Shigeo Yamaki

Quantitative analysis of pulmonary vascular disease in simple cardiac anomalies with the Down syndrome.

Intimal changes and medial thickness of small pulmonary arteries were morphometrically examined in 21 cases of simple cardiac anomalies with the Down syndrome, and their correlations with age and with pulmonary arterial peak pressure were then compared with those of 20 cases of simple cardiac anomalies without the Down syndrome and 17 cases of complete transposition of the great arteries (TGA). Results indicate that (1) intimal changes developed at an earlier age in patients with simple cardiac anomalies and the Down syndrome than in those without the Down syndrome, (2) the intimal changes were more severe than those in simple cardiac anomalies without the Down syndrome at the same level of pulmonary arterial pressure and milder than those in TGA, and (3) the media of small pulmonary arteries in simple cardiac anomalies with the Down syndrome was thinner than the media in cases without the syndrome at the same radius and the same level of pulmonary arterial pressure but thicker than the media in TGA. Retarded development of medial hypertrophy in the Down syndrome or TGA in response to pulmonary hypertension appears to make the pulmonary arteries susceptible to even moderate pressure load and appears to be responsible for early development of severe intimal changes.

Pulmonary Vascular Changes Induced by Congenital Obstruction of Pulmonary Venous Return

BACKGROUND Pulmonary venous obstruction (PVO) induces pulmonary arterial hypertension, as well as pulmonary venous hypertension, and jeopardizes the repair of cardiac lesions. METHODS Four cases of congenital mitral stenosis and 4 cases of cor triatriatum (Lucas type A), ages ranging from 2 months to 16 years, were histologically examined on pulmonary vasculature. Histometrical analysis was performed on medial thickness and intimal changes of both pulmonary arteries and veins. For comparison, the examination of pulmonary vasculature in ventricular septal defect (VSD) cases was also performed. RESULTS Medial thickening and intimal fibrosis, in both pulmonary arteries and veins with widespread lymphangiectasia, were characteristic vascular changes of PVO cases. Medial thickness of pulmonary arteries was correlated with preoperative pulmonary arterial pressure (PAP) (r = 0.77, p = 0.03 for systolic PAP), and greater than that of VSD cases. Medial thickness of pulmonary veins was also greater in PVO cases. Intimal fibrosis of pulmonary arteries and veins was seen extensively at the advanced ages, whereas no plexiform lesions or more advanced stages of pulmonary vascular disease were present. CONCLUSIONS Congenital PVO induced progressive medial thickening and intimal fibrosis in pulmonary arteries and veins accompanied by lymphangiectasia. However, no plexiform lesions or more advanced stages of pulmonary vascular disease were present, which may explain the reversibility of pulmonary hypertension due to congenital PVO.

Pulmonary arterial changes in patients dying after a modified Fontan procedure following pulmonary artery banding

SummaryPulmonary arterial changes were histometrically analyzed in four cases of postoperative death following a modified Fontan procedure in which pulmonary artery banding had previously been performed because of pulmonary hypertension. Case 1 was a 3-year-old girl with corrected transposition of the great arteries (TGA), ventricular septal defect, and double-inlet left ventricle; case 2 was a 6-year-old girl with single ventricle (SV) and complete TGA; case 3 was a 25-month-old boy with SV and doubleoutlet right ventricle; and case 4 was a 21-year-old man with tricuspid atresia. The cause of death in cases 1, 2, and 3 was pulmonary hypertensive crisis due to postoperative vasoconstriction of the small pulmonary arteries. Medial hypertrophy remained in half of the preacinar small pulmonary arteries although it was not observed in all the intraacinar arteries in cases 1 and 2, even after banding. The postoperative course of case 4 was uneventful despite multiple thromboembolism in the small pulmonary arteries. However, the patient died due to a thrombosed artificial valve. The results suggest that residual medial hypertrophy of the small pulmonary arteries was a major risk factor in these cases. Lung biopsy is recommended to determine the indications for the Fontan procedure in these hemodynamically critical cases.

Quantitative evaluation of hypertensive pulmonary arterial change.

A new method to quantitatively evaluate pulmonary arterial change in pulmonary hypertension is presented in this paper. Hypertensive pulmonary arterial changes are classified into four grades according to severity and a score from 1 to 4 is given to each arterial change according to the grading. An index of pulmonary vascular disease is then defined as a relative mean value of all scores. It is concluded that this index accurately expresses the grade of pulmonary arterial change in the whole pulmonary arterial system in any given case and makes possible a detailed statistical analysis of large numbers of cases.

