Mediastinum (Hong Kong, China)最新文献

Cardiovascular implantable electronic devices (CIEDs) such as pacemakers and implantable cardioverter defibrillators require the placement of a transvenous lead through the superior vena cava (SVC), which can be difficult if there is stenosis or obstruction of the SVC. Moreover, SVC syndrome may occur after the lead is inserted even if the SVC was intact before the implantation. Therefore, there is need of an appropriate strategy for handling stenosis or obstruction of SVC during lead placement. In addition, advances are being made in CIEDs that do not require transvenous leads, and thus CIEDs without a transvenous lead should be considered depending on the indications and urgency of the particular case. This manuscript is divided into (I) device therapy for patients with SVC obstruction and (II) therapeutic strategy for SVC obstruction after lead implantation. In patients with SVC syndrome, treatment of the SVC occlusion should be based on the individual pathophysiology, and depending on the indications and urgency of the case, treatment with CIEDs that do not require transvenous leads should be considered. Further data must be accumulated to clarify the long-term prognosis of device implantation after treatment of SVC occlusion. In addition, transvenous lead extraction is now widely used for device-related SVC obstruction, and this procedure also merits further accumulation of data.

Background and objective: Acute respiratory distress syndrome (ARDS) is a severe, life-threatening medical condition characterized by poor oxygenation due to non-compliant lungs secondary diffuse alveolar damage. Encouragingly, the incidence of ARDS has declined steadily recently, attributed mainly to implementation of keystone guidelines and continuous research efforts. Mechanical ventilation is the cornerstone of supportive care for ARDS patients. This review aims to consolidate the current knowledge on pneumothorax (PNX) and pneumomediastinum (PMD) and to enhance the understanding of the readers. The objectives are to (I) explore the etiology and risk factors of PNX and PMD, (II) discuss the various diagnostic modalities available, (III) evaluate management options, and (IV) recent advancements.

Methods: A search of the literature was conducted using PubMed, MEDLINE, and Google Scholar for relevant articles pertaining to PNX and PMD in ARDS population. The clinical presentation, diagnostic and management strategies of PNX, PMD, and ARDS were summarized, and all authors reviewed the selection and decide which studies to include.

Key content and findings: The adoption of lung-protective ventilation strategies, based on the review of literature from the recent years, shows that it has played a significant role in reducing the occurrence of barotrauma, such as PNX and PMD. However, PNX and PMD remains to be a challenging complication to manage. With a specific focus on PNX and PMD, this review provides valuable insights into effectively managing and understanding these critical complications among ARDS patients.

Conclusions: ARDS, with its evolving definition, continues to pose a life-threatening threat. Despite the widespread adoption of lung-protective ventilation strategies, PNX and PMD present persistent challenges in management. Further research is imperative to enhance the risk assessment of ARDS patients prone to developing PNX and PMD and to institute more effective prevention and treatment measures.

Lung cancers and mediastinal masses can invade the veins in the upper mediastinum and neck. It can be challenging to determine management options and the feasibility of resection particularly when tumors involve the major venous junctions. Furthermore, impaired flow in these veins can have devastating complications such as Paget-Schroetter syndrome, which describes a constellation of symptoms (arm swelling, cyanosis, pain) due to stenosis of the subclavian vein. This section will provide an overview of venous drainage of the brain, which can be divided into two major systems-superficial medullary venous system and deep medullary venous system. The anatomy and function of the great veins of the neck and upper mediastinum, including the internal jugular vein, subclavian vein, and brachiocephalic (i.e., innominate) vein will be described. Also discussed will be principles of ligation of the venous structures and the importance of keeping the venous junctions intact to facilitate and maximize the development of collateral flow. This section will also discuss ensuing complications when blood flow is impaired, such as development of upper extremity deep venous thrombosis and cerebral venous thrombosis (CVT). CVT can result in a stroke and is an umbrella term that refers to problems in cerebral venous outflow due to numerous etiologies.

