Hidetoshi Tsuboi

RELATIONSHIP BETWEEN RESPIRATORY DISTRESS AND CYTOKINE RESPONSE AFTER CARDIOPULMONARY BYPASS

The influence of cytokines on the inflammatory response in surgery has recently been the subject of investigations. We measured tumor necrotic factorga (TNF-α), interleukin 1β (IL-1β), interleukin 6 (IL-6), interleukin 8 (IL-8), and granulocyte elastase (GEL) in 26 patients undergoing elective cardiac operations using cardiopulmonary bypass (CPB), preoperatively, immediately after CPB, and on postoperative days (PODs) 1, 3, and 6. To evaluate the effect of these cytokines on pulmonary function, the patients were divided according to whether the oxygenation index (OI) on POD I was > 250 or < 250, into groups A and B, respectively. TNF-α and IL-1 β were undetectable and there were no significant differences in the preoperative IL-6, IL-8, and GEL levels. However, immediately following CPB, the mean IL-6, IL-8 and GEL levels in both groups were significantly higher than the preoperative levels (P < 0.01). Moreover, all these levels were significantly higher in group B than in group A, at 162 ± 150 pg/mlvs 64 ± 53 pg/ml (P < 0.05) for IL-6; 53 ± pg/mlvs 22 ± 20 pg/ml (P < 0.01) for IL-8; and 2477 ± 1642 mg/1vs 1397 ± 774 mg/l (P < 0.01) for GEL. The IL-6 levels returned to the preoperative values in both groups on POD 1; however, the GEL levels remained significantly higher in group B than in group A postoperatively, at 616 ± 326 mg/lvs 378 ± 70 mg/l on POD 1, and at 292 ± 70 mg/lvs 218 ± 62 mg/1 on POD 3 (P < 0.05). Thus high levels of cytokines such as IL-6, IL-8, and GEL may be detrimental to respiratory function.

Coronary Arteriovenous Fistulas with Giant Aneurysm: Two Case Reports

Coronary arteriovenous fistulas are rare, particularly in association with coronary aneurysms. Two rare cases of patients with coronary arteriovenous fistulas and giant aneurysmal formation are described. A right coronary fistula that drained into the superior vena cava was demonstrated in one patient. The remaining patient had a documented left coronary fistula that drained into a main pulmonary artery and had evidence of several plexal vessels that transversed through the pulmonary trunk and toward the pericardial reflex. Under cardiopulmonary bypass, the fistulas and plexal vessels were successfully ligated without any injury to the native coronary circulation.

Shock-reinfusion injury to the central organs and the effect of free radical scavengers in the rat

Hemorrhagic shock-reinfusion injury produces critical changes in various organs with the generation of oxidant-free radicals. Some papers have reported that shock-reinfusion injury to the intestine is effectively reduced by the scavengers of free radicals; however, few reports mention the central organ damage caused by systemic hemorrhagic shock-reinfusion injury. Using a rat systemic hemorrhagic shock model, injury to the central organs, being the brain, heart, lungs, liver, and kidneys was assessed by measuring malondialdehyde (MDA). The MDA levels in the lungs, kidneys, and liver were elevated significantly after reinfusion, although there was no elevation of MDA in the brain or heart. These data show that the lungs, liver, and kidneys are easily damaged by shock-reinfusion, but that the brain and heart are relatively resistant. The efficacy of the free radical scavengers, superoxide dismutase plus catalase and allopurinol, were evaluated 30 min after reinfusion. Pathological examination showed that superoxide dismutase plus catalase and allopurinol reduced reinfusion injury in the lungs, liver, and kidneys. Moreover, superoxide dismutase plus catalase reduced MDA levels in both the liver and kidneys, whereas allopurinol reduced MDA levels only in the kidneys after reinfusion. However, these free radical scavengers could not suppress the elevation of MDA in the lungs after reinfusion.

Stress caused by minimally invasive cardiac surgery versus conventional cardiac surgery: incidence of systemic inflammatory response syndrome.

Abstract. The present study was conducted to evaluate the degree of stress in patients induced by minimally invasive cardiac surgery (MICS) in comparison with that caused by conventional cardiac surgery. We did this by assessing the incidence of systemic inflammatory response syndrome (SIRS). A total of 48 adult patients who underwent surgery for single valve disease were included in this study, 27 of whom underwent conventional surgery and 21 MICS. We evaluated the stress inflicted on the patients in these two groups by analyzing the duration and degree of SIRS and the level of C-reactive protein (CRP). SIRS was assessed by measuring body temperature, heart rate, respiratory rate, and white blood cell counts. There were no significant differences in the operating times, perfusion times, or aorta clamp times between the two groups; and the mean volume of blood transfusion did not differ significantly either. There was no significant difference in the incidence of SIRS or the mean duration of SIRS between the two groups. The CRP levels did not differ significantly between the two groups. Thus although MICS is superior to conventional cardiac surgery in that only a small skin incision is required, the stress experienced by the patient may be the same as that experienced by the patient undergoing conventional cardiac surgery.

Clinical trial of nicardipine cardioplegia in pediatric cardiac surgery

To clarify the effectiveness of nicardipine, one of the dihydropyridine calcium-channel blockers, for myocardial protection during cold potassium cardioplegic arrest in pediatric cardiac surgery, a clinical trial of nicardipine (0.25 mg/L) added to potassium cardioplegic solution was performed in children undergoing surgical repair of congenital heart diseases. Twenty patients were selected to receive nicardipine cardioplegia and 13 patients received a standard potassium cardioplegia, serving as a control group. Nicardipine cardioplegia provided better cardiac performance in the early postoperative period and reduced release of the MB isozyme of creatine kinase, as determined during a 48-hour postoperative period. These results suggest that nicardipine added to cold potassium cardioplegic solution offers additional protection for the myocardium during ischemia and postischemic reperfusion in pediatric cardiac surgery.

