Exploring at the molecular level the effects of blood and blood-insulin cardioplegias used during open-heart surgeries on myocardial prevention

AIM

The aim of this study was to measure the changes in the levels of soluble adhesion molecules involved in acute inflammation during ischemia-reperfusion in adults who underwent open-heart surgery using blood and blood-insulin cardioplegia and to examine the differences in tissue damage at the molecular level as a consequence of insulin's effect on myocardial energy metabolism.

METHODS

Non diabetic 36 patients were enrolled. Blood cardioplegia was used at all cases; insulin and glucose were added at the study group. Blood samples were taken from the coronary sinus and the radial artery before cross-clamp (T1), at 1st (T2) and 30th(T3) minutes after reperfusion. Soluble intercellular adhesion molecules-1 (sICAM-1), soluble vascular adhesion molecules-1 (sVCAM-1), soluble platelet/endothelial cells adhesion marker-1 (sPECAM-1) and serum lactate levels were measured in these samples. Cardiac enzymes (CK-MB, troponin, and myoglobin) were measured at postoperative 1th, 8th and 16th hours. The total duration of mechanical ventilatory support during postoperative period, and the number of days in the intensive care unit and hospital were recorded.

RESULTS

No significant differences were observed in sVCAM-1 levels in blood taken from the radial artery at T1, T2 and T3 in either group. There were significant increases between T1 and T3 and between T2 and T3 in samples obtained form the coronary sinus (P=0.000 and P=0.003, respectively). Significant increases in sPECAM-1 in samples obtained from both sites between T2 and T3 in both groups (P=0.000) were observed. These differences were similar in both groups. Troponin levels at 8th and 16th hours in the blood-insulin cardioplegia group were higher than the blood cardioplegia group (P=0.003 and P=0.032, respectively).

CONCLUSION

Supplementation of blood cardioplegia with insulin did not yield a significant improvement in adhesion molecules. Therefore, superiority of one cardioplegia over the other in delivering myocardial protection during open-heart surgery has not been shown.

Use of Tunnelled Catheters in Haematological Malignancy Patients with Neutropenia

This prospective study analysed 83 patients (age 45 ± 17 years) with haematological neoplasms, implanted with 93 tunnelled catheters, who were neutropenic or developed neutropenia during treatment. Catheters were implanted in the right ( n = 82) or left ( n = 11) jugular vein by the same surgical team using the same technique. They remained in place for 124 ± 88 days: 29% were removed due to infection; 18% due to treatment termination and 2% due to mechanical problems. Seventeen patients died with catheters in place. At 30, 60, 90, 120 and 200 days mean catheter duration rates were 82%, 75%, 65%, 60% and 35%, respectively, and freedom from catheter removal due to infection was 92%, 88%, 80%, 77% and 67%, respectively. Patient diagnosis and history of previous catheter infection did not increase catheter infection risk, but patients undergoing stem cell transplantation had an increased infection risk. Tunnelled catheters can be used in high-risk patients with neutropenia. Systemic infections can be managed in most patients without catheter removal.

The effects of heparin coated circuits on pulmonary injury. A clinical study

AIM

Heparin-coated circuits have dramatic effects on the coagulation cascade, but their role on complement activation has not been clearly defined. In this clinical study the effect of heparin-coated circuits on static lung compliance and pulmonary vascular resistance is described.

METHODS

Thirty patients were randomly divided into two groups: with either a heparin-coated circuit or an identical but non-coated circuit control group. In the heparin-coated group, all the blood contacting surfaces were treated with immobilized heparin (Duraflo II.)

RESULTS

Early postoperative pulmonary function is determined with measurements of static lung compliance, pulmonary vascular resistance and arterial blood gases. Static lung compliance was significantly better in the heparin coated (HC) group in the early postoperative period (p=0.001). Pulmonary vascular resistance was significantly lower in the heparin-coated (HC) group in the early postoperative period (p=0.001).

CONCLUSION

We believe that the method of heparin binding may play a role in its diminished effect on complement activation, but the general augmentation of the circuit's biocompatibility may explain its beneficial effect on pulmonary vascular resistance and static lung compliance.

