Noninvasive diagnosis of deep vein thrombosis in postoperative patients

The accuracy of noninvasive testing for the diagnosis of deep vein thrombosis (DVT) generally is less in asymptomatic patients than it is in those with symptoms suggestive of thrombosis. This is because asymptomatic DVT often is confined to the distal veins and, when it involves the proximal veins, the thrombi usually are smaller than in symptomatic patients with proximal thrombosis. Because the positive predictive value of noninvasive tests for asymptomatic DVT generally is 80% or less, abnormal results should be confirmed by venography. There are two main reasons why asymptomatic DVT is sought in the postoperative period: (1) to identify the need for full-dose anticoagulant therapy to prevent symptomatic episodes of venous thromboembolism (VTE), including fatal pulmonary embolism (this represents a form of secondary prophylaxis), and (2) to use this outcome as a surrogate for episodes of clinically important VTE in studies that are designed to evaluate methods of venous thrombosis prophylaxis. In relation to the first of these indications, evidence suggests that routine surveillance of high-risk patients to detect asymptomatic postoperative DVT does not result in improved clinical outcomes in patients who received appropriate VTE prophylaxis. In relation to the second indication, there is concern that asymptomatic VTE may not be a reliable surrogate for clinically important VTE, particularly if the effectiveness of different antithrombotic agents is being compared. Coupled with the comparatively low accuracy of noninvasive testing for asymptomatic DVT, this suggests that the results of such testing are unsuitable for the evaluation of new methods of prophylaxis in clinical trials.     

Real-time ultrasound for the detection of deep venous thrombosis

PURPOSE: Accurate diagnosis of deep venous thrombosis (DVT) is a clinical problem in emergency practice. A prospective trial was conducted comparing real-time ultrasound with contrast venography in the diagnosis of proximal DVT. METHODS: Seventy patients whose clinical presentations mandated diagnostic evaluation for DVT had real-time ultrasound of the involved leg followed by contrast venography. Initial readings of ultrasound and venography were compared with each other and with final readings to assess reliability of interpretation. RESULTS: Final ultrasound readings agreed with final venogram readings in all patients. Negative initial ultrasound readings agreed with final venogram readings in 56 of 56 patients (negative predictive value, 100%; 95% confidence interval, 94 to 100). Eighteen patients had positive initial ultrasound readings compared with 14 who had positive final venogram readings (positive predictive value, 78%; 95% confidence interval, 55 to 91). CONCLUSION: Negative real-time ultrasonography reliably excludes proximal DVT. Positive ultrasound reliably diagnoses proximal DVT only in experienced hands.     

Light reflection rheography as a noninvasive screening test for deep venous thrombosis.

STUDY OBJECTIVE: To determine if light reflection rheography is a useful screening tool for the diagnosis of proximal leg deep venous thrombosis. DESIGN: Light reflection rheography was compared with duplex ultrasonography and/or contrast venography on emergency patients being evaluated for proximal leg deep venous thrombosis. SETTING: University hospital emergency department. TYPE OF PARTICIPANTS: Seventy-five ED patients being evaluated for acute leg deep venous thrombosis. INTERVENTIONS: Seventy-five patients being evaluated for clinically suspected deep venous thrombosis had light reflection rheography performed on the involved extremity immediately before duplex ultrasonography and/or contrast venography. Duplex ultrasonography and/or contrast venography was the definitive diagnostic test. MEASUREMENTS AND RESULTS: Seventy-five patients had light reflection rheography performed, 72 had duplex ultrasonography, 19 had contrast venography, three had contrast venography alone, and 16 had both duplex ultrasonography and contrast venography. A comparison of light reflection rheography with duplex ultrasonography and/or contrast venography reveals that 39 light reflection rheography examinations were true-negative, 17 were true-positive, one was false-negative, and 18 were false-positive. The sensitivity of light reflection rheography for the detection of proximal leg deep venous thrombosis is 94.4% (95% confidence interval [CI], 72.7-99.9%), the negative-predictive value is 97.5% (95% CI, 86.8-99.9%), the specificity is 68.4% (95% CI, 54.8-80.1%), and the positive-predictive value is 48.6% (95% CI, 31.4-66%). CONCLUSION: Light reflection rheography proved to be an excellent screening tool for emergency patients with the clinical suspicion for an acute proximal leg deep venous thrombosis. A normal light reflection rheography examination was 97.5% accurate as a negative predictor. That is, a normal light reflection rheography excluded the diagnosis of proximal leg deep venous thrombosis when compared with duplex ultrasonography and/or contrast venography when the duplex ultrasonography and/or contrast venography showed no evidence of proximal leg deep venous thrombosis. An abnormal light reflection rheography does not equate to an acute leg deep venous thrombosis as the specificity was only 68.4%. An abnormal light reflection rheography mandates further diagnostic studies such as duplex ultrasonography and/or contrast venography to confirm a diagnosis of proximal leg deep venous thrombosis.     

