2. CASE REPORT
A 59-year-old male patient was referred to the Department of Otolaryngology and Head and Neck Surgery, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico of Milan, Italy due to a painful right facial swelling caused by a recurrent parotid abscess treated by means of multiple percutaneous drainages elsewhere. An ultrasonography (US) assessment of the region using a 7.5 MHz Hitachi H21 scanner (Hitachi High-Technology Corporation Ltd., Tokyo, Japan) identified a 7-mm parenchymal stone in the right parotid gland, and a Cone Beam Computed Tomography scan (CBCT - GE LightSpeed 64 Slice CT scanner, GE Medical Systems, Waukesha, WI) and a magnetic resonance imaging (MRI - Philips Gyroscan Intera, Eindhoven, The Netherlands) were used to confirm the location and size of the stone; imaging results prompted us to adopt a sialendoscopy-assisted transfacial removal of the stone. The patient was selected to priority surgery by our internal interdisciplinary medical board because of long-lasting infectious disease. The patient was asymptomatic for COVID-19 and 48 hours before surgery underwent two consecutive nasopharyngeal swabs to detect RNA of SARS-COV-2, both negative.
The procedure was done under general anaesthesia and an orotracheal tube was used. After disinfection with a povidone iodine solution, placement of sterile dressing over and around the head, leaving the mouth and the right side of the face and neck uncovered, the possible location of the stone was marked on the facial skin. Patient’s head and chest were enclosed in a chamber created with a transparent microscope cover (Galstar LTD, ) (Fig. 1a). Non-penetrating towel clamps were used to secure the plastic cover to the bed to keep the drape taught over the surgical field. Two fenestrations were created in the plastic drape to allow passage of instruments for either a transoral and external approach, respectively over patient’s mouth and parotid area (Fig. 1b-1c). These materials were readily available at our institution and are currently used by most otolaryngological surgeons performing ear and laryngeal surgery. After dilatation with lacrimal dilators (Karl Storz, Tuttlingen, Germany) of the opening orifice of Stensen’s duct performed through the opening in the plastic cover over the patient’s mouth, a sialendoscopic exploration of the duct system of the affected parotid gland by means of a semirigid sialendoscope (0.8 mm, Nahlieli sialoendoscope, Karl Storz Co., GmbH, Tuttlingen, Germany) was done. Once the surgeon could visualise the stone in a lower secondary parenchymal branch of the duct system, the high-powered light at the tip of the endoscope allowed to confirm the location of the stone as marked on the facial skin (Fig. 1d). Continuous aspiration of oral secretions through the small hole of the plastic transparent drap was done during the hole procedure to minimize aerosol dispersal. A skin flap was subsequently raised and the dissection continued involving the parotid fascia in order to expose the parotid gland in front of the stone and the proximal tract of Stensen’s duct, through the second opening in the plastic cover. During the blunt dissection, the buccal branch of the facial nerve close to the duct surgery was identified. A neurostimulator (Neuro-Pulse®, Bovie Medical Corporation, ) was used to check the functioning of the buccal branch and other possible branches of the VII cranial nerve met during dissection. The light at the tip of the endoscope allowed the exact position of the stone to be located, and a secondary parenchymal branch was incised over the stone (Fig. 2a) and parallel to its direction using a size 11 scalpel; after gentle dissection using dedicated instruments, the stone was grasped with forceps, and then removed (Fig. 2b). The duct was then irrigated with saline and an endoscopic search was done for any residual stones or debris. A net of hemostatic patch (Tabotam, Ethicon Sarl, ) was positioned over the incisional area to cover parotid tissue as previously described5 and preauricular incision was sutured. A compressive dressing and 48 hours without eating and drinking was prescribed; peri-operative antibiotic prophylaxis and one week of postoperative antibiotic therapy with amoxicillin plus clavulanic acid was given.
A 7-mm nonpalpable salivary stone embedded into the secondary parenchymal branch of the right Stensen duct was successfully removed using a sialendoscopy-assisted transfacial approach performed through STAPID; the presence of the drape did not interphere with the surgical procedure as well as the senior salivary surgeon (P.C.) did not find any particular discomfort compared to traditional surgery [5]. The surgical time was 85 minutes. The stone was completely removed, no residual debris remained in the duct system and no further surgery was required. No major or minor complication (i.e., facial nerve palsy, sialocele, salivary fistula, sialadenitis) occurred during or after the procedure; postoperative mild gland swelling resolved in a few days with the application of a pressure dressing. The patient was satisfied with its facial scar.