The presacral retroperitoneal approach for axial lumbar interbody fusion: a prospective study of clinical outcomes, complications and fusion rates at a follow-up of two years in 26 patients.

The presacral retroperitoneal approach for axial lumbar interbody fusion (presacral ALIF) is not widely reported, particularly with regard to the mid-term outcome. This prospective study describes the clinical outcomes, complications and rates of fusion at a follow-up of two years for 26 patients who underwent this minimally invasive technique along with further stabilisation using pedicle screws. The fusion was single-level at the L5-S1 spinal segment in 17 patients and two-level at L4-5 and L5-S1 in the other nine. The visual analogue scale for pain and Oswestry Disability Index scores were recorded pre-operatively and during the 24-month study period. The evaluation of fusion was by thin-cut CT scans at six and 12 months, and flexion-extension plain radiographs at six, 12 and 24 months. Significant reductions in pain and disability occurred as early as three weeks postoperatively and were maintained. Fusion was achieved in 22 of 24 patients (92%) at 12 months and in 23 patients (96%) at 24 months. One patient (4%) with a pseudarthrosis underwent successful revision by augmentation of the posterolateral fusion mass through a standard open midline approach. There were no severe adverse events associated with presacral ALIF, which in this series demonstrated clinical outcomes and fusion rates comparable with those of reports of other methods of interbody fusion.

Permanent iodine-125 interstitial implants for the treatment of recurrent glioblastoma multiforme.

OBJECTIVE: Brachytherapy with temporary implants may prolong survival in patients with recurrent glioblastoma multiforme (GBM), but it is associated with relatively high costs and morbidity. This study reports the time to progression and survival after permanent implantation of iodine-125 seeds for recurrent GBM and examines factors predictive of outcome. METHODS: Forty patients with recurrent GBM were treated with maximal resection plus permanent placement of iodine-125 seeds into the tumor bed. A total dose of 120 to 160 Gy was administered, and patients were followed up with magnetic resonance imaging scans every 2 to 3 months. RESULTS: Actuarial survival from the time of implantation was 47 weeks, with 7 of 40 patients still alive at a median of 59 weeks after implantation. Survival was significantly better for patients younger than 60 years, and a trend for longer survival was demonstrated with gross total resection and tumors with a low MIB-1 (a nuclear antigen present in all cell cycles of proliferating cells) staining index. Median time to progression was 25 weeks and, on multivariate analysis, was favorably influenced by gross total resection and patient age younger than 60 years. After implantation, 27 of 30 patients with failure had a local component to the failure. No patient developed symptoms attributable to radiation necrosis or injury. CONCLUSION: Permanent iodine-125 implants for recurrent GBM result in survival comparable with that described in previous reports on temporary implants, but with less morbidity. Results are most favorable for patients who are younger than 60 years, and who undergo gross total resection. Despite this aggressive treatment, most patients die as a consequence of locally recurrent disease.

Image-guided neurosurgery.

The linking of digitizing pointers to computer programs that reformat diagnostic studies has resulted in the development of image-guided surgery, also called frameless stereotactic surgery. With frameless stereotaxy, the neurosurgeon transposes the three-dimensional physical space of the patient's skull and cranial contents in the operating room with the three-dimensional image space of preoperative computerized tomography (CT) or magnetic resonance imaging (MRI) scans shown in the computer.

Stereotactic resection of brain metastases in eloquent brain.

