Akio Ohtaki

Abdominal Aortic Dilatation in Japanese Residents.

The correlation between abdominal aortic dilatation and arteriosclerotic risk factors was studied in 2514 Japanese residents (947 men, 1567 women, mean age 70 years old). The aortic diameter was measured by ultrasound and an aortic dilatation was defined as above 30 mm in diameter, including abdominal aortic aneurysm (AAA). Forty-three (1.7%) patients with a dilated aorta and 2471 with a normal-sized aorta were compared. Abdominal aortic dilatation was significantly (p<0.01) more frequent in men than in women (3% vs 0.7%). Obesity and hyperlipidemia were slightly (p<0.1) more frequent in patients with a dilated aorta than in those with a normal-sized aorta. There were no significant differences between the two groups in mean age, frequency of smoking, diabetes mellitus, and coronary artery disease. In conclusion, male obesity and hyperlipidemia may be risk factors for aortic dilatation in Japan. Women may not be screened because of cost-effectiveness. The prevalence of aortic dilatation in Japan was lower than in European countries. However, screening for AAA using ultrasound would be advantageous when considering the grave prognoses of ruptured AAA.

PEEP Therapy for Patients With Pleurotomy During Coronary Artery Bypass Grafting

Abstract Severe pulmonary oxygenation impairment resulting from peripheral lung atelectasis occurred in some patients with pleurotomy during the harvest of the internal mammary artery graft followed by coronary artery bypass grafting (CABG). We studied the efficacy of intraoperative positive end‐expiratory airway pressure (PEEP) therapy for the prevention of postoperative pulmonary oxygenation impairment. A total of 66 patients with solitary CABG procedure were included in this study. The pleural cavity was intraoperatively opened in 44 patients and not opened in 22. PEEP therapy was not used in any patient before May 1996 (referred to herein as the former period) and was used more recently in eight patients with pleurotomy (referred to herein as the latter period). PEEP was initiated immediately after pleurotomy during the harvest of the internal mammary artery graft. Without PEEP therapy, values of PaO2, A‐aDO2, and respiratory index (RI) were worse in patients with pleurotomy than in those without pleurotomy. Meanwhile, there were no major differences in these values between patients with or without pleurotomy after the induction of PEEP therapy. Respiratory insufficiency (A‐aDO2 > 400 mmHg and RI > 1.5) was detected in six patients with pleurotomy in the former period. Three of these six patients required over 1 week of long‐term mechanical respiratory support. No respiratory insufficiency occurred in patients of the latter period. In conclusion, PEEP therapy, which is initiated just after pleurotomy, may prevent oxygen impairment and pulmonary atelectasis after extracorporeal circulation (ECC) and is recommended for patients with pleurotomy, especially for patients with preoperative low respiratory function.

Use of ultrasound-guided percutaneous needle biopsy in the diagnosis of mediastinal tumors

We herein report the usefulness of ultrasoundguided percutaneous needle biopsy for histological diagnosis in 18 patients with mediastinal tumors. Computed tomography revealed these tumors to be in contact with the chest wall. The preoperative diagnosis was thymoma in 7 patients, germinoma in 5, neurogenic tumor in 3, and “other” in 3. The most commonly encountered indication for an ultrasound-guided percutaneous needle biopsy was an anterior mediastinal lesion (78%; 14 of 18 patients). In 16 (89%) of the 18 patients, the biopsy diagnosis corresponded to the post-operative diagnosis. No complications were encountered in any of the patients. This new technique of ultrasound-guided percutaneous needle biopsy is both relatively simple and highly accurate and may thus be useful for outpatients. Preoperative ultrasound-guided percutaneous needle biopsy is thus considered to be a safe and reliable method for the histological diagnosis of mediastinal tumors, and a good alternative to traditional biopsy techniques such as mediastinoscopy or thoracotomy.

