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Biomedical subjects

F E Vermeulen

Publications and source records attributed to F E Vermeulen.

At least 19 recordsLinked to original sources
PubMed2001

Repeated thromboembolic and bleeding events after mechanical aortic valve replacement.

BACKGROUND: The choice of a valve substitute in young adults requires a decision balancing the risks of long-term anticoagulation versus reoperation(s). This article analyzes the long-term risk and determinants of thromboembolic (TE) and bleeding (BLE) complications after mechanical aortic valve replacement (AVR). METHODS: From December 1963 to January 1974, 249 patients survived a mechanical AVR at our institution. Mean age was 41.8+/-12.4 years and 81% (n = 202) were male. Ball valves were implanted in 24% (n = 61) and disc valves in 76% (n = 188). Patients were anticoagulated with vitamin K antagonists and dipyridamole. A total of 4,855 patient-years was available for analysis. Mean follow-up was 19.5+/-9.4 years and was 100% complete. Analyses were performed with Kaplan-Meier and multivariable Cox regression methods. RESULTS: One hundred and two patients had one TE or BLE postoperative event and 58 patients had two postoperative events. Six patients had more than five postoperative events. Freedom from a first postoperative event was 74.8%+/-2.9%, 55.3%+/-3.5%, and 46.8%+/-4.0% at 10, 20, and 30 years, respectively. Freedom from a second postoperative event was 45.4%+/-5.4%, 29%+/-6.0%, and 23.2%+/-7.1% at 10, 20, and 30 years, respectively. Multivariate predictors for TE or BLE complications were ball valve (Odds Ratio (OR) = 2.9), postoperative endocarditis (OR = 2.2), and any surgery (OR = 2.2). The incidence of events was highest the first 5 postoperative years. CONCLUSIONS: The risk of adverse events is highest the first 5 postoperative years. Once an event has occurred, the risk for a second event is increased. The incidence and frequency of events is substantial and should be considered in the choice of a valve substitute.

Adult↗
PubMed2001

Different behavior of sequential versus single left internal mammary artery to left anterior descending area grafts(1).

To study echo Doppler characteristics of sequential versus single left internal mammary artery (LIMA) to left anterior descending (LAD) area grafts transthoracic echo Doppler at the LIMA origin and angiography were performed pre- and postoperatively. In 17 patients single LIMA to LAD (group I) and in 45 patients sequential LIMA to LAD area (group II) bypass grafting was performed. All patients show an early postoperative shift towards diastolic coronary Doppler velocity spectra. Only group II shows a further significant late increase in diastolic, velocity time integral and some systolic echo Doppler parameters at rest. Diastolic peak and diastolic as well as total mean and velocity time integral maximal values are significantly higher in group II in late postoperative hyperemic response. Preoperative and late control angiography showed no significant differences in overall grading of native LAD stenosis between both groups. The large coronary reserve in LIMA sequential grafts may contribute to an improved long-term patency.

Aged↗
PubMed2001

Differences in LIMA Doppler characteristics for different LAD perfusion areas.

OBJECTIVES: To correlate supraclavicular left internal mammary artery (LIMA) to left anterior descending artery (LAD) area Doppler characteristics with angiographically perfused area. METHODS: Sixty patients (50 male, mean age 62+/-7.3 years) with LIMA to LAD area grafting were prospectively entered in a follow up study. Supraclavicular echo Doppler of the LIMA was studied at the LIMA origin preoperatively, and at 4.8+/-3.8 months and 1.8+/-0.9 years postoperatively. The potential area to be revascularized judged from preoperative angiography was called the 'target' area. Control angiography (native and LIMA) was done at 1.5+/-0.9 years. The perfused area % was classified into group I < or =17.0% (n=16), group II >17.0% and <22.50% (n=17), and group III > or =22.50% (n=18) and related to LIMA Doppler characteristics. Multivariate linear regression analyses (MLRA) were performed to assess the relations between Doppler variables and the perfused area, target area and ratio of perfused/target area. RESULTS: At MLRA perfused area was significantly related to the natural logarithm of diastolic peak velocity (DPV) (P=0.013) and diastolic mean velocity (P=0.048) and the ratio only to the degree of LAD stenosis (P=0.004). In hyperaemic response maximal DPV (DPV max) showed significant correlation to the perfused area (P=0.005) as well as to the ratio (P=0.017). When analyzing the additive power of both investigations, only DPV max (P=0.005) correlated significantly to the perfused area and for the ratio only the degree of stenosis of the LAD emerged as significant (P=0.004). CONCLUSIONS: At MLRA the diastolic flow pattern at rest and the maximal DPV in hyperaemic response correlated significantly with the LIMA run-off area whereas the last variable is the strongest predictor of the LIMA run-off area.

