Preoperative Evaluation

A complete history and physical examination is mandatory in the evaluation of a patient with an adrenal mass. While a complete discussion of the metabolic evaluation of adrenal lesions is beyond the scope of this chapter, a distinct effort to rule out the diagnosis a pheochromocytoma is crucial, as dire consequences may result from a misdiagnosis. This can be accomplished by evaluating the patient’s plasma free metanephrines, along with confirmatory urinary catecholamine and metanephrine levels if necessary. A complete endocrinologic evaluation should also include measurement of serum electrolytes, serum hormone levels, and urine levels of steroid hormones and their metabolites. The exact tests ordered will depend on the observed clinical signs and symptoms as well as the patient’s history and physical exam. In addition, stimulation studies such as the low- and high-dose dexamethasone suppression tests and measurement of plasma renin and aldosterone levels can be obtained if clinically warranted. It is also important to note that in the setting of micronodularity or bilateral adrenal masses, adrenal vein sampling must be performed when assessing a patient for adrenalectomy for a functional adrenal mass.

Radiographic imaging is essential in the evaluation of an adrenal mass. While a pathologic evaluation can yield a definitive diagnosis, invaluable information can be obtained from a properly performed radiographic study. Computed tomography (CT) scans with and without intravenous contrast, with thin 1–3 mm cuts, are vital in assessing adrenal lesions. Lipid-rich adenomas are commonly homogeneous lesions with an attenuation less than 10 Hounsfield units on noncontrast CT, while lipid-poor adenomas may be differentiated by measuring levels of enhancement or percent contrast washout. Lymphadenopathy and local invasion are features that are more consistent with a malignant lesion.

Magnetic resonance imaging (MRI) scans are also commonly obtained in the evaluation of adrenal masses. This study can provide additional information such as identifying adipose tissue within lesions and can improve the identification of invasion into surrounding structures. Metaiodobenzylguanidine (MIBG) scans have poor spatial resolution and play a limited role in the evaluation of adrenal lesions. However, this study can be helpful in localizing small pheochromocytomas or extra-adrenal locations. This is especially true for those patients with multiple endocrine neoplasia (MEN) syndromes who are high risk for extra-adrenal pheochromocytomas. Additionally, MIBG scans are useful in suspected cases of malignant or bilateral pheochromocytomas.

Once an adrenal lesion is determined to require removal, standard preoperative evaluation and preparation are required. Patients diagnosed with a pheochromocytoma require a more thorough preoperative assessment and preparation. This includes alpha blockade for 2 weeks prior to surgery, along with the addition of beta blockers to treat tachycardia or arrhythmias if present. Beta blockers should only be given once complete alpha blockade is achieved. Furthermore, these patients also require cardiac consultation for the evaluation of occult cardiomyopathy.

Relevant Anatomy

The arterial supply to the adrenal gland is highly variable. The adrenal glands typically draw their blood supply from arterial cascades arising from the inferior phrenic artery, aorta, and renal artery. Adrenal venous drainage also displays great variability. On the right side, a short adrenal vein typically provides drainage into the posterolateral aspect of the vena cava. On the left side, the adrenal vein usually drains into the left renal vein. Not uncommonly, accessory adrenal veins are present near the superior and medial diaphragmatic attachments and provide additional drainage into the inferior phrenic vein. Meticulous dissection and appreciation of retroperitoneal anatomy is required in order to avoid inadvertent vascular injury.

Patient Preparation, Operating Room Setup, and Patient Positioning

Informed consent with explanation of pertinent risks is obtained prior to the procedure. Patients are instructed to maintain a clear liquid diet for 12–24 hours prior to surgery and administer a bowel preparation consisting of 300 ml of magnesium citrate on the prior day. Sequential compression devices are placed on the lower extremities and a single dose of intravenous antibiotics is given 60 minutes prior to surgical incision. After induction of general anesthesia, an orogastric tube and Foley catheter are placed to decompress the stomach and bladder, respectively. Bilateral intravenous access may be beneficial as upper extremity exposure is limited once positioning is completed. Administration of nitrous oxide can lead to bowel distention and should be avoided.

