Biomedical subjects

N Shiiya

Publications and source records attributed to N Shiiya.

At least 55 records · Page 3Linked to original sources

PubMed2000

Lazaroid reduces production of IL-8 and IL-1 receptor antagonist in ischemic spinal cord injury.

BACKGROUND: 21-aminosteroids (lazaroids) have demonstrated the protective effect against cerebral ischemic injury through the inhibition of lipid peroxidation. We examined whether lazaroids affected the production of proinflammatory and antiinflammatory cytokines in ischemic spinal cord injury model. MATERIALS: Anesthetized New Zealand white rabbits underwent a 20-minute infrarenal aortic cross-clamping (AXC) with pretreatment of either an intravenous 3 mg/kg lazaroid U74389G (group L; n = 10) or the same volume saline (group P; n = 10). Sham operation group (group S; n = 6) underwent only exposure of the aorta. Plasma concentrations of interleukin (IL)-8, -1beta, -1 receptor antagonist (IL-1ra) and tumor necrosis factor (TNF)-alpha were measured at four time points. Functional assessment with Tarlov score at 24 and 48 hours after pretreatment, pathologic assessment of the spinal cord, and measurements of cytokine levels in the spinal cord were performed. RESULTS: The maximum elevation of plasma IL-8 and -1ra levels occurred at 1 hour after declamping in four measurement points. Plasma IL-8 and -1ra levels in group L were significantly lower than those in group P (*p < 0.05). Plasma TNFalpha peaked at 5 minutes after declamping, but decreased afterwards. Plasma TNFalpha levels were not different among three groups. Spinal IL-8 levels in group L (0.98 +/- 0.34 ng/g tissue) were lower than those in group P (7.26 +/- 2.26 ng/g tissue)(*p < 0.05). Spinal IL-1ra and TNFalpha were not significantly different. Tarlov score and pathologic assessment were better in group L. CONCLUSIONS: Lazaroid U-74389G reduced the production of systemic IL-8 and -1ra and spinal IL-8 when AXC caused spinal cord injury. These results indicate that lazaroids may attenuate ischemic endothelial cell injury or activation of leukocytes.

Animals↗

PubMed2000

Surgical management of atherosclerotic aortic arch aneurysms using selective cerebral perfusion: 7-year experience in 52 patients.

OBJECTIVE: Patients with atherosclerotic aortic arch aneurysms are at greater risk for brain complication. We report our techniques and results of operation using selective cerebral perfusion. METHODS: We retrospectively analyzed 52 consecutive patients with atherosclerotic aortic arch aneurysms (mean age, 70 years, range, 53-86 years), who underwent operation between April 1992 and March 1999. The operation was non-elective in 11 patients (21.1%). Concomitant operations included eight coronary artery bypass grafting and one aortic valve replacement. Simultaneous distal aortic reconstruction was performed in three patients. The operation was performed through median sternotomy. To avoid brain embolism, total arch replacement with a branched prosthesis was performed in 48 patients, in an attempt to exclude affected segments of aorta. In addition, retrograde femoral artery perfusion was avoided and cerebral circulation was isolated before aortic manipulation. To achieve even blood flow distribution, we employed perfusion and continuous pressure monitoring of all the three arch vessels. The perfusion rate was 12+/-2 ml/kg per min and the pressure was kept around 50 mmHg. Deep hypothermic arrest of the lower torso (bladder temperature, 22 degrees C) was used during open distal aortic anastomosis. RESULTS: The hospital mortality rate was 11.5% (six of 52), and 7.3% (three of 41) for elective cases. Only one patient (1. 9%) developed permanent focal neurological deficit. Six other patients showed temporary brain complications, which was global (delirium) in three and focal in three others. CONCLUSIONS: Selective cerebral perfusion is a safe brain protection method, and our strategy seems effective for embolic stroke prevention.

Aged↗

PubMed2000

[Surgery for intrathoracic recurrence of non-small cell lung cancer].

