Robotic adrenalectomy, a progression from laparoscopic adrenalectomy, has become increasingly popular since its initial report in 2002. This chapter describes contemporary indications, techniques, and perioperative management for robotic adrenalectomy.
Anatomy
The adrenal glands are paired retroperitoneal structures positioned superior and slightly medial to the kidneys and anterior to the crus of the diaphragm. Each adrenal gland is embedded in perirenal fat and enclosed by the Gerota fascia, with a thin layer of loose connective tissue separating the adrenal capsule from the kidney. The right adrenal gland lies posterior to the liver and lateral to the posterolateral surface of the inferior vena cava (IVC). The first part of the duodenum may lie inferior and slightly anteromedially to the right adrenal gland. The left adrenal gland lies posterior to the stomach, pancreatic tail, and splenic vessels, and lateral to the aorta.
The arterial supply to the adrenal gland is diffuse while the venous drainage is solitary. The superior adrenal gland is supplied by the inferior phrenic artery, with rare branches arising from the aorta, celiac axis, or intercostal arteries. The middle adrenal is supplied directly from the aorta, with its origin typically just proximal to the origin of the renal artery, although infrequent branches may arise from the inferior phrenic or renal artery. The inferior adrenal is supplied from the superior aspect of the ipsilateral renal artery, while branches may also arise from an accessory renal artery or a superior polar artery. Before penetrating the adrenal gland, the main adrenal arteries branch freely into cascades of smaller arteries.
The venous drainage of the adrenal gland differs with laterality. The short and wide right adrenal vein most often drains directly into the posterior aspect of the IVC ( Fig. 22.1 ). The territory of potential drainage extends from the right hepatic vein superiorly to the right renal vein inferiorly. Occasionally, the insertion of the right adrenal vein is adjacent to these vessels, or even more infrequently, directly confluent. This close proximity increases risk of damage to these fragile structures either with direct injury or shearing by undue traction, causing brisk bleeding. The left adrenal vein, in contrast, is relatively long and joins the inferior phrenic vein prior to entering the left renal vein ( Fig. 22.2 ). Typically, it courses along the anteromedial aspect of the adrenal gland and inserts into the renal vein medial to the insertion of the gonadal vein. Variant secondary adrenal veins may be encountered on either side. Care must be taken to identify the adrenal venous drainage during surgical dissection with definitive ligation to avoid loss of control of the adrenal vein stump.
Indications and contraindications
Diseases of the adrenal gland that may require surgical management include hormonally functional lesions and masses suspicious for malignancy ( Table 22.1 ). A detailed history and physical examination can lead to a diagnosis of hypersecretory states including hyperaldosteronism (Conn syndrome), hypercortisolism (Cushing syndrome), and catecholamine excess (pheochromocytoma). When these syndromes are diagnosed, imaging is indicated to identify an adrenal lesion. Conversely, patients with adrenal lesions greater than 1 cm in diameter that are incidentally discovered on cross-sectional imaging should undergo biochemical screening for hormonal alterations. Imaging evaluation includes adrenal protocol computed tomography or magnetic resonance imaging to distinguish benign adenomas from nonadenomas based on intracellular lipid content and perfusion characteristics. Primary malignancy of the adrenal gland is rare but can present a surgical challenge as adrenocortical carcinoma (ACC) tends to be large and locally invasive at presentation. An adrenal lesion that is larger than 6 cm in diameter or rapidly growing (more than 1 cm) should be considered malignant until proven otherwise, although most experts recommend excision of lesions greater than 4 cm. The adrenal gland is also a common site for metastasis from other malignancies, including lung, gastrointestinal, breast, kidney, pancreas, and skin, where resection may be indicated depending on the underlying disease and overall therapy. Neuroblastoma may be seen in the pediatric population, and pheochromocytoma may rarely be malignant.
| Functional | Aldosterone-producing adenoma |
| Cortisol-producing adenoma | |
| Pheochromocytoma | |
| Nonfunctional | Incidentaloma size > 4–6 cm or enlarging > 1 cm |
| Nonadenoma characteristics on imaging | |
| Symptomatic mass (e.g., cysts, myelolipomas) | |
| Malignant | Adrenocortical carcinoma |
| Solitary metastasis from nonadrenal primary | |
| Neuroblastoma |
Adrenalectomy may be performed through an open incision or through a variety of minimally invasive approaches. While laparoscopic adrenalectomy is still utilized for many adrenal masses, robotic assisted surgery with the da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA) has become increasingly standard. Although more expensive, robotic surgery offers several advantages that make it an ideal platform for delicate dissection of the adrenal gland, including improved ergonomics, three-dimensional magnification of the operative field, tremor filtering, and enhanced degrees of freedom of the instruments. While relative contraindications for robotic surgery include history of extensive prior abdominal surgery and obesity, these challenges can be overcome safely with increasing robotic experience. Traditionally, suspected adrenocortical carcinomas have been an absolute contraindication for minimally invasive surgery due to concern for tumor fragility and risk of tumor spillage. However, an expanding body of evidence suggests that in well-selected patients, ACC can be resected successfully with minimally invasive surgery in expert hands. Nevertheless, caution should be used, and the surgeon must be prepared for potential open conversion as well as en bloc resection with removal of adjacent organs.
Partial adrenalectomy may be indicated in select patients, including those with a solitary adrenal gland or with a high propensity for recurrent or bilateral adrenal disease, such as multiple endocrine neoplasia or von Hippel-Lindau syndromes. Those at greatest risk for need of lifelong steroid replacement should most strongly consider partial adrenalectomy. While steroid independence can be achieved with as little as 15% to 30% of adrenal tissue remaining in situ, careful monitoring with possible temporary corticosteroid supplementation in the early recovery phase is necessary until return of adequate adrenal function. Nevertheless, if primary adrenal malignancy is suspected, partial adrenalectomy should not be undertaken.
