Groin collections are common because the groin is where many procedures are done through the femoral artery and vein, like coronary angiograms. Groin collections also encompass collections found throughout the body. When we say fluid collection, it implies a organized collection of fluid of various consistencies. The groin is the area where the thigh meets the abdomen to the right and left side of midline.
The fluid can be simple, bloody, Or full of pus. Collections after procedures done through the femoral artery are common. There can be some blood in the region or an injury to the blood vessel wall causing what we call a pseudoaneurysm. There is injury to the vessel wall, with blood extending into the adjacent tissues. This needs to be promptly recognized and treated.
I see collections after biopsies and surgeries to the inguinal or groin region. This usually looks organized and either simple fluid or blood. It is not possible to say whether the collection is infected based on imaging. Often these collections will decrease in size over time. There will usually be a history of a procedure tot the area.
Groin collections can also be infected or represent abscesses. Abscesses are collections of infected fluid and pus. On imaging, they are organized thick walled and often have bubbles of gas inside. A groin abscess can occur from prior procedures or surgery to the area. An abscess may also form from soft tissue infections in the area. Abscesses are treated with antibiotics and drainage.
Groin fluid collections can also occur from trauma. These are often bloody. Active bleeding can be identified on a CT done after giving contrast through the vein. Active bleeding will show the contrast spilling into the tissues next to the vessel and blood. In these cases, this may need to be treated urgently to prevent continued bleeding.
Groin fluid collections are often imaged using either ultrasound or CT. Both can be used to guide treatment and drainage if necessary. Groin collections may need to be sampled when infection is suspected. Abscesses will often be drained. Groin collections which represent active bleeding or pseudoaneurysms from vessel wall injury will need to be treated urgently.