Repermeabilization of the airway with tracheobronchial prostheses – 300 cases

Author: Ricardo Isidoro

Endoscopy Section, Pneumotisiology Division, Dr. E. Tornú Hospital – Buenos Aires

Abstract

Objective

To report interventions carried out to treat obstruction of the airways in 300 patients at the Respiratory Endoscopy Unit, Tornu Hospital, Buenos Aires.

Materials

The study was a retrospective review of reports on bronchoscopies carried out in 300 patients with total or partial obstruction of the airways due to benign or malignant conditions between 15 September 1997 and 31 December 2009. The study included patients with signs of benign tracheal stenosis, i.e. with a lumen diameter reduced to 8 mm or less, all cases of benign bronchial stenosis compromising 50% of the lumen, and patients with endotracheobronchial tumors obstructing 50% or more of the lumen. Patients who could be treated through surgical resection and those who had images of lung compromise or distal bronchial obstruction were excluded. Also patients with pleural effusion or atelectasis for more than two months were excluded.

Results

Among the 300 patients, 115 were females (38.33%) and 185 males (61.66%) from 14 to 86 years of age. Mean age was 52 years ± 16.26. The obstruction was solved in 96.33% of 388 interventions. Stents were well tolerated in 99.68% of cases and non metallic silicone prostheses in 100% of cases. The complication rate was 6.32%; hemorrhage was the most frequent complication. Case fatality attributable to the therapeutic intervention was 0.25%.

Conclusions

Rigid bronchoscopy was effective in treating obstructions of the airways; the overall success rate, irrespective of the etiology of the obstruction, was more than 96%; case fatality was very low. The silicone prostheses designed for stenosis are certainly more effective than right models for the treatment of benign tracheal stenoses.

Introduction

The endoscopic treatment of lesions that produce occlusion or subocclusion of different magnitude in the trachea, bronchi source or in some lobular, has achieved sufficient diffusion within the international medical community to the point where its implementation is well established1. The indication to apply a method that can recover the pulmonary ventilation suspended by the presence of an obstructive lesion appears immediately in the bronchoscopist. However, it has been limited to those cases in which an open-pit excresis treatment is not possible.

The use of silicone stent is another widely used resource in order to provide additional support to the airway after treatment and to prolong its effectiveness. Thus, the endo-surgical treatment has been simplified and interventional physicians have accumulated experience in its implementation, a task that has been shown to provide benefits that are proportional to the magnitude of the difficulties resolved during its implementation (2, 3).

Material and methods

The data was obtained retrospectively from the reports of interventional bronchoscopy corresponding to procedures performed to treat 300 patients, with benign and malignant conditions that partially or completely occluded the large airway. The interventionism applied to patients was performed in one or several sessions.

In none of them was the resection treatment by conventional surgery and all were subjected to a flexible bronchoscopy in order to evaluate the characteristics of the lesion. Thus, the indication of the procedure was maintained considering the possibility of lung reexpansion and the clinical presumption of improving dyspnea with treatment, in all cases of malignant disease and in benign stenoses that reduced light by 50% or more. This subjective evaluation was established by comparing the diameter in the affected area with that existing in the healthy airway near the lesion; and with the reference of the known caliber of the bronchoscope in use. The patients underwent treatment with rigid or flexible bronchoscope, under general anesthesia and muscle relaxation, in the operating room and under continuous control of cardiac and respiratory function. They received 2 grams of intravenous cephalothin in rapid injection minutes before the procedure. The treatments were carried out by two experienced pulmonologists, dedicated exclusively to bronchoscopy. For recanalization of the airway, dilatation maneuvers were performed with spark plugs of increasing diameter, balloon and / or rigid bronchoscope. An electrocautery was also used to make cuts in some benign stenoses and thermocoagulation with tissue vaporization in the malignant lesions. The cases, for the most part, were treated using a rigid bronchoscope of interchangeable tubes of different calibers, set of optics, prosthesis introducers, clamps suitable for their mobilization, probes and tapes for application of T-tubes of the Montgomery type.

In a few cases, the treatment was performed or completed with a flexible olympus bronchoscope BF1T30. The application of different models and dimensions of silicone stents for the airway was arranged, although dynamic and self-expanding stents were also used. Tolerance to the prosthesis was defined in the absence of symptoms attributable to them that led to their removal. The therapeutic success of the restitution of tracheobronchial lumen was defined: in benign stenoses, it was established to determine as satisfactory tracheal or bronchial repermeabilization, all those in which the light of the affected area had reached 75% or more of the normal caliber for that case, after finishing your treatment. Immediate complications were considered to all those situations attributable to the procedure (haemorrhage, desaturation with a decrease greater than 4%, rupture of the airway wall, migration of the stent) occurred during or until 48 hours after the procedure was performed. The cases of death were recorded when this was due to the treatment instituted or as a direct consequence of it, during its application or subsequent to it.

