Endoscopic management of benign tracheobronchial tumors
1Department of Oncology; 2Department of Neurology, PLA General Hospital of Chengdu Military Region, Chengdu, PR China
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Review Article
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Abstract
Even though benign tracheobronchial tumors are quite rare, they still can induce airway obstruction, result in suffocation, and need emergent management to remove the obstructing lesions and make the respiratory tracts unobstructed. Although the preferred therapy is surgery, it is still difficult to deal with the tumors in some cases, and the complications of surgery are common. Therefore, bronchoscopic managements, such as Nd: YAG laser, electrocautery, APC and Cryotherapy, are very important to treat benign tracheobronchial tumors and can cure most of them.
The efficacy of therapeutic endoscopy for the treatment of patients with benign airways obstruction has been established. However, in order to maximally eradicate the benign tumors with minimal damage to patients, the success of bronchoscopic managements for the treatment strongly depends on the diligent identification of the various factors, including the location, size, shape of tumor, and the age, status, cardio respiratory function of patients, and full comprehension of the limits and potential of each particular technique.
Because the advantages and disadvantages of above mentioned interventional methods, single method can not solve all clinical issues. Therefore, in order to remove benign tracheobronchial tumors completely, and reduce the incidence of recurrence as far as possible, many doctors combine several methods of them to treat complicated benign tracheobronchial tumors. This article reviews the core principles and techniques available to the bronchoscope managing benign tracheobronchial tumors.
Key words
Benign tracheobronchial tumors; bronchoscope; electrocautery; argon plasma coagulation; Nd: YAG laser, cryotherapy
J Thorac Dis 2011;3:255-261. DOI: 10.3978/j.issn.2072-1439.2011.09.02
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Introduction
Primary tracheobronchial tumors are tumors originating from trachea or bronchi and quite rare. Most published data are case reports, experiences from very small series, or retrospective studies (1-3). According to the SEER database of National Cancer Institute, there were 574 cases of primary tracheobronchial tumors between 1973 and 2004, and the incidence was about 2.6 patients per 100 000 peoples (4). However, primary benign tracheobronchial tumors are more seldom seen. Gaissert et al (5) reported 357 cases of primary tracheobronchial tumors that had been diagnosed and treated in Massachusetts general hospital in the last 40 years. Of the mentioned 360 tumors (3 patients had two different types of tumor), there were 326 malignant tumors (90.6%), 135 squamous cell carcinoma (37.5%), 135 adenoid cystic carcinoma (37.5%), 11 carcinoid tumor (3.1%), 14 sarcoma (3.9%), and 34 benign tumors (9.4%). Shah et al (6) reported 185 cases of benign tracheobronchial tumors that had been diagnosed and treated in single hospital from 1980 to 1991. They found that the most common tumors were papillary epithelioma (28.6%), hamartoma (24.3%), and amyloid tumor (11.4%).
Regardless of malignant or benign tumors, they all can obstruct the respiratory tract and threat the life of the patients. So, rapid management of airway obstruction and recovery of ventilation of respiratory tract is the chief purpose of therapy (7). For benign tracheobronchial tumors, the preferred therapy is surgery including sleeve resection (8). However, for the benign tumors locating in trachea, main bronchi, and eminence, surgery is difficult and bring great trauma to the patients (9). Therefore, bronchoscopic managements, such as neodymium-yttrium-aluminum-garnet laser (Nd: YAG) laser (10-11), electrocautery (12-13), argon plasma coagulation (APC) (14-15), and Cryotherapy (16-17), are very important to treat benign tracheobronchial tumors and can cure most of them. Because a few of them are prone to recurrent or change to malignancy, it is very important to repeat bronchoscopes to follow up and we must carefully practice interventional bronchoscope to avoid hampering possible surgery in future. According our experience and literature, the following conditions are considered as indications for endoscopic treatment: (i) tumors are strictly located in tracheobronchial lumen and don’t exceed subsegmental bronchi; (ii) the basilar part of tumors is not wide, and do not across more than 3 bronchial cartilage rings; (iii) tumors with peduncular structure are more suitable; (iv) tumors have low probability of recurrence; (v) the patients’ condition is not suitable for surgery (Table 1).
This article reviews the core techniques available to the
bronchoscope managing benign tracheobronchial tumors,
summarizes the advantages and disadvantages of each technique,
and .discusses the combined use of these techniques.
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Rigid bronchoscope or flexible bronchoscope
Rigid bronchoscope has been used for more than 100 years.
From 1970s, because that its practice need general anesthesia and
its poor visual scope in tracheobronchial, it has been replaced
gradually by flexible bronchoscope. From 1980s, with the
emergence of interventional bronchoscope, rigid bronchoscope
has been applied by more and more doctors again. In Italy,
the usage of rigid bronchoscope has achieved to 17.6% (18).
