{"id":20599,"date":"2026-04-09T11:19:26","date_gmt":"2026-04-09T11:19:26","guid":{"rendered":"https:\/\/hlsllc.org\/tos\/?page_id=20599"},"modified":"2026-04-14T07:38:17","modified_gmt":"2026-04-14T07:38:17","slug":"causes-of-venous-tos","status":"publish","type":"page","link":"https:\/\/hlsllc.org\/tos\/causes-of-venous-tos\/","title":{"rendered":"Causes of Venous TOS"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-page\" data-elementor-id=\"20599\" class=\"elementor elementor-20599\" data-elementor-post-type=\"page\">\n\t\t\t\t<div class=\"elementor-element elementor-element-abb0d85 e-con-full e-flex e-con e-parent\" data-id=\"abb0d85\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-e2ff0e0 elementor-widget elementor-widget-heading\" data-id=\"e2ff0e0\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Causes of Venous Thoracic Outlet Syndrome\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-054fb9d e-con-full e-flex e-con e-parent\" data-id=\"054fb9d\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t<div class=\"elementor-element elementor-element-4e405cf e-con-full e-flex e-con e-child\" data-id=\"4e405cf\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-607465d elementor-widget elementor-widget-text-editor\" data-id=\"607465d\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<div class=\"fusion-title title fusion-title-2 fusion-sep-none fusion-title-text fusion-title-size-paragraph\">\n\n<p class=\"fusion-title-heading title-heading-left title-heading-tag fusion-responsive-typography-calculated\">\nTable of Contents\n<\/p>\n\n<\/div>\n\n<div class=\"awb-toc-el awb-toc-el--1\">\n\n<div class=\"awb-toc-el__content\">\n\n<ul class=\"awb-toc-el__list awb-toc-el__list--0\">\n\n<li class=\"awb-toc-el__list-item\">\n<a href=\"#toc_Causes_of_venous_thoracic_outlet_syndrome_are_different\">\nCauses of venous thoracic outlet syndrome are different for each patient\n<\/a>\n<\/li>\n\n<li class=\"awb-toc-el__list-item\">\n<a href=\"#toc_Different_mechanisms_for_similar_syndromes_resulting_from_venous\">\nDifferent mechanisms for similar syndromes resulting from venous obstruction\n<\/a>\n<\/li>\n\n<li class=\"awb-toc-el__list-item\">\n<a href=\"#toc_Different_names_for_similar_syndromes_resulting_from_venous\">\nDifferent names for similar syndromes resulting from venous obstruction\n<\/a>\n<\/li>\n\n<li class=\"awb-toc-el__list-item\">\n\n<a href=\"#toc_Anatomy_of_Venous_Thoracic_Outlet_Syndrome\">\nAnatomy of Venous Thoracic Outlet Syndrome\n<\/a>\n\n<ul class=\"awb-toc-el__list awb-toc-el__list--1\">\n\n<li>\n<a href=\"#toc_Anteroposterior_View_of_the_Prescalene_Space\">\nAnteroposterior View of the Prescalene Space\n<\/a>\n<\/li>\n\n<li>\n<a href=\"#toc_Lateral_View_of_the_Prescalene_Space\">\nLateral View of the Prescalene Space\n<\/a>\n<\/li>\n\n<li>\n<a href=\"#toc_Subclavius_muscle_and_tendon\">\nSubclavius muscle and tendon\n<\/a>\n<\/li>\n\n<li>\n<a href=\"#toc_Costoclavicular_ligament\">\nCostoclavicular ligament\n<\/a>\n<\/li>\n\n<\/ul>\n\n<\/li>\n\n<li class=\"awb-toc-el__list-item\">\n<a href=\"#toc_Symptoms_of_Venous_Thoracic_Outlet_Syndrome\">\nSymptoms of Venous Thoracic Outlet Syndrome\n<\/a>\n<\/li>\n\n<li class=\"awb-toc-el__list-item\">\n<a href=\"#toc_Diagnosis_of_Venous_Thoracic_Outlet_Syndrome\">\nDiagnosis of Venous Thoracic Outlet Syndrome\n<\/a>\n<\/li>\n\n<li class=\"awb-toc-el__list-item\">\n<a href=\"#toc_Treatment_of_Venous_Thoracic_Outlet_Syndrome\">\nTreatment of Venous Thoracic Outlet Syndrome\n<\/a>\n<\/li>\n\n<\/ul>\n\n<\/div>\n<\/div> \t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-f8d8e1b e-con-full e-flex e-con e-child\" data-id=\"f8d8e1b\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-edbf3a3 e-con-full e-flex e-con e-parent\" data-id=\"edbf3a3\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t<div class=\"elementor-element elementor-element-2d9d829 e-con-full e-flex e-con e-child\" data-id=\"2d9d829\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-cde5059 elementor-widget elementor-widget-heading\" data-id=\"cde5059\" data-element_type=\"widget\" data-e-type=\"widget\" id=\"toc_Causes_of_venous_thoracic_outlet_syndrome_are_different\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Causes of venous thoracic outlet syndrome are different for each patient\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-e77f1d7 elementor-widget elementor-widget-text-editor\" data-id=\"e77f1d7\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<div