Thromboembolic Complications Following Spine Surgery Assessed with Spiral CT Scans

Spine surgery is associated with a significant risk of postoperative pulmonary embolism (PE) and/or deep vein thrombosis (DVT). The goal of this study was to determine which symptoms and risk factors were associated with spiral CT scans positive for PE and/or DVT in the postoperative spine surgery patient. We conducted a retrospective review of all spine patients who underwent a postoperative CT to rule out PE during the period of March 2004–February 2006. The type of surgical procedure, risk factors, symptoms prompting scan ordering, anticoagulation, and treatment were recorded. Logistic regression models were used to determine significant predictors of a positive CT in this patient population. Of the 3,331 patients that had spine surgery during the study period, 130 (3.9%) had a spiral CT scan to rule out PE and/or proximal DVT. Thirty-three of the 130 (25.4%) CT scans were positive for PE only, five (3.8%) for PE and DVT, and three (2.3%) for DVT only. Only 24.5% (32) patients had risk factors for thromboembolic disease, and of these, a history of PE and/or DVT was the only significant risk factor for a positive scan (p = 0.03). No presenting symptoms or demographic variables were noted to have a significant association with PE and/or DVT. The type of surgical procedure (i.e., anterior, posterior, and percutaneous) was not associated with an increased risk for PE and/or DVT. Patients who are undergoing spine surgery with a history of thromboembolic disease should be carefully monitored postoperatively and may benefit from more aggressive prophylaxis.     

Is repeated head computed tomography necessary for traumatic intracranial hemorrhage?

This study was performed to determine the need for repeat head computed tomography (CT) in patients with blunt traumatic intracranial hemorrhage (ICH) who were initially treated nonoperatively and to determine which factors predicted observation failure or success. A total of 1,462 patients were admitted to our level II trauma center for treatment of head injury. Seventeen per cent (255/1,462) were diagnosed with ICH on initial head CT. Craniotomy was initially performed in 15.7 per cent (40/255) of patients with ICH. Two hundred sixteen patients with ICH were initially observed. Ninety-seven per cent (179/184) of observed patients with ICH and repeat head CT never underwent a craniotomy, 2.7 per cent (5/184) of patients with ICH initially observed underwent craniotomy after repeat head CT, and four patients (80%) had deteriorating neurologic status. Multivariate analysis revealed the following significant admission risk factors were associated with a need for repeat head CT indicating the need for craniotomy: treatment with anticoagulation and/or antiplatelet medications, elevated prothrombin time (PT), and age greater than 70 years. In patients with blunt traumatic intracranial hemorrhage initially observed, there is little utility of repeated head CT in the absence of deteriorating neurologic status. The only admission risk factors for a repeat CT indicating the need for craniotomy were advanced age and coagulopathy.     

Treatment of patients with venous thromboembolism and malignant disease: Should vena cava filter placement be routine?

Purpose: It has been proposed that inferior vena cava filter placement should be the initial treatment of deep venous thrombosis (DVT) or pulmonary embolus (PE) in patients with coexisting malignant disease. We have chosen instead to selectively place filters only in patients with either a contraindication to anticoagulation therapy or a subsequent complication from anticoagulation therapy. The treatment efficacy and mortality rates in patients with concomitant malignant disease and venous thromboembolism using this approach was determined. Methods: We retrospectively reviewed all patients at our institution with malignant disease in whom venous thromboembolism developed between August 1991 through August 1996 and identified 166 patients with PE (n = 8), DVT (n = 147), and DVT/PE (n = 11). Of these patients, 138 (83.1%) were initially treated with anticoagulation therapy, and 28 (16.9%) had primary filter placement because of contraindications to anticoagulation therapy (10 for intracranial tumors, 11 for recent or upcoming operations, 6 for recent hemorrhage, and 1 for a malignant bloody pericardial effusion). Results: Thirty-two (23%) of the 138 patients who initially underwent anticoagulation therapy subsequently required a filter for the following reasons: bleeding (n = 15, 10.9%); recurrent thromboembolism (n = 6, 4.3%); heparin-induced thrombocytopenia (n = 1, 0.7%); and perceived high risk for bleeding with continued anticoagulation therapy (n = 11, 8%). Both bleeding and recurrent thromboembolism developed in 1 patient. Sixty patients (36%) received filters. No major technical complications occurred from filter placement. Major recurrent thromboembolic complications developed in 10 patients: DVT (n = 6, 10%), PE (n = 2, 3.3%), inferior vena cava thrombosis and phlegmasia cerulea dolens (n = 1, 1.7%), superior vena cava thrombosis (n = 1, 1.7%). Venous gangrene developed in 1 patient with DVT. The 1-year actuarial survival rates for patients treated with filter and anticoagulation therapy were 35% and 38%, respectively (P = NS). Conclusion: In summary, our experience suggests that 64% of patients with malignant disease and venous thromboembolism are effectively treated with anticoagulation alone; 17% require primary filter placement for standard indications, and an additional 19% require subsequent filter placement because of complications (primarily bleeding) or failure of anticoagulation therapy. Although technical complications of filter placement are low, serious life-threatening or limb-threatening thromboembolic complications developed in 17% of patients. Survival was poor in all patients, regardless of treatment. These data support a conservative approach of routine anticoagulation therapy with selective filter placement. (J Vasc Surg 1998;28:800-7.)     

