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T Ohki

Publications and source records attributed to T Ohki.

At least 37 records · Page 2Linked to original sources
PubMed2001

Increasing incidence of midterm and long-term complications after endovascular graft repair of abdominal aortic aneurysms: a note of caution based on a 9-year experience.

OBJECTIVE: To analyze the late complications after endovascular graft repair of elective abdominal aortic aneurysms (AAAs) at the authors' institution since November 1992. SUMMARY BACKGROUND DATA: Recently, the use of endovascular grafts for the treatment of AAAs has increased dramatically. However, there is little midterm or long-term proof of their efficacy. METHODS: During the past 9 years, 239 endovascular graft repairs were performed for nonruptured AAAs, many (86%) in high-risk patients or in those with complex anatomy. The grafts used were Montefiore (n = 97), Ancure/EVT (n = 14), Vanguard (n = 16), Talent (n = 47), Excluder (n = 20), AneuRx (n = 29), and Zenith (n = 16). All but the AneuRx and Ancure repairs were performed as part of a U.S. phase 1 or phase 2 clinical trial under a Food and Drug Administration investigational device exemption. Procedural outcomes and follow-up results were prospectively recorded. RESULTS: The major complication and death rates within 30 days of endovascular graft repair were 17.6% and 8.5%, respectively. The technical success rate with complete AAA exclusion was 88.7%. During follow-up to 75 months (mean +/- standard deviation, 15.7 +/- 6.3 months), 53 patients (22%) died of unrelated causes. Two AAAs treated with endovascular grafts ruptured and were surgically repaired, with one death. Other late complications included type 1 endoleak (n = 7), aortoduodenal fistula (n = 2), graft thrombosis/stenosis (n = 7), limb separation or fabric tear with a subsequent type 3 endoleak (n = 1), and a persistent type 2 endoleak (n = 13). Secondary intervention or surgery was required in 23 patients (10%). These included deployment of a second graft (n = 4), open AAA repair (n = 5), coil embolization (n = 6), extraanatomic bypass (n = 4), and stent placement (n = 3). CONCLUSION: With longer follow-up, complications occurred with increasing frequency. Although most could be managed with some form of endovascular reintervention, some complications resulted in a high death rate. Although endovascular graft repair is less invasive and sometimes effective in the long term, it is often not a definitive procedure. These findings mandate long-term surveillance and prospective studies to prove the effectiveness of endovascular graft repair.

Aged↗
PubMed2001

Comparison of various reproductive status in Sika deer (Cervus nippon) using fecal steroid analysis.

The feasibility of fecal steroid analysis for pregnancy diagnosis and sex determination were tested in sika deer (Cervus nippon). Feces were collected from captive sika deer in June (non-breeding season and late-pregnancy period) and October (breeding season), and also from the rectum of 24 female sika deer (19 pregnant and 5 non-pregnant females) shot as part of programs for population control in February and March (mid-pregnancy period). In mid- and late-pregnancy periods, fecal progesterone concentrations were significantly higher in pregnant female than in male and non-pregnant female deer. In October, fecal testosterone concentrations were higher in adult male deer, and no difference was found between young males and females. These results suggest that fecal steroid analysis would be a useful means for estimating pregnancy status and for detecting adult male among wild deer.

Animals↗
PubMed2001

Reconstruction of heavily calcified aorta and its visceral branches without extracorporeal circulation.

A 61-year-old Japanese female was referred to our hospital for surgical treatment of a localized heavily calcified abdominal aorta. Preoperative angiograms and computed tomograms revealed severe stenosis of the aorta, resembling a slit. Bypass grafting between the thoracic and abdominal aorta was successfully performed together with the reconstruction of the celiac artery, superior mesenteric artery, and bilateral renal arteries without extracorporeal circulation. Postoperative angiograms showed patency of the graft and branches. A localized heavily calcified abdominal aorta is relatively rare, and the cause of this entity might be Takayasu's aortitis.

Aged↗
PubMed2001

Carotid artery stenting: utility of cerebral protection devices.

Neurologic deficits secondary to embolic events have been the most significant concern regarding carotid bifurcation stenting. Experimental studies utilizing human carotid plaques have shown that embolic particles were released from all specimens. In addition, transcranial Doppler studies have confirmed the fact that multiple emboli are released during each case. Preliminary experiences with the use of cerebral protection devices for carotid stenting have shown encouraging results with embolic particles recovered from each case, although these experiences have also revealed some of the down sides of its use. The present article provides the rationale for routine use of these protection devices and also reviews various protection devices, some of which are currently undergoing clinical trials.

