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A Muacevic

Publications and source records attributed to A Muacevic.

24 records · Page 2Linked to original sources
PubMed1999

Computer-assisted resection of cerebral arteriovenous malformations.

OBJECTIVE: A series of 22 patients with arteriovenous malformations (AVMs) were surgically treated using computer-assisted image guidance. The value of image guidance for nidus definition and detection of feeding arteries and draining veins was assessed. METHODS: Seven of the 22 patients presented with hemorrhage. The sizes of the AVMs ranged from 1 to 8 cm. Six patients underwent preoperative embolization. For 18 patients (81.8%), the AVMs were located in highly eloquent areas. A passive-marker-based neuronavigation system (BrainLab, Heimstetten, Germany) was used for intraoperative image guidance. Segmentation of the pathological vessels was performed preoperatively, on the basis of 2-mm helical computed tomographic angiographic slices, to obtain three-dimensional reconstructions of the AVMs. Temporary clips were initially placed on all identifiable feeding arteries, for intranidal pressure reduction before AVM dissection. Dissection of the AVMs was then performed along the main draining veins, as identified by neuronavigation. Patient follow-up monitoring ranged from 3 to 16 months (median, 7 mo). RESULTS: The computer-calculated registration accuracy ranged between 1.1 and 3.1 mm (median, 1.4 mm). Exact nidus definition was possible for all 22 patients. The principal draining veins were also identified for all patients. Feeding arteries could be detected after the segmentation process when the vessels were at least 3 mm in diameter (19 patients). Complete collapse of the AVMs was achieved with initial clip application for 3 patients; partial intranidal pressure reduction was observed for 12 patients. No significant decompression by feeder clipping was possible for pre-embolized AVMs. Perioperative mortality and morbidity rates were 0 and 14%, respectively. CONCLUSION: This image-guided technology allows observation of the relationship between AVMs and adjacent brain structures, increasing spatial orientation during surgery. Definition of an optimal surgical approach and early localization of feeding arteries for temporary occlusion minimize tissue manipulation and enhance the safety of direct dissection along the draining veins, which is necessary in eloquent areas.

Adolescent↗
PubMed1999

Surgery and radiotherapy compared with gamma knife radiosurgery in the treatment of solitary cerebral metastases of small diameter.

OBJECT: The aim of this retrospective study was to compare treatment results of surgery plus whole-brain radiation therapy (WBRT) with gamma knife radiosurgery alone as the primary treatment for solitary cerebral metastases suitable for radiosurgical treatment. METHODS: Patients who had a single circumscribed tumor that was 3.5 cm or smaller in diameter were included. Treatment results were compared between microsurgery plus WBRT (52 patients, median tumor dose 50 Gy) and radiosurgery alone (56 patients, median prescribed tumor dose 22 Gy). In case of local/distant tumor recurrence in the radiosurgery group, additional radiosurgical treatment was administered in patients with stable systemic disease. Survival time was analyzed using the Kaplan-Meier method, and prognostic factors were obtained from the Cox model. The patient groups did not differ in terms of age, gender, pretreatment Karnofsky Performance Scale (KPS) score, duration of symptoms, tumor location, histological findings, status of the primary tumor, time to metastasis, and cause of death. Patients who suffered from larger lesions underwent surgery (p < 0.01). The 1-year survival rate (median survival) was 53% (68 weeks) in the surgical group and 43% (35 weeks) in the radiosurgical group (p = 0.19). The 1-year local tumor control rates after surgery and radiosurgery were 75% and 83%, respectively (p = 0.49), and the 1-year neurological death rates in these groups were 37% and 39% (p = 0.8). Shorter overall survival time in the radiosurgery group was related to higher systemic death rates. A pretreatment KPS score of less than 70 was a predictor of unfavorable survival. Perioperative morbidity and mortality rates were 7.7% and 1.6% in the resection group, and 8.9% and 1.2% in the radiosurgery group, respectively. Four patients presented with transient radiogenic complications after radiosurgery. CONCLUSIONS: Radiosurgery alone can result in local tumor control rates as good as those for surgery plus WBRT in selected patients. Radiosurgery should not be routinely combined with radiotherapy.

Adolescent↗
PubMed1997

[Surgical strategy in cases of multiple aneurysms].

Over a 4 year period 50 patients (34 women, 16 men; median age 48.5 years, range 24-69 ys.) were operated on multiple intracranial aneurysms (MA) and 283 patients (178 women, 105 men, median age 50.0 years; range 22-82 ys.) on single aneurysms (SA). A subarachnoid hemorrhage (SAH) occurred in the MA-group (in total 123 aneurysms, 5 giant aneurysms) in 43 cases, in the SA-group in 257 cases. Fifty-seven percent of all patients were operated on within 48 hours after SAH, 14% between day 3 and 7, 29% after day 7. There were no significant differences in the Hunt & Hess grading or in the distribution of ruptured aneurysms between both groups. Operation time was longer by 70 min in MA-patients than in SA-patients, but did not significantly influence the outcome in that group (rs = 0.200; p = 0.163). In 74% of the patients all aneurysms could be eliminated in one stage, among them 18 had bilateral or supra-infratentorial aneurysms. The step by step occlusion of the aneurysms was performed by dissecting all aneurysms and by clipping the deepest one and the bleeding source first. In 8 cases, all aneurysms were clipped through a contralateral keyhole approach.--After a mean follow up period of 1 year, 72% of the MA-patients and 65% of the SA-patients had made an excellent or good recovery. The morbidity rate was 22% in the MA- and 30% in the SA-patients. The operative mortality amounted to 6% in the MA- and 5% in the SA-group. The differences in outcome of both groups were not significant. Considering a bleeding risk of 1-2% per year, we suggest the operative treatment of all identified aneurysms, if possible in a one-stage, if necessary in a two-stage procedure in an individually tailored approach.

Adult↗