Is Virtual Bronchoscopy an Efficient Diagnostic Tool for the Thoracic Surgeon?

Blunt Traumatic Tracheobronchial Injury: a Clinical Pathway

Background

Motor vehicle collisions (MVC) are a major burden on healthcare systems. Saudi Arabia is one of the countries with a high mortality rate of MVC. Blunt tracheobronchial injuries are rare; however, it is a catastrophic event that requires a high center of care. Lack of experience and advanced faculty prompt early stabilization and transfer of the victim for advanced care. Due to the uncertainty of management of these injuries, we would like to share our experience in dealing with such injuries.

Objective

To address the difficulties in initial management and transfer of patient with blunt traumatic tracheobronchial injuries.

Methods

This is a single-center retrospective case-series study including patients admitted as cases of trauma including all age groups with blunt acute tracheobronchial injuries confirmed by imaging or bronchoscope.

Results

In our study, four patients with tracheobronchial injuries were identified, and a retrospective analysis was performed. Two of the males and one of the females are adults, while the other two are pediatrics. Two of them have a right main bronchial injury and the other two have a left main bronchial injury. Posterolateral thoracotomy and bronchial anastomosis were performed on all four patients and were followed up.

Conclusion

In Saudi Arabia, blunt trauma is a prevalent type of injury, although tracheobronchial injuries are uncommon. In the event of trauma, a high index of suspicion of tracheobronchial injuries in a high mechanism injury warrants prompt treatment. Due to a lack of experienced and specialized hands in this field, management may be delayed, and eventually lead to unfavorable outcomes, hence we thought of a guide to facilitate the decision-making.

STUDIES ON THE APPLICATION OF THE VIRTUAL BRONCHOSCOPY METHOD FOR TRACHEAL AND BRONCHIAL RUPTURES

Traumatic injuries of major airways (trachea and main bronchus) are rare in medical practice but represent extremely life-threatening conditions. The study aims to present a summary of research findings on the diagnostic capabilities of Virtual bronchoscopy (VB) in ruptures of trachea and bronchi. There is very little research into the applicability of VB in Bulgaria. Still, the modern equipment for MDCT VB during the last years provides to use the VB in diagnostic practice and for scientific examinations. The method of VB is recognized as a reliable tool in diagnostic practice and the research of tracheal and bronchial ruptures.

Management of tracheobronchial injuries

Tracheobronchial injury is one of cases which are relatively uncommon, but must be suspected to make the diagnosis and managed immediately. In such a case, primary initial goals are to stabilize the airway and localize the injury and then determine its extend. These can be possible mostly with flexible bronchoscopy conducted by a surgeon who can repair the injury. Most of the penetrating injuries occur in the cervical region. On the other hand, most of the blunt injuries occur in the distal trachea and right main bronchus and they can be best approached by right posterolateral thoracotomy. The selection of the manner and time of approaching depends on the existence and severity of additional injuries. Most of the injuries can be restored by deploying simple techniques such as individual sutures, while some of them requires complex reconstruction techniques. Apart from paying attention to the pulmonary toilet, follow-up is crucial for determination of anastomotic technique or stenosis. Conservative treatment may be considered an option with a high probability of success in patients meeting the criteria, especially in patients with iatrogenic tracheobronchial injury.

Surgical treatment of non-malignant laryngotracheal stenosis

The objectives of this study were the following: (1) to analyze the results of surgical treatment of non-malignant subglottic laryngeal and tracheal stenosis, (2) to evaluate the feasibility and technical aspects of the video mediastinoscopy for the mobilization of the mediastinal trachea, (3) to evaluate the influence of the early internal condition of the anastomosis on the development of restenosis. From 1996 up to 2013, 75 patients aged 11-78 years underwent surgery for post-intubation/tracheostomy (71 patients), post-traumatic (3 patients), and idiopathic (1 patient) subglottic laryngeal and tracheal stenosis. Twenty-three (30.7 %) patients with subglottic laryngeal and upper tracheal stenosis underwent cricotracheal resection and thyrotracheal anastomosis (group A), while 52 (69.3 %) patients with tracheal stenosis underwent tracheal resection and cricotracheal or tracheotracheal anastomosis (group B). The length of the resected segment in patients of groups A and B was 28-55 (42 ± 11) mm and 18-65 (36 ± 14) mm, respectively, (p = 0.22). Perioperative complications within 30 days occurred in eight (34.8 %) patients of group A, and in six (11.5 %) patients of group B (p = 0.04). There was one intraoperative and one postoperative death on the third day due to heart failure. The excellent results were achieved in 63 (86.3 %), satisfactory in 8 (11.0 %), and unsatisfactory in 2 (2.7 %) patients. The incidence rate of perioperative complications is related to the location of the stenosis and the type of the resection and anastomosis. Video mediastinoscopy simplifies the mobilization of the mediastinal trachea, which allows for carrying out the anastomosis with minimal tension. Early internal abnormalities of the anastomosis predict its restenosis.

