Introduction

Difficult airway is a serious condition that is frequently encountered during general anesthesia and can be fatal. According to the analysis of Difficult Airway Society (DAS) 2016-2021 data, it was stated that 50% of difficult airway events were unexpected (1).

Tracheobronkopathy osteochondroplasty (TBO) is a disease characterized by the protrusion of submucosal nodules originating from bone and cartilage tissue in the tracheobronchial wall into the lumen. Nodules can cause stenosis and complete obstruction over time (2). It was first encountered in 1,875 by Wilks in the autopsy of a patient who died due to tuberculosis. Its etiology is unknown (3).

We aimed to present a patient with TBO, one of the rare causes of unpredictable difficult airway, who we detected in our clinic, in the light of the literature.

Case Report

A 45-year-old male patient was transferred to the operating room for laparoscopic cholecystectomy due to cholelithiasis. He had no additional disease in his medical history. The American Society of Anesthegiology score was evaluated as 1. There was no history of previous surgery. There were no findings on physical examination that would suggest a difficult airway. In preoperative evaluation, sternomental distance, thyromental distance and mouth opening, which were among the parameters we used to predict the possibility of a difficult airway, were evaluated as normal. Mallampati score 2 was calculated. Standard monitoring was applied to the patient (non-invasive blood pressure, SpO₂, ECG). After premedication was provided with 0.01 mg/kg iv midazolam, 1 mg/kg iv lidocaine, 2 mg/kg iv propofol and 1 mcg/kg iv fentanyl were administered for anesthesia induction. After effective ventilation was achieved with a mask, 0.6 mg/kg rocuronium was administered iv. Mask ventilation was continued for 2 minutes to ensure the muscle relaxant effect. It was detected as Cormack Lehane Class 1 on direct laryngoscopy. Orotracheal intubation was attempted with a size 8.0 endotracheal tube (ETT). After the vocal cords were passed, the ETT could not be pushed forward. Then, orotracheal intubation was tried by the specialist anesthesiologist with ETT numbers 7.0, 6.0 and 5.0, respectively. However, ETT could not be pushed forward again after passing the vocal cords. It was determined that the ETT could not be pushed forward due to resistance at the level just below the vocal cords. After mask ventilation with 100% oxygen for 3 minutes, the vocal cords were passed and the tracheal lumen was visualized using a 2.8 mm inner diameter and 3.7 mm outer diameter pediatric fiberoptic bronchoscopy. Diffuse nodular lesions protruding inward, narrowing the lumen, were observed on the tracheal wall (Figures 1, 2). Intubation attempts were not repeated to avoid complications such as edema and bleeding in the narrowed lumen. The patient was consulted to the thoracic surgery clinic during the procedure, and it was decided to wake him up to plan a rigid bronchoscopy at a later date under elective conditions. After 4 mg/kg sugammadex was administered iv to reverse the neuromuscular blockade, the patient, whose muscle activity fully returned, was transferred to the post-anesthesia care unit. The patient, whose SpO₂ level was around 90% and had intercostal retractions during follow-up, was administered 1 mg/kg iv prednisolone, inhaler bronchodilator and cold steam therapy to prevent edema in the airway and for bronchodilation. The patient, whose SpO₂ in room air was 100% and who had no respiratory distress, was transferred to the ward. The posterior anterior chest radiograph performed before the operation of the patient, who had no respiratory complaints in the preoperative evaluation, was re-evaluated. It was observed that the tracheal lumen was irregularly limited.

Rigid bronchoscopy performed electively revealed many hard papillamatous lesions starting just below the vocal cords and extending to the main bronchi. Lesions narrowing the lumen were excised. By pathological examination of the samples taken, the diagnosis of TBO was made. A cholecystectomy was planned one week after the diagnosis. After routine preoperative monitoring and standard anesthesia induction, intubation was attempted with a size 7 ETT. The patient, whose intubation was successful, was extubated without any problems after the operation and transferred to the ward.

Discussion

Tracheobronchopathia osteochondroplastica is a rare benign disease. Its etiology is unknown. It may be asymptomatic. Persistent dry cough, hemoptysis, shortness of breath, recurrent lower respiratory tract infection, atelectasis and difficult intubation may occur. The diagnosis of some patients can be made in the operating room due to difficult intubation (2,4). Patients with severe tracheal stenosis may require invasive airway intervention or may have fatal course (5,6). In patients with previously known TBO, the use of a laryngeal mask in the perioperative period may be an ideal option (5). Ishii et al. (5) presented a patient who was to undergo elective hepatectomy. They could not push forward the ETT after passing the vocal cords, just like us, and they woke the patient up, thinking that the lesions might be due to malignancy and could lead to bleeding. When the patient underwent surgery again after the diagnosis of TBO was made, they completed the surgery safely using a laryngeal mask when the tube could not be pushed forward (5). Our patient was not previously diagnosed as having TBO and we had no idea about the characteristics of the lesions. Therefore, we did not consider using a laryngeal mask. Since there was a risk of laryngeal edema and bleeding after repeated intubation attempts, we chose to wake our patient.

Warner et al. (4) could not push forward ETT during laryngoscopy in a patient who was to undergo elective prostatectomy, similar to our patient, and they preferred to wake the patient. In the postoperative period, they diagnosed TBO first with CT and then with bronchoscopy. They argued that bronchoscopy would be useful in the diagnosis of TBO and in relieving obstructive symptoms by excising the lesions (4). Based on this, we think that it is important to first visualize papillomas, which are the cause of unexpected difficult airway, using a fiberoptic bronchoscope under operating room conditions, and then to relieve airway access by excising the lesions with planned rigid bronchoscopy.

We would also like to draw attention to the importance of the posterior anterior chest radiography performed in the preoperative evaluation. In our patient, we noticed that the trachea was irregularly bordered by careful retrospective examination. A more careful examination in the preoperative period can prevent unexpected situations.

Unexpected difficult airway management in the operating room is important for anesthesiologists. According to the DAS algorithm, waking the patient from a planned operation is the safest way until the problem is detected (7). As a result of our patient’s comfortable mask ventilation, we provided adequate oxygenation and did not require invasive airway intervention. Additionally, since he was going to have an elective planned surgery, we woke our patient as indicated by DAS as safe.

As a result, although TBO is a rare disease, it may cause difficult intubation. Knowledge and experience regarding difficult airway management come to the fore, especially in patients encountered in operating room conditions. We think that our patient will contribute to unexpected difficult airway management.

Ethics

Informed Consent: The patient was asked to sign a voluntary consent form to parcipate in the case report study, stating that his identiy information would not be shared.

Peer-review: Externally peer reviewed.

Authorship Contributions

Surgical and Medical Practices: S.Y., O.C.A., Concept: S.Y., K.K., Design: A.Ş., S.Y., K.K., Data Collection or Processing: A.Ş., Analysis or Interpretation: A.Ş., S.Y., Literature Search: A.Ş., Writing: A.Ş.

Conflict of Interest: No conflict of interest was declared by the authors.

Financial Disclosure: The authors declared that this study received no financial support.