Aortic dissection late after aortic valve replacement

We experienced 3 cases of an aortic dissection occurring late after an aortic valve replacement, and sucessfully treated by an aortic root replacement. An aortic dissection involving the ascending aorta can develop late after an aortic valve replacement, and such an occurrence is associated with a high mortality and morbidity. The development of effective surgical strategies at the initial aortic valve surgery, strict control of blood pressure after aortic valve replacement, serial evaluations of aortic size, and the prophylactic replacement of the ascending aorta for patients with aortic dilatation after aortic valve replacement, all play clinically important roles in preventing an aortic dissection after aortic valve replacement. When an aortic dissection occurs in patients with a previous aortic valve replacement, an aortic root replacement should be performed in order to avoid leaving the fragile diseased aortic wall including the sinus of Valsalva.     

Acute aortic dissection after aortic valve replacement

A 53-year-old male who had been performed aortic valve replacement 15 weeks before was admitted to our hospital because of severe chest pain. Cjest computerized tomography showed dissection of aorta from ascending to descendig aorta and hemorrhage around ascending aorta. An emergency operation was performed under hypothermic circulatory arrest with a selective cerebral perfusion. An entry of dissection was found at posterior wall where was 3 cm upper from an artificial valve. Total arch replacement was successfully performed. There is a few caces of aortic dissection after aortic valve replacement, but careful peri and post operative care is necessary after aortic valve replacement.     

Aortic valve replacement for aortic stenosis with a small mechanical prosthetic valve

BACKGROUND: Although aortic valve replacement (AVR) is the only effective treatment for patients with aortic stenosis (AS), it is recognized that the use of small prosthetic valves due to a small aortic root often affects postoperative course after AVR. The aim of this study was to determine whether the use of small prosthetic valves was a risk factor of AVR for AS. METHODS: We compared various perioperative factors and operative outcomes between patients with a small mechanical prosthetic valve (small group) and patients with a large mechanical prosthetic valve (large group). RESULTS: Early mortality was 0% in each group and the 5-year mortality was 25% in the small group and 10% in the large group. There were no significant differences in perioperative factors between the two groups. The small group patients were significantly older and smaller compared to the large group patients. The valve size was significantly correlated with age and BSA. CONCLUSIONS: The use of small mechanical prostheses was not a risk factor of AVR for AS when it was proportionate to the BSA even for elderly patients. AVR using a small mechanical prosthetic valve may be performed with good results in the short- and long-term.     

Aortic valve replacement in adult patients with small aortic annuli

Fifty-five patients with small aortic annuli underwent valve replacement either isolated or combined with other procedures. Patch enlargement of the aortic annulus in the area of the noncoronary sinus was used in 32 patients. The width of the patch was calculated by multiplying the desired increase in diameter by pi and adding 8 mm for suturing. The remaining 23 patients had aortic valve replacement with a prosthesis larger than the aortic annulus. The prosthesis was sutured in a supraannular position in the area corresponding to the noncoronary sinus. This slightly tilted position does not compromise function of Carpentier-Edwards or Bj?rk-Shiley prostheses. Prosthetic gradients ranged from 0 to 18 mm Hg (9.2 +/- 3.9 mm Hg) in patients with patch enlargement of the aortic annulus and from 0 to 22 mm Hg (7.2 +/- 5.8 mm Hg) in patients with supraannular aortic prostheses. Although these techniques allow for insertion of prosthetic valves only one and two sizes larger than the aortic annulus, they appear to be satisfactory in most adult patients with a small aortic annulus.     

Mitral valve replacement in patients after aortic valve replacement

BACKGROUND: Mitral valve replacement in patients who previously had undergone aortic valve replacement is a technical challenge. The rigid aortic prosthesis limits visualization of the anterior mitral annulus and placement of sutures. METHODS: Reoperative mitral valve replacement was performed in five patients after aortic valve replacement. Two patients underwent resternotomy to allow verification of normal aortic prosthetic valve function. Anterolateral right thoracotomy was used for reentry in the remaining three patients. Exposure of the anterior mitral annulus was accomplished by initial traction on the intact anterior leaflet, with resection of this leaflet only after placement of sutures. RESULTS: All patients survived the surgical procedure and are well 2 to 30 months after operation. In one patient it was impossible to open one cusp of the mitral prosthesis, nor was it possible to rotate the valve. The valve was reimplanted, but sutures were tied only after testing for full free cusp motion. CONCLUSIONS: When appropriate, right thoracotomy incision offers excellent exposure of the mitral valve with minimal dissection. Placement of sutures along the anterior portion of the annulus is facilitated by traction downwards on the anterior leaflet. Full range of motion of the prosthetic cusps should be verified before tying the sutures.     

