Reconstruction of the trachea with a tubed radial forearm free flap

Challenges and Opportunities in Developing Tracheal Substitutes for the Recovery of Long-Segment Defects

Tracheal resection and reconstruction procedures are necessary when stenosis, tracheomalacia, tumors, vascular lesions, or tracheal injury cause a tracheal blockage. Replacement with a tracheal substitute is often recommended when the trauma exceeds 50% of the total length of the trachea in adults and 30% in children. Recently, tissue engineering and other advanced techniques have shown promise in fabricating biocompatible tracheal substitutes with physical, morphological, biomechanical, and biological characteristics similar to native trachea. Different polymers and biometals are explored. Even with limited success with tissue-engineered grafts in clinical settings, complete healing of tracheal defects remains a substantial challenge due to low mechanical strength and durability of the graft materials, inadequate re-epithelialization and vascularization, and restenosis. This review has covered a range of reconstructive and regenerative techniques, design criteria, the use of bioprostheses and synthetic grafts for the recovery of tracheal defects, as well as the traditional and cutting-edge methods of their fabrication, surface modification for increased immuno- or biocompatibility, and associated challenges.

Tissue-engineered tracheal implants: Advancements, challenges, and clinical considerations

Restoration of extensive tracheal damage remains a significant challenge in respiratory medicine, particularly in instances stemming from conditions like infection, congenital anomalies, or stenosis. The trachea, an essential element of the lower respiratory tract, constitutes a fibrocartilaginous tube spanning approximately 10-12 cm in length. It is characterized by 18 ± 2 tracheal cartilages distributed anterolaterally with the dynamic trachealis muscle located posteriorly. While tracheotomy is a common approach for patients with short-length defects, situations requiring replacement arise when the extent of lesion exceeds 1/2 of the length in adults (or 1/3 in children). Tissue engineering (TE) holds promise in developing biocompatible airway grafts for addressing challenges in tracheal regeneration. Despite the potential, the extensive clinical application of tissue-engineered tracheal substitutes encounters obstacles, including insufficient revascularization, inadequate re-epithelialization, suboptimal mechanical properties, and insufficient durability. These limitations have led to limited success in implementing tissue-engineered tracheal implants in clinical settings. This review provides a comprehensive exploration of historical attempts and lessons learned in the field of tracheal TE, contextualizing the clinical prerequisites and vital criteria for effective tracheal grafts. The manufacturing approaches employed in TE, along with the clinical application of both tissue-engineered and non-tissue-engineered approaches for tracheal reconstruction, are discussed in detail. By offering a holistic view on TE substitutes and their implications for the clinical management of long-segment tracheal lesions, this review aims to contribute to the understanding and advancement of strategies in this critical area of respiratory medicine.

Full circumferential human tracheal replacement: a systematic review

Full Circumferential Tracheal Replacement (FCTR) is a surgical challenge, indicated in rare cases of extensive tracheal resection, with no consensus on surgical technique or materials. A systematic review according to PRISMA guidelines was carried out from 2000 to 2022 to identify cases of FCTR, to compare surgical indications, the nature of the tracheal substitutes and their immunological characteristics, surgical replacement techniques and vascularization. Thirty-seven patients, including five children, underwent FCTR surgery using 4 different techniques: thyrotracheal complex allograft (n = 2), aorta (n = 12), autologous surgical reconstruction (n = 19), tissue-engineered decellularized trachea (n = 4). The mean follow-up was 4 years. Of the 15 deceased patients, 10 died of the progression of the initial pathology. For the majority of the teams, particular care was given to the vascularization of the substitute, in order to guarantee long-term biointegration. This included either direct vascularization via vascular anastomosis, or an indirect technique involving envelopment of the avascular substitute in a richly vascularized tissue. Stent placement was standard, except for autologous surgical reconstructions where tracheal caliber was stable. Internal stents were frequently complicated by granulation and stenosis. Although epithelial coverage is essential to limit endoluminal proliferation and act as a barrier, fully functional ciliated airway epithelium did not seem to be necessary. In order to facilitate future comparisons, a standardized clinical trial, respecting regulatory constraints, including routine follow-up with tracheal biomechanics assessment and scheduled biopsies could be proposed. It would help collecting information such as dynamics and mechanisms of tracheal bio-integration and regeneration.