class=\"fusion-title title fusion-title-text fusion-title-size-paragraph\"><div class=\"fusion-text\"><div class=\"fusion-li-item-content\"><div class=\"fusion-text fusion-text-1\"><p><a href=\"https:\/\/www.tosmri.com\/what-is-thoracic-outlet-syndrome\/causes-of-thoracic-outlet-syndrome\/causes-of-venous-thoracic-outlet-syndrome\/\">Venous thoracic outlet syndrome<\/a>\u00a0occurs quite uncommonly, but has potentially serious complications. Of all cases of thoracic outlet syndrome, only about 5% are the type of thoracic outlet syndrome known as venous thoracic outlet syndrome. Middle-aged people can develop venous TOS, while other patients are young athletes. Some patients with\u00a0<a href=\"https:\/\/www.tosmri.com\/thoracic-outlet-syndrome-in-baseball-players\/\">venous thoracic outlet syndrome have a history of an episode of significant exertion<\/a>. Others practice at their athletic specialty on a regular basis, with no specific inciting event. As a result, the causes of venous\u00a0<a href=\"https:\/\/www.tosmri.com\/what-is-thoracic-outlet-syndrome\/thoracic-outlet-syndrome\/\">thoracic outlet<\/a>\u00a0syndrome result in different syndromes with different names.<\/p><\/div><\/div><\/div><\/div>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-e43801c elementor-widget elementor-widget-image\" data-id=\"e43801c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" width=\"600\" height=\"400\" src=\"https:\/\/hlsllc.org\/tos\/wp-content\/uploads\/2026\/04\/Gray-veins-axilla-cropped-third-page-1.jpeg\" class=\"attachment-large size-large wp-image-20608\" alt=\"\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-777e68f elementor-widget elementor-widget-heading\" data-id=\"777e68f\" data-element_type=\"widget\" data-e-type=\"widget\" id=\"toc_Different_mechanisms_for_similar_syndromes_resulting_from_venous\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Different mechanisms for similar syndromes resulting from venous obstruction\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-4649689 elementor-widget elementor-widget-text-editor\" data-id=\"4649689\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p>The causes of venous\u00a0<a title=\"Zack Wheeler, Phillies\u2019 Ace, Struck Down by Thoracic Outlet Syndrome\" href=\"https:\/\/www.tosmri.com\/zack-wheeler-phillies-ace-struck-down-by-thoracic-outlet-syndrome\/\" data-wpil-monitor-id=\"115\">thoracic outlet syndrome<\/a>\u00a0comprise three possible interwoven processes. Initially, arm motion creates compression of the subclavian vein between the\u00a0<em>subclavius muscle<\/em>\u00a0tendon and the first\u00a0<em>costal<\/em>\u00a0(rib)\u00a0<em>cartilage<\/em>. If compression persists or recurs, it may cause damage of the wall of the subclavian vein, with resulting scar and\u00a0<em>stenosis<\/em>\u00a0(narrowing) of the vein. Eventually, depending on the severity and frequency of vein compression, blood clot may form at the damaged area of the subclavian vein.<\/p><p>The clinical presentation of patients with venous\u00a0<a title=\"Dr. Scott Werden, MD \u2013 Diagnostic Leadership in Thoracic Outlet Syndrome\" href=\"https:\/\/www.tosmri.com\/dr-scott-werden-md-diagnostic-leadership-in-thoracic-outlet-syndrome\/\" data-wpil-monitor-id=\"160\">thoracic outlet syndrome<\/a>\u00a0depends on the underlying mechanisms of vein compression and narrowing. Some patients may experience symptoms of venous\u00a0<a title=\"Why Athletes are More at Risk for Thoracic Outlet Syndrome\" href=\"https:\/\/www.tosmri.com\/why-athletes-are-more-at-risk-for-thoracic-outlet-syndrome\/\" data-wpil-monitor-id=\"234\">thoracic outlet syndrome<\/a>\u00a0caused only by extrinsic compression of the subclavian vein. In this case, the subclavian vein is structurally normal and no blood clot is present. Other patients may develop scarring and stenosis of the subclavian vein, which causes a fixed and non-positional narrowing of the subclavian vein. This stenosis limits venous return of blood to the heart, causing swelling of the affected arm.<\/p><p>Ultimately, it is the formation of blood clot that creates the most dramatic clinical presentation of venous TOS. These patients will frequently present to an emergency room with swelling and bluish color of the arm, along with the appearance of new superficial veins over the chest on the same side. These patients already have the underlying compression of the subclavian vein, with a damaged vein wall, but it is the relatively rapid blood clot formation that creates the dramatic clinical picture.