Outcomes of tracheal resection and anastomosis in patients with tracheal stenosis: a clinical perspective

Abstract

Background

Tracheal stenosis results from an altered inflammatory response to mucosal damage, which leads to impairment of breathing and can even be fatal if not treated promptly (Ind J Otolaryngol Head Neck Surg 73(4):447–454, 2020). ENT and head and neck surgeons face difficulties while treating tracheal stenosis. Mechanical stress from extended endotracheal intubation or tracheostomy, combined with hypoxic metabolic disturbances during an underlying event, is the most frequent cause of tracheal stenosis (Al-Azhar Int Med J 3(10):149-57, 2022). The main objective of the study is to assess the outcomes of tracheal resection and anastomosis in patients who presented with tracheal stenosis. This emphasizes the need for proper case selection and timely surgical intervention to relieve the airway obstruction and to ensure the effectiveness of tracheal resection and anastomosis as the less morbid approach by avoiding a midline sternotomy.

The study was conducted in a tertiary care center on 25 patients who were admitted in ENT ward from the year 2011 to year 2021. Case records of those patients who underwent tracheal resection and anastomosis were analyzed on a retrospective basis. Detailed history taking and clinical examination with appropriate investigations like flexible bronchoscopy, computed tomography with 3-dimensional reconstruction, video laryngoscopy, direct laryngoscopy, and lung function tests were carried out for all the patients in the study as required. An evaluation of GERD was also done. Appropriate surgical procedure was done with regular post-operative follow-up for 18 months.

Results

In our study, 92% of patients had satisfactory outcomes following tracheal resection and anastomosis, while some patients experienced minor complications. In 8% of patients, the primary surgery failed, among whom one patient underwent revision surgery and is doing well. The other patient with post-traumatic stenosis with a long stenotic segment underwent Shiann Yann Lee procedure in an outside center which resulted in failure following which T tube insertion was done. The patient showed improvement and was decannulated after a month.

In our study of 25 patients with tracheal stenosis, postoperative complications occurred and were managed accordingly. However, there was no significant correlation between these complications and patient age, sex, extent of stenosis, preoperative Cotton-Myer grading, or the type of surgical procedure performed. This lack of correlation may be attributed to the limited sample size.

Conclusion

Tracheal resection and anastomosis are challenging procedures and should be done only in centers with experience. Standard treatment consists of resection of the stenotic segment with end-to-end anastomosis. The geometry of the ends to be anastomosed is matched properly to avoid gaps or weak points and for air-tight seal anastomosis.

Background

Tracheal stenosis occurs due to an inflammatory reaction to mucosal damage, either with or without cartilage involvement. Excessive circumferential scar formation during healing causes fibrosis and luminal constriction, which compromises the airway and may even be fatal [1]. Tracheal stenosis is a challenge to the head and neck surgeon and otolaryngologist. The most common cause of tracheal stenosis is mechanical stress caused by prolonged endotracheal intubation or tracheostomy [2]. Other causes include neck trauma, idiopathic, inflammatory, and neoplastic conditions [3]. Tracheal stenosis is believed to be caused by cuff-induced ischemic injury to the trachea following prolonged intubation with inadequate care. Post-intubation tracheal stenosis should be suspected in patients who develop stridor or unexplained dyspnea after a variable period following extubation [3]. The affection of the airway by the inflated cuff of the endotracheal tube depends upon its location. Endotracheal tubes injure the glottis through constant pressure, which may present with significant commissural scarring that can be difficult to treat. The trachea or subglottic area may have severe stomal stenosis following tracheostomy. The cuff of the tube has the potential to cause pressure necrosis, which can be avoided [4]. Damaged cartilage is the most important cause of stenosis at the stoma site [4]. There are various treatment options available, depending on the severity of the disease.

• Endoscopic laser treatments with or without dilatation or stenting are available for reconstruction using anterior, posterior, or mixed costal cartilage grafts [2].

• Endoscopic dilation is usually performed as a temporary measure prior to definitive therapy. Re-stenosis may develop within days to weeks. It is mostly used in the emergency treatment of tracheal strictures [3].

• Laser vaporization and radial cuts of tracheal strictures are other methods available. Thin, web-like stenotic lesions, which are uncommon, respond best to laser therapy; otherwise, laser treatment may worsen the severity of the lesion [2].

Endoscopic dilation and laser vaporization are less successful in cases of stenosis that is circumferential, without cartilaginous support, or longer than 1 cm.

The most severe grades of stenosis are treated with partial cricotracheal resection and extended partial cricotracheal resection.

