Biomedical subjects
Publications and source records attributed to M Merlo.
Primary cardiac neoplasms are rare in animals. Hemangiosarcoma is the most common primary cardiac tumour in the dog, but has not been reported in the cat. We describe the clinical signs, the gross examination, and the morphological and immunohistochemical features of a haemangiosarcoma in the right atrium of a 13-year-old domestic shorthair cat. In addition, a distant metastasis was found in the liver.
We have studied hadronic four-body decays of D(+) and D(+)(s) mesons with a K(S) in the final state using data recorded during the 1996-1997 fixed-target run of the Fermilab high energy photoproduction experiment FOCUS. We report a new branching ratio measurement of gamma(D(+)-->K(S)K-pi(+)pi(+))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0768+/-0.0041+/-0.0032. We make the first observation of three new decay modes with branching ratios gamma(D(+)-->K(S)K+pi(+)pi(-))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0562+/-0.0039+/-0.0040, gamma(D(+)-->K(S)K+K-pi(+))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0077+/-0.0015+/-0.0009, and gamma(D(+)(s)-->K(S)K+pi(+)pi(-))/gamma(D(+)(s)-->K(S)K-pi(+)pi(+)) = 0.586+/-0.052+/-0.043, where in each case the first error is statistical and the second error is systematic.
Using a large sample of photoproduced charm mesons from the FOCUS experiment at Fermilab (FNAL-E831), we observe the decay D0-->K+pi- with a signal yield of 149+/-31 events compared to a similarly cut sample consisting of 36 760+/-195 D0-->K-pi+ events. We use the observed ratio of D0-->K+pi- to D0-->K-pi+ (0.404+/-0.085+/-0.025)% to obtain a relationship between the D0 mixing and doubly Cabibbo suppressed decay parameters.
BACKGROUND AND AIM OF THE STUDY: Limited data are available regarding the efficacy of mitral valve repair in patients affected by active, acute infective endocarditis. In addition, the predictivity of transesophageal echocardiography (TEE) for guiding the surgical decision-making process in these patients has not yet been reported. The study aim was to evaluate the long-term results of mitral valve repair and role of TEE in active, acute infective endocarditis. METHODS: The study population consisted of patients affected by infective endocarditis of the mitral valve who underwent surgery. TEE was performed intraoperatively to guide the best surgical approach. All patients were followed up (mean 73+/-8 months) after surgery. RESULTS: Twenty-eight patients underwent surgery for infective endocarditis; of these, 13 had mitral valve repair for active, acute infective endocarditis and formed the basis of the study. Sensitivity, specificity, positive predictive value, negative predictive value of TEE in detecting the mechanism of mitral regurgitation were 87%, 100%, 100% and 92%, respectively. The predictivity test of TEE in guiding surgical strategy was 94%. All patients were alive at the time of follow up; 10 (77%) were in NYHA class I and three in class II (23%). Mitral regurgitation was severe in one patient (8%), moderate in three (23%), mild in four (31%), and absent in five (38%). No relapses of active infective endocarditis were observed during the follow up period. CONCLUSION: Mitral valve repair appears to be an effective treatment for active, acute infective endocarditis with mitral regurgitation and should be considered as a therapeutic strategy when surgery is contemplated. TEE has a fundamental role in the surgical decision-making process in these patients.
BACKGROUND: Aim of this study was to evaluate the results of endovascular repair of abdominal aortic aneurysm (AAA) in patients considered not suitable for traditional open surgical repair because of the high anesthesiological risk. METHODS: We have retrospectively evaluated the result of the endovascular treatment of 11 patients with AAA of more than 6 cm diameter and high surgical risk due to cardiac hypokinesia and/or respiratory insufficiency. Patients were selected by a team composed of vascular surgeons and vascular radiologists who decided to implant the graft according to anatomical features of the AAA and of the iliac arteries. The treatment was performed in loco-regional anesthesia. The main end-points were: implantation success, mortality, morbidity, the absence of endoleak during the follow up that lasted two years. RESULTS: All the grafts were successfully implanted. There were no complications caused by anesthesiological manouvres. We had a minor intra-operative vascular complication and we performed three adjunctive endovascular procedures. A patient died of acute myocardial infarction, in the post operative period. Mean stay was six days. Pre-discharge scan showed 3 endoleaks (type I), two of these healed spontaneously and one sealed by percutaneous endovascular treatment. During follow-up (3-24 months) no patient died. One endoleak (type II) still persists. CONCLUSIONS The use of loco-regional anaesthesia allows us to treat high risk patients. Following strictly the criteria of patient selection, the surgical high risk seems not to influence significantly the mid term results that are almost equal to the ones obtained in low-risk patients.
