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Biomedical subjects

K Yasuda

Publications and source records attributed to K Yasuda.

At least 37 records · Page 2Linked to original sources

[Risk factors for the surgical repair of ventricular septal perforation; an 8-year multiinstitutional analysis].

OBJECTIVE: The purpose of this study was to determine the surgical outcomes and risk factors for surgical repair of the ventricular septal perforation (VSP). METHOD: From 1995 to 2003, 41 patients with VSP underwent surgical repair. There were 18 males and 23 females, with the mean age of 71.7 +/- 9.2. Sixteen patients (39.0%) had the preoperative shock, while 30 patients received intraaortic balloon pumping (IABP) assistance and 1 of those required percutaneous cardiopulmonary support (PCPS). Mean durations from onset of myocardial infarction and VSP to operation were 5.8 +/- 9.4 and 2.4 +/- 8.1 days, respectively. Twenty-six patients underwent infarct exclusion technique, 11 underwent patch closure, and 4 Daggett operation. Mean cardiopulmonary and aortic cross-clamp time were 211 +/- 85 and 105 +/- 43 minutes, respectively. RESULTS: Thirty days mortality was 11 (26.8%). Nine patients (22%) required PCPS after repair, however, 2 weaned off the support and only 1 discharged the hospital. Residual shunt was found in 12 patients (29.3%), and 4 underwent the reclosure of the residual shunt 13 +/- 8.6 days after the initial operation, whereas none of patients with PCPS had residual shunt. Univariate analysis revealed the preoperative shock (p = 0.03), longer cardiopulmonary bypass time (p < 0.01), and the need for PCPS after repair (p < 0.01) were the risk factors for the early mortality. Multivariate analysis indicated the cardiopulmonary time over 210 minutes and the need for PCPS to be the significant risk factors. CONCLUSION: The long cardiopulmonary bypass support after repair and the subsequent need for PCPS imply the poor left ventricular function. Since the residual shunt was not the cause of PCPS, the surgical outcome for VSP may be limited in patients with poor left ventricular function. In these patients, other therapeutic strategies may be required, such as ventricular assisting devices, transplantation, or regenerative therapy.

Aged↗

[Overlapping ventriculoplasty for ischemic cardiomyopathy].

We have previously reported overlapping cardiac volume reduction operation (OLCVR) for dilated cardiomyopathy. Because of the acceptable clinical outcome and especially the excellent ellipsoidal shape of the left ventricle (LV) after surgery, we extended this indication for ischemic cardiomyopathy (ICM) with dilated LV. In such cases we combined OLCVR with mitral annuloplasty and papillary muscles approximation (PMA), called integrated overlapping ventriculoplasty (IOLVP). From March 2003 to July 2004, we performed IOLVP with coronary artery bypass grafting (CABG) for 8 patients who were diagnosed ICM. There is no operative mortality. Pre- and postoperative hemodynamics data are follows: LV ejection fraction (LVEF) improved from 22.4 +/- 11.9 to 33.4 +/- 10.5%, LV end-diastolic volume index (LVEDVI) decreased from 155.5 +/- 26.5 to 93.7 +/- 13.5 ml/m2 and LV end-diastolic diameter (LVDd) diminished from 66.0 +/- 8.9 to 60.5 +/- 8.4mm. Mitral regurgitation changed from 2.6 +/- 0.8 to 0.1 +/- 0.2 degree. New York Heart Association (NYHA) functional class improved from 3.3 +/- 0.5 to 1.3 +/- 0.5. LV shape became ellipsoidal without akinesis lesion. IOLVP is considered as a good option for ICM with dilated left ventricle.

Aged↗

[Acute type A aortic dissection associated with intestinal necrosis].

We report a case with acute type A aortic dissection associated with occlusion of the celiac artery (CA) and the superior mesenteric artery (SMA) who underwent replacement of the aortic valve and the ascending aorta concomitant with CA and SMA bypass grafting and partial resection of the ileum and the cecum. A 79-year-old man who has a history of Y-graft replacement of abdominal aortic aneurysm developed re-dissection of thrombosed type A acute dissection 2 weeks after the onset. We performed CA and SMA bypass grafting followed by replacement of the aortic valve and the ascending aorta. In spite of successful revascularization of the CA and SMA, residual necrosis in the ileum and the cecum necessitated resection of them. He was discharged 11 months postoperatively without neurological sequelae.

