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Biomedical subjects

F Iwaya

Publications and source records attributed to F Iwaya.

At least 19 recordsLinked to original sources
PubMed2002

[Eleven cases of surgery for Marfan syndrome].

The surgical outcomes in 11 patients with a Marfan syndrome (mean [+/- SD] age, 32 +/- 16: range 0.5 to 60) were evaluated. Echocardiography demonstrated annuloaortic ectasia (AAE) in nine patients, mitral regurgitation (5 months baby: valve replaced) and abdominal aortic aneurysm in one each. Among 9 AAE, root were replaced in 8 patients and aortic valve was preserved only one patient. Our early-time result is encouraging in our valve-sparing operation.

Adolescent↗
PubMed2002

[Coronary sinus atrial septal defect diagnosed by cyanosis after operation of ventricular septal defect].

We have experienced a case of coronary sinus atrial septal defect (ASD) with ventricular septal defect (VSD). Cardiac catheterization revealed a step-up of oxygen saturation in right ventricle, L-R shunt 70.3%, R-L shunt 6.9% and pulmonary hypertension (PH). Since diagnosis of coronary sinus ASD was difficult, the operation was performed under diagnosis of VSD. Although the operation was success, cyanosis appeared after the operation. Contrast echocardiography using subcostal 4 chamber view showed coronary sinus ASD with a large Thebesian valve and the right-to-left shunt of the ASD. The Thebesian valve seemed to lead the venous return flow to the left atrium. Coronary sinus ASD was closed using a Xenomedica patch.

Cyanosis↗
PubMed2001

Bland white Garland syndrome with type A aortic dissection.

We report the case of a 72-year-old patient with a left main coronary artery originating from the pulmonary trunk with type A aortic dissection. He is the oldest patient among those reported in the literature, operated due to acute type A aortic dissection and has survived 4 year after the operation without surgery on the coronary artery.

Aged↗
PubMed2001

Results of 256 consecutive abdominal aortic aneurysm repairs using extraperitoneal approach.

Two hundred and fifty-six consecutive abdominal aortic aneurysms were repaired using three approaches for extraperitoneal exposure of the aorta and iliac vessels from February 1990 through September 1998. The perioperative mortality rate was 3.1% in 228 elective repairs and 14.3% in 28 ruptured cases. The initial 23 cases were repaired using Sicard's method. The duration of endotracheal intubation was 1.0+/-2.8 h, alimentation initiation was 2.7+/-1.6 days, and narcotic requirements were 1.2+/-1.1 times. Following these initial cases, we employed Williams' method for 192 abdominal aneurysms, however; repeated incisional pain and three cases of deforming bulge led us to avoid dividing muscles. In the last 13 cases, our approach was performed without muscle dividing. The narcotic requirements decreased to 0.3+/-0.7 times. As for postoperative complications, the larger skin incision approach had no shower embolism. However, the shorter skin incision had four cases of shower embolisms, one lymphorrhea and one vascular trauma by the aortic clamp. The extraperitoneal approach offers certain physiologic advantages with minimal disturbance of gastrointestinal and respiratory function. We believe that this method is useful for rapid approach to the proximal aorta in case of emergency. Postoperative wound complications could be prevented via an oblique incision without muscle dividing.

Adult↗
PubMed2001

[A case of tracheo-bronchial stenosis after extended end-to-end aortic arch anastomosis for interrupted aortic arch treated with suspension of the ascending artery and pulmonary artery].

A 9-day-old boy had pulmonary artery banding and extended end-to-end aortic arch anastomosis for ventricular septal defect (VSD) and type A interrupted aortic arch. Severe dyspnea gradually developed. At 3 months of age, intracardiac repair of VSD was performed. Weaning from the ventilator was difficult. Endoscopic examination and chest CT revealed stenosis of the right and left main bronchi and compression of tracheal bifurcation and the right and left main bronchi by the ascending aorta and pulmonary artery. Suspension of the ascending aorta and pulmonary artery was performed 15 days after VSD closure. Nine days after this procedure, the patient was weaned from respirator. Postoperative course was uneventful. Bronchial stenosis may be caused from extended end-to-end aortic arch anastomosis.

Anastomosis, Surgical↗
PubMed2000

Intravascular Imaging Methods for Venous Disorders.