In this study, we defined a solitary lung nodle in the same histology which could be traced its' origin from carcinoma in situ or was found over than two years' follow up as a second primary lung cancer. These cases were excluded. Eighteen cases underwent second surgery for intrathoracic recurrence. Fourteen cases were male and four cases were female. Their ages ranged from 23 to 75 (average 59.6) years. The histology were adenocarcinoma in 9 cases, squamouscarcinoma in 7, adenosquamous carcinoma in 1, large cell carcinoma in 1. The initial surgical procedures were lobectomy in 17, partial resection in 1. The initial stage were I in 13, II in 2, IIIA in 1. Pulmonary recurrence were found in 10, bronchial stump recurrence were found in 4, pulmonary hilus lymph node recurrence were found in 2, mediastinal lymph node recurrence were found in 2, pulmonary stump recurrence was found in 1. The second surgical procedures were completion pneumonectomy in 7, completion lobectomy in 1, lobectomy with segmentectomy in 1, segmentectomy or partial resection in 7, mediastinal dissection in 2. The overall 5-year survival rate of the patients with recurrence after reoperation was 31.8%. An aggressive surgical approach for recurrent lung cancer should be recommended.

Adult↗

PubMed2000

Mitral valve repair and septal myectomy for hypertrophic obstructive cardiomyopathy.

Combined mitral valve repair using the sliding leaflet technique and septal myectomy were employed to successfully treat left ventricular outflow tract (LVOT) obstruction and mitral regurgitation due to hypertrophic obstructive cardiomyopathy (HOCM). A 46-year-old man was diagnosed with HOCM along with congestive heart failure and was treated medically. These symptoms, however, were resistant to medical treatments with a beta-blocker, a Ca-antagonist, and disopyramide, and he was referred to our hospital for surgery. Doppler echocardiography demonstrated an LVOT obstruction at rest with a peak pressure gradient of 138 mmHg. The interventricular septum thickness was 14 mm. Mitral regurgitation of 3+ with severe SAM was also observed. Temporary dual chamber pacing was tried without significant improvement. Following these examinations, the patient underwent surgery. A transaortic septal myotomy-myectomy was performed first, and the mitral valve was then approached through the left atrium. Mitral valve repair was performed with the sliding leaflet technique to reduce the height of the posterior leaflet from 2 cm to 1 cm. Postpump transesophageal echocardiography revealed no MR and a peak LVOT gradient of 15 mmHg. The patient recovered well except for a residual mild SAM, and MR2+. We therefore concluded that this surgical approach might provide results which are superior to those of myectomy alone.

Cardiomyopathy, Hypertrophic↗

PubMed2000

[Clinical evaluation of hepatic blood flow and oxygen metabolism during thoracoabdominal aortic surgery using pulse dye-densitometry combined with hepatic venous oxygen saturation].

OBJECTIVE: There has been no report that pulse dye-densitometry (PDD), a novel non-invasive modality for monitoring hepatic blood flow (HBF), was applied during cardio-pulmonary bypass (CPB). We investigated weather PDD was useful to measure HBF during thoracoabdominal aortic surgery using partial CPB. Furthermore, HBF and hepatic metabolism were assessed during selective visceral perfusion or shunt using PDD, hepatic venous oxygen saturation (ShO2), and analysis of hepatic metabolic products. METHODS: A prospective study was carried out in eight patients who underwent thoracoabdominal aortic surgery from April 1998 to October 1999. Operative adjuncts were partial CPB with mild hypothermia in six (femoral veno-arterial bypass: FF group) and deep hypothermic circulatory arrest in two (DHCA group). Measurements were performed at following five time points; just before initiating CPB, just after establishing CPB, during selective visceral perfusion, during selective visceral shunt, and just after weaning CPB. RESULTS: Plasma clearance rate of indocyanine green measured by PDD well correlated with that obtained by in vitro spectrophotometry (p < 0.0001, R2 = 0.644). PDD demonstrated that decreased IIBF during selective visceral perfusion or shunt was well compensated by increased hepatic oxygen extraction rate in FF group and reduced oxygen consumption in DHCA group. Lactic acid extraction ratio and arterial ketone body ratio also decreased during this period. ShO2 during selective visceral shunt correlated with systemic systolic arterial pressure (SAP), and it showed a marked decrease under 20% when SAP was below 80 mmHg. Postoperative time course of serum total bilirubin and alanine aminotransferase of almost patients were within acceptable limits except the patient who required large amount of homologous blood transfusion. CONCLUSIONS: PDD proved to be a useful modality that enabled non-invasive monitoring of HBF even during partial CPB. Decreased HBF during selective visceral perfusion or shunt in thoracoabdominal aortic surgery was within physiological compensation, which led us conclude that it might be effective adjuncts, for visceral organ protection.

