Laparoscopic adrenalectomy for large-volume adrenal masses is technically feasible and seems to replicate open surgical oncologic principles of achieving a wide-margin, en bloc excision of the adrenal gland and periadrenal fat. Successful laparoscopic resection is not impacted by the large size of the adrenal mass per se but rather by the presence of local invasion and poorly defined tissue planes that may be encountered in adrenal malignancy. As such, laparoscopic adrenalectomy for large masses should be attempted only by experienced laparoscopic surgeons and then with a low threshold for open conversion.
Pheochromocytomas arise from chromaffin tissue, usually in the adrenal medulla, and are a cause for curable hypertension. Nearly all patients with this tumor are symptomatic, the most common symptoms being headache, palpitations and inappropriate perspiration. Diagnosis is confirmed by finding high levels of plasma catecholamines or increased excretion of catecholamine metabolites (metanephrines, vanillymandelic acid) in the urine. Localization of tumors(s) is important for the surgeon and is accomplished by CT scan, 131I-metaiodobenzylguanidine scintiscans or abdominal aortography. Treatment is surgical extirpation by an experienced team after depleted plasma volume has been replenished. Ten percent of tumors are malignant, 10% are bilateral in the adrenal medullae and 10% are extra-adrenal.
To assess the role of the sympathetic nervous system in mineralocorticoid hypertension in humans, results from 24 patients with aldosterone-producing adenoma were compared with those in 27 appropriately matched essential hypertensive subjects and 26 normotensive subjects. Resting plasma catecholamine levels averaged 292 +/- 140 (SD) pg/ml in patients with aldosterone-producing adenoma, 305 +/- 101 in patients with essential hypertension, and 260 +/- 120 in normotensive subjects; none of the differences among the three groups was significant. With head-up tilt (60 degrees for 10 min) plasma catecholamine levels increased similarly in the aldosterone-producing adenoma and essential hypertensive groups (up to 681 +/- 111 and 611 +/- 57 pg/ml respectively, NS). beta-Blockade (propranolol, 10 mg i.v.) in eight aldosterone-producing adenoma patients decreased heart rate (from 78 +/- 5 to 68 +/- 3 beats/min, p less than 0.005) and cardiac output (from 5.5 +/- 0.4 to 4.6 +/- 0.3 liter/min, p less than 0.001), but left mean blood pressure unchanged (127 +/- 4 to 127 +/- 2 mm Hg). Combined alpha- and beta-blockade with phentolamine and propranolol in five patients with aldosterone-producing adenoma produced no detectable changes in blood pressure. Thus, results from biochemical, functional, and pharmacological studies in humans showed no evidence of enhanced peripheral sympathetic activity in the hypertension of primary aldosteronism.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.