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.

Laryngotracheal Reconstruction for Subglottic and Tracheal Stenosis

Laryngotracheal stenosis is the common endpoint for any process that results in the narrowing of the airway at the level of the glottis, subglottis, or trachea. Although endoscopic procedures are effective in opening the airway lumen, open resection and reconstruction can be necessary to reconstitute a functional airway. When resection and anastomosis are insufficient due to extensive length or location of the stenosis, autologous grafts can be used to expand the airway. Future directions in airway reconstruction include tissue engineering and allotransplantation.

Pre-epithelialized cryopreserved tracheal allograft for neo-trachea flap engineering

Background: Tracheal reconstruction presents a challenge because of the difficulty in maintaining the rigidity of the trachea to ensure an open lumen and in achieving an intact luminal lining that secretes mucus to protect against infection. Methods: On the basis of the finding that tracheal cartilage has immune privilege, researchers recently started subjecting tracheal allografts to "partial decellularization" (in which only the epithelium and its antigenicity are removed), rather than complete decellularization, to maintain the tracheal cartilage as an ideal scaffold for tracheal tissue engineering and reconstruction. In the present study, we combined a bioengineering approach and a cryopreservation technique to fabricate a neo-trachea using pre-epithelialized cryopreserved tracheal allograft (ReCTA). Results: Our findings in rat heterotopic and orthotopic implantation models confirmed that tracheal cartilage has sufficient mechanical properties to bear neck movement and compression; indicated that pre-epithelialization with respiratory epithelial cells can prevent fibrosis obliteration and maintain lumen/airway patency; and showed that a pedicled adipose tissue flap can be easily integrated with a tracheal construct to achieve neovascularization. Conclusion: ReCTA can be pre-epithelialized and pre-vascularized using a 2-stage bioengineering approach and thus provides a promising strategy for tracheal tissue engineering.

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.

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.

Fabricating Flaps in the Forearm Prior to Tracheal Reconstruction

Background  The process of reconstruction of tracheal defects is complex and still not optimum. Options range from using staged reconstructions, combining flaps with autologous or alloplastic implants, as well as use of tissue-engineered constructs combined with vascularized tissues which are lined with cell cultures. Staged reconstructions using prelaminated epithelium, and prefabricated flaps, help in reconstruction of this complex structure. Prefabricating the flap at a different site allows for integration of the tissues prior to its transfer. Method  This article reports two patients planned for tracheal reconstruction for the purpose of advanced papillary carcinoma of the thyroid invading the trachea. Staged reconstruction using a prefabricated radial artery forearm flap (RAFF) and split rib cartilage was performed. In the second patient, a young girl, a similar construct of the RAFF, prelaminated with buccal mucosa, was performed. However, in the latter case, an intraoperative decision by the head and neck team to limit excision of the trachea sparing the mucosa was taken; the reconstruct in the forearm was redundant and needed to be discarded, replacing the defect with a free superficial circumflex iliac artery perforator (SCIP) flap. Result  At 3 years follow-up, both the patients are free of disease, with the construct serving its purpose in the older female.

Successful tracheal necrosis management using a pedicle pectoralis flap: A case report

Thyroidectomy is considered an overall low-risk procedure. However, severe life-threatening complications, including tracheal necrosis may occur postoperatively. A 45-year-old male patient was referred to our clinic for papillary thyroid carcinoma surgery. The patient had mediastinitis signs and symptoms seven days after total thyroidectomy. Subsequent imaging demonstrated air leak and with mediastinitis as the primary diagnosis, and the patient underwent reoperation. During the operation, four necrotic tracheal rings were found to be the source of air leak. Due to tissue inflammation and infection, neither primary repair with tracheal resection and anastomosis, nor strap muscle plugging procedure were feasible. Therefore, a pedicle flap derived from the right pectoralis major muscle was transferred to the necrotic trachea. The patient"s clinical condition improved after the operation and subsequent bronchoscopies confirmed healing of trachea. During six-month follow-up, no complications were observed. In conclusion, the technique discussed in the current report shows promising outcomes for reconstructing large tracheal defects in inflammatory conditions where primary repair techniques are not suitable.

