4 AJTCCM VOL. 31 NO. 1 2025
EDITORIAL
Transbronchial lung cryobiopsy (TBLC) for the assessment of inter-
stitial lung disease (ILD) has become a more sought-aer procedure as
evidence has emerged to support high diagnostic yield.[1,2] TBLC can
help to mitigate the need for diagnostic lung biopsy via video-assisted
thoracic surgery or open thoracotomy, making it an ideal alternative
for patients with ILD, given their high degree of frailty.[3,4] In much
of the published literature, TBLC has been done under general
anaesthesia,[1] but this is not easily accessible to all bronchoscopists.
e article by Buckley etal.[5] in this issue of AJTCCM,[5] ‘e utility
of transbronchial cryobiopsy performed under conscious sedation for
interstitial lung diseases in a resource-constrained setting’, describes
an alternative approach to this procedure.
is study prospectively enrolled 20 sequential patients referred
for lung biopsy for the investigation of ILD at a single centre in
South Africa. TBLC was performed under conscious sedation,
achieved by propofol bolus, with fluoroscopic guidance and
prophylactic bronchial blocker deployment to monitor for bleeding
aer the biopsy. e main outcome was nal diagnosis or need for
subsequent surgical biopsy, based on a decision by the specialist
multidisciplinary team (MDT).
e authors found that rates of adverse events were low, in keeping
with previously published literature. e rate of pneumothorax not
requiring chest drain placement was 10% (n=2), and signicant
bleeding occurred in 5% (n=1) but resolved with tamponade.
Importantly, there were no sedation-related side-eects requiring
inotropic support, and no conversion to general anaesthesia. A nal
diagnosis could be made by the MDT aer histological examination
in 85% of cases (n=17). Of the three patients without a clear diagnosis,
only one proceeded to surgical biopsy. e authors conclude that
TBLC is safe to perform for ILD biopsy under conscious sedation
and provides a valuable diagnostic yield, although they acknowledge
that the sample size was small and the TBLCs were performed by
a single experienced bronchoscopist. Strengths of the study are its
prospective nature and the clear description of the technique in a
reproducible manner.
A second article in this issue, by Esmail et al.[6] and entitled
‘Feasibility and safety of transbronchial lung cryobiopsy and
mediastinal lymph node cryobiopsy: Experience from a resource-
limited African setting’, similarly explores the use of cyrobiopsy for
ILD, but in addition includes cases of endobronchial ultrasound-
guided transbronchial mediastinal lymph node cryobiopsy (EBUS-
TMC). ese procedures were performed under general anaesthesia,
and cryobiopsy was only utilised when EBUS transbronchial needle
aspiration was not diagnostic with rapid on-site pathology evaluation.
ey report on 16 patients, 8 undergoing only TBLC, 5 having only
EBUS-TMC, and the remainder requiring both procedures. eir
diagnostic yield was lower at ~64% for TBLC and 50% for lymph
node cryobiopsy. However, this lower yield may relate to where the
operators are on their learning curve, as the previous experience and
number of operators involved are not reported. Further, the article
describes poor ultrasound visualisation of the cryoprobe and diculty
in accessing the tract aer 19G needle use, which is uncommon in our
experience and in the published literature.[7]
Both studies are to be commended for implementing advanced
bronchoscopy techniques in resource-limited areas with the aim of
decreasing strain on operating theatres followed by inpatient admissions.
One key dierence between the studies is that Buckleyetal.[5] performed
their procedures with conscious sedation, while Esmail etal.[6] used full
general anaesthesia in the bronchoscopy suite.
e conclusion by Buckley etal.
[5]
that TBLC can be done safely
under conscious sedation should be interpreted with caution within
the constraints of the strength of the evidence. Namely, the described
sedation approach is with intermittent propofol boluses, which is
not a common practice in bronchoscopist-led sedation centres,
where a combination of a benzodiazepine such as midazolam and a
rapid-acting narcotic such as fentanyl is traditionally used.
[8]
e use
of propofol in this study is important, as the line between conscious
sedation and deep sedation is dicult to navigate with propofol,
and patients are often sedated past the goal of an Observer’s
Assessment of Alertness/Sedation scale of 2 - 3. In this study, the
level of sedation achieved is not reported. Further details regarding
the procedure length, required patient monitoring, such as end-
tidal carbon dioxide, and method of oxygenation would have been
of benet. ere is some evidence to suggest that conscious sedation
can be optimised with high-ow nasal oxygen,
[9]
so this may be
of benet when using deeper sedation techniques. Additionally,
more detailed information about the patients’ respiratory status,
including baseline pulmonary function, would have claried the
generalisability of the results. Patient selection is an essential aspect
in balancing diagnostic yield and safety of both the procedure and
conscious sedation.