The purposes are to assess the problems associated with intravascular imaging methods such as angioscopy and intravascular ultrasound (IVUS) and to evaluate their efficacy through the results of our observations. A total of 54 limbs in 53 patients, 50 patients with chronic venous insufficiency and 3 patients with deep vein thrombosis, were diagnosed and operated on using angioscopy (Olympus OES, order made type) and IVUS (Endosonics, model 82700). The imaging catheters were inserted through a branch of the long saphenous vein and the valves and the intraluminal views were observed. By angioscopy, intraluminal views were clearly observed in 98% of all lesions. However, observation became more difficult in iliac veins compared to in femoral and in long saphenous veins (p < 0.01). Venous wall and thrombus were detected more by IVUS than by angioscopy (p < 0.01), but only 21 valves (24%) were visualized by IVUS among the 88 valves observed by angioscopy. The intravascular imaging method of angioscopy is more suitable for observing valves and intraluminal views compared with IVUS, whereas IVUS is more suitable for observing the cross-sectional venous wall.

Journal Article↗
PubMed2000

Prevention of paraplegia in transluminally placed endoluminal prosthetic grafts for descending thoracic aortic aneurysms.

OBJECTIVE: To evaluate the efficacy of a temporary balloon occlusion test for the prevention of paraplegia following transluminally placed endoluminal prosthetic grafts for descending thoracic aortic aneurysms. SUBJECTS AND METHODS: Two occlusion balloons were inserted via the brachial and femoral arteries and positioned in the proximal and distal neck of the descending thoracic aortic aneurysms using fluoroscopy. After temporary occlusion of the thoracic aorta by inflation of both the proximal and distal balloons, the evoked spinal potential was measured for 15 mins. A maximum amplitude during temporary balloon occlusion test decreasing by more than 20% of the pre-balloon occlusion level was considered to be significant, enough to not perform transluminally placed endoluminal prosthetic grafts, but instead an open repair. The test was applied in 12 cases (9 males and 3 females, 50-86 years old). All aneurysms were located between the Th6 and Th12 with a maximum diameter of 40-70 mm, and average of 56 mm. RESULTS: The changes in maximum amplitude of evoked spinal potential remained within 20% of the value before balloon occlusion in 11 cases. Transluminally placed endoluminal prosthetic grafts were performed in these 11 cases and no instance of paraplegia or other complication relating to the test was observed. Deployment of stent-grafts was successful in 10 cases (91%). CONCLUSION: It is suggested that the preoperative measurement of evoked spinal potential during temporary balloon occlusion is clinically useful for the assessment of the risk to paraplegia occurring in transluminally placed endoluminal prosthetic grafts.

Aged↗
PubMed2000

[Effect of low dose aprotinin on reduction of blood loss after extracorpreal circulation].

Aprotinin administration during open heart surgery has been reported to reduce blood loss after extracorporeal circulation (ECC). We administered aprotinin to 12 patients undergoing CABG or prosthetic valve replacement. We examined the blood loss, the coagulation, and the fibrinolytic system in comparison with that in non-aprotinin group of 12 patients. In the aprotinin group, 1,000,000 units of aprotinin was infused intravenously before initiation of ECC and mixed with priming volume of ECC. After ECC, 250,000 units/hr was continuously infused until 1 hour after operation. The aprotinin group showed a significantly enhanced level of alpha 2 plasmin inhibitor and a significantly reduced level of plasmin-alpha 2 plasmin inhibitor complex and D-dimer. Post operative blood loss was not different between two groups. Operation time and closure time after heparinneutralization was shorter and postoperative blood use was lower in the aprotinin group. In conclusion, The administration of low dosed of aprotinin suppresses the fibrinolytic system resulting in the reduction of operation and closure time.

Adult↗
PubMed1999

Cerebral blood flow and oxygen metabolism during cardiopulmonary bypass with moderate hypothermic selective cerebral perfusion.

