injure the compromised mucosa and worsen the output through the stula. To avoid this problem, it is very important to try to place the stent avoiding the coincidence of the studs with the stulous ori ce. Assisted rigid bronchoscopy with forceps is essential for the insertion and placement of silicone prostheses. It is important to choose a relatively long stent in order to cover the stulae and to have both ends of the stent with a safe distance from the stula to avoid complications.

The indications for placing a prosthesis in the airway will be conditioned by the effectiveness of the esophageal prosthesis. Sometimes the airway prosthesis placement is essential to achieve good palliation of symptoms, when the esophageal prosthesis does not completely cover the stula and cannot be replaced by another one or in cases that esophageal stenting is not possible due to location, as well as when the lesion has affected a large portion of the esophageal wall or when there is a degree of esophageal stenosis that makes progression of the stent dif cult or impossible. Of course if there is evidence of airway obstruction, it may be another indication for airway stent placement.

When dual stenting (both esophageal and airway) is considered, it has to be carefully planned and discussed in a multidisciplinary fashion, given the risks involved, since double stenting can enlarge the stula and worsen clinical situation [39]. In case it is considered appropriate, it is recommended to place the respiratory prosthesisrst followed by the esophageal one, to avoid extrinsic compression or collapse of the airway secondary to the digestive prosthesis pressing on the tracheal or bronchial wall.

Although there seems to be a general consensus on the use of dual stents for ADF, its application is still controversial with authors preferring to place only one prosthesis. As mentioned, a case by case multidisciplinary discussion is in order to make the best decision for the patient [39].

Regarding airway stent choice, it will depend mainly on location, and size of the stulous ori-ce, as well as the characteristics of the wall abnormalities [38]. Straight and hourglass-­ shaped stents are commonly used in the trachea while Y-shaped or L-shaped stents are usually

used in lower airway stula, near the carina, or affecting both carina and mainstem bronchi. When the esophageal stula ori ce is located in middle and distal esophagus without main airway stenosis, an esophageal covered stent is adequate, and there is no need for an airway stent [40].

Chaddha et al. [41] suggested that the ideal stent should meet the following requirements: (i) cover the stula ori ce completely and t perfectly to the tracheal wall; (ii) press rmly against the tracheal wall to prevent dislocation; (iii) the membrane of the metallic stent has to be secure and durable; (iv) the stent has to be able to keep a certain tension for a long period; and (v) it can be placed and withdrawn easily.

A careful clinical, radiological, and endoscopic examination is mandatory in order to decide the kind, size, shape, diameter, and length of the prosthesis. After placement, endoscopic follow-up will help determine status of the stent, presence of obstruction or migration, granulation or tumor tissue growing, or retention of secretions.

We recommend using a rigid bronchoscope for all these procedures, since it is easier, more effective, and safer than the beroptic bronchoscope, especially when silicone stents are involved. With SEMS, after deployment through the ber bronchoscope, we also recommend always having a rigid bronchoscope at hand, and the necessary accessories to use them, in case there is need to treat complications during the procedure.

Clinical Results

Many articles have been published evaluating the ef cacy and safety of stent placement in malignant digestive-respiratory stulas (DRF).

Herth et al. published the ef cacy of dual stenting versus single stenting regarding quality of life (QoL) in a group of cancer patients suffering from malignant DRF. Some patients received a single prosthesis in the airway, while the other two groups received either only in the esophagus or dual stenting. The overall QoL scores of the patients improved signi cantly after placement of stents. The improvement in QoL 10 days post

stent insertion was quite evident in most of the patients. There was no signi cant difference between the groups, demonstrating that airway and/or esophageal stent insertion was appropriate in improving the overall QoL. The authors concluded that airway and/or esophageal stent insertion provides an effective approach to improve QoL in patients with malignant ADF [42].

