Patterns and distribution of isolated calf deep vein thrombosis.

PURPOSE: In the search for calf deep vein thrombosis (DVT) with color-flow duplex scanning (CFDS), most vascular laboratories investigate only the posterior tibial and peroneal veins. Few laboratories assess the soleal and gastrocnemial veins. This study was designed to determine the patterns and distribution of isolated calf DVT, including the soleal and gastrocnemial veins. METHODS: In the last 3 years, 5250 patients (mean age, 66 +/- 15 years; range, 22 to 93 years) were referred to the vascular laboratory for clinical suspicion of DVT and underwent examination with CFDS. All superficial and deep named veins, excluding the anterior tibial from groin to ankle, were imaged. Of the deep veins in the calf, the peroneal, the posterior tibial, the gastrocnemial, and the soleal veins were examined throughout their length. RESULTS: DVT was detected in 14% of the patients. Isolated calf DVT was detected in 282 limbs of 251 patients (4.8%). No significant difference was noted for the sex (114 men vs 137 women; P =.15) or the limb preference (145 left vs 137 right; P =.5). The peroneal veins were most frequently involved, with 115 limbs (41%) affected. The soleal veins were involved in 109 limbs (39%), followed by the posterior tibial in 105 limbs (37%) and the gastrocnemial in 79 limbs (29%). Thrombus in the soleal vein alone was found in 57 limbs (20%), in the gastrocnemial in 48 limbs (17%), in the peroneal in 41 limbs (15%), and in the posterior tibial vein in 35 limbs (12%). Thrombus confined to a single or paired vein was found in 181 limbs (64%). Thrombus involving two different veins (27%) was the second most frequent pattern, and thrombus in three (7%) or four (1.4%) different veins was less prevalent. Isolated thrombosis in veins not routinely investigated was found in 113 limbs (40%; soleal, n = 57; gastrocnemial, n = 48; soleal + gastrocnemial, n = 8). Multifocal origin of thrombosis, defined as thrombi in two different veins that do not anatomically communicate, was identified in 63 limbs (22%). CONCLUSION: Forty percent of the patients with acute isolated calf DVT would be judged to have normal CFDS examination results if the muscular veins in the calf were not imaged. Multifocal origin of thrombosis was found in 22% of the involved limbs. The prevalence of thrombosis in any calf vein either alone or in combination is comparable. Accordingly, the soleal and gastrocnemial veins should be examined routinely.     

The natural history of calf vein thrombosis: Lysis of thrombi and development of reflux

Purpose: Although the fact is well accepted that deep venous thrombosis (DVT) of the iliac, femoral, and popliteal veins can lead to the post-thrombotic (postphlebitic) syndrome, the significance of isolated calf DVT on the development of late venous sequelae and physiologic calf dysfunction is unknown. The purpose of this study was to review the outcome of 58 limbs with isolated calf DVT and report the clinical, physiologic, and imaging results up to 6 years after the onset of DVT. Methods: The study consisted of 58 limbs of 54 patients in whom isolated calf vein DVT was diagnosed between 1990 and 1995. Proximal propagation of clot, lysis of thrombi, and development of symptomatic pulmonary emboli were examined. Of the patients, 28 received anticoagulation therapy, and 26 did not, but they had follow-up with serial duplex scans. At late follow-up 1 to 6 years later (median, 3 years), 23 patients were examined for the post-thrombotic syndrome, and all 23 underwent clinical examination, color-flow duplex scanning, and air plethysmography. Results: Proximal propagation of DVT from the calf veins into the popliteal or thigh veins occurred in 2 of 49 cases (4%) within 2 weeks of diagnosis. No patient had clinically overt pulmonary emboli develop regardless of whether anticoagulation therapy was received or not. The most common site for calf DVT was the peroneal vein (71%). Complete lysis of calf thrombi was found in 88% of the cases by 3 months. At 3 years, 95% of the patients were either asymptomatic or mildly symptomatic, and 5% had discoloration of the limb. No ulcers occurred. By air plethysmography, physiologic abnormalities were found in 27% of the cases, which was not significantly different from normal controls. Valvular reflux by duplex scanning of the calf vein segment with DVT was found in 2 of 23 cases (9%). However, reflux in at least one venous segment not involved with DVT was found in 7 of 23 cases (30%), which was higher than, but not statistically different from, normal controls, with reflux occurring in 5 of 26 cases (19%). Conclusions: Isolated calf vein DVT leads to few early complications (ie, clot propagation, pulmonary emboli) and few adverse sequelae at 3 years. The peroneal vein is most commonly involved and should be a part of the routine screening for DVT. Lysis of clot usually occurs by 3 months. Although valvular reflux rarely is found in the affected calf vein at 3 years, reflux may be found in adjacent uninvolved veins in approximately 30% of the cases. The question of whether this will lead to future sequelae, such as ulceration, will require longer follow-up. (J Vasc Surg 1998;28:67-74.)     

