Laparoscopic retroperitoneal adrenalectomy—posterior approach

Laparoscopic Retroperitoneal Adrenalectomy—Posterior Approach Eren Berber, MD, and Allan E. Siperstein, MD

here have been dramatic changes in adrenal surgery in the past decade with the introduction of laparoscopic techniques. The adrenal gland is particularly amenable to a laparoscopic approach because of its small size, the benign nature of most adrenal tumors, and the difficulty in reaching the organ via open means. The first laparoscopic adrenalectomy was performed transabdominally by Gagner and coworkers in 1992.1 This was followed a year later by Mercan’s description of the technique for laparoscopic posterior adrenalectomy.2 Both the transabdominal and the retroperitoneal laparoscopic approaches represent a significant benefit in terms of patient recovery as opposed to open surgery and in the past decade, laparoscopic adrenalectomy has become the procedure of choice for removing benign adrenal tumors. Laparoscopy provides a magnified view of the operative field allowing the precise identification of small vessels, and a more precise dissection with less blood loss compared with open surgery. Laparoscopic adrenalectomy has been shown to be associated with reduced narcotic requirements, shorter hospital stay and convalescence compared with open procedures.3-7

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INDICATIONS The current indications for laparoscopic adrenalectomy include:8 1. Aldosterone-secreting adenoma 2. Glucocorticoid-secreting adenoma 3. Androgen-secreting adenoma 4. Pheochromocytoma (small to moderate-sized) 5. Bilateral macronodular adrenal hyperplasia 6. Selected cases of bilateral adrenal hyperlasia (if ectopic ACTH-producing tumors can not be located or pituitary tumor is unsuccessfully removed by transphenoidal hypophysectomy) 7. Hormonally inactive tumors larger than 3 to 5 cm 8. Nonfunctioning adrenal tumors less than 3 cm that have shown progressive growth on serial imaging studies

From the Department of General Surgery, The Cleveland Clinic Foundation, Cleveland, OH, USA. Address reprint requests to Allan E. Siperstein, MD, The Cleveland Clinic Foundation, Department of General Surgery/A 80, 9500 Euclid Avenue, Cleveland, OH Copyright 2002, Elsevier Science (USA). All rights reserved. 1524-153X/02/0404-0118$35.00/0 doi:10.1053/otgn.2002.35352

9. Solitary adrenal metastases The management of an incidentaloma deserves further attention. Once clinically significant hormonal activity is ruled out with biochemical and hormonal studies, malignancy also needs to be excluded. It is very important that fine needle aspiration is appropriately used in this workup. Pheochromocytoma needs to be definitely ruled out biochemically before attempting needle biopsy, because the procedure can provoke a hypertensive crisis in a patient with pheochromocytoma. The advent of the minimally invasive approaches to adrenal surgery has resulted in the decrease in size of the incidentalomas referred to surgery. The referral of patients for surgical removal based on the size of the tumor on radiological studies is, on the other hand, controversial because transverse size on computed tomography (CT) often underestimates the longitudinal axis dimension. Many authors advocate surgical resection on lesions greater than 4 cm.9,10 Adrenal carcinomas are generally greater than 5 cm although there are increasing reports of adrenal carcinomas as small as 3 cm. Invasive adrenal carcinoma is currently considered a contraindication to the laparoscopic approach due to the need for en bloc excision of the adrenal cancer and surrounding tissues and organs.4 Open surgery also seems to be indicated for patients with malignant pheochromocytoma.

