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Biomedical subjects

S Hirabayashi

Publications and source records attributed to S Hirabayashi.

At least 55 records · Page 3Linked to original sources

A spheno-orbital encephalocele with unilateral exophthalmos.

Encephaloceles are rare congenital defects in the skull, through which the meninges and brain tissue have herilated. We report a case of an 11-year-old boy with a spheno-orbital encephalocele that presented with pulsatile exophthalmos. A two-stage operation resulted in a good outcome.

Child, Preschool↗

Reduction of lumbar spondylolisthesis using a CDI pedicle screw system.

To evaluate reduction methods using two of the several types of Cotrel-Dubousset instrumentation (CDI), 39 patients with low-grade (Meyerding grades I and II [12]) lumbar spondylolisthesis were followed clinically and radiologically for a minimum of 6 months. Our surgical methods were classified into three types as follow: reduction by 2-level assembly using double-threaded screws (type I); reduction by single-level assembly using the double-threaded screws (type II); and reduction by single-level assembly using tulip screws (type III). We found that satisfactory reduction could be achieved by single-level assembly using either the double-threaded or tulip screw without resection of disc material or the posterior leverage method. We found that the tulip screw was superior in obtaining stable reduction. We discuss the mechanism of reducing spondylolisthesis in comparison with that of previously reported methods.

Adolescent↗

Papillary dilation vs sphincterotomy in endoscopic removal of bile duct stones. A randomized trial with manometric function.

To circumvent the long-term effects of papillary ablation for extracting common bile duct stones (< 12 mm in diameter) in endoscopic sphincterotomy (EST), endoscopic papillary dilation (EPD) was attempted in 20 patients. To evaluate papillary function before and after the procedures, manometry of the sphincter of Oddi was carried out in 13 with EPD and 10 of 20 patients with EST. Extraction of all stones was successful (100%) in both groups at an equal rate. Repeated numbers of procedures were common in both groups. However, the mean duration of the procedure was high in EPD compared to EST (63 min vs 42 min, P < NS). Adjunctive therapies like mechanical lithotripsy (ML), nasobiliary drainage, and choledochoscopy were included in EPD, while EST required a basket catheter and ML. There was no significant difference on manometry before and after the procedures (P = NS), although papillary function was found to have decreased after the EPD. In contrast, all patients in the EST group lost papillary function after the procedure. Thirty-day morbidity and mortality rate were absent in both groups. Immediate and 2.5-year follow up complications were uncommon in both groups. As a simple method, EPD may be an effective and safe alternative to EST in the management of patients with bile duct stones who require maintenance of papillary function.

Aged↗

Reconstruction of the umbilicus using a single triangular flap.

Many techniques for reconstruction of an absent umbilicus have been described; however, none has achieved a perfect result. We report a new alternative for constructing an umbilicus using a conical flap and present two representative clinical cases. Our technique creates an umbilicus with sufficient depth with good results, including maintenance of depth after more than 1 year.

Humans↗

[Laparoscopic radical nephrectomy. Analysis of 10 cases and preliminary report of retroperitoneal approach].

PURPOSE: To examine the efficacy of laparoscopic radical nephrectomy (LPRNX) for patients with small renal cell carcinoma, the clinical result of 10 patients treated with this procedure was analysed. MATERIALS: Ten patients with renal cell carcinoma measuring diameter less than 5 cm were treated by LPRNX between July 1992 and October 1994. Four cases had T1N0M0 disease and 6 had T2N0M0 disease. Of the 10 patients, seven had right sided tumor and three had left sided tumor. METHOD: Trans-abdominal approach was employed for the initial 8 cases. Retroperitoneal approach was applied for the last 2 cases. Five trocars were placed through lateral abdominal wall. Intraperitoneal or retroperitoneal cavity was insffulated with CO2 at 12 mmHg. A kidney was dissected endoscopically with Gerota's fascia, peri renal fatty tissue and adrenal gland as en bloc fashion. It was trapped into the laparoscopy sack and pulled out of the body through a 4 to 5 cm incision without morcellation. RESULTS: Average operation time was 331 minutes and average bleeding was 380 ml. All the kidneys were removed by endoscopic technique. As major complications, we experienced a cases of splenic injury and a cases of adrenal injury. The bleeding of both cases was successfully managed by endoscopical procedure, however, transfusion was needed for the last case. Pathological examination of specimens revealed renal cell carcinoma in all ten cases. Average hospital stay after surgery was 10.6 days and average duration to the convalescence was 20 days. There was no episode of recurrence in all 10 patients for 2 to 29 months (Mean: 15.2 months) followed up period. CONCLUSION: Although further technical progress was expected, LPRNX is a potential operative procedure that realizes minimally invasive therapy for the patients with small volume of renal cell carcinoma.