A potentially expanded role for enoxaparin in preventing venous thromboembolism in high risk blunt trauma patients

BACKGROUND: Venous thromboembolism (VTE) is a frequent and potentially life-threatening complication after trauma. The purpose of this study is to investigate the effectiveness of enoxaparin in preventing deep venous thrombosis (DVT) and pulmonary embolism (PE) after injury in patients who are at high risk for developing VTE. STUDY DESIGN: A prospective single-cohort observational study was initiated for seriously injured blunt trauma patients admitted to a Level I trauma center during a 7-month period. Patients were eligible for the study if time hospitalized was > or = 72 hours, Injury Severity Score (ISS) was > or = 9, enoxaparin was started within 24 hours after admission, and one or more of the following high risk criteria were met: age > 50 years, ISS > or = 16, presence of a femoral vein catheter, Abbreviated Injury Score (AIS) > or = 3 for any body region, Glasgow Coma Scale (GCS) Score < or = 8, presence of major pelvic, femur, or tibia fracture, and presence of direct blunt mechanism venous injury. Patients with closed head injuries and nonoperatively treated solid abdominal organ injuries were also potential participants. The primary outcomes measured were thromboembolic events--either a documented lower extremity DVT by duplex color-flow doppler ultrasonography or a PE documented by rapid infusion CT pulmonary angiography or conventional pulmonary angiography. RESULTS: There were 118 patients enrolled in the study. Two patients (2%) developed DVT, one of which was proximal to the calf (95% confidence interval, 0% to 6%). Two of 12 patients (17%) with splenic injuries who received enoxaparin failed initial nonoperative management. There were no other bleeding complications, and no clinical evidence or documented episodes of PE. One patient died from multiple system organ failure. CONCLUSIONS: Enoxaparin is a practical and effective method for reducing the incidence of VTE in high risk, seriously injured patients. This study supports further investigation into the safety of enoxaparin prophylaxis in patients with closed head injuries and nonoperatively treated solid abdominal organ injuries.     

Prophylactic and therapeutic inferior vena cava filters to prevent pulmonary emboli in trauma patients

HYPOTHESIS: Insertion of inferior vena cava filters (IVCFs) can prophylactically reduce pulmonary embolism (PE) in trauma patients. DESIGN: Retrospective review. SETTING: Urban, level I trauma center. PATIENTS: Two hundred blunt trauma patients undergoing IVCF placement. INTERVENTIONS: In 122 patients who had already been diagnosed as having deep vein thrombosis (DVT) (112 patients) and/or PE (22 patients), the insertion of the IVCF was considered "therapeutic." In 78 patients who had no evidence of DVT or PE but who were considered to be at high risk for a PE, the IVCF was considered "prophylactic." MAIN OUTCOME MEASURES: Incidence of PE and related mortality and morbidity in therapeutic vs prophylactic IVCFs. RESULTS: The number of prophylactic IVCFs inserted increased significantly from only 4% (3/68 cases) from 1991 through 1996, up to 57% (75/132 cases) from 1997 to June 2001. Although the mean +/- SD age (51 +/- 20 years vs 41 +/- 15 years; P<.001) was higher in the therapeutic group, there was no difference in the mean +/- SD Injury Severity Scores (20 +/- 12 vs 21 +/- 11). Therapeutic filters were placed much later after injury (mean +/- SD time, 11 +/- 7 vs 3 +/- 2 days; P<.001). The mortality rate was 11% (13/122 patients) in patients having a therapeutic IVCF, as compared with only 3% (2/78 patients) in those placed prophylactically (P =.07). None of the patients who had placement of a prophylactic IVCF developed subsequent PE. The incidence of PE decreased in all blunt trauma patients from 0.29% before 1997 to 0.15% after January 1, 1997, when 57% of the IVCF inserted were prophylactic (P =.06). CONCLUSIONS: Prophylactic IVCFs should be inserted within 48 hours of injury in specific trauma patients at high risk for PE and with contraindications to anticoagulation.     

