Histopathological study of carcinoma showing thymus-like differentiation (CASTLE).

INTRODUCTION: Carcinoma showing thymus-like differentiation (CASTLE) is a rare tumour that mainly arises from the thyroid gland, or occasionally, from the head and neck. Although the 10-year survival rate of patients with CASTLE is approximately 80%, local recurrence and distant metastasis are observed in some cases. A recent systematic review for CASTLE indicated that the prognostic factors are treatment-dependent, and postoperative radiotherapy significantly improves patient survival. CASE REPORT: Herein, we describe and compare three cases of CASTLE, including a case with distant metastasis despite administering postoperative chemotherapy. Thus, the mechanisms underlying metastasis of CASTLE are unclear. This case study helps to elucidate the histopathological risk factors of metastasis in CASTLE. DISCUSSION: We found that prominent lymphovascular invasion and higher proliferative activities might be risk factors of metastasis in CASTLE. In addition, we have summarised the cytological, morphological, and immunohistochemical features of CASTLE for an accurate diagnosis.

Primary solitary fibrous tumour of the prostate: A case report and literature review.

INTRODUCTION: Solitary fibrous tumour (SFT) is a rare mesenchymal tumour with intermediate malignant potential. Although this tumour arises in several sites, prostatic SFT is an extremely rare neoplasm and may prove confusing owing to the lack of clinical experience because of tumour rarity. The diagnosis may be further difficult because SFTs can manifest positive immunoreactivity for CD34 and progesterone receptor, which are known markers of prostatic stromal tumours. Herein, we describe a case of prostatic SFT that was difficult to differentiate from a prostatic stromal tumour of uncertain malignant potential because of positive immunoreactivity to CD34 and progesterone receptor. CASE REPORT: A 40-year-old Japanese man presented with lower abdominal pain. Computed tomography revealed a prostatic mass; furthermore, prostate core needle biopsy revealed proliferating bland spindle cells, without necrosis or prominent mitoses. Tumour cells were positive for CD34 and progesterone receptor on immunohistochemical analysis; thus, a prostatic stromal tumour of uncertain malignant potential was initially suspected. However, as the tumour cells showed positive immunoreactivity for STAT6, the final diagnosis was an SFT of the prostate. The patient underwent tumour resection, and at the 6-month postoperative follow-up, neither local recurrence nor distant metastasis occurred. CONCLUSION: For an accurate diagnosis of an SFT of the prostate, STAT6 immunohistochemistry should be conducted for all mesenchymal tumours of the prostate. When STAT6 immunohistochemical analysis is unfeasible, pathologists should be aware that the morphological and immunohistochemical characteristics of SFT variable from case to case and diagnose with combined analysis of several immunohistochemical markers.

Extensive first-principles molecular dynamics study on Li encapsulation into C60 and its experimental confirmation.

The aim of increasing the production ratio of endohedral C60 by impinging foreign atoms against C60 is a crucial matter of the science and technology employed towards industrialization of these functional building block materials. Among these endohedral fullerenes, Li+@C60 exhibits a wide variety of physical and chemical phenomena and has the potential to be applicable in areas spanning the medical field to photovoltaics. However, currently, Li+@C60 can be experimentally produced with only ∼1% ratio using the plasma shower method with a 30 eV kinetic energy provided to the impinging Li+ ion. From extensive first-principles molecular dynamics simulations, it is found that the maximum production ratio of Li+@C60 per hit is increased to about 5.1% (5.3%) when a Li+ ion impinges vertically on a six-membered ring of C60 with 30 eV (40 eV) kinetic energy, although many C60 molecules are damaged during this collision. On the contrary, when it impinges vertically on a six-membered ring with 10 eV kinetic energy, the production ratio remains at 1.3%, but the C60 molecules are not damaged at all. On the other hand, when the C60 is randomly oriented, the production ratio reduces to about 3.7 ± 0.5%, 3.3 ± 0.5%, and 0.2 ± 0.03% for 30 eV, 40 eV, and 10 eV kinetic energy, respectively. Based on these observations we demonstrate the possibility of increasing the production ratio by fixing six-membered rings atop C60 using the Cu(111) substrate or UV light irradiation. In order to assess the ideal experimental production ratio, the 7Li solid NMR spectroscopy measurement is also performed for the multilayer randomly oriented C60 sample irradiated by Li+ using the plasma shower method combined with inductively coupled plasma atomic emission spectroscopy (ICP-AES). Time-of-flight mass spectroscopy measurements are also performed to cross check whether Li+@C60 molecules are produced in the sample. The resulting experimental estimate, 4% for 30 eV incident kinetic energy, fully agrees with our simulation results mentioned above, suggesting the consistency and accuracy of our simulations and experiments.

