Population Study: (Table1)
Ninety-four consecutive patients operated on for a tuberculum sellae meningioma were enrolled in this study, including 83 females (88%) and 11 males (12%), with a mean age of 55 years (range 21-86).
Clinical Features: (Table1)
The foremost symptoms were the visual disturbances (91%). Eighty patients (85%) reported decrease of vision. Sixty-one percent of patients presented unilateral visual acuity loss, and 24% manifested bilateral impairments. The visual acuity ranged widely from normal vision (19 patients - 20%) to blindness (2 patients - 2%). Ninety-four percent of the patients showed VFD on Goldmann perimetric examination. The mean duration of visual symptoms was 8 months (range 0.5-48 / median 6 months).
Fourteen patients (15%) suffered from nonspecific headaches, anosmia (3%), seizure (1%). One patient (1%) presented with symptoms related to hypopituitarism.
Radiological Features: (Table1)
The mean tumor volume was 5.6 cc (range 0.7-14.5 / median 4.1 cc); the mean maximal diameter was 25 mm (range 10-78 / median 24 mm). The meningioma showed asymmetric growth with paramedian insertion in 84% of cases, while a median insertion was found in 15 patients (16). A median insertion was statically more frequently found in the male than female population (45% vs 12%, respectively – p=0.04). The dominant extension side was correlated to the clinical visual impairments in all cases, which was determinant to define the side of the approach.
Surgical Features: (Table1)
According to the main ON anatomical compression, 38% of the tumors (36 patients) were operated on through a contralateral craniotomy, whereas 43 patients (46%) underwent an ipsilateral approach, regardless the side of poorer vision. Patients whom presented midline lesions (15 patients – 16%) compromising bilateral vision underwent a right-sided craniotomy. Those patients have been excluded from the logistic regression analysis. Tumors originated from optic sulcus in 32% of cases, from TS in 19% and both optic sulcus and TS in 17%; from OC in 15%, both optic sulcus and OC in 7%, and both tuberculum sellae and OC in 9% of cases.
Tumor entering into the OC was found in 59 patients (63%). Only 3 patients had both canals involved (3%). Fifty-seven percent (57%) of the patients presenting with an OC involvement were operated through a contralateral approach, whereas 43% underwent an ipsilateral approach.
The tumor was invading the pia-mater of the frontal lobe in 5 cases (5%). The ON and pituitary stalk were anatomically preserved in all patients. The ipsilateral olfactory nerve was damaged or avulsed due to the spontaneous collapse of the frontal lobe during surgery in 34 cases (36%) (Figure 5). There was a higher rate of olfactory nerve avulsion in patients operated through a contralateral than an ipsilateral approach (46% vs 26% respectively, p=.04).
Seventy patients underwent a Simpson Grade 2 resection (74%). In 24 patients (26%), the tumor was resected subtotally because of severe adhesion to the ON (16 patients) or ICA (2 patients), or extension to the cavernous sinus (6 patients). A tumor residue was left near the ON in 33% of cases when tumor resection was performed through an ipsilateral approach, while only 17% when a contralateral approach was preferred (p=.11). In case of OC invasion, the tumor fragment could be successfully resected in 94% of cases through a contralateral whereas 75% through an ipsilateral approach (p=0.04).
Eight meningiomas (9%) were classified as WHO grade II tumors. The mean duration of surgery was 140 min (range 60-350 / median 138 min). The mean hospital stay was 10 days (range 4-41 / median 8 days).
Visual outcome:
Forty-four percent of the preoperative visual acuity loss totally resolved after surgery. Twenty six had varying degrees of improvement (total of 70% favorable outcome), while 24% were stationary. In the same way, 72% of the VFD evolved favorably (44% recovery, 28% improvement), while 19% remained unchanged. Eight patients showed long-term postoperative aggravated visual disturbances (9%). A contralateral approach seemed to be predictive of VFD improvement after surgery (OR=0.4), with borderline significant results (p=.08).