A multicentre study of abdominal aorta diameters in a Turkish population

The aim of this study was to determine the normal values for aortic diameters and the prevalence of aortic dilatation in a mixed Turkish population. Between March 1998 and May 2000, patients who were undergoing abdominal ultrasonography examination for pathologies not involving the aorta, in three different cities, were enrolled into the study prospectively. The anterior posterior aortic diameters were measured at the subdiaphragmatic and aortic bifurcation levels using ultrasonography. A total of 596 patients were included (302 females, 294 males). The mean age was 48 +/- 16 years (range, 6-88 years). The mean aortic diameter in the whole group was 19.0 +/- 3.9 mm (10-45 mm) at the subdiaphragmatic level and 15.7 +/- 3.6 mm (9-65 mm) at the aortic bifurcation level. The mean subdiaphragmatic aortic diameter was 18 +/- 3 mm in females and 19 +/- 4 mm in males. The mean aortic diameters at the bifurcation level was 15 +/- 3 mm in females and 16 +/- 4 mm in males. An aortic bifurcation diameter > 30 mm was encountered in 0.67% of the population. This ratio increased to 1.8% in patients over 55 years of age, regardless of sex. A subdiaphragmatic aorta diameter above 30 mm was observed in 1.2% of the population. In patients over the age of 55 years, this ratio increased to 2.7% (3.6% in males and 1.9% in females). In this national study, the subdiaphragmatic aortic diameters were similar to mean values reported in the world literature. The mean aortic bifurcation diameters were generally lower when compared with the literature, which may be due to difficulties in standardization of the measurements. Aneurysmal dilatation rates in this study also conform to those reported in studies conducted in other countries. Considering the significant number of patients with aneurysmal dilatation of the aorta in the elderly population, we believe it would be prudent to evaluate the aorta in all patients undergoing abdominal ultrasonographic examination.

A new minimally invasive method of aortofemoral revascularization

In recent years, minimal invasive surgical applications have been used in every field of surgery and became a routine application for some kinds of operations. Mini-laparotomy has been limited to abdominal incisions between 3 and 10 cm long. Four aortobifemoral and one aortofemoral bypass cases that were performed with mini-laparotomy incision between January 1997 and February 1998 are presented. In all cases, revascularization of lower extremities was performed successfully without enlarging the incision. The average operation time was shorter and the number of transfused blood units was significantly lower in that group when compared to the conventional laparotomy group of 12 cases. In all cases, bowel sounds appeared in 2 to 8 hours and at the end of 24 hours, oral nutrition was started. The mean discharge time from the hospital was 4.7 days. With the advantages of less operation time, optimal aortic exposure, ability in safe cross-clamping, less postoperative pain, less scar tissue occurrence, early resumption of intestinal functions, early mobilization and shorter hospitalization time, the mini-laparotomy technique is a safe reliable method for use in aortobifemoral bypass operations.

Nisoldipine Cardioplegia in the Isolated Rabbit Heart

BACKGROUND: The metabolic and hemodynamic effects of nisoldipine supplementation in cardioplegia after ischemic injury were investigated in 13 isolated rabbit hearts. Group 1 consisted of 6 hearts, which received St. Thomas II cardioplegic solution. In group 2, nisoldipine was added to the cardioplegic solution at a concentration of 0.1 mg/kg in 7 hearts. METHODS: The explanted hearts were suspended from Langendorff apparatus and were perfused with Krebs-Henseleit solution. Left ventricular pressure, heart rate, malondialdehyde, glutathione peroxidase, glutathione reductase, reduced glutathione, oxidized glutathione, creatine kinase MB, (CK-MB), aspartate transaminase, and lactate dehydrogenase (LDH) were measured before and after 60 minutes of ischemia. Peak generated pressure after ischemia was significantly higher in group 2 versus group 1 while end-diastolic pressure was significantly lower in group 2 after ischemic arrest (P <.05). RESULTS: Malondialdehyde levels were lower in group 2 (P <.05). Glutathione peroxidase and glutathione reductase levels were significantly higher in group 2 (P <.05). The only enzymatic significant difference was observed between the preischemic and postischemic levels of aspartate transaminase in group 2 (P <.05). CONCLUSIONS: These findings show beneficial effects of nisoldipine cardioplegia, although its use as a cardioplegic additive is not yet possible. We believe, however, the effects of oral nisoldipine before cardiac surgery can be studied in a clinical setting.