Interventional pulmonology is
now an integral part of optimal
multimodal management of
advanced lung cancer.
Milton Rochman. Mindshift. Acrylic on canvas, 30″ × 40″. Courtesy of Lewis~Atkinson
Galleries, St. Petersburg, Fla.
Endobronchial Management of
Advanced Lung Cancer
Michael J. Simoff, MD, FCCP
Background: Patients with lung cancer often have bulky endobronchial disease, endobronchial extension, or
airway compression. Many endobronchial treatment modalities are available to supplement traditional
therapies for advanced lung cancer.
Methods: The author reviews the use of several endobronchial treatment modalities that can augment
standard antitumor therapies for advanced lung cancer, including rigid and flexible bronchoscopy, laser
therapy, endobronchial prosthesis, and photodynamic therapy.
Results: Since the early 1980s, technical advances in interventional techniques have enhanced symptom-free
survival and quality of life for patients with lung cancer. Although interventional procedures are not definitive
therapies, they often relieve the strangling sensation produced by airway occlusion.
Conclusions: Endobronchial interventions are important adjuncts in the multimodality management of
lung cancer and should become standard considerations in the management of patients with advanced
lung cancer. For patients with respiratory symptoms associated with their disease, these interventions provide
symptom palliation and improved quality of life.
Most of the estimated 169,500 new cases of lung
cancer diagnosed in the United States in the year 2001
From the Division of Pulmonary and Critical Care Medicine,
Allergy and Immunology, Henry Ford Hospital, Detroit, Michigan.
Address reprint requests to Michael J. Simoff, MD, Pulmonary and
Critical Care Medicine, Henry Ford Hospital, 2799 West Grand
Blvd, Detroit, MI 48202. E-mail: [email protected]
No significant relationship exists between the author and the companies/organizations whose products or services may be referenced in this article.
July/August 2001, Vol. 8, No.4
will be in an advanced stage.1 More than 50% of these
patients will have involvement of the central airways.2
This can be in the form of bulky endobronchial disease,
endobronchial extension, or extrinsic compression of
the airways by the tumor or by lymphadenopathy. Many
of these patients have respiratory symptoms due to
their disease. Shortness of breath, hemoptysis, and
cough are often the complaints that bring patients to a
physician and to the complex treatment programs currently used for the management of lung cancer. Some of
these patients may benefit from endobronchial intervention as part of the management of their disease.
Cancer Control 337
Standard management techniques of lung cancer —
surgery, radiation therapy, and chemotherapy —
measure treatment response, 5-year survival, and
recurrence rates. When treating endobronchial disease,
the concepts of symptom-free survival, dyspnea
indices, and quality-of-life scores also need to be evaluated. Some patients become incapacitated by their
symptoms of dyspnea. Many studies not only demonstrate improvement in clinical symptoms and quality of
life, but also suggest increased overall survival with the
use of endobronchial management techniques.3-16
stenting) may be necessary to provide the most efficacious management of the disease. Offering a multitude
of modalities allows the best selection of approaches
for the patient.17,18
Not all endobronchial disease causes complete
obstruction of the airways. Sometimes patients have
partial obstruction, which often has a less severe symptom complex. As these patients enter treatment programs, the endobronchial component of their disease,
in response to these treatments, can lead to more complicated concerns. External-beam radiotherapy can
induce endobronchial inflammation and swelling, further compromising the airways. Radiation or chemotherapy can lead to necrosis of the endobronchial component of the cancer. The inflammation and necrotic
tissue can cause further airway compromise by inducing airway obstruction, lung collapse, and possible postobstructive pneumonia. Therefore, endobronchial
techniques should be considered throughout the management of lung cancer patients.17,18
The following sections discuss a variety of techniques and tools available to the interventionalist. In
many cases, no one technique is better than the others,
and some combination of these techniques often offers
the greatest benefit to the patient.