Detection of Pulmonary Embolism in the Postoperative Orthopedic Patient Using Spiral CT Scans

Orthopedic surgery is associated with a significant risk of postoperative pulmonary embolism (PE) and/or deep vein thrombosis (DVT). This study was performed to compare the clinical presentations of a suspected versus a documented PE/DVT and to determine the actual incidence of PE/DVT in the post-operative orthopedic patient in whom CT was ordered. All 695 patients at our institution who had a postoperative spiral CT to rule out PE/DVT from March 2004 to February 2006 were evaluated and information regarding their surgical procedure, risk factors, presenting symptoms, location of PE/DVT, and anticoagulation were assessed. Statistical analysis was performed using an independent samples t test with a two-tailed p value to examine significant associations between the patient variables and CT scans positive for PE. Logistic regression models were used to determine which variables appeared to be significant predictors of a positive chest CT. Of 32,854 patients admitted for same day surgery across all services, 695 (2.1%) had a postoperative spiral CT based on specific clinical guidelines. The incidence of a positive scan was 27.8% (193/695). Of these, 155 (22.3%) scans were positive for PE only, 24 (3.5%) for PE and DVT, and 14 (2.0%) for DVT only. The most common presenting symptoms were tachycardia (56%, 393/695), low oxygen saturation (48%, 336/695), and shortness of breath (19.6%, 136/695). Symptoms significantly associated with DVT were syncope and chest pain. A past medical history of PE/DVT was the only significant predictor of a positive scan. Patients who have a history of thromboembolic disease should be carefully monitored in the postoperative setting.     

Routine prophylactic vena cava filtration is not indicated after acute spinal cord injury

BACKGROUND: Acute spinal cord injury (SCI) is a devastating problem, with over 10,000 new cases annually. Pulmonary embolism (PE) is a well-recognized risk in SCI patients, although no clear recommendations for prophylaxis exist. We therefore evaluated whether routine placement of prophylactic inferior vena cava filters is indicated in SCI patients. METHODS: The trauma registry of a regional trauma center was used to identify patients sustaining acute SCI resulting in tetraplegia or paraplegia after blunt or penetrating trauma for a 5-year period beginning in January 1995. Patients were analyzed for demographics, mechanism of injury, Injury Severity Score, associated long bone or pelvic fracture, severe closed-head injury, type of deep venous thrombosis (DVT) prophylaxis, level of SCI, and incidence of DVT and PE. DVT prophylaxis was performed in all patients with sequential compression devices (SCDs) when extremity fracture status permitted. Data are expressed as mean +/- SD and analyzed using Fisher's exact test. RESULTS: There were 8,269 admissions during the study period, with an overall incidence of DVT and PE of 11.8% and 0.9%, respectively. There were 111 (1.3%) patients who sustained SCI, with an incidence of DVT and PE of 9.0% and 1.8%, respectively, and no deaths. Of these 111 patients, 41.4% were paraplegics and 58.6% were tetraplegics, and 17.1% of patients had severe closed-head injury. Mean hospital length of stay was 23 +/- 20 days for SCI patients. Surveillance duplex ultrasound was performed an average of 2.3 +/- 2.1 times during each hospitalization. Mean Injury Severity Score was 30.0 +/- 12.2. The incidence of DVT and PE in those patients with SCDs alone was 7.1% and 2.3%; for SCDs plus subcutaneous heparin, the incidence was 11.1% and 2.8%; and for SCDs plus low-molecular-weight heparin, the incidence was 7.4% and 0%, respectively, with no statistical difference between groups. The incidence of DVT in SCI patients with long bone fractures was 37.5%, which was significantly greater than the total SCI population (p < 0.02). CONCLUSION: The incidence of DVT and PE in SCI patients was similar to that of the overall trauma population when appropriate DVT prophylaxis was used. Subgroup analysis demonstrated that SCI associated with long bone fracture significantly increases the incidence of DVT. On the basis of the low incidence of PE in the present study, routine placement of prophylactic caval filters does not appear warranted in all SCI patients. However, SCI patients with long bone fractures, patients with DVT formation despite prophylactic anticoagulation, or patients with contraindications to anticoagulation may be appropriate candidates for prophylactic caval filtration.     

