Robotic excision of parapharyngeal and retropharyngeal lesions.

Introduction: Robotic surgery is currently transforming Head and Neck cancer surgery by providing novel approaches to previously challenging procedures, with a wide range of benefits including reduced morbidity and length of stay for patients. Currently at Guy's and St. Thomas' hospital, extended applications are constantly being evaluated to advance the scope of robotic surgery further, which includes using it for parapharyngeal (PPS) and retropharyngeal space (RPS) tumours. Literature suggests over 50% of PPS tumours are pleomorphic adenomas, whereas RPS tumours often represent nodal metastasis or soft tissue inflammatory masses(4,9). We have collated a case series of fifteen patients who had either PPS or RPS tumours excised via robotic surgery.

Methods: A prospective study of fifteen patients collected between October 2018 and August 2024 with retrospective swallow assessment, for all patients with a mass in the PPS or RPS treated by trans-oral robotic surgery. Excision was performed by the Intuitive da Vinci Xi robotic surgical system.

Results: The average age was 51 yrs (10 males, 5 females), with an average radiological tumour diameter of 3.79 cm and volume of 35.48 cm³. 33% of PPS cases were pleomorphic adenoma, whilst 33% of cases were malignant (carcinoma ex-pleomorphic adenoma). There was no surgical capsular breach, with complete excision in all cases and no cases required conversion to open. Close margins were seen in 40%. Median length of stay was 2 days with patients starting oral diet on day 1 post operation, however three patients later required NG-tube insertion due to wound dehiscence. There have been no recurrences with mean follow up currently at 3.32 years.

Conclusions: TORS provides a safe and feasible option for excision of both PPS and RPS tumours, with no sacrifice of surgical or oncological outcomes. Given the successful results, further adoption of TORS for PPS and RPS tumours is recommended. Careful patient selection and specialist radiological input to aid three-dimensional anatomical understanding are fundamental to these outcomes.