Biomedical subjects

Daniele Maselli

Publications and source records attributed to Daniele Maselli.

8 recordsLinked to original sources

PubMed2006

Evaluation of 17-mm St. Jude Medical Regent prosthetic aortic heart valves by rest and dobutamine stress echocardiography.

BACKGROUND: The prosthesis used for aortic valve replacement in patients with small aortic root can be too small in relation to body size, thus showing high transvalvular gradients at rest and/or under stress conditions. This study was carried out to evaluate rest and Dobutamine stress echocardiography (DSE) hemodynamic response of 17-mm St. Jude Medical Regent (SJMR-17 mm) in relatively aged patients at mean 24 months follow-up. METHODS AND RESULTS: The study population consisted of 19 patients (2 men, 17 women, mean age 69.2 +/- 7.3 years). All patients underwent rest Doppler echocardiography before and after surgery and basal and DSE at follow up (infused at rate of 5 microg/Kg/min and increased by 5 microg/Kg/min at 5 min intervals up to 40 microg/Kg/min). The following parameters were evaluated at rest and/or under DSE: heart rate (HR), ejection fraction (EF), cardiac output (CO), peak and mean velocity and pressure gradients (MxV, MnV, MxPG, MnPG), effective orifice area (EOA), indexed EOA (EOAi), left ventricular mass (LVM), indexed LVM (LVMi), Velocity Time Integral at left ventricular outflow tract (VTI LVOT) and transvalvular (Aortic VTI), Doppler velocity index (DVI). At rest MxPG and MnPG were 29.2 +/- 7.1 and 16.6 +/- 5.8 mmHg, respectively; EOA and EOAi resulted 1.14 +/- 0.3 cm(2) and 0.76 +/- 0.2 cm(2)/m(2); DVI was normal (0.50 +/- 0.1). At follow-up LVM and LVMi decreased significantly from pre-operative value of 258 +/- 43 g and 157.4 +/- 27.7 g/m(2) to 191 +/- 23.8 g and 114.5 +/- 10.6 g/m(2), respectively. DSE increased significantly HR, CO, EF, MxGP (up to 83.4 +/- 2 1.9 mmHg), MnPG (up to 43.2 +/- 12.7 mmHg). EOA, EOAi, DVI increased insignificantly (from baseline up to 1.2 +/- 0.4 cm(2), 0.75 +/- 0.3 cm(2)/m(2) and 0.48 +/- 0.1 respectively). Two patients developed significant intraventricular gradients. CONCLUSION: These data show that SJMR 17-mm prostheses can be safely implanted in aortic position in relatively aged patients, offering a satisfactory hemodynamic performance at rest and under DSE, with full utilization of its available orifice, suggesting that a possible mild prosthesis-patient mismatch is not an issue of clinical relevance when this small prosthesis is used. Rest and Dobutamine stress echocardiography is a useful and effective means for evaluating prosthesis hemodynamics and for monitoring the expected LVH regression.

Aged↗

PubMed2006

Percutaneous mitral annuloplasty: an anatomic study of human coronary sinus and its relation with mitral valve annulus and coronary arteries.

BACKGROUND: To allow performance of "stand-alone" mitral annuloplasty with minimal invasiveness, percutaneous techniques consisting of delivery into the coronary sinus (CS) of devices intended to shrink the mitral valve annulus have recently been tested in animal models. These techniques exploit the anatomic proximity of the CS and mitral valve annulus in ovine or dogs. Knowledge of a detailed anatomic relationship between the CS, coronary arteries, and mitral valve annulus in humans is essential to define the safety and efficacy of percutaneous techniques in clinical practice. We sought to determine the qualitative and quantitative anatomic relationships between CS and surrounding structures in human hearts. METHODS AND RESULTS: The distance from the CS to the mitral valve annulus and the relationship between the CS and surrounding structures were studied in 61 excised cadaveric human hearts. Maximal distance from the CS to the mitral valve annulus was found to be up to 19 mm (mean, 9.7+/-3.2 mm). A diagonal or ramus branch, main circumflex artery, or its branches were located between anterior interventricular vein/CS and the mitral valve annulus in 16.4% and 63.9% of cases, respectively. CONCLUSIONS: Surgical anatomy suggests that in humans the CS is located behind the left atrial wall at a significant distance from the mitral valve annulus. Percutaneous mitral annuloplasty devices probably shrink the mitral valve annulus only by an indirect traction mediated by the left atrial wall; a theoretical risk of compressing coronary artery branches exists. Chronic studies are needed to address this problem and to determine long-term efficacy of such methods.

