Chapter 162 - SVC Occlusion and Management Flashcards
SVC occlusion cause breakdown into broad categories
60% malignant
40% benign
Type of malignant causes of SVC occlusion
1) Non-small cell lung cancer 50%
2) SCLCa 22%
3) Lymphoma 12%
4) metastatic cancer 9%
5) germ cell cancer 3%
6) Thymoma 2%
Others: medullary + follicular Cancer of thyroid
teratoma
angiosarcoma
synovial cell cancer
Benign causes of SVC obstruction
1) indwelling CVC and PM 7-33%
2) most common used to be mediastinal fibrosis and granulomatous fungal disease (histoplasmosis)
3) radiation
4) retrosternal goiter
5) aortic dissection
SVC syndrome first described by
William Hunter 1757 with aortic aneurysm compressing SVC
SVC syndrome found in this % with CVC and PM respectively
1-3% with CVC
0.2-3.3% with PM
Risk of venous thrombosis increased by
1) thrombophilia (factor V leiden)
2) deficiency in anticoagulation factors: antithrombin III, protein S, protein C
Symptoms of SVC syndrome
1) fullness in head/neck (number of pillows needed)
2) dyspnea
3) orthopnea
4) headache
5) dizziness
6) syncope
7) visual changes
8) confusion
9) cough
Signs of SVC syndrome
1) dilated neck veins
2) swelling of face/neck/eyelids and UE
3) chest wall collateral veins
4) ecchymosis and cyanosis of face
malignancy can also cause:
5) hemoptysis
6) hoarseness
7) dysphagia
8) lethargy
9) weight loss
10) palpable cervical tumor or lymph nodes
Diagnosis of SVC syndrome relies on:
clinical + CXR alone > 90% detected
CXR signs of SVC syndrome
1) mediastinal widening
2) hilar mass right side
3) pleural effusion
4) bilateral diffuse infiltrates
5) upper lobe collapse
6) enlarged azygos
7) enlarged superior intercostal vein (aortic nipple) drains into the hemiazygous system
Aortic nipple
enlarged superior intercostal vein
Ultrasound in SVC syndrome
only indirect detection
lack of respiratory variations
Radionuclide imaging in SVC syndrome pro and con
Tc 99m inject to bilateral arms
Pro: functional aspect, collateral pathway, use in F/U to detect changes
Con: low resolution, cannot identify cause
CTA in SVC syndrome
1) identifies mass
2) identifies CVC, PM presence
3) defines collateral pathway
4) differentiate benign vs malignant causes
Collateral pathways in SVC syndrome
1) azygous-hemiazygous pathway
2) internal mammary pathway
3) lateral thoracic-thoracoepigastric pathway
4) vertebral pathway + small mediastinal veins
5) hepatic parenchyma and pulmonary pathway
Venography in SVC syndrome
Gold standard
1) anatomic roadmap
2) presence, direction of collateral flow
Types of SVC syndrome
Type 1: partial obstruction
Type 2: complete/near complete obstruction, antegrade azygous
Type 3: complete/near complete obstruction, retrograde azygous
Type 4: IVC drainage only, incomplete azygous/hemiazygous system
MRV in SVC syndrome
non-invasive without iodinated contrast use but cannot do in some PM
risk of NSF
Initial management of SVC syndrome
1) elevate head
2) behavioural modification
3) LMWH + LT A.C.
4) thrombolysis if benign
5) radiation and chemo if malignant
Ratio of malignant cause of SVC syndrome non-responsive to radiation or chemo
1/4
Candidates for types of malignancy for surgery resection
1) lymphoma
2) thymoma
3) metastatic medullary carcinoma of thyroid
First endo for SVC done by
Sherry 1986; cause was a PM wire
Stents used in SVC syndrome (uncovered)
1) Gianturco Z (self-expand) with large stent interstices (risk tumor ingrowth)
2) palmaz: short and precise but poor flexibility
3) wallstent
4) smart stent
5) protege stent
6) E luminexx
7) sinus XL
9) Zilver vena
Perforation of SVC in POBA treatment
1) prolonged inflation
2) covered stent
Surgery options for SVC obstruction
1) GSV connect EJV/IJV to FV with 2 GSV segment with PTFE protection outside
2) spiral GSV (described by Chiu and Doty)
3) FV but risk LE edema in this population
4) PTFE need fistula if poor inflow like subclavian; ringed enforced
5) spiral bovine
6) cryograft
7) patch only if tumor partial
Chiu equation
l = RL/r
r and l for GSV
R and L for eventual graft
typically one GSV from thigh to knee gives 10 cm graft
Surgical exposure for SVC operation
1) Median sternotomy extending to IJ on medial SCM
2) enter mediastinum and resect tumour
3) enter pericardial sac
4) right atrial appendage or SVC as outflow
5) unilateral enough because of face + neck collaterals
Current surgical algorithm in SVC treatment
1) endo first
2) similar endo and sx patency
3) covered stent better than uncovered
4) vein better than PTFE
Graft restenosis key points in SVC obstruction
most within 1-2 years
always with symptom recurrence
