A novel procedure of endobronchial ultrasound-guided transbronchial needle aspiration for pulmonary parenchymal lesions: The ZUTAM technique.

Convex probe-endobronchial ultrasound (CP-EBUS) has been proven to be safe and accurate for identifying malignancy and granulomatous disease affecting the mediastinum and hilum. CP-EBUS can be used for intraparenchymal lesions also and has been shown to be efficacious. A subset of lesions particularly suited for CP-EBUS are those completely surrounded by lung parenchyma, centrally located, and typically close to but without an airway leading directly to them. We report a case of transbronchial needle aspiration (TBNA) done from a nodule of size 11 mm in the superior segment of the right lower lobe. EBUS-TBNA was done from this lesion, which was 5 mm away from the bronchus in the lung parenchyma with intervening normal lung tissue in between. TBNA was performed by compressing the abutting normal lung tissue, thus causing compression collapse of the intervening normal lung. We labeled this Zealous Unique Trans Arterial Maneuver as the "ZUTAM" technique.

INTRODUCTION

The diagnosis of peripheral pulmonary lesions remains a clinical challenge. Peripheral lung nodules and masses can be diagnosed by a variety of techniques, including bronchoscopy, computed tomography (CT)-guided needle biopsy, and video-assisted thoracoscopic surgery. Transbronchial needle aspiration (TBNA) was first described in 1949 by Schieppati.[1] The ability to perform ultrasound inside the thorax both in the bronchus and esophagus has changed the approach to certain types of intrathoracic diseases. With new invasive options, intrathoracic ultrasound is being used in applications ranging from less invasive staging of the mediastinum, to targeted delivery of chemotherapeutic agents.[2] With the development of real-time endobronchial ultrasound (EBUS) TBNA, TBNA could provide more accurate diagnoses of mediastinal and hilar lymphadenopathies.[1] Both convex probe EBUS (CP-EBUS) and radial probe EBUS have been used in a variety of novel ways to enhance the abilities of the bronchoscopist.

EBUS-TBNA is a safe and effective technique for the assessment and sampling of hilar and mediastinal lymph nodes paratracheal and peribronchial lung masses.[3] It has a high sensitivity for identifying malignancy when used for cytological sampling.[4] It is a valuable option in the early diagnosis of peripheral lung cancer, especially in small sized lesions and in patients who are not eligible for surgery.[5] In addition to mediastinal nodes and masses, CP-EBUS is useful for diagnosing parenchymal lung lesions.

Here, we report a case of EBUS-TBNA from a intraparenchymal lesion which is away from bronchus using a novel technique. We labeled this Zealous Unique Trans Arterial Maneuver as the “ZUTAM” technique.

CASE REPORT

A 57-year-old male patient was referred to our outpatient department. He was diagnosed to have carcinoma colon in 2015 (adenocarcinoma of sigmoid colon) and had underwent hemicolectomy with lymphadenectomy with eight cycles of adjuvant chemotherapy (XELOX scheme). His follow-up colonoscopy was negative and he was on regular follow-ups. Positron emission tomography (PET) CT was done in April 18, 2018, which showed micronodules with a bigger nodule of 7 mm in the lower lobe of the right lung [Figure 1]. Subsequent PET-CT in October 23, 2018, showed increase in the size of this nodule to 11 mm in the superior segment of the right lower lobe. Contrast-enhanced CT (CECT) chest was also done [Figure 2].

Figure 1

Computed tomography of the thorax showing 7 mm right lower lobe nodule

Figure 2

Computed tomography of thorax showing 11 mm right lower lobe nodule

The case was discussed in multidisciplinary meet and it was decided to do EBUS fine-needle aspiration cytology of the nodule. Hemogram, serum electrolytes, prothrombin time, activated partial thromboplastin time, and international normalized ratio were unremarkable. As seen in the CT scan, the pulmonary nodule was 5 mm away from the airway with intervening normal lung tissue in between. It was not accessible through conventional technique of EBUS [Figure 3]. EBUS was performed by compressing the abutting normal lung tissue, thus causing compression collapse of the intervening normal lung tissue which helped in visualization of the pulmonary parenchymal nodule. After reaching into the bronchus intermedius, EBUS probe was turned to the left side (−90) and then we inflated the balloon and pushed down the lever to compress the lung tissue. The lung sliding sign which was visualized initially was replaced with isoechoic lesion [Figure 4 and Video 1]. We labeled this technique as the ZUTAM technique. TBNA was done from the lesion with an Olympus 22 gauge needle. There were no complications related to the procedure. EBUS-TBNA report confirmed the lesion to be metastasis from adenocarcinoma of the colon.

Figure 3

Endobronchial ultrasound bronchoscopy image at the site of the lesion

Figure 4

Endobronchial ultrasound Image of the ZUTAM as the technique showing the lung as an isoechoic lesion on compression with the endobronchial ultrasound bronchoscope

[MULTIMEDIA:1]

DISCUSSION

Lesions in the periphery of the lungs are not visible in conventional bronchoscopy. The “bronchus sign,” which is characterized by the presence of a bronchus leading to the lesion is an important sign in CT scan predicting the success of biopsy/TBNA by which ever guidance system used.[6] These lesions need guidance systems such as radial EBUS, electromagnetic navigation bronchoscopy (ENB), and virtual bronchoscopy which guide sample collection. A multimodality investigation by combining EBUS with ENB enhances the diagnostic yield of bronchoscopy in peripheral lung lesions compared with either procedure alone. The improved yield is independent of the lesion size or lobar distribution.[7] Physicians often use CP-EBUS to diagnose the lung lesions that are centrally or peripherally located and completely surrounded by lung parenchyma and that lack the radiographic bronchus sign.

Argento and Puchalski had done a retrospective study, and they concluded that CP-EBUS can be used to diagnose lung lesions, particularly those that are centrally located, completely surrounded by lung parenchyma and that lack the radiographic bronchus sign. In this study, the procedure was done by traversing the normal lung tissue.[8] The incidence of pneumothorax would be higher with more lung traversed. In our case, we have explained a novel method of approaching the peripherally located nodule without the bronchus sign. The lesion which is surrounded by a normal lung parenchyma can be approached for sampling by collapsing the abutting normal lung parenchyma by compressing the CP-EBUS on the wall of the nearest airway (membranous part). We labeled this novel technique as the ZUTAM technique an abbreviation which described our “Zealous Unique Trans Arterial Maneuver” and the core team performing the procedure. The core interventional pulmonology team consisted of two of the authors who discovered and performed this procedure in their institute. They are also referred to as the team “ZUTAM” in their institute. There were no newer navigational systems used in our case.

CONCLUSION

Here, we report a case of EBUS-TBNA from a lesion 5 mm away from the bronchus in the lung parenchyma with intervening normal lung tissue in between. TBNA was performed by compressing the abutting normal lung tissue, thus causing compression collapse of the intervening normal lung, which helped in visualization of the lesion. We had extensively searched the literature and as far as our knowledge this technique has not been reported till date. We labeled this Zealous Unique Trans Arterial Maneuver as the “ZUTAM” technique.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.