Blood Vessel Prosthesis Implantation↗
PubMed2001

Limited role for IVUS in the endovascular repair of aortoiliac aneurysms.

BACKGROUND: To determine the need for routine versus selective intraoperative IVUS during endovascular aortoiliac aneurysm (AIA) repair. METHODS: One-hundred and eighty-eight endovascular AIA repairs performed over a 5-year period were reviewed and included in the study. Surgeon-made aorto-uni-femoral grafts (n=78) and industry-made bifurcated or tube grafts (n=110) were used. In the initial 51 cases IVUS was routinely performed. In the latter 137 cases IVUS was used selectively. In this group graft deformities suspected on completion angiography or pullback pressure measurements were treated with balloon dilatation and stenting. IVUS was then performed only in the presence of a persistent pressure gradient or inconclusive angiographic findings. RESULTS: In the initial 51 cases IVUS revealed 20 lesions of which 8 were not initially detected angiographically and which required further treatment. In the latter 137 cases IVUS was necessary in only 1 case, and guided the treatment of an angiographically undetectable lesion. There have been no late episodes of graft compression, kinking, or thrombosis in the selective IVUS group. CONCLUSIONS: The use of pullback pressure measurements with a low threshold for angioplasty and stenting, especially in unsupported grafts, followed by the selective use of IVUS decreases the overall requirement for IVUS and its associated costs.

Angiography↗
PubMed2001

[Central nervous system involvements in Duchenne/Becker muscular dystrophy].

Duchenne/Becker muscular dystrophy (DMD/BMD) are the most common inherited muscular diseases caused by mutations in the dystrophin gene. The identification of novel dystrophins in the brain has recently implicated its absence or malfunction etiologically in mental retardation (MR). We therefore examined the relationship between molecular abnormalities and clinical phenotypes. Deletions of the dystrophin gene were analyzed in a total of 137 DMD/BMD patients (DMD 94, BMD 43) to determine central nervous system (CNS) symptoms. The mental capacity was assessed and patients with IQs below 70 were defined as mentally retarded. Thirty-nine percent of DMD boys and 12% of BMD patients were classified as mentally retarded. Eight DMD and 2 BMD patients were diagnosed as having autism. Forty-four percent of DMD and 79% of BMD patients had deletions in the dystrophin gene. All the DMD/BMD patients with deletions upstream of the 5' end of the gene were mentally normal. All of DMD/BMD patients with MR and/or autism had deletions containing the 3' end, although some patients with similar deletions were mentally normal. Our data suggest that Dp140, Dp71 and/or Dp116, the C-terminal translational products of dystrophin, may be related to MR and/or autism in DMD/BMD. However, there was an exception in our series. Three of eight sibling pairs in our cases had different phenotypes, although they had the same mutations in the dystrophin gene. Thus the CNS phenotypes were not determined by the mutations of dystrophin gene alone, and the interaction of dystrophin with other nuclear genes may play important roles.

Adolescent↗
PubMed2000

Identification of the novel developmentally regulated gene, Bdm2, which is highly expressed in fetal rat brain.

Most of the neurogenesis take place during the embryonic stage; the genes expressed predominantly in this stage may play important roles in the control of development of the central nervous system. Using a differential display method, we identified the novel rat gene, brain development-related molecule 2 (Bdm2), that is expressed more abundantly in the embryonic brain than in the adult brain. Full-length Bdm2 cDNA consists of 1842 base pairs (bp) and contains an open reading frame of 1260 bp. Northern blot analysis demonstrated that Bdm2 was strongly expressed in the late embryonic brain and was still detected at lower levels in an early postnatal period; in adults, Bdm2 mRNA was decreased to an undetectable level in brain, though the expression of this mRNA was revealed in other tissues. Level of Bdm2 mRNA was maintained during neuronal differentiation of mouse embryonal carcinoma cell P19, but decreased during the differentiation to glial and unidentified non-neuronal cells. In situ hybridization study demonstrated the wide distribution of Bdm2 mRNA in the embryonic brain; in the adult brain, the hybridization signals became more restricted to the hippocampus, olfactory bulb, cerebellum, and neocortex, almost coinciding with the regions where nascent and immature neurons are present. Thus, it appears likely that Bdm2 encodes a protein that is involved in both the regulation of growth of undifferentiated neural cells and the terminal differentiation of neuronal cells.

