Haemorrhage Risk Reduction Using Endovascular Embolisation in Place of Vessel Ligation for Patients Undergoing Transoral Robotic Surgery (HELPR)

The incidence of squamous cell carcinoma of oropharynx has increased at an alarming rate attributed to human papillomavirus (HPV).The prognosis of patients with HPV-associated oropharyngeal cancer is significantly improved, and as such, consideration of functional outcomes has become increasingly important. Transoral robotic surgery (TORS) has been shown to offer excellent oncological outcomes and low incidence of positive margins with promising functional outcome at multiple subsites of the head and neck. Like many oropharyngeal surgeries, bleeding is the most common complication after TORS. Postoperative oropharyngeal haemorrhage, particularly when severe, can lead to airway compromise, aspiration, asphyxiation, and cardiopulmonary arrest. Its incidence has been variable in literature, with rates ranging from 3.1% to 13.1%. It is an area of current interest because of the increasing adoption of TORS and the active recruitment to current multi-centre randomized controlled trials, such as ECOG 3311 (NCT01898494) and PATHOS. Ligation of the individual feeding vessels from the external carotid artery (e.g. ascending pharyngeal, lingual and facial branches) has shown to limit the risk of postoperative haemorrhage and is highly recommended. This is usually done when concomitant neck dissection is carried out with transoral resection. However, in the absence of any nodal disease, for instance in salvage TORS for recurrent oropharyngeal cancer, the neck is surgically explored for the sole purpose of tying the vessel. This is particularly more difficult surgically and carries a higher risk of failure in patients who had exposure to prior radiation where healing can be dramatically delayed. Embolisation, first described in 1974, is now a well-recognised treatment for refractory epistaxis and an effective measure to reduce intraoperative bleeding for vascular tumours of the head and neck. The latter is often carried out from 24 to 72 hours prior to the surgical resection to allow time for maximal thrombosis of the occluded vessels and prevent recanalization of the occluded arteries or formation of collateral arterial channels. This procedure has been proven to be minimally invasive, safe and effective in controlling haemorrhage even in cases of acute carotid blowout syndrome. The targeted vessels for embolisation are also branches of the external carotid artery, of similar calibre and size to the feeding vessels which are ligated in TORS. Although endovascular embolisation of branches of external carotid artery has not been carried out for the purpose of TORS in the past, it has been highly successful in controlling of bleeding in the case of benign vascular tumours of head and head. The investigators propose that this standard endovascular embolisation can also be applied to patient undergoing TORS who do not require neck dissection. The investigators believe that this is a feasible, safe and acceptable intervention and a plausible alternative to conventional open neck vessel ligation.