Montgomery T-Tube

What It Is

• Upper (vertical) limb - extends superiorly through the subglottis/stenotic segment toward the glottis
• Lower (vertical) limb - extends inferiorly in the trachea
• Horizontal (external) limb - exits through the tracheostomy stoma for access, suctioning, and ventilation

Material & Design

• Made of implant-grade silicone - soft, pliable, and non-adherent smooth surface
• Available in clear or radiopaque material
• MRI-safe
• Comes in multiple series: Pediatric, Standard, Thoracic, Extra-Long, and Tapered
• A safety ring-and-groove system secures a plug to cap the external limb, allowing the patient to breathe and speak normally via the upper airway when plugged

Indications

Contraindications

• Aspiration by the patient (risk of material entering the lung through the stent)
• Patients requiring positive pressure-assisted respiration (the T-tube is not compatible with standard mechanical ventilation via the tracheal route without special adaptors)

Advantages Over Solid Stents

Placement

• Inserted by an ENT or thoracic surgeon experienced with the device
• Placed under general anesthesia, typically with rigid bronchoscopy or direct laryngoscopy
• The external limb is plugged with the provided ring/plug system when the patient breathes spontaneously through the upper airway
• For anesthesia: a balloon catheter is used to occlude the upper end of the T-tube to create a closed system for ventilation

Nursing & Post-Operative Care

• Humidification and regular suctioning of both upper and lower limbs are essential - mucous plugging and crusting are the most common complications - Tintinalli's, Ch. 247
• Daily saline nebulizers are prescribed
• Carbocysteine may be added if mucus plugging is problematic
• The patient must be educated about the single-lumen design and its inherent higher risk of obstruction compared to double-cannula tubes

Complications

Early (perioperative)

• Postoperative fever
• Bleeding
• Excessive mucus secretion
• Irritating cough
• Short-term dyspnea

Late (long-term)

• Granulation tissue formation - most common at the upper edge, often due to friction from tube displacement during swallowing or speaking
• Mucous plugging / obstruction - from impaired expectoration
• Secondary infection / microbial colonization
• Tube dislodgement - migration from coughing or swallowing
• Ischemic mucosal injury - if pressure on mucosa exceeds 20-40 mmHg capillary pressure

Emergency Management of T-Tube Obstruction

1. Suction both the upper and lower vertical limbs
2. If obstruction persists after suctioning - remove the entire T-tube
3. Re-establish airway via tracheostomy with an appropriately sized tracheostomy tube or endotracheal tube
4. Do NOT attempt to pass an endotracheal tube blindly if the T-tube is still in situ
5. Consult specialist (ENT/thoracic surgery) for re-insertion - Tintinalli's Emergency Medicine, Ch. 247

Relationship to Other Tracheal Stents

Tracheal Reconstruction

Anatomy Relevant to Surgery

Surgical Access by Level

Tracheal Resection and Primary Anastomosis

Patient Positioning

• Supine with inflatable pad beneath shoulders to extend the neck maximally
• The pad is deflated after resection to allow neck flexion for a tension-free anastomosis

Key Intraoperative Steps

1. Subplatysmal flaps developed superiorly to thyroid cartilage, inferiorly to clavicular heads
2. Strap muscles separated in midline; thyroid isthmus divided and retracted
3. Tracheal mobilization - dissection kept immediately adjacent to the tracheal wall (preserves recurrent laryngeal nerves and lateral blood supply)
4. Lesion localization - intraoperative bronchoscopy + 25-gauge needle through the tracheal wall at the upper and lower extents of the stenosis
5. Stay sutures placed in proximal and distal ends before division to assist alignment and gauge tension
6. Distal airway management - proximal ETT withdrawn; sterile armored ETT placed in distal trachea across the surgical field for ventilation during resection
7. Frozen section of resection margins (especially for malignant tumors)

Anastomosis Technique

• Posterior membranous wall: continuous running absorbable suture
• Anterior cartilaginous wall: interrupted simple absorbable sutures (e.g., 4-0 Vicryl) placed circumferentially, every 5 mm, knots tied outside the lumen
• Sutures are placed through the cartilage ~4 mm from the cut edge and 4 mm apart
• Anastomosis tested by insufflation to 20-30 cm H₂O while submerged in saline - must be completely airtight