Transcription-reverse transcription concerted reaction and minimal residual disease in axillary sentinel nodes of breast cancer.

AIMS: To investigate the use of transcription-reverse transcription concerted reaction (TRC) to detect axillary lymph node metastases. METHODS: Metastases in 423 lymph nodes obtained from 50 breast cancer patients were investigated by routine pathological hematoxylin and eosin (H and E) staining and quantitative analysis of carcinoembryonic antigen (CEA) mRNA by TRC. Enhanced pathological studies, serial sectioning and immunohistochemistry were conducted for cases which were negative by routine pathology, but positive by TRC. RESULTS: Pathological examination identified metastatic disease in 67 lymph nodes. TRC CEA mRNA results were concordant with 89.8% of these cases at a threshold of 100 copies. TRC identified 30 false negative nodes, which was reduced to 15 by excluding node biopsies yielding less than 40 microg total RNA. Twelve nodes were histologically negative for cancer, but positive according to TRC. Serial sectioning and immunohistochemical analysis of these nodes revealed macrometastatic lesions in three, micrometastasis in one, and isolated tumor cells in two. CONCLUSION: TRC for the detection of CEA mRNA may complement routine pathological examination by sentinel lymph node biopsy (SNB) in early breast cancer. We have started an enhanced pathological examination with serial sectioning on all excised sentinel nodes to set the best threshold for the TRC method.

Pulmonary vein isolation under direct visual identification of the left atrium-pulmonary vein junction using intra-cardiac echography.

INTRODUCTION: Intra-cardiac echocardiography (ICE) which has some benefits, can be used to obtain detailed anatomy of the heart chambers or large vessels, and the catheter positions, and it has been considered useful for improving the outcome of the ablation. In the present study, we performed pulmonary vein isolation (PVI) under real time monitoring of ICE imaging utilizing an ICE catheter placed at the junction of the left atrium (LA) and PVs (LA-PV junction). METHODS: PVI for atrial fibrillation (AF) was performed in 30 cases with drug-resistant AF (mean age: 66-years-old; including 22 males). An ICE catheter utilizing a 9 MHz frequency was inserted into the LA via the atrial septum, and placed at the LA-PV junction. Circumferential ablation was performed in the LA outside of the PV ostium, encircling both the superior and inferior ostia together under ICE imaging. RESULTS: The anatomy of the LA to the PVs and catheter sites were clearly identified by the ICE during the procedure, which enabled a precise and safe catheter manipulation with minimal fluoroscopy. Further, the wall thickness of the PV and LA, and position of the esophagus could be obtained by ICE, facilitating care in adjusting the power and/or duration of the current delivery. CONCLUSION: ICE imaging of the LA-PV junction permitted real time monitoring of the target sites for PVI during the ablation procedure, and was considered a useful technique for performing PVI.

Relations of preoperative hemodynamics and coronary blood flow to improved left ventricular function after valve replacement for aortic regurgitation.