Tracheal replacement

Tracheal reconstruction is one of the greatest challenges in thoracic surgery when direct end-to-end anastomosis is impossible or after this procedure has failed. The main indications for tracheal reconstruction include malignant tumours (squamous cell carcinoma, adenoid cystic carcinoma), tracheoesophageal fistula, trauma, unsuccessful surgical results for benign diseases and congenital stenosis. Tracheal substitutes can be classified into five types: 1) synthetic prosthesis; 2) allografts; 3) tracheal transplantation; 4) tissue engineering; and 5) autologous tissue composite. The ideal tracheal substitute is still unclear, but some techniques have shown promising clinical results. This article reviews the advantages and limitations of each technique used over the past few decades in clinical practice. The main limitation seems to be the capacity for tracheal tissue regeneration. The physiopathology behind this has yet to be fully understood. Research on stem cells sparked much interest and was thought to be a revolutionary technique; however, the poor long-term results of this approach highlight that there is a long way to go in this research field. Currently, an autologous tissue composite, with or without a tracheal allograft, is the only long-term working solution for every aetiology, despite its technical complexity and setbacks.

Tracheal replacement

Non-malignant and malignant obstruction of the tracheal airway causes significant morbidity and mortality. With increased use of artificial airways, benign and iatrogenic complications are increasing. A tracheal stenosis that is less than 5 cm in length can be resected with end-to-end anastomosis. Longer tracheal lesions can be treated in a palliative way by placement of a stent to secure airway lumen patency. The management of tracheal defects is an evolving field. Tracheal transplantation and tracheal regeneration may bring major treatment advances to cases with long-segment tracheal involvement. This review examines the current possibilities and future prospects in the area of tracheal transplantation and regeneration.

Plastic surgeons and the management of trauma: from the JFK assassination to the Boston Marathon bombing

The fiftieth anniversary of the death by assassination of President John Kennedy is an opportunity to pay homage to his memory and also reflect on the important role plastic surgeons have played in the management of trauma. That reflection included a hypothetical scenario, a discussion of the surgical treatment of Kennedy (if he survived) and Governor Connally. The scenario describes the management of cranioplasty in the presence of scalp soft-tissue contracture, reconstruction of the proximal trachea, reconstitution of the abdominal wall, and restoration of a combined radius and soft-tissue defect. The development of diagnostic and therapeutic advances over the past 50 years in the care of maxillofacial trauma is described, including the evolution of imaging, timing of surgery, and operative techniques. Finally, contemporary measures of triage in situations involving mass casualties, as in the Boston Marathon bombings, complete the dedication to President Kennedy.

One-stage reconstruction of a tracheal defect with a free radial forearm flap and free costal cartilage grafts

Reconstructing the trachea is challenging because of its multilayer structure and airway function; multiple procedures are often required. We report a case of one-stage reconstruction for a tracheal defect. The surgery was performed with a free radial forearm flap and free costal cartilage grafts. Air leakage occurred postoperatively but healed without additional surgery. The reconstructed trachea has retained its shape, diameter and airway function for 14 months despite the patient's history of radiotherapy. This one-stage procedure with well-vascularised tissue was successfully used to reconstruct a stable, well-functioning trachea.

Successful tracheal replacement in humans using autologous tissues: an 8-year experience

BACKGROUND

Fifty years of surgical research using synthetic materials and heterologous tissues failed to find a good, durable replacement for the trachea. We investigated autologous tracheal substitution (ATS) without synthetic material or immunosuppression.

METHODS

For ATS, we used a single-stage operation to construct a tube from a forearm free fasciocutaneous flap vascularized by radial vessels that was reanastomosed to internal mammary vessels and reinforced by rib cartilages interposed transversally in the subcutaneous tissue. Tracheal resections 7 to 12 cm long (mean, 11 cm) were done to treat 8 primary tracheal neoplasms, including 5 adenoid cystic carcinomas (ACC) and 3 squamous cell carcinomas (SCC); 3 secondary tracheal neoplasms, including 1 thyroid carcinomas and 2 lymphomas; and 1 postintubation tracheal destruction after a long history of stenting. Transitory tracheotomy was associated to the absence of mucociliary clearance.

