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Biomedical subjects

T Ebels

Publications and source records attributed to T Ebels.

At least 55 records · Page 3Linked to original sources
PubMed1994

The rectus abdominis cardiomyoplastic procedure: preliminary results.

The rectus abdominis myofascial flap (RAMF) was investigated as a viable alternative to the latissimus dorsi flap for dynamic cardiomyoplasty. In human and animal cadaver experiments and live sheep, it was possible to use the RAMF for innervated intrathoracic use. The RAMF was stimulated by a specially designed cardiomyostimulator (Medtronic Inc., Maastricht, The Netherlands). The flap might be promising as an addition to the currently available dynamic cardiomyoplastic techniques.

Abdominal Muscles↗
PubMed1994

Improved gas exchange after pneumonectomy in an adult with incomplete pulmonary vein atresia.

Atresia of the pulmonary veins of the left lung and the right upper lobe with moderate pulmonary hypertension was diagnosed in a 20 year old man presenting with exertional dyspnoea and haemoptysis. After left pneumonectomy gas exchange appeared to have improved. This was shown by improved arterial oxygen pressures during all steps of exercise in a cycle ergometer test in comparison with values obtained before surgery. This improvement could be entirely attributed to a decrease in physiological dead space ventilation.

Adult↗
PubMed1994

Influence of age on survival, late hypertension, and recoarctation in elective aortic coarctation repair. Including long-term results after elective aortic coarctation repair with a follow-up from 25 to 44 years.

The optimal age for elective repair of aortic coarctation is controversial. The optimal age should be associated with a minimal risk of recoarctation, late hypertension, and other cardiovascular disorders. The purpose of this retrospective study is to determine the actuarial survival after aortic coarctation repair 25 years or more after operation and to calculate the optimal age for elective aortic coarctation repair. From 1948 to 1966, 120 consecutive patients underwent aortic coarctation repair. Eighty-seven were male (72.5%). The mean age at operation was 15.5 years (SD +/- 9.1 years). Resection and end-to-end anastomosis was performed in 103 patients (85.8%). Early mortality occurred in 6 patients as a result of surgical problems, whereas late mortality in 15 patients was predominantly caused by cardiac causes. The mean follow-up period was 32 years (range 25 to 44.2 years). Ninety-two patients 96.8%) were in New York Heart Association class I. The probability of survival 44 years after operation was 73%. Patients younger than 10 years at operation had the highest probability of survival at 97%. Multivariate analysis produced age at operation as the only incremental risk factor for the occurrence of recoarctation, of late hypertension, and of premature death. So that these sequelae can be avoided, elective aortic coarctation repair should be performed around 1.5 years of age. At that age, the probability of recoarctation will have decreased to less than 3%, and the probability of upper body normotension and long-term survival will be optimal.

Actuarial Analysis↗
PubMed1994

Arterial revascularization with the right gastroepiploic artery and internal mammary arteries in 300 patients.

From September 1989 to September 1992, the right gastroepiploic artery in combination with one or both internal mammary arteries was used as a graft in 300 patients who underwent coronary artery bypass grafting. The gastroepiploic artery was the primary choice in preference to the saphenous vein. The study comprised 263 men and 37 women, ranging in age from 31 to 77 years (median age 59 years). Thirty-nine patients (13%) underwent previous bypass procedures with autologous vein grafts. In 17 patients (5.7%) the gastroepiploic artery was used as a single graft. In 150 patients (50%) the gastroepiploic artery in conjunction with one internal mammary artery was used (in 6 patients combined with a vein graft). In 133 patients (44.3%) the gastroepiploic artery was used with both internal mammary arteries. Revascularization in nine patients (3%) was combined with another cardiac procedure; three aortic valve replacements, two mitral valve repairs, and four resections of a left ventricular aneurysm. Ten patients died in the hospital (3.3%; 70% confidence limits 2.3% to 4.8%); two of these patients had an infarction in the area revascularized by the gastroepiploic artery. At late follow-up, 0.5 to 39 months (mean 14 months) after the operation, we found no mortality. One patient with an occluded gastroepiploic artery graft underwent reoperation with the use of the right internal mammary artery. One patient underwent percutaneous transluminal coronary angioplasty of the right coronary artery after occlusion of the gastroepiploic artery. Elective recatheterization was done in 88 patients 1 to 25 months after operation (mean 10 months). Graft patency in gastroepiploic artery grafts increased steadily from 77% in the first semester of the study to 95% in the fourth semester and then equaled the patency of the internal mammary artery grafts (97%), which was almost constant during the whole period. We conclude that patency of the gastroepiploic artery was initially related to a "learning curve" but eventually equaled that of the internal mammary artery grafts. Furthermore, the gastroepiploic artery may well be the graft of choice in conjunction with the internal mammary arteries.

Arteries↗
PubMed1993

Congenital quadricuspid aortic valve.