In this study of the limits of reversibility of left ventricular function after aortic valve replacement for aortic regurgitation, measurements were made of pre- and postoperative coronary blood flow and left ventricular volumes. Eighteen patients who had undergone aortic valve replacement for pure aortic regurgitation using the Björk-Shiley valve or the Bicerval valve were restudied an average of 8 +/- 3 months after surgery. Postoperative left ventricular end-systolic and end-diastolic volumes returned to near normal values. The slight left ventricular wall thickening apparent before surgery remained unchanged after surgery and, consequently, left ventricular mass, though somewhat reduced, remained abnormally high. Ejection fraction, which was low preoperatively, returned to normal postoperatively. Total coronary sinus blood flow decreased after surgery, but coronary sinus blood flow per 100 g of left ventricular mass increased. This recovery of coronary flow per unit mass was believed to cause the improvement in left ventricular function. A significant correlation was found between postoperative systolic function and preoperative left ventricular end-systolic and end-diastolic volumes, wall thickness and, especially, left ventricular mass, the latter indicating that, if preoperative left ventricular mass is less than 350 g/m2, postoperative improvement of systolic function is attainable. Another significant correlation was indicated by measurements of coronary sinus blood flow per 100 g of left ventricular mass. If this is greater than 35 ml/min before surgery, a postoperative improvement in systolic function to within the normal range may be expected.

Clinical results and in vivo valve function after implantation of a Bicer valve prosthesis in the aortic position.

Between December 1981 and June 1987, 71 patients underwent aortic valve replacement with a Bicer monostrut tilting disc prosthesis. Clinical results and in vivo function of the artificial valve were assessed. The average age of the 71 patients at the time of operation was 51.3 +/- 11.5 years. The hospital mortality rate was 2.8% (two patients) and there were no further deaths during a mean (+/- SD) follow-up period of 2.4 +/- 1.6 years (range 1 month to 5.5 years) after surgery. There was also no occurrence of thromboembolism or valve dysfunction. Function of the Bicer valve prosthesis was assessed in 17 patients: 5 with a 21 mm valve, 7 with a 23 mm valve and 5 with a 25 mm valve. Examination was performed on average 10.3 +/- 8.1 months after surgery. Valve function was examined at rest and during exercise performed with a bicycle ergometer. Pressure gradients at rest were low: 21 mm valve = 8 mm Hg, 23 mm valve = 3 mm Hg and 25 mm valve = 2 mm Hg; the gradients during exercise were 11, 8 and 8 mm Hg, respectively. The valves had the following effective orifice area at rest: 21 mm valve = 1.54 cm2, 23 mm valve = 4.20 cm2 and 25 mm valve = 3.76 cm2; during exercise, the respective areas were 1.57, 3.48 and 3.01 cm2. These valves are deemed to be sufficiently wide for effective valve function. Aortographic observation indicated mild regurgitation that was within reasonable limits and posed no problem.(ABSTRACT TRUNCATED AT 250 WORDS)

Significance of coupling device for vessel anastomosis in esophageal reconstruction.

BACKGROUND/AIMS: To prevent an anastomotic failure due to impaired blood supply, several trials have been performed such as preoperative ischemic conditioning by transarterial embolization of the left gastric, right gastric and splenic arteries or microvascular anastomosis. We assess the significance of an automatic anastomotic coupling device for vessel anastomosis, which we have continuously utilized, to simplify the task and shorten the anastomotic time since March 1999. METHODOLOGY: 8 patients who underwent venous anastomosis by an automatic anastomotic coupling device were evaluated for the time of anastomosis, total ischemic time and outcomes. RESULTS: Venous anastomosis was completed within 5 minutes on average. Microscopic arterial anastomosis by hand took 35 minutes on average. For gastric tube reconstruction, venous anastomosis by an automatic coupling device took only 5 minutes. The top of the gastric tube showed congestion before venous anastomosis, but rapidly recovered from it after anastomosis. Postoperative endoscopic observation of the mucosal color of the replaced intestine or gastric tube was started 3 days after surgery and revealed no ischemia or congestion. The postoperative course was uneventful except one case suffering from pneumonia but leakage was not observed in any case. CONCLUSION: An automatic anastomotic coupling device can perform an easy and reliable vascular anastomosis for patients who undergo esophageal reconstruction. The device may shorten the operating time and consequently the ischemic time of the gastric tube or jejunal or colonic graft, which in turn may lead to a decrease of complications.

[Congenital cystic adenomatoid malformation detected by prenatal sonography; report of 2 cases].