In order to assess the ef cacy of the stent treatment in patients with ADF and based on an existing classi cation for central airway stenosis (the Freitag Classi cation System [43]), Wang et al. [44] developed a thorough system that could be useful in the choice of one stent for the treatment of ADF, depending on the location. They included 63 patients with malignant ADF, 12 patients with lung cancer, and 46 patients with esophageal cancers.

They differentiate eight different zones according to location:

\1)\ Zone I, upper trachea \2)\ Zone II, middle trachea \3)\ Zone III, lower trachea \4)\ Zone IV, carina

\5)\ Zone V, right main bronchus \6)\ Zone VI, middle lobar bronchus

7)\\ Zone VII, proximal mainstem bronchus 8)\\ Zone VIII, distal left mainstem bronchus

A total of 63 malignant tracheo-esohageal s- tula (MTEF) patients were included: 12 patients with lung cancer and 46 patients with esophageal cancers. Most stulas were located in Zone II.

Different stents were placed based on different locations and sizes of stulas.

Airway stents were successfully inserted in all patients, and both airway and esophageal stents in eight patients. The stents included 10 “I” shaped, 8 “L” shaped, and 45 “Y” shaped.

Complete closure was achieved in 45 patients (71.4%), and incomplete closure and leakage in 18 patients. Most of the patients improved their quality of life after the placement of stents for relieving symptoms. Mean survival time was 163 days.

The authors concluded that airway stent insertion provides an effective approach to improve

symptoms and quality of life and suggested that a stent choice according to location and size of thestula can be of use in clinical practice.

In benign ADF, some retrospective studies have shown that the degree of success (de ned as complete closure after 6 months) was mainly related with the size of the stula. Debourdeau et al. [45] in a retrospective study describe the endoscopic management of 22 patients with benign ADF. In this group of patients, stulas were postoperative, secondary to esophageal dilation, post radiotherapy, mechanical ventilation, and post tracheotomy. They all received endoscopic procedures, including stent placement or clips, and sometimes a combination of both. Endoscopic success rate was 45.5%, with the highest percentage in pinpointed stulas, followed by medium-sized ones. Large stulas had only a 14% response rate. Fistula persistence after 6 months of endoscopic treatment was associated with failure. Large-sized stulas were also associated with a high mortality rate, 71% in this group of patients.

Another publication [46] reports good results in closure when esophageal stulas were located distally, with worse rates of clinical and technical success being in proximal stulas.

In conclusion, it seems to be a good response rate for endoscopic treatment in benign ADF when they are small and distally located. Endoscopic treatment allows advancement of diet and has minor adverse events. As suggested, these patients have to be carefully selected and discussed in multidisciplinary teams, to personalize the best approach.

Stent Complications

When applied to ADF, stents can result in various complications ranging from minor to lethal. The most common ones include pain, stent migration, restenosis, mucosa erosion, aspiration, tracheal obstruction, tumor overgrowth, food impaction,stula neoformation, stent fracture, gastroesophageal refux, massive bleeding, and early unexpected deaths. Most of these complications occurred in malignant stulas [6, 47–52].

Some rare complications have been published exceptionally, such as superior vena cava occlusion 24 h after implantation of dual prosthesis due to a tracheoesophageal stula [53]. Migration and perforation of the airway, with subsequent airway obstruction, has also been reported [54].

Many of the minor complications, such as retention of secretions, aspiration, granulomas at the distal ends of the prostheses, or food impactation, can be avoided preventively with good fol- low-­up, carrying out protocolized endoscopic controls according to location, type of prosthesis, and patient’s condition in terms of symptoms and prognosis. An early endoscopic intervention can easily eliminate secretions, food impaction, granuloma, or incipient tumor growth. Unfortunately, many of these patients are unable to tolerate procedures to resolve serious complications related to the prosthesis, such as perforation, tumor obstruction, or displacement.

