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Biomedical subjects

Y Louagie

Publications and source records attributed to Y Louagie.

At least 37 records · Page 2Linked to original sources
PubMed1995

Operative risk assessment in coronary artery bypass surgery, 1990-1993: evaluation of perioperative variables.

Patient characteristics and the results of cardiac surgery change with time. To achieve the best possible treatment a continual analysis of results is necessary. The present study analyzes 1225 consecutive patients undergoing isolated aortocoronary bypass surgery for the four-year period ending September 1993. Average age was 63 years (range 32-86 years), 927 (75.7%) patients were male and 298 (24.3%) were female. Hospital mortality was 2.2% (17/787) for elective surgery, 6.3% (21/336) for urgent surgery, and 9.8% (8/82) for emergency surgery. Intraoperative variables increasing independently operative mortality as evidenced by multivariate analysis were the following: prolonged aortic cross-clamping time (p < 0.0001), absence of cold-blood cardioplegia (p = 0.0012), absence of bilateral use of internal mammary artery (p = 0.0035). Likewise, intraoperative variables influencing major adverse outcome (operative mortality and/or need for intra-aortic balloon pulsation) were the following: prolonged aortic cross-clamping time (p < 0.0001), absence of cold-blood cardioplegia (p = 0.0360). In conclusion, global ischemic time was the dominant variable in predicting operative outcome. Furthermore, a protective effect of cold blood cardioplegia and bilateral internal mammary artery grafting was evidenced.

Anesthesia, General↗
PubMed1994

Quantitative angiographic follow-up study of the free inferior epigastric coronary bypass graft.

BACKGROUND: Attempts to improve late results of bypass coronary surgery have focused on the use of arterial conduits because of the high attrition rate of venous grafts. METHODS AND RESULTS: In our institution, 150 patients received an inferior epigastric artery (EPIG) as a free bypass graft, anastomosed to the right coronary artery in 73% and to a marginal branch in 20% of cases. These patients were followed prospectively by qualitative and quantitative angiography. Angiographic studies were performed in 122 patients (81%) early after surgery (11 +/- 5 days), and in 72 cases, a late evaluation (11 +/- 6 months) was also obtained. Quantative angiography (basal and after isosorbide dinitrate [ISDN]) was performed on the in situ EPIG in a large subset of these patients, as well as in 59 patients before bypass surgery. The patency rate was 98% at early control and remained high (93%) at late control. However, at late control, 14 EPIGs were occluded or threadlike, but of these 14, eight were grafted on a coronary artery with a moderate stenosis (< or = 60%) and with good anterograde perfusion. Mean basal EPIG diameter increased from 2.23 +/- 0.42 mm before surgery to 2.57 +/- 0.52 mm at 11 days (P < .01) but decreased to 2.20 +/- 0.47 mm in late study (P < .01 versus 11 days and P = NS versus before surgery). Vasodilation of EPIG with ISDN was observed before surgery (+0.34 +/- 0.20 mm, P < .001) and at late control (+0.20 +/- 0.17 mm, P < .001) but not in the early postoperative period for the whole group. Early after surgery, basal diameter was not different from native EPIG dimensions after ISDN (2.57 +/- 0.52 versus 2.56 +/- 0.39 mm), suggesting maximal dilation. However, vasodilation with ISDN was observed in a subgroup of patients at this time. These responder patients (n = 51) had a smaller basal diameter (2.47 +/- 0.49 versus 2.67 +/- 0.54 mm, P < .05) and a smaller runoff (P < .001) than nonresponder patients. CONCLUSIONS: EPIG grafts have a good early patency rate. The mid-term patency rate remains high and seems to depend, at least partially, on flow through the native coronary artery. EPIGs initially increase their lumen size, probably to meet the increased blood flow due to myocardial requirements. Over time, EPIG diameters decrease mainly as a result of a higher basal vasomotor tone. Long-term angiographic follow-up (eg, 5 to 10 years) is needed to assess late patency rate and the relation with these early findings and will define the place of this new coronary bypass conduit.

Abdominal Muscles↗
PubMed1993

Postcardiopulmonary bypass lung edema. A preventable complication?