The origin of thrombi in the deep veins of the lower limb: a venographic study

A series of 952 patients was examined by ascending venography; 812 with clinically diagnosed deep vein thrombosis (DVT) (group 1) and 140 with clinical features suggestive of pulmonary embolism (group 2). Thrombus was demonstrated in 401 (49.4 per cent) of group 1 and in 74 (53 per cent) of group 2 patients. A total of 535 limbs contained thrombus. In 493 (92 per cent) thrombus was present in the calf with either no further clot, or clot in continuity with that in more proximal veins. In the remaining 42 legs (8 per cent) thrombus either originated from multiple discontinuous sites in the legs and pelvis, or in proximal major veins without concomitant calf involvement. The clinical implications of these findings are discussed.     

Patterns of venous insufficiency after an acute deep vein thrombosis

BACKGROUND: The purpose of this study was to investigate patterns of venous insufficiency during a 12-month period after an acute deep vein thrombosis. STUDY DESIGN: Seventy limbs in 67 patients with an acute deep vein thrombosis (DVT) involving 147 anatomic segments were evaluated with duplex scanning at 1 month, 3 months, 6 months, and 1 year. Venous segments were examined whether they were occluded, partially recanalized, or totally recanalized, and the development of venous reflux was evaluated. RESULTS: The segments investigated were the common femoral vein (38 segments), femoral vein (33 segments), popliteal vein (36 segments), and calf veins (40 segments). There were 35 limbs with isolated DVT and the remaining 35 had multisegment DVT. At 1 year, thrombi had fully resolved in 76% of the segments, 20% remained partially recanalized, and 5% were occluded. The venous occlusion was most predominant in the femoral vein (21%) at 1 year. On the contrary, rapid recanalization was obtained in calf veins than in proximal veins at each examination (p < 0.01). Deep vein insufficiency was detected as early as 1 month after development of DVT, and the reflux was most predominant in popliteal veins (56%), followed by femoral veins (18%). No reflux was found in calf veins. Multisegment DVTs had a significantly higher incidence of deep vein insufficiency than single segment DVTs at 1 year. Development of superficial venous insufficiency was found in 5 limbs (7%) and perforating vein insufficiency in 5 (7%). CONCLUSIONS: Lower extremity venous segments showed different proportions of occlusion, partial recanalization, and total recanalization. Calf veins showed more rapid recanalization than proximal veins. Venous reflux was noted as early as 1 month. The limbs involving multisegment DVTs on initial examination had a higher incidence of deep vein insufficiency and could require much longer followup studies.     

Re-evaluation of iliac compression syndrome using magnetic resonance imaging in patients with acute deep venous thromboses

