PROSPECTIVE SURVEILLANCE FOR PERIOPERATIVE VENOUS THROMBOSIS - EXPERIENCE IN 2643 PATIENTS

Background: Patients who undergo neurosurgical procedures are at high risk for perioperative deep vein thrombosis (DVT) and pulmonary emboli sm (PE), which have been reported in 6% to 43% of these patients. Obje ctives: To (1) determine the utility of prospective DVT surveillance i n patients who undergo neurosurgical procedures by using venous duplex ultrasound scanning (VDUS), (2) assess the efficacy of DVT prophylaxi s (elastic stockings and intermittent pneumatic compression), (3) iden tify subgroups of patients who are at higher risk, and (4) determine w hether DVT surveillance would reduce the incidence of fatal PE. Design : All patients had undergone preoperative VDUS of both lower extremiti es, and postoperative VDUS was performed on days 3 and 7, and weekly t hereafter until patients were ambulatory or discharged. Patients: Duri ng a 5-year period, 2643 patients who underwent neurosurgical procedur es were enrolled in prospective DVT surveillance. Setting: University- affiliated community hospital. Results: Acute DVT was diagnosed in 147 (5.6%) of the 2643 patients. Eighty-one percent of the patients with acute DVT were asymptomatic at the time of diagnosis. Deep vein thromb osis developed de novo in the proximal veins in 98% of the patients. P atients in whom a craniotomy was done had a significantly higher risk for DVT (7.7%, P = .006),and patients who underwent cervical or lumbar spinal surgical procedures had a significantly lower risk (1.5%, P < .001). Among those patients in whom a craniotomy was performed for tre atment of a tumor and who had DVT, 87% had malignant neoplasms. Signif icant lower-extremity neuromotor dysfunction was present in 69% of all patients with DVT, and this finding predominated among patients with DVT in the subgroups with a lower risk. A PE was diagnosed in 5 patien ts (0.19%) while they were hospitalized, and a PE was fatal in 2 (0.07 % of all patients). Conclusions: Most perioperative DVTs were clinical ly silent and formed spontaneously in proximal venous segments where t here would be a risk for a PE. The overall incidence of DVT (5.6%) was low, suggesting effective DVT prophylaxis. Patients who underwent spi nal surgical procedures were at a significantly lower risk for DVT, an d future surveillance is not indicated in this patient group unless ot her conditions exist (paralysis, malignancy). Patients in whom a crani otomy was performed had a significantly higher risk of DVT, particular ly when other risk factors existed. The low incidence of a fatal PE (0 .07%) reflected that early detection and treatment of proximal DVT wer e facilitated by prospective VDUS surveillance in these patients.