Aged↗

Long-term results of treatments for varicose veins due to greater saphenous vein insufficiency.

AIM: The purpose of this study was to determine the long-term recurrence rates of greater saphenous vein (GSV) insufficiency after treatments for primary varicose veins, and to elucidate risk factors for recurrence. METHODS: This was a multicenter retrospective analysis of 376 limbs of 296 patients treated for primary varicose veins due to GSV insufficiency from January 1996 to December 1997. The recurrence-free rates after stripping surgery, saphenofemoral ligation, and sclerotherapy were estimated. The risk factors for the recurrence of primary varicose veins were estimated by multiple regression analysis. RESULTS: The follow-up period was 3.1+/-1.3 (mean+/-SD) years. The recurrence-free rates at 4 years after stripping, saphenofemoral ligation and sclerotherapy were 80.7%, 64.5%, and 51.3%, respectively. The saphenofemoral ligation group and sclerotherapy group had significantly higher recurrence rates than the stripping group (P=0.002, P<0.001, respectively). There was no difference in recurrence rates between the saphenofemoral ligation group and sclerotherapy group (P=0.074). Logistic regression analysis revealed that being female (P<0.029) and treatment without stripping (P<0.001) increased the recurrence rate. CONCLUSIONS: Stripping surgery may be the treatment of first choice for patients with varicose veins due to GSV insufficiency. Patients who have not received stripping surgery and female patients require closer follow-up.

Aged↗

The less incisional retroperitoneal approach for abdominal aortic aneurysm repair to prevent postoperative flank bulge.

One of the postoperative complications of retroperitoneal incision is a flank bulge that is suggested to be caused by 11th intercostal nerve injury leading to denervation of the ipsilateral muscles. To avoid this complication, we have tried to minimize retroperitoneal incision for abdominal aortic aneurysm (AAA) repair. The feasibility of the less incisional retroperitoneal approach for the repair of AAA to prevent postoperative flank bulge was investigated. Twenty-seven patients undergoing elective repair for infrarenal AAA through the left retroperitoneal approach were divided into group-L (less incision: 11.9+/-1.8 cm, n = 7) and group-C (conventional incision: 17.8+/-1.9 cm, n = 20). All operations were performed by a traditional hand-sewn anastomosis without laparoscopic support. Five bifurcated grafts were used in group-L and 15 in group-C. The postoperative course of all patients was uneventful except that one patient in group-C required reoperation for bleeding. Intraoperative parameters of both groups were almost comparable. All patients in group-L were extubated in the operating theater, whereas it was possible only for 11 patients in group-C. Resumption of alimentation was significantly earlier in group-L (P = 0.0117). There was no significant difference in postoperative hospital stay between groups. No late flank bulge was experienced. Significant late atrophy of the left rectus muscle (left/right thickness-ratio = 0.59+/-0.24) was seen in group-C (P = 0.0042 vs preoperative value), which was not observed in group-L (P = 0.0008 between groups). The less incisional retroperitoneal AAA repair seems feasible and safety technique that might prevent postoperative flank bulge and reduce surgical stress.

Aged↗

Laparoscopy-assisted distal gastrectomy for early gastric cancer in obese and nonobese patients.