Quantitative analysis of postoperative changes in the pulmonary vasculature of patients with complete transposition of the great arteries and pulmonary hypertension

Postoperative changes in the medial thickness of the small pulmonary arteries and the degree of pulmonary vascular disease were estimated histometrically and histopathologically in three cases of late death after total correction of complete transposition of the great arteries with large ventricular septal defect and pulmonary hypertension. In the postoperative course of two of the three cases extreme medial hypertrophy of the small pulmonary arteries as well as severe pulmonary vascular disease were found. In the third case, the thickening of the media was mild and pulmonary vascular disease had not progressed owing to a residual ventricular septal defect. Examination of three additional cases of late death and 15 autopsy cases of complete transposition of the great arteries revealed that hypertrophy of pulmonary arterial media after radical surgery for complete transposition of the great arteries is a common phenomenon. In cases of complete transposition of the great arteries with severe pulmonary hypertension, the deveopment of marked hypertrophy of the media accompanied by pulmonary vascular disease after total correction is usually seen and seems to be the most likely cause of death in the postoperative period.

Pulmonary Vascular Changes Induced by Unilateral Pulmonary Venous Obstruction

AbstractThe relation of pulmonary hemodynamics to pathological change in the pulmonary vasculature was examined in a model of unilateral pulmonary venous (PV) obstruction. The left upper pulmonary vein (A group, n=6) or both the left upper and left lower pulmonary veins (B group, n=6) of two-week-old piglets were banded; the control group (n=6) was sham operated. At eight weeks after PV banding, mean pulmonary arterial pressure was highest in the B group, intermediate in the A group and lowest in the control group. In all groups, the media of the pulmonary artery was equally thickened in both lungs, whereas the media of the pulmonary vein was thickened only in those lung lobes having stenotic pulmonary veins. For all animals from three groups, left pulmonary arterial wedge pressure (PAWP) correlated with medial thickness of the pulmonary arteries of the right lung (r=0.76, p=0.003), the left upper lobe (r=0.54, p<0.03), the left lower lobe (r=0.49, p=0.04). This finding suggests that the pathogenesis of PAWP-related medial thickening of the bilateral lung pulmonary artery begins with the sensing by the bilateral lung of PV pressure buildup in the unilateral lung.

Surgical indication for congenital heart disease with extremely thickened media of small pulmonary arteries

BACKGROUND Nineteen patients (mean age, 7.6 months) with a percent wall thickness of more than 33% in the small pulmonary arteries were found to have extremely thickened media. Based on our findings, a criterion of operative indication is proposed. METHODS The percentage of extremely thickened media of small pulmonary arteries for all pulmonary arteries was determined on microscopic lung sections and was introduced as an index for operative indication. RESULTS Operative repair was performed in 16 patients: 9 died intraoperatively and 7 survived more than 12 months. In 4 of 5 patients that had pulmonary artery banding, medial hypertrophy remained despite pulmonary artery banding. Operative repair also had no positive effect. In operative and late deaths and in survivors without a decrease of pulmonary arterial pressure, the percentage of extremely thickened media of small pulmonary arteries was shown to be more than 10%, whereas in 5 survivors and 1 operative death with a significant postoperative decrease of pulmonary arterial pressure, the value was less than 7%. CONCLUSIONS If a patient has less than 7% of small pulmonary arteries with extremely thickened media, operative repair is likely to be effective. When the value is higher than 10%, not only operative repair but also pulmonary artery banding cannot be recommended because of ineffectiveness and hazard.