Potential etiologic factors of postcardiopulmonary bypass (post-CPB) lung edema (LE) were investigated (phase 1 study). Further patient treatment was modified according to the results of phase 1 study and the influence that these changes had on the incidence of the complication was assessed (phase 2 study). In phase 1 study, among 100 patients who underwent coronary bypass graft surgery, prolonged assisted ventilation was required for severe LE in 7 cases, and 6 patients had a moderate form of LE. Patients who suffered from severe LE had left and right ventricular dysfunction and normal pulmonary vascular resistance. Three predictors of LE were evidenced by logistic regression analysis: number of bypass grafts completed with internal mammary arteries (p = 0.013), transfusions of blood collected in mobile units (p = 0.014), and the combination of a significant lesion of the left main stem and the right coronary artery at preoperative angiography (p = 0.040). In phase 2 study, a further group of 100 patients was treated differently by improving myocardial protection during surgery, achieving a higher rectal temperature at the end of CPB, and reducing the amount of transfusions. This resulted in only one case of LE (p < 0.001). In conclusion, the cases of post-CPB LE evidenced in our study were related to postoperative ventricular dysfunction and blood transfusions. Any means of improving postoperative hemodynamic stability and reducing the need for transfusions could thus prevent the latter complication.

Blood Transfusion↗
PubMed1992

Use of the Carpentier-Edwards porcine bioprosthesis: assessment of a patient selection policy.

The Carpentier-Edwards bioprosthesis was implanted in 369 patients (414 valves) between May 1977 and December 1987 (age 67.2 +/- 0.5 years); 242 had aortic valve replacement, 80 had mitral valve replacement, 44 had multiple valve replacement, of which 41 were aortic and mitral valve replacement, 2 had isolated tricuspid valve replacement, and 1 had a pulmonary valve replacement. The selection criteria were the following: shorter life expectancy (253 patients) or contraindications to anticoagulants for organic (113 patients) or psychologic (38 patients) reasons, or both. The early mortality rate was 11.1% (aortic valve replacement, 9.1%; mitral valve replacement, 12.4%; aortic and mitral valve replacement, 23.1%). Total cumulative follow-up was 1456 pt-yr (mean 4.4 years, range 1 to 148 months), and the patient evaluation was 99.5% complete. Late mortality was 4.9%/pt-yr. Five-year survival was 70.4% +/- 2.7% overall, 74.3% +/- 3.2% after aortic valve replacement, 60.9% +/- 6.2% after mitral valve replacement (p < 0.03), and 60.7% +/- 8.1% after aortic and mitral valve replacement. Eight patients were reoperated on for primary tissue failure, and freedom from reoperation for structural valve deterioration was 97.5% +/- 1.2% at 5 years and 95.6% +/- 1.8% at 8 years. Failing aortic bioprostheses were explanted in four patients (0.4%/pt-yr) and mitral bioprostheses in seven (1.6%/pt-yr). No patient whose valve was inserted after the age of 70 had to be reoperated on for structural valve dysfunction. The probability of freedom from thromboembolism after 5 and 8 years of follow-up was 93.1% +/- 1.6% and 92.2% +/- 1.8%, respectively. The prevalence of anticoagulant-related hemorrhage was 0.8%/pt-yr (major 0.6%, minor 0.2%). Anticoagulants had to be maintained in 16.3% of the patients: 5.9% after aortic valve replacement, 35.7% after mitral valve replacement, and 45.8% after aortic and mitral valve replacement, while 80.0% were on a regimen of antiplatelet drug therapy. Prosthetic valve endocarditis happened in five patients (0.3%/pt-yr). Freedom from all valve-related morbidity and mortality, including hospital deaths, was 71.0% +/- 2.7% at 5 years and 58.6% +/- 4.6% at 8 years and was significantly better in the aortic valve replacement group (61.3% +/- 6.6% at 8 years) compared with the mitral valve replacement group (54.4% +/- 7.7% at 8 years; p = 0.04). This study confirms the satisfactory performance of the Carpentier-Edwards valve after aortic valve replacement in elderly patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1992

Use of the inferior epigastric artery for coronary bypass.