Value of real time B mode ultrasound imaging in the diagnosis of deep vein thrombosis of the lower limbs

In order to determine the value and the role of real time B mode ultrasound imaging (USI) in the diagnosis of deep vein thrombosis (DVT) of the lower limbs, it was compared to bilateral contrast ascending venography used as a standard of reference, prospectively and systematically on 430 patients suspected of having DVT or pulmonary embolism. A total of 854 limbs were thus studied double blindly both by the two methods. The results corresponded in 95% of the legs with a sensitivity of 98% and a specificity of 95% for USI. Isolated thrombosis of the calf were detected in 91% of the legs and proximal thrombosis were in 100% in this series whatever their topography and extent should be and whatever be the degree of obstruction of the vein. The discrepancies between the two methods are related to: (a) Vein thrombosis especially located in the calf, in the soleal sinuses and the gastrocnemius with in most cases the direct image of the thrombus detected by U.S.I. more often than by venography, provided that the technique and the equipment are appropriate. (b) The absence of visualisation of venous segments with venography which is not specific of venous thrombosis. These veins when non affected by the thrombosis are not filled by the contrast medium if located above an occluded ilio-femoral or ilio-caval junction or when they are the site of extrinsic compression. The direct imaging of the vein and the surrounding structures obtained with USI enhances the diagnostic sensitivity and specificity and provides precision of the exact extension of the thrombosis. Venous study by USI is always coupled with the Doppler.(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparative study of radionuclide venography and contrast venography in the diagnosis of deep venous thrombosis

Background: The value of the radionuclide blood pool venogram in detecting deep venous thrombosis (DVT) has to date been inadequately evaluated. This is despite its lower complication rate than the gold standard of contrast X-ray venography. Aims: To compare the relative accuracy and inter observer variability of radionuclide blood pool and X-ray contrast venography as well as evaluate previous literature on radionuclide venography. Methods: Prospective comparison of radionuclide and contrast venography was performed in 39 patients. Sensitivity and specificity of radionuclide venography were compared to contrast venography and confidence intervals were measured using standard error calculations. A meta-analysis of previous studies was also performed. Results: Significant inter observer variation in reports was present in both radionuclide (37%) and contrast (22%) venograms. Using consensus reports sensitivity of radionuclide venography was 87% compared to contrast venography and specificity was 83%. These results are similar to those obtained in previous studies. Furthermore, sensitivity in specificity in the proximal veins were 90% and 92% respectively which were superior to sensitivity and specificity in the distal veins where it was 74% and 90% respectively. Conclusion: The radionuclide venogram appears accurate in the proximal veins and in excluding but not diagnosing distal venous thrombosis. (Aust NZ J Med 1993; 23: 641–645.)     