PREOPERATIVE PREPARATION Appropriate preoperative preparation of patients is essential to prevent complications. Preoperative preparation is similar with Cushing and Conn syndromes, addressing primarily the hypertension and electrolyte disturbances. Patients with Cushing syndrome should also receive steroid supplementation for the perioperative period of stress and to prevent the withdrawal syndrome after resection of the gland. In patients with pheochromocytoma, emphasis is given at controlling hypertension and associated hypovolemia. Alpha blockade should be started at least 10 to 14 days preoperatively with phenoxybenzamine. Beta-blockers may be added once adequate alpha- blockade is established and if tachycardia develops. If alpha-blockade fails to provide adequate blood pressure control, consideration should be directed at administrating metyrosine (Demser), a tyrosine hydroxylase inhibitor.8

Operative Techniques in General Surgery, Vol 4, No 4 (December), 2002: pp 331-337

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LAPAROSCOPIC POSTERIOR RETROPERITONEAL ADRENALECTOMY Although the indications for the posterior or the transabdominal approach in open surgery were well-established, the choice of a certain approach in a given patient in the laparoscopic era has not been resolved. So far, the transabdominal laparoscopic approach has been favored over the posterior approach in most of the patients because of technical difficulty and inexperience with the true laparoscopic posterior approach. Although the majority of the surgeons show a preference for the transabdominal technique, laparoscopic posterior adrenalectomy offers a more direct access to the adrenal gland, minimizing the need for intraabdominal dissection. The first structure identified in this procedure is, in fact, the adrenal gland. Furthermore, it offers the advantage of the dissection without the interference of the intraabdominal organs. It is not necessary to mobilize the liver with section of the right triangular ligament for right adrenalectomy, and for left adrenalectomy, mobilization of the spleen and splenic flexure of the colon are avoided. This approach also facilitates dissection in the individual with previous intraabdominal surgery by avoiding adhesions. Furthermore, there is no need to reposition the patient for bilateral tumors except to convert to an open procedure. The patient is already in the prone position, so that bilateral adrenalectomy can be performed without repositioning. The disadvantage of laparoscopic posterior adrenalec-

tomy seems to be the limited space that determines the size of the tumor removed. The diameters of the tumors removed in the literature range from 1.5 to 8 cm2,5,11 The inability to visualize the intra-abdominal cavity to assess for the possibility of malignancy has been regarded as a drawback of laparoscopic posterior adrenalectomy but with the currently available advanced imaging techniques and laparoscopic ultrasound, we do not believe that this can be considered a disadvantage. We advocate the posterior approach to be considered in patients with tumors less than 6 cm, bilateral tumors, or extensive previous abdominal surgery.3,12

Transcutaneous Ultrasound Transcutaneous ultrasonography is performed with a standard 3.5 MHz transabdominal transducer. The outline of the underlying kidney and adrenal mass, as determined by the ultrasound examination, is then drawn onto the skin of the back so as to direct placement of the trocars into Gerota’s space. The outline of the 12th rib is drawn by palpation. Such a mapping of the kidney is important as the location of the kidney relative to the 12th rib is quite variable especially in tall individuals. It is also important to do the ultrasound examination with the patient properly positioned for surgery as these structures shift in position with changes in posture.

SURGICAL TECHNIQUE

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Patient Positioning. The patient is taken to the operating room and general endotracheal anesthesia is induced on the gurney. Pneumatic sequential compression stockings are applied. The patient is then flipped onto the operating table with the chest and abdomen supported laterally by a Wilson frame or parallel bolsters. This allows the abdominal contents to fall anteriorly so that during the procedure a minimum of CO2 insufflation is required as the posterior rib cage forms a rigid dome under which to work. The table is flexed in a jack knife position with the back level. This serves to open up the space between the posterior costal margin and the pelvis.

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Trocar Entry and Creation of a Potential Space. The back is then sterilely prepped and draped. Local anesthesia is used at the trocar sites. A 1.5-cm incision is then made 2 cm inferior and parallel to the 12th rib, positioned laterally at the level of the lower pole of the kidney. A 12-mm optical access trocar with inserted 0° laparoscope is then used to enter Gerota’s space under direct vision by dilating the fascial and muscle layers of the posterior abdominal wall until Gerota’s space is entered as confirmed by perinephric fat seen superiorly and the renal capsule inferiorly. A gentle side to side motion is made to further develop this space and the trocar is advanced to the level of the superior pole of the kidney. This trocar is then replaced with a 10-cm diameter spherical dissecting balloon and while viewing within the balloon using a 0° laparoscope, the balloon is manually inflated using a hand pump to create a potential space within Gerota’s fascia. Using anatomical orientation, this space is bounded anteriorly by the kidney, superiorly by the diaphragm, and posteriorly by the rib cage. The 12-mm optical access trocar is then reinserted into this space and 10 to 15 mm of CO2 insufflation is applied. A 45° laparoscope is used to perform the procedure. If the creation of the working space is done properly, then the adrenal is directly visible at this point. Two additional 5-mm optical access trocars are placed under direct vision, one on either side of the initial port.

