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.     

Prospective evaluation of unsuspected pulmonary embolism on contrast enhanced multidetector CT (MDCT) scanning

AIM: To quantify the incidence of unsuspected pulmonary emboli (PE) in an unselected inpatient population undergoing contrast enhanced multidetector CT (MDCT) scanning of the thorax and to assess aetiological factors in their development. METHODS: All inpatients undergoing MDCT scanning of the thorax over a 10 month period were prospectively identified. Patients with previous or suspected current PE were excluded. CT scans were reviewed and the degree of contrast enhancement and presence of PE recorded. Where PE was found, the level of the most proximal thrombus was identified. Patient age, length of admission, slice scan thickness and clinical indication were noted. RESULTS: 547 inpatients who had undergone MDCT scanning were identified. Following exclusions 487 remained, 28 of whom (5.7%) had PE. Unsuspected PE was more common with increasing age, occurring in 9.2% (20/218) of all patients over 70 years and 16.7% (11/66) of those over 80 years (p<0.001). Eighteen of the 28 positive scans (64.3%) were at the segmental or subsegmental level. No other aetiological factor was identified which significantly increased the incidence of unsuspected PE. No significant difference was noted between 4-slice and 16-slice MDCT. Nine of the cases of incidental PE (32.1%) were not identified by the original reporting radiologists. CONCLUSION: PE is an unsuspected finding on contrast enhanced MDCT scanning of the thorax in 5.7% of all inpatients. The incidence is higher in older patients. Most are peripheral and >30% are missed on initial review. PE should be routinely sought in all contrast enhanced MDCT scans of the chest, irrespective of the indication for the CT scan.     

Surveillance Venous Duplex Is Not Clinically Useful after Total Joint Arthroplasty When Effective Deep Venous Thrombosis Prophylaxis Is Used

The early detection of deep venous thrombosis (DVT) and treatment with systemic anticoagulation to prevent pulmonary embolism (PE) are essential in the management of patients undergoing total joint arthroplasty (TJA). However, improvements in prophylactic measures have significantly decreased the occurrence of DVT in these patients. The purpose of this study was to determine whether routine postoperative duplex surveillance for DVT remains clinically useful. The medical records of all patients undergoing total knee or total hip arthroplasty between October 1997 and January 2002 at a University Hospital and its Veterans Affairs (VA) affiliate were reviewed. The type of operation and occurrence of complications (e.g., DVT, PE, and hemorrhage) were noted. All patients were treated postoperatively with both enoxaparin 30 mg b.i.d. and bilateral lower extremity sequential compression devices (SCDs). A venous duplex scan was performed prior to discharge. Three hundred ninety-eight patients underwent 441 TJAs for 149 hips and 292 knees. The average age was 65 years (range, 23-95). Venous duplex scans were performed within 1 week (median, 4 days) of operation. Initial inpatient scans revealed acute, ipsilateral DVT in five patients (1.3%). Three patients experienced documented PE—one as an inpatient and two after hospital discharge; both outpatients had negative in-hospital duplex scans. One of the 398 patients did not have a duplex scan as an inpatient and returned 6 weeks later with a popliteal DVT. Complications included one upper gastrointestinal hemorrhage, and one patient died postoperatively of unknown causes. These data demonstrate that routine postoperative venous duplex scans rarely found DVT (5 of 398 patients) after TJA when effective prophylaxis was used. Furthermore, surveillance scanning did not enable reliable prediction of PE. Therefore, we conclude that postoperative inpatient surveillance duplex scans for DVT provide very minimal benefit and that a routine screening program is not clinically useful for patients managed with effective DVT prophylaxis.Presented at the Twenty-eighth Annual Meeting of the Peripheral Vascular Surgery Society, Chicago, IL, June 7, 2003.     

