Adrenal Surgery Treatment & Management

Primary hyperaldosteronism

The management of bilateral adrenal hyperplasia is centered on medical therapy. Spironolactone, an aldosterone antagonist, is used to normalize serum potassium levels and blood pressure. The major side effect of this drug is painful gynecomastia. Unilateral adrenal adenomas are generally treated surgically.

Cushing syndrome

Bilateral adrenalectomy was the suggested treatment for patients with micronodular or macronodular hyperplasia, incurable pituitary Cushing syndrome, or an unknown source of ACTH. Today, with the advancements in localization, Cushing disease is treated with bilateral adrenalectomy only when ablation of the pituitary through radiation or surgery has failed or when medical therapy does not control secretion. The major role for surgery in this patient population occurs with primary adrenal hypercorticalism either due to adenomas or to adrenal carcinomas. The first line of therapy for unilateral hypercorticalism is unilateral adrenalectomy.

Pheochromocytoma

The medical and surgical management of the pheochromocytoma was first described in the United States by Mayo, ^[1] and it remained relatively unchanged until the 1960s, when Crout et al ^[2] elucidated the biochemical pathways and diagnostic catecholamine studies. Preoperative management of pheochromocytoma is aimed at control of the catecholamine secretion and its cardiovascular sequelae. Hypertension is usually alleviated with preoperative alpha-adrenergic blockade, and most authors recommend preoperative fluid loading to prevent rapid onset of hypotension after the alpha-adrenergic secretion is stopped. Some centers also recommend beta-adrenergic blockade; however, its definitive use remains unclear.

Neuroblastoma

Surgery of neuroblastoma is an important element in diagnosis, staging, and treatment of children with neuroblastoma. Surgery is curative therapy for patients with stage I and early stage II neuroblastoma, with a reported 2-year survival rate of 89%. Reviews regarding safety reveal a low complication rate, most commonly less than 10%. Advanced-stage tumors usually require a combination of surgery, chemotherapy, and/or radiation therapy to provide a complete response.

Adrenocortical carcinoma

Chemotherapy largely has been unsuccessful in treating adrenocortical carcinoma. The most common chemotherapeutic agent used is mitotane. In a review of 551 cases of adrenocortical carcinoma, mitotane induced a tumor response in 35% of patients. However, mitotane has thus far shown no increase in survival benefit. ^[6]

The basic principle for all adrenal excisions is to handle the adrenal gland as little as possible, or to dissect the patient away from the tumor, because the adrenal is an extremely fragile organ. Gentle traction can be obtained by using the kidney as a handle. Typically, posterior, modified posterior, or laparoscopic approaches are used with smaller tumors. Larger tumors may require flank, transabdominal, or thoracoabdominal approaches, but they also have been removed successfully with laparoscopic approaches. The right adrenal vein is short and enters the IVC posteriorly. Therefore, a right adrenalectomy is best approached through a posterior or modified posterior incision. The left adrenal gland is in close contact with the upper pole of the left kidney. Therefore, for large left adrenal lesions, a flank approach or thoracoabdominal approach offers the best exposure. The laparoscopic approach is now considered the criterion standard for most adrenal surgery.

Posterior approach

The posterior approach typically is used for small tumors and in the past was recommended for bilateral exploration in bilateral hyperaldosteronism. Today, localization studies are mandatory prior to bilateral exploration for adenomas. The posterior approach to the adrenal was first described by Young in 1936.

Generally, incisions are made over the 11th or 12th ribs with the patient in a prone position or in a face down jackknife position. After rib resection for better exposure, the Gerota fascia is swept away, revealing an open space superior to the adrenal. The liver or spleen is taken off the anterior surface of the adrenal, and cranial blood supplies are ligated. The dissection then is carried medially to the IVC, which is followed inferiorly until the short adrenal vein is visualized and ligated. The adrenal gland can be drawn caudally by traction on the kidney, and the medial arterial blood supply then can be ligated. Care must be taken to avoid accessory renal artery branches to the upper pole of the kidney. The remaining portion of the adrenal then can be dissected off the kidney and removed.

Modified posterior approach

The posterior approach may be modified in a number of different manners. One may use a true posterior approach in a more cephalad manner and gain transthoracic access to the adrenals. Another modified posterior approach is aimed at decreasing the drawbacks of the jackknife positioning. The primary advantage of the posterior approach is that of obtaining rapid exposure to the adrenal gland as well as excellent exposure and control of the short right adrenal vein.

