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Biomedical subjects

Ichiro Sakamoto

Publications and source records attributed to Ichiro Sakamoto.

At least 19 recordsLinked to original sources
PubMed2007

Extrahepatic collaterals and liver damage in embolotherapy for ruptured hepatic artery pseudoaneurysm following hepatobiliary pancreatic surgery.

AIM: To evaluate the effects of extrahepatic collaterals to the liver on liver damage and patient outcome after embolotherapy for the ruptured hepatic artery pseudoaneurysm following hepatobiliary pancreatic surgery. METHODS: We reviewed 9 patients who underwent transcatheter arterial embolization (TAE) for the ruptured hepatic artery pseudoaneurysm following major hepatobiliary pancreatic surgery between June 1992 and April 2006. We paid special attention to the extrahepatic arterial collaterals to the liver which may affect post-TAE liver damage and patient outcome. RESULTS: The underlying diseases were all malignancies, and the surgical procedures included hepatopancreatoduodenectomy in 2 patients, hepatic resection with removal of the bile duct in 5, and pancreaticoduodenectomy in 2. A total of 11 pseudoaneurysm developed: 4 in the common hepatic artery, 4 in the proper hepatic artery, and 3 in the right hepatic artery. Successful hemostasis was accomplished with the initial TAE in all patients, except for 1. Extrahepatic arterial pathways to the liver, including the right inferior phrenic artery, the jejunal branches, and the aberrant left hepatic artery, were identified in 8 of the 9 patients after the completion of TAE. The development of collaterals depended on the extent of liver mobilization during the hepatic resection, the postoperative period, the presence or absence of an aberrant left hepatic artery, and the concomitant arterial stenosis adjacent to the pseudoaneurysm. The liver tolerated TAE without significant consequences when at least one of the collaterals from the inferior phrenic artery or the aberrant left hepatic artery was present. One patient, however, with no extrahepatic collaterals died of liver failure due to total liver necrosis 9 d after TAE. CONCLUSION: When TAE is performed on ruptured hepatic artery pseudoaneurysm, reduced collateral pathways to the liver created by the primary surgical procedure and a short postoperative interval may lead to an unfavorable outcome.

Aged↗
PubMed2007

Up-regulation of a BCL9-related beta-catenin-binding protein, B9L, in different stages of sporadic colorectal adenoma.

Aberrant activation of Wnt signaling is a critical event in the development of human colorectal tumors. The aim of this study was to elucidate the role of B9L and its association with beta-catenin in each stage of the adenoma-carcinoma sequence of human colorectal tumorigenesis. We investigated the expression levels of B9L in sporadic colorectal adenomas and carcinomas, categorized according to the Vienna classification, using real-time quantitative polymerase chain reaction (RTQ-PCR) and immunohistochemical analysis. B9L was expressed in the nuclei of non-neoplastic colonic mucosa cells and was overexpressed in the nuclei of neoplasias and invasive carcinoma cells. Immunoreactivity to B9L protein was correlated with the progressive grades of colorectal neoplasias, as was the expression of B9L mRNA. A high level of immunoreactivity to nuclear B9L was present in 27% of low-grade neoplasias and in more than 50% of high-grade neoplasias and invasive carcinomas, whereas a high level of nuclear B9L immunoreactivity was not observed in any of the non-neoplastic mucosa samples. The expression of B9L was dramatically increased in low-grade neoplasias compared with that in non-neoplastic mucosa. B9L may play an important role in tumorigenesis induced by aberrant activation of Wnt signaling and may act as a key protein in the progressive dysplasia of adenoma.

Adenocarcinoma↗
PubMed2006

Parameters associated with changes in liver volume in patients undergoing portal vein embolization.

BACKGROUND: To identify predictors of changes in hepatic volumes after portal vein embolization (PVE) before hepatectomy, we examined the relationship between clinicopathological parameters and changes in volume of embolized and nonembolized liver and regeneration of remnant liver after hepatectomy. MATERIALS AND METHODS: The subjects were 25 patients who underwent laparotomy. PVE was performed through transileocolic vein (n = 15) and percutaneous transhepatic puncture (n = 10). RESULTS: Significant atrophy and hypertrophy of the embolized and nonembolized liver were observed after PVE, respectively, and further increase of remnant liver volume was observed after hepatectomy. Background liver disease did not seem to influence the results. Alkaline phosphatase (ALP) level correlated negatively with atrophy of embolized lobe (r = -0.433). Platelet count correlated positively with hypertrophy of nonembolized lobe (r = 0.412, P < 0.05) and percent increase between lobes and (r = 0.515, P < 0.05). Seven (32%) patients developed postoperative complications, such as long-term ascites or cholestasis. Changes in embolized liver and percent increase between lobes in patients with postoperative cholestasis (-94 +/- 97 cm(3) and 9.6 +/- 5.1% gain) were significantly lower than those in patients without cholestasis (17 +/- 54 cm(3) and 6.6 +/- 1.3% gain, P < 0.05). CONCLUSION: ALP and platelet counts might be able to predict PVE effect and were related to postoperative course. Identification of more specific predictors is desirable.