BACKGROUND: The rupture of an aortic aneurysm is the most frequent and most severe complication, with an incidence of approximately 20-40/100,000 persons each year. The aim of this study was to identify the preoperative, intraoperative and postoperative factors that may influence the mortality rate. METHODS: Between January 1996 and December 1999 145 patients underwent emergency abdominal aortic repair surgery. One hundred and twenty-three patients represented a ruptured AAA and 22 a fissured aneurysm. One hundred and thirty-one patients were males and 14 were females; their mean age was 75+/-5.06 years. We selected a number of parameters after a review of the international literature and these were analysed in the two classes of survivors. No statistical analyses were performed on fissured aneurysms owing to the scant number of cases examined. RESULTS: Mortality was 41.4% (44.7% in ruptured aneurysms alone). The following were negative preoperative prognostic factors: old age, hypertension, ASA V, intraoperative anuria and platelet count <100,000. Intraoperative factors included: hypotension, cardiac arrest, onset of anuria, aortic clamping in more than one site, duration of surgery, quantity of RBC and plasma transfused. The main postoperative variables correlated to mortality were: hypotension, hypothermia, onset of anuria, need for further transfusions, high creatinine levels. CONCLUSIONS: Rapid intervention can minimise mortality in structures with expert teams of surgeons and anesthetists experienced in treating this type of pathology.
The authors report the observation of one case of vagal paraganglioma occurred in a young woman. The tumor manifested itself as a left sub-mandibular tumescence; the very first diagnostic approach was achieved through echography, which showed a mass behind the internal carotid artery and compressing the internal jugular vein. The following examinations, represented by neck CT, NMR, angiography and fine needle aspiration initially directed towards the suspicion of chemodectoma. Only at operation, the anatomical situation of the tumor, which encapsulated the vagus nerve and the subsequent results of the hystological examination revealed the correct diagnosis of vagal paraganglioma.
BACKGROUND: Traumatic rupture of the aortic isthmus is a highly lethal lesion. Controversy currently exists regarding the best management of the lower body circulation system during repair of an acute aortic transsection. The aim of this study was to evaluate our results using different methods of distal aorta perfusion in order to prevent ischemia of the spinal cord. METHODS: Between October 1987 and October 1999, 23 patients (20 males, 3 females, mean age 28 years) with rupture of the thoracic aorta underwent surgical repair; 18 of these were acute ruptures and 5 post-traumatic pseudoaneurysms. RESULTS: All cases of rupture were associated with violent, sudden deceleration and in all but one subject it was due to a traffic accident. Twenty patients had severe associated lesions involving the cranium, abdomen, thorax or leg fractures. The operation was performed with a left postero-lateral thoracotomy in all but one case which underwent sternotomy (the patient with an associated lesion of the distal part of the arch). In 1 patient repair was accomplished using simple aortic cross-clamping, in another with total cardiopulmonary bypass, deep hypothermia and cardiac arrest and in 4 cases with partial cardiopulmonary bypass (1 left atrium-femoral artery and 3 femoro-femoral bypass). Seventeen patients were treated using the centrifugal pump (Bio-Medicus) for left atrium-femoral artery bypass. The perioperative mortality was 8.6%, including 2 patients operated in cardiogenic shock. In the 21 surviving patients the postoperative period was free from any cardiovascular complications, with no cases of paraplegia. There were no late deaths (mean follow-up 4 years) and all patients are in good clinical conditions. CONCLUSIONS: These results indicate that the outcome mainly depends on preoperative clinical conditions, associated lesions and the timing of the operation. We conclude that the Bio-Medicus centrifugal pump is a simple and safe means of perfusing the lower body, kidney, and spinal cord without heparinization in a patient with multiple injuries.
The authors report two cases of internal carotid artery stenosis associated with brain tumors. After the presentation of the rarity of this combination little described in the literature, they point out their therapeutic behaviour explaining their technical decisions.