BACKGROUND: Conventional open gastrectomy has been reported to result in increased morbidity in obese patients. To date, there has been no study evaluating laparoscopic gastrectomy in such patients; therefore, we assessed the short-term results of this procedure in a group of obese patients. METHODS: The study included 99 consecutive patients who underwent laparoscopy-assisted distal gastrectomy (LDG) for the cure of early gastric cancer. The patients were divided into two groups: obese (body mass index [BMI] > or =25.0, n = 16) and nonobese (BMI <25.0, n = 83). Patient characteristics, operative details, and postoperative outcomes were compared and analyzed. RESULTS: Patient characteristics, including age, sex, American Society of Anesthesiologists (ASA) status, and disease stage, were not different between obese and nonobese patients. Operating time was significantly longer in obese patients than in nonobese patients (271 vs 239 min, p < 0.05). However, there was no significant difference between obese and nonobese patients in time to first flatus (3.7 vs 3.3 days), time to solid diet (6.3 vs 5.2 days), length of postoperative hospital stay (18.7 vs 17.9 days), or frequency of major (25% vs 16%) and minor (19% vs 12%) postoperative complications. There were no conversions to conventional open surgery and no perioperative deaths. CONCLUSION: The only difference between our two study groups was that LDG required a longer operating time in obese patients; morbidity and length of hospital stay were not increased. Thus, we believe that LDG is likely to become the treatment of choice for obese patients with early gastric cancer.

Adult↗

Laparoscopically assisted distal gastrectomy for early gastric cancer in the elderly.

BACKGROUND: Open gastrectomy is associated with increased morbidity and a longer hospital stay than laparoscopically assisted gastrectomy. The aim of this study was to clarify the value of laparoscopically assisted distal gastrectomy (LDG) in the elderly, in whom co-morbid disease is generally more common. METHODS: Forty-five elderly patients (aged 70 years or more) and 57 younger patients who underwent LDG, and 28 elderly patients who underwent open distal gastrectomy (ODG) for early gastric cancer between January 1994 and April 2003 were studied. Demographics and postoperative outcomes were compared. RESULTS: : Co-morbidity was more common in elderly patients than in younger patients who underwent LDG (25 of 45 versus 16 of 57; P = 0.004). The postoperative complication rate, time to solid diet and postoperative hospital stay were similar in these two groups. Elderly patients who underwent LDG had a significantly reduced medical complication rate (two of 45 versus six of 28; P = 0.023), time to first flatus (3.7 versus 4.2 days; P = 0.042), time to solid diet (4.6 versus 5.5 days; P = 0.011) and postoperative hospital stay (16.3 versus 23.9 days; P = 0.011) than elderly patients who had ODG. CONCLUSION: LDG offers particular advantages to elderly patients with early gastric cancer, including rapid return of gastrointestinal function, fewer complications and a shorter hospital stay.

Aged↗

Adenovirus-mediated CTLA4 immunoglobulin G gene therapy in cardiac xenotransplantation.

BACKGROUND: CTLA4 immunoglobulin (CTLA4 Ig), which binds with high affinity to B7-1 and B7-2, interrupts T-cell activation by inhibiting the costimulatory signal. CTLA4Ig has been used to achieve antigen-specific tolerance induction in cardiac allografts. On the other hand, we have shown that short-term administration of deoxyspergualin (DSG) and daily cyclosporine (CsA) induces long-term survival of cardiac xenotransplants. We hypothesized that the combination therapy of DSG and adenovirus-mediated CTLA4IgG might induce long-term, survival or tolerance in cardiac xenotransplantation. OBJECTIVES: Syrian hamster hearts were transplanted heterotopically into Lewis rats. We compared the survival time and immunopathology of the following five groups: (1) no treatment; (2) DSG (5 mg/kg per day intramuscularly [IM], days -1 to +7) alone; (3) CsA (15 mg/kg per day IM, day 0 to rejection) plus DSG; (4) AdexLacZ (LacZ-adenovirus 1 x 10(9) (PFU intravenously [IV], day -7) plus DSG; and (5) AdexCTLA4IgG (CTLA4IgG-adenovirus 1 x 10(9) PFU IV, day -7) plus DSG. RESULTS: The survival times were: (1) no treatment, 3.7 days; (2) DSG alone, 12.4 days; (3) CyA plus DSG, >100 days; (4) AdexLacZ plus DSG, 11.0 days; and (5) AdexCTLA4IgG plus DSG, 23.6 days. Adenovirus-mediated CTLA4IgG therapy with DSG prolonged survival time significantly compared with DSG alone or AdexLacZ plus DSG, but CTLA4IgG therapy was not as effective as CsA. Immunopathology showed the deposition of C3 and IgM on the endothelium in the AdexCTLA4IgG plus DSG group. CONCLUSIONS: We showed that the effectiveness of adenovirus-mediated CTLA4IgG gene therapy in cardiac xenotransplantation in less than that of CsA. Combination therapy with inhibition of the B7/CD28 constimulatory signal and DSG administration might not be sufficient for long-term survival or tolerance in cardiac xenotransplantation.