Between December 1988 and April 1991, 74 free inferior epigastric arteries were used in 73 patients for coronary artery bypass grafts. In addition, 72 of the patients received a left internal mammary artery for single or sequential grafting to the left anterior descending system and 62 a right internal mammary artery to the circumflex or the right coronary artery. Twenty-seven patients had no saphenous vein available, and two had no suitable internal mammary artery; in an attempt to make a complete arterial revascularization, we chose the inferior epigastric artery as an alternative conduit in 24 young patients and in 10 reoperations; bilateral internal mammary artery dissection was avoided in four patients with impaired lung function and in six patients with selected two-vessel disease to spare one internal mammary artery. The technique for harvesting the inferior epigastric artery is described. Fifty-three inferior epigastric artery grafts were anastomosed to the distal right coronary artery or to its branches, 18 to the distal obtuse marginals of the circumflex artery (three as sequential grafts and one as a natural Y graft), and three to the left anterior descending system. The mean number of distal anastomoses is 3.60 per patient. Seventy proximal anastomoses of the inferior epigastric artery were made to the aorta and four to one internal mammary artery. There were four early deaths and one nonfatal myocardial infarction. Four abdominal wound hematomas needed surgical drainage. Sixty-one patients underwent angiographic study on postoperative day 10:59 of 61 inferior epigastric artery grafts (63 of 65 inferior epigastric artery distal anatomoses) and 111 of 111 internal mammary artery grafts (155 of 156 internal mammary artery distal anastomoses) were patent. Clinical follow-up of all the survivors (100% follow-up) could be obtained with a mean period of 9 months (1 to 28 months). There was no late cardiac death, no infarction, and all the patients were free of angina. Nineteen patients underwent a 6-month postoperative angiographic study. Seventeen of 19 inferior epigastric artery grafts were patent and 16 of 19 were intact; 34 of 34 internal mammary artery grafts (46 of 47 internal mammary artery distal anastomoses) were patent and intact. In conclusion, free inferior epigastric artery grafts can reach the diaphragmatic ischemic areas of the heart. The early patency rate and the clinical results are encouraging but only long-term evolution and evaluation can determine the true efficacy of the inferior epigastric artery graft as a reliable conduit for coronary artery bypass graft operations.

Abdominal Muscles↗
PubMed1990

[Esophagorespiratory tract fistula treated by primary suture. Apropos of 2 cases of esophago-pleural fistula and 2 cases of esophagobronchial fistula].

We describe two oesophago-pleural fistulas arriving respectively 40 months and 15 years after pneumonectomia, and two oesophago-bronchial fistulas due to perforated oesophageal diverticula. We evaluate diagnostic methods and discuss etiology of these oesophageal fistulas. Pleural fistulas treatment associate thoracic drainage, direct surgical treatment of the fistula with primary suturing of oesophagus. For oesophago-bronchial fistula treatment, we have made pneumonectomia one time and primary bronchial suturing another. In these two cases, oesophagus was only sutured without pleural or muscular flap. Transient alimentary gastrostomy was made. No fistula recidive of postoperative complication occurred. There is no operative mortality.

Adult↗
PubMed1989

Assessment of two venous drainage techniques in coronary artery bypass graft surgery.

We compared the influence on immediate postoperative cardiac performance, incidence of supraventricular tachyarrhythmia, fluid balance, and respiratory function of two methods of venous drainage during cardiopulmonary bypass (CPB). Two groups of 50 patients were studied. All 100 patients were operated electively for coronary artery bypass grafting. In group 1, cardiac drainage was achieved by using a two-stage cavo-atrial cannula, group 2 patients had drainage cannulae in the superior and inferior vena cava with caval tapes. There were no significant differences between both groups regarding postoperative hemodynamics. Right ventricular stroke work index in groups 1 and 2 differed insignificantly. The incidence of episodes of supraventricular tachyarrhythmia were 19 in group 1 and 23 in group 2 (p NS). Peroperative fluid balance was higher in group 1, but hematocrit during CPB was in the same range. Blood gas analysis values did not differ among the groups during the first 32 hours. The average duration of assisted ventilation was 30.3 +/- 5.4 hours in group 1 and 27.8 +/- 3.1 hours in group 2 (p NS). Thus, in patients undergoing coronary artery bypass grafting with standard techniques of intermittent cardioplegia, double caval cannulation is not superior to single atrio-caval drainage as far as postoperative left and right heart performance, and prevention of supraventricular tachyarrhythmia is concerned. Single cannulation did not increase the risk of undue hemodilution or respiratory dysfunction.

