Version May 2024
INTRODUCTION — Venous obstruction often affects the central veins in the chest (ie, thoracic central venous obstruction [TCVO]) and impairs adequate drainage from the head and upper extremities. Venous obstruction can be due to a variety of pathologies causing venous stenosis related to intimal injury or external venous compression or causing venous thrombosis in the presence or absence of underlying venous stenosis. The majority of cases can be linked to the presence of an intravascular device [1]. Symptoms vary based upon the degree of obstruction and time course of its development.
The clinical features and diagnosis of thoracic central venous obstruction are reviewed. An overview of central venous obstruction and of treatment are reviewed separately. (See "Overview of thoracic central venous obstruction" and "Endovenous intervention for thoracic central venous obstruction".)
THORACIC VENOUS ANATOMY — The subclavian and brachiocephalic veins (figure 1) and the superior vena cava (figure 2) are the main thoracic central veins (figure 3) that drain blood from the head, neck, and upper extremities, starting from the lateral border of the first rib to the right atrium. Compared with the brachiocephalic veins and superior vena cava, which traverse the superior and middle mediastinum, the subclavian veins (ie, "beneath the clavicle") are relatively superficial, lying in front of the anterior scalene muscle. The internal jugular veins are predominantly found in the neck but extend through the superior thoracic aperture caudal to the first ribs to join the subclavian veins, forming the brachiocephalic veins. At the inferior thoracic aperture, the suprahepatic inferior vena cava exits the diaphragm at the level of the eighth thoracic vertebra to eventually join the right atrium.
RISK FACTORS
Central venous devices — Thrombotic complications associated with central venous devices are often related to an underlying venous stenotic lesion due to intimal injury but may also be related to other factors (algorithm 1).
●Centrally inserted central venous catheters – While central venous stenosis can be associated with any central venous access sites, use of the subclavian vein as a central venous catheter access is associated with high rates of venous stenosis. The incidence is reported to range from 20 to 40 percent in patients with chronic catheters but is probably underestimated since many patients are asymptomatic. Because of this, the use of a subclavian access site for central venous access is discouraged, particularly in patients with end-stage kidney disease. While the number of hemodialysis patients using central venous catheters has decreased, over 80 percent of patients in the United States are still initiated via hemodialysis catheters [2]. In a review of 100 patients using a subclavian venous catheter for hemodialysis, angiographic evidence of central venous stenosis was apparent in 42 percent of patients after just 31 days [3]. Even among those without immediate complications, a history of prior central venous catheterization increased risk of future stenosis even after the catheter was removed [4]. (See "Central venous catheters: Overview of complications and prevention in adults", section on 'Central venous obstruction'.)
●Peripherally inserted central catheters – Peripherally inserted central catheters (PICCs) are increasingly popular for short and intermediate intravenous uses. The incidence of central venous stenosis is not as well studied for PICCs compared with centrally inserted central venous catheters (CICCs), but superficial and deep venous thrombosis are known complications [5]. Overall, 3.9 percent of patients develop some degree of venous thrombosis, with higher incidences of occlusion for larger catheter sizes. (See "Peripherally inserted central catheter (PICC)-related venous thrombosis in adults", section on 'Incidence and risk factors'.)
●Pacemaker/defibrillator – More than 200,000 pacemakers and 150,000 defibrillators are implanted in the US annually [6,7]. About 50 percent of these patients were noted to have >50 percent central venous stenosis with venography at 45 months due to longstanding inflammation from the presence of these devices [8]. A series of 280 patients with endocardial leads reported that those with a history of lead placement had a greater than four-fold increased risk of venous stenosis/occlusion [9].
Arteriovenous hemodialysis access — While many patients with end-stage kidney disease have central venous stenosis related to prior central venous catheters, those who are dialyzing using an arteriovenous (AV) access (ie, AV fistula or AV graft) can have stenotic lesions due to increased flow in the vein and the resultant extreme shear forces or tortuous venous anatomy [10,11]. These can occur anywhere along the venous outflow tract, most commonly in association with the AV anastomosis; however, central venous lesions can also occur. (See "Central vein obstruction associated with upper extremity hemodialysis access".)