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Laparoscopic Ultrasound. After the ports have been placed, laparoscopic ultrasound is performed to help localize the adrenal gland and determine its relationship with surrounding structures. A rigid, side-viewing, linear array transducer that fits through a conventional 10 mm laparoscopic port is used for the laparoscopic ultrasound. The use of flow doppler also helps to identify the aorta and the inferior vena cava and display the adrenal vasculature. The kidney is identified based on the characteristic appearance of its parenchyma with the cortex and the collecting system. The transducer is advanced cephalad in the longitudinal plane until the adrenal gland is identified. The rigid tip of the transducer can be used to further dissect the retroperitoneal fatty tissue to expose the adrenal gland. The use of a special effects generator (picture-in-picture box) enables the surgeon to see both images on the same monitor by superimposing the sonographic image as an inset on the laparoscopic image. The identification of the adrenal vein at this point will permit safe and accelerated dissection of the adrenal. Nonsecreting and secreting adenomas have a similar ultrasonographic appearance. They are usually less than 3 cm, and have very low echogenecity. Pheochromocytomas might appear as solid, cystic or have both solid and cystic components. Adrenal cortical carcinoma of 3 to 6 cm in size, shows a homogenous echo pattern similar to renal cortical tissue. Larger lesions vary in ultrasonographic appearance. Laparoscopic ultrasound is extremely useful in identification of small tumors in obese patients. It can also demonstrate rest tumor tissue in the adrenal bed in patients with nodular hyperplasia after excision. The right adrenal has a more fixed anatomic location on the vena cava facilitating its localization. Laparoscopically, the left adrenal is more difficult to localize, especially in an obese patient, because the location of the gland is more variable.

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Vascular Pedicle Control. The adrenal gland receives its blood supply from the inferior phrenic, renal and adrenal vessels. The Harmonic scalpel can be safely used to secure and divide those less than 3 mm in diameter. A “double ligation technique” is used to divide the blood vessels. The device is applied across the vessel near the gland until the vessel is sealed, but not yet divided. Then the device is then moved along the vessel several millimeters away and the vessel is sealed and divided. This double ligation technique minimizes the chance of vessel hemorrhage. Larger vessels need to be dissected and secured with clips. The adrenal vein is usually the largest vessel. It needs to be clearly identified and dissected, using fine-tip dissectors, if necessary. We prefer to use 2 clips on the caval or aortic side.

RESULTS

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Dissection. After the adrenal tumor has been localized with laparoscopic ultrasound, dissection is begun, using the harmonic scalpel (Laparoscopic coagulating shears, 10 mm or 5 mm) to perform essentially all of the dissection, with an atraumatic grasper used for counter traction. There is a minimum of instrument switching during the procedure. The dissection typically begins at the superior margin of the adrenal, separating it from the diaphragm. With division of the superior adrenal artery, the gland may then be displaced inferiorly to facilitate mobilization. The lateral side is dissected next, followed by the inferior border with the kidney. The medial border is dissected last with control of the adrenal vein(s).