Results

388 procedures were performed in 300 patients (1.29 procedures per patient). Those performed with rigid bronchoscope totaled 383 (98.7%), while in 5 cases the flexible bronchoscope (1.3%) was used. In 11 of the 300 cases, the recovery of the bronchial lumen was not possible and was considered as failure of the procedure. All of them corresponded to patients diagnosed with carcinoma, and the endobronchial tumor lesion was also intramural and infiltrating. The repermeabilization of the airway was possible in 289 patients (96.33%) (Table 1).

Of the total, 115 were women (38.33%) and 185 men (61.66%). In an age range from 14 to 86 years. The mean age was 52 ± 16.26 years. 311 silicone prostheses (97.8%), a polyflex® self-expanding stent and 6 Freitag dynamic prostheses were used for the treatment, totaling 318 devices. Thus, 126 benign stenosis were treated in the trachea and bronchi (42%), and 174 conditions “not benign stenosis” (58%) (Tables 2, 3). This last group includes 110 cases of carcinomas that include 10 metastases of extrapulmonary primary tumors.

This last group includes 110 cases of carcinomas that include 10 metastases of extrapulmonary primary tumors. Regarding the use of prostheses by pathology, the 126 benign stenosis required 107 stents for their treatment (0.84 stent per patient). For the group of lesions “no benign stenosis”, of 174 cases, 211 devices were used (1.2 ± 4.6 prostheses per patient) (Table 3).

In 51 of the 300 cases treated, no prostheses were used in the first therapeutic session. Of these, 11 corresponded to the group of benign stenosis and 40 to non-benign lesions. Of the latter, 32 cases in which a stent was not initially used, had malignant tumor disease.

Of the 388 procedures, complications occurred in 44 of them (11.34%), which will be detailed below.

Benign stenosis group

From the 126 cases with benign stenosis, 122 affected the trachea (96.82%) and 4 (31.8%) to the source bronchi. 100 of the total, (79.40%) were post-intubation stenosis. From the remaining 26, 4 occurred at the site of a previous tracheostomy, 4 were recurrent at the end-to-end anastomosis site of open surgery performed previously for the resection of the tracheal stenosis, 4 after rupture of the trachea, one after severe trauma to the larynx and another due to aortic aneurysm. The cause could not be determined in 9 cases.

Four benign stenotic lesions were found in the bronchial sources, two were sequelae of pulmonary tuberculosis, one after traumatic bronchial lesion and the other with bronchial anesthetic intubation.

The tracheal stenosis were of complex conformation in 113 cases, (89.7%) simple in 11 (8.7%), and 2 were subglottic (1.6%) (Table 4).

“Non-benign stenosis” Group

The group of patients not included with benign stenosis is formed by all the cases that presented other invasive lesions of the tracheobronchial lumen or that developed its growth in it, and although it is composed in a greater number of carcinomas bronchial, other etiologies were also found in this set, and none of them, as mentioned, can be included in any way with the benign strictures that affect the airway.

Thus, this group includes 174 patients, of whom 38 had their condition located in the trachea, 101 in the bronchi and 35 shared both locations. Table 5 Location

In 11 (10%) of the 110 cases of carcinoma, reconstruction of the tracheal or bronchial lumen was not possible (Table 1).

Regarding the histological type of the lesions, 28 squamous cell carcinomas, 25 adenocarcinomas, 10 small cell carcinomas, 2 giant cell carcinomas and 8 carcinoid tumors were found. Endobronchial metastases totaled 10 cases. In another 13, the endoscopic biopsy identified the carcinoma, but it was not sufficient to establish its histology.

In addition, 1 chondroma, 1 neurofibroma, 11 carcinomas of the esophagus invading the bronchial lumen, tracheal, or both were found; 7 thyroid carcinomas involving the tracheal wall, 4 mediastinal tumors and 1 lymphoma. In one case, the diagnosis was papilloma, in another leimiosarcoma, 1 granuloma and 2 bronchial amyloidosis. In 45 other cases the diagnosis could not be established by flexible bronchoscopy, being also subjected to endoscopic treatment of unclogging. Squamous cell carcinoma was the most frequent tumor with 25.45% of cases, followed by adenocarcinoma: 22.72% and oat cell (9.09%) (Table 6).

In this group, 211 prostheses were used for 174 patients (Table 3).

Three patients with bronchopleural fistula also received bronchoscopic treatment in which the fistula was blocked with a solid, cylindrical silicone device.

