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Biomedical subjects

J Laas

Publications and source records attributed to J Laas.

65 records · Page 4Linked to original sources
PubMed1986

Extra-intracranial bypass procedure with saphenous vein grafts.

This study reports on 13 cases of extra-intracranial bypass procedures using saphenous vein grafts. Ten patients had arteriosclerotic occlusive vascular disease, one patient had a giant aneurysm of the internal carotid artery, another 2 females, 18 and 28 years of age, respectively, suffered from Takayasu's disease. Preoperatively all patients had severe neurological symptoms. To keep the venous graft as short as possible, as a first choice the carotid artery, in case of occlusive disease of the latter as a second choice the ipsilateral subclavian artery, or as a third choice the ascending aorta, were used as donor vessels. Perioperatively, one patient sustained an intracerebral/intraventricular hemorrhage and, despite immediate reoperation, died in a vegetative state early postoperatively. Another patient had a minor perioperative cerebral stroke with complete recovery. None of the other patients had any additional neurological deficit perioperatively, and they had complete relief from ischemic attacks postoperatively. There was one early occlusion due to high competitive collateral flow, and one late occlusion due to technical problems. The overall patency rate of surviving patients was 83.3% (follow-up 3 to 23 months).

Adolescent↗
PubMed1986

[I.v. DSA in the diagnosis and follow-up of thoracic aortic dissection].

Intravenous DSA was performed in 53 patients with suspected dissection of the thoracic aorta and in 13 patients following surgery for aortic dissection. In 36 patients, the suspected diagnosis could be excluded definitely and, in 14 cases out of 17, a dissection was correctly diagnosed. All 11 type B dissections were correctly diagnosed. Of six type A dissections, only three were adequately demonstrated by IV DSA. In type B dissections, IV DSA is reliable, but in type A dissection with massive aortic insufficiency or pericardial tamponade the findings are not reliable. In all 13 patients who had surgery for dissection, IV DSA proved suitable for showing the anastomosis and progress of the disease.

Aortic Dissection↗
PubMed1984

Tetralogy of Fallot. Development of hypoplastic pulmonary arteries after palliation.

Thirty-one patients with tetralogy of Fallot were studied angiographically before and after palliation with Blalock-Taussig operation (n = 9), Brock operation (n = 12), or enlargement of the right ventricular outflow tract with extracorporeal circulation (ECC) (n = 10). The relative diameter of the pulmonary vascular ring (PVR), pulmonary trunk (PT), and right and left pulmonary arteries (RPA, LPA) were measured before and 24.8 +/- 20.9 months after palliation. Using correlation analysis, the magnitude of growth of the pulmonary artery system was inversely related to its initial size. Mean pressure in the pulmonary artery after palliation as well as the period between date of surgery and recatheterization did not correlate significantly with growth. After Blalock-Taussig operation, the ipsilateral pulmonary artery predominantly increased in size without significant growth of PVR and PT. Brock operation and enlargement of the right ventricular outflow tract with ECC, improving the flow in the pulmonary vascular system centrally, induced a significant, symmetrical growth of the pulmonary vascular system and, therefore, are our methods of choice for palliation in patients with tetralogy of Fallow combined with hypoplastic pulmonary arteries.

Adolescent↗
PubMed1984

The treatment of tetralogy of Fallot: early repair or palliation?

Between 1974 and 1983, 380 consecutive patients with tetralogy of Fallot underwent surgery. In 73 patients, undergoing palliative surgery, the operative mortality and late mortality was 6.8%. Twenty-five of these patients have undergone subsequent complete repair, while 38 are awaiting correction. During the last 4 years we preferred operative procedures with enlargement of the right ventricular outflow tract (80%) to shunt operations (20%). In contrast to shunts, enlargement of the outflow tract induces a symmetrical growth of hypoplastic pulmonary arteries without the risk of acquired pulmonary atresia or peripheral stenosis at the site of anastomosis. Three hundred twenty-nine patients have undergone repair. In 101 patients, who had palliative operations before complete repair, the operative mortality was 12.9% and late mortality 2.9%. Those patients undergoing repair as a first operation had an operative mortality of 8.8%, and a late mortality of 1.3%. In the last 5 years the operative mortality for all patients, whether or not they had had previous palliative surgery, was 4.7%. The incidence of transannular outflow tract patching was not greater in children less than 2 years of age (16.9%) than in older children, 2 to 14 years of age (16.5%). However, in our experience the requirement for subvalvular outflow patches was higher in younger children (52.1%) than in the older children (34.1%). Because of this high incidence, particularly in younger patients, we have now begun to repair tetralogy of Fallot using the transatrial approach, thus reducing our use of subvalvular patches.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1981

Reduction of myocardial infarct size in swine: a comparative study of intraaortic balloon pumping and transapical left ventricular bypass.