• The gold standard for treating tracheal stenosis is tracheal resection and primary anastomosis [1]. Tracheal resection is well established as the definitive treatment for tracheal stenosis. Tracheal resection is currently standardized with strong, consistent, and dependable outcomes. The length of the resected segment is the most important determinant of outcome.

• Tracheal stents [4] have been used in patients who are not good surgical candidates. Recently, expandable vascular stents are used in the trachea, as an alternative to tracheal resection.

• Tracheostomy is the management option in patients with tracheal stenosis who are poor candidates for surgery [5].

Some strategies for the prevention of tracheal stenosis [4]:

• ❖ It is important to avoid oversizing the tracheostomy stoma and forcing a large tube into a small stoma. Careful placement of the stoma, avoiding large stomal openings, and meticulous care of the tracheostomy must be done.

• ❖ Wound sepsis and prior cervical or tracheal trauma negatively affect stoma healing.

• ❖ Avoiding damage of the 1st tracheal ring or cricoid cartilage during tracheostomy prevents subglottic stenosis. High tracheostomy should be avoided.

• ❖ Open tracheostomy is considered to be safer than percutaneous tracheostomy, but with expertise, both are safer.

• ❖ The incidence of postintubation stenoses can be reduced by the use of large-volume, low-pressure cuffs [4].

In our study, we reviewed 25 cases of tracheal stenosis who underwent tracheal resection and end-to-end anastomosis over the past 10 years.

Method

A retrospective case series study was carried out in a tertiary care hospital. Case records of 25 patients who underwent tracheal resection and anastomosis in the ENT ward for tracheal stenosis over the past 10 years were studied. The case records of patients with tracheal stenosis aged more than 15 years were reviewed for the clinical history, physical examination, and investigations such as flexible bronchoscopy which was done to find the exact site and size of stenosis aided by computed tomography (Fig. 1) (helical CT with high resolution and 3-dimensional reconstruction) and video laryngoscopy (Fig. 2). Additionally, some patients were evaluated for pulmonary function tests (for patients who are chronic smokers or complaints of chronic cough) and GERD via upper GI endoscopy (for patients with history of heart burn). General anesthetic fitness was obtained and patients were taken up for appropriate surgical procedure.

Fig. 1

Radiologic images showing the stenotic segments

Fig. 2

Grade IV Cotton-Myer stage

The principles of operative repair include tracheal mobilization, dissection close to the trachea to avoid recurrent laryngeal nerve injury, and precise anastomotic technique [3]. General anesthesia was given in all patients via flexo-metallic tube inserted through the tracheostoma. A collar incision was made with the excision of the tracheostoma in tracheostomized patients, and subplatysmal flaps were elevated. Strap muscles were separated on either side. The thyroid isthmus was divided. Dissection started to expose the trachea. In one patient with post traumatic stenosis, peritracheal fibrosis was noticed and managed by careful dissection using the Ryle’s tube as a guide. Dissection continued as close to the trachea as possible in order to avoid injury to the recurrent laryngeal nerve. The stenotic segment was delineated (Fig. 3) and transected horizontally till healthy cartilage was identified.

Fig. 3

Hourglass configuration of stenotic segment showing extraluminal narrowing

Suprahyoid laryngeal drop (Fig. 4) (Montgomery drop/suprahyoid release) was done in all cases that aided in additional 2–3 cm tracheal mobilization which in turn reduced tension at the anastomotic site. Tracheal lower segment mobilization was done along the anterior wall below the sternal notch avoiding the lateral wall to prevent jeopardizing the blood supply. Lower segment anchoring was done, and sutures were made through the upper and lower segments—3 mm circumferential intermittent suturing of posterior wall followed by lateral wall was done. Absorbable 4–0 Vicryl sutures were used with the submucosal passage of the suture, and the knot was tied extraluminally (Fig. 5). The patient was then shifted to orotracheal intubation, and anterior wall sutures were applied similarly.

Fig. 4

Suprahyoid laryngeal drop

Fig. 5

Submucosal extraluminal sutures applied and ends approximated

Sutures were tied in the reverse order, and complete anastomosis was done. Air leak was checked. Second-tier thyrotracheal suturing (Fig. 6) was done with 3–0 Vicryl. Third-tier tension relieving suture from the chin to the chest (Fig. 7) was done, and the procedure was completed.

Fig. 6

Second-tier thyrotracheal suturing

Fig. 7

Tension relieving suture from the chin to the chest

Postoperatively, patients were maintained in a chin-flexed position with adequate back support for 7 days. They were allowed to converse but with minimal neck twisting movements. Ryle’s tube feeding was given for 5 days, followed by straw feeding. Steam nebulization was given. Adequate hydration was ensured. Antibiotics, mucolytics, steroids, and proton pump inhibitors were given. Postoperative flexible endoscopy was done on the 10th postoperative day, and patients were kept on regular follow-up for an average period of 18 months after discharge (Fig. 8).

