© Borgis - New Medicine 2/2003, s. 2-3
Lidia Zawadzka-Głos, Mieczysłw Chmielik, Anna Gabryszewska
Treatment of postintubation laryngeal stenosis using argon plasma coagulation
Department of Paediatric Otorhinolaryngology, Medical University of Warsaw, Poland
Head: Prof. Mieczyław Chmielik M.D.
Subglottic stenosis of the larynx in children is still a difficult problem. Endoscopic dilation of the laryngeal lumen is one of many ways of treatment. The article disccusses preliminary results concerning treatment of postintubation laryngeal stenosis by argon plasma coagulation (APC). The investigation was based on 12 children with postintubation laryngeal stenosis, with I to IV degrees of stenosis according to the Myer-Cotton grading system. Improvement was observed in all treated children. The method of treatment, its advantages and disadvantages are described in the article.
Postintubation laryngeal stenosis develops due to prolonged intubation, most commonly resulting in local ischaemia in the subglottic region exerted by compression from the endotracheal tube. It can also occur due to inflammatory lesions in the subglottic region, or as a reaction to the endotracheal tube material. Disturbances of the microcirculation in the mucus, secondary to shock or metabolic diseases, facilitates development of subglottic stenosis in addition.
The diagnosis is based on endoscopic examination of the larynx, allowing the degree of stenosis to be assessed. Radiological examination, by spiral helical computed tomography or magnetic resonance of the larynx and trachea, can confirm the diagnosis. The Myer-Cotton grading system, used to estimate the degree of stenosis, defines Ist degree stenosis from 0 to 50% of the laryngeal lumen, IInd degree from 51 to 70%, IIIrd degree 71 to 90%, the IVth degree being atresia of the larynx (6).
The treatment of postintubation stenosis is difficult. There are a lot of endoscopic methods for treatment of the larynx including laser, typical microsurgery with a separator or T-tube, and surgical procedures through an external approach with chondral grafts, titanicum plates, or resection of the stenotic area (5, 6). The qualification for surgery is based on the degree and level of the laryngeal stenosis, earlier performed surgical procedures, the anatomic condition of the region, and the experience of the surgeon or custom of the Medical Centre.
Endoscopic methods of treatment of the laryngeal stenosis using a separator have been performed in the Department of Paediatric Otorhinolaryngology in Warsaw for many years, while stenoses of the subglottic region of the larynx have been dilated using argon plasma coagulation (APC) for 2 years (15).
Twelve children aged from 11 months to 10 years (6 girls and 6 boys) had endoscopic treatment for postintubation laryngeal stenosis using argon plasma coagulation. Eleven children had a tracheostomy because of IInd, IIIrd or IVth degree stenosis. One boy was found to have Ist degree stenosis and was breathing through natural air passages; a small laryngeal stridor was heard only on exercise. Five children were found to have IVth degree stenosis, 4 were found to have IIIrd, and 2 children had IInd degree stenosis.
APC was used for treatment of postintubation laryngeal stenosis. A source of argon gas (APC 300) and a high – frequency unit (ICC 350 of Erbe Electromedizin) were used. Rigid applicators ending with a ceramic nozzle set at 0° or 90° to the axis of the probe were used. The coagulation was performed with an argon flow of 1.0-1.2 l/min in short (i.e. 1-3 sec) applications, repeated several times. All procedures were performed under general anaesthesia. Control endoscopy of the larynx was performed using a directoscopy tube and Kleinsasser´s set, and using bronchoscopic tubes. The degree of stenosis was measured before and after dilation. A separator was not inserted in the dilated site of the larynx. The procedures were repeated every 6-8 weeks.
Various degrees of improvement were observed in all children treated with APC. The diameter of the lumen of the larynx was stabilised in 5 children with IVth degree stenosis: IInd degree stenosis persisted in 2 of them, and IIIrd degree persisted in 3 of them.
In the group of children with IIIrd degree stenosis the results were: the lumen was dilated to the IInd degree in 3 children, and one child was decannulated.
Two children with IInd degree stenosis before treatment were decannulated after endoscopic treatment with APC.
A proper laryngeal lumen of the larynx was achieved after endoscopic treatment with APC in a child with Ist degree stenosis.
The number of procedures differ with individuals. Improvement was observed after the first procedure with APC, but the lumen of the larynx gradually diminished. A stable lumen of the larynx was achieved after 3 to 5 procedures. No severe complications were observed. Transient dysphony was seen during the first 2 days after the procedure. It probably develops due to oedema at the coagulation site and it disappears in a few days.
Argon plasma coagulation is applied in many kinds of ENT procedures – tonsillectomy (2, 9), reduction of the nasal concha (1), laryngeal papillomatosis (3, 4), neoplastic lesions of the lower respiratory tract (7, 13), removal of granulation tissue (14), and in other procedures concerning the lower respiratory tract.
The article presents preliminary information about the new treatment of postintubation laryngeal stenosis. Endoscopic dilation of the larynx using APC led to complete recovery in 4 children, 3 children were decannulated, and another 8 patients are still being treated. Fifty-one procedures using APC have been performed. Severe complications did not occur in any cases. Progression of cicatrix lesions at the subglottic level was not observed.
Endoscopic dilation of the lumen of the larynx using APC cannot replace surgical treatment through an external approach in cases of IIIrd and IVth degree stenosis with deformation of the chondroskeleton of the larynx. The laryngeal chondroskeleton of the treated children was intact.
The advantages of the described method include minimized intraoperative bleeding, no formation of granulation tissue in the coagulated area, short operation time, controllable dose of energy, and shorter hospitalization and postoperative care time compared to cases treated with intralaryngeal incisions with separator insertion. Carbonization of the tissues does not occur.
However, APC is not a perfect method. Although argon gas does not react with other gases, it may displace them from the air passages. Thus, blood oxygenation must be monitored during the operation and in the postoperative period.
The described method of dilation of postintubation stenosis of the larynx has been used in our Department of Paediatric Otolaryngology for 2 years (15). Patients remain under constant laryngeal follow-up. Endoscopic treatment of postintubation laryngeal stenosis with APC seems to be effective and safe.
1. The endoscopic method of dilation of the laryngeal lumen using argon plasma coagulation is a safe and effective method of the treatment of Ist and IInd degree stenosis according to the Myer-Cotton grading system for laryngeal stenosis.
2. The advantages of the method are minimal intraoperative bleeding, no formation of granulation tissue in the coagulated area, and a short time of postoperative care and hospitalization.
3. The endoscopic method of dilation of the lumen of the larynx using argon plasma coagulation cannot replace surgical methods of reconstruction of the laryngeal skeleton in cases of IIIrd and IVth degree stenosis and deformation of the chondroskeleton of the larynx.
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