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Takanori Uchida

Publications and source records attributed to Takanori Uchida.

7 recordsLinked to original sources
PubMed2006

Nonsuture dural repair using polyglycolic acid mesh and fibrin glue: clinical application to spinal surgery.

BACKGROUND: In spinal surgery, repair of the dura is difficult when it is torn or fragile or is ossified as in cases with ossification of posterior longitudinal ligament. We report our experience with a nonsuture dural repair technique in patients undergoing spinal surgery; it uses a dura substitute composed of polyglycolic acid (PGA) mesh and fibrin glue. Here, we report the efficacy and safety of nonsuture duroplasty using PGA mesh and fibrin glue (PGA-fibrin sheet). METHODS: The artificial dura mater is composed of a PGA-fibrin sheet. The dural defect is covered with a patch sprayed with fibrin glue without suturing to the dura mater. We first evaluated this technique in an experimental study by performing water leakage tests. Between May 2001 and January 2005, we used it in 160 spinal surgeries that required intraoperative dura repair. RESULTS: Our preliminary tests showed that the threshold for water pressure without leakage was 161 +/- 42 and 96.5 +/- 32 mm Hg when the unsprayed margin around the perimeter of the patch was 5 and 2 mm, respectively. Of the 160 operated patients, 10 (6.3%) experienced subcutaneous cerebrospinal fluid (CSF) leakage. Of these, 6 required a second operation; in the other 4, the CSF collection diminished spontaneously. There were no other complications such as allergic reaction, adhesion, or infection. CONCLUSION: In combination with CSF diversion, the PGA-fibrin sheet is a viable alternative method for dural repair in spinal surgery.

Arnold-Chiari Malformation↗
PubMed2006

Fibrin glue and polyglycolic Acid nonwoven fabric as a biocompatible dural substitute.

OBJECTIVE: A novel biocompatible dural substitute created using fibrin glue and polyglycolic acid nonwoven fabric was examined for closing ability and histology. METHODS: A rabbit skin model of dural defect was repaired using fibrin glue-covered polyglycolic acid fabric without suture and subjected to a water leakage test to investigate closing ability. In addition, the dural defects created on 12 hemispheres in 6 beagle dogs were repaired with the dural substitute and subjected to macroscopic and histological examination of the dural substitute and adjacent tissue 1 and 2 months later. RESULTS: The dural substitute showed a breaking pressure of 109.9 +/- 37.1 mmHg. Macroscopically, no cases of excessive granulation, infection, or liquorrhea, either on the dural substitute or surrounding tissue, were observed. Histology indicated favorable tissue replacement of the dural substitute with collagenous fiber, although slight foreign body reaction was associated with its absorption. There was no evidence for adhesion to the brain surface or influence on nerve cells. CONCLUSION: Dural substitute created using fibrin glue and polyglycolic acid fabric is advantageous in that it exerts excellent closing ability without requiring suture and can replace biological tissue without causing incompatibility.

Animals↗
PubMed2006

[A novel method of dural repair using polyglycolic acid non-woven fabric and fibrin glue: clinical results of 140 cases].

This paper presents a report based on the results obtained from clinical applications of a biocompatible dural substitute made of polyglycolic acid non-woven fabric and fibrin glue. The cases subjected to this study were the ones needing reconstruction of dura mater which had become defective due to injury or brain tumor and the ones in which primary suture of the dura mater was considered to be too difficult or inadequate with ordinary methods. The dural substitute was used in 140 cases during the period between June, 2001 and July, 2005. The operations were performed using the supratentorial approach in 66 cases and infratentorial approach in 74 cases. Among these procedures, 39 cases were indicated for microvascular decompression, the commonest operation performed, then cranial base surgery in 27 cases and tumor resection in 24 cases, and so on. Lumber spinal fluid drainage or re-operation was required in 3 cases (2.1%) due to formation of post-operative cerebrospinal fluid leakage or subcutaneous accumulation of cerebrospinal fluid. With the dural substitute no infection was observed as a complication in any of the cases. Among the 140 cases presented this time, 27 cases were cranial base surgery and 74 cases were performed, using the infratentorial approach. Nevertheless, the study showed that the closing ability of the dural substitute was adequate even in actual clinical settings it is reported above that the incidence rate of post-operative cerebrospinal fluid leakage or subcutaneous accumulation of cerebrospinal fluid which require additional intervention was only 2.1%.

Adult↗
PubMed2005

Basilar artery dissection.