Background and objective: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive, safe, and well-established method for diagnosing and staging lung cancer and other conditions associated with mediastinal lymphadenopathy. Efforts have been made to enhance the material adequacy of EBUS-TBNA, including the recent introduction of EBUS-guided transbronchial mediastinal cryobiopsy (EBUS-TMC). This advancement facilitates the acquisition of larger and better-preserved tissue samples from the mediastinum. We evaluated the diagnostic accuracy and safety of EBUS-TMC in the diagnosis of malignant lesions and its effectiveness in relation to benign conditions, such as tuberculosis and sarcoidosis.

Methods: We searched the PubMed^® database for relevant English articles published up to July 1, 2023. Subsequently, we conducted a comprehensive bibliographic analysis with a particular emphasis on diagnostic yield, safety profile, and procedural technicalities.

Key content and findings: Our narrative review, comprising seven publications, emphasizes the significance of EBUS-TMC as an effective technique for obtaining diagnostic tissue in malignant and benign conditions while maintaining an excellent safety profile. Furthermore, its capability for obtaining larger tissue samples facilitates molecular and immunological analysis in non-small cell lung cancer.

Conclusions: EBUS-TMC exhibits significant efficacy with regard to obtaining diagnostic tissue in malignant and benign conditions. However, further studies are needed to evaluate uncertainties regarding the selection of suitable cases and technical intricacies.

The hemiclamshell incision is a combination of partial median sternotomy and anterolateral thoracotomy, allowing excellent exposure of mediastinum, one pleural cavity and the neck. It can be used for superior sulcus tumors with mediastinal involvement or to resect bulky mediastinal lesions or lesions requiring cervical, mediastinal and pleural exposition. Although the vast majority of mediastinal lesions can now be approached by minimally invasive techniques, the hemiclamshell incision still plays a pivotal role in the case of bulky lesions involving cervical, mediastinal and pleural cavities. In the case of cardiac or great vessel involvement, the procedure should be performed in experienced high-volume centers with the availability of cardio-pulmonary bypass, extra-corporeal membrane oxygenator or venous shunts. Although the vast majority of mediastinal lesions can now be approached by minimally invasive techniques, the hemiclamshell incision still plays a pivotal role in the case of bulky lesions involving cervical, mediastinal and pleural cavities. It consists of a combination of subtotal median vertical sternotomy and antero-lateral thoracotomy in the 4^th intercostal space, providing excellent exposure of the neck, mediastinum and one pleural cavity. The objective of this paper is to describe the standard steps for performing a hemiclamshell incision by using modern devices and technology which contribute to make this procedure easier, faster and safer.

Primary spontaneous pneumomediastinum is a rare, often benign and self-limited condition defined by air within the mediastinum. However, correctly distinguishing primary spontaneous pneumomediastinum from secondary causes, especially esophageal perforation, remains a diagnostic challenge. There is significant debate regarding the balance of completing a thorough but not overly invasive and costly diagnostic workup. This clinical review aims to gather the limited data regarding spontaneous pneumomediastinum management from case series and retrospective cohort studies, and presents an evaluation algorithm and treatment plan stratified by clinical history. Understanding specifically if the patient presents with coughing versus forceful vomiting is critical to help elucidate the etiology and guide management of pneumomediastinum. Patients who present with forceful vomiting or retching should be considered with higher degree of suspicion for secondary causes of pneumomediastinum, specifically esophageal perforation. However, especially in children, aggressive diagnostic workup is not warranted in every case. After ruling out other etiologies of pneumomediastinum, spontaneous pneumomediastinum can be commonly treated with symptomatic management without the aggressive use of antibiotics or diet restriction. Hospital length of stay may also be minimized on a case-by-case basis. Overall, recurrence of spontaneous pneumomediastinum is rare and outpatient follow up may be safely limited to those at highest risk of recurrence.

Background and objective: Mediastinal lesions are uncommon. However, because of the vital structures in the mediastinum, large lesions specifically can lead to life-threatening situations. Treatment and management vary considerably with the disease. Therefore, the correct histopathologic diagnosis is important. Here we review lesions that have the potential to present as a giant lesion in the mediastinum. While we focus on the review of histopathologic, immunohistochemical (IHC), and molecular features of these lesions, clinical symptoms and characteristics and prognosis will also be discussed.

