Adrenal Surgery

Functional and non-functional adrenal disease forms a relatively small part of any endocrine surgery practice, with adrenalectomy accounting for less than 10% of the operative workload. Resection of the adrenal gland is ideally suited for a laparoscopic approach because open removal requires a relatively large incision for retrieval of a small gland, with greater morbidity and mortality as a result. Improvements in endoscopic instrumentation and technique has meant that most adrenal surgery can now be performed laparoscopically, the main criteria for an open approach being a tumour greater than 6 cm in diameter and the presence of malignant disease. The unit policy in fit patients is to remove any functioning adrenal tumour and any incidentaloma greater than 4 cm in diameter.

Adrenalectomy preparation

Laparoscopic adrenalectomy is safe and effective if the surgeon has a thorough knowledge of the anatomy, and the patient is rendered endocrinological^ safe prior to any surgical procedure. This is particularly important in the case of phaeochromocytoma and in Conn's syndrome, where the patient must be pre-treated with appropriate drugs to block the excess hormone effects. Anaesthesia for these patients is highly specialised and should only be undertaken by those with appropriate training and experience.

Conn's syndrome patients require electrolyte abnormalities and hypertension to be corrected by administration of spironolactone prior to surgery. Patients with phaeochromocytoma must have alpha-adrenergic blockade, with or without beta blockade, to prevent dangerous episodes of hypertension during adrenalectomy. Both require some weeks of stabilisation on medications, which will make hypertension less likely and diminish the risk of excessive blood loss during surgery.

There are a variety of approaches to the adrenal gland, either open or laparoscopic and via transperitoneal or retroperitoneal routes. The most common laparoscopic approach and the favoured route of the authors, is transperitoneal, with the patient in the lateral decubitus position. The retroperitoneal approach has the advantage of a more direct route to the adrenal vein, but is a technically demanding operation for a surgeon more familiar with intraperi-toneal anatomy. The open approach tends to be via the transperi-toneal route, rather than the retroperitoneal route through the bed of the 12th rib. For very large tumours access can be improved by extending the incision into a thoracoabdominal approach, but this is rarely required.

Laparoscopic adrenalectomy

Like laparoscopic cholecystectomy, the approach to the adrenal gland via the laparoscopic route has clear advantages over open operation. The absence of an upper abdominal incision results in less postoperative pain, lower blood loss, and faster recovery.29 Approximately 60% of adrenal operations can be undertaken with the laparoscope, the main exclusions being large tumours and those suspected or proven malignant.30 Three or four ports are required, depending on the side of the operation, plus a liver retractor, a multi-fire ligaclip applicator, and a suction irrigator apparatus. Care must be taken, as in any laparo-scopic operation, to avoid abdominal wall vessels when placing the access ports. Bilateral laparoscopic adrenalectomy can be undertaken by turning the patient and redraping between sides.

The anatomy of the adrenal gland would suggest that it is a very vascular organ, with three separate arteries and, often, two veins. In practice, however, the arteries are small and not easily identified. They rarely require formal ligation, with only the inferior adrenal artery likely to need ligaclipping.31 The dissection is performed using the ultrasonic shears or a laparoscopic diathermy hook, which give excellent haemostasis. The main adrenal vein tends to be singular, and control is normally achieved through multiple ligaclip ligation. There have been some reports of clip dislodgement with associated bleeding, particularly if the adrenal vein is short.32 This danger can be overcome using extracorporeal ligation of the vein or by the application of an Endoloop (Ethicon Endo-surgery, Cincinatti, Ohio, USA) suture. An accessory adrenal vein may be emptying into the hepatic veins from the superior aspect of the adrenal, therefore, care must be taken during this aspect of the mobilisation to ensure haemostasis.

Partial adrenalectomy is possible for patients with small, potentially benign tumours, such as, aldosterone-producing adenomas. This means that the patient has a lower risk of functional deficit after adrenalectomy. Additional care must be taken, however, to secure haemostasis of the cut edge of the gland. Generally, the use of the ultrasonic shears is sufficient or, alternatively, a vascular stapler can be used.33 If there is an oozing raw surface, the application of fibrin glue may help to prevent haematoma formation.34

The operation is completed by removal of the specimen in a bag, which should be extracted by enlarging one of the port sites to prevent rupture of the bag and spillage of the contents. The placement of a surgical drain is rarely required, and it can usually be removed after 24 hours. Port removal should be performed under direct vision to check for bleeding from an abdominal wall vessel that may have been tamponaded during the procedure.

Open adrenalectomy

The indications for open adrenalectomy have been narrowing rapidly as experience with the laparoscopic technique has evolved. The open approach is now confined to patients with larger tumours and suspected or known malignancy. In the authors' unit, none of the past 85 laparoscopic adrenalectomies required conversion to open operation because of the careful case selection of appropriate patients preoperatively.

Open adrenalectomy can be performed via a posterior, loin, or anterior transperitoneal approach. The authors favour an extraperitoneal posterior approach through the bed of the 12th rib, providing the most direct route to the adrenals. It is also a useful approach in patients who have had previous abdominal surgery and are likely to have complex and difficult adhesions. If the tumour is very large a thoracoabdominal incision can be used, but is very rarely needed. The open transperitoneal anterior approach can be necessary for bilateral adrenalectomy in Cushing's syndrome, but laparoscopic approaches are now favoured if possible.

Was this article helpful?

0 0

Post a comment