# Tracheal Stenosis > Tracheal stenosis for NEET-PG Surgery: post-intubation cuff injury, biphasic stridor, Myer-Cotton grades, dilation, T-tube and resection limits. - Canonical URL: https://prepelephant.com/topics/neet-pg/surgery/tracheal-stenosis - Exam / course: NEET-PG · Subject: Surgery - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Tracheal Stenosis", PrepElephant, https://prepelephant.com/topics/neet-pg/surgery/tracheal-stenosis ## Direct answer A patient who cannot be extubated after intensive care, or who presents weeks to months after a difficult intubation or tracheostomy with exertional dyspnoea and biphasic stridor often mislabelled as "asthma", has an acquired tracheal stenosis until proved otherwise — the commonest cause in adults is pressure necrosis from an endotracheal or tracheostomy tube cuff (cuff pressure above the mucosal capillary pressure of roughly 20–30 cm H2O) producing cartilage-level ischaemia, ulceration and a fibrous ring. Evaluation combines flow-volume loops (a fixed upper airway obstruction flattens both inspiratory and expiratory limbs), CT with multiplanar or virtual bronchoscopic reconstruction, and rigid bronchoscopy under anaesthesia — the gold standard that measures length and calibre and grades severity on the Myer-Cotton scale (grade I up to 50 per cent obstruction, II 51–70, III 71–99, IV no lumen). Treatment spans endoscopic dilation (temporising, high restenosis), laser radial incisions, stents or a Montgomery T-tube for patients unfit for open surgery, and definitive segmental tracheal resection with end-to-end anastomosis — safe for roughly half the adult trachea, about 4–5 cm, with release manoeuvres (laryngeal release, hilar release) and neck flexion extending the limits. ## What you must remember - Causes ranked: post-intubation or post-tracheostomy stenosis (cuff site and stoma site are the two classic levels) overwhelmingly commonest in adults; post-traumatic; tuberculous tracheitis (an important Indian cause, often long strictures); idiopathic subglottic stenosis (young women); Wegener granulomatosis, relapsing polychondritis, amyloidosis and extrinsic compression (goitre, vascular rings, mediastinal masses). - Cuff pressure physiology: capillary perfusion pressure of tracheal mucosa is roughly 20–30 cm H2O; sustained higher cuff pressure (overinflation, low-volume high-pressure cuffs, prolonged ventilation) causes ischaemic ulceration exposing cartilage, granulation and finally a cicatricial ring. - Presentation: dyspnoea on exertion progressing to stridor, biphasic (both phases) because the lesion is fixed; recurrent "failures" of weaning or extubation; acutely, biphasic stridor with saturation dips is an emergency — humidified oxygen, heliox, and senior airway help; never blindly paralyse and intubate across an unknown stenosis. - Myer-Cotton grading (of subglottic/tracheal stenosis by cross-sectional area lost): I — under 50 per cent; II — 51–70 per cent; III — 71–99 per cent; IV — no detectable lumen. Grades III–IV and any significant symptoms generally need definitive intervention. - Investigations: flow-volume loop (flattening of both limbs = fixed obstruction), CT with multiplanar reconstruction or virtual bronchoscopy to map length and level, and rigid bronchoscopy in theatre — which is both diagnostic and immediately therapeutic (dilation to secure the airway and size the lesion). - Endoscopic options: gentle bougie or balloon dilation — immediate but usually recurs within weeks; radial laser incisions with dilation for short web-like stenoses; steroid injection into the ring mitigates restenosis in selected cases; silicone or (less favoured) covered metallic stents for palliation or unfit patients, with migration, granulation and infection as costs. - Montgomery T-tube: a silicone T-shaped tube whose vertical limb exits through the stoma and whose horizontal limb stents the trachea across the stenosis, allowing speech and toilet — a bridge or destination device in unfit patients and after complex reconstruction. - Definitive surgery: segmental resection with end-to-end anastomosis — the benchmark, with approximately up to half the adult trachea (about 4–5 cm) resectable safely; cricotracheal resection for subglottic involvement (cricoid split with mucosal preservation); release manoeuvres (suprahyoid laryngeal release, inferior hilar release) gain further length; postoperatively the neck is kept flexed (chin-to-chest stay sutures) to offload the anastomosis. - Pitfalls after repair: anastomotic dehiscence and restenosis at the suture line, and injury to the recurrent laryngeal nerves; tracheostomy tubes, when needed long-term, should use soft, correctly sized cuffs at the lowest leak-proof pressure. ## A typical case walked through A 30-year-old woman, ventilated for two weeks after severe COVID pneumonia through an oral tube and then a tracheostomy, fails two extubation attempts over the next month and is labelled a difficult asthmatic; spirometry shows a flattened, truncated flow-volume loop with both limbs boxed. CT reconstruction demonstrates a 2 cm circumferential ring at the previous cuff level reducing the lumen to about 4 mm, with normal trachea above and below — post-intubation stenosis, Myer-Cotton grade III. Sequence the plan: secure the airway first — she is taken to theatre for rigid bronchoscopy, where the stenosis is dilated with bougies to buy an immediate, safe airway; because she is young, fit and has a short, well-localised stenosis, definitive treatment is segmental tracheal resection (two to four rings) with end-to-end anastomosis, done through a collar incision, keeping the neck flexed postoperatively with a chin stitch for about a week. She decannulates and breathes normally. The forks: a 60-year-old with poor respiratory reserve and a long, inflamed post-tubercular stricture is a poor resection candidate — she is better served by a silicone stent or a Montgomery T-tube with periodic changes; and a patient stenosing acutely while still in intensive care needs dilation as a bridge while inflammation matures — resecting an actively inflamed airway invites restenosis, so definitive surgery waits weeks to months. ## Where students slip First, the misdiagnosis: exercise dyspnoea and stridor after an intensive care stay get treated as asthma — the flow-volume loop with a fixed upper airway pattern is the discriminator the exam rewards. Second, quoting grades wrongly: Myer-Cotton grades follow percentage obstruction (I under 50, II 51–70, III 71–99, IV no lumen) — students invert them. Third, overestimating resectable length: about half the adult trachea (roughly 4–5 cm) without release, more with release manoeuvres — claiming the whole trachea can be resected is a viva-ending error, and forgetting neck flexion postoperatively misses the practical detail that protects the anastomosis. ## Frequently asked questions ### What is the commonest cause of acquired tracheal stenosis in adults? Prolonged intubation or tracheostomy — cuff pressure necrosis above mucosal capillary pressure (about 20–30 cm H2O) at the cuff site, and scarring at the stoma site. ### What does the flow-volume loop show in fixed tracheal stenosis? Flattening of both inspiratory and expiratory limbs (a boxed pattern), distinguishing a fixed upper airway obstruction from the variable intrathoracic or extrathoracic patterns. ### What are the Myer-Cotton grades? Grade I — up to 50 per cent obstruction; II — 51–70 per cent; III — 71–99 per cent; IV — complete (no detectable lumen); grading guides endoscopic versus open management. ### How much trachea can be safely resected in an adult? Roughly half the tracheal length, about 4–5 cm, for primary end-to-end anastomosis; release manoeuvres (suprahyoid laryngeal release, hilar release) extend this further in selected cases. ### What is a Montgomery T-tube? A silicone T-shaped stent with an external limb through the stoma, stenting the trachea across a stenosis while permitting speech and airway toilet — used in unfit patients or as a bridge after complex reconstruction.