CHAPTER 14 Adrenalectomy
Step 1. Surgical anatomy
♦ The adrenal glands are located at the superior-medial aspect of each kidney and are composed of a cortex and medulla with distinct endocrine functions. The steroid hormones (cortisol, aldosterone, and the adrenal androgens) are synthesized and secreted in the adrenal cortex, and the adrenal medulla synthesizes the catecholamines, norepinephrine and epinephrine. Catecholamines may also be synthesized in extra-adrenal chromaffin tissue in the paraganglia.
♦ Each adrenal gland is embedded in Gerota’s fascia and is surrounded by retroperitoneal fat. The adrenal gland has a golden yellow appearance because of the high lipid content of the cortex.
♦ The right adrenal gland is pyramidal in shape and lies superior to the right kidney, whereas the left adrenal is more flattened and is in intimate contact with the medial aspect of the superior pole of the left kidney.
♦ Bordering structures for the right adrenal are the inferior vena cava medially, the liver anteriorly, and the kidney inferiorly. A portion of the anteromedial border of the gland usually extends posterior to the vena cava. The right triangular ligament of the liver crosses the anterior surface of the adrenal gland superiorly, which means that the upper portion of the gland has no peritoneum covering its surface. Structures that border the posterior aspect of the right adrenal are the diaphragm superiorly and the anteromedial portion of the superior pole of the right kidney inferiorly.
♦ Structures neighboring the left adrenal gland are the spleen and fundus of the stomach superiorly, the splenic flexure of the colon, the tail of pancreas, and splenic vessels inferiorly, and the left crus of the diaphragm posteromedially and the medial aspect of the left kidney posterolaterally. The renal vessels lie just below the inferior border of the adrenal, and in the setting of a large tumor, they may overlie the renal artery and vein.
♦ The adrenal blood supply is derived from numerous branches of the inferior phrenic, aortic, and renal arteries. A single central vein drains each adrenal.
The right adrenal vein is short (0.5 to 1 cm in length) and runs from the medial aspect of the gland directly into the posterolateral aspect of the inferior vena cava. A second right adrenal vein may occasionally enter either the vena cava or right hepatic vein more superiorly.
The left adrenal vein is longer than on the right (2 to 3 cm in length) and is found at the inferior-medial aspect of the gland, where it runs obliquely to empty into the left renal vein. The inferior phrenic vein typically joins the left adrenal vein proximal to its entry into the renal vein (Figure 14-1).
Step 2. Preoperative considerations
♦ Most indications for adrenalectomy today are appropriate for a laparoscopic approach. The only absolute contraindication for laparoscopic adrenalectomy is an adrenal malignancy with evidence of local invasion or involved regional lymph nodes. However, surgeons should be cautious in approaching large tumors laparoscopically for a number of reasons: (1) large tumors are more difficult to remove, (2) the tumor is more likely to be malignant (especially adrenal cortical lesions >6 cm in size), and (3) the surgeon should be highly experienced in laparoscopic adrenalectomy.
♦ All patients undergoing adrenalectomy should have completed a biochemical evaluation to assess for a functioning tumor. The minimal workup should consist of the following:
Plasma fractionated metanephrines or 24-hour urine catecholamines and metanephrines to exclude a pheochromocytoma
Preoperative preparation for adrenalectomy should entail the following:
♦ Control of hypertension and correction of any electrolyte abnormalities.
♦ Pharmacologic preparation of patients with pheochromocytomas with alpha-adrenergic blockade for 7 to 10 days preoperatively to mitigate against hypertensive exacerbations intraoperatively. Most commonly, phenoxybenzamine is used starting at 10 mg twice daily, with the dose increasing until hypertension and tachycardia are controlled and the patient is mildly orthostatic.
Equipment and instrumentation
♦ Laparoscopic adrenalectomy is carried out with standard laparoscopic dissecting instruments, atraumatic graspers, and a hook electrocautery.
♦ Additional equipment that facilitates the procedure may include the following:
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