Venous thoracic outlet syndromes — The costoclavicular junction is a well described area of upper extremity venous obstruction. As the subclavian vein passes between the clavicle, first rib, and subclavius muscle, the vein can be compressed, and repeated abduction can lead to intimal injury and subsequent vascular stenosis (image 1). Young athletes may be prone to this with hypertrophy of the subclavius muscle from repeated overhead motions [12]. (See "Overview of thoracic outlet syndromes" and "Primary (spontaneous) upper extremity deep vein thrombosis" and "Overview of peripheral vascular problems in athletes", section on 'Quadrilateral space syndrome'.)
Malignancy — Malignancy is associated with a higher risk of thrombosis associated with central venous devices, but tumor can also compress venous structures. Bronchogenic tumors are the most numerous thoracic malignancy-associated with central venous obstruction. Approximately 39 percent are of small cell and 42 percent of non-small cell origin [1]. The remainder are associated with lymphoma and germ cell tumors (14 and 4 percent, respectively). Rarely, metastatic disease may also be responsible for symptoms.
Malignancy is the most common cause of superior vena cava (SVC) obstruction (ie, SVC syndrome), accounting for roughly 60 to 80 percent of cases [1,13]. The presentation of SVC obstruction depends upon the time course of SVC invasion or compression, the degree of luminal compromise, and whether recruitment of venous collaterals has compensated for the narrowing. While this often occurs over a protracted period, acute thrombosis of a prior stable partial obstruction can also occur, leading to abrupt symptoms. (See "Malignancy-related superior vena cava syndrome".)
Others — Other causes of central venous obstruction include postradiation fibrosis, fibrosing mediastinitis, infection with nocardiosis, and the rare situation of agenesis of the superior vena cava [14,15].
As many as 50 percent of cases of nonmalignant SVC syndrome are attributable to fibrosing mediastinitis, for which the most common cause is an excessive host response to a prior infection with Histoplasma capsulatum. Other infections that have been associated with fibrosing mediastinitis include tuberculosis, nocardiosis, actinomycosis, aspergillosis, blastomycosis, and Bancroftian filariasis. These conditions are reviewed separately. (See "Mediastinal granuloma and fibrosing mediastinitis" and "Pathogenesis and clinical features of pulmonary histoplasmosis" and "Nocardia infections: Epidemiology, clinical manifestations, and diagnosis" and "Lymphatic filariasis: Epidemiology, clinical manifestations, and diagnosis" and "Clinical manifestations and diagnosis of blastomycosis".)
CLASSIFICATIONS
Clinical classifications — The clinical presentation of TCVO depends upon the time course, severity, location and extent of obstruction, and the effectiveness of any compensatory changes.
Based on clinical presentation and imaging findings, TCVO is classified as acute or chronic based on duration; thrombotic or nonthrombotic, depending upon the presence or absence of thrombus, respectively; primary or secondary, depending upon whether there is a provocative etiology (ie, secondary) or not (ie, primary); extrinsic or intrinsic, depending upon the nature of the inciting etiology relative to the vein; and partial or complete, depending upon the degree of obstruction.
Modeled after reporting standards for lower extremity venous occlusions, a multidisciplinary committee recommended categorizing symptom duration into three categories: acute, subacute, and chronic [16,17].
●Acute symptoms onset is 14 days or less.
●Subacute symptom onset is between 14 and 28 days.
●Chronic symptom onset is greater than 28 days.
This classification is at least in part based on historical norms, though, and those presenting with acute symptoms can have superimposed chronic disease due to the insidious nature of venous disease.
Grading symptom severity — A grading system has been proposed for SVC syndrome based on symptom severity (table 1) [18]. (See "Malignancy-related superior vena cava syndrome".)
Anatomic classification — Reporting standards published by a committee of the Society of Interventional Radiology presented a comprehensive review of issues that should be determined in evaluating patients and for data dealing with TCVO (figure 4) [19]. An important aspect of this document was the establishment of an anatomic classification reflecting increasingly severe degrees of anatomic involvement. This classification is as follows:
●Type 1: Both brachiocephalic veins and the superior vena cava are patent, but one internal jugular vein or subclavian vein is obstructed.
●Type 2: Any form of TCVO that causes unilateral brachiocephalic vein obstruction or ipsilateral obstruction of the internal jugular vein and subclavian vein (equivalent to unilateral brachiocephalic vein obstruction).