Virtual and fiber-optic bronchoscopy in patients with indication for tracheobronchial evaluation

OBJECTIVE

The aim of this study was to compare the results of virtual bronchoscopy (VB) images in defining tracheobronchial pathologies with those of fiber-optic bronchoscopy (FOB) in patients with clinical indication for bronchoscopy.

METHODS

Twenty-two patients with bronchoscopy indication were evaluated with FOB and VB. The VB results were evaluated blindly, independent of the FOB results.

RESULTS

In 19 of the 22 patients, tracheobronchial abnormalities were present on FOB, whereas 3 patients had normal findings on FOB. In 17 of 19 patients, VB demonstrated the FOB diagnosis of tracheobronchial abnormality. While FOB detected 11 endoluminal lesions, VB detected 6. While FOB detected 20 obstructive lesions, VB detected 26. In evaluating external compression, FOB detected 2 lesions and VB detected 15.

CONCLUSIONS

VB is a non-invasive, uncomplicated, and reproducible examination method in patients with an indication for thorax examination. Virtual bronchoscopy could find a clinically broader field of application in the future.

Virtopsy: Postmortem Imaging of Laryngeal Foreign Bodies

Context.—Death from corpora aliena in the larynx is a well-known entity in forensic pathology. The correct diagnosis of this cause of death is difficult without an autopsy, and misdiagnoses by external examination alone are common.

Objective.—To determine the postmortem usefulness of modern imaging techniques in the diagnosis of foreign bodies in the larynx, multislice computed tomography, magnetic resonance imaging, and postmortem full-body computed tomography–angiography were performed.

Design.—Three decedents with a suspected foreign body in the larynx underwent the 3 different imaging techniques before medicolegal autopsy.

Results.—Multislice computed tomography has a high diagnostic value in the noninvasive localization of a foreign body and abnormalities in the larynx. The differentiation between neoplasm or soft foreign bodies (eg, food) is possible, but difficult, by unenhanced multislice computed tomography. By magnetic resonance imaging, the discrimination of the soft tissue structures and soft foreign bodies is much easier. In addition to the postmortem multislice computed tomography, the combination with postmortem angiography will increase the diagnostic value.

Conclusions.—Postmortem, cross-sectional imaging methods are highly valuable procedures for the noninvasive detection of corpora aliena in the larynx.

Systematic review of baseline low-dose CT lung cancer screening

The purpose of this systematic review was to provide physicians and patients with a synthesis of the available data and an assessment of the operating characteristics associated with baseline LDCT screening for lung cancer. Various databases, meeting abstracts, clinical trials in progress, and major textbooks for relevant data from 1966 to 2006 were searched for relevant studies. The median value of sensitivity, specificity, positive predictive value and negative predictive value were 81%, 81%, 8% and 99%, respectively. Of the studies that compared LDCT with other lung cancer screening maneuvers, it was found that LDCT detected a greater number of cancerous nodules. On average, 80% of lung cancers detected by baseline LDCT screening were categorized as Stage I cancers. Current data demonstrate that both the operating characteristics of baseline LDCT screening and the relatively high proportion of Stage I cancers detected with LDCT may potentially lead to effective screening programs. However, evidence of reduced mortality and morbidity with the use of LDCT is not established. Therefore, LDCT for lung cancer screening should be considered as investigative and needs to be confirmed by well-designed randomized controlled trials prior to community and institutional implementation.

