Biochemical and hemodynamic effects of ascorbic acid and alpha-tocopherol in coronary artery surgery.

This study was undertaken to evaluate the effects of alpha-tocopherol and ascorbic acid on markers of myocardial reperfusion injury and myocardial contractile function after coronary artery surgery. Forty-eight patients were divided into 4 groups; 300 mg/day alpha-tocopherol was given orally to the patients in group I for 14 days. In groups II and III, 4g of ascorbic acid was administered intravenously prior to induction and in the cardioplegic solution, respectively. Group IV was the control group. Blood samples were taken to determine the concentrations of creatine phosphokinase MB isoenzyme, malondialdehyde, uric acid, ascorbic acid and alpha-tocopherol in the perioperative period. Left ventricular functions were determined by means of MUGA scans and echocardiography preoperatively and on the 3rd and 7th days, postoperatively. The changes in serum creatine phosphokinase MB and malondialdehyde were significantly lower in study groups. when compared with the control group. We observed no significant changes in ventricular function, requirement for (+) inotropic agents and the incidence of ventricular arrhythmias among the groups, postoperatively. Biochemical findings are consistent with the free radical hypothesis. But we could not confirm these data with hemodynamic findings. This is probably due to the population of low-risk elective coronary surgery patients in this study.

Long-term effects of combined iliac dilatation and distal arterial surgery.

PURPOSE: When standard aortofemoral surgical procedure is combined with lower extremity vascular surgery, problems related with the hospital stay, morbidity, mortality and the cost of treatment will exist. The number of reports relating to combined iliac artery PTA and distal bypass surgery is limited. After the development of stenting procedures, the results of arterial system plasty have much more improved. This report reviews our preliminary experience with iliac artery angioplasty with distal bypass procedures. PATIENTS AND METHODS: A total of 41 patients have undergone combined iliac artery dilatation and distal arterial revascularization. Angioplastic procedures were performed in the angiography suite and distal surgery was carried out at the same day or the day after. Of all patients, 29 underwent percutaneous transluminal angioplasty (PTA) and 12 underwent combined PTA and stent placement. Ipsilateral femoropopliteal bypass was performed as a distal revascularization procedure in all patients. RESULTS: Mean systolic iliac artery pressure gradients improved from 34.7+/-8.6 mmHg to 3.9+/-3.2 mmHg after angioplastic procedures (P < 0.0001). Six patients needed reangioplasty because of restenosis in the follow-up period. Thrombectomy was performed on 1 patient in the early postoperative period and re-do femoropopliteal bypass was performed on two patients in the 2nd and 23rd months. Three minor wound infections were successfully treated with antibiotics and local care. Mean follow-up was 21.4 months (range 1-48 months). By life-table analyses, the overall 4-year cumulative primary patency of combined procedures was 78.1%. CONCLUSION: The results show that the combined procedure is a suitable method for the treatment of patients with multiple stenotic lesions at the iliac and distal arterial levels. We believe that the combined use of PTA and distal vascular surgery by an experienced surgical team will give beneficial results and a highly satisfactory outcome in this group of patients.

An unusual indication for surgical treatment of iliac artery aneurysm treated with stented graft previously.

A 70-year-old man was seen with an iliac artery aneurysm and this was treated by an intraluminal graft-stent device introduced through the femoral artery. After the procedure, patency of the artery was proved to be good with control angiography but the mass effect of the aneurysmal sac on the gastrointestinal system did not disappear and we replaced the aneurysmatic segment with a collagen coated graft. The patient then recovered without any complications and gastrointestinal symptoms.

Hydatid disease and massive cardiac involvement.

Cardiac hydatid cysts are rare and represent 0.5-2% of all cases. Cardiac localization of hydatid cysts usually occurs in adults. Diagnosis is difficult because of the long latency between infection and manifestation of the disease, and also symptoms are nonspecific. We present a case study of 13-year-old girl with lots of hydatid cysts localized in the neighbourhood of the inferior vena cava right atrium and the superior vena cava right pulmonary artery aorta and posterior portion of the left atrium and the left ventricle, and the intramyocardium of the posterior wall of the left ventricle. An abdominal computed tomography scan showed a solitary cyst in the right posterior lobe of the liver. Following albendazole therapy for 3 weeks, she was operated on without cardiopulmonary bypass. Numerous alive and dead cysts were removed. Hepatic cysts were drained by percutaneous ultrasonography guided aspiration technique after surgery. On the 8th postoperative day, she was discharged while she was still on albendazole therapy.

Effects of protamine on nitric oxide level in the pulmonary circulation.