However, the jackknife position can lead to high pulmonary ventilation pressures, high intraperitoneal pressures, and poor visualization in larger patients. Vaughan and associates (1987) reasoned that a modified prone position could be used without the morbidity of the jackknife position. Vaughan recommends a slight rolling of the thorax with less flexion, which should reduce intra-abdominal compression. An incision then is carried posteriorly along the 11th or 12th rib, avoiding the pleura. The pleura and peritoneum are dissected away, the hepatic attachments are divided, the adrenal is exposed at the base of this incision, and the multiple arteries are ligated. The IVC then is be exposed, and the short adrenal vein is in plain view for ligation.

Flank approach

An extraperitoneal, extrapleural 11th or 12th rib flank approach as used for a radical nephrectomy provides excellent exposure for right or left adrenalectomy. The Gerota fascia is exposed in a typical fashion, and, with this approach, the kidney is used as a means of traction on the adrenal gland. The superior vasculature to the Gerota (and to the adrenal gland) is ligated and divided, providing exposure to the medial edge and main vasculature to the adrenal gland. Patients with large malignancies might require en bloc nephrectomy with the adrenal specimen for cancer control.

Transabdominal approach

Numerous transabdominal approaches for adrenalectomy have been suggested. Typically, transabdominal approaches are used in the pediatric population and for patients with large malignancies. Transverse, chevron, subcostal, and midline approaches are the most common. The midline approach commonly is used if suspicion of a paraganglionoma (ie, extra-adrenal pheochromocytoma) exists. After entering the peritoneal cavity, the abdomen is explored for evidence of metastasis, and the colonic reflection is taken down, exposing the great vessels and retroperitoneum.

As with the flank approach, the kidney is used for retraction, and the superior attachments are divided, providing exposure. On the right side, this may necessitate ligation of the accessory hepatic veins for sufficient exposure of the vena cava and the (posteriorly located) short adrenal vein. After exposure of the IVC, the vein is ligated and then the multiple adrenal arteries are taken. The adrenal gland is removed from the kidney. On the left side, the renal vein is exposed first, providing exposure to the adrenal vein. After ligation, the dissection proceeds medially along the vascular pedicle where the multiple arteries are taken.

Thoracoabdominal approach

The thoracoabdominal approach via the eighth, ninth, or 10th intercostal space is the incision of choice for large adrenal tumors, especially right-sided pheochromocytomas. The incision is made along the appropriate intercostal space and carried medially along the space, across the costal margin to the midline, and then extended caudally, as needed, for exposure. With the division of the diaphragm, the superior dissection of large adrenal tumors, as well as cephalad access to the IVC, is made easier. The colon then is reflected, allowing the great vessels and retroperitoneum to be exposed. As in the flank incision, the kidney may be used for gentle traction. The posterior and superior attachments are divided, leaving the adrenal gland attached to the kidney for traction. The posteromedial vein can be divided first, and then, proceeding caudally, the multiple adrenal arteries can be ligated.

Laparoscopic approach

Little debate exists in the literature that laparoscopic approaches decrease operative morbidity. The laparoscopic approach typically is used for smaller adrenal tumors. At many laparoscopic centers, the laparoscopic adrenalectomy has become the criterion standard. Although case reports of laparoscopy used with large tumors have occurred, most centers recommend laparoscopy in tumors smaller than 6 cm. Laparoscopy should be avoided in patients with bowel obstruction, severe cardiopulmonary disease, or hypovolemic shock because of increased morbidity. Adhesions represent a relative contraindication that greatly depends on the surgeon's skills.

Trocar placement is variable, but usually a minimum of 3, and typically 4, ports are used under the costal margin. The surgery proceeds much as through a transabdominal approach, dissecting the colonic flexure into the retroperitoneum. On the right after dissecting under the liver, the liver is retracted cephalad and the superior pole of the kidney again is used as a handle. With gentle traction on the kidney, a plane of dissection along the IVC allows the surgeon to "walk up" the IVC and identify the short right adrenal vein, which can be clipped. The superior and anterior aspects, as well as arterial supply, also may be taken using clips. The inferior aspect of the adrenal abutting the kidney is dissected last; then, the adrenal is placed in an entrapment sack and removed.

