Search PubMed⌕ Search

Biomedical subjects

A Kalangos

Publications and source records attributed to A Kalangos.

At least 19 recordsLinked to original sources
PubMed2001

Inhaled nitric oxide versus aerosolized iloprost in secondary pulmonary hypertension in children with congenital heart disease: vasodilator capacity and cellular mechanisms.

BACKGROUND: Inhaled nitric oxide (iNO) has been used to assess the vasodilator capacity of the pulmonary vascular bed in children with congenital heart disease and elevated pulmonary vascular resistance. Inhaled iloprost is a pulmonary vasodilator for the long-term treatment of pulmonary hypertension (PHT). Because these 2 vasodilators act through different pathways (release of cGMP or cAMP, respectively), we compared the pulmonary vasodilator capacity of each. METHODS AND RESULTS: A total of 15 children with congenital heart disease and PHT who had elevated pulmonary vascular resistance (preoperative, n=10; immediately postoperative, n=5) were first given 20 ppm of iNO for 10 minutes; then, after baseline values were reached again, they were given aerosolized iloprost at 25 ng. kg(-1). min(-1) for another 10 minutes. Finally, iNO and iloprost were given simultaneously for 10 minutes. With iNO, the pulmonary vascular resistance and systemic vascular resistance ratio decreased from 0.48+/-0.38 to 0.27+/-0.16 (P:<0.001). Similarly, iloprost decreased the ratio from 0.49+/-0.38 to 0.26+/-0.11 (P:<0.05). The combination had no additional effect on the resistance ratio. Plasma cGMP increased from 17.6+/-11.9 to 34.7+/-21.4 nmol/L during iNO (P:<0.01), and plasma cAMP increased from 55.7+/-22.9 to 65.1+/-21.2 nmol/L during iloprost inhalation (P:<0.05). CONCLUSIONS: In children with PHT and congenital heart disease, both iNO and aerosolized iloprost are equally effective in selectively lowering pulmonary vascular resistance through an increase in cGMP or cAMP, respectively. However, the combination of both vasodilators failed to prove more potent than either substance alone. Aerosolized iloprost might be an alternative to iNO for early testing of vascular reactivity and for the postoperative treatment of acute PHT.

Administration, Inhalation↗
PubMed2001

Pericardial reinforcement after partial atrial resection in idiopathic enlargement of the right atrium.

A 2-year-old boy in whom idiopathic enlargement of the right atrium was diagnosed in utero by fetal echocardiography underwent surgical intervention because of progression of right atrial dilatation. During operation, the lateral right atrial wall was externally reinforced after partial resection by approximating and fixing the neighboring autologous pericardium around the external circumference of the right atrium. This technique is a useful means of preventing recurrence of dilatation in histologically abnormal right atrial tissue that predisposes the patient to possible reintervention.

Child, Preschool↗
PubMed2000

Oxidized low-density lipoprotein is associated with apoptosis of vascular smooth muscle cells in human atherosclerotic plaques.

BACKGROUND: Cytotoxic oxidized LDL (oxLDL) has been shown to promote apoptosis in cultured vascular smooth muscle cells (VSMCs). We investigated the localization of oxLDL and its association with apoptosis and the expression of apoptosis-related proteins in early and advanced atherosclerotic lesions. METHODS AND RESULTS: Atherosclerotic plaques (n=23) from patients undergoing aortic, carotid, or femoral arterial surgery were studied. In early lesions, oxLDL was located predominantly in the superficial intima and in the media just beneath the internal elastic lamina. Medial VSMCs staining positive for oxLDL showed expression of BAX, a proapoptotic protein of the BCL-2 family. Apoptosis, as detected by DNA in situ terminal deoxynucleotidyl transferase end-labeling (TUNEL), was not present in these early lesions. In advanced plaques, areas of the intima positive for oxLDL showed lower alpha-smooth muscle actin immunoreactivity (P<0.01) and higher BAX immunoreactivity (P<0.05). Furthermore, these areas showed an increased number of apoptotic VSMCs (P<0.01). Western blot analysis revealed that oxLDL increases BAX expression in cultured human coronary VSMCs. CONCLUSIONS: We conclude that in early atherosclerotic lesions, oxLDL-positive VSMCs express BAX, which increases the susceptibility of these cells to undergo apoptosis. This could be important in our understanding of the transition of early lesions into advanced atherosclerotic plaques, which are characterized by regions of cell death. In advanced plaques, oxLDL-positive areas of the intima show higher BAX immunoreactivity and TUNEL-positive VSMCs, and this may contribute to plaque instability and rupture.

Actins↗
PubMed2000

Aorticoright atrial tunnel.

