Changing pattern of the intraoperative blood pressure during endoscopic adrenalectomy in patients with Conn's syndrome

Background: Primary hyperaldosteronism caused by an aldosterone-producing adenoma of the adrenal gland is regarded as the most common type of endocrine hypertension. The aim of this study was to analyze the changing pattern of the intraoperative blood pressure during endoscopic adrenalectomy recorded in patients with Conn's syndrome compared to patients with hormone-inactive incidentaloma and its possible influence by the surgical approach. Methods: From February 1994 to March 2004, 40 patients underwent endoscopic adrenalectomy for Conn's syndrome. All patients had arterial hypertension over a median period of 84 (5-240) months and were pretreated with an aldosterone antagonist in 76.3% and with specific antihypertensive medication in 85%. Over the same period of time, endoscopic adrenalectomy was carried out in 80 patients with incidentaloma. Of these, 41 (53.2%) displayed arterial hypertension requiring drug therapy. Results: The adrenal gland was resected using the retroperitoneal in 25 and the transperitoneal approach in 15 patients with Conn's syndrome. Conversion to an open procedure was required in two patients. Intraoperative increases in blood pressure necessitating antihypertensive therapy were observed in 17 of 40 patients (44.7%), in 11 of 40 patients (28.9%) blood pressure peaks of > 200 mmHg (> 1 min) were noted. Differences between the preoperative and maximum intraoperative blood pressure were significant for the retroperitoneal approach only (systolic: p = 0.0001; diastolic: p = 0.0005), but not for the transperitoneal technique. The increase in intraoperative blood pressure in patients with Conn's syndrome was significantly higher, for both systolic (p < 0.0001) and diastolic (p = 0.0037) readings, compared to that in patients with incidentaloma undergoing endoscopic adrenalectomy during the same period of time. Conclusion: Our results demonstrate that relevant intraoperative increases in blood pressure occur in patients with Conn's syndrome despite prior therapy with an aldosterone antagonist, necessitating specific precautionary measures during anesthesia. Intraoperative blood pressure was significantly higher for the retroperitoneal than for the transperitoneal procedure, which leads us to advocate the latter approach for endoscopic adrenalectomy.