Setsuo Kuraoka

Optimal blood flow for cooled brain at 20°C

Abstract Background . Optimal conditions for deep hypothermic perfusion and protective brain blood flow remain unclear. Methods . Dogs (n = 52) underwent 120 minutes of cardiopulmonary bypass at 20°C with perfusion flow rates of 2.5, 5, 10, 20, 40, and 100 mL · kg −1 · min −1 . We examined the effect of the various flow rates and different perfusion pressures on brain blood flow, metabolism, and intracellular pH. Results . The brain was ischemic and acidotic when the perfusion flow rate was less than 5 mL · kg −1 · min −1 and pressure was less than 10 mm Hg. When perfusion pressure was higher than 10 mm Hg, cerebral cortex blood flow was more than 9 mL · 100 g −1 · min −1 and intracellular pH, higher than 6.95. The cerebral metabolic rate for oxygen decreased at a flow rate of 2.5 mL · kg −1 · min −1 . The cerebral metabolic ratio of glucose to oxygen and the cerebral vascular resistance were lowest when perfusion pressure was 10 to 30 mm Hg. Full-flow (100 mL · kg −1 · min −1 ) perfusion caused paradoxical brain acidosis; a flow of 40 mL · kg −1 · min −1 provided the best results. Conclusions . Both extremely low-flow perfusion and excessive perfusion cause brain acidosis. Low-flow perfusion at a pressure of 20 mm Hg provides cerebral vasorelaxation and aerobic metabolism during operations at 20°C.

Coexistence of primary pulmonary Hodgkin lymphoma and gastric MALT lymphoma associated with Epstein-Barr virus infection: a case report.

We describe a 66‐year‐old woman with Epstein‐Barr virus‐associated lymphoproliferative disorder with lung and gastric tumors. We identified two lung tumors measuring 13 and 20 mm in diameter that consisted of CD30‐, CD15‐, and CD20‐positive Hodgkin‐ and Reed‐Sternberg‐like cells and heterogeneous cellular infiltrates in a pronounced nodular pattern, with necrosis and vasculitis, diagnosed as nodular sclerosis classical Hodgkin lymphoma. A gastric tumor showed low‐grade extranodal marginal zone B‐cell lymphoma of the mucosa‐associated lymphoid tissue type. Neoplastic cells in all tumors expressed Epstein‐Barr virus‐encoded RNA based on in situ hybridization. The present case is a rare composite lymphoma arising from different extranodal organs, associated with EBV infection. Her medical history included gamma‐knife therapy for clinical diagnosis with a suspicion of cerebral lymphoma.

Posttraumatic Tricuspid Insufficiency Successfully Repaired by Conventional Technique

Abstract  A 22‐year‐old man developed exertional dyspnea 2 years after blunt chest trauma due to a horse kick. Preoperative echocardiography showed severe tricuspid insufficiency (TI) caused by chordal rupture and prolapse of the anterior leaflet. A novel repair technique, the “clover technique,” was applied, but was unsuccessful in this case. The valve was then repaired successfully using conventional techniques, that is, insertion of an artificial chordae, plication of the prolapsing leaflet, and DeVegas annuloplasty. We present here a brief review of posttraumatic TI, and discuss effective and less expensive techniques for repair.

Accelerated myocardial metabolic and functional recovery with terminal nicorandil-Mg cardioplegia in heart transplantation

SummaryCardiac reperfusion injury after heart transplantation or cardiopulmonary bypass has been difficult to control due to the variable degree of myocardial damage with respect to the length of ischemia and the complexity of the surgical procedure. Here, we evaluated the myocardial metabolic and functional recovery of hearts infused with a nicorandil vasodilator-magnesium (Mg) solution just prior to reperfusion (terminal cardioplegia). Donor hearts (20 dogs) were removed and immersed in a 4°C water bath containing 20 mEq/1 KCL-5% glucose for 6 hours, and then were transplanted to recipient dogs. Orthotopically transplanted dog hearts were either reperfused without any further treatment or received a terminal cardioplegic solution containing 8 mg/ 1 nicorandil, 30 mEq/1 Mg, and 50 g/1 glucose, which was infused at a pressure of 75 cm H2O for 2 minutes. During the reperfusion period, myocardial tissue PCO2 (t-PCO2) and calcium ion (t-Ca) were continuously monitored by an ISFET (ion-sensitive field effect transistor) sensor. Myocardial oxygen consumption and lactate flux were calculated/monitored at 5, 10, 20, and 40 minutes of reperfusion. Thereafter, myocardial function was evaluated at 45 minutes of reperfusion using LVSWI. Just after reperfusion, the treatment group (group B, n = 10) had a significantly greater coronary flow than the control group (Group A, n = 10, 35.0 ± 10.1; group B, 47.4 ± 8.5 ml/100 g/min, p < 0.025). Myocardial tissue PCO2 and calcium ion levels in group B were significantly decreased at 5 minutes of reperfusion (A: 110 ± 21 → 88 ± 16; B: 126 ± 24 mmHg → 44 ± 7 mmHg, t-PCO2, p < 0.001; A: 3.5 ± 0.7 → 3.2 ± 0.7; B: 2.7 ± 0.7 mM → 1.7 ± 0.6 mM, t-Ca, p < 0.001). Also, group B had better metabolic recovery, as evaluated by increased myocardial oxygen consumption and increased lactate flux. Thus, terminal nicorandil-Mg cardioplegia improved myocardial blood flow, which in turn markedly improved tissue acidosis, thereby reducing the extent of reperfusion injury.

