Fluroscopic assisted airway intubation in temporomandibular joint ankylosis: A novel technique.

Airway management is considered one of the most difficult and challenging procedures among the various anesthetic procedures. It becomes tougher when there is a diseased temporomandibular joint (TMJ) due to inadequate mouth opening. In the current scenario there are only a few methods that ensure a safe, uneventful intubation in a TMJ ankylosis patient with a difficult airway. These include techniques ranging from minimally invasive techniques like blind nasal intubation, retrograde intubation using a guide wire, the latest technique of intubating with the help of a fiberoptic laryngoscope and the time tested tracheostomy. All these techniques have got their own disadvantages. So we report a case series of five patients with TMJ ankylosis who underwent fluoroscopic-assisted intubation for airway management. We found that this technique is 100% successful in managing the airway in these patients. To the best of our knowledge, this is the first case series detailing this novel technique in the entire English medical literature.

INTRODUCTION

Airway management in patients with temporomandibular joint (TMJ) ankylosis is an ever challenging situation in spite of a much focused effort for more than a century. Throughout its course of development the technique has evolved from blind nasal intubation, retrograde intubation using a guide wire, intubating with the help of a fibreoptic laryngoscope, and the time tested tracheostomy.

There is a massive reluctance among the number of physicians in performing who are trained to perform these procedures. According to Reier et al., “There is reason to believe that the number of physicians trained and willing to perform these procedures in emergencies is dwindling in large teaching institutions and unavailable in most other venues”.[1] The reasons could be varied in nature from physician related to instrument related like unavailability of fiberoptic laryngoscope. This made authors to think of an innovative and cost-effective solution for this daunting task. We made use of the C-arm available in every theatre for guiding the tube into the trachea. We report a case series of five patients with TMJ ankylosis in which we found our technique was one hundred percent successful.

CASE REPORT

An 18-year-old female patient (48 kg, 150 cm, ASA physical status I) was admitted to the hospital for release of bilateral fibrous ankylosis of TMJ. Examination of the airway revealed <15 mm mouth opening with a minimal gap between the overriding incisors, no movements at both the TMJs, severe retrognathia, and micrognathia [Figure 1]. Both nares were patent and the neck mobility was normal. Lateral neck radiograph demonstrated a minimal inter-incisor gap, severe retrognathia, submandibular tongue and epiglotic shadow, and long air shadow of extended oropharynx in direct alignment with the esophagus. There was no history of hoarseness of voice, breathlessness, difficulty in swallowing, or frequent sleep awakenings at night. Among the other four cases, three were of bilateral congenital ankylosis and one was unilateral post-infectious ankylosis and mouth opening was <15 mm. In view of non-availability of a fiberoptic bronchoscope and reluctance for tracheostomy, tracheal intubation with fluoroscopic-assisted technique was planned. After explanation of the procedure, an informed consent was obtained from the patient.

Figure 1

Lateral photograph of the patient showing maximum mouth opening and severe retrognathia and micrognathia

Preoperatively, the patient was prepared with aspiration prophylaxis, nasal decongestants, and IM glycopyrrolate. Patient was positioned supine in a C-arm compatible operating table and both AP and lateral views were taken to confirm the tracheal air shadow. Routine monitoring was applied and 4% topical lidocaine was given as nebulization for 4 min followed by intravenous midazolam 2 mg. Lidocaine 2% topical jelly was used as a lubricant in introducing the tube. Cuffed nasotracheal tube of size 6 mm (PORTEX) was gradually introduced through the right nare and advanced into the hypopharynx. We now follow a two step-maneurving technique to guide the tube into the larynx. Firstly, using the radioopaque line of the nasotracheal tube centralize the tube in relation to the air shadow of oropharynx by doing a sidewards tilt of the neck. This is performed by taking AP projection using C-arm. After the midline correction the next step starts by taking a lateral view and further steps are taken with respect to the lateral view. Two options can arise at this juncture, i.e. distal end of the tube being anteriorly placed in relation to the air shadow of larynx, then we have to flex the neck by placing four fingers beneath the occiput and thumb at the forehead thereby we can guide the tube into the larynx. If the tube is posteriorly directed, i.e. pointing into the esophagus which is the most common scenario we face as these patients have an anterior larynx [Figure 2], using the same grip extend the neck at cervical region the tube is maneuvered in to the larynx and a gush of air is felt at the opening of the tube which confirms the entry into the larynx [Figure 3]. Finally, tube is properly positioned and confirmed by C-arm. The cuff is inflated and the airway is secured. Then release and arthrolysis of TMJ were undertaken successfully. There were no post-operative complications pertaining to the airway management.

Figure 2

Fluroscopic image showing how tube is maneuvered into trachea by extending the neck

Figure 3

Fluroscopic image showing final tube position in the larynx

All the five patients were managed with the same technique. We found that this technique was 100% successful in all the five patients.

DISCUSSION

In the current scenario there are only a few, methods that ensure a safe, uneventful intubation in a TMJ ankylosis patient with a difficult airway. The technique of retrograde intubation was originally described in 1960.[2] There has been several modifications in this technique throughout these years.[34] Fluroscopy is used to assist in placing the guide wire in retrograde technique especially in patients with difficult mouth opening.[5] Use of fibreoptic laryngoscope may be the method of choice in difficult airway. In the presence of bleeding this may also end up in failure.[6] In many centers the scope may not be available. Alternative options will be necessary in such situations. In TMJ ankylosis the technique of blind nasal intubation was traditionally recommended.[7] It can fail and repeated attempts may injure the involved structures resulting in complications like bleeding airway obstruction etc. To the best of our knowledge this is the first reported novel case series in the English medical literature.

Our patient presented with bilateral fibrous ankylosis of the TMJ with no mouth opening, most importantly, severe retrognathia that resulted in submandibular tongue leading to an extended oropharynx and an anterior larynx. Since the technique involves awake intubation we were able to assess the positioning of the tube from fluoroscopic image and the gush of air at the opening of the tube as well. It is noteworthy that instruments of support required to manage a difficult airway like fiberoptic laryngoscope, retrograde intubation instruments are unavailable in a rural setting, whereas C-arm fluoroscopy is becoming universally available in hospitals thereby making this technique more and more feasible.

CONCLUSION

To conclude among the different techniques available in difficult airway management our technique is an efficient and foolproof technique as it does not require mouth opening, and tube position is confirmed by C-arm. It offers definitive advantage over the other techniques. However there is always further scope of improvement in the technique and it is necessary to conduct the study in a larger cases series.