Meanwhile, with the development of electronical technique,
the blind zone of rigid bronchoscope has disappeared. Rigid
bronchoscope can maintain the respiratory tract unobstructed,
and has a lateral aperture, which can connect with breathing
machine. So, it is also called ventilating bronchoscope (19-20). The value of rigid bronchoscope is that it can allow flexible
bronchoscope, or other instruments to go straight through
its lumen, which allows rigid bronchoscope complete almost
all operations including stenting, laser ablation, argon plasma
coagulation, foreign bodies removing and cryotherapy.
There several advantages of rigid bronchoscope. The first,
rigid bronchoscope has several tunnels which can allow suction
catheter, lasing fiber, or electrode reach target simultaneously. So
we can execute suction and ablation simultaneously, and remain
the visual field clean to make for practice. Because suction
catheter is larger, we can rapidly remove the secretion and blood.
The second, rigid bronchoscope has larger tunnel than flexible
bronchoscope, which allow biopsy forceps to remove large tissue
and flexible bronchoscope to permeate itself to reach target. The
third, when performing thermal ablation, it is easier for flexible
bronchoscope to be injured. The fourth, rigid bronchoscope can
connect with ventilating machine in order to prove the patient’s
breathing, support enough oxygen, avoid asphyxia. Finally, the
patients are submissive and not painful due to general anesthesia
(Table 2).
Although rigid bronchoscope with general anesthesia is safe when experienced doctors performing it, the patients still
face the risk induced from general anesthesia. Hanowell et al
(21) reported 73 cases of Nd: YAG laser therapy with general
anesthesia. In this paper, they reported the death of the patients
was zero; total incidence of complications was 30.1%. The most
common complications are hypotension (10.9%), ventricular
ectopy (8.2%), hypertension (5.5%), and supraventricular
tachycardias (5.5%). The incidence of heart block, myocardial
infarct, and myocardial ischemia is 1.4% respectively. According
our experience, the contraindication of rigid bronchoscope
should be unstable angiocardiopathy, arrhythmia threatening life,
acute respiratory failure combined intractable hypoxemia, head
and neck malformation, and cervical cord diseases.
Although there is no blind zone for rigid bronchoscope
due to modern optical techniques, it is still difficult for rigid
bronchoscope to treat the tumors locating in the bronchi
which form acute angle, or bronchi of superior lobe (Fig. 1). In
addition, sometimes rigid bronchoscope can not pass stenosis.
In these conditions, we have to use flexible bronchoscope to
reach the target, or pass through the stenosis to observe mucosa
of distal bronchi and basilar part of tumors roundly. In modern
time, the instruments of argon plasma coagulation, Nd: YAG
laser and cryotherapy can be fitted into flexible bronchoscope.
So, for the majority of cases, we can handle endobronchial
tumors via flexible bronchoscope. But for some cases, we have to
turn to rigid bronchoscope because that flexible bronchoscope
can not control the respiratory tract, or perform artificial
ventilation.
So, we must decide which bronchoscope is optimal
according to the location, size, shape of tumor, and the age,
status, cardio respiratory function of patients. Generally, for
those patients who have good status and cardio respiratory
function, if their tumors are small and easy to remove, or
the risk of perforation and hemorrhea is low, we use flexible
bronchoscope. However, for those patients who have bad status
and cardio respiratory function, if their tumors are large and
difficult to remove (predicted operation time is more than 30
minutes), or the risk of perforation and hemorrhea is high, we
use rigid bronchoscope. According our experience, we usually
use the two kinds of bronchoscope simultaneously. We use rigid
bronchoscope to control respiratory tract, remove secretion and
blood, stop bleeding, treat tumors with cryotherapy or argon
plasma coagulation, and use flexible bronchoscope to reach the
target which rigid bronchoscope can not reach.
 Figure. 1 The applicability of rigid or flexible bronchoscope.
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Electrocautery
From 1930s, electrocautery has been used in interventional
bronchoscope. However, only until coil of electrocautery was
improved by Hooper and Jackson (22), electrocautery was used
extensively. Electrocautery remove tumors by its thermal effects which can degenerate protein, induce tissue coagulation necrosis.
Electrocautery is suitable for tumors with peduncular structure.
Coulter et al (23) treated 25 cases of benign tracheobronchial
tumors with electrocautery. Of these tumors, there were 12 cases
of granulation tissue, 6 cases of papillary epithelioma, 3 cases
of hamartoma and lipoma respectively. Except for granulation
tissue, all tumors were cured one time. The complications were
hemorrhage (10.5%) and cough (2.6%). Electrocautery can
be used in flexible or rigid bronchoscope. We can use snare
to remove the stem of tumors. For those large tumors, or the
tumors without stem, we can use electrocautery to fulgerize the
tumors to the depth of 2-3mm (24), then use biopsy forceps to
clear eschar and necrotic tissue, and then repeat those steps. If
the removed tumor is too big to pass the tunnel, we can take it
out with bronchoscope together, or let patients expectorate the
lesion immediately. In addition, electrocautery can also be used
to stop bleeding (Table 3).