Abatacept↗

Pattern modification of a neuronal network for individual-cell-based electrophysiological measurement using photothermal etching of an agarose architecture with a multielectrode array.

A new type of individual-cell-based on-chip multielectrode array (MEA) cell-cultivation system with an agarose microchamber (AMC) array for topographical control of the network patterns of a living neuronal network has been developed. The advantages of this system are that it allows control of the cell positions and numbers for cultivation using AMCs, as well as easy and flexible control of the pattern of connections between the AMCs through photothermal etching where a portion of the agarose layer is melted with a 1480 nm infrared laser beam. With adequate laser power, narrow micrometer-order grooves (microchannels) can easily be fabricated that can be used to combine neighbouring AMCs to enable topographical control of the neural network pattern. Using this system, an individual-cell-based neural network pattern was formed of rat hippocampal cells within the AMC array without cells escaping from the electrode positions in the microchamber during an eight-day cultivation, and could record cell firing in response to 1.5 V, 500 kHz stimulation through an electrode. This demonstrated the potential of the on-chip AMCMEA cell cultivation system for long-term single-cell-based electrophysiological measurement of a neural network system.

Journal Article↗

Off-pump ascending to descending aorta bypass grafting with descending aneurysm exclusion.

We performed an ascending to descending aorta bypass grafting with exclusion of the descending thoracic aortic aneurysm through a median sternotomy incision without cardiopulmonary bypass in a patient with severe chronic obstructive pulmonary disease. The patient was a 75-year-old man who had undergone endovascular stent-graft placement for a descending thoracic aortic aneurysm. The operation became necessary because the aneurysm continued to expand without evidence of endoleak. The postoperative course was uneventful, and without respiratory morbidity.

Aged↗

Differentially expressed Maf family transcription factors, c-Maf and MafA, activate glucagon and insulin gene expression in pancreatic islet alpha- and beta-cells.

A basic-leucine zipper transcription factor, MafA, was recently identified as one of the most important transactivators of insulin gene expression. This protein controls the glucose-regulated and pancreatic beta-cell-specific expression of the insulin gene through a cis-regulatory element called RIPE3b/MARE (Maf-recognition element). Here, we show that MafA expression is restricted to beta-cells of pancreatic islets in vivo and in insulinoma cell lines. We also demonstrate that c-Maf, another member of the Maf family of transcription factors, is expressed in islet alpha-cells and in a glucagonoma cell line (alphaTC1), but not in gamma- and delta-cells. An insulinoma cell line, betaTC6, also expressed c-Maf, albeit at a low level. Chromatin immunoprecipitation assays demonstrated that Maf proteins associate with insulin and glucagon promoters in beta- and alpha-cell lines, respectively. c-Maf protein stimulated glucagon promoter activity in a transient luciferase assay, and activation of the glucagon promoter by c-Maf was more efficient than by the other alpha-cell-enriched transcription factors, Cdx2, Pax6, and Isl-1. Furthermore, inhibition of c-Maf expression in alphaTC1 cells by specific short hairpin RNA resulted in marked reduction of the glucagon promoter activity. Thus, c-Maf and MafA are differentially expressed in alpha- and beta-cells where they regulate glucagon and insulin gene expression, respectively.

Animals↗

[Individual temperature management during thoracoabdominal aortic aneurysm repair using separate perfusion of upper and lower torso].

We report thoracoabdominal aortic aneurysm repair using separate perfusion of upper and lower torso that can control temperature of each organ individually. This novel modality can maintain mild hypothermic organ perfusion in upper torso and protect the heart under empty beating, while lower torso is further cooled to protect the spinal cord and visceral organs. Therefore this technique may be useful for patients with heart disease who require complex reconstruction of the intercostal arteries or visceral branches. We used this technique successfully in a patient who has a history of surgical repair of the aortic arch and the abdominal aorta. A 70-year-old male who had a history of abdominal aortic aneurysm repair and aortic arch aneurysm repair using stented elephant trunk underwent Crawford's type II thoracoabdominal aortic aneurysm repair. Three pairs of the intercostal arteries and 4 visceral branches were reconstructed using this technique successfully.

