Impact of Institutional Volume on Outcomes of Catheter Directed Thrombolysis in the Treatment of Acute Proximal Deep Vein Thrombosis: A 6-Year US Experience (2005-2010)

Background-The use of catheter-directed thrombolysis (CDT) in the treatment of acute proximal lower-extremity deep vein thrombosis is increasing in the United States and has been linked to higher bleeding rates. Whether this relationship is interrelated with institution volume of CDT is unknown. Methods and Results-The Nationwide Inpatient Sample database was used to identify all patients admitted with a principal diagnosis of proximal or inferior vena caval deep vein thrombosis and treated with CDT from 2005 to 2010. Institutions were divided into high-volume (≥6 procedures a year) and low-volume (<6 procedures a year) centers. Propensity score matching was used to create 2 matched groups for comparative analysis. A total of 90 618 patients were hospitalized for proximal lower-extremity deep vein thrombosis, and 3649 patients (4.1%) underwent CDT. In-hospital mortality was significantly lower at high-volume centers (0.6% versus 1.5%; P=0.04) with a trend toward lower intracranial hemorrhage rates compared with low-volume centers (0.4% versus 1%; P=0.07). No significant difference was seen with blood transfusion (10.4% versus 10.8%; P=0.70), gastrointestinal bleeding (1.4% versus 1.8%; P=0.35), or pulmonary embolism rates (18.4% versus 17.9%; P=0.72). Median length of stay was similar (6 days) and hospital charges were higher ($65 500 versus $75 870) at high-volume centers. Conclusions-In this observational study, we found that an increase in institutional volume of CDT was associated with lower in-hospital mortality and lower intracranial hemorrhage rates. Further studies are needed to assess whether standardization of CDT protocols across all institutions in the United States improves outcomes.