Multiple centers have attempted to emphasize a particular approach or laparoscopic method, and, regardless of which approach is advocated, one point remains applicable across the board: cure rate and operative morbidity are similar for laparoscopic and open adrenalectomy (in small tumors).

No method is best for all patients, and, in general, using the approach based on patient and tumor characteristics combined with surgeon approach familiarity yields the best results.

Hirano et al reported their experience with laparoscopic adrenalectomy, including retroperitoneoscopic adrenalectomy via a single large port (RASLP) and conventional laparoscopic adrenalectomy, in the treatment of adrenal tumors in 134 patients since 1992. Complications were graded according to the modified Clavien system. The mean operation time for RASLP was 166 minutes; for conventional laparoscopic adrenalectomy, 205 minutes. Intraoperative estimated blood loss was significantly lower for the patients who underwent conventional adrenalectomy (85 vs 247 mL). Conversion to open surgery was required in 3 patients (5%) in the RASLP group and in 5 patients (7%) in the conventional adrenalectomy group. Grade 1 postoperative complications occurred in 3 patients in who underwent RASLP and in 1 patient who underwent conventional laparoscopic adrenalectomy. The authors concluded that conventional laparoscopic adrenalectomy is preferable to RASLP for patients with adrenal tumors. ^[7]

Robotic approach

Robotic approaches appear to yield results comparable to those of laparoscopic surgery for the treatment of most adrenal lesions. A meta-analysis that compared robotic with laparoscopic adrenalectomy demonstrated no differences in the rate of complications or the rate of conversion to an open procedure. The robotic approach was associated with less intraoperative blood loss and a shorter hospital stay than laparoscopic adrenalectomy; however, the duration of the procedure was longer. ^[8]  In a retrospective observational study of adrenal surgical procedures, Piccoli et al reported similar outcomes with robotic and laparoscopic approaches. ^[9]

Partial adrenalectomy

Traditionally, the standard treatment for patients with adrenal lesions has been total adrenalectomy. Recently, successful treatment of these lesions with partial adrenalectomy has been reported. A study that compared partial versus total adrenalectomy for the treatment of primary hyperaldosteronism found that both approaches were equally effective. In fact, at 5-year follow-up, the partial adrenalectomy group demonstrated greater improvement in returning to normal physiologic renin and aldosterone levels. Another study that compared 100 patients with partial adrenalectomy versus 225 patients with total adrenalectomy found that no recurrences occurred in the partial adrenalectomy group, while local recurrence was noted in 6 patients after total adrenalectomy. The adrenocortical function in 14 of 15 patients with bilateral diseases was preserved. ^[10] Consider patients with bilateral disease for partial adrenalectomy.

Janetschek et al reported the first laparoscopic partial adrenalectomy in 1997. ^[11] Since then, many other successful laparoscopic partial adrenal resections have been reported. Because of the vascular nature of the adrenal gland, the surgeon must obtain excellent hemostasis when performing a partial adrenalectomy.

A study by Castinetti et al suggested that adrenal-sparing surgery should be the surgical approach of choice in patients with multiple endocrine neoplasia type 2 (MEN2) and bilateral pheochromocytoma. In the study, 438 (79%) of 552 operated patients were treated by adrenalectomy and 114 (21%) had adrenal-sparing surgery. Pheochromocytoma recurrence occurred in 3% (four of 153) of the operated glands following adrenal-sparing surgery with a follow-up of 6 to 13 years, compared with 2% (11 of 717) of glands removed by adrenalectomy. The authors cautioned that after approximately 20 years, nearly all patients who have adrenal-sparing surgery would have recurrence of pheochromocytoma so patients need a prolonged follow-up after 10 years. ^{[12, 13]}

Cryosurgery and other ablative techniques of adrenal masses

Although cryoablation has gained popularity in the treatment of tumors such as prostate, liver, lung and brain tumors, very limited reports exist of successful use with adrenal tumors. In 2003, Munver et al described the first case of adrenal cryosurgery in a patient with primary hyperaldosteronism secondary to bilateral adrenal hyperplasia. ^[14] Schulsinger et al demonstrated that cryoablation was successful in destroying adrenal tissue in a canine model. ^[15] More studies are needed to assess the long-term efficacy of this procedure.