Amino Acid Sequence↗
PubMed2000

Adverse outcome following transfemoral endovascular stent-graft repair of an abdominal aortic aneurysm in a patient with severe liver dysfunction: report of a case.

We describe herein the case of a patient with severe liver failure in whom an abdominal aortic aneurysm (AAA) extending to the right iliac artery was diagnosed. Because the risk of performing a standard open repair was considered too high in this patient, the aneurysm was uneventfully repaired using a technique of transfemoral endovascular stent-grafting with femorofemoral bypass and occlusion of the left common and right internal iliac arteries. Unfortunately, multiorgan failure associated with adult respiratory distress syndrome (ARDS) and disseminated intravascular coagulation (DIC) suddenly developed on postoperative day (POD) 2 and the patient died on POD 9. Thus, although endovascular stent-grafting is generally assumed to be less invasive and therefore feasible for high-risk patients, patients with severe liver dysfunction may not be suitable candidates.

Aged↗
PubMed2000

Hypogastric artery coil embolization prior to endoluminal repair of aneurysms and fistulas: buttock claudication, a recognized but possibly preventable complication.

PURPOSE: Hypogastric artery embolization is considered to be necessary to prevent retrograde flow and potential endoleaks when a stent-graft crosses the origin of the hypogastric artery. The authors assess the incidence of buttock claudication, which is the primary complication encountered. The effect of coil location and the presence of antegrade flow at the completion of embolization are evaluated. MATERIALS AND METHODS: Hypogastric artery embolization and endoluminal repair of aneurysms and fistulas was performed in 34 patients (30 men; four women) aged 27-91 years (mean, 76 years). Ten patients were being treated for solitary abdominal aortic aneurysms, 13 were being treated for aortoiliac aneurysms, and six patients were being treated for isolated common iliac aneurysms, three for hypogastric artery aneurysms and two for iliac arteriovenous fistulas. Eleven patients had coils placed completely above the bifurcation of the hypogastric artery and 23 patients had coils placed at the bifurcation, or within the branches of the hypogastric artery. Preservation of antegrade flow after embolization was noted in 14 of 34 patients. RESULTS: Thirty-four patients underwent stent-graft repair after hypogastric artery embolization. There were two perioperative deaths, three proximal leaks, and one collateral leak. Of the 32 patients who survived the procedure, there was one retrograde leak, even though 13 of 32 (41%) patients had continued antegrade flow at completion of the hypogastric artery embolization. When coils were placed at or in the bifurcation of the hypogastric artery, 12 of 22 (55%) experienced claudication. When coils were placed in the proximal hypogastric artery, one of 10 (10%) claudicated. CONCLUSION: It is probably not necessary to completely occlude antegrade flow in the hypogastric artery to prevent a distal endoleak. Buttock claudication is rare when coils are placed in the proximal hypogastric artery rather than at its bifurcation or in its branches.

Adult↗
PubMed2000

Complicated emergent endovascular repair of a life-threatening bilateral internal jugular vein occlusion.

A 62-year-old woman had painful facial swelling that progressed to extensive periorbital and perioral edema with loss of vision, hearing, and consciousness. Her past surgical history was significant for right radical neck dissection including internal jugular vein (IJV) resection, laryngectomy, partial esophagectomy, tracheoesophageal fistula repair, and tracheostomy for squamous cell carcinoma of the oropharynx. In addition, the patient had received radiation therapy to the neck. A venogram revealed occlusion of the left IJV. A guidewire from the femoral vein was passed through the occluded segment; however, attempts to introduce an angioplasty balloon failed. A percutaneous basilic vein approach allowed passage of a dilator sheath over a guidewire, thereby enabling Wallstent deployment across the IJV occlusion. A second Wallstent was inserted across a stenosis in the brachiocephalic vein; however, this second stent reoccluded the IJV. Surgical removal of the second Wallstent was required through a segmental claviculectomy and venotomy. Patency was restored in the IJV and the brachiocephalic vein with the return of baseline neurologic function. This case demonstrates a complicated emergent endovascular repair of a life-threatening IJV occlusion that required surgical salvage.

Constriction, Pathologic↗
PubMed2000

Acute enlargement and subsequent rupture of an abdominal aortic aneurysm in a patient receiving chemotherapy for pancreatic carcinoma.