Two unusual cases of aorticoright atrial tunnel are described. Both patients were referred to our institution for evaluation of a continuous heart murmur best heard along the right upper sternal border. Ascending aortography showed the tunnel taking its origin from the aortic root and entering the right atrium through a tortuous link. Both patients underwent surgical closure. In addition, a review of similar cases in the literature is presented.

Adolescent↗
PubMed2000

Anterior mitral leaflet prolapse as a primary cause of pure rheumatic mitral insufficiency.

BACKGROUND: This study was designed to revise the mechanisms and repair techniques of anterior mitral leaflet prolapse observed during the correction of pure rheumatic mitral regurgitation in children. METHODS: From March 1993 to May 1998, 36 children suffering from pure rheumatic mitral regurgitation due to anterior leaflet prolapse underwent mitral valve repair. The mean age was 12.5 years (range, 6 to 16 years). Anterior leaflet prolapse was due to chordal elongation in 25 patients (group A), chordal rupture in 6 patients (group B), and retraction of anterior secondary chordae tendineae, creating a V-shaped deformity in the middle of the anterior leaflet, thus moving the free edge of the anterior leaflet away from the coaptation plane, in 5 patients (group C). Chordal shortening, transposition, and resection of anterior secondary chordae tendineae were used to correct anterior leaflet prolapse according to the predominantly responsible mechanism. RESULTS: All patients were available for clinical follow-up, which ranged from 6 months to 5 years (mean follow-up, 3 years). Echocardiographic studies were obtained until the 3rd postoperative month, and all patients showed significant improvement in their left ventricular and atrial dimensions. There was one late death related to endocarditis. Two patients in group C who had mitral valve repair underwent mitral valve replacement on the 19th and 24th postoperative months, respectively, because of failure of mitral valve repair. CONCLUSIONS: Mitral valve repair for pure mitral regurgitation due to rheumatic anterior leaflet prolapse can be performed safely for all types of mechanisms. Although the techniques we used provide stable short-term results in each of these groups, midterm results are better in groups A and B, where tissue thickening is less important, recurrences of rheumatic carditis are lower, and the interval between the first rheumatic attack and the surgical procedure is shorter than in group C.

Adolescent↗
PubMed2000

Transaortic inflow and outflow cannula for centrifugal mechanical assistance.

A specific cannula allowing single site transaortic inflow and outflow cannulation for centrifugal assist devices is described. The cannula is inserted through a straight 18 mm collagen coated Dacron tube anastomosed to the anterior aspect of the ascending aorta. The inflow conduit of the cannula is positioned into the left ventricle through the aortic valve, and the end hole of the outflow conduit is positioned in the ascending aorta. The cannula was evaluated in vivo in 3 adult pigs by the institution of a centrifugal pump for left ventricular support. Optimal flow varied between 5 and 6 L/min and mean aortic pressure between 55 and 70 mm Hg throughout the 3 days of left ventricular support. Recently, we employed this cannula in a patient who was not able to be weaned from cardiopulmonary bypass for the institution of left ventricular support using a centrifugal pump. The cannula provided effective inflow and outflow drainage with an optimal flow of 5.2 L/min throughout the 72 h of support. The patient was successfully weaned from support on the fourth postoperative day. This rational transaortic approach of cannulation using this specific cannula is a refined implantation technique which allows direct left ventricular inflow drainage, reduces the time of implantation, spares left ventricular myocardium, avoids bleeding that is sometimes encountered at other cannulation sites, and avoids compression of the heart by cannulas.

Aged↗
PubMed2000

Etiology and management of pediatric chylothorax.

OBJECTIVES: To determine the incidence and etiology of chylothorax and to assess our therapeutic management approach. STUDY DESIGN: We reviewed 51 patients diagnosed with chylothorax over a 12-year period. Cause, interval between operation and diagnosis, duration of chylothorax, and total volume loss per weight were recorded. RESULTS: Chylothorax was diagnosed in 46 children after cardiothoracic surgery, giving an incidence of 2.5% (46/1842); in 1 child chylothorax occurred after chest trauma, and in 4 the chylothorax was congenital or a manifestation of lymph angiomatosis. Three etiologic groups were identified: group 1, direct injury to the thoracic duct (33/51 = 65%); group 2, thrombosis and/or high venous pressure in the superior vena cava (14/51 = 27%); and group 3, congenital (4/51 = 8%). Conservative treatment was the only treatment in 80% of the patients. Surgical procedures consisted of 4 ligations of the thoracic duct, placement of 7 pleurodesis shunts, and placement of 2 pleuroperitoneal shunts. Patients in groups 2 and 3 were at higher risk for failure of conservative treatment (P <. 005). Longer duration of chylothorax and higher volume of drainage were present in group 2 compared with group 1 (P <.01). CONCLUSION: Conservative treatment was successful in 80% of the patients with our management approach. Prevention, early recognition, and treatment of potential complications, such as superior vena cava thrombosis or obstruction, may further improve success of conservative treatment. Congenital chylothorax seems different and may require a specific approach.

