Post-intubation tracheal stenosis and surgery Levent Elbeyli, MD Gaziantep University, Medical Faculty, Depart.of Thoracic Surgery
We all of us remember themwith respect Prof.Dr.Hadi AKAY Prof.Dr.N Göksel KALAYCI
Tracheal anatomy: • Trachea: • 10-12 cm length • 15-23 mm width • Has approximately 20 “C” shaped cartilages • Fibro-muscular tube
Trachea • Because of its anatomic placement and structure, trachea is captive for resection and manipulations. • It is so closed to cardio-vascular organs. Since there are so many adhesions between trachea and these structures, dissection is not so easy. • Arterial blood supply is weak and segmental. For this reason, surgeon must pay more attention for unnecessary devascularization. • Being a stretched organ is one of anatomic properties. Edges move away from each other approximately for 1.5-2 cm when trachea is cut. • Angles of tracheal rings must not be damaged since “C” shape is important for its rigidity. • Main problem in tracheal surgery is to prevent its anatomic and physiological structure.
Basic principles in tracheal surgery defined by Grillo and Pearson have been used.
The Principles of Tracheal Surgery • Extended mobilization is necessary: • Dissection of pulmonary ligament, • Complete mobilization of right hilus (3 cm), • Intrapericardial dissection of pulmonary vessels (0.9 cm), • Re-implantation of left bronchus to right intermediary bronchus (2.7 cm), • Suprahyoid laryngeal release, • Increasing cervical flexion
Tracheal Surgery • First experimental anostomosis was defined by Gluck and Zeller in 1881. • Kuester performed first primary end to end anostomosis after circular resection in 1885. • Resection margin was limited to 2 cm in 1960’s. • Primary anostomosis after 6.5 cm resection of trachea became possible with mobilization techniques that was developed by Grillo between 1960 and 1965.
Tracheal Surgery • Belsey (1951) reported the criteria for tracheal reconstruction as: • Lateral rigidity • Longitudinal elasticity and flexibility • Sufficient lumen • Continuing of ciliated columnar epithelium • Today, it has reached at the end of resection limits. • However, tracheal reconstruction after long segmental resection is still an important problem. • Various materials and methods that has been used for reconstruction have limited success. • Studies on ideal prosthesis material for extended resections beyond limits have been continuing.
Tracheal Surgery • Methods for replacement after tracheal resection: • Synthetic materials have migration, anostomotic insufficiency and stenosis problems; • Immune suppression in homografts; • Anatomic and functional defects, late stenosis in autogenic materials For this reason, primary end to end anostomosis have to be forced in tracheal reconstruction.
Tracheal Surgery • Despite recent developments in tracheal surgery, there are still important problems. High tension on suture line of anostomosis may lead stenosis and dehiscence.Cantrell and Folse (1961) found that tension under 1700 gr was safe for anostomosis in dogs. • Fibrotic tissue reaction that increase the space between cartilages and cause stenosis can develop even in existence of lower tension on suture line. • Anostomotic insufficiency, stenosis and dysfunction due to foreign body reaction of tracheal tissue are serious problems.
Tracheal Surgery • Circular resection is more recommended since a wedge resection on anterior wall causes stenosis due to fold.
Tracheal Surgery • Intubation have been used widelyfor supportive mechanical ventilation in respiratory insufficiency with oro-tracheal, naso-tracheal or tracheostomy tubes.
Intubation and airway • Severe airway injuries caused by intubation can be sorted as: • Tracheo-esophageal fistula • Tracheo-arterial fistula (Innominate arter) • Subglottic or laryngotracheal stenosis
Tracheal surgery • Upper tracheal stenosis can accompany subglottic stenosis and is originated from 3 main causes: • Erosion caused by prolonged stay of endotracheal tube that has greater dimension for patient. • Tracheotomy above criciod cartilage. • Usage of crico-thyroidotomy • Single stage operation for both subglottic and accompanyingtracheal stenosis is to circular resection of stenotic segment and to perform thyro-tracheal anastomosis.
Tracheal Surgery • Lindhom (1970) reported that intubation tube could trigger obstruction on laryngeal level even after intubation for 48 hours.
PETS physiopathology • Post-intubation tracheal stenosis is essentially caused by hyper inflated cuff. This situation leads locally ischemic necrosis of tracheal cartilage and granulation tissue. • High volume, low pressure cuffed tubes have to be used and close control to prevent stenosis. • However, over inflation of these low pressure cuffs can make injury to tracheal cartilages.
PETS physiopathology • Etiological principals of cuff stenosis have different properties: • Pressure necrosis caused by cuffs • Irritative quality of tubes and cuffs (Plastic and silver tubes cause chemical reactions) • Irritative substances produced by gas sterilization. • Hypotension and bacterial infection
Tracheal Surgery • Granulomas on tracheostomy area can obstruct airway. Stenosis occurs if: • Stoma was opened widely by using wide flab • A big window was opened • Tracheostomy tube more great considering to stoma. • Erosion caused by sepsis occurs • In these patients, posterior wall of trachea may be healthy relatively to anterior wall.
