Fig. 4.1
Dr. JF Dumon
Fig. 4.2
Dumon’s rigid bronchoscope
The head of the rigid bronchoscope can be adapted to the desired tube, according to the different needs (Figs. 4.3 and 4.4).
Fig. 4.3
Universal head of the rigid bronchoscope
Fig. 4.4
Rigid bronchoscope with ancillary tools and connection for ventilation
The Dumon-Harrell rigid bronchoscope comes with a separate deployment system for the silicon (Dumon) prosthesis.
Another Dumon-Harrell system innovation is the fact that it is possible to lift the superior part of the lateral door, allowing the aspiration of large tumor fragments without modifying the position of the suction catheter. The securing caps are made of Silastic, with one or several orifices of different sizes. These caps are much more solid than the usual rubber ones, allowing a more hermetic closure, optimizing ventilation.
The rigid optics offer direct 0° vision (Fig. 4.5); they come in three diameters, 3.5, 5.5, and 7 mm; and they are not fixed. There is also a smaller optics for pediatric use. These instruments easily slide through the Silastic caps and can be moved back and forth according to need. It is a very useful feature to avoid sudden movements that can injure the airway. The rigid optic can be pulled back to avoid midst or loss of visualization due to blood or detritus. The rigid optic, suction catheter, and laser fiber are independent inside the rigid tube, making handling easier.
Fig. 4.5
Rigid telescope (optic)
The most comfortable position when applying laser is placing the tip of the laser fiber advanced within the airway, the suction catheter located slightly back to the laser tip, and the rigid optic further back from the working field (Fig. 4.6). The independence of these elements allows modifying at any time their position according to the intervention needs.
Fig. 4.6
Correct position of the suction catheter and laser fiber into the RB. It is important to always see the tip of the bronchoscope during the procedure
The RB has been designed to present a universal character; in other words, to adapt to multiple endoscopic situations. In addition to laser application settings described above, this instrument can take other configurations: all or some of the entrance ports can be used (from one to three), open or closed ventilation circuit (for “jet ventilation,” manually assisted ventilation, or spontaneous ventilation), and use of short or long tubes and adult or pediatric tubes, allowing diagnostic and/or therapeutic procedures on practically any group of patients.
The Storz rigid bronchoscope was designed by Shapshay from Boston, USA. It is specially manufactured for jet ventilation, and for this reason it has a fixed port designed to serve this purpose. It is available in 10 mm internal diameter size (12 mm external diameter), presenting also a connection for ventilation and two additional ports [5].
A recently introduced rigid bronchoscope, called rigid integrated bronchoscope developed by Wolf, presents separate channels for optics and instruments and integrates the operator head with the camera. It has also an irrigation port to wash the distal lens. It has the advantage of increasing the working space and thus improves manipulation within the bronchoscope. However, the vision is limited since the camera does not go further distal to the end of the rigid bronchoscope.
It is clear that the RB, although keeping its original basic shape, has suffered several modifications to adapt to specialized procedures, like laser application, prosthesis placements, and dilatation of tracheobronchial strictures. The RB allows flexible bronchoscopes to get through it, taking advantage of both instruments at the same time.
Ancillary Equipment
Suction catheters : they play a very important role during procedures. In addition to suction of blood, smokes, and debris, they are useful in palpating lesions to give an idea on consistency. They are also used to instill medications such as saline, epinephrine, and lidocaine. It is recommended that they do not exceed 3 mm in diameter and are made of rigid transparent material. In that way the laser beam will not burn them, and they will not collapse during suction.
Other ancillary instruments that should be available are foreign body rigid forceps (used to retrieve different elements from the airway and to adjust position of silicone stents), scissors, scalpel, balloons, mechanical dilators, endoscopic resectors, prostheses, and laser equipment, most of them designed by Dumon (Fig. 4.7).
Fig. 4.7
Ancillary equipment designed by Dr. Dumon
The capability of project images is very important as well. That serves various purposes: it allows all the team to follow the procedure in detail and anticipate steps. It also permits recording the procedure, for both educational and documentation purposes.