●Type 3: Both brachiocephalic veins are obstructed, but flow to the right atrium passes through the superior vena cava.
●Type 4: Superior vena cava obstruction that prevents or impedes direct thoracic venous flow to the right atrium with any constellation of brachiocephalic vein, internal jugular vein, or subclavian vein obstruction.
CLINICAL FEATURES
Symptoms and signs — Symptoms associated with thoracic central venous obstruction (TCVO) (algorithm 1) can include upper extremity/neck edema and pain; collateral venous patterning; respiratory difficulties; malfunction in those with central venous catheters or arteriovenous access; or, rarely, extremity ischemia.
Patients with acute onset TCVO are often symptomatic; however, up to 40 percent of patients may be asymptomatic [20-23]. Many asymptomatic patients experience no progression of symptoms or need for intervention [24].
While patients with sudden onset central venous obstruction are more likely to be symptomatic, for those with obstruction that occurs over a prolonged time course, the presentation is more variable. The severity of obstruction (partial versus complete), nature of the obstruction (intermittent/continuous), and effectiveness of any compensatory changes play a role in determining whether a patient will have symptoms and to what extent, although there may be other confounders that remain unknown.
Edema and pain — Symptoms of TCVO are predominantly related to reduced venous outflow leading to venous congestion. Edema (upper extremity, neck, chest, face) and pain are the hallmark symptoms and are present in at least 50 percent of patients [25]. Edema and pain can be severe, particularly in the acute setting when there is inadequate time to develop collateral venous flow.
Patients with partial or complete obstruction of the superior vena cava (SVC; ie, SVC syndrome) frequently complain of facial swelling or head fullness, which may be worsened by bending forward or lying down, or arm swelling [1,26-28]. Distension of the veins in the neck and on the chest wall may be apparent (picture 1). Arm edema, cyanosis, and facial plethora are less frequent [29-31]. While swelling of the scalp and neck is visually striking, it is generally of little clinical consequence; however, swelling of deeper neck structures can cause respiratory distress. (See 'Respiratory distress' below.)
In addition, patients with SVC syndrome can develop cerebral edema, causing headache, confusion, or visual/auditory disturbances. Severe cerebral edema can lead to brainstem herniation and possibly death.
Collateral venous patterning — As the main outflow vessels become obstructed, the venous system may remodel to enhance drainage through alternative pathways if enough time is permitted. This can be seen on physical examination as large chest wall venous collaterals (picture 1) in upwards of 91 percent of patients with TCVO [32]. The same phenomena can be seen on angiography with deeper collaterals in 62 percent of patients [24]. Depending upon the site of the lesion, these may be superficial chest wall collaterals, intercostals, or vertebral plexus veins attempting to decompress the obstruction. Radiographic resolution of these vessels is frequently used to assess adequate luminal gain and treatment of flow-limiting stenosis (image 1).
Respiratory distress — Patients with unilateral or bilateral thrombotic TCVO can present with symptoms of pulmonary embolism (PE) with tachycardia, tachypnea, dyspnea, hypoxia, or pleuritic chest pain [33]. The occurrence of PE from thoracic central or upper extremity deep venous thrombosis is relatively rare, accounting for 3 to 6 percent of cases of PE [34,35]. (See "Clinical presentation, evaluation, and diagnosis of the nonpregnant adult with suspected acute pulmonary embolism".)
Respiratory symptoms can also be related to edema from SVC syndrome, which can narrow the lumen of the nasopharynx and larynx, causing dyspnea, stridor, cough, hoarseness, and dysphagia [1,30,36,37]. Respiratory distress can also be related to pleural effusion or from pulmonary restriction from severe chest or breast swelling.
Catheter or AV access malfunction — For patients with central venous catheters or with arteriovenous hemodialysis access, catheter or AV access dysfunction may raise suspicion that TCVO is present. (See "Catheter-related upper extremity venous thrombosis in adults", section on 'No symptoms' and "Malfunction of chronic hemodialysis catheters", section on 'Extrinsic thrombus'.)
