Microsurgical treatment of symptomatic vestibular schwannomas in patients under 40: different results before and after age of 30

Abstract

Background: In 10-15% of cases of vestibular schwannoma (VS) age at diagnosis is 40 years or less.Little is known about the differences in natural history, surgical ndings and postoperative outcomes of such younger patients as compared to those of greater age. Objectives : To analyze clinical and surgical and imaging data of a consecutive series of n=50 patients with unilateral sporadic VS, aged 40 years or younger -separated in a very young group (15-30 years) and a moderately young group (31-40 years). Study design: Retrospective case series Methods: 50 consecutive patients under 40 years of age underwent microsurgical resection of unilateral sporadic VS via the retrosigmoid approach. The study cohort was subdivided into two groups according to the age range: Group A, age range 15-30 years (n=23 patients) and Group B, age range 31-40 years (n=27 patients). The adherence of VS capsule to surrounding nervous structures and the tendency of the tumors to bleed were evaluated by reviewing video records; the course of the FN in relation to the tumor's surface was assessed in each case. Microsurgical removal of tumor was classi ed as total (T), near total (residual tumor volume <5%), subtotal (residual tumor volume 5-10%) or partial (residual tumor volume >10%).Results: Mean tumor size of entire cohort was 2,53 (range: 0,6-5,8) cm: 2,84 cm in Group A and 2,36 cm in Group B (p=NS). Facial nerve course and position within the cerebellopontine angle did not differ signi cantly between the two groups. At 6-month follow-up, FN functional outcome was: HBI-II in 69,5% in Group A, versus 96,3% in Group B (p<,001). Hearing preservation was achieved in 60,0% of patients of Group A and in 58,3% of Group B (p=NS). Total and near-total resection was feasible in 95,6% of cases of Group A and in 88,9% of Group B (p=NS). Tumor capsule was tightly adherent to nervous structures in 69,6% patients of Group A and in 22,2% of Group B (p<,05). Signi cant bleeding was encountered in 56,5% of Group A tumors, and in 29,6% of Group B tumors (p<,01).Conclusions: Microsurgery of VS in patients aged 40 or less is associated with good functional results, and with high rates of total and near total tumor removal. Patients <30 years of age have more adherent tumor capsules. Furthermore, their tumors exhibit a tendency to larger sizes, to hypervascularization, to profuse intraoperative bleeding and they present worse long-term functional FN results when compared to patients in their fourth decade of life. Our limited experience seems to suggest that a near total resection in very young VS patients with large tumors should be preferred in adherent and hypervascularized cases, in order to maximize resection and preserve function.

A Nomogram to Predict Recurrence-Free Survival Following Surgery for Vestibular Schwannoma

“…Luciano et al. found that in younger patients, tumor adhesions were more common and tended to be larger in size, abundant in blood supply, and excessive intraoperative bleeding ( 21 ). This suggests that vestibular schwannomas in young patients seem to have special characteristics, which should be paid attention to during the treatment.…”

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“…In a retrospective cohort study of 596 patients conducted by Nick et al, the risk of tumor recurrence was significantly higher in younger patients than in older patients and suggested that this may be due to some host-related factor that promotes tumor growth (7). Luciano et al found that in younger patients, tumor adhesions were more common and tended to be larger in size, abundant in blood supply, and excessive intraoperative bleeding (21). This suggests that vestibular schwannomas in young patients seem to have special characteristics, which should be paid attention to during the treatment.…”