transvalvular gradient > or =40 mmHg (p = 0.001), and prevalent aortic incompetence (p <0.001) were factors influencing LVMR, independently of baseline effective orifice area and prosthesis size. CONCLUSION: AVR with the CryoLife-O'Brien stentless prosthesis resulted in significant LVMR. These findings encourage the use of this bioprosthesis in appropriate patients.     

Unusual complication after aortic valve replacement with the Freedom Solo stentless bioprosthesis

The case is presented of an unusual complication after aortic valve replacement with a Freedom Solo bioprosthesis. Excision of the aortic valve created a discontinuity of the aortic annulus that was missed intraoperatively and left uncorrected after supra-annular placement of the bioprosthesis; this created a pseudoaneurysm with direct communication to the pericardial cavity. When implanting the Freedom Solo bioprosthesis, care must be taken to exclude the presence of any aortic annular discontinuity. Implantation of the Freedom Solo bioprosthesis is not precluded by this possible complication, provided that any annular disruption is promptly recognized and adequately closed before placement of the supra-annular sutures.     

Three cases of iatrogenic coronary ostial stenosis after aortic valve replacement.

BACKGROUND: Iatrogenic coronary ostial stenosis (ICOS) is a rare but potentially life-threatening complication of aortic valve replacement (AVR). This complication is usually diagnosed by angiography and treated with aortocoronary bypass surgery. CASE REPORTS: In the present 3 cases pre-operative coronary angiography confirmed normal coronary arteries and they underwent uncomplicated AVR. Coronary lesions were clinically manifest within 4 months after surgery, and repeat coronary angiography demonstrated bilateral ostial stenosis in 1 patient and left main trunk stenosis in the other 2. Two cases were detected by multidetector computed tomography (MDCT) before angiography. MDCT and Virtual Histology suggested fibrous tissue formation in the lesions. All 3 patients were successfully underwent percutaneous coronary intervention (PCI) and stenting. The post-procedure clinical course has been uneventful, except for elective stenting of a recurrent lesion in 1 asymptomatic patient. CONCLUSIONS: The incidence of ICOS after AVR is low. Noninvasive MDCT is useful for early diagnosis and PCI is a possible alternative treatment. ICOS may be caused by fibrous tissue formation, and therefore be distinct from conventional atherosclerosis.     

Bilateral coronary ostial stenosis and aortic valvular disease after radiotherapy

A 44-year-old woman with a history of chest radiotherapy developedostial coronary artery disease associated with aortic valvulardisease and a lesion of the right internal mammary artery.     

Cardiac computed tomography in the management of iatrogenic coronary ostial stenosis after aortic valve replacement

Although rare, iatrogenic coronary ostial stenosis is an important complication of aortic valve replacement and Bentall procedure. We report a 32-year-old male presenting an acute coronary syndrome post-Bentall procedure and the role of computed tomography in diagnosis and management of iatrogenic coronary ostial stenosis. Such occlusions are commonly identified in the left main coronary artery, but can develop in venous bypass grafts at anastomoses with Dacron aortic grafts. Cardiac computed tomography is valuable to exclude noncoronary causes of chest pain, assess ostial stenosis of manipulated arteries post reimplantation, and shed light on mechanisms and management of these lesions.     

Durability and prevalence of aortic regurgitation nine years after aortic valve replacement with the Toronto SPV stentless bioprosthesis

BACKGROUND AND AIM OF THE STUDY: Stentless aortic bioprostheses have excellent hemodynamics. Previous investigations of the Toronto SPV valve described a correlation between the occurrence of significant aortic regurgitation (AR) and dilation of the sinotubular junction. The study aim was to determine the long-term durability and determinants of AR at nine years in a large, multicenter study of the Toronto SPV valve. METHODS: The study included 447 patients from six centers. Clinical outcomes and echocardiographic data (gradients, effective orifice area index (EOA-I), left ventricular mass, aortic root dimensions, and presence and severity of AR) were collected prospectively. A multivariable logistic regression model was used to evaluate clinical and echocardiographic variables for impact on the occurrence of AR. RESULTS: Total follow up was 2,660 patient-years (mean 6.0 +/- 2.5 years; range: 0 to 11.1 years). Mean gradient and EOA-I remained unchanged through nine years. There were 17 cases of structural deterioration, of which 15 underwent explantation. The mechanism of failure was predominantly leaflet tear in the setting of sinotubular dilation. Freedom from explant for structural failure was 90.1% at nine years (100% for patients aged > or = 65 years). Freedom from hemodynamically significant AR was 96.9% at five years and 82.5% at nine years. Determinants of AR were longer duration of follow up, larger valve size, and increase in the ratio of sinotubular junction to the size of valve implanted. CONCLUSION: At nine years after implantation of the Toronto SPV valve, hemodynamics remained excellent. There was good freedom from structural deterioration through nine years, and structural failure occurred due to aortic root dilation and leaflet tear, without significant valve calcification. AR tends to occur with longer follow up, larger valve sizes, and dilation of the sinotubular junction.     

Extensive dehiscence of a stentless bioprosthesis with only mild paravalvular regurgitation after replacement of a degenerated bicuspid aortic valve

We report the case of a 54-year-old patient admitted for rehabilitationafter implantation of a stentless bioprosthesis due to severeinsufficiency of a degenerated bicuspid aortic valve. The patientcould fully participate in a standard cardiac rehabilitationprogram without any signs of haemodynamic instability. Transthoracicechocardiography showed a small mobile subvalvular structureand only mild paravalvular reflux. Transesophageal echocardiography,however, revealed extensive dehiscence of the bioprosthesiswith the need for urgent reoperation. We discuss the probablecauses and encourage routine echocardiography after valve operationswith generous application of transesophageal echocardiographyin every suspicious case.     