Effects of recombinant activated factor VII in traumatic nonsurgical intracranial hemorrhage

OBJECTIVE: To determine whether treatment with recombinant activated factor VII (rFVIIa) will prevent progression of bleeding in nonsurgical hemorrhagic traumatic brain injury (TBI). METHODS: Chart review from the trauma registry of a level 1 trauma center between January 1, 2002 and December 31, 2004 identified 2 patients who received rFVIIa for progressive hemorrhagic TBI. These patients were given a single dose of rFVIIa (120 mcg/kg) after a repeat head computed tomography (CT) scan showed worsening of intracranial bleeding. Pre-rFVIIa and post-rFVIIa coagulation parameters and postintervention CT scans were performed. A matched convenience sample was drawn from the institution's trauma registry reflecting similar injury patterns. RESULTS: The 2 patients who received rFVIIa were ages 61 and 79 years; the patients in the matched convenience sample were 57 and 63 years. Both sets of patients comprised 1 man and 1 woman who had suffered blunt trauma, including hemorrhagic TBI, and were matched according to age, gender, and injury severity score (ISS). During their hospital course, repeat CT scans documented worsening of intracranial hemorrhage in both cohorts. In the rFVIIa patients, follow-up CT showed overall improvement of head injury compared with the convenience sample. The rFVIIa patients also saw an appreciable decrease in both prothrombin time (PT) and international normalized ratio (INR). CONCLUSIONS: In hemorrhagic TBI, rFVIIa has the potential to limit or even halt the progression of bleeding that would otherwise place growing pressure on the brain. A prospective, randomized multicenter trial is planned to elucidate this hypothesis.     

Prospective evaluation of the safety of enoxaparin prophylaxis for venous thromboembolism in patients with intracranial hemorrhagic injuries

BACKGROUND: Patients with traumatic intracranial hemorrhagic injuries (IHIs) are at high risk for venous thromboembolism (VTE). The safety of early anticoagulation for IHI has not been established. HYPOTHESIS: Enoxaparin can be safely administered to most patients with IHI for VTE prophylaxis. SETTING: Level I trauma center. DESIGN: Prospective, single-cohort, observational study. PATIENTS AND METHODS: One hundred fifty (85%) of 177 patients with blunt IHI received enoxaparin beginning approximately 24 hours after hospital admission until discharge. Brain computed tomographic (CT) scans were performed at admission, 24 hours after admission, and at variable intervals thereafter based on clinical course. Patients were excluded for coagulopathy, heparin allergy, expected brain death or discharge within 48 hours, and age younger than 14 years. Complications of enoxaparin prophylaxis were defined as Marshall CT grade progression of IHI, expansion of an existing IHI, or development of a new hemorrhagic lesion on follow-up CT after beginning enoxaparin use. RESULTS: Thirty-four patients (23%) had CT progression of IHI. Twenty-eight CT scans (19%) worsened before enoxaparin therapy and 6 (4%) worsened after beginning enoxaparin use. No differences between operative patient (2/24, 8%) and nonoperative patient (4/126, 3%) complications were identified (P =.23). Study group mortality was 7% (10/150). All 6 patients who developed progression of IHI after initiation of enoxaparin therapy survived hospitalization. A deep vein thrombosis was identified in 2 (2%) of 106 patients. CONCLUSION: Enoxaparin can be safely used for VTE prophylaxis in trauma patients with IHI when started 24 hours after hospital admission or after craniotomy.     

Incidence of asymptomatic pulmonary embolism in moderately to severely injured trauma patients

BACKGROUND: Chest computed tomographic (CT) scanning is used frequently to evaluate symptomatic patients for pulmonary embolus (PE). The incidence of PE diagnosed by helical CT scanning in asymptomatic patients is unknown. METHODS: Asymptomatic trauma patients with an Injury Severity Score > or = 9 were studied with contrast-enhanced helical CT images of the chest, pelvis, and lower extremities. Clot burden was assessed using an anatomic scoring system. Patients not receiving anticoagulation were followed. RESULTS: Twenty-two of 90 patients had a PE. Four had major clot burden, including one patient with a saddle embolus. Risk factors for asymptomatic PE include age (odds ratio [OR], 1.04), head injury (OR, 6.78), chest injury (OR, 4.51), lower extremity injury (OR, 5.03), and transfusion (OR, 3.42). Thirty percent of patients receiving pharmacologic prophylaxis had a PE. CONCLUSION: Asymptomatic PE occur in 24% of moderately to severely injured patients. Age, head, chest, and lower extremity injury are associated with an increased risk. Standard thromboembolic prophylaxis is not reliably protective.     

