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Archive for the ‘Anatomy’ Category

IVC Filters, May-Thurner Syndrome, Pelvic Vein Stents

| Anatomy, Deep vein thrombosis (DVT), IVC filters, Postthrombotic syndrome, Therapy | Comments Off on IVC Filters, May-Thurner Syndrome, Pelvic Vein Stents

Stephan Moll, MD writes… An article for patients discussing (a) IVC filters (inferior vena cava filters; also often referred to as “Greenfield filters”), (b) narrowing of the main left pelvic vein (referred to as May-Thurner syndrome) and (c) stents in veins in the pelvis has just been published (  Color images are included helping explain what these conditions are.

Reference:  Carroll S, Moll S. Circulation. 2016;133:e383-e387


Last updated: Feb 18th, 2016

DVT in Young Adults – Vena Cava Abnormalities

| Anatomy, Deep vein thrombosis (DVT), Young adults and blood clots | Comments Off on DVT in Young Adults – Vena Cava Abnormalities

Dr. Stephan Moll writes…..

When a young person is diagnosed with extensive pelvic DVT or a clot in the big vein in the abdomen, the inferior vena cava (IVC), it is worthwhile to ask whether that person has some congenital abnormality of the IVC, such as a congenital absence or narrowing of the IVC Read the rest of this entry »

PFO = Patent Foramen Ovale

| Anatomy, Arterial clots, Deep vein thrombosis (DVT), Diagnosis, Medical tests | 1 Comment »


Some people have a “hole in the heart”, called a “patent foramen ovale” (PFO). This is a connection between the right and the left chamber (atrium) of the heart. We are all born with it – the unborn needs this connection for proper blood circulation. In most people the hole closes in the first few weeks after birth. However, in up to 25 % of people it stays open, equally often in men and women. A PFO usually does not cause symptoms. However, when a person has an acute DVT (deep vein thrombosis) and a clot breaks off and travels with the blood stream, it may cause problems.

DVT and PE in the person without PFO

In the person who does not have a PFO, a clot that breaks off from a DVT travels with the blood stream through the main vein in the abdomen to the chambers of the right side of the heart (color blue in figure 1 and 2). From there, it travels into the lung vessels, where it gets lodged, causing a pulmonary embolism (figure 1).

Figure 1. DVT and PE, no PFO present (graphic design: Jeff Harrison, Wilmington, NC; ©Stephan Moll)

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Arm and Leg Veins – Anatomy and Terminology

| Anatomy, Deep vein thrombosis (DVT), Superficial blood clots (superficial thrombophlebitis) | Comments Off on Arm and Leg Veins – Anatomy and Terminology

Confusion as to which veins of arms and legs are superficial and which are deep can lead to an incorrect diagnosis. As treatment of clots in superficial veins (= superficial thrombophlebitis) is different to that of clots in deep veins (DVT = deep vein thrombosis), the distinction between superficial and deep veins is important. Read the rest of this entry »

May-Thurner Syndrome

| Anatomy, Deep vein thrombosis (DVT) | 18 Comments »


Some people have a narrowing of their big left pelvic vein (= left common iliac vein) that can put them at risk for a blood clot (deep vein thrombosis = DVT) in that area and in the left leg. The narrowing is due to pressure onto the vein by the overlying big pelvic artery (= right common iliac artery), shown on image 1 . This condition is called May Thurner syndrome. Read the rest of this entry »