Endocrine Surgery
Tracy S. Wang
MD, MPH, FACS
Assistant Professor
Department of Surgery
9200 W. Wisconsin Avenue
Milwaukee, WI 53226
Office: (414) 805-5755
Fax: (414) 805-5771
Key words: Endocrine surgery, thyroid, parathyroid, adrenal,
fellowship training
Abstract: The increasing complexity in the management of surgical
disorders of the thyroid, parathyroid, adrenal glands, and neuroendocrine
pancreas tumors have led to the emergence of endocrine surgery as a surgical
subspecialty. Studies demonstrating the relationship between
hospital/surgeon volume and patient outcomes highlight the importance of
advanced postgraduate training in this field.
The discipline of endocrine surgery encompasses the surgical management of disorders of the thyroid, parathyroid, and adrenal glands and neuroendocrine tumors of the pancreas and gastrointestinal tract. The management of patients with surgical endocrine disease is intellectually stimulating and often complex, requiring a multidisciplinary team of endocrinologists, radiologists, pathologists, and surgeons. Over the past several decades, as the incidence of surgical endocrine disorders has increased, endocrine surgery has emerged as a recognized specialty within the discipline of general surgery.
The increasing incidence of diseases of the thyroid, parathyroid, and adrenal glands is likely a combination of improved radiographic imaging and diagnostic techniques as well as a true increase in the incidence of disease.[1,2] Primary hyperparathyroidism affects 1 in 500 women and 1 in 2,000 men >40 years, with an incidence of 100,000 new cases each year.[3] Palpable thyroid nodules are present in 4%-7% of American adults and thyroid cancer, with an estimated 37,000 new cases in 2007, accounts for 1.5% of all new cancers in the United States.[4,5] Incidental adrenal nodules have been reported in up 4% of abdominal CT scans and up to 32% of autopsy studies.[6,7]
There also have been advances in the understanding of the pathophysiology and genetic basis for surgical endocrine diseases. As diagnostic modalities and radiographic imaging techniques have improved, the preoperative, intraoperative and postoperative management of patients has become more refined and increasingly intricate, involving multimodality preoperative imaging, minimally invasive procedures, intraoperative parathyroid hormone monitoring, radioguided parathyroid surgery, laparoscopy, video-assisted surgery, and, more recently, robotic surgery. Despite this growing complexity in surgical technique, studies have demonstrated that across the United States, the majority of endocrine procedures (thyroidectomy, parathyroidectomy, and adrenalectomy) are performed by surgeons whose practice is not focused on endocrine surgery. Saunders et al. analyzed data from the National Inpatient Sample between 1988 and 2000 and found that surgeons whose practice was made up of <25% of endocrine procedures performed 82% of all thyroidectomies, 78% of parathyroidectomies, and 94% of adrenalectomies. Surgeons with >76% endocrine practices made up only 1% of all surgeons performing thyroidectomy, parathyroidectomy, and adrenalectomy.[8]
One possible explanation for these findings is that graduating general surgery chief residents have a highly variable experience in endocrine procedures, with the majority having minimal exposure to endocrine surgery. In a review of data from the Residency Review Committee, Harness et al. have shown that most residents have inadequate experience in thyroid, parathyroid, and adrenal surgery. The most common number of thyroidectomies performed ranged from 7-10 per graduating resident; this decreased to a common number 2 parathyroidectomies and zero adrenalectomies or neuroendocrine pancreatectomies.[9,10] Sosa et al. found that graduating chief residents performed just 11% of the average experience of endocrine surgery fellows.[11]
Yet surgical volume has been shown to be associated with improved patient outcomes. Birkmeyer et al. found that higher hospital volume was linked to decreased mortality for 14 cardiovascular and oncologic procedures.[12] Surgeon volume also is associated with improved outcomes; based on Maryland data, surgeons performing ≥100 thyroidectomies had the fewest complications, with no association observed between hospital volume and outcomes.[13] High surgeon volume has also been linked to improved outcomes in children and in elderly patients undergoing thyroidectomy and parathyroidectomy.[14,15]
For all of the above reasons, advanced postgraduate training in endocrine surgery for general surgery residents seeking to develop expertise in the management of surgical endocrine diseases is essential.
Fellowship training in Endocrine Surgery
Endocrine Surgery fellowships are sponsored by the American Association of Endocrine Surgeons (AAES). In response to the growing need for advanced postgraduate training and the emergence of Endocrine Surgery fellowships at several high-volume centers, the Education and Research Committee of the AAES developed a formal Fellowship curriculum, which was ratified by the AAES Executive Council in 2005. The curriculum was designed to ensure similar high-quality training across different institutions; overall objectives are to:
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Demonstrate knowledge and understanding of endocrine gland anatomy and physiology, both the normal and pathological states.
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Demonstrate the ability to diagnose clinical endocrinopathies associated with endocrine surgical diseases.
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Develop knowledge of the inherited endocrine disorders and understand the role of genetic counseling and testing.
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Have an appreciation of the current controversies and current areas of research in the literature within endocrine surgical diseases.