Since the inception of flexible fiberoptic bronchoscopy in the late 1960s in Japan and in 1970 in the
United States, the flexible bronchoscope has become
the most widespread tool for evaluating and diagnosing
diseases of the airways and lungs.20 The rigid bronchoscope, the flexible bronchoscope’s predecessor, was in
many regards forgotten as a tool until interventional
pulmonology evolved in the 1980s. Interventional pulmonologists reevaluated this tool and found its properties advantageous to the procedures that are currently
performed. A survey in 1991 by the American College
of Chest Physicians reported that only 8% of responding pulmonologists used a rigid bronchoscope.21
Most endobronchial techniques are performed on
an outpatient basis. Unless a patient presents with respiratory failure, many of the procedures performed provide immediate relief of symptoms. This rapid symptomatic improvement allows patients to return home
with an improved quality of life or better prepares
them to continue treatment at their local programs.
Although interventional procedures are not definitive
therapies, they often provide partial to total relief of the
strangling sensation produced by complete airway
Overall, the concurrent use of the flexible bronchoscope with the rigid bronchoscope is necessary for
the practice of interventional pulmonology. The rigid
bronchoscope offers many advantages to the interventional pulmonologist, one of which is the superior control of the airway achieved with its use. Ventilation is
performed through the scope itself rather than around
the flexible bronchoscope. The larger-bore rigid bronchoscopes allow optical systems, large caliber suction
catheters, and the laser to pass through the scope
simultaneously. Large biopsy forceps are used through
the rigid bronchoscope, which can provide more significant tissue biopsies as well as assist in mechanical
debulking of lesions. However, the rigid bronchoscope
is a more difficult tool to use that requires additional
training. In addition, rigid bronchoscopy is most commonly performed in the operating room with general
anesthesia. Overall, in difficult airway conditions, rigid
bronchoscopy is an excellent technique for the management of endobronchial disease.
Interventional pulmonary programs that include
endobronchial procedures need an armamentarium of
therapeutic modalities rather than a single invasive
approach to manage patients with complicated lung
cancer. As each patient’s anatomy differs, the manner in
which the patient’s cancer leads to symptoms varies.
Several procedures used in conjunction (eg, laser and
The rigid bronchoscope itself can be used as a tool
in the management of endobronchial disease. The distal end of the bronchoscope has a beveled end. This
edge can be used to shear large sections of endobronchial tumor away from the airway wall in a technique often referred to as applecoring. In a report on
56 patients with endobronchial obstruction from the
Lastly, when all management options have been
used, end-stage patients will often develop compromise
of their airways as the cancer continues to progress.
Endobronchial management options may help to
relieve some of their symptoms, allowing them freedom from shortness of breath as they go home in conjunction with hospice or other palliative therapies.17-19
338 Cancer Control
July/August 2001, Vol. 8, No.4
trachea to the distal mainstem bronchi, Mathisen and
Grillo22 described improvement in 90% of their
patients. Only 3 of the 56 patients had more than
minor bleeding with this procedure. Although this procedure is technically difficult, applecoring combined
with the use of larger biopsy forceps allows tumor to
be quickly resected from the obstructed airway.
Laser, an acronym coined from light amplification
by stimulated emission of radiation, has many medical
uses, including the endobronchial management of lung
cancer. Several laser types are currently used within
the bronchi: neodymium:yttrium-aluminum-garnet
(Nd:YAG), potassium-titanyl-phosphate (KTP), and carbon dioxide (CO2). The most common laser used endoscopically is the Nd:YAG, which delivers energy at a
wavelength of 1,064 nm. The laser energy can be conducted via a quartz monofilament and thus can be easily used with either the rigid or flexible bronchoscope.
Normally, Nd:YAG is used at 10-40 watts, but it has a
wide range of power outputs, up to 100 watts. Depending on the energy level used, the laser can affect tissue
several millimeters to several centimeters in depth.
The predominant tissue effects of Nd:YAG lasers
are thermal necrosis and photocoagulation. Thermal
necrosis uses higher energy levels to destroy tissue,
causing the formation of eschar. The problem with
this approach is the significant vascularity of most
lung cancers. In destroying tissue with laser energy,
large blood vessels can also be destroyed. These blood
vessels can be perforated with the tissue destruction,
leading to significant hemorrhage and an increase
rather than a decrease in morbidity and mortality with
The most commonly used effect of laser energy is
photocoagulation. Using lower energy levels, the surface of the tumor is heated, causing shrinkage of the
tumor and diminishing the blood flow to that region.
