Direct oxymetric peripheral tissue perfusion monitoring during open heart surgery with the use of cardiopulmonary bypass: preliminary experience

BACKGROUND

Regional hypoperfusion has been associated with the development of postoperative organ dysfunction in cardiac surgery involving cardiopulmonary bypass (CPB). Direct tissue oxymetry is a potentially new method for monitoring the quality of the peripheral tissue perfusion during CPB. The aim of this study was to assess the effects of CPB in skeletal muscle oxygenation when measured in the deltoid muscle by direct oxymetry during perioperative period.

METHOD

Seven patients underwent on-pump coronary artery bypass grafting. Direct oxymetry was performed by an optical cathether introduced into the deltoid muscle. Continuous measurement was made during the surgical procedure and the postoperative period. Mean arterial blood pressure, blood flow during CPB, laboratory markers of tissue hypoperfusion, blood gases and body temperature were also recorded.

RESULTS

Interstitial muscle tissue oxygen tension (pO(2)) decreased after the introduction to anaesthesia and, more significantly, during CPB. After the disconnection from CPB at the end of the operation, the pO(2) returned to pre-anaesthetic values. During the first hours after admission of the patients to the intensive care unit, the pO(2) progressively decreased, reached a minimum value after four hours, and increased slowly thereafter. There was a significant correlation of pO(2) with mean arterial blood pressure and blood flow during that time.

CONCLUSION

The result of this first measurement seems to demonstrate that the standard technique of conducting cardiopulmonary bypass produces low muscle oxygen tension and, thus, little perfusion of skeletal muscle. The data also indicate that both high mean arterial blood pressure and high flow are necessary during CPB to ensure skeletal muscle perfusion. The investigation is continuing.

[The effect of preoperative administration of heparin on the heparin resistance development]

BACKGROUND

Heparin resistance is relatively frequent problem in cardio surgery. We were try to determine real occurrence heparin resistance before operation.

AIM OF THE STUDY

Purpose of the project--to find the real frequency of heparin resistance in patients who will undergo a cardio surgical operation. To find out the dependence between the pre-operational application of heparin and the development of heparin resistance.

METHODS

We recorded pre-operative administration heparin in patients. If the dose of heparin was 5 mg/kg and more then we insert patients to the group heparin resistant.

RESULTS

In our collection was heparin resistance in 203 patients from 624, it was 32.5%. Test agreement relative frequency with 22% was throw out--p < 0.001--heparin resistance in our group statistically different from 22% heparin resistance was higher than hypothesis. Heparin before operation was administrate 181 patients, which make to 29%. For administration of heparin was hypothesis of independence thrown (p < 0.001).

CONCLUSION

Results of our works confirmed statistically significant occurrence of heparin resistance in patients that was administration heparin pre-operative. Heparin resistance occurred against presumption 22% in 32.5% in our group. It is statistic significant difference.

Contribution to technique of endarterectomy of the right coronary artery

We present our technique of performing endarterectomy of coronary arteries by means of injecting cardioplegic solution into the plane of dissection of the endarterium. This simple and gentle technique in combination with manual endarterectomy helps in separation of the core far into the periphery of the diseased vessel and thus helps to perform revascularization in patients with diffuse atherosclerotic changes. During the last 6 years (1991-1996) endarterectomy in coronary revascularization was used in 116 cases (it was 5.7 % (116/2031) of all myocardial revascularization procedures). On right coronary artery endarterectomy was used in 82 patients. Mortality rate in our group of patients was 4.88 % (4/82) and perioperative myocardial infarction developed in 4.88 % (4/82). According to our own experience with this technique of endarterectomy on right coronary artery we are convinced that in desperate patients with diffuse coronary artery disease our method can bring better and wider application of surgical treatment.

[Results of open valvotomy in congenital stenosis of the aortic valve]

Between 1977 and 1992 at the Cardiosurgical Clinic of the Faculty Hospital in Hradec Králové on account of congenital valvular aortic stenosis 142 patients were subjected to catheterization. Valvotomy of a stenotic aortic valve was performed in 69 patients. The submitted paper evaluates the progression of aortic stenosis based on investigations of the aortic gradient and the area of the aortic orifice in repeatedly catheterized patients before and after valvotomy and evaluates also the results of surgery after a 1-15-year interval after surgery.

[Surgery in mitral stenosis]

Commissurotomy of a stenotic mitral valve on the closed heart was the beginning of the cardiosurgery. It helped hundreds of thousands of patients. At present in mitral stenosis surgery with extracorporeal circulation is recommended. The idea to eliminate the stenosis of the mitral valve by the closed route was adopted in percutaneous transvenous commissurolysis. The author discusses the submitted paper the development of mitral stenosis surgery at the cardiosurgical department in Hradec Králové during 45 years since the first commissurotomy implemented in 1951 by academician Bedrna.

