Determinants of late survival of 105 patients operated for dissection of the aorta.

In the surgery of aortic dissection, only a small section of aorta compared to the extent of the aortic damage, is usually replaced. The disease is not cured by surgery and needs continuous postoperative surveillance and medical therapy. We report the follow-up of 105 patients who were operated upon between January 1970 and April 1986 and discharged from hospital. Overall actuarial survival was 90% at 5 years, 52% at 10 years and 39% at 15 years. There were 20 deaths, mostly (85%) related to cardiovascular causes. Survival times were correlated, using multivariate methods, with several pre-, peri- and postoperative variables to identify significant risk factors and to calculate actuarial survivals. We found that postoperative low output syndrome (p = 0.007) and stroke (p = 0.04) adversely affected survival and that previous aortic disease or operation (p = 0.004) was associated with an increased rate of dissection-related complications. On the contrary, preoperative hypertension was related to a significantly better survival (p = 0.01) and survival free of dissection-related complications (p = 0.001). When dissection was related to hypertension, adequate postoperative medical treatment neutralized the progression of the aortic damage and its consequences. When dissection was not due to hypertension, the observed survival was unsatisfactory, probably because of a more fragile aorta and inadequate medical follow-up therapy.

Early and late determinants of survival after surgery of left ventricular aneurysm.

The fate of 103 patients consecutively operated upon for chronic left ventricular aneurysm between 1978 and 1986 was examined with a multivariate statistical approach to verify the operative indications and results. In the early risk phase, up to 39 days after operation, 15 patients (15%) died. Mortality was mostly due to a low output syndrome and was significantly related to older age and to functional (NYHA) and anginal (CCS) class. In the late risk phase, starting 1.9 years after surgery, 9 patients died (10%) and the significant risk factors were anterior aneurysm and older age at operation. Actuarial survival curves showed 82% survival at 5 years and 61% at 9.5 years. In 25 patients older than 50 years and with an anterior aneurysm, these rates were 51% and 34%, respectively. Improved functional class was observed in 87% of the patients interviewed, but 30% complained of angina or new infarctions. Survival free of ischemia was 64% at 5 years and 13% at 9.5 years. This development of ischemic recurrences was significantly related to older age and to incomplete revascularization despite multiple grafts. These results suggest modification of the grafting policy and of the techniques of repair in identified high-risk subsets.

T-wave changes in patients with hemodynamic evidence of systolic or diastolic overload of the left ventricle: a retrospective study on 168 patients with isolated chronic aortic valve disease.

The effect of systolic and diastolic overload of the left ventricle on the T wave was studied in 86 patients with pure aortic stenosis and in 82 patients with pure aortic insufficiency documented by hemodynamic investigation. All patients had hemodynamically significant, chronic isolated aortic valve disease with electrocardiographic evidence of left ventricular hypertrophy (Sokolow index greater than or equal to 45 mm). All had undergone selective coronary angiography. Flattened or negative T waves were present in 44 patients with aortic stenosis (51%) and in 66 (80%) with aortic incompetence. Inversion of the T wave in left ventricular leads was unrelated to the presence of ventricular conduction disturbances or to coronary artery disease or to low cardiac index. It was significantly related to older age (P = 0.0001) and, in patients with aortic incompetence, to the end-diastolic volume (P = 0.04). Digitalis intake was a nonsignificant (P = 0.10) independent variable. These findings suggest that patients with aortic stenosis cannot be distinguished from patients with aortic incompetence by the electrocardiogram and that the theory of Cabrera and Monroy is not valid in this set of patients.

The risk of surgical treatment of tetralogy of Fallot: an appraisal.

The risk of surgical treatment of tetralogy of Fallot was analyzed with multivariate statistical techniques in a recent surgical series (1975-1983) of 159 corrected and 59 palliated patients. The overall mortality of correction was 12.6% and that of palliation was 15.3%. The significant and independent risk factors that increased the mortality of palliation were the use of a shunt other than the Blalock or its modifications (mostly Waterston) (P = 0.01), and very young age (P = 0.02). Risk factors that increased the mortality of correction were high left over right ventricular pressure ratio (P-RV/LV) (P = 0.02), persistent patency of the arterial duct (P = 0.02), other major associated lesions (P = 0.02), and the use of a transannular patch (P = 0.04). Cardioplegia significantly decreased the risk (P = 0.03). With present techniques, correction can be performed in favorable cases with a mortality approaching zero. Staged procedures neutralized the age related risk of correction, but Blalock shunts carried a mortality rate ranging from 9.5% at 1 month to 1.7% at 12 months of age. This was due to the lack of prostaglandins along with technical faults. Predicted two-stage mortality rates ranged in infants (less than 12 months) from 6.2 to 16% and compared favorably with our observed 27% mortality of primary correction. Our results show that the transannular patch becomes a fully expressed risk only in those patients with restrictive pulmonary arteries or isolated branch stenosis. This is because it decreases the force the right ventricle can generate in maintaining the cardiac output. The chances of survival, when compared with those of patients without transannular patch, are significantly less when the P-RV/LV is between 0.6 and 1.0. We therefore discuss the measures to decrease or neutralize this risk related to insertion of a transannular patch. Among the associated lesions, we discuss briefly the potential for residual right outflow tract stenosis, anomalous origin of the left anterior descending coronary artery and anomalous muscle bundle of the right ventricle.

Operative risk of correction of atrioventricular septal defects.

