The Larry Tube: Customized 3D Printed Laryngectomy Tubes Following Total Laryngectomy

Introduction

Laryngeal cancer is one of the most common types of head and neck (H&N) cancers in the United States, representing about one-third of all H&N cancer cases, and effecting approximately 100 000 people. Laryngeal function determines voice production, safe swallowing, and respiratory function, all of which directly impact quality of life. Treatment of laryngeal cancer is often associated with loss of function, which can result in significant morbidity.^1-3 Treatment paradigms and strategies have evolved over the last 20 years, and while definitive chemoradiation therapy (CRT) offers potential organ preserving therapy, definitive surgical management with total laryngectomy (TL), either in the primary or salvage setting, may be required.^4-8

Standard post-operative care after a TL includes placement of a flexible silicone laryngectomy tube into the stoma to ensure patency and expedite the healing process, but commercially available products have standardized sizes and designs, with limited options to adhere to patient specific anatomy. ⁹ If a correct and comfortable fit cannot be achieved, patients can undergo significant complications cited as high as 60%, either from the poorly fitting tube or from sequelae of foregoing the tube due to discomfort. ¹⁰ Due to the lack of variability and customizability, the available options may not be effective for the anatomical variations that present in some patients who have previously undergone radiation, revision surgery, or have unique anatomical abnormalities. Unique custom designed patient devices may better improve comfort, functionality, and even outcomes in some patients requiring total and salvage total laryngectomies.

Three-dimensional (3D) printing has recently become more widely utilized in healthcare and can be used to create unique customizable laryngectomy tubes for patients with complex anatomy that may lead to more favorable outcomes. Personalized laryngectomy tubes, produced from 3D printed molds, may better maintain the stomal lumen, help prevent obstruction due to airway crusting, and may give patients with no other treatment options a realistic choice.

In this article, we highlight the cases of 2 patients that used customized laryngectomy tubes to help overcome specific anatomical challenges that could not be reconciled by commercially available laryngectomy tubes. We focus not only on the process of 3D printing, but also on the unique obstacles that each patient faced and how the use of point of care product design and delivery promptly and significantly improved individual patient outcomes and quality of life.

Methods

All patients in this manuscript were treated by the University of Michigan Department of Otolaryngology or the Ohio State University Department of Otolaryngology and had a customized laryngectomy tube placed between January, 2019, and November, 2020. All laryngectomy tubes were manufactured in-house through a clinical engineering lab and deployed through the FDA expanded access protocol for emergency use. The patients in this study were chosen based on the unique anatomical demands of each of their pathologies.

In both highlighted cases, both patients underwent a salvage total laryngectomy (STL) and were approved for fitting and placement of a customized laryngectomy tube after the subsequent disease process extended beyond the maximum available length (55 mm) of common commercially available laryngectomy tube (Blom-Singer(R) Silicone Laryngectomy Tube). Thus, a more personalized, longer device was required for each patient. A CT chest scan of each patient’s airway was molded into a 3D airway model using Mimics (Materialise, Leuven, Belgium). A one-piece customized mold was created from this design using a combination of Dassault SolidWorks 2021 (Dassault SolidWorks, Massachusetts, USA), and Materialise 3-matic with intentions of injection molding the tube. The mold was then printed with a Formlabs Form 3B in Formlabs Clear V4 resin (Formlabs, Somerville, MA, USA) and post-processed following the recommended Form Wash and Cure time and temperature. Factor II A-RTV-3045 (Factor II, Inc., Lakeside, AZ, USA) medical grade silicone, similar to commercial product, was injected into the 3D printed mold, before post-processing prior to patient application.

Results

Our first highlighted example is of a 64-year-old male who originally had a pT0N2M0 lung adenocarcinoma treated with CRT and VATS lobectomy. He re-presented 3 years later with locally advanced T3N2M0 small cell neuroendocrine laryngeal carcinoma—again treated with CRT. Due to the overlapping fields of radiation, he suffered significant radiation damage to his larynx, trachea, and esophagus resulting in significant subglottic stenosis, complete esophageal stenosis, and a dysfunctional larynx requiring STL. Due to the extensive radiation induced soft tissue necrosis, severe radiation fibrosis, and recurrent suction trauma, he frequently suffered from severe airway obstruction due to crusting that required numerous urgent emergency department (ED) evaluations and debridement to prevent catastrophic airway obstruction.