Complete compression ultrasound for the diagnosis of venous thromboembolism

PURPOSE OF REVIEW: Since its first appearance in the 1980s, venous ultrasound has increasingly gained interest of both clinicians and researchers. However, a majority of authors currently are convinced that venous ultrasound has inherent limitations that preclude it from safely ruling out distal deep vein thrombosis (DVT) in symptomatic patients and from detecting proximal and distal DVT accurately in asymptomatic patients. The aim of this review is to present recent lines of evidence indicating that venous ultrasound has developed beyond these limitations. RECENT FINDINGS: The major development does not arise from technical progress of imaging but from standardizing the examination procedure. The most efficient protocols now focus on B-mode sonography only but extend the examination to the paired deep calf veins and the calf muscle veins. For such an examination protocol, the term complete compression ultrasound (CCUS) has been coined. Interobserver variability of CCUS resembles that of venography, as do the technical failure rates. By means of a CCUS protocol, the diagnostic work-up of patients with suspected DVT can be simplified significantly. Studies in asymptomatic patients indicate that CCUS has the potential to generate valid data in prevalence and incidence studies and in intervention trials. SUMMARY: Complete compression ultrasound protocols are ready for implementation into clinical practice for diagnosing patients with symptomatic DVT. Research has already benefited from CCUS and benefits further with an increasing number of CCUS-driven trial designs. However, the value of a CCUS protocol critically depends on sound training and on strict compliance with all its details.     

Deep vein thrombosis: Current diagnostic strategy

Over the last 15 years, diagnostic strategies to diagnose deep vein thrombosis (DVT) and pulmonary embolism (PE) have changed significantly. The gold standard for detecting DVT is still venography, but invasivity, radiation, contrast media, and the painful injection in pedal veins are limiting factors for initial and repeat examinations. The introduction of DVT scores, D-dimer testing, and venous ultrasound has made venography replaceable in most cases. This review focuses on different diagnostic strategies for clinicians in hospitals as well as for general practitioners using practical approaches.     

Venous thromboembolism associated with long-term use of central venous catheters in cancer patients

OBJECTIVES: Increased incidence of cancers and the development of totally implanted venous access devices that contain their own port to deliver chemotherapy will lead to a greater than before numbers of central venous catheter related thrombosis (CVCT). Medical consequences include catheter dysfunction and pulmonary embolism. Compared with lower extremity deep venous thrombosis (DVT) (3 d) and with non CVC associated thrombosis (5 d), CVCT is associated with an increased duration of hospitalisation (9 d). CVCT oftentimes leads to the need to replace such ports at an average cost of 4500 euros. CURRENT KNOWLEDGE AND KEY POINTS: Vessel injury caused by the procedure of CVC insertion is the most important risk factor for development of CVCT. This event could cause the formation of a fresh thrombus, which is reversible in the large majority of patients. The incidence of CVC-related DVT assessed by venography has been reported to vary from 30 to 60% but catheter-related DVT in adult patients is symptomatic in only 5% of cases. The majority of patients with CVC-related DVT is asymptomatic or has non-specific symptoms: arm or neck swelling or pain, distal paresthesias, headache, congestion of subcutaneous collateral veins. In the case of clinical suspicion of CVC-related DVT, compressive ultrasonography (US), especially with Doppler and color imaging, currently is first used to confirm the diagnosis. The main criteria of color-Doppler US are visualization of mural thrombi or incompressibility of the veins. Consequently, contrast venography is reserved for clinical trials and difficult diagnostic situations. There is no consensus on the optimal management of patients with CVC-related DVT. Treatment of CVC-related VTE requires a 5- to 7-day course of adjusted-dose unfractionated heparin or LMWH followed by oral anticoagulants. Long-term LMWH that has been shown to be more effective than oral anticoagulant in cancer patients with lower limb DVT could be used in these patients. The optimal duration of oral anticoagulation treatment for CVC-related DVT is unknown, but patients with active cancer should be treated for at least 6 months or indefinitely. FUTURE PROSPECTS AND PROJECTS: The efficacy and safety of pharmacologic prophylaxis for CVC related thrombosis is not established. Additional studies performed in high risk populations are needed to define if LMWH or oral anticoagulation is indicated in this clinical setting.     

