The Role of Laparoscopic Surgery in Adrenal Disease

THE PRACTICE of abdominal surgery was dramatically changed in 1987 when the technique of laparoscopic cholecystectomy was reported by Dubois and associates (1). The procedure was rapidly and widely adapted in Europe, the Americas, and Asia and quickly becoming the standard method of removing the diseased gall bladder. Over the last decade minimally invasive operations have been employed in the management of many surgical disorders, particularly in the abdominal and thoracic cavities and the retroperitoneum (2–4). With the initiation of each new laparoscopic technique there have been predictable cycles characterized by an“ introductory phase,” where the surgical technique is perfected (virtually always associated with a learning curve), a “definition phase” with exploration of technical variations and clarification of the operative indications, and an “educational phase,” where the new technique is taught to house officers and surgical colleagues. This phase sequence is somewhat flexible, and there is often much overlap during the development, refinement, and maturation of a given procedure. Unfortunately, with the introduction of each new laparoscopic procedure there have been no prospective randomized controlled trials comparing the new technique to the standard “open” technique. Such comparative analyses were precluded by the clear demonstration, initially with laparoscopic cholecystectomy, that the “minimally invasive procedures” had advantages such as shorter hospital lengths of stay, less postoperative pain, and more rapid convalescence and return to work. Furthermore, the patients, the hospitals, the employers, and the health care providers found the minimally invasive techniques preferable to the standard operative procedures. There are no long-term reports of experience with any of the established laparoscopic procedures. In 1992 Gagner and associates (5) reported the first case of laparoscopic adrenalectomy (LA) in a patient with Cushing’s syndrome due to an adrenocortical adenoma. The technique proved highly attractive to clinical endocrinologists, and within a short period of time several medical centers reported their clinical series of patients treated by this procedure (6–8). Currently, the technique has gained wide acceptance among endocrine surgeons as the procedure of choice for the resection of most adrenal tumors. However, there are some controversial issues among the experts, as demonstrated in this Round Table. We will review the most significant issues about LA and focus especially on the controversies evidenced in the current presentations. Even though there have been no prospective randomized trials comparing LA to open adrenalectomy (OA), there have been retrospective comparative evaluations. Thompson and associates (9) performed a matched case-control study comparing 50 patients having open adrenalectomy to 56 patients having adrenalectomy through a posterior approach. They found that LA, compared to OA, was significantly associated with shorter hospital stay, less postoperative narcotic use, more rapid return to normal activity, increased patient satisfaction, and less late morbidity. However, the laparoscopic procedure was associated, with longer operating room time and higher cost. Similar results have been reported by Prinz (10) and by Brunt et al (11), who found that LA had distinct advantages compared to OA. It has been noted by several authors that a posterior retroperitoneal LA is preferable to an anterior LA, especially in patients who have either bilateral adrenal tumors, prior to extensive abdominal procedures with resultant adhesions and scar tissue formation, or pre-existing cardiopulmonary disease (12–14). Posterior LA is not indicated in patients with large adrenal tumors. In laparoscopic adrenalectomy one sacrifices the tactile sense and must manipulate the fragile adrenal gland with instruments in a two-dimensional plane. This is a significant deficit for two reasons: 1) the adrenal gland is small and flat, and its true extent is often difficult to define, even under direct observation; 2) the adrenal gland is vascular and friable, and there is risk of damaging its capsule and the parenchyma during instrumentation. This is a particular problem in patients with Cushing’s disease, where adrenal cortical cells spilt at surgery may increase to nodules under constant endogenous ACTH stimulation. In the present report of Lacroix (in this discussion), 3 of their 100 patients had incomplete resection of adrenal glands, as evidenced by ACTH stimulation test in 2 patients and the recognition of a 1 mm remnant of adrenal cortex left in situ in the third. Only 1 of these patients had a functioning tumor and is at risk for recurrent disease. Ushiyama and associates (15) reported a case of adrenocortical carcinoma with recurrence 19 months after LA. At the original operation for Cushing’s syndrome a 5-cm left adrenal cortical tumor was resected. The histologically benign tumor was removed intact. The patient developed recurrent symptoms and at reoperation had multiple metastases both in the previous resection bed and at other intraabdominal sites. It should be noted that there have been reports of tumor recurrence at abdominal port sites in patients treated laparoscopically for colon carcinoma or gall bladder carcinoma (16, 17). Also, one must also take great care not to damage the vasculature to the kidney, especially on the left side where adrenal tumors often overlie the renal hilus. The development of postoperative hypertension is often the manifestation of an ischemic injury to the kidney occurring at the time of adrenalectomy. Laparascopic adrenalectomy was first performed in patients with benign tumors of the adrenal cortex, but it soon was used to resect pheochromocytomas. At present the procedure is used to resect a broad range of benign adrenal tumors and even the adrenal glands in some patients with nontumorous conditions, such as congenital adrenal hyperplasia (see Merke and Cutler in this Controversy). Lapara-scopic adrenalectomy is contraindicated for malignant adrenal lesions because the tumors are often large, technically difficult to remove, and vulnerable to breakage or incomplete resection. Also the tumors may invade adjacent organs or regional lymph nodes, which also require resection. It is of interest that Merke and Cutler, in the present report, cite the use of LA in three infants with neuroblastomas found during a mass screening program in Japan (18, 19). Perhaps the generally good prognosis of neuroblastomas in this age group precludes this rule, but it will be very interesting to learn of the long-term evaluation of these patients. Size is the best indication that an adrenal tumor is malignant, a matter that was controversial among the Round Table participants. Lacroix and associates do not consider size of major importance and report laparoscopic resection of adrenal tumors as large as 10 or 13 cm. It is of interest that in their series, Lacroix refers to two patients with nonfunctioning adrenal tumors that met histological criteria for malignancy and two of four patients with cortisol secreting adenomas, who were later shown to have metastatic adrenal cortical carcinoma. There is no mention of the size of these four lesions. It has been reported by Page and associates (19) and Ross and associates (20) that tumors larger than 6 cm in diameter or weighing more than 100 g are highly likely to be malignant. Norton (in this Controversy) cites their work in recommending that such large lesions should be resected by an open technique. There is no reliable preoperative radiographic or biochemical test that indicates the biological nature of an adrenal tumor; even on histological examination it is very difficult, if not impossible, to tell if the neoplasm is cancerous. Often this only becomes evident when tumor spread is demonstrated beyond the confines of the adrenal capsule. The matter of resecting incidentally found adrenal tumors is also controversial. Lacroix and associates reported the removal of 15 nonfunctioning adrenal adenomas and 2 myelolipomas. Relatively clear guidelines have been developed for the management of patients who incidentally are found to have adrenal tumors (21–23). If these tumors have no endocrine function, are less than 6 cm in size, and do not enlarge with time, they can be left alone as virtually all such lesions are benign and harmless. The availability of a technique for easily removing these lesions is not necessarily an indication for doing so. Laparascopic adrenalectomy has clear applicability in the management of patients with benign adrenal neoplasms. Even though LA has distinct advantages compared with OA, much thought needs to be given to the indications for the application of the technique. There is still controversy in certain areas that will only be clarified as the“ definition phase” matures and there is long term evaluation of large numbers of patients who have been treated by this technique.