[Valve replacement in congenital aortic stenosis]

BACKGROUND

Hemodynamically significant congenital aortic stenosis is usually surgically solved by valvotomy, infrequently aortic valve replacement is necessary. The aim of this retrospective study (period 1979-1995) is to find reasons for valve replacement, frequency of these procedures and early and long term results after aortic valve replacement for congenital aortic stenosis.

METHODS AND RESULTS

Congenital aortic stenosis was solved by aortic valvotomy in 82 patients and by aortic valve replacement in 18 patients. Aortic valve replacement was performed 6x for congenital valvar aortic stenosis with mean aortic gradient 53.7 +/- 13.9 mm Hg and aortic valve area 0.42 +/- 0.04 cm2/m2 and 4x for valvar and subvalvar stenosis with mean aortic gradient 87.0 +/- 31.3 mm Hg, valve area 0.45 +/- 0.03 cm2/m2 and associated regurgitation 44.7 +/- 25.6%. In the remaining 8 patients aortic valve replacement was performed as reoperation after aortic valvotomy (after 20 +/- 8.4 years). In this group mean aortic gradient was only 32.2 +/- 13.8 mm Hg but regurgitation was 54.0 +/- 15.8%. Infective endocarditis occurred in 8 patients (44.5%) preoperatively. There were two hospital deaths (sudden death and multiorgan failure) and one death 3 years after operation (prosthetic endocarditis). Remaining 15 patients are in very good condition (NYHA I.-II.) 1-13 years after aortic valve replacement.

CONCLUSIONS

Severely calcified aortic valve, endocarditis and associated incompetence are indications for valve replacement in patients with congenital aortic valve disease. Prevention of infective endocarditis is necessary pre and postoperatively, too. Long-term results after valve replacement for aortic valve stenosis are very good.

[Results of pericardiectomy in the treatment of constrictive pericarditis]

Between 1981 and 1990 at the Cardiosurgical Clinic in Hradec Králové pericardectomy on account of chronic constrictive pericarditis was performed in 20 patients. The authors evaluated the duration of complaints, preoperative symptomatology, surgical procedure and results of the operation. Symptoms of right-sided cardiac congestion were recorded in 80% of the patients. Calcifications of the pericardium were found in 70% of the patients. During the postoperative period one patient died (5%). The long-term results evaluated at least three years after operation were very good in 65% of the operated patients. Treatment of chronic constrictive pericarditis is surgical and involves subtotal pericardectomy from medial sternotomy.

[Results of surgical treatment of aortic coarctation]

The authors summarize the results of surgical treatment of coarctation of the aorta in 98 patients. Te group comprised 70 children aged 3 to 15 years and 28 adults. The most frequently used technique was resection of the coarctation with a direct end-to-end anastomosis. It was used in a total of 83 patients. Three patients died, i. e. 3.1%. Of 32 patients who were invited for a check-up examination 16 came. Three of them had undergone a plastic operation with a dacron patch. All were subjected to angiographic examination in a lateral projection by injection of the contrast substance into the aortal arch and pressure readings were taken in the aorta above and below the site of anastomosis. Residual gradients were found in three patients (10, 12, 20 torr). Hypertension persists in 6 patients. In four patients slight stenosis of the aorta was found without a gradient, in one patient a small pseudoaneurysm. None of the findings called for further surgical intervention.

[Mediastinal inflammation as a complication of heart surgery under extracorporeal circulation]

The authors describe mediastinitis in two patients operated on account of ischaemic heart disease. In both patients they used the closed approach which involved suture of the sternum and surgical wound, perfect drainage and the administration of antibiotics (general and local). They describe the applied method of fixation of the sternum. In both patients the sternum and surgical wound healed.

[Malignant tumors of the heart from the viewpoint of the surgeon]

The authors present three cases of malignant affections of the heart. In two instances a primary haemangiosarcoma was involved which originated in the right atrium, in the third patient a secondary of a left ovarian carcinoma was involved. They draw attention to the similar symptomatology of the disease and the possibility of echocardiographic visualization of intracardiac formations. The possibilities of radical removal of malignant tumours of the heart are very limited and call for the use of extracorporeal circulation. The incidence of this disease is very rare.

Effect of acute ethanol administration on the thoracic duct lymph flow in man

In 17 patients the thoracic duct was cannulated and the lymph continuously collected. Thoracic duct lymph flow and the concentration of total protein in the lymph and blood serum were repeatedly measured for 6 hours. Group I (9 subjects) received 0.7 g/kg of oral ethanol in the form of 40% solution, group II (8 subjects) an intravenous infusion of 0.75 g/kg of ethanol. Oral but not intravenous administration of ethanol significantly increased the thoracic duct lymph flow. Lymph total protein significantly decreased in group I only.