Left ventricular function in the early postoperative stage--cardioplegic baneful effect is lost in the first 24 hours.

Early postoperative left ventricular function was investigated in 42 patients with left ventricular volume overload caused by valvular regurgitation. Preoperatively, left ventricular contractile function, stroke work and stress relations were all evaluated. Anoxic index (AnI) was considered as an index of myocardial preservation. Postoperatively, the cardiac function was estimated as the left ventricular stroke work index (SWI) after 3, 6, 24 and 48 hours of post-cardiopulmonary bypass. The release of CK-MB isoenzyme was also measured at the same time as an indication of myocardial injury. AnI and the postoperative SWI3 and SWI6 showed negative correlations in 6 hours, while preoperative SWI0 and postoperative SWI24 and SWI48 showed positive correlations after 24 hours, and SWI0 showed positive or negative correlations to the preoperative 8 parameters. It was observed that ejection fraction, end-systolic wall stress to end-systolic volume index ratio and tension volume ejection showed positive, while left ventricular end-diastolic pressure showed negative correlations to SWI48. However, none of these indexes showed any significant correlations during the first 24 hours following surgery. On the other hand, AnI and the total release of CK-MB isoenzyme showed a positive correlation. These data suggest that the cardioplegic baneful effect on cardiac function might be lost in the first 24 hours after surgery.

Squamous cell carcinoma of the lung in association with sarcoidosis.

A 76-year-old man who was known to have sarcoidosis, developed a lung tumor. He had previously undergone cardiac and abdominal vascular surgery, at which sarcoidosis was confirmed by lymph node biopsy. A right lower lobectomy was carried out. Postoperative pathology showed limited disease, but cancer recurred 1 year later. Issues regarding the combination of sarcoidosis and a malignant tumor are discussed.

Ross procedure for aortic insufficiency due to doubly committed subarterial ventricular septal defect in adults.

Abstract  A 52‐year‐old female, with aortic insufficiency due to doubly committed subarterial ventricular septal defect (VSD) underwent a successful surgical repair by the Ross procedure. Preoperatively, she developed congestive heart failure because of less compliance to oral medication, raising concerns regarding life‐threatening thromboembolism if she undergoes mechanical valve replacement. Despite the pulmonary autograft being defective, there were no difficulties in completing the surgery. The defect of pulmonary autograft and the VSD was closed by an expanded polytetrafluoroethylene patch. She tolerated the procedure well and now enjoys improved quality of life. We present a discussion of the indication of Ross procedure in the rare presentation of congenital heart disease, as well as several issues raised in this case.

Myocardial tissue pCO2 and calcium content during ventricular fibrillation and reperfusion periods

Forty-one patients who underwent cardiac surgery under conditions of systemic hypothermia and intermittent cold crystalloid potassium cardioplegia were studied, in order to elucidate the effects of ventricular fibrillation and reperfusion on the myocardium, by using the intramyocardial pCO2 and temperature sensor. All patients were assigned to 2 groups, namely; group A (21 cases), in which the time between the aorta declamping and defibrillation was under 10 minutes, and group B (20 cases) in which the time was over 10 minutes. In both groups A and B, myocardial pCO2 increased at the rate of 3.58±1.70 and 2.16±0.62 mmHg/min (p<0.05) after aorta declamping, respectively and the myocardial pCO2 decreased at the rate of 5.59±0.60 and 4.18±0.76 mmHg/min (p<0.05) after defibrillation, respectively. In group A, the myocardial calcium content, pre-CPB (cardio pulmonary bypass) was 10.98±1.62 nmol/mg/dry weight and at the time of aorta declamping it was 15.90±1.81 nmol/mg/dry weight (p<0.05). In group B, the myocardial calcium content, pre-CPB, was 14.62±2.15 nmol/mg/dry weight and at the time of aorta declamping it was 18.23±4.36 nmol/mg/dry weight (p<0.05). At both three and dix hours after the operation, the left ventricular work index per minute (LVWI) in group A showed better cardiac pump function than that in group B. We therefore conclude that when reperfusion is encountered, acidosis can be minimized by prompt defibrillation.

Intramural bronchogenic cyst of the oesophagus

Bronchogenic cysts are relatively common mediastinal cysts. Here, we report removal of a rare paraoesophageal-type bronchogenic cyst by video-assisted thoracoscopic surgery in a 52-year-old male patient. The defect of the oesophageal wall was successfully reinforced with an intercostal muscle flap.