Medical Association, Orlando, Fla, July 25-20, 1989. Requests ... Department of Surgery, University of Michigan Medical Center, ..... Adrenal surgical tech-.
COMPLICATIONS FOLLOWIN ADRENAL SURGERY Michael K. McLeod, MD Ann Arbor, Michigan
The morbidity associated with adrenalectomy can be as high as 40% and the mortality is approximately 2% to 4%. Morbidity following adrenalectomy is associated with intraoperative injury to an adjacent or contiguous structure, postoperative infection, thromboembolism, or adrenal insufficiency. Mortality is most often associated with pulmonary emboli, sepsis, a myocardial event (myocardial infarction or arrhythmia), or as a direct result of the underlying disease for which adrenalectomy is being performed. The posterior approach to adrenalectomy is associated with less blood loss and morbidity, and is best tolerated by the patient. However, the anterior transabdominal approach offers superior access to both adrenals, as well as other pertinent abdominal and retroperitoneal sites, and structures requiring concomitant exploration. Key words * adrenalectomy * pulmonary embolimyocardial infarction * Cushing's syndrome
From the Department of Surgery, University of Michigan Medical Center, Ann Arbor, Michigan. Presented at the 94th Annual Convention and Scientific Assembly of the National Medical Association, Orlando, Fla, July 25-20, 1989. Requests for reprints should be addressed to Dr Michael K. McLeod, Department of Surgery, University of Michigan Medical Center, 2920F Taubman Center, 1500 E Medical Center Dr, Ann Arbor, Ml 48109-0331. JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 83, NO. 2
There are few areas in surgery that are as intellectually and emotionally rewarding as the successful management of surgically amenable adrenal disease. The physiological consequences of adrenal dysfunction can be dramatic, bewildering, and devastating to the patient. Moreover, the intricate anatomy associated with exposure and excision of the responsible diseased adrenal can be both demanding and challenging. In this discussion and under the context of today's symposium on complications in surgery, I will elaborate on complications associated with, but not necessarily unique to, surgical adrenalectomy. There are, however, certain complications that patients who undergo adrenalectomy are more susceptible to because of the nature of their disease. For example, it is well-documented that patients with Cushing's syndrome will have a higher incidence of wound, infection, and thromboembolic complications following surgery because of their increased susceptibility from hypercortisolism. 1-3 First, it is appropriate to make a few comments regarding the surgical approach to the adrenal gland. I believe this approach is becoming less and less controversial because there appears to be a general consensus that when adrenal exploration is being undertaken for the treatment of pheochromocytoma, adrenocortical cancer, (ACC) and/or non-localized adrenocortical hyperfunction, an anterior, transabdominal approach is indicated. 14 The anterior approach allows examination of both adrenals before removing one or both. The possibility 161
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of adrenal rests can be evaluated thoroughly by exploring the entire abdomen and retroperitoneal space. When the adrenal is being approached for management of adrenocortical cancer, the extent of the cancer, presence or absence of regional node involvement, or involvement of adjacent organs, structures, or distant metastasis to the liver, can best be evaluated through an anterior abdominal approach. However, for treatment of localized adrenocortical adenomas and aldosteronomas, a posterior or flank approach is appropriate. Management of an incidentaloma depends on its size, the clinical setting, and diagnosis. The thoracoabdominal approach to an adrenal lesion is rarely necessary. Currently, the problem is that we are finding smaller and smaller, asymptomatic, adrenal lesions because of the increasingly widespread use of computerized axial tomography (CAT scan) of the abdomen. Only when large and extensive lesions are found, we require a thoracoabdominal approach for excision. When necessary, it is usually used to excise a large ACC with extensive local and/or regional spread.
