Devanand Anantham

Diagnosis of Mediastinal Adenopathy—Real-Time Endobronchial Ultrasound Guided Needle Aspiration versus Mediastinoscopy

Background: Real-time endobronchial ultrasound has increased the accuracy of conventional transbronchial needle aspiration biopsy in sampling mediastinal lymph nodes. Nevertheless, direct comparisons with mediastinoscopy are not available to determine the role of endobronchial ultrasound in pathologic staging. Objectives: To compare the diagnostic yield of endobronchial ultrasound against cervical mediastinoscopy in the diagnosis and staging of radiologically enlarged mediastinal lymph nodes stations accessible by both modalities in patients with suspected nonsmall cell lung cancer. Methods: Prospective, crossover trial with surgical lymph node dissection used as the accepted standard. Biopsy results of paratracheal and subcarinal lymph nodes were compared. Results: Sixty-six patients with a mean age 60 ± 10 years were studied. The prevalence of malignancy was 89% (59/66 cases). Endobronchial ultrasound had a higher overall diagnostic yield (91%) compared with mediastinoscopy (78%; p = 0.007) in the per lymph node analysis. There was disagreement in the yield between the two procedures in the subcarinal lymph nodes (24%; p = 0.011). There were no significant differences in the yield at other lymph node stations. The sensitivity, specificity, and negative predictive value of endobronchial ultrasound were 87, 100, and 78%, respectively. The sensitivity, specificity, and negative predictive value of mediastinoscopy were 68, 100, and 59%, respectively. No significant differences were found between endobronchial ultrasound (93%) and mediastinoscopy (82%; p = 0.083) in determining true pathologic N stage (per patient analysis). Conclusions: In suspected nonsmall cell lung cancer, endobronchial ultrasound may be preferred in the histologic sampling of paratracheal and subcarinal mediastinal adenopathy because the diagnostic yield can surpass mediastinoscopy.

Narrow-Band Imaging Bronchoscopy Increases the Specificity of Bronchoscopic Early Lung Cancer Detection

Background: Detection of nonsmall cell lung cancer at the intraepithelial stage is believed to improve cure rates. New bronchoscopic technologies, including white light videobronchoscopy (WLB), autofluorescence imaging (AFI), and narrow band imaging (NBI), are aiming to diagnose airway neoplasia at a preinvasive stage. Objectives: To evaluate the diagnostic yields of NBI individually and in combination with WLB and AFI. Methods: A 10-month review of patients who were referred for airway screening or surveillance. Patients were randomized as to the order of AFI and NBI examinations. The airway mucosa was graded endoscopically as “normal,” “abnormal,” “suspicious,” or “tumor.” All areas that were not normal were biopsied. Biopsies with a histologic grading of moderate to severe dysplasia or carcinoma in situ were considered positive for intraepithelial neoplasia. Results: Sixty-two patients with a mean age of 56.2 ± 9.8 years were studied. Five patients had invasive cancers and were excluded from the analysis. The remaining 57 cases had a 30% prevalence of intraepithelial neoplasia. The sensitivity of WLB was 0.18 and the specificity was 0.88. The relative sensitivities (compared with WLB) of AFI and NBI were 3.7 (p = 0.005) and 3.0 (p = 0.03), respectively. The relative specificities of AFI and NBI were 0.5 (p < 0.001) and 1.0 (p = 0.72), respectively. Combining AFI and NBI did not increase diagnostic yield significantly. The sequence of performing AFI and NBI did not impact findings. Conclusions: NBI is an alternative to AFI in the detection of early lung cancers because it has a comparatively higher specificity without significantly compromising the sensitivity.

Electromagnetic Navigation Bronchoscopy-Guided Fiducial Placement for Robotic Stereotactic Radiosurgery of Lung Tumors: A Feasibility Study

BACKGROUNDnStereotactic radiosurgery (Cyberknife; Accuray Incorporated; Sunnyvale, CA) is a treatment option for patients who are medically unfit to undergo lung tumor resection. For precise tumor ablation, the Cyberknife requires fiducial marker placement in or near the target tumor. Fiducial placement under transthoracic CT guidance is associated with a high risk of iatrogenic pneumothorax. Electromagnetic navigation bronchoscopy (ENB) may offer a less morbid alternative to accurately deploy fiducials to bronchoscopically invisible peripheral lung lesions.nnnOBJECTIVEnOpen-label, feasibility study to assess fiducial placement in peripheral lung tumors by ENB.nnnMETHODnConsecutive patients with peripheral lung tumors and who were evaluated to be nonsurgical candidates underwent fiducial placement under ENB. This procedure was considered successful if fiducials were placed in or near the tumors and remained in place without migration for radiosurgery to proceed. The need for alternative or additional intrathoracic fiducial placement was documented as procedure failure.nnnRESULTSnA total of 39 fiducials markers were successfully deployed in eight of nine patients (89%). Of these eight successful cases, seven had fiducials placed directly within the tumor (88%). At Cyberknife planning, 7 to 10 days after fiducial placement, 35 of 39 fiducial markers (90%) were still in place and were adequate to allow radiosurgery to proceed. No immediate bronchoscopic complications were observed. One patient had a COPD exacerbation. Another patient returned within 1 day with transient, self-limiting fever.nnnCONCLUSIONSnENB can be used to deploy fiducial markers for Cyberknife radiosurgery of lung tumors safely and accurately without the complications associated with transthoracic placement.