By devascularizing the tumor, more rapid mechanical
debulking can be performed with improved control of
The reported success rate of symptom palliation
using laser energy in the endobronchial management of
lung cancer is high. Reports of clinical improvement
rates range from 84% to 92% following laser bronchoscopy.7,10,23-25 Further review of the literature identifies studies that demonstrate improved survival in
patients treated with laser bronchoscopy.9,13,14,26 Brutinel et al9 compared 25 historical controls (ie, patients
who would have been candidates for laser management
but did not receive it secondary to the unavailability of
the procedure at the time of their management) to 71
patients treated with laser bronchoscopy as part of the
treatment program. The authors reported 76% and
100% mortality rates at 4 months and 7 months, respectively, in the control population. In the group treated
with laser bronchoscopy, survival rates at 7 months and
1 year were 60% and 28%, respectively. Although no
definitive randomized studies are available, review of
historical studies would suggest improved survival in
patients treated with endobronchial techniques.
Endobronchial prostheses are stents that can be
used in several clinical situations: intrinsic, extrinsic,
or mixed endobronchial obstruction. Stents work well
in conjunction with other modalities such as laser and
mechanical debulking of tumors. Currently, stents are
composed of silastic rubber and metal alloys. Advantages and disadvantages of each are noted in the Table.
Advantages/Disadvantages of Silastic and Metal Stents
• Removable and replaceable
• No growth through stent
• Low cost
• Low likelihood of granulation
July/August 2001, Vol. 8, No.4
• Potential for
• Rigid bronchoscopy needed
• Possible secretion adherence
• Easy to place
• Good wall/internal diameter
• Powerful radial force
Laser therapy can be performed via either flexible
or rigid bronchoscopy. The majority of interventionalists use rigid bronchoscopy as the predominate tool
for the performance of laser procedures when possible. Nd:YAG laser fibers can be passed through the
working channel of most flexible bronchoscopes.
Using the flexible bronchoscope, laser energy can be
delivered to areas that cannot be reached with the
• Excellent conformity for
irregular tracheal or
• Good epithelialization
• Tumor regrowth (noncovered)
• Possible migration of covered
• Significant granulation tissue
• Epithelialization affecting wall
mechanics and secretion
• Radial force causing necrosis
of bronchial wall, erosion,
Cancer Control 339
solid walls prevent tumor growth from reobstructing
airways. Endobronchial tumors are often debulked and
then a stent is placed prior to the initiation of radiotherapy or chemotherapy, or both. Another advantage
of the Dumon stent is the ease of removal. This can be
significant when endobronchial procedures are used
early in the management of cancer patients. After
definitive therapies have been used (radiation,
chemotherapy), re-evaluation of the airway can be performed, and the stent can be either left in place,
removed (if deemed of no further clinical advantage),
or replaced with a larger stent that would further
improve the caliber and stability of the airway. The disadvantages of the Dumon stent are the potential for
migration and the need for a rigid bronchoscope for
placement. The migration issue, although often
referred to, occurs less often when the stent is placed
by an experienced interventional endoscopist.27,30-35
Fig 1. — Montgomery T-tubes.
Many of the silastic stents now in use evolved from
the Montgomery T-tube, which was first used in the early
1960s. This T-shaped stent supports the entire trachea
with an arm that extends through a permanent tracheostomy (Fig 1). In patients with a patent tracheostomy, the Montgomery T-tube remains an excellent tool
for the management of endotracheal disease.27-29
In 1990, Dumon30 reported the use of what is now
referred to as the Dumon stent (Bryon Corp, Woburn,
Mass). Developed in 1987, it is a silastic stent with evenly spaced studs along its outside walls (Fig 2). These
studs not only assist in maintaining placement of the
stent in the airway, but also allow the clearance of secretions around the walls of the stent. Although the use of
expandable wire mesh stents is increasing, the Dumon
stent probably is currently the most common stent currently used by interventionalists.
The Dumon stent is effective in maintaining the
structural integrity when placed endobronchially. Its
Fig 2. — Dumon silastic stents.