Successful ablation of adrenal masses has been described using selective arterial infusion of ethanol. In a study of 33 cases of primary hyperaldosteronism, this technique was successful in 27 cases (82%). ^[16] Few reports exist of radiofrequency ablation (RFA) of adrenal masses. ^[14] Most of these reports have involved patients with metastatic adrenocortical carcinoma. Currently, RFA is used primarily for palliation in patients with metastatic disease for whom conventional treatment with surgery or chemotherapy is not possible.

Primary hyperaldosteronism

The preoperative management for primary hyperaldosteronism is aimed at achieving blood pressure control with spironolactone. Typically, the causative agent is a unilateral adenoma or adrenocortical carcinoma.

Pheochromocytoma

Preoperative management of pheochromocytoma is aimed at control of the catecholamine secretion and its cardiovascular sequelae. Hypertension usually is alleviated with preoperative alpha-adrenergic blockade. Patients undergo alpha-adrenergic blockade with agents such as phenoxybenzamine for a minimum of 2 weeks preoperatively, and they maintain adequate hydration. Preoperative beta-blockers (ie, propranolol) are administered after alpha-blockers to help control arrhythmias. Administer alpha-blockers first; otherwise, hypertension may be exacerbated. Some centers now administer long-acting calcium-channel blockers (ie, verapamil SR, nifedipine XL) as preoperative monotherapy, which control both hypertension and arrhythmias.

Most authors recommend preoperative fluid loading to prevent rapid onset of hypotension after the alpha-adrenergic secretion is stopped.

Adrenocortical carcinoma

No special preoperative evaluation exists, other than the determination of whether the lesion functions or not.

Primary hyperaldosteronism

As long as the tumor or gland is small, a posterior, modified posterior, or laparoscopic approach is suggested.

Cushing syndrome

As long as the tumor or gland is small, a posterior, modified posterior, or laparoscopic approach is suggested.

Pheochromocytoma

The operative management of the pheochromocytoma is different from other adrenal tumors in that, primarily, clear communication between the surgical and anesthesia teams must occur due to the cardiovascular lability. Secondly, the surgical approaches are aimed at early control of the adrenal vein. After it is ligated, a marked hypotensive episode often occurs. Several centers have reported laparoscopic approaches as well as partial adrenalectomies. Other reviews reexamined the role of calcium channel blockers instead of alpha blockade and still found low complication rates and determined that adrenalectomy is safe. Patients with multiple endocrine adenopathy or a family history of pheochromocytoma should be considered at high risk for multiple lesions, and a thorough abdominal exploration should be performed during surgery.

Neuroblastoma

Surgery of neuroblastoma is an important element in diagnosis, staging, and treatment of children with neuroblastoma. Surgery is curative therapy for patients with stage I and early stage II neuroblastoma, with a reported 2-year survival rate of 89%. Reviews regarding safety reveal a low complication rate, most commonly less than 10%. Advanced-stage tumors usually require a combination of surgery, chemotherapy, and/or radiation therapy to provide a complete response.

Adrenocortical carcinoma

The adrenocortical carcinoma typically is a large lesion, and, for that reason, a flank, thoracoabdominal, or, in rare cases, laparoscopic approach has been advocated.

Postoperative details

Adequate hydration is necessary for patients with pheochromocytoma, and meticulous follow-up is necessary for patients with malignancy. Patients with cortisol-producing tumors require glucocorticoid replacement throughout the surgical procedure and postoperatively until the function of the contralateral adrenal gland is regained.

Follow-up

Postoperative follow-up is routine, with wound checks and close follow-up for malignant disease that is aimed at detecting early evidence of metastases.

Laparoscopic approach

Little debate exists in the literature that laparoscopic approaches decrease operative morbidity. The laparoscopic approach typically is used for smaller adrenal tumors. At many laparoscopic centers, the laparoscopic adrenalectomy has become the criterion standard. Multiple centers have attempted to emphasize a particular approach or laparoscopic method, and regardless of which approach is advocated, one point remains applicable across the board: cure rate and operative morbidity are similar for laparoscopic and open adrenalectomy (in small tumors). No method is for all patients, and, in general, selecting the approach based on patient and tumor characteristics and with consideration of surgeon approach familiarity yields the best results.