Mediastinum (Hong Kong, China)最新文献

Background and objective: Linear endobronchial ultrasound (EBUS) has become a key tool for diagnosing pulmonary diseases, offering high diagnostic yield for both malignant and non-malignant conditions. With its increased use, more complications are being reported. The objective of this narrative review is to discuss the complications associated with linear EBUS.

Methods: A literature search using PubMed and Google Scholar from 2009 to 2024 was done. We included case reports, prospective, and retrospective studies reporting linear EBUS complications.

Key content and findings: Overall complications from EBUS range from 0.04% to 17%. Most common are infectious complications which are 0.04-4%. These include mediastinitis, pneumonia, pericarditis, bacteremia, tumor bed infection, lung abscess, empyema, and septic shock. Other complications include pneumothorax, pneumomediastinum, pneumopericardium, pneumoperitoneum, and subcutaneous emphysema. Complications due to anesthesia or equipment malfunction can occur as well. Hemorrhagic complications have been reported as well. Mortality is low 0.01-0.04%, and four cases have been reported that led to death from complications.

Conclusions: With increased use of EBUS as a diagnostic tool, number of complications will increase. Clinicians performing the procedures should be aware of types of possible complications that can occur and follow the patients closely after the procedure. Rapid diagnosis and treatment should be done to avoid fatal outcomes.

Background: Although lymph node metastasis may be an adverse prognostic factor for survival after resection of thymic epithelial malignancies, recommendations for intraoperative lymph node dissection (LND) lack consistency across various guidelines. This study aimed to investigate feasibility and characteristics of LND.

Methods: This is a work-in-progress report of our prospective, multi-institutional observational study to evaluate the feasibility and characteristics of LND in patients with resectable thymic epithelial malignancies that exhibit radiological invasive features such as size >5 cm, standardized uptake value >5, or suspected invasion of surrounding organs.

Results: In total, 25 patients were enrolled in this study. All patients underwent complete resection of the primary lesion with N1-level or N2-level LND. Among these, 22 (88%) patients underwent N1-level LND, and 20 (80%) patients underwent N2-level LND. No significant differences between the open and minimally invasive approaches were observed in the number of dissected stations (P=0.71), N1-level LND (P=0.49), or N2-level LND (P=0.69).

Conclusions: Intraoperative LND may be feasible in both approaches and may contribute to accurate nodal staging in resectable thymic malignancies with radiologically invasive features.

Many studies have demonstrated that 18-fluorine fluorodeoxyglucose positron emission tomography (FDG-PET) is useful for predicting the grade of malignancy of thymic epithelial tumors (TETs), and there is a close relationship between the maximum standardized uptake value (SUVmax) and tumor stage. However, more specific usage of FDG-PET for TETs has not been proposed, and the actual value of FDG-PET in routine clinical practice should be firmly clarified. In this review, following three cutoff values of SUVmax that may be helpful in determining treatment strategies in cases of anterior mediastinal masses, particularly presented as discrete and resectable lesions, are identified: (I) SUVmax of 7.5 as an indicator for pretreatment biopsy: differential diagnosis between TETs and mediastinal lymphoma (ML); (II) SUVmax of 4.2 as an indicator for a minimally invasive approach (MIA): differentiation of noninvasive TETs and invasive TETs; and (III) SUVmax of 5.9 as a reference value for the necessity of lymph node dissection (LND). There are still several challenges in using FDG-PET for routine clinical practice that need to be addressed, such as variations between instruments and institutions, leading to lower reproducibility. Harmonization methods should be applied to make clinical practice more uniform. Due to the rarity of these diseases, multi-institutional studies are warranted.

Mediastinal masses are a common finding in patients and can represent a diagnostic challenge for thoracic surgeons. The differential diagnosis for these masses is broad and ranges from benign solid or cystic lesions to aggressive cancers. They can present with vague symptoms, but these masses are often found incidentally in asymptomatic people. Patients with mediastinal masses should be evaluated by a multidisciplinary team of specialists, including thoracic surgeons. Determining the etiology of the mass is essential since this heavily determines the management and prognosis. The work up involves clinical evaluation, laboratory work and always involves imaging, but deciding which imaging modality will offer the most information about the lesions and guide management is not always clear. The most common imaging studies for mediastinal masses are computed tomography (CT) scans, magnetic resonance imaging (MRI), and positron emission tomography (PET) scans. The role of PET scans in the work up of these masses is not well-established, but these scans have been shown to be especially useful in certain circumstances and can help guide further work up and decision making. This review article evaluates how and when PET scans can be used to guide work up and management in a variety of mediastinal masses.