RESULTS

ATS has been performed in 12 patients since 2004, with additional resections in 4 patients, comprising 1 carinal resection alone, 1 associated with lobectomy, and 2 pharyngolaryngectomies. All patients were extubated on postoperative day 1. Eight patients are alive at a mean of 36 months (range, 2 to 94 months) postoperatively, with no respiratory distress. The 2 patients with ATS and carinal resections died of pulmonary infection. No airway collapse has been detected by endoscopy, dynamic computed tomography scan, or spirometry. Two patients still have a tracheotomy because the procedure was performed too low at the level of the proximal anastomosis. One patient with a chronic severe respiratory insufficiency recently required a distal, short stent.

CONCLUSIONS

ATS is a good, durable, tracheal substitution that resists respiratory pressure variations because of transverse rigidity, without any immunosuppression.

Autologous tracheal replacement: from research to clinical practice

BACKGROUND

Despite numerous attempts, synthetic materials and heterologous tissues failed to replace durably the trachea. Autologous tracheal substitution (ATS) without synthetic material or immunosuppression was investigated to replace extended tracheal defect. We present our experience regards to this innovative challenge.

METHOD

After a previous research study, we developed a novel reconstruction technique for extended tracheal defects on animals. Through a single stage operation, a tube from a forearm free fascio-cutaneous flap vascularized by radial vessels is re-anastomosed to cervical vessels. This flap is reinforced by rib cartilages interposed transversally in the subcutaneous tissue. It provides also a reliable ATS. Twelve patients benefits from an extended tracheal resections, 7-12 centimeter (mean 11 cm) long. Indications were eight Primary tracheal Neoplasms (including 5 adenoid cystic carcinoma [ACC] and 3 squamous cell carcinoma [SCC]), three secondary tracheal neoplasms (including 1 thyroid carcinoma and 2 lymphoma) and one post-intubation tracheal destruction after long history of stenting. Daily bronchoscopy and transitory tracheotomy was associated due to absence of mucociliary clearance.

RESULTS

The research work leads to present the first described animal model for tracheal resection and replacement with an autologous conduit. It was constructed from costal cartilages and a pediculed cervical skin flap. From 2004 to 2012, 12 patients have had ATS with associated resections in four cases. All patients were extubated on the first postoperative days; eight patients are alive at 2 to 94 months (mean=36) postoperatively, with no respiratory distress. The two patients with ATS after resection extended to the carina died due to pulmonary infection. No airway collapse has been detectable, either by endoscopy, dynamic CT scan or spirometry. Two patients still have a tracheotomy because performed too low at the level of the proximal anastomosis. One patient with a chronic severe respiratory insufficiency required recently a distal and short stent.

CONCLUSION

ATS is actually a good, durable tracheal substitute that can resist respiratory pressure variations because of their transverse rigidity without any immunosuppression. The limits of this technique are probably, chronic respiratory insufficiency and cartilage calcifications. Research to develop a method for lining the neo-trachea with ciliated respiratory epithelium is needed.

Tracheal reconstruction with a modified infrahyoid myocutaneous flap

Reconstruction of a tracheal defect is a challenge because it often requires invasive surgery associated with relatively high morbidity. We recently invented a less-invasive method using a modified infrahyoid myocutaneous (IHMC) flap for the reconstruction of a tracheal defect in an 83-year-old male. A tracheal defect, the right half of the cricoid cartilage plus the right three quarters of the I-IV tracheal cartilage (about 3 × 4 cm), was reconstructed with a modified IHMC flap composed of the sternohyoid and platysma muscles and a skin pedicle. Considering the age of patient, we avoided rigid reconstruction and used a soft silicone tracheal opening retainer (Koken Co., Ltd., Tokyo, Japan) as an anterior wall dilator after surgery and waited for the scarring of the flap until it become rigid enough. The postoperative course was uneventful and the trachea was reconstructed safely. Tracheal reconstruction with an IHMC flap is a useful and less-invasive alternative compared to end-to-end anastomosis or reconstruction with a forearm flap, which is currently used as a mainstay.