Coronary Angiography↗
PubMed2000

Durability of aortic valve preservation and root reconstruction in acute type A aortic dissection.

BACKGROUND: The aim of this study was to determine the durability of aortic valve preservation and root reconstruction in type A aortic dissection with involvement of the aortic root. METHODS: From November 1976 to February 1999, 246 patients underwent surgical treatment for acute type A aortic dissection at our institution. In 121 patients (49%), all with acute type A dissection and aortic root involvement, the aortic valve was preserved and one or more of the sinuses of Valsalva were reconstructed. The mean age of this group was 59 +/- 11 years and 70 (58%) were men. Thirty patients (25%) were operated in cardiogenic shock. Criteria for aortic root reconstruction were technical feasibility and surgeon preference. Techniques used for reconstruction were valve resuspension in all patients and additional reinforcement of the aortic root with Teflon (L.R. Bard, Tempe, AZ) felt (n = 21), gelatin-resorcinol-formaldehyde-glue (GRF-glue, Fii, Saint-Just-Malmont, France) (n = 103), or fibrinous glue (Tissu-col, Immuno AG, Vienna, Austria) (n = 5). Mean follow-up was 43.5 +/- 46 months. RESULTS: The operative mortality was 21.5% (n = 26). Actuarial survival was 72% +/- 4%, 64% +/- 5%, and 53% +/- 6% at 1, 5, and 10 years, respectively. Median aortic regurgitation in patients with retained native aortic valve at follow-up was 1+. All root reoperations included aortic valve replacement (n = 12). Freedom from aortic root reoperation was 95% +/- 2% at 1 year, 89% +/- 4% at 5 years, and 69% +/- 9% at 10 years. The incidence of aortic root reoperation was 23%, 11%, and 40%, respectively, when Teflon felt, GRF-glue, and fibrinous glue were used for root reconstruction. Multivariate Cox proportional hazard analysis revealed the use of fibrinous glue (RR = 8.7; p = 0.03) as well as the presence of an aortic valve annulus more than 27 mm (RR = 4.2; p = 0.04) as independent risk factors for aortic root reoperation. CONCLUSIONS: Aortic valve preservation in acute type A dissection provides relatively durable results. The use of fibrinous glue for root reconstruction seems to compromise the long-term durability of the repair compared with Teflon felt and GRF-glue. A dilated aortic annulus requires a more extensive root procedure.

Actuarial Analysis↗
PubMed2000

Association of intraoperative transcranial doppler monitoring variables with stroke from carotid endarterectomy.

BACKGROUND AND PURPOSE: The outcomes of carotid endarterectomy (CEA) are, in addition to patient baseline characteristics, highly dependent on the safety of the surgical procedure. During the successive stages of the operation, transcranial Doppler (TCD) monitoring of the middle cerebral artery (MCA) was used to assess the association of cerebral microembolism and hemodynamic changes with stroke and stroke-related death. METHODS: By use of data pooled from 2 hospitals in the United States and the Netherlands, including 1058 patients who underwent CEA, the association of various TCD emboli and velocity variables with operative stroke and stroke-related death was evaluated by univariable and multivariable logistic regression analyses in combination with receiver operating characteristic (ROC) curve analyses. The impact of basic patient characteristics, such as age, sex, preoperative cerebral symptoms, and ipsilateral and contralateral internal carotid artery stenosis, on the prediction of operative stroke was also evaluated. RESULTS: We observed 31 patients with ischemic and 8 patients with hemorrhagic operative strokes. Four of these patients died. Emboli during dissection (odds ratio [OR] 1.5, 95% CI 0.8 to 2.9) and wound closure (OR 2.3, 95% CI 1.2 to 4.4) as well as > or =90% decrease of MCA peak systolic velocity at cross-clamping (OR 3.3, 95% CI 1.3 to 8.5) and > or =100% increase of the pulsatility index of the Doppler signal at clamp release (OR 7.1, 95% CI 1.4 to 35.7) were independently associated with stroke. The ROC area of this model was 0.69. Of the patient characteristics, only preoperative cerebral ischemia (OR 1.9, 95% CI 1.0 to 3.7) and > or =70% ipsilateral internal carotid artery stenosis (OR 0.5, 95% CI 0.2 to 0.9) were associated with stroke. Adding these patient characteristics to the model, the area under the ROC curve increased to 0.73. CONCLUSIONS: In CEA, TCD-detected microemboli during dissection and wound closure, > or =90% MCA velocity decrease at cross-clamping, and > or =100% pulsatility index increase at clamp release are associated with operative stroke. In combination with the presence of preoperative cerebral symptoms and > or =70% ipsilateral internal carotid artery stenosis, these 4 TCD monitoring variables reasonably discriminate between patients with and without operative stroke. This supports the use of TCD as a potential intraoperative monitoring modality to alter the surgical technique by enhancing a decrease of the risk of stroke during or immediately after the operation.

