Biomedical subjects

Hiromu Segawa

Publications and source records attributed to Hiromu Segawa.

3 recordsLinked to original sources

PubMed2005

[A case of spinal dural arteriovenous fistula draining to the ventral coronal venous plexus].

Here we report a case of spinal dural areteriovenous fistula (AVF) draining to the anterior spinal vein. An 80-year-old female presented with progressive weakness of lower extremities. MRI showed spinal enlargement at the Th10 to L1 with high intensity signals on T2-weighted image and multiple flow voids on the dorsal and ventral surface of the spinal cord. Angiogram of the left L2 lumbar artery demonstrated a hairpin-shaped vessel with ascending and descending limbs, mimicking radiculomedullary artery. Oblique view angiogram of the left L2 lumbar artery showed that radiculomedullary vein drained to the dilated anterior spinal vein, which then drained cranially and caudally on the anterior and posterior surface of the spinal cord. The patient underwent T9-L2 laminectomy. Several large tortuous dilated veins in the subarachnoid space were found. Examination of the inner surface of the dura revealed an arterialized vein that began at the level of L2 and coursed superiorly. The arterialized vein was coagulated and interrupted. The postoperative angiogram demonstrated the obliteration of the fistula. Postoperative MRI returned to normal with complete disappearance of T2 high signal, cord enlargement. In most spinal dural AVF, the venous drainage is predominantly upward on the posterior surface of the spinal cord. The spinal dural AVF draining to the anterior spinal vein is atypical, and cause difficulty in differentiating the anterior spinal artery from the anterior spinal vein. Oblique view angiogram may be helpful to differentiate the anterior spinal vein from anterior spinal artery.

Aged↗

PubMed2003

Microsuture-tying forceps with attached scissors for bypass surgery.

BACKGROUND: Bypass surgery requires the shortest temporary occlusion time of a recipient artery during anastomosis. For this purpose, we have devised a microforceps with attached scissors that makes it possible to perform the multiple steps involved in anastomosis without exchanging instruments. This microforceps avoids having to exchange instruments twice in one suturing, such as that between a microsuture-tying forceps or a microneedle holder and microscissors in conventional methods. METHODS: The instrument is made of stainless steel and is 15.5 cm long. Using this microforceps with scissors, we can suture, tie, and cut a ligature fluently for consecutive sutures without exchanging instruments. The mean time during one suturing was compared between two patient groups treated by conventional method and with use of this instrument. RESULTS: This instrument was used for 34 patients with ischemic cerebrovascular disease (including three who needed deep-site anastomoses) and allowed us to perform superficial temporal artery-middle cerebral artery (STA-MCA) anastomoses uneventfully. This instrument saved 15.2 s in the mean time during one suturing. CONCLUSIONS: Although it is of paramount importance to practice tying sutures well, this new instrument removes the need to exchange conventional instruments, and we believe it will save time and, therefore, decrease complications during bypass surgery.

Anastomosis, Surgical↗

PubMed2002

[Cranioplasty using the patient's autogenous bone preserved by freezing--an examination of post-operative infection rates].

The current technique for cranioplasty using artificial bone requires further improvement with regard to infection, strength and comfort through good fitting. We have carried out cranioplasty using the patient's autogenous bone flap obtained during first surgery. It was immersed in 200 mg of Amikacin Sulphate, and frozen at -16 degrees C until its use in cranioplasty. From 1980 to 1998, cranioplasty has been carried out on 206 patients. They consisted of 118 males and 88 females, and their age ranged in our institute from 1 to 81; average age 51.1. Ruptured aneurysm (48%), head injury (14%), intracranial hemorrhage (23%) and cerebral infarction (12%) were the major causes requiring decompression surgery. We analyse the bone preservation period and the time between cranioplasty and the onset of infection. The infection rates per bone preservation periods, the causes of decompression and age groups are studied. Of the 208 case studies, infection necessitating bone removal or debridement was noted in 8 cases (3.88%). Average bone preservation period in the infected group was 31.1 days as compared with 54.9 days for the non-infected group (p < 0.05). Not patient age but the type of head injury is also a significant factor in post cranioplasty infection.

Adolescent↗