Perioperative management - Left adrenalectomy, laparoscopic

Adrenal tumors may be primary or secondary. Primary adrenal tumors are rarely malignant, although tumor size and probability of malignancy do correlate in cortical tumors.

At present, endoscopic adrenalectomy is the procedure of choice.

Compared with the retroperitoneal endoscopic approach, laparoscopy offers the benefit of a more familiar anatomy.

• Laparoscopic surgery is indicated in all hormone producing tumors < 6cm.
• In non-hormone producing tumors between 3cm and 6cm in size, particularly in young patients, the indication for laparoscopic surgery is relative. The alternative is close follow-up every three months.
• Due to the risk of malignancy in hormone producing tumors > 6cm, open surgeryis recommended.
• In the absence of other metastasis and whenever resection would result in freedom of tumor, adrenal metastases should be resected.

With its better visual differentiation between normal and neoplastic tissue, minimally invasive adrenal surgery offers the prospect of function sparing procedures.

• Laparoscopic subtotal adrenal resection, i.e., preserving parts of the organ, is indicated in hereditary bilateral pheochromocytoma and aldosterone producing adenomas, which almost always are benign, small and are located off-center.

• Surgery is not indicated in non-hormone producing primary adrenal tumors < 3cm.
• Myelolipomas and adrenal cysts should only be resected in case of clinical symptoms stemming from the displacement of adjacent structures.
• In Conn syndrome with cortical hyperplasia of both adrenals total adrenalectomy is not indicated.

No adrenalectomy without prior measurements of hormone activity!

Ruling out pheochromocytoma is importantsince pretreatment with alpha blockers prior to surgery is mandatory!

• The other contraindications depend on the underlying disorders (surgical risk) and the impact of adrenalectomy on the quality of life and life expectancy of the patient.

With the increasing use of imaging modalities, adrenal tumors are often diagnosed as incidental findings (incidentalomas).

Typical hormone producing disorders include Conn syndrome (hyperaldosteronism), Cushing syndrome (hyperadrenocortisolism) and pheochromocytoma (excessive catecholamine levels). Almost all of these elevate the arterial blood pressure.

Diagnostic work-up includes patient history and physical examination with mandatory measurement of the blood pressure and heart rate. In addition, the work-up must also include endocrinology and imaging studies.

Hormone diagnostics:

• Plasma aldosterone/plasma renin activity ratio in the morning
• Plasma cortisol and plasma ACTH
• Dexamethasone suppression test
• Metanephrine and normetanephrine levels in 24-hour urine collection
• Measurement of steroid precursors Androstenedione, DHEA-S, 17-alpha-hydroxyprogesterone

Imaging:

• CT: Highest local resolution
• MRI: Additional diagnostic clues regarding type
• FDG-PET optional in suspected malignoma
• Endoscopic ultrasound prior to organ preserving surgery

Scintigraphic imaging:

• MIBG-scintigraphy
• Dopa-PET
• Only in diagnostic work-up of pheochromocytomas concomitant with suspected genetic-familial type, ruling out bilateral disease and extra-adrenal location.

Adrenal venous sampling: In Conn syndrome

Differentiates between hyperplasia and adenoma.

Confirms hormone production in adrenal tumors below detection threshold Identification of hormone production location in bilateral tumors.

Pheochromocytomas mandate about two weeks of preoperative pretreatment with alpha receptor blockers (increasing dosage of oral phenoxybenzamine up to about 50mg t.i.d.) In case of tachycardia also administration of a beta-blocker.

All other adrenal tumors do not require specific preoperative medication.

Single-shot antibiotic prophylaxis with a cephalosporin

The risks involved in this surgery depend on the age and overall condition of the patient, particularly regarding any adrenal hyperfunction.

General risks of surgery

• Thrombosis
• Embolism
• Infections
• Vascular/nerve injury
• Hemorrhage/secondary bleeding with allogeneic blood transfusions
• Injury to adjacent organs
• Conversion to standard open surgery
• Trocar site hernia

Special aspects of informed consent

• Injury to spleen with possible need for splenectomy
• Injury to left renal vein with hemorrhage
• Injury to pancreatic tail with formation of fistula or abscess
• Injury to the diaphragm
• Injury to the left colic flexure
• Injury to the stomach
• Hormone reaction, Addison crisis
• Persistent arterial hypertension in Conn syndrome
• High risk of thromboembolism and infection in Cushing syndrome
• In bilateral adrenalectomy life-long replacement of cortisone and mineralocorticoid; in 10%-25% of patients development of Nelson tumors (ACTH producing pituitary gland tumor) after about 10 years
• In pheochromocytoma risk of local recurrence through opening of tumor capsule with cell seeding.