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L Parenzan

Publications and source records attributed to L Parenzan.

At least 19 recordsLinked to original sources
PubMed2001

Left-side approach to the mitral valve.

BACKGROUND AND AIM OF THE STUDY: The standard, minimally invasive surgical approach to the mitral valve is usually accomplished from the right side, through a longitudinal incision posterior and parallel to the interatrial groove. The left-side approach should perhaps be reconsidered for its suitable exposure of the mitral valve. METHODS: Eleven consecutive patients underwent mitral valve surgery via a left lateral minithoracotomy, with cardiopulmonary bypass performed through the left femoral artery and vein. The left internal mammary artery was used as a coronary graft in one patient. Cardioplegic solution was delivered through the ascending aorta. After direct aorta cross-clamping, mitral surgeries were performed, including mechanical and bioprosthetic implants, redo operations, annuloplasties and repairs. RESULTS: An excellent view of the mitral valve was obtained in all cases, with optimal vision of the whole annulus, chordae tendineae, papillary muscles and aortic valve possible. Exposure of the mitral valve was superior to that achieved with the standard approach from the right, notably with a wider angle of vision and greater flexibility of movement available. Moreover, mitral valve structures were closer to the operator, making the procedure easier to perform. CONCLUSION: The left-side approach to the mitral valve offers excellent vision and exposure of the valve. Although awaiting additional cases to validate results, in the absence of major complications we recommend this technique.

Aged↗
PubMed1995

Mitral dilatation with the Multi-Track system: an alternative approach.

We developed a simple and versatile new technique (Multi-Track) for percutaneous mitral valvotomy using two two separate balloon catheters positioned on a single guidewire. The first catheter, with only a distal guidewire lumen and a proximal balloon, is introduced over the guidewire into the vein and then advanced into the mitral valve orifice. Subsequently, a normal balloon catheter running on the same guidewire is inserted and lined up with the first catheter so the two are positioned side by side. The balloons are then inflated simultaneously. The technique was applied in 12 patients between 10 and 44 years of age (mean, 27.1) and weighing 24-80 kg (mean, 50.3). Valve area increased from 0.66 cm2 (range, 0.3-0.9 cm2) to 1.97 cm2 (range, 1.3-3.1 cm2) and mean left atrial pressure dropped from 31 mmHg (range, 18-52 mmHg) to 12 mmHg (range, 5-22 mmHg). Mitral dilatation with the Multi-Track system gives results comparable to those with previously described techniques and uses simpler and less costly catheters.

Adolescent↗
PubMed1993

Thrombotic and hemorrhagic complications in patients with mechanical heart valve prosthesis attending an anticoagulation clinic.

This study evaluated the advantage of an anticoagulation clinic in terms of the improvement of the clinical quality of oral anticoagulation (i.e. prevention of thromboembolism and low rate of hemorrhagic complications). The incidence of thromboembolic events and major hemorrhagic complications was assessed in a series of 271 patients on oral anticoagulation for mechanical heart valve prosthesis before and after their enrollment in our anticoagulation clinic from January 1987 to December 1990. Risk factors for hemostatic events were also analyzed. The incidence of major hemostatic complications was significantly lower when patients attended the clinic: 1.0 vs 4.9%/pt-yr for hemorrhage and 0.6 vs 6.6%/pt-yr for thrombosis. This depended on three main factors: better dose regulation of warfarin, continuous patient education and early identification of clinical conditions potentially at risk for thrombosis and hemorrhage. Only previous hemorrhagic or thromboembolic events were recognized as major risk factors for hemostatic complications. In conclusion, our study shows that an anticoagulation clinic offers a real advantage to patients with mechanical heart valve prosthesis in terms of prevention of thromboembolic events and hemorrhagic complications.

Administration, Oral↗
PubMed1992

[Emergency surgery of acute coronary insufficiency].