Aged↗
PubMed1999

A numerical approach to non-circular birdcage RF coil optimization: verification with a fourth-order coil.

It is demonstrated that birdcage resonators, satisfying conditions of quadrature operation and radiofrequency field homogeneity, can be realized in practice on formers of non-circular cross section described by an equation of the form (x/a)n + (y/b)n = 1 where a and b are constants and n > or = 2 is an integer. Using a ladder network analogous to that of a conventional circular birdcage, optimization algorithms were employed to determine the elemental current distribution on the non-circular cylindrical surfaces. A comparison of circular, elliptical, symmetric and asymmetric fourth-order (n = 4) section birdcage current distributions is presented. A short, asymmetric fourth-order cage was constructed and tested experimentally at 3 T and compared with a conventional circular-section head coil.

Algorithms↗
PubMed1999

A 23-year experience with composite valve graft replacement of the aortic root.

BACKGROUND: This is a retrospective study of early and long-term results of composite valve graft replacement of the aortic root. METHODS AND RESULTS: Between July 1974 and July 1997, 244 patients underwent aortic root replacement with a composite valve graft. Mean age was 54+/-15 years. The inclusion technique was used in 178 patients (73.0%), the open technique in 65 (26.5%), and the Cabrol II technique in 1 patient (0.5%). Hospital mortality was 7.8% (70% confidence limit, 6.1% to 9.5%). Independent determinants of hospital mortality were preoperative creatinine level more than 150 micromol/L (p = 0.04), prolonged cardiopulmonary bypass time (p = 0.006), intraoperative technical problems (p = 0.048), and year of operation (p = 0.015). Follow-up was 99.6% complete, median 96 months (range, 2 to 256 months). Fifty-seven patients (25.3%; 70% confidence limit, 22.4% to 28.2%) died during follow-up. Cumulative survival at 5, 10, and 20 years was 76%, 62%, and 33%. Independent risk factors for late death were postoperative complications (p = 0.027), technique for coronary reattachment (p = 0.028), and concomitant aortic arch operation (p = 0.01). Twenty patients (8.8%; 70% confidence limit, 7.0% to 10.6%) underwent reoperation on the aortic root. Estimated freedom from reoperation for pseudoaneurysms at 3 years was 96% in the inclusion group and 94% in the open group (p = 0.236). CONCLUSIONS: Aortic root replacement with a composite valve graft can be performed with low hospital mortality and morbidity. Pseudoaneurysms did occur in the inclusion group, but also in the open group.

Adolescent↗
PubMed1999

Impact of left heart bypass on the results of thoracoabdominal aortic aneurysm repair.

BACKGROUND: This study evaluated the role of left heart bypass on the results of thoracoabdominal aortic aneurysm (TAAA) operations. METHODS: Two hundred fifty-eight patients had surgical repair of a thoracoabdominal aortic aneurysm between 1981 and 1998 using the inlay technique. Simple cross-clamping was used in 47.7% and left heart bypass (atriodistal) in 52.3%. Further surgical technique was identical: liberal intercostal or lumbar artery reimplantation, cerebrospinal fluid drainage (since 1989), administration of a renal cooling solution, permissive mild hypothermia, and no pharmacologic protection. Both univariate and multivariate analysis were used. RESULTS: The hospital mortality rate was 10.1% overall: 14.6% in the cross-clamp group, and 5.9% in the bypass group (p = 0.02). The risk of hospital death increased with aneurysm rupture (odds ratio 5.6) and when the patient needed postoperative dialysis (odds ratio 7.5). The use of left heart bypass had a mild protective effect on hospital death (odds ratio 0.56). The incidence of postoperative renal failure requiring dialysis was 8.3% overall: 10.9% in the cross-clamp group, and 5.9% in the bypass group (p = 0.16). After multivariate analysis, a longer operative procedure (odds ratio 1.01 per minute) and a longer reappearance time of blue dye in the urine (odds ratio 1.05 per minute) increased the risk of dialysis, whereas the use of atriodistal bypass reduced that risk (odds ratio 0.08). Paraplegia or paraparesis occurred in 10.9% of patients overall: 13.2% in the cross-clamp group, and 8.8% in the bypass group (p = 0.27). After logistic regression, rupture increased the risk of paraplegia or paraparesis (odds ratio 3.2) and dissection reduced it (odds ratio 0.23). CONCLUSIONS: The use of atriodistal bypass is beneficial in patients who had thoracoabdominal aortic aneurysm repair. Hospital mortality rates, postoperative dialysis, and paraplegia/paraparesis were reduced.

