Mediastinal Nodular Lymphocyte Predominant Hodgkin Lymphoma Achieved by Endoscopic Transesophageal Cryobiopsy

Feasibility and Safety of Transesophageal Mediastinal Cryobiopsy in the Diagnosis of Mediastinal Pathologies

INTRODUCTION

Endobronchial ultrasound-guided transbronchial needle aspiration remains the gold standard for the diagnosis of mediastinal pathologies. Its greatest limitation has been the low diagnostic yield in lymphoproliferative disorders as well as insufficient samples for molecular testing. Transesophageal examinations using an EBUS scope have helped increase the diagnostic yield by allowing for additional biopsies of paraesophageal and intra-abdominal lesions. Similarly, the novel approach of transbronchial mediastinal cryobiopsy has further increased the yield by providing larger and better-preserved biopsies. Both complimentary techniques have shown great individual feasibility and safety. However, the feasibility of transesophageal cryobiopsies in the evaluation of mediastinal pathologies remains a subject of debate.

AIM

The aim of the study was to investigate the safety and feasibility of transesophageal EBUS-guided mediastinal cryobiopsies performed at our center.

METHODS

We conducted a retrospective review of 30 patients who underwent mediastinal cryobiopsy through the esophagus at our institution between October 2023 and March 2024. Data on patient demographics, diagnostic yield, and complications were collected and analyzed.

RESULTS

The mean patient age was 43 years, with a gender distribution of 60% male and 40% female. The primary indications included suspicion of lymphoproliferative disorders, suspected sarcoidosis, and malignancies with paraesophageal lesions. The overall diagnostic yield was 93%. No major complications were noted in any of the patients.

CONCLUSION

Transesophageal mediastinal cryobiopsy appears to be a promising complimentary technique for mediastinal evaluation with a relatively high diagnostic yield and favorable safety profile. However, further studies with larger cohorts are warranted to validate the findings at our institution.

Utility and safety of endobronchial ultrasound-guided transbronchial mediastinal cryobiopsy (EBUS-TMC): A systematic review and meta-analysis

BACKGROUND

Modalities to improve tissue acquisition during endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) have been investigated. Endobronchial ultrasound-guided transbronchial mediastinal cryobiopsy (EBUS-TMC) is a modality to obtain larger histological samples by inserting a cryoprobe into the mediastinal lesion. We aimed to study the diagnostic yield and safety of EBUS-TMC.

METHODS

We performed a systematic search of the PubMed and Embase databases to extract the relevant studies. We then performed a meta-analysis to calculate the diagnostic yield of EBUS-TMC and compare it with EBUS-TBNA.

RESULTS

Following a systematic search, we identified 14 relevant studies (869 patients undergoing EBUS-TMC and EBUS-TBNA). We then performed a meta-analysis of the diagnostic yield of EBUS-TMC and EBUS-TBNA from studies wherein both procedures were performed. The pooled diagnostic yield of EBUS-TMC was 92% (95% confidence interval [CI], 89%-95%). The pooled diagnostic yield of EBUS-TBNA was 81% (95% CI, 77%-85%). The risk difference in yield was 11% (95% CI, 6%-15%, I2 = 0%) when EBUS-TMC and EBUS-TBNA were compared. The only complication reported commonly with EBUS-TMC was minor bleeding. The complication rate was comparable with EBUS-TBNA.

CONCLUSION

EBUS-TMC provides a greater diagnostic yield with a similar risk of adverse events compared to EBUS-TBNA. Future studies are required to clearly establish which patients are most likely to benefit from this modality.

Transbronchial needle aspiration combined with cryobiopsy in the diagnosis of mediastinal diseases: a multicentre, open-label, randomised trial

BACKGROUND

Transbronchial mediastinal cryobiopsy is a novel sampling technique for mediastinal disease. Despite the possibility of lung cancer misdiagnosis, the improved diagnostic yield of this approach for non-lung-cancer lesions compared with standard endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) highlights its diagnostic potential as a complementary technique to conventional biopsy. We aimed to evaluate the safety profile and added value of the combined use of transbronchial mediastinal cryobiopsy and standard EBUS-TBNA for the diagnosis of mediastinal diseases.

METHODS

We conducted an open-label, randomised trial at three hospital sites in Europe and Asia. Eligible patients were aged 15 years or older, with at least one mediastinal lesion of 1 cm or longer in the short axis that required diagnostic bronchoscopy. Participants were randomly assigned (1:1) using a block randomisation scheme generated by a computer (block size of four participants based on a random table from an independent statistician) to the combined use of EBUS-TBNA and transbronchial mediastinal cryobiopsy (combined group) or EBUS-TBNA alone (control group). Because of the nature of the intervention, neither participants nor investigators were masked to group assignment. The coprimary outcomes were differences in procedure-related complications and diagnostic yield (defined as the proportion of participants for whom mediastinal biopsy led to a definitive diagnosis), assessed in the full analysis set, including all the patients who met the eligibility criteria and had a biopsy. A fully paired, intraindividual diagnostic analysis in participants who had both needle aspiration and mediastinal cryobiopsy was conducted, in addition to interindividual comparisons. This trial is now complete and is registered with ClinicalTrials.gov, NCT04572984.

