Endobronchial ultrasound-guided intranodal forceps biopsy (EBUS-IFB) using 19G needle tract: First case series from India

Abstract

EBUS-TBNA is a well-established procedure for diagnosis of mediastinal lymphadenopathy replacing the need for mediastinoscopy. In certain diseases like lymphomas, the yield is reportedly 50%, sarcoidosis lymph nodes also give a yield of 80% with EBUS and at times, more material is needed for better characterization of malignancies. EBUS-intranodal forceps biopsy may be useful in these situations. In our series of seven cases, we describe a unique and safe technique of obtaining forceps biopsy from mediastinal lymph nodes under real-time endobronchial ultrasound guidance using a 19G EBUS-TBNA needle tract and thin biopsy forceps. Lymph node biopsy was able to give a conclusive diagnosis in 42% patients negative with TBNA, and was able to suggest a diagnosis in one case. No complications were seen. Thus, surgical biopsy can be avoided in nearly 50% of failed EBUS-FNAC cases.

INTRODUCTION

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a well-established procedure for diagnosis of intrathoracic lymphadenopathy. It is documented to be safe with a very good diagnostic yield.^[1]

EBUS-TBNA samples are adequate for immunohistochemistry and molecular/genetic analysis of lung cancer replacing the need for mediastinoscopy in various guidelines, especially when combined with endoscopic ultrasound.^[2,3] However, there is a need for more tissue to detect ever-increasing targets required for individualized treatment of lung cancer.

Its accuracy for diagnosis and characterization of lymphomas has always been questioned with a poor reported yield of 50%.^[4] For benign disorders like sarcoidosis, the yield is around 80%, thus it is usually combined with endobronchial and transbronchial lung biopsies entailing a risk of pneumothorax.^[5]

EBUS-guided intranodal forceps biopsy (EBUS-IFB) is a novel technique of obtaining small forceps biopsies of lymph nodes under real-time ultrasound guidance using convex-probe endobronchial ultrasound bronchoscope. Small/mini-forceps are passed into the targeted lymph nodes through the 19G EBUS-TBNA needle puncture tract. The material obtained via EBUS-IFB is then processed as a histological specimen.

The challenge in obtaining biopsy is to pass a blunt instrument like biopsy forceps into the lymph node. Traditionally, a cautery knife was used to make a tract in the lymph nodes, and then, biopsy forceps were used to obtain tissue.^[6] This technique has a mild risk of bleeding and potential pneumomediastinum, apart from being technically more challenging. Recently, EBUS-guided transbronchial cryo-node biopsy has come to the forefront as a novel modality for sampling mediastinal nodes.^[7,8] However, with the use of cryoprobes and cautery, underdiagnosis of infective pathologies remains a matter of concern as frozen specimens cannot be utilized for microbiological cultures.

Herein, we report a series of seven cases where a 19G EBUS TBNA needle was used to make multiple passes at the same site on the lymph node to create a tract, following which a thin biopsy forceps was used to obtain tissue samples. All patients had undergone an EBUS-FNAC as the first diagnostic procedure earlier which failed to provide a specific diagnosis leading to need for doing lymph node biopsy.

MATERIAL AND METHODS

All seven patients had undergone EBUS-FNAC earlier which was non-diagnostic. They were referred for a repeat procedure and were offered intranodal forceps biopsy. Following which they were taken up for the same after detailed informed consent.

The procedures were carried out under moderate sedation or general anaesthesia using the laryngeal mask airway. After identification of lymph nodes and inspection of airways, aspirate was taken with 19G EBUS-TBNA needle [Figure 1]. 19G needle passes usually leave a tract in the node, where the point of entry is visible endobronchially [Figure 2]. Two to three needle passes were done trying to use the same tract each time. Subsequently, a thin biopsy forceps (1.5 mm) was introduced into the tract created by needle punctures [Figure 2]. It can be challenging at times as the forceps is flexible and not stiff like a needle. Proper angulation of the scope to align the direction of the forceps trajectory to the needle tract is required. The whole process is done under direct vision and USG guidance provided by EBUS. Even the opening [Figure 3a] and closing [Figure 3b] of forceps within the node can be appreciated on ultrasound. Four to six biopsies from the lymph node were taken in this manner and the sample sent in formalin for pathology and saline for microbiological analysis.

