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Biomedical subjects

A F Corno

Publications and source records attributed to A F Corno.

At least 19 recordsLinked to original sources
PubMed2001

Treatment of congenital aortic valve stenosis: impact of the Ross operation.

GOAL: To evaluate the impact of the Ross operation, recently (1997) introduced in our unit, for the treatment of patients with congenital aortic valve stenosis. METHODS: The period from January 1997 to December 2000 was compared with the previous 5 years (1992-96). Thirty-seven children (< 16 yrs) and 49 young adults (16-50 yrs) with congenital aortic valve stenosis underwent one of these treatments: percutaneous balloon dilatation (PBD), aortic valve commissurotomy, aortic valve replacement and the Ross operation. The Ross operation was performed in 16 patients, mean age 24.5 yrs (range 9-46 yrs) with a bicuspid stenotic aortic valve, 7/10 adults with calcifications, 2/10 adults with previous aortic valve commissurotomy, 4/6 children with aortic regurgitation following PBD, and 1/6 children who had had a previous aortic valve replacement with a prosthetic valve and aortic root enlargement. RESULTS: PBD was followed by death in two neonates (fibroelastosis); all other children survived PBD. Although there were no deaths, PBD in adults was recently abandoned, owing to unfavourable results. Aortic valve commissurotomy showed good results in children (no deaths). Aortic valve replacement, although associated with good results (no deaths), has been recently abandoned in children in favour of the Ross operation. Over a mean follow-up of 16 months (2-40 months) all patients are asymptomatic following Ross operation, with no echocardiographic evidence of aortic valve regurgitation in 10/16 patients and with trivial regurgitation in 6/16 patients. CONCLUSIONS: The approach now for children and young adults with congenital aortic valve stenosis should be as follows: (1) PBD is the first choice in neonates and infants; (2) Aortic valve commissurotomy is the first choice for children, neonates and infants after failed PBD; (3) The Ross operation is increasingly used in children after failed PBD and in young adults, even with a calcified aortic valve.

Adolescent↗
PubMed2001

Surgery for aortic coarctation: a 30 years experience.

OBJECTIVE: A retrospective study to review the experience of a single center with surgery for aortic coarctation over a period of 30 years (1970-1999). METHODS: Criteria for inclusion: (a) aortic coarctation, isolated or associated with congenital heart defect; (b) surgery between 1970 and 1999. Data recorded: (1) date of surgery; (2) age at surgery; (3) associated lesions; (4) surgical technique; (5) simultaneous surgical procedures; (6) early and late surgical results in term of: (a) deaths; (b) need for reoperation because of re-coarctation or other cardiac lesion; (c) residual/recurrent pressure gradient, evaluated at cuff/Doppler at rest; (d) systemic hypertension, requiring medical treatment. RESULTS: One hundred and forty-one patients underwent surgery for aortic coarctation: 30 neonates, 29 infants, 45 children and 37 adults. Associated lesions were found in 8/37 (=21.6%) adults and in 73/104 (=70.1%) pediatric patients. There were no hospital deaths. During the follow-up there were one late death in the adults group (1/37=2.7%) and three late deaths in the pediatric group (3/104=2.9%), all unrelated with aortic coarctation. Re-operation because of re-coarctation occurred only in ten late survivors of the pediatric group (10/101=9.9%), 9/10 operated on before 1980 (P<0.00001). End-to-end anastomosis, enlarged to the aortic arch in neonates, was associated with the lowest incidence of re-coarctation (P<0.005). A significant (>20 mmHg at rest) pressure gradient was found in none of the adults, and in seven of the 91 pediatric patients (7/91=7.7%) late survivors. Three adults (3/36=8.3%) late survivors are on medical treatment to control systemic hypertension. CONCLUSIONS: The long-term results of our retrospective study confirm that surgery has to be considered the gold standard for the treatment of aortic coarctation. The interventional angioplasty techniques have to provide long-term outcome at least similar to the results obtained with surgery.

Age Factors↗
PubMed2001

Tolerance of isolated rat hearts to low-flow ischemia and hypoxia of increasing duration: protective role of down-regulation and ATP during ischemia.

