2 MATERIALS AND METHODS
2.1 Participants
We analyzed the incidence of infection to healthcare workers and clinical characteristics of patients with COVID-19 who underwent a tracheotomy from April 2020 to August 2021. We have performed hybrid modified percutaneous dilatational tracheotomy in 20 patients with COVID-19. The patients’ preoperative physical condition was evaluated using Charlson Comorbidity Index Score (CCIS) and Acute Physiology and Chronic Health Evaluation II (APACHE II) Score. Mean time from intubation to the tracheostomy and decannulation, survival rate, operation time, and complications for tracheostomy were measured.
2.2 Ethical considerations
This study was approved by the Institutional Ethics and Research Committee of our institution (No. 2021-05-008) and performed in accordance with the Declaration of Helsinki and good clinical practice guidelines. All participants provided written informed consent
2.3 Surgical technique
At our institute, tracheostomy is performed in a negative pressure intensive care unit at a pressure -2.5 Pa by a tracheostomy team consisting of three individuals, that is, a surgeon (otolaryngologist), a first assistant (2nd or 3rd -year residents in the otolaryngology residency program), and a nurse (Figure 1). All members of the team wear level D protective clothing and powered air-purifying respirator (PAPR) equipment. Hybrid MPDT was devised to minimize the risk of SARS-CoV-2 transmission during and immediately after tracheostomy. The hybrid MPDT technique means a combination of conventional surgical tracheostomy and modified PDT. Initially, a small skin incision and minimal dissection are performed to access the trachea as for conventional tracheostomy, and then modified PDT is done using four instruments in the Ciaglia Blue Rhino Percutaneous Dilatational Tracheostomy KitⓇ(Cook Critical Care, Bloomington, IN, USA). In detail, hybrid MPDT requires an initial horizontal minimum skin incision of < 1 cm in the neck, like conventional open surgical tracheotomy. Briefly, the trachea is exposed by making a vertical incision at the fascia center, and then the 2nd or 3rd tracheal cartilage is exposed. Using a cold knife, a 5 mm long incision is placed in tracheal membrane without tracheal cartilage resection, and then a hole (the tracheal window) is opened slightly with a mosquito forceps and the position of the endotracheal tube (ETT) is checked (Figure 2A). The location of the ETT tip is confirmed through the tracheal window by naked eye without using a bronchoscope. When the tip of ETT was not visible while slowly withdrawing the ETT, the ETT balloon was inflated to fix its position. A gradual dilator is inserted into the tracheal window (Figure 2B), and a guide wire is inserted along the dilator (Figure 2C). The dilator is then removed, and the guide wire left in place (Figure 2D). The tracheal window is then expanded using a 36Fr dilator (Figure 2E), and the tracheostomy tube is inserted along the guide wire, which is then removed (Figure 2F).