Autologous Tracheal Replacement

Tracheal Replacement Techniques and Associated Mortality: A Systematic Review

OBJECTIVE

Tracheal replacement is a crucial operation to enhance the quality of life for patients with extensive tracheal lesions. The most suitable surgical techniques for different clinical conditions remain a topic of debate. Through a reviewing of the relevant literature, this study investigated the association between surgical techniques and mortality rate.

DATA SOURCES

Studies were collected from PubMed, Embase, the Web of Science, the Cochrane Center Register of Controlled Trials, and ClinicalTrials.gov.

METHODS

This systematic review encompassed literature from the inception of each database to May 10, 2023, focusing on tracheal replacement for patients who underwent circumferential resection of the trachea or partial resection with preservation of the posterior membranous wall. Non-human and non-clinical studies were excluded.

RESULTS

About 31 studies were included in the assessment comprising a combination of case reports and case series, and 118 patients underwent tracheal replacement through four underlying methodologies, including tracheal allotransplantation, autologous tissue reconstruction, bioprosthetic reconstruction, or tissue engineering surgery. Each modality exhibits unique advantages and disadvantages, leading to variable outcomes in clinical application.

CONCLUSION

Tracheal replacement is challenging due to the absence of an ideal substitution or graft material. Despite limited clinical successes observed across various modalities, we believe autologous tissue reconstruction for tracheal replacement has the advantage of broadest indications, low rejection rate, and avoidance of immunosuppressive agents. Future research should focus on achieving tracheal replacement that preserves mucociliary clearance, lateral rigidity, and longitudinal flexibility.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:1517-1522, 2024.

Extended autologous tracheal replacement by a novel pedicled thoraco-chondro-costal flap: a cadaveric proof of concept

OBJECTIVES

Our aim was to report an anatomic model of an autologous flap based on the internal thoracic blood supply: the pedicled thoraco-chondro-costal flap; and establish the feasibility of various types of extended tracheal replacement with this novel flap, according to a newly proposed topographic classification.

METHODS

In a cadaveric model, a cervicotomy combined with median sternotomy was performed. The incision was extended laterally to expose the chest wall. The internal thoracic pedicle was freed from its origin down to the upper limit of the delineated flap to be elevated. The perichondria and adjacent periostea were incised longitudinally to remove cartilages and adjacent rib segments, preserving perichondria and periostea. A full-thickness quadrangular chest wall flap pedicled on internal thoracic vessels was then elevated and shaped into a neo conduit to replace the trachea with the pleura as an inner lining.

RESULTS

Various types of extended non-circumferential and full-circumferential tracheal replacements were achieved with this composite flap. No anastomosis tension was noticed despite the absence of release manoeuvres.

CONCLUSIONS

This model could represent a suitable autologous tracheal substitute, which is long, longitudinally flexible and eventually transversely rigid. No microsurgical vascular anastomoses are required. The technique is reproducible. The perichondria and periostea would regenerate vascularized neo-cartilaginous rings, potentially decreasing the need for long-term stenting. The inner pleural lining could potentially transform into ciliated epithelium as shown in previous preclinical studies.

Biomimetic in situ tracheal microvascularization for segmental tracheal reconstruction in one-step

Formation of functional and perfusable vascular network is critical to ensure the long-term survival and functionality of the engineered tissue tracheae after transplantation. However, the greatest challenge in tracheal-replacement therapy is the promotion of tissue regeneration by rapid graft vascularization. Traditional prevascularization methods for tracheal grafts typically utilize omentum or muscle flap wrapping, which requires a second operation; vascularized segment tracheal orthotopic transplantation in one step remains difficult. This study proposes a method to construct a tissue-engineered tracheal graft, which directly forms the microvascular network after orthotopic transplantation in vivo. The focus of this study was the preparation of a hybrid tracheal graft that is non-immunogenic, has good biomechanical properties, supports cell proliferation, and quickly vascularizes. The results showed that vacuum-assisted decellularized trachea-polycaprolactone hybrid scaffold could match most of the above requirements as closely as possible. Furthermore, endothelial progenitor cells (EPCs) were extracted and used as vascularized seed cells and seeded on the surfaces of hybrid grafts before and during the tracheal orthotopic transplantation. The results showed that the microvascularized tracheal grafts formed maintained the survival of the recipient, showing a satisfactory therapeutic outcome. This is the first study to utilize EPCs for microvascular construction of long-segment trachea in one-step; the approach represents a promising method for microvascular tracheal reconstruction.