We tested the hypothesis that down-regulated hearts, as observed during low-flow ischemia, adapt better to low O2 supply than non-down-regulated, or hypoxic, hearts. To address the link between down-regulation and endogenous ischemic protection, we compared myocardial tolerance to ischemia and hypoxia of increasing duration. To that end, we exposed buffer-perfused rat hearts to either low-flow ischemia or hypoxia (same O2 shortage) for 20, 40 or 60 min (n = 8/group), followed by reperfusion or reoxygenation (20 min, full O2 supply). At the end of the O2 shortage, the rate-pressure product was less in ischemic than hypoxic hearts (p < 0.0001). The recovery of the rate-pressure product after reperfusion or reoxygenation was not different for t = 20 min, but was better in ischemic than hypoxic hearts for t = 40 and 60 min (p < 0.02 and p < 0.0002, respectively). The end-diastolic pressure remained unchanged during low-flow ischemia (0.024 +/- 0.013 mmHg x min(-1)), but increased significantly during hypoxia (0.334 +/- 0.079 mmHg x min(-1)). We conclude that, while the duration of hypoxia progressively impaired the rate-pressure product and the end-diastolic pressure, hearts were insensitive of the duration of low-flow ischemia, thereby providing evidence that myocardial down-regulation protects hearts from injury. Excessive ATP catabolism during ischemia in non-down-regulated hearts impaired myocardial recovery regardless of vascular, blood-related and neuro-hormonal factors. These observations support the view that protection is mediated by the maintenance of the ATP pool.

Adenosine Triphosphate↗
PubMed2001

Preliminary clinical experience with the Heartflo anastomosis device.

UNLABELLED: A clinical, prospective trial to evaluate a multi-suture anastomotic device (Heartflo) is currently underway. This new surgical tool can be used during CABG to perform end-to-side or side-to-side coronary arteries anastomoses with interrupted suture technique. This reports our interim preliminary clinical experience. METHODS: From February to November 2000, we attempted 15 anastomoses with the multi-suture anastomotic device (Heartflo) in 11 patients with coronary artery disease. RESULTS: 7 males, 4 females, mean age 64 +/- 3 yrs received 15 anastomoses with the device. The target vessels were: 8 RCA, 3 LAD, 4 OM. Mean coronary diameter was 2 +/- 0.3 mm. Grafts used were 14 saphenous veins and 1 IMA. 13/15 anastomoses were completed with the device. 5/13 required 0 - 1 additional stitches versus 8/13 requiring more due to inappropriate tissue capture on the native coronary side. Average time was 17.7 +/- 2 min. In 2/15 cases, the procedure was converted to a traditional handsaw anastomosis. Postoperative CK movement without Q-wave in the EKG was observed in 1/11 patients. CONCLUSIONS: This device is a reliable instrument that provides reproducible coronary anastomoses with interrupted suture technique, although it also requires additional measures to improve tissue capture and process of handling sutures before extensive clinical application.

Aged↗
PubMed2000

Surgery for congenital heart disease.

General agreement has been reached on the indications for treating most congenital cardiac malformations. Strong disagreement exists, however, about timing and methods of treatment, either for congenital heart defects, for which the approach should be standardized after years of use, and even more when a new technique or a new approach is introduced to replace the existing ones. The ideal solution should be to perform prospective, randomized studies, with long-term follow-up, possibly with preliminary experimental studies to support the hypothesis. Unfortunately this is rarely possible, either because of the nonreproducibility of the malformation in an experimental environment, or because prospective, randomized studies with adequate follow-up are rarely feasible, due to the relatively small number of children with the same congenital heart defect. An updated review of the current trends in congenital heart surgery, based on the papers published in the past year, is presented here.

Airway Obstruction↗
PubMed1999

Modified Blalock-Taussig shunt with compensatory properties.

Determination of the proper length of the tubular prosthesis is a major issue when performing a systemic-pulmonary artery shunt. The procedure is simplified by using a prosthesis with accordionlike properties. This was demonstrated in 7 consecutive infants with complex congenital heart defects, in whom systemic-pulmonary artery shunts were placed without early or late complications.

Blood Vessel Prosthesis Implantation↗
PubMed1999

Divided right atrium. Diagnosis by echocardiography, and considerations on the functional role of the Eustachian valve.

A child presented at birth with severe cyanosis. Echocardiography showed hypoplasia of the right heart with a right-to-left shunt at atrial level. A conservative approach was adopted initially, and the situation improved over a few months, with reversal of the atrial shunt. Surgery was successfully performed at 4 years of age after further echocardiography revealed a congenitally large Eustachian valve and an atrial septal defect.

Child, Preschool↗
PubMed1999

Impact of a remote pump head on neonatal priming volumes.

Reduction of priming volumes of the cardiopulmonary bypass (CPB) circuit in neonatal cardiac surgery to decrease haemodilution and blood transfusion requirements can be achieved with the use of neonatal low prime oxygenators and smaller diameter tubing. We have further reduced our prime volume with the use of a custom-designed arm allowing for remote positioning of a double-headed roller pump. This arm enables the double pump to be placed alongside the main heart-lung machine close to the operating table, and to position the pump inlet and outlet tubing immediately at the reservoir outlet and oxygenator inlet, respectively, therefore reducing tubing lengths. Priming volumes of four cases using this configuration were compared to four cases using our standard neonatal bypass setup. Results showed a 29% decrease in priming volume and a 58% reduction in blood utilization during CPB. This reduction in priming volume is clinically significant as it lowers the ratio of priming volume to patient blood volume and reduces homologous blood requirements.