Applications and Contraindications
RB’s most important applications are therapeutic and include laser application, electrocautery, argon plasma coagulation or cryotherapy, dilatation of tracheobronchial stenosis using balloon dilatation or directly with the rigid tube, airway stent placement, and foreign body removal, particularly in children. Massive hemoptysis is also another therapeutic indication. Diagnostic applications are hemoptysis and the need for deep biopsies, better obtained with the rigid biopsy forceps (Table 4.1) [6].
Table 4.1
Indications for rigid bronchoscopy
– Foreign body removal |
– Hemoptysis |
– Tracheobronchial stenosis |
– Tracheobronchiomalacia |
– Central airway obstruction |
– Extrinsic compression |
– Therapeutic procedures: |
Stents |
Laser |
Electrocautery |
Cryotherapy |
Argon plasma coagulation |
Dilatational balloons |
There are not many absolute contraindications for the use of the rigid bronchoscope: unstable cardiovascular state, significant cardiac arrhythmias, severe hypoxemia that will not improve with the procedure, and cervical spine instability. The most important contraindication is lack of appropriately trained personnel [7].
Some clinical situations, however, must be considered as relative contraindications for RB: an unstable neck that makes unsafe the excessive mobilization during the bronchoscopy, microstomy, maxillofacial trauma, or other oral lesions that prevent an appropriate mouth opening to introduce the rigid tube and technical difficulties related with cervical ankylosis and severe kyphoscoliosis, among the most important ones.
Rigid Bronchoscopy Applications
Laser Bronchoscopy
Laser bronchoscopy application has diminished in the last years. Reasons include high cost of the equipment, lack of adequate training, need for RB in most of the cases, long procedure time, the absence of improvement in mortality when applied to malignant conditions (even though quality of life and survival definitely get better), and the insufficient number of patients in some centers. In addition to this, other therapeutic modalities such as electrocautery and argon plasma coagulation have become more popular given their availability, low cost, and similar good results.
However, the application of laser therapy through the RB has not been replaced in some indications, and it is still the technique offering the best results. RB laser resection is an important tool in treating central airway obstructions (benign or malignant) and provides an immediate reopening of the trachea or bronchus when stenotic lesions are found. Most of the treatments are performed with Nd-YAG laser (neodymium-doped yttrium alulminum garnet) or Nd-YAP laser (neodymium-doped yttrium aluminum phosphate). Diode laser is also equally useful and has become more popular given its lower cost.
In a published series about laser applications in malignant lesions, 1585 patients were treated with 2253 therapy sessions of Nd-YAG laser during a period of 11 years. More than 93% showed immediate good results. Complications included 18 hemorrhages, 6 pneumothoraxes, and 10 deaths [8].
Similar results have been published on low-grade malignant tumors that are unresectable or present in nonsurgical candidates for advanced age or severe cardiorespiratory insufficiency. In a prospective study of 19 patients that presented with carcinoid tumor and cylindroma with inoperability criteria, the use of laser was associated with an immediate symptomatic improvement following the treatment in 100% of the cases. Fifteen patients were free from disease during a follow-up time of average 20 months (from 6 to 50 months), and two patients died of unrelated causes at 21 and 6 months of treatment. Although low-grade malignant tumor recurrence is hard to predict, the use of laser is an excellent way to keep inoperable patients free from symptoms [9].
In a retrospective review on laser bronchoscopy application, laser resection was offered to 17 patients with inoperable lung carcinoma requiring mechanical ventilation secondary to acute respiratory failure. All of them received Nd-YAG laser treatment through a RB, with respiratory assistance (jet ventilation) at the operating room. A subgroup of seven patients could be weaned from mechanical ventilation and were able to receive other therapies showing an improved survival. The rest of the patients had tumoral extrinsic compression of the airway or submucosal growing of the tumor and had almost no benefit from laser application. They died on mechanical ventilation or after been extubated when the order “comfort measures only” was established. Survival improvement seen in the first group of patients (p = 0.0038) was associated with the presence of obstructive endobronchial tumor as the cause of respiratory insufficiency [10]. These results show that even those patients with acute respiratory failure due to obstructive lesions can be treated with laser bronchoscopy with good results.