Protamine reversal of heparin anticoagulation often causes systemic hypotension by releasing nitric oxide (NO) from vascular endothelium. We investigated the hypothesis that protamine prevents severe pulmonary vasoconstriction by increasing NO. Twenty patients undergoing elective coronary artery bypass graft surgery were included in the study. Nitrite and nitrate levels--as end-metabolites of NO--were measured in blood samples obtained before and after protamine administration. Mean arterial pressure, heart rate, mean pulmonary artery pressure, central venous pressure and left atrial pressure were noted as hemodynamic data. Nitrite levels were 4.64 +/- 0.67 mumol in the right atrium and 4.84 +/- 0.95 mumol in the left atrium before protamine administration. The difference was insignificant statistically. These measurements were 4.85 +/- 0.92 in the right atrium and 5.28 +/- 0.66 mumol in the left atrium after protamine administration. This increase was significant (p < 0.05). The measurements of nitrate levels were completely parallel with those of nitrite. Mean arterial pressures were 78.9 +/- 7.59 mm-Hg before protamine and 74.1 +/- 8.55 mm-Hg after protamine (p = 0.03). The changes in other hemodynamic parameters were not significant. Protamine augments NO production and prevents the pulmonary circulation from possible vasoconstriction.

Metoprolol prevents ischemia-reperfusion injury by reducing lipid peroxidation.

Myocardial ischemia and reperfusion result in endothelial and ventricular dysfunction. Beta-blockers protect the myocytes from injury by acting as anti-ischemia agents. These anti-ischemic effects of the beta-blockers are due not only to their negative inotropic/chronotropic effects but also to a lipid peroxidation reducing mechanism. Thus, beta-blockers enhance myocardial recovery. In the present study 20 isolated guinea-pig hearts were perfused with Krebs-Henseleit buffer (KHB) using a Langendorff apparatus. The animals were allocated into 2 groups. In the study group (Group I), metoprolol, as the beta-blocker agent, was added into the KHB and in the control group (Group II) perfusion was performed without metoprolol. The percentage change (%change) of heart rate, developed pressure and dP/dtmax; malondialdehyde (MDA) and glutathione (GSH) levels of the perfusate and heart tissue were obtained as data. The %change of heart rate was 70.5+/-9.2 in the study group and 87.3+/-8.2 in the control (p = 0.003). The %change of developed pressure was 68.7+/-14.4 and 55.9+/-8.6 in the study group and control group, respectively (p = 0.04). The % change of dP/dt was 63.3+/-10.0 in the study group and 54.4+/-5.3 in the control group (p = 0.01). The tissue MDA level was 31.0+/-5.5 nmol/g tissue in the study group and 53.5+/-4.2 nmol/g tissue in the control group (p = 0.0002). The tissue GSH levels were 1.08+/-0.20 and 0.80+/-0.07 (mol/g tissue) in Groups I and II, respectively (p = 0.001). The levels of the perfusate MDA decreased and the levels of the perfusate GSH increased significantly in the metoprolol group in the postreperfusion period in comparison with the preischemia term (p = 0.003 and p = 0.03, respectively). Metoprolol reduces ischemic injury via prevention of lipid peroxidation and reduces the myocardial energy demand by decreasing the heart rate.

Evaluation of heparin-coated circuits with full heparin dose strategy.

Heparin-coated cardiopulmonary circuits (HCC) in combination with a reduced systemic heparin dose has been demonstrated to reduce postoperative hemorrhage after cardiac surgery. But, it has still been equivocal whether this effect was related to the improved bio-compatibility or to the reduced exposure of the circulating heparin. Sixty patients undergoing elective coronary artery bypass grafting were randomly allocated into two groups either to be operated by HCC (30 patients) or uncoated but otherwise identical circuits (NHCC). Full systemic heparinization was induced in both groups. Hemodynamic parameters, hematological and biocompatibility tests were monitored within 24 hours. Postoperative blood loss, requirements for transfusions, clinical performance were recorded. Arterial filters were examined electron microscopically. Platelet levels remained significantly higher in the HCC group starting at the tenth minute following the institution of cardiopulmonary bypass until postoperative 24 hours. Electron microscopy showed significantly more platelet adhesion and pseudopod formation in the NHCC group. The mean amount of shed pleural and mediastinal blood measured from the time of the sternal closure was significantly lower in the HCC group (316 +/- 30 cc for HCC and 550 +/- 35 cc for NHCC). Mean postoperative transfusion requirements were also lower in the HCC group (230 +/- 23 cc for HCC and 320 +/- 25 cc for NHCC). The use of HCC and full systemic heparinization did not change the inflammatory response or biocompatibility but demonstrated benefits in platelet preservation and postoperative bleeding.