This study compared intraaortic balloon pumping (IABP) and transapical left ventricular (LV) bypass for their effectiveness in reducing infarct size in swine. In 28 pigs (25.4 +/- 4.7 kg) the left anterior descending coronary artery was ligated distal to the first diagonal branch. Nine animals served as controls. Nine animals were treated with IABP and the remaining 10, with transapical bypass. Ten animals-3 control, 3 IABP, and 4 transapical bypass--died prior to completion of the study, thereby resulting in 6 animals in each group. Both assist devices were begun 45 minutes after coronary ligation, this being as rapid as mechanical intervention could be accomplished in the patient after infarction. With transapical LV bypass, 70 to 100% bypass was accomplished and the LV systolic pressure remained in the range between mean aortic pressure and 30 mm Hg less than that. All animals were killed after 24 hours. The hearts were excised and stained with nitroblue tetrazolium, and infarct size was quantitated in grams of infarct per 100 gm of LV and septal mass. After 24 hours the mean aortic pressure was 73 +/- 12 mm Hg in controls, 105 +/- 20 mm Hg in animals with IABP (p less than 0.01), and 91 +/- 13 mm Hg in those with transapical LV bypass (p less than 0.05). The infarct size was 22.7 +/- 4.9 gm per 100 gm of LV and septal mass in control animals. With IABP, the infarct size was nonsignificantly changed to 19.4 +/-5.9 gm per 100 gm (p greater than 0.3). With transapical LV bypass, the infarct size was significantly reduced to 15.9 +/- 3.5 gm per 100 gm (p less than 0.025). This represented a 30% reduction of infarct size from controls. These results demonstrate that despite hemodynamic improvement with IABP, transapical LV bypass is necessary to markedly decrease myocardial work and significantly reduce infarct size.

Animals↗
PubMed1981

Effect of coronary artery reperfusion on infarct size in swine.

Several authors have reported a low mortality and salvage of ischemic myocardium in patients undergoing coronary revascularization after recent myocardial infarction. In this study, 20 surviving pigs with a coronary circulation similar to that of man were divided into two groups of 10 animals each. In the first group, the left anterior descending coronary artery (LAD) was ligated just beyond the first diagonal branch. Five animals were put to death at 24 hours and the remaining five animals, at 7 days. In the other group of 10 animals, the LAD was occluded just beyond the first diagonal branch and reperfused 3 hours after occlusion. Five of these animals were put to death at 24 hours and the remaining five animals, at 7 days. The left atrial pressure (LAP), heart rate, mean arterial pressure (MAP), and cardiac output were continuously monitored. Myocardial infarct size was determined planimetrically after the myocardium was sliced and stained with nitroblue tetrazolium. In five animals subjected to ligation for 24 hours, myocardial infarct size was 20.3 +/- 0.53 standard error mean (SEM) grams infarct per 100 gm left ventricular and septal mass (gm/100 gm LVS). In five animals subjected to occlusion, reperfusion in 3 hours, and death at 24 hours, the infarct size was 22.9 +/- 1.7 SEM gm/100 gm LVS. At 1 week in the ligated animals the infarction decreased to 15.5 +/- 1.7 SEM gm/100 gm LVS. In the reperfused animals at 1 week the infarction size was 14.5 +/- 1.7 SEM gm/100gm LVS. There was no significant difference in these values (Student's t test). Light and electron micrographs demonstrated hemorrhagic necrosis in every instance with reperfusion. Cardiac output, LAP, and MAP remained unchanged after reperfusion. These data suggest that in human beings without well-developed inherent collaterals sustaining myocardial infarction with coronary occlusion, that reperfusion as early as 3 hours after infarction would not be beneficial.

Animals↗
PubMed1980

Failure of intra-aortic balloon pumping to reduce experimental myocardial infarct size in swine.

Although intra-aortic balloon pumping (IABP) is reported to reduce myocardial infarct size in dogs, this phenomenon may be due to pre-existing collaterals in this species. Pigs more closely approximate human coronary anatomy, having poor inherent collateralization. This study evaluates hemodynamic changes and quantitates myocardial infarct size 24 hours after coronary occlusion in swine, with and without IABP. Eighteen pigs underwent ligation of the left anterior descending coronary artery distal to the first diagonal branch: Nine were treated with IABP beginning 45 minutes after coronary occlusion and nine served as control subjects. Three in each group died prior to completion of the study. In both groups myocardial infarction resulted in a significant (p less than 0.05) decrease of cardiac output (28.5%) and mean aortic pressure (p less than 0.05) improvement of mean aortic pressure (4 to 7%) during the switch on period. After 24 hours, mean aortic pressure in IABP-treated animals (105 +/- 20 mm Hg) was significantly (p less than 0.01) higher than in control pigs (73 +/- 12 mm Hg). Myocardial infarct size as detected by staining with nitroblue tetrazolium was 22.7 +/- 4.9 gm infarct/100 gm left ventricular and septal mass in control pigs and 19.4 +/- 5.9 gm infarct/100 gm left ventricular and septal mass in treated animals (p less than 0.3). In conclusion, IABP, despite significantly improving circulatory parameters, does not significantly reduce the size of an acute myocardial infarction after coronary ligation in swine.

Animals↗