BACKGROUND: The majority of proximal deep venous thromboses (DVTs) are thought to have propagated as a contiguous column from the calf veins. However, several authors have proposed that ileofemoral DVT commonly originates in the left common iliac vein (LCIV) at a site of compression by the overlying right common iliac artery (RCIA/LCIV compression). This mechanism could explain both the left-sided predominance of ileofemoral DVT and the finding that ileofemoral DVT frequently occurs either in the absence of calf vein thrombosis (isolated ileofemoral DVT) or is not contiguous with calf vein thrombosis (noncontiguous ileofemoral DVT). This mechanism remains unconfirmed. OBJECTIVES: The purpose of this study was to detect RCIA/LCIV compression using multimodal magnetic resonance imaging in thrombosed and patent iliac veins, to determine whether RCIA/LCIV compression occurs more frequently in cases of left ileofemoral DVT than other types of DVT, and to determine if RCIA/LCIV compression is specifically associated with left isolated and noncontiguous ileofemoral DVT. PATIENTS AND METHODS: This prospective study conducted at the 1355-bed University Hospital included 18 patients with ileofemoral DVT, 23 with femoropopliteal DVT, 15 with isolated calf DVT recruited consecutively, and 28 control patients in whom DVT had been excluded. Interventions included magnetic resonance direct thrombus imaging (MRDTI), venous enhanced peak arterial magnetic resonance venography (VESPA) and magnetic resonance arteriography (MRA) within 48 hours of routine conventional venography (CV). RCIA/LCIV compression of patent LCIVs was assessed using VESPA and MRA; RCIA/LCIV compression of thrombosed LCIVs was assessed using MRDTI and MRA. The extent of calf and popliteal thrombosis was detected using CV; the extent of femoral and iliac thrombosis was detected using VESPA and MRDTI. RESULTS: RCIA/LCIV compression was more commonly detected in cases of left ileofemoral DVT (9/16 cases) than in cases of left femoropopliteal DVT (1/11 cases; P = .018), right femoropopliteal DVT (2/12 cases; P = .054), left isolated calf DVT (1/9 cases; P = .037), right isolated calf DVT (0/6 cases; P = .046) and control patients (4/28 cases; P = .006). RCIA/LCIV compression was more commonly detected in cases of left isolated ileofemoral DVT (6/6 cases; P = .005), and cases of left noncontiguous ileofemoral DVT (2/2 cases; P = .067) than in cases in which thrombosis was contiguous from the calf to the iliac veins (1/8 cases). CONCLUSION: RCIA/LCIV compression was strongly associated with left ileofemoral DVT and was specifically associated with cases that involve independent ileofemoral thrombosis.     

Incidence of deep vein thrombosis after varicose vein surgery

BACKGROUND: Varicose vein surgery is generally considered to have little risk of postoperative deep vein thrombosis (DVT). This prospective study examined the incidence of DVT in patients undergoing varicose vein surgery. METHODS: Lower leg veins were assessed before operation by duplex ultrasonography in 377 patients, and reassessed 2-4 weeks after surgery, and again at 6 and 12 months. Patients were instructed to contact a physician if symptoms consistent with DVT occurred before the scheduled follow-up appointment. Preoperative prophylaxis (a single dose of subcutaneous heparin) was left to the discretion of the vascular surgeon. RESULTS: DVT was detected in 20 (5.3 per cent) of the 377 patients. Of these, only eight were symptomatic and no patient developed symptoms consistent with pulmonary embolus. Eighteen of the 20 DVTs were confined to the calf veins. Subcutaneous heparin did not alter the outcome. No propagation of thrombus was observed and half of the DVTs had resolved without deep venous reflux at 1 year. CONCLUSION: The incidence of DVT following varicose vein surgery was higher than previously thought, but these DVTs had minimal short- or long-term clinical significance.     

Evolution of deep venous thrombosis: a 2-year follow-up using duplex ultrasound scan and strain-gauge plethysmography

OBJECTIVE: The development of the post-thrombotic syndrome (PTS) and recurrence of deep venous thrombosis (DVT) are not yet fully understood. The aim of the study was to identify factors that lead to the long-term complications of DVT. METHODS: In a 2-year prospective follow-up study, duplex scanning and strain-gauge plethysmography were used to evaluate DVT in relation to the development of long-term complications. Each of the 12 segments examined was assigned as a thrombosis score (TS). A total TS was calculated for each leg. Patent segments were assigned a TS = 0, noncompressible vein segments with flow TS = 1 and noncompressible vein segments without flow TS = 2. The degree of resolution of DVT and the incidence, timing, and outcome of further thrombotic events were measured during 24 months of follow-up. RESULTS: The study involved 86 legs with DVT. The 2-year follow-up was completed for 70 legs. Within 3 months, only 1% of the originally occluded proximal deep vein segments were still occluded. Between all time intervals, from month 12 to month 24, for example, thrombus regression continued in 36% of the legs and thrombus propagation continued in 27%. Multiple regression analysis revealed that an increase in age (P = .008) and proximal location of the original DVT (P = .05) was significantly related to thrombus propagation. Multiple regression analysis showed that the risk factors for clinical signs of PTS were a high venous outflow resistance after 1-month and 12-month follow-ups (P 相似文献   

Lower extremity calf thrombosis: to treat or not to treat?

