Introduction

Iatrogenic airway injury after tracheotomy and endotracheal intubation continues to be a serious clinical problem [₁,₂,₃]. Endotracheal tube causes pressure injury to the glottis and may result in severe commissural scarring that is difficult to treat [¹,²,₄]. Tracheotomy tubes may result in severe stomal stenosis in the trachea or subglottic region [¹,²,₅,₆]. Both methods of airway intubation may result in pressure necrosis, which is a preventable problem, from the tube cuff [¹,⁵,⁶]. This report reviews the postintubation tracheal stenosis in 45 patients with special regard to etiology and treatment of the stenoses.

Materials And Methods

Between, February 1985 and January 2002, 45 patients with postintubation tracheal stenosis had been admitted at our Department. Four patients were pediatric age group. Patients' characteristics are included in Table 1. Case records were reviewed for etiologic factors, diagnostic methods, surgical therapy and outcome. The severity of stenoses was classified as mild if less than 50% of the tracheal lumen was obstructed; moderate was 50% to 90%, or severe more than 90%. All patients were intubated or undergone tracheostomy for ventilation support in other clinics.

Figure 1

Table 1: Patients' characteristics

The cuffs of tubes accounted for 12 lesions. Eight of these patients had an endotracheal intubation only. Duration of the intubation was 10.5 (2 – 14) days. In other 4 patients tracheostomy was performed 8.3 (6-14) days after endotracheal intubation. Duration of the tracheostomy was 23.7 (20-26) days. The interval for the stenoses development was 29.5 ± 11.3 days, after extubation or decanulation. Two patients with subglottic stenosis had an endotracheal intubation only. In these patients, durations of the intubation were 10 and 13 days.

In 29 patients, stenoses were located at the stoma site only. Duration of tracheal intubation was 5.6 (4-14), and the tracheostomy was 28.3 (16-52) days. 22 patients underwent open tracheostomy. In these patients, predisposed factors of the stenoses are infection at stoma site in 10 patients, and cervical soft tissue trauma in 6 patients. In 4 patients, tracheotomy was performed urgently by an untrained person.

7 patients had a percutaneous procedure. In 5 of these patients, high tracheostomy was performed by mistake resulting in subglottic stenosis. In another patient, a large tube was used, and tracheal stenosis developed resulting from tracheal cartilage damage. Duration of the tracheostomy was 8.7 (3 – 20) weeks. Time interval for the stenoses development varied from 1, days to 2 months (19.8 ± 18.9 days) after decanulation.

Two patients had double stenoses both of at the stoma and the cuff site. Durations of the tracheostomy were 8 and 15 days. One of these patients had infection at stoma site and pneumonia.

All patients were performed rigid bronchoscopy. If the severity of stenosis was mild and the length of the stenotic segment was less than 1 cm, bronchoscopic treatment including forceps resection, cryosurgery, local steroid injection and repeated dilations were applied. In the patients, who had a severe or moderate stenosis, resection was performed. Surgical approach was made through a cervical incision in all patients. The addition of right thoracotomy was required in two patients, who had double stenoses.

All surgical procedures were performed under general anesthesia. Rigid bronchoscope was used at the time of resection. Dilation was done serially with dilators and pediatric bronchoscopes. After the stenotic segment was resected, and the distal airway was divided, ventilation was obtained by inserting an armored endotracheal tube in the distal tracheal segment by using sterile connections across the operative field. Existing stomas were often used for intubation, especially in cases of subglottic stenoses.

Tracheal resection:

Subglottic resection:

In 4 of 7 patients with subglottic stenosis, complete resection of the trachea and anterior cricoid was done. Anastomosis of the trachea to the cricothyroid membrane or thyroid cartilage was performed as described by Grillo [¹]. In the other 3 patients, a costal cartilage graft was used at anterior wall of the subglottic area because of the large defect, after the resection of the anterior cricoid and trachea (Figure 1).

Figure 2

Figure 1: Operative photograph of a patient with subglottic stenosis. In this patient, costal cartilage graft was used in order to close the anterior large defect after the stenotic segment had been resected.

All anastomosis were done with using interrupted 3-0 nonabsorbable sutures in these patients. Endoscopic control of anastomosis was performed between postoperative day 7 and 15. An endoscopic resection sometimes was necessary for granulomata. The long-term follow-up included endoscopic examinations at 6 months after surgery.

Results

Eleven patients were treated by bronchoscopic treatment. Overall, 14 procedures were performed. All these patients had tracheal stenosis. Outcome was successful in this group of patients.

27 patients were treated with tracheal resection and primary anastomosis. The length of resected segment ranged from 1.5 to 4 cm. In 23 patients, treatment was successful. In 3 patients, granulation tissue formed at the anastomosis line. These patients were managed by bronchoscopic removal of granulation tissue. In one patient restenosis occurred, and a second resection required. This patient is without symptoms 9 months after the second operation.

In 5 of the 7 patients who had subglottic stenosis, treatment was successful. Stenosis recurred in two patients. One patient in whom costal cartilage graft had been used at anterior wall was not treated by bronchoscopic resection. Reoperation was required after 5 months. Anterior wall was resected partially and closed with adjacent tissue. This patient could perform normal activities, but he died of the chronic respiratory disease and pulmonary insufficiency 3 months after the second operation. The other patient, who had a restenosis, needed a T - tube. It wasn't successful and second operation was performed 7 month later after the first operation. Anterior wall of the anastomosis was resection, and costal cartilage graft was replaced. But, it is failed and severe infection developed. This patient died 6 days later because of sepsis.