Intratracheal Stent Intubation under Extracorporeal Lung Assist

An artificial stent was intubated using extracorporeal lung assist (ECLA) in two patients with inoperable tracheal stenosis. In a patient with an endotracheal tumor, an airway obstruction due to a partial stent collapse was overcome by an immediate ECLA perfusion. In another patient with chronic inflammatory tracheal stenosis, a repetitive balloon dilation of the trachea could be safely performed utilizing ECLA perfusion. Preventive femoral cannulation, employing the assistance of an ECLA circuit, is thus considered to be a safe and effective procedure for the treatment of inoperable tracheal stenosis.

Left ventricular fibroma in an aged patient: Report of a case

We report herein the case of a 77-year-old man with a left ventricular tumor originating from the papillary muscle of the left ventricular wall, in whom a successful tumor resection with mitral valve replacement was performed. The pathological diagnosis of the tumor was confirmed as cardiac fibroma. His postoperative course was uneventful and he is currently well with no signs of recurrence 2 years after surgery.

Thoracoscopic Closure of a Congenital Partial Pericardial Defect

We describe our technique for performing direct thoracoscopic closure of a congenital partial pericardial defect, which was successfully employed in a 15-year-old boy. This is the first such report of a procedure that is noninvasive and may therefore become the treatment of choice for patients with a small congenital pericardial defect.

Arterial embolization as preoperative treatment for pulmonary aspergillosis with hemoptysis

Pulmonary aspergillosis associated with old tuberculosis is generally resistant to treatment. Thus, if patients are treated only with conservative therapy, their condition continues to deteriorate due to repetitive hemoptysis, and may even become critical. Surgical treatment is required for these patients; however, it is extremely difficult to resect the lesion due to severe adhesions to the chest wall and vascular proliferation surrounding the lesion. We performed preoperative arterial embolization, achieving good results in three patients with hemoptysis caused by pulmonary aspergillosis. The feeding arteries were embolized using microcoils and/or gelatin sponges, and a lobectomy was safely carried out in all patients. We concluded that preoperative arterial embolization is a safe and effective technique to prevent massive hemorrhage occurring at the time of surgery.

Obesity and postoperative oxygenation after coronary artery bypass grafting.

OBJECTIVE The relationship between obesity and postoperative oxygenation after coronary artery bypass grafting was studied. METHODS Subjects were 68 patients undergoing solitary coronary artery bypass grafting--49 men and 19 women with a mean age of 64 years--divided into 3 groups by body mass index: group L with a body mass index of < 20 kg/m2 (n = 10), group M with a 20 < or = body mass index < 25 (n = 46), and group H with a 25 < or = body mass index (n = 12). Perioperative oxygenation was evaluated using respiratory indices measured preoperatively and 3 and 15 hours postoperatively. RESULTS Postoperative respiratory indices significantly increased from 0.23 to 0.67 (p < 0.001) at 3 hours and to 0.97 (p < 0.01) at 15 hours postoperatively in group L, from 0.27 to 0.80 (p < 0.001) and to 0.94 in group M, and from 0.31 to 1.39 (p < 0.001) and to 1.45 in group H. The postoperative respiratory index in group H was significantly higher (p < 0.01) than that in groups M and L both at 3 and 15 hours postoperatively. Multivariate analysis showed that the coefficients of determination of body mass index to postoperative respiratory index, 23% at 3 hours and 16% at 15 hours postoperatively, were the highest among perioperative factors. CONCLUSIONS Obesity is a major factor impairing postoperative oxygenation. Careful management in a semirecumbent position and/or nasal intermittent positive pressure ventilation may thus be required in obese patients.