Virtual bronchoscopy aids management of lung cancer

The development of CT scanning has been beneficial for clinical medicine. In this case, virtual bronchoscopy (VB) was of clinical benefit. A 71-year-old woman with suspected lung cancer in the upper left lobe remained undiagnosed after investigation at another hospital. VB was used to confirm the location of the tumour, which facilitated an appropriate trans-bronchial lung biopsy being performed. The volume-rendering technique yielded information regarding an arterial anomaly, allowing high-quality and safe medical treatment to be provided. VB assists navigation in bronchoscopy, and the volume-rendering technique is effective in finding congenital anomalies of the vessels during preoperative assessment.

Traumatic injury to the trachea and bronchus

Tracheobronchial injuries are relatively uncommon, often require a degree of clinical suspicion to make the diagnosis, and usually require immediate management. The primary initial goals are twofold: stabilize the airway and define the extent and location of injury. These are often facilitated by flexible bronchoscopy, in the hands of a surgeon capable of managing these injuries. Most penetrating injuries occur in the cervical area. Most blunt injuries occur in the distal trachea or right mainstem, and are best approached by a right posterolateral thoracotomy. Choice and timing of approach are dictated by the presence and severity of associated injuries. The mainstay of intraoperative management remains a single-lumen endotracheal tube. Most injuries can be repaired by simple techniques, using interrupted sutures, but some require complex reconstructive techniques. Follow-up to detect stenosis or anastomotic technique is important, as is attention to pulmonary toilet.

Magnetic resonance colonography vs computed tomography colonography for the diagnosis of colorectal cancer: an indirect comparison

OBJECTIVE

The primary aim of this study was to use meta-regression techniques to compare the diagnostic accuracy of computed tomography colonography (CTC) and magnetic resonance colonography (MRC), compared with conventional colonoscopy for patients presenting with colorectal cancer (CRC).

METHOD

Quantitative meta-analysis was performed using prospective studies reporting comparative data between CTC and MRC individually to conventional colonoscopy. Study quality was assessed and sensitivities, specificities, diagnostic odds ratios (DOR) were calculated. Summary receiver operating characteristic (SROC) curves and sensitivity analysis were utilized. Meta-regression was used to indirectly compare the two modalities following adjustment for patient and study characteristics.

RESULTS

Overall sensitivity and specificity for CTC (0.96, 95% CI 0.92-0.99; 1.00, 95% CI 0.99-1.00 respectively) and MRC (0.91, 95% CI 0.79-0.97; 0.98, 95% CI 0.96-0.99 respectively) for the detection of CRC was similar. Meta-regression analysis showed no significant difference in the diagnostic accuracy of both modalities (beta=-0.64, P=0.37 and 95% CI of 0.12-2.39). Both tests showed high area under the SROC curve (CTC=0.99; MRC=0.98), with high DORs (CTC=1461.90, 95% CI 544.89-3922.30; MRC=576.41, 95% CI 135.00-2448.56). Factors that enhanced the overall accuracy of MRC were the use intravenous contrast, faecal tagging and exclusion of low-quality studies. No factors improved diagnostic accuracy from CTC except studies with more than 100 patients (AUC=1.00, DOR=2938.35, 95%CI 701.84-12 302.91).

CONCLUSION

This meta-analysis suggested that CTC and MRC have similar diagnostic accuracy for detecting CRC. Study quality, size and intravenous/intra-luminal contrast agents affect diagnostic accuracies. For an exact comparison to be made, studies evaluating CTC, MRC and colonoscopy in the same patient cohort would be necessary.

[Progressive primary tuberculosis with endobronchial involvement. Benefits of multislice helical computed tomography]

OBJECTIVES

To assess computed tomography (CT) imaging findings in progressive primary tuberculosis and to determine the use of the multislice images obtained.

PATIENTS AND METHODS

We report the case of a 37-day-old infant admitted to hospital because of persistent fever despite antimicrobial therapy. Thoracic X-ray and multislice helical CT (CT Light speed i1.6 GE) were performed with 3-dimensional and virtual endoscopy reconstructions.

RESULTS

CT showed mediastinal and hilar necrotic lymph nodes, pulmonary parenchymal involvement with miliary pattern, and multiple cavitated consolidations. Endobronchial involvement was clearly visualized by virtual endoscopy and was confirmed by fiberoptic bronchoscopy.

CONCLUSIONS

Virtual endoscopy is a new, less invasive alternative radiological technique to fiberoptic bronchoscopy that may influence the management of patients with tuberculosis with endobronchial involvement.