Seventy-five patients with isolated calf vein thrombi were prospectively monitored with sequential duplex scans at 3- to 4-day intervals. Twenty-four patients (32%) propagated and 11 of these 24 (46%) into the popliteal or larger veins of the thigh. Sex, age, obesity, trauma, estrogen use, malignancy, varicose veins, smoking, surgery, and activity level were not predictive for proximal propagation. Proximal soleal vein thrombi had the highest incidence in both propagating and non-propagating groups. Thrombus extent and bilateral involvement were not predictive of propagation. Five percent (4 of 75 patients) had highly probable ventilation perfusion scans as their initial indication for duplex scanning. Deep vein thrombosis isolated to the calf is not a benign problem. If anticoagulant therapy is contraindicated, the progress of the thrombus can be followed by duplex scanning.     

Proximal extent of pelvic vein thrombosis and its association with pulmonary embolism

OBJECTIVE: Conventional methods such as duplex ultrasound scanning do not provide accurate information about proximal extension of pelvic vein thrombosis. We evaluated proximal extent of thrombus toward pelvic veins with magnetic resonance imaging in patients with suspected deep vein thrombosis (DVT) proximal to the inguinal ligament on the basis of duplex ultrasound scans. In addition, frequency of pulmonary embolism (PE) and early (4 weeks) clinical outcome were evaluated. METHODS: Two hundred twelve patients with acute symptomatic DVT proximal to the inguinal ligament, diagnosed at duplex ultrasound scanning, were enrolled in this prospective study. All patients underwent magnetic resonance imaging of the abdominal and pelvic veins, as well as lung scintigraphy to detect the presence of pulmonary embolism. RESULTS: In 24 of 212 patients (11%), thrombus was restricted to the femoral vein. The thrombus extended into iliac veins in 142 patients (67%) and into the inferior vena cava in 46 patients (22%). The frequency of PE was not associated with the most proximal extension of thrombus (P =.61). No patients died as a consequence of thromboembolic events. CONCLUSIONS: Extension of DVT into the inferior vena cava occurs relatively frequently. In our patients this finding was not associated with higher risk for PE compared with DVT of the femoral or iliac veins.     

Duplex Venous Imaging: Role for a Comprehensive Lower Extremity Examination

Real-time compression ultrasound (CU) along with venous duplex imaging is the most commonly performed noninvasive vascular examination. It has become the definitive diagnostic test for most patients with deep venous thrombosis (DVT). Some practioners have recommended that CU alone of the common femoral vein (CFV) and of the popliteal vein (PV) are all that is required since a complete examination is time consuming and calf veins are difficult to visualize. However, if only the CFV and PV are examined, all patients with isolated superficial femoral vein (SFV) and calf DVT remain undiagnosed. The purpose of this study is to establish the value of a comprehensive venous duplex examination compared to CFV and PV compression alone for detecting both proximal and infrapopliteal DVT. From January 1996 through December 1997, the initial venous duplex examinations of 5767 extremities in 3067 patients were reviewed and results tabulated according to presence and location of clot. The ATL 3000 with a 7-14 mHz probe was utilized. Studies were interpreted as normal, proximal DVT (popliteal and above, with or without calf DVT), isolated calf, or isolated SFV deep venous thrombosis. If only the CFV and PV had been examined, 30.3% (isolated SFV + isolated calf vein DVT) of all DVT and 4.5% of proximal DVT would have been missed. A complete venous duplex examination altered the care in 288 (30.3%) of all patients examined who had DVT, and is therefore recommended as the standard noninvasive examination when evaluating patients for acute DVT.     

