Intrasellar pressure in pituitary tumors . Relation study: intrasellar pressure vs hypothalamic-pituitary function

THESES

Intrasellar pressure in pituitary tumors . Relation study: intrasellar pressure vs hypothalamic–pituitary function. (Abstract)^*. Dissertation. São Paulo, 2004

Jackson Augusto Gondin Oliveira^**

Between August 2002 and May 2003, 30 patients with pituitary adenomas had their intrasellar (tumoral) pressure measured during transsphenoidal endoscopic surgery for these tumors. The age varied between 19 and 73 years, 16 were males and 14 females. The adenomas had a volume smaller than 1 cm³ in nine cases, between 1 and 4 cm³ in six cases and in 15 patients, the volume was superior to 4 cm³. Of the 30 cases studied 21 (70%) were functional adenomas (9 producing adrenocorticotropin hormone, 4 producing growth hormone – prolactine hormone, 3 producing growth hormone, 3 producing prolactin hormone, and 2 cases were plurihormonal adenomas).

The presence of an increased intrasellar pressure in patients with hypopituitarism is evidenced in this series: 17 patients presented a medium intrasellar pressure of 20.3 mmHg while in the 13 patients with normal pituitary function the pressure was 16.2 mmHg. This result suggests that the increase of the intrasellar pressure would be involved in the pathogenesis of the hypopituitarism, either by the intrasellar tumoral compression of the pituitary or by the extrasellar hypothalamic compression of the macroadenomas. However in our cases this results did not present statistical significance.

The intrasellar pressure (PIS) was measured based on the classification of Hardy and Vezina (1976). It was more elevated in the type I microadenomas with average 32.6 mmHg, sharply superior to the value of a normal intracranial pressure. In the type 0 adenomas PIS was of 7.66 mmHg, in the type II it was 19.2 mmHg, in the type III it was11 mmHg, and in type IV it was 14.8 mmHg. These values showed that the macroadenomas confined in the sella without destruction of the floor and integrity of the diaphragm presented a value of PIS much higher than extrasellar macroadenoma's. The statistical study of these data showed that the patients classified as degree I differed from the others.

It was evidenced that these patients presented the highest intrasellar pressure and they were different from all the other degrees. The patients with adenomas classified as degrees II, III and IV presented an intrasellar pressure comparatively similar. The adenomas classified as degree 0 and III were also considered statistically the same.

Key words: intrasellar pressure, pituitary, adenoma, endoscopy, sella turcica.

Publication Dates

• Publication in this collection
  23 June 2004
• Date of issue
  June 2004