Mediastinal Masses




Abstract


Providing anesthesia for the patient with a mediastinal mass is challenging due to the potential for life-threatening complications. Mediastinal masses can compress neighboring structures and cause superior vena cava syndrome, tracheobronchial tree compromise, or compression of the heart and great vessels. While anticipation and prevention of these complications is the best approach, strategies for management of acute cardiopulmonary collapse are vital. Here we present a challenging case describing the management of a patient with an anterior mediastinal mass for general anesthesia and discuss strategies for anesthetic planning.




Keywords

cardiac compression, cardiorespiratory complications, mediastinum, SVC syndrome, tracheobronchial tree compression

 




Case Synopsis


A 23-year-old previously healthy man is scheduled for cervical mediastinoscopy for tissue diagnosis of a mediastinal mass. He presents with a 3-month history of fatigue and dyspnea on exertion and reports that he cannot sleep on his left side because it makes him feel short of breath. Chest computed tomography (CT) demonstrates a 10 × 8 × 5 cm mass adjacent to the right atrium, ascending aorta, and main pulmonary artery, with no other abnormalities. After induction with propofol and succinylcholine, the patient is easily intubated but rapidly becomes hypoxic. Vigorous manual ventilation fails to improve oxygenation, and the patient becomes progressively hypotensive.




Problem Analysis


Definition


Patients with anterior mediastinal masses are prone to develop certain potentially life-threatening complications because of the influence of these masses on neighboring structures (superior vena cava, tracheal bifurcation or mainstem bronchi, main pulmonary artery, aortic arch, and heart). Principal anesthetic considerations for patients with anterior mediastinal masses involve the following three potential complications:




  • Tracheobronchial tree compression or obstruction



  • Superior vena cava syndrome



  • Compression of the heart and pulmonary vessels



Also, patients may present for anesthesia or monitored anesthesia care for a variety of reasons, including the following:




  • Excision of intrathoracic tumor (primary or metastatic)



  • Lymph node biopsy (for tissue diagnosis)



  • Central line placement (for chemotherapy)



  • Biopsy of intrathoracic mass (open or thoracoscopic)



  • Any other procedure, either related to the disease (e.g., open reduction and internal fixation of pathologic fracture) or not (cesarean section)



  • Imaging studies (children)



Although these masses are referred to as “anterior,” they are often at the confluence of the anterior, superior, and middle mediastina ( Fig. 64.1 ).




Fig. 64.1


The mediastinum is divided into superior and inferior portions. The inferior mediastinum is divided into anterior, middle, and posterior portions.

From Benumof JL: Anesthesia for thoracic surgery, 2nd ed. Philadelphia, WB Saunders, 1995, p 39.


Recognition


Tracheobronchial Tree Compression or Obstruction


Tracheobronchial tree compression or obstruction is the most common of the three potential complications arising from anterior mediastinal masses. There can be both static and dynamic components to such compression or obstruction. The dynamic components may not be unmasked until after supine positioning ( Fig. 64.2 ), induction of general anesthesia, or administration of paralytic agents ( Table 64.1 ). Difficulty in mask ventilation in the absence of upper airway obstruction or difficulty ventilating despite successful endotracheal intubation are classic scenarios.




Fig. 64.2


Fiberoptic bronchoscopic appearance of the lower trachea in an anesthetized patient in the supine position (A) with a large anterior mediastinal mass that almost totally obstructs the trachea in the anteroposterior plane. With the patient in the sitting position (B), the lumen appears normal.

From Prakash UBS, Abel MD, Hubmayr RD: Mediastinal mass and tracheal obstruction during general anesthesia. Mayo Clin Proc 63:1004-1011, 1988.


TABLE 64.1

Perioperative Complications That May Arise From Mediastinal Masses

































Complication Manifestation Mechanism
Airway compromise Difficult intubation SVC obstruction causing upper airway edema
Upper airway obstruction Mass effect or surgical trauma to recurrent laryngeal causing vocal cord dysfunction/paralysis
Respiratory compromise Tracheobronchial obstruction Distortion, malacia, or dynamic collapse of the trachea and/or mainstem bronchi leading to difficult ventilation/oxygenation
Pulmonary edema Left atrial compression causing increased pulmonary venous pressure
Hemodynamic compromise Decreased preload Cardiac compression of the right or left atrium or right ventricle impairing cardiac filling
Right ventricular strain/failure Compression of right ventricular outflow tract or pulmonary artery causing right ventricular pressure overload
Hemorrhage Bleeding from tumor after surgical manipulation, potentially exacerbated by SVC obstruction

Only gold members can continue reading. Log In or Register to continue

Feb 18, 2019 | Posted by in ANESTHESIA | Comments Off on Mediastinal Masses
Premium Wordpress Themes by UFO Themes