Duplex ultrasound diagnosis of lower limb deep venous thrombosis

To compare a non-invasive technique with contrast venography in the diagnosis of lower limb deep venous thrombosis (DVT), 355 patients (380 limbs) were examined over 15 months, using Duplex ultrasound. During this period, ascending venograms were performed in 53 of these patients (56 limbs) and the results were compared. Duplex detection of intraluminal thrombus was based on venous compressibility, Doppler-derived flow spectra, and visualization of thrombus within the lumen. Venography was designated the 'gold standard'. Duplex scanning had a sensitivity of 90.9%, and specificity of 91.3% in diagnosing DVT anywhere in the lower limb. Sensitivity, specificity, and accuracy were best in the femoral segment (95.2%, 100%, 98.2%, respectively), and fell slightly in the more distal limb: popliteal segment (90.4%, 97.1% and 94.6%), and calf veins (88.8%, 92.0% and 90.4%). These results indicate that duplex scanning produces sufficiently accurate data in the diagnosis of lower limb DVT to warrant its clinical use. It provides both the facility for diagnosis without the risks of contrast venography, and permits repeated imaging to follow the immediate progression of disease and efficacy of treatment.     

Air plethysmography: the answer in detecting past deep venous thrombosis

PURPOSE: In this study we assessed the accuracy of air plethysmography (APG) as a means of detecting earlier deep venous thrombosis (DVT), in comparison with venography, to develop a preoperative test for patients with varicose veins. METHODS: In this retrospective analysis of prospectively acquired data, 202 patients referred with the clinical suspicion of chronic venous obstruction (224 lower limbs) and 41 patients (41 lower limbs) who had symptoms and signs suggestive of DVT, but had deep veins that appeared normal on venography, were studied with both venography and APG. RESULTS: The results of venography were negative for past DVT in 169 legs and confirmed past DVT in 96 limbs. The DVTs were confined to the calf in 19 limbs and were found at popliteal level, more proximal, or both in 77 limbs. A total of 95% of the limbs that had earlier proximal DVT (73 of 77) were identified by means of an APG outflow fraction with occlusion of the superficial veins in the first second (OFs) of less than 28%. This is analogous to the Q wave of the electrocardiogram, which is a means of denoting the presence of myocardial infarction. The specificity rate of the method in the detection of past proximal DVT was 96%, the positive predictive value was 92%, and the negative predictive value was 98%. CONCLUSION: APG is a practical, inexpensive, easy-to-perform, accurate, noninvasive method for the diagnosis of hemodynamically significant (ie, proximal or extensive calf DVT) chronic venous obstruction that could replace venography.     

Incidence and distribution of lower extremity deep vein thrombosis in rehabilitation patients: implications for screening

Patients admitted to in-patient rehabilitation programs have an increased risk for developing deep venous thrombosis (DVT). However, the utility of screening for lower extremity DVT using duplex ultrasound in this high-risk population is not well characterized. The purpose of this study is to identify whether or not screening lower-extremity duplex exams are indicated in this high-risk population. Screening lower extremity duplex exams were performed on all patients admitted to the rehabilitation center at Mt. Sinai Hospital over a 3-year period. Charts were reviewed for patient age, gender, diagnosis, date of screening and follow-up duplex exams, presence and location of venous thrombosis at each duplex exam, history of anticoagulation, and medical DVT prophylaxis. The presence of DVT at screening, the location of DVT along the lower extremity, and the outcome of calf DVT were analyzed in terms of gender, underlying diagnosis, and history of DVT prophylaxis. Lower extremity DVT was detected in 34% of patients. Twenty-three percent of patients had isolated calf vein thrombosis. Men were more likely than women to have DVT. Calf DVTs progressed in 3% of patients over an average follow-up of 2 weeks. The presence of DVT, its location along the lower extremity, and the outcome of calf vein DVT had no significant relationship to underlying diagnosis or history of prophylaxis. Screening duplex exams to detect lower extremity DVT in rehabilitation patients is useful. Screening altered management in 26% of patients, prompting either anticoagulation or repeat duplex exam.     

