Rosario Gregorio

Variables predicting adverse outcome in patients with deep sternal wound infection

BACKGROUND Mortality after deep sternal wound infection (DSWI) ranges between 5% and 47%. Variables predicting hospital mortality and prolonged hospital stay are still to be assessed. METHODS Among 13,420 patients who underwent cardiac surgery in our institution between 1979 and 1999, DSWI developed in 112 cases (0.8%). Multiple variables were recorded prospectively and analyzed retrospectively as predictors of hospital death and prolonged (>30 days) hospital stay. The analyzed variables were divided into three groups: (1) related to the patient, including demographic variables and preoperative conditions; (2) related to cardiac operation; and (3) related to infection. Predictive variables were assessed by univariate and multivariate logistic regression analysis. RESULTS Hospital mortality was 16.9%. The hospital stay of the 93 discharged patients ranged between 16 and 180 days (mean 31.3 +/- 15.2). Length of cardiac operation, length of stay in intensive care unit, interval between symptoms of DSWI and wound debridement were found to be the most significant predictors of bad outcome following DSWI. CONCLUSIONS In our study demographic variables and preoperative conditions did not affect the prognosis of DSWI. Lower mortality rate and shorter hospital stay could be achieved with earlier and aggressive treatment of DSWI.

Recurrent infective endocarditis: a multivariate analysis of 21 years of experience

BACKGROUND To evaluate which variables predict recurrence of endocarditis after surgical treatment, we reviewed our 21-year experience. METHODS Between January 1979 and May 2000, 308 consecutive valve replacement procedures for infective endocarditis were performed in 271 patients. Univariate and multivariate time-related analyses were performed to retrospectively evaluate the role of the following variables in the development of recurrent postoperative endocarditis: gender, site of endocarditis, previous valve disease, drug abuse, diabetes, positive valve/blood cultures, sepsis, perivalvular involvement, previous embolic events, type of replacement device, and persistent postoperative fever. RESULTS Clinical and echocardiographic follow-up was 97.36% complete, mean follow-up time was 53.2+/-3.4 months. Recurrent endocarditis developed in 58 cases (22.5%). Variables predicting recurrence were prosthetic endocarditis (p = 0.00001), positive valve culture (p = 0.0039), and persistence of fever at the seventh postoperative day (p = 0.000001). CONCLUSIONS Correct protocols of antibiotic therapy guided by microbiology may reduce the incidence of recurrent endocarditis to allow for surgery on sterile tissues and to prevent prosthetic infection. Recurrence rate is not affected by the choice of valve substitute, but can be prevented by complete surgical debridement.

Deep sternal wound infection: the role of early debridement surgery

OBJECTIVE This retrospective chart review study aimed to evaluate whether a more aggressive staged approach can reduce morbidity and mortality following post-cardiotomy deep sternal wound infection. METHODS Between 1979 and 2000, 14620 patients underwent open heart surgery: mediastinitis developed in 124 patients (0.85%). Patients were divided in two groups: in 62 patients (Group A) (1979-1994) an initial attempt of conservative antibiotic therapy was the rule followed by surgical approach in case of failure; in 62 patients (Group B) (1995-2000) the treatment was staged in three phases: (1) wound debridement, removal of wires and sutures, closed irrigation for 10 days; (2) in case of failure open dressing with sugar and hyperbaric therapy (11 patients, 17%); (3) delayed healing and negative wound cultures mandated plastic reconstruction (three patients, 4%). Categorical values were compared using the Chi-square test, continuous data were compared by unpaired t-test. RESULTS Incidence of mediastinitis was higher in Group B (62 out of 5535; 1.3%) than in Group A (62 out of 9085; 0.7%) (P=0.007). Mean interval between diagnosis and treatment was shorter in Group B (18+/-6 days) than in group A (38+/-7 days) (P=0.001). Hospital mortality was higher in Group A (19/62; 31%) than in Group B (1 out of 62; 1.6%) (P<0.001). Hospital stay was shorter in Group B (30.5+/-3 days) than in group A (44+/-9 days) (P=0.001). In Group B complete healing was observed in all the 61 survivors: 47 cases (76%) after Stage 1; 11 (18%) after Stage 2; three (4.8%) after Stage 3. CONCLUSIONS Although partially biased by the fact that the two compared groups draw back to different decades, this study showed that an aggressive therapeutic protocol can significantly reduce morbidity and mortality of deep sternal wound infection.