Adult↗

PubMed2000

Surgical results of Stanford type B aortic dissection. Comparisons between partial and subtotal replacement of the dissected aorta.

BACKGROUND: Surgical results for Stanford type B aortic dissection were retrospectively compared between the subtotal prosthetic replacement of the thoracoabdominal dissected aorta (STR) and partial replacement of the descending aorta at the intimal tear (PR). METHODS: Twenty-two patients (11 males and 11 females with mean age of 56.9+/-2.6 years) undergoing repair of aneurysms were analyzed. All operations were performed with the aid of femorofemoral partial cardiopulmonary bypass. Reconstruction of the critical artery for spinal cord blood supply was determined by evoked spinal cord potential (ESP) monitoring in non-urgent cases. Operative mortality and incidence of complications were compared between the PR group (Group I; n=15) and the STR group (Group II; n=7). RESULTS: There were one operative death and one late death in Group I. No early or late deaths occurred in Group II. Postoperative paraplegia occurred in 1 patient in Group I and 2 patients in Group II. Among patients undergoing selective reconstruction of the critical intercostal arteries, paraplegia occurred in only one patient. Incidence of postoperative complications was not significantly different between Group I and Group II. Presence of rupture (p<0.001) and development of acute renal failure (p<0.05) revealed significant determinants of postoperative mortality by multivariate analysis. Operative procedure did not influence postoperative mortality or occurrence of paraplegia. CONCLUSIONS: Operative results of STR with selective reconstruction of the critical arteries and PR for aortic dissection were comparable. Subtotal replacement of the thoracoabdominal dissected aorta is encouraged to apply for patients with diffuse, large postdissection aneurysms or those with a high risk of future enlargement of remaining false channels such as Marfan syndrome, under adequate reconstruction of the critical segmental arteries.

Acute Kidney Injury↗

PubMed2000

Arterial thoracic outlet syndrome with embolic cerebral infarction. Report of a case.

Cerebral embolism is a very rare but recognized manifestation of arterial complications of thoracic outlet syndrome, and is associated with retrograde embolization in the cerebral arteries. We herein report a case of embolic brain infarction due to arterial thoracic outlet syndrome while discussing the etiology, diagnosis, and surgery.

Cerebral Infarction↗

PubMed1999

Abdominal aortic aneurysms in aged patients: analysis of risk factors in non-ruptured cases.

BACKGROUND AND METHODS: A retrospective analysis of 304 patients (274 males and 30 females) surgically treated for non-ruptured, infrarenal abdominal aortic aneurysm (AAA) to determine the relative contribution of preoperative, operative, and postoperative factors to mortality and to the development of postoperative complications. 1) Risk factors, hospital mortality and long-term survival rate were compared between patients aged 75 or older (- group I; n=79) and those under 75 years of age (group II; n=225). 2) These risk factors were subjected to univariate and multivariate analysis to determine their relative contribution to patient hospital mortality and to the development of major postoperative complications in aged patients. RESULTS: Maximum diameter of AAA, the prevalence of respiratory dysfunction, diabetes mellitus and the total volumes of intraoperative blood loss were significantly different between the two groups. A higher hospital mortality was noted in the aged patients (10.1% versus 3.1%, p<0.05). The majority of deaths in group I resulted from organ dysfunctions, especially involved with respiratory failure. The long term survival rate at 3 and 5 years was not different between operative survivors in the two groups. Incremental risk factors for hospital death in aged patients included the presence of symptomatic AAA, the maximum diameter of AAA, the postoperative development of myocardial infarction, respiratory complications and gastrointestinal bleeding. Operation time and the volumes of intraoperative blood loss significantly correlated with the postoperative development of respiratory failure, renal failure and multiple organ failure. CONCLUSIONS: 1) A higher operative mortality and higher prevalence of postoperative complications were noted in aged patients with AAA. 2) To reduce operation time and the volumes of intraoperative blood loss would be essential to improve surgical results of AAA in aged patients.