Background and objective: The formation of pathologic communication between respiratory and digestive tracts is a morbid condition which possesses management challenges regardless of its etiology. Severity of the symptoms related to contamination of the respiratory tract with oral and gastric secretions calls for timely seal and closure translating into improved mortality. The aim of this article is to review the latest data in regards of tracheoesophageal fistulas (TEFs) and the endoscopic methods of their management.

Methods: A literature review was conducted in the National Institute of Health's PubMed database in July 2024. Only studies published in English with abstracts available were included. Over 2,700 articles were found. The first 800 abstracts for "tracheoesophageal fistula" were reviewed and used to guide more detailed searches. Fifty-seven publications were considered relevant, and their full text studied to collate information for this review.

Key content and findings: We summarized the endoscopic approaches to management of both benign and malignancy associated TEFs as reported in the literature to this date. Despite several new non-operative approaches, esophageal stenting with or without airway stenting remains the mainstem of the endoscopic treatment of the fistulas. Self-expanding metallic stents are the mainstay of this approach. Esophageal stenting in particular has been associated with improved fistula closure and quality of life, as well as possible improvement in mortality for malignancy associated fistulas. More novel methods such as suturing or clips, occluding devices, and tissue adhesives also show promise. The quality control after the initial endoscopic management sets the future steps. Early multidisciplinary discussion among aerodigestive specialists including endoscopists and surgeons with involvement of palliative care team is strongly recommended.

Conclusions: The ever-evolving landscape of endoscopic therapies offers minimally invasive approach to TEFs especially for patients with prohibitive conditions to surgery or for patients needing a temporizing measure until the definitive surgical treatment is possible.

While it is not uncommon to see central mediastinal diseases on cross-sectional imaging, it is important to understand the pathway influencing the spread of disease at a radiological point of view. The advent of minimally invasive thoracic surgeries has led to the discovery of unknown tissue planes in the mediastinum such as the aorto-esophageal (AE) and aorto-pleural (AP) ligaments. In particular, the AE ligament is a portion of the mediastinal visceral fascia, which courses from the anterior aspect of the aorta to the left lateral aspect of the esophagus. It can be visualized on computed tomography (CT) and magnetic resonance imaging (MRI); it courses longitudinally from the level of the aortic arch to the level of the diaphragm. This recently discovered unknown anatomy aids us in understanding the possible pathway of spread of disease processes such as air, fluid, and soft tissue in the mediastinum. In addition, it acts as an important anatomical landmark in determining the location of lymph node metastases from esophageal cancer, which will further influence the possibility of thoracic duct resection/sparing. Finally, the AE ligament can be utilized in the preoperative planning of minimally invasive thoracic surgeries and can potentially be used as a dissection plane during esophagectomies.

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is the preferred initial method to diagnose and stage non-small cell lung cancer. EBUS-guided transbronchial cryobiopsy (EBUS-TBC) is a newer technique with the potential to address the limitations of EBUS-TBNA. Only a few studies have explored this technique and compared its diagnostic yield to that of EBUS-TBNA. This review aims to summarize the existing literature and provide insights into the optimal yield and technique for performing EBUS-TBC. A comprehensive search of the PubMed database was conducted for studies published up to May 2024 related to EBUS-TBC. The PICO framework (Participants, Intervention, Comparison, and Outcome) was used to evaluate the diagnostic yield, techniques employed, and associated complications. Eleven studies involving 857 patients were identified. In these trials, EBUS-TBC was performed after EBUS-TBNA at the same lymph node station. Techniques varied among bronchoscopists, with most procedures conducted under moderate sedation. The TBNA needle sizes ranged from 19G to 22G. Three trials used a needle knife for the initial mucosal incision, while others utilized the initial puncture site for cryoprobe insertion. Nine studies employed a 1.1-mm Erbe cryoprobe, with a median freezing time of 4 seconds (range, 3-7 seconds). The overall diagnostic yield of EBUS-TBC was 91.9%, compared to 76.6% for EBUS-TBNA alone, with EBUS-TBC yielding larger specimens. Mild bleeding was the most common complication reported. The addition of EBUS-TBC to EBUS-TBNA enhances the diagnostic yield without significantly increasing complications. The larger biopsy samples obtained can be particularly valuable for next-generation sequencing in lung cancer and for improving diagnostic accuracy in benign diseases and rare malignancies like lymphoma.

Background and objective: Thymectomy continues to be a standard treatment strategy for patients with thymic neoplasms and myasthenia gravis. The total thymectomies performed has exponentially increased by 69.8% between 2012 and 2019. Trans-sternal and minimally invasive thymectomy increased by 62.8% and 83.7%, respectively. Our objective is to provide a narrative overview of the various approaches of thymectomy. We have briefly described the indications for thymectomy, discussed important preoperative considerations and an operative description of the different techniques of the procedure. We have aimed to summarize the pros and cons of each approach and narrated the technique we have adopted at the University of Minnesota.