In a series of 31 patients undergoing laparoscopic posterior adrenalectomy,12 there was no conversion to an open procedure. Mean patient age was 49 years (range 27 to 81). Tumors were located on the left in 17 patients (55%) and on the right in 12. Two patients (6%) had bilateral tumors. Indications for operation included hormone secretion in 23 patients (74%), suspected or known malignant neoplasms in 7 (23%) and local symptoms in 1 patient (3%). Sixteen patients had aldosteronoma (52%), 6 patients (19%) malignant neoplasms, 5 patients (16%) Cushing syndrome, and 1 patient each (3%) had pheochromocytoma, mixed pheochromocytoma-neuroblastoma, nonfunctional adenoma and cortical nodular hyperplasia. The mean ⫾ SD tumor size was 3.2 ⫾ 1.8 cm (range 0.8 to 7.0 cm). Excluding the bilateral cases, the mean operative time was 176 minutes. Bilateral proce-

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(122.6 ⫾ 19.3 versus 114.3 ⫾ 15.2 minute). Most of the operating time was spent for dissection of the adrenal gland with both techniques (lateral, 57% versus posterior, 64%). Exposure of the adrenal gland was longer in the lateral compared with the posterior approach (15.1 ⫾ 1.8 versus 5.8 ⫾ 0.3 minute, respectively: P ⬍ 0.05). In the lateral approach, dissection time was dependent on tumor size (r ⫽ 0.90, P ⬍ 0.05), but not Body Mass Index (BMI); whereas, in the posterior approach, both tumor size and BMI were positively correlated (r ⫽ 0.56 and r ⫽ 0.64, respectively, P ⬍ 0.05). Dissection took longer for those with BMI ⬎25 than for those with BMI ⬍25 (P ⬍ 0.05) in the posterior group. Mean ⫾ SEM time spent for laparoscopic ultrasonography in the posterior approach was 9.2 ⫾ 2.1 minutes.

CONCLUSIONS

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Extraction, Irrigation-Aspiration. The excision of the tumor is then completed. Especially in cases of nodular hyperplasia, laparoscopic ultrasound may be repeated to ensure that no rest tumor is left behind. The operative field is then irrigated and aspirated. The gland is then placed in an endoscopic specimen retrieval bag and withdrawn through the abdominal wall with morcellation if needed. The trocars are removed under direct view. Fascial and skin closure is done in the usual manner.

dures took an average of 479 minutes. There was no difference between right-sided versus left-sided lesions regarding operative time. The estimated blood loss averaged 32 mL (range 10 to 200 mL). There were no intraoperative complications. The average hospital stay was 1 day (range 1 to 3 days). There were 3 (10%) postoperative complications: 1 patient operated for pheochromocytoma with preoperative anemia received 2 packs of red blood cells in the postoperative period. Two patients with Cushing syndrome had transient left-sided nerve root pain for 3 months, which was thought to be related to the trocar sites. There were no operative mortalities. In our time analysis study13 comparing the lateral transabdominal technique with the posterior retroperitoneal approach for the component parts of laparoscopic adrenalectomy, it was seen that, although tumor size was larger in the lateral compared with the posterior approach (mean ⫾ SD; 5.5 ⫾ 0.9 cm versus 2.5 ⫾ 0.3, P ⬍ 0.001), there was no difference between the two approaches regarding total operating time

Laparoscopic posterior adrenalectomy is a safe and efficacious technique for removing a wide range of adrenal tumors. Although technically more demanding, laparoscopic posterior adrenalectomy should be considered in patients with tumors less than 6 cm, bilateral tumors or extensive previous abdominal surgery. Laparoscopic ultrasonography is useful to localize the tumor and establish its relationship with vital structures early in the procedure thereby facilitating dissection.

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Laparosopic Retroperitoneal Adrenalectomy Recent advances in basic concepts and clinical management. Ann Intern Med 130:759-771, 1999 11. Bonjer HJ, Lange JF, Kazemier G, et al: Comparison of three techniques for adrenalectomy. Br J Surg 84:679-682, 1997 12. Siperstein AE, Berber E, Engle KL, Duh Q-Y, Clark OH: Laparo-

337 scopic posterior adrenalectomy: Technical considerations. Arch Surg 135:967-971, 2000 13. Berber E, Duh Q-Y, Clark OH, Siperstein AE: A critical analysis of intraoperative time utilization in laparoscopic adrenalectomy. Surg Endosc 16:258-262, 2002