Treatment of trauma patients with intracranial hemorrhage on preinjury warfarin

BACKGROUND: Preinjury warfarin anticoagulation has been shown to increase the mortality of traumatic intracranial hemorrhage. We have evaluated the impact on patient mortality of the rapid triage of patients at risk for warfarin associated traumatic intracranial hemorrhage. METHODS: A "Coumadin Protocol" was implemented in January, 2001 in the Emergency Department that expedited triage of anticoagulated trauma patients to immediate physician evaluation. Patient outcomes during a 2 year period were compared with a matched control group of similarly injured, anticoagulated patients who were treated before protocol initiation. RESULTS: Thirty-five patients were treated after implementation of the Coumadin Protocol. Mean time until warfarin reversal was 4.3 +/- 4.4 hours, and there was a 37% mortality. Twenty-two control patients had a mean time to reversal of 4.2 +/- 2.9 hours, with a 45% mortality (p = 0.610). Ten protocol patients were shown to have intracranial hemorrhage progression by computed tomography (CT) scan, with a 60% mortality rate. Seventeen patients had follow-up CT scan and showed no progression; only one of these patients (6%) died (p = 0.004). Hemorrhage severity based on the initial CT scan did not predict mortality or hemorrhagic progression. CONCLUSIONS: We conclude from these data that a trauma center protocol for rapid identification of intracranial bleeding without a concomitant therapeutic protocol does not improve survival in head injured patients on preinjury warfarin.     

Utility of Once-Daily Dose of Low-Molecular-Weight Heparin to Prevent Venous Thromboembolism in Multisystem Trauma Patients

Introduction Venous thromboembolism is a preventable cause of death in the severely injured patient. Low-molecular-weight heparins (LMWHs) have been recommended as effective, safe prophylactic agents. However, LMWH use remains controversial in patients at risk for bleeding, those with traumatic brain injury, and those undergoing multiple invasive or operative procedures. We hypothesized that a protocol utilizing once-daily LMWH prophylaxis in high-risk trauma patients, regardless of the need for invasive procedures, is feasible, safe, and effective. Methods From August 1998 to August 2000, all patients admitted to our American College of Surgeons-verified Level I trauma facility following injury were evaluated for deep venous thrombosis (DVT) risk and prospectively followed. Patients at high risk for DVT, including those with stable intracranial injuries, were placed on our institutional protocol and prospectively followed. Patients on the protocol received daily injections of the LMWH, dalteparin; DVT screening was performed with duplex ultrasonography within 48 hours of admission and after 7 to 10 days after injury. Regimen compliance, bleeding complications, DVT rates, and pulmonary embolus (PE) rates were analyzed. Results During the 2-year study period, 6247 trauma patients were admitted; 743 were considered at high risk for DVT. Most of the patients were men (72%), with a mean age of 38.7 years (range 15–89 years) and a mean injury severity score (ISS) of 19.5. Compliance with the daily regimen was maintained in 74% of patients. DVT was detected in 3.9% and PE in 0.8%. The wound complications rate was 2.7%, and the need for unexplained transfusions was 3%. There were no exacerbations of head injury following dalteparin initiation due to bleeding. There were 16 patient deaths; none was caused by PE or late hemorrhage. Conclusions Once-daily dosing of prophylactic LMWH dalteparin is feasible, safe, and effective in high-risk trauma patients. Our protocol allows one to “operate through” systemic prophylaxis and ensures timely prophylaxis for brain-injured and multisystem trauma patients.     