Cadaver↗

PubMed2006

Myocardial damage prevented by volatile anesthetics: a multicenter randomized controlled study.

OBJECTIVE: The purpose of this study was to evaluate the effects of volatile anesthesia versus total intravenous anesthesia on cardiac troponin release in off-pump coronary artery bypass grafting (OPCAB). DESIGN: The authors performed a multicenter randomized controlled study to compare cardiac troponin release in patients receiving either volatile anesthetics or total intravenous anesthesia for cardiac surgery on the beating heart, which is an excellent model of human myocardial ischemia. SETTING: Three university hospitals. PARTICIPANTS: The authors randomly assigned 57 patients to desflurane (volatile anesthetic) and 55 patients to propofol (intravenous anesthetic) in addition to an opiate-based anesthesia for OPCAB. INTERVENTIONS: The 2 groups of patients received either desflurane (volatile anesthetic) or propofol in addition to an opiate-based anesthesia for OPCAB. Peak postoperative troponin I release was measured as a marker of myocardial necrosis. Prolonged hospitalization was considered as a secondary outcome. MEASUREMENTS AND MAIN RESULTS: Patient mean age was 69 years, and 82% were men. There was a significant (p < 0.001) reduction in postoperative median (25th-75th percentiles) peak of troponin I in patients receiving volatile anesthetics, 1.2 (0.9-1.9) ng/dL, compared with patients receiving total intravenous anesthesia, 2.7 (2.1-4.0) ng/dL. This myocardial protection resulted in a reduced (p = 0.04) number (percentage) of patients requiring postoperative inotropes, 20 (35%) versus 31 (56%), and a reduced number (percentage) of patients submitted to prolonged hospitalization (> or =7 days), 7 (12%) versus 20 (36%) in the 2 groups (p = 0.005). One patient receiving total intravenous anesthesia died within 30 days of surgery. CONCLUSIONS: Myocardial damage measured by cardiac troponin release could be reduced by volatile anesthetics during OPCAB. Because patients underwent cardiac surgery on the beating heart, these results could have implications for cardiac patients undergoing noncardiac surgery.

Aged↗

PubMed2005

A technique to reposition sinotubular junction in aortic valve reimplantation procedures with the De Paulis Valsalva graft.

Sinotubular junction reconstruction in reimplantation type of valve-sparing aortic procedure can present some problem when a Valsalva graft is used. Since in the Valsalva graft the sinotubular junction height is predetermined, correct matching with native commissures height can be difficult. We propose a method by which it is possible to create a new sinotubular junction in Valsalva graft without altering its original configuration.

Aortic Aneurysm↗

PubMed2005

The ideal theoretical graft oversizing in valve-sparing aortic operations with a standard tubular or a Valsalva graft.

OBJECTIVE: We sought to determine, by a mathematical model, the ideal theoretical degree of ascending aortic graft oversizing needed to obtain normal sinuses dimension in the reimplantation type of valve-sparing aortic operations. METHODS: To define a normal-range value, size of sinuses of Valsalva was conventionally expressed as the area surrounding fully opened aortic cusps, the so-called beyond leaflets area (BLA), and measured in 50 healthy subjects. A mathematical relationship between aortic annulus diameter, aortic sinuses diameter and resulting BLA was defined. By simulating intra-operative scenarios, the effect of different degrees of a standard or Valsalva graft oversizing on BLA extension was tested. RESULTS: The same degree of graft oversizing resulted in a bigger beyond leaflets area for the Valsalva graft than for a standard graft. Oversizing degrees exceeding +7mm for a standard graft and +3mm for the Valsalva graft resulted in a beyond leaflets area over normal limits. Results were expressed in a visual form as two different normograms, one for the standard graft and one for the Valsalva graft. CONCLUSIONS: A less pronounced graft oversizing is needed to achieve normal-range sinuses size when using a Valsalva graft, the ideal theoretical graft oversizing was +7mm for a standard graft and +3mm for the Valsalva graft, our normograms can be helpful in selecting a proper graft size when performing a valve-sparing aortic procedure.