Two patients with a quadricuspid aortic valve are described, one of them with concomitant juxtaposed coronary orifices facing the right hand facing sinus. The etiology and incidence of this congenital anomaly will be discussed.

Adult↗
PubMed1993

Sustained atrial flutter around the tricuspid valve in pigs: differentiation of procainamide (class IA) from flecainide (class IC) and their rate-dependent effects.

The wavelength theory considers two determinants of reentry, i.e., refractoriness and conduction velocity. It does not take excitability into account primarily. We evaluated frequency-dependence of excitability and refractoriness before and after flecainide or procainamide administration in relation to termination of reentrant atrial flutter. After making a Y-shaped lesion in the right atrium, we induced 62 flutters (cycle length 171 +/- 15 ms) by electrical stimulation in 15 pigs. Strength-interval curves were determined to assess excitability and refractoriness. Multiple cycle lengths were used to establish rate-dependent changes. Flutter cycle length increased after flecainide (to 290 +/- 67 ms) or procainamide (to 295 +/- 54 ms). The flutters always terminated abruptly (flecainide dose 103 +/- 104 mg, plasma concentration 370 +/- 21 ng/ml; procainamide dose 1,150 +/- 686 mg, concentration 51 +/- 24 mg/l). Flecainide caused an increase in diastolic thresholds from 0.3 +/- 0.2 to 0.8 +/- 0.5 mA (p < 0.006) and procainamide from 0.5 +/- 0.3 to 0.9 +/- 0.5 mA (p < 0.02). The increase in threshold was frequently dependent. Procainamide increased refractoriness at longer cycle lengths (> or = 250 ms), but this effect was abolished at shorter cycle lengths, indicating that only after significant slowing of the rate, prolongation of refractoriness may appear. Thus, both drugs interrupt reentrant flutter mainly by reducing excitability. Subclassification into IA and IC may be less relevant at high rates. Construction of strength-interval curves and assessment of rate-dependent "postrepolarization refractoriness" should be considered when one studies drugs that influence excitability.

Animals↗
PubMed1992

Interruption of the aortic arch, distal aortopulmonary window, arterial duct and aortic origin of the right pulmonary artery in a neonate: report of a case successfully repaired in a one-stage operation.

The case of a 4-day-old male neonate with the rare combination of interruption of the aortic arch beyond the left subclavian artery, distal aortopulmonary window, persistent arterial duct and aortic origin of the right pulmonary artery is presented. Review of the literature reveals this patient to be the thirteenth reported case and the fifth case with successful repair.

Aorta, Thoracic↗
PubMed1992

Mechanical heart valve prostheses: sound level and related complaints.

In a randomised study, we investigated the sound production of mechanical heart valve prostheses and the complaints related to this sound. The CarboMedics, Björk-Shiley monostrut and StJude Medical prostheses were compared. A-weighted levels of the pulse-like sound produced by the prosthesis were measured in 25 patients after aortic valve replacement. Additionally, 141 patients, 117 after aortic valve replacement, 20 after mitral valve replacement and 4 after double valve replacement were interviewed. The average sound pulse pressure levels were 46.0 +/- 2.9 dB(A) in the Carbomedics group, 55.4 +/- 1.2 dB(A) in the Björk-Shiley monostrut group and 44.1 +/- 4.4 dB(A) in the StJude Medical group, measured at a distance of 1 cm from the chest. The Björk-Shiley monostrut was louder than the other two prostheses (p less than 0.0005). Twenty (14.2%) of all patients had complaints related to the valve sound such as sleeping disturbances, irritation, nervousness or fear. Significantly more patients with a Björk-Shiley monostrut could hear their valve or had complaints when compared to the other two prostheses. Younger patients and patients with a mitral valve prosthesis could hear their valve more often than older patients or patients after aortic valve replacement. We conclude that sound characteristics and related complaints differ considerably among heart valve prostheses.

Aged↗
PubMed1992

Growth of the hypoplastic aortic arch after simple coarctation resection and end-to-end anastomosis.

Surgical treatment of a hypoplastic aortic arch associated with an aortic coarctation is controversial. The controversy concerns the claimed need to surgically enlarge the diameter of the hypoplastic arch, in addition to resection and end-to-end anastomosis. The purpose of this prospective study is to determine the fate of the hypoplastic aortic arch after resection of the aortic coarctation and end-to-end anastomosis. Between July 1, 1988, and January 1, 1990, 15 consecutive infants less than 3 months of age with an aortic coarctation were evaluated echocardiographically. A Z-value was calculated, being the number of standard deviations the aortic arch differs from the expected value, derived from a control group. Eight of these 15 infants had a hypoplastic aortic arch with a mean Z-value of -7.14 +/- 1.39. The other seven infants had a "normal" aortic arch with a mean Z-value of -1.85 +/- 1.08. All 15 infants underwent simple coarctation resection and end-to-end anastomosis. Six months after operation the mean Z-value increased significantly in those with a hypoplastic arch to -1.08 +/- 0.69 (p less than 0.0001) and in those with a "normal" aortic arch to 0.106 +/- 0.99 (p = 0.004). No infant died in our series (0%; CL 0% to 12%) and a recoarctation developed once (12.5%; CL 2% to 36%). Therefore we believe that simple resection and end-to-end anastomosis is the operation of choice for aortic coarctation associated with a hypoplastic aortic arch despite the presence of a ventricular septal defect and that enlargement of the hypoplastic aortic arch is not necessary.