Extremity ischemia — Severe manifestations of venous outflow obstruction can reduce perfusion pressure, potentially leading to ischemia and venous gangrene, limb loss, and even death [38,39]. However, this is extremely rare, with one retrospective review reporting only 38 cases in the literature [38]. Most patients were between 45 to 65 years old and had unilateral disease and a history of malignancy.
Also rare, paradoxical embolism via a patent foramen ovale can produce symptoms and signs of acute limb or digit ischemia. (See "Embolism to the lower extremities" and "Overview of upper extremity ischemia", section on 'Arterial embolism'.)
Chest radiography — Chest radiography is the initial imaging study obtained in the evaluation of suspected intrathoracic pathology, though its utility in evaluating the venous vasculature is limited. However, radiography can evaluate positioning of any intravascular devices such as central catheters and pacemaker or defibrillator leads, rule out bony abnormalities (eg, cervical rib), and identify obvious masses causing central venous compression. Among patients with SVC syndrome, abnormal chest radiograph with a widened mediastinum and pleural effusion are the most common findings [40].
Laboratory studies — Routine work-up includes a complete blood count, complete metabolic panel, coagulation studies (prothrombin time, activated partial thromboplastin time), and D-dimer.
Specific abnormal laboratory results or a positive assay of a tumor marker may increase suspicion for malignancy as a cause of TCVO. (See "Malignancy-related superior vena cava syndrome", section on 'Laboratory studies'.)
DIAGNOSIS — A diagnosis of TCVO is often suspected based upon characteristic risk factors and the clinical features (algorithm 1). Vascular imaging is necessary to demonstrate the obstruction and characterize the degree of stenosis or demonstrate thrombotic occlusion. Additional studies may be required depending upon the clinical presentation.
Vascular imaging — The approach to imaging depends predominantly upon symptom severity [41]. (See 'Classifications' above.)
Mild-to-moderate symptoms — For patients who present with mild to moderate symptoms (edema, pain), including suspected superior vena cava (SVC) syndrome (grade 0,1,2 (table 1)) with or without a known malignancy, either a venous duplex study or cross-sectional imaging (computed tomographic [CT] venography, magnetic resonance [MR] venography) may be used as the initial study.
●Duplex ultrasound is useful for excluding thrombus in the subclavian, axillary, and brachiocephalic veins and is the initial imaging study for patients with mild-to-moderate symptoms who present with extremity swelling and who have an indwelling device, or those with a known malignancy at low risk to cause venous obstruction. Additional imaging studies may be needed depending upon the suspected etiology. (See 'Ultrasound' below.)
●CT or MR venography can define the level and extent of venous blockage, identify and map collateral pathways of venous drainage, and often permit identification of the underlying cause of venous obstruction. The presence of collateral vessels on CT (image 2) is a strong indicator of SVC obstruction, with a specificity of 96 percent and sensitivity of 92 percent [42-44]. (See 'Computed tomography' below and 'Magnetic resonance imaging' below.)
Severe symptoms — For patients with severe or life-threatening symptoms (eg, severe acute primary venous thrombosis, grade 3,4 SVC syndrome (table 1)), cross-sectional imaging with either CT or MR venography is typically recommended as the initial imaging modality to establish the diagnosis and for surgical planning, depending upon the clinical scenario and availability of institutional resources. (See 'Computed tomography' below and 'Magnetic resonance imaging' below.)
Venography provides a means to alleviate TCVO with endovenous recanalization (eg, mechanical thrombolysis, pharmacologic thrombolysis, angioplasty) and stenting, as necessary, with the aid of intravascular ultrasound (if available). (See 'Venography and intravascular ultrasound' below.)
Vascular imaging modalities
Ultrasound — The central vasculature offers several challenges to ultrasonography. As compared with the peripheral vasculature, evaluation of the central veins using ultrasonography is more indirect. Doppler is used to assess respiratory variations and waveforms while color Doppler is used to assess flow and direction. Findings that suggest central venous occlusion include dampening of the waveforms with loss of venous pulsatility and loss of respiratory variation. Typical maneuvers used during peripheral ultrasonography such as venous compression and other supportive maneuvers are limited because of anatomic constraints.