Other Available Stents

•\ Cuf ink-shaped prosthesis (DJ-Fistula stent)® made in silicone was designed exclusively for closure of malignant aero-digestive stulas. The DJ® stent presents some advantages over the prosthesis used for palliation of malignant tracheoesophageal and bronchoesophageal

a

stulas (Fig. 39.8a, b). It is soft and easy to place, sized exactly to the stula diameter, and occluding completely the abnormal communication in both sides [55]. Some articles reported a combination of the DJ®stent with a Y tracheobronchial silicone stent in order to avoid dislodgement of the DJ® prosthesis secondary to cough, with good results [56]. A similarly designed prosthesis called septal button (Micromedics, St Paul, Minnesota, USA) has been also used successfully to treat post-laryngectomy tracheoesophageal stulas [57].

•\ Cardiac septal defect occluder devices were originally designed for transcatheter closure of cardiac defects with the goal of inducing an endothelial response and closure of the defect. Amplatzer® is a shape-memory, self-­ expanding, double-disk device composed of nitinol and interwoven polyester that promotes occlusion and tissue in-growth. Amplatzer device has been used for other non-­ cardiological pathologies such as gastrointestinal stulas [58], gastrotracheal stula [59], bronchopleural stulas [60–63] (Fig. 39.9), and ADF [48, 63, 64] with success. Some related complications, such as migration of the device with secondary airway obstruction [64], have raised concerns on safety discouraging its use on ADF, due to the risk of airway

b

Fig. 39.9  Amplatzer device occluding a bronchoesophageal stula (mediastinal wall)

obstruction and the possibility of increasing the size of the stula, mucostasis, granulation tissue formation, migration and respiratory mucosa erosion, and hemoptysis. A new similar device has been proposed for tracheoesophageal stula [48]. It is dumbbell-shaped and made of laminated nitinol mesh with two self-expanding disks connected by a thin waist allowing mechanical closure of both ends of the stula, giving a potential substrate for subsequent organized in-growth. According to the authors, this new model device reduces tracheal mucosal erosion and obstruction due to its size, as well as facilitates its endoscopic extraction if necessary. This new device was recently successfully used in a 69-year-old patient with a chronic tracheoesophageal s- tula [65].

Other Endoscopic Methods

•\ Submucosal fbrin injections: In stulas with a small ori ce, punch and glue has been recommended in a recent publication [66]. Small bronchopleural stulas resulting from suture failure after pneumonectomy can be solved

with endoscopic submucosal injection of polidocanol (sclerotherapy) and application of cyanoacrylate with good results [67]. Combining a covered stent and brin sealant has been reported as well [68]. Placement of metallic coils plus brin also has been used for small stulas [69].

•\ Endoscopic chemocauterization of congenital and recurrent stulas, using trichloroacetic acid 50%, could be an effective, simple, and safe technique in pediatric patients and avoids the morbidity of open surgery [70, 71].

•\ Laser application or argon plasma coagulation can be a good remedy if applied super - cially at low power and only with the intention of creating granulation tissue surrounding thestula ori ce that leads to closure (Figs. 39.2c and 39.3b). The procedure must be done very carefully to avoid increasing the size of the s- tula ori ce [34, 72].

•\ Autologous corticocancellous bone grafts have been applied with good results. In an excellent study and with good results, Chittithavorn et al. implanted in post-­ pneumonectomy bronchopleural stulas, at the bronchial stump, an autologous corticocancellous bone graft from the adjacent rib in order to create a completely airand water-­ tight sealing. Autologous corticocancellous bone grafts were sewn to the inner wall of the bronchial lumen in a spiral pattern from below to close the stula and induce rapid healing [73].

•\ OTSC system® (Ovesco Endoscopy GmbH, Tubingen, Germany) is a new endoscopic tool for compression of large tissue areas, which was originally introduced for the closure of gastrointestinal defects and also indicated for dif cult-to-control non-varicose bleeding. It consists of a nitinol clip, attached to an applicator integrated onto the tip of an endoscope. Good outcomes have been reported with its use in the management of ADF [74–76].

•\ Size-adjusted sponge placed endoscopically, combined with continuous suction has resolved post-esophagectomy ADF [48]. This system creates negative pressure by placing a sponge within the stula lumen. The sponge is