Cardiopulmonary Bypass↗
PubMed1989

Prevention of reperfusion injury in the neonatal heart with leukocyte-depleted blood.

Activated leukocytes release oxygen free radicals and cause microvascular occlusion. This experiment tests the hypothesis that reperfusion with leukocyte-depleted blood reduces injury after extended ischemic preservation. An in vitro model consisting of an isolated, working neonatal piglet heart and an adolescent support pig was used. Hearts were arrested with a cold crystalloid cardioplegic solution, excised, and stored in 4 degrees C saline for 12 hours. Two groups were compared. In group 1 piglets (n = 8), reperfused with whole blood, the maximum stroke work index was 0.91 +/- 0.29 x 10(3) erg/gm (mean +/- standard error of the mean). Group 2 piglets (n = 6), reperfused with blood depleted of leukocytes by a polyester filter, had a maximum stroke work index of 11.6 +/- 1.0 x 10(3) erg/gm. This difference was highly significant (p less than 0.0001). Group 1 exhibited severe injury with myofibrillar necrosis, mitochondrial disruption, nuclear chromatin clumping, and moderate interstitial edema. Group 2 had normal ultrastructure on electron microscopic examination. We conclude that reperfusion with leukocyte-depleted blood prevents reperfusion injury and results in excellent myocardial function after long-term heart preservation.

Animals↗
PubMed1988

Long-term neonatal heart preservation.

UNLABELLED: Donor availability is a major limiting factor in neonatal heart transplantation. Prolonging donor heart preservation would facilitate distant heart procurement. Forty-two neonatal (1 to 5 days) piglet hearts in seven groups were arrested with cold cardioplegic solutions, stored for 12 hours at 4 degrees C in storage solutions, and reperfused with blood from an adult support pig. The cardioplegic solutions used were a crystalloid solution with potassium chloride 30 mEq/L and bicarbonate (Stanford), the Stanford cardioplegic solution with the addition of calcium (1.2 mmol/L), or an intracellular solution (Sacks) with added glucose. Storage solutions were normal saline, Sacks II, or Sacks II with glucose 20 gm/L. Reperfusion was done with normal blood or modified blood for 20 minutes with superoxide dismutase, catalase, aspartate, glutamate, citrate-phosphate-dextrose, potassium, tromethamine, and 50% dextrose followed by normal blood. Evaluation of stroke work index after 60 minutes of recovery (as percent of control) was performed using the isolated, blood perfused, working heart preparation in all groups: Group I (Stanford cardioplegia, saline storage, normal blood reperfusion) had a recovery of 11%; group II (Stanford + calcium, saline, normal blood) 8%; group III (Stanford + calcium, saline, modified blood, superoxide dismutase 35,000 U/L, catalase 35,000 U/L) 37%; group IV (Stanford + calcium, Sacks II, modified blood, superoxide dismutase 35,000 U/L, catalase 35,000 U/L), 47%; group V (Stanford + calcium, Sacks + glucose, modified blood, superoxide dismutase 35,000 U/L, catalase 105,000 U/L) 89%; group VI (Stanford + calcium, Sacks + glucose, modified blood, superoxide dismutase 150,000 U/L, catalase 150,000 U/L) 107%; group VII (Sacks + glucose, Sacks + glucose, modified blood, superoxide dismutase 35,000 U/L, catalase 105,000 U/L) 115%. CONCLUSIONS: The neonatal heart stored hypothermically for 12 hours tolerates normal blood reperfusion poorly. Modified blood reperfusion markedly improves the recovery. Complete functional recovery was achieved by the intracellular Sacks plus glucose storage solution and modified blood reperfusion with oxygen-derived free radical scavengers (high catalase). Extended preservation of the neonatal heart is feasible.

Animals↗
PubMed1987

Palliative Mustard operation: an expanded horizon.

From March 1982 to December 1983, five patients with a mean age 7 years (4 months-16 years) underwent a palliative Mustard operation for complex cardiac anomalies. The diagnoses were: univentricular heart with pulmonary vascular obstructive disease (PVOD) (2 cases); criss-cross heart with intact atrial septum, ventricular septal defect (VSD), transposition of the great arteries (TGA) and moderate pulmonary stenosis; isolated atrioventricular discordance with VSD; TGA, diminutive right ventricle and multiple VSDs. Cardiac catheterization showed unfavourable direction of flow: the oxygen saturation in the aorta was lower than in pulmonary artery, with a mean difference of 13.5% (range 6% to 30%). In no case was anatomical or physiological repair considered advisable because of the unfavourable intracardiac anatomy or the presence of PVOD. In two patients the atrial rerouting was accompanied by pulmonary artery banding. There were no hospital or late deaths in a mean follow-up of 36 months (range 29 to 50 months). The mean post-operative arterial oxygen saturation was 95.4% (range 92% to 99%).

Adolescent↗