Tracheobronchial Prosthesis
On the last years, tracheobronchial stenosis has received much interest from bronchoscopists due to the several available techniques to treat this problem. Endoscopic treatment of tracheobronchial stenosis can be achieved through balloon dilatation, stent placements, laser resection, and even with dilatation with the rigid bronchoscope.
Balloon dilatation can be done through a RB or through a fibrobronchoscope with a wide working channel. The balloons are designed for esophagus dilatation but are also used in the airway; angioplasty balloons can be used as well.
RB dilatation is performed by applying a smooth rotation to the rigid tube, simultaneously advancing, and passing through the stenotic area several times until a safe airway diameter is achieved. Laser resection can be applied before this dilatation if needed. All fibrous stenoses treated by mechanical dilatation have the tendency to recur, and repeated procedures are needed to keep the airway open. In addition, sometimes forceful maneuvers cause mucosal damage with more scar formation, and in the long term, they can worsen the stenosis. Thus, mechanical dilatation is only recommended to solve an acute situation and as a bridge to a more definitive treatment. Benign airway stenosis is discussed in detail in a dedicated chapter of this book.
Tracheobronchial prostheses can be indicated in benign or malignant airway stenosis [11].
Several types of prosthesis are available to use with both the RB and the flexible bronchoscope. Many of the autoexpandable metallic prostheses have been designed specially to allow placement with the flexible bronchoscope under fluoroscopic control. Airway prosthesis is discussed in detail someplace else in this book. However, we have to say that the RB is the only instrument suited for silicon prosthesis placement. We recommend the use of silicon prosthesis to treat most of the airway lesions, particularly benign conditions since metallic stents are associated with significant complications that have been recognized for many experts and made clear by the FDA during 2005, when it recommended against metallic stent application to airway benign conditions. (Available at www.fda.gov/cdrh/safety/072905-tracheal.html.)
Results on the application of the RB are presented in a study where this instrument was used under general anesthesia to insert silicone prostheses (Dumon) in 31 adult patients with more than 50% malignant airway obstruction. After laser resection, a stent was placed, and all patients presented immediate improvement in respiratory symptoms. All patients but three tolerated well the prostheses. Stents were placed in the trachea in 14 cases, right main bronchus 13, left main bronchus 8, and intermedius bronchus 3. Complications included migration in five patients, mucous obstruction in two patients, and hemoptysis in one patient [12].
We consider training in RB use crucial to any interventional pulmonologist. Regardless of the type of stent selected for a given treatment, expertise working with the RB will be needed at some point during the course of therapy. For instance, when a complication arises (i.e., migration, stent disruption) and the prosthesis needs to be removed or replaced, the best instrument to retrieve it is the RB. In addition, most of the prostheses placed via FB are very difficult to remove with fibrobronchoscope, requiring the application of the RB to extract or adjust them. When metallic uncovered stents stay for a given period of time within the airway, they became embedded to the mucosa. In order to remove them, the beveled end of the RB should be placed between the metallic stent wall and the tracheal mucosa, and with soft rotating movements, the RB is advanced distally “dissecting” the stent from the airway wall until it is totally detached. Then it can be removed with a forceps (Fig. 4.8).
Fig. 4.8
Metallic prosthesis removal with the rigid bronchoscope
Likewise, the growth of tumor tissue through uncovered metallic stents requires RB and laser to relieve the obstruction, remove the prosthesis, and replace it in case of need. Training in RB is one of the most important skills that an interventionist has to learn and be proficient at and is a requisite when placing silicon (Dumon) prosthesis [12, 13]. Such training also involves the staff assisting and collaborating during the procedure: assisting nurse or scrub nurse, anesthesiologist, circulating assistant, etc.
Transbronchial Needle Aspiration
Transbronchial needle aspiration (TBNA) of subcarinal and paratracheal nodules was described in 1950. Wang, in 1978, reported a diagnostic sensibility of 90% for this technique when applied with the RB [14]. After the introduction of the FB during the 1960s, most of the bronchoscopists have been using this instrument to perform TBNA in lymph nodes located subcarinal and parahilar. Diagnostic sensibility for TBNA when performed with the FB has been reported as 80–89%, especially when the 19-gauge needle is used [15, 16].
