Blood Clots During and After Surgery

Surgeon reaching for surgical scissors in operating room

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Blood clots are a serious complication that surgical patients can experience during and after a procedure. While a blood clot that forms in the leg is a serious condition, blood clots can quickly become life-threatening conditions. These complications are very serious and must be treated quickly to minimize the damage caused to the body.


Common Causes & Risk Factors for Blood Clots

What Causes Blood Clots After Surgery?

A blood clot is more likely to form during or after surgery than it is during your routine day to day life. There are multiple reasons for this, but one major cause is lying still on the operating table for an extended period of time. This inactivity makes it easier for blood to clot because you are not moving. Muscle use typically squeezes blood out of your veins and does not allow it to pool. Pooling blood is what can lead to blood clots forming.

Some people are inactive after their surgery because they are in pain, very sick, or unable to walk. For these patients, the risk of clot formation is increased after the procedure has finished as well as during surgery because they continue to be inactive.

The type of surgery you are having can also increase the risk of having blood clots after the procedure. If your surgery requires your arteries or veins to be cut or repaired, the risk of a blood clot is higher because your body works to stop bleeding by forming clots. If you are having a surgery where your heart is stopped, typically a heart bypass surgery (CABG), your risk of a blood clot is also increased.

Your medical and social history may also contribute to clot formation. For example, if you are a smoker, you are at higher risk for the formation of blood clots than the average individual, even without having surgery.

Risk Factors for Blood Clots After Surgery

  • Atrial Fibrillation: Patients with an irregular heartbeat have an increased risk of forming blood clots.
  • Pregnancy: The chance of blood clots increases as the body makes blood clot faster in preparation for childbirth.
  • Cancer: Some types of cancer make blood clot more easily.
  • History of Blood Clots: If you have had a blood clot in the past, you are more likely to have one in the future.
  • Family History of Blood Clots: If there are multiple people in your family who have experienced blood clots, you may have an inherited tendency to form clots more easily than the average person.
  • Hormone Replacement Therapy (HRT): One known side effect of HRT is the increased risk of forming blood clots.
  • Smoking: Quitting smoking will reduce your risk of forming blood clots after surgery or during your normal day to day life. 
  • Obesity
  • Prolonged Immobility: This includes the time spent under anesthesia and time recovering if you are unable to walk and return to some normal activities.
  • Heart Valve Issues: People with replacement heart valves or heart valve problems have a higher risk of forming clots that can then travel to the lungs or brain.
  • Dehydration: Water is a large component of blood and when there isn't enough, the blood can clot more easily. Drinking adequate water after surgery can help prevent clots from forming.
  • Genetics: If your immediate family is prone to forming clots, you may be as well.

Preventing Blood Clots After Surgery

Getting up and moving during your recovery from surgery is one of the best ways to prevent blood clots. Staying well hydrated by drinking ample amounts of water can also reduce your risk of forming clots. You should also know the signs and symptoms of a blood clot.

In addition to these simple measures, your doctor may also prescribe medication to prevent clots from forming. As always, prevention is better than treatment. Injectable medications — such as Lovenox or Heparin — are very common during a hospital stay after surgery, this medication is given to prevent the formation of a blood clot. It is less commonly prescribed for use at home. 

Treatments for Blood Clots

The treatment for blood clots depends on their location. Coumadin, or the generic warfarin, is given to help the body remove a clot from the bloodstream. Heparin may also be given to prevent additional clots from forming or to prevent clots from growing in size.

Clots that form in the legs are called deep vein thrombosis (DVT) and are the most common type of blood clot after surgery. They have a variety of causes and typically remain in the legs, but can break free and begin to move through the bloodstream. Clots can move from the legs to the lungs and cause a life-threatening condition called a pulmonary embolism. While a pulmonary embolism can be treated, there is a high mortality rate associated with this type of blood clot.

Typically, clots in the legs are treated with medication, but in cases where there is a high risk of the clot moving to the lungs,or there is a contraindication to coagulation, a device called an inferior vena cava filter may be placed. This device acts as a tiny basket, catching clots before they can lodge in the lungs and cause damage. These filters are placed through a small incision in the groin or neck, through which the filter is threaded into place in the inferior vena cava. The filter may be placed temporarily or permanently.

A Word From Verywell

Blood clots after surgery can be a very serious complication. If you experience unexplained pain or a dramatic increase in pain after surgery, particularly in the legs, there could be an issue with blood clots. It is far better to reports the possibility of a blood clot to your care provider than to ignore it and experience a life-threatening issue such as a pulmonary embolism. 

After surgery, safe is always better than sorry, especially when blood clots are a possibility.

Blood Clots Doctor Discussion Guide

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Article Sources
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  1. National Heart Lung and Blood Institute. Venous thromboembolism.

  2. National Blood Clot Alliance. Blood Clot Treatment.