Endonasal Transsphenoidal Pituitary Surgery: Institutional Review of Initial Experience

Objects: In the abstract we collected all available data concerning to transnasal transsphenoidal pituitary surgery performed from February 2007 to July 2013 in our department. This is a retrospective summary of single-center's initial experience.

Methods: All transnasal transsphenoidal surgeries were performed in the clinic of neurological surgery of Kazan Interregional Clinical Diagnostic Center. Two main surgical techniques – transnasal microsurgical and endonasal endoscopic approach (EEA) were applied. Demographic, pathological and complication data were collected. A total 256 patients with pituitary tumors were operated. Transnasal transsphenoidal microsurgical approach was performed in 105 cases, and EEA with frameless image-guidance was applied at the 151 patients respectively, in 8 cases of them an anterior expanded approach was performed.

Results: According to gender there were 106 males and 150 females. Patient's age was between 18–77 years, with mean age of 47,18 years. Mean period of follow-up is 31 month. Working in Russian Federation we use our national classification of tumor size. It consists of five grades and they are next:

• Microadenoma (up to 15 mm)

• Small adenoma (16–25mm)

• Mid-size (26–35 mm)

• Large (36–59 mm)

• Giant (> 60 mm)

With regard to this classification in our series there were: microadenoma – 49(19,14%); small adenoma – 84(32,8%); mid-size adenoma – 77(30%); large adenoma – 46(18%). Tumor parasellar invasion and suprasellar extension were classified by Knosp classification and Modified Hardy's(MH) classification. Minimal tumor diameter was 3mm and maximum diameter 59mm. Mean preoperative tumor volume was 7,60cm3. We also classified tumors according to hormone activity. All available data are presented in Table 1.

Table 1

		n	P(%)
Knosp	0	127	49,61
	1	58	22,66
	2	34	13,28
	3	12	4,69
	4	12	4,69
	Data lost	13	5,08
MH	0	94	36,72
	A	78	30,47
	B	50	19,53
	C	25	9,77
	Data lost	9	3,52
Hormone activity	Null cell	144	56,25
	GH	75	29,30
	PRL	25	9,77
	GH/PRL	3	1,17
	ACTH	9	3,52

Gross total resection was achieved for 136 patients (53,13%), near total - 29 (11,33%), subtotal - 58 (22,66%), and partial - 33(12,9%). In 15(5,86%) cases a repeated surgery due to residual/recurrent lesions was performed. Mortality rate was 0,79% - 2 patients with large pituitary tumors. Among complications there were: ICA injury – 1(0,34%), massive subarachnoid bleeding due to aneurism rapture – 2(0,79%), tumor bed bleeding– 6(2,35%), SCF-leak – 7(2,74%), epistaxis – 3(1,18%), meningitis – 2 (0,79%), visual disturbance – 5(1,96%), diabetes insipidus - 24(9,38%), cerebral salt-wasting syndrome – 2 (0,79%).

Conclusions: Transnasal transsphenoidal approach for pituitary tumors is effective and safe. EEA combined with expanded approaches allows make tumor resection more radical due to best illumination and wide exposure of skull-base structures.