We report a case of ruptured abdominal aortic aneurysm (AAA) in a patient receiving chemotherapy for pancreatic cancer. We reviewed the literature on the effects of corticosteroids and chemotherapy on aaa formation and discuss possible mechanisms for drug action to promote aneurysm expansion and rupture. If cancer and AAA coincide and curative chemotherapy is possible, a potential impact of chemotherapy on AAA expansion should be considered.

Adenocarcinoma↗
PubMed2000

Alternative techniques for management of distal anastomoses of aortofemoral and iliofemoral endovascular grafts.

PURPOSE: Techniques for managing the distal anastomoses of aortofemoral and iliofemoral endovascular grafts are described. METHODS: Over a 2(1/2)-year period 46 endovascular grafts were successfully placed to treat severe iliac artery occlusive disease. Endovascular grafts were anchored proximally in the distal aorta or iliac arteries with Palmaz balloon-expandable stents. The distal anastomoses were performed with the use of open, sutured anastomotic techniques. In contrast to stented distal anastomoses, these techniques allowed us to (1) treat occlusive lesions extending from the distal aorta to below the inguinal ligament, (2) terminate endovascular grafts in the groin where stents are contraindicated, (3) vary the distal anastomotic site depending on the local pattern of disease, and (4) standardize the preinsertion length of the endovascular graft. RESULTS: Two distal perianastomotic stenoses and one graft occlusion were detected postoperatively in 11 bypass grafts that had distal anastomoses sewn endoluminally without an overlying patch angioplasty. Only one perianastomotic stenosis was found among 35 anastomoses performed with other techniques. There were no significant differences in primary and secondary patency between grafts originating in the distal aorta or iliac arteries. CONCLUSIONS: Hand-sewn distal anastomoses can simplify the insertion of endovascular grafts used for the treatment of aortoiliac occlusive disease. These anastomoses permit tailoring of the graft according to the patients' pattern of disease and eliminate the need to precisely measure the length of the graft preoperatively. In addition, because a distal stent is not required, endovascular grafts can be safely terminated in the groin instead of the external iliac artery where disease progression can lead to graft failure. Finally, endovascular distal anastomoses should be closed with a patch or the hood of a more distal bypass graft to prevent perianastomotic stenoses or occlusions in the postoperative period.

Adult↗
PubMed2000

Does the endovascular repair of aortoiliac aneurysms pose a radiation safety hazard to vascular surgeons?

OBJECTIVES: Endovascular aortoiliac aneurysm (EAIA) repair uses substantial fluoroscopic guidance that requires considerable radiation exposure. Doses were determined for a team of three vascular surgeons performing 47 consecutive EAIA repairs over a 1-year period to determine whether this exposure constitutes a radiation hazard. METHODS: Twenty-nine surgeon-made aortounifemoral devices and 18 bifurcated devices were used. Three surgeons wore dosimeters (1) on the waist, under a lead apron; (2) on the waist, outside a lead apron; (3) on the collar; and (4) on the left ring finger. Dosimeters were also placed around the operating table and room to evaluate the patient, other personnel, and ambient doses. Exposures were compared with standards of the International Commission on Radiological Protection (ICRP). RESULTS: Total fluoroscopy time was 30.9 hours (1852 minutes; mean, 39.4 minutes per case). Yearly total effective body doses for all surgeons (under lead) were below the 20 mSv/y occupational exposure limit of the ICRP. Outside lead doses for two surgeons approximated recommended limits. Lead aprons attenuated 85% to 91% of the dose. Ring doses and calculated eye doses were within the ICRP exposure limits. Patient skin doses averaged 360 mSv per case (range, 120-860 mSv). The ambient (> 3 m from the source) operating room dose was 1.06 mSv/y. CONCLUSIONS: Although the total effective body doses under lead fell within established ICRP occupational exposure limits, they are not negligible. Because radiation exposure is cumulative and endovascular procedures are becoming more common, individuals performing these procedures must carefully monitor their exposure. Our results indicate that a team of surgeons can perform 386 hours of fluoroscopy per year or 587 EAIA repairs per year and remain within occupational exposure limits. Individuals who perform these procedures should actively monitor their effective doses and educate personnel in methods for reducing exposure.

Aortic Aneurysm↗
PubMed2000

Endovascular grafts and other image-guided catheter-based adjuncts to improve the treatment of ruptured aortoiliac aneurysms.