Usefulness of arterial blood gas analysis and D-dimer measurement in the assessment of pulmonary embolism after orthopedic surgery

Background Deep venous thrombosis (DVT) and pulmonary embolism (PE) after spinal or lower extremity surgery are well recognized as common complications. Since 1995 we have investigated the incidence of PE after orthopedic surgery using ventilation-perfusion (V/Q) lung scans, and the prevalence of PE was about 10%. With a view to detecting early-stage PE by simple examinations, we evaluated the use of both the blood gas analysis and the D-dimer measurement after spinal or lower extremity surgery. Methods Altogether, 85 patients who underwent spinal or lower extremity surgery were eligible for the study. Pneumatic sequential leg compression devices (PSLCDs) were utilized continuously both intra- and postoperatively. Arterial blood gas analysis and D-dimer measurement were performed pre- and postoperatively on days 3 and 7. We set lung scan criteria as follows: postoperative decrease in Pao2 (ΔPao2) by ≥10 torr (group G), postoperative D-dimer of ≥1μg/ml (group D), or both. Patients with the criteria went on to undergo lung scans, and PE was diagnosed by the existence of any mismatch between ventilation-perfusion (V/Q) lung scans. Results A total of 44 (51.8%) patients met the lung scan criteria and underwent perfusion lung scans, 10 (11.7%) of whom were diagnosed as PE. In groups G and D, about 30% showed PE. Moreover, six (85.7%) of the seven patients with both criteria showed a significant increase (83.7%) in the prevalence of PE. Conclusions Patients with the above criteria showed a high prevalence of PE. Moreover, 10 (11.7%) of the 85 patients were diagnosed as having PE, which corresponded to the prevalence in our former studies where lung scans were performed in all patients. The blood gas analysis and the D-dimer measurement may be utilized as the first screening examinations.     

多排螺旋CT非螺旋低剂量扫描筛查肺结节

目的探讨4排螺旋CT非螺旋低剂量扫描方式在肺结节诊断中的价值。方法对30例胸片可疑肺结节患者分别行螺旋低剂量和非螺旋低剂量扫描。采用Toshiba 4排多层螺旋CT（Asteion 4）扫描机。螺旋扫描采用预设35.5 mAs,床进20 mm/圈（即螺距1）,0.75 s/圈,非螺旋扫描预设24 mAs,床进20 mm/圈（层厚=层距）,0.48 s/圈,其他扫描参数相同：120 kV,准直0.5×4,DFOV 300 mm,重建层厚5mm。根据出现伪影程度及是否分辨出肺结节来评价CT图像质量,对肺结节进行简单计数。比较两者发现肺结节的差异及有效放射剂量的差异。结果两种扫描方式检查30例患者均为阳性,发现各种肺结节都是108个。非螺旋扫描的有效放射剂量低于螺旋扫描方式（P〈0.001）。结论非螺旋方式扫描与螺旋方式扫描在胸部低剂量检查中对于肺内病灶的发现及诊断无统计学差异,扫描剂量相对更低的非螺旋方式扫描应用于胸部疾病的诊断及筛查是可行的。     

Duplex Ultrasonography Has Limited Utility in Detection of Postoperative DVT After Primary Total Joint Arthroplasty

Background

Duplex ultrasound is routinely used to evaluate suspected deep venous thrombosis after total joint arthroplasty. When there is a clinical suspicion for a pulmonary embolism, a chest angiogram (chest CTA) is concomitantly obtained.

Questions/Purposes

Two questions were addressed: First, for the population of patients who receive duplex ultrasound after total joint arthroplasty, what is the rate of positive results? Second, for these patients, how many of these also undergo chest CTA for clinical suspicion of pulmonary embolus and how many of these tests are positive? Furthermore, what is the correlation between duplex ultrasound results and chest CTA results?

Methods

A retrospective chart review was conducted of total joint replacement patients in 2011 at a single institution. Inclusion criteria were adult patients who underwent a postoperative duplex ultrasonography for clinical suspicion of deep venous thrombosis (DVT). Demographic data, result of duplex scan, clinical indications for obtaining the duplex scan, and DVT prophylaxis used were recorded. Additionally, if a chest CTA was obtained for clinical suspicion for pulmonary embolus, results and clinical indication for obtaining the test were recorded. The rate of positive results for duplex ultrasonography and chest CTA was computed and correlated based on clinical indications.

Results

Two hundred ninety-five patients underwent duplex ultrasonography of which only 0.7% were positive for a DVT. One hundred three patients underwent a chest CTA for clinical suspicion of a pulmonary embolism (PE) of which 26 revealed a pulmonary embolus, none of which had a positive duplex ultrasound.