Body Fluids↗
PubMed1987

Left ventricular aneurysm with predominating congestive heart failure. A comparative study of medical and surgical treatment.

From 1979 to 1985, 109 patients were treated for congestive heart failure caused by postinfarction left ventricular aneurysm. Congestive heart failure was predominant in all patients at the time of diagnosis, 73% of whom were in Functional Class III or IV. Left ventricular end-diastolic pressure averaged 23.8 +/- 0.8 mm Hg (mean +/- standard error of the mean), total ejection fraction 29.7% +/- 1.0%, and telediastolic volume of the aneurysm 76.2 +/- 5.8 ml. Aneurysmectomy was performed in 49 patients (45%), whereas the remaining 60 patients were treated medically. The two groups did not differ in regard to clinical and hemodynamic data on admission, except for a more extensive coronary artery disease in the surgical group. Follow-up was obtained for all patients (100%) and averaged 48 +/- 3 months. Actuarial survival curves were similar, and the 5-year survival rates for surgical and medical groups were 70 +/- 7% and 64% +/- 7%, respectively (not significant). However, the 5-year complication-free rate was significantly (p = 0.05) higher among surgical patients (52% +/- 8%) than among the medical group (31% +/- 7%). Multivariate analysis showed the following variables to influence survival independently (p less than 0.05): contractile segment ejection fraction, right ventricular failure, antecedents of cardiac arrest or cardiogenic shock, and corrected contractile score. Independent variables decreasing the risk of cardiac-related complications and death (p less than 0.05) were as follows: surgical treatment, shorter interval between initial infarction and diagnosis of aneurysm, and absence of right ventricular failure. Functional improvement was directly related to surgical treatment and to residual segment contractile score (p less than 0.05). Thus, in patients with congestive heart failure caused by left ventricular aneurysm, surgical treatment improved the quality of life and prognosis for cardiac-related complications, but did not increase overall survival, compared to medical management of similar patients.

Adult↗
PubMed1986

Measurement of flow in large veins by the continuous thermodilution method.

Simple methods for measuring percutaneously blood flow in veins characterized by a large oscillatory component of flow are lacking. Therefore, a thermodilution technique with a constant infusion rate was used for the measurement of inferior vena cava flow in anesthetized dogs. The accuracy of the method was studied both in an artificial circuit and in in vivo experiments. The thermal catheter was introduced upstream in a flow of water ranging from 50 to 1,200 ml/min produced in an artificial circuit maintained at 37 degrees C. With a volume of cold injectate of 43 ml/20s, the correlation between the values obtained by direct measurement and by thermodilution technique was highly significant (r = 0.993; n = 37) with a slope practically equal to 1.0 (Y = 1.03 X + 2.42). With the thermal catheter introduced through the jugular vein and an electromagnetic flowmeter probe placed around the exposed vessel, volumetric flows were registered in the subhepatic vena cava, infrarenal vena cava, as well as renal and iliac veins of eight dogs. Comparison of the values obtained by the two techniques yielded a regression equation of Y = 0.96 X + 34.31 with a correlation coefficient r = 0.943 (range 50-1,000 ml/min; n = 40). The continuous injection method was as accurate at low flows as at high. Qualitatively, thermodilution curves were comparable to electromagnetic flowmeter curves, reproducing instantaneously the cyclic respiratory variations. The method is thus particularly suitable for use in those veins in which there is a large oscillatory component of flow.

Animals↗
PubMed1986

Morphology and fibrinolytic activity of canine autogenous mesothelium used as venous substitute.