In relation to the 10 metastases, 8 of them were from clear cell renal carcinoma, one from a breast tumor and the other from the colon (Table 7).

Complications occurred in 11 cases (6.32%); headed by hemorrhages that matched the suction capacity of the aspiration system, 3 in total (1.71%) resulted from the treatment of an untyped carcinoma, an adenocarcinoma and a carcinoid tumor.

The complications of the present group of lesions “non-benign stenosis” continue with a case with intense edema of the mucosa at the end of a dynamic stent (0.54%), reversible cardiac arrest, during the treatment of a tracheal rupture (0.54%); a superior cava vein syndrome (0.54%) followed by death at 48 hours, in a patient with adenocarcinoma invading the trachea and both source bronchi (0.54%), an atrial fibrillation in a case with adenocarcinoma (0.54%) and a pneumothorax partial in a patient who lacks histopathological diagnosis.

Thus, the mortality determined for this group of 300 patients is 0.33%, and considering the mortality linked to the procedure, it is reduced somewhat more: 0.25% (Table 8).

Intolerance to the prosthesis was extremely rare. Only one case was observed in the whole series, which represents 0.33% in relation to the treated patients and somewhat lower, 0.31% if it is considered depending on the stents used.

It is a dynamic “Y” prosthesis implanted in a patient with intrabronchial metastasis of a clear primary renal cell tumor. The intolerance, manifested by an incoercible cough, was attributed to the intimate contact of the proximal end of the prosthesis with the tracheal mucosa contiguous to one of its rings. The stent was shortened and reinstalled without symptomatic relief and had to be removed and replaced.

Discussion

The usefulness of the method is well established and the selection of patients has been widely discussed and published. Thus exposed, the debate on these points would be, depending on the lack of novelty and the even less contribution of knowledge, monotonous and unnecessary. Observing the frequencies of appearance of inconveniences or the lack of them, considerations arise that are the beginning of this discussion. The series of 300 cases contains a large group of benign stenosis, mostly tracheal. All of them recovered the caliber of the airway with endoscopic interventionism. Then, the procedure in general was clearly satisfactory, with a success in reaching its purpose of 96.33%. Having announced electrocautery as the only device for cutting, vaporization and thermocoagulation used in this series, its resolutive possibilities are bound to 96.33% of resolved cases (4-6). The 3.66% of failures correspond to 11 cases with diagnoses of carcinoma. In them, the procedure fails to find light distal to the obstruction of the airway (5), as happens when the lesions turn out to be intramural and very infiltrating, that is, when the light sought does not exist. The analysis of the group “no benign stenosis” first revealed a greater number of prostheses used (211 units), and its cause is the need to use more than one stent per patient and also in the need for more than one procedure. per patient. This, in turn, indirectly shows that the probable extension of survival allows the malignant disease to progress and thus resort to obstructing the airway in the same or different site, motivating a new intervention. Most of the cases in this group had carcinomas, bronchopulmonary or neighboring organs. Among the latter, the thyroid, with locoregional extension and invasion of the tracheal lumen, circumstance and etiology that in no way modifies the behavior of the bronchoscopist. Eleven cases of carcinoma of the esophagus that, unlike the previous one, injures and bursts through the posterior wall of the trachea or, when its location is lower, involving the left main bronchus once more in its posterior wall, since it is there where the esophageal path intersects with this bronchus. Many times the damage is localized to the left breast, passing the esophagus to the bronchial lumen. It has been very useful to realign the left source bronchus endoscopically, displace the esophagus and cover the fistulas that are a frequent companion in this table, the use of a smooth wall silicone stent, since anchors are not necessary in this circumstance. One end of the device widens in a cone shape and coincides anatomically with the source bronchus birth.

The distal end is beveled and by its shape makes simple the entrance maneuver to the bronchus and the introduction of the stent.

Migration of prostheses, although less common in malignant conditions, is also possible. We describe here only two migrations (1.49%), in which one of them corresponds to a carcinoid tumor in which an error in the early typing of the lesion, led to the treatment of the obstruction with stent implantation. Few comments will be made about two fortunately infrequent events, such as stent intolerance, whose reasons were already clearly developed; and death, as a result of the procedure, which in our report was 0.25%. It corresponded to a patient with mediastinal disease due to an adenocarcinoma.

Since the mediastinal syndrome makes rigid bronchoscopy risky for diagnostic purposes, this risk will be reasonably increased when the procedure is also therapeutic. Since the same factors that operate in the first, will be more influential in the second, because the time necessary for the intervention will be, for reasons easy to understand, much higher. Thus, the maneuvers that this entails and the displacement of tissues caused by the rigid bronchoscope, lead to an increase in local inflammation and aggravation of the already compromised venous return to the mediastinum. Such happened in our case.

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