Adult↗
PubMed1999

Antegrade selective cerebral perfusion in operations on the proximal thoracic aorta.

BACKGROUND: To determine the factors that influence hospital death and neurologic complications after surgery on the thoracic aorta using circulatory arrest and antegrade selective cerebral perfusion. METHODS: From May 1989 through April 1997, 106 patients underwent surgery on the thoracic aorta using circulatory arrest and antegrade selective cerebral perfusion. Mean age was 64.0 +/- 11.5 years. Unilateral antegrade cerebral perfusion was used in 37 patients (35%), bihemispheric antegrade cerebral perfusion in 69 patients (65%). Mean antegrade cerebral perfusion time was 50.5 +/- 20.5 minutes. Indication for surgery was atherosclerotic aneurysm in 60 (56.5%) patients, postdissection aneurysm in 26 (24.4%), acute type A dissection in 16 (15.1%), other in 4 (4.0%). RESULTS: Hospital mortality was 8.5% (n = 9; 70% CL: 5.8%-11.2%). Independent predictors of hospital mortality were rethoracotomy (odds ratio 5.7, p = 0.02), postoperative temporary (odds ratio 17.3, p = 0.02) or permanent (odds ratio 7.5, p = 0.03) neurologic dysfunction, postoperative dialysis (odds ratio 9.9, p = 0.008). Bilateral antegrade selective cerebral perfusion had a favorable impact on hospital mortality (odds ratio 0.08, p = 0.007). Temporary neurologic dysfunction occurred in 3.8% of patients (n = 4; 70% CL: 2.0%-5.6%); preoperative hemodynamic instability (odds ratio 14.8, p = 0.05) and perioperative technical problems (odds ratio 22.2, p = 0.033) were independent determinants of temporary neurologic dysfunction. Permanent central neurologic damage occurred in 5.4% of patients (n = 6; 70% CL: 3.2%-7.6%). Preoperative hemodynamic instability (odds ratio 18.9, p = 0.009) and approach through a left thoracotomy (odds ratio 9.4, p = 0.031) were significant predictors of permanent neurologic damage. CONCLUSIONS: Hospital mortality is affected significantly by the choice of technique used for antegrade cerebral perfusion. The incidence of both temporary and permanent postoperative central neurologic damage is influenced by preoperative hemodynamic instability. Duration of cerebral perfusion had no influence on the postoperative neurologic outcome.

Acute Disease↗
PubMed1997

Clinical outcome in venous coronary artery bypass grafting: a 15-year follow-up study.

OBJECTIVE: We investigated the clinical outcome of venous coronary artery bypass graft surgery. METHODS: A study group consisting of 428 consecutive patients-operated on between 1 April 1976 and 1 April 1977-was followed prospectively. Single or sequential saphenous vein grafts were performed with a mean of 3.2 coronary anastomoses per patient. A left ventricular aneurysmectomy was performed in 25 patients. RESULTS: Complete revascularisation was achieved in 78% of the patients. Follow-up was 99.8% complete and averaged 15.4 years for the survivors. Actuarial survival after 5, 10, and 15 years was 91.4%, 79.9%, and 61.1%, respectively. The cumulative probabilities of event-free survival at 10 years were as follows: cardiac death, 87.3%; acute myocardial infarction, 84.1%; reoperation, 88.6%; coronary artery balloon angioplasty, 94.1%; angina pectoris, 48.7%; and any event, 40.8%. CONCLUSIONS: The results are comparable with those of the few other long-term studies that have been published. With isolated venous bypass grafting, satisfactory results can be obtained until approximately 7 years after operation. Thereafter mortality increases, as does the rate of myocardial infarction, reoperation, and balloon angioplasty.

Adult↗
PubMed1997

Spontaneous resolution late after aortic dissection.

A 50-year-old man was operated on for acute type I (DeBakey classification) aortic dissection. The supracoronary ascending aorta was replaced with an interposition graft. Postoperative computed tomography and angiography clearly revealed a double-barrelled aortic arch, left common carotid artery and descending thoracoabdominal aorta with contrast filling of both true and false lumen starting from the distal anastomosis. The same finding was noted at 1 year follow-up with severe compression of the true lumen by the false lumen. At this time, anticoagulation therapy was stopped. One year later, computed tomography showed spontaneous resolution of the dissection in the aortic arch, left common carotid artery and descending aorta over its full length. This was confirmed by angiography. This case reports illustrates that spontaneous resolution of a dissected descending aorta can occur late after surgery from type 1 dissection, but it remains very rare.