<\/p><p>Venous compression by itself is necessary but not sufficient to create this blood clot. Damage to the wall of the vein by itself is necessary but not sufficient to create the blood clot. While these mechanisms create the opportunity for blood clot, the final step that causes blood clot is currently unknown. Nonetheless, in these patients, it is the formation of blood clot that causes partial or complete blockage of venous drainage from the arm and results in the most severe form of venous thoracic outlet syndrome.<\/p><p>In addition, blood clot in the subclavian vein can break loose and travel through the heart to the pulmonary arteries in the lungs. This\u00a0<em>pulmonary embolism<\/em>\u00a0is rare but potentially life-threatening. To be sure, blood clots in leg veins are more likely to cause pulmonary embolism than blood clots in the subclavian vein. Nonetheless, blood clot in the subclavian vein may cause serious complications if not promptly diagnosed and treated.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-27bb94a elementor-widget-divider--view-line elementor-widget elementor-widget-divider\" data-id=\"27bb94a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"divider.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-divider\">\n\t\t\t<span class=\"elementor-divider-separator\">\n\t\t\t\t\t\t<\/span>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-020efc5 elementor-widget elementor-widget-heading\" data-id=\"020efc5\" data-element_type=\"widget\" data-e-type=\"widget\" id=\"toc_Different_names_for_similar_syndromes_resulting_from_venous\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Different names for similar syndromes resulting from venous obstruction\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-3dae410 elementor-widget elementor-widget-text-editor\" data-id=\"3dae410\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<div class=\"fusion-title title fusion-title-text fusion-title-size-paragraph\"><div class=\"fusion-text\"><div class=\"fusion-li-item-content\"><div class=\"fusion-text fusion-text-3\"><p>In 1875, Sir James Paget in London\u00a0<a href=\"https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC8569271\/\" target=\"_blank\" rel=\"noopener\">published the first description of venous thoracic outlet syndrome<\/a>, caused by a blood clot in the subclavian vein. Paget felt this blood clot arose spontaneously. Interestingly, Leopold von Schrotter in Vienna recorded a very similar case in Berlin at the same time, but did not publish the case until 1884. Von Schrotter felt the blood clot had formed due to muscular contractions surrounding the subclavian vein. Both Paget and Von Schrotter are credited with the first description of venous thoracic outlet syndrome, which is now frequently referred to as \u2018Paget-Schrotter syndrome.\u2019<\/p><p>Paget-Schrotter syndrome includes cases with spontaneous blood clot formation and those thought to be due to activity. The name \u2018effort thrombosis\u2019 or \u2018primary effort thrombosis\u2019 is used by many physicians to refer to those latter cases where blood clot formation associated with active use of the upper extremity. The distinction may be of little real performance, and is unlikely to affect diagnosis or treatment.<\/p><p>The causes of venous thoracic outlet syndrome are widely-accepted to result from venous blood clot in the arm. However, some patients experience similar symptoms, but in the absence of a venous blood clot in the arm. In these patients, the cause of venous thoracic outlet syndrome results from positional changes of the arm that create intermittent obstruction of the subclavian vein. Symptoms are quite similar to those patients with a subclavian vein blood clot, although no clot is present. This is known as McCleery syndrome. In fact, the syndrome was first described by McLaughlin and Popma in 1939, then described in detail by McCleery in 1951.<\/p><p>Venous thoracic outlet syndrome occurs as a result of three possible interwoven processes. Initially, arm motion creates compression of the subclavian vein between the\u00a0<em>subclavius muscle<\/em>\u00a0tendon and the first\u00a0<em>costal<\/em>\u00a0(rib)\u00a0<em>cartilage<\/em>. If compression persists or recurs, it may cause damage of the wall of the vein, with resulting scar and\u00a0<em>stenosis<\/em>\u00a0(narrowing) of the vein. Blood clot may form at the damaged area of the vein.