Tracheal reconstruction: in vitro and in vivo animal pilot study

In order to further address the problem of tracheal stenosis, an animal model was created to simulate both local and regional tracheal injury. An epithelial equivalent created from a fibroblast-collagen matrix was used to attempt to either inhibit or lessen the degree of tracheal stenosis that was evident in animal models. Preliminary data appears to show that the epithelial equivalent is effective in limiting and perhaps even abolishing the development of tracheal stenosis.

Circumferential tracheal replacement with costal cartilage

Long-term incorporation of foreign material or tissue in circumferential tracheal replacement will lead to progressive growth of granulation tissue, provoking either airway stenosis or a reduction of subepithelial blood supply and thereby preventing the appearance of functioning ciliated epithelium in the replaced segment. In experience with dogs, a 5 cm length of the thoracic trachea was replaced circumferentially with fresh autogenous untreated circularly positioned cartilage-perichrondrium strips. During the period of strengthening of this neotracheal wall, a temporary tracheal prosthesis made of tubular silicone rubber with absorbable sewing rings of polyglactin 910 placed 3 mm from the end of the tube served as a tracheal replacement. Six months after the cartilage transplantation, the neotracheal wall had stabilized sufficiently for the silicone rubber tube to be extracted with an endoscope. Four weeks after extraction of the silicone rubber tube the neotracheal segment was completely covered with ciliated epithelium over a thin subepithelial, well-vascularized layer. Subepithelial vessels had a diameter of 180 microm. They were a continuation of the intercartilaginous main vessels of the neotracheal wall. The presence of normal cilia on the epithelium was proved through transmission electron microscopy. Even the tubules of the cilia were arranged in the right order. In the ink test, movement of the transport marker across the neotracheal segment at a speed of 18 to 21 mm/min was proof of mucociliary clearance. In a process of migration starting from the margin of the trachea, the ciliated epithelium pervaded and replaced the preexisting temporary one-layer stratified squamous epithelium. This completely new technique of circumferential tracheal replacement with autogenous cartilage, avoiding permanent incorporation of foreign material, succeeds within the observation period of up to 7 months.

[Endotracheal dystopia of thyroid tissue]

Endotracheal ectopic thyroid tissue is rare. It can cause gradual obstruction of the tracheal lumen culminating in sudden dyspnoea. The diagnosis is relatively easy to make with the aid of a laryngeal mirror, by endoscopy, or by x-rays. However, it is most important to take the clinical picture into consideration. It is thought that the ectopic tissue arises from splitting of the thyroid gland during the descent in the embryonal stage. Treatment consists of removal via a tracheofissure. The tracheal mucous membrane must be treated with special care to prevent cicatricial stenosis of the trachea.

[Elective coniotomy. Experiences with 103 personal cases]

The view held for the last 60 years that coniotomy often leads to subglottic stenosis has recently been called into question. In the present study 103 elective coniotomies are analysed. The operation was much easier than tracheotomy, and there were no severe complications during or after operation. Six months after decannulation 31 patients were alive and 28 available for follow-up examination. No evidence of subglottic stenosis was found. The main disadvantage of this operation would seem to be a tendency for the development of voice changes.

Tracheostome construction during laryngectomy--a method to prevent stenosis

A new technique for construction of the tracheostome at the time of total laryngectomy is described. It involves making an X-shaped incision on the lower skin flap and four slits on the divided trachea. The result is a serrated suture line at the tracheocutaneous junction. The incidence of stenosis in 116 patients who did not have this method of construction was 31%. Sex difference and previous irradiation was not found to be related to the occurrence of stenosis. Of 25 patients who had the new method of tracheostome construction, only one patient had to wear a tube until she died at 7 months. The rest, followed up for at least 9 months, did not have stenosis. It is concluded that this new method of tracheostome construction will reduce the incidence of stenosis.

Prevention of tracheal stricture in end-to-end anastomosis

The development of stenosis at the suture line after tracheal resection and end-to-end anastomosis of the trachea is associated with failure to approximate the tracheal ends. Evidently, stenosis invariably will occur if the viable mucosal edges are not properly adapted to each other. We developed a method of anastomosis affording accurate approximation of the tracheal ends and particularly of the mucosa by doing Z-plasties in the mucosa. This method of tracheal anastomosis, which is comparatively easy and safe to perform, may be used reliably and without the development of mucosal structures.

Superiorly based tracheostomal flap to counteract tracheal stenosis: experimental study

A superiorly based tracheal flap raised from the anterior tracheal wall was rotated anteriorly and superiorly to be sutured to the subcutaneous tissues. A series of 16 tracheostomies were performed on mongrel dogs. The stenosing effects of conventionally performed operations were compared to those of the new method. Autopsy sections of the post-tracheostomy sites demonstrated a significant loss of anteroposterior diameter averaging 16.5% as compared to the original unoperated-on luminae. No signs of tracheal stenosis were found whenever the proposed new technique was employed. This technique seems applicable to patients in whom assisted ventilation is contemplated.