Adult↗
PubMed2006

Diagnosis of perfusion abnormality of the pulmonary artery in Takayasu's arteritis using contrast-enhanced MR perfusion imaging.

To determine the clinical efficacy of contrast-enhanced magnetic resonance (MR) perfusion imaging in the diagnosis of perfusion abnormality in the pulmonary artery (PA) in Takayasu's arteritis (TA). Twenty-one patients were evaluated. Pulmonary MR perfusion images were acquired using a 2-dimensional (2D) fast spoiled gradient echo sequence with single-slice technique (TR/TE, 5.3/1.3; flip angle, 30 degrees; receiver bandwidth, 31.2 kHz/pixel; acquisition time, 0.7 s; and total acquisition time, 49 s). Seventy continuous subtracted MR images were evaluated, and the presence of perfusion abnormality was determined in lobe-based (n=126) and patient-based (n=21) analyses. Sensitivity, specificity, positive predictive value (PPV), and negative predictive values (NPV) were calculated using perfusion scintigraphy as a standard reference. For lobe-based analysis, sensitivity was 91.7-95.8%, specificity was 92.2-93.7%, and PPV and NPV were 73.3-76.7% and 97.9-99.0%, respectively. For patient-based analyses, sensitivity was 100%, specificity was 72.7%, and PPV and NPV were 76.9% and 100%, respectively. Kappa values for each analysis were between 0.78-1.00. In conclusion, MR perfusion imaging appears to be a valuable, noninvasive method to estimate PA involvement in patients with TA.

Adult↗
PubMed2006

Response of temporomandibular joint intermittent closed lock to different treatment modalities: A multicenter survey.

This study investigated the clinical picture and different treatment methods and results at a number of institutions with the aim of establishing an effective method of treatment for intermittent closed lock (intermittent lock) of the temporomandibular joint (TMJ). The subjects were 104 patients (29 males, 65 females) diagnosed with intermittent lock among 1787 temporomandibular disorder patients. The cases were classified into two types based on the time and occasion when the intermittent lock occurred. The sudden onset type developed in 69.2%, and the habitually occurring type in 29.8%. The most common treatment was disk repositioning exercises alone (in 41 cases) followed by stabilization splints during sleeping. The highest efficacy rate (60.0%) was obtained with the combination of disk repositioning exercise and a repositioning splint followed by a rate of 52.6% with stabilization splints and 41.7% with disk repositioning exercise alone.

Adolescent↗
PubMed2006

Effect of etidronic acid on arterial calcification in dialysis patients.

BACKGROUND: Bisphosphonate drugs, including etidronic acid, are effective agents for the treatment of osteoporosis and may reduce arterial calcification. The aim of this randomised control trial was to characterise the effect of etidronic acid on arterial calcification in patients undergoing chronic haemodialysis. METHODS: Patients undergoing chronic haemodialysis were assigned to one of two groups by a simple randomisation method: an etidronic acid group (n = 8; 400 mg/day for 24 weeks) and a control group (n = 6; no etidronic acid therapy). Serum calcium, phosphate, calcium-phosphate product, alkaline phosphatase, lactate dehydrogenase, activated colecalciferol and parathyroid hormone levels were measured at baseline and then at 4-weekly intervals thereafter. RESULTS: Calcification scores of the coronary arteries and the thoracic and abdominal aorta were determined by volume-correcting data collected by a multi- detector-row computerised tomographic scanner at baseline, at 6 months and at 1 year. Two patients in the etidronic acid group were excluded from the final analysis because of medical complications. The remainder of the patients (n = 6) showed no significant temporal changes in serum levels of assessed parameters. While no significant temporal changes in coronary calcification score were observed in either group, the mean aortic calcification score significantly decreased over time from 1000 +/- 460mm(3 )at baseline to 970 +/- 580mm(3) at the completion of treatment and 350 +/- 180mm(3) at 1 year (p = 0.009), corresponding to a mean percentage decrease of -64.1% (range -86.5% to -50.1%). By contrast, in the control group, the mean aortic calcification score significantly increased with time from 1460 +/- 1280mm(3) to 1510 +/- 1150mm(3) at the completion of treatment and 2070 +/- 1200mm(3) at 1 year (p = 0.006), corresponding to a mean percentage change in the calcification score of +130.0% (range 2.1-414%). CONCLUSION: Etidronic acid markedly reduced aortic calcification in patients with end-stage renal disease undergoing chronic haemodialysis. The effect of this agent on aortic calcification may attenuate the increase in aortic stiffness and result in improved long-term outcomes in patients undergoing chronic haemodialysis.