Eleven complications appeared in 6 patients. Complications in all patients are demonstrated in Table 2. During post-hospital period, 13 patients died as a result of the primary disease. In 30 patients, the follow-up period ranged from 6 month to 7 years (mean, 3.2 years).

Figure 3

Table 2: Postoperative Complications

Discussion

Oral or nasal endotracheal tubes or tracheostomy tubes are most commonly used to deliver mechanical ventilatory support in respiratory failure [₇]. Despite technological improvements and more skilful patient care, tracheal and laryngotracheal stenoses still represent an important group of complications after intubation and tracheostomy [¹,²,³,⁴,⁵,⁶,⁷]. The reported incidence of tracheal stenoses following tracheostomy and laryngotracheal int0ubation ranges from 0.6% to 21% and 6% to 21%, respectively [⁵,⁷].

Tracheal stenoses mostly occurs of the location of cuff of the tube [¹,⁵,⁶]. But, in our series, ratio of the cuff stenoses is lower than these of published series. The large-volume, low-pressure cuffs markedly reduce the occurrence of cuff injury [¹]. The most important reason of the stenoses in the stoma site is a damaged cartilage [¹,²,⁵,⁶]. The stoma must not been made too large, and the large size tube must not been inserted into small stoma by force [¹,⁵,⁶]. Wound sepsis and previous cervical or tracheal traumas negatively affect healing phase of the stoma [¹,⁷,₈,₉,₁₀]. In our series, wound sepsis was found as a causative factor in approximately 42% of the patients who had stomal stenosis following open tracheostomy.

Although subglottic stenoses most commonly result from endotracheal tube damage, it may occur following damage of the first tracheal ring or cricoid cartilage during tracheostomy [²,³,⁶,⁷]. In our study, 5 patients had subglottic stenosis, which developed secondarily to the damage of this area, after percutaneous tracheostomy. If the damage of this area is noticed during the tracheostomy, the stoma site must be changed immediately.

Although complications of the open tracheostomy are higher than percutaneous procedure, according to the recent literature, percutaneous tracheotomy procedures can be associated with a high rate of complications, some fatal [⁸,₁₃]. Excessive strength on the trachea must not be applied to prevent cartilage damage particularly during the percutaneous tracheostomy. Particularly during the percutaneous tracheostomy, placement of the stoma must be careful by the bronchoscopy [⁸,⁹,¹⁰,₁₁,₁₂,¹³]. However, either open tracheostomy or percutaneous tracheostomy should been used only by physicians who are able to master any eventual surgical complications by virtue of their experience and training [⁸,⁹]. Our preference is in favor of open tracheostomy.

Conservative treatments may carry out for the lesions with no circumferential scarring, no loss of cartilaginous support, and stenosis smaller than 1 cm in length [₁₄]. In this study, 11 patients (85% patient with mild stenosis) was applied bronchoscopic treatment successfully and without complication.

Tracheal resection and end-to-end anastomosis is now a well-established technique under well-codified indications, which requires no commentary [¹,²,³,⁵,⁶]. According the literature success rate is 71- 97% [¹,²,³,⁵,⁶]. In our series, good result was obtained in 96 % of tracheal resection.

Resection of the long tracheal segment may necessary in-patients with multiple stenoses. Resection both segments in continuity may result in a tracheal defect too extensive for primary tracheal anastomosis [²,³,⁶]. Therefore, we preferred dual resection in two patients who had distinctly obstructive double stenoses with intervening areas of adequate lumen.

Lesions that involve the subglottic larynx as well as the upper trachea are much more difficult to repair surgically [¹,²,³,⁴]. Subglottic stenoses after the high tracheostomy are more extensive than subglottic stenoses due to endotracheal tube. Although 5 patients in the present series were managed successfully, 2 other patients had a failed airway reconstruction because of extensive subglottic scarring despite numerous procedures. Although costal cartilage plasty is usually used in the children, may be used at large anterior large wall defect after the resection in the patients with subglottic stenoses as in our patients [₁₅].

Complication rate is generally low for tracheal lesions. Serious complications more often follow laryngotracheal resections [¹,²,³,⁴,⁵,⁶,⁷]. In our series, complication rate was 18%. The most common late complication has been the formation of granulations at the suture line [¹,³,⁵,⁶]. Granulations may usually be managed with bronchoscopic removal. Grillo reported that this problem could largely be eliminated with the use of absorbable suture material and meticulous surgical technique [¹]. In our series, it isn't any relation with suture materials and complications. But, we have preferred absorbable suture in recent years.

Conclusion

The incidence of postintubation stenoses can be reduced by use of large-volume, low-pressure cuffs, careful placement of the stoma, avoidance of large apertures, elimination of heavy and prying ventilatory connecting equipment, and meticulous care of the tracheostomy. Furthermore, it seems that percutaneous procedure is a safe method shouldn't encourage to physicians who are inexperienced especially. Concurrent bronchoscopic visualization is essential in reducing complication of percutaneous tracheostomy. Tracheal stenoses often are very easy to cure. However, the treatment of laryngotracheal stenoses is difficult particularly stenosis with large laryngeal defect and cases originated from failure of previous surgical attempts.

Correspondence to

Alpay Sarper, MD Akdeniz Üniversitesi Tip Fak. Gögüs Cerrahisi Anabilim Dali (07070) Antalya TÜRKIYE Telephone number: +90 242 227 43 43 / 21120 Fax number: +90 242 227 88 44 E-mail address: Sarper@med.akdeniz.edu.tr