PETS physiopathology • Circular erosion on the cuff level of wheter endotracheal or tracheostomy tube may occur. If this erosion is deep enough, all layers of trachea can be damaged and circular stenosis develops. The advanced form may result as tracheo-esophageal fistula posteriorly or tracheo-innominate fistula anteriorly. • Below this level, granuloma can occur because of irritation of distal end of tube and wrong aspiration. • Between stoma and cuff level, chondro-malasy may develop. Cartilages become thinner at this segment. Bacterial infection promotes this situation also.
Symptoms of PETS: • Dyspnea • Cough • Stridor • Cough and effort dyspnea cause wrong diagnosis such as asthma or COPD.
Symptoms • In some patients, symptoms occur in 2 days after extubation. • However, most of manifest symptoms develop in 10-42 days after extubation. In some cases, this interval may be as months. • In patients with symptoms of airway obstruction and have intubation story for 24 hr or more in last 2 years, organic obstruction have to be imagined unless opposite diagnosis is proved. • Airway may tighten to 4-5 mm diameter before symptoms become distinctive if patients are not followed up during healing period of primary disease. This openness can be fatal.
Diagnosis of PETS • Preoperative: • A complete radiological evaluation Endoscopic examination (Larynx-Trachea; panendoscopy if necessary) • Condition of tracheal mucosa • Localization of stenosis • Dimensions of lesionshould be done.
Treatment in PETS • Dilatation (Fiber optic or rigid bronchoscopy or percutaneous dilatation) Failure in endoscopic intervention is due to: Circular stenosis Tracheomalasy or loss of cartilages Bacterial infection Posterior laryngeal scars and arytenoids dysfunction • Local and systemic steroid • Cryosurgery • Fulguration • Laser • T-tube or other stents can be used for prolonged or permanent stenting. • Tracheostomy • Surgical resection and reconstruction
Surgical approach: • Cervical incision in cervical stenosis; • Partial or total sternotomy (With or without right thoracotomy)in cervico-thoracic stenosis; • Right thoracotomy in distal tracheal or carinal stenosis.
Surgical principles • Most of complications can be prevented when basic principles are applied correctly: • Avoid from over anastomotic tension; • Protect blood supply of trachea; • Carefully dissection and anastomosis; • Absorbable sutures have to be used.(3/0, 4/0 polyglactin, polydioxone)
Postoperative complications: • Granulation formation- bronchoscopic resection; • Dehiscence or re-stenosis- re-operation or T-tube insertion; • Laryngeal dysfunction (It may occur in cases that suprahyoid or thyrohyoid releasing was performed)- tracheostomy or T-tube insertion; • Tracheomalasy- tracheostomy or T-tube; • Hemorrhage (Innominate artery)- Surgery • Anastomotic edema- steroid or temporary T-tube, tracheostomy; • Infection- debridement and anti-biotics; • Others (MI, pneumothorax, venous thrombosis, atrial fibrillation)
Grillo and tracheal surgery: • In his series: • There were 503 patients with post-intubation tracheal stenosis. • 521 resection and reconstruction have been performed. (13 patients had re-operation because of re-stenosis and 5 had residual tracheomalasy) • Mean tracheal resection length was 3.3 cm • Failure rate in tracheo-tracheal anastomosis was 2.2 %; 6 % in crico-tracheal anastomosis and 8.1 % in thyro-tracheal anastomosis. • Mortality was 2.4 % • Results have been defined as “well” when patient had normal daily activities and intact airway in radiological and bronchoscopic examinations; • Results have been defined as “satisfactory” when normal daily activities but stress in exercise have been found; existence of findings due to partial chord vocal paralysis and narrowing in radiological and bronchoscopic examination even if patients have been normal. • Failure generally have required tracheostomy.
Clinical experience • There were 4 patients with post-intubation tracheal injury in our clinic last year. • Two of them underwent primary resection and end to end anastomosis; • We performed first primary repair and then resection and primary anastomosis in one patient. • In one case who had been treated in an other institution because of tracheal stenosis, re-stenosis had occurred and this patient is in follow up with recurrent dilatations.
Cricoid split and free costal cartilage usage can be necessary in long segment tracheal resections and subglottic stenosis. However, granulation tissue can develop due to prolonged intubation.In these cases, vascular pedicled costal cartilage can provide evolution. K. Hashizume J. Of Ped: Surg.39; 12: 1769 - 1771
Conclusion • The most appropriate procedure in tracheal stenosis and tumors is primary resection and end to end anastomosis in order to get anatomic and functional continuing. • Most common indication for tracheal resection and reconstruction is post-intubation tracheal injury.
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