RESULTS
Fifteen patients with no clinical evidence of COVID-19 underwent operations for head and neck cancer: 3 patients with metastatic squamous cell carcinoma of unknown primary underwent examination under anaesthesia, transoral robotic (TORS) tonsillectomy and tongue base mucosectomy and modified radical neck dissection; 2 patients underwent radical tonsillectomy, modified radical neck dissection, free anterolateral thigh flap reconstruction and tracheostomy for tonsillar carcinoma; 2 patients with carcinoma of the tongue underwent glossectomy and selective neck dissection followed by free anterolateral thigh flap reconstruction and tracheostomy; 1 patient underwent total laryngectomy for recurrent carcinoma of larynx; 3 patients with recurrent pharyngo-esophageal carcinoma underwent total laryngectomy (n=3), circumferential pharyngectomy (n=3) and cervico-esophagectomy after manubrial resection (n=1), followed by reconstruction with free jejunal flap (n=3); 3 patients with recurrent nasopharyngeal carcinoma underwent tracheostomy followed by maxillary swing nasopharyngectomy, 1 patient required selective neck dissection and free vastus lateralis flap coverage of exposed internal carotid artery; 1 patient with carcinoma of maxilla underwent tracheostomy, total maxillectomy, selective neck dissection and free anterolateral thigh flap reconstruction. (Table 1)
There were a total of 45 procedures of which 26 involved mucosa along the upper aerodigestive tract. There were 12 procedures which involved manipulation of the airway including temporary tracheostomy (n=8) and laryngectomy (n=4). Operating surgeon and scrub nurse were involved in all surgical procedures (n=45). First assistant was involved in all but tracheostomy operations (n=37). Second assistant was not involved in TORS, tracheostomy and free flap harvest procedures (n=25). Overall droplet size ranged from 0.3mm to 3.0 mm. Percentage of procedures with droplet contamination was 57.8% for the operating surgeon (n=26), 59.5% for the first assistant (n=22) and 8.0% for the second assistant (n=2). No droplets were noted on all face shields of the scrub nurse (n=45).
Average droplet count was highest for procedures involving osteotomies such as maxillectomy (n=1), maxillary swing (n=3) and manubrial resection (n=1). Droplet spread was more widespread (zones 2-12) for maxillectomy procedures (n=4), involving face shields of the operating, first and second assistant surgeons.
Non-osteotomy surgical procedures involving mucosa of the nasopharynx (n=3), oropharynx (n=5), oral cavity (n=2), laryngo-pharyngeal apparatus (n=4), and trachea (n=8) yielded minimal droplet count on face shields of the operating surgeon and first assistant, affecting zones 6-11 which were over the lower half of the face. There was one droplet splash at zone 2 of the first assistant during nasopharyngectomy, corresponding to upper half of the face. No droplet splash was noted on the second assistant’s face shield. No droplet splash was documented on face shields of the operating surgeon and first assistant for TORS.
Average droplet count from non-mucosal, non-osteotomy related surgical procedures such as neck dissection (n=9) and free flap harvest (n=9) was minimal on both the operating surgeon’s and first assistant’s face shields, mainly affecting zones 6, 7, 10 and 11 which were concentrated on the lower half of the face. One drop was noted in zone 6 of the second assistant’s face shield during modified radical neck dissection.