In this retrospective study, we analyzed the data of 5576 patients who had completed EBUS-TBNA in the center during the past 10 years. The results showed that the number of patients underwent EBUS-TBNA increased over years of time, demonstrated the increased need of EBUS-TBNA in clinical. As recommended [1,2], the patients with central lung cancer are the most important indications for EBUS-TBNA, Recently, a survey in India reported, suspected granulomatous mediastinal lymphadenopathy (TB/sarcoidosis) (67.2%) and lung cancer (32.8%) were the most common indications of EBUS-TBNA, which were different from our date [13]. Moreover, in this study, it showed that, besides the highest proportion of tumor patients, it was also applied for the diagnosis of different kind of diseases, like, infection diseases, sarcoidosis and lymphoma, et al. As we know, EBUS-TBNA is guided by an ultrasound bronchoscope to obtain real-time structural imaging of the bronchial wall and extramural tissue to clarify the location and character of the lesion, and at the same time, it can display the blood supply of the target or surrounding the lesion to avoid bleeding caused by puncturing the blood vessel by mistake. Under the guidance, a disposable suction biopsy needle is used for puncture or suction to obtain a biopsy sample. Because of its minimally invasive characteristics, good preoperative anesthesia intervention, and good tolerance by patients, this technology can be promoted in clinical practice [14]. So, EUBS-TBNA can be used for the diagnosis of different kind of diseases that the lesions can be reached [15,16].
The overall diagnostic sensitivity was 67.9% of all patients, with highest positive rate (89.3%) in lung cancer patients, higher than previous reports [4,11]. The positive rate of pulmonary infectious diseases was 37.4%, however, there had not include the results of bronchoalveolar lavage fluid (BALF) for etiology, which may highly increase the diagnostic sensitive rate. Mycobacterial infection accounted for the highest proportion of the infection diseases; Most of these patients have unexplained mediastinal lymphadenopathy, which is easily confused with tumor and needs to be clearly identified. Recent literature also reported that EBUS-TBNA has a good diagnostic value for mediastinal tuberculosis [16–18].
In this study, higher diagnostic yield was found in male patients. The date showed that there was a significant difference of the proportion of male and female patients, which caused by the different kind of diseases. There was higher morbidity of lung cancer of male than female, while the proportion of patients with infectious diseases higher in females. For the higher sensitivity of TBNA in the diagnosis of lung cancer, totally the diagnosis sensitivity was 70.2% of male patients, and 62.9% of female patients. Previous studies also showed that there were little higher percent of males than females that underwent TBNA [19–21]. There was few study compared the diagnostic value of EBUS-TBNA between male and female patients.
In this study, lymph nodes were the main sites obtained, with highest percent in sarcoidosis patients, however, the positive rate was slightly higher obtained in lung lesions than that of lymph nodes. Some studies have discussed the application of EBUS-TBNA in the diagnosis of mediastinal enlarged lymph nodes and central pulmonary lesions [4,11]. In this study, a little proportion of patients had both lymph nodes and intrapulmonary lesions punctured with positive rate (60.4%) lower than those patients with lymph node and intrapulmonary lesion obtained only, which might be for the difficulty of target or lesion been punctured of these patients. EUBS-TBNA can be used in different kind of diseases that the lesions can be reached [15,16]. However, the choose of puncture site might depend of the disease and location of the lesion.
Anesthesia is very important to protect the patients to tolerate the operation of EBUS-TBNA [13,14,20]. In this study, the anesthesia method was mainly general intravenous anesthesia with spontaneous breathing, which was safe with little trauma of the patient and caused less adverse effects. Most of the patients can tolerate the operation well, even in elder patients that more than 80 years old [21–23]. The operation can also be completed by mild anesthesia of sedation and analgesia with the patients awake, which is suitable for some patients with poor cardiopulmonary function or who cannot tolerate deep anesthesia [20]. There was an interesting trends in this study that more and more patients anesthetized by general intravenous anesthesia with spontaneous breathing (more than 90% since 2017), and less patients anesthetized by deep general anesthesia of intravenous and inhalation with tracheal intubation and mechanical ventilation follow the years, which consisted with the results reported in previous study that EBUS-TBNA performed under conscious sedation with meperidine and midazolam is feasible and well-tolerated and has a good diagnostic yield [20].
There were few limitations of this study, first, in this retrospective study, clinical application of EBUS-TBNA in the diagnosis of different diseases were described, we need some prospectively comparisons of the diagnostic yield of EBUS-TBNA in different diseases; Second, the different positive rate between male and female patients may be caused by different proportions of patients with different diseases, and case-control study or paired comparisons should be performed; Third, more concern should be paid on the complications of EBUS-TBNA.
In conclusion, EBUS-TBNA has been mainly used for the diagnosis of mediastinal and hilar lesions diseases, however, other diseases were also good candidates, like, infectious diseases, sarcoidosis and lymphoma. Under mild anesthesia, most patient can tolerant EBUS-TBNA, and the punctured site can be enlarged lymph nodes and pulmonary lesions. There was a difference in the diagnostic sensitivity of EBUS-TBNA between male and female patients, which need more study and subgroup analysis.