Methods: "Giant" was arbitrarily defined as a size of at least 10 cm in greatest dimension. The 2021 World Health Organization (WHO) classification of mediastinal tumors was searched for tumors reported to be larger than 10 cm. Tumors that can present as giant mediastinal lesions based on our own experience were also included. PubMed search was then performed for these lesions.

Key content and findings: A great variety of mediastinal lesions can present as giant mass. Those include for instance tumors of blood and lymph vessels, tumors of neurogenic origin, mesenchymal neoplasms, thymic epithelial tumors (TETs), and non-neoplastic cysts. Lesions range from benign to malignant. This review focuses on the most common lesions.

Conclusions: Many benign and malignant lesions can become a large mass in the mediastinum. Their correct diagnosis is important for the treatment and management of the patient.

Background and objective: Thymic epithelial tumors (TETs) are frequently diagnosed at an advanced stage, highlighting the importance of understanding the treatment strategies for these cases. Surgical intervention after chemotherapy or chemoradiotherapy presents specific challenges and underscores the crucial role of perioperative management. This study aimed to explore the perioperative management and postoperative outcomes in patients with locally advanced TETs.

Methods: Relevant studies published between 2000 and 2022 were identified through PubMed searches using a combination of the following terms: "Locally advanced TETs", "Thymoma", "Thymic cancer", "Surgery", "Induction therapy", and "Postoperative outcomes". We analyzed available data to describe the perioperative management and postoperative outcomes of locally advanced TETs.

Key content and findings: Surgical outcomes after induction therapy for locally advanced TETs were analyzed for 18 references (total n=646) between 2000 and 2022. The primary objective of induction therapy for locally advanced TETs is complete tumor resection. In recent years, many medical centers have adopted systemic chemotherapy and chemoradiation for the treatment of thymoma and thymic carcinoma, respectively. During surgical intervention, resecting the surrounding organs, such as the lungs, pericardium, and phrenic nerves, is a common practice. Additionally, there may be cases wherein vascular resection of the superior vena cava (SVC) and innominate veins is necessary. Techniques and strategies for revascularization without complications are crucial in these situations. The incidence of postoperative complications varied significantly, ranging from 4.8% to 42%. However, perioperative mortality is typically reported to be approximately 0%, with only two reports showing mortality rates of 1.8% and 9.0%.

Conclusions: The short-term postoperative outcomes of surgical treatment following induction therapy for locally advanced TETs were generally deemed acceptable. However, incomplete resection may occur, particularly when the tumor invades the pulmonary artery or aorta. Hence, careful evaluation the indications for surgery is crucial, considering the patient's overall condition and treatment response.

Background: Minimally invasive thymectomy via subxiphoid is increasingly being used for thymic tumors. Limited by the small space behind the sternum, the subxiphoid approach is sometimes difficult to perform. In this study, we introduce a modified subxiphoid thoracoscopic thymectomy which is performed via subxiphoid approach using an auxiliary sternal retractor to elevate the sternal to create a larger space behind the sternum. Therefore, the phrenic nerves on both sides were revealed more clearly and the left innominate vein was mobilized safer and easier.

Case description: This study describes the treatment process of a 27-year-old female patient with an incidental finding of a thymic mass. Chest contrast computed tomography revealed a 35 mm × 25 mm lesion in the anterior mediastinum which might be adherent to the left innominate vein. A careful preoperative evaluation was well done and no contraindications to the operation were found. This patient underwent modified subxiphoid thoracoscopic thymectomy, successfully completed without complications occurred during the perioperative period. The patient was discharged home well on post-operative day 2. The pathological diagnosis was mature teratoma.

Conclusions: In conclusion, modified subxiphoid thoracoscopic thymectomy using an auxiliary sternal retractor makes minimally invasive thymectomy safer and simpler and is an alternative option for patients with early-stage thymic tumors.