340 Cancer Control
Other silastic stents include the Hood stent (Hood
Laboratories, Decatur, Ga) and the hybrid Rüsch Y stent
(Rüsch Inc, Duluth, Ga). The Hood stent is similar to
the Dumon stent in design and use. The Hood stent is
placed in the same manner as the Dumon stent.36 The
Rüsch-Y stent (Fig 3) is a silastic stent with stainless
steel c-rings that artificially represent the cartilage. The
posterior wall of the stent is made of a thinner silastic
plastic to make it more functional, similar to the membranous trachea itself. The three available sizes of this
stent are designed to traverse the entire length of the
trachea with branches into the right had left mainstem
bronchi. The Rüsch Y stent requires rigid bronchoscopy and is difficult to place, remaining uncommon in clinical practice.
Metal stents, such as the Gianturco (Cook Inc,
Bloomington, Ind), the Palmaz (Johnson & Johnson
Interventional Systems, Warren, NJ), the Wallstent
(Schneider Inc, Minneapolis, Minn), and the Ultraflex
(Boston Scientific, Natick, Mass), have been used in
the endobronchial management of lung cancer. The
advantage of metal stents is the relative ease for placement via a flexible bronchoscope with fluoroscopic
Fig 3. — Rüsch Y stent.
July/August 2001, Vol. 8, No.4
risk with the use of metal stents is the erosion that can
occur through bronchial/tracheal walls. This is particularly serious when erosion occurs into blood vessels,
leading to massive uncontrollable hemoptysis.
Fig 4. — Covered Wallstent.
assistance. This ease of placement allows some bronchoscopists to use these stents as their sole modality
in the management of endobronchial disease. However, this practice limits the options to patients that
may otherwise be available if all interventional modalities were offered. The wire mesh design of many of
the original metal stents did not prevent the tumor
from growing through the stent over time. The Wallstent and Ultraflex stents are now available in covered
versions. A wrap is applied to the outside of the wire
mesh to prevent tumor invasion through the stent.
Data that support the use of both of these stents for
the endobronchial management of lung cancer is
The Wallstent is composed of woven stainless steel
wires with exposed proximal and distal ends (Fig 4).
These exposed ends imbed in the endobronchial
mucosa to fix the stent into place. Significant stimulation of granulation tissue development at both the
proximal and distal ends of the exposed Wallstent is a
concern for long-term endobronchial management.
Studies using this stent demonstrate excellent initial
outcomes, particularly with the release of the covered
Stents are effective tools for the endobronchial
management of lung cancer. The choice of stent to use
should be made carefully, weighing advantages and
disadvantages of each, so the proper tool is used in all
situations. Multiple stent types need to be available to
the endoscopist to allow the proper choice for the
Photodynamic therapy (PDT) has received
increased attention in recent years. PDT is an important adjunctive modality to the management of endobronchial disease, but it does not replace Nd:YAG
lasers, stents, and rigid bronchoscopy. PDT also can be
used with bulky disease, but most interventionalists feel
that it is of limited benefit in this role.41,42 The most
Fig 5. — Covered and uncovered Ultraflex stents.
The Ultraflex stent is made of nitinol, a titanium and
nickel alloy, which has little bioreactivity. This stent has
excellent inner to outer diameter and conforms well to
various airway shapes, maintaining an equal pressure
along the entire length of the stent. The Ultraflex stent
is available in a variety of lengths and diameters. Overall the covered version of this stent is excellent for use
in palliation of airway obstruction (Figs 5-6).
Metal stents epithelialize as they remain in the airways, thereby becoming incorporated into the wall of
the bronchus. The epithelization changes the mechanics
of the airways with time by making them stiffer, which
may lead to further airway complications.34,39 Another
consideration with the use of metal stents is the fact that
once they are endoscopically placed, their removal is difficult and often impossible. Although uncommon, the
July/August 2001, Vol. 8, No.4
Fig 6. — Proximal view of an Ultraflex stent in the right mainstem bronchi.
