Outline the principles of management of superior vena caval obstruction.
Principles of management include:
Diagnose it clinically
History - dyspnoea, head fullness, cough, lines, tumour
Examination - plethoric cyanosed facies, periorbital oedema, exopthalmos, conjunctival injection, fundal venous engorgement, raised non-pulsatile JVP, lymphadenopathy, Pemberton's sign, dilated arm and chest collaterals
Look for associated features
Central airway compression, recurrent laryngeal involvement, phrenic nerve paralysis, Horner'ssyndrome, cardiac tamponade, pleural effusion
Confirm by investigation and look for cause
Thoracic neoplasm (usually bronchogenic Ca or Non Hodgkin’s Lymphoma), retrosternal thyroid,mediastinal fibrosis (post infection), thrombosis from intravascular device, aneurysm
High resolution CT is the most useful investigation. Also consider CXR, bronchoscopy/biopsy, echocardiograph, mediastinoscopy/biopsy, Magnetic Resonance Imaging
Peripheral tissue diagnosis often successful - node biopsy, sputum cytology, Bone Marrow biopsy
Steroids, Deep X-Ray Therapy, chemotherapy, surgery when indicated. Anticoagulation andthrombolytic Rx for acute catheter related thrombosis.
Support as necessary
Initial vascular access - IVC territory. Prepare for peri-operative/anaesthesia risks - CVS collapse(tamponade), central airway obstruction, laryngeal dysfunction, associated respiratory dysfunction(pleural and pulmonary involvement)
Few candidates considered the significant risk of sedating/anaesthetising patients with a mediastinal mass.
The causes of SVC obstruction can be divided into malignant and non-malignant.
The non-malignant causes are well summarised in a nice table in the below-referenced article.
I will paraphrase it in the structured answer offered below.
Type of SVC obstruction
Malignant mass in thoracic inlet
History (eg. smoking)
Suspicious history, CT, CXR, aspiration and AFB/ZN stain/PCR of the contents
Specific antituberculosis therapy
CT, CXR, aspiration and gram stain / culture of the contents
CXR, CT, TFTs, biopsy of the mass
History of IJ CVC
Antioagulation; clot retrieval by interventinal radiology procedure, or surgical embolectomy
Surgical relief of obstruction
Ct with contrast; TOE
Surgical management of aneurysm;
Superior vena cava obstruction receives a (slightly) more detailed treatment in the "Required Reading" section, in a level of detail proportional to its value for the exam candidate.
MAURIEMARKMAN, MD. "Diagnosis and management of superior vena cava syndrome." Cleveland Clinic journal of medicine 66.1 (1999): 59.