Evolution of individualized management of tracheal obstruction

The current state of congenital tracheal stenosis

Congenital tracheal stenosis (CTS) is an uncommon condition that has challenged pediatric surgeons for decades. Patients with CTS can present with a wide spectrum of symptoms and varying degrees of severity. In addition, a variety of techniques have been devised to repair this malformation. A review of these procedures and our suggestions for clinical standards and practice guidelines will be presented in this paper. A retrospective review of the literature on CTS from 1964 to 31 March, 2006. There is not one standard technique for the repair of CTS, as individualized approach to each patient and airway lesion is necessary to optimize patient management; nevertheless there is a consensus about segmental resection and anastomosis being best for short segment stenosis while slide tracheoplasty is most effective for the long-segment ones. Conservative management is also an option for select group of patients with careful and close follow up. Survival following surgery over the years has improved, but mortality remained high, particularly in a specific subset of patients presenting at the age less than 1 month with associated cardiac malformations. In conclusion, CTS remains a significant challenge for pediatric surgeons. Additional research is required to improve our understanding of the pathogenesis of CTS, and to develop evidence-based treatment protocols for the entire spectrum of presentation including conservative management.

Microsurgical reconstruction of the trachea in rats (an experimental study)

This study was carried out to evaluate the use of 'Zenoderm' (enzyme treated procine dermis) as a patch for the repair of tracheal defects in rats, with particular reference to its application in the treatment of some cases of tracheal stenosis. Fifty-three rats were included in the study. Using microsurgical techniques, a defect was created in the cervical trachea and repaired using a suitable patch of 'Zenoderm' (two groups with different sized defects). In a further group of rats, healing of the trachea was studied after excision of a segment and end to end anastomosis. A set number of rats were sacrificed after intervals of 14, 28, 91 and 182 days when the trachea was excised and evaluated. Healing of the tracheae following end to end anastomosis was satisfactory in all cases with no evidence of stenosis. The two groups of tracheae with Zenoderm patches showed progressive stenosis at the area of the repair but there was no evidence of respiratory obstruction or distress. The Zenoderm patch and the regenerating epithelium were both evaluated by light microscopy and scanning electromicroscopy. The Zenoderm patch showed gradual absorption and was replaced by host collagen. There was gradual regeneration of epithelium which showed slow maturation from flat non-ciliated epithelium to partially cuboidal and columnar epithelium with some cilia showing early differentiation to respiratory epithelium. In conclusion, this experimental study confirmed the biocompatibility of 'Zenoderm' in rats. It provided a suitable surface for regeneration of tracheal epithelium. Replacement of the patch by the host collagen is promising but requires further study to assess its rigidity and ability to withstand pressure changes in the trachea.

Intercostal muscle and myo-osseous flaps in difficult pediatric thoracic problems

Intercostal muscle pedicle flaps have been successfully utilized in the treatment of recurrent tracheoesophageal fistulae and esophageal perforations in the pediatric age group. An intercostal myo-osseous pedicle flap was also created to repair a distal congenital tracheal stenosis at the carina. The viable intercostal flap has the advantage of multiplicity of uses and of considerable mobility. The presence of a blood supply assures healing. The option of retaining periosteum on the flap encourages bone regeneration at the site of tracheal or bronchial repair. The pleura of the flap provides an epithelial surface for intratracheal repair. The rib graft prevents stricture at the site of tracheal repair.

Tracheal resection in infancy

Tracheal resection, commonly used in adults, has not been applied to the infant age group because of concerns regarding subsequent tracheal growth. Upper tracheal narrowing in infants may often be satisfactorily treated, but patients with long segment distal tracheal stenosis do not respond to usual therapy and rarely survive. In this case, resection of the distal third of the trachea was accomplished successfully and the trachea appears capable of normal growth in the area of the anastamosis.