Figure 1: 19G needle puncture

Figure 2: Puncture mark and forceps

Figure 3: Forceps within the node. (a): Forceps open within the node. (b): Forceps closed within the node

No major complication was noted in any of the procedures. The procedure of biopsy will take 10 minutes more than an FNAC, thereby requiring more sedation. We also noted that in patients where general anaesthesia was used, they tolerated the procedure better in addition to being operator friendly as the patient had lesser cough and respiratory excursions making it easier to align the forceps in the correct direction of the needle puncture.

CASES

Seven procedures were done over four months. All patients had a negative or inconclusive earlier done EBUS-FNAC.

One or more lymph nodes were targeted in each patient. Lymph nodes targeted were subcarinal (6), right paratracheal (3) and left hilar (2).

Out of seven patients, intranodal forceps biopsy was able to give us a diagnosis of granulomatous lymphadenitis in three patients, two out of which were treated as sarcoidosis on the basis of other parameters and one of them had TB XPert positive in the sample confirming tuberculosis and treated for the same.

In one of the patients, it suggested the possibility of an inflammatory lesion comprising chiefly of plasma cells, lymphocytes and few eosinophils. On IHC, scattered IgG4 plasma cells were seen. This patient had an elevated serum IgG4 and was subjected to a surgical lymph node biopsy confirming the diagnosis of IgG4-related disease as the cause of his mediastinal adenopathy.

In three patients, as their earlier FNAC, even the biopsy sample was inadequate as per the pathologists and a repeat biopsy was suggested.

Therefore, lymph node biopsy was able to give a conclusive diagnosis in 42% patients, it was able to suggest a diagnosis in one case, and in three out of seven, i.e., 42%, it was not able to suggest any pathology.

DISCUSSION

EBUS-FNAC has proved to be an excellent tool to sample mediastinal lymph nodes with very high sensitivity and specificity. However, in a few, the material obtained by aspiration is insufficient to reach a definitive diagnosis and a surgical biopsy, mediastinoscopic or thoracoscopic, may be required significantly adding to the cost, hospital stay and morbidity.

The technique described above to take forceps biopsy (or cryobiopsy using a cryo-mini-probe) from lymph nodes under EBUS-guidance is now been increasingly used as a minimally invasive technique obviating the need for more invasive surgery. Our series suggests that in almost 50% of these patients, a diagnosis could be achieved with this minimally invasive procedure.

Masahide et al.^[9] were the first to report this technique in 2004, where 22 cases underwent conventional TBNA using a 19G needle to create a tract in subcarinal lymph node and a mini-biopsy forceps was pushed into the node through the tract. Placement of forceps was confirmed using fluoroscopy, without using EBUS. Three additional cases were diagnosed with biopsy, whilst reporting one pneumomediastinum.

In 2008, Herth et al.^[10] reported a significant increase in diagnosis of sarcoidosis and lymphomas using a biopsy compared to EBUS-FNAC without any major complications in 75 patients. Chrissian et al.,^[11] in their study of 50 patients (74 lymph nodes), reported an overall diagnostic yield of 81% and 91% for EBUS-TBNA and EBUS-IFB, respectively, combined diagnostic yield of 97%, a significant improvement over FNAC alone (P < 0.001) without any complications.

Ray et al.^[12] in their retrospective analysis showed that the diagnostic yield of both FNAC and biopsy is comparable for malignant nodes with biopsy giving more tissue but not adding significantly to diagnosis. However, there was a significant difference in the yield for biopsy for sarcoidosis and lymphomas.

Mehta et al.^[6] used intranodal forceps biopsy with a cautery knife in 30 patients with ROSE showing inadequate material on EBUS-FNAC. They had a positive diagnosis in 8/30 patients with mild bleeding in 2.

Zhang et al.^[7] reported an overall diagnostic yield of 91.8% when they used the 1.1 mm cryoprobe to take biopsies from mediastinal nodes. Yield was similar for malignant nodes. Cryobiopsy was more sensitive for uncommon tumours including lymphomas and benign disorders.

We studied seven consecutive cases, our series had mostly benign disorders as they are more prevalent in our population. Doing forceps biopsies from mediastinal lymph nodes is feasible, safe and without any major complications as shown by above studies. The tract made by 19G needle is adequate for the biopsy forceps to be pushed into the node obviating the need for using cautery knife. It helps in increasing the yield in benign mediastinal disorders as seen in the case series.

However, larger, multicentre studies doing a head-to-head comparison between nodal FNACs and biopsies in patients with diverse aetiologies are required to gain more insight into the subject.

CONCLUSION

Till more data are available, intranodal biopsies may be reserved for patients who have a failed EBUS-FNAC or rapid-onsite cytology showing inadequate material and might avoid a surgical procedure in at least 50% of such patients.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.