Vincenzo Gallucci

Calcific degeneration as the main cause of porcine bioprosthetic valve failure.

Sixty-seven glutaraldehyde-processed porcine bioprostheses (PBs), recovered at autopsy or reoperation from 65 patients, were evaluated by roentgenologic and pathologic examination. Seven patients with 8 PBs were younger than 20 years of age. The time interval of function was 2 to 138 months (average 62). Pathologically, 53 explants had signs of intrinsic dysfunction, which was ascribed to calcification in 36 (68%). By x-ray examination, calcific deposits were found in 55 of 67 PBs (82%). The mean duration of function was 70 +/- 32 months in calcified PBs vs 27 +/- 18 months in noncalcified PBs (p less than 0.001). All 26 PBs that had been in place for longer than 6 years were calcified. In 45 PBs the Ca++ deposits were considered severe (mean time of function 76 +/- 32 months) and mild in 10 (mean time of function 44 +/- 22 months) (p less than 0.005). The Ca++ deposits were located at the commissures in 54 PBs (98%), at the body of cusps in 41 (75%), at the free margin in 37 (67%) and at the aortic wall in 37 (67%). When mild, Ca++ deposits involved the commissures in 90% of cases, the body of cusps in 30% and the free margin only in 10%. Forty-seven calcified PBs were mounted on a flexible stent, and 8 had a rigid stent, with an average time of function of 63 +/- 28 and 113 +/- 18 months, respectively (p less than 0.00001). Ca++ dysfunction occurred earlier in the aortic than in the mitral position (59 +/- 19 vs 86 +/- 35 months, p less than 0.05). All the PBs explanted from young patients and 47 of 59 PBs removed from adult patients were calcified, with an average time of function of 50 +/- 21 vs 73 +/- 33 months, respectively (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical excision of intracardiac myxomas: A 20-year follow-up

Since November 1968, 54 patients have undergone excision of an intracardiac myxoma, which was located in the left atrium in 46 (85%), in the right atrium in 6 (11%), and in the right ventricle in 2 (4%). There were 35 female and 19 male patients with a mean age of 48 +/- 14 years (range, 7 to 68 years). Four patients were asymptomatic; the others were seen mostly with exertional dyspnea, palpitation, signs of systemic illness, and syncopal episodes. Before operation, embolic episodes occurred in 13 patients with a left atrial myxoma. There were two early (3.7%) and two late deaths (3.8). Actuarial survival at 20 years is 91% +/- 4%, and most of the current survivors are asymptomatic at a mean follow-up of 6.5 +/- 5 years (range, 0.2 year to 20 years). Noninvasive reevaluation was performed with echocardiographic studies in 44 patients and 24-hour electrocardiographic monitoring in 34. No instances of tumor recurrence were observed, and there was a low incidence of major supraventricular arrhythmias late postoperatively. We conclude that excision of intracardiac myxomas is curative and long-term survival is excellent. The transseptal approach provides adequate exposure and allows complete removal of the tumor regardless of its location.

Histological survey of the saphenous vein before its use as autologous aortocoronary bypass graft.

A histological examination has been carried out on the saphenous veins used in 150 consecutive patients undergoing aortocoronary bypass. Morphological changes were observed frequently and consisted mainly of fibrosis of the intima and of the medial longitudinal muscular layer. Intimal fibrosis was rarely severe enough to narrow the lumen significantly. Statistical analysis disclosed that the fibrosis of the intima and the medial longitudinal muscular layer do not increase with age. The use of frozen histological sections of the saphenous vein in patients undergoing aortocoronary bypass operations could be considered in order to discard unsuitable grafts and to direct the surgeon to alternative conduits.