Adult↗

[Endoscopic lithotomy using sublingual nitroglycerin].

After medical sphincter dilation using sud-lingual nitroglycerin, endoscopic removal of common bile duct stones in 15 patients was carried out. Complete stone removal was obtained in 14 of 15 patients. Only 0.3 mg to 0.6 mg nitroglycerin was needed to give an enough dilation of the orifice for cannulating the basket catheter into the bile duct. Mechanical lithotriptor was smoothly cannulated in one patient because of possible impaction. Blood pressure was dropped transiently in one patient by nitroglycerin, however, the general condition of the patient was stable. This procedure is safe, easy and effective in preserving sphincter function. Acute cholecystitis, a common complication of persistent gallbladder stone after endoscopic sphincterotomy, may be avoided by employing this method. More clinical studies, on long term and in a large scale of patients, are necessary to reduce complications that usually occur after sphincterotomy.

Female↗

Relationship between the anatomic and dermatomal levels of spinal cord tumors in the thoracic region.

In neurologic examination of patients with a suspected compressive lesion at the thoracic region, the dermatomic level of sensory disturbance is the only index indicating the anatomic level of a lesion. Because spinal cord tumors usually are solitary compressive lesions, the relationship between the anatomic and dermatomic levels is conveniently examined. We examined the relationship between the highest dermatomic level of sensory disturbance and the anatomic level, axial location, and type of spinal cord tumors in the thoracic region in 19 patients (8 men and 11 women aged 27-78 years; 11 neurinomas, 7 meningiomas, 1 neurofibroma). The distribution of sensory disturbance was evaluated with 3-g Frey hair and 1-g pin-prick examinations. The dermatomic distribution of sensory disturbance was diagnosed according to the dermatome chart of Keegan and Garrett. The anatomic level and axial location of the tumor were highly related to the sensory disturbance. Eight of 12 tumors in which the dermatomic level of sensory disturbance was within one vertebral segment of the anatomic level were situated in the middle or lower thoracic region (T6-T10). All five tumors in which the dermatomic level was two or more vertebral segments away from the anatomic level were situated at the conus medullaris (T12) or upper thoracic region (T1-T5); the highest level of sensory disturbance was from 4 to 11 segments below the anatomic level of the tumor. In two patients with no sensory disturbance, the tumor was in the upper thoracic region (T5) and compressed the spinal cord from the dorsal side. When a spinal cord tumor at the thoracic region is suspected, imaging examinations should be performed sufficiently cranially.

Adult↗

Laparoscopic nephrectomy using a retroperitoneal approach: comparison with a transabdominal approach.

To evaluate the efficacy of the retroperitoneal approach in laparoscopic nephrectomy, our procedures involving laparoscopic nephrectomy using a retroperitoneal approach are described and the clinical results of six patients treated in this way are compared with those of 32 transabdominally nephrectomized patients. Of the six retroperitoneally nephrectomized patients, six kidneys were successfully removed without severe complication, and 28 kidneys were successfully removed in the 32 intraabdominally approached group. Three of the 28 patients had complications requiring open laparotomy. The operating time was 2.7 hours in the 6 retroperitoneal patients and 4.4 hours in the 28 transabdominal patients. Estimated blood loss was 92 ml in the retroperitoneal group and 450 ml in the transabdominal group. The mean postoperative hospital stay was 8 days and 9 days, respectively. These results indicate that the retroperitoneal approach might be preferable in laparoscopic nephrectomy.

Abdomen↗

Postfusion instability at the adjacent segments after rigid pedicle screw fixation for degenerative lumbar spinal disorders.

Sixty-five patients who underwent wide laminectomy, Cotrel-Dubousset instrumentation, and fusion for lumbar degenerative disorders were reviewed radiographically to investigate the incidence and contributing factors of the postfusion instability at the adjacent segments immediately above or below the level of fusion. Thirty-four were men and 31 were women. The mean age was 55.8 years. The average follow-up time was 39 months. Postfusion instability was studied at a total of 107 adjacent segments in 65 patients. The incidence of postfusion instability noted at final follow-up was 24.6% (15 of 61 patients). The incidence was significantly more often observed in the adjacent segments above the fusion than below the fusion, at rates of 25.5 and 2.6%, respectively. The most common instability was posterior translation (9 of 15 patients). Regarding contributing factors for instability at the adjacent segment above the fusion levels, the age of patients was the most significant factor. The incidence was 36.7% (11 of 30 patients) in older patients (> 55 years old) and 12% (3 of 25 patients) in younger patients (< 55 years old). In four patients with a preoperative of > 3 mm anterior translation, instability progressed further postoperatively. To prevent postoperative instability, attention must be paid especially above the fusion levels of the elderly and the preoperative minimal anterior translation.