Impedance plethysmography in the diagnosis of asymptomatic deep vein thrombosis in hip surgery. A venography-controlled study

We prospectively evaluated the accuracy of computerized impedance plethysmography (CIP) in the diagnosis of asymptomatic deep vein thrombosis (DVT) in 246 consecutive high-risk patients scheduled for hip surgery, with bilateral venography used for comparison. The CIP was performed as a surveillance program every third day. If the CIP remained negative, bilateral venography was performed on postoperative day 10 +/- 1 or on day of treatment 14 +/- 1 in nonoperated-on patients. If the CIP became positive, venography was performed within 24 hours. The sensitivity and specificity of CIP for proximal and distal DVT were 19% (confidence interval [CI], 13% to 24%) and 91% (CI, 87% to 94%), respectively. The positive and negative predictive values were 52% (CI, 38% to 65%) and 70% (CI, 65% to 74%), respectively. The sensitivity and specificity of CIP for proximal DVT were 24% (CI, 13% to 34%) and 90% (CI, 87% to 94%), respectively; the positive and negative predictive values were 31% (CI, 20% to 51%) and 87% (CI, 83% to 90%), respectively. We conclude that, because of its low sensitivity, CIP cannot be used in the surveillance of DVT in high-risk patients or for outcome measurements in clinical trials on DVT prophylaxis.     

The normal Doppler venous examination

The clinical diagnosis of acute deep vein thrombosis (DVT) is but 50% accurate when compared to the results of contrast venography. This clinical inaccuracy had led to the dependence of the physician upon laboratory diagnosis. Whereas contrast venography is the gold standard of diagnosis, its expense, special equipment, personnel, and discomfort make it unsuitable for evaluating large numbers of patients. For this reason, numerous noninvasive tests utilizing plethysmographic and Doppler techniques have been developed to evaluate patients with suspected venous disease, and when expertly performed have a degree of accuracy of approximately 90%. This degree of accuracy coincides with the experience of our peripheral vascular laboratory using the Doppler venous examination. Based on these statistics, our current practice is to evaluate patients suspected of having DVT with a Doppler venous examination (Figure 1). If the test is abnormal or equivocal, contrast venography is usually obtained and anticoagulation recommended. Contrariwise, if the Doppler venous examination is normal, venography is not obtained, and anticoagulation treatment is not recommended. This practice should reduce the number of venograms in a patient population that is not at an increased risk of pulmonary embolism or repeated deep venous thrombosis. To evaluate the validity and safety of this practice, one hundred eighty-six patients with normal Doppler venous examinations in whom contrast venography was not obtained were evaluated and form the basis of this report.     

Frequency of deep venous thrombosis in asymptomatic patients with coronary artery bypass grafts.

The frequency of deep vein thrombosis (DVT) in patients undergoing coronary artery bypass graft (CABG) surgery has not been established. Therefore to estimate the frequency of clinically silent DVT, we performed ultrasound examinations of the leg veins in 29 asymptomatic CABG patients before hospital discharge. We used high-resolution B-mode ultrasonography with color Doppler imaging. Fourteen (48.3%, 95% confidence interval 30.1 to 66.4%) had 20 documented leg vein thromboses, and all but one patient had DVT limited to the calf veins. Of the 20 thrombi 10 (50.0%) were present in the leg ipsilateral and 10 (50.0%) in the leg contralateral to the saphenous vein harvest site. None of the DVTs were suspected clinically. DVT was not associated with any local sign attributed to saphenous vein harvest such as pitting edema, incisional drainage, or local tenderness or with any putative risk factor for DVT such as cigarette use, distant history of malignancy, or varicose veins. Follow-up of these patients 5 to 11 months after CABG surgery showed no clinical evidence of DVT or pulmonary embolism. Our findings indicate that asymptomatic DVT of the calf occurs with surprisingly high frequency, 44.8% after CABG surgery. Future studies in patients undergoing CABG surgery should address the natural history of asymptomatic DVT, determine its clinical importance, and develop optimal strategies for prophylaxis and treatment.     

Detection of previous proximal venous thrombosis with Doppler ultrasonography and photoplethysmography

