Three-dimensional Printing as an Aid to Airway Evaluation After Tracheotomy in a Patient With Laryngeal Carcinoma

Bin Han; Yajie Liu; Xiaoqing Zhang; Jun Wang

Disclosures

BMC Anesthesiol. 2016;16(6) 

In This Article

Case Presentation

A 77-year-old man diagnosed with a pelvic mass was admitted to the operating room for resection of the mass. The patient had a 15-year history of diabetes as well as nephropathy during a period of uremia, hypertension with irregular use of an antihypertensive drug, laryngeal carcinoma for 37 years, lacunar infarct, and cataract. He had undergone cataract surgery and total laryngectomy previously, with the tracheostomy cannula removed 3 months ago. Physical examination revealed that a fistula had formed at the site of the tracheotomy incision. Computed tomography (CT) of the neck (Fig. 1) revealed that the soft tissue around the airway was asymmetrical below the hyoid bone, with thickening on the left side. The preanesthesia evaluation indicated American Anesthesiologists Association (ASA) category III, and we might confront two possible difficulties during the intubation: 1) the patients had removed tracheostomy cannula for 3 months, whether the stoma retracted? 2) Whether there existed tracheostenosis below the stoma? These suspected predictors indicated the infra-hyoid difficult airway.

Figure 1.

Computed tomography of the neck

The CT examination of the trachea was performed using a CT scanner (SOMATOM Definition flash; Siemens, Erlangen, Germany). Scanning parameters were as follows: slice thickness 3 mm, intervals 3 mm, 120 kV, and 252 mAs. Scan acquisitions were imported into a software program (Mimics 15.0; Mimics, Gilching, Germany). The tracheal area was selected to set the threshold using the thresholding function. The sliced images were then created using the region growing function and were ultimately reconstructed by calculation using the 3D function. The 3D reconstructed image was then exported in standard tessellation language (STL) format. These images were directly loaded into the 3D printer (MakerBot Replicaor 2; MakerBot, Brooklyn, NY USA) to enable production of 3D polylactic acid models of the inside and outside tracheal diameters (Fig. 2). Almost 10 h was needed to prepare the STL file and to print the models. These models were white and moderately hard, which met our needs.

Figure 2.

3D models of the inside and outside tracheal diameters

With the aid of the 3D model, we found slight scar retraction surrounding the stoma created by the tracheostomy and slight stenosis below the stoma in the trachea as suspected. With accurate data for the tracheal inner diameter, we created an anesthesia plan. We then practiced every intubation step on the 3D model, finally choosing a No. 8 tracheal catheter and No. 8 tracheostomy cannula. Because the patient would be transferred to the intensive care unit (ICU) postoperatively, where he would be given assisted mechanical ventilation and respiratory therapy, we decided to use the No. 8 tracheostomy cannula, which would be well tolerated and allow easy fixation.

In the operating room (OR), routine monitoring was performed with electrocardiography, noninvasive blood pressure, and pulse oximetry. The initial arterial blood pressure was 152/79 mmHg with a heart rate of 78 beats/min. Sinus rhythm was present, and the peripheral oxygen saturation (SpO2) was 98 %. A radial arterial line was placed after the Allen test indicated it was safe. The patient was premedicated with intravenous atropine (0.5 mg) to reduce airway secretions. Topical anesthesia was achieved with 3 ml of 2 % lidocaine. A fiberoptic bronchoscope was then inserted though the stoma to reevaluate the airway. An intravenous propofol bolus of 30 mg was given, after which the No. 8 tracheostomy cannula was inserted. An otolaryngologist was present in the OR and was ready to enlarge the stoma if it was difficult to establish the artificial airway. Immediately after intubation, intravenous propofol and atracurium were administered to induce general anesthesia and to establish mechanical ventilation. Maintenance was provided with sevofluorane 2 %, atracurium, and remifentanil. Urologists performed the tumor resection and partial cystectomy. At the end of the procedure, the patient was transferred to the ICU with the tracheostomy cannula in place. Three days later, the patient was transferred to the inpatient floor with no respiratory or hemodynamic impairment.

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