Question 25

Created on Fri, 05/29/2015 - 18:44
Last updated on Tue, 08/11/2015 - 18:42
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Outline the principles of management of superior vena caval obstruction.

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College Answer

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

Treat obstruction

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.

Discussion

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

Aetiology

Diagnosis

Management

Malignant

Malignant mass in thoracic inlet

History (eg. smoking)
CT
MRI
CXR

Surgical excision
SVC stenting by interventional radiology
Dexamethasone 
Radiation therapy

Non-malignant

Tuberculosis

Suspicious history, CT, CXR, aspiration and AFB/ZN stain/PCR  of the contents

Specific antituberculosis therapy
Surgical relief of obstruction
SVC stenting by interventional radiology

Abscess

CT, CXR, aspiration and gram stain / culture of the contents

Surgical drainage
Appropriate antibiotics

Goitre

CXR, CT, TFTs, biopsy of the mass

Surgical excision
Thyroid-suppressing medication eg. carbimazole
SVC stenting by interventional radiology

Thrombus

History of IJ CVC
CT with contrast, ultrasound

Antioagulation; clot retrieval by interventinal radiology procedure, or surgical embolectomy

Fibrosing mediastinitis

CT;
History of mediastinitis or mediastinal radiotherapy

Surgical relief of obstruction
SVC stenting by interventional radiology

Aortic aneurysm

Ct with contrast; TOE

Surgical management of aneurysm;
SVC stenting by interventional radiology

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.

References

MAURIEMARKMAN, MD. "Diagnosis and management of superior vena cava syndrome." Cleveland Clinic journal of medicine 66.1 (1999): 59.