Patients Have Power to Lower Post-Surgery Clot Risk

Deep vein thrombosis, pulmonary embolism and other blood clot conditions tied to surgery length

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) The risk for blood clots may go up after surgery, but patients can take steps to lower that risk.

A new study tied longer surgery times to a higher rate of blood clot conditions like deep vein thrombosis and pulmonary embolism.

"It makes sense that the study found a higher risk of deep venous thromboses with longer surgical duration," said Sarah Samaan, MD, cardiologist and physician partner at the Baylor Heart Hospital in Plano, Texas. "That's because blood clots are often caused by pooling of the blood. Inactivity is one of the things that causes blood to stagnate. Being in the operating room in one position for hours at a time is the perfect set up. So is prolonged bed rest."

Patients can take several steps to avoid blood clots. Always follow the doctor's orders, take walking breaks during recovery if the doctor says it's OK and know the symptoms of a blood clot, recommends the Agency for Healthcare Research and Quality (AHRQ).

According to the AHRQ, common blood clot symptoms include swelling, red skin, pain, or soreness in the arm or leg. Anyone experiencing these symptoms after surgery should see a doctor right away to receive the proper treatment.

"Walking, when your surgeon clears you to do so, may help to keep the blood moving and thereby reduce the risk of blood clots forming in the legs," said Dr. Samaan, who was not involved in this study.

"Surgery may also increase susceptibility due to other factors that are not well defined. Specifically, it is possible that simply going through the stress and trauma of surgery may produce factors in the blood that increase the risk for blood clots," Dr. Samaan said. "People with cancer are especially prone to blood clots. Dehydration maybe another risk factor. After some surgeries, such as orthopedic operations, the surgeon may actually prescribe a blood thinner for a few weeks to help protect against blood clots. It's important to take these drugs as prescribed."

This new research, which was led by John Y. S. Kim, MD, of the Feinberg School of Medicine at Northwestern University in Chicago, studied whether the length of surgery was tied to a risk of venous thromboembolism.

Venous thromboembolism is a group of blood clot conditions that includes deep vein thrombosis and pulmonary embolism. In deep vein thrombosis, a blood clot develops in a major vein. In pulmonary embolism, the clot moves into the lungs.

Dr. Kim and colleagues looked at data from a total of 1,432,855 patients who underwent surgery.

These patients' data came from 315 different hospitals across the US between 2005 and 2011. These hospitals participated in the American College of Surgeons National Surgical Quality Improvement Program.

Venous thromboembolism that occurred in the 30 days following surgery were recorded, as well as the length of surgery. The patients were divided into five groups based on the length of their procedures.

A total of 13,809 of the patients had venous thromboembolism — only 0.96 percent of the entire group. Dr. Kim and colleagues found that, as length of surgery increased, so did the risk of venous thromboembolism.

When comparing patients with the longest procedures to those with average-length procedures, the patients with the longest surgeries had a 1.27 times greater risk of having a venous thromboembolism.

Dr. Kim and colleagues found that venous thromboembolism and surgery length were linked — not necessarily that one caused the other. Continued research is needed to better understand the relationship between the two issues, they noted.

This study was published Dec. 3 in JAMA Surgery.

The authors disclosed no funding sources or conflicts of interest.

Review Date: 
December 3, 2014
Last Updated:
December 4, 2014