<\/p><p>Ultimately, it is the formation of blood clot that creates the most dramatic clinical presentation of venous TOS. Venous compression by itself is necessary but not sufficient to create this dramatic. Damage to the wall of the vein by itself is\u00a0<a href=\"https:\/\/www.tosmri.com\/what-is-thoracic-outlet-syndrome\/\">necessary but not sufficient to create venous TOS<\/a>. As the final step in the process, the formation of blood clot causes partial or complete blockage of venous drainage from the arm. This is the cause of symptoms in venous TOS.<\/p><p>Blood clot in the subclavian vein can break loose and travel through the heart to the pulmonary arteries in the lungs. This\u00a0<em>pulmonary embolism<\/em>\u00a0is rare but potentially life-threatening. To be sure, blood clots in leg veins are more likely to cause pulmonary embolism than blood clots in the subclavian vein. Nonetheless, blood clot in the subclavian vein may cause serious complications if not promptly diagnosed and treated.<\/p><\/div><\/div><\/div><\/div>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-7358c5f elementor-widget-divider--view-line elementor-widget elementor-widget-divider\" data-id=\"7358c5f\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"divider.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-divider\">\n\t\t\t<span class=\"elementor-divider-separator\">\n\t\t\t\t\t\t<\/span>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c9f2489 elementor-widget elementor-widget-heading\" data-id=\"c9f2489\" data-element_type=\"widget\" data-e-type=\"widget\" id=\"toc_Anatomy_of_Venous_Thoracic_Outlet_Syndrome\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Anatomy of Venous Thoracic Outlet Syndrome\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-aa3eabf elementor-widget elementor-widget-text-editor\" data-id=\"aa3eabf\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<div class=\"fusion-text fusion-text-4\"><p>In venous TOS, compression of the subclavian artery occurs in the\u00a0<i>prescalene space<\/i>. To understand venous TOS, it is important to first understand the key anatomic structures of the prescalene space:<\/p><ul><li>The first rib and its cartilage\u00a0<em>(<\/em><em>first\u00a0<\/em><i>costal cartilage)<\/i>\u00a0form the floor of this space. The costal cartilage sits at the anterior aspect of the rib, and attaches to the\u00a0<i>sternum<\/i>\u00a0(breastbone).<\/li><li>The\u00a0<i>clavicle<\/i>\u00a0(collarbone) forms the roof of the prescalene space.<\/li><li>The\u00a0<i>anterior scalene muscle<\/i>\u00a0forms the posterior wall of the prescalene space.<\/li><li>The\u00a0<i>costoclavicular ligament<\/i>\u00a0forms the anterior wall of the prescalene space. This ligament links the costal cartilage to the undersurface of the\u00a0<i>clavicle<\/i>\u00a0(collarbone).<\/li><li>The tendon of the\u00a0<i>subclavius muscle<\/i>\u00a0contributes to the anterior wall and roof of the prescalene space. This muscle arises from the first costal cartilage and extends along the undersurface of the clavicle, towards the shoulder.<\/li><\/ul><\/div>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-40b6eab elementor-widget-divider--view-line elementor-widget elementor-widget-divider\" data-id=\"40b6eab\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"divider.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-divider\">\n\t\t\t<span class=\"elementor-divider-separator\">\n\t\t\t\t\t\t<\/span>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8df9080 elementor-widget elementor-widget-heading\" data-id=\"8df9080\" data-element_type=\"widget\" data-e-type=\"widget\" id=\"toc_Anteroposterior_View_of_the_Prescalene_Space\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Anteroposterior View of the Prescalene Space\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-23ed16b elementor-widget elementor-widget-aic-image-comparison\" data-id=\"23ed16b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"aic-image-comparison.