To evaluate the reliability of two noninvasive tests, the photoplethysmograph (PPG) and venous Doppler ultrasound, in determining the presence or absence of previous proximal deep vein thrombosis (DVT), we performed a blinded retrospective cohort study of patients with objectively confirmed (DVT+) or refuted (DVT-) previous episodes of suspected DVT. Twenty-nine of 33 DVT+ patients had abnormal PPG and/or reflux by venous Doppler ultrasound, whereas 39 of 49 DVT- patients had normal PPG and no Doppler reflux (sensitivity, 88%; specificity, 80%). Of 33 DVT+ patients, 20 had abnormal Doppler results (sensitivity, 61%), in contrast to 46 of 49 DVT- patients with normal results (specificity, 94%). Moreover, 23 of 33 DVT+ patients showed abnormal PPG results (sensitivity, 70%), whereas 40 of 49 DVT- patients had normal PPG (specificity, 82%). Based on our findings, the presence of Doppler reflux is specific for previous proximal DVT, whereas a combination of normal PPG and Doppler ultrasound is reliable for excluding previous proximal DVT. Abnormal PPG with normal Doppler ultrasound does not reliably predict the presence or absence of previous DVT. However, this occurred in only 16 of 82 patients. Therefore, the combination of PPG and venous Doppler ultrasound can reliably predict the presence or absence of previous proximal DVT in most patients.     

Cost effectiveness of non-invasive tests including duplex scanning for diagnosis of deep venous thrombosis. A prospective study carried out on 511 patients.

Recent studies have elucidated the cost-effectiveness of various diagnostic methods used to detect deep venous thrombosis (DVT) of the lower limbs. These methods include Doppler, plethysmography and labelled fibrogen tests. However, duplex scanning has recently proven to be a more reliable examination. With a view to establishing a realistic appraisal of matters as they stand, the authors have carried out a prospective study to compare the relative cost-effectiveness of purely physical examination, duplex scanning associated with strain-gauge plethysmography, contrast venography indicated for each proximal DVT, and contrast venography as a first-choice examination. 511 consecutive patients suspected of DVT of the lower limbs were examined using the various non-invasive methods cited above. 185 of the patients underwent contrast venography. When compared with those of the non-invasive tests, the results of the latter examination provided for extrapolation to the total population of 511 patients so as to better evaluate costs. We are able to conclude that physical examination alone is neither cost-effective nor risk free. Non-invasive tests, which are more reliable, provide annual savings greater than 1,500,000 FF ($ 240,000) with respect to venography. Performing venography for each proximal DVT increases spending by little: savings are again greater than 1,200,000 FF ($ 192,000).     

Real-time ultrasound in the diagnosis of acute deep venous thrombosis of the lower extremity

One hundred twenty-six patients with clinically suspected acute deep venous thrombosis of the lower extremity (DVT) were examined comparatively with ultrasound and venography. In total, 174 lower extremity venograms were obtained. Ultrasonic examinations were performed on patients in the supine position. The venous segments were evaluated almost exclusively with transversal scanning. In the thigh, the only criterion for DVT was the reduced or absent compressibility of the venous lumen when gently compressed with the transducer. In the calf, normal unobstructed veins can usually not be viewed in the supine patient, whereas thrombotic veins appear as sonolucent, incompressible channels. Eight-three of the 174 lower extremity venograms were positive for DVT. In the majority of cases (53 of 83) the thrombotic process had involved two or more segments in combination. The sites of involvement of the different venous segments were distributed as follows: 24 occlusions of the common femoral vein, 52 of the superficial femoral vein, 56 of the popliteal vein, and 71 of the calf veins. Ultrasound had a sensitivity of 100% for thrombosis of the common femoral vein, 96% for the superficial femoral veins, 98% for the popliteal vein, and 93% for the calf veins. For the entire lower extremity, in regard to the diagnosis of thrombosis, the overall sensitivity was 95%. In 90% the extension of the occlusion was foreseen correctly. In no cases were false-positive results reported. Thus the overall specificity was 100%. The authors conclude that real-time ultrasound is a highly accurate method for the diagnosis of DVT of the lower extremity. It is the only indirect method capable of evaluating the venous system of the thigh, as well as that of the calf, with high accuracy. It should be the first choice of diagnostic imaging method in the diagnosis of deep venous thrombosis of the lower extremity.     