Adult↗

PubMed1999

[Long-term results of mitral valve regurgitation after surgical repair of incomplete atrioventricular septal defect].

Although the postoperative outcome in patients with incomplete atrioventricular septal defect (iAVSD) is excellent, deterioration of mitral valve regurgitation (MR) is still remained to be resolved. Therefore, this study was undertaken to compare surgical procedures for mitral cleft repair with their long-term results of MR. From 1991 to 1996, 52 patients underwent surgical repair of iAVSD. Age at operation ranged from 2 months to 62 years old with mean age of 14.2 years. Mean follow-up period was 8.6 +/- 4.4 years. All patients underwent patch closure of ostium primum defect. Two patients did not have cleft (Group A). Seven patients did not close the cleft at all (Group B), while 40 patients had the repair of valve by closing cleft near septal attachment only (Group C). The latest 3 patients had the complete closure of cleft from annulus to margin of leaflet where chorda is attached. MR was evaluated by echocardiography grading 0 to IV and regurgitation more than grade II was considered to be significant. In Group A, MR remained grade I. In Group B, MR was deteriorated in 5 patients (71%). Consequently, 6 patients (86%) had grade II or more regurgitation and 4 patients (57%) revealed grade III/IV regurgitation including one (14%) reoperation. In Group C, MR was deteriorated in 10 patients (55%). Consequently, 22 patients (86%) had grade II or more regurgitation and 5 patients (13%) had grade III/IV regurgitation including 3 (7.5%) reoperations. In Group D, no deterioration of MR was noted and all had grade I or less regurgitation. These results suggest that the closure of cleft near septal attachment is not sufficient to prevent MR in late phase and the complete closure of cleft from annulus to margin of leaflet, where chorda is attached, would be useful to prevent the deterioration of MR in late phase.

Adolescent↗

PubMed1999

Ruptured abdominal aortic aneurysms: analysis of factors influencing surgical results in 184 patients.

BACKGROUND: Rupture is often the first manifestation in patients with abdominal aortic aneurysms. Although elective surgery for non-ruptured abdominal aortic aneurysms has provided satisfactory surgical results, operative mortality of ruptured abdominal aortic aneurysms (rAAA) has not improved. The purpose of this study was to identify predictors for early hospital death in patients with rAAA. METHODS DESIGN: A retrospective study. SETTING: A university hospital and 20 affiliated hospitals. PATIENTS: PATIENTS undergoing surgical treatment for rAAA (n=183) between 1968 and 1997. INTERVENTIONS: All patients were surgically treated and divided into operative survivors (n=119) and non-survivors (n=64). MEASURES: The patient-related, procedure-related, and postoperative factors were compared between the two groups. A multivariate analysis was also conducted to determine predictors for hospital deaths. RESULTS: In univariate analysis, age at operation (p=0.004), preoperative hemodynamic conditions (p<0.0001), extent of hematoma (p<0.0001), preexistent renal dysfunction (p=0.001), and volumes of blood loss at operation (p=0.001) were significantly different between the two groups. The morbidity of postoperative renal failure (p<0.0001), gut ischemia (p=0.003), heart failure or ischemic heart disease (p<0.0001), and multiple organ dysfunction syndrome (p<0.0001) was higher in the non-survivors' group. Multivariate analysis also identified preoperative hemodynamic conditions, blood loss volume at operation, pre-existent renal dysfunction, postoperative renal failure, heart failure, and multiple organ dysfunction syndrome as incremental risk factors for hospital deaths. CONCLUSIONS: Every effort to maintain preoperative hemodynamic conditions, to reduce volumes of blood loss at operation, and to minimize deterioration of organ functions postoperatively is all essential to improve patient survival.

