Ahmet Hamulu

Easy Harvesting of Radial Artery With Ultrasonically Activated Scalpel

BACKGROUND The radial artery was proposed and then abandoned as a coronary artery bypass graft in the 1970s. Development of new pharmacologic antispasmodic agents and minimally traumatic harvesting techniques has led to a revival of the use of the radial artery in coronary artery bypass surgery. Usually the main reasons for the spasm are thermal injury caused by electrocautery and traumatic harvesting technique. METHODS In our technique an ultrasonically activated scalpel (Harmonic Scalpel; Ultracision Inc, Smithfield, RI) was used for radial artery harvesting without using hemostatic clips for vessel side branches. The patients in the study were divided into two groups of 10 patients each. In the first group radial arteries were harvested with this technique, and in the second group with hemostatic clips, scissors, and minimal electrocautery. Harvesting time, frequency of spasm, and use of hemostatic clips were compared between the two groups. RESULTS The Harmonic Scalpel decreased the harvesting time, frequency of spasm, and excessive use of hemostatic clips. CONCLUSIONS Good coagulation capacity with markedly decreased use of hemostatic clips and minimized thermal injury offers the surgeon the ability to perform less traumatic, spasm free, and rapid radial artery harvesting.

The effects of modified hemofiltration on inflammatory mediators and cardiac performance in coronary artery bypass grafting

Cardiopulmonary bypass increases the blood levels of various immune mediators, thereby leading to a systemic inflammatory response syndrome, e.g. sepsis, with some hemodynamic alterations, such as vasodilatation, tachycardia, and a decrease in systemic vascular resistance. Perioperative hemofiltration is one of the treatment modalities proposed to prevent this syndrome. Modified hemofiltration has been introduced recently by investigators who recommend that the former standard techniques are ineffective in eliminating the inflammatory mediators. The purpose of this study was to determine the effects of the modified technique on these mediators and on hemodynamic parameters. Forty patients undergoing coronary artery bypass grafting were randomized into equal control and hemofiltered groups. The hemodynamic parameters, as well as blood samples, were taken before and after hemofiltration to assess blood concentrations of interleukin-6, interleukin-8 and neopterin. The hemodynamic parameters and immune mediator levels did not differ between the two groups during the course of the study, except in the immediate postoperative periods, where cardiac output, cardiac index, and systemic vascular resistance values were significantly greater in the hemofiltered group while there were no differences in the immune mediators. The results of our study suggest that the effects of modified hemofiltration on immune mediators are still debatable. The improvement found in cardiac performance could be attributed to the prevention of hemodilution and hypervolemia.

Effect of pulsatile flow during cardiopulmonary bypass on thyroid hormone metabolism

Changes in thyroid hormone levels during and after cardiopulmonary bypass (CPB) are well documented. However, little is known about the effects of pulsatile flow during CPB on thyroid hormone metabolism. To examine the effect of flow pattern, a prospective study was carried out using 30 patients undergoing coronary artery bypass grafting. Fifteen patients had pulsatile flow during CPB and 15, nonpulsatile flow. Serum samples were obtained preoperatively, during bypass, and at 2 and 24 hours postoperatively. Thyroid-stimulating hormone, thyroxine (T4), triiodothyronine (T3), free T4, and free T3 levels were measured by radioimmunoassay. All measured hormone levels except free T4 and thyroid-stimulating hormone decreased after the initiation of CPB. There were no differences in preoperative values between the two groups. However, levels of T3 and free T3 during and after CPB showed a significant difference between the two groups, with a smaller decrease in patients in whom pulsatile flow was used during bypass (p < 0.05). Thyroxine, and thyroid-stimulating hormone free T4 values showed no difference between the two groups at any sampling time. These data provide support for the use of pulsatile flow during CPB to establish a more physiologic state and maintain better thyroid hormone metabolism.