Cancer Control 341
suitable lesions for PDT are in situ carcinomas or those
limited to 4-5 mm of microinvasion.43
A photosensitizing drug is intravenously administered to the patient 48 to 72 hours prior to the procedure. Porfimer sodium (Photofrin) is the most common
agent currently used for this. This photosensitizer penetrates all cells systemically. It is not cleared as quickly
in cancer cells as in other cells and is therefore found
in higher concentrations in cancer cells as opposed to
the endothelium surrounding the tumor.43,44 An argon
dye laser is then used to provide the 630-nm wavelength light energy required to activate the intracellular
porfimer sodium. The laser energy is transmitted via a
flexible quartz fiber, which can be used through either
a flexible or rigid bronchoscope. The fiber tip can be
placed in close approximation to the tumor mass, or it
can be imbedded into the tumor to provide the energy
needed to start the intracellular activation of the porfimer sodium. This reaction leads to cellular destruction by a variety of mechanisms. Tissue necrosis then
ensues as the cancer cells die.43-45
As the neoplastic tissue necrotizes, it must be
removed by repeated bronchoscopies. Flexible bronchoscopy is commonly performed daily or every other
day for up to 1 week to remove the necrotic tissue. The
necrosis of bulky tumor can be dangerous to the patient
if the necrotic tissue separates from the bronchial wall
and occludes the airway. In some programs that use
only PDT, patients remain intubated following the procedure for 1-2 days secondary to this concern. If necrotic tissue is removed over the first 24-48 hours, a second
laser application to the cancer can be performed, thus
improving the cancer tissue destruction.
PDT is an excellent therapeutic modality for
patients with early-stage cancers. It destroys neoplastic
tissue effectively and is an outstanding therapeutic
modality in carcinoma in situ and microinvasive cancers. PDT is a necessary tool in our armamentarium of
endobronchial treatments, but the time delays and multiple steps of management make it a more cumbersome
therapy for the management of late-stage endobronchial lung cancer.45
Cryotherapy is another modality for the endobronchial destruction of malignant tissue that obstructs
the tracheobronchial tree. This technique uses cold
instead of the heat used in laser-based technologies. A
probe is placed onto or into an obstructing tumor
mass. Liquid nitrogen (–196oC) or nitrous oxide
(–80oC) cools the probe tip when performing cryo342 Cancer Control
therapy. This tissue freezing leads to the destruction of
all cells in an area of approximately 1 cm in diameter
around the probe tip. Vascular thrombosis occurs with
the super-cooling of tissue, minimizing the bleeding
during resection of the tumor.
The limiting factor to using cryotherapy is that the
tissues destroyed with the freezing procedure take time
to die and necrose. This requires returning to the lesion
to remove the necrosed material and, in some cases,
repeating treatments. Although cryotherapy is effective
at tumor destruction and management, the necessity of
repeated procedures makes this a more time-consuming procedure to perform, limiting its usefulness in
management of bulky endobronchial disease.46
Electrocautery uses electrical energy via one of
several introducer devices to cut and/or destroy tumor
cells. The various tools of electrocautery can be introduced through a flexible bronchoscope (one that is
grounded and designed for this therapy) and can then
debulk endobronchial disease using the electrical energy to cauterize tissue, thus minimizing the bleeding that
occurs with tumor resection. Endobronchial electrocautery treatment can be used similarly to laser therapy
and/or cryotherapy for managing advanced endobronchial lung cancer. Overall, this therapy holds great
promise for endobronchial disease management.47
Balloons used for intravascular procedures can also
help to manage endobronchial stenosis secondary to
both malignant and benign disease. At our institute, we
are currently using the Cordis PTA Dilatation Catheter
(Cordis Europa N.V., The Netherlands) for endobronchial narrowings. The Cordis balloon comes in a
variety of diameters and lengths to help dilate areas of
bronchial compromise. Occasionally, strictures are
dilated prior to the placement of a stent or even used
to fully expand a stent already in place.
The balloon is passed endobronchially via either a
rigid or flexible bronchoscope. The appropriate diameter and length of the balloon are chosen for the particular lesion. Ideally, 5-10 mm of balloon should
extend beyond the lesion both proximally and distally.