Long-term outcomes of microsurgical reconstruction for large tracheal defects

BACKGROUND

Reconstruction of large tracheal defects has been largely unsuccessful. The purpose of this study was to review the authors' experience with microsurgical reconstruction of these defects.

METHODS

Seven cases of microsurgical tracheal reconstruction were performed between May 2002 and April 2008. All but 1 patient had recurrent thyroid cancer; the other patient had primary adenocystic carcinoma of the trachea. The radial forearm free flap was used for lining in all cases. Rigid support was provided with a variety of prosthetic materials.

RESULTS

All defects involved the cervical trachea, with an average length of 5.8 cm ± 1.0 cm (range, 5 cm-7.5 cm). The width of defects ranged from half of the tracheal circumference to the entire circumference. Major complications included air leak in 4 patients, exposure and removal of prosthesis in 2 patients, and cardiopulmonary complications in 2 patients. One patient with postoperative retroperitoneal hematoma, abdominal compartment syndrome, and multiple organ failure died 2 months after surgery. Two patients died of other causes 1 year and 4 years, respectively, after surgery. The other 4 patients were alive and disease free, with follow-up ranging from 1 to 4.5 years. Four patients are asymptomatic, with normal speech and swallowing functions. Two patients remained tracheostomy dependent, but vocal ability was intact. All patients tolerated a regular diet.

CONCLUSIONS

Microsurgical reconstruction is a viable option in selected patients with large cervical tracheal defects that are beyond primary repair.

Two-stage tracheal reconstruction of primary tracheal non-Hodgkin lymphoma with nitinol mesh stent and cervical myocutaneous flap

Primary tracheal non-Hodgkin lymphoma is an extremely rare entity without consensus management strategy. We present a case of primary tracheal lymphoplasmacytoid lymphoma masquerading as asthma with wheezing and progressive dyspnea. A patented nitinol mesh stent was implanted in the right lateral cervical region 3 weeks before tumor resection. After 5.5-cm-long segmental tracheal resection, a neotracheal tube was constructed with cervical myocutaneous flap sandwiched around the implanted mesh stent, which was then anastomosed with the residual of the patient's trachea. The patient has been well for 30 months.

Tracheal replacements: part 1

In this review, we summarize the history of tracheal reconstruction and replacement as well as progress in current tracheal substitutes. In Part 1, we cover the historical highlights of grafts, flaps, tube construction, and tissue transplants and address the progress made in tracheal stenting as a means of temporary tracheal support. This is followed in Part 2 by an analysis of solid and porous tracheal prostheses in experimental and clinical trials. We conclude Part 2 with a summary of recent efforts toward generating a bioengineered trachea. Finally, we provide an algorithm on the spectrum of options available for tracheal replacement.

Human Tracheal Reconstruction With a Composite Radial Forearm Free Flap and Prosthesis

Reconstruction of large tracheal defects has been largely unsuccessful. We report a novel single-stage tracheal reconstruction for a 6.5-cm long defect involving the anterior two thirds of the tracheal circumference in a patient with deeply infiltrative thyroid cancer into the tracheal lumen. The reconstruction was completed using a conduit composed of a radial forearm free flap for lining with a combined PolyMax mesh (Synthes, Paoli, PA) and Hemashield vascular graft (Boston Scientific, Natick, MA) for rigid support. At a 6-month follow-up the patient has normal swallowing and preoperative voice quality, and she maintains a patent, non-stented airway.

Primary Tracheal Malignant Neoplasms: The University of Texas MD Anderson Cancer Center Experience

BACKGROUND

Primary malignant neoplasms of the trachea are very rare and data relating to them are limited. This study was conducted to review the presentation, management, and outcomes of primary tracheal cancers at our institution, a large multidisciplinary cancer center.

STUDY DESIGN

Retrospective chart review was conducted for all patients found to have a pathologic diagnosis of primary tracheal malignancy.