OPERATIVE COMPLICATIONS There is a real hazard of injury to adjacent structures during adrenalectomy. Pneumothorax has been the most frequent complication, occurring as a result of inadvertent injury to a contiguous anatomic structure (in this case, parietal pleura), and has occurred almost exclusively with posterior approaches.2-5 Splenic and pancreatic injuries are more prevalent with anterior abdominal approaches and are influenced by the type of intraabdominal approach to the adrenal gland used. In addition, both are more prevalent with left-sided transabdominal adrenalectomy than with right-sided adrenalectomy. It should also be noted that on rare occasions (at least as reported in the literature), the tail of the pancreas has been mistaken for the left adrenal gland, resulting in lethal hemorrhage in one case, and a difficult pancreatic fistula in another.3-5 Splenic injuries occur more frequently in patients with Cushing's syndrome than in those without hypercortisolism.5 Inferior vena caval and adrenal vein injury occur with equal frequency from either flank, posterior, or anterior approaches. Nevertheless, injuries of the inferior vena cava are more easily managed from the anterior approach since vascular control is easier. Portal vein injuries are much more common during an anterior approach.2
POSTOPERATIVE COMPLICATIONS Pulmonary complications are observed in 10% to 162
30% of all abdominal operations. In a retrospective study of 238 patients who underwent bilateral adrenalectomies for advanced breast cancer, incidence of postoperative pulmonary complications was 29%.6 The incidence of atelectasis and pulmonary embolus is higher with adrenal explorations and resection through the anterior abdominal approach than through the flank or posterior approaches. However, in one reported series, only the difference in the incidence of pulmonary embolus between anterior and flank approaches was statistically significant.2 Moreover, pulmonary embolism and wound infections occur more often in bilateral transabdominal operations than in unilateral transabdominal operations. The incidence of wound infections is higher following an anterior transabdominal approach than either posterior or flank approaches, and staphylococcus aureus is generally the most common etiologic organism.2'7 The incidence of wound infections or subdiaphragmatic abscesses was not influenced by the type of intra-abdominal approach used. Interestingly, when one-stage transabdominal bilateral adrenalectomies were compared with two-stage bilateral adrenalectomies via bilateral flank incisions, there was no difference in the incidence of complications.2
CUSHING'S SYNDROME Patients with hypercortisolism associated with Cushing's syndrome are more susceptible to complications from infection, secondary to the adverse effects of excess steroids on immune function. Thromboembolic phenomena occur more frequently in patients with Cushing's syndrome, with an 11% incidence of deep venous thrombosis or pulmonary embolus. The incidence of pulmonary emboli postoperatively is reported as 2% to 3%.8 In patients with Cushing's syndrome, the increased frequency of thromboembolic events is believed to be secondary to the prevalence of the predisposing factors: obesity, hypertension, elevated hematocrit, and increased Factor VIII levels.8'9 The development of increasing cutaneous pigmentation associated with very high plasma ACTH levels following adrenalectomy is referred to as the postadrenalectomy syndrome.'0
CUSHING'S DISEASE Patients with severe Cushing's disease, ie, patients with extreme hypertension and advanced bone disease, in whom delayed effective therapy could be potentially life-threatening, and those who have failed pituitary irradiation or microsurgical hypophysectomy, require JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 83, NO. 2
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bilateral adrenalectomy for therapy." However, 10% to 30% of patients with Cushing's disease treated with total adrenalectomy acquire Nelson's syndrome, a late complication (2 to 3 years postoperatively) caused by enlargement of an ACTH-producing pituitary adenoma.'" noa12,13 The practice of performing subtotal adrenalectomy to treat Cushing's disease is no longer recommended because of the postoperative complication of recurrent Cushing's disease, occurring in 5% to 30% of cases, as well as the associated problem of intermittent adrenal cortical insufficiency.7"1"l4 Therefore, it has been proven that postoperative management of patients following total adrenalectomy is easier and more predictable than following subtotal adrenalectomy.
regional and/or local recurrences are associated with iatrogenic rupture of the tumor capsule during surgical excision. The larger the ACC, the more difficult it is to avoid rupturing the capsule. ACCs may be complicated by intravascular extension of the tumor with or without tumor thrombus. Such an event dictates extraction, increasing the risk of hemorrhage and tumor embolus complicating surgical excision. Approximately 40% to 50% of ACCs are functional, ie, they secrete glucocorticoid or other hormone(s), and consequently suppress ACTH secretion resulting in the suppression of contralateral adrenal gland activity. Therefore, cortisol replacement is indicated postoperatively to avoid adrenal insufficiency.
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PHEOCHROMOCYTOMA Nitroprusside is currently the drug of choice for managing acute intraoperative hypertension.'5 Acute hypotension following excision of a pheochromocytoma can be managed with intravenous norepinephrine or phenylephrine, in conjunction with fluid and blood volume replacement. The most common causes of recurrent pheochromocytoma are local implantation with capsular rupture at the time of surgical excision, and the failure to identify multiple pheochromocytomas at initial exploration. A small percentage of patients have both adrenal and extra-adrenal pheochromocytomas. Therefore, common sites for extra-adrenal pheochromocytomas should be explored even when an adrenal tumor has been identified and excised. Extraadrenal sites that should be specifically explored include the renal hilum bilaterally, the periaortic area from the celiac axis to the bifurcation of the aorta, the junction of the left renal vein and the inferior vena cava, and the origin of the inferior mesenteric artery to the bifurcation of the abdominal aorta.
PRIMARY ALDOSTERONISM Postoperative complications associated specifically with primary aldosteronism are transient hypoaldosteronism, occurring in approximately 10% of cases, usually manifested by hypotension, acidosis, and hyperkalemia. This is best treated with saline and desoxycorticosterone acetate. Hypertension must be managed with antihypertensive medication, and adrenal insufficiency should be treated with appropriate doses of corticosteroids (hydrocortisone).
