Biomedical subjects

Massimo Massetti

Publications and source records attributed to Massimo Massetti.

25 records · Page 2Linked to original sources

PubMed2003

Mechanisms of sevoflurane-induced myocardial preconditioning in isolated human right atria in vitro.

BACKGROUND: The authors examined the role of adenosine triphosphate-sensitive potassium channels and adenosine A(1) receptors in sevoflurane-induced preconditioning on isolated human myocardium. METHODS: The authors recorded isometric contraction of human right atrial trabeculae suspended in oxygenated Tyrode's solution (34 degrees C; stimulation frequency, 1 Hz). In all groups, a 30-min hypoxic period was followed by 60 min of reoxygenation. Seven minutes before hypoxia reoxygenation, muscles were exposed to 4 min of hypoxia and 7 min of reoxygenation or 15 min of sevoflurane at concentrations of 1, 2, and 3%. In separate groups, sevoflurane 2% was administered in the presence of 10 microm HMR 1098, a sarcolemmal adenosine triphosphate-sensitive potassium channel antagonist; 800 microm 5-hydroxy-decanoate, a mitochondrial adenosine triphosphate-sensitive potassium channel antagonist; and 100 nm 8-cyclopentyl-1,3-dipropylxanthine, an adenosine A(1) receptor antagonist. Recovery of force at the end of the 60-min reoxygenation period was compared between groups (mean +/- SD). RESULTS: Hypoxic preconditioning (90 +/- 4% of baseline) and sevoflurane 1% (82 +/- 3% of baseline), 2% (92 +/- 5% of baseline), and 3% (85 +/- 7% of baseline) enhanced the recovery of force after 60 min of reoxygenation compared with the control groups (52 +/- 9% of baseline). This effect was abolished in the presence of 5-hydroxy-decanoate (55 +/- 14% of baseline) and 8-cyclopentyl-1,3-dipropylxanthine (58 +/- 16% of baseline) but was attenuated in the presence of HMR 1098 (73 +/- 10% of baseline). CONCLUSIONS: In vitro, sevoflurane preconditions human myocardium against hypoxia through activation of adenosine triphosphate-sensitive potassium channels and stimulation of adenosine A(1) receptors.

ATP-Binding Cassette Transporters↗

PubMed2003

A complex mitral valve reconstruction: a case report.

Several techniques are currently in use for mitral valve reconstruction. We report a mitral repair case in which the use of a combination of different surgical techniques resulted in the necessary correction. A 47-year-old woman underwent surgical intervention to treat severe mitral valve insufficiency due to A1/A2/A3 and P2 prolapsed valve tissue. A combination of quadrangular resection, sliding leaflet, single chordal transposition, "flip-over" leaflet, and ring annuloplasty techniques were applied, and postsurgical correct valve function was documented by results of a left ventricular saline filling test and transesophageal echocardiography control. Complex mitral valve repairing techniques can be combined to reestablish valvular function.

Female↗

PubMed2002

Early and long-term outcome in patients undergoing aortic root replacement with composite graft according to the Bentall's technique.

OBJECTIVE: The aims of this study were: (i) to evaluate the early and long-term outcome in patients undergoing aortic root replacement (ARR) with a composite graft; (ii) to identify the predictors for poor overall survival in this pool of patients. MATERIAL AND METHODS: Between January 1989 and December 2000, 212 patients underwent ARR with a CG. Mean age was 56+/-14 years, ranging from 16 to 77. Annuloaortic ectasia was the most frequent cause of aortic disease in this series, 81 (38%) patients, followed by atherosclerotic aneurysm 57 (27%) and type A acute aortic dissection 52 (24.5%). Marfan's syndrome was present in 37 (17.5%) patients. Duration of follow-up ranged from 1 to 120 months, mean 59+/-35 months. RESULTS: The overall hospital mortality was 16 (7.5%) patients. Eight of them had aortic dissection and four Marfan syndrome. The most frequently found complication resulted to be renal failure in 22 (10%) patients and low cardiac output in 15 (7%) patients. The incidence of perioperative myocardial infarction, neurological complications, respiratory complications, renal failure and coagulopathy incidence were significantly higher in patients with cardiopulmonary bypass (CPB) time >170 min, CA >40 min, and total aortic arch replacement. The actuarial survival at 1, 3 and 5 years resulted to be 91.8, 86 and 81.5%, instead the actuarial survival without re-operation resulted to be 89, 82 and 78%. The actuarial survival in patients with aortic dissection was significantly lower versus non-dissection (P=0.022). The multivariate analysis revealed the aortic dissection (P=0.03), age >65 years (P=0.014), associated coronary artery disease (P=0.002), NYHA functional class>/=3 (P=0.027), LVEF <35% (P=0.002) and total arch reconstruction (P=0.003) as strong predictors for poor overall survival in patients undergoing ARR. CONCLUSIONS: The ARR with a CG offers acceptable early and long-term outcome. The predictors for poor overall survival in patients undergoing ARR seems to be preoperative aortic dissection extended into the aortic arch, older age, depressed left ventricular function and associated coronary artery disease.