Adult↗

PubMed1999

Takayasu's aortitis treated surgically by extensive aortic replacement. A case report.

A case report of Takayasu's arteritis with aneurysmal involvement of the ascending aorta, aortic arch and descending thoracic aorta is presented. The patient underwent successful two-stage operation by use of Elephant trunk technique. During the first operation, replacement of ascending aorta and aortic arch was done under selective cerebral perfusion. During the second-stage operation, replacement of the descending thoracic aorta was performed under partial cardiopulmonary bypass. The postoperative course was uneventful and one year after surgery the patient is doing well. Specific conditions and operative strategy required in case of extensive aortic involvement in Takayasu's arteritis are discussed.

Aortography↗

PubMed1998

Determinants of postoperative and long-term survival of patients with ruptured abdominal aortic aneurysms.

To compare the surgical results of patients with ruptured (rAAA) and nonruptured abdominal aortic aneurysms (NrAAA), 267 consecutive patients surgically treated for abdominal aortic aneurysms (AAA) were reviewed. The patients' characteristics, preexistent risk factors, perioperative factors, and postoperative early and long-term survival were compared between the rAAA group (n = 27) and the NrAAA group (n = 240). A multivariate analysis to predict postoperative survival was also conducted in the rAAA group. The hospital mortality rate was 3.3% (8/232) for the NrAAA group and 22.2% (6/27) for the rAAA group (P < 0.001). The maximum size of aneurysms, period of preoperative hypotension, and intraoperative bleeding volume were significantly higher in the rAAA group than in the NrAAA group. The 5- and 10-year cumulative survival rates in the rAAA group were 88.1% and 42.0%, which were comparable to those in the NrAAA group. The incremental risk factors for hospital death in the rAAA group included advanced age, preoperative hypotension (< 80 mmHg), and postoperative renal failure requiring dialysis. These findings showed that the interval from rupture to cross-clamping must be shortened, maintaining hemodynamic stability to avoid prolonged hypotension. Reducing risk factors and minimizing deterioration of organ functions postoperatively would be essential to improve the prognosis of patients with rAAA.

Aged↗

PubMed1998

Myxoma of the mitral valve prolapsing into the left atrium and ventricle: report of a case.

A rare case of myxoma originating from the mitral valve is reported. A 25-year-old woman was found to have a mobile mass around the mitral valve that prolapsed into the left atrium and the left ventricular outflow tract. The mitral valve was approached via the left atrium and aorta, and was excised completely along with the tumor; it was thus replaced with a mechanical prosthesis. The patient recovered and demonstrated no signs of recurrence 16 months postoperatively.

Adult↗

PubMed1998

[Surgical treatment for perforated aorta caused by mediastinitis after bidirectional Glenn shunt and closure of atrial septal defect--a case report].

A 24-year-old man with Ebstein anomaly underwent a bidirectional Glenn shunt and closure of an atrial septal defect. Postsurgical prulent mediastinitis was treated by irrigation and drainage, but was followed by rupture of the ascending aorta. During emergency surgery, hypothermic circulatory arrest became necessary due to massive bleeding. Since he had undergone a bidirectional Glenn shunt, left heart venting was essential to obtain deep hypothermic circulatory arrest without cardiac distention and was successfully performed via an anterior thoracotomy approach. The perforated site of the ascending aorta was repaired with a Xeromedica patch. The anterior mediastinum was wrapped with the omentum. Transthoracic left heart venting via an anterior thoracotomy is an useful approach when hypothermic circulatory arrest is required to perform a median sternotomy and to approach the heart.

Adult↗

PubMed1998

Simultaneous total aortic replacement without a sternotomy incision.