The treatment should be performed as a series of dilatations with gradual increase in the balloon diameter to
minimize the risk of tracheobronchial rupture. Once
inflated to the prescribed pressure, this dilatation pressure should be maintained for 1-2 minutes. Two minJuly/August 2001, Vol. 8, No.4
utes is preferable if the patient can tolerate this without
discomfort or hypoxia.
Although balloon dilatation is an adjunctive therapy to bronchoscopy, laser, and/or stenting, acquiring
skills with this modality is beneficial to the interventionalist and important for the complete endobronchial
management of patients with lung cancer.
1. Cancer Facts and Figures, 2001. Atlanta, Ga: American Cancer Society; 2001.
2. Luomanen RKJ,Watson WL. Autopsy findings. In: Watson WL,
ed. Lung Cancer: A Study of Five Thousand Memorial Hospital
Cases. St Louis, Mo: CV Mosby Co; 1968:504-510.
3. Hetzel MR, Millard FJ, Ayesh R, et al. Laser treatment for carcinoma of the bronchus. Br Med J. 1983;286:12-16.
4. Mehta AC, Golish JA, Ahmad M, et al. Palliative treatment of
malignant airway obstruction by Nd-YAG laser. Cleve Clin Q.
5. McDougall JC, Corese DA. Neodymium-YAG laser therapy of
malignant airway obstruction: a preliminary report. Mayo Clin Proc.
6. Toty L, Personne C, Colchen A, et al. Bronchoscopic management of tracheal lesions using the neodymium yttrium aluminum garnet laser. Thorax. 1981;36:175-178.
7. Dumon JF, Reboud E, Garbe L, et al. Treatment of tracheobronchial lesions by laser photoresection. Chest. 1982;81:278-284.
8. Arabian A, Spagnolo SV. Laser therapy in patients with primary lung cancer. Chest. 1984;86:519-523.
9. Brutinel WM, Cortese DA, McDougall JC, et al. A two-year
experience with the neodymium-YAG laser in endobronchial obstruction. Chest. 1987;91:159-165.
10. Beamis JF Jr,Vergos K, Rebeiz EE, et al. Endoscopic laser therapy for obstructing tracheobronchial lesions. Ann Otol Rhinol
11. Sonett JR, Keenan RJ, Ferson PF, et al. Endobronchial management of benign, malignant, and lung transplantation airway stenosis. Ann Thorac Surg. 1995;59:1417-1422.
12. Macha HN, Becker KO, Kemmer HP. Pattern of failure and survival in endobronchial laser resection: a matched pair study. Chest.
13. Desai SJ, Mehta AC, Vanderbug Medendorp S, et al. Survival
experience following Nd:YAG laser photoresection for primary bronchogenic carcinoma. Chest. 1988;94:939-944.
14. Stanopoulos IT, Beamis JF Jr, Martinez FJ, et al. Laser bronchoscopy in respiratory failure from malignant airway obstruction.
Crit Care Med. 1993;21:386-391.
15. Cavaliere S, Foccoli P,Toninelli C, et al. Nd:YAG laser therapy
in lung cancer: an 11-ear experience with 2,253 applications in 1,585
patients. J Bronchol. 1994;1:105-111.
16. Ross DJ, Mohsenifar Z, Koerner SK. Survival characteristics
after neodymium:YAG laser photoresection in advanced stage lung
cancer. Chest. 1990;98:581-585.
17. Edell ES, Cortese DA, McDougall JC. Ancillary therapies in the
management of lung cancer: photodynamic therapy, laser therapy,
and endobronchial prosthetic devices. Mayo Clin Proc. 1993;68:685690.
18. Cortese DA, Edell ES. Role of phototherapy, laser therapy,
brachytherapy, and prosthetic stents in the management of lung cancer. Clin Chest Med. 1993;14:149-159.
19. Sutedja G, Schramel F, van Kralingen K, et al. Stent placement
is justifiable in end-stage patients with malignant airway tumours.
20. Ikeda S. Flexible bronchofiberscope. Ann Otol Rhinol
21. Prakash UB, Stubbs SE. The bronchoscopy survey: some
reflections. Chest. 1991;100:1660-1667.
22. Mathisen DJ, Grillo HC. Endoscopic relief of malignant airway
obstruction. Ann Thorac Surg. 1989;48:469-475.