Adolescent↗

PubMed2002

Bypassing a dilemma: intraoperative coronary angiography in acute aortic dissection.

Untreated coronary artery disease may complicate the clinical course of patients with Stanford type A acute aortic dissection. In these patients the role of coronary angiography for the assessment of coronary circulation is controversial and it is considered by some time consuming thus increasing the risk of rupture. We describe a case of acute type A aortic dissection that illustrates our approach to this problem.

Aged↗

PubMed2002

Extrathoracic cannulation of the left common carotid artery in thoracic aorta operations through a left thoracotomy: preliminary experience in 26 patients.

BACKGROUND: In aortic operations performed through a left thoracotomy, which require total bypass and deep hypothermic circulatory arrest, femoral artery cannulation is commonly used for arterial perfusion. This route limits the time of safe circulatory arrest and is associated with the risks of retrograde embolization or, in the case of aortic dissection, malperfusion of the vital organs. To overcome these problems, we have used cannulation of the extrathoracic left common carotid artery to ensure a central a route of arterial perfusion in these operations. The preliminary results are presented. METHODS: Between December 1999 and April 2001, we used left common carotid artery cannulation in 26 operations on the thoracic aorta performed through a posterolateral thoracotomy with an open technique during deep hypothermic circulatory arrest. Institutional review board approval and informed consent were obtained. The indications included perforating atherosclerotic ulcer (n = 5), chronic aortic aneurysm (n = 9), acute type B aortic dissection (n = 3), and chronic dissection of the thoracic aorta (n = 9). Transcranial Doppler ultrasonographic monitoring of both the right and left middle cerebral arteries was used to assess the adequacy of cerebral bihemispheric perfusion and to determine the differences in blood flow velocities throughout the procedure. RESULTS: Left common carotid artery cannulation was successful in all patients. All patients awoke from the operation, and none had cerebrovascular accidents. None died in the hospital, and complications related to carotid artery cannulation were not observed. None of the patients experienced postoperative paraplegia. In all patients transcranial Doppler monitoring indicated the absence of cerebral embolic phenomena throughout the entire procedure. Significant differences in middle cerebral artery flow velocities were observed at different phases of the procedures and between the right and left middle cerebral arteries during carotid cannulation and during selective cerebral perfusion. Nevertheless, the maximal drop of right middle cerebral artery blood velocity during selective perfusion through the left common carotid artery was within 50% of the left middle cerebral artery velocity, indicating adequate bihemispheric perfusion. CONCLUSIONS: In patients undergoing aortic operations through a left thoracotomy, extrathoracic left common carotid artery cannulation was a safe and effective means of providing proximal arterial inflow during cardiopulmonary bypass, which can be used to selectively perfuse the brain, as well as to prevent embolic phenomena in the arch vessels.

Adult↗

PubMed2002

Mechanisms of desflurane-induced preconditioning in isolated human right atria in vitro.