Anastomosis, Surgical↗
PubMed1991

Repair of aortic coarctation in infants.

Fifty-three consecutive infants younger than 2 years underwent coarctation repair. A recoarctation occurred in 11 infants (21%). To determine variables associated with recoarctation, we entered preoperative and operative data into a multivariate stepwise logistic regression analysis. Patient weight was an incremental risk factor for recoarctation instead of age, in contrast to previously published studies. Furthermore, the residual gradient after the operation was a strong incremental risk factor. This risk factor was even more significant when expressed as a ratio of the systolic arm pressure, which takes background hemodynamics into account. Because weight is a more significant risk factor than age, we conclude that deferring operation is indicated only when the infant gains weight. Furthermore, a residual gradient is more important in the hemodynamic setting of a lower systolic arm pressure.

Age Factors↗
PubMed1990

Patency of arm vein grafts used in aorto-coronary bypass surgery.

Arm veins have been used in myocardial revascularisation procedures as a last resort bypass conduit because of their associated low patency. Nevertheless, leg veins and mammary arteries, which are the most commonly used, are sometimes not sufficient, leaving little choice as to the bypass conduit. To assess the properties of arm veins in bypass surgery, we compared a group of 28 patients that underwent an arm vein graft coronary bypass procedure with a matched group of patients in which leg veins were used. In 28 patients, 40 arm vein grafts with 77 distal anastomoses were used (mean 1.9 +/- 0.9; range 1-5). A cerebrovascular accident was the cause of the sole death (2%) during the study period. The mean follow-up was 4.6 years (Standard deviation, SD: 1.5 years). More antianginal medication was used in the arm vein group (P = 0.017). Additionally, the percentage of the expected maximal frequency during exercise testing was lower in the arm vein group as compared to the leg vein group. Digital subtraction angiography showed that the patency of the arm vein bypass grafts was 47% (70% confidence limits, CL: 32%-62%) while the patency of the leg vein grafts was 77% (CL: 64%-87%), which was statistically significant (P = 0.051). Comparison of these figures with the few published reports on arm veins used as coronary bypass grafts reveals similar results. We conclude that the arm vein as a coronary bypass graft is only to be used when mammary arteries and leg veins are not available.

Arm↗
PubMed1990

Anomalies of the left atrioventricular valve and related ventricular septal morphology in atrioventricular septal defects.

A characteristic feature of atrioventricular septal defects is a deficiency of the inlet part of the ventricular septum that results in a "scooped out" appearance. The depth of the scoop in relation to the disposition of the atrioventricular valves has been debated. To clarify the relation between the morphology of the ventricular septum and the disposition of the atrioventricular valves, we quantified these anatomic features in 151 hearts at autopsy to determine whether those features identified particular groups within the overall lesion. We found that 137 hearts had left atrioventricular valves with three leaflets. The left valve in the other 14 hearts exhibited a dual orifice, a two-leaflet or one-leaflet arrangement, or was imperforate. These anomalies could be analyzed in terms of a sequence of diminishing formation of the commissures. Also, three-leaflet valves displayed a variability in which the angular size of the mural leaflet correlated negatively with that of the inferior leaflet. In some of the hearts with a common atrioventricular orifice, the bridging leaflets did not meet over the ventricular septum, thus creating a "gap." The mural leaflet's angular size corresponded to a deficiency of the combined inferior-mural leaflet complex. Hearts with an abnormal disposition of the left atrioventricular valve had the ventricular septum "scooped" to a greater extent than those with a common orifice, although most had separate right and left atrioventricular orifices.

Heart Septal Defects↗
PubMed1989

Rates of thromboembolism with three different mechanical heart valve prostheses: randomised study.

In 434 operations for valvular heart disease, patients were randomised to receive Björk-Shiley, Edwards-Duromedics, or Medtronic-Hall mechanical prostheses. At a median follow-up time of 37.5 months there were no differences in hazard of death or non-embolic events. In the first six postoperative months the incidence of thromboembolism was about the same for the three valves. Subsequently, however, the incidence of thromboembolism for the Edwards-Duromedics valve was 3.9 times higher than for the Björk-Shiley valve, and for the Medtronic-Hall valve 2.6 times higher than for the Björk-Shiley valve.

Adult↗