In our centre, during the last five years, emergency operations (within 6 hours) and urgent operations (within 72 hours) have represented 1/4 of all coronary surgery. 295 patients (pts) have been operated on since 1972: of these, 279 with simple revascularization, 5 with combined major surgery, and 11 as a consequence of mechanical complications of acute myocardial infarction. These last were all in cardiogenic shock: the overall 30-day mortality rate was 5.4% (3.6% in those pts with simple revascularization, 20% in those with combined major surgery, and 45.4% in pts with cardiogenic shock). In the subgroup with simple revascularization, the incidence of non fatal perioperative acute myocardial infarction (AMI) was 4.7% in 253 pts with unstable angina, 52.2% in 23 pts with abrupt closure during coronary angioplasty, and obviously 100% in 3 pts surgically treated during evolving AMI. We were able to identify in the univariate analysis as the only 30-day risk mortality factors: 1) a reduced ejection fraction (< 30%) and 2) the combination with endarterectomy. Other factors (female sex, age > 70, severity of angina, diffuse coronary artery disease and more than 3 by pass grafts) have shown a tendency to increase the mortality rate without statistical significance. No deaths occurred in pts revascularized in emergency situations due to coronary angioplasty complications. In recent years emergency and urgent coronary surgical operations have been increasing, with an increase in pts with higher risk factors. In pts with simple revascularization, 30-day mortality and incidence of myocardial infarction are similar to those of elective surgery. In pts with abrupt closure as a consequence of coronary angioplasty the mortality rate seems very low, while the incidence of infarction remains extremely high. These observations have allowed the development of an integrated protocol of intervention in acute unstable coronary syndromes.

Acute Disease↗
PubMed1991

Long-term results after atrial correction of complete transposition of the great arteries.

This study presents the late results for the first 104 consecutive patients surviving and atrial repair for transposition of the great arteries (TGA) between January 1971 and December 1978 (group 1). Mean follow-up was 12 years (range, 0.1 to 17.7 years). The actuarial survival rate at 18 years was 84.2% (70% confidence limits, 79% to 88%) for simple TGA and 93.7% (70% confidence limits, 84% to 97%) for complex TGA. Nine of the 11 deaths were sudden. Two (2.6%) of the 78 late survivors operated on for simple TGA are in New York Heart Association functional class III or IV versus 4 (26.7%) of the 15 survivors with complex TGA; the other patients are doing very well. To better assess long-term results, we report the findings for randomly obtained electrocardiograms, Holter monitor recordings, radionuclide angiographic studies, and cardiac catheterizations performed in 1987 in a larger group of 159 long-term survivors of atrial repair operated on at Ospedale Riuniti di Bergamo from January 1971 to December 1984 (group 2), which includes all of group 1. The findings confirm that the arterial switch repair is the procedure of choice for complex TGA and that there is a major incidence (approximately 10%) of systemic right ventricular dysfunction and rhythm disturbances after the atrial repair. On the other hand, our late survival rate at 18 years of 84% for simple TGA with 97.5% of the patients in functional class I is a result that should be kept in mind, especially in institutions where the arterial switch is a relatively new approach and presumably is a higher risk to cause early death.

Cardiac Catheterization↗
PubMed1991

Assisted circulation for myocardial recovery after repair of congenital heart disease.

Between January 1987 and May 1990, six children underwent ventricular assisted circulation for recovery of myocardial function after cardiac surgery. Their ages ranged from 9 months to 12 years. Three patients had tetralogy of Fallot and one had atrioventricular discordance with ventriculoarterial concordance, ventricular septal defect, and under-over ventricles. Double outlet left ventricle and a large ventricular septal defect with pulmonary hypertension was present in the remaining two. The duration of circulatory support averaged 126 +/- 57 h. An extracorporeal membrane oxygenator (ECMO) was used in four patients, biventricular assistance with centrifugal pumps in one, and left ventricular assistance followed by ECMO in the last patient. Circulatory support was begun in the operating room in two patients who could not be weaned from cardiopulmonary bypass. Both these patients are long-term survivors. Assisted circulation was implanted in four patients in the intensive care unit because of low cardiac output refractory to any pharmacological treatment. Only one of these patients could be weaned from circulatory support but he died 20 days later because of multiorgan failure due to persistent poor myocardial function. The causes of death in the remaining three patients were intracranial hemorrhage, untreatable bleeding, and failure of myocardial recovery, respectively. We believe that early postoperative use of circulatory support can be a major determinant for recovery of myocardial function in patients who have severe low cardiac output following repair of congenital cardiac lesions. Our initial experience with the use of biventricular assistance in small children is encouraging. Nevertheless, further observations are clearly necessary to establish the role of postoperative circulatory support in children with congenital cardiac lesions.

