Biomedical subjects

Eitan Snir

Publications and source records attributed to Eitan Snir.

3 recordsLinked to original sources

PubMed2004

Impact of intraoperative transesophageal echocardiography in patients undergoing valve replacement.

BACKGROUND: The role of intraoperative transesophageal echocardiography (IOTEE) in valve replacement surgery is not well established. The aim of this study was to explore the impact of immediate postpump IOTEE in valve replacement surgery at a single tertiary medical center. METHODS: The departmental database was screened for valve replacement operations (mechanical or bioprosthetic valves) performed during a 55-month period that were succeeded by immediate postpump IOTEE. Data was gathered regarding the impact of IOTEE on the immediate postoperative course. RESULTS: The study group included 417 patients (44.8% male, 55.2% female, age 65.2 +/- 13.9 years). Prepump IOTEE was performed in 352 patients (84.4%). A single valve was replaced in 336 patients (80.6%) and two or more valves were replaced in 81 patients (19.4%). Overall 501 valves were inserted: mitral, 237 (131 mechanical, 106 biological); aortic, 221 (89 mechanical, 132 biological); tricuspid, 43 (2 mechanical, 41 biological). Unexpected pathologic echocardiographic findings on postpump IOTEE necessitated immediate surgical correction in 15 patients (3.6%): perivalvular leak in 8 patients (4 mitral, 4 aortic), immobilized leaflet in 4 patients (3 mitral, 1 tricuspid), coronary obstruction by an aortic bioprosthesis in 2 patients, and incompetent xenograft in 1 patient. Prolonged removal of air was necessary in 45 patients (10.8%). In 47 patients (11.3%) the postpump IOTEE contributed to the evaluation of difficult weaning from the bypass pump and to its appropriate therapeutic management (volume expansion, inotropic agents, vasodilators, or mechanical assistance). CONCLUSIONS: Immediate postpump IOTEE is an important diagnostic and therapeutic role in valve replacement surgery and should be widely implemented.

Adult↗

PubMed2004

Platelet function changes as monitored by cone and plate(let) analyzer during beating heart surgery.

BACKGROUND: Off-pump coronary artery bypass (OPCAB) is believed to reduce cardiopulmonary bypass (CPB)-related complications, including platelet damage. A hypercoagulable state instead of coagulopathy has been reported following OPCAB surgeries due to CPB. Whether platelet function is changed when the injurious effect of CPB is eliminated was investigated. METHODS: Platelet function was determined with the cone and plate(let) analyzer (CPA) method. The 2 parameters, average size (AS) and surface coverage (SC) of platelet aggregates, were measured with the CPA method to assess platelet aggregation and adhesion. These parameters were evaluated, and their values were compared at several stages of OPCAB surgery. The correlations of postoperative bleeding with platelet function at different stages of the surgery and with other factors, such as platelet count, hematocrit, and transfusions, were studied. RESULTS: Both AS and SC increased during several stages of the operation, and postoperative values (mean +/- SD) were significantly higher than preoperative values (30.4 +/- 8.1 microm 2 versus 23.3 +/- 6.9 microm 2 for AS [ P =.02] and 7.6% +/- 3.6% versus 5.2% +/- 1.8% for SC [ P =.04]). The mean total bleeding volume was 875 micro 415 mL. Preoperative AS and SC were the only parameters significantly ( P =.01) and linearly ( r = 0.7) related to postoperative bleeding. CONCLUSIONS: An increased platelet function, as determined by the CPA method, is found following OPCAB surgery. This phenomenon is probably at least partially responsible for the thrombogenic state after OPCAB surgery. Lack of platelet injury attributed to CPB may divert the system toward a more thrombogenic state. Preoperative platelet function, as evaluated by the CPA method, is an independent risk factor determining postoperative bleeding.

Blood Platelet Disorders↗

PubMed2003

Improvement in mitral regurgitation after aortic valve replacement.

BACKGROUND: Concomitant mitral valve regurgitation is often present in patients with aortic stenosis. The additional MV replacement is associated with high operative risk. Previous studies have shown an amelioration of MV regurgitation after aortic valve replacement but most of the patient groups were heterogenous. OBJECTIVES: To determine whether AV replacement for aortic stenosis has any effect on MV regurgitation. METHODS: We reviewed two-dimensional echocardiography and color flow Doppler assessment of both aortic stenosis and MV regurgitation severity in 30 patients. Patients with previous MV surgery, organic MV disease, occlusive carotid artery disease, ejection fraction < 50%, and coexisting significant AV regurgitation were excluded. Preoperatively, MV regurgitation was mild in 23 patients (77%) and moderate in 7 (23%); in no patient was the condition severe. All patients had severe atrial stenosis (peak average aortic gradient 86 +/- 22 mmHg in the mild MV regurgitation group and 83 +/- 26 mmHg in the moderate group). The patients were divided into two groups according to the severity of MV regurgitation (associated mild, and moderate). Group 2, with moderate MV regurgitation, was the most problematic in terms of decision making for concomitant MV surgery. Therefore, additional assessment of several parameters was required. RESULTS: There was a significant decrease in MV regurgitation area (7.6 +/- 1.9 vs. 3.0 +/- 1.2 cm2, P < or = 0.012) and percent (28 +/- 5% vs. 12 +/- 6%, P < or = 0.001) between pre- and postoperative evaluation. Thus, the severity of the condition in all patients with moderate MV regurgitation decreased after AV replacement; in the mild group it remained unchanged in 53% or improved in 47%. There was no association between the preoperative gradient on the aortic valve and the degree of MV regurgitation. CONCLUSIONS: In our population of patients with severe atrial stenosis there were no patients with coexisting severe MV regurgitation. The decision to repair or replace a severely leaking mitral valve is an easy one, as in mild MV regurgitation. The clinical problem often presents in patients with severe aortic stenosis and moderate MV regurgitation. We believe that additional MV surgery is not necessary, at least in patients with preserved left ventricular function and without organic MV disease.

Aged↗