FINDINGS

Between Oct 12, 2020, and Sept 9, 2021, 297 consecutive patients were assessed for eligibility and 271 were enrolled and randomly assigned to the combined group (n=136) or the control group (n=135). The addition of cryobiopsy to standard sampling significantly increased the overall diagnostic yield for mediastinal lesions, as shown by both interindividual (126 [93%] of 136 participants in the combined group vs 109 [81%] of 135 in the control group; risk ratio [RR] 1·15 [95% CI 1·04-1·26]; p=0·0039) and intraindividual (126 [94%] of 134 vs 110 [82%] of 134; RR 1·15 [95% CI 1·05-1·25]; p=0·0026) analyses. In subgroup analyses in the intraindividual population, diagnostic yields were similar for mediastinal metastasis (68 [99%] of 69 participants in the combined group vs 68 [99%] of 69 in the control group; RR 1·00 [95% CI 0·96-1·04]; p=1·00), whereas the combined approach was more sensitive than standard needle aspiration in benign disorders (45 [94%] of 48 vs 32 [67%] of 48; RR 1·41 [95% CI 1·14-1·74]; p=0·0009). The combined approach also resulted in an improved suitability of tissue samples for molecular and immunological analyses of non-small-cell lung cancer. The incidence of adverse events related to the biopsy procedure did not differ between trial groups, as grade 3-4 airway bleeding occurred in three (2%) patients in the combined group and two (1%) in the control group (RR 0·67 [95% CI 0·11-3·96]; p=1·00). There were no severe complications causing death or disability.

INTERPRETATION

The addition of mediastinal cryobiopsy to standard EBUS-TBNA resulted in a significant improvement in diagnostic yield for mediastinal lesions, with a good safety profile. These data suggest that this combined approach is a valid first-line diagnostic tool for mediastinal diseases.

FUNDING

National Natural Science Foundation of China.

Esophageal submucosal tumor diagnosed with EBUS-guided transbronchial mediastinal cryobiopsy: A case report

Cryobiopsy is advantageous for collecting larger specimens with minimum crushing compared to forceps biopsy and transbronchial needle aspiration (TBNA), but it has not been widely used for mediastinal tumors. In this report, a leiomyoma of the thoracic esophagus was diagnosed with endobronchial ultrasound-guided transbronchial mediastinal cryobiopsy (EBUS-cryo). An asymptomatic 49-year-old woman had a 2.6-cm sized submucosal tumor (SMT) of the esophagus adjacent to the trachea and left main bronchus. EBUS-TBNA and EBUS-guided intranodal forceps biopsy were performed, followed by EBUS-cryo. The biopsy forceps could not be inserted into the tumor, but the cryoprobe was smoothly inserted. EBUS-TBNA could not obtain enough spindle-shaped tumor cells for immunohistochemical staining, but EBUS-cryo provided sufficient specimens for diagnosing the leiomyoma. Adding EBUS-cryo to EBUS-TBNA has recently been reported to achieve high diagnostic yields for lymphomas, uncommon tumors, and benign diseases. EBUS-cryo seems a valid diagnostic option for esophageal SMTs that are difficult to diagnose with needles and forceps.

Primary Mediastinal Large B-Cell Lymphoma Achieved by Non-Cautery Assisted Transbronchial Mediastinal Cryobiopsy

Transbronchial mediastinal cryobiopsy is a novel sampling strategy that shows improved diagnostic utility for mediastinal lesions, particularly in rare tumors and benign disorders, as compared to standard endobronchial ultrasound-guided transbronchial needle aspiration. During this procedure, electrocautery incision is frequently needed to advance the cryoprobe through the airway into the mediastinal lesion, which however results in increased operative difficulty and prolonged procedural time. Here we present a case of mediastinal large B-cell lymphoma successfully diagnosed by transbronchial mediastinal cryobiopsy without cautery-induced airway incision.

Crown-Cut Endobronchial Ultrasound Guided Transbronchial Aspiration Needle: First Real-World Experiences

Advancements in personalized medicine have increased the demand for quantity and preservation of tissue architecture of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) samples. These demands may be addressed by the SonoTip TopGain^® needle, which has a 3-point crown-cut design that contrasts with the standard single bevel design of the ViziShot 2^®. The objective was to compare the SonoTip TopGain^® and ViziShot 2^® needles by considering biopsy sample characteristics, diagnostic accuracy, and patient safety. The primary endpoint of the study was the number of high-power fields (HPFs) in the center of the formalin-fixed paraffin-embedded cell block per sample. The lymph node with the highest probability for malignant infiltration based on size and sonographic appearance was chosen as the target lymph node for 20 patients. The same lymph node in each patient was sampled using both the ViziShot 2^® and SonoTip TopGain^® needles. The samples were measured, sliced, and analyzed by a pathologist. Sixteen patients were biopsied with both needles. Four patients could not be biopsied with the SonoTip TopGain^® needle since it could not penetrate cartilage or be repositioned to bypass cartilage. HPFs and sample dimensions were significantly greater in the patients where sampling with the SonoTip TopGain^® needle was possible (p = 0.007 and p = 0.005, respectively). Diagnostic accuracy and safety profiles were comparable. Significantly more material can be sampled using the SonoTip TopGain^® needle when cartilage penetration can be avoided. This improves the yield for molecular workup in the era of personalized medicine.