Aortic dissection detected 40 days after mitral valve replacement

We report a case of a 61-year-old man with aortic dissection, which was detected after mitral valve replacement. The presenting manifestation was a moderate, dull and steady pain in his right scapular region, which started on the 40th postoperative day and irradiated to the back and lower limbs. The dissection and its extent was diagnosed on transthoracic echocardiography and CT scanning and the patient improved on conservative management with beta blockers. The main purpose of reporting this case is to emphasize challenges involved with early diagnosis of this ominous condition due to nonspecific symptoms and unreliable clinical examination, and to highlight the role of the imaging studies to confirm the diagnosis of this entity.     

Aortic valve replacement through right anterolateral thoracotomy for aortic stenosis after mediastinal radiation therapy

A 76-year-old woman had severe aortic stenosis on transthoracic echocardiography [aortic valve area (AVA): 0.7 cm2, max pressure gradient (PG): 108 mmHg]. Since she was on radiation therapy for breast cancer, we considered that median sternotomy was a risk factor for mediastinitis, and right thoracotomy was chosen for aortic valve replacement. The operation was performed through a right anterolateral thoracotomy. Cardiopulmonary bypass was established with right femoral artery cannulation, right atrial cannulation, and right superior pulmonary vein cannulation for venting. The patient's postoperative course was uneventful. This method appears to be an alternative approach for aortic valve replacement in patients that are not suitable candidates for median sternotomy.     

Sutureless aortic valve replacement with concomitant valvular surgery

Objectives

Sutureless aortic valve replacement (SU-AVR) is an alternative technique to standard aortic valve replacement. We evaluated our experience with the Perceval SU-AVR with concomitant mitral valve surgery, with or without tricuspid valve surgery, and aimed to discuss the technical considerations.

Aortic valve replacement for aortic regurgitation and stenosis, in patients with severe left ventricular dysfunction.

OBJECTIVE: Aortic valve replacement for aortic valve stenosis (AS) and regurgitation (AR) in patients with severe left ventricular (LV) dysfunction contains an increased risk. Few data are available on the outcome of such patients. METHODS: Fifty-five consecutive patients with severe LV dysfunction (ejection fraction, EF; <30%) and aortic valve replacement for AS (n=35) or AR (n=20) were investigated between 1994 and 2001. EF was 25+/-5%, mean transvalvular gradient 26+/-6mmHg (AS), aortic valve area 0.66+/-0.18cm(2) (AS), cardiac index (CI) 2.4+/-0.9l/min/m(2), enddiastolic LV diameter (LVEDD) 64+/-8mm and endsystolic LV diameters (LVESD) was 55+/-3mm. Ninety percent of patients were in New York Heart Association (NYHA) functional class III/IV at admission to the hospital. Concomitant coronary artery bypass grafts (CABG) were performed in 14 patients. Follow-up examinations including chest X-ray, echocardiography, exercise testing, were performed among survivors. RESULTS: The survival rates for AS were: 1-year 76%, 2-year 68.8%, 5-year 64.2%; for AR: 1-year 94.4%, 2-year 86.5%, 5-year 74.2%. NYHA functional class improved from 90% in class III/IV to 45 (AR group) and 24% (AS group) at follow-up (P<0.02). The LVEDD decreased to 54+/-8mm after 1 year. The EF improved to 38+/-4 (AR group) and 40+/-5% (AS group) at follow-up. CONCLUSIONS: Despite severe LV dysfunction, increased 1-year mortality especially in the AS group, aortic valve replacement was associated with improved functional status, symptoms and EF in both groups and in most patients. We, therefore, conclude that aortic valve replacement in patients with severe LV dysfunction can be performed with acceptable risk.     

