24–48 hour preoperative “surveillance” lower extremity venous Doppler's: Aren’t they worthwhile prior to spine surgery?

BACKGROUND: Most previous studies focused on the utility of Doppler surveillance to determine the incidence of deep venous thrombosis (DVT) following spine surgery. Here, we utilized Doppler surveillance to assess the frequency of DVT prior to spine surgery. METHODS: We asked, how often do patients exhibit preoperative DVT? To answer this, for over a 7-month period, bilateral lower extremity venous Doppler's were prospectively obtained 24–48 hours prior to a variety of spinal operations among 45 patients. This did not include an analysis of postoperative venous Doppler's/incidence of pulmonary embolism for these patients. RESULTS: Of the 45 patients, 3 (6.7%) exhibited preoperative positive/abnormal venous duplex studies (unilaterally) that led to cancellation of spinal surgery. One patient, a 56-year-old female, with a C6-C7 cervical disc, demonstrated a proximal right lower extremity DVT; she required full-dose anticoagulation and her surgery was cancelled. In two cases, a 42-year-old female and a 55-year-old male, exhibited DVT in the right posterior tibial and left peroneal veins respectively; both operations were cancelled, and they were placed on anticoagulants by their internists. CONCLUSIONS: Over a 7-month period, prospective “surveillance Dopplers” of both lower extremities obtained 24–48 hours prior to spinal surgery documented 3 (6.7%) positive studies out of a series of 45 patients. One instance of DVT was proximal (e.g. femoral in local) whereas 2 were distal. These data showed that preoperative surveillance Doppler of both lower extremities was “worthwhile.” However, performing these studies earlier than 24-48 hrs prior to surgery would help avoid last minute cancellations.