Inoperable Pulmonary Vascular Disease in Infants With Congenital Heart Disease

BACKGROUND Among 120 infants less than 12 months of age who had lung biopsy and autopsy, 20 were inoperable because of severe irreversible pulmonary vascular disease. METHODS The infants were classified into three groups. Group 1 comprised 6 patients who showed complete obstruction of the small pulmonary arterial lumen and atrophy of the peripheral arterial media and who were considered to have absolute operative contraindications. Group 2 comprised 6 patients who had no pathologic findings of absolute operative contraindication and had an index of pulmonary vascular disease of more than 2.2. They were isolated as having advanced plexogenic pulmonary arteriopathy. Group 3 comprised 8 patients who had extremely thickened media of small pulmonary arteries, with abnormally thickened media extending into the small peripheral arteries characterized by extremely narrow lumina and medial thickness exceeding luminal diameter. RESULTS Six of the 9 patients in whom operative repair was abandoned on the basis of preoperative or intraoperative lung biopsy are still alive. Of the 11 patients who underwent operation without biopsy, none survived. CONCLUSIONS Preoperative or intraoperative lung biopsy and assessment of arteriopathy based on the above criteria are recommended in all patients in whom fatal pulmonary vascular disease is suspected.

Hypoplasia of the small pulmonary arteries in total anomalous pulmonary venous connection with obstructed pulmonary venous drainage

OBJECTIVE Preoperative pulmonary venous obstruction has been reported to be a risk factor negatively impacting survival in total anomalous pulmonary venous connection. We examined lung tissue from total anomalous pulmonary venous connection patients with pulmonary venous obstruction and demonstrated hypoplasia of small pulmonary arteries to elucidate the mechanism underlying the poor outcome. METHODS Ten total anomalous pulmonary venous connection patients with preoperative pulmonary venous obstruction between the ages of 2 days and 10 months were studied. As histological parameters, we assessed the size of small pulmonary arteries in relation to the size of accompanying bronchioles to identify small pulmonary artery underdevelopment. Other parameters, such as the radial alveolar count, which reflects alveolar maturity, intimal lesions, lymphangiectasia, and the medial thickness of small pulmonary arteries and small pulmonary veins, were also examined. As a control group, we examined 24 autopsy cases with no congenital heart or pulmonary disease. RESULTS When the radius of the accompanying bronchiole was 100 microm, the radius of small pulmonary artery in the control group was found to enlarge for the first 2 months and then remain stable at approximately 80 microm from 2 to 10 months. In total anomalous pulmonary venous connection with preoperative pulmonary venous obstruction, the radius was significantly lower than in the control (47.0 +/- 21.8 microm versus 75.9 +/- 9.8 microm, P <.001), and the difference between dead and surviving patients was significant at P <.001 (33.0 +/- 14.6 microm versus 68.2 +/- 9.2 microm). Examination of the alveoli yielded an radial alveolar count of 4.6 +/- 1.5 in the control group and 4.4 +/- 0.8 in the total anomalous pulmonary venous connection patients, and the difference was not significant (P =.71). CONCLUSIONS The small pulmonary arteries of total anomalous pulmonary venous connection patients with preoperative pulmonary venous obstruction were underdeveloped compared with controls but their alveolae were not hypoplastic. These results suggested that the small pulmonary artery hypoplasia may be responsible for the poor outcome of these patients.

Pulmonary vascular disease associated with pulmonary hypertension in 445 patients: diagnosis from lung biopsy and autopsy

PurposeDiagnosis from lung biopsy or autopsy was performed in 445 patients with congenital (385) or acquired (60) heart disease from all over Japan. The purpose of this study is the presentation of these prospective data collections.MethodsOf the patients with congenital heart disease, 354 were biopsied to determine whether surgery was indicated. Decisions regarding surgery were based on the index of pulmonary vascular disease in simple cardiac anomalies or atrioventricular septal defects (AVSD). In total anomalous pulmonary venous connection (TAPVC), operative indication was determined by the degree of hypoplasia of small pulmonary arteries. Operability of Fontan procedure was based on the degree of residual medial hypertrophy after pulmonary artery banding.ResultsIn patients with simple cardiac anomalies, radical surgery was indicated in 166. Radical surgery was indicated in 50 patients with AVSD. In 26 patients with TAPVC, radical surgery was not indicated in 10. In 68 Fontan candidates, surgery was not indicated in 49. Among 7 patients with tetralogy of Fallot, 1 was not a surgical candidate. Of the 60 acquired heart disease patients, 16 had idiopathic pulmonary arterial hypertension and 36 had chronic thromboembolic pulmonary hypertension. In 6 patients, lung biopsy revealed pulmonary veno-occlusive disease; 2 patients had combined valvular disease.ConclusionThe cardiac surgeon, pediatric cardiologist, and cardiologist who requested diagnosis from lung biopsy or autopsy were gratified with the results.