July/August 2001, Vol. 8, No.4
23. Cavaliere S, Foccoli P, Farina PL. Nd:YAG laser bronchoscopy.
A five-year experience with 1,396 applications in 1,000 patients.
24. Kvale PA, Eichenhorn MS, Radke JR, et al. YAG laser photoresection of lesions obstructing the central airways. Chest. 1985;87:
25. Eichenhorn MS, Kvale PA, Miks VM, et al. Initial combination
therapy with YAG laser photoresection and irradiation for inoperable
non-small cell carcinoma of the lung: a preliminary report. Chest.
26. Petrovich Z, Stanley K, Cox JD, et al. Radiotherapy in the management of locally advanced lung cancer of all cell types: final report
of randomized trial. Cancer. 1981;48:1335-1340.
27. Colt HG, Dumon JF. Tracheobronchial stents: indications and
applications. Lung Cancer. 1993;9:301-306.
28. Cooper JD, Pearson FG, Patterson GA, et al. Use of silicone
stents in the management of airway problems. Ann Thorac Surg.
29. Montgomery WW. T-tube tracheal stent. Arch Otolaryngol.
30. Dumon JF. A dedicated tracheobronchial stent. Chest.
31. Tojo T, Iioka S, Kitamura S, et al. Management of malignant tracheobronchial stenosis with metal stents and Dumon stents. Ann
Thorac Surg. 1996;61:1074-1078.
32. Dumon JF, Cavaliere S, Diaz-Jimenez JP, et al. Seven-year experience with the Dumon prosthesis. J Bronchol. 1996;3:6-10.
33. Diaz-Jimenez JP, Munoz EF, Ballarin JIM, et al. Silicone stents
in the management of obstructive tracheobronchial lesions: 2-year
experience. J Bronchol. 1994;1:15-18.
34. Freitag L, Eicker K, Donovan TJ, et al. Mechanical properties
of airway stents. J Bronchol. 1995;2:270-278.
35. Clarke CP, Ball DL, Sephton R. Follow-up of patients having
Nd:YAG laser resection of bronchostenotic lesions. J Bronchol.
36. Gaer JA, Tsang V, Khaghani A, et al. Use of endotracheal silicone stents for relief of tracheobronchial obstruction. Ann Thorac
37. Colt HG, Dumon J-F. Airway obstruction in cancer: the pros
and cons of stents. J Respir Dis. 1991;12:741-744, 746, 748-749.
38. Bolliger CT, Probst R,Tschopp K, et al. Silicone stents in the
management of inoperable tracheobronchial stenoses: indications
and limitations. Chest. 1993;104:1653-1659.
39. Gelb AF, Zamel N, Colchen A, et al. Physiologic studies of tracheobronchial stents in airway obstruction. Am Rev Respir Dis.
40. Tsang V, Williams AM, Goldstraw P. Sequential silastic and
expandable metal stenting for tracheobronchial strictures. Ann Thorac Surg. 1992;53:856-860.
41. Lam S. Photodynamic therapy of lung cancer. Semin Oncol.
42. Sutedja T, Lam S, LeRiche JC, et al. Response and pattern of
failure after photodynamic therapy for intraluminal stage I lung cancer. J Bronchol. 1994;1:295-298.
43. Furuse K, Fukuoka M, Kato H, et al. A prospective phase II
study on photodynamic therapy with Photofrin II for centrally located early-stage lung cancer: the Japan Lung Cancer Photodynamic
Therapy Study Group. J Clin Oncol. 1993;11:1852-1857.
44. Hayata Y, Kato H, Konaka C, et al. Photodynamic therapy
(PDT) in early stage lung cancer. Lung Cancer. 1993;9:287-294.
45. Moghissi K, Dixon K, Stringer M, et al. The place of bronchoscopic photodynamic therapy in advanced unresectable lung cancer:
experience of 100 cases. Eur J Cardiothorac Surg. 1999;15:1-6.
46. Maiwand MO, Homasson JP. Cryotherapy for tracheobronchial disorders. Clin Chest Med. 1995;16:427-443.
47. Gerasin VA, Shafirovsky BB. Endobronchial electrosurgery.
Cancer Control 343