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Alexandros N Karavas

Publications and source records attributed to Alexandros N Karavas.

9 recordsLinked to original sources
PubMed2005

Impact of concomitant coronary artery bypass grafting on hospital survival after aortic root replacement.

BACKGROUND: We examined the impact of concomitant coronary artery bypass grafting (CABG) on hospital survival after aortic root replacement. We sought to determine whether CABG procedures that were not originally planned but rather added after the aortic root procedure was completed (CABG/bailout) skewed the results to shift patients with bad outcomes to the CABG group, making the non-CABG group appear undeservedly low risk. METHODS: Between May 1992 and January 2001, 369 consecutive patients underwent aortic root replacement. Concomitant CABG was required in 95 patients (26%). Indications for CABG were significant coronary artery disease in 73 patients (20%), active endocarditis or acute aortic dissection involving the coronary orifices in 14 patients (4%), and difficulty weaning from bypass because of regional wall motion abnormality from presumed but unconfirmed coronary artery disease or technical error at coronary ostial reimplantation (CABG/bailout) in 8 patients (2%). RESULTS: Operative mortality for the entire cohort was 5.7% (21 patients). The operative mortality rate for the non-CABG group was 0.4% (1 of 274 patients), and for the CABG group, 21% (20 of 95 patients; p < 0.001). Independent predictors of operative mortality in the CABG group were New York Heart Association functional class III or IV (odds ratio, 3.9; 95% confidence interval, 1.07 to 14.5), active endocarditis (odds ratio, 9.2; 95% confidence interval, 2.06 to 41.5), acute aortic dissection (odds ratio, 7.6; 95% confidence interval, 1.81 to 32.0), and failure to use retrograde cardioplegia (odds ratio, 6.4; 95% confidence interval, 1.06 to 38.8). The use of CABG/bailout was not a predictor. CONCLUSIONS: Adding CABG at the end of an aortic root procedure is a rare event, and because it is rare, there is no significant shift of risk as a result of the CABG/bailout patients on the overall CABG group.

Adult↗
PubMed2004

Outcomes in patients with normal serum creatinine and with artificial renal support for acute renal failure developing after coronary artery bypass grafting.

This retrospective study of cardiac surgical patients with normal serum creatinine who developed acute renal failure requiring artificial renal support was undertaken to (1) determine the prevalence of acute renal failure and hospital mortality in this subgroup, (2) identify the independent predictors of early mortality, and (3) determine long-term survival and prognosis.

Acute Kidney Injury↗
PubMed2004

Left anterior descending coronary endarterectomy: early and late results in 196 consecutive patients.

BACKGROUND: With advances in percutaneous coronary interventions, many patients now referred for coronary artery bypass grafting have diffuse coronary artery disease. We undertook this retrospective study to determine whether left anterior descending (LAD) coronary endarterectomy is a safe and effective long-term adjunct to coronary artery bypass grafting in patients who cannot otherwise be completely revascularized. METHODS: Between January 1992 and March 2000, 196 of 7,633 (2.5%) consecutive patients underwent LAD coronary endarterectomy with coronary artery bypass grafting. Median age was 67 years (range, 33 to 97 years), 101 patients (52%) had unstable angina, and 182 (93%) were in New York Heart Association class III or IV. Thirty-three patients (17%) had ongoing myocardial infarction; another 17 (9%) had myocardial infarction less than 1 month. Thirty patients (15%) required intraaortic balloon pump preoperatively and 19 (10%) were reoperations. RESULTS: All patients underwent LAD endarterectomy with coronary artery bypass grafting to the LAD. The left internal mammary artery was grafted to the LAD in 151 patients (77%), and 46 of 151 (30%) of these required an additional vein patch to the endarterectomized bed. Concomitant valve procedures were performed in 8 (4%) patients. Overall hospital mortality was 3% (6 of 196). Perioperative myocardial infarction in the LAD territory was 3%. One-year survival was 94% (95% confidence interval, 90% to 97%), whereas 5-year survival was 74% (95% confidence interval, 66% to 80%). Freedom from cardiac events (angina, myocardial infarction, congestive heart failure, percutaneous coronary interventions) was 90% (95% confidence interval, 84% to 94%) at 1 year and 84% (95% confidence interval, 75% to 90%) at 5 years. CONCLUSIONS: Despite the presence of diffuse coronary artery disease, coronary artery bypass grafting with LAD endarterectomy offers excellent results with very low hospital mortality and morbidity, and favorable long-term survival.

