The development of three dimensional video microscope system for clinical application in neurosurgery

OBJECTIVE: The employment of surgical microscopy in the field of neurosurgery has significantly contributed not only to the advancement of surgical technique, but also the operative outcome as well. This technology has allowed surgeons to meet the demands for increasingly difficult levels of surgery, which usually require a long operative time. However, the surgeon and the assistant are restricted in their posture for a long time, leading to excessive muscular and ocular stress. To solve these problems, we have developed and clinically applied a three dimensional video microscope system for surgery, using a two binocular camera method, that allows surgical procedures to be performed over a video monitor. METHOD: Two 3CCD cameras were installed on the assistant's lens attachment and the camera lens attachment of the microscope for neurosurgery, manufactured by Carl Zeiss Co., Ltd. The surgery was performed by viewing the three dimensional picture on the monitor, which was created by processing the images from the cameras by a time-division method. In November 1998, the prototype was completed and, with numerous modifications, its clinical application has become possible. Currently, we have used it in 42 clinical cases. RESULTS: 1) Instead of viewing the surgical field through a conventional surgical microscope, the surgeon and the assistant were able to perform microsurgery by viewing the stereoscopic vision on the video monitor, through polarized glasses. 2) The assistant is provided with a separate video monitor, so that the assistant can freely adjust the angle of vision 90-180 degrees, according to where he stands. 3) The nurses, resident surgeons and students can view the same three dimensional images displayed to the surgeon. This effectively contributes to the educational environment. CONCLUSION: Even during a long surgical procedure, the posture of surgeon and assistant became less restricted since there was no need to look through the eyepiece of the microscope and led to significant decrease in physical fatigue and ocular strain. In the 42 clinical trials, the operation proceeded uneventfully, without any serious complications.     

Usefulness of dynamic digitized cerebral parenchymography for cerebral vascular disease

Aortic arch injections according to Theron's method have been performed in patients with cerebral ischemia. Digital subtraction angiograms with modified windowing (low and narrow) have been used for better visualization of cerebral parenchymal condition. This "cerebral parenchymography" allows much easier understanding of cerebral parenchymal vascularization on angiographic imaging. Although further study is necessary to estimate accurate cerebral blood flow, this technique can enable an easy and quick understanding of the overall cerebral hemodynamics.     

Three cases of successful stenting for radiation-induced carotid arterial stenosis

We report three cases of radiation-induced carotid arterial stenosis that underwent successful angioplasty with stenting. The patients had received radiation therapy for tongue or laryngeal cancers and developed minor completed strokes 6 to 14 years after irradiation. All patients had multiple and bilateral stenosis, measuring more than 50%, of the carotid arteries. The stenosis was located in the internal, external, and common carotid arteries. We performed percutaneous transluminal angioplasty with stenting. All interventions were successful and carotid stenosis decreased to less than 28%. No permanent complications occurred. During follow-up periods of up to 26 months, all of these cases were free from ischemic symptoms. Neither carotid angiography nor ultrasound sonography showed evidence of restenosis. The present results suggest the usefulness of angioplasty with stenting for radiation-induced carotid arterial stenosis.     

The clinical evaluation of maxacalcitol on therapy for secondary hyperparathyroidism of chronic hemodialysis patients

The spectrum of bone disease in end-stage renal failure is changing, but secondary hyperparathyroidism is still a troublesome complication. The vitamin D3 analog, maxacalcitol, has reduced calcemic action compared to vitamin D3, but show equivalent suppression of parathyroid hormone(PTH) secretion. In the first step of the study, we investigated the severity of secondary hyperparathyroidism in 670 chronic hemodialysis patients, whose age, sex(male/female), and duration on dialysis were 63.5 +/- 12.4 years, 383/287, and 7.3 +/- 6.0 years, respectively. The number of patients with serum intact-PTH concentrations over 300 pg/ml was 118. Most patients in this group(87.3%) were already being prescribed oral vitamin D3 analog. In the second step, maxacalcitol was administered intravenously, instead of the oral vitamin D3 analog, to 92 patients selected from the above-described group. The age, sex(male/female), and duration of dialysis were 59.4 +/- 11.5 years, 56/36, and 7.3 +/- 6.0 years, respectively. Serum intact-PTH concentration and alkaline phosphatase activity decreased significantly, from 612.3 +/- 32.7 to 414.2 +/- 26.8 pg/ml, and from 329.3 +/- 17.3 to 277.0 +/- 12.5 IU/l, respectively. Serum calcium phosphorous concentration increased significantly, and maxacalcitol administration was interrupted because of hypercalcemia in 17 patients(18.5%). Serum intact-PTH concentration did not decrease in patients with serum Ca concentrations of 10.5 mg/dl or more before maxacalcitol therapy. In conclusion, maxacalcitol suppressed PTH secretion more effectively in hemodialysis patients with secondary hyperparathyroidism than did oral active vitamin D3 therapy, especially in patients with serum Ca concentrations lower than 10.5 mg/dl.     