A Review of Woven Tracheal Stents: Materials, Structures, and Application

The repair and reconstruction of tracheal defects is a challenging clinical problem. Due to the wide choice of materials and structures, weaving technology has shown unique advantages in simulating the multilayer structure of the trachea and providing reliable performance. Currently, most woven stent-based stents focus only on the effect of materials on stent performance while ignoring the direct effect of woven process parameters on stent performance, and the advantages of weaving technology in tissue regeneration have not been fully exploited. Therefore, this review will introduce the effects of stent materials and fabric construction on the performance of tracheal stents, focusing on the effects of weaving process parameters on stent performance. We will summarize the problems faced by woven stents and possible directions of development in the hope of broadening the technical field of artificial trachea preparation.

The Growing Medical Need for Tracheal Replacement: Reconstructive Strategies Should Overcome Their Limits

Breathing, being predominantly an automatic action, is often taken for granted. However, respiratory diseases affect millions of people globally, emerging as one of the major causes of disability and death overall. Among the respiratory dysfunctions, tracheal alterations have always represented a primary challenge for clinicians, biologists, and engineers. Indeed, in the case of wide structural alterations involving more than 50% of the tracheal length in adults or 30% in children, the available medical treatments are ineffective or inapplicable. So far, a plethora of reconstructive approaches have been proposed and clinically applied to face this growing, unmet medical need. Unfortunately, none of them has become a well-established and routinely applied clinical procedure to date. This review summarizes the main clinical reconstructive attempts and classifies them as non-tissue engineering and tissue engineering strategies. The analysis of the achievements and the main difficulties that still hinder this field, together with the evaluation of the forefront preclinical experiences in tracheal repair/replacement, is functional to promote a safer and more effective clinical translation in the near future.

Tissue Engineering for Tracheal Replacement: Strategies and Challenges

The critical feature in trachea replacement is to provide a hollow cylindrical framework that is laterally stable and longitudinally flexible, facilitating cartilage and epithelial tissue formation. Despite advanced techniques and sources of materials used, most inherent challenges are related to the complexity of its anatomy. Limited blood supply leads to insufficient regenerative capacity for cartilage and epithelium. Natural and synthetic scaffolds, different types of cells, and growth factors are part of tissue engineering approaches with varying outcomes. Pre-vascularization remains one of the crucial factors to expedite the regenerative process in tracheal reconstruction. This review discusses the challenges and strategies used in tracheal tissue engineering, focusing on scaffold implantation in clinical and preclinical studies conducted in recent decades.

Serratus Anterior-Rib Composite Flap as a Novel Approach for Tracheal Reconstruction

OBJECTIVE

To report a novel case of tracheal reconstruction using a serratus anterior-rib composite flap.

METHODS

Case report and literature review.

RESULTS

A 46-year-old male with a 4 cm anterior tracheal wall defect underwent reconstruction with a serratus anterior-rib composite flap. The patient experienced excellent results regarding phonation, swallowing, and cosmesis.

CONCLUSION

The serratus anterior-rib composite flap appears to be a suitable candidate for tracheal reconstruction and merits further analysis in this context. The flap's intrinsic incorporation of a perfused rib segment allows for reliable reconstruction of the neotrachea and maintenance of proximal dynamic airway support.

Development and clinical translation of tubular constructs for tracheal tissue engineering: a review

Effective restoration of extensive tracheal damage arising from cancer, stenosis, infection or congenital abnormalities remains an unmet clinical need in respiratory medicine. The trachea is a 10-11 cm long fibrocartilaginous tube of the lower respiratory tract, with 16-20 tracheal cartilages anterolaterally and a dynamic trachealis muscle posteriorly. Tracheal resection is commonly offered to patients suffering from short-length tracheal defects, but replacement is required when the trauma exceeds 50% of total length of the trachea in adults and 30% in children. Recently, tissue engineering (TE) has shown promise to fabricate biocompatible tissue-engineered tracheal implants for tracheal replacement and regeneration. However, its widespread use is hampered by inadequate re-epithelialisation, poor mechanical properties, insufficient revascularisation and unsatisfactory durability, leading to little success in the clinical use of tissue-engineered tracheal implants to date. Here, we describe in detail the historical attempts and the lessons learned for tracheal TE approaches by contextualising the clinical needs and essential requirements for a functional tracheal graft. TE manufacturing approaches explored to date and the clinical translation of both TE and non-TE strategies for tracheal regeneration are summarised to fully understand the big picture of tracheal TE and its impact on clinical treatment of extensive tracheal defects.