Early experience with retrievable inferior vena cava filters in high-risk trauma patients

BACKGROUND: This study describes the use of retrievable IVC filters in a select group of trauma patients at high risk for deep vein thrombosis (DVT) and pulmonary embolism (PE). STUDY DESIGN: Retrievable IVC filters were placed in selected trauma patients who met high-risk criteria for deep vein thrombosis and PE according to institutional clinical management guidelines. All filters were placed percutaneously in the interventional radiology suite. Indications for filter placement were based on injury complex, weight-bearing status, and contraindications to enoxaparin or pneumatic compression devices. IVC filters were either removed or maintained. RESULTS: Retrievable IVC filters were placed in 35 patients after blunt trauma. Twenty-six patients (74%) sustained at least one orthopaedic injury; 17 patients (49%) were diagnosed with a pelvis fracture. Activity was limited to bed rest or spinal precautions in 18 patients (51%). Enoxaparin was contraindicated in 32 patients (91%) and injuries precluded the use of pneumatic compression devices in 11 (31%). IVC filters were removed in 18 patients (51%), with no reported complications. Patients with orthopaedic injuries and pelvis fractures were less likely to have their filters maintained (p = 0.040). CONCLUSIONS: Retrievable IVC filters offer a versatile option for prophylaxis in trauma patients at high risk for PE. Filter retrieval potentially spares the longterm complications of permanent filters in younger trauma patients. Retrievable filters warrant consideration in patients who meet high-risk criteria for deep vein thrombosis or PE who cannot receive effective mechanical prophylaxis and in whom contraindications to anticoagulation are expected to be temporary.     

Predictive factors of thromboembolic events in patients undergoing Roux-en-Y gastric bypass.

BACKGROUND: Obesity is a major risk factor for postoperative deep venous thrombosis (DVT) and pulmonary embolism (PE). Identifying those patients at the greatest risk for DVT/PE is essential to prevent thromboembolic events among patients undergoing Roux-en-Y gastric bypass (RYGB) for clinically significant obesity. This aim of the study is to identify factors associated with an increased likelihood of developing DVT/PE after RYGB. METHODS: Prospectively collected data from 660 consecutive patients who underwent RYGB were reviewed. Patients received perioperative prophylaxis with low molecular weight heparin and sequential compression devices. Diagnosis was based on clinical, radiologic, and/or necropsy findings. Patients with and without postoperative DVT/PE were compared using chi(2) and multivariate logistic regression analysis. RESULTS: A total of 23 patients (3.5%) developed postoperative DVT/PE. Age > 50 years (P = .04), previous DVT/PE (P = .02), history of smoking (P < .01), revisional operation (P = .03), open RYGB (P = .02), and anastomotic leak (P < .0001) significantly increased the likelihood of developing DVT/PE. On the other hand, gender, body mass index > 50 kg/m(2) and history of sleep apnea, hypertension, diabetes, or myocardial infarction did not increase the likelihood of DVT/PE. Multivariate analysis revealed that age > 50 years (P = .04), postoperative anastomotic leak (P < .001), smoking (P < .01), and previous DVT/PE (P < .001) increased the likelihood of postoperative DVT/PE. CONCLUSIONS: Age > 50 years, anastomotic leak, smoking, and history of DVT/PE all increase the likelihood of postoperative thromboembolic events in patients undergoing RYGB. Further preoperative screening and/or postoperative prophylaxis may be needed in this subset of high-risk patients.     

Postoperative low-dose heparin decreases thromboembolic complications in neurosurgical patients.

Thromboembolic complications are a major cause of postoperative morbidity and mortality in the neurosurgical patient. Prophylaxis with lower extremity pneumatic compression boots (PCBs) reduces the incidence of lower extremity deep vein thrombosis (DVT) but has not been shown to affect the incidence of pulmonary embolism (PE). Prophylaxis with low-dose heparin has consistently reduced the incidence of both DVT and PE in studies on general surgical patients but has not been adopted for use in neurosurgery primarily for fear of causing catastrophic hemorrhage. We report on a series of 138 consecutive adult patients who underwent major neurosurgical procedures on a general neurosurgical service at our institution. Patients were treated with intraoperative PCBs and, starting on the morning of the first postoperative day, with a regimen of 5000 U of heparin administered subcutaneously twice daily. This treatment was continued until patients were fully ambulatory. PCBs were discontinued 24 hours after the first administration of heparin. None of the heparin-treated patients suffered postoperative hemorrhage. We compared this series with a control group of 473 adult patients who had previously undergone major neurosurgical procedures on the same neurosurgical service. These patients had been treated with intraoperative and postoperative PCBs alone. The control group had a 3.2% incidence of thromboembolic complications (15 of 473; eight DVT, seven PE). Prophylaxis with PCBs plus heparin significantly (P = 0.020) reduced the incidence of thromboembolic complications: no PCBs/heparin-treated patient exhibited clinical evidence of PE or DVT (0%, 0/138). We conclude that a combination of intraoperative PCBs and postoperative low-dose heparin is a safe and effective method by which to reduce thromboembolic complications in the neurosurgical patient.     