Effects of flow types in cardiopulmonary bypass on gastric intramucosal pH

The aim of this study was to determine the relationship between splanchnic perfusion and oxygen consumption, and flow types in cardiopulmonary bypass (CPB), by measuring gastric intramucosal pH. Twenty patients undergoing elective open-heart surgery were prospectively randomized to receive either pulsatile or nonpulsatile flow during CPB. Gastric intramucosal pH was measured using gastric tonometry. A flowmeter was used to measure the inferior caval vein flow. A catheter was inserted through the femoral vein to sample blood from the iliac vein. Systemic vascular resistance index, gastric intramucosal pH, inferior caval vein flow and arterial, inferior vena caval and iliac venous blood gases were recorded at different times. Gastric intramucosal pH decreased in all patients; only in the nonpulsatile group was this decrease statistically significant. After 45 min of CPB, the pH was 7.37 ± 0.03 compared with the prebypass value of 7.48 ± 0.04 (p = 0.00016). After weaning from CPB, the pH was 7.358 ± 0.02 compared with the prebypass value (p = 0.000037). At 2 h post-operatively the pH was 7.416 ± 0.025 (p = 0.02). Systemic vascular resistance index rose in all patients during bypass in both groups. These changes did not have any statistical significances and after weaning from bypass returned to prebypass levels. We conclude that nonpulsatile flow in CPB is associated with reduced gastric intramucosal pH and the measurement of intramucosal pH during open-heart surgery provides important information about splanchnic perfusion.

Techniques for retrograde cerebral perfusion in the treatment of aortic lesions via left thoracotomy.

Abstract Retrograde cerebral perfusion under deep hypothermic circulatory arrest is a simple and useful adjunct in aortic surgery and is performed by many surgeons in the treatment of aortic arch pathology. In recent years, this technique has been recommended in the surgery of distal arch and proximal descending aortic lesions through a left thoracotomy incision. The aim of the technique is to increase the right atrial pressure for retrograde cerebral perfusion. After cooling using femorofemoral bypass, circulatory arrest is initiated. The right atrial pressure is increased to 20 mmHg, and retrograde cerebral circulation results. In this article, five patients with distal aortic arch and proximal descending thoracic aortic lesions who were operated on by using this technique were evaluated. It is suggested that this technique can be used with a lateral thoracotomy approach that is suitable for procedures on a distal aortic arch and proximal descending aorta.

Predictive values of risk factors in carotid duplex scanning before peripheral vascular surgery

The objective of this study was to determine the predictive values of multiple atherosclerotic risk factors in using routine carotid duplex scanning for patients with peripheral vascular disease, even in the absence of any sign of carotid disease. From 1998 through 2000, 108 patients admitted for peripheral vascular reconstruction to our institution were preoperatively screened for carotid artery stenosis. Patients were examined for neurologic status and cervical bruits. As atherosclerotic risk factors, hyperlipidemia, diabetes, smoking, sex and age, coronary artery disease (CAD), coronary artery bypass surgery (CABG), and previous vascular operation were recorded, preoperative ankle-brachial pressure indexes (ABI) were calculated. All patients underwent routine carotid color duplex examinations preoperatively. Eighty five patients (78.7%) had mild (<50%) or no carotid artery stenosis, and 23 patients (21.3%) had significant (≥50%) carotid artery stenosis. Age (≥60 years), coronary artery disease, and carotid bruit were individual factors, and the combination of age ≥55 and hyperlipidemia had a significant value in predicting presence of ≥50% stenosis of one or both carotid arteries by univariate analysis. By multivariate logistic regression analysis, however, only carotid bruit was associated with carotid artery stenosis of ≥50% (p<0.001). Screening for asymptomatic carotid artery stenosis is indicated in patients with only carotid artery bruit and might be indicated in elderly patients with peripheral vascular disease. Routine screening or carotid artery stenosis in all patients is not an effective strategy.

Simple and Cost-Effective Gas Jet for Non-Pump Coronary Bypass Surgery

A gas jet is one method of achieving a bloodless surgical field. We describe a simple and cost-effective oxygen blower system for coronary artery bypass surgery performed without cardiopulmonary bypass.