Extending Blood Clot Prevention Reduces Complications in Breast Reconstruction Patients

• Patients who took an extended course of blood thinners following breast reconstruction surgery had significantly lower rates of deep vein thrombosis and pulmonary embolism compared to those on a shorter regimen.
• Pulmonary embolism rates dropped from 4.9% to 0% by extending medication duration, with no increased risk of bleeding.
• Extended medication was also associated with reduced hospital readmission rates.

PHILADELPHIA (March 24, 2026) - Researchers at Fox Chase Cancer Center have demonstrated that extending postoperative blood clot prevention medication for patients undergoing DIEP flap breast reconstruction significantly reduces the risk of venous thromboembolism (VTE), a potentially life-threatening complication.

The new study represents one of the first institutional efforts to evaluate and standardize this type of preventive protocol specifically for postmastectomy microsurgical breast reconstruction patients. DIEP flap (deep inferior epigastric perforator) is a procedure in which tissue, including skin and fat, is taken from the patient's abdomen and transplanted to the chest to reconstruct the breast following mastectomy.

VTE, which includes deep vein thrombosis (DVT) and pulmonary embolism (PE), causes mortality in approximately 100,000 patients in the United States each year. While the American College of Chest Physicians has issued guidelines recommending an extended 4-week protocol of medication to prevent blood clots for high-risk patients undergoing abdominal or pelvic cancer surgery, patients undergoing postmastectomy microsurgical breast reconstruction are excluded from those recommendations.

Seeking the Best Outcomes

"There are no national guidelines specifically addressing how to manage blood clot prevention for our breast reconstruction patients after they leave the hospital," said Natalia Mejia, MD, a postdoctoral research fellow in the Division of Plastic and Reconstructive Surgery at Fox Chase Cancer Center and first author on the study.

"Every surgeon makes decisions for their patients based on their own training and experience. So, we wanted to take our institutional data and ask: What approach is actually giving our patients the best outcomes?" added Mejia. She conducted the study with senior author Sameer Patel, MD, FACS, Chief of the Division of Plastic and Reconstructive Surgery at Fox Chase, Adam Walchak, MD, Assistant Professor at Fox Chase and Program Director of the Temple University Hospital Plastic Surgery Residency, and other researchers.

Study Finds Risk Reduction, Better Outcomes

• PEs were eliminated. PE rates fell from 4.9% in the cohort that took enoxaparin, a form of heparin, for less than two weeks (short-term) to 0% in the group that took heparin for more than two weeks (extended).
• DVT rates decreased from 2.48% for the short-term group to 1.87% for the extended group.
• The extended protocol did not increase bleeding risk, which is a key concern with longer timelines for anticoagulation therapy. Hematoma rates showed no statistically significant difference between the two groups.
• Rates of flap failure, return to the operating room, and surgical site infection were all lower in the extended prophylaxis group.
• The extended protocol was associated with lower rates of hospital readmission. This is not only a benefit for patients recovering from surgery but also reduces the burden on the healthcare system.

'Very Encouraging' Results

Because the DIEP flap procedure involves both the abdominal donor site and the chest reconstruction site, patients face an elevated risk of VTE during recovery. Preventing blood clots with enoxaparin is standard for these patients, but there is no formalized data-backed guidance for healthcare providers when it comes to how long patients should take the drug.

To investigate this question, the research team examined the records of 358 female patients who underwent DIEP flap reconstruction at Fox Chase and Temple University Hospital between January 2017 and June 2025. Of these, 62 patients received short-term enoxaparin prophylaxis (less than two weeks) and 296 received extended prophylaxis (more than two weeks), with both cohorts treated at 40 mg daily.

"Seeing the pulmonary embolism rate drop to zero in the extended prophylaxis group was very encouraging," said Mejia. "These are patients who have already been through a cancer diagnosis and a major surgery. The last thing we want is for them to face a life-threatening blood clot after they've gone home."

The team believes the approach described in this study could inform protocol development across a broader range of cancer-related reconstructive surgeries.

The study, "Assessing the Impact of Extended Lovenox Prophylaxis on Outcomes Following Postmastectomy Microsurgical Breast Reconstruction," was presented at the Robert H. Ivy Pennsylvania Plastic Surgery Society Annual Meeting, held March 21 in Harrisburg, Pennsylvania.