The primary consideration of electrocautery is safety.
Because tracheobronchial is adjacent to heart, arteriae aorta, and
pulmonary artery, we must pay careful attention to this practice
to avoid tracheobronchial injury, perforation, mediastinal
emphysema, and severe hemoptysis. Another consideration is
that electrocautery may induce airway fire as a kind of thermal
cautery, especially when oxygen concentration is higher than
40%. So, we should keep oxygen concentration lower than 40%,
and igniting material away.
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Argon plasma coagulation
Argon plasma coagulation is a new kind of uncontiguous electrocautery technique, which can produce uncontiguous
current between probe and tissue by iodinating argon. The argon
plasma beam reaches target not only along straight line, but also
from lateral exits (25). The depth of treatment is about 3-4mm,
and the tissue can be divided into three zones from surface to
bottom: dehydration zone, coagulation zone, and inactivation
zone. From naked eyes, three zones show as eschar. Meanwhile,
Argon plasma coagulation has the effect of hemostasis. Because
the depth of treatment is superficial, it is relatively safer in the
aspect of perforation and severe hemoptysis (26).
However, if you continue to treat after the formation of
eschar, the fever can not penetrate the eschar to treat deep
issue. Therefore, in order to treat large tumor, we have to clear
eschar after every electrocautery. The traditional instrument of
clearing eschar is biopsy forceps. However, because the tissue
cleared by biopsy forceps every time is small, it will prolong the
operation time and increase the risk of bleeding when repeating
clearance. In addition, as a kind of thermal cautery, the oxygen
consumption is so big that it is easy for the patients to suffer
from hypoxemia, which can result in interruption of operation
and airway fire. According to Reddy’s report (27), argon plasma
coagulation also can induce air embolism, which is related to
the velocity of air current. So, we recommend that we should
lower down the velocity of air current as far as possible if we can
complete our operations.
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Nd: YAG laser
In 1982, Dumont (28) first used Nd: YAG laser to treat
111 cases of tracheobronchial diseases including 6 cases of
benign tumors. The advantages of Nd: YAG laser include
good directionality, gasificated lesions which don’t obstruct
respiratory tract, less hemorrhage, less secretion, and less injury
to normal tracheobronchial. Cavaliere et al (29) treated 59 cases
of benign tracheobronchial tumors with Nd: YAG laser. Of these
tumors, there were 14 cases of hamartoma, 11 cases of papillary
epithelioma, 7 cases of amyloid tumor, 4 cases of tracheopathia
osteoplastica, polyp and hemangioma respectively, 1 case of
plasmocytoma, neurilemmoma, chondroma, ndometriosis
and lipoma respectively, 1 case o+f fibroma, myofibroma,
fibrohistiocytoma, scleroma and syphilis respectively. Except
for 1 case of amyloid tumor, tracheopathia osteoplastica, and
papillary epithelioma respectively, all patients were cured
completely. No recurrence was observed in the follow up of 1 to
3 years.
In the practice of Nd: YAG laser, we should pay attention
to some points: First, we should clear the necrotic tissue and
secretion immediately in order to avoid them obstructing
respiratory tract and hypoxemia. Once hypoxemia happens, we
should stop therapy immediately, increase oxygen concentration,
and clear the necrotic tissue and secretion. If necessary, we can use rigid bronchoscope or mechanical ventilation to remain the
respiratory tract unobstructed. Second, optical fibers should be
paralleled with tracheobronchial in order to avoid hemorrhage
resulted from irradiating the wall of tracheobronchial vertically.
Upon hemorrhage happening , we should stop therapy
immediately, use rigid bronchoscope to oppress, or sprinkle
adrenalin hydrochloride or thrombin to stop blooding. Third, the
power should be restricted under 40W to avoid perforation and
hemorrhage (30-31,34). Fourth, Nd: YAG laser also may induce
airway fire when oxygen concentration is higher than 40% (32).
We can prevent airway fire by reducing oxygen concentration,
prolonging the interval of two irradiations, lowering the power,
keeping optical fiber 1cm longer than bronchoscope or more.
Fifth, we should clear the fume produced by tissue gasification
to avoid cough and atmospheric pollution. Finally, if pulmonary
veins are perforated and contact with air, it will result in air
embolism (33). Other rare complications include myocardial
infarction, bradycardia and cardiac arrest.