Aortic Dissection↗
PubMed1997

Aortitis, aortic valve incompetence, and left coronary ostium stenosis in a patient with C-ANCA-associated necrotizing vasculitis.

Aortitis with involvement of the aortic valve is rarely associated with vasculitis syndromes. We present a patient with antibodies to a neutrophil cytoplasmic antigen-associated (ANCA) vasculitis with renal failure who developed aortic incompetence as a result of aortitis which involved the aortic valve. Thickening of the aortic wall also caused stenosis of the left coronary ostium.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1996

Smoking and cardiac events after venous coronary bypass surgery. A 15-year follow-up study.

BACKGROUND: The long-term clinical effects of smoking and smoking cessation after venous coronary bypass surgery have not been well established. METHODS AND RESULTS: Four hundred fifteen patients who underwent venous coronary bypass surgery between April 1976 and April 1977 were followed up prospectively for 15 years. Multivariate Cox survival analysis revealed that patients who smoked at the time of surgery had no elevated risks for clinical events compared with nonsmokers. However, smoking behavior at 1 and 5 years after surgery appeared to be an important predictor of clinical events during the subsequent follow-up period. Compared with patients who stopped smoking since surgery, smokers at 1 year after surgery had more than twice the risk for myocardial infarction and reoperation. Patients who were still smoking at 5 years after surgery had even more elevated risks for myocardial infarction and reoperation and a significantly increased risk for angina pectoris compared with patients who stopped smoking since surgery and patients who never smoked. Patients who started to smoke again within 5 years after surgery had increased risks for reoperation and angina pectoris. No differences in outcome were found between patients who stopped smoking since surgery and nonsmokers. CONCLUSIONS: Our results show that smoking cessation after coronary bypass surgery may have important beneficial effects on clinical events during long-term follow-up.

Adult↗
PubMed1996

Early mortality after surgical repair of postinfarction ventricular septal rupture: importance of rupture location.

BACKGROUND: The aim of this study was to identify factors influencing early outcome after surgical treatment of postinfarction ventricular septal rupture. We investigated the influence of proximal or distal rupture location. METHODS: Between 1980 and 1992 109 patients were treated surgically for ventricular septal rupture using a standardized technique. A division in time periods was made. The rupture was categorized according to its anterior or posterior site and proximal or distal location. RESULTS: The 30-day mortality rate was 27.5%. Multivariate logistic regression analysis identified preoperative shock (p = 0.0007) and right atrial oxygen saturation less than 60% (p = 0.021) as predictors for early death; the risk for early death declined over the time periods from 50% to 12.8% (p = 0.0007). Proximal ventricular septal rupture location (p = 0.0092) and interval between infarction and ventricular septal rupture less then 1 day (p = 0.034) were risk factors for the occurrence of preoperative shock. CONCLUSIONS: Proximal ventricular septal rupture location was the main determinant of preoperative cardiogenic shock, which in turn was the strongest predictor of early mortality. Over the time periods a decrease in early mortality was reached.

Aged↗
PubMed1996

Different clinical outcome in coronary artery bypass with single and sequential vein grafts: a fifteen-year follow-up study.

OBJECTIVE: In trying to answer the question about the controversial use of sequential grafts, we determined the long-term clinical outcome of patients in whom coronary artery bypass was done with different types of vein grafts. METHODS: A total of 428 consecutive patients who underwent isolated coronary artery bypass with vein grafts between April 1, 1976, and April 1, 1977, were prospectively observed. In these patients three groups could be defined with single grafts only, sequential grafts only, and combined single and sequential grafts. Follow-up was 99.8% complete and averaged 15.4 years for the survivors. The Kaplan-Meier method and multivariate analysis done with the Cox regression model were used for survival, myocardial infarction, reintervention, and "any event." RESULTS: Perioperative mortality and perioperative myocardial infarction rate were not statistically different among the three groups. During follow-up more myocardial infarctions (hazard ratio: 2.06; 95% confidence interval: 1.08 to 3.93; p = 0.0293) or any events (hazard ratio: 1.54; 95% confidence interval; 1.01 to 2.36; p = 0.0450) occurred in patients with sequential grafts only than in patients with single grafts only. CONCLUSION: Although more complete revascularization was obtained in patients with sequential vein grafts only, more events during a 15-year follow-up occurred in these patients than in patients with single vein grafts only.

Adult↗