We report 2 cases of congenital cystic adenomatoid malformation (CCAM) detected by prenatal sonography. The first CCAM was diagnosed by fetal sonography in a female fetus at 30 weeks' gestation. The infant was born at 37 weeks' gestation, with a body weight of 2,770 g. After birth, chest computed tomography (CT) showed a multicystic mass in the middle lobe of the lung. She remained asymptomatic until age 21 months, when she suffered pneumonia. Two months later, middle lobectomy was performed. The second CCAM was diagnosed by fetal sonography in a female fetus at 25 weeks' gestation. She was born at 39 weeks' gestation, with a body weight of 3,292 g. Four days after birth, CCAM type II was diagnosed by chest CT. The infant was asymptomatic, and left lower lobectomy was performed 11 months after birth.

Compensation techniques in NIRS proton beam radiotherapy.

Proton beam has the dose distribution advantage in radiation therapy, although it has little advantage in biological effects. One of the best advantages is its sharp fall off of dose after the peak. With proton beam, therefore, the dose can be given just to cover a target volume and potentially no dose is delivered thereafter in the beam direction. To utilize this advantage, bolus techniques in conjunction with CT scanning are employed in NIRS proton beam radiation therapy planning. A patient receives CT scanning first so that the target volume can be clearly marked and the radiation direction and fixation method can be determined. At the same time bolus dimensions are calculated. The bolus frames are made with dental paraffin sheets according to the dimensions. The paraffin frame is replaced with dental resin. Alginate (a dental impression material with favorable physical density and skin surface contact) is now employed for the bolus material. With fixation device and bolus on, which are constructed individually, the patient receives CT scanning again prior to a proton beam treatment in order to prove the devices are suitable. Alginate has to be poured into the frame right before each treatments. Further investigations are required to find better bolus materials and easier construction methods.

Biophysical characteristics of HIMAC clinical irradiation system for heavy-ion radiation therapy.

PURPOSE: The irradiation system and biophysical characteristics of carbon beams are examined regarding radiation therapy. METHODS AND MATERIALS: An irradiation system was developed for heavy-ion radiotherapy. Wobbler magnets and a scatterer were used for flattening the radiation field. A patient-positioning system using X ray and image intensifiers was also installed in the irradiation system. The depth-dose distributions of the carbon beams were modified to make a spread-out Bragg peak, which was designed based on the biophysical characteristics of monoenergetic beams. A dosimetry system for heavy-ion radiotherapy was established to deliver heavy-ion doses safely to the patients according to the treatment planning. A carbon beam of 80 keV/microm in the spread-out Bragg peak was found to be equivalent in biological responses to the neutron beam that is produced at cyclotron facility in National Institute Radiological Sciences (NIRS) by bombarding 30-MeV deuteron beam on beryllium target. The fractionation schedule of the NIRS neutron therapy was adapted for the first clinical trials using carbon beams. RESULTS: Carbon beams, 290, 350, and 400 MeV/u, were used for a clinical trial from June of 1994. Over 300 patients have already been treated by this irradiation system by the end of 1997.

Surgery for coronary heart disease due to mucocutaneous lymph node syndrome (Kawasaki disease). Report of 6 patients.

Early and late surgical results in 6 patients with coronary heart disease secondary to mucocutaneous lymph node syndrome (MLNS) (Kawasaki disease) are presented. There were 5 male patients and 1 female patient, ranging in age from 2.5 to 26 years at the time of operation. They had severe coronary artery narrowings, obstructions, and aneurysms with or without mitral regurgitation. Previous myocardial infarction was documented in 5 patients. Aortocoronary bypass grafting utilizing the autologous saphenous vein was performed in 5 patients; in the remaining patient, mitral valve replacement was carried out. No operative or late deaths have been encountered. A long-term bypass graft patency was demonstrated in patients aged 26, 17, and 10 years with resulting clinical, angiographic, or scintigraphic improvements, or a combination of these. However, the graft that had been patent in a 4-year-old boy was found completely obstructed 3 years after surgery without any symptomatic changes. The formation of rich collateral channels was found. The risk of saphenous vein graft closure may be high in young growing children. In older children or adolescents, however, coronary vein bypass grafting for this specific inflammatory coronary artery lesion has been effective with long-term graft patency. Severe mitral regurgitation is also an indication for surgery, but poor left ventricular function associated with mitral regurgitation, probably secondary to myocarditis, persists after surgery and may give rise to future problems.

