Human Tracheal Transplantation

Abstract

Long-segment tracheal airway defects may be congenital or result from burns, trauma, iatrogenic intubation damage, or tumor invasion. Although airway defects <6 cm in length may be reconstructed using existing end-to-end reconstructive techniques, defects >6 cm continue to challenge surgeons worldwide. The reconstruction of long-segment tracheal defects has long been a reconstructive dilemma, and these defects are associated with significant morbidity and mortality. Many of these defects are not compatible with life or require a permanent extended-length tracheostomy that is fraught with complications including mucus plugging and tracheoesophageal fistula. Extensive circumferential tracheal defects require a reconstructive technique that provides a rigid structure able to withstand the inspiratory pressures, a structure that will biologically integrate, and contain functional ciliated epithelium to allow for normal mucociliary clearance. Tracheal transplantation has been considered the reconstructive “Holy Grail;” however, there has been a long-held scientific dogma that revascularization of the trachea was not possible. This dogma stifled research to achieve single-staged vascularized tracheal transplantation and prompted the introduction of many creative and inventive alternatives. Throughout history, alloplastic material, nonvascularized allografts, and homografts have been used to address this dilemma. However, these techniques have largely been unsuccessful. The recent introduction of a technique for single-staged vascularized tracheal transplantation may offer a solution to this dilemma and potentially a solution to management of the fatal tracheoesophageal fistula.

Human tracheal transplantation: A systematic review of case reports

“…Compared to the clinical experience reported for stented aortic allografts 37 and autologous tissue composites, 38 tracheal transplantation is still at an embryonic stage. The need for immunosuppression, at least temporarily, represents a contraindication for patients who are affected by malignant tumors, and poses an ethical concern also for patients affected by benign pathologies: besides the risks associated with the procedure, is lifelong immunosuppression preferable to long‐term airway stenting? 44 Because tracheal transplantation is still at an experimental phase, several secondary aspects of this procedure, such as compatibility of tracheal procurement in the context of multi‐organ donation, or hospital reimbursement for tracheal transplantation, are yet to be defined. Regarding this last aspect, none of the published studies specify the source of funding.…”

Case Report: Human Tracheal Transplantation Undergoes Progressive Reepithelialization Over Time

“…[1][2][3] Although multiple options for reconstruction, including implants and grafts, have been attempted, they do not generally provide sustainable improvements in quality of life. 4 For example, alloplastic stents may serve as a temporary palliative measure to manage long-segment stenosis; however, they carry significant complications including infection, mucous plugging, and soft tissue erosion.…”

“…A functioning tracheal transplant is predicated not only on being a rigid biocompatible structure, but also containing functional tracheal epithelium which allows for proper mucociliary clearance. 4 Our group performed the first successful vascularized singlestaged tracheal transplantation in January 2021, with the patient now fully decannulated 2 years after surgery. 5 On an initial examination of serial biopsies posttransplantation from the first tracheal transplant, ciliated epithelium was observed by 29 days after surgery.…”

“…Search for a viable option for repair of these long‐segment stenotic lesions is ever‐more pressing given the long‐term sequelae that were seen subsequent to prolonged intubations and tracheostomies during the COVID‐19 pandemic 1–3 . Although multiple options for reconstruction, including implants and grafts, have been attempted, they do not generally provide sustainable improvements in quality of life 4 . For example, alloplastic stents may serve as a temporary palliative measure to manage long‐segment stenosis; however, they carry significant complications including infection, mucous plugging, and soft tissue erosion.…”

“…Tracheal transplantation provides an ideal option for the repair and reconstruction of long‐segment circumferential tracheal defects as it completely replaces the injured segment. A functioning tracheal transplant is predicated not only on being a rigid biocompatible structure, but also containing functional tracheal epithelium which allows for proper mucociliary clearance 4 . Our group performed the first successful vascularized single‐staged tracheal transplantation in January 2021, with the patient now fully decannulated 2 years after surgery 5 .…”