Efficacy of cryohypophysectomy in the treatment of acromegaly. Evaluation of 54 cases

Recent developments in the treatment of acromegaly

In acromegaly the microsurgical transsphenoidal removal of the pituitary adenoma has become the most widely used method of treatment. In experienced hands, the therapeutic goal of rapid normalization of hormone excess and preservation of pituitary function can be achieved in most of the patients if the tumours are not too large. Medical treatment or radiotherapy alone, or in combination, are less successful for primary treatment. They are indispensable as alternative therapy in those patients not suitable for operation, and as additional methods after incomplete tumour removal. Large invasive adenomas still present a challenge for further improvement of therapeutic facilities. Intraoperative GH-measurements, as recently introduced by us, help to identify tumour residues and justify additional surgical exploration at higher risk.

A decade of pituitary microsurgery. The Herbert Olivecrona lecture

The author reviews his experience with surgical treatment of 1000 pituitary tumors, the majority of which were endocrine-active. The criteria of grading, the microsurgical technique used, and the postoperative results are presented. The mortality rate was 0.2% overall, with no deaths in the group of 774 patients with endocrine-active adenomas.

Pituitary surgery for endocrine disorders

The use of pituitary surgery for patients with over-production of growth hormone, corticotrophin and prolactin is reviewed. The value of specialized neuroradiological techniques is discussed including computerized tomography, air-encephalography and cavernous sinus venography. The indications for transcranial as opposed to trans-sphenoidal surgery are considered. The place of trans-sphenoid surgery in the treatment of acromegaly is emphasized and the indications for surgical treatment are reviewed. The two syndromes due to over-production of ACTH are considered--Cushing's disease and Nelson's syndrome. The increasing use of pituitary surgery for the treatment of Cushing's syndrome due to increased ACTH production is noted, but a warning is given about the small ACTH-secreting pulmonary carcinoid tumour that may closely mimic Cushing's disease. The difficulties encountered in trying to treat patients with Nelson's syndrome are stressed. It is recommended that in the rate case where total adrenalectomy is required in Cushing's disease, pituitary irradiation should be given before or shortly after adrenalectomy. The present position relating to the surgical treatment of the small prolactin-secreting pituitary tumour is reviewed. Published data and personal experience suggests that for many of these patients, treatment with bromocriptine is preferable to trans-sphenoidal surgery. Large prolactinomas usually need transfrontal surgery and X-ray therapy, sometimes followed by bromocriptine treatment. The need for steroid cover for pituitary surgery is discussed and it is suggested that a glucocorticoid with less salt-retaining action than cortisol should be used. The importance of post-operative endocrine assessment is emphasized and a convenient method suggested. The incidence of complications after transsphenoidal surgery is low, although panhypopituitarism occurred in 14% of the cases reported.

Functional treatment of acromegaly by transsphenoidal microsurgery

The authors have analyzed the results from 41 acromegalic patients who underwent transsphenoidal surgery. In 31 patients, postoperative growth hormone (GH) levels fell and remained below 10 ng/ml. This represents an endocrinological "cure" of 78%. In the remaining 10 cases, postoperative GH values have not stabilized below 10 ng/ml, although seven show some clinical improvement. The results were particularly good in those cases of localized adenomas, which allowed a selective removal while maintaining pituitary function within normal limits in 65.5% of cases. The postoperative GH level in this group fell and remained below 10 ng/ml in more than 90% of cases. Four patients required reoperation to normalize the GH levels which had not been sufficiently modified after the first operation; only one of them remained with plasma GH levels above normal limits. There were no deaths in this series. Rhinorrhea occurred as a postsurgical complication in four cases. In three this disappeared with bed rest and lumbar drainage; in the other, surgical repair was necessary. The occurrence of surgical complications has decreased as our experience has increased, and the need for reoperation has been unusual after the first year of our study.

Evaluation of the results of trans-sphenoidal surgery in acromegaly by assessment of the growth hormone response to thyrotrophin-releasing hormone

Eighteen acromegalic patients GH-responsive to TRH were reinvestigated following trans-sphenoidal surgery and radiotherapy. Basal serum GH decreased below 10 microgram/1 in thirteen cases; nine of them became GH-unresponsive to TRH 1 month after operation, and another one following conventional pituitary irradiation. Four of these ten patients also showed a normal GH response to L-Dopa after treatment, and five responded normally to insulin-induced hypoglycaemia; two patients had a normal GH secretory pattern after both these stimuli. No recurrences were observed over a follow-up period of 15-80 months among the ten patients who became GH-unresponsive to TRH following operation, while one of the three subjects still responsive to TRH in spite of normalized basal serum GH concentration relapsed 10 months after surgery. Three patients with normalized TRH test following operation were repeatedly reinvestigated over a 3-6 years period and always found unresponsive. The present study shows that the 'paradoxical' GH responses to TRH and L-Dopa frequently disappear after surgery, that complete normalization of GH secretory pattern may rarely be attained, and that the disappearance of GH response to TRH probably indicates satisfactory treatment of acromegaly. These data suggest that the 'paradoxical' GH responses frequently found in acromegaly are dependent on the adenoma per se and not on hypothalamic dysfunction.