e choice of propofol sedation is likely to have added to the success
of the study by Buckley etal., as cough from biopsy or pulmonary
haemorrhage can increase the risk of the procedure but is less likely
with deeper sedation. Although this may seem like an ideal sedation
strategy given the procedure, it is important to highlight that even
though complications may be rare, having an appropriate plan for
respiratory failure, airway management and haemodynamic instability
is essential. ese considerations are highlighted as lessons learned in
the study by Esmail etal.[6]
As respiratory physicians, we are well placed to manage common
complications such as pneumothorax or minor to moderate bleeding.
ese are oen the complications that are discussed with regard to
procedural safety. However, greater risk lies in complications the
proceduralist may be less equipped to manage, such as those arising
from the sedation approach described in the study by Buckley etal.[5]
e authors did not comment on these safety measures, and in our view,
emergency airway plans and sedation support are essential to consider
if implementing a conscious sedation approach to TBLC. Incontrast,
there is an abundance of evidence to suggest that EBUS-TMC can
be performed safely under traditional conscious sedation[10,11] with
a low rate of complications, which could be considered for future
implementation in resource-limited settings.
One key conclusion of these studies is that performing TBLC or
lymph node cryobiopsies in the endoscopy suite, with conscious
sedation or under general anaesthesia, would increase accessibility in
Resources in the bronchoscopy suite and the utility of cryobiopsy
AJTCCM VOL. 31 NO. 1 2025 5
EDITORIAL
resource-limited settings. Physician-led sedation instead of general
anaesthesia can save on resources, including personnel and operating
theatre time, and decrease the need for specialised post-anaesthesia
care. However, TBLC remains a high-cost procedure that may not be
accessible to resource-limited areas owing to the cost of consumables
(Erbe cryoprobes and Arndt blockers are expensive items), availability
of uoroscopy, and the costs involved in learning the procedure and
managing complications.
As the eld of interventional bronchoscopy advances and new
techniques are developed, it is important to consider sedation as one
of the core components of the procedure. One option is to improve
the training of physicians to achieve safe levels of conscious sedation
in bronchoscopy suites with the use of a propofol bolus or infusion.
Advanced airway management training is an essential aspect of this
skill, as no procedure should be performed without the ability or a
strategy to manage complications. ere are equally strong grounds
to suggest that anaesthetic support is not a resource to compromise
on in advanced bronchoscopy. Having this support does not mandate
the use of general anaesthesia or even operating theatre time, but
means that safe levels of deep sedation can be provided. Performing
procedures under these circumstances improves airway control,
simplifying the technical aspect for the bronchoscopist, which could
improve learning curves, technical safety, and potentially diagnostic
yield.
e authors of these studies should be commended for well written
and clear articles outlining their approaches to incorporating cryobiopsy
as a diagnostic tool. e diagnostic yield in these studies is similar to
that in a recent randomised controlled trial that found TBLC to be
comparable to surgical biopsy with a lower patient burden.[12] Studies
like these have important roles in expanding the reach of research and
clinical trials. ey help to provide implementation evidence and
improve understanding of procedural safety in a range of practices.
Before TBLC under conscious sedation can be broadly considered,
further prospective data with more traditional conscious sedation
methods and information on the characteristics of patients who can
tolerate such procedures are needed.
Disclosures. MLM has no relevant disclosures. NN is supported by
a Medical Research Council Clinical Academic Research Partnership
(MR/T02481X/1). is editorial was partly undertaken at University
College London Hospital/University College London, which received
a proportion of funding from the Department of Health’s National
Institute for Health Research Biomedical Research Centre’s funding
scheme. NN reports honoraria for non-promotional educational talks
or advisory boards from Amgen, Astra Zeneca, AXANA, Boehringer
Ingelheim, Bristol Myers Squibb, EQRx, Fujilm, Guardant Health,
Intuitive, Janssen, Lilly, Merck Sharp & Dohme, Olympus, Roche and
Sano. RT has received honoraria for non-promotional educational
talks and travel from Fujilm, Medix, MIMS and Olympus, and is on
the Intuitive Surgical advisory board.
M L Mullin MD, FRCPC
Lungs for Living Research Centre, UCL Respiratory, University
College London, UK; Department of oracic Medicine, University
College London Hospital, London, UK; DivisionofRespiratory
Medicine,DepartmentofMedicine,University of British Columbia, Vancouver,
Canada
R akrar, PhD, MRCP
Department of oracic Medicine, University College London Hospital,
London, UK
N Navani, PhD, FRCP
Lungs for Living Research Centre, UCL Respiratory, University College London,
UK; Department of oracic Medicine, University College London Hospital,
London, UK
n.navani@ucl.ac.ukf
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