Review of evolving etiologies, implications and treatment strategies for the superior vena cava syndrome
Straka et al. SpringerPlus
Review of evolving etiologies, implications and treatment strategies for the superior vena cava syndrome
Christopher Straka 2
James Ying 2
Feng‑Ming Kong 1
Christopher D. Willey 4
Joseph Kaminski 3
D. W. Nathan Kim 0
0 Department of Radiation Oncology , Texas Oncology, 1700 W. Highway 6, Waco, TX 76712 , USA
1 Department of Radiation Oncology, GRU Cancer Center and Medical College of Georgia , Augusta, GA , USA
2 Department of Radiation Oncology, University of Texas Southwestern Medical Center , 5801 Forest Park Rd, Dallas, TX 75390 , USA
3 Dattoli Cancer Center , 2803 Fruitville Rd, Sarasota, FL 34237 , USA
4 Department of Radiation Oncology, The University of Alabama Birmingham , Birmingham, AL , USA
Superior vena cava syndrome (SVCS) is a relatively common sequela of mediastinal malignancies and may cause significant patient distress. SVCS is a medical emergency if associated with laryngeal or cerebral edema. The etiologies and management of SVCS have evolved over time. Non‑ malignant SVCS is typically caused by infectious etiologies or by thrombus in the superior vena cava and can be managed with antibiotics or anti‑ coagulation therapy, respectively. Radiation therapy (RT) has long been a mainstay of treatment of malignant SVCS. Chemotherapy has also been used to manage SVCS. In the past 20 years, percutaneous stenting of the superior vena cava has emerged as a viable option for SVCS symptom palliation. RT and chemotherapy are still the only modalities that can provide curative treatment for underlying malignant etiologies of SVCS. The first experiences with treating SVCS with RT were reported in the 1970's, and several advances in RT delivery have subsequently occurred. Hypo‑ fractionated RT has the potential to be a more convenient therapy for patients and may provide equal or superior control of underlying malignancies. RT may be combined with stenting and/or chemotherapy to provide both immediate symptom palliation and long‑ term disease control. Clinicians should tailor therapy on a case‑ by‑ case basis. Multi‑ disciplinary care will maximize treatment expediency and efficacy.
Superior vena cava syndrome (SVC syndrome; SVCS); Stenting; Thoracic malignancies; Hypo‑ fractionation; Multi‑ modality therapy
Background
Superior vena cava syndrome (SVCS), a clinical
manifestation arising from compression of the thin-walled
superior vena cava (SVC), was first described by William
Hunter in 1757 and can be caused by a variety
malignancies
(Hunter and Johnston 1757)
. SVCS is a significant
disorder affecting up to 10 % of small cell lung cancer
(SCLC) patients and 2–4 % of all lung cancer patients
(Wan and Bezjak 2010)
. The prognosis of SVCS caused by
malignancies is primarily determined by the tumor type
(Yu et al. 2008)
. Traditionally, malignant SVCS has been
considered to be an indication for emergent intervention,
typically with radiation therapy (RT). However,
accumulating evidence has suggested that accurate diagnosis and
biopsy should precede emergent therapeutic
intervention in most cases
(Yu et al. 2008)
. Timely and effective
intervention aimed at treating the malignant cause of this
syndrome can relieve significant suffering and improve
SVCS patients’ quality of life.
Anatomy and physiology
The SVC carries approximately one-third of the venous
return to the heart. Situated slightly to the right of
midline and coursing through the superior and middle
mediastinum, the SVC is the major drainage outlet for venous
return from the head, arms, and upper torso. Despite its
high flow volume, the SVC is quite distensible and can be
compressed by an adjacent mass originating in the
middle or anterior mediastinum, the right paratracheal or
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precarinal lymph node stations, or the right lobe
bronchus
(Wan and Bezjak 2010; Wilson et al. 2007)
.
Rightsided masses are more likely to cause SVCS, presumably
due to the anatomic location of the SVC
(Sculier et al.
1986)
. Rarely, a thrombus can occlude the SVC even in
the absence of an external mass.
The superior and middle mediastinum is an
anatomically confined space populated by a large number of
lymph nodes. The SVC is thin walled and is opened by
relatively low venous pressure, making it particularly
susceptible to compression by adjacent masses
(Koetters
2012)
. In the event of SVC obstruction, venous pressure
in collateral vessels increases and, over time, a collateral
blood-flow network develops
(Lacout et al. 2012)
. Many
different vessels may enlarge in response to the increased
blood pressure (...truncated)