Cerebral blood flow was measured using transcranial doppler during cardiopulmonary bypass in nine patients with selective cerebral perfusion for surgery of arch aorta (group S). For comparison, 11 adult open heart patients (group C) were also measured. The authors' selective cerebral perfusion at 28 degrees C resulted in moderate hypothermia and antegrade perfusion using independent pumps for three branches. Total flow in the three branches was 500 ml/min. A Labodop DP-100 doppler ultrasound velocimeter was used to measure middle cerebral arterial blood flow velocity. Hemoglobin concentration and oxygen saturation were also measured in arterial and jugular venous blood. The arteriovenous oxygen content difference (Ca-vO2) was calculated and multiplied by the middle cerebral arterial blood flow velocity value, which resulted in the cerebral metabolic rate for oxygen (CMRO2). The cerebral perfusion pressure of group S was lower than in group C, and the arterial carbon-dioxide tension (PaCO2) of group S was higher than in group C during cardiopulmonary bypass. Middle cerebral arterial blood flow velocity values of both groups remained constant before, during and after cardiopulmonary bypass. The CMRO2 decreased during cardiopulmonary bypass and showed no difference between the two groups. The changes in PaCO2 might be significant factors in the increase in cerebral blood flow during selective cerebral perfusion. This study supports the conclusion that, compared with our routine open heart surgery procedures, our selective cerebral perfusion procedures had the same cerebral blood flow and oxygen metabolism during cardiopulmonary bypass.

Adult↗
PubMed1999

Graft-wall endoleak 18 months after successful endoluminal AAA repair.

PURPOSE: To describe a case of graft-wall endoleak 18 months after successful endoluminal repair of an abdominal aortic aneurysm (AAA). METHODS AND RESULTS: A 71-year-old man with infrarenal AAA was successfully treated with an endoluminal aortomonoiliac graft and femorofemoral crossover bypass with surgical ligation of the right external iliac artery. The stent-graft was made from 2 Gianturco Z-stents and a tapered thin-walled (0.1-mm) Dacron graft. Eighteen months after endografting, the patient complained of a pulsatile abdominal mass. Angiography and computed tomography showed graft-wall endoleak. Aneurysmectomy was performed, and the aneurysm was successfully replaced with a Y-shaped knitted Dacron graft. A hole in the graft wall was found 3 cm from the proximal edge of the stent-graft. CONCLUSIONS: This case suggests that the use of thin-walled graft material in endografts may not be sufficiently durable.

Aged↗
PubMed1998

[Partial median sternotomy for pediatric cardiac surgery].

In order to minimize scarring and thereby improve the postoperative cosmetic appearance of pediatric cardiac surgery patients, we perform partial median sternotomy incisions. A short midline skin incision, from 1 to 2 cm below the articular notch of the second rib to the xiphoid process, is made. The sternum was divided from the xiphoid process to the articular notch of the second rib. The thymus is mobilized and the pericardium incised longitudinally. The aorta and superior and inferior vena cava are mobilized to facilitate direct cannulation. Cardiopulmonary bypass is instituted in the usual fashion. Twenty-four pediatric patients underwent repair of cardiac anomalies through a partial median sternotomy incision at our institution between June 1997 and September 1998. The average age of the patients was 4 years and 4 months (range, 4 days to 12 years) and the average weight was 16.0 kg (range, 3.2 to 40.5 kg). Cases included 13 VSD (ventricular septal defect) [including one DCRV (double chambered right ventricle) and one PS (pulmonary stenosis)], 9 ASD (atrial septal defect), one ECD (endocardial cushion defect), and one DORV (double outlet right ventricle) with mitral atresia. All patients were extubated within 3 hours after surgery and the average length of the ICU stay was within 24 hours (except for one 4-day-old baby who died of LOS (low cardiac output syndrome) on the 16th postoperative day). There were no wound infections or hospital mortalities. In our experience, this approach is safe, provides good exposure, and provides excellent cosmetic results.

Cardiac Surgical Procedures↗
PubMed1998

[Partial median sternotomy for pediatric cardiac surgery].

In order to minimize scar appearance and thereby improve postoperative cosmetic appearance for pediatric cardiac surgery patients, we performed partial median sternotomy incisions. A short midline incision, from 1 to 2 cm below the articular notch of the 2nd rib to the xiphoid process, was made. The sternum was divided from the xiphoid process to the articular notch of the 2nd rib. The thymus was mobilized and the pericardium incised longitudinally. The aorta and superior and inferior vena cava were mobilized to facilitate direct cannulations. Cardiopulmonary bypass was instituted in the usual fashion. From June to December 1997, 14 patients between the ages of 4 days and 12 years have undergone cardiac repair using this technique. Cases included 7 VSD (including 4 pulmonary hypertension and 1 DCRV), 5 ASD, 1 ECD and and 1 DORV with mitral atresia. All patients were extubated within 3 hours after surgery, and there were no wound infections or hospital mortalities (except one 4 day old baby who died by LOS on the 16th postoperative day). In our experience, this approach is safe and provides good exposure with excellent cosmetic results.