Aged↗
PubMed2006

CT analysis of the growth rate of aortic diameter affected by acute type B intramural hematoma.

OBJECTIVE: The purpose of this study was to evaluate the growth rate of aortic diameter affected by acute type B intramural hematoma and the factors that influence its enlargement. MATERIALS AND METHODS: Fifty-four patients were entered into this study, and regular follow-up CT studies (mean +/- SD, 46.9 +/- 27.2 months; range, 5-136 months) were performed. The affected aortas and iliac arteries were divided into five segments. A total of 127 segments were evaluated (aortic arch, n = 47; descending thoracic aorta, n = 51; suprarenal abdominal aorta, n = 24; infrarenal abdominal aorta, n = 3; and iliac artery, n = 2). The growth rate of each segment was obtained on CT. The factors influencing increase in the diameter and growth rate--age, sex, diabetes mellitus, atherosclerotic disease, history of smoking 20 years, chronic renal failure, blood pressure, initial diameter of the lumen, the presence of blood flow in the false lumen--were evaluated by univariate analysis and a multivariate logistic regression model. RESULTS: Twenty (37.0%) of 54 patients had one or more segments that increased in size during the follow-up period. Of a total of 127 segments, 35 (27.6%) increased in size, and for all, the mean growth rate was -0.5 +/- 2.9 mm/year. This negative growth rate represents shrinkage. The mean growth rates within the first year and after 1 year from onset were -2.2 +/- 5.7 and 0.4 +/- 3.2 mm/year, respectively, and a significant difference was observed between them (p < 0.0001). An initial diameter of 40 mm or greater and the presence of blood flow in the false lumen were significant risk factors for an increase in the diameter, as confirmed by univariate and multivariate analyses. CONCLUSION: In patients with type B intramural hematoma, the affected aortas did not show a high incidence of enlargement during the follow-up period, but the affected aortas tended to increase in size after 1 year from onset. An initial diameter of 40 mm or greater and the presence of blood flow in the false lumen were important risk factors for enlargement during the follow-up period.

Adult↗
PubMed2006

MRI of Takayasu's arteritis: typical appearances and complications.

OBJECTIVE: Although Takayasu's arteritis (TA) is more common in Asian countries, it has a worldwide distribution. MRI is widely used for its diagnosis. Our purpose is to present a comprehensive pictorial review of its typical appearances and complications on MRI. CONCLUSION: MRI can effectively provide almost all anatomic information in patients with TA. MRI is very useful for accurate diagnosis of TA and its complications. Knowledge of MRI findings is essential for improving patient outcome.

Adult↗
PubMed2006

Teeth contacting habit as a contributing factor to chronic pain in patients with temporomandibular disorders.

Many different factors are known to cause and perpetuate the symptoms of temporomandibular disorders (TMD). However, the roles of parafunctional factors have not been clearly elucidated. We found one of these habits in the clinical setting. This parafunctional habit involves daily light touching of the upper and lower teeth, when the mouth is closed. We named this habit Teeth Contacting Habit (TCH). [OBJECTIVES] To investigate the following hypotheses: 1) TCH is associated with perpetuation of chronic pain of TMD patients; 2) TCH is associated with other behavioral factors. [METHODS] Two hundred and twenty-nine TMD outpatients with chronic pain were analyzed with multivariate logistic regression models. [RESULTS] TCH was found in 52.4% of patients. Patients with TCH and pain lasting for more than four months were less likely to experience improvements in pain at the first visit (OR = 1.944, p = 0.043). Other factors associated with TCH were as follows: unilateral chewing (OR = 2.802) and involvement in a precision job (OR = 2.195). [CONCLUSION] TCH can prolong TMD pain and is associated with other behavioral factors.

Adult↗
PubMed2005

Endovascular surgery using an original occluder for patent ductus arteriosus in an adult patient.

The patient was a 67-year-old woman in whom patent ductus arteriosus was diagnosed in childhood but not treated. In April 2000, she was hospitalized for exacerbation of heart failure. Marked restrictive impairment was seen: %VC was 36.1%, and FEV1% was 77.0% (respiratory function tests). As calcification was present, and since the aortic opening measured 20 mm, coil occlusion or thoracoscopic surgical interruption were considered difficult to perform. Because of concerns about postoperative respiratory complications associated with thoracotomy, the ductus was occluded under local anesthesia using an original occluder consisting of a vascular graft and modified Z-stent. Postoperatively, during more than three years of follow-up, the patient has remained well with no residual shunt or occluder migration. Consequently, patent ductus arteriosus occlusion using an original occluder appears to be a superior, minimally invasive technique that can successfully treat large ductus arteriosus complicated by calcification.

Aged↗
PubMed2005

Endovascular treatment of iliac artery aneurysms.