Adult↗
PubMed2003

Biological vs. mechanical aortic root replacement.

OBJECTIVES: Although age and co-existing coronary disease are major determining factors when deciding valve choice (mechanical vs. biological) in simple aortic valve replacement, no studies have documented selection criterion for biological (BIO) vs. mechanical (MECH) aortic root prosthesis. METHODS: Two hundred and twenty-one consecutive patients underwent elective aortic root replacement with either BIO (homograft, n=111, Freestyle, n=25) or MECH composite grafts (n=85). Median age in BIO was 53 years and in MECH 54 years (P=NS). Groups were similar in gender, NYHA class and ejection fraction (BIO, EF=59% vs. MECH, EF=55%), but the need for concomitant coronary artery bypass grafting (CABG) did differ between groups (MECH=35% vs. BIO=17%, P=0.003). Mean follow-up was 42+/-28 months for mortality and 39+/-28 months for morbidity. RESULTS: Full root replacement was performed in 213 patients (96%) and hemi-root in eight (4%). The most common underlying etiologies were annulo-aortic ectasia (n=82, 37%), calcified-degenerative (n=73, 33%) and bicuspid/congenital aortic valve disease (n=39, 18%). Operative mortality was 1.5% for BIO and 2.4% for MECH (P=0.5). By univariate analysis there was a trend towards greater 5-year survival in BIO (92.4% vs. 88.2%, P=0.068). By multivariate analysis, increasing age (HR=2.4, P=0.003), previous valve replacement (HR=4.7, P=0.024), concomitant CABG (HR=3.7, P=0.032), and perioperative stroke (HR=9.9, P=0.0005) were all independent predictors of late death. The 5-year freedom from valve-related complications was similar in both groups (BIO=93% vs. MECH=86%, P=0.5). CONCLUSIONS: Elective aortic root replacement is an exceedingly safe operation. At mean follow-up of 4 years, there is no meaningful difference in early or mid term valve-related results between BIO and MECH aortic root replacement. Continued evaluation for late valve-related complications in this cohort will be necessary to determine the advantages, if any, of one prosthesis over the other.

Adult↗
PubMed2002

Aortic valve surgery after previous coronary artery bypass grafting with functioning internal mammary artery grafts.

BACKGROUND: Aortic valve surgery after coronary artery bypass grafting (CABG) in the setting of patent pedicled internal mammary artery (IMA) grafts poses a high risk because of the underlying ischemic and valve disease. Unlike mitral valve surgery or CABG, in which aortic clamping (AoX) may be optional, aortic valve surgery uniformly requires AoX unless circulatory arrest is used. Management of the IMA graft in these circumstances has traditionally involved dissection and clamping to prevent regional myocardial warming and cardioplegia "washout" during AoX. An alternative strategy involves avoiding dissection of the IMA, leaving the IMA graft open and establishing moderate-to-deep hypothermia during AoX and cardioplegic arrest. To date, no study has been published documenting the safety and efficacy of the latter practice. METHODS: A total of 94 patients who had patent IMA graft and underwent aortic valve surgery under AoX and cardioplegia between April 1992 and March 2001 were analyzed. The IMA was avoided and left open during AoX, and the patients were cooled systemically (median 20 degrees C). Patients ranged in age from 55 to 90 years (median 73.5 years). Ejection fraction was 15% to 83% (median 50%). Of the patients, 18 (19%) underwent minimally invasive upper hemi-resternotomy. Analysis for predictors of outcome was performed. RESULTS: The operative mortality, perioperative myocardial infarction (MI), and stroke rates were 6.4%, 7%, and 11%, respectively. No significant independent predictors of operative mortality or MI could be identified in the multivariate analysis, although a trend was shown for operative mortality with urgent procedures and patients requiring concomitant surgery of the ascending or arch aorta or aortic root. Advanced age and prolonged cardiopulmonary bypass predicted stroke in the multivariate analysis. There were five (5%) IMA injuries, all occurring during reentry or mediastinal dissection, but none in the subgroup of patients who underwent minimally invasive procedures. All patients survived. CONCLUSIONS: Patients undergoing aortic valve surgery after CABG in the presence of patent IMA represent a potentially high-risk group. Because AoX is almost uniformly required, a decision regarding the management of the IMA pedicle is needed. We have found that leaving the IMA undissected and unclamped is a reasonable strategy, provided that systemic cooling for myocardial protection is established to prevent regional warming and to compensate for cardioplegia washout effect during AoX.