Changes in gastric intramucosal pH and circulating blood volume following coronary artery bypass grafting

Purpose: To determine the changes in gastric intramucosal pH (pHi) following coronary artery bypass grafting (CABG) in comparison with systemic hemodynamic variables and circulating blood volume (BVc).Methods: Twenty patients who underwent CABG under mild hypothermic cardiopulmonary bypass (CPB) were included. Hemodynamic variables and the values of pHi were obtained at 3, 6, 12 and 24 hr after admission to the intensive care unit (ICU). The pHi was measured by gastric tonometric catheter. The BVc was measured by carbon monoxide (CO)-labeled hemoglobin (CO-Hb) dilution method (CO method) at 6 and 24 hr after ICU admission.Results: Systemic vascular resistance index (SVRI) and pulmonary vascular resistance index (PVRI) decreased with time. Systemic oxygen delivery index (DO2I) and systemic oxygen consumption index (VO2I) showed a gradual increase during the study period. By contrast, pHi decreased to the lowest value (7.26±0.05) at six hours and returned to normal levels (7.34±0.04) at 24 hr after ICU admission. Changes in BVc between six and 24 hr ranged from −242 ml to 978 ml (mean, 334±338 ml). The pHi increased in patients whose BVc increased by >300 ml. Mean fluid balance was negative in this period (−386±667 ml; range, −1786− + 423 ml).Conclusion: The pHi showed the lowest value at six hours and returned to normal at 24 hr after ICU admission. The pHi increased with the decrease in vascular resistance and with the increases in BVc in this period. The improvement of pHi, an indicator of splanchnic perfusion, appears to be related to systemic vasodilatation and an increase in BVc.RésuméObjectif: Déterminer les changements de pH gastrique intramuqueux (pHi) qui suivent un pontage aortocoronarien, comparés aux variables hémodynamiques générales et au volume sanguin circulant (VSc).Méthode: Vingt patients qui ont subi un pontage aortocoronarien sous circulation extracorporelle (CEC) légèrement hypothermique ont participé à l’étude. Les variables hémodynamiques et le pHi ont été mesurés à 3, 6, 12 et 24 h après l’admission à l’unité des soins intensifs (USI). La mesure du pHi a été faite avec un cathéter gastrique tonométrique. Le VSc a été mesuré par la méthode de dilution de l’hémoglobine marquée à l’oxyde de carbone (CO-Hb), à 6 et à 24 h après l’admission à l’USI.Résultats: L’indice de résistance vasculaire générale (IRVG) et l’indice de résistance vasculaire pulmonaire (IRVP) ont baissé en fonction du temps. L’indice de distribution d’oxygène générale (DO2I) et l’indice de consommation d’oxygène générale (VO2I) ont affiché une augmentation graduelle pendant l’étude. Par ailleurs, le pHi a présenté sa plus basse valeur (7,26±0,05) à six heures et est revenu à la normale (7,34±0,04) à 24 h après l’admission à l’USI. Le VSc s’est modifié entre 6 et 24 h, de −242 ml à 978 ml (moyenne, 334±338 ml). Le pHi s’est élevé chez les patients dont le VSc a augmenté de > 300 ml. Le bilan hydrique moyen a été négatif pendant cette période (−386±667 ml; limites, −1786− +423 ml).Conclusion: Le pHi le plus bas a été noté à 6 h et est revenu à la normale à 24 h après l’admission à l’USI. Le pHi a augmenté selon la baisse de résistance vasculaire et l’augmentation du VSc pendant ce temps. L’amélioration du pHi, un indicateur de perfusion splanchnique, semble relié à une vasodilatation générale et à une augmentation du VSc.

Effect of short-term coronary perfusion after cold storage for long-term heart preservation: a comparative study of University of Wisconsin solution and diluted blood as the perfusate.

THE DURATION of preservation is currently limited to 4 to 6 hours in clinical heart transplantation. Extending the period of preservation could expand the available donor pool. We previously attempted to combine simple cold storage and coronary perfusion and reported that additional coronary perfusion after cold storage was useful for myocardial protection and improved graft viability. In this study, we compared two different solutions as the perfusate, which was assessed through preservation and transplantation.