ADRENOCORTICAL CARCINOMA In dissemination of adrenocortical carcinoma (ACC), JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 83, NO. 2
Adrenal insufficiency can potentially follow the removal of an apparently nonfunctioning adrenal adenoma (incidentaloma) that is actually capable of producing sufficient excess hormone to suppress the contralateral gland, but not demonstrate as excess hormone production by the standard tests used to assess adrenal function.16 Adrenal insufficiency has also occurred following unilateral adrenalectomy for an apparently hormonally-nonfunctioning adrenal pseudocyst.17
CONCLUSION Overall, morbidity associated with adrenalectomy can be as high as 40%, and mortality, approximately 2% to 4%.7 The morbidity following adrenalectomy is usually associated with an injury to an adjacent structure/organ, infection, thromboembolism, or adrenal insufficiency. Mortality is most often associated with pulmonary emboli, sepsis, a myocardial event, or a result of the underlying disease. Death is an infrequent intraoperative complication, but when it does occur, it is due to uncontrollable hemorrhage, usually from an injury to the inferior vena cava, aorta, or pancreas.5"18 The primary disadvantage of the posterior approach is that exposure, ie, visibility and control, of the great vessels is limited.18 Results of several studies corroborate the contention that the posterior approach to adrenalectomy is associated with less blood loss and morbidity, and is best tolerated by the patient.1'19'20 However, for management of pheochromocytoma, non-localized Cushing's syndrome, large adrenal masses, or adrenocortical carcinoma, the anterior transabdominal approach offers superior access to both adrenals, as well as other pertinent abdominal and retroperitoneal sites and structures requiring concomitant exploration. 163
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Literature Cited 1. Bruining HA, Lamberts WJ, Ong EGL, van Seyen AJ. Results of adrenalectomy with various surgical approaches in the treatment of different diseases of the adrenal glands. Surg Gynecol Obstet. 1984;1 58:367-369. 2. Pezzulich RA, Mannix H. Immediate complications of adrenal surgery. Ann Surg. 1970;1 72:125-130. 3. Carey LC, Ellison EH. Adrenalectomy: technique, errors, and pitfalls. Surg Clin North Am. 1966;1283-1292. 4. Hauss J, Moeller A, Bunte H. Adrenalectomy in adrenal hypertension. Cardiology. 1985;72(suppl 1):167-173. 5. Blichert-Toft M, Bagerskov A, Lockwood K, Hasner E. Operative treatment, surgical approach, and related complications in 195 operations upon the adrenal glands. Surg Gynecol Obstet. 1972;135:261-266. 6. Van de Water JM, Watring WG, Linton LA, et al. Prevention of postoperative pulmonary complications. Surg Gynecol Obstet. 1972;1 35:229-233. 7. Scott HW Jr, Liddle GW, Mulherin JL Jr, et al. Surgical experience with Cushing's disease. Ann Surg. 1977;185:524534. 8. Small M, Lowe GD, Forbes CD, Thomson JA. Thromboembolic complications in Cushing's syndrome. Clin Endocrinol (Oxf). 1 983;1 9:503-51 1. 9. Dal Bo Zanon R, Fornasiero L, Boscaro M, et al. Increased factor Vil associated activities in Cushing's syndrome: a probable hypercoagulable state. Thromb Haemost. 1982;47:1 16-117. 10. Barwick DD. EMG in treated Cushing's syndrome with particular reference to the post-adrenalectomy syndrome. Electroencephalogr Clin Neurophysiol. 1968;25:41 1-41 1.
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11. Egdahl RH, Melby JC. Recurrent Cushing's disease and intermittent functional adrenal cortical insufficiency following subtotal adrenalectomy. Ann Surg. 1967;1 66:586-595. 12. Cohen KL, Noth RH, Pechinski T. Incidence of pituitary tumors following adrenalectomy: a long-term follow-up study of patients treated for Cushing's disease. Ann Intern Med. 1978; 1 38:575-579. 13. Nelson DH, Meakin JW, Thorn GW. ACTH producing pituitary tumors following adrenalectomy for Cushing's syndrome. Ann Intern Med. 1960;52:560. 14. Hardy JD. Surgical management of Cushing's syndrome with emphasis on adrenal autotransplantation. Ann Surg. 1978; 1 88:290-307. 15. Hoover EL, Weaver WL. Recent advances in the surgical management of pheochromocytomas. J Natl Med Assoc. 1989;81(7):777-779. 16. Huiras CM, Pehling GB, Caplan RH. Adrenal insufficiency after operative removal of apparently nonfunctioning adrenal adenomas. JAMA. 1989;261:894-898. 17. Mohler JL, Flueck JA, McRoberts JW. Adrenal insufficiency following unilateral adrenalectomy: a case report. J Urol. 1986; 1 35:554-556. 18. Gonzalez-Serva L, Glenn JF. Adrenal surgical techniques. Urol Clin North Am. 1977;4:327-336. 19. Russell CF, Hamberger B, van Heerden JA, et al. Adrenalectomy: anterior or posterior approach? Am J Surg. 1982; 1 44:322-324. 20. Brunicirdi FC, Rosman PM, Lesser KL, Andersen DK. Current status of adrenalectomy for Cushing's disease. Surgery. 1985;98:1 127-1134.
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