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Demonstrate the ability to apply this knowledge and safely perform the appropriate surgical operation for a given endocrine surgical disease.
A formal curriculum has also been created for general surgery residents.
At present, there are no Board examinations for graduating fellows. There are currently 19 clinical fellowships in the United States, the majority of which are one year in length. Fellowship programs participate in the AAES match program. The application process should begin one academic year prior to the anticipated date of entry to the fellowship. Further information on the fellowship, including a list of programs and requirements, can be found at the AAES Website (http://www.endocrinesurgery.org/fellowships/fellowships.htm).
Membership in SocietiesThe American Association of Endocrine Surgeons (AAES) is the premier organization for this specialty. Established in 1980, its mission is the "advancement of the science and art of endocrine surgery and maintenance of high standards in the practice of endocrine surgery." Active membership is limited to surgeons who are Fellows of the American College of Surgeons (ACS) or its international equivalent and who have a major interest and devote "significant portions" of his/her practice or research to endocrine surgery. Active members must be certified by the American Board of Surgery or its equivalent in Canada, Central, or South America and have attended at least one prior meeting of the AAES. Surgeons who have completed their surgical training and awaiting qualifications to become an Active member may apply for Candidate membership in the AAES; a letter of sponsorship from an Active of Senior AAES member is required. Resident/Fellow membership is limited to those in a residency, research, or clinical fellowship training program.
The AAES annual meeting is held each spring. The AAES encourages the submission of abstracts by residents and fellows for the annual meeting; prizes are awarded to the best resident/fellow papers in both clinical and basic science research. Prizes are also awarded for the Poster Competition and Interesting Case sessions. More information on the AAES can be found at www.endocrinesurgery.org.
Other surgical organizations of interest include the Society of Surgical Oncology, International Association of Endocrine Surgeons, Australian Endocrine Surgeons, British Association of Endocrine and Thyroid Surgeons, Asian Association of Endocrine Surgeons, and the American Society for Head and Neck Surgery. Non-surgical societies include the American Association of Clinical Endocrinologists, American Society of Clinical Oncology, the Endocrine Society, and the American Thyroid Association.
References
1. Chen, AY, Jemal, A, Ward, EM. Increasing
incidence of differentiated thyroid cancer in the United States, 1988 -
2005. Cancer 2009; 115:3801.
2. Davies L, Welch HG. Increasing incidence of thyroid cancer in the United
States, 1973-2002. JAMA. 2006;295:2164-2167.
3. Lal G, Clark OH. Diagnosis of primary hyperparathyroidism and indications for parathyroidectomy. In: Clark OH, Duh QY, Kebebew E, editors: Textbook of Endocrine Surgery. 2nd edition. Philadelphia: Elsevier Saunders; 2005. p. 384-392.
4. Hegedus L. The thyroid nodule. N Engl J Med 2004; 351:1764-1771.
5. Jemal, A, Siegel, R, Ward, EM, et al. Cancer statistics 2008. CA Cancer J Clin 2008; 58:71.
6. Kloos RT, Gross MD, Francis IR, Korobkin
M, Shapiro B. Incidentally discovered adrenal masses. Endocr Rev
1995;16:460-84.
7. Bovio S, Cataldi A, Reimondo G, et al. Prevalence of adrenal
incidentaloma in a contemporary computerized tomography series. J
Endocrinol Invest 2006;29:298-302.
8. Saunders BD, Wainess RM, Dimick JB, Doherty GM, Upchurch GR, Gauger PG.
Who performs endocrine operations in the United States? Surgery 2003;
134:924-931.
9. Harness JK, Organ CH, Thompson NW. Operative experience of U.S. general
surgery residents with diseases of the adrenal glands, endocrine pancreas,
and other less common endocrine organs. World J Surg 1996;
20:885-891.
10. Harness JK, Organ CH, Thompson NW. Operative experience of U.S. general
surgery residents in thyroid and parathyroid disease. Surgery 1995;
118:1063-1070.
11. Sosa JA, Wang TS, Yeo HL, Mehta PJ,
Boudourakis L, Udelsman R, Roman SA. The maturation of a specialty:
Workforce projections for endocrine surgery. Surgery 2007;142:876-83.
12. Birkmeyer JD, Siewers AE, Finlayson EV, Stukel TA, Lucas FL, Batista I,
et al. Hospital volume and surgical mortality in the United States. N
Engl J Med 2002;346:1128-1137.
13. Sosa JA, Bowman HM, Tielsch HM, Powe NR, Gordon TA, Udelsman R. The
importance of surgeon experience of clinical and economic outcomes from
thyroidectomy. Ann Surg 1998;228:320-330.
14. Sosa JA, Tuggle CT, Wang TS, Boudourakis L, Thomas DC, Rivkees S, Roman
SA. Clinical and Economic Outcomes of Thyroid and Parathyroid Surgery in
Children. J Clin Endocrinol Metab 2008; 93:3058-3065.
15. Tuggle CT, Roman SA, Wang TS, Boudourakis L, Thomas DC, Udelsman R, Sosa
JA. Pediatric endocrine surgery: Who is operating on our children?
Surgery 2008; 144:869-877.