Conclusion

Postoperative duplex scans have a low rate of positive results. A substantial number of patients with negative duplex results subsequently underwent chest CTA for clinical suspicion for which a pulmonary embolus was found, presumably resulting from a DVT despite negative duplex ultrasound result. A negative duplex ultrasonography should not rule out the presence of a DVT which can embolize to the lungs and thus should not preclude further workup when clinical suspicion exists for a pulmonary embolus.

     

Noninvasive venous testing in the diagnosis of pulmonary embolism: The impact on decisionmaking

Purpose: To characterize the use and utility of lower extremity noninvasive venous testing (NIVT) in the diagnosis of pulmonary embolism (PE).Methods: The study is a retrospective case series of consecutive patients in whom PE was suspected who were referred to a large, urban tertiary care center for NIVT. The main outcome measures of the study were the rate of positive results of NIVT, the amount of new information provided by NIVT, and the frequency of management changes that were attributable to NIVT.Results: Forty-one of 450 patients (9%) had deep venous thrombosis (DVT) by NIVT. The prevalence of DVT by NIVT among patients not evaluated by ventilation/perfusion (V/Q) scanning was 8%. The prevalence of DVT by NIVT among patients with a high-probability V/Q scan result before NIVT was 39%, but no management decisions in this group were based on a positive NIVT result and only two decisions were based on negative NIVT results. The prevalence of DVT according to NIVT among patients who had a negative “diagnostic” (low, or very low probability, or normal) result of V/Q scan before NIVT was 2%. The overall frequency of management changes attributed to NIVT was only 2.5%. In the remaining 97% of patients, management was determined by the result of V/Q scanning or of subsequent pulmonary arteriography.Conclusions: In patients in whom PE is suspected, results of NIVT are usually negative for acute DVT. Management decisions are almost always based on V/Q scan or results of pulmonary arteriography and not on NIVT. The utility of NIVT to identify DVT in these patients appears limited, and a more selective approach to its application for the diagnosis of PE should be considered. (J Vasc Surg 1997 26:757-63.)     

Utility of spiral and cine CT scans in pediatric patients suspected of aspirating radiolucent foreign bodies.

OBJECTIVE: To review our experience with spiral and cine CT imaging for the diagnosis of foreign body aspiration. STUDY DESIGN AND SETTING: Fifty-one consecutive pediatric patients suspected of aspirating radiolucent FBs underwent chest radiography and a 3-dimensional spiral CT scan with 12 also undergoing a cine CT scan within 24 hours before rigid bronchoscopy. Bronchoscopic and CT results were compared. RESULTS: Rigid bronchoscopy showed that FBs were present in the main bronchus or bronchus intermedius of 42 patients. Spiral CT scans localized airway FBs in these same 42 patients. In the remaining nine patients without FBs, six were true-negatives and three were false-positives on CT scan interpretation, making the overall sensitivity, specificity, accuracy, and positive and negative predictive values of CT scans 100% (95% confidence interval, 91%-100%), 66.7% (29%-92%), 94.1% (64%-99%), 93.3% (81%-98%), and 100% (54%-100%), respectively. The cine CT scan correctly diagnosed nine of 12 patients as true-positives and three as true-negatives with identification of air trapping and secondary lung changes. CONCLUSION: These findings suggest that CT scans may be used in airway FB management of pediatric patients, especially with diagnostic dilemmas, and further prospective evaluations should be considered to assess its overall efficacy.     

Excessive thoracic computed tomographic scanning in sarcoidosis.

