Gianmaria Ottino

Major sternal wound infection after open-heart surgery: a multivariate analysis of risk factors in 2,579 consecutive operative procedures

From January, 1979, to December, 1984, at the Cardiac Surgery Department of the University of Torino Medical School, major sternal wound infections developed in 48 (1.86%) of 2,579 consecutive patients. These patients underwent open-heart procedures through a midline sternotomy and survived long enough for infection to appear. Possible risk factors were evaluated by means of a multivariate analysis. For the group of patients, we considered age, sex, hospital environment (different locations of our surgical facilities over the years), interval between hospital admission and operation, antibiotic prophylaxis, type of surgical procedure, elective or emergency surgical procedure, reoperation, duration of surgical procedures, duration of cardiopulmonary bypass, amount of blood transfused, postoperative blood loss, chest reexploration, rewiring of a sterile sternal dehiscence, duration of mechanical ventilation, and days of treatment in the intensive care unit. Univariate analysis indicated that age, sex, type and mode of surgical procedure, antibiotic prophylaxis, and duration of mechanical ventilation were not significantly associated with wound infection. For all other predisposing factors, a p value of less than .05 was demonstrated. These variables were entered in a multiple stepwise logistic regression. Six emerged as significant: hospital environment (p = .0001), interval between admission and surgery (p = .041), reoperation (p less than .0001), blood transfusions (p = .031), early chest reexploration (p less than .0001), and sternal rewiring (p less than .0001). Contamination of patients may occur before, during, and after operation, and any kind of reintervention may predispose to wound infection.

Reoperations on heart valve prostheses : an analysis of operative risks and late results

To evaluate risks and complications of reoperations on heart valve prostheses, we reviewed data on 183 patients who underwent reoperation because of prosthetic valve malfunction. The incremental effect of the redo procedure on hospital mortality and morbidity was studied by comparing primary and reoperative procedures and analyzing a series of possible predisposing factors. Late survival after first and second reoperations was computed, and possible determinants of late mortality were examined. Overall operative mortality was 8.7%; emergency operation (p = 0.0001), previous thromboembolism (p = 0.05), and advanced New York Heart Association functional class (p = 0.031) were the independent determinants. In a series of 1,355 patients having primary or secondary isolated valve replacement, the redo procedure was a significant risk factor in the univariate analysis (p = 0.025) but not in the multivariate analysis except for the subset of patients having mitral valve replacement (p = 0.052). The postoperative course was quite complicated, as evidenced by the long mean stay in the intensive care unit (mean stay, 3.8 days; longer than 2 days for 26% of the survivors). Nevertheless, postoperative complications were not significantly greater after a redo procedure than after a primary operation. Actuarial survival at 7 years was 57.3% +/- 8%. A comparison with a nonhomogeneous series from our institution did not demonstrate significant differences. In the subset of 16 patients having a second reoperation, late survival was 37.8% +/- 16% at 2 years. Advanced New York Heart Association class (p = 0.0001), double prosthetic valve dysfunction (p = 0.003), and any indication other than primary tissue failure (p = 0.06) were determinants of late mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Results of Total Correction of Tetralogy of Fallot Performed in Adults

Today, total correction of tetralogy of Fallot is rarely performed in adults. In a 10-year period, 40 patients aged 20 to 67 years underwent intracardiac repair in our institution. Twenty-eight of them had had a palliative procedure 11 to 30 years earlier. Preoperatively, 23 patients were in New York Heart Association (NYHA) Functional Class II, 14 were in Class III, and 3 were in Class IV. Operative mortality was 2.5% (1/40). Follow-up ranged from 1 year to 11 years (average, 3 years). One patient died of a noncardiac cause 4 years after operation. Residual cardiac defects were observed in 4 patients. Postoperatively, 30 patients were in NYHA Functional Class I, 8 were in Class II, and 1 was in Class III. Major ventricular arrhythmias were recorded in 7 (35%) of 20 patients. Radionuclide angiography demonstrated impaired right ventricular function in 8 patients. Left ventricular impairment was present in 2. Total correction of tetralogy of Fallot can be performed safely in adults with low mortality and good functional improvement. The incidence of residual cardiac defects is low. The long-term importance of impaired ventricular function and arrhythmias remains to be ascertained.

Effect of pleurotomy on pulmonary function after coronary artery bypass grafting with internal mammary artery

Coronary artery by-pass grafting with internal mammary artery (IMA) has become the graft conduit of choice, due to improved survival and its long term patency rate. However, some studies have shown that, in comparison with saphenous vein grafts, after IMA grafting, there is increased postoperative impairment of pulmonary function, possibly due to the frequent performance of pleurotomy. In 57 consecutive patients, admitted for elective CABG with IMA, we prospectively evaluated the early (2nd and 6th day) postoperative chest X-ray complications and the late (2 months) respiratory function tests changes. Thirty-two patients had been subjected to pleurotomy (group 1) and 25 not (group 2). The incidence of pulmonary atelectasis and pleural effusion in 2nd and in 6th postoperative days was not different in the two groups: 22 vs. 19%, 74 vs. 52% in 2nd, and 29 vs. 19%, 48 vs. 38% in 6th postoperative day respectively. The incidence of elevated hemidiaphragm in 6th postoperative day was not different in the two groups (18.5 vs. 14%). Two months after surgery the mean values of spirometric tests were significantly lower than the preoperative values: VC from 88.5 +/- 1.26 to 80 +/- 1.65% of predicted, P < 0.001, FEV1 from 96.1 +/- 1.27 to 84.7 +/- 1.73% of predicted, P < 0.001, MEF50 from 84.9 +/- 3.14 to 69.2 +/- 3.18% of predicted, P < 0.001. No significant changes were detected in RV and in AaPO2.(ABSTRACT TRUNCATED AT 250 WORDS)