OBJECTIVE: To report a new management approach for the treatment of ruptured aortoiliac aneurysms. METHODS: This approach includes hypotensive hemostasis, minimizing fluid resuscitation, and allowing the systolic blood pressure to fall to 50 mmHg. Under local anesthesia, a transbrachial guidewire was placed under fluoroscopic control in the supraceliac aorta. A 40-mm balloon catheter was inserted over this guidewire and inflated only if the blood pressure was less than 50 mmHg, before or after the induction of anesthesia. Fluoroscopic angiography was used to determine the suitability for endovascular graft repair. When possible, a prepared, "one-size-fits-most" endovascular aortounifemoral stented PTFE graft was used, combined with occlusion of the contralateral common iliac artery and femorofemoral bypass. If the patient's anatomy was unsuitable for endovascular graft repair, standard open repair was performed using proximal balloon control as needed. RESULTS: Twenty-five patients with ruptured aortoiliac aneurysms (18 aortic, 7 iliac) were managed using this approach. Balloon inflation for proximal control was required in nine of the 25 patients. Twenty patients were treated with endovascular grafts. Five patients required open repair. The ruptured aneurysm was excluded in all 25 patients; 23 survived. Two deaths occurred in patients who received endovascular grafts with serious comorbidities. The surviving patients who received endovascular grafts had a median hospital stay of 6 days, and the preoperative symptoms resolved in all patients. CONCLUSIONS: Hypotensive hemostasis is usually an effective means to provide time for balloon placement and often for endovascular graft insertion. With appropriate preparation and planning, many if not most patients with ruptured aneurysms can be treated by endovascular grafts. Proximal balloon control is not required often but may, when needed, be an invaluable adjunct to both endovascular graft and open repairs. The use of endovascular grafts and this approach using other image-guided catheter-based adjuncts appear to improve treatment outcomes for patients with ruptured aortoiliac aneurysms.

Aged↗
PubMed2000

Preparation and characterization of acrylic hydrogels neutralized by basic amino acids.

Basic amino acids were used as neutralizers in the gellation of Eudispert as an acrylic hydrogel. Arginine and lysine successfully neutralized Eudispert, as did sodium hydroxide, and formed hydrogels. A gentle rise of pH was observed as the dosage of the base increased when arginine and lysine were used, in contrast to the sharp rise of pH observed when sodium hydroxide was used. The rank of viscosity of the prepared hydrogels was as follows: lysine > arginine > NaOH. The release rate of model drugs (salicylic acid, theophylline, and bovine insulin) from the prepared hydrogels ranked as follows: NaOH>lysine>arginine, the sustained-release profile being observed with arginine. The rate of diffusion of the model drug from the hydrogel was inversely proportional to the molecular weight of the cationized neutralizer used. It is concluded that the strategy of neutralization of acidic polymers by basic amino acids has advantage with the respect to both the sustained-release characteristics of the gel and the biocompatibility of the basic amino acids themselves.

Amino Acids↗
PubMed2000

Quantitative evaluation of the bitterness of commercial medicines using a taste sensor.

The bitterness of 11 commercial medicines was evaluated both by a multichannel taste sensor and in human gustatory sensation tests with 15 volunteers. For basic drugs with amino groups in the molecule, such as quinine, there was a comparatively strong relative response electric potential (mV) of channels 1 or 2, those containing negatively charged membranes and the bitterness determined by human gustatory sensation tests. The suppression of the bitterness of quinine by sucrose and aspartame could be quantified using the artificial taste sensor and the results concurred with those from gustatory sensation tests. The usefulness of the sensor was thus confirmed for this type of compound. Anionic drugs, such as diclofenac sodium or salicylic acid gave rise in a negative response electric potential in channels 5 or 6, those containing positively charged membrane, seemed to be useful information even though their tastes are being sour rather than bitter. For drugs with both an amino (cationic) group and carboxylic acid (anionic) group in the molecule, such as theophylline, caffeine, and metronidazole, the relative response electric potential (mV) of channels containing negatively charged membranes was not increased, even though bitterness was observed in human gustatory sensation tests. Therefore, a different design of membrane component is required for more general evaluation of the bitterness of various medicines.

Aspartame↗
PubMed2000

Overview of techniques and devices for endovascular abdominal aortic aneurysm repair.

The endovascular treatment of abdominal aortic aneurysms (AAAs) is rapidly evolving. Since the onset of clinical investigations in 1990 there has been a rapid proliferation in the number of available devices, both surgeon-made and industry-made. This chapter reviews endovascular AAA repair with regard to available devices, patient selection for each device based on anatomic criteria, and techniques for graft deployment.

Angiography↗