For cases of pheochromocytomas, invasive arterial monitoring, large bore intravenous access, or central line placement is recommended. These patients must be aggressively hydrated prior to surgery, as hypotension is frequently encountered after the induction of anesthesia or following excision of the tumor. Anesthetic agents such as propofol, ketamine, and halothane should be avoided.

The patient is placed in a modified lateral decubitus position (45°–60°) with the flank situated over the kidney rest. The table may be flexed to increase the area between the iliac crest and costal margin. A bean bag or large gel rolls are used to support the patient in this position. Pillows are placed between the legs and the dependent leg is flexed at the knee while the opposite leg is placed straight. The arms are placed parallel onto well-padded arm boards. The ankles, knees, dependent hip, shoulders, and brachial plexus are adequately padded. After verifying that all areas prone to pressure injury are well-padded, the patient is secured to the operating table using 3″ cloth tape across the shoulder and arm as well as across the hip. Figure 4.1 demonstrates proper patient positioning for left laparoscopic adrenalectomy. Positioning for right laparoscopic adrenalectomy is the mirror image of that for the left side. Furthermore, a needlescopic technique with 2–3 mm trocars can be employed.

Equipment

The instrumentation and setup for laparoscopic adrenalectomy is similar to that for laparoscopic renal surgery and consists of a video tower with a color monitor, video system, and CO₂ insufflator. Both 0°- and 30°-degree lenses are commonly used. A liver retractor is useful for right-sided procedures, and several types of retractors are commercially available. The liver retractor is held in place by an assistant or a self-retaining device that is attached to the operating table. The surgeon utilizes an atraumatic grasper, laparoscopic Kittner, or suction-irrigator in the nondominant hand and a dissecting instrument in the surgeon’s dominant hand. A variety of laparoscopic thermal energy devices are available. Ultrasonic shears may be useful for colon mobilization and adrenal vein dissection. A bipolar device has excellent hemostatic properties and is may be used for performing the adrenal dissection. This device has been shown to significantly decrease blood loss and operative time during adrenal dissection compared to other devices. Furthermore, this device can be used to ligate and divide the adrenal vein, which obviates the need for hemostatic clips. Intraoperative ultrasound has shown to be helpful in localizing small adrenal lesions, especially in obese individuals with extensive amounts of retroperitoneal adipose tissue. The use of indocyanine green to help highlight adrenocortical tissue from surrounding retroperitoneal tissues may also be considered when attempting to localize small adrenal lesions [13]. A laparoscopic specimen retrieval bag is required. The robotic approach with the da Vinci™ Surgical System (Intuitive Surgical Inc., Sunnyvale, CA) utilizes a three- or four-arm robot which is controlled at the robotic console by the operating surgeon, while a bedside first assistant uses an accessory port for clip placement, suction, and additional maneuvers as needed. A variety of robotic instruments are available for robot-assisted adrenal surgery.

Equipment List for Laparoscopic Adrenalectomy

Equipment List for Robot-Assisted Adrenalectomy

Surgical Technique

Left Transperitoneal Laparoscopic Adrenalectomy

1. 1.
   
   
   

   The patient is placed in the right lateral decubitus position. The patient should be positioned close to the abdominal edge of the bed to prevent laparoscopic instruments from colliding with the frame of the bed. The table may be flexed to increase the intra-abdominal working area if necessary, and the kidney rest can be partially elevated if desired. A bean bag or gel rolls are used to position the patient in the lateral decubitus position. An axillary roll is placed two fingerbreadths below the axilla. The lower arm is positioned on a well-padded armboard. The upper arm is supported either with a commercially available device or in another fashion such that it is parallel to the lower arm. The right scapula should be supported to prevent the arm from rotating posteriorly. The lower leg is gently bent, and the upper leg remains straight, with adequate pillows and padding. Once all of the areas prone to pressure are well-padded, the patient is secured using 3-inch tape or an alternative method of choice. A Foley catheter and orogastric tube should be placed before starting the procedure.

   
   
    
   
   
2. 2.
   
