Reoperation for Growth-Hormone Secreting Pituitary Adenomas: Endonasal Endoscopic Series and Systematic Review of the Literature

Introduction: Surgery is generally the first line therapy for acromegaly. For patients who fail surgery with residual or recurrent tumors, several treatment options exist including repeat surgery, medical therapy and radiation. The results of reoperation for recurrent acromegaly have been mediocre. We wished to review our experience using extended endonasal approach (EEA) for recurrent acromegaly and compare it to the existing literature.

Methods: A database of all patients treated in our center between July 2004 and February 2016 was reviewed. Patients with acromegaly secondary to GH-secreting adenomas who underwent EEA were selected for chart review and divided in two groups: first-time surgery and reoperation. Cure was defined by 2010 guidelines. Clinical, radiological and outcomes characteristics were extracted. The systematic review was done through a MEDLINE database search (2000–2016) to identify studies on the surgical treatment of acromegaly. Using PRISMA guidelines, the included studies were reviewed for surgical approach, tumor size, cavernous sinus invasion, disease control and complications. Patients were divided into reoperation or first-time surgery for comparative analysis.

Results: 44 patients were included in the study, of which 11 (25%) were reoperations. Reoperated tumors had a mean size of 14.8 mm (±10.0) with 5 micro- and 6 macroadenomas. Patients in the reoperation group were younger (34.3 ± 12.8 versus 49.1 ± 15.7, p = 0.007) and had lower preoperative GH levels (25.6 ± 36.8 versus 7.7 (± 13.1), p = 0.04) than first-time surgery patients. Disease control in the reoperation (8/11 (72.7%) and first-time surgery (25/33 (75.5%) groups was similar. Age, size, preop GH and IGF-1 levels and cavernous sinus invasion were significantly negatively related with disease control in the first-time surgery group while only cavernous sinus invasion had a trend in the reoperation group (p = 0.061). There was one case (9%) of transient diabetes insipidus and hypogonadism and one (9%) postoperative nasal infection after reoperation. The systematic review retrieved 33 papers with 172 reoperation and 2,189 first-time surgery cases. Overall disease control for reoperation compared with first operation was 45.9%, versus 57.5% (p = 0.003). Reoperation and first-time surgery had similar control rates for microadenomas (77.7% versus 76.4%, respectively; p = 0.98), however reoperation had lower control rates for tumors invading the cavernous sinus (10/52, 19.2%, vs. 121/328, 36.8%, p = 0.01).

Conclusion: Reoperative EEA for acromegaly had similar results to first-time surgery and was better than historical rates of control for macroadenomas. Cavernous sinus invasion continues to be a negative prognosticator for cure, however, results with EEA are improving compared with the prior literature.

No conflict of interest has been declared by the author(s).