For detecting upper extremity venous thrombosis, ultrasound is reported to have a specificity of 94 to 100 percent and sensitivity of 56 to 100 percent [45-47]. In one large series of 214 patients with primary venous disease, the false negative rate was 21 percent, suggesting that despite some of its advantages, ultrasound should not be the modality of choice for diagnosing central occlusions [48]. However, ultrasound is quite useful for access planning for intervention.
Computed tomography — Both noncontrast and contrast-enhanced CT can provide can demonstrate overall size, position, and calcifications of the thoracic central venous vasculature.
Contrast-enhanced CT combines the diagnostic benefit of CT with the same degree of enhanced vascular detail as digital subtraction venography, but it must be properly timed to avoid oversaturation and to minimize flow artifacts arising from unopacified blood [41,49]. Those with congenital anomalies or hemodialysis arteriovenous access may require special protocols to completely visualize the venous system. Contrast-enhanced CT has a 96 to 98 percent sensitivity and 97 to 99 percent specificity for detecting central venous lesions [50-52]. Complications, including excessive bleeding from venipuncture sites, are uncommon [1,53].
Magnetic resonance imaging — MR venography can be as equally sensitive and specific as contrast-enhanced CT in visualizing the central venous vasculature, with sensitivity and specificity values approaching 100 percent; the addition of electrocardiogram gating can further enhance imaging [41,54-58]. Correlation between MR and invasive catheter-based techniques have also been studied, demonstrating very high correlation in high resolution studies [59]. Use of traditional gadolinium is contraindicated in patients with chronic kidney disease due to the risk of nephrogenic systemic fibrosis [60]. Fortunately, ferumoxytol injections can produce similarly high-quality and accurate images for these patients [61].
Venography and intravascular ultrasound — Conventional, catheter-based venography remains the gold standard for vascular imaging though is rarely necessary for initial diagnosis [62,63]. While CT or MR provides a broad picture, in addition to providing visualization of stenosis, thrombus, and collateral pathways, catheter-based venography provides real-time clinical information regarding flow patterns and rates and better "resolution" of smaller vessels, often with less contrast than less invasive modalities. [42,64]. Furthermore, catheter-based venography offers an opportunity to treat any hemodynamically significant lesions. However, catheter-based venography does not image the surrounding structures, and thus will not identify the specific cause of TCVO unless thrombosis is the sole etiology.
Frequently performed in the same setting as venography, intravascular ultrasound (IVUS) is an invasive technique that images the lumen of the vessel [65]. It has become increasingly popular for evaluating venous disease due to its ability to accurately identify stenoses from a three-dimensional cross-section as compared with the planar images of venography [66]. One review reported that conventional venography missed up to one-third of luminal stenoses in their series, and IVUS was able to identify intraluminal trabeculations in 75 percent of their patients not otherwise seen with venography alone [67].
Differential diagnosis — A central arteriovenous fistula (eg, following penetrating trauma, ruptured aneurysm) can increase collateral venous flow, mimicking the clinical features of TCVO (ie, swelling, venous patterning), but with an absence of vascular occlusion on imaging studies.
A variety of conditions can cause peripheral edema; however, these usually present symmetrically and often without associated pain. (See "Clinical manifestations and evaluation of edema in adults" and "Causes and treatment of refractory edema in adults".)
Acute heart failure can present with venous congestion and shortness of breath, and similarly, acute respiratory failure due to pneumonia or acute respiratory distress syndrome also present clinically with stridor and cough. The clinical history, arterial blood gas, fever, and patchy pulmonary infiltrates on chest radiography distinguish these from TCVO. (See "Approach to the patient with dyspnea".)
DIAGNOSTIC EVALUATION OF SPECIFIC ETIOLOGIES — Once a diagnosis of TCVO is made, the clinical features including the age of the patient, medical history, and presence or absence of inciting factors generally determines the underlying etiology. Depending upon the suspected etiology, further evaluation may be necessary.
●Hemodialysis access dysfunction (See "Central vein obstruction associated with upper extremity hemodialysis access".)
●Venous thoracic outlet syndrome (See "Primary (spontaneous) upper extremity deep vein thrombosis", section on 'Imaging'.)
●Malignancy (See "Malignancy-related superior vena cava syndrome", section on 'Histologic diagnosis' and "Cancer-associated hypercoagulable state: Causes and mechanisms".)
