An audit of the clinical and sub-clinical changes in the first year following an acute deep vein thrombosis.

BACKGROUND: An audit of 100 proximal (above knee) deep vein thromboses (DVT) was carried out to document the dynamic status of the condition during the first year. METHODS: Duplex ultrasound was used to diagnose the presence of an acute deep vein thrombosis in a consecutive series of patients. Follow-up bilateral ultrasound scans were performed at one week, one month, six months and at one year and clot retraction, lysis or extension were recorded. The patients' treatment regime and symptoms were also recorded at each follow-up examination. RESULTS: There were 100 proximal DVT's from 89 patients (11 bilateral thromboses). The patient population included those with a previous history of DVT or in the end stages of a major illness and those with reversible risk factors. The mortality rate over the one-year period was 14 percent, most of the deaths occurring in the first month. The majority of deaths occurred as a result of an underlying primary disease (e.g. cancer) and 3 percent died from a pulmonary embolism. All patients were treated initially with either intravenous (IV) heparin or subcutaneous low molecular weight (SCLMW) heparin. Following heparin all patients were treated with warfarin. The duration of anticoagulant therapy varied with most physicians treating the patient for six months. Symptomatic and asymptomatic events (pulmonary emboli, extension of thrombi, new DVT's) were recorded in the follow-up period especially in the initial and late phase. CONCLUSIONS: The audit concluded that the diagnosis and treatment of DVT continues to be a major clinical problem with uncertainty as to the type and length of treatment required. The mobility of the patient was not considered in the choice of initial heparin treatment. Anticoagulants were generally continued for a period of up to six months regardless of the patient's risk factors. Little consideration was given to asymptomatic events with physicians still depending on unreliable clinical symptoms to determine if recurrences had occurred. Generally, no consideration was given to the long-term consequences of a post-thrombotic limb at the initial stage of treatment of a DVT.

Underlying factors influencing the development of the post-thrombotic limb.

PURPOSE: This study was designed to determine whether patients having underlying venous disease in their contralateral limbs indicates a more severe long-term clinical outcome in the ipsilateral limb after a deep vein thrombosis (DVT) and to determine what other factors may influence the long-term outcome. METHODS: An acute DVT was initially diagnosed by means of duplex ultrasound scanning. Follow-up clinical examinations and bilateral duplex reflux studies were performed for a mean period as long as 3 years. The patients were divided into two groups: group I, those with no history of a contralateral DVT, and group II, those with a history of a contralateral DVT. The patients were classified at their final examination according to the Clinical, Etiology, Anatomic, Pathophysiologic (CEAP) classification, and the ipsilateral and contralateral limbs were compared. Predisposing factors were compared with the final clinical outcome. RESULTS: Sixty-three patients were monitored in a mean follow-up period of 3 years. There was a significant difference in the incidence of symptoms between the ipsilateral limbs (P <.01) and the contralateral limbs (P <.001) for both groups. There was no significant difference between the incidence of superficial reflux between the ipsilateral and contralateral limbs, but the deep venous system and perforator veins were involved more often in the ipsilateral limbs. In group I, only six patients (10%) had no evidence of venous dysfunction (CEAP = 0) in their ipsilateral or contralateral limbs at the time of the final examination, and all patients had reversible risk factors. Of patients who had a mild clinical outcome (CEAP score, 1 to 3), 64% had a healthy contralateral limb, and the remaining 36% had mild to moderate disease. Eighty percent of patients with the most severe clinical outcome (CEAP > 3) had mild to moderate venous disease in their contralateral limb and had nonreversible risk factors. CONCLUSION: There are a significant number of patients with an acute DVT who had an underlying venous disease in the uninvolved contralateral limb. An ipsilateral post-thrombotic limb is more likely to develop in patients with primary venous reflux after an acute DVT. The level of venous dysfunction in the contralateral limb is an indication of the severity of disease developing in the ipsilateral limb. The initial risk factors of the patients have an influence on the final clinical outcome.

The patterns and distribution of residual abnormalities between the individual proximal venous segments after an acute deep vein thrombosis.

INTRODUCTION: The subsequent course of residual abnormalities after an acute deep vein thrombosis (DVT) can vary within individual venous segments. To investigate the pattern of response within the individual venous segment, we used sequential duplex scanning to determine whether certain segments are more likely to recanalize or remain occluded. METHODS: The anatomic segments involved in 63 above-knee DVTs were examined with duplex scanning at 1 week, 1 month, 6 months, and 1 year after the acute event. The segments under investigation were the external iliac vein (EIV), common femoral vein (CFV), superficial femoral vein (SFV), and popliteal vein (PV). Reflux studies were performed at each follow-up examination. During the follow-up period the segments were examined to see whether they were occluded, partially recanalized, or totally recanalized and the development of reflux was noted. RESULTS: Most DVTs were multisegmental with a total number of 171 sites involved. Initially, a greater number of segments were occluded (71%) than partially thrombosed (29%). The occluded segments were predominantly in the SFV and PV. At 1 year the thrombi had fully resolved in 60% of the venous segments, 27% remained partially recanalized, and 13% were occluded. The venous segments that resolved within the first 6 months had a higher rate of valvular competence than those that resolved from 6 months to 1 year. The SFV and PV had a higher incidence of valvular incompetence than the EIV and CFV. All venous segments that were partially recanalized at 1 year were found to have significant reflux. The SFV had the highest incidence of total occlusion at the end of 1 year (36%). Many of the occluded SFVs had established collateral pathways that displayed no evidence of reflux. CONCLUSION: The lower extremity venous segments differ in respect to their tendencies to partially or fully recanalize or remain occluded. All partially recanalized segments displayed reflux. Fully resolved segments that recanalized within the first 6 months were more likely to have competent valves than those that recanalized after 6 months. In the presence of an occluded SFV, collateral pathways establish rapidly. No reflux was found in these collaterals.

Determining the stage of organisation and natural history of venous thrombosis using computer analysis.

BACKGROUND: In vitro studies have shown that as the organisation of a thrombus progresses its ultrasound appearance becomes more echogenic. When diagnosing a deep vein thrombosis (DVT) using duplex ultrasound, an estimation of the degree of organisation of the thrombus is made by assessing its echogenicity. This method is purely subjective and has many pitfalls. METHODS: A study was performed on 100 proximal DVTs from 89 patients diagnosed by duplex ultrasound. These images were transferred to a computer and standardised using, the adobe Photoshop. The thrombus in the image frame was outlined and the grey scale median (GSM) calculated. The grey scale median which is a measure of the echogenicity of the thrombus (indicating the degree of organisation), varied considerably from patient to patient. RESULTS: The results show that the level of organisation of a thrombus on initial diagnosis is unrelated to the clinical signs or duration of symptoms of the patient. This has further implications when considering a therapy regimen based on the duration of symptoms (e.g. thrombolysis). Additionally, the age of the patient, predisposing factors and bulk of the thrombus appear to be unrelated to the value of the grey scale median at the initial visit. The initial grey scale median values were then compared to those at a one week's follow-up examination. Those with a low initial value of the grey scale median were found to increase, indicating further organisation, as expected. However, patients with higher initial grey scale median values were found to fluctuate, some increasing and some decreasing. The increase the grey scale median was due to a more homogenous appearance across the thrombus as the organisation process became more established. A decrease in grey scale median indicated areas of lysis occurring within the thrombus. CONCLUSIONS: Measuring the value of