Adult↗

Pedicle screws and bone mineral density.

STUDY DESIGN: Thirty-five consecutive patients who underwent surgeries for decompression, and one-level fusions with Cotrel-Dubousset pedicle screws for spinal canal stenosis were included in this study. The relationship between bone mineral density of the lumbar spine and the rate of successful fusion and screw problems was studied. OBJECTIVES: Bone mineral density of the third lumbar vertebral body was measured by quantitative computed tomography preoperatively, and the degree of osteoporosis was graded by radiographic films of lumbar spines. The films were followed with anteroposterior and lateral dynamic radiographic examinations of lumbar spines. These examinations were evaluated clinically after surgery. Follow-up duration was at least 19 months, with a mean of 28 months. SUMMARY OF BACKGROUND DATA: The mean bone mineral density of all the patients was 117.1 mg/mL (SD = 42.5). The rate of successful fusion was 88.6%, the non-union rate was 5.7%, and the rate of fusions that were undetermined was 5.7%. The incidence of screw loosening occurred in 5.7% of the patients, screw breakage occurred in 5.7% of patients, and symptomatic screws related to non-union were present in 5.7% of patients. The degree of bone mineral density or radiographic gradings of osteoporosis and the successful fusion or the incidence of symptomatic screws, which were defined as screws related to non-union, were not related. METHODS: The patients were divided into two groups. One group consisted of 12 patients who had less than 100 mg/mL of bone mineral density, with a mean of 72.0 mg/mL (SD = 21.2). The other group consisted of 23 patients who had more than 100 mg/mL of bone mineral density, with a mean of 140.6 mg/mL (SD = 30.0). The rate of successful fusion or non-union and the rate of screw problems such as screw loosening or screw breakage were compared in the two groups. The presence of bony trabeculation in grafted bone is the most important criterion for successful fusion. RESULTS: A statistical difference did not occur between the two groups. Non-union, screw breakage, and screw loosening were observed in patients with both increased and decreased bone mineral density and those with increased and decreased grade osteoporosis. Radiographic grading of osteoporosis was not correlated to bone mineral density, but patients with unexpected bone mineral density were frequent in this series. CONCLUSIONS: The use of decompression and pedicle screws for spinal canal stenosis due to degenerative lumbar disorders can be done safely with one-level fusion in patients with decreased bone mineral density if patients with grade III osteoporosis are excluded. Bone mineral density is more reliable than radiographic grading to evaluate the degree of osteoporosis and should be included in the preoperative evaluation of patients with osteoporosis.

Bone Density↗

Direct dissolution of gallstones with methyl tert-butyl ether (MTBE) via endoscopic transpapillary catheterization in the gallbladder (ETCG).

In a pilot study of direct dissolution therapy of gallstones with methyl tert-butyl ether (MTBE), endoscopic transpapillary catheterization in the gallbladder (ETCG) was performed. Complete dissolution was seen in 8 out of 12 (66%) patients and partial dissolution was seen in 2 (16%) patients. In one of the 8 complete dissolution patients, combined extracorporeal shock wave lithotripsy (ESWL) and dissolution therapy was carried out successfully. These 8 patients were followed up for 12-20 months with regular ultrasonography. During this period, 1 patient underwent laparoscopic cholecystectomy due to stone recurrence. Thickening of the gallbladder wall was seen in 2 patients, but there were no other complications. Using Tsuchiya's classification based on ultrasound, complete dissolution was seen in type Ia stones. This pilot study suggests that the direct dissolution of gallstones with MTBE via ETCG might be a useful and safe non-invasive treatment in patients with cholesterol stones in preserved gallbladders.

Adult↗

Rupture of inferior phrenic artery aneurysm. An unusual complication of mesenteric arteritis due to postcoarctectomy syndrome.

Postcoarctectomy syndrome was developed in a boy with Williams syndrome. Angiogram revealed widespread changes of visceral arteries and extravasation of the contrast material from the right inferior phrenic artery. Emergency laparotomy was successful. This unusual complication makes clear that the mesenteric arteritis after coarctectomy can cause aneurysm with a risk of rupture.

Abnormalities, Multiple↗

[CT evaluation of the pelvic cavity after total cystectomy].