Deep venous thrombosis screening in patients with inherited bleeding disorders and central venous catheters

Summary. Children with inherited bleeding disorders often require central venous catheters (CVCs). Although CVCs are known to be complicated by deep venous thrombosis (DVT), little is known about the timeline of DVT development or risk of post‐thrombotic syndrome (PTS). The aim of this study was to determine the timeline and confirm the incidence of thrombosis in patients with bleeding disorders who have CVCs. In 2002, we instituted a screening programme to monitor for CVC‐related complications in children with haemophilia and von Willebrand disease. This is a retrospective review of this cohort. All children with CVC followed up between 1 January 2000 and 1 June 2009 were evaluated for DVT every 24 months with contrast venography and Doppler sonography. An institutional PTS severity scale was utilized at each visit. Thirty‐six patients had 37 CVCs placed. Thirty patients had imaging studies, with DVT observed in 14 (47%). Most cases of DVT were diagnosed at the first venogram (median CVC duration 26 months). There were no abnormal ultrasound results. Sixteen patients (44%) had clinical findings consistent with PTS, including 10 (71%) with an abnormal venogram. Dilated chest wall veins appeared to be more strongly associated with underlying DVT (positive predictive value of 0.8) than arm circumference discrepancy. Successful transition to use of peripheral veins occurred at a median of 11 months after abnormal venograms. CVC‐related DVT is common in children with inherited bleeding disorders and likely occurs earlier than previously thought. Clinical signs of PTS are also common, but long‐term sequelae and severity of PTS are not known.     

Indirect CT venography following CT pulmonary angiography: spectrum of CT findings

SUMMARY: Pulmonary embolism (PE) and deep venous thrombosis (DVT) represent two manifestations of the same syndrome, venous thromboembolism. Contrast-enhanced computed tomography (CT) angiography is a practical, efficient alternative to conventional imaging for PE. Following the pulmonary examination, the inferior vena cava (IVC) and the iliac, femoral, and popliteal veins can be studied with CT without additional intravenous contrast administration. Indirect CT venography (CTV) after CT pulmonary angiography (CTPA) simplifies and shortens venous thromboembolism work-up. Initial studies indicate that CTV is comparable to ultrasound in the evaluation of femoral/popliteal DVT. CTV has the advantage of evaluating the iliac veins and inferior vena cava, vessels poorly seen on sonography and venography. Combining CTV with CTPA increases confidence in withholding treatment when results for both the pulmonary arteries and leg veins are negative and increases the diagnosis of venous thromboembolism by 25% over CTPA alone. This pictorial essay will review the normal venous anatomy, CTV technique, and the findings of acute and chronic DVT. Interpretive pitfalls and alternative diagnoses are also reviewed.     

Diagnosis of deep-vein thrombosis using an objective Doppler method

STUDY OBJECTIVE: To determine the diagnostic criteria (phase I) and to assess the accuracy (phase II) of an objective Doppler-Valsalva pressure method as compared with contrast venography for the diagnosis of acute deep-leg-vein thrombosis in symptomatic outpatients. DESIGN: A two-phase prospective study in consecutive patients. Doppler ultrasound strip-chart recordings and venograms were independently analyzed by experienced observers. SETTING: Referral-based medical clinics at university medical centers. PATIENTS: One hundred and ten (phase I) and one hundred and fifty-five (phase II) patients who had clinically suspected venous thrombosis and were referred by their general practitioners were included. METHODS AND MEASUREMENTS: A normal Doppler test result was defined as a cyclic spontaneous signal (S-signal), a continuous S-signal with a Valsalva pressure of less than 6.5 mm Hg, or an absent S-signal with flow after cessation of the Valsalva maneuver. A continuous S-signal with a Valsalva pressure of 6.5 mm Hg or more or an absent S-signal without flow after cessation of the Valsalva maneuver were defined as abnormal test results. The accuracy indices for proximal vein thrombosis in phase II (155 patients; prevalence, 31%) were sensitivity, 91% (95% CI, 79% to 98%), and specificity, 99% (CI, 97% to 100%). All 3 patients with isolated calf-vein thrombosis had normal Doppler test results. CONCLUSIONS: The objective Doppler method is an accurate, reproducible, and simple method for detection of venous thrombosis in symptomatic outpatients.     