Cardiac Surgical Procedures↗
PubMed1997

Evaluation of hemolysis in a pulsatile assist device for centrifugal pump.

To evaluate the blood trauma caused by a new device for producing a pulsatile flow of the centrifugal pump, the pulsatile assist device for the centrifugal pump (PAD-CP) that we have developed, a hemolysis study was performed in vitro and in animal experimentation. For the in vitro testing, 2 identical sets of hemolysis test circuits were prepared with 2,400 ml of bovine blood. The 2 circuits were pumped simultaneously. Plasma total hemoglobin levels were less than 40 mg/dl after 3 h, under a pump flow of 2 L/min. Hemolysis increased to a severe level after 4 h of 4 L/min pump flow. The cause of this hemolysis was thought to be a vibration of the circuit because of incomplete compression of the polyurethane tube in the PAD-CP. Five adult sheep (average body weight, 47 kg) were used for in vivo evaluation of hemolysis. Hemolysis was less than 30 mg/dl of plasma hemoglobin after 4 h of open chest extracorporeal circulation with 3.0-3.6 L/min of flow rate using the PAD-CP. Other hematologic changes after PAD-CP driving were within normal limits. We conclude that the PAD-CP has proven to have possible clinical applications.

Animals↗
PubMed1996

[A case of left ventricular myxoma].

Left ventricular myxoma is very rare, and only 37 cases have been reported at present time. We here report a case of surgical extirpation of a left ventricular myxoma arising from the septal wall of the left ventricule. A 74-year-old woman was examined by transesophageal echocardiography because of palpitation. It revealed a small mass in the left ventricular cavity. This mass was then diagnosed and confirmed as a myxoma by echocardiogram, CT and MRI. MRI imaging showed the intensity of the myxoma to be higher than that of the myocardium. The myxoma was removed by transaortic approach using extracorponeal circulation. The grayly gelatinous mass was 11 x 12 x 12 mm and weighed 0.6 g. It was diagnosed as a myxoma pathohistologically. The patient recovered uneventfully and was discharged four weeks after the operation.

Aged↗
PubMed1996

[A case of malignant lung fibrous histiocytoma].

Malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma in adults. However primary MFH of the lung is very rare and only a few cases have been reported in the literature. A 79-year-old man complained of coughing and was treated at our hospital. The chest X-ray and CT scan showed a mass shadow in left lung. He underwent partial resection of the left upper lobe (S 5). No other abnormal lesions were detected in the abdomen or extremities, and the tumor was diagnosed as malignant fibrous histiocytoma (MFH) of the lung. He has been well for 18 months since the operation.

Aged↗
PubMed1996

[Total cavopulmonary connection using a knitted dacron prosthesis impregnated with gelatin (GELSEAL) as an intracardiac conduit].

It is important to find a suitable vascular prosthesis as an intracardiac conduit for a total cavopulmonary connection because of the need for long-term patency. A 7-year-old girl with a double outlet of right ventricle, hypoplastic left ventricle, pulmonary atresia and single atrium with azygos connection underwent a total cavopulmonary connection using a knitted dacron prosthesis impregnated with gelatin (GELSEAL) as an intracardiac conduit. Her postoperative course was uneventful. GELSEAL is soft, easy to hand and effective at preventing blood loss. The conduit is also expected to have long-term patency because of good healing with thin and uniform pseudointimal formation. However, long-term patency especially in the right side of the heart is still unknown. She should be followed with close anticoagulant therapy and careful observation.

Anastomosis, Surgical↗
PubMed1996

[A case of congenital tricuspid regurgitation associated with atrial septal defect and peripheral pulmonary stenosis].

This report describes a 5-year-old girl with congenital tricuspid regurgitation associated with an atrial septal defect and peripheral pulmonary stenosis. The girl was diagnosed with the heart murmur at birth and recently developed the cardiomegaly. Cardiac echocardiography and catheterization showed severe tricuspid regurgitation, an atrial septal defect of the secundum type and peripheral pulmonary stenosis. In the operative findings, the tricuspid annulus was dilated to 33 mm in diameter, and leaflets were attached normally to the antomic annulus. There was a large cleft of the anterior leaflet of the tricuspid valve. Suture of the cleft and annuloplasty of the tricuspid valve, suture closure of the atrial septal defect and patch dilatation of peripheral pulmonary stenosis were successfully performed. Including this case, 19 other cases with congenital tricuspid regurgitation undergoing surgery were reported to date.

Child, Preschool↗