Galectin-3 expression in various thyroid neoplasms and its possible role in metastasis formation.

Galectin-3 is a member of the beta-galactoside-binding protein family that plays an important role in cell-cell adhesion and in cell-matrix interaction. We have examined the expression of galectin-3 in normal, adenomatous, and malignant thyroid tissues and also in metastatic lesions. Galectin-3 was rarely expressed in normal thyroid tissue but was abundant in the cytoplasm of the neoplastic lesions. Among neoplastic lesions, galectin-3 was expressed to a greater extent in follicular carcinomas than in follicular adenomas and was present in greater amounts in papillary carcinomas than in follicular adenomas or carcinomas. Primary lesions of papillary carcinoma with metastasis contained significantly higher concentrations of galectin-3 than tumors of this type without metastases. However, the expression of galectin-3 was significantly decreased in metastatic lesions in the lymph nodes compared with their primary lesions. From these results, we assumed that galectin-3 works in different ways at different stages of thyroid neoplasm proliferation. Among primary tumors, galectin-3 expression is significantly different in 3 histological types. However, the continuity of progression among these tumors is not yet proven. In later stages, decreased expression of galectin-3 may aid the release of cancer cells from the primary lesions for invasion and metastasis.

Changes in myocardial oxygen consumption and coronary sinus blood flow before and after resection of left ventricular aneurysm after myocardial infarction.

The patients in this study consisted of eight men who underwent resection of left ventricular aneurysm. Right and left heart catheterization at rest and measurement of coronary sinus blood flow by continuous thermodilution were performed preoperatively and an average of 6 months after the operation. Coronary sinus blood flow decreased significantly from 161 to 118 ml/min and myocardial oxygen consumption decreased significantly from 17.2 to 10.5 ml/min postoperatively. Cardiac index increased postoperatively. Ejection fraction increased from 0.31 to 0.49 and mean velocity of circumferential fiber shortening significantly increased from 0.53 to 1.0 circ/sec postoperatively. Left ventricular end-diastolic volume decreased significantly from 166 to 120 ml/m2 postoperatively. The mean systolic circumferential tension significantly decreased postoperatively. We believe that the decrease in wall tension postoperatively brought about the reduction in myocardial oxygen consumption. Thus the high wall tension and myocardial oxygen demand, present preoperatively, were improved postoperatively, with a resultant lowering of oxygen consumption and equivalent or better left ventricular function.

Severe mitral regurgitation due to coronary arteritis of mucocutaneous lymph node syndrome. A new surgical entity.

Case histories are reported of three patients, 1 to 4 years of age, with severe mitral regurgitation that occurred as a sequela of mucocutaneous lymph node syndrome (MCLS). These patients were found among 12 patients with coronary artery lesions such as aneurysms, narrowings, and obstructions. One of them with multiple coronary aneurysms and also severely impaired left ventricular function died of congestive heart failure in the 2 years and 7 months' follow-up period after the acute illness. The second patient, 1 year of age, had multiple coronary aneurysms and mitral regurgitation. Because of the difficulty in treating coronary artery lesions at this patient's age and also because of medically controllable mitral regurgitation at present, this patient is now under careful observation. The third patient, whose condition was complicated by inferior wall myocardial infarction due to occlusion of the right coronary artery, underwent mitral valve replacement for intractable heart failure and cardiac cachexia. This patient had slow but definite improvement postoperatively. Mitral regurgitation secondary to MCLS usually is complicated by the associated difficult coronary artery lesions and impaired left ventricular function. Although this fact causes an extra-difficult situation, mitral regurgitation consequent to MCLS is amenable to surgical treatment and this disease should now be considered as a new surgical entity.

Long-term outcome of myocardial revascularization in patients with Kawasaki coronary artery disease. A multicenter cooperative study.