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目的　探讨二维彩色多普勒超声显像 (CDFI)对下肢深静脉血栓形成 (DVT)的诊断价值。方法　1998～ 2 0 0 3年对 97例下肢DVT病人进行CDFI检查 ,了解病肢深静脉的管壁、管径、血栓位置、大小、范围、静脉瓣功能及静脉血流情况。结果　 97例 (98条 )下肢DVT病例中 ,伴有下肢深静脉瓣功能不全者 6例。其中 ,中央型 2 1条 (2 1 4 2 % ) ,周围型 4 6条 (4 6 94 % ) ,全肢型 31条 (31 6 4 % )。病肢左右侧之比为 3 3:1(P <0 0 0 1)。结论　CDFI在下肢DVT方面具有特异性表现 ,可以成为下肢DVT诊断、预后判断和随访的首选方法。     

Deep venous thrombosis and superficial venous reflux

OBJECTIVE: Although superficial venous reflux is an important determinant of post-thrombotic skin changes, the origin of this reflux is unknown. The purpose of this study was to evaluate the frequency and etiologic mechanisms of superficial venous reflux after acute deep venous thrombosis (DVT). METHODS: Patients with a documented acute lower extremity DVT were asked to return for serial venous duplex ultrasound examinations at 1 day, 1 week, 1 month, every 3 months for the first year, and every year thereafter. Reflux in the greater saphenous vein (GSV) and lesser saphenous vein (LSV) was assessed by standing distal pneumatic cuff deflation. RESULTS: Sixty-six patients with a DVT in 69 lower extremities were followed up for a mean of 48 (SD +/- 32) months. Initial thrombosis of the GSV was noted in 15 limbs (21.7%). At 8 years, the cumulative incidence of GSV reflux was 77.1% (SE +/- 0.11) in DVT limbs with GSV involvement, 28.9% (+/- 0.09%) in DVT limbs without GSV thrombosis, and 14.8% (+/- 0.05) in uninvolved contralateral limbs (P <.0001). For LSV reflux, the cumulative incidence in DVT limbs was 23.1% (+/- 0.06%) in comparison with 10% (+/- 0.06%) in uninvolved limbs (P =.06). In comparison with uninvolved contralateral limbs, the relative risk of GSV reflux for DVT limbs with and without GSV thrombosis was 8.7 (P <.001) and 1.4 (P =.5), respectively. The relative risk of LSV reflux in thrombosed extremities compared with uninvolved extremities was 3.2 (P =.07). Despite these observations, the fraction of observed GSV reflux that could be attributable to superficial thrombosis was only 49%. CONCLUSIONS: Superficial venous thrombosis frequently accompanies DVT and is associated with development of superficial reflux in most limbs. However, a substantial proportion of observed reflux is not directly associated with thrombosis and develops at a rate equivalent to that in uninvolved limbs.     

Progress in the diagnosis of deep venous thrombosis: the efficacy of real-time B-mode ultrasonic imaging

Seventy-six limbs with clinically suspected acute deep venous thrombosis (DVT) were evaluated by means of ultrasonic imaging (UI) to define the ability of this technique to detect acute and chronic venous obstruction and to determine the origin and distribution of venous thrombi. UI was compared with ascending contrast phlebography in 46 limbs and was found to be 100% accurate in detecting both acute and chronic venous thrombosis. Overall, acute DVT was present in 63 of 76 limbs (83%) studied. Acute DVT was found in 24% and recurrent acute DVT in 76%. Our results indicate that although the calf veins are the most common site of involvement (89%), thrombi may frequently arise simultaneously in multiple anatomic sites. All limbs with recurrent acute DVT had evidence of previous calf thrombi but only 13% had previous proximal disease. This suggests that asymptomatic calf DVT is common and the prevalence of recurrent acute DVT is significantly greater than previously believed. We found UI is a practical, accurate, non-invasive method for investigating the pathogenesis of venous disease.     

Massive pulmonary embolism caused by internal iliac vein thrombosis with free-floating thrombus formation in the inferior vena cava

Nowadays, compression ultrasonography (CUS) is the gold standard for the routine diagnosis of deep venous thrombosis (DVT). The drawback of CUS is the low sensitivity concerning the diagnosis of isolated pelvic vein thrombosis, especially referring to isolated internal iliac vein and ovarian vein thromboses. Therefore, magnetic resonance (MR) venography has become a valuable alternative. We present the case of a 45-year-old female patient with a massive pulmonary embolism with the indication for thrombolytic therapy due to severe right ventricular overload. We were not able to detect a DVT in the lower limbs of this patient with CUS. However, further DVT workup by MR venography showed a free-floating thrombus formation originating from the right internal iliac veins into the inferior vena cava. Owing to the fact that this thrombus was free floating, surgical removal of the thrombus was scheduled and performed successfully. In some patients it might be important to look for so-called rare causes of pulmonary embolism, even when CUS of the lower limbs does not reveal any DVTs. The diagnostic procedure of choice for these patients seems to be MR phlebography, as iliac and pelvic veins can be evaluated without radiation exposure with this procedure.     