Transdiaphragmatic graft replacement for coarctation suprarenal abdominal aorta.

A 17-year-old boy was referred to us with severe hypertension, headache and intermittent lower extremity claudication. Approximately 3 months prior to admission, he began to experience headache and pain in the posterior aspect of the right thigh and calf upon walking only 20 m. Occasionally, similar symptoms developed in the left leg which were nearly always of the same intensity as on the right. Arterial blood pressure on admission to our hospital was 220/140 mmHg in the arm. After physical examination and diagnostic tests, he was operated on with the diagnosis of coarctation of the abdominal aorta. The purpose of this paper is to report on a patient having an area of coarctation just above the level of renal arteries who presented with severe hypertension and intermittent claudication and in whom there was complete relief of signs and symptoms after appropriate surgical intervention.

Eight year experience with the CarboMedics bileaflet valvular prosthesis.

Two hundred and two patients (97 female and 105 male; mean age: 45. 5+/-9 years) received CarboMedics bileaflet valves during a period of eight years. Ninety-one patients received mitral, 72 aortic and 39 aortic+mitral valve prosthesis. Tricuspid plasty and coronary artery bypass surgery were the concomitant operations in 17 and 12 patients, respectively. The mean follow-up period was 24.7 months and the ratio was 91%. Overall operative mortality was 3.96% (8 patients); 2.78% for aortic valve replacement (AVR), 3.29% for mitral valve replacement (MVR) and 7.7% for double valve replacement (DVR). The late mortality rate was 2.89% for AVR, 2.2% for MVR and 8. 3% for DVR. The main cause of mortality was low cardiac output. The overall survival rate was 91.5% in 2 years. The actuarial freedom from thromboembolism in 2 years was 97% for AVR, 95% for MVR and 84% for DVR. No mortality due to heamorrhagic events was observed. CarboMedics prosthetic heart valves may be used satisfactorily with a low incidence of valve-related morbidity and mortality.

Cardiopulmonary bypass technique for treatment of renal cell carcinoma extending into the vena cava.

Cardiopulmonary bypass (CPB) is a unique technique used widely for renal cell carcinoma patients showing inferior vena cava invasion. We used a modification of CPB technique for 2 patients. These patients were managed with CPB without cross clamping and so without cold potassium cardioplegia. The primary tumor was a renal cell carcinoma propagating into the inferior vena cava and going into the right atrium as a thrombus in both patients. As a surgical procedure the urology team did nephrectomy and then with our clinical techniques we used CPB to cool the patients to 20 degrees C and decreased the flow to 500 ml/min/m2. The heart went into spontaneous ventricular fibrillation without using cross clamping and cardioplegia. Then we did atrial and inferior vena caval thrombectomy in a bloodless and visible operation field within a safe time interval. The aim of using this technique is to prevent myocardial injury and to protect the brain from hypoxia by using this low flow technique. This method can be used safely for the management of renal cell carcinomas and for some retroperitoneal malignancies associated with vena caval and atrial involvement.

Coronary artery bypass grafting (CABG) after successful percutaneous transluminal coronary angioplasty (PTCA): is PTCA a risk for CABG?

We studied patients who underwent a coronary artery bypass grafting (CABG) procedure with previous percutaneous transluminal coronary angioplasty (PTCA). Forty patients had undergone successful PTCA, and required subsequent CABG, between January 1993 and June 1996 (Group I). These patients were matched with 40 patients surgically revascularized without previous PTCA at the same term (Group II). There were no statistical differences among sex, diabetes mellitus, hypertension, family history, smoking, hypercholesterolemia and prior myocardial infarction within the groups. The mean ages were 50.7+/-9.4 and 54.7+/-7.7 years, respectively, in Group I and Group II (P = 0.02). Preoperative mean ejection fraction values were 59+/-5% in Group I and 56+/-7% in Group II (P = 0.01). The mean follow-up period was 21.0+/-9.8 months (1-38 months) for both groups. CABG operations were performed 11.4+/-6.0 months after PTCA. Number of grafts were 2.1+/-0.7 and 2.3+/-0.8 per patient in Group I and Group II, respectively. Mean aortic cross-clamping times were 18+/-3 and 17+/-4 min/graft (P = 0.01) and cardiopulmonary bypass (CPB) times were 34+/-7 and 29+/-7 min for Group I and Group II, respectively, (P = 0.0001). The duration of hospital stay were 9.1+/-2.5 days for Group I and 8.0+/-1.1 days for Group II (P = 0.008). Freedom from angina at the end of 3 years was 82.5% and 87.5% for Group I and Group II, respectively. One early and two late deaths occured in Group I. One early death and one late death occured in the other group. Survival rates for three years were 92.5% and 95% in Group I and in Group II, respectively. In conclusion, the method of initial revascularization procedure should be considered carefully, as markers of more severe disease may indicate primary CABG and avoidance of an initial PTCA. The initial PTCA may complicate the operation and may increase postoperative morbidity and mortality.