Isolated Mitral Valve Replacement with the Hancock Bioprosthesis: A 13-Year Appraisal

Four hundred seventy-six patients underwent isolated mitral valve replacement (MVR) with the glutaraldehyde-preserved porcine Hancock bioprosthesis from March, 1970, through December, 1981. There were 312 female and 164 male patients ranging in age at operation from 9 to 68 years (average, 53 years). Associated surgical procedures were performed in 35 patients. Hospital mortality was 13%, the main cause of death being low-output syndrome. The survivors were followed from 1.6 to 13.2 years (mean, 5.2 years). Cumulative duration of follow-up is 2,180 patient-years and is 97% complete. Overall late mortality is 3.1 +/- 0.3% per patient-year, and actuarial survival is 73.8 +/- 3.4% at 13 years. Embolic accidents occurred in 45 patients and were fatal in 13; the linearized incidence of postoperative systemic thromboemboli is 2.1 +/- 0.3% per patient-year. Reoperation was necessary in 49 patients: in 4 because of valve endocarditis, with 3 deaths; in 6 because of perivalvular leak, with no deaths; in 2 because of left atrial thrombosis; and in 37 because of valve dysfunction due to primary tissue failure, caused mainly by calcific degeneration of the tissue, with 5 operative deaths. Actuarial freedom from primary tissue failure is 58 +/- 6.6% at 13 years. Extended follow-up after MVR with the Hancock bioprosthesis confirms the satisfactory performance and low thrombogenicity of this device up to 13 years after operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Anomalies of the Systemic Venous Return: A Review

Congenital anomalies of the systemic venous connection to the heart represent a rather wide and heterogeneous group of malformations, whose physiological consequences may vary from nil to the most severe form of systemic arterial desaturation. The malformations may be summarized as follows: (1) Left superior vena cava connected to the coronary sinus, interrupted inferior vena cava and absent right superior vena cava that do not indicate surgical repair ‘per se’, but require some technical attention during open heart surgery performed for other anomalies; (2) Left superior vena cava connected to the left atrium, due to incorporation of the coronary sinus into the left atrial cavity, resulting in a right‐to‐left shunt; (3) Right superior vena cava or inferior vena cava draining into the left atrium, both are extremely rare and require treatment for the ensuing right‐to‐left shunt; (4) Total anomalous systemic venous connection to the left atrium, usually combined with atrial isomerism and other very complex heart malformations; (5) Cor triatriatum dexter, which has been frequently diagnosed as an anomalous venous connection for its similar hemodynamic consequences. Such anomalies are reviewed with particular respect to their surgical implications.

Pregnancy in patients with a porcine valve bioprosthesis

Seven patients who became pregnant after valve replacement with a Hancock bioprosthesis were followed up during 8 pregnancies. Six had undergone isolated mitral valve replacement, and 1 had mitral and aortic valve replacement. Their age at the time of operation ranged from 14 to 31 years (average 24); delivery occurred 21 to 88 months (average 51.3) after valve replacement. All women were in sinus rhythm at the time of gestation, and administration of oral anticoagulants was avoided in all. No embolic episodes occurred either after operation or during pregnancy, labor, or puerperium. The only major complication during pregnancy was cardiac failure in 1 patient, associated with onset of atrial fibrillation. Four women had vaginal delivery and 3 required cesarean section. All but 1 delivered a normal, healthy baby. One premature infant died soon after birth because of respiratory distress. No maternal or fetal hemorrhagic complications were observed. One patient died 3 months after delivery in severe heart failure caused by diffuse calcification of both mitral and aortic xenografts. Another women underwent successful reoperation soon after the second pregnancy because of calcific stenosis of the mitral porcine valve. It is concluded that (1) bioprosthetic valves can be considered the most suitable devices employed in women of childbearing age because anticoagulants can be avoided, therefore eliminating the risks related to inappropriate administration of oral anticoagulants as well as the hazards associated with the potential teratogenic effect of coumarin drugs; and (2) pregnancy might favor calcification of porcine heterografts, leading to bioprosthetic failure. Until further data are available to support this suspicion, close clinical and echocardiographic follow-up study of these patients is recommended after pregnancy.

The release of β- thromboglobulin and platelet factor 4 during extracorporeal circulation for open heart surgery

Abstract. Cardiopulmonary bypass is extremely damaging to platelets and it causes a quantitative and qualitative alteration in their functions. We evaluated the release of two platelet‐specific proteins, β‐thromboglobulin (βTG) and platelet factor 4 (PF4), in patients who underwent extracorporeal circulation for open heart surgery. A parallel release (basal value βTG: 119.6 ng/ml, PF4 30 ng/ml) was present for both proteins in a time dependent fashion until the end of extracorporeal circulation. High average levels were observed in patients in whom the bypass was stopped after about 1 h (βTG 1606 ng/ml, PF4 745 ng/ml) and similarly in those in whom the bypass was stopped after about 2 h (βTG 1540 ng/ml, PF 4754 ng/ml). No correlation was found either between the level of PF4 and the additional heparin administered after the initial standard dose (r= 0.29, P>0.10) and between the level of PF4 and the amount of heparin consumed during the bypass (r= 0.05, P>0.5).