Vascular plasminogen activator and deep vein thrombosis

In attempts to determine the aetiology of deep vein thrombosis (DVT) it has been established that some patients with a history of lower limb DVT have a low level of vascular plasminogen activator (VPA) in their superficial hand veins and this combined with a poor VPA release is thought to predispose to thrombosis (1). Hand veins rarely develop thrombosis and so the level of VPA has been measured quantitatively in the more commonly at risk veins of the lower limb. In 6 limbs operated on for varicose veins, paired samples of vein from the groin and from the calf were examined. The median activity score for the groin veins (8138 cpm/micrograms) was significantly higher than the activity in the calf veins (2353 cm/micrograms)(P = 0.01). In 9 limbs amputated for critical ischaemia, paired samples of calf long saphenous vein and soleal vein were examined. The VPA in the former was 1675 cpm/micrograms compared with 6796 cpm/micrograms in the soleal veins. This difference is significant at the 1 per cent level. A correlation has been shown between the VPA content of these two sets of veins (R = 0.87). The low level of VPA in the superficial calf veins may be an aetiological factor in superficial thrombophlebitis, but the commonest site for DVT, the soleal veins of the calf, have a high level of VPA.     

Differences in pressures of the popliteal, long saphenous, and dorsal foot veins

PURPOSE: The purpose of this study was to examine the relationship among pressures obtained simultaneously in the popliteal, long saphenous, and dorsal foot veins. METHOD: Eight limbs were studied. One limb had an isolated popliteal vein reflux, and two had moderate long saphenous vein incompetence. No perforator or short saphenous vein insufficiency was detected. Pressures and recovery times of the popliteal/tibial and long saphenous veins were obtained with cannulation at the ankle level and insertion of catheters with a pressure transducer tip. The dorsal foot vein pressure was measured with the insertion of a scalp needle (14-gauge) connected to an external transducer. During 10 toe stands, recordings were simultaneously made in the three veins at the level of the knee joint, in the middle third of the calf, and 5 to 7 cm above the ankle with all the transducers at the same level (ie, same reference point). RESULTS: In one limb the popliteal/tibial pressure increased at all calf levels, whereas pressures decreased in both saphenous and dorsal foot veins. The pressures decreased in all three systems in the remaining seven limbs. There was no statistical difference between the pressure drop in the long saphenous vein and the deep vein. However, the decrease of the dorsal foot venous pressure was significantly more marked compared with the other two veins at all levels. The recovery time was significantly increased in the long saphenous vein compared with the deep vein; recovery time was further prolonged in the dorsal foot vein. CONCLUSION: The dorsal foot, long saphenous, and popliteal/posterior tibial veins clearly exhibit different pressure waveforms in response to calf exercise. The postexercise pressure, the percentage pressure drop, and the recovery times are widely different, which indicates that the three veins behave hydraulically as separate compartments in limbs without significant venous insufficiency.     

经腘静脉插管定向溶栓治疗下肢深静脉血栓形成的临床研究

目的评价腘静脉插管定向溶栓治疗下肢深静脉血栓的疗效。方法 62例下肢深静脉血栓患者,行患肢腘静脉穿刺插管,在可视条件下将导管插入至血栓近心端,经导管首次推注尿激酶20万单位后,持续注射尿激酶10万单位／h溶栓,同时每12 h皮下注射低分子肝素钠400 U。以下肢肿胀消退情况评价疗效,以深静脉造影评价溶栓效果。结果经导管溶栓治疗不仅使深静脉血栓部分或完全消融,而且侧支循环开放较治疗前显著增加。患肢总消肿率(78±22)％,总溶栓率(67± 27)％,其中急性、急慢性和慢性病例溶栓率分别为75％、71％,49％,前两者显著高于后者(P< 0．05)。21例患者血栓完全消融,无严重并发症发生。结论 腘静脉插管定向溶栓治疗下肢深静脉血栓形成能够快速溶解血栓,恢复深静脉血流通畅,患者临床症状改善效果满意,治疗方案安全可靠。