Total aortic replacement is preferably performed by staged operations, and reports of a simultaneous operation are few. In these reports, both a median sternotomy and a thoracoabdominal incision are employed. We report a patient who successfully underwent simultaneous total aortic replacement without a sternotomy incision. The technique and the feasibility of the operation are discussed.

Aortic Dissection↗

PubMed1998

Evaluation of 18-hour lung preservation with oxygenated blood for optimal oxygen delivery.

BACKGROUND: Previous studies have shown that availability of oxygen during lung preservation to maintain aerobic metabolism may be essential for the optimal viability of preserved lung tissue. The purpose of this study was to evaluate lung preservation with oxygenated blood for optimal oxygen delivery to the lung graft in a rabbit model. METHODS: Eighteen excised rabbit lungs were flushed and stored for 18 hours at 10 degrees C with one of the following: Euro-Collins solution (EC; n=6), oxygenated homologous blood (OB; n=6), or low-potassium dextran solution (LPD; n=6). Poststorage lung functions were evaluated with isolated, blood-perfused lung model for 10 minutes. RESULTS: The mean oxygen tensions after reperfusion for the EC, OB, and LPD groups (47.0+/-2.8, 76.9+/-13.1, 96.2+/-10.9 mm Hg at 10 minutes, respectively) were significantly different throughout the perfusion period (EC < OB < LPD, p < 0.05; EC < LPD, p < 0.01). Pulmonary artery pressure during the reperfusion period in the EC group (35.8+/-4.4 mm Hg at 10 minutes) was higher than that in the OB and LPD groups (29.8+/-4.3 and 22.4+/-2.2 mm Hg, respectively) (EC > OB, EC > LPD, p < 0.05). However, the E-selectin level in the reperfused blood in the OB group (5.04+/-0.24 ng/mL) was significantly elevated compared with that in other groups (EC, 3.56+/-0.54; LPD, 2.92+/-0.35 ng/mL, p < 0.05), which indicated enhanced neutrophil recruitment in the OB group. Comparisons of thrombomodulin and endothelin among the three groups did not reach statistical significance. CONCLUSIONS: We conclude that OB may enhance lung preservation as compared with EC solution, probably through its enriched oxygen delivery during storage and extracellular composition. However, the availability of oxygenated blood does not exceed that of LPD solution because of augmented neutrophil recruitment, which may activate neutrophil-endothelial interactions.

Animals↗

PubMed1998

Application of the reversed elephant trunk technique during total thoracoabdominal replacement in patients with Marfan's syndrome.

The reversed elephant trunk operation has been applied in patients with extensive aortic involvement as a scheduled staged operation. We report application of the same technique in two patients with Marfan's syndrome. The two patients underwent total replacement of the thoracoabdominal aorta for a DeBakey IIIb aortic dissection. The proximal end of the prosthetic graft was invaginated to facilitate future proximal operation. No complication related to the trunk had been observed during the follow-up period.

Adult↗

PubMed1998

Surgical experiences with peripheral arterial aneurysms due to vasculo-Behçet's disease.

BACKGROUND: Vascular involvement of Behçet's disease is currently considered as an important sign of the clinical evolution of patients with Behçet's disease. In addition, Behçet's disease is important in that it causes peripheral arterial aneurysms. METHODS: In this report, 4 patients with vasculo-Behçet's peripheral arterial aneurysms are presented. These aneurysms were distributed in the carotid artery (n=1), popliteal artery (n=1) and femoral arteries (n=3). Operative procedures included patch closure of a perforated wall for the carotid aneurysm, arterial reconstruction with the autogenous saphenous vein for the femoral and popliteal aneurysms. RESULTS: All four patients tolerated the operation well, however, two of four patients required re-operation due to anastomotic insufficiency later. CONCLUSIONS: Aneurysms associated with Behçet's disease have a sudden onset in many cases and often result in rupture. Appropriate operative procedures, including an adequate choice of anastomotic sites and reinforcement of the suture, may reduce the incidence of complications in patients with arterial aneurysms due to Behçet's disease.

Adolescent↗