Endovascular treatment is now an alternative to surgery for the treatment of iliac artery aneurysms (IAAs). A variety of minimally invasive therapeutic options are available (eg, coil embolization, stent-graft placement), and choosing an appropriate option is essential for achieving excellent long-term results and reducing potential complications. Preprocedural imaging with multi-detector row computed tomography or magnetic resonance imaging is necessary for evaluating patient eligibility and planning the interventional procedure. An imaging classification system for IAAs that is based on anatomic features and endovascular treatment options has been developed and may help determine therapeutic strategies for affected patients. Early experience indicates that endovascular treatment is safe and effective in treating IAAs, and it is expected that various devices that will make endovascular treatment easier to perform will soon become commercially available. However, large, long-term follow-up studies will be needed to determine whether this approach is a practical alternative to open surgery.

Aged↗
PubMed2005

Visceral and peripheral arterial pseudoaneurysms.

OBJECTIVE: Pseudoaneurysms are not rare, and various conditions can cause a pseudoaneurysm in all the cardiovascular systems. In this article, we discuss and show images of pseudoaneurysms of various arteries caused by various conditions. CONCLUSION: CT, MRI, sonography, and angiography may all be valuable in the imaging workup of pseudoaneurysms. Knowledge of the various appearances of pseudoaneurysms and of the proper management is essential to prevent a catastrophic outcome in cases of pseudoaneurysm.

Aneurysm, False↗
PubMed2004

Growth rate of aortic diameter in patients with type B aortic dissection during the chronic phase.

BACKGROUND: The purpose of this study was to evaluate the growth rate of type B double-barrel aortic dissection with computed tomography (CT) and the factors influencing its enlargement. METHODS AND RESULTS: Sixty-two patients were entered into this study, and regular follow-up CT studies (mean; 49.1 months) were performed. The affected aortas and iliac arteries were divided into 5 segments (aortic arch, descending thoracic, suprarenal abdominal, infrarenal abdominal aorta, and iliac artery). Fifty-two of 62 patients (83.9%) had 1 or more segments increased in size during follow-up period. In a total of 177 segments, the presence or absence of blood flow in the false lumen and aortic diameter were evaluated on CT during the follow-up period. The factors (gender, diabetes mellitus, atherosclerotic disease, smoking, entry site in arch, initial diameter, chronic obstructive pulmonary disease, blood pressure, and age) influencing increase in the diameter and growth rate were also evaluated. Of 177 segments, 132 segments (74.6%) increased in size during the follow-up period. The presence of blood flow in the false lumen was the only significant risk factor for increase in the diameter in the univariate and multivariate analysis. The group with blood flow in the false lumen had a significantly higher mean growth rate (3.3 mm/year) than the group without blood flow (-1.4 mm/year) (P<0.0001). The growth rate of aortic dissections in thoracic aorta and abdominal aorta were 4.1 and 1.2 mm/year, respectively. There was a significant difference in the growth rate between the 2 groups (P=0.0003). CONCLUSIONS: In type B aortic dissection, the affected aortas have shown a high incidence of enlargement during the follow-up period, and more careful follow-up study is needed for aortic dissections in the thoracic aorta. The presence of blood flow in the false lumen is the most important risk factor for aortic enlargement.

Adult↗
PubMed2004

Long-term outcome of type B aortic intramural hematoma: comparison with classic aortic dissection treated by the same therapeutic strategy.

BACKGROUND: The long-term clinical course and therapeutic strategy of patients with type B aortic intramural hematoma (IMH) are not completely known. The purpose of this study was to clarify long-term prognosis of patients with type B IMH by comparison with type B classic aortic dissection (AD). METHODS: Clinical data were compared retrospectively between 37 patients with acute type B IMH (IMH group) and 69 patients with acute type B AD (AD group). Our therapeutic strategy for all patients was medical therapy with frequent follow-up imaging studies and timed surgical repair in cases with progression. RESULTS: Initially, medical therapy was selected for 104 of 106 (98%) patients. In two patients of the AD group, immediate surgical treatment was performed because of aortic rupture. As for complications, no significant difference was seen between the two groups. There was no significant difference in the incidence of the total number of deaths; early death, late death, or causes of deaths. The actuarial survival rates for the IMH group at 1, 2, 5, and 10 years were 97 +/- 3, 97 +/- 3, 85 +/- 9, and 85 +/- 9%, respectively; the values were 96 +/- 1, 96 +/- 1, 89 +/- 4, and 71 +/- 9%, for the AD group. The actuarial survival rates of the two groups were not significantly different from each other (p = 0.398). CONCLUSIONS: Patients with type B IMH have similar long-term prognosis to patients with type B AD. Medical therapy with frequent follow-up imaging studies and timed surgical repair in cases with progression can be a rational therapeutic strategy in patients with type B IMH.

Aged↗