Wound Closure

• Sternohyoid muscle or thyroid isthmus used to cover and buttress all suture lines
• If innominate artery was dissected, a pedicled strap muscle flap is interposed between the artery and trachea
• Flat suction drains placed in pretracheal and substernal spaces

Tension Reduction: Mobilization Maneuvers

Montgomery Suprahyoid Release

Guardian (Chin-to-Chest) Stitch

Subglottic / Cricoid Involvement

• Anterior-only involvement: anterior cricoid arch resected, distal trachea beveled to match the defect - recurrent laryngeal nerves are spared
• Circumferential involvement: may require laryngectomy, or the oblique cricoid resection (Pearson technique): resection line begins anteriorly at the inferior thyroid cartilage border and passes posteriorly below the cricoid plate, below the recurrent nerve entry point; the distal trachea is "telescoped" in front of the residual cricoid shell (thyrotracheal anastomosis)
• In pediatric CTR (cricotracheal resection): laryngeal release is usually not required - Scott-Brown's Otorhinolaryngology

Carinal Resection and Reconstruction

1. Carinal restitution (for small/central tumors only): medial walls of right and left mainstem bronchi are approximated to create a neo-carina, then anastomosed to the distal trachea
2. Standard carinal reconstruction (most common): trachea anastomosed end-to-end to one mainstem bronchus (usually left); the other bronchus anastomosed to the lateral wall of the trachea above the first anastomosis
3. The left mainstem bronchus is relatively fixed by the aorta, limiting approximation - this is why most carinal reconstructions are right-sided approaches

Postoperative Management

• Extubation in the OR is preferred after tracheal resection
• If airway is unsatisfactory: small ETT with cuff deflated left for 24-48 hours, with IV dexamethasone (4 mg q6h), diuretics, fluid restriction, head elevation to reduce laryngeal edema
• Re-examine under anesthesia at 48 hours; if still problematic, a small tracheostomy tube placed 2 rings below the anastomosis (not through it)
• Contraindications to repair (Sabiston): (1) inadequately treated laryngeal problem; (2) need for permanent ventilatory support (ALS, myasthenia gravis, quadriplegia); (3) high-dose steroids; (4) inflamed/recent tracheostomy

Tracheal Substitutes (When Primary Anastomosis Is Not Possible)

Contraindications to Surgical Resection (Tracheal Tumors)

• Invasion of critical mediastinal structures (aorta, esophagus, superior vena cava)
• Tumor involving an extensive tracheal length precluding tension-free anastomosis
• Bilateral recurrent laryngeal nerve sacrifice (requires permanent tracheostomy)
• Poor functional status / inability to undergo major surgery

Palliative / Endoscopic Options for Unresectable Disease

• Dilation (bougie or balloon) - temporizing only
• Rigid bronchoscopic debridement / coring out
• Nd:YAG laser vaporization - best for pedunculated, vascular tumors; can be done through flexible scope under topical anesthesia
• Photodynamic therapy (PDT) - useful for circumferential or submucosal tumors
• Cryotherapy
• Brachytherapy
• Tracheal stenting (Dumon or Montgomery T-tube) - maintains lumen, especially in long-segment or subglottic stenosis

Outcomes

• For benign stenosis (post-intubation): success rates >90% with segmental resection and primary anastomosis - Cummings Otolaryngology
• Primary tracheal malignancies: surgical resection with primary anastomosis is the therapy of choice when feasible; adenoid cystic carcinoma and squamous cell carcinoma are the two most common types
• Subglottic involvement and impaired vocal cord movement are associated with poorer outcomes
• Anastomotic complications (dehiscence, restenosis) are the most feared postoperative problems and are directly related to anastomotic tension and devascularization

Slide Tracheoplasty

Background and Indication

• K.J. Lee's Essential Otolaryngology, p. 1035

Concept and Geometric Principle

• The stenotic segment is divided at its midpoint
• The proximal half is incised anteriorly in the midline
• The distal half is incised posteriorly in the midline
• The two segments are slid together (overlapped), matching the open anterior of one to the open posterior of the other

1. Length reduced by half (minimizing anastomotic tension compared to full resection)
2. Circumference nearly doubled
3. Cross-sectional luminal area quadrupled