ORIGINAL RESEARCHINTERVENTIONAL PULMONOLOGYElectromagnetic Navigation Bronchoscopy-Guided Fiducial Placement for Robotic Stereotactic Radiosurgery of Lung Tumors: A Feasibility Study

BACKGROUNDnStereotactic radiosurgery (Cyberknife; Accuray Incorporated; Sunnyvale, CA) is a treatment option for patients who are medically unfit to undergo lung tumor resection. For precise tumor ablation, the Cyberknife requires fiducial marker placement in or near the target tumor. Fiducial placement under transthoracic CT guidance is associated with a high risk of iatrogenic pneumothorax. Electromagnetic navigation bronchoscopy (ENB) may offer a less morbid alternative to accurately deploy fiducials to bronchoscopically invisible peripheral lung lesions.nnnOBJECTIVEnOpen-label, feasibility study to assess fiducial placement in peripheral lung tumors by ENB.nnnMETHODnConsecutive patients with peripheral lung tumors and who were evaluated to be nonsurgical candidates underwent fiducial placement under ENB. This procedure was considered successful if fiducials were placed in or near the tumors and remained in place without migration for radiosurgery to proceed. The need for alternative or additional intrathoracic fiducial placement was documented as procedure failure.nnnRESULTSnA total of 39 fiducials markers were successfully deployed in eight of nine patients (89%). Of these eight successful cases, seven had fiducials placed directly within the tumor (88%). At Cyberknife planning, 7 to 10 days after fiducial placement, 35 of 39 fiducial markers (90%) were still in place and were adequate to allow radiosurgery to proceed. No immediate bronchoscopic complications were observed. One patient had a COPD exacerbation. Another patient returned within 1 day with transient, self-limiting fever.nnnCONCLUSIONSnENB can be used to deploy fiducial markers for Cyberknife radiosurgery of lung tumors safely and accurately without the complications associated with transthoracic placement.

Clinical review: Independent lung ventilation in critical care

Independent lung ventilation (ILV) can be classified into anatomical and physiological lung separation. It requires either endobronchial blockade or double-lumen endotracheal tube intubation. Endobronchial blockade or selective double-lumen tube ventilation may necessitate temporary one lung ventilation. Anatomical lung separation isolates a diseased lung from contaminating the non-diseased lung. Physiological lung separation ventilates each lung as an independent unit. There are some clear indications for ILV as a primary intervention and as a rescue ventilator strategy in both anatomical and physiological lung separation. Potential pitfalls are related to establishing and maintaining lung isolation. Nevertheless, ILV can be used in the intensive care setting safely with a good understanding of its limitations and potential complications.

Role of endobronchial ultrasound in the diagnosis of bronchogenic cysts.

Diagnosis of bronchogenic cysts is possible with computed tomography, but half of all cases present as soft tissue densities. Two such cases are highlighted where asymptomatic bronchogenic cysts that presented as soft tissue masses were evaluated by endobronchial ultrasound (EBUS). After studying the ultrasound image characteristics, the diagnosis was confirmed using EBUS-guided transbronchial needle aspiration (EBUS-TBNA). The first case had ultrasound findings of an anechoic collection, and the aspirate was serous with negative microbiologic cultures. The second was an echogenic collection within a hyperechoic wall. Needle aspirate was purulent and cultured Haemophilus influenza. The diagnosis of a bronchogenic cyst complicated by infection was made, and the lesion was surgically resected. This potential for EBUS in the diagnosis of bronchogenic cysts and in identifying complications such as infection should be considered in the management of such cases.