BACKGROUND: The authors examined the role of adenosine triphosphate-sensitive potassium (K(ATP)) channels, adenosine A1 receptor, and alpha and beta adrenoceptors in desflurane-induced preconditioning in human myocardium, in vitro. METHODS: The authors recorded isometric contraction of human right atrial trabeculae suspended in oxygenated Tyrode's solution (34 degrees C; stimulation frequency, 1 Hz). Before a 30-min anoxic period, 3, 6, and 9% desflurane was administered during 15 min. Desflurane, 6%, was also administered in the presence of 10 microm glibenclamide, a K(ATP) channels antagonist; 10 microm HMR 1098, a sarcolemmal K(ATP) channel antagonist; 800 microm 5-hydroxy-decanoate (5-HD), a mitochondrial K(ATP) channel antagonist; 1 microm phentolamine, an alpha-adrenoceptor antagonist; 1 microm propranolol, a beta-adrenoceptor antagonist; and 100 nm 8-cyclopentyl-1,3-dipropylxanthine (DPX), the adenosine A1 receptor antagonist. Developed force at the end of a 60-min reoxygenation period was compared (mean +/- SD). RESULTS: Desflurane at 3% (95 +/- 13% of baseline), 6% (86 +/- 6% of baseline), and 9% (82 +/- 6% of baseline) enhanced the recovery of force after 60 min of reoxygenation as compared with the control group (50 +/- 11% of baseline). Glibenclamide (60 +/- 12% of baseline), 5-HD (57 +/- 21% of baseline), DPX (63 +/- 19% of baseline), phentolamine (56 +/- 20% of baseline), and propranolol (63 +/- 13% of baseline) abolished desflurane-induced preconditioning. In contrast, HMR 1098 (85 +/- 12% of baseline) did not modify desflurane-induced preconditioning. CONCLUSIONS: In vitro, desflurane preconditions human myocardium against simulated ischemia through activation of mitochondrial K(ATP) channels, adenosine A1 receptor, and alpha and beta adrenoceptors.

Adenosine Triphosphate↗

PubMed2002

Nonocclusive intestinal ischemia in patients with acute aortic dissection.

BACKGROUND: In aortic dissection, visceral complications that result from aortic branch compromise have been described extensively, whereas intestinal ischemia not associated with the false lumen anatomy has rarely been discussed. The aim of this report is to identify clinical factors that may contribute to the development of this form of acute mesenteric ischemia, to profile the patients at greatest risk, and to review diagnostic and treatment methods that emerged from our experience. METHODS: With a computerized database, we identified 371 patients who underwent treatment in our institution with a diagnosis of aortic dissection between July 15, 1985, and January 10, 2001. Mesenteric ischemia was present in 73 patients (19%). In 36 patients (9%), bowel ischemia was not associated with a false lumen anatomy or an extension of the dissection process. From a general analysis of the determinants of mesenteric ischemia in aortic dissection, we investigated, with univariate and multivariate analysis, the specific characteristics of these patients with nonocclusive ischemia. A retrospective analysis of the oxygen metabolic profile of patients who underwent operation also was performed. RESULTS: The mortality rate in patients with nonocclusive mesenteric ischemia was 86%; sepsis and multiple organ failure were the causes of death in all nonsurvivors. Surgical treatment was beneficial only in the early phases of the disease. The results of the multivariate analysis showed the multifactorial origin of nonocclusive mesenteric ischemia; cerebral ischemia, thrombosis of the false lumen, severe coagulation disorders, chronic obstructive pulmonary disease, aortic calcinosis, prolonged hypotension, chronic renal insufficiency, and low cardiac output were independent predictors of the condition. In patients who underwent operation, the significant risk factors were severe coagulation disorders, postoperative cerebral ischemia, maximal oxygen extraction rate of more than 0.40, aortic calcinosis, chronic obstructive pulmonary disease, thrombosis of the false lumen, inotropic support, and chronic renal insufficiency. An oxygen extraction rate of more than 0.4 at 6 hours after operation was found to be an index of intestinal damage sufficient to initiate an evaluation for visceral ischemia. Significant differences with occlusive ischemia also were evidenced with this study. CONCLUSION: In aortic dissection, nonocclusive mesenteric ischemia shows some unique clinical and individual predisposing factors. Most instrumental investigations are of poor diagnostic value, and prognosis is poor, especially when mesenteric gangrene had already taken place. Prevention can be exercised only with a heightening of our awareness of this condition and with timely correction of metabolic disturbances. In suspected cases, an aggressive surgical attitude may represent the only means for reducing mortality.

Acute Disease↗