Celiac dissection after blunt abdominal trauma complicated by acute hepatic failure: case report and review of literature

Injuries of the abdominal visceral vessels are uncommon but devastating entities resulting in extremely high rates of mortality. The most common cause of abdominal vascular injuries is penetrating trauma, accounting for 90% to 95% of these injuries. In contrast, blunt trauma accounts for 5% to 10% of all abdominal vascular lesions. Although traumatic injury to the celiac artery is among the rarest of all vascular injuries, mortality can be as high as 75%. We report a 66-year-old patient who sustained multiple injuries in a motor vehicle crash. The initial whole-body computed tomography (CT) scan revealed a combination of severe brain injury and bilateral thoracic lesions. On day 6 after the accident, the patient's clinical situation deteriorated rapidly. At this time, the abdominal arterial CT scan showed a dissection of the celiac artery. Therapeutic anticoagulation was not feasible because of the intracranial hemorrhage. Also the patient's clinical situation worsened so rapidly that interventional therapy, including surgical and endovascular treatment, could not be performed. Finally, the patient died of fulminant hepatic failure, therefore not surviving a potentially treatable injury. The diagnosis of celiac artery dissection in this patient was significantly delayed because the initial trauma CT protocol did not include an arterial phase of the abdominal vessels.     

Incidence and management of pulmonary embolism following spinal surgery occurring while under chemical thromboprophylaxis

Patients undergoing spinal surgery are at risk of developing thromboembolic complications even though lower incidences have been reported as compared to joint arthroplasty surgery. Deep vein thrombosis (DVT) has been studied extensively in the context of spinal surgery but symptomatic pulmonary embolism (PE) has engaged less attention. We prospectively followed a consecutive cohort of 270 patients undergoing spinal surgery at a single institution. From these patients, only 26 were simple discectomies, while the largest proportion (226) was fusions. All patients received both low molecular weight heparin (LMWH) initiated after surgery and compressive stockings. PE was diagnosed with spiral chest CT. Six patients developed symptomatic PE, five during their hospital stay. In three of the six patients the embolic event occurred during the first 3 postoperative days. They were managed by the temporary insertion of an inferior vena cava (IVC) filter thus allowing for a delay in full-dose anticoagulation until removal of the filter. None of the PE patients suffered any bleeding complication as a result of the introduction of full anticoagulation. Two patients suffered postoperative haematomas, without development of neurological symptoms or signs, requiring emergency evacuation. The overall incidence of PE was 2.2% rising to 2.5% after exclusion of microdiscectomy cases. The incidence of PE was highest in anterior or combined thoracolumbar/lumbar procedures (4.2%). There is a large variation in the reported incidence of PE in the spinal literature. Results from the only study found in the literature specifically monitoring PE suggest an incidence of PE as high as 2.5%. Our study shows a similar incidence despite the use of LMWH. In the absence of randomized controlled trials (RCT) it is uncertain if this type of prophylaxis lowers the incidence of PE. However, other studies show that the morbidity of LMWH is very low. Since PE can be a life-threatening complication, LMWH may be a worthwhile option to consider for prophylaxis. RCTs are necessary in assessing the efficacy of DVT and PE prophylaxis in spinal patients.     

Intratumoral hemorrhage from a posterior fossa tumor after cardiac valve surgery--case report.

A 53-year-old woman suffered intracranial hemorrhage from a cerebellar tumor several days after aortic valve replacement. Surgical intervention was not performed because the patient refused blood infusion for religious reasons (Jehovah's Witness). Instead, the anticoagulation therapy was interrupted for a week, and the patient was conservatively treated with administration of mannitol and steroid. The anticoagulation therapy was restarted 7 days after the hemorrhage. The intratumoral hemorrhage did not recur, and no systemic embolism occurred. The tumor was treated with gamma knife radiosurgery 6 weeks after the hemorrhage, under the radiological diagnosis of meningioma. Anticoagulation therapy is routinely used for patients following cardiac surgery to decrease the risk of thromboembolic complications, but also increases the risk of hemorrhagic events which often involve the central nervous system. Temporary discontinuation of anticoagulation therapy is an option for intratumoral hemorrhage in patients with replacement heart valves, and patients with known brain tumors should be informed about the risk of intracranial hemorrhage before cardiac surgery.     

