Lorenzo Guerrieri Wolf

Long-term results of the valve reimplantation technique using a graft with sinuses

OBJECTIVE Aortic valve reimplantation is the most commonly used technique to spare the aortic valve. Long-term results data are scarce and available only with the use of standard straight graft. We examined the long-term results of reimplantation of the aortic valve using a graft incorporating sinuses of Valsalva. METHODS From May 2000 to December 2014, 124 patients had an aortic valve reimplanted into a graft with sinuses of Valsalva. The mean age was 53 ± 13 years and the majority were men (87%). Marfan syndrome was present in 21 patients (17%) and 12% had a bicuspid valve. Patients were prospectively followed by means of transthoracic echocardiography. The mean follow-up was 63 ± 52 months. RESULTS Overall survival at 5, 10, and 13 years was 94.4% ± 2.2%, 90.5% ± 4.4%, and 81.4% ± 7.3%, respectively. Six patients required reoperation within a time frame of 6 to 96 months. None of the patients died at reoperation. Freedom from reoperation was 95.4% ± 2.3% at 5 years and 90.1% ± 4.3% at 10 and 13 years. All patients who needed reoperation had surgery during the first 5 years. Three patients had residual aortic insufficiency >2. Considering also all patients who underwent reoperation because of aortic insufficiency, freedom from moderate to severe residual aortic insufficiency was 94.1% ± 2.6% at 5 years, and 87.1% ± 4.7% at 10 and 13 years. CONCLUSIONS The majority of patients who had their valve reimplanted in a graft with sinuses continue to perform well after 10 years.

Solid and gaseous cerebral microembolization after biologic and mechanical aortic valve replacement: investigation with multirange and multifrequency transcranial Doppler ultrasound.

OBJECTIVE Cerebral microembolization is a well-recognized phenomenon after cardiac valve replacement, but the relative proportion of solid and gaseous emboli is uncertain. Particulate microemboli are thought to be the most damaging. With the use of multifrequency transcranial Doppler ultrasound, we compared the number and nature of microemboli in recipients of biologic and mechanical aortic valve prostheses. METHODS The middle cerebral arteries of 60 patients were monitored bilaterally with a new-generation transcranial Doppler ultrasound (Embo-Dop, DWL Elektronische Systeme GmbH, Singen, Germany) that rejects artefacts online and automatically discriminates between solid and gaseous microemboli. All recordings were performed during a 30-minute period 1 day before and at a mean of 5 days and 3 months after isolated aortic valve replacement with a biologic (30, group B) or mechanical (30, group M) prosthesis. RESULTS The patients in group B were older, with a mean age of 70.6 +/- 9.7 years versus 55.4 +/- 9.4 years (P < .005) in the patients in group M. Biologic prosthesis recipients were all taking aspirin (no warfarin); patients with mechanical valves were well anticoagulated with warfarin both 5 days and 3 months after surgery. None of the patients had solid microemboli preoperatively. Five days postoperatively, the absolute number of cerebral microemboli was 145 and 594 for total microemboli (P = .001) and 41 and 182 for solid microemboli (P = .002) in groups B and M, respectively. At 3 months, the absolute number was 65 and 608 for total microemboli (P < .001) and 10 and 188 for solid microemboli (P < .001) in groups B and M, respectively. Solid microemboli accounted for 16% of the total microembolic load in group B compared with 31% in group M (P = .05) at 3 months. CONCLUSIONS Solid cerebral microemboli represent approximately one third of the total cerebral microembolic load after mechanical aortic valve replacement and are detectable in the majority of such patients both 5 days and 3 months after surgery. The neurofunctional consequences of this phenomenon should be carefully assessed.

The combined role of sinuses of Valsalva and flow pulsatility improves energy loss of the aortic valve

OBJECTIVES Normal aortic valve opening and closing movement is a complex mechanism mainly regulated by the blood flow characteristics and the cyclic modifications of the aortic root. Our previous in vitro observations demonstrated that the presence of the Valsalva sinuses, independently from root compliance, is important in reducing systolic pressure drop across the aortic valve. This in vitro study was designed to ascertain if this effect is dependent on the flow characteristics. METHODS Stentless 21, 23 and 25 mm aortic prostheses were sutured inside Dacron graft with and without sinuses. Hydrodynamic performance of the root models was investigated in steady-state (continuous) and unsteady-state (pulsatile) flow regimes. Aortic transvalvular pressure drop and effective orifice area (EOA) were evaluated. RESULTS The continuous flow analysis revealed that no marked differences in pressure drop characterized the two root configurations at flow regimes lower than 15 l/min, independently of valve size. Conversely, at higher flow regimes (up to 30 l/min) a relatively low pressure drop continued to characterize grafts with sinuses, whereas marked increments in pressure drop were measured in straight grafts, especially in the smaller size (77.05 ± 4.58 vs 23.80 ± 2.44 mmHg; 18.40 ± 1.31 vs 7.66 ± 0.37 mmHg and 29.54 ± 0.17 vs 7.12 ± 0.07 mmHg, for 21, 23 and 25 mm valve, respectively). Under pulsatile conditions, the presence of sinuses clearly confirmed lower pressure drops also more evident in the smaller valve sizes (53.89 ± 1.06 vs 11.6 ± 0.24 mmHg at 7 l/min for 21 mm valve). EOA values were always lower in the absence of sinuses. In continuous flow regimes, at 30 l/min EOA of 25 mm valve size was 3.67 ± 0.02 cm(2) in the Valsalva model versus 1.79 ± 0.01 cm(2) for the Straight model. In pulsatile tests, at 7 l/min a 25-valve size demonstrated an EOA of 5.47 ± 0.60 in the Valsalva model versus 2.50 ± 0.02 cm(2) in the Straight model. CONCLUSIONS These findings (i) confirm the hypothesis that the sinuses of Valsalva play a key role in optimizing the aortic haemodynamics during systole, minimizing energy losses; (ii) suggest that the sinuses of Valsalva are needed because of the complex nature of blood flow during ejection.