Porcine Cardiac Bioprostheses: Evaluation of Long-term Results in 990 Patients

Clinical results with porcine bioprostheses were reviewed for 990 patients who underwent heart valve replacement from January, 1974, to December, 1980. Eight hundred and seventy-four Hancock, 283 Carpentier-Edwards, and 10 Liotta bioprostheses were used. In 23 patients, 26 mechanical prostheses were implanted as well. Overall operative mortality was 60 out of 990 (6.06%): 30 out of 506 (5.9%) for mitral valve replacement (MVR), 13 out of 287 (4.5%) for aortic valve replacement (AVR), 1 out of 4 (25%) for tricuspid valve replacement, 0 out of 2 for pulmonary valve replacement, and 16 out of 191 (8.4%) for multiple valve replacement. Cumulative follow-up covered 1,793 patient-years. (Actuarial survival at 7 years was 76.6 +/- 3% for MVR. At 6 years, it was 83.2 +/- 2.8% for AVR and 55 +/- 13.5% for multiple valve replacement.) Prosthesis-related survival at 7 years was 91.7 +/- 1.9% for MVR, and at 6 years, it was 96.6 +/- 1.5% for AVR and 95.1 +/- 2.2% for multiple valve replacement. Bioprosthesis survival, considering deaths or complications that led to reoperation as final events, was 84.2 +/- 3.7% at 7 years for mitral valves and 87.7 +/- 3.8% at 6 years for aortic valves. Emboli per 100 patient-years numbered 3.2 for MVR, 0.5 for AVR, and 1.6 for multiple valve replacement. Twenty-seven patients underwent reoperation, 12 for perivalvular leak, 5 for endocarditis, 6 for valve thrombosis, and 4 for primary tissue failure (linearized rates of 0.7, 0.3, 0.3, and 0.2% per patient-year, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Endocarditis in patients with bioprostheses: pathology and clinical correlations

We studied 13 porcine bioprostheses removed from patients with endocarditis at our institute during the last 4.5 years. All bioprostheses had been removed at reoperation and were analyzed using anatomical and histological techniques. Each bioprosthesis was found to have developed rather constant lesions which were not related to the type of bioprosthesis. The stage of infection was not related to the duration of implantation. The presence of perivalvular abscesses was an ominous finding, often being the seat of persistent endocarditis. Our good clinical results of reoperation lead us to suggest that this be performed early once valvular or prosthetic malfunction is detected. Bioprostheses are, in our experience, the best choice in the surgical treatment of prosthetic valve endocarditis.

Morphological comparison of primary tissue failure (PTF) in porcine mitral and aortic bioprostheses in the same patient

Clinical and pathological studies have not clearly demonstrated whether primary tissue failure (PTF) in porcine bioprostheses occurs more often in the mitral than in the aortic position. We have studied morphological alterations in both positions in the same individual in 15 patients (14 mitroaortic and 1 mitroaortotricuspid) reoperated upon for PTF. Bioprostheses explanted were photographed, radiographed and observed in transmitted polarizing light. All lesions received a score on the basis of morphological criteria. The creep of the stent was measured. Calcification was slightly heavier and the degree of creep was significantly greater in the mitral position. Tears, infiltration and pannus growth did not differ between the two positions. According to our study, there is no conclusive demonstration that bioprostheses degenerate earlier and more extensively in the mitral than in the aortic position.

Protection of the heart by nifedipine cardioplegia during coronary artery surgery. A clinical-haemodynamic evaluation.

This study was undertaken to evaluate the myocardial preservation obtained by adding a Ca++ channel blocker, nifedipine, to cold potassium cardioplegia (4 mcg/Kg/L) in 24 patients undergoing coronary artery surgery. They were randomly divided into a treated (N) and a control (C) group. Significant differences between the two groups were noted in the cardiac arrest time (p less than 0.001), in the mechanical recovery mode (p less than 0.01) and in the inotropic support needed (p less than 0.01). Cardiac index increased significantly in group N but decreased in group C (p less than 0.01). Peripheral delta P/delta t and endocardial viability ratio (EVR) decreased in both groups. Coronary sinus and serum CK and CK-MB release were significantly lower in the treated group. ECG ischaemic changes occurred in 8 patients in group C but only in 1 case in group N (p less than 0.001). Arrhythmias occurred in 3 cases in group C (p less than 0.05). The incidence of perioperative myocardial infarction was not significant (2 cases in group C). These data suggest that nifedipine can protect the myocardial cell from ischaemic injury without depressing myocardial contractility or AV conduction.