Emergency operation for thoracic aortic aneurysm caused by the Ehlers-Danlos syndrome

Two patients were treated emergently for impending ruptured thoracic aortic aneurysms caused by type IV Ehlers-Danlos syndrome. One patient had typical physical evidence of type IV Ehlers-Danlos syndrome. The other patient had a normal phenotype. Type IV Ehlers-Danlos syndrome was diagnosed by electrophoresis of the collagen extracted from the skin. The clinician must be aware of the variations in presentation of type IV Ehlers-Danlos syndrome.

A Video - Assisted Thoracoscopic Surgical Technique for Interruption of Patent Ductus Arteriosus

We describe herein a technique for patent ductus arteriosus (PDA) closure using a method of video-assisted thoracoscopic surgical (VATS) interruption derived from video-assisted endoscopic surgery. This technique of repair was performed on five patients with a mean age of 3 years and a mean weight of 13.7 kg during 1994 and 1995. Under general anesthesia, two 10-mm trocars and two or three 5-mm trocars were inserted through the left thoracic wall. A video camera and specially designed surgical tools including scissors, dissectors, and a clip applicator were then introduced. The ductus was dissected, and two titanium clips were applied to interrupt the ductus completely. Successful closure of the PDA by this video-assisted technique was achieved in all patients. The only complication which developed in one patient was hoarseness for 2 weeks postoperatively. The hospital stay ranged from 7 to 12 days and there were no serious complications of deaths. There results indicate that video-assisted thoracoscopic surgical interruption is a safe and effective technique for achieving closure of PDA.

Changes in the morphology and components of the coronary arteries during the progression of coronary arteriosclerosis following cardiac transplantation in rats

In order to examine the changes in coronary artery morphology following cardiac transplantation, the intimal and medial areas and vascular components were measured 30 and 60 days postoperatively in rats receiving both iso- (n = 5, each time) and allotransplantations (n = 7, each time). Although cyclosporine A was administered intramuscularly (10 mg/kg per day) for 20 days following transplantation, graft rejection progressed gradually in the allotransplanted group. There were no clear changes in the intimal or medial areas following transplantation in the isotransplanted group. The intimal area of the coronary arteries in the allograft group was significantly thicker 30 and 60 days following transplantation, while the medial area of the coronary arteries in this group was significantly thinner than that of the isotransplantation group at these same time points. In the thickened intimal areas in the allotransplantation group, only the density of smooth muscle cells was higher following transplantation. In the thinned medial areas in the allotransplantation group, the densities of the smooth muscle cells and collagen were less than those in the isotransplantation group. These changes suggest that following transplantation, smooth muscle cells proliferate in the intimal areas, while smooth muscle cells and collagen are degraded in the medial areas.

Chimney Technique for Aortic Dissection Involving an Aberrant Right Subclavian Artery

We report a case involving a ruptured acute type B aortic dissection originating from an aberrant right subclavian artery (ARSA). A thoracic stent-graft was deployed in the distal arch close to the origin of the ARSA; the entry site at the origin of the ARSA was embolized with metallic coils. Perfusion of the left subclavian artery was preserved without a surgical bypass by using a chimney graft. This procedure is a feasible and less invasive treatment for high-risk sternotomy patients and is an effective strategy for acute aortic dissections involving an ARSA.

Effect of Cardioplegic Arrest and Reperfusion on Coronary Reserve and Autoregulation

BACKGROUND The effects of cardioplegic arrest and reperfusion on the coronary vasculature remain to be characterized. This study was designed to investigate changes in coronary reserve and autoregulation after hypothermic cardioplegic arrest and reperfusion. METHODS Isolated rabbit hearts were perfused in a retrograde manner with Krebs-Henseleit bicarbonate buffer solution at a pressure of 80 cm H2O. Baseline measurements were performed for (1) coronary flow; (2) vasodilatory response to 5-hydroxytryptamine (10(-7) mol/L) and nitroglycerin (10(-4) mol/L); (3) autoregulatory capacity, quantified as closed-loop gains; and (4) isovolemic left ventricular function. Hearts were then subjected to cardioplegic arrest for 90 minutes. Twenty minutes after reperfusion, measurements were repeated. RESULTS Coronary flow decreased significantly after reperfusion (6.2 +/- 1.1 versus 5.3 +/- 1.1 mL.min-1.g-1; p < 0.01). The response to 5-hydroxytryptamine as percentage increase of flow decreased significantly after reperfusion (134.0% +/- 12.0% versus 109.1% +/- 6.8%; p < 0.01). However, there was no significant change in the response to nitroglycerin after reperfusion (121.3% +/- 17.6% versus 136.6% +/- 13.3%). The closed-loop gain demonstrated negative values before arrest but became positive after reperfusion, indicating loss of autoregulation after reperfusion. There was no significant change in left ventricular function. CONCLUSIONS The coronary flow reserve in response to 5-hydroxytryptamine and autoregulation were impaired after cardioplegic arrest and reperfusion, whereas nitroglycerin-induced vasodilatory response and left ventricular function were preserved.