   
   

   A skin incision is made 2 cm superior to the umbilicus and to the left of the midline. The location of the incision can be modified in patients with a large abdominal pannus, in which case the initial trocar can be placed slightly more lateral and cephalad. Insufflation with a Veress needle to 15 mm Hg or a Hasson technique is used to obtain pneumoperitoneum. A 5 mm or 12 mm trocar is placed at this site and a laparoscope is used to inspect the abdominal contents. A 5 mm or 12 mm trocar is placed 2 cm below the xiphoid process to the left of the midline and is used for the a 30°-degree laparoscope lens. A 12 mm trocar is placed 2 cm above the umbilicus in the midclavicular line (MCL). An accessory 5 mm trocar can be placed below the costal margin at the anterior axillary line (AAL) to assist in retraction of the kidney and other maneuvers. The periumbilical and MCL trocars are used for instrument passage, starting with atraumatic grasping forceps at the periumbilical trocar and ultrasonic shears or alternative energy device in the MCL trocar. Two options for trocar placement during left transperitoneal laparoscopic adrenalectomy are illustrated in Fig. 4.2.

   
   
    
   
   
3. 3.
   
   
   

   The descending colon is mobilized along the white line of Toldt, avoiding entry into the Gerota fascia (Fig. 4.3). The spleen is mobilized extensively to allow visualization of the upper pole of the kidney and adrenal gland. Careful mobilization of the tail of the pancreas is required to avoid injury to this organ during this maneuver.

   
   
    
   
   
4. 4.
   
   
   

   Dissection and exposure of the adrenal gland can begin either at the inferomedial aspect or the superomedial aspect. Initial dissection of the inferomedial aspect of the adrenal gland is performed in order to identify the renal hilum. In patients with a large amount of perinephric adipose tissue, an intraoperative ultrasound device may be useful to assist with localization of the adrenal gland.

   
   
    
   
   
5. 5.
   
   
   

   The renal vein is identified and used as a landmark to identify the adrenal vein. A right-angle clamp is used to dissect the adrenal vein (Fig. 4.4). Once completely free from surrounding structures, the left adrenal vein can be divided between hemostatic polymer clips or with a bipolar vessel-sealing device. Figure 4.5 demonstrates use of a bipolar vessel-sealing device to ligate the vein. If a bipolar vessel-sealing device is used, the tissue should be sealed in several areas before transecting the vein in the middle of the sealed tissue.

   
   
    
   
   
6. 6.
   
   
   

   After division of the adrenal vein, the adrenal gland can be retracted medially. The parenchyma of the kidney is identified as seen in Fig. 4.6. Lateral attachments of the adrenal gland are divided. Any remaining medial attachments are also divided. The ultrasonic shears or bipolar vessel-sealing device can be used as the adrenal attachments are often highly vascular. Small arterial branches from the inferior phrenic or renal arteries can be encountered and should be carefully divided with clips or the bipolar vessel-sealing device. The adipose tissue between the renal vein and the infero-lateral margin of the adrenal gland often contains segmental branches of the adrenal artery. Avoidance of these vessels is facilitated by carefully dissecting the tissue before dividing. Carrying the dissection closer to the margin of the adrenal gland can also assist in avoiding inadvertent vascular injury. Any additional superior attachments of the adrenal gland are divided. Figure 4.7 shows division of the remaining adrenal attachments using a bipolar vessel-sealing device.

   
   
    
   
   
7. 7.
   
   
   

   The specimen is placed in a laparoscopic retrieval bag (Fig. 4.8).

   
   
    
   
   
8. 8.
   
   
   

   The pneumoperitoneum is decreased to 5 mm Hg and the adrenal bed is inspected for bleeding. Hemostatic maneuvers, such as the use of oxidized cellulose polymer, can be used based on surgeon preference. Oxidized cellulose polymer can be used in the setting of minor bleeding. If indicated, a hemostatic matrix such as Floseal™ can be used as well.

   
   
    
   
   
9. 9.
   
   
   

   The specimen may be extracted from any of the trocar sites. Often, the trocar site incision will require enlargement in order to accommodate the specimen.

   
   
    
   
   
10. 10.
    
    
    

    After specimen extraction, all trocar sites 10 mm or larger are closed under direct vision using a fascial closure device or open closure. Inspection of the trocar sites after removal of the trocars should be performed to confirm the absence of bleeding. Skin incisions are closed using subcuticular sutures or skin staples.