[Tracheal stenosis and keloid disposition (author's transl)]

Patients with disposition for cicatricial keloid are expected to get tracheal stenosis by long time intubation. Latest after 48 hours the respiration done by respirator should be managed by tracheotomy tube. Instead of classic tracheotomy an epitheliced tracheotomy should be preferred. For the therapy of tracheal stenosis--excision of tracheal stenosis and end to end anastomosis as well as tracheal groove by Rethi with transplantation of mucosa--the application of triaminolonacetonoid has proved to avoid restenosis by secondary keloid.

[Prevention and pretherapeutic evaluation of laryngo-tracheal stenosis in adult (author's transl)]

The prevention of laryngo-tracheal stenosis and their etiological factors are the subject of this study. The used material (tube, balloon,...) and the patient could be the principal reason of these etiology, either for intubation or tracheotomy. The pressure in the balloon and the tracheal mucosal puls are developed. The knowledgement of the principal etiologic factors in the constitution of laryngo-tracheal stenosis, make us able to prevent them with efficacity. Finaly, a preoperative evaluation by tomography and endoscopy is establiched.

Intubation injuries of the trachea in children. Management and prevention

The problem of intubation injuries of the trachea in children has been summarized. Preventive measures designed to protect the trachea from injury have been outlined. In spite of these measures, acute intubation injuries have occurred in 15 children. An aggressive approach combining bronchoscopic evaluation, intratracheal injection of steroids, tracheal stenting with an endotracheal tube and systemic steroids has been employed in the treatment of these injuries. We feel that this therapy has prevented the development of cicatrical stenosis in many of the cases and has allowed permanent decannulation of the trachea.

Management of the flap tracheostomy. An experimental study

The flap tracheostomy was studied in 25 adult canines to further investigate its best management. Tracheostomies were performed by employing the inverted U flap incision in the trachea. After decannulation, the flap was either formally resewn to the trachea, bluntly dissected from the surrounding soft tissues, or left in place. The time required for epidermal closure over the tracheostomy site was measured, along with fixation of skin to soft tissues in the area. Histologic examinations were made, and tracheal dimensions were calculated on sections through the stomal area. More rapid skin closure and less soft tissue fixation occurred in animals that underwent resuturing or release of the tracheal flap. In all groups, cartilage viability and regrowth were noted. Tracheal diameters were maintained in all groups, but smoother contouring was seen with resuturing. Additional support for the flap tracheostomy is provided from this animal experimentation.

[Tracheal and bronchial ruptures (author's transl)]

Rupture of the major airways is rare. Open injuries usually involve the trachea; injuries to the airways in closed chest trauma are in 80-90% of the cases located at the bifurcation or the main bronchus. Rupture of the bronchial system may cause an immediate threat to life, but may also produce few symptoms. The possibility of such an injury should always be taken into consideration, even if at first the clinical signs only point to damage of the lung parenchyma. Intubation and continuous suction drainage are life-saving emergency measures to be followed as soon as possible by bronchoscopy to establish the diagnosis. Treatment is by prompt suture or anastomosis. Failure to diagnose rupture of a bronchus results very soon in stenosis and, later on, in damage to the lungs and jeopardizes the success of subsequent reconstructive surgery. The repair of extended stenoses presents particularly difficult technical problems. Alloplastic grafts may be the answer. During 1961-1978 7 persons with injuries to the trachea and bronchi were treated at the Department of Surgery, Giessen. 3 persons were saved by immediately performing an anastomosis.

[Effects of pull upon the growth of the trachea (author's transl)]

The effect of pull following segmental resection with subsequent anastomosing was studied in animal experiments in regards to the growth of the trachea. A corresponding decrease in body-weight is demonstrated following resection of 4-7 tracheal segments. Even a small pull leads to a decrease of cartilage thickness of the entire trachea. The correlation between the number of the resected cartilage segments and the resulting stenosis in the region of the anastomosis is significant. The decreased area of the canal in the anastomosed region amounts to a maximum of 66% after resection of 7 tracheal segments without the appearance of disorders of ventilation in form of an in- and expiratory stridor. After resection of up to 3 tracheal segments telescopic cartilage overlappings are observed. The mucosa shows a metaplastic regeneration at the anastomosis.

[Tracheotomy superior, media and inferior? (author's transl)]

The traditional classification of tracheotomy in superior, media and inferior is not important. It only is important that the tracheotomy tube is in a tensionless position and does neither irritate the larynx nor the thyreoid gland. This can be obtained by strict conservation of at least the first tracheal ring and by dissection of the isthmus of the thyreoid gland.