Adult↗

PubMed2005

Transaxillary aortic endoclamping for ascending aortic pseudoaneurysm and dissected descending aorta.

Patients presenting with pseudoaneurysm of the aortic root close to the sternum, severe aortic regurgitation, and chronic dissection of the descending aorta represent a formidable surgical challenge. Closed chest circulatory arrest in this setting carries a high risk of myocardial or brain damage. We propose a modification of the port-access technique that allows control and access of the pseudoaneurysm, avoiding the need for closed chest circulatory arrest. Our strategy is based on transaxillary endoclamping of the ascending aorta and combines the advantages of antegrade aortic flow with the possibility of stopping the heart and venting the left ventricle before sternotomy.

Aortic Dissection↗

PubMed2005

Endovascular aortic clamping for pseudoaneurysms of the aortic root with aortic regurgitation.

BACKGROUND: We propose a safer strategy for surgical treatment of retro-sternal pseudoaneurysms of the aortic root with severe aortic regurgitation. The objective was to allow safer re-entry in a quite and bloodless field eliminating the risk of ventricular distension and avoiding deep hypothermia. METHODS: In 6 patients presenting with postsurgical aortic root pseudoaneurysms in close proximity to the sternum associated with aortic regurgitation, we used the following techniques: femorofemoral cardiopulmonary bypass; transfemoral aortic endoclamping; percutaneous retrograde cardioplegia administration before sternotomy in patients with normal descending aorta; femoroaxillary cardiopulmonary bypass; transaxillary aortic endoclamping; percutaneous retrograde cardioplegia administration before sternotomy in patients with concomitant disease of the descending aorta. RESULTS: All patients survived the operation and were discharged home. Arterial cannulation and endoclamp insertion were uneventful. Reentry was uncomplicated. Deep hypothermia was avoided in all cases. No occurrences of even minor neurologic problems were observed. None of these patients experienced a postoperative low cardiac output syndrome. Postoperative course was complicated in 1 patient with re-entry for bleeding; acute renal insufficiency requiring hemofiltration in 2 patients; pneumonia in 1 patient; and soft tissues sternotomy infection in 1 patient. CONCLUSIONS: In patients presenting with a pseudoaneurysm of the aortic root attached to the sternum and concomitant aortic regurgitation it is possible, by closed chest endovascular aortic clamping, to eliminate risks of ventricular distension and to avoid deep hypothermia.

Adult↗

PubMed2005

A normogram to anticipate dimension of neo-sinuses of valsalva in valve-sparing aortic operations.

OBJECTIVE: The aim of the present study was to define a method to pre-determine the correct size of neo-sinuses of Valsalva in the reimplantation type of valve-sparing aortic operation. METHODS: The objective was achieved in three steps: (1) evaluation in the healthy population, of the normal size of sinuses of Valsalva expressed as the area surrounding fully opened aortic cusps, the so-called beyond leaflets area; (2) elaboration of a normogram by which, given a known annular diameter, it is possible to select the appropriate graft size to obtain a normal beyond leaflets area; (3) validation of the normogram by comparing, in a population of 20 patients undergoing a valve-sparing procedure, the predicted and observed beyond leaflets area. RESULTS: The following values for beyond leaflets area were observed: mean normal 320.6+/-120.6mm(2), mean predicted 355+/-63.2mm(2), mean observed 364.7+/-72.8mm(2).No significant differences were obtained for predicted versus observed values. Regression analysis showed a linear distribution with an r value of 0.95. CONCLUSIONS: We proposed a simplified approach for sizing of the neo-aortic root in the reimplantation type of valve-sparing aortic operation focussed on the size of sinuses of Valsalva. Our normogram showed to be reliable in anticipating beyond leaflets area. It can be helpful in avoiding the selection of an undersized or excessively oversized graft.

Adult↗