Advantages Over Other Techniques

Preoperative Assessment

• Flexible or rigid bronchoscopy: delineates the proximal and distal extents of stenosis, the degree of narrowing, and identifies associated bronchomalacia/bronchial stenosis
• Intraoperative localization trick: place the scope at the proximal end of stenosis, turn off the room lights - if the light is visible superior to the clavicles, a cervical approach is feasible; if inferior, a thoracic approach is needed
• CT with contrast + 3D reconstruction: maps the full extent of stenosis and identifies associated vascular anomalies (especially LPA sling)
• Cardiac echocardiogram: for concurrent cardiac defects requiring simultaneous repair

Surgical Technique (Detailed)

Setup and Access

• Performed on cardiopulmonary bypass (CPB) or ECMO - this is standard for LSCTS
  • CPB improves tracheal exposure by allowing retraction of the innominate artery away from the underlying trachea
  • Allows simultaneous repair of concurrent cardiovascular anomalies
• Cervical approach (low collar incision): accesses upper two-thirds of the trachea
• Intrathoracic approach: original description; used for more distal stenosis

Localization of the Stenosis

• An assistant performs bronchoscopy (rigid or flexible) while the surgeon places a 30-gauge needle into the airway at the proximal and distal extents
• The length of stenosis is measured and the midpoint is marked on the anterior airway surface
• Alternatively, transillumination can be used

Tracheal Division

• Circumferential dissection of the trachea is performed only at the midpoint of the stenosis (lateral blood supply preserved above and below)
• Retention sutures placed in the distal segment before division
• Bevelled transection commencing on the anterior trachea proximal to the midpoint, extending over two rings distally, with the posterior transection point at or just distal to the midpoint
• Result: the transection itself is oblique, not flat

Incisions on Each Segment

• Distal trachea: split in the midline posteriorly to just beyond the distal extent of the stenosis
• Proximal trachea: split anteriorly to just beyond the proximal extent - typically up to the thyroid cartilage
• The most damaged/stenotic tissue at the midpoint may be resected if desired
• The right-angled edges are trimmed to allow better approximation

Anastomosis

• Suture: double-armed PDS (polydioxanone), typically 4-0 with RB-1 needles in older children/adults
• Running suture technique (not interrupted) - no attempt is made to keep sutures extraluminal, but the suture is carefully tightened as the anastomosis proceeds
• Completed with a single proximal anterior knot
• Anastomosis is leak-tested then sealed with fibrin glue
• Patient is typically extubated at the end of the procedure

Optional Adjunct Maneuvers for Tension

• Suprahyoid release for upper segment mobilization
• Right intrapericardial hilar pulmonary release for lower segment
• Pedicled thymic lobe interposed between the reconstructed trachea and the innominate artery (protection)

Special Cases

• Pre-existing tracheostomy: can be incorporated into the anterior proximal incision
• Combined subglottic stenosis (SGS): if SGS co-exists and a graft to the anterior cricoid is feasible, the lower trachea can be slid into a split anterior cricoid instead of using a costal cartilage graft
• Slide into posterior cricoid: technically possible but challenging with unpredictable results - not recommended - Scott-Brown's Otorhinolaryngology Vol 2

When to Operate

• Severely symptomatic patients in the first few months of life
• Patients with poor exercise tolerance around age 5 years
• Short-segment stenosis (1-2 rings): resection and anastomosis is still preferred over slide tracheoplasty
• Long-segment stenosis (extending the entire trachea in extreme cases): slide tracheoplasty is the only option since resection would be impossible

Postoperative Care

• Multiple flexible bronchoscopies for bronchoalveolar lavage required following surgery (secretion management)
• Often requires several balloon dilations until the trachea fully relaxes and remodels
• Absorbable PDS stents (preferred over metallic stents) used for post-operative malacia, particularly bronchomalacia
• Granulation tissue at the anastomosis: treated with balloon dilation ± endoscopic debridement
• Over 50% of patients can be extubated within 48 hours in experienced centers

Outcomes

• Cummings Otolaryngology, Ch. 210 (Ywakim & El-Hakim series: slide n=149 vs other repairs n=122)

• Pre-operative bronchomalacia
• Bronchial stenosis (though survival still >70% in these groups)
• Scott-Brown's Otorhinolaryngology Vol 2, Ch. 31

Comparison with Patch Tracheoplasty