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t        \n        <div id=\"aic-image-comparison-23ed16b\" class=\"aic-image-container\" data-offset=\"0.5\" data-orientation=\"horizontal\" data-before_label=\"Before\" data-after_label=\"After\" data-overlay=\"no\" data-onhover=\"yes\" data-click_to_move=\"no\">\n\t\t\t<img decoding=\"async\" class=\"aic-before-img\" alt=\"Before image alt\" src=\"https:\/\/hlsllc.org\/tos\/wp-content\/uploads\/2026\/04\/Normal-AP-Cropped-Final-2-copy-640.jpeg\">\n\t\t\t<img decoding=\"async\" class=\"aic-after-img\" alt=\"After image alt\" src=\"https:\/\/hlsllc.org\/tos\/wp-content\/uploads\/2026\/04\/Prescalene-Anatomy-AP-Labeled.jpeg\">\n        <\/div>\n\n        \t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0e6d7a3 elementor-widget elementor-widget-text-editor\" data-id=\"0e6d7a3\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<div class=\"fusion-text fusion-text-4\"><div class=\"fusion-text fusion-text-5\"><p>The prescalene space is outlined in lavender.\u00a0<\/p><\/div><\/div>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-dcb606d elementor-widget-divider--view-line elementor-widget elementor-widget-divider\" data-id=\"dcb606d\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"divider.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-divider\">\n\t\t\t<span class=\"elementor-divider-separator\">\n\t\t\t\t\t\t<\/span>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1a03919 elementor-widget elementor-widget-heading\" data-id=\"1a03919\" data-element_type=\"widget\" data-e-type=\"widget\" id=\"toc_Lateral_View_of_the_Prescalene_Space\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Lateral View of the Prescalene Space\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6a26743 elementor-widget elementor-widget-aic-image-comparison\" data-id=\"6a26743\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"aic-image-comparison.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t        \n        <div id=\"aic-image-comparison-6a26743\" class=\"aic-image-container\" data-offset=\"0.5\" data-orientation=\"horizontal\" data-before_label=\"Before\" data-after_label=\"After\" data-overlay=\"no\" data-onhover=\"yes\" data-click_to_move=\"no\">\n\t\t\t<img decoding=\"async\" class=\"aic-before-img\" alt=\"Before image alt\" src=\"https:\/\/hlsllc.org\/tos\/wp-content\/uploads\/2026\/04\/Normal-Lateral-Isolated-Cropped-640.jpeg\">\n\t\t\t<img decoding=\"async\" class=\"aic-after-img\" alt=\"After image alt\" src=\"https:\/\/hlsllc.org\/tos\/wp-content\/uploads\/2026\/04\/Prescalene-Anatomy-Lateral-Labeled.jpeg\">\n        <\/div>\n\n        \t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-4a061d7 elementor-widget elementor-widget-text-editor\" data-id=\"4a061d7\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p>The prescalene space is outlined in lavender.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c96fe56 elementor-widget-divider--view-line elementor-widget elementor-widget-divider\" data-id=\"c96fe56\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"divider.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-divider\">\n\t\t\t<span class=\"elementor-divider-separator\">\n\t\t\t\t\t\t<\/span>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d71a8d7 elementor-widget elementor-widget-heading\" data-id=\"d71a8d7\" data-element_type=\"widget\" data-e-type=\"widget\" id=\"toc_Subclavius_muscle_and_tendon\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Subclavius muscle and tendon\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-fcbf6de elementor-widget elementor-widget-aic-image-comparison\" data-id=\"fcbf6de\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"aic-image-comparison.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t        \n        <div id=\"aic-image-comparison-fcbf6de\" class=\"aic-image-container\" data-offset=\"0.5\" data-orientation=\"horizontal\" data-before_label=\"Before\" data-after_label=\"After\" data-overlay=\"no\" data-onhover=\"yes\" data-click_to_move=\"no\">\n\t\t\t<img decoding=\"async\" class=\"aic-before-img\" alt=\"Before image alt\" src=\"https:\/\/hlsllc.org\/tos\/wp-content\/uploads\/2026\/04\/Grays-Pec-Minor-Subclavius.jpeg\">\n\t\t\t<img decoding=\"async\" class=\"aic-after-img\" alt=\"After image alt\" src=\"https:\/\/hlsllc.org\/tos\/wp-content\/uploads\/2026\/04\/Grays-Pec-Minor-Subclavius-Labeled.jpeg\">\n        <\/div>\n\n        \t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-73ea175 elementor-widget-divider--view-line elementor-widget elementor-widget-divider\" data-id=\"73ea175\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"divider.