BACKGROUND--The clinical value of computed tomographic (CT) scanning of the chest in the initial assessment of sarcoidosis was investigated. METHODS--One hundred consecutive patients referred to the sarcoidosis outpatient services of the Mount Sinai Medical Center, New York from 1990 to 1992 with a presumptive diagnosis of sarcoidosis were studied. The diagnosis was subsequently confirmed in all by a positive tissue biopsy sample or the Kveim-Siltzbach test. Clinical and laboratory data of each patient were reviewed. Chest radiographs were classified according to the classical stages of sarcoidosis. Thirty five of the 100 patients had a CT scan of the chest performed before presentation. The CT scans were compared with the presenting clinical data and standard chest radiographs in order to determine if they yielded useful additional information regarding diagnosis or treatment. RESULTS--The chest CT scan revealed no additional clinically relevant information compared with conventional chest radiographs in any of the 35 studies performed. In two patients mediastinal adenopathy was detected by CT scan which was not seen on standard radiographs. Two patients thought to exhibit hilar adenopathy and pulmonary infiltrations by standard radiography had no parenchymal disease on the CT scan. Bilateral parenchymal infiltrates were seen in one patient which were interpreted as unilateral infiltrates by standard radiographs. The variance between conventional radiographs and CT scans in these five patients was not clinically valuable. CONCLUSIONS--CT scans of the chest do not add clinically useful information to the standard chest radiographs in the initial assessment of sarcoidosis in patients presenting with the typical standard radiological patterns. CT scanning of the thorax is indicated in patients with proven or suspected sarcoidosis when the standard chest radiographs are normal or not typical of sarcoidosis, when signs or symptoms of upper airway obstruction are present, when the patient has haemoptysis, if there is a suspicion of a complicating second intrathoracic disease, or the patient is a candidate for lung transplantation.     

Current diagnostic techniques for pulmonary embolism

The diagnosis of venous thromboembolism (VTE) includes deep venous thrombosis (DVT) and pulmonary embolism (PE) and requires objective testing. The clinician uses a combination of risk factors and nonspecific clinical findings to identify patients who warrant such an evaluation. The recommended approach begins with ventilation/perfusion (V/Q) lung scans or lower extremity noninvasive studies by compression ultrasonography. Nondiagnostic V/Q scans or negative noninvasive studies require further testing. A high-probability V/Q scan or a positive noninvasive study warrant treatment. A normal V/Q scan excludes the diagnosis of PE. Helical computed tomography (CT) can diagnose PE of major vessels but is not sufficiently sensitive to exclude PE because of its poor sensitivity for subsegmental pulmonary vessels. Newer D-dimer assays have a high negative predictive value, but results vary with the specific assay and do not perform well in patients with cancer. Future studies are needed to validate magnetic resonance imaging (MRI) or magnetic resonance angiography (MRA).     

Prospective study of the clinical predictors of a positive abdominal computed tomography in blunt trauma patients

BACKGROUND: CT scans are often used in the evaluation of blunt trauma patients. Many scans are negative. Clinical predictors of positive abdominal CT scans would be beneficial in patient care. METHODS: A prospective study of 213 patients at a Level I trauma center presenting with blunt trauma who underwent abdominal CT scan. Indications for CT scan were analyzed statistically, using univariate and multivariate models. RESULTS: Univariate chi2 tests showed abnormal pelvis x-ray (p = 0.0002) and an intubated patient (p = 0.03) were predictors of a positive CT scan. When subjected to multivariate logistic regression, these two indications were significant predictors of a positive CT scan, abnormal pelvis x-ray (p = 0.0005, OR=6.6, 95% CI), and an intubated patient (p = 0.02, OR=2.6, 95% CI). Univariate chi2 tests also showed that alcohol intoxication was statistically significant predictor of a negative CT scan (p = 0.03). CONCLUSION: Our data suggest that an abnormal pelvis x-ray and intubation are significant risk factors for a positive CT scan. Alcohol intoxication, mechanism of injury, and unreliable examination, without other associated indication for a scan, may warrant further study.     