Molecular analysis of arterial stenosis in rat carotids

A new model of surgical injury for the induction and development of stenosis in common rat carotids is described. This model differs from balloon angioplasty or vein graft systems currently applied on animals to develop stenosis, since it involves the entire vessel wall layers and mimics the injury occurring during arterial grafts, endarterectomy or organ transplantation. At different times following arterial damage, the pattern of expression of genes already known to be involved in the proliferation, differentiation, and apoptosis of smooth muscle cells (c‐myc, Angiotensin II receptor 1, Bcl‐2 and Bax α), as well as of Rb and Rb2 genes, whose pattern of expression after arterial injury has not yet been reported, was analyzed by semi‐quantitative reverse transcription‐polymerase chain reaction technique. Histological and histochemical analysis on carotid sections shows the morphological changes which occurred 30 days after surgical injury in the vessel wall. Molecular and histological data demonstrate that this model of surgical injury induces neointimal proliferation in about 30% of rats. In about 70% of the remaining rats, it induces the processes responsible for negative remodelling, namely the significant accumulation of extracellular matrix and fibers and disorganization of arterial tunics. This model is therefore available for further studies on the expression of genes involved in the arterial stenotic process, as well as for testing drugs aimed at limiting this recurrent pathophysiological phenomenon. J. Cell. Physiol. 186:307–313, 2001.

Does antegrade blood cardioplegia alone provide adequate myocardial protection in patients with left main stem disease

BACKGROUND The optimum route for cardioplegia administration in patients with severe coronary disease is still under debate. This study compared clinical, echocardiographic, and biochemical results in patients with left main stem disease treated with 2 different strategies of myocardial protection. METHODS Between March 2000 and November 2002, 148 consecutive patients with left main stem disease undergoing coronary artery bypass grafting were divided into 2 groups according to the route of cardioplegia delivery: antegrade in 87 patients (group A) or antegrade followed by retrograde in 61 patients (group B). Electrocardiography, troponin I, MB-creatine kinase, and MB-creatine kinase mass were performed at 12, 24, 48, and 72 hours postoperatively. Echocardiography was performed preoperatively and before hospital discharge. Data were stratified in subgroups of patients with the following associated risk factors: left ventricular hypertrophy, diabetes, and right coronary stenosis. RESULTS Groups were homogeneous in preoperative and intraoperative variables, apart from the higher incidence of unstable angina and severity of left main stem disease in group B. Hospital deaths, intensive therapy unit and hospital stay, perioperative acute myocardial infarction, and intraaortic balloon pump support were similar in both groups. Postoperative recovery of left ventricle ejection fraction and wall motion score index did not differ between the 2 groups. However, postoperative atrial fibrillation was higher in group A (P =.015), especially in patients with diabetes (P <.0001). Troponin I was significantly higher in group A from postoperative hours 12 to 72 (P <.01), and the same pattern was observed in patients with diabetes (P <.001), critical right coronary stenosis (P <.001), and left ventricle hypertrophy (P <.001). CONCLUSION The combined route of intermittent blood cardioplegia allows better results in left main stem disease. Such data are confirmed even in risk subgroups.

Surgery for tricuspid valve endocarditis: A selective approach

SummaryThe authors report their 18-year experience in the surgical treatment of infective tricuspid endocarditis. Between January 1981 and January 1999, 238 cases of infective endocarditis were seen, with a tricuspid involvement in 21 cases (8.8%). Tricuspid valve repair was performed in 9 patients with infective lesions involving one single leaflet. The surgical principle of the repair was to avoid any prosthetic material implantation. Posterior leaflet vegetectomy was performed in another 2 patients with infected intracavitary leads. Tricuspid valve replacement was performed in 10 patients with involvement of the whole valvular apparatus. One patient died of septic shock 3 days postoperatively. All the other patients had a good postoperative recovery. Follow-up ranged between 12 and 155 months (mean 68.9 ± 55 months). Five cases of late mortality were observed: 3 for cardiac reasons and 2 of cancer. All the other patients are alive. Late postoperative echocardiography in the patients with tricuspid repair showed tricuspid regurgitation to be absent in 6 patients, mild in 2, moderate in 1, and severe in 1. No recurrent infections were observed either in patients with valve repair or in those with valve replacement. Good early and long-term results can be achieved in the surgical treatment of tricuspid endocarditis as long as complete excision of the infected tissue is performed and risk factors are controlled.

Brucella Endocarditis: Seven Cases Treated Surgically

Brucella endocarditis is a lifethreatening, often under-diagnosed complication of brucellosis. Seven cases of brucella endocarditis treated surgically in the last 25 years are described. The infection was localized on the aortic valve in 5 cases and on a prosthetic mitral valve in 2. All patients had a positive history of risk factors for brucella infection and all were in cardiac failure (5 in New York Heart Association functional class III and 2 in class IV). All underwent valve replacement followed by antibiotic therapy. Follow-up ranged from 1 and 206 months. One patient died following prosthetic valve replacement to treat a periprosthetic leak unrelated to the brucella infection. Brucella antibody tests and careful clinical history are mandatory in all patients with negative blood cultures in order to identify brucella earlier during the course of the infection before embolization or annular involvement occur.