Methods: A literature search was conducted encompassing original full-length articles, meta-analyses, review articles and case reports up to July 2024 from the MEDLINE and Google Scholar databases.

Key content and findings: Complete surgical resection remains the goal to decrease the risk of recurrence for non-myasthenic thymomas and thymic carcinomas. Surgical procedures have evolved from traditional open approaches to a wide variety of minimally invasive methods. A variety of factors specific to the tumor, patient and surgeon have to be considered while planning a thymectomy.

Conclusions: As of today, there is no consensus on the best surgical technique, with each approach providing specific pros and cons. Each technique may be a viable option in the management of thymic pathologies, thus preoperative evaluation in patients is necessary to optimize prognosis and outcomes.

Background and objective: Descending necrotizing mediastinitis (DNM) is a severe and life-threatening infection that originates from oropharyngeal or cervical infections and spreads downward into the mediastinum. Despite advancements in medical and surgical treatments, DNM remains a condition with high morbidity and mortality. This narrative review aims to summarize the etiology, diagnostic strategies, and management approaches for DNM, emphasizing the importance of a multidisciplinary approach.

Methods: A comprehensive literature search was conducted using PubMed/MEDLINE, Western University Libraries, and Google Scholar databases, without restriction on publication date. Articles were included if they discussed: (I) the etiology of mediastinitis, focusing on anatomy and pathogens; (II) the diagnosis of DNM; and (III) the treatment and surgical approach to mediastinitis.

Key content and findings: DNM is commonly caused by oropharyngeal infections that spread downward through normal anatomical pathways. Diagnosis is challenging due to the subtle and varied presentation of symptoms. Diagnosis is primarily made with contrast-enhanced CT scans of the neck and thorax, but a convincing history should prompt appropriate suspicion and concern. Management requires a multidisciplinary approach, including sepsis management particularly with broad-spectrum antibiotics and early surgical intervention for source control. The choice of surgical technique, whether transcervical, thoracotomy, or video-assisted thoracoscopic surgery (VATS), is crucial for effective drainage and reducing mortality.

Conclusions: DNM is a complex and critical condition that demands prompt recognition and aggressive treatment. The high mortality associated with DNM underscores the need for a multidisciplinary approach. Surgical drainage, tailored to the extent of the infection, and comprehensive post-operative care are essential for improving patient outcomes. Future research should focus on optimizing diagnostic criteria, refining surgical techniques, and exploring adjunct therapies to further reduce morbidity and mortality in DNM.

Background: A thymoma is a tumor originating from thymic epithelial cells variably associated with non-neoplastic lymphocytes. T-lymphoblastic leukemia/lymphoma (T-LBL) is thought to arise from precursor T-cells from bone marrow-derived hematopoietic stem cells that migrate to the thymus. While the association of secondary hematopoietic malignancies in thymoma is well established, only rarely in the literature have T-LBL and thymoma been seen in association and the relationship is poorly understood. Occasionally, distinction between the two can be difficult as immature lymphocytes in thymoma resemble T-LBL both morphologically and immunophenotypically. An accurate diagnosis is essential as treatments vary between these two entities.

Case description: We present the interesting case of a 64-year-old male, former smoker, originally from Uzbekistan, with a mediastinal mass diagnosed as small cell carcinoma in his home country and treated with chemotherapy. After immigrating to the United States, a positron emission tomography (PET) scan demonstrated a large, metabolically active mediastinal mass. He presented to our institution where a biopsy with histomorphologic and immunohistochemical analysis was diagnostic of type B1 thymoma. He was lost to follow-up, but represented months later with B symptoms. Flow cytometry, cytogenetics, and bone marrow biopsy were diagnostic of T-LBL. Although he was started on chemotherapy, his disease progressed and he expired 6 months after initial presentation. Post-mortem analysis of the mediastinal mass revealed the co-occurrence of benign thymocytes and neoplastic T-LBL lymphoblasts, further confirmed as two distinct entities by T-cell receptor (TCR) sequencing.

Conclusions: Co-occurrence of thymoma and T-LBL is a well-documented, though poorly understood, phenomenon. Literature review for this phenomenon reveals that type B thymoma is most commonly associated with T-LBL in these co-occurrences. Most cases are diagnosed synchronously, though in metachronous cases, the diagnosis of thymoma has always preceded the diagnosis of T-LBL. Of note, recently developed LMO2 immunohistochemical stain is positive in malignant lymphoblasts but negative in benign thymocytes, allowing for post-mortem evaluation of this case to be determined as a synchronous presentation. These entities are difficult to distinguish and require a multimodal diagnostic approach including histology, immunohistochemistry, flow cytometry, cytogenetics, and TCR sequencing.