The dose-dependent effects of L-carnitine in myocardial protection in normothermic ischemia.

L-Carnitine has been shown to improve the post-ischemic recovery of myocardial function and metabolic measurements that are reduced in the course of ischemia and reperfusion of the heart. In this study we used 40 male guinea-pigs in order to determine if the effect of L-carnitine which is used in the protection of the post-ischemic reperfused heart, is dose-dependent or not. All harvested hearts were perfused for 30 min on modified Langendorf apparatus with oxygenized Krebs-Henseleit solution. After this period, in (n = 10), 5 mmol and 10 mmol (group B, n = 10) of L-carnitine were added into a Krebs-Henseleit solution. After 20 min, perfusion was complete and the hearts were then exposed to normothermic ischemia for 20 minutes. Following the ischemia, hearts were reperfused with the same solutions for 30 min. In group C (n = 10), 10 mmol of L-carnitine was added into the solution at the post-ischemic reperfusion step. In the control group, the same procedures were performed without using L-carnitine. Matching was done according to the contractile force of the heart rate and the levels of malondialdehyde and adenosine deaminase. When 10 mmol L-carnitine was added into the perfusion solutions at the pre-ischemic period, the best results were obtained and myocardial damage was much less than the control group. The protective effects of L-carnitine in normothermic ischemia is dose-dependent and it must be given at the pre-ischemic period.

Effects of selenium enriched reperfusion solutions on isolated guinea pig hearts.

A comparative study on isolated guinea pig hearts was carried out to determine the role of selenium enriched reperfusion solutions on postischemic reperfusion injury. The hearts of 20 control and 20 study group guinea pigs were mounted on a Langendorff perfusion apparatus and were perfused by gassed Krebs-Henseleit solution at 37 degrees C. The hearts were then arrested by discontinuing the Krebs-Henseleit perfusion. After 20 minutes of normothermic ischemia, in the study group, the hearts were reperfused by selenium enriched Krebs-Henseleit solution (10(-3) mMol/L) and in the control group only Krebs-Henseleit solution was used. Postischemic percentage recovery of mechanical cardiac functions (heart rate and contractile force) and postischemic tissue degeneration indicators. Malondialdehyde (MDA) and Adenosine deaminase (ADA) were compared between the groups. Mean percentage change of heart rate, contractile force and heart work were significantly higher (p < or = 0.0001) and tissue MDA and ADA levels were lower (p < or = 0.001) in the selenium reperfused group. Our results demonstrated that addition of selenium to reperfusion solutions significantly improved cardiac functional recovery and decreased postischemic myocardial injury.

Bland-White-Garland syndrome in an adult. Case report and review of diagnostic and predictive strategies.

In a 27-year-old man with Bland-White-Garland syndrome (anomalous origin of the left coronary artery from the pulmonary artery), comparison was made between conventional diagnostic techniques and radionuclide imaging for selection of surgical procedure and evaluating the outcome. Dynamic 99mTc imaging exactly located the left coronary artery orifice, which was not seen on angiography, thereby determining the surgical approach, and 123I study revealed that, despite absence of symptoms, the adrenergic activity of the heart was globally diminished, with limited response to revascularization.

Psychiatric complications of cardiac surgery postoperative delirium syndrome.

Psychiatric disturbances due to cardiopulmonary bypass, especially postoperative delirium syndrome, are among the immediate complications of open-heart surgery. In a series of 32 male and 18 female patients the prevalence of such disorders was investigated and search was made for possible risk factors for their occurrence. Psychiatric, neurologic and electroencephalographic evaluation was made pre- and postoperatively, in addition to haemodynamic, echocardiographic, angiographic and regional cerebral blood flow studies. Nine of the 50 patients had significantly reduced perfusion of certain cerebral lobes in single photon emission computed tomography, and in six of them the psychiatric tests indicated postoperative delirium; three of these six also had moderate electroencephalographic changes. The cerebral hypoperfusion persisted on day 15 in four patients, while psychiatric tests were negative. The study showed possible risk factors to be patient age, long aortic cross-clamp time, high-dose inotropic support and excessive transfusion of blood or blood products.