Aged↗
PubMed2002

Cardiac decortication (epicardiectomy) for occult constrictive cardiac physiology after left extrapleural pneumonectomy.

Constrictive cardiac physiology typically does not occur in the absence of parietal pericardium. However, we report eight patients who, after left extrapleural pneumonectomy and removal of the parietal pericardium for malignancy, presented with dyspnea, jugular venous distension, and peripheral or generalized edema unresponsive to diuretics. Cardiac decortication (epicardiectomy) was performed whereby a thickened peel encasing the heart was surgically excised, resulting in vigorous contraction and expansion of the heart. In one patient, decortication occurred early after pneumonectomy and was incomplete. Acute signs of inflammation were present, and recurrence necessitated repeat decortication. When patients present with dyspnea, hepatojugular reflux, and peripheral edema refractory to diuretics, constrictive cardiac physiology should be considered in the differential diagnosis, even in the absence of parietal pericardium.

Constriction, Pathologic↗
PubMed2002

Risk factors and management of endocarditis after mitral valve repair.

BACKGROUND AND AIMS OF THE STUDY: The authors' nine-year experience with patients requiring mitral valve reoperations for endocarditis after previous mitral valve repair is reported. METHODS: Between June 1991 and June 2000, 1,275 mitral valve repairs were performed at the authors' institution. During this time, nine patients with prior mitral valve repair presented with mitral valve (non-recurrent) endocarditis requiring surgical correction. Etiology at the initial mitral valve repair was ischemic in four patients (44%), floppy valve in one patient (11%), Libman-Sacks endocarditis in one (11%), irradiation-induced degeneration in one (11%), and endocarditis in two cases (22%). Median patient age was 61 years (range: 36-81 years). Median ejection fraction was 50% (range: 23-70%), and seven patients (78%) presented urgently or emergently. The median time interval between the two procedures was 8.6 months (range: 28 days to 14.3 years). RESULTS: Certain risk factors were identified in these patients, including systemic infections, prosthetic implants in the bloodstream, and subsequent invasive procedures. The mitral valve was re-repaired in one patient (11%), while eight patients (89%) required valve replacement. All required excision of the ring. Hospital mortality was 11% (n = 1). Postoperative complications included perioperative myocardial infarction in two cases (25%), low cardiac output in two (25%), and prolonged ventilatory support in four (50%). There was no perioperative stroke, and no late recurrence of endocarditis. CONCLUSION: The study findings suggest that the incidence of (non-recurrent) endocarditis after mitral valve repair requiring surgical intervention is infrequent. Attempts at re-repair may be successful only in selected patients. Reoperation was accomplished with acceptable morbidity and mortality, and often required mitral valve replacement; however, late results indicated the absence of prosthetic valve endocarditis.

Adult↗
PubMedDate not supplied

Management of mild aortic stenosis during coronary artery bypass surgery: an update, 1992-2001.

BACKGROUND: "Prophylactic" aortic valve replacement (AVR) in patients with asymptomatic, mild-to-moderate aortic stenosis (AS) at the time of CABG is controversial. In 1994, we reported our initial experience involving 44 patients and have now updated our series in an attempt to further evaluate outcomes. METHODS: Between January 1992 and July 2001, 100 consecutive patients underwent reoperative AVR following previous CABG. Forty patients had their initial surgery at the Brigham & Women's Hospital (BWH) and 60 patients had their coronary surgery elsewhere. None of the 40 BWH patients had a mean valve gradient greater than 25 mmHg at the time of CABG. RESULTS: The mean time interval from CABG to AVR for the entire group was 9.0 years (range: 1.4-21 years). Overall operative mortality (OM) was 7% including 5 deaths (10.2%) among 49 patients requiring additional CABG at the time of AVR and 2 deaths (3.9%) among 51 patients without additional coronary artery intervention. This OM rate was a notable decrease from our earlier report of 18.2% (P = 0.07). Furthermore, operative mortality decreased progressively from 15.4% in 1992-1993 to 0% in 2000-2001 (P = NS). CONCLUSION: The OM of reoperative AVR following CABG has fallen in recent years. Given the relevance of newer techniques and approaches, it may be reasonable to adopt an expectant management approach in patients with asymptomatic mild-to-moderate AS (i.e., mean systolic gradient less than 25 mmHg) at the time of CABG.

Aged↗