Pulmonary embolism: a frequent occurrence in Indian patients with symptomatic lower limb venous thrombosis

OBJECTIVE: Pulmonary embolism (PE) is the most severe complication of deep venous thrombosis (DVT). There have been very few studies to assess the prevalence of PE in Asian patients. The objective of this study was to define the prevalence of PE in patients presenting with suspected lower limb DVT. METHODS: This was a prospective cohort study at Sir Ganga Ram Hospital, a large multispecialty hospital in New Delhi, India. From January 2001 to July 2004, 1,552 consecutive inpatients and outpatients who presented with clinically suspected lower limb DVT were enrolled in the study. Combined ascending radionuclide venography and lung perfusion scan was performed in all patients. Patients with evidence of pulmonary perfusion defects underwent ventilation lung scan. RESULTS: Radionuclide venography-detectable DVT was noted in 744 patients, of whom 521 (70%) had suprapopliteal DVT. Of patients with DVT, 294 (39.5%) showed a high-probability lung scan and 135 (18.1%) had an intermediate-probability lung scan. Overall, 47% of patients with a high-probability scan had no clinical manifestations suggestive of PE. CONCLUSION: PE occurs frequently in Indian patients with symptomatic DVT. Increasing awareness will provide us with clearer ideas about the prevalence of venous thromboembolism in Asian countries.     

The utility of head CT scans in geriatric patients with hip fractures following a low energy injury mechanism: A retrospective review

ObjectivesHip fractures are common low-energy orthopaedic injuries in the geriatric population. The purpose of this study is to determine the frequency of CT head exams and the incidence of clinically significant intracranial bleed in patients with low energy hip fractures.DesignA retrospective cross-sectional review was completed to identify hip fractures presenting to an academic health centre between 2006 and 2015. Our inclusion criteria were those patients with low energy hip fractures and medical records were reviewed to determine whether a CT head scan was utilized as part of their workup.ResultsA total of 2114 patients were reviewed with an average age of 83.2 years. Hip fractures were treated with a hemiarthroplasty in 59.1% of the patients and with a dynamic hip screw in 40.9% of the patients. 26.9% (n = 502) of the patients received a CT head scan as part of their workup. Sixty-two patients (12.3% of patients who received a CT scan or 2.9% of the study population) were found to have had an acute intracranial bleed. None of these patients required neurosurgical intervention and only 9 (14.5% of patients with a positive CT head) had a modification to their thromboprophylaxis post-op. Of the 15 (26.4%) patient on home anticoagulation for a pre-existing medical condition, 10 (67%) had a delay in reinitiating their anticoagulation greater than 24 h post-operatively.ConclusionDuring the study period, 26.7% of patients received a CT scan, with only 2.9% of patients suffering from a concurrent intracranial bleed. None of the patients with a positive scan required neurosurgical intervention, and scan results did not routinely alter DVT prophylaxis. Resuming home anticoagulation was delayed greater than 24 h post-operatively in ten (67%) of cases. With the challenges of resource allocation, potential delays to surgery and costs associated with CT scans, these investigations should be reserved for patients who have a history or physical exam findings of head trauma or are on anticoagulation pre-injury in the low energy hip fracture population.Level of EvidenceLevel III     

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.     

The role of surveillance duplex scanning in preventing venous thromboembolism in trauma patients

BACKGROUND: This study was performed to determine the role of duplex scanning in preventing pulmonary embolism (PE), the correlation of venous thromboembolism (VTE) risk score with the incidence of deep venous thrombosis (DVT), and patients who may benefit from surveillance duplex scanning. METHODS: Age, sex, Injury Severity Score (ISS), VTE score, length of stay, diagnoses, and bleeding risk were recorded from the trauma registry in patients who had a duplex scan from 1995 to 2000. RESULTS: There were 1,513 duplex scans obtained (10,141 trauma admissions), 253 (2.5%) cases of DVT (52% above-knee, 8% upper extremity), and 30 cases of PE (0.3%). Only 5 of 21 duplex scans were positive in PE patients. DVT patients were older (52.9 vs. 46.7 years), with higher ISS (24.0 vs. 20.8) than patients without DVT. Regression analysis showed poor correlation between VTE score and DVT incidence (r2 = 0.27). Univariate analysis identified age, ISS, and VTE score as risk predictors for DVT. CONCLUSION: Adherence to an evidence-based VTE prophylaxis protocol is more important than surveillance duplex scanning in preventing VTE in trauma patients.     

