Robotic adrenalectomy – transabdominal approach

Indications

Minimally invasive adrenalectomy is the gold standard of care for functional and nonfunctional adrenal masses. Laparoscopic adrenalectomy has been popularized over the last three decades and has been demonstrated to be a safe and effective method of adrenalectomy. Laparoscopic adrenalectomy has been shown to be superior to open adrenalectomy with respect to postoperative pain, blood loss, length of stay, return to activity, and transfusion requirements.

The indications for robotic adrenalectomy mirror those of laparoscopic adrenalectomy, and the advantages of robotic adrenalectomy over a straight laparoscopic approach have become apparent in recent years. Overall benefits of the robotic technique include finer movements in the vascular planes, minimized tissue handling, stable retraction, and stable, three-dimensional visualization.

Robotic adrenalectomy is a suitable operation for the resection of functional tumors, as well as nonfunctional tumors, if there is concern for malignancy. Adrenal incidentalomas that are increasing in size, have radiographic abnormalities (e.g., calcifications or high Hounsfield units, each of which can be an indicator of malignancy), or are over 4 cm in diameter should be removed ( Table 33.1 ). Studies have shown that 6% of tumors that are 4–6 cm in diameter are malignant, whereas approximately 25% of tumors 6 cm and larger are likely to be primary malignancies. This is the rationale behind removing tumors of 4 cm and larger.

The relative contraindications to a robotic approach include large adrenocortical carcinomas, pheochromocytomas over 8 cm, and malignant pheochromocytomas. Surgeons should consider prior extensive upper abdominal surgery prior to planning a robotic approach, although this is not a contraindication to a robotic adrenalectomy ( Table 33.2 ).

Robot-assisted adrenalectomy has particular advantages over the straight laparoscopic approach in patients with a high body mass index (BMI) or large tumors. The challenges that were faced with the Si da Vinci platform (Intuitive Surgical, Inc., Sunnyvale, CA, USA), particularly with respect to docking, collisions between the robot arms, and positioning of the robotic arms away from the patient, have been alleviated with the Xi da Vinci robot platform (Intuitive Surgical, Inc.).

Several studies have demonstrated little difference between laparoscopic and robotic adrenalectomy. However, recent studies demonstrate a benefit of robotic adrenalectomy over laparoscopic adrenalectomy, particularly with respect to rates of conversion to open surgery, blood loss, and lengths of stay. ^,

Work up of adrenal tumors

Imaging studies

Computed tomography (CT) is often the first study to reveal an adrenal tumor and is the most common modality that identifies adrenal incidentalomas. Adrenal cortical adenomas often appear homogenous and round, with low Hounsfield units and rapid washout of IV contrast ( Fig. 33.1 A). Magnetic resonance imaging (MRI) is also commonly used to image adrenal tumors. Tumors that are malignant appear bright on T2-weighted images ( Fig. 33.1 B). In addition, with both CT and MRI, malignant adrenal tumors are often seen as large and heterogeneous, with high Hounsfield units, and delayed washout of IV contrast.

Patient preparation

Patients who have hormonally active tumors must be optimized prior to any operation to reduce perioperative morbidity and mortality. Patients with pheochromocytomas require alpha-blockage for 7–10 days (with the goal of mild orthostatic hypotension), followed by beta-blockage for 1–2 days prior to the operation to manage ongoing tachycardia. If a patient’s hypertension is not controlled preoperatively, the operation must be delayed until adequate pressure control is achieved. Aldosterone-secreting tumors also require optimal blood pressure control, as well as preoperative correction of hypokalemia. Patients with cortisol-secreting tumors, or Cushing’s Syndrome, require perioperative steroid planning. We recommend close collaboration with an endocrinologist for patients with hormonally active adrenal tumors in the pre- and postoperative periods.

Operating room setup and patient positioning

Equipment: See Table 33.3 . Our standard practice is the use of the da Vinci Xi Robotic system. Anesthesia must prepare the patient, including additional IV or arterial lines, especially in cases of pheochromocytoma. General anesthesia is always used, and perioperative antibiotics, sequential compression devices, and any additional deep venous thrombosis prophylaxis are all given prior to the incision. Prior to patient positioning, an orogastric tube is placed. We use urinary catheters in all adrenalectomy cases, but this is not required.