Fig. 8

Pre op grade III and 6-month follow-up videolaryngoscopic image

Results

The case series study consisted of 25 cases of tracheal stenosis (summarized in Table 1) evaluated from a 10-year study period between 2011 and 2021. Among 25 patients, 23 (92%) were male, and only 2 (8%) were female (Fig. 9) with an age range of 19–36 years (average age of 25.16); 72% of the patients were in the age group of 19–25 years. In 23 (92%) of our cases, the cause was postintubation stenosis, and 2 (8%) cases were post blunt trauma to the neck. In 20 cases (80%), prior tracheostomy was done, hence anesthetized via the tracheostomy site. In 3 cases (12%), intraoperative tracheostomy was done and proceeded. In 2 cases (8%) without tracheostomy, the endotracheal tube was kept proximal to the stenotic site and proceeded. Twenty-two cases were done independently by our ENT team, and 3 cases were done along with the assistance from the cardiothoracic team.

Table 1 Summary of patient’s preoperative, intraoperative, and postoperative data

Fig. 9

Sex distribution of patients

Twenty-four percent of our patients had Cotton-Myer grade IV stenosis, whereas 76% had grade III stenosis (Fig. 10). Fifty-two percent of our cases (n = 13) had involvement of 4–5 tracheal rings with a maximum of 7 tracheal ring involvement in one case (Fig. 11). In 4 cases (16%), cricotracheal anastomosis was done; in the remaining 21 (84%), tracheotracheal anastomosis was performed. Suprahyoid laryngeal drop was done in all 25 cases. One case with postoperative vocal cord palsy had excessive paratracheal fibrosis and scarring around the tracheostomy site which made the tracheal mobilization difficult. All patients were extubated immediately after surgery after reversal from general anesthesia. Postoperatively, except 1 case requiring tracheal stent, other cases were maintained on steroids and antibiotics, avoiding neck extension to prevent extensive traction at the anastomotic site.

Fig. 10

Preoperative Cotton-Myer grading

Fig. 11

Extent of stenotic segments

We encountered the following postoperative complications (Fig. 12).

Fig. 12

Postoperative complications encountered

Five patients developed granulation at the anastomotic site noted during follow-up around the 2nd and 3rd postoperative week. Patients presented with cough and minimal dyspnea. Three patients with minimal granulation resolved spontaneously, whereas the other two were treated with intravenous dexamethasone and antibiotics. Granulation formation occurred in our cases only during the early learning curve due to lack in technique of submucosal extraluminal suturing and inadequate anastomosis.

Two patients developed subcutaneous emphysema, out of which one patient had minimal subcutaneous emphysema in the immediate postoperative period which was relieved on removal of two skin sutures. The other patient developed unrelenting subcutaneous emphysema and had to undergo revision surgery. Thus, subcutaneous emphysema may be considered as one of the earliest indicators of failure of surgery [6].

Unilateral vocal cord paralysis was encountered among three patients which was identified on endoscopic examination. Patients had no symptoms of voice change or aspiration. Two cases gradually resolved spontaneously on follow-up over 6 months. In one of the post traumatic patients where there was difficulty encountered intraoperatively during dissection, the paralysis remained persistent.

Two patients in our study developed mild hypoxemia of SpO₂ 92–95% in the 1st and 2nd postoperative day. This might have been due to dehydration in the early postoperative days which resulted in thick viscid secretions. This led to mild airway compromise and was relieved on nebulization with steroids, salbutamol, IV antibiotics, and adequate fluid management.

Out of the 25 patients, 2 cases underwent revision surgery. Failures occurred in the initial phase of the learning curve. One is due to faulty technique where the patient developed dyspnea on postoperative day 10; the patient underwent revision surgery which resulted in a successful outcome. The second patient underwent Shiann Yann Lee procedure but could not be decannulated due to the separation of anterior anastomosis and wound dehiscence; since the posterior wall was intact, Montgomery T tube was inserted to maintain the airway, and the wound granulated and healed well over a period of 2 weeks following which the patient was successfully decannulated from Montgomery T tube 1 month later (data summarized in Table 2). No mortality was reported, and decannulation was achieved in all our patients with all of them returning to their regular lifestyle.