Autogenous mesothelium was used as venous substitute in ten dogs. Patches of mesothelium of three different origins were grafted into the anterior wall of the common iliac veins (CIV): peritoneum taken from and including the posterior rectus sheath (PRS), simple peritoneum (P) and mesentery (M). Animals were killed after 2, 4, 8, and 16 days and after 3 months. The segments of CIV, including the patches, were removed for study. On light microscopy, the PRS grafts showed a normal mesothelium but marked submesothelial fibrosis. The M and P grafts showed normal mesothelium and only mild fibrous thickening. On scanning electron microscopy, there was a perfect continuity of the mesothelial cells and the normal endothelium at the suture line. In the center of the graft, the cells had become elongated along the axis of blood flow. Fibrinolytic activity (FA) was measured by a standardized fibrin plate technique and quantitated in tissue activator units per gram of tissue (TAU/g). The mean FA of iliac vein specimens was 1101.7 +/- 133.3 TAU/g (mean +/- SEM). The mean FA determined before grafting for each kind of mesothelium was the following: PRS = 418.8 +/- 26.9 TAU/g; P = 873.0 +/- 107.1 TAU/g; M = 1142.3 +/- 91.4 TAU/g where only PRS showed values significantly lower than iliac vein mean FA (P less than 0.001). Postoperatively, the mesothelial FA, after an initial reduction, increased on day 4 and reached values significantly higher than the control values (1445.7 +/- 204.1 TAU/g tissue vs 853.1 +/- 62.3 TAU/g tissue; P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Experience with the selective use of the Carpentier-Edwards bioprosthesis.

Between April, 1977, and November 1984, 136 porcine bioprosthetic valves were implanted in 122 patients principally selected on the basis of age and contraindication to anticoagulants. The following procedures were carried out: aortic valve replacement (AVR) 88, pulmonary valve replacement (PVR) 1, mitral valve replacement (MVR) 38, and tricuspid valve replacement (TVR) 9. The ages ranged from 25 to 84 years (mean 64.6 years). The 30-day mortality was 11.5% overall. Survivors were followed up to 7 years (mean 29.2 months). Actuarial survival rates at 5 years, including operative deaths, were as follows: AVR 76.2 +/- 9.3%, MVR 59.7 +/- 12.6% and combined valve replacement (CVR) 47.1 +/- 19.4%. The 5-year probability of freedom from valve-related complications was 76.8 +/- 6.9% for all patients. The rate of thromboembolic events was 3.80% per patient-year after AVR and 2.72% per patient-year after MVR and CVR. The embolic rate did not differ between patients treated with anticoagulants and those treated with platelet antiaggregators. Primary tissue valve failure occurred in 2 patients for a linear incidence of 0.77% per patient-year. Postoperative echocardiography was performed in 83% of the survivors. Patients are now prospectively followed up by bidimensional echography and pulsed Doppler in order to detect early valvular dysfunction. The performance of the Carpentier-Edwards porcine bioprosthesis is, thus, satisfactory in this group of elderly patients.

Aged↗
PubMed1984

Factors influencing postoperative survival in aortic regurgitation. Analysis by Cox regression model.

From 1965 to 1981, 114 patients underwent aortic valve replacement for severe aortic regurgitation in our institution. Catheterization was performed preoperatively in 103 patients. Follow-up was possible in 98% of the survivors. Long-term survival was significantly different between patients in preoperative Functional Class I-II and those in Class III-IV (p less than 0.03); those with a preoperative cardiothoracic ratio less than 0.64 versus greater than or equal to 0.64 (p less than 0.001); and those with a preoperative ejection fraction greater than 0.50 versus less than or equal to 0.50 (p less than 0.03). A multifactorial analysis was used to identify the dominant preoperative prognostic variables affecting survival. Three of the 13 parameters examined simultaneously were found to independently influence survival rates: cardiothoracic ratio (p = 0.001), strain pattern on the electrocardiogram (p = 0.072), and left ventricular end-systolic pressure (p = 0.127). After stratification of the population into two groups according to preoperative functional class, the predictive variables were cardiothoracic ratio (p = 0.014), strain pattern (p = 0.050), and acute/chronic form of aortic regurgitation (p = 0.034). This statistical analysis enabled us to derive a mathematical equation for predicting an individual patient's probability of survival. We found a close fit between the survival rate predicted by the mathematical model and the observed survival rate.

Adolescent↗
PubMedDate not supplied

Beating heart surgery using the Octopus tissue stabilizers: initial experience including triple vessel disease and high-risk patients.

