Effect of Sphenoid Sinus Pneumatization on the Surgical Windows for Extended Endoscopic Endonasal Transsphenoidal Surgery.

BACKGROUND: Little is known on the impact of the pattern and extent of pneumatization of the sphenoid sinus (SS) on the dimensions of the surgical windows used in extended endoscopic endonasal transsphenoidal approaches. We therefore investigated whether the distances between the 2 optic canals and between the paired paraclival carotid arteries are influenced by the pattern and extent of pneumatization of the SS. METHODS: One hundred high-resolution computed tomography scans from 47 adult female and 53 adult male patients were analyzed. The pattern of SS pneumatization was classified into conchal, presellar, and sellar types. Sellar-type sinuses were then classified according to a newer detailed classification system. Maximal anteroposterior (AP), transverse (TR), and craniocaudal diameters of the SS, interoptic distance at the limbus sphenoidale (IODL) and at the entrance of the optic canal (IODE) and the intercarotid distance between the paraclival carotids (ICD) were measured. A 2-tailed Mann-Whitney U test and Pearson correlation coefficient (R) were used for statistical analysis. A P value <0.05 was considered statistically significant. RESULTS: Positive correlation was found between IODL and both AP and TR diameters of the SS; between IODE and both AP and TR diameters of the SS; and between ICD and all diameters of the SS. The highest correlation for each of the IODL, IODE, and ICD was noted with the TR diameter of the SS. CONCLUSIONS: During the development of the SS, pneumatization progress likely exerts quantitative and direction-specific forces, which gradually increase the interoptic and intercarotid distances.

Efficacy and Safety of the Rotational Technique for Endoscopic Transforaminal Excision of Colloid Cysts of the Third Ventricle.

BACKGROUND: The main criticism of endoscopic excision of colloid cysts of the third ventricle is the decreased ability to completely resect the cyst wall, therefore increasing the risk of recurrence. The extent of resection varies widely across the endoscopic series and is largely influenced by the surgical technique. We report the results of the rotational technique for endoscopic transforaminal excision of colloid cysts in a series of consecutive patients. Our objective is to contribute to the current literature and to shed more light on an effective and safe yet less commonly used technique. METHODS: Retrospective analysis was performed on 19 patients. Preoperative magnetic resonance imaging (MRI) was evaluated for cyst characteristics. Postoperative MRI was evaluated for residual cyst membranes. Operative records were reviewed for residual cyst components. Excision grade was determined based on the Barrow Neurological Institute grading scale. Symptom resolution was documented clinically. RESULTS: The study included 13 men and 6 women, with a mean age of 35 years (range, 19-56 years) and mean follow-up of 27.74 months (range, 4-55 months). Total excision was achieved in 17 of 19 cysts (89.5%). A small residual was seen intraoperatively but not radiographically in 1 patient. In another patient, residual cyst membrane seen intraoperatively and radiologically led to recurrence 18 months postoperatively. No mortalities or permanent morbidities occurred. CONCLUSIONS: Our high total excision rate and low complication profile are in concordance with the recent reports of endoscopic resection of colloid cysts. The rotational technique for the endoscopic transforaminal approach is highly effective and a safe alternative to the bimanual dissection technique.

Endoscopic Endonasal Excision of Large and Giant Pituitary Adenomas: Radiological and Intraoperative Correlates of the Extent of Resection.

BACKGROUND: Despite the superb visualization offered by the endoscopic endonasal transsphenoidal approach, the resection rates of large and giant pituitary adenomas have remained much lower than those of smaller macroadenomas. Various tumor characteristics can influence the extent of resection (EOR) and have been variably reported. Additional understanding of these factors is mandatory to improve the results. We analyzed the radiological and intraoperative tumor characteristics influencing the EOR in a cohort of patients with large and giant pituitary macroadenomas undergoing endoscopic endonasal transsphenoidal excision under our care. METHODS: Twenty-eight patients were included. Magnetic resonance images were retrospectively analyzed for pre- and postoperative tumor volumetric analysis; preoperative tumor volume calculation using the formula (A × B × C/2); preoperative radioanatomical characteristics, including tumor shape, radiological structure, contrast enhancement, and extension; and the EOR. Intraoperative data were retrieved and included. RESULTS: The preoperative calculated tumor volume was 38.14 ± 23.02 cm3 and the preoperative measured tumor volume was 50.345 ± 17.36 cm3. A statistically significant difference was found between the calculated and measured tumor volumes for the whole cohort and for tumors with a maximum diameter >3.9 cm. A statistically significant difference in the EOR was found at a volume threshold of 26.2 cm3. Large cysts, heterogeneous enhancement, Knosp grade ≤2, soft tumor consistency, and tumor hemorrhage were significantly associated with gross total resection. CONCLUSIONS: Volumetric analysis should replace 2-dimensional methods in determining the size of large and giant pituitary adenomas. Specific tumor characteristics were associated with the EOR and could help in predicting the EOR for these tumors.