Anatomical study of truncus arteriousus communis with embryological and surgical considerations.

Twelve specimens of truncus arteriosus communis have been studied anatomically, with special reference to the conal anatomy and to the associated cardiac anomalies which can create additional problems if surgical repair is planned. A wide spectrum of conal morphology has been observed, suggesting that differential conal absorption is a developmental characteristic of truncus arteriousus as well as of transposition complexes. The invariable absence of septation of the ventricular infundibula and semilunar valves, in spite of the variable anatomy of the free wall of the conus, indicates that all types of truncus arteriosus, ontogenetically, should be considered as a single undivided conotruncus. Various types of ventircular septal defect were found: (a) ventricular septal defect with absent crista, in which no remnants of conal septum are present; (b) supracristal ventricular septal defect, in which vestigial conal septum is seen in front of the membranous septum; (c) bulloventricular foramen, associated with univentricular origin of the truncus from the right ventricle. Frequent associated anomalies are underdevelopment of the aortic arch, truncal valve malformations, and obstructive ventricular septal defect. The AV conduction system studied in one case showed an arrangement similar to Fallots tetralogy with the His bundle and the left bundle-branch in a safe position behind the posteroinferior rim of the defect. The postoperative fate of the frequently abnormal truncal valve and the theoretical indications for total repair for Type IV truncus are also discussed.

Performance of the Hancock Porcine Bioprosthesis Following Aortic Valve Replacement: Considerations Based on a 15-Year Experience

All patients undergoing isolated aortic valve replacement with a standard Hancock porcine bioprosthesis (PB), from 1970 to 1983, were reviewed. There were 196 patients, 162 male and 34 female patients, with a mean age of 48 +/- 12 years. Operative survivors were followed up from 3 to 15.6 years (mean follow-up, 6.6 +/- 1.5 years), with a cumulative follow-up of 1,140 patient-years, being 100% complete. Actuarial survival was 51 +/- 15% at 14 years. Eight patients sustained systemic embolic episodes (0.7 +/- 0.2%/patient-year); actuarial freedom from emboli is 89.4 +/- 4.3% at 14 years. Reoperation was performed in 53 patients: in 6 because of endocarditis (0.5 +/- 0.2%/patient-year), in 7 because of perivalvular leak (0.6 +/- 0.2%/patient-year), and in 40 because of PB primary tissue failure (3.5 +/- 0.5%/patient-year). Actuarial freedom from PB-related deaths, PB failure, and overall PB-related complications at 14 years was 66.3 +/- 19, 34.3 +/- 11, and 30 +/- 10%, respectively. This long-term experience shows that the performance of the Hancock PB appears satisfactory up to 8 years, while it progressively deteriorates beyond 10 years because of the impact of primary tissue failure on valve durability, justifying the restriction of its use in the aortic position in selected patients.

Surgical pathology of aortic valve disease. A study based on 602 specimens.

A consecutive series of 602 surgically excised aortic valves was evaluated by means of macroscopic and histological study. Pure aortic stenosis was diagnosed in 140 patients, pure incompetence in 254 and combined dysfunction in 208. Of the cases with pure aortic stenosis, 38% were rheumatic, 34% were calcified bicuspid valves and 23% showed dystrophic calcification. Half the patients with pure aortic regurgitation showed aortic root dilatation. Most cases of combined aortic stenosis and regurgitation were the sequelae of rheumatic fever. A male prevalence was detectable in each group (mean male: female ratio = 2.6), and was highest in infective endocarditis and aortic root dilatation. Infective endocarditis was a frequent complication of congenitally bicuspid valves. In conclusion, rheumatic disease is still a frequent cause for surgical replacement of the aortic valve. At least half the explanted aortic valves have degenerative or congenital diseases which are often the site of a superimposed infective endocarditis.