OBJECT: Little is understood about the clinical manifestations of basilar artery (BA) dissections, which can present with subarachnoid hemorrhage (SAH), brainstem compression, or ischemia. In any instance, the prognosis seems poorer than that for vertebral artery (VA) dissection. The authors analyzed clinical presentations and radiological features of BA dissection with and without rupture. METHODS: Between 1998 and 2003, the authors treated 10 patients (eight men and two women, ranging in age from 32-78 years; mean age 54 years) with BA dissection. Diagnosis was based on clinical and radiological findings, including those from magnetic resonance imaging and cerebral angiography studies. Of the 10 patients, five had impaired consciousness at disease onset. Among four patients presenting with SAH, two were treated conservatively and had fair outcomes without recurrent hemorrhage. The other two patients with SAH were treated using unilateral endovascular VA occlusion, but one of them subsequently suffered fatal rebleeding. A fifth patient presented with progressive signs of a mass involving the brainstem, whereas the remaining five patients showed brainstem ischemia; all were treated conservatively. Four patients could not return to their previous daily activities. CONCLUSIONS: Basilar artery dissections are rare lesions associated with significant morbidity and death. The natural course of and the treatment options for BA dissection differ considerably from those for VA dissections. Management of these lesions is controversial and difficult, and requires particular care.

Adult↗
PubMed2004

Rabbit aneurysm model mediated by the application of elastase.

The concentrations and application methods of elastase in the rabbit aneurysm model were optimized to control the initiation of aneurysms and to cause rupture in a stepwise, controlled fashion. The common carotid artery of male Japanese albino rabbits was exposed. No aneurysm was generated if the adventitia was not dissected. After gentle removal of the adventitia, a two-fold dilution series of elastase was applied to the lesion and observed over a period of 2 hours. Various stages of aneurysmal lesions, from spindle-shaped enlargement to rupture, were produced in proportion to the elastase concentration. Application of elastase stock solution (5 U/mg of type I porcine pancreatic elastase) resulted in rupture within 30 minutes in all six animals. Elastase 1:2 solutions caused oozing in all animals, but subsequent rupture in only three of six animals. Histological examination found serious destruction of the internal elastic lamina and media, with expansion of the very thin wall. Elastase 1:4 to 1:16 solutions caused spindle-like distention of the entire artery and the development of tortuosity at the lesion. Elastase 1:32 or weaker solutions caused only localized dilatations. Overall, the destruction of the tunica media became less severe with decreased elastase concentration. Furthermore, the bursting pressure of the aneurysms decreased with increasing elastase concentrations. In particular, aneurysms produced by the elastase 1:2 solution ruptured at less than 150 mmHg, whereas aneurysms induced by the elastase 1:4 or weaker solutions did not rupture within the physiological range of blood pressure. The present aneurysm model requires shorter preparation time and enables accurate control of aneurysm development and rupture.

Aneurysm↗
PubMedDate not supplied

Quinapril treatment restores the vasodilator action of insulin in fructose-hypertensive rats.

1. Angiotensin-converting enzyme (ACE) inhibitors have been shown to improve insulin-resistance both experimentally and clinically. We therefore investigated the effects of quinapril, which has high tissue specificity for ACE, regarding the contribution of insulin to vascular contractions, as well as insulin sensitivity in a dietary rat model of insulin resistance. 2. Male Sprague-Dawley rats were divided into three groups: (i) rats fed normal chow (normal diet group); (ii) rats fed fructose-rich chow containing 40% fructose and 7% lard (fructose diet group); and (iii) rats fed fructose-rich chow plus quinapril (10 mg/kg per day; quinapril-treated group). 3. After 2 weeks, we evaluated systolic blood pressure, insulin sensitivity as assessed by steady state plasma glucose (SSPG) levels, response of aortic rings to phenylephrine (10-9 to 10-6 mol/L) in the presence or absence of insulin and the response of aortic rings to acetylcholine. 4. Feeding rats fructose-rich chow resulted in an elevation of blood pressure (P < 0.01) and SSPG levels (P < 0.01). Quinapril treatment significantly prevented increases in both blood pressure and SSPG, with a return to the levels seen in the normal diet group. 5. In the absence of insulin, the maximal contractile response to phenylephrine did not differ between the three groups. However, in the presence of insulin (100 mU/mL), the contractile response to phenylephrine (10-6 mol/L) was reduced by 22.8 +/- 1.2% in the normal diet group, although no insulin effects were observed in the fructose diet group (P < 0.01). Quinapril restored the inhibitory effect of insulin on phenylephrine-induced contractions. 6. In addition, the reduction in relaxation induced by acetylcholine in the fructose diet group was significantly reversed by quinapril treatment. 7. It is concluded that the fructose diet impairs the vasodilator effects of insulin as well as acetylcholine-induced relaxation in rat thoracic aortas. Quinapril prevented deterioration in the responses of the aortic rings, suggesting that ACE inhibitors may be useful for treating vascular insulin resistance.

Acetylcholine↗