Endobronchial ultrasound for detection of tracheomalacia from chronic compression by vascular ring

Natural History of Asymptomatic and Unrepaired Vascular Rings: Is Watchful Waiting a Viable Option? A New Case and Review of Previously Reported Cases

Vascular rings are a rare form of congenital heart disease in which abnormal aortic arch anatomy leads to encircling of the esophagus and/or trachea by the aortic vasculature. Symptoms can develop from this and prompt the need for surgery. A natural history study has been done on mildly symptomatic patients but no such study has been done on asymptomatic patients. We present a case report of three children with asymptomatic vascular rings who continue to receive follow-up without intervention and review all published cases of asymptomatic or unrepaired vascular rings. Clinical observation of asymptomatic and mildly symptomatic vascular rings, regardless of aortic arch anatomy, seems to be a safe approach. Children with mild symptoms almost invariably seem to have resolution of their symptoms by four years of age.

Combined optical coherence tomography and endobronchial ultrasonography for laser-assisted treatment of postintubation laryngotracheal stenosis

OBJECTIVES

We describe the use of combined optical coherence tomography (OCT) and endobronchial ultrasonography (EBUS) to identify the residual hypertrophic tissues and persistent inflammation that are known contributors to stricture recurrence after laser-assisted mechanical dilation (LAMD) oflaryngotracheal stenosis (LTS).

METHODS

Commercially available high-frequency EBUS (approximately 100-microm resolution) and time-domain OCT (approximately 10- to 20-microm resolution) systems were used to visualize airway wall microstructures in the area of hypertrophic tissue formation before and after LAMD in 2 patients with complex circumferential postintubation LTS.

RESULTS

Before LAMD, EBUS revealed a homogeneous layer consistent with hypertrophic tissue overlying a hyperechogenic layer corresponding to tracheal cartilage. OCT revealed a homogeneous light backscattering layer and an absence of layered microstructures within hypertrophic tissue. Immediately after LAMD, OCT of the laser-charred tissue showed high backscattering and shadowing artifacts; OCT of noncharred tissue showed bright light backscattering regions that suggested acute inflammation. EBUS revealed thinner but persistent hypertrophic tissue overlying the cartilage. Stenosis recurred in both patients.

CONCLUSIONS

Intraoperative use of EBUS and OCT could potentially identify residual hypertrophic tissues and persistent inflammation during or after LAMD. It might help physicians predict stricture recurrence, prompting alternative therapeutic strategies and avoidance of repeated endoscopic treatments for LTS.

The role of endobronchial ultrasound in central early lung cancer

Central early lung cancers (CELC) are tumors arising from the central airways, roentgenographically occult, which are usually diagnosed by bronchoscopy after a positive sputum cytology. Most CELCs are undetectable for conventional white light bronchoscopy (WLB) but can be identified under autofluorescence bronchoscopy (AFB). Although AFB increases the sensitivity of WLB in detecting CELC, its low specificity remains a problem. Surgery has been the most accepted treatment for CELCs; however 20-30% of patients suffering CELC tend to have multicentricities and usually present with poor cardiopulmonary status. Therefore, surgery is not suitable in most of the cases and other therapeutic options such as bronchoscopic treatments should be considered. Because most endoscopic treatments are unlikely to be curative if the tumor has spread beyond the bronchial cartilage, accurate evaluation of CELC bronchial wall invasion is critical before selecting a bronchoscopic treatment. Endobronchial ultrasound (EBUS) is a relatively new technique that has proven to be useful in the evaluation of the normal and cancer-invaded bronchial wall. Some authors have demonstrated that after adding EBUS assessment to AFB in autofluorescence-positive lesions the specificity increases from 50 to 90%. Other studies have focused on the ability of EBUS to detect bronchial wall invasion in patients with CELCs. They compared the EBUS images with pathological findings of surgical specimens of patients that underwent surgery; in most of the cases the correlation between EBUS and pathological findings increased over 90%. Furthermore, in patients not eligible for surgery, EBUS has proven to predict patients expected response to endoscopic treatments.

Scientific evidence and principles for the use of endobronchial ultrasound and transbronchial needle aspiration

Endobronchial ultrasound (EBUS), using the radial EBUS probe and convex-probe EBUS-guided transbronchial needle aspiration, are increasingly advocated for a wide array of minimally invasive thoracic procedures. The effectiveness of EBUS-guided procedures has been demonstrated to a degree that, in many institutions, EBUS is becoming standard of practice for the diagnosis, staging and restaging of mediastinal lymphadenopathy in lung cancer, the diagnosis of sarcoidosis, and for bronchoscopic biopsy of peripheral lung lesions. Its role in other bronchoscopic procedures requires further study despite an already strong body of literature: diagnosis of lymphoma and benign infectious disease, diagnosis of early lung cancer and airway wall disorders, imaging of thoracic vascular disease such as pulmonary embolism, and therapeutic procedures such as placement of fiducial markers. In this article, we illustrate some of the principles of EBUS, describe major technical aspects pertaining to the procedure itself and provide a narrative review of original research addressing proposed roles of EBUS in a variety of indications. In closing, we describe future perspectives including new educational processes and philosophies that could favorably impact the rapid and safe dissemination of this evolving technology into clinical practice.

Interventional bronchoscopy from bench to bedside: new techniques for early lung cancer detection

Lung cancer is a leading cause of cancer-related death in the world, and it accounts for more deaths than breast, colon, and prostate cancer combined in the United States. From a historical perspective, the premise behind early lung cancer detection strategy is that early detection of lung cancer is justified if early treatment improves the outcome. New optical technologies such as those presented in this article allow dynamic study of these processes at the cellular level, and it is hoped that opportunities for targeted therapy will be provided in the future. Investigators are on the verge of discovering a multidimensional bronchoscopic platform that can be used to narrow in on airway structures, explore vascular flow and angiogenesis, and discover new features of bronchogenic carcinogenesis.

Multimodality bronchoscopic [corrected] imaging of tracheopathica osteochondroplastica

Results of a commercial optical coherence tomography system used as part of a multimodality diagnostic bronchoscopy platform are presented for a 61-year-old patient with central airway obstruction from tracheopathica osteochondroplastica. Comparison to results of white-light bronchoscopy, histology, and endobronchial ultrasound examination are accompanied by a discussion of resolution, penetration depth, contrast, and field of view of these imaging modalities. White-light bronchoscopy revealed irregularly shaped, firm submucosal nodules along cartilaginous structures of the anterior and lateral walls of the trachea, sparing the muscular posterior membrane. Endobronchial ultrasound showed a hyperechoic density of 0.4 cm thickness. optical coherence tomography (OCT) was performed using a commercially available, compact time-domain OCT system (Niris System, Imalux Corp., Cleveland, Ohio) with a magnetically actuating probe (two-dimensional, front imaging, and inside actuation). Images showed epithelium, upper submucosa, and osseous submucosal nodule layers corresponding with histopathology. To our knowledge, this is the first time these commercially available systems are used as part of a multimodality bronchoscopy platform to study diagnostic imaging of a benign disease causing central airway obstruction. Further studies are needed to optimize these systems for pulmonary applications and to determine how new-generation imaging modalities will be integrated into a multimodality bronchoscopy platform.