The appearance of EBUS (endobronchial ultrasound ) has completely changed the approach to lymph node sampling, and this technique has virtually replaced all blind procedures given the high diagnostic yield, particularly in mediastinal sampling [17]. However, in spite of EBUS generalized use, it can still be a place for blind TBNA applied both with the RB and the FB, particularly where EBUS is not available given its high cost.
A study published in 1996 described results on needle aspiration through the RB. Twenty-four procedures were performed in 24 patients using RB and a 2-cm long rigid needle, under general anesthesia and guided with computerized tomography. Samples taken were the tracheal wall (n = 11), main carina (n = 3), right secondary carina (n = 3), left principal bronchus (n = 2), and right principal bronchus (n = 3). The average amount of samples was 6 (from 1 to 19). An in situ cytopathologist immediately reviewed the samples to determine the number of samples needed. Diagnostic sensibility and specificity were 88% and 100%, respectively. TBNA resulted diagnostic in 18 patients. Findings helped in therapeutic decisions in 21 patients. There were no false positives during a follow-up period of 6 months. Three false negatives were present, and follow-up showed that these three patients ultimately had malignant lesions. There were no complications [18]. Those findings suggest that even though the technique has been improved by using EBUS or blind TBNA with the FB, the RB can have a role in the diagnostic of intrathoracic lymphadenopathies if no other method is available.
Rigid Bronchoscope in Other Treatments for Bronchial Obstruction
Laser treatments in tracheobronchial obstructions are effective but expensive. As a result, other therapeutic options have been developed and applied with good results. Electrocautery is broadly available, and results in airway resections are comparable to laser. Also, cryotherapy and argon plasma coagulation can be applied with RB.
Results on electrocautery application with the RB are depicted in a study that performed this procedure under general anesthesia in 29 patients with tracheobronchial obstruction, 24 of which had malignant conditions. In nine patients, stents were placed immediately after electrocoagulation. All patients but one presented immediate improvement of the symptoms, and an objective improvement in the pulmonary function was also observed in eight patients who had been tested with spirometry before surgery. There were neither intraoperative deaths nor complications [19]. Electrocautery can be also applied through the FB, but similar to laser applications, procedures are more time-consuming since the RB allows better vision, optimal suction, and the possibility to remove large tumoral pieces. Cryotherapy has been presented as an alternative therapy for obstructions. However, it is called a “slow” opening method since it lacks immediate effects. Initially, all treatments with cryotherapy were performed with RB, but more recently, the cryotherapy probes have been designed for application with the FB, and new modalities of cryotherapy are available, such as cryoextraction or cryoresection and also cryospray, that make this technique more versatile and can be applied as a fast method to open the airway.
Balloon dilatation can be applied both with the RB or FB.
Mechanical Debridement
Even though laser, electrocautery, cryotherapy, and argon plasma coagulation are useful coagulating during debridement of airway lesions, most of the obstructive tumors are generally extracted in a mechanical mode. In fact, all opening procedures involve the use of forceps. When performed with a FB, this procedure is invariably long and tedious, especially if large tumors are involved. The removal of big tumor pieces through the narrow channel of FB is very complicated, since the biggest pieces that can be extracted fits in a small biopsy forceps. It is obvious that a bigger channel such as the one of the RB will accomplish the same task in a much short period of time.
Most of the experienced bronchoscopists use laser only to coagulate the tumor, and when that is accomplished, dissect large tumoral pieces with the beveled rigid tube, (Figs. 4.9 and 4.10) obtaining a much efficient procedure [20]. Grillo et al. [21] affirm that the use of auxiliary methods like laser is not necessary to reopen the airway and only adds costs and risks to the procedure. However, their study on 56 patients whose tumors were removed only by mechanical means showed a 7% mortality associated to the treatment; considerately higher than when other methods are applied, including laser.
