Konstantina Karabatsou

Pure endoscopic endonasal approach for pituitary adenomas: early surgical results in 200 patients and comparison with previous microsurgical series.

OBJECTIVEnThe aim of this study was to report the results of a consecutive series of patients undergoing pituitary surgery using a pure endoscopic endonasal approach and to evaluate the efficacy and safety of this procedure.nnnPATIENTS AND METHODSnWe reviewed 200 consecutive patients with pituitary adenoma who underwent purely endoscopic transsphenoidal resection of their lesions. The patients clinical outcomes, including remission rates, degrees of tumor removal, and complications, were evaluated and compared with a previous microscopic series.nnnRESULTSnThere were 111 nonfunctioning adenomas and 34 growth hormone-secreting, 27 adrenocorticotropin hormone-secreting, 25 prolactin-secreting, and 3 thyroid-stimulating hormone-secreting adenomas. The degree of gross total removal for tumors with suprasellar or parasellar extension and without cavernous sinus involvement was 96% and for intrasellar lesions was 98%. After a median follow-up period of 19 months, the remission results for patients with functioning adenomas were 71% for growth hormone-secreting, 81% for adrenocorticotropin hormone-secreting, and 88% for prolactin-secreting adenomas, with no recurrence at the time of the last follow-up. This compares with similar results reported from series using a standard microsurgical approach (growth hormone-secreting adenomas, 67%; adrenocorticotropin hormone-secreting adenomas, 78%; and prolactin-secreting adenomas, 62%). Endoscopic surgery for recurrent or residual nonfunctioning adenomas that had been previously treated using a microscopic approach revealed in the majority of cases a more limited exposure during the initial surgery, frequently with incomplete tumor removal. Complication rates have been low, and the average length of hospital stay was reduced.nnnCONCLUSIONnA purely endoscopic approach for pituitary adenoma treatment is a safe and effective alternative to the traditional microscopic procedure. Although our results reveal excellent tumor-removal rates, comparable remission rates in functioning tumors, and a very low rate of complications, additional studies with longer follow-up periods are required to confirm whether this approach should be considered the preferred procedure for pituitary surgery.

Expanded endoscopic endonasal approach for treatment of clival chordomas: early results in 12 patients.

OBJECTIVEWe report our recent experience with an expanded purely endoscopic endonasal approach for the treatment of clival chordomas. METHODSTwelve patients underwent an expanded endoscopic approach for excision of cranial base chordomas at Toronto Western Hospital. Two patients had undergone a previous craniotomy for excision of a significant lateral intracranial extension of the tumor. All other patients had mainly centrally located lesions. Three patients had recurrent tumors. This study focused on the surgical approach, results, and complications associated with this approach. RESULTSDiplopia caused by VIth nerve palsy was the most common presenting symptom and was observed in seven patients. Gross total resection of the tumor was achieved in seven patients (58%). Four patients had complete recovery of their preoperative diplopia. One patient (8%) presented with new hemiparesis postoperatively. Four patients (33%) had a cerebrospinal fluid leak postoperatively; two were treated by lumbar drainage, and two required a secondary surgical repair. All newly diagnosed patients underwent adjuvant radiotherapy. There was no mortality. The short-term outcome was excellent in all but one patient. No recurrence was observed at the median follow-up period of 16 months. CONCLUSIONThe expanded endoscopic endonasal approach is a valid minimally invasive alternative for the treatment of centrally located clival chordomas or as an adjunct for the central part of chordomas with lateral extension. The early results of this technique indicate at least equivalency to more extensive open approaches, and its versatility may widen the horizon of surgical management of these aggressive lesions. The challenge with the cerebrospinal fluid leakage is being addressed with novel local flap repair techniques. This approach should be in the armamentarium of cranial base surgeons as an option in the management of clival chordomas.

Fronto-basal interhemispheric approach for tuberculum sellae meningiomas; long-term visual outcome

We report our experience with the treatment of tuberculum sellae meningiomas using the fronto-basal interhemispheric approach. A retrospective analysis was performed on a series of 24 patients with tuberculum sellae meningiomas who were operated between March 2000 and January 2007. Patients presenting symptoms, radiological images, operative reports, and clinical follow-up data were reviewed with special consideration for visual outcome. Visual deterioration was the presenting symptom in all patients, followed by headache in 9 patients (37.5%). The average duration of visual symptoms was 17.6 months. The average tumor diameter was 2.63 cm; encasement of the carotid artery was identified in 7 patients (29%). Complete tumor removal was achieved in 21 patients (87.5%). Mean follow-up period was 52 months. Vision improved in 19 patients (79%), remained stable in 4 (17%) and deteriorated in 1 patient (4%). The degree of tumor removal or visual outcome were both unrelated to the tumor size (p = 0.2 and p = 0.6 respectively). While the degree of preoperative visual deficit did not affect the visual improvement rate in the whole group (p = 0.9), those patients with improvement to good functional vision (>20/40) after the surgery, had a less severe preoperative deficit (p < 0.001). The most common complication was anosmia (29.1%) and there was no mortality. The frontobasal interhemispheric approach is safe and provides a direct anatomical approach to tuberculum sellae meningiomas with relatively low incidence of complications. Patients with improved vision to good functional level had a better preoperative visual status.

Potential role of 18fluorodeoxyglucose-positron emission tomography/computed tomography in differentiating benign neurofibroma from malignant peripheral nerve sheath tumor associated with neurofibromatosis 1.

OBJECTIVEBenign plexiform neurofibromas (PNfib), especially those occurring in patients with neurofibromatosis type 1, are at a significant risk of progressing to a malignant peripheral nerve sheath tumor (MPNST). Early diagnosis, followed by radical surgery and adjuvant radiation to maintain local tumor control, is of critical importance to prevent metastasis and subsequent mortality from MPNSTs. However, early diagnosis is hampered by the sensitivity of current imaging modalities such as computed tomography (CT) or magnetic resonance imaging to reliably detect this malignant transformation, which can occur heterogeneously in a PNfib to a MPNST. 18Fluorodeoxyglucose (18FDG)–positron emission tomography (PET) is linked to metabolism and proliferation of tissues and has been widely used in oncology including PNSTs. 18FDG-PET/CT has the added advantage of fusing metabolic and anatomic imaging data sets. METHODSIn this prospective study, 9 neurofibromatosis type 1–associated PNfibs suspected to have undergone transformation to an MPNST were preoperatively evaluated by 18FDG-PET/CT and magnetic resonance imaging. A detailed histological evaluation correlated the average and regional standard uptake value (SUV) from the 18FDG-PET/CT to grade of malignancy of the suspected MPNST. RESULTSImaging from 18FDG-PET/CT and associated SUV of the suspected MPNSTs demonstrated either a homogeneous or a heterogeneous pattern. Stratification of the maximal SUV to low (<4.0), intermediate (4.0–7.0), or high (>7.0) correlated to the proliferative index (Ki-67) and grade of MPNST. A maximal SUV of more than 7.0 was closely correlated to a focus of malignant transformation. CONCLUSIONThis study, on a limited number of cases, demonstrates the potential use of 18FDG-PET/CT to augment management of PNfibs, especially in the context of neurofibromatosis type 1, which is characterized by multiple tumors. The addition of CT anatomic imaging to 18FGD-PET can facilitate targeting biopsies to metabolic hot spots, to further augment diagnostic sensitivity. Much larger numbers of MPNSTs, which can only be accrued in a collaborative manner among institutions, are required to further assess the specificity and sensitivity of 18FDG-PET/CT in the diagnosis of MPNSTs.