The long-term outcome of myocardial revascularization by coronary artery bypass grafting in patients with severe coronary obstruction caused by Kawasaki disease is largely unknown. A multicenter follow-up study was performed in 1991. A total of 168 patients with Kawasaki disease (127 male [75.6%] and 41 female patients [24.4%]) who had undergone coronary bypass grafting were enrolled. Obstructive coronary artery disease affected the left main trunk in 11.8%, the right coronary artery in 77.6%, the left anterior descending in 87.6%, and the left circumflex in 25.9%. Old myocardial infarction was noted in 46.0% of the patients. Fifty-four patients (32%, 12.4 +/- 9.8 years) underwent bypass grafting with saphenous vein grafts alone. The remaining 114 patients (68%, 9.8 +/- 7.1 years) received at least one internal thoracic artery graft to the left anterior descending coronary artery. Gastroepiploic artery grafts were used in 12 patients. There were no significant differences between the saphenous vein and internal thoracic artery groups in the mean age at operation (12.4 versus 9.8 years), female ratio (22% versus 25%), the number of patients over 20 years of age (9.3% versus 9.6%), previous history of infarction (51.9% versus 41.2%), impaired left ventricular function (ejection fraction < 0.5) (13.0 versus 11.4%), left main trunk disease (11.1% versus 10.5%), the number of vessels involved (2.2 +/- 0.8 versus 2.0 +/- 0.6 per patient), or the mean number of grafts used (1.7 +/- 0.7 versus 1.7 +/- 0.7 per patient). The operative death rate was also the same in the two groups (1.9% versus 0%), but the late cardiac death rate was significantly higher in the saphenous vein graft group (13.0%) than in the internal thoracic artery group (0.9%) (p < 0.003). Actuarial analysis showed a significantly higher survival in the internal thoracic artery group (98.7% +/- 1.2% versus 81.6% +/- 7.0%, p < 0.05) at 90 months after the operation. Late death was strongly related to the absence of an internal thoracic artery graft (p < 0.003) and to the age at the time of operation (p < 0.05). The actuarial patency rate was significantly higher for arterial grafts (77.1% +/- 1.1%, n = 151) than for vein grafts (46.2% +/- 6.3%, n = 126) 85 months after the operation (p < 0.003). Arterial grafts were used for the non-left anterior descending coronary arteries in only 41 of 155 grafts (26.5%); in contrast, vein grafts were used in 85 of 133 grafts (63.9%) (p < 0.005 to 0.001).(ABSTRACT TRUNCATED AT 400 WORDS)

Hemodynamic assessment during exercise after left ventricular aneurysmectomy.

The exercise hemodynamics of eight patients who underwent cardiac catheterization were assessed at rest and during exercise, before and after left ventricular aneurysmectomy by the classical technique. Left ventricular end-diastolic volume increased before operation and then significantly decreased after the operation (p < 0.05). The ejection fraction increased from 0.27 before the operation to 0.46 after the operation (p < 0.01). The cardiac index, which was low before operation, increased within the normal range after operation. Mean systolic circumferential tension also decreased significantly (p < 0.01) after the operation. Thus, the indexes at rest showed improvement. Left ventricular end-diastolic pressure showed a decreasing tendency after the operation both at rest and during exercise in comparison with that before the operation. However, the difference was not significant. The stroke work index increased significantly during exercise after the operation (p < 0.05). Before the operation, the stroke work index did not increase despite the elevation of left ventricular end-diastolic pressure; however, after the operation, the stroke work index increased during exercise without much increase of left ventricular end-diastolic pressure. This indicated improvement in the Frank-Starling curve and recovery of preload reserve by the resection of the left ventricular aneurysm. Thus, an important factor for demonstrating improvement in postoperative cardiac function was clarified through its relation to exercise load.

Severe Kawasaki heart disease treated with an internal mammary artery graft in pediatric patients. A first successful report.