RESULTS

Since 1945, 74 patients were diagnosed with primary tracheal cancers. Among these, 34 (45.9%) were squamous cell carcinomas, 19 (25.7%) were adenoid cystic carcinomas, and 21 (28.4%) were of other histologic types. Presenting symptoms were most frequently dyspnea (55.4%), hemoptysis (48.6%), cough (41.9%), and hoarseness (35.1%). Most patients (77.3%) were former or current smokers, particularly those with squamous cell carcinoma (93.3%). For the entire group of 74 patients, the 5-year disease-specific mortality rate was 72.9% and the 5-year all-cause mortality rate was 79.3%. Patients who had adenoid cystic carcinoma and those with cervical primaries had better rates of disease-specific and overall survival than others (p = 0.036 and 0.006 for the former patient group and p = 0.006 and 0.030 for the latter patient group). Among patients with incident disease treated at our institution (n = 45), those undergoing primary operation with adjuvant radiotherapy appeared to have better disease-specific and overall survival rates compared with those undergoing primary radiotherapy with or without chemotherapy (p = 0.0002 and 0.0003, respectively). Although those undergoing operation and receiving radiotherapy did better than those undergoing operation alone, the difference was not statistically significant.

CONCLUSIONS

Primary tracheal cancers are very rare, and our results should be viewed with caution, given that our population comprised a small heterogeneous group treated over a 60-year period. Although squamous cell carcinoma was the most common pathology in smokers, adenoid cystic carcinoma was more prevalent among nonsmokers. Operation with adjuvant postoperative radiotherapy is recommended for most patients.

Engineering a Composite Neotrachea in a Rat Model

BACKGROUND

Attempts to reconstruct the trachea have been largely unsuccessful because of its rigidity and opening to the outside environment. Materials that impart rigidity are usually alloplastic, so they cannot be exposed to the open environment without an unacceptably high risk of infection and rejection. The authors hypothesized that tissue engineering principles can be employed to construct a well-integrated neotrachea with rigid support and an epithelial lining to mimic the structure and function of the native trachea.

METHODS

A 30-mm-long segment of polytetrafluoroethylene vascular graft with a diameter of 10 mm was lined with a fascial flap based on the superficial inferior epigastric artery with full-thickness skin grafts on its luminal surface. The composite unit was then buried under the abdominal skin of 20 rats and harvested 3 weeks later. Microfil and methylene blue dye were injected into the superficial inferior epigastric arteries and histologic analyses were performed to assess microcirculation and polytetrafluoroethylene-tissue integration.

RESULTS

Two composite neotracheas experienced minor damage due to chewing by the rats, but all other neotracheas were viable and without infection. Injection studies demonstrated excellent circulation throughout the fascial flaps and skin grafts and across the polytetrafluoroethylene grafts to the overlying abdominal skin. Histologic analyses revealed abundant muscle-walled blood vessel ingrowth within the polytetrafluoroethylene grafts and all layers of the neotracheas with minimal inflammatory reactions.

CONCLUSION

The authors successfully have engineered a well-integrated neotrachea in rats that possesses rigid support, an epithelial lining, and reliable coverage-the prerequisites for successful trachea reconstruction.

Circumferential Tracheal Reconstruction for the Functional Treatment of Airway Compromise

OBJECTIVES/HYPOTHESIS

The objective was to describe a surgical technique for replacement of long tracheal defects with a totally autologous free prefabricated cutaneous chondromucosal forearm tubular flap, applied to humans.

STUDY DESIGN

Surgical reconstruction of the trachea.

METHODS

A three-stage surgery was performed in a 25-year-old patient who presented with a long tracheal defect not resolved by previous resection with primary anastomosis and laser surgery.

RESULTS

The staged surgery has been well tolerated by the patient, and no problems at all were reported. The postoperative computed tomography scan and the bronchofibroscopy examination of the "neo-trachea" at 2 and 6 months revealed normal caliber, good healing of the suture lines, absence of crusts or granulation tissue, and a well-vascularized internal mucosal lining.

CONCLUSION

The modified flap reconstruction technique has the potential to be considered reliable for the definitive circumferential reconstruction of extensive laryngotracheal defects not amenable to being cured by conventional techniques.