Predictive factors of unfavorable postoperative visual acuity outcome (Table 2)
Epidemiological factors:
Age and duration of symptoms were associated with non-recuperation of preoperative visual acuity loss as continuous variables (p=.03 & p=.00, respectively). Patients who presented with a preoperative visual acuity > to LogMar 1.3 experienced poorer recovery after surgery than those with visual acuity ≤ to LogMar 1.3 (41% favourable outcome vs 79%, respectively – OR=27.7, p=.00). The tumor volume appeared to be related to the visual outcome as a continuous variable: the larger the meningioma, the more likely was the patient to recover after surgery (p=.00 – OR=.73).
Intraoperative factors:
Seventy-four percent of the patients who presented with an optic canal involvement showed favorable visual outcome, versus 62% when the OC was freed from tumor (p=.09). The extent of resection was associated with better visual outcomes: the visual acuity loss improved in 77% of the patients who underwent Simpson Grade 2 resection, whereas 45% after subtotal Simpson Grade 4 resection (OR=18.9; p=.01).
Predictive factors of unfavorable postoperative visual field outcome (Table 3)
A young age appeared to be related to improvement of the VFD after surgery (p=.00). The preoperative status of the visual field was statistically associated with its postoperative evolution. Patients harboring preoperative complete hemianopia experienced poorer recovery than those who presented with incomplete preoperative VFD (51% vs 89% of recuperation, respectively - OR=8, p=.00).
Olfactory status:
Two patients who presented with preoperative anosmia remained unchanged over time. Postoperative olfactory nerve disorders were transient in two cases only. Postoperative olfactory impairment were observed in 24 patients (26%). Fourteen patients (15%) retained long-term postoperative hyposmia, whereas 10 (11%) reported complete anosmia. There was significantly a higher rate of new permanent postoperative olfactory nerve impairment in patients operated through a contralateral than an ipsilateral approach (37% vs 17% respectively, p=.03).
Other complications:
The other immediate postoperative complications were seizure (4 patients - 4%), operative site hematoma (5 patients – 5%) and prolonged hospital stay in the ICU (3 patients – 3%), transient diabetes insipidus (4 patient – 4%), meningitis (1 patient – 1%), chronic subdural hematomas (2 patients – 2%) and one pseudo-meningocele requiring ventriculo-peritoneal shunting (1%). Intraoperative ICA injury occurred in 1 patient (1%), managed by clipping and exclusion of the CA, who experienced postoperative transient hemiparesis with further complete recovery. Two patients (2%) required cosmetic revision surgery, including late wound erosion on a titanium plate. None of the patients reported CSF leak, while 12 (13%) had frontal sinus opening during surgery (managed using TachoSil® Fibrin Sealant Patch - Baxter International Inc. Deerfield, Illinois).
Tumor Control: (Figure 6)
The overall mean radiological follow-up was 63 months (2-210 / median 50 months). Ten (11%) cases of regrowth were diagnosed during the FU period, with a mean delay from surgery to regrowth of 73 months (range 13-190 / median 56). Two of them had received Simpson Grade 2 resection, while 8 harbored a postoperative residue (97% vs 64% tumor control in these selected groups, respectively – p=.00). Half of the tumor regrowth were detected during radiological follow-up examination, whereas the other half presented with a worsening of vision. The 2-, 5- & 7-year tumor progression free survival (PFS) were 100% (n=41), 100% (n=22) & 100% (n=11) in the Simpson Grade 2 group, and 85% (n=17), 74% (n=11) & 67% (n=5) in the Simpson Grade 4 group, respectively (p=.00).
Two of those growing residues were treated with complementary GKS, 4 received postoperative radiotherapy. Four underwent salvage surgery (5%). One of these patient presented continuous growth of the residue after the second stage surgery (WHO grade II meningioma). He received adjuvant postoperative radiotherapy, then chemotherapy (Avastin®). This 79 years old patient died 38 months after surgery.