Due to the considerable radiation damage, a 3D printed customized silicone laryngectomy tube was printed with a length of 75 mm and incorporated a safety flange to prevent aspiration events. The customized tube served 3 main purposes: to protect the tracheal mucosa that would not otherwise be covered by a standard laryngectomy tube to promote epithelization, to decrease the amount of crusting and subsequent suction trauma, and to stent open the area of stenosis, preventing cicatricial scarring, and ensuring long-term stoma and tracheal patency. After initial placement, it was noted that patient could benefit from an even longer tube (~85-90 mm; Figure 1) which was reprinted and subsequently exchanged. Following placement, the patient had dramatic improvement in airflow and breathing, with no further episodes of airway crusting and irritation or displacement, and no additional presentations to the ED. The patient continued to use his customized laryngectomy tube without issue until he passed away from complications related to his widely metastatic disease.

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Figure 1.

(a) Dassault solid works rendering of the customized laryngectomy tube mold viewed from an oblique view, (b) Materialise 3-matic rendering of the customized laryngectomy tube mold viewed from an oblique view, (c) Formlabs 3D printed customized laryngectomy tube mold viewed from an oblique view, (d) unique laryngectomy tube injection molded with Factor II medical grade silicone and ready for patient placement, and (e) customized laryngectomy tube well fitted and resting comfortably in patient.

Our second example is from a 61-year-old-male who was initially treated with definitive radiation for a T1N0M0 laryngeal squamous cell carcinoma (SCC). A little over a year later, he developed a recurrent T1N0M0 laryngeal SCC and underwent a transoral salvage partial laryngectomy. Due to his worsening thick secretions and progressive tracheal irritation, he ultimately required an extended STL with manubriumectomy and a mediastinal tracheal stoma. This operation resulted in a severely distorted trachea characterized by a right-angle contour from the neck skin down into his mediastinum. This unique anatomy caused him to easily develop recurrent airway obstructions and extensive tracheal stenosis which was only further complicated by a new mediastinal mass that now compressed the distal trachea. As his airway obstruction progressed, he required frequent self-delivered airway dilations with an endotracheal tube to help remove crusting and stent open his obstruction. Despite these efforts, he still had several episodes of critical airway obstruction requiring emergency debridement.

Based on CT imaging data, the patient’s disease process extended 70 mm into the trachea, traversing a unique course. Following the same protocol, the printed laryngectomy tube aimed to maintain a patent airway and the tube was trimmed to extend 72 mm in length, to stent the airway distal to his pathology (shown in Figure 2). Once placed, the patient noticed immediate improvement in breathing. On follow-up visits, the patient noted that he only needed to self-dilate with an endotracheal tube every 3 to 4 days as opposed to the previous burden of every 2 to 3 hours. At 3-month follow-up, his stenosis had completely resolved and he no longer required self-dilations; his significant tracheal improvement can be appreciated in Figure 3. He also reported that his secretions were easier to manage, he had less crusting of the stoma, and had significant improvement in his quality of life due to improved sleep and activity level. The patient had no further airway events and has achieved a complete response for his metastatic disease with immunotherapy.

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Figure 2.

(a) Sagittal computed tomography (CT) scan of the unique tracheal defect, (b) Materialise 3-matic 3D rendering of the trachea and creation of customized laryngectomy tube, and (c) unique laryngectomy tube injection molded with Factor II A-RTV-3045 medical grade silicone and ready for patient placement.

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Figure 3.

(a) Tracheal stenosis visualized endoscopically before customized laryngectomy tube placement, (b) trachea with improved stenosis visualized endoscopically after customized laryngectomy tube placement, (c) distal tracheal stenosis just superior to the carina visualized endoscopically before customized laryngectomy tube placement with significant inflammatory changes and surrounding erythema, and (d) distal trachea just superior to the carina visualized endoscopically with improved stenosis and improved inflammation and erythema after customized laryngectomy tube placement.

