Aspirin raises bleeding risk in partial nephrectomy

Remaining on preventive antiplatelet therapy with aspirin significantly increases the risk of bleeding complications in patients undergoing partial nephrectomy, according to research presented at the European Association of Urology annual congress in Madrid, Spain.

Madrid, Spain-Remaining on preventive antiplatelet therapy with aspirin significantly increases the risk of bleeding complications in patients undergoing partial nephrectomy, according to research presented at the European Association of Urology annual congress in Madrid, Spain.

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Researchers from Fox Chase Cancer Center, Philadelphia analyzed effects of antiplatelet therapies on perioperative outcomes of partial nephrectomy using data from 754 patients operated on between 2010 and 2013. The cohort was comprised of 26 patients who remained on low-dose aspirin (81 mg) during surgery, 156 patients who had been on chronic antiplatelet therapy but stopped it at least 5 days prior to surgery, and 572 patients who were not on any chronic antiplatelet therapy. Fifteen (58%) of the patients who stayed on aspirin had been using clopidogrel (Plavix) preoperatively, but discontinued it prior to surgery; 77% had a drug-eluting stent and continued its use based on advice from their cardiologist.

Patients who remained on aspirin had a significantly higher rate of bleeding complications compared with their counterparts whose chronic antiplatelet therapy was withheld and those who were never on antiplatelet therapy (11.5% vs. 1.9% and 3.0%, respectively). In a multivariable analysis that controlled for age, American Society of Anesthesiologists classification, gender, race, minimally invasive surgery use, and nephrometry score, ongoing aspirin use independently predicted bleeding complications, increasing the risk 5.5-fold.

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“While our study found an increased rate of bleeding complications when partial nephrectomy was performed on aspirin, this, as in all surgery, must be balanced with the risks associated with stopping aspirin. Patients with drug-eluting stents require long-term antiplatelet therapy due to the risk of in-stent thrombosis, which is a serious and potentially fatal complication. In patients who must remain on aspirin, counseling about the potential risk for increased bleeding after partial nephrectomy is important to manage expectations,” said Timothy Ito, MD, a urologic oncology fellow at Fox Chase.

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“In addition, surgeons should consider the increased risk of bleeding complications in their postoperative follow-up and factor it into their surgical approach so that they may make technique modifications that may limit hemorrhage,” added Dr. Ito, who worked on the study with Serge Ginzburg, MD, and colleagues.

Patients remaining on aspirin older

In the study, patients who remained on aspirin during surgery were significantly older than the other groups, and the patients remaining on aspirin also had a significantly higher ASA classification. The three groups were similar in race distribution, the proportion undergoing minimally invasive versus open partial nephrectomy, and mean nephrometry score.

“We did not include information on heparin use for DVT prophylaxis during surgery, and it is unclear what effect, if any, it might have had on surgical outcomes,” Dr. Ito said.

For the purpose of the study, a bleeding complication was defined as transfusion of >2 units packed red blood cells during the initial hospitalization or any readmission or procedure performed primarily due to hemorrhage. Other outcomes assessed included operative time, estimated blood loss, ischemia time, transfusion rate, length of stay, overall complication rate, and major complication rate (≥Clavien grade III). There were no significant differences between groups for any of those endpoints in the univariate or multivariate analysis.

Dr. Ito and colleagues were interested in investigating potential risks of aspirin use by patients undergoing partial nephrectomy, recognizing the large population of patients with a drug-eluting stent for coronary artery disease who are being maintained on preventive antiplatelet therapy and the lack of published information on this topic.

“There are reports from several robotic prostatectomy series that found perioperative low-dose aspirin did not increase the risk of bleeding. Perhaps the reconstructive nature of partial nephrectomy versus the extirpative nature of robotic prostatectomy may explain why our findings were different,” Dr. Ito said.

A multi-institutional pooled cohort study is being planned to try to validate the results.