Angiomatosis↗
PubMed2000

Aortic valve replacement with the freestyle stentless bioprosthesis with respect to spacial orientation of patient coronary ostia.

OBJECTIVE: This study evaluates our results for safety and efficacy of aortic valve replacement using the Freestyle bioprosthesis (Medtronic, Inc, Minneapolis, Minn) with a new modified subcoronary implantation technique. This technique takes into account the spacial orientation of the stentless bioprosthesis in the aortic root with respect to the patient's coronary ostia rather than the native commissures. METHODS: Fifty-two consecutive patients with predominant aortic valve stenosis underwent aortic valve replacement with a Freestyle bioprosthesis by means of the described modified subcoronary technique over a 15-month period. Fifty of them were followed up by means of echocardiography at discharge, 6 months, and 1 year. There were 19 men and 31 women, with a mean age of 76 +/- 7 years (range, 58-87 years). Valve size ranged from 21 to 27 mm. RESULTS: Patients with bicuspid aortic valves had a significantly larger angle between both coronary ostia than patients with tricuspid aortic valves (P =.0001). The peak and mean systolic gradients decreased significantly during the first postoperative year for each valve size (P </=.001), and the effective valve areas increased significantly during this time interval for each valve size (P </=.01). Only 13 patients had aortic insufficiency at discharge, which was trivial in 9 and mild in 4 patients. The prevalence of trivial aortic insufficiency decreased during the first postoperative year, and that of mild aortic insufficiency remained unchanged. The sinotubular junction diameter was significantly greater than that of the aortic anulus for each valve size before operation (P <.001). The sinotubular junction diameter decreased significantly after aortic valve replacement and remained unchanged during the first postoperative year for each valve size (P <.001). CONCLUSIONS: Aortic valve replacement with the Freestyle bioprosthesis using the modified subcoronary technique, which takes into account the spacial orientation of the patient's coronary ostia, has hemodynamic results similar to those of other series with different subcoronary implantation techniques. This technique is reproducible, safe at the coronary ostial level, and effective in accommodating variability in angles between human coronary ostia, ranging from 130 degrees to 170 degrees. Moreover, the great preoperative discrepancies between aortic anulus and sinotubular junction diameters are corrected immediately after operation.

Aged↗
PubMed2000

Aprotinin does not impair renal haemodynamics and function after cardiac surgery.

Patients undergoing cardiac surgery with moderate hypothermic cardiopulmonary bypass (CPB) were allocated randomly to receive either saline (control group, n = 29) or a high-dose regimen of aprotinin (aprotinin group, n = 28). In both groups, CPB was associated with similar and transient increases in effective renal plasma flow (+54% in controls and +48% in aprotinin-treated patients) and in fractional excretion of sodium and potassium, but glomerular filtration rate remained unchanged. Plasma and urinary ratios of 6-keto-PGF1 alpha to thromboxane B2 (TxB2) increased significantly, indicating systemic and renal release of vasodilatory prostaglandins. Osmolar clearance correlated with urinary excretion of cyclic GMP (r = 0.79 and 0.86 in the control and aprotinin groups, respectively) and 6-keto-PGF1 alpha (r = 0.63 and 0.69 in the control and aprotinin groups, respectively). Compared with preoperative values, plasma atrial natriuretic peptide increased after weaning from CPB (+71% and +93% in the control and aprotinin groups, respectively). Aprotinin had no apparent adverse effect on renal function and it did not alter mechanisms involving prostanoids and atrial natriuretic peptide during cardiac surgery.

6-Ketoprostaglandin F1 alpha↗
PubMed2000

Epidural sufentanil during paediatric cardiac surgery: effects on metabolic response and postoperative outcome.

The metabolic and neuroendocrine effects of caudal epidural analgesia were studied during paediatric cardiac surgery. Combined epidural and general anaesthesia (EPI group; n=12) was compared with deep opioid anaesthesia (DOA group; n=12). During anaesthesia and surgery, haemodynamic stability was similar in the two groups. There was no significant difference between groups concerning the metabolic response to surgery but circulating catecholamines were significantly lower in the EPI group during and after surgery. Perioperative release of IL-6 was higher in the EPI group possibly reflecting a longer aortic clamp time. Incidence of postoperative life-threatening dysrhythmias was very low in the two groups. No significant reduction of postoperative mechanical ventilation, intensive care unit or hospital stays was reported with epidural analgesia. The incidence of postoperative infections was higher than expected in the two groups because of the poor properative clinical status of most of the children included in the study.

Analgesia, Epidural↗
PubMed2000

[Follow-up of patients treated by conduits between the right ventricle and the pulmonary artery].