Preoperative considerations
Patients should receive anesthesia clearance and be counseled about risks of bleeding, infection, damage to surrounding structures, conversion to open operation, and postoperative adrenal insufficiency. Cross-sectional imaging is carefully reviewed, paying attention to the adrenal gland’s relationship to adjacent structures such as the renal hilum and any aberrant vasculature.
Special considerations should be taken for functional adrenal diseases. Hyperaldosteronism is often associated with hypokalemia and hypertension. Patients may require aldosterone antagonism with spironolactone for at least 3 weeks prior to surgery. Potassium-sparing diuretics or calcium channel blockers for blood pressure control and potassium replacement should be implemented as appropriate. Hypercortisolism is associated with hypertension, electrolyte disturbances, and glucose derangement, all needing optimization preoperatively. Perioperative administration of corticosteroids should be considered. As pheochromocytoma can present intraoperative challenges including hypertensive crisis and cardiac arrhythmia, a detailed and multidisciplinary preoperative evaluation with anesthesiology, cardiology, and endocrinology expertise should be undertaken. Preoperative alpha-1 adrenoreceptor antagonism should be initiated with doxazosin or phenoxybenzamine. Beta blockers, calcium channel blockers, and rarely metyrosine may be required as adjuncts for blood pressure control. Salt and fluid repletion is important to reverse catecholamine-induced intravascular volume contraction.
Patient positioning and port strategy
Sequential compression devices are placed on the lower extremities. Following induction of general anesthesia and endotracheal tube placement, a Foley catheter and orogastric or nasogastric tube are placed to decompress the bladder and stomach, respectively. In cases of pheochromocytoma, an arterial line and central venous catheter should be placed for close hemodynamic management. Antibiotic prophylaxis typically with a first-generation cephalosporin is administered. The patient is positioned in the full lateral decubitus position (retroperitoneal approach) or a modified flank position with the patient approximately 30 degrees back from vertical (transperitoneal approach) with the 10th rib over the break in the table. The lower arm is extended on a standard arm board. An axillary roll is placed, and the upper arm is positioned on a padded double arm board, sling, or pillows. Both arms should be padded and extended to a neutral position to avoid excessive strain on the shoulder joint and brachial plexus. The lower leg should be flexed slightly, and pillows should be placed between the lower and upper leg, which remains straight. The table is then flexed to optimally expand the space between the costal margin and the iliac crest for retroperitoneal approach. For the transperitoneal approach, surgeon preference and patient body habitus dictate table flexion ( Fig. 22.3 ). Extreme flexion should be avoided to prevent excessive neuromuscular strain or diminished venous return. The table is tilted as appropriate to create a horizontal operating surface. All bony prominences should be well padded, and a beanbag or padded roll may be used to keep the patient in position. The patient is secured with broad adhesive tape and safety straps over the buttocks and chest. Surgical preparation should be carried from the nipple line to the pubis and from the umbilicus to the spine. We favor the Xi da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA) as it allows for more versatile positioning and docking of the robot.
The surgical approach to the adrenal gland depends on a variety of factors. The transperitoneal approach offers the benefit of wider working space and easily identifiable surgical landmarks. The retroperitoneal approach avoids encounters with adhesive disease in patients with history of intraperitoneal surgeries. Additionally, the retroperitoneal approach decreases hemodynamic and respiratory compromises associated with insufflation of the peritoneum. Ultimately, both approaches are safe, and surgeon experience and comfort level are primary determining factors.
Port placement for transperitoneal approach
Right- and left-sided adrenalectomy follows the same general port strategy. Pneumoperitoneum is established through either the open Hasson technique or with a Veress needle, which is typically inserted two fingerbreadths superior and medial to the anterior superior iliac spine at the midclavicular line, where the anterolateral abdominal wall muscles meet with the lateral edge of the rectus sheath. An 8-mm port is placed just superior to the umbilicus at the lateral edge of the rectus muscle. A robotic camera with a 30-degree down lens is inserted. Two additional 8-mm robotic ports are placed under direct visualization at least 8 cm apart from the other robotic ports. The superior-most port is placed just below the costal margin, and an inferior port is positioned in the lower quadrant, both along the midclavicular line. If needed, a fourth robotic port is placed just cephalad to the iliac crest to provide additional retraction, just lateral to the midclavicular line. A 10/12 mm assistant port is placed medially between the camera port and superior-most port to allow easy access to the surgical field for suctioning and delivery of clips and sutures. Alternatively, a 5 mm assistant port may be placed for suction, and a robotic clip applier may be used to deliver clips, and sutures can be passed through the 8 mm robotic ports by temporarily removing the instrument. On the right side, an optional 5-mm port for a laparoscopic liver retractor can be placed medially just inferior to the costal margin ( Fig. 22.4 ). Ports may be shifted laterally and cephalad in obese patients. The robot is ideally docked approaching from patient’s dorsum. The assistant stands on the patient’s ventral side at the upper abdomen ( Fig. 22.5 ). However, if operating room configuration limitation exists, the boom on the Xi platform can be rotated 180 degrees, allowing the robot to approach from the patient’s ventral side. If docking the robot from the ventrum, it is helpful to approach from the feet in order to maintain adequate space for the assistant to stand. A curved monopolar scissors and a grasper such as Maryland bipolar, fenestrated bipolar, or ProGrasp (Intuitive Surgical, Sunnyvale, CA) forceps are typically used as primary instruments in the two superior working ports, and a ProGrasp forceps can be placed in the inferior-most fourth arm port.
