Treatment
Inclusion criterium for robotic transoral removal of submandibular stones is the presence of palpable stones >7 mm. Exclusion criteria include trismus (inability to open the mouth) and stones not palpable in the oral floor notwithstanding the external cervical finger pressure independently of size.
The procedure was performed under general anesthesia with a nasotracheal tube. The Flex Robotic system was docked behind the head of the patient. Two robotic instruments, a Maryland dissector and a monopolar cautery, were placed into arms of the robot. The Flex retractor was positioned to retract the tongue to the contralateral side and to flatten the oral floor. The robotic surgeon moved the Flex scope looking at three-dimensional High Definition (3D-HD) monitor through a controller on top of the Flex console. The assistant provided suction and external pressure over the submandibular gland. The stone was localized through transoral palpation and its projection marked on the mucosal surface of the oral floor (Figure 1b). A mucosal incision was performed along the marked line using the monopolar cautery of the robot. The proximal third of the Wharton’s duct was exposed till the hiloparenchymal area through a blunt dissection with Maryland dissector and the help of the assistant surgeon who moved it upward through external finger pressure. The lingual nerve was identified and mobilized from the duct and retracted medially. An incision over the stone was done with the monopolar cautery (Figure 1c); the stone was then dissected en bloc with the help of the spatula and the Maryland dissector and finally removed. The Flex Robotic system was moved away in order to complete the surgical procedure with a traditional transoral approach. Surgical cavity was irrigated with saline solution to clear any debris. A hemostatic and antimicrobial surgical net (Tabotamp, Johnson & Johnson Medical Limited, Gargrave, Skipton, UK) was positioned over the duct incision and the oral mucosa was closed with absorbable 3-0 vycril stitches. The stone was then measured in size and compared to the shape in the CT images. Antibiotic therapy (amoxicillin and clavulanic acid) was delivered as prophylaxis for five days after the operation.