Impacts of aortic valve replacement on cardiac function in patients with aortic stenosis

To prevent patient-prosthesis mismatch (PPM) after aortic valve replacement (AVR), we set up our original standard criteria for the selection of the size of the prosthetic valve. We also routinely perform supra-annular enlargement in patients with small aortic annuli. The objective of this study was to assess the impact of our procedure on the postoperative cardiac function of patients suffering from aortic stenosis (AS). We retrospectively reviewed 102 consecutive surgical patients with AS from 1999 to 2004. The patients were classified into the following 3 groups based on the sizes of their prosthesis (group S : 19 mm prosthesis, n = 34; group M : 21 mm prosthesis, n = 51; and group L : > 23 mm prosthesis, n = 17). Cardiac function was evaluated using echocardiography preoperatively, immediately postoperatively, and 6 months after the operation. There were no hospital deaths during the study period. A favorable hemodynamic outcome of all 3 groups was achieved. Our surgical strategy for AS was thought to be useful to prevent PPM after AVR.     

Right ventricular function in patients with aortic stenosis undergoing aortic valve replacement.

The effects of aortic stenosis (AS) on right ventricular function during cardiac surgery are not fully understood. Forty patients undergoing aortic valve replacement with either a systolic transvalvular gradient of less than 100 mm Hg (82.1 +/- 5.5 mm Hg; group 1, n = 20) or greater than 120 mm Hg (131.1 +/- 6.9 mm Hg, group 2, n = 20) were investigated with regard to right ventricular function in the perioperative period. Right ventricular ejection fraction (RVEF), right ventricular end-systolic volume (RVESV), and right ventricular end-diastolic volume (RVEDV) were measured by means of the thermodilution technique. Before cardiopulmonary bypass (CPB), RVEF was significantly lower in group 2 patients (34% +/- 6%) than in group 1 (45% +/- 5%). After CPB, RVEF increased significantly in group 2 (28% +/- 4% to 49% +/- 5%), and no further differences were noted between the groups. In the patients with a higher systolic transvalvular gradient, RVEDV and RVESV were lower at the start of surgery, but increased after opening the pericardium. Cardiac index was also lower in these patients. Pericardiotomy resulted in a decrease in right ventricular end-systolic pressure (RVESP) only in the patients of group 2. In these patients more epinephrine was necessary to maintain stable hemodynamics during the post-bypass period. It is concluded that patients with AS are at risk of reduced right ventricular function when the systolic transvalvular pressure gradient is more than 120 mmHg. Knowledge of the complex interaction between the two sides of the heart may enable anesthesiologists to optimize management during the perioperative period.     

A case of ascending aortic dissection after aortic valve replacement in congenital bicuspid aortic valve]

Congenital bicuspid aortic valve is a risk factor of aortic dissection, but the case is rare in Japan. Several reports described ascending aortic aneurysm after aortic valve replacement. In these reports, most of aneurysms were false aneurysm, but the cases of ascending aortic dissection were rare. In this case, dissecting aneurysm of the ascending aorta occurred 4 years after aortic valve replacement, which was performed with mechanical prosthesis because of infective endocarditis, and it was repaired successfully by the modified Cabrol's method. This case was congenital bicuspid aortic valve, and had already been complicated with moderate aortic dilatation in the ascending aorta. In patients of congenital bicuspid aortic valve with aortic dilatation, consideration of complete replacement of the ascending aorta with aortic valve replacement is important.     

Aortic root motion remodeling after aortic valve replacement--implications for late aortic dissection

Aortic root motion was previously identified as an additional risk factor for aortic dissection. This study analyzed if the magnitude of aortic root motion changed in patients after aortic valve replacement (AVR) and acute proximal aortic dissection. An institutional database (1984-2005) was used to measure the downward motion of the aortic root (perpendicular to the plane of the sinotubular junction) in contrast injections in 48 patients with aortic insufficiency (AI), aortic stenosis (AS) and proximal aortic dissection pre- and postoperatively, when available. Postoperative aortic root motion was significantly reduced after AVR for AI, while it was significantly increased after AVR for AS. By contrast, aortic root motion was unchanged when functional AI due to paravalvular leak was present post-AVR for AI. In patients with acute aortic dissection, both aortic root motion and aortic diameter were unchanged from pre-dissection. However, in patients who dissected again, aortic root motion was significantly smaller than pre-dissection, and the aortic diameter was significantly less than at first dissection. Removal of aortic stenosis was associated with increased aortic root motion, theoretically heightening the threat of dissection posed to the aortic wall by mechanical stress, although this was not confirmed by our study of dissection patients. Yet, mechanical principles command to include higher magnitude of aortic root motion during follow-up of patients after AVR as an additional risk factor for dissection.