Non-Invasive Diagnosis of Pulmonary Embolism,Anno 2005

Pulmonary angiography is the gold standard for segmental pulmonary embolism (PE) but no longer for sub-segmental PE, because the inter-observer agreement for angiographically documented subsegmental PE is only 60%. Two non-invasive tools exclude PE with a negative predictive value of > 99%: a normal perfusion lung scan and a normal rapid ELISA VIDAS D-dimer test. The positive predictive value is 85 to 88% for a high probability ventilation-perfusion lung scan (VP-scan) and > 95% for helical spiral CT. The prevalence of PE in management studies of symptomatic patients with a non-diagnostic VP-scan is 20 to 24%. Helical spiral CT detects all clinically relevant PE and a large number of alternative diagnoses in symptomatic patients with a non-diagnostic VP-scan or a high probability VP-scan. Single-slice helical CT as the primary diagnostic test in patients with suspected PE in three retrospective studies and in two prospective management study indicate that the negative predictive value of a normal helical spiral CT, a negative compression ultrasonography of the legs (CUS) together with a low or intermediate pre-test clinical probability is > 99%. Therefore, helical spiral Ct can replace both the VP-scan and pulmonary angiography to safely rule in and out PE. The combination of clinical assessment, a rapid ELISA VIDAS D-dimer followed by CUS will reduce the need for helical spiral CT by 40 to 50%.     

Non-invasive diagnosis of pulmonary embolism, anno 2005

Pulmonary angiography is the gold standard for segmental pulmonary embolism (PE) but no longer for subsegmental PE, because the inter-observer agreement for angiographically documented subsegmental PE is only 60%. Two non-invasive tools exclude PE with a negative predictive value of >99% : a normal perfusion lung scan and a normal rapid ELISA VIDAS D-dimer test. The positive predictive value is 85 to 88% for a high probability ventilation-perfusion lung scan (VP-scan) and >95% for helical spiral CT. The prevalence of PE in management studies of symptomatic patients with a non-diagnostic VP-scan is 20 to 24%. Helical spiral CT detects all clinically relevant PE and a large number of alternative diagnoses in symptomatic patients with a non-diagnostic VP-scan or a high probability VP-scan. Single-slice helical CT as the primary diagnostic test in patients with suspected PE in three retrospective studies and in two prospective management study indicate that the negative predictive value of a normal helical spiral CT, a negative compression ultrasonography of the legs (CUS) together with a low or intermediate pre-test clinical probability is >99%. Therefore, helical spiral CT can replace both the VP-scan and pulmonary angiography to safely rule in and out PE. The combination of clinical assessment, a rapid ELISA VIDAS D-dimer followed by CUS will reduce the need for helical spiral CT by 40 to 50%.     

Therapeutic anticoagulation can be safely accomplished in selected patients with traumatic intracranial hemorrhage

ABSTRACT: INTRODUCTION: Therapeutic anticoagulation is an important treatment of thromboembolic complications, such as DVT, PE, and blunt cerebrovascular injury. Traumatic intracranial hemorrhage has traditionally been considered to be a contraindication to anticoagulation. Hypothesis Therapeutic anticoagulation can be safely accomplished in select patients with traumatic intracranial hemorrhage. METHODS: Patients who developed thromboembolic complications of DVT, PE, or blunt cerebrovascular injury were stratified according to mode of treatment. Patients who underwent therapeutic anticoagulation with a heparin infusion or enoxaparin (1 mg/kg BID) were evaluated for neurologic deterioration or hemorrhage extension by CT scan. RESULTS: There were 42 patients with a traumatic intracranial hemorrhage that subsequently developed a thrombotic complication. Thirty-five patients developed a DVT or PE. Blunt cerebrovascular injury was diagnosed in four patients. 26 patients received therapeutic anticoagulation, which was initiated an average of 13 days after injury. 96% of patients had no extension of the hemorrhage after anticoagulation was started. The degree of hemorrhagic extension in the remaining patient was minimal and was not felt to affect the clinical course. CONCLUSION: Therapeutic anticoagulation can be accomplished in select patients with intracranial hemorrhage, although close monitoring with serial CT scans is necessary to demonstrate stability of the hemorrhagic focus.     