Cardiac Output, Low↗
PubMed1991

Nature and extent of glomerular injury induced by cyclosporine in heart transplant patients.

We sought to clarify whether low-dose cyclosporine (5.0 +/- 2.2 mg/kg/day) given for more than two years to prevent cardiac graft rejection induced glomerular injury and to quantify the extent of the lesions. After renal hemodynamic studies, renal biopsy specimens were obtained from 10 patients on cyclosporine and analyzed by a novel morphometric technique consisting of a tridimensional reconstruction of the glomerular tuft. Autopsy kidney specimens from three patients with no clinical history of renal disease, and from four patients who died with dilatative cardiomyopathy served as controls. The glomerular filtration rate and renal plasma flow were significantly depressed below normal values in transplant recipients given cyclosporine, averaging 35 +/- 8 and 325 +/- 94 ml/min/1.73 m2, respectively. Conventional light microscopy of specimens from controls and from patients who died with dilatative cardiomyopathy did not reveal renal structural abnormalities. By contrast kidney specimens from cyclosporine-treated patients had obliterative arteriolopathy and ischemic-type changes, with thickening and wrinkling of glomerular capillary wall. Morphometrical analysis of 28 control glomeruli and 40 glomeruli from patients with dilatative cardiomyopathy showed glomerular capillary tuft volumes (VCT) ranging between 1.2 and 2.3 microns 3 x 10(-6), whereas of 102 glomeruli from cyclosporine-treated patients 42.1% had VCT lower than 1.2 microns 3 x 10(-6) and 24.4% VCT higher than 2.3 microns 3 x 10(-6).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Cor triatriatum. Clinical presentation and operative results.

From November 1973 to January 1988, 15 patients with cor triatriatum underwent surgical correction at the Department of Cardiac Surgery, Ospedali Riuniti, Bergamo, Italy. Their ages ranged from 15 days to 48 years. Eight patients (53%) were younger than age 1 year. Evidence of congestive heart failure was present in five infants, whereas three infants, three children, and two adults initially had signs of pulmonary venous obstruction, and two children had a heart murmur only. Five patients had cor triatriatum alone; in ten cases there also was an atrial septal defect. Associated anomalies in four patients included left superior vena cava, ventricular septal defect and left superior vena cava, partial anomalous pulmonary venous connection, and bilateral partial anomalous pulmonary venous connection. Cor triatriatum was repaired with the aid of cardiopulmonary bypass in all patients. Excision of the membrane was accomplished with a right atrial approach in 13 patients and a left atriotomy in one patient. Both atria were opened in one case. All associated anomalies were simultaneously corrected. Three patients (20%) died early after operation. Among the 12 survivors, no late events have occurred, and all of them are presently in New York Heart Association functional class I. A recent echocardiogram shows absence of residual obstruction or shunt and good development of the left cardiac chambers.

Adolescent↗
PubMed1990

Late left atrioventricular valve insufficiency after repair of partial atrioventricular septal defects: anatomical and surgical determinants.

Risk factors for late left atrioventricular (AV) valve insufficiency, which occurred in 16 (18%) of 90 patients evaluated after repair of partial AV septal defect, were examined. The operative findings in 9 patients undergoing reoperation were also examined. Preoperative left AV valve insufficiency was significantly more common in the group with late left AV valve incompetence, as were associated valvular malformations as a whole and fenestrations of valve leaflets in particular. Conversely, the higher incidence of malformed or malpositioned papillary muscles, accessory clefts, and double-orifice left AV valves in the group with late left AV valve insufficiency did not reach significance. The method of surgical treatment of the septal commissure was not a significant factor. In the group having reoperation, additional valvular malformations were found in association with inappropriate treatment of the septal commissure in 7 patients. The 2 remaining patients had either a directly sutured ostium primum or dilatation of the annulus. Three re-repairs were successful. Five patients required prosthetic valve replacement. Preoperative left AV valve insufficiency and associated valvular malformations are major determinants of late left AV valve insufficiency in partial AV septal defect.

Adolescent↗
PubMed1990

[Circulatory assistance in high-risk coronary angioplasty].