Myelopathy due to scoliosis with vertebral hypertrophy in Klippel-Trenaunay-Weber syndrome

We describe a 37-year-old man complaining of right back pain and gait disturbance. He had a big soft tumor on his right back, hemihypertrophy of the right lower extremity, and right thoracic scoliosis. We diagnosed Klippel-Trenaunay-Weber syndrome based on the pathological findings of the soft tumor. Computed tomography (CT) scan revealed severe spinal stenosis due to a hypertrophic vertebral body and facet joint at T7. Treatment by decompression of hypertrophic bone led to complete neurological recovery. To our knowledge, no case has been reported of Klippel-Trenaunay-Weber syndrome with myelopathy which originated from thoracic scoliosis with a hypertrophic facet joint and vertebral body. We suggest that the cause of myelopathy in Klippel-Trenaunay-Weber syndrome originated not only from arteriovenous fistula, medullary angioma, and extradural hemangioma but also vertebral hypertrophy with scoliosis.     

Bilateral cervicomediastinal neurofibroma originating from the vagal nerve in a patient with von Recklinghausen's disease: report of a case

A 19-year-old woman with von Recklinghausen's disease was admitted with symptoms of hoarseness. A computed tomography scan showed a bilateral cervicomediastinal tumor. An extirpation of the left cervicomediastinal tumor was performed for the purpose of diagnosis and treatment. On thoracotomy, the tumor, which measured 9 × 8 × 4 cm in size, arose from the intrathoracic vagal nerve and the left tumor was resected with a segment of the vagal nerve and recurrent nerve. The pathological diagnosis of the tumor was a neurofibroma. The tumor on the right side was left untreated due to concerns about possibly causing palsy of the bilateral recurrent nerve and also because of the asymptomatic state of the right tumor. Mediastinal neuofibroma in a patient with von Recklinghausen's disease often arises from the intrathoracic vagal nerve. To our knowledge, this is the first report of bilateral cervicomediastinal neurofibroma originating from the vagal nerves. Received: November 15, 2001 / Accepted: May 7, 2002 Reprint requests to: M. Ohta     

Laparoscopic cholecystectomy after coronary artery bypass grafting using the right gastroepiploic artery: report of a case

A laparoscopic cholecystectomy (LC) was successfully performed on a 61-year-old man who had undergone coronary artery bypass grafting (CABG) using the right gastroepiploic artery (RGEA). He complained of right hypochondralgia 20 days after CABG. Gallstones were diagnosed and a cholecystectomy was performed 9 months after CABG. Under general anesthesia, the operation was performed using a pneumoperitonium. When a laparoscope was inserted, the RGEA pedicle could be clearly recognized. The pedicle obstructed the operating field and made the working space narrower than usual. No ST changes on the electrocardiogram were seen during LC, especially during the initiation of pneumoperitonium, the insertion of the ports, or when retracting the gallbladder. The postoperative course was uneventful. To avoid complications, care should be taken not to stretch the RGEA pedicle during LC, and careful monitoring of the electrocardiogram is also necessary. It is difficult to view the operating field and the RGEA pedicle together. It is therefore better to insert another laparoscope for concomitant monitoring of the RGEA pedicle. Received: June 25, 2001 / Accepted: January 8, 2002