The purpose of this study is to determine how frequently children undergoing elective neurosurgical procedures develop blood clots in the deep veins of the legs while hospitalized. The information gained from this study will help us determine when children children need to receive therapy to help prevent this type of blood clot from forming.

Inclusion Criteria:

• Patients age 1 month-12 years undergoing elective neurosurgical procedures.

Exclusion Criteria:

• Patients undergoing outpatient neurosurgical procedures
• Patients with known DVT
• Patients with known hypercoagulable state
• Patients at high risk for DVT (discretion of surgeon in consultation with the hematology service)

100 children between the ages of 1 month-12 years having an elective neurosurgical procedure at James Whitcomb Riley Hospital for Children.

91 subjects received study procedures and were analyzed. 9 additional subjects were consented but withdrawn prior to completion of study procedures.

Adverse event data was not collected as this was a minimal risk study

All-Cause Mortality, Serious, and Other (Not Including Serious) Adverse Events were not monitored/assessed