疑诊肺栓塞患者337例中合并下肢深静脉血栓的发生率

目的 评价疑诊肺栓塞患者中合并下肢深静脉血栓的发生率.方法 顺序收集2004年1月至2006年6月在北京首都医科大学附属朝阳医院和宁夏医学院附属医院内疑诊肺栓塞的患者,进行CT肺动脉造影(CTPA)联合下肢CT静脉造影检查(CTV)或CTPA联合下肢静脉超声检查.分析肺栓塞患者中合并下肢深静脉血栓的发生率以及下肢深静脉血栓的发生部位有无不同.采用SPSS 11.5统计软件进行数据分析,描述性结果采用频数分析法,组间比较采用卡方检验.结果 共337例患者纳入研究,男189例,女148例,中位年龄62岁,范围19～84岁.CTPA诊断肺栓塞者144例,CTV和下肢超声检查诊断下肢深静脉血栓患者100例.肺栓塞患者合并下肢深静脉血栓的发生率为44%(63/144),其中76%(48/63)发生于近端深静脉内;而下肢深静脉血栓形成患者中合并肺栓塞的发生率为63%(63/100).结论 无论肺栓塞患者合并下肢深静脉血栓,还是下肢深静脉血栓患者合并肺栓塞的发生率均很高,有必要同时进行肺动脉和下肢深静脉检查.     

Postthrombotic syndrome after hip or knee arthroplasty: a cross-sectional study

BACKGROUND: Although the incidence of the postthrombotic syndrome (PTS) has been addressed in patients with symptomatic deep vein thrombosis (DVT), less information is available on the incidence in patients who develop asymptomatic DVT after major hip or knee arthroplasty. OBJECTIVES: To determine whether symptomatic PTS occurs more frequently in patients who develop DVT after hip or knee arthroplasty than those who are free of DVT and to provide an estimate of the incidence of PTS in patients who had undergone major hip or knee arthroplasty and had proximal DVT, distal (calf) DVT, or no DVT. DESIGN AND SETTING: A cross-sectional study conducted at the Hamilton Health Sciences Corporation, Hamilton, Ontario, and the Academic Medical Centre, Amsterdam, the Netherlands. SUBJECTS AND METHODS: Two hundred fifty-five subjects who had undergone major hip or knee arthroplasty 2 to 7 years previously and had routine predischarge venography showing proximal DVT (n = 25), distal DVT (n = 66), or no DVT (n = 164) were enrolled from March 1993 through December 1998. The presence of symptomatic PTS confirmed by the presence of objectively confirmed venous valvular incompetence was ascertained. RESULTS: The rates of PTS were low and not significantly different among the 3 subgroups: 1 (4.0%, 95% confidence interval [CI] = 0.1%-20.4%) of 25 patients with proximal DVT, 4 (6.1%, 95% CI = 1.7%-14.8%) of 66 patients with distal DVT, and 7 (4.3%, 95% CI = 1.7%-8.6%) of 164 patients with no DVT. CONCLUSIONS: Symptomatic PTS is an uncommon complaint after major hip or knee arthroplasty. Patients who develop postoperative proximal or distal DVT and who receive 6 to 12 weeks of anticoagulant therapy are not predisposed to PTS.     

深静脉血栓形成的危险因素及临床分析

目的　提高对深静脉血栓形成 (DVT)和肺血栓栓塞症 (PTE)的危险因素和临床特点的认识。方法　对 338例DVT患者的临床资料进行回顾性分析。结果　近 10年来住院患者中DVT患者的比例呈逐年上升趋势。 80 4 %的DVT患者存在危险因素。最常见的危险因素为年龄≥ 4 0岁(88 9% )、心脏病 (4 3 0 % )、高血压 (35 1% )、长期卧床 (2 1 1% )、感染性疾病 (2 0 1% )等。DVT最常见的临床症状为患肢肿胀 (6 6 2 % )和疼痛 (4 0 5 % ) ,87 2 %的患者两侧小腿周径差值≥ 1cm。DVT易累及左下肢 ,近端静脉多见。 34 5 %的DVT患者合并PTE ,其中 74 6 %以PTE为首发症状。DVT发生PTE的比率在左、右下肢及静脉远、近端之间差异无显著性。结论　DVT在住院患者中所占比例逐渐增加 ,大多数存在危险因素 ,DVT在并发PTE前常无明显症状 ,应引起重视