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-divider\">\n\t\t\t<span class=\"elementor-divider-separator\">\n\t\t\t\t\t\t<\/span>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c7914e3 elementor-widget elementor-widget-heading\" data-id=\"c7914e3\" data-element_type=\"widget\" data-e-type=\"widget\" id=\"toc_Costoclavicular_ligament\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Costoclavicular ligament\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-79e3eae elementor-widget elementor-widget-aic-image-comparison\" data-id=\"79e3eae\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"aic-image-comparison.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t        \n        <div id=\"aic-image-comparison-79e3eae\" class=\"aic-image-container\" data-offset=\"0.5\" data-orientation=\"horizontal\" data-before_label=\"Before\" data-after_label=\"After\" data-overlay=\"no\" data-onhover=\"yes\" data-click_to_move=\"no\">\n\t\t\t<img decoding=\"async\" class=\"aic-before-img\" alt=\"Before image alt\" src=\"https:\/\/hlsllc.org\/tos\/wp-content\/uploads\/2026\/04\/Sobo_1909_192-Costoclavicular-Ligament-Unlabeled.jpeg\">\n\t\t\t<img decoding=\"async\" class=\"aic-after-img\" alt=\"After image alt\" src=\"https:\/\/hlsllc.org\/tos\/wp-content\/uploads\/2026\/04\/Sobo_1909_192-Costoclavicular-Ligament-Labeled-1.jpeg\">\n        <\/div>\n\n        \t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-b8176e3 elementor-widget-divider--view-line_icon elementor-view-default elementor-widget-divider--element-align-center elementor-widget elementor-widget-divider\" data-id=\"b8176e3\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"divider.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-divider\">\n\t\t\t<span class=\"elementor-divider-separator\">\n\t\t\t\t\t\t\t<div class=\"elementor-icon elementor-divider__element\">\n\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-angle-down\" viewBox=\"0 0 320 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M143 352.3L7 216.3c-9.4-9.4-9.4-24.6 0-33.9l22.6-22.6c9.4-9.4 24.6-9.4 33.9 0l96.4 96.4 96.4-96.4c9.4-9.4 24.6-9.4 33.9 0l22.6 22.6c9.4 9.4 9.4 24.6 0 33.9l-136 136c-9.2 9.4-24.4 9.4-33.8 0z\"><\/path><\/svg><\/div>\n\t\t\t\t\t\t<\/span>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-a52a951 e-con-full e-flex e-con e-child\" data-id=\"a52a951\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-373f6e6 e-con-full e-flex e-con e-parent\" data-id=\"373f6e6\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t<div class=\"elementor-element elementor-element-528f3d7 e-con-full e-flex e-con e-child\" data-id=\"528f3d7\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-47a14e2 elementor-widget elementor-widget-heading\" data-id=\"47a14e2\" data-element_type=\"widget\" data-e-type=\"widget\" id=\"toc_Symptoms_of_Venous_Thoracic_Outlet_Syndrome\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Symptoms of Venous Thoracic Outlet Syndrome\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-56f1324 elementor-widget elementor-widget-text-editor\" data-id=\"56f1324\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<div class=\"fusion-title title fusion-title-text fusion-title-size-paragraph\"><div class=\"fusion-text\"><div class=\"fusion-li-item-content\"><div class=\"fusion-text fusion-text-7\"><div class=\"fusion-text fusion-text-7\"><p>Venous blood clot in the arm delays venous blood returning from the arm to the heart. This is the most common cause of venous thoracic outlet syndrome. The venous blood clot creates symptoms of venous thoracic outlet syndrome including arm swelling, tightness, blue or purple discoloration of the affected arm, and new prominent veins of the chest wall. Click through to learn more about the symptoms of venous thoracic outlet syndrome.<\/p><\/div><\/div><\/div><\/div><\/div>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-35a6bdc elementor-widget elementor-widget-button\" data-id=\"35a6bdc\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm\" href=\"https:\/\/hlsllc.org\/tos\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\"> Symptoms of Venous Thoracic Outlet Syndrome<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8511924 elementor-widget-divider--view-line elementor-widget elementor-widget-divider\" data-id=\"8511924\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"divider.