BACKGROUND: Left atrial myxomas are the most common benign intracardiac tumors. The aim of this study was to compare our experience with the data reported in the literature. METHODS: Between May 1985 and August 1999, 26 patients (8 males, 18 females) with left atrial myxomas underwent surgical resection of these tumors at the Department of Cardiac Surgery, Ospedali Riuniti of Bergamo (Italy). Symptoms included congestive heart failure, dyspnea, arrhythmias, chest pain and syncope. Diagnosis was established preoperatively in all patients by echocardiography and angiocardiography was performed in 8 cases. All tumors were excised with a wide margin of uninvolved atrial septum. Two patients underwent concomitant coronary artery bypass. RESULTS: There was 1 early death due to irreversible ventricular fibrillation. Follow-up was completed for the 25 late survivals. Three patients died, years after operation, due to extracardiac causes. One patients had recurrence of the tumor, which was successfully removed 4 years after initial operation. All other patients are asymptomatic and free from disease. CONCLUSIONS: Operation for left atrial myxoma can be undertaken solely on the basis of echocardiographic findings, but coronary angiography should be performed in older patients who are at risk for coronary artery disease. Surgical excision of left atrial myxomas must be performed as soon as possible after diagnosis is established because of the high risk of valvular obstruction or systemic embolization. Biatrial approach allows for the inspection of the four cardiac chambers, limits manipulation of the mass, and facilitates the complete excision of the tumor. Thus, surgical intervention can be curative for patients with left atrial myxomas and most of these can expect an excellent outcome. Since late recurrence, although rare, has been reported, especially in familial myxomas, long-term clinical and echocardiographic follow-up is recommended.
Hypercholesterolemia and hypertension are frequently associated with elevated sympathetic activity. Both are independent cardiovascular risk factors and both affect endothelium-mediated vasodilation. To identify the effects of cholesterol-lowering and antihypertensive treatments on vascular reactivity and vasodilative capacity, we studied 30 hypercholesterolemic hypertensive subjects. They received placebo for 4 weeks, either enalapril or simvastatin for 14 weeks, and, finally, both medications for an additional 14 weeks. Postischemic forearm blood flow (MFBF) and minimal vascular resistance (mFVR) were used as indices of vasodilative capacity and structural vascular damage, respectively. Total (resting-stress-recovery phases) cardiovascular (blood pressure [BP] and heart rate [HR]) and regional hemodynamic (FBF and FVR) reactivity to stressful stimuli were calculated as area-under-the-curve (auc) (valuextime). Compared with baseline levels, simvastatin reduced total (TOT-C) and LDL cholesterol (LDL-C) (1.27 mmol/L, P<0.001 and 1.33 mmol/L, P<0.001, respectively). Enalapril also reduced TOT-C and LDL-C (0.6 mmol/L, P<0.001 and 0.58 mmol/L, P<0.05, respectively). MFBF was increased substantially by both treatments (P<0.001). Enalapril had a greater effect (-1.7 arbitrary units (AU), P<0.001) than simvastatin (-0.6 AU, P<0.05) on mFVR. During stress, FBF increased more with enalapril (4.4 FBFxminutes, P<0.001) than with simvastatin (1.8 FBFxminutes, P<0.01). Conversely, FVR stress response was reduced more with enalapril (9.1 FVRxminutes, P<0.001) than with simvastatin (2.9 FVRxminutes, P<0.01). During combination treatment, a significant (0.001>P<0.05) additive effect on hypercholesterolemia, structural vascular damage, BP, and FVR was shown. The findings suggest that angiotensin-converting enzyme (ACE) inhibition induces a larger reduction than HMG-CoA reductase blockade in vascular reactivity and structural damage in hypercholesterolemic hypertensive subjects.
BACKGROUND: Atherosclerotic lesions of the brachiocepfialic trunk are relatively rare compared with other types of vascular diseases. Median sternotomy with direct endothoracic repair is recommended because of good early and long-term results. Nevertheless, this procedure is not without risks such as hemorrhaging, embolism, aortic dissection, infection or death. METHODS: This report therefore, describes our experience in intraoperative balloon angioplasty and additional stent placement of isolated stenosis of the brachiocephalic trunk with cerebral protection ensured by common carotid artery clamping. Through an anterolateral cervical approach the right common carotid artery was surgically exposed. After dilating the brachiocephalic trunk and positioning the stent, the vessel was repaired with a continuous suture. RESULTS: In all patients the dilation of the stenosis of the brachiocephalic trunk and the stent placement were successful without any side-effects. No distal embolism with neurologic events, innominate artery dissection, rupture, occlusion or neck hematoma occurred. All patients were discharged three days after the intervention. CONCLUSIONS: This technique offers a safe, effective approach to stenoses of innominate arteries because it is less invasive than conventional transthoracic or extrathoracic surgery and offers excellent early and mid-term results. We believe that this technique is a safe and effective alternative to conventional surgery.