Between 1981 and 1998, 77 right ventricle-pulmonary artery conduits were implanted in 67 patients (37 boys, 30 girls, average age 6.3 years; range: 3 months to 17 years). The diagnoses were transposition of the great arteries with ventricular septal defect and obstruction of the pulmonary outflow tract (N = 22), tetralogy of Fallot (N = 16), truncus arteriosus (N = 9), double outlet right ventricle with pulmonary stenosis or atresia (N = 8) and agenesis of the pulmonary valve with pulmonary stenosis (N = 2). The implanted conduits were homografts in 50 cases (43 aortic and 7 pulmonary), 11 valved Dacron grafts, 4 valved polystans grafts and 2 non-valved conduits. The average follow-up period was 3.6 years (range: 1 month to 17 years). Early death was observed in 8 patients (12%) and late death in 6 patients (9%). The 5, 10 and 15 year survival rates were 78.4%, 65.3%, and 65.3%, respectively. The conduits had to be replaced in 10 patients (15%). The non-replacement rate of all conduits at 5, 10 and 15 years was 81.4%; 40.7% and 40.7%, respectively. The causes of replacement were pure stenosis (54.5%), pure regurgitation (9%) and mixed stenosis and regurgitation (27.2%). These results are comparable to other published series showing a 15 year survival rate of 65% and a 59% reoperation rate at 15 years. Homografts have a slightly longer life compared with valved Dacron conduits but the difference is not statistically significant.

Adolescent↗
PubMed2000

[Usefulness of clinical examination in detecting infectious foci prior to cardiac surgery].

INTRODUCTION: In many institutions patients are evaluated to rule out an infectious focus in the ENT sphere prior to cardiac surgery. In a prospective clinical study we assessed the contribution of history and clinical examination in the detection of ENT infections. METHODS: From October 1998 to January 2000, 68 patients were evaluated by self-administered questionnaire and an ENT examination. Dental status was evaluated separately by a dentist. RESULTS: The patient population was divided into two groups: The first group consisted of 23 patients (33.8%) with at least one ENT symptom: in 22 the examination was normal and one patient had viral pharyngitis. 5 patients in this group presented a postoperative infectious complication. The second group comprised 45 patients (66.2%) without a history suggestive of a possible infectious focus: in 44 the examination was normal and one patient presented otitis media with effusion. 2 patients in this group had a postoperative infectious complication. DISCUSSION: Routine ENT examination is not necessary prior to cardiac surgery. The patient history can be used to select patients for further evaluation.

Adolescent↗
PubMed1999

[High-risk PTCA assisted by the Hemopump 14F: the Geneva experience].

INTRODUCTION: The hemopump is a transvalvular, catheter-mounted, left ventricular assist device, intended for surgical placement via the femoral artery (hemopump 21 Fr. outer diameter). This device has demonstrated its ability to unload the left ventricle, leading to myocardial protection and haemodynamic stabilisation in patients with cardiogenic shock and those undergoing high-risk coronary angioplasty (PTCA). Since 1994, a new hemopump system (14 Fr. in external diameter, flow rates of 1.5-2.2 l/min) has been developed for percutaneous insertion. The aim of this study is to describe the immediate and mid-term results obtained during Hemopump 14 Fr. assisted high-risk PTCA. PATIENTS: Between September, 1993 and July, 1996, 8 males and 5 female patients (mean age 68.5 +/- 8.6 years) underwent Hemopump 14 Fr. supported high-risk PTCA. RESULTS: Mean duration of hemopump assistance was 108 +/- 62 min. Hemopump support on maximum speed led to an increase of cardiac index from 2.0 +/- 0.3 to 2.2 +/- 0.5 l/min (p = 0.04) and a decrease of pulmonary wedge pressure from 17 +/- 8 to 14 +/- 8 mm Hg (p = 0.004). LDH increased (463 +/- 305 to 558 +/- 237 u/l-p = 0.05) and the platelet count remained stable (192,840 +/- 60,904 to 190,230 +/- 56,492/mm3). Successful balloon angioplasty was performed in all patients. There was no hospital mortality. Three patients (23%) required blood transfusion. During follow-up, 1 patient (7.7%) developed femoral artery occlusion necessitating surgical repair, and 3 patients (23%) died from cardiac causes 3, 9 and 14 months after the procedure. CONCLUSIONS: The 14 Fr. Hemopump device may constitute a useful percutaneous mode of haemodynamic support for patients undergoing high-risk PTCA. The haemolysis it causes is mild and not clinically significant, but the hemopump is associated with a significant rate of local vascular complications. Recent improvements in interventional techniques and hardware have decreased the necessity for circulatory assistance during elective PTCA, even for very ill patients. Nevertheless, indications such as cardiogenic shock, the "bridge" period prior to heart transplantation and video-assisted minimally invasive cardiac surgery, or haemodynamic support of the right ventricle are the new applications of the hemopump.

Aged↗