Endocrine Abstracts

Introduction: Pheochromocytoma and paraganglioma (PPGLs) are rare neuroendocrine tumors. Some of them are catecholamine-secreting tumors responsible for hypertension or adrenergic symptoms. Among 10% are malignant with a higher rate of malignancy in the inherited syndromes. Management of patients with hereditary pheochromocytoma and PPGLs is well defined and standard treatment is surgical resection.

Case report: We report the case of a 53-year-old man who had been discovered a SDHB gene mutation (c.594C>A) through a familial genetic screening. An interaortocaval mass of 8mm corresponding to a non-secreting PPGL was highlighted by [18F]-fluorodeoxyglucose PET and ⁶⁸Ga-DOTATATE. Tumor did not appear on ²³I-metaiodobenzylguanidine (mIBG) scintigraphy. After two years follow-up, tumor was growing from 8mm to 12 mm and patient decided to undergo surgical resection. In order to reduce surgical morbidity, robotic-assisted interaortocaval dissection of the PPGL in supine position via a trans-peritoneal approach was proposed. Surgical method: Under general anesthesia, the patient was placed in a supine position. An 8 mm robotic optic port was positioned below the umbilicus, at the level of the right umbilical ligament. Three operative 8 mm port were positioned then in a linear configuration, along with an assistant 12 mm port in the right iliac fossa. The DaVinci Xi robot was docked and directed cephalad. The dissection began by mobilization of the caecum and incision of the posterior peritoneum overlying the right common iliac artery, in order to expose the inferior vena cava and the aorta. The dissection was then advanced cranially, taking care to ligate any perforating vessel, until the renal bifurcation was encountered. The mass was identified in the inter aortocaval region and fully dissected. The operative time was 130 minutes and estimated blood loss was <50 ml. No drain was positioned and no opioid analgesics were required in the post-operative setting. The patient was discharged on POD 1. Final pathology revealed a sympathetic extra-adrenal paraganglioma, 20×13×10 mm and negative margins: pT1R0.

Conclusion: Robotic-assisted interaortocaval dissection is safe and feasible with great reduction of surgical morbidity and minimal blood loss. This approach can be efficiently be implemented to address tumors or malignant lymph node pathology of this surgical region. Large prospective studies are required to define the role of robotic assisted surgery in the field of retroperitoneal neuroendocrine tumors.