We have treated 14-patients with metastatic tumors located in eloquent cortical areas by a stereotactic-guided keyhole craniotomy and total microsurgical excision utilizing the Pelorus stereotactic device. Patients ranged in ages from 26 to 82 years with a median age of 59 years. There were 9 women and 5 men. Ten patients presented with hemiparesis and 4 with aphasia. Primary tumor location was lung in 7, colon in 2, melanoma in 2, and breast, renal, and bone in 1 case each. Gross total resection was accomplished in all cases, with postoperative imaging confirmation of complete removal. Single metastatic tumors were removed in 12 cases, and multiple lesions in 2 cases. Twelve patients had postoperative whole brain irradiation (30 Gy/10 fractions); 2 patients had previously received whole brain irradiation, yet demonstrated tumor growth. Complete resolution of neurologic deficits was accomplished in 8 patients, 3 had improved and 2 were unchanged. One patient had resolution of preoperative deficit but developed hemiparesis secondary to a hemorrhagic infarction contralateral to the operative site. Nonneurologic morbidity includes deep venous thrombosis in 3 patients, and pneumonia in 1. Thirty-day perioperative mortality is zero, and to date no patient had died of intracranial disease. We believe that with the assistance of stereotactic localization, metastases in vital regions of the cortex can be removed with very low neurologic morbidity, and with a high proportion of patients having improvement in their level of neurologic function. The morbidity in this series compares favorably with that of stereotactic radiation series reported in the literature with local disease control and resolution of neurologic deficits that equals or exceeds stereotactic radiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Implantation of intracerebral depth electrodes for monitoring seizures using the Pelorus stereotactic system guided by magnetic resonance imaging. Technical note.

The Pelorus stereotactic system guided by magnetic resonance imaging was used to implant intracerebral depth electrodes for monitoring seizure activity. This stereotactic system is frameless and does not require the use of a computer. It is based on the concept of a ball-and-socket type stereotactic arc director and uses the center-of-arc principle to establish a trajectory for electrode placement. The system not only allows the use of the orthogonal approach, but also provides ample working space and flexibility to choose different entry points and trajectory angles.

Acute effect of the Nd:YAG laser on the cerebral arteriovenous malformation: a histological study.

The acute effect of Nd:YAG laser beam on cerebral arteriovenous malformations (AVMs) was examined. Histological examination of the specimens after treatment with the Nd:YAG laser revealed that the most prominent effect of the laser was shrinkage of the collagen of the vessels of the AVM, which led to laser-induced narrowing of blood vessels. The brain tissue confined to the resected AVM did not contain any histological evidence of acute damage. The resection of 10 cases of AVMs was safely accomplished with no morbidity or increased neurological deficits attributable to the laser technique.

Epidural lipomatosis and renal transplantation.

A 34-year-old man presented with progressive myelopathy 4 months after cadaveric renal transplant for endstage renal disease. Radiographic evaluation gave findings consistent with epidural lipomatosis and compression of the thoracic thecal sac. Decompressive laminectomy resulted in dramatic improvement of his neurologic deficit. This case is unusual in the brevity of steroid treatment prior to onset of the myelopathy, as well as the relatively small dose. The 10 previous cases of epidural lipomatosis are also reviewed.

Multiple intracranial aneurysms in identical twins.

Familial intracranial aneurysms are well documented, with the highest association occurring among siblings. Five pairs of identical twins with subarachnoid hemorrhage have been previously reported. We present the sixth set of identical twins with multiple aneurysms. These cases represent the first report in the literature of multiple mirror aneurysms in identical twins. One twin presented with subarachnoid hemorrhage. Her sister, who was asymptomatic, had elective angiography which demonstrated multiple aneurysms in locations identical to her sister's aneurysms. In families in which a twin presents with subarachnoid hemorrhage, it is appropriate to recommend angiography to the asymptomatic twin.

Chronic posttraumatic lumbar intradural arachnoid cyst with cauda equina compression: case report.

An unusual case of a chronic posttraumatic lumbar intradural arachnoid cyst causing compression of the cauda equina is reported. The etiological, pathological, and clinical features are discussed. Emphasis is placed on the importance of a correct interpretation of radiological findings.

Successful laser-assisted excision of a metastatic midbrain tumor.

Metastatic lesions to the midbrain are rare. They are found in 1 to 3% of autopsy series of solitary brain metastases. The consensus of opinion in the current literature is that they are inoperable lesions and should be treated by radiation therapy alone. This is the first case report of a completely excised metastatic adenocarcinoma to the midbrain. The patient's clinical course has been stable, and there is no computed tomographic evidence of recurrence at 18 months follow-up.