Femoral vein to artery cardiopulmonary by-pass was used during coronary angioplasty in five high risk patients. In four patients the target vessel supplied more than half of the viable myocardium; in one of these, the ejection fraction of the left ventricle was less than 20%. In one patient the relative contraindications for surgery were the patient's age and the presence of concomitant renal failure. Cardiopulmonary support was established by using cut-down cannulae insertion in three patients and by using the percutaneous system in two. In the latter, the support was stand-by, but the abrupt closure of the artery ten minutes after the end of the successful procedure, required the prompt activation of the support and the patient was treated with emergency saphenous graft. The use of the cardiopulmonary support either as a prophylactic or as a stand-by, enabled coronary angioplasty to be performed on these high-risk patients. The clinical and anatomical data relative to the five patients as well as the possible use of the cardiopulmonary support system either as a prophylactic or standby application during high-risk PTCA are discussed.

Adult↗
PubMed1990

[Supraventricular aortic stenosis. A different surgical approach].

A 15-year old female with William's syndrome became symptomatic for congenital supravalvular aortic stenosis. Surgery was carried out using an unpublished technique which consisted in a symmetrical enlargement of the aortic root by inserting three triangular patches of autologous pericardium. This method has the advantage of restoring normal valvular competence while respecting coronary orifices .

Adolescent↗
PubMed1989

Clinical experience with a new pulsatile pump for infant and pediatric cardiopulmonary bypass.

A pulsatile pump of new concept has been developed for infant and pediatric cardiopulmonary bypass (cpb) (Parenzan-Fumero pump). A segment of elastic tubing is compressed by a pneumatically driven pushing plate under control of a microprocessor. Flow parameters such as pulse rate and stroke volume can be set. The pump can be synchronized with the patient's ECG for counterpulsation heart assist. A total of 87 open-heart procedures were performed using randomly either a conventional roller pump or the Parenzan-Fumero pump (respectively 39 and 48 patients). A previously published cpb protocol and anesthetic regimen were adopted in all cases. The results show increased cooling and rewarming rate (p less than 0.05) and urinary output, decreased vascular resistance, intensive care unit time and need for blood transfusion in the pulsatile group compared to the continuous perfusion group. In the pulsatile group, mortality was significantly lower (10.4% vs 25.6%) and low cardiac output syndrome was less frequent in the post-operative course.

Cardiopulmonary Bypass↗
PubMed1988

The modified Fontan operation for double inlet left ventricle. Surgical results, early haemodynamic and functional assessment.

Twenty-one patients with a double inlet left ventricle underwent a modified Fontan between May 1979 and August 1987. All but the first patient in this series were operated upon after August 1984. Their age at operation ranged from 4 to 23 years with a median age of 8 years. Initial palliation was required in 12 patients and the mean interval to repair was 77.1 months, ranging from 38 to 112. Only one of the criteria of Choussat was exceeded in 12 patients. The pulmonary vascular resistance was always less than 4 Um2. A direct atriopulmonary anastomosis was performed in 19 patients and an aortic homograft interposition was used in 2. There was one hospital death due to acute cardiac failure and no late deaths. The average of the mean right and left atrial pressures measured early postoperatively was 12.9 and 8 mmHg respectively. A prolonged hospitalization with a mean of 23 days, ranging from 9 to 69, was required because of recurrent pleural and pericardial effusions which usually resolved after the first 6 postoperative months. The need for early anticoagulation is recommended to prevent the risk of pulmonary thromboembolism observed in 2 of our patients. Cardiac catheterization performed in 19 patients within 1 year after surgery showed that the average of the mean right atrial pressure had decreased to 11.3 mmHg without a gradient across the anastomosis in any case. Two patients required reoperation: one for enlargement of a restrictive ventricular septal defect and the other for closure of a recurrent dehiscence of the patch used for closure of the right a-v valve. Three patients developed a significant subaortic obstruction and have been scheduled for reoperation. Ventricular function was assessed at a mean interval of 11.9 months (17 patients) and 25.5 months (13 patients) from surgery. Gated equilibrium radionuclide ventriculography showed that the ejection fraction was normal (greater than or equal to 50%) and it had increased with time in 10. Yet, the response to exercise was normal in only 5 of the 13 patients re-evaluated. Treadmill exercise testing showed an increase in exercise tolerance from a mean of 7.4 min to a mean of 8.7 min.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