Physicians performing percutaneous coronary interventions (angioplasty) frequently encounter a number of challenges during the procedure. Among the complications is retroperitoneal hematoma, the pooling of blood just outside the abdominal cavity — a condition associated with high mortality and morbidity. Identifying risk factors for this complication could lead to modifying angioplasty strategies to reduce the chance of occurrence.
Mauro Moscucci, M.D., M.B.A., professor and vice chair of medicine at the Miller School, led a study that has identified the prevalence and risk factors of retroperitoneal hematoma following an angioplasty procedure. Those results are published in the August issue of the Journal of the American College of Cardiology: Cardiovascular Interventions.
The data was compiled from a pool of more than 112, 000 patients who were part of the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2) Registry, and represents the largest experience of retroperitoneal hematoma (RPH) reported. Moscucci is currently consulting co-chair of the Consortium, which he developed in 1997 as a regional collaborative effort to improve quality of care and outcomes for patients who undergo percutaneous coronary intervention (PCI). Each of the patients for this study underwent PCI between October 2002 and December 2007.
Complications related to angioplasty performed through the femoral artery, in the thigh, continue to occur frequently. Detecting and managing issues that develop below the femoral artery are usually quick and are rarely eventful. However, a retroperitoneal hematoma can harbor a large volume of blood with minimal external signs, and it can lead to much more serious outcomes.
Examining the data from this pool of patients, Moscucci and his colleagues identified a clear set of risk factors that appear to predict a greater chance of developing RPH. The research team found that RPH occurred more frequently in women; in patients with a smaller body surface area (<1.8 m2); and in patients with chronic obstructive pulmonary disease. In addition, patients who experienced RPH were more likely to have undergone an emergency procedure, been given the blood thinner heparin or a glycoprotein IIb/IIIa inhibitor prior to the procedure, were more likely to have the arterial entry site treated with a vascular closure device and had angioplasty using a larger sheath size (≥8-F) in the artery.
Moscucci, an interventional cardiologist and chief of the Cardiovascular Division, points out that in-hospital mortality was significantly (6 times) higher in patients who developed RPH, and the length of the hospital stay was significantly longer for that group. “Determining methods to reduce the risk of RPH,” says Moscucci, “is clearly in the best interests of the patient.”
The team found that emergency procedures, the use of IV heparin and overall more aggressive anticoagulation were independently associated with an increased risk for the development of RPH. The data regarding the size of the sheath suggests that using a smaller catheter is preferable, regardless of other factors. Women have different arterial properties than men, including more mobility, which may increase the need for more punctures, in turn, contributing to a higher chance of bleeding. Importantly, the use of devices which have been developed to close the arterial entry site was found to be associated with an increased risk of RPH. This finding further fuels the controversy surrounding the use of these devices.
While more studies are needed, researchers say the risk factors may indicate that angioplasty be performed via the radial artery (wrist) in some high-risk patients. “This study identified specific risk factors,” says Moscucci. “We must continue to narrow down those factors and then adopt new strategies to reduce the occurrence of RPH in high risk patients. In addition, it remains to be determined whether emerging invasive management with covered stents that can seal the arterial laceration can improve survival in patients who develop RPH .”