
110 AJTCCM VOL. 29 NO. 3 2023
ORIGINAL RESEARCH: ARTICLE
biopsy revealed necrotising granuloma. is
was a learning experience for us, because in a
tuberculosis-endemic country such as India,
we should always keep an infectious cause
in mind when a patient has radiological
features suggestive of ILD. PTB shares many
radiological features with sarcoidosis and
HSP and may therefore masquerade as an
ILD. e diagnosis becomes more dicult
in an inadequately treated patient with
PTB, because the clinical features in such
cases are sometimes not prominent, and
radiological evidence of fibrosis and/or
lymphadenopathy may lead the physician to
suspect an ILD.
With regard to complications, moderate
bleeding was associated with TBLC in the
majority (72.5%) of patients in the present
study. Massive life-threatening bleeding did
not occur in any patient. In the study by
Ravaglia etal.,[6] moderate to severe bleeding
was seen in 13% of patients, and no patient
had a fatal haemorrhage. In the MULTICRIO
study,[11] 6.5% of the 124 patients had moderate
bleeding. Bleeding rates in our study were
therefore considerably higher than in other
contemporary studies, but bleeding was
managed conservatively in all cases and no
patient required intensive care unit admission.
In a meta-analysis, Johannson etal.[12] found
high levels of heterogeneity among studies
reporting bleeding aer TBLC (mean 26.6%,
range 0 - 78%).[12] They postulated that the
varying rates of bleeding may be due to
differences in procedural technique (e.g.
duration of freeze time, probe positioning),
inconsistent definitions of adverse events
such as bleeding, and differences in study
populations. In our study, echocardiography
was not part of the pre-procedure work-up.
We suspect that undiagnosed pulmonary
hypertension in some patients may have
resulted in our relatively high rate of bleeding.
The rate of pneumothorax in our study
was 13.8%, which is similar to the pooled
estimate of 12% (95% confidence interval
3 - 21) emerging from the meta-analysis by
Johannson et al.[12] despite the fact that we
did not use a fluoroscopy-guided biopsy
technique. is nding is reassuring, because
in a resource-limited country such as India,
routine use of uoroscopy may not always be
feasible. Furthermore, none of our patients
had a large air leak, as 11 pneumothoraces
resolved on high-ow oxygen therapy and only
1 patient required intercostal tube placement
with a 3-day hospital stay. Ravaglia et al.[6]
found that cryobiopsies using a 2.4 mmprobe
were associated with increased rates of
pneumothorax compared with 1.9 mm probes,
but had similar diagnostic yields. We used the
1.9 mm probe in our study, which may have
reduced the risk of pneumothorax while not
decreasing the diagnostic yield. Pneumothorax
is also dependent on the number of biopsy
sites and the number of biopsy samples taken.
However, there is no consensus regarding the
optimal number of biopsies required for a
condent diagnosis of ILD, or the number of
biopsy sites or segments. Further studies are
required in this area.
Our study had certain limitations. The
sample size was small, and the study was
conducted in a single institution. As both
the procedures, TBLB and TBLC, were
done in same setting, we could not attribute
complications to a single procedure. Routine
echocardiography and work-up for pulmonary
hypertension were not done in our study, and
these would have helped us to identify the
patients with an increased risk of bleeding.
Conclusion
Our study clearly shows that TBLC is a
relatively safe procedure that can be performed
in a day-care setting with a diagnostic yield
much better than that of conventional TBLB.
Head-to-head comparisons with surgical lung
biopsy and TBLC should be done to ascertain
the diagnostic yield of TBLC as opposed to
surgical interventions.
Declaration. e research for this study was
done in partial fullment of the requirements
for KSM’s DNB (Diplomate of National Board)
in Respiratory Medicine degree at the National
Board of Examinations, India.
Table2. Macroscopic and microscopic features of TBLB and TBLC specimens
(N=87patients)
TBLB, n (%)* TBLC, n (%)*
Diameter of biopsy sample (mm), mean (SD) 1.91 (0.964) 3.99 (1.78)
Histopathological ndings
Granuloma 9 (10.3) 18 (20.7)
Necrosis 3 (3.4) 15 (17.2)
Fibroblastic foci 21 (24.1) 30 (34.5)
Septal inammation 15 (17.2) 30 (34.5)
Intra-alveolar macrophages 12 (13.8) 21 (24.1)
Z-N staining AFB 0 0
Alveolar tissue 21 (24.1) 66 (75.9)
Crush artifacts 51 (58.6) 0
TBLB = conventional transbronchial forceps lung biopsy; TBLC = transbronchial lung cryobiopsy; Z-N = Ziehl-Neelsen;
AFB = acid-fast bacilli.
*Except where otherwise indicated.
Table3. Final histopathological diagnoses in TBLB and TBLC biopsy samples
(N=87patients)
Diagnosis TBLB, n (%) TBLC, n (%)
Usual interstitial pneumonia 0 6 (6.8)
Hypersensitivity pneumonitis 3 (3.4) 15 (17.2)
Sarcoidosis 6 (6.8) 15 (17.2)
Idiopathic bronchiolocentric interstitial
pneumonitis
3 (3.4) 3 (3.4)
Pulmonary Langerhans cell histiocytosis 3 (3.4) 3 (3.4)
Pleuroparenchymal broelastosis 0 3 (3.4)
Silicosis 3 (3.4) 3 (3.4)
Pulmonary tuberculosis 6 (6.8) 15 (17.2)
Nonspecic inammation 3 (3.4) 3 (3.4)
Carcinoma 0 3 (3.4)
Inconclusive 60 (68.9) 18 (20.7)
TBLB = conventional transbronchial forceps lung biopsy; TBLC = transbronchial lung cryobiopsy.