Tracheal reconstruction with nail grafts: A novel approach

Background

Methods

Results

Conclusions

Long-term outcomes of differentiated thyroid cancers with tracheal invasion: A 15-year experience

BACKGROUND

Tracheal invasion is reported to occur in approximately one-third of the patients of locally advanced thyroid cancers. There is a paucity of data in literature with regard to the long-term outcomes of thyroid cancers with tracheal invasion.

METHODS

A total of 37 patients from our tertiary care center underwent radical surgery for tracheal involvement for differentiated thyroid cancers between the years 2002 and 2016. The variables pertaining to the demographics, clinical presentation, imaging, operative details and histopathology reports were captured from the patient's case records and analyzed.

RESULTS

Among the 37 patients, there were 21 males and 16 females. Majority of the patients (56.8%) were >55 years of age. Surgery (tracheal resection) was performed in the primary setting in 29 patients, whereas it was performed in a recurrent setting in 8 patients. As per the Shin classification, 3 patients belonged to Shin stage 1, 3 to Shin stage 2, 16 patients to Shin stage 3 and 15 patients to Shin stage 4. There was no 30 day postoperative mortality in our cohort. The median follow-up of our cohort was 175 months. The 5-, 10-, and the 15-year overall survivals of the entire cohort were 81.7%, 47.8%, and 35.9%, respectively.

CONCLUSION

Our series shows favorable long-term oncological outcomes of selected patients of thyroid cancers with tracheal resection and adds to the limited long-term data available in literature.

Repair of a defect in the cervical trachea with thyroid-pericardium flap: A case report

RATIONALE

Primary end-to-end anastomosis is common in adult trachea resection. Nevertheless, considering that the utilization of grafts is still essential for restoring defect in long-segment tracheal resection surgery, long-segment tracheal resection and reconstruction still remain challenging. Herein we present a novel case in which we resected a large tracheal mass and reconstructed the long-segment defect through using a thyroid-pericardium flap, which has not been reported yet.

PATIENT CONCERNS

A 35-year old male patient was admitted due to 'Repeated dry cough for 2 years, shortness of breath after activities for 1 month'. Patient had no other obvious symptoms.

DIAGNOSES

CT revealed that a large neoplasm was located in the cervical trachea and the pedicle was in the tracheal membrane, with total length of approximately 6 cm. Positron emission tomography computed tomography demonstrated an abnormally elevated levels of glucose metabolism in the upper part of the posterior tracheal wall. Therefore, this lesion was primarily considered as a malignancy.

INTERVENTIONS

The patient was performed by a primary resection of long-segment tracheal mass followed by thyroid-pericardium composite tissue flap for reconstruction.

OUTCOME

The operation was successful, without hydrops or pneumatosis in the mediastinum. One week postoperatively, CT showed that there was no pneumomediastinum and mediastinal abscess. Three weeks postoperatively, fiber bronchoscope showed the flap with normal color and the unobstructed tracheal cavity. The patient healed without complication.

LESSONS

The thyroid-pericardium flap is a convenient, secure, and effective material for long-segment trachea mass resection and reconstruction.

Healing Effect of Platelet-rich Plasma on Decellularized Tracheal Allotransplantation in Rabbits

BACKGROUND/AIM

The purpose of this study was to explore the effect of platelet-rich plasma (PRP) on enhancing healing of trachea allotransplantation and confirm the effect via parallel histological and tracheoscopic examinations in seven adult New Zealand White rabbits.

MATERIALS AND METHODS

Harvested trachea was inserted into recipients with end-to-end anastomosis by a simple interrupted suture. PRP-treated rabbits were treated with 0.5 ml of PRP at the trachea grafts, while control rabbit allografts were treated with 0.5 ml of saline.

RESULTS

Tracheoscopy of tracheal allografts treated with PRP revealed that the trachea was well healed with no stenosis. The healing effect in the PRP-treated rabbits increased tracheal activity and produced faster trachea regeneration compared to that in control rabbits. There was a good correlation between the subjective symptom of noisy breathing and the objective grading of tracheal stenosis. The tracheal allografts with suture materials appeared slightly pale and looked more like mucosa erosion than normal mucosa at four weeks post-surgery. Contact of trachea-to-transplanted grafts in PRP-treated rabbits was intimate with the surface of the transplanted region and showed high-density epithelialization. After 8 weeks, blood vessels were observed in the transplanted graft in PRP-treated rabbits. Normal epithelium was present in grafts at 8 weeks after allotransplantation. No CD20⁺ cells were detected in grafts but a few CD3⁺ cells were observed under the epithelium.

CONCLUSION

The results of this study show that it is possible to perform tracheal reconstruction in rabbits treated with PRP after tracheal transplantation.