Do technical parameters affect the diagnostic accuracy of virtual bronchoscopy in patients with suspected airways stenosis?

PURPOSE

Virtual bronchoscopy has gained popularity over the past decade as an alternative investigation to conventional bronchoscopy in the diagnosis, grading and monitoring of airway disease. The effect of technical parameters on diagnostic outcome from virtual bronchoscopy has not been determined. This meta-analysis aims to estimate accuracy of virtual compared to conventional bronchoscopy in patients with suspected airway stenosis, and evaluate the influence of technical parameters.

MATERIALS AND METHODS

A MEDLINE search was used to identify relevant published studies. The primary endpoint was the "correct diagnosis" of stenotic lesions on virtual compared to conventional bronchoscopy. Secondary endpoints included the effects of the technical parameters (pitch, collimation, reconstruction interval, rendering method, and scanner type), and date of publication on the diagnostic accuracy of virtual bronchoscopy.

RESULTS

Thirteen studies containing 454 patients were identified. Meta-analysis showed good overall diagnostic performance with 85% calculated pooled sensitivity (95% CI 77-91%), 87% specificity (95% CI 81-92%) and area under the curve (AUC) of 0.947. Subgroups included collimation of 3mm or more (AUC 0.948), pitch of 1 (AUC 0.955), surface rendering technique (AUC 0.935), and reconstruction interval of more than 1.25 mm (AUC 0.914). There was no significant difference in accuracy accounting for publication date, scanner type or any of the above variables. Weighted regression analysis confirmed none of these variables could significantly account for study heterogeneity.

CONCLUSION

Virtual bronchoscopy performs well in the investigation of patients with suspected airway stenosis. Overall sensitivity and specificity and diagnostic odds ratio for diagnosis of airway stenosis were high. The effects of pitch, collimation, reconstruction interval, rendering technique, scanner type, and publication date on diagnostic accuracy were not significant.

Virtual Bronchoscopy: Accuracy and Usefulness—An Overview

Multidetector CT generated virtual bronchoscopy (VB) represents one of the most recent developments in three-dimensional (3D) visualization techniques which allows a 3D evaluation of the airways down to the sixth- to seventh-generation. In comparison with real bronchoscopy, VB has some advantages: it is a non-invasive procedure that can visualize areas inaccessible to the flexible bronchoscope. Virtual bronchoscopy is able to evaluate bronchial stenosis and obstruction caused by both endoluminal pathology (tumor, mucus, foreign bodies) and external compression (anatomical structures, tumor, lymph nodes), can be helpful in the preoperative planning of stent placement and can be used to evaluate surgical sutures after lung transplantations, lobectomy or pneumectomy. In children, in some indications, VB can replace fiber optical bronchoscopy (FB) when this technique is considered too invasive. Finally, VB can also be used to evaluate anatomical malformations and bronchial variants. Virtual bronchoscopy is accurate but its accuracy is not 100% because false-positives and false-negatives occur. Virtual bronchoscopy contributes to a better understanding of tracheo-bronchial pathology. Fiber optical bronchoscopy will, without doubt, remain the golden standard but it can be expected that in the near future, the technique of VB will find a place in the daily routine.

Summary receiver operating characteristic curve analysis techniques in the evaluation of diagnostic tests

The number of studies in the literature using summary receiver operating characteristic (SROC) analysis of diagnostic accuracy is rising. The SROC is useful in many such meta-analyses, but is often poorly understood by clinicians, and its use can be inappropriate. The academic literature on this topic is not always easy to comprehend. Interpretation is therefore difficult. This report aims to explain the concept of SROC analysis, its advantages, disadvantages, indications, and interpretation for the cardiothoracic surgeon. We use a practical approach to show how SROC analysis can be applied to meta-analysis of diagnostic accuracy by using a contrived dataset of studies on virtual bronchoscopy in the diagnosis of airway lesions.

Use and abuse of lung biopsy

The lung biopsy is widely recognized as a valuable tool for the diagnosis and management of diverse pulmonary disorders. The transbronchial lung biopsy, open lung biopsy, and video assisted thoracoscopic surgery biopsy are the principal tools that have been developed for obtaining lung tissue for histopathological examination. Whereas these various types of lung biopsies are highly sensitive and specific tests available for diagnosis, they may be fraught with potential problems. This review hopes to inform the reader of the indications and limitations of the lung biopsy.