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-divider\">\n\t\t\t<span class=\"elementor-divider-separator\">\n\t\t\t\t\t\t<\/span>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-5346e00 elementor-widget elementor-widget-heading\" data-id=\"5346e00\" data-element_type=\"widget\" data-e-type=\"widget\" id=\"toc_Diagnosis_of_Venous_Thoracic_Outlet_Syndrome\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Diagnosis of Venous Thoracic Outlet Syndrome\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ae5c38c elementor-widget elementor-widget-text-editor\" data-id=\"ae5c38c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<div class=\"fusion-text fusion-text-8\"><div class=\"fusion-text fusion-text-8\"><p>Your doctor cannot directly see the venous blood clot in the arm causing venous thoracic outlet syndrome. However, she can observe secondary signs of the venous blood clot, such as distended veins and swelling of the chest or arm. Modern medical imaging tests including ultrasound, CT scan and MRI scan are quite accurate in finding a venous blood clot. Click through to learn more about the\u00a0<a title=\"Thoracic Outlet Syndrome MRI: Diagnosis and Treatment Options\" href=\"https:\/\/www.tosmri.com\/thoracic-outlet-syndrome-mri-diagnosis-and-treatment-options\/\" data-wpil-monitor-id=\"214\">diagnosis of venous thoracic outlet syndrome<\/a>.<\/p><\/div><\/div>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6054cdf elementor-widget elementor-widget-button\" data-id=\"6054cdf\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm\" href=\"https:\/\/hlsllc.org\/tos\/diagnosis-of-venous-thoracic-outlet-syndrome\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Diagnosis of Venous Thoracic Outlet Syndrome<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-fe18ee6 elementor-widget-divider--view-line elementor-widget elementor-widget-divider\" data-id=\"fe18ee6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"divider.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-divider\">\n\t\t\t<span class=\"elementor-divider-separator\">\n\t\t\t\t\t\t<\/span>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0fa390e elementor-widget elementor-widget-heading\" data-id=\"0fa390e\" data-element_type=\"widget\" data-e-type=\"widget\" id=\"toc_Treatment_of_Venous_Thoracic_Outlet_Syndrome\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Treatment of Venous Thoracic Outlet Syndrome\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0c0b6a4 elementor-widget elementor-widget-text-editor\" data-id=\"0c0b6a4\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<div class=\"fusion-text fusion-text-9\"><div class=\"fusion-text fusion-text-9\"><p>Critical treatment decisions center around removal of the venous blood clot in the arm. Severe or total\u00a0<a href=\"https:\/\/www.tosmri.com\/treatment-of-thoracic-outlet-syndrome\/treatment-of-venous-thoracic-outlet-syndrome\/\">venous occlusion demands urgent treatment<\/a>. After doctors remove the venous blood clot in the arm, they are able to address the underlying causes of vein compression and damage. Click through to learn more about the treatment of venous thoracic outlet syndrome.<\/p><\/div><\/div>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1343922 elementor-widget elementor-widget-button\" data-id=\"1343922\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm\" href=\"https:\/\/hlsllc.org\/tos\/treatment-of-venous-tos\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\"> Treatment of Venous Thoracic Outlet Syndrome<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Causes of Venous Thoracic Outlet Syndrome Table of Contents Causes of venous thoracic outlet syndrome are different for each patient Different mechanisms for similar syndromes resulting from venous obstruction Different names for similar syndromes resulting from venous obstruction Anatomy of Venous Thoracic Outlet Syndrome Anteroposterior View of the Prescalene Space Lateral View of the Prescalene [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-20599","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/hlsllc.org\/tos\/wp-json\/wp\/v2\/pages\/20599","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hlsllc.org\/tos\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/hlsllc.org\/tos\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/hlsllc.org\/tos\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/hlsllc.org\/tos\/wp-json\/wp\/v2\/comments?post=20599"}],"version-history":[{"count":18,"href":"https:\/\/hlsllc.org\/tos\/wp-json\/wp\/v2\/pages\/20599\/revisions"}],"predecessor-version":[{"id":21958,"href":"https:\/\/hlsllc.org\/tos\/wp-json\/wp\/v2\/pages\/20599\/revisions\/21958"}],"wp:attachment":[{"href":"https:\/\/hlsllc.org\/tos\/wp-json\/wp\/v2\/media?parent=20599"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}