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Office and ambulatory pulse pressure have been recognized as independent predictors of cardiovascular mortality and atherosclerosis in hypertensives as well as in normotensives. On the other hand, the vascular reactivity, in subjects with high pulsatile component of blood pressure, has not been studied yet. The purpose of our study was to identify the regional muscular hemodynamics and the cutaneous microvascular changes during laboratory stimuli in young adult very mild hypertensives with high pulse pressure. The cardiovascular (Finapres), the forearm vascular (plethysmography) and the microvascular cutaneous (laser-Doppler flowmetry and transcutaneous oximetry) responses to psychophysiological stimuli were measured. In addition, the hyperemic forearm vascular response to the ischaemic test was measured as haemodynamic index of vascular damage. We studied 15 very mild hypertensives with higher office pulse pressure and 15 patients with similar age, history of hypertension, metabolic parameters and systodiastolic blood pressure but lower pulse pressure values. Patients with high pulse pressure demonstrated reduced hyperemic response and increased residual vascular resistance at the forearm ischaemic test. They did not vary for all the parameters, except pulse pressure, during the baseline period but the total stress response, as residualized area-under-the-curve, was notably different. Patients with higher office pulse pressure demonstrated a significant increased heart rate, systolic and pulsatile blood pressure reactivity. On the contrary, they showed a reduced forearm and cutaneous blood flow response combined to a reduced transcutaneous tissutal oxygenation. The findings suggest that the increased pulsatile component of blood pressure might be associated to structural and functional vascular impairments since the very early stages of hypertension in young adults without metabolic disorders.
BACKGROUND: The purpose of this study was to define a correct anesthesiological and surgical approach in patient who present a significant carotid stenosis with contralateral carotid occlusion. METHODS: Between 1996 and 1998 in our Department of Vascular Surgery of the Hospital S. Giovanni Battista has been executed 337 Carotid Endoarterectomies (CEA). Of these, 44 patient (13%) had a contralateral internal carotid occlusion. Forty was male (91%), and 4 female (9%). Echo Doppler, angiography, angioTC or angio-RMN and TCD were performed in all patients. In all cases was executed a traditional CEA. RESULTS: Because of the presence of a large ischaemic cerebral lesion or clamping intolerance 12 operation were performed under general anesthesia (27%). Shunt was used in 15 patients (34%) and patch was used in 10 cases (23%). In 2 cases (4.5%) there was be a thrombosis of the operated internal carotid artery and one patient died (2.3%). CONCLUSIONS: The presence of contralateral internal carotid occlusion with carotid stenosis > 70% increase the risk of peroperative stroke because of the difficulty of collateral cerebral blood flow. The execution of echo Doppler, angiography, angioTC or angioRM and TCD and their evaluation permit to choice the best anesthesiological and surgical treatment. The utilization of narcosis with thiopental protection and shunting reducing the rate of perioperative stroke, but the local anesthesia allows the best monitoring of intraoperative cerebral function. This behaviour was correctly when in patient with contralateral internal carotid occlusion there is an insufficient intracranic vascularization or an extensive ischaemic lesion or clamping intolerance.
Deep vein thrombosis in patient with superficial thrombophlebitis of the leg. Description of two cases. Two clinical cases already observed at our Department of Vascular Surgery, regarding patients with superficial thrombophlebitis (STF) associated with a deep venous thrombosis (DVT) are presented. The diagnosis of DVT was achieved exclusively on the basis of the duplex scanner because the two patients were completely asymptomatic. The chance that symptoms and clinical signs of STF cover a DVT is a possibility that should always be considered. For this reason every STF should be further investigated with duplex scanner in order to exclude that the deep venous circulation get involved at the same time. The DVT in these cases is generally due to the spreading of the thrombosis process from the perforating branches. The chance of a multiple onset of thrombosis in the superficial and deep circulation represents anyway an hypothesis worth of studying.
The splenic artery aneurysms usually have an asymptomatic course; their rupture is associated with high mortality. The clinical history and the treatment of two patients with splenic artery aneurysm are reported. Of the two cases, one was asymptomatic, diagnosed with upper abdomen ultrasound, the other one was treated as an emergency because presented with shock. Both patients underwent surgical procedure; ligature of the splenic artery and splenectomy were performed. Early diagnosis is important in these lesions because the progressive enlargement and eventual rupture are the natural history. Ultrasonography (US) and computed tomography (TC) are very helpful as diagnostic tools, however angiography represents the method of choice since it could be the first step of the embolization treatment. If the diameter is more than 2.5 cm surgical treatment must be performed. Ruptures are treated with emergency operations, when possible. In high-risk patients non operative management by selective embolization may be a suitable alternative.
Successful one-stage repair of a Berry syndrome (interrupted aortic arch, distal aortopulmonary septal defect, right pulmonary artery branch originating from the ascending aorta, and intact ventricular septum) in the neonatal period has been reported in only 2 cases. We report the case of a newborn operated on with deep hypothermic arrest and isolated myocardial perfusion in whom the interrupted aortic arch was corrected by direct anastomosis between the ascending and descending aorta and the aortopulmonary septal defect was treated with reconstruction of the pulmonary trunk and right pulmonary artery, using a flap of aortic tissue. A native pericardial patch was used to reconstruct the ascending aorta.