Vibration Response Imaging in the Detection of Pleural Effusions: A Feasibility Study

Background: Computerized analysis of the regional distribution of breath sound intensity during respiration has generated interest as a possible diagnostic modality. Objectives: We hypothesized that pleural effusions would create a dependent region of absent breath sounds and thus vibration response imaging (VRI) could be used in the detection of such pleural effusions. Methods: A prospective, single-blinded and open-labeled trial was carried out, and VRI recordings were compared to upright chest X-rays, bedside ultrasound examinations and volume of fluid drained via thoracentesis. VRI images were interpreted by a physician who was blinded to the patients’ clinical history, physical examination and diagnostic tests. Quantitative assessment of pleural effusion size in the VRI images was performed by ImageJ software and an automatic pixel count analysis. Results: VRI recordings were performed on 57 consecutive patients and correctly predicted the diagnosis in 45 cases (45/56, 80%) as compared to chest X-rays. The calculated sensitivity, specificity, positive predictive value and negative predictive value for diagnosis of pleural effusion were 86% (62/72), 93% (37/40), 95% (62/65) and 79% (37/47), respectively, in a per-hemithorax analysis. In the quantification of effusion size, there were high correlations between VRI images and chest X-ray area as assessed by ImageJ (r = 0.67) and pixel count (r = –0.77). The level of agreement between VRI readings and ultrasonography was 75% (41/55), and correlation with the volume of fluid drained in therapeutic thoracentesis was moderate (r = –0.49). No side effects from the VRI recordings were documented. Conclusions: VRI can be used to detect and quantify pleural effusions.

Endoscopic Management of Emphysema

Lung volume reduction surgery has proven benefits in emphysema. However, high postoperative morbidity and stringent selection criteria for suitable candidates are limitations in clinical practice. Endoscopic approaches to lung volume reduction have used a range of different techniques such as endobronchial blockers, airway bypass, endobronchial valves, biologic sealants, and airway implants to address the limitations of surgery. The underlying physiologic mechanisms of endoscopic modalities vary, and homogeneous and heterogeneous emphysema are targeted. Currently available data on efficacy of bronchoscopic lung volume reduction are not consistently conclusive, and subjective benefit in dyspnea scores is a more frequent finding than improvements on spirometry or exercise tolerance. The safety data are more promising, with rare procedure-related mortality, fewer complications than lung volume reduction surgery, and short hospital length of stay. The field of bronchoscopic lung volume reduction continues to evolve as ongoing prospective randomized trials aim to clarify the efficacy data from earlier feasibility and safety studies.

Bronchoscopic Lung Volume Reduction

The application of lung volume reduction surgery in clinical practice is limited by high postoperative morbidity and stringent selection criteria. This has been the impetus for the development of bronchoscopic approaches to lung volume reduction. A range of different techniques such as endobronchial blockers, airway bypass, endobronchial valves, thermal vapor ablation, biological sealants, and airway implants have been employed on both homogeneous as well as heterogeneous emphysema. The currently available data on efficacy of bronchoscopic lung volume reduction are not conclusive and subjective benefit in dyspnoea scores is a more frequent finding than improvements on spirometry or exercise tolerance. Safety data are more promising with rare procedure-related mortality, few serious complications, and short hospital length of stay. The field of bronchoscopic lung volume reduction continues to evolve as ongoing prospective randomized trials build on earlier feasibility data to clarify the true efficacy of such techniques.

Evaluation of Pulmonary Nodules: Clinical Practice Consensus Guidelines for Asia

BACKGROUNDnAmerican College of Chest Physicians (CHEST) clinical practice guidelines onxa0the evaluation of pulmonary nodules may have low adoption among clinicians in Asianxa0countries. Unique patient characteristics of Asian patients affect the diagnostic evaluation of pulmonary nodules. The objective of these clinical practice guidelines was to adapt those of CHEST to provide consensus-based recommendations relevant to practitioners in Asia.nnnMETHODSnA modified ADAPTE process was used by a multidisciplinary group of pulmonologists and thoracic surgeons in Asia. An initial panel meeting analyzed all CHEST recommendations to achieve consensus on recommendations and identify areas that required further investigation before consensus could be achieved. Revised recommendations were circulated to panel members for iterative review and redrafting to develop the final guidelines.nnnRESULTSnEvaluation of pulmonary nodules in Asia broadly follows those of the CHEST guidelines with important caveats. Practitioners should be aware of the risk of lung cancer caused by high levels of indoor and outdoor air pollution, as well as the high incidence of adenocarcinoma in female nonsmokers. Furthermore, the high prevalence of granulomatous disease and other infectious causes of pulmonary nodules need to be considered. Therefore, diagnostic risk calculators developed in non-Asian patients may not be applicable. Overall, longer surveillance of nodules than those recommended by CHEST should be considered.nnnCONCLUSIONSnTB in Asia favors lesser reliance on PET scanning and greater use of nonsurgical biopsy over surgical diagnosis or surveillance. Practitioners in Asia are encouraged to use these adapted consensus guidelines to facilitate consistent evaluation of pulmonary nodules.