Practical utility of the D-dimer assay for excluding thromboembolism in severely injured trauma patients

BACKGROUND: We have advocated the use of a D-dimer assay to exclude the diagnosis of pulmonary embolism (PE) and deep venous thrombosis (DVT) in surgical and trauma patients suspected of having these diagnoses. Injury is known to increase D-dimer levels independent of thromboembolism. The purpose of this study was to assess the period after injury over which the D-dimer assay remains positive because of injury exclusive of thromboembolism. METHODS: We prospectively sampled the plasma of severely injured patients for D-dimer using an enzyme-linked immunosorbent assay method at admission; at hours 8, 16, 24, and 48; and at days 3, 4, 5, and 6. Patients were then screened for DVT with a routine duplex Doppler at day 7. Patients were followed for PE, adult respiratory distress syndrome, and disseminated intravascular coagulation. RESULTS: One hundred fifty-four patients (mean Injury Severity Score of 23) underwent a total of 1,230 D-dimer assays. Twenty-six (17%) had thromboembolism. Nine (6%) patients developed DVT, 2 (1%) developed PE, 13 (8%) developed disseminated intravascular coagulation, and 11 (7%) developed severe adult respiratory distress syndrome. None of the trauma patients with thromboembolism had a (false) negative D-dimer at or after the time of their thromboembolic complication. True-negative D-dimer results as a function of time from injury are: 0 hours, 18%; 8 hours, 16%; 16 hours, 17%; 24 hours, 22%; 48 hours, 37%; day 3, 34%; day 4, 32%; day 5, 30%; and day 6, 30%. The negative predictive value of the assay was 100%. D-dimer levels were significantly higher in those who developed a thromboembolic complication than in those who did not (independent of Injury Severity Score). CONCLUSION: These data serve to validate D-dimer as a means of excluding thromboembolism, specifically in patients with severe injury (100% negative predictive value). Before 48 hours after injury, however, the vast majority of these patients without thromboembolism had positive D-dimer assays. Because of the high false-positive rate early after severe injury, the D-dimer assay may be of little value before postinjury hour 48.     

Does routine serial computed tomography of the head influence management of traumatic brain injury? A prospective evaluation

BACKGROUND: Computed tomography (CT) of the head is the current standard for diagnosing intracranial pathology following blunt head trauma. It is common practice to repeat the head CT to evaluate any progression of injury. Recent retrospective reviews have challenged the need for serial head CT after traumatic brain injury (TBI). This study intends to prospectively examine the value of routine serial head CT after TBI. METHODS: Consecutive adult blunt trauma patients with an abnormal head CT admitted to an urban, Level I trauma center from January 2003 to September 2003 were prospectively studied. Variables collected included: initial head CT results, indication for repeat head CT (routine versus neurologic change), number and results of repeat head CT scans, and clinical interventions following repeat head CT. RESULTS: Over the 9-month period, there were 128 patients admitted with an abnormal head CT after sustaining blunt trauma. The 16 patients who died within 24 hours and the 12 patients who went directly to craniotomy were excluded. The remaining 100 patients make up the study population. Abnormal head CT findings were subarachnoid hemorrhage (47%), intraparenchymal hemorrhage (37%), subdural hematoma (28%), contusion (14%), epidural hematoma (11%), intraventricular hemorrhage (3%), and diffuse axonal injury (2%). Overall, 32 patients (32%) had only the admission head CT, while 68 patients (68%) underwent 90 repeat CT scans. Of the repeat head CT scans, 81 (90%) were performed on a routine basis without neurologic change. The remaining 9 (10%) were performed for a change in Glasgow Coma Scale (n = 5), change in intracranial pressure (n = 1), change in Glasgow Coma Scale and intracranial pressure (n = 1), change in pupil size (n = 1), or sudden appearance of a headache (n = 1). Three patients had their care altered after repeat head CT: two underwent craniotomy and one was started on barbiturate therapy. All three patients had their repeat head CT after neurologic change (decrease in Glasgow Coma Scale in 2 and increase in intracranial pressure in 1). CONCLUSIONS: Serial head CT is common after TBI. Most repeat head CT scans are performed on a routine basis without neurologic change. Few patients with TBI have their management altered after repeat head CT, and these patients have neurologic deterioration before the repeat head CT. The use of routine serial head CT in patients without neurologic deterioration is not supported by the findings of this study.