●Unprovoked venous thrombosis (See "Evaluating adult patients with established venous thromboembolism for acquired and inherited risk factors".)
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Superficial vein thrombosis, deep vein thrombosis, and pulmonary embolism" and "Society guideline links: Venous access".)
SUMMARY AND RECOMMENDATIONS
●Thoracic central venous obstruction – Thoracic central venous obstruction (TCVO) impedes drainage from the head, neck, and upper extremities and can be thrombotic (ie, deep vein thrombosis) with or without an underlying venous stenosis or nonthrombotic due to a variety of pathologies. TCVO can affect any, or all of, the thoracic central veins, including the subclavian veins, brachiocephalic veins, and superior vena cava (SVC) (figure 2). The clinical manifestations of TCVO depend upon the location of obstruction, severity of obstruction (partial versus complete), time course (acute versus chronic), and the presence and effectiveness of any collateral venous flow. (See 'Introduction' above and 'Thoracic venous anatomy' above and 'Classifications' above.)
●Risk factors – TCVO may be due to venous injury from indwelling venous devices or repetitive external venous compression, or due to venous thrombosis in the presence or absence of underlying venous stenosis. Most cases of TCVO can be linked to the presence of an intravascular device (eg, central venous catheter, cardiac implantable electronic device [eg, pacemaker, defibrillator]). Other factors include thoracic outlet syndromes, malignancy, prothrombotic states, and others. (See 'Risk factors' above.)
●Symptoms and signs – Symptoms and signs can range from none to severe. On physical examination, superficial venous collaterals, which develop in response to progressive venous obstruction, may be seen on examination of the anterior chest wall. (See 'Symptoms and signs' above.)
•Symptomatic patients may present with minimal symptoms, central venous catheter or hemodialysis arteriovenous access malfunction, or mild edema and pain limited to one or both extremities.
•Severe bilateral upper extremity edema and pain accompanied by head and neck edema (which can include ocular swelling) or cerebral edema are manifestations of SVC obstruction (ie, SVC syndrome).
•Rare clinical presentations include respiratory symptoms from pulmonary embolism, pharyngeal or laryngeal edema, and ischemia from phlegmasia cerulea dolens or paradoxical embolism.
●Clinical classifications – Based on clinical presentation and imaging findings, TCVO is classified as (see 'Classifications' above):
•Acute (onset <14 days), subacute (onset 14 to 28 days), or chronic (onset >28 days)
•Thrombotic or nonthrombotic
•Secondary or primary depending upon whether there is provoking etiology or not, respectively
•Extrinsic or intrinsic depending upon the nature of the inciting etiology
•Partial or complete depending upon the degree of obstruction
•An anatomic classification for TCVO reflects increasingly severe degrees of central vein involvement (figure 4)
●Diagnosis – A clinical diagnosis of TCVO can often be made based on history and physical examination (eg, catheter dysfunction in a patient with upper extremity swelling). However, confirmation of the diagnosis of TCVO relies of vascular imaging, which characterizes the location and severity of venous obstruction (stenosis, nonthrombotic occlusion, thrombotic occlusion). (See 'Diagnosis' above.)
•For patients with no or only mild symptoms, venous duplex ultrasound is an appropriate initial imaging study. Indirect findings on ultrasound that suggest TCVO include dampened venous waveforms with loss of venous pulsatility and respiratory variation. Additional imaging may be needed depending upon suspected the suspected etiology. (See 'Ultrasound' above.)
•For patients with moderate-to-severe symptoms, we suggest initial CT or MR venography. Compared with ultrasound, CT and MR venography are more accurate and directly demonstrate the venous obstruction, the presence of collateral vessels, as well as any abnormalities of the surrounding structures that may be the cause of obstruction. (See 'Computed tomography' above and 'Magnetic resonance imaging' above.)
•Catheter-based venography is confirmatory and provides a means to treat TCVO using a variety of endovenous techniques (eg, mechanical thrombolysis, pharmacologic thrombolysis, angioplasty, stenting). Intravascular ultrasound is increasingly used as an adjunctive imaging technique to aid intervention. (See 'Venography and intravascular ultrasound' above.)
آیا می خواهید مدیلیب را به صفحه اصلی خود اضافه کنید؟