Differences in aortic cusp coaptation between the reimplantation and the remodeling techniques of aortic valve–sparing surgery: An in vitro porcine model study

OBJECTIVES We sought to evaluate the effects of the reimplantation type versus the remodeling type of aortic valve-sparing technique on the geometry of the same aortic root. METHODS Fifteen fresh isolated porcine hearts with normal aortic valves and a standard aortoventricular junction size of 23 mm were processed. An aortic valve-sparing replacement was performed by reimplanting the native aortic root inside a 28-mm Valsalva graft (Vascutek Ltd, Renfrewshire, UK). Hearts were subsequently implanted with instruments in a test circuit, and the aortic roots were pressurized at a fixed pressure of 100 mm Hg. Diameters of the aortoventricular junction, of the sinuses, and of the sinotubular junction, as well as effective height and coaptation height of aortic valve leaflets, were measured by echography. Transition from the reimplantation to the remodeling configuration was then achieved by longitudinally cutting the skirt of the graft from the annulus to the top of each commissure. The same measurements were then repeated. RESULTS After transition from the reimplantation to the remodeling configuration, significant increases in the sizes of the aortoventricular junction and of the sinuses were observed. Effective height and coaptation height significantly decreased, and the rounded cross-sectional profile of the aortic valve leaflets flattened. CONCLUSIONS In the same aortic root, transition from the reimplantation to the remodeling configuration of aortic valve-sparing surgery results in a significant increase in aortic root sizes and in a significant reduction of effective height and coaptation height, suggesting a less satisfactory result.

Mitral repair with the sole use of a semi-rigid band in a sub-population of patients with Barlow's disease: a 4-year follow-up with stress echocardiography

OBJECTIVES Surgical treatment of Barlows disease is usually demanding. In a sub-population of Barlow patients with bileaflets prolapse and central regurgitant jet, we performed mitral repair using only a semi-rigid annuloplasty band. Stress echocardiography follow-up was evaluated. METHODS Of a total of 350 consecutive patients with mitral prolapse, 69 had anatomical features of Barlows disease. Of these, 40 with multiple large central jets without chordal rupture were repaired only using an annuloplasty band, and these constituted the study group. An echocardiographic study of the acute change in valvular and ventricular morphology before and after surgery was carried out. Patients were evaluated at discharge and after a mean follow-up of 4.7 ± 3.2 years by stress echocardiography. RESULTS No death or reoperation occurred. Acute echocardiographic study revealed that mitral annuloplasty led to a significant migration of the leaflets towards the apex of the left ventricle. Coaptation length increased dramatically from 2.7 ± 0.8 to 11.3 ± 2.7 mm and a reduction in annular diameters and leaflet length was observed. The left ventricle was elongated (72.8 ± 6.9 vs 63.2 ± 8.1 mm) and the distance from the papillary muscle tip to the mitral annulus increased (anterior 30 ± 3.9 vs 20.3 ± 4.8 mm, posterior 29.7 ± 4.3 vs 20.8 ± 5.6 mm). At discharge, residual mitral regurgitation was mild in 1 case and trivial in 3. The results were confirmed at stress echocardiography follow-up with normal valve function at peak exercise. CONCLUSIONS In patients with severe mitral regurgitation due to Barlows disease with multiple central jet and without chordal rupture, mitral annuloplasty is effective in restoring mitral valve function owing to profound changes in mitral valve and left ventricle geometry. At follow-up, stress echocardiography confirms the results and the stability of the repair.

Negative pressure wound treatment improves Acute Physiology and Chronic Health Evaluation II score in mediastinitis allowing a successful elective pectoralis muscle flap closure: Six-year experience of a single protocol

OBJECTIVES Optimal management of poststernotomy mediastinitis is controversial. Negative pressure wound treatment improves wound environment and sternal stability with low surgical invasiveness. Our protocol was based on negative pressure followed by delayed surgical closure. The aim of this study was to provide the results at early follow-up and to identify the risk factors for adverse outcome. METHODS In 5400 cardiac procedures, 44 consecutive patients with mediastinitis were enrolled in the study. Mediastinitis treatment was based on urgent debridement and negative pressure as the first-line approach. After wound sterilization, chest closure was achieved by elective pectoralis muscle advancement flap. Each patients hospital data were collected prospectively. Variables included patient demographics and clinical and biological data. Acute Physiology and Chronic Health Evaluation (APACHE) II score was calculated at the time of diagnosis and 48 hours after debridement. Focus outcome measures were mediastinitis-related death and need for reintervention after pectoralis muscle closure. RESULTS El Oakley type I and type IIIA mediastinitis were the most frequent types (63.6%). Methicillin-resistant Staphylococcus aureus was present in 25 patients (56.8%). Mean APACHE II score was 19.4±4 at the time of diagnosis, and 30 patients (68.2%) required intensive care unit transfer before surgical debridement. APACHE II score improved 48 hours after wound debridement and negative pressure application (mean value, 19.4±4 vs 7.2±2; P=.005) independently of any other variables included in the study. One patient in septic shock at the time of diagnosis died (2.2%). CONCLUSIONS Negative pressure promotes a significant improvement in clinical status according to APACHE II score and allows a successful elective surgical closure.