Conclusion

For patients diagnosed with laryngeal cancer, TL is common procedure for patients who fail CRT and who are unable to maintain the goals of organ preservation. ⁵ In patients who are initially treated with RT or CRT therapy, up to 25% to 36% eventually require STL due to tumor recurrence or residual disease. ¹¹ Unfortunately, STL has been shown to have a higher complication rate as the initial radiation destroys the tissue microvasculature, causing hypoxic changes that impair traditional healing conditions. ¹² The subsequent worsened environment results in lower survival rates, shorter disease-free survival time, and higher rates of recurrence and complications when compared to primary TL. ¹³ The new post-laryngectomy airway created by the stoma bypasses the natural humidification process of the upper airway which can commonly lead to tracheal irritation, stomal crusting, and concurrent overproduction of mucus among others with some reports citing total complications rates as high as upwards of 60%. ¹⁴

Laryngectomy tubes are commonly applied following TL and STL to help maintain tracheal and stomal lumen patency, prevent stenosis and mucosal surface damage due to suction trauma and airway irritation, and reduce excessive mucus production. These protective effects aim to ultimately prevent life-threating obstructive airway crusting from occurring.

Though laryngectomy tubes are widely used, the design and specifications of common tubes do not readily adhere to unique patient anatomy and pathology. The U.S. Food and Drug Administration (FDA) expanded access pathway is an influential tool that can be utilized to effectively care for rapidly changing medical and personal emergencies. Expanded access protocols, or compassionate use protocols, allow for prompt access to unapproved medical products for single use application outside of a clinical trial when no other comparable medical options exist. To be approved, the device or therapy in question must be previously approved under an existing investigational device exemption (IDE); if available, a request must be submitted as an IDE supplement. ¹⁵ If necessary, a physician may request compassionate use access through the telephone; though this request subsequently requires a formal written request within 15 days of FDA authorization, it gives the opportunity to further expedite necessary and life-saving therapies in the appropriate emergent circumstances. ¹⁶

Point-of-care manufacturing allows for better patient customization, and even more rapid production and time to treatment with more flexibility and access to swift adjustments when necessary; commercial manufactures have limited adaptability and can require weeks for model delivery.^17,18 When printing from an in-house model, the laryngectomy tubes can be delivered in as little as 36 hours in an emergency situation. At the University of Michigan and The Ohio State University, the physicians and engineers have created an in-house 3D printing workflow, that allows for accelerated production of emergency and compassionate use devices, and thus, quicker therapeutic patient benefit that can be widely applied for cancer patients especially at tertiary care centers.

In summary, after a patient undergoes a TL, it is common to require individualized airway support, and may prove especially important following STL as the higher complication rate may demand more unique post-operative solutions.^19-22 The current standardized sizes and shapes of commercial laryngectomy tubes can be uncomfortable and poor fitting, which can accelerate and compound patient complications including stomal crusting, patient discomfort, respiratory distress, and airway emergencies.^23-25 In this manuscript, we have highlighted the use of 2 customized laryngectomy tubes that have helped to deliver effective patient specific care in complex cases where commercially available products were ineffective. For each patient, the customized laryngectomy tube extended beyond the maximum standard 55 mm length of commercial laryngectomy tubes, was manipulated to help solve the unique anatomical challenges that occurred in each patient following STL and was rapidly constructed and employed due to the in-house clinical engineering labs previously established. Both highlighted patients benefited from their unique laryngectomy tube and had a substantial improvement in their breathing and reduction of airway events following customized tube placement. In the future, this technique should be considered for all patients with difficult airway anatomy when standard care fails to adequately address their pathology.

The flexibility and creativity that 3D printing provides allows clinicians to continue to develop unique solutions to help solve complex patient presentations and problems. Each patient was treated via the expanded access or compassionate use pathway available through the FDA; this unique protocol has allowed clinicians to develop out-of-the-box solutions, and when combined with the power of in-house 3D printing, can continue to offer rapid and effective options and realistic solutions for the multitude of patients with especially difficult pathologies such as those presenting following TL and STL.