Aged↗

[Strategy for spinal cord protection during thoracoabdominal aortic surgery].

INTRODUCTION: Our basic strategy for spinal cord protection during thoracoabdominal aortic surgery has been established since August 1994 such as: 1) distal aortic perfusion using partial cardiopulmonary bypass (32-34 degrees C), 2) multi-segmental sequential clamping, 3) deep hypothermic circulatory arrest when sequential clamping is impossible, 4) evoked spinal cord potential-guided reconstruction of the critical intercostal arteries (preoperative evaluation using multi-detector row computed tomography), 5) cerebrospinal fluid drainage, and 6) administration of naloxone hydrochloride and methylprednisolone. In this paper, we analyzed clinical outcome of thoracoabdominal aortic surgery according to this strategy. MATERIALS AND METHODS: We have performed thoracoabdominal aortic surgery for 84 patients (52 male, mean 62 +/- 12 years old) during 1991-2003. Their etiology was 34 dissection, 44 non-dissection degenerative disease, 3 pseudo-aneurysm, and 3 infection. Ten operations were performed urgently and 8 emergently. Crawford's classification (type I/II/III/IV/V) was 17/28/17/13/9 for each type. We used partial cardiopulmonary bypass for 67 cases and deep hypothermic circulatory arrest for 14. RESULTS: For overall/elective cases (n = 84/66), we experienced 13.1/12.1% of incidence of spinal cord injury (paraplegia/paraparesis) and 8.3/4.5% of in-hospital mortality. Within 65 cases (55 elective) operated after August 1994, they decreased up to 7.7/5.5% (0% in type II) and 4.6/1.8%, respectively. Paraplegia was experienced in 2 patients before and 2 patients (emergent operations due to infective aneurysm) after August 1994 (4.8%). Thus, we have experienced no paraplegia in elective cases after establishment of our strategy. CONCLUSIONS: Our strategy for spinal cord protection during thoracoabdominal aortic surgery could provide acceptable clinical outcome and seemed justified.

Adult↗

[Aortic root replacement with free-style stentless valve for aorto-left and right ventricular communication due to infective endocarditis; report of a case].

Aortic root abscess remains a major determinant of both early and late results of surgical treatment of endocarditis. This complication rarely progresses to intracardiac shunt followed by cardiac failure. We report a surgical case of a 40-year-old man, who had been diagnosed as prosthetic valve endocarditis with aortic root abscess ruptured into left and right ventricle creating aorto-left and right ventricular communication. Because of complete debridment of infective and/or dead tissue, aortic root replacement was required. We used free-style stentless valve, xenograft, since homograft was not available at the time of operation. We believe that this prosthesis has easier handling and is more resistant to infection, therefore, it might be an option for infective endocarditis with aortic root abscess.

Abscess↗

[Off-pump coronary artery bypass via left thoracotomy in patient with infective pancreatic fistula after surgery for bile duct carcinoma; report of a case].

A 62-year-old man with infective pancreatic fistula after surgery for bile duct carcinoma underwent off-pump coronary artery bypass (OPCAB) through left thoracotomy to avoid the use of cardiopulmonary bypass and the postoperative mediastinitis, since this patient has infective pancreatic fistula close to the xiphoid process. The coronary arterial revascularizations were performed: left internal thoracic artery to left anterior descending branch and saphenous vein graft to descending thoracic aorta. The aortic mechanical anastomosis device, aortic connector, was utilized the proximal anastomosis of saphenous vein graft so as to avoid aortic clamp, while the distal anastomoses were completed with stabilizer and apical retraction device. Postoperative angiogram showed both grafts were patent. No signs of infection or recurrence of malignant neoplasm was observed. OPCAB via left thoracotomy is one of useful options for patients in whom median sternotomy is not suitable approach for myocardial revascularizations.

Bile Duct Neoplasms↗