The effect of selenium added cardioplegia in guinea pigs.

1. The aim of the study was to determine the effect of selenium added cardioplegic solutions on postischemic myocardial recovery. 2. The hearts were mounted on Langendorf perfusion apparatus and perfused with Krebs-Henseleit solution. The hearts were arrested by one of the following cardioplegic solutions; (a) K+ 20 mmol/l (control group); (b) K+ 20 mmol/l+selenium 10(-3) mol/l (experimental group). After 20 min of normothermic ischemia the hearts were reperfused by the same buffer. 3. Postischemic percentage changes of heart rate, contractile force and heart work were compared between the groups. 4. Addition of selenium to the cardioplegic solution significantly decreased the postischemic myocardial injury.

The effects of thyroid hormones on the heart following global ischemia. A clinical and experimental study.

Cardiopulmonary bypass is associated with a reduction in plasma thyroid hormone concentrations in patients undergoing cardiac surgery. However, studies of the effects of cardiopulmonary bypass on thyroid function are limited and many studies report conflicting data concerning only the period of cardiopulmonary bypass. In this study, we tried to clinically determine the effects of cardiopulmonary bypass on concentrations of thyroid hormones by comprehensive thyroid function tests in 10 patients before and after surgery, and observed the benefits of triiodothyronine supplementation after global ischemia on myocardial function experimentally in guinea pigs. In patients undergoing surgery, concentrations of total triiodothyronine and free triiodothyronine decreased progressively on the institution of cardiopulmonary bypass and remained below normal levels until 24 hours postoperatively. In the guinea pig hearts studied in a Langendorf perfusion apparatus, T3 supplementation enhanced percentage recovery of ventricular contractile force, heart work and heart rate with respect to other groups receiving no T3 supplementation or T3 supplementation without any ischemic interval.

Effect of allopurinol on myocardial recovery during reperfusion.

A comparative study on isolated guinea pig hearts was carried out to determine the effect of allopurinol added to reperfusion solution on myocardial recovery after global ischaemia. After 20 min of normothermic ischaemia two groups of solutions (1-Krebs Solution 2-Krebs Solution + Allopurinol 1 mmol l-1) were used for reperfusion (10 animals in each group). Post-ischaemic myocardial functions (ventricular contractile force and heart work) and enzyme activities (CK-MB, LD) were compared with their preischemic values. Addition of allopurinol 1 mmol l-1 to reperfusion solution improved post-ischaemic myocardial functions and decreased myocardial injury.

Cardioplegia with adenosine and adenosine triphosphate in the isolated guinea pig heart.

In order to determine the effect of adenosine triphosphate (ATP) and adenosine in cardioplegic solutions, a comparative study has been undertaken in isolated guinea pig hearts using the Langendorff perfusion technique as a model of cardiopulmonary bypass. The hearts (n = 10 in each group) previously being perfused by Krebs-Henseleit solution, were arrested by one of the following cardioplegic solutions: 1) Potassium 20 mM/L (Plegisol), 2) Potassium 20 mM/L+ATP 10 mM/L, 3) Adenosine 10 mM/L, 4) Adenosine 10 mM/L+ATP 10 mM/L. After 45 min of hypothermic ischemia, postischemic recovery of heart rate, ventricular contractility, heart work and postischemic changes in tissue enzymes (LDH, SGOT, SGPT) were compared among the 4 different cardioplegic solutions. Arrest time and number of arrest beats were also recorded and compared among the groups. Although similar beneficial results on postischemic recovery were achieved with adenosine cardioplegia and with ATP supplemented potassium cardioplegia, ATP supplemented adenosine cardioplegia did not show any beneficial effects on postischemic recovery.

Dipyridamole induced myocardial recovery after global ischemia.

1. An experimental comparative study on isolated guinea pig hearts was carried out to determine the effect of dipyridamole added to the reperfusion solution on myocardial recovery after global ischemia. 2. After 20 min of normothermic ischemia two groups of solutions: (1) Krebs solution; (2) Krebs + dipyridamole 20 micrograms/l (10 experiments in each group) were used for reperfusion. 3. Postischemic myocardial functions (heart rate, ventricular contractility, heart work) and tissue enzymes (CPK-MB, LDH) were compared with their preischemic values. 4. Addition of dipyridamole 20 micrograms/l to reperfusion solution improved postischemic myocardial functions and decreased myocardial injury.