Pregnancy and transcatheter aortic valve replacement in a severely stenotic Freestyle full aortic root stentless bioprosthesis

Symptomatic degenerative prosthetic aortic valve stenosis during pregnancy represents a significant risk to both mother and fetus, and until recently, surgical aortic valve replacement (SAVR) during pregnancy was often the only choice for women opting to continue pregnancy. However, symptomatic severe stenosis in a pregnant woman with a degenerated full aortic root Freestyle stentless bioprosthesis (FSB) and reimplanted coronary arteries presents additional complexities that require an alternative surgical approach. In this case report, we describe the first successful transcatheter aortic valve replacement (TAVR) in SAVR for a severely stenotic degenerative FSB in a pregnant woman and subsequent delivery of a healthy infant several months later. TAVR in SAVR of a severely stenotic aortic FSB should be considered as a surgical option in symptomatic pregnant women. Short‐term and long‐term implications for future pregnancy should be discussed by a multidisciplinary team and with the patient.     

Determinants of ascending aortic dimensions after aortic valve replacement with a stented bioprosthesis

BACKGROUND AND AIM OF THE STUDY: Concomitant replacement of the mildly dilated ascending aorta during aortic valve replacement (AVR) is controversial because progress of aortic dilatation is uncertain after elimination of the valvular lesion. The study aim was to determine factors influencing the aortic dimensions, to analyze their clinical impact, and to identify criteria for concomitant surgery on the aorta. METHODS: Between February 1994 and May 1999, 100 patients with tricuspid aortic valve disease received the stented porcine Mosaic prosthesis within a FDA approval study. Follow up (mean 4.8 years; range: 0.1-8.8 years; total 483.4 patient-years) included documentation of adverse events and transthoracic echocardiography with measurements of the aortic sinus, sinotubular junction, and ascending aorta. RESULTS: Baseline aortic dimensions were dependent on gender and body surface area, but independent of the type and extent of valvular lesion, patient age, and atherosclerotic risk factors. Larger baseline aortic diameters were associated with smaller postoperative annual aortic expansion rates (r = -0.47, p <0.001). In patients with baseline aortic dilatation > or =40 mm (10.2%; mean 42.5+/-2.6 mm), aortic diameter decreased during follow up (p = 0.032; expansion rate -1.9+/-2.0 mm/year). Baseline aortic dilatation did not influence postoperative morbidity and mortality. Prosthetic regurgitation was associated with increases in aortic diameter (p <0.001). Survival was reduced in patients with aortic expansion rates >3.6 mm/year (0.0% versus 68.2+/-9.7%; p <0.001). CONCLUSION: AVR without concomitant surgery on the aorta in patients with mild aortic dilatation is feasible, as aortic diameters were decreased after removal of the diseased valve. The aortic expansion rate had a strong prognostic importance, even on aortic diameters, which are considered to be within normal ranges.     

Iatrogenic coronary ostial stenosis of left main stem following aortic valve replacement: Visualization with optical coherence tomography

Iatrogenic coronary ostial stenosis following aortic valve replacement (AVR) occurs in up to 3.4% of cases and usually presents within the first 6 months following surgery. We present the case of an 85 year old man who developed an acute coronary syndrome 2 months following AVR. Coronary angiography revealed a severe de novo lesion in the left main stem, which, on optical coherence tomography, was shown to be due to severe intimal hyperplasia. The most likely underlying mechanism is vessel wall trauma caused by the rigid tip cannula used for administration of cardioplegia solution. Surgeons should be aware of this possibility when administering this solution via the antegrade approach.     

Aortic valve replacement with a stentless bioprosthesis using the full-root technique.

BACKGROUND: In aortic valve replacement stentless bioprostheses results in improved hemodynamic function compared to stented valves. Using the root replacement technique even larger prostheses are implantable. We present our experience with stentless bioprostheses implanted in the "full-root" technique. PATIENTS AND METHODS: Between 01/1997 and 12/2000, 149 patients underwent root replacement with a stentless xenograft (age 70 +/- 9y, women 52 %, ejection-fraction 58 +/- 15 %). Isolated stenosis was present in 34 %, incompetence in 24 %, and mixed disease in 42 % of patients. Bacterial endocarditis was found in 16 %, and 3 patients suffered from acute aortic dissection. RESULTS: Mean bypass time was 118 +/- 45 min, ischemic time 83 +/- 26 min and operating time 201 +/- 62 min. Concomitant procedures were CABG (32 %), replacement of ascending aorta (22 %) and aortic arch (13 %), mitral valve repair (6.7 %), and carotid thrombendarterectomy (1.3 %). Total in-hospital mortality was 6.7 %, with a 1.8 % mortality rate for patients with isolated aortic valve disease. CONCLUSION: Aortic valve replacement using stentless bioprostheses in the root replacement technique is a safe surgical option. In patients with small aortic roots or ring abscesses it guarantees remodelling of the aortic annulus.     

Bicuspid aortic valve replacement with stentless autologous pericardial valve

Bicuspid aortic valve is a common congenital cardiac anomaly that poses a surgical challenge in young patients. We describe replacement of a bicuspid aortic valve with a stentless glutaraldehyde-treated autologous pericardial prosthesis in a 16-year-old girl.