OBJECTIVE: The aim of this study was to evaluate initial results in beating heart coronary artery bypass grafting performed on patients with multivessel disease, using suction-based tissue stabilizers. METHODS: Forty patients (mean age 65.5 years, range 39-83) underwent beating heart coronary bypass by median sternotomy, with the use of the Octopus 1 (n = 27) and Octopus 2 (n = 13) devices. Twenty patients had unstable angina, four had pulmonary oedema, and four required preoperative intra-aortic balloon counterpulsation. Five interventions were repeat procedures. Mean ejection fraction was 54.4%(range 20-82%). Eighteen patients had triple-vessel disease, 18 patients had double-vessel disease and > 50% left main stem stenosis was present in six patients (isolated or in association). The average number of distal anastomoses was 2.5 (range 1-5, total 101). A mean of 1.5 (range 1-3) anastomoses was achieved with arterial grafts (45 mammary and 12 gastroepiploic arteries). RESULTS: Immediate graft patency was evaluated by Doppler flowmeter and five anastomoses were successfully corrected, based on an occlusion pattern. The perioperative myocardial infarction rate was zero. Transient episodes of supraventricular arrhythmias were detected in 19 patients. The administration of dobutamine at an inotropic concentration > 5 gamma-1 kg-1 min-1 was required in one patient. There were two in-hospital deaths (one non-cardiac-related). Overall survival and cardiac event-free rate at 20 months were 92.4% +/- 4.2% and 81.8% +/- 11.6%, respectively. CONCLUSIONS: Satisfactory results can be achieved in multivessel disease high-risk patients with beating heart coronary bypass surgery.

Adult↗
PubMedDate not supplied

Ischemic complications of abdominal aortic surgery.

From 1982 through 1988, 634 consecutive patients underwent abdominal aortic reconstruction for occlusive (37%) or aneurysmal (63%) disease. We studied the ischemic problems affecting the branches of the aorta, excluding the coeliac and superior mesenteric arteries. Ischemic colitis (0.6%), spinal cord ischemia (0.16%), renal insufficiency (17%), and lower limbs ischemia (6.5%) were the major problems encountered. We identified the most significant factors associated with these complications such as hypotension, emergency, hypovolemia, preoperative renal function, suprarenal clamping, the quality of the preoperative investigation, and have suggested some specific preventive measures.

Adult↗
PubMedDate not supplied

Ligation of the superficial femoral vein in prevention of pulmonary embolism: an old fashion procedure?

From 1974 to 1988, interruption of the superficial femoral vein (SFV) was performed to prevent pulmonary embolism (PE) in 73 patients. The mean age of the patients was 62 years. Phlebography showed thrombi in the following localizations: calf veins (67.3%), superficial femoral or popliteal veins (56.6%), common femoral veins (19.5%) and iliac veins (2.7%). A floating thrombus in the popliteal or femoral vein was the main indication for surgery in 97.3% of patients. Pulmonary embolism had occurred in 76.7% and was associated with neoplasm in 13.7%. Ligation of the SFV was performed in 93 limbs and completed iliac or femoral thrombectomy in 32.3%. The procedure was performed under locoregional anesthesia in 82.9% of the cases. Hospital mortality was 1.4% and 3 year survival, considering only PE related deaths was 95.3 +/- 2.7%. Follow-up was complete for all patients and averaged 3.0 years, for a 3 years PE-free rate of 90.8 +/- 3.6%. Persistent symptoms included increased limb tenseness in 12.5% and mild ankle edema in 25%. Bilateral strain-gauge plethysmography (SGP) was obtained in 65 limbs. The time necessary to obtain a 50, 75 and 100% decrease in calf volume (respectively T1/2, T3/4 and TT) was calculated for the operated limb and compared with the untreated limbs used as controls. A prolongation of T1/2 from 2.5 +/- 0.3 sec in controls to 4.3 +/- 0.4 sec in the operated limb (p less than 0.01) was found. Thus, our experience with ligation of the superficial femoral vein is favourable since long-term ill effects have been minimal and strain gauge plethysmography (SGP) showed only mildly altered venous drainage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