In addition, high power Nd: YAG laser can induce reactive
hyperplasia of granulation tissue, so it is not suitable for treating
tuberculosis. And extensive irradiation can induce severe edema
so that aggravate obstruction.
Brutinel (34) reported 116 cases of airway obstruction with
Nd: YAG laser. Among the 176 times therapy, hemorrhage
happened 10 times, and 3 cases died from asphyxia induced
by hemorrhage. Fever happened 7 times, and prolonged
mechanical ventilation happened 7 times. Airway obstruction
and pneumothorax happened 2 times respectively. Of the 116
patients, 9 patients suffered from benign tracheobronchial
tumors. After 1 year follow up, one patient died and the 1
year survival rate was 86%. All the 3 patients who died from
hemorrhage were practiced with the condition of more than 90
W. After the death of these patients, the author restricted the
power to 50W and there were no more deaths.
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Cryotherapy
Cryotherapy can freeze the tumor and make necrosis of tumor
by inducing liquid CO2 to the tissue along the probe (35).
Because the probe is muticous, and the depth of perforation is
only 3mm, so it can not insert to the deep part of tumor (36).
Therefore, cryotherapy is only suitable for superficial tumor,
especially for those colloid tumor and sledged blood. The
methods of cryotherapy include freezing cutting and freezing
thawing. Freezing cutting means we use cryotherapy to freeze
the tumor to an icefall, and then clear it with biopsy forceps.
Freezing thawing means we freeze the tumor and let it thaw and
fall off naturally. The advantages of cryotherapy include hat it
does not induce hypoxemia, lower risk of perforation, no risk of
air fire and fume, and small effect on cartilaginous rings. After
cryotherapy, the necrotic tissue falls off gradually. Meanwhile, the peripheral mucosa grows to cover the lesion, so cryotherapy
dose not induce cicatricial constriction (37).
One of the disadvantages is the superficial therapy, which
means we have to repeat cryotherapy to treat large tumor.
Another disadvantage is that the necrotic tissue will not fall off
immediately, and we have to perform another bronchoscope
to clear the necrotic tissue. Tchakaroff et al (38) reported two
disadvantages of cryotherapy. The first is the tip of bronchoscope
sometimes could be freezed by probe. The second is that it is
prone to bleed after freezing thawing and cryotherapy had not
the function of haemostasis.
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Cryotherapy combined with argon plasma coagulation
Because the advantages and disadvantages of above mentioned
interventional methods, single method can not solve all clinical
issues. Therefore, in order to remove benign tracheobronchial
tumors completely, and reduce the incidence of recurrence as far
as possible, many doctors combine several methods of them to
treat complicated benign tracheobronchial tumors.
It is reported that cryotherapy combined with argon plasma
coagulation can rapidly remove large tracheobronchial tumors,
shorten operation time, and prevent severe hemorrhage (39-40). The reason maybe that: (i) after cryotherapy, immediate
argon plasma coagulation can reduce the risk of hemorrhage
and shorten operation time; (ii) after argon plasma coagulation,
freezing cutting can remove the necrotic tissue more
conveniently than biopsy forceps. Usually, 2-3 times freezing
cutting can remove eschar completely, which can also shorten
operation time; (iii) after argon plasma coagulation, risk of
hemorrhage when performing cryotherapy is reduced; (iv) we
can repeat these steps until a large tumor is completely removed.
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Nd: YAG laser or electrocautery combined with
argon plasma coagulation
Nd: YAG laser or electrocautery combined with argon plasma
coagulation can rapidly remove tumor with lower risk of
perforation and severe hemorrhage (41-42). For large tumors,
we can use electrocautery to remove tumor, then Nd: YAG laser
to make the gasification of the residual tumor, finally argon
plasma coagulation to treat basilar part of tumor to prevent
recurrence. Because the superficial treatment depth, it is effective
to avoid perforation and severe hemorrhage.
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Conclusion
Benign tracheobronchial tumors are quite rare, and the preferred therapy is surgery. But many bronchoscopic treatments are very effective and the risk of recurrence or malignant change is very low, especially when several .treatments such as Nd: YAG laser, electrocautery, cryotherapy and argon plasma coagulation, are combined to treat tumors. This article introduced several bronchoscopic treatments and their combination with each other. To achieve the aim of radical cure and reduce the risk of recurrence as far as possible, we believe that we should evaluate
each method including bronchoscopic treatments and surgery, and select the most suitable methods for out patients and make use of them synthetically.
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References
Cite this article as: Gao H, Ding X, Wei D, Cheng P, Su XM, Liu H, Zhang T. Endoscopic management of benign tracheobronchial tumors. J Thorac Dis 2011;3(4):255-261. doi: 10.3978/j.issn.2072-1439.2011.09.02
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