Between 1 January 1975 and 31 December 1982, 111 patients with atrioventricular septal defect underwent surgical repair. Of these, 43 had the complete, 11 the intermediate, and 57 the partial form. The postoperative mortality rate was 37%, 9%, and 6% respectively. To determine which factors were independently responsible for the operative risk multivariate analysis of the surgical mortality was applied simultaneously to all three forms of the malformation. The form of defect, although strongly influencing the natural history and clinical presentation, was not by itself an operative risk factor. The risk was related primarily to failure to obtain a well functioning atrioventricular valve, to the presence of left ventricular dominance, to the degree of pulmonary vascular resistance, and, finally, to the technique of reconstructing a two leaflet left atrioventricular valve. The small size of the patient was also a significant incremental risk factor, but if the other factors were not unfavorable good results could be achieved in small infants with mortality rates less than 10%. Multivariate analysis showed that severe postoperative left atrioventricular valve malfunction was related to the technique used to reconstruct a "normal" two leaflet left atrioventricular valve. These findings support the policy of reconstructing the left atrioventricular valve as a three leaflet valve. Nevertheless, the implicit beneficial effect of this technique has not as yet proved to be statistically significant.

Dehiscence of aortic valve prostheses: analysis of a ten-year experience.

Up to the end of 1982, reoperation for dehiscence of an aortic prosthesis was necessary in 5% of patients operated on for primary aortic valve replacement in the previous decade at the University of Padova Cardiac Surgery Center. This complication occurred early (median time to diagnosis 4 months) and was associated with an elevated 30-day operative mortality (27%, 70% CL 19-37%). This is probably (P = 0.09) related to preoperative heart failure. The follow-up of the traced surviving patients (92%) indicates a continuing poor prognosis with a 6-year survival rate of only 13.5% (70% CL 5.0-30%). All the events were cardiac related and directly or indirectly connected with the persistence or recurrence of dehiscence that was observed in 72% of the cases. In the face of these results, a retrospective study has been performed to identify, on the basis of the available data, the subsets of patients more prone to develop this complication. Our results suggest that a significant increased risk (P less than 0.001) can be identified in patients presenting with bacterial endocarditis (12.2% rate), in patients with concomitant aneurysm of the ascending aorta (10.9%) and in patients with degenerative regurgitation or severe calcifications of their native valve, with rates of 7.0 and 6.0 respectively. In these situations particular care is required to avoid undue stress on the annular tissue. We also suggest the use of buttressed interrupted sutures.

Progress in the surgical treatment of ventricular septal defect: an analysis of a twelve years' experience.

Two hundred sixty-seven patients underwent surgical closure of a ventricular septal defect (VSD) over a 12-year period between January 1, 1970 and December 31, 1982. In 152 patients (57%) an associated lesion was present complicating the treatment of the primary lesion: 7 patients had multiple VSDs and among those with single defects, 189 were large (unrestrictive). The median age was 5.2 years ranging from 1 month to 46 years. Sixty-nine were infants under 10 kg of weight. The 30-day operative mortality was 8.6% (23 cases). The main cause of death was a low output syndrome in 16 cases. Thirty-two variables have been collected and their relationship with the death of the patients has been analyzed with univariate and multivariate methods. Logistic analysis has identified the independent significant incremental effect on hospital mortality of low weight (P greater than 0.00001), early operative date (P greater than 0.00001), multiplicity of defects (P = 0.0008), presence of major associated lesions (P = 0.019); the large size of the defect was only probably significant (P = 0.18). Inspection of the nomograms, relating the probability of operative death to weight and age in patients with a large defect, shows that the risk is significantly higher in the 3 kg baby (median age 3.3 months), particularly if major associated lesions are present. In infants with multiple VSDs the risk of operation remains, at the end of 1982, significantly higher than in single defects. However, our data suggest that the risk of open correction in patients over 12 kg of weight approaches that of single VSD if concomitant lesions do not complicate the surgical treatment.

Mitral valve prosthesis dehiscence necessitating reoperation. An analysis of the risk factors involved.

Between January 1970 and December 1981, a total of 21 reoperations for periprosthetic leak were performed on 20 patients out of 999 with previously implanted prosthetic mitral valves. In most of them reoperations were performed within the first year, since the initial procedure and the leading indications were intractable congestive heart failure or infection of the mitral prosthesis. The mortality rate was 30% and was related to the preoperative cardiac functional status. The preoperative variables significantly related to an increased incidence of dehiscence of the mitral prosthesis necessitating reoperation were a degenerative disease (P = 0.016) or an infective endocarditis (P = 0.0006) of the native valve, both causing mitral regurgitation. Rheumatic disease, type of prosthesis, supra- or subannular insertion, age of the patient, and operative year, were not significant, neither were calcifications that are probably neutralized by the routine use of special surgical techniques. It is suggested that the use of techniques specifically designed to eliminate periprosthetic leak in patients affected by mitral regurgitation due to degenerative or infective disease of the native valve, might lead to a further reduction of reoperations for this complication.

[Early hemodynamic changes after mitral valve replacement with the Hancock prosthesis]. / Modificazioni emodinamiche precoci dopo sostituzione valvolare mitralica con protesi di Hancock.

In mitral valve replacement for mitral stenosis the persistence of a depressed cardiac performance immediately after operation has been outlined by several authors. The choice of a porcine central flow prosthesis, that has several theoretical advantages, should allow better acute hemodynamic results. Therefore ten patients have been studied by thermodilution methods and the variations in their hemodynamic parameters has been evaluated with a paired T-Test. Results confirm the persistence of a depressed cardiac function throughout the time span of the study (36 hours). This behaviour could be related to the use of Kirsch solution for myocardial protection. Therefore the authors compare a similar group of nine patients that underwent mitral valve replacement with differently designed prosthesis and the use of a St Thomas analogue cardioplegic solution. They conclude for the persistence, in the acute postoperative period, of an intrinsic myocardial dysfunction.