Efficacy and Safety of Mechanical IVC Filtration for Preventing Pulmonary Embolism in High-Risk Orthopedic Patients Undergoing Total Hip or Knee Arthroplasty

BackgroundTo determine the efficacy and safety of inferior vena cava (IVC) filters in preventing pulmonary embolism (PE) in high-risk patients undergoing hip or knee arthroplasty.Methods2857 hip or knee arthroplasty procedures between January 2013 and December 2018 were retrospectively reviewed. Patients with a preoperative history of venous thromboembolism (VTE), either PE or deep venous thrombosis (DVT), were categorized as high-risk patients. The incidence of overall VTE, PE, and DVT were compared between patients with filters and those without. The subgroup analysis was also performed by patient risk, and filter status and the incidence of VTE, PE, and DVT were compared. Variables such as filter placement, history of hypercoagulability etcetra were evaluated as risk factors for the development of postoperative VTE.ResultsIn the high-risk group, the use of IVC filters was significantly associated with a lower incidence of pulmonary embolism (0.8% vs 5.5%, P = .028). When compared with the low-risk group, the high-risk group had significantly higher incidence of PE (3.8% vs 2.0%, P = .038), DVT (11.6% vs 5.3%, P < .001), and overall VTE (15.0% vs 6.8%, P < .001). The history of VTE was associated with postoperative VTE (P < .001), PE (P = .042), and DVT (P < .001). There was no significant correlation between filter placement and postoperative VTE, DVT, or PE in the low-risk group. Filter retrieval was successful in 100% (96/96) of attempted patients with no complications.ConclusionThe use of IVC filters is significantly associated with a lower incidence in pulmonary embolism in high-risk arthroplasty patients. High-risk patients demonstrated an incidence of postoperative VTE over two times greater than other patients. Prophylactic placement of IVC filters in hip/knee arthroplasty is safe.     

Frequency of pulmonary embolism in patients who have iliofemoral deep vein thrombosis and are treated with once- or twice-daily low-molecular-weight heparin

Purpose: The purpose of this study was to compare the efficacy and safety of treating mobile iliofemoral patients with deep venous thrombosis (DVT) with subcutaneous low-molecular-weight heparin (dalteparin sodium) either 200 IU/kg once-daily (group 1) or 100 IU/kg twice-daily (group 2).Methods: Consecutive patients with suspected iliofemoral DVT diagnosed by duplex ultrasonography and verified by radionuclide venography were randomized to one of the two low-molecular-weight heparin (LMWH) regimens. Perfusion and when necessary ventilation scans were performed for diagnosis of pulmonary emboli (PE) in all patients immediately after admission and were repeated after approximately 10 days, whereupon oral anticoagulation was started unless contraindicated. Minimal and maximal anti-factor Xa activity was measured after 2 to 3 days of therapy. All patients were kept mobile with compression bandages. The primary end point was reduction in frequency of PE as assessed on the second lung scan.Results: A total of 140 patients with confirmed DVT were randomized, 76 to group 1 and 64 to group 2. The two groups were comparable in their baseline clinical characteristics. In the initial lung scans 36 (47.4%) patients in group 1 and 29 (45.3%) patients in group 2 had objectively verified PE, but only 11 (14.5%) and 8 (12.5%) patients, respectively, had symptoms. After dalteparin treatment PE disappeared in two patients in group 1, but in two other cases new PEs occurred, (NS). In group 2 a resolution of PEs was observed in eight patients, whereas only one new PE could be detected. This change reflects the efficacy of therapy as defined by resolution of existing PEs and by the occurrence of new PEs and is statistically significant according to Mc Nemar's χ ² test with the exact binomial method pair procedure ( p < 0.05). Symptomatic PE was reduced from 14.5% to 5.3% in group 1 (96% to CI for the difference, -1.5% to +17.3%) and from 12.5% to 1.6% in group 2 (95% CI for the difference 0.7% to 18%, p < 0.05). There was one single fatal PE, one serious and three minor bleeding episodes in group 1, and one minor bleeding episode in group 2 (95% CI for the difference: -3.6% to + 8.1%).Conclusions: Treatment of ambulant iliofemoral patients with DVT with 100 IU/kg dalteparin twice-daily appears to be more safe and effective than 200 IU/kg given once-daily. Bed rest is not necessary for treating mobile patients. (J Vasc Surg 1996;24:774-82.)