Introduction

A variety of maxilla-mandibular surgeries require the surgeon to check dental occlusion, which is precluded by orotracheal intubation. Hence, nasotracheal intubation is done routinely in these circumstances. But nasotracheal intubation is contraindicated in few situations: suspected epiglottitis, midface instability (Lefort fractures), coagulopathy, etc., to name a few. Previous surgical corrective surgery for the treatment of cerebrospinal fluid rhinorrhea is one such contraindication for nasotracheal intubation. Conventional tracheostomy has many inherent complications. With the knowledge of submental endotracheal intubation most of the complications of tracheostomy can be avoided.

Case report

A 22-year-old male was posted for mandibular advancement procedure to treat obstructive sleep apnea and for cosmetic results to treat severe hypognathism. The maxillofacial surgeon made a specific request to avoid orotracheal intubation, since he needed to check dental occlusion intraoperatively. During her preanesthesia clinic visit we discovered that she had a surgery previously to treat cerebrospinal fluid rhinorrhea, rendering option of nasotracheal intubation very risky. When we discussed the option of awake nasotracheal intubation, patient refused firmly. Though tracheostomy was discussed, we opted for submental intubation over tracheostomy to avoid complications of tracheostomy.

After ensuring adequate fasting, preoxygenation with 100% O2 given for 3 minutes. Glycopyrolate 0.2 mg given intravenously to ensure dry field of airway. Induction and maintenance of anesthesia was achieved with propofol TCI 3-4 mcg/mL and remifentanyl TCI 5 ng/mL, effect site concentrations, using Bispectral Index monitoring of depth anaesthesia. After confirmation of ability to mask ventilate, atracurium 0.6 mg/kg was injected. We used C-MAC laryngoscope, D blade to visualize and intubate with 38G flexometallic tube. Despite using videolaryngoscope, we still ended up using bougie to railroad the ETT over it, since the larynx was quite anterior. Throat packing was done. Now 3 cm incision was made in the right submental region by the surgeon. It was extended intraorally. Endotracheal tube disconnected from the circuit, connector was removed. The pilot balloon was grasped by the artery forceps and was pulled out gently, taking care not to damage it. Now by pulling the pilot tube, while stabilizing the tracheal end of ETT by Magill’s forceps, proximal end of ETT was removed out. Connector and circuit were attached and breathing resumed. ETT was fixed with sutures around it.

Throat packing was done to provide extra margin of safety against aspiration of blood. Surgery went uneventfully for a duration of 5 hours. After the end of surgery, submental intubation was converted to oral by pulling the pilot tube into oral cavity and submental wound was closed. After confirmation of extubation criteria, patient was extubated.

Figure 1

Orotracheal intubation.

Figure 2

Orotracheal intubation converted to submental intubation.

Discussion

Description of submental intubation dates back to 1986 by Altemir, a maxillofacial surgeon.[1] This technique offers a secure airway to the anaesthesiologist, optimal operating field, opportunity to check dental occlusion to the surgeon and less morbidity to the patient. This technique was appreciated, well deservedly, by all the team members.

Nasotracheal intubation is contraindicated in unstable maxillofacial fractures, previous surgeries on cribriform plate, bleeding diathesis etc. [2-4]

Tracheostomy, an alternative plan, has built in complications like severe hemorrhage, damage to neurovascular structures, pneumothorax, subcutaneous emphysema, tracheal stenosis, tracheomalacia, cosmetic disfigurement etc. [5]

Submental intubation though has few complications like infection, orocutaneous fistula, can at times be challenging if attention is not paid to proper section of tube. [6] Connector should be loose enough to facilitate easy disconnection, yet tight enough to prevent accidental disconnection or gas leak.

Amin et al describes the use of capnography during the process of converting orotracheal to submental and also throughout the surgery, to confirm the position of tube and serve a warning tool against accidental extubation. Our experience also matches the author’s opinion. [7]

Drolet et al described the use of tracheal tube exchanger in case of limited mouth opening. But the associated complications were thought to be too high and is not used in our hospital. [8]

MacInnis et al described the use of midline incision to avaoid excessive bleeding, we adopted classical paramedian approach to prevent injury to delicate structures. [9]

Contraindications to submental intubation are infection at the site of incision, mandibular symphysis fracture, inability to open mouth etc., which we ruled out before hand, during preanesthesia visit.

The list of procedures, where submental intubation can be used safely where orotracheal or nasotracheal tube hinders surgical access are innumerable, like oral surgery in patients with nasal obstruction, plastic surgery for cleft lip correction, rhinoplasty etc. [10]

Altemir et al described the use of laryngeal mask airway via submental approach, in conditions where endotracheal tube has to be avoided, or simply is not desired. [11]

We conclude that the knowledge of submental intubation enables the anaesthesiologist and the surgeon to deliver better quality of patient care if used in appropriate cases.