Table 2 Distribution of patients’ demographic profile and predictive variables

A chi-square analysis was done to study the relationship between various patients and treatment characteristics and the occurrence of postoperative complications (Table 3). Patients with grade III Cotton-Myer grading had a higher complication rate (52.6%) compared to grade IV patients (16.7%), but this was not statistically significant (P = 0.12). This might be due to more number of patients with grade III stenosis in our study (n = 19) than grade IV stenosis (n = 6). Patients with an extent of stenosis affecting less than 3 tracheal rings had a 40.0% complication rate, compared to 46.7% in patients with more than 3 rings affected which was also statistically insignificant (P = 0.74). There was no significant difference in the rate of complications between cricotracheal (50.0%) and tracheotracheal (42.9%) anastomosis types (P = 0.48).

Table 3 Statistical correlation between different variables and postoperative complications

In this cohort of 25 patients with tracheal stenosis, postoperative complications were minor and relatively common but did not significantly correlate with patient age, sex, extent of stenosis, pre-operative Cotton-Myer grading, or type of surgical procedure performed. This might be due to the limited sample size. Further studies with larger sample sizes may help elucidate these relationships more clearly.

Discussion

The most frequent and well-known causes of tracheal stenosis are endotracheal intubation and tracheostomy [7]. The prevalence of post-intubation or post-tracheostomy stenosis continues to rise as a result of more intensive care facilities and increasing numbers of individuals requiring artificial ventilation for various reasons [8]. In our study, 92% of the cases had a history of intubation.

The pressure exerted on the tracheal wall by the cuff is hypothesized to be the primary cause of stenosis, which results in a loss or reduction of regional blood flow. Fortunately, the prevalence of cuff-related tracheal injury has significantly decreased since the introduction of high-volume, low-pressure cuffs [9].

According to M.F. Sahin et al., there was no statistically significant difference between the resection lengths of the stenotic segment and bronchoscopic measurements, but there was a statistically significant difference between the resection length and preoperative CT measurements. When estimating the length of the resection before surgery, bronchoscopy measurements produce more accurate results than CT measurements. Therefore, bronchoscopy is one of the most effective diagnostic methods for assessing airway stenosis [5].

The gold standard for treating tracheal stenosis is tracheal resection and primary anastomosis [2]. Tracheal resection is the definitive treatment for tracheal stenosis. Tracheal resection is now a standardized operation with good results [10]. In our study, all cases underwent tracheal resection and anastomosis. Our results are consistent with previously reported studies that although tracheal resection and anastomosis is a challenging procedure the outcomes are predictable and reliable [11].

The extension of the neck and sufficient release of the trachea from the surrounding tissue allows for resection and reconstruction of the middle third stenosis without the need for a sternotomy. None of our cases were subjected to mid-line sternotomy. Suprahyoid laryngeal drop [12] and superior mediastinal mobilization were done to achieve sufficient mobilization of the trachea in all our cases, whereas infrahyoid laryngeal drop was not performed in our patients. As described by Grillo [13] and Monnier [14], with adequate laryngeal release procedures, successful resection of up to eight tracheal rings is possible.

Similar to previous studies [15], complications were encountered in our patients during the early period of our learning curve. Granulation at the site of anastomosis was the most commonly encountered complication in our study. On refining our technique of placement of submucosal extraluminal knots, we did not encounter this complication as frequently. Although all our patients were relieved with intravenous corticosteroids, severe cases can typically be treated by locally clearing away tissue using the tip of a rigid bronchoscope [16]. Injecting corticosteroids around the granulation area post-debridement might offer additional benefits. Several studies such as the study by Bibas et al. [17] have reported re-anastomosis as the most frequently encountered complication, while we encountered 2 such situations in our study where there was a need for revision surgery.

Postoperative neck flexion was maintained with the help of guardian sutures in our center but a minority of surgeons do not use these sutures. Some studies suggest that avoiding the guardian stitch decreases the duration of hospital stay [18]. Tracheal stenosis is one among the many diseases where prevention is the much easier route than cure.

Conclusion

Tracheal resection and anastomosis are challenging and should be done only in centers with experience.

Standard treatment consists of resection of the pathologic segment of the trachea with end-to-end anastomosis which provides a > 95% success rate. Tracheal resection followed by end-to-end anastomosis is now a well-established technique. In our study, 92% of cases had successful outcome in a single-stage procedure. Minor complications were noted among 44% cases.

Careful attention in matching the geometry of the ends to be anastomosed is important to avoid gaps or weak points and for air-tight seal anastomosis; nonetheless, some telescoping of the anastomosis ends is allowed.

Adequate planning of ENT surgeon and anesthesia support is essential for ventilation, hemostasis, and better visualization.