Two Japanese boys, 6 and 10 years old, required operation for severe Kawasaki heart disease. Both had multiple coronary arterial aneurysms and stenoses, and one had mitral regurgitation as well. The operations consisted of anastomosis between the left internal mammary artery and the left anterior descending artery and insertion of an autologous saphenous vein between the aorta and the posterior descending artery in both patients. The mitral valve was replaced in the one with mitral regurgitation. Angina pectoris has been completely relieved as confirmed by postoperative angiocardiography. Late results of coronary bypass grafting with the saphenous vein in pediatric patients with Kawasaki disease have been less than satisfactory because of the high occlusion rate of the graft. The internal mammary artery may be superior, at least theoretically, to the saphenous vein graft because it is a "living graft" with a high possibility of growing and with less susceptibility to degeneration. This is the first report of successful operation utilizing an internal mammary artery graft in coronary bypass for Kawasaki disease.

A quantitative study of postoperative luminal narrowing of the internal thoracic artery graft in coronary artery bypass surgery.

We used quantitative angiography to determine the postoperative diameter of the internal thoracic artery graft at the point close to the anastomosed site in 147 patients who received the graft for the left anterior descending coronary artery. We performed generalized multiple linear regression analysis (Type I quantification method) to assess the effects of the following factors on the internal thoracic artery graft diameter: age, gender, time of angiography, laterality of the internal thoracic artery used, presence of an undivided major side branch of the internal thoracic artery, presence of a saphenous vein graft having blood flow competition with an internal thoracic artery graft, presence of distal stenosis of the recipient left anterior descending coronary artery, severity of postoperative left anterior descending coronary artery stenosis, and presence of coronary risk factors. The standardized category scores for 25% left anterior descending coronary artery stenosis, 50% left anterior descending coronary artery stenosis, and presence of a saphenous vein graft having blood flow competition with an internal thoracic artery graft were -1.418, -0.767 and -0.622, respectively. Thus, the internal thoracic artery diameter was smaller in patients with well-preserved flow of the recipient coronary artery. The internal thoracic artery diameter had a particularly strong correlation with the degree of left anterior descending coronary artery stenosis (partial correlation coefficient: 0.670). The other factors seemed to have little or no correlation with the postoperative internal thoracic artery diameter. With the criterion that the internal thoracic artery diameter below 1.0 mm represents the "string sign" of internal thoracic artery graft, this phenomenon was observed in nine patients (6.1%). In all of these patients, left anterior descending coronary artery flow was well-preserved, and no ischemia was disclosed in the left anterior descending coronary artery-perfused area. These results indicate that internal thoracic artery grafts have flow adaptability responding to the flow demand of the recipient coronary artery and that the string sign of internal thoracic artery grafts is mainly an outcome of its physiologic characteristics.

Bilateral internal mammary artery grafts for coronary artery bypass operations in children.

We performed myocardial revascularization with bilateral internal mammary arteries in eight children for coronary artery complications consequent to Kawasaki disease. Subjects included seven boys and one girl, ranging in age from 3 to 13 years (mean age, 8.3 +/- 3.4 years). The body surface area ranged from 0.65 to 1.65 m2 (average, 1.08 +/- 0.35 m2). Three patients had a previous myocardial infarction. The right internal mammary artery was anastomosed to the right coronary artery and the left internal mammary artery was sutured to the left anterior descending artery in all patients. The patients received an average of 2.4 grafts. Magnifying loupes of 3.5 X were used for anastomosis with 8-0 monofilament polypropylene sutures. Subjects were followed up from 12 to 38 months (23 +/- 10.8 months) after operation. All were doing well with no recurrence of angina, and body development was normal, including the sternum and thorax according to chest x-ray films and computed tomography of the chest. Patency of the bilateral internal mammary arteries was 100% in the early (within 1 month) postoperative period and remained so in the late (over 1 year) postoperative period. Anastomotic junctions between the internal mammary artery and the coronary artery developed well angiographically in the late postoperative period. The internal mammary artery is the graft of choice for pediatric myocardial revascularization because of its excellent long-term patency and growth potential. Bilateral internal mammary arteries should be used whenever indicated, and the use of bilateral internal mammary arteries did not adversely influence chest wall development in the children.