OBJECT: Convexity meningiomas are expected to have a low recurrence rate given their classically "easy resectability." Nonetheless, recurrence can occur. Factors playing a role in their recurrence are analyzed here, including the extent of resection and tumor histological type, among others, with a special emphasis on the cleavage plane. METHODS: The authors reviewed 100 cases of convexity meningiomas surgically treated between 1987 and 2001 with a median follow-up of 86 months (range 2-16 years). Preoperative and postoperative functional status, Simpson resection grade, histological type, and intraoperative surgical plane with pial vessel invasion were studied and correlated with the recurrence rate. RESULTS: The average tumor size was 3.6 ± 0.4 cm. The pre- and postoperative Karnofsky Performance Scale scores were 92.6 ± 4.6 and 97.9 ± 2.2, respectively. Ninety-five lesions were benign (WHO Grade I) and 5 were atypical (WHO Grade II). Ninety-one and 9 tumors were subjected to Simpson Grade 1 and 3 resections (three Grade 3a and six Grade 3b), respectively. Surgical deaths did not occur. After a mean follow-up of 7.2 years, 4 meningiomas recurred; 2 (2.2%) after Simpson Grade 1 resections and 2 after Simpson Grade 3 (3a and 3b) resections (22.2%; p = 0.0034). When just the subgroup of Simpson Grade 1/WHO Grade I was studied, the recurrence rate decreased to 1.2% (1 of 86 cases). The recurrence of WHO Grade I tumors was higher in the subpial group than in the extrapial group (p = 0.025). No difference in recurrence according to the cleavage plane was seen in the WHO Grade II subgroup (p = 0.361). As for the subpial group, no difference in recurrence was noted between the WHO Grade I and II subgroups (p = 0.608). Importantly, however, the extrapial subgroup of WHO Grade II lesions had a higher recurrence rate compared with its counterpart in the WHO Grade I subgroup (p = 0.005). CONCLUSIONS: Pial and vascular invasion affect the recurrence rate in convexity meningioma surgery. The recurrence rate of WHO Grade I tumors was higher among those with a subpial plane of dissection than among those with an extrapial one. Histological type did not determine the degree of pial invasion in WHO Grade I and II lesions.
OBJECT: Convexity meningiomas are expected to have a low recurrence rate given their classically "easy resectability." Nonetheless, recurrence can occur. Factors playing a role in their recurrence are analyzed here, including the extent of resection and tumor histological type, among others, with a special emphasis on the cleavage plane. METHODS: The authors reviewed 100 cases of convexity meningiomas surgically treated between 1987 and 2001 with a median follow-up of 86 months (range 2-16 years). Preoperative and postoperative functional status, Simpson resection grade, histological type, and intraoperative surgical plane with pial vessel invasion were studied and correlated with the recurrence rate. RESULTS: The average tumor size was 3.6 ± 0.4 cm. The pre- and postoperative Karnofsky Performance Scale scores were 92.6 ± 4.6 and 97.9 ± 2.2, respectively. Ninety-five lesions were benign (WHO Grade I) and 5 were atypical (WHO Grade II). Ninety-one and 9 tumors were subjected to Simpson Grade 1 and 3 resections (three Grade 3a and six Grade 3b), respectively. Surgical deaths did not occur. After a mean follow-up of 7.2 years, 4 meningiomas recurred; 2 (2.2%) after Simpson Grade 1 resections and 2 after Simpson Grade 3 (3a and 3b) resections (22.2%; p = 0.0034). When just the subgroup of Simpson Grade 1/WHO Grade I was studied, the recurrence rate decreased to 1.2% (1 of 86 cases). The recurrence of WHO Grade I tumors was higher in the subpial group than in the extrapial group (p = 0.025). No difference in recurrence according to the cleavage plane was seen in the WHO Grade II subgroup (p = 0.361). As for the subpial group, no difference in recurrence was noted between the WHO Grade I and II subgroups (p = 0.608). Importantly, however, the extrapial subgroup of WHO Grade II lesions had a higher recurrence rate compared with its counterpart in the WHO Grade I subgroup (p = 0.005). CONCLUSIONS: Pial and vascular invasion affect the recurrence rate in convexity meningioma surgery. The recurrence rate of WHO Grade I tumors was higher among those with a subpial plane of dissection than among those with an extrapial one. Histological type did not determine the degree of pial invasion in WHO Grade I and II lesions.
Authors: Henry Ruiz-Garcia; Daniel M Trifiletti; Nasser Mohammed; Yi-Chieh Hung; Zhiyuan Xu; Tomas Chytka; Roman Liscak; Manjul Tripathi; David Arsanious; Christopher P Cifarelli; Marco Perez Caceres; David Mathieu; Herwin Speckter; Gregory P Lekovic; Gautam U Mehta; Jason P Sheehan Journal: World Neurosurg Date: 2020-11-03 Impact factor: 2.104