الفهرس 
Tarek Abd El-Hamid HamdyOnly 14 pages are availabe for public view
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Abstract
VS is a benign intracranial neoplasm arising from Schwann cells which mylinate the vestibular portion of the vestibulocochlear nerve.
The treatment modalities for VS include conservative observation, microsurgery, stereotactic radiosurgery and fractionated radiotherapy. Gamma knife radiotherapy has been the most common type of radiotherapy for treatment of VS.
Surgical approaches for VSsinclude the middle cranial fossa, retrosigmoid (hearing preserving approaches) and translabyrinthine (non hearing preserving approach). The choice of a surgical approach chiefly depends on the size of the tumor and whether preservation of hearing function is attempted.
The aim of surgery is to achieve control by complete resection of the tumour (no risk of future growth). However GKS induces avascular necrosis and fibrosis (the tumor is still present after treatment and carries the risk of further growth).
Debate exists about the best option for management of tumors less than 3 cm in size so; this size was the target of our study. Larger tumors are best treated with microsurgery.
Many studies were done but still no randomized controlled study was conducted to ascertain the best option. Our review was conducted to compare between both modalities regarding tumor control, facial function and hearing preservation.
The following results were obtained
The mean age was (51.6 years) for microsurgery population while it was (55.6 years) for GKS population.
• In microsurgery, tumor was controlled in 473/482 (98.1%), while it was controlled in 765/796 (96.1%) of GKS treated patients. There was no significant difference between both modalities.
• Facial function was preserved in 1336/1523 (87.8%) of microsurgery treated patients and 712/734 (97%) of GKS treated patients. There was a significant difference in favor of GKS.
• Hearing was preserved in 319/790 (40%) of patients treated with microsurgery and 185/321 (57.6%) of GKS treated patients. There was a significant difference in favor of GKS.
We conclude that there was no significant difference regarding control rates. However GKS has better preservation of both facial and hearing functions.
We compared these results with those obtained by the meta-analysis by Kaylie et al (2000), GKS could achieve better outcomes than before. This may be due to lower doses of radiation used in our review.
The number of patients presented with hearing loss was evaluated and was found to be 777/ 1786 (43.5%).
The most common surgical approach was the retrosigmoid approach, done on (40%) of patients. The second most common surgical technique was the middle cranial fossa done on (38.6%). The translabyrenthine approach was used on (16.6%) of patients. Other approaches were the widened retrolabyrenthine (4.6%) and combined approach (0.2%).
Facial outcomes had better results concerning facial function preservation in smaller tumors less than 10 mm than larger ones (86.86% vs. 76.29%).
We compared between MCF and RS approaches regarding their impact on hearing and found that MCF approach has better results (49.3% vs. 32.53%).
Facial function had better results on the long term (at least one year) than the short term (immediately after surgery) in microsurgery treated patients (90.7% vs 81.1%).
Comparing the outcomes of GKS on the short term (< 3 years) and long term (> 3 years), results for tumor control were almost the same on both the short and the long terms (96.7% vs. 96.1%).
Facial function was better on the short than the long term (96% vs. 94.8%). Also, hearing preservation was better on the short than the long term (51.72% vs. 40%).
There was no significant difference regarding tumor control rates. GKS achieves better outcomes regarding facial function and hearing preservation. This means that GKS is the method of choice in management of VSs up to 3 cm in size.