CT scans were performed 40 times in 28 postcystectomy patients to identify the type and location of tumor recurrence. Sixteen patients showed tumor recurrence. Patients without recurrence showed a complete symmetric pelvis and a thin string that looked like an operation scar. Cutaneous ureterostomy showed small tube-like structures, and ileal conduit looked like herniation of the ileum. Cases with recurrent tumors were divided into 3 patterns, 1) pelvic abscess recurrence, 2) anterior abdominal wall thickening, 3) pelvic lateral wall thickening, and combinations of these types. The abscess-recurrence type often showed air within the mass or a fuzzy contour that could not be differentiated from true inflammatory abscess. Anterior abdominal wall thickening was usually accompanied with abscess-type recurrence and appeared as thickening of the operation scar. Lateral wall thickening was usually seen at the site of the obturator internus muscle or obturator node. Patients without recurrence had no complaints except for two who had ileus. All patients with recurrence except one had complaints of pain, abnormal secretion, or a palpable mass. Because all patients with recurrence already had a relatively large tumor at the time of CT, routine follow-up CT is recommended even if the patient has no complaints.

Carcinoma, Transitional Cell↗

Usefulness of MRI in the preoperative diagnosis of cervical disk herniation.

We investigated the preoperative diagnostic value of MRI, myelography, and CT myelography (CTM) in a retrospective analysis of 17 patients (15 men and two women) who were surgically treated for cervical disk herniation. Their ages ranged from 29 to 63 years, with a mean of 49 years. Anterior interbody fusion using iliac bone grafts was performed following microscopic diskectomy in all patients. MRI, myelography, and CTM were performed in 13 patients, while four patients were operated on after MRI alone. Neurological improvement was observed in all 17 patients after the surgery. MRI proved useful for determining the level of symptomatic cervical disk herniation. Surgery can be carried out on the basis of MRI findings alone when there is disk herniation at a single level which corresponds with the patient's symptoms and signs.

Adult↗

Mandibular lengthening by gradual distraction: analysis using accurate skull replicas.

Bone lengthening in the upper and lower extremities by gradual distraction has become an accepted procedure. We have used an extraoral device to lengthen the mandible in four patients with unilateral mandibular hypoplasia. Using an accurate skull replica, the proposed corticotomy line, intended direction of lengthening, and appropriate position for the screws were determined. Following distraction, a significant increase in the dimensions of the affected mandible was obtained in each case. In this series, accurate skull replicas proved very useful for defining the anatomy, for surgical simulation and for pre- and postoperative evaluation.

Adolescent↗

Microdiscectomy and second operation for lumbar disc herniation.

To prevent recurrence and avoid the second operation, the authors analyzed the clinical features and surgical outcome of 214 patients (157 males and 57 females) who underwent lumbar microdiscectomy, 16 of whom required second operation. The mean age was 34.6 years (range, 12-62 years). The average follow-up period was 4 years 5 months. The overall incidence of second operation was 7.5%. Second operation was performed because of recurrence of herniation in nine patients, and residual bony compression at the lateral recess in two. The incidence of second operation was significantly higher in teenagers than in patients in other age decades (P < 0.01), and in patients with protrusion-type herniation than in those with extrusion-type or sequestration-type herniation (P < 0.01). To prevent the necessity for second operation, careful and thorough discectomy, especially deep to the posterior longitudinal ligament, and decompression at the lateral recess are useful.

Adolescent↗

Surgical treatment of epilepsy due to cortical dysplasia: clinical and EEG findings.

Seventeen patients with cortical dysplasia who had surgical resection for medically intractable partial epilepsy were studied. Compared with two groups of surgically treated patients with intractable epilepsy due to tumour (n = 20) and mesial temporal sclerosis (n = 40), patients with cortical dysplasia showed significantly more frequent extratemporal lesions, more frequent non-epileptiform EEG abnormalities and less favourable surgical outcome for seizure control. Patients with cortical dysplasia were younger at onset of seizures and had a lower detection rate of CT abnormalities compared with the tumour group, and lower IQ compared with the mesial temporal sclerosis group. MRI was abnormal in five of seven patients. Six patients became seizure-free or almost seizure-free but eight did not experience relief of seizures. Surgical outcome related to the extent of pathology but not to the histological abnormality. Lesions outside the temporal and frontal lobes were correlated with poor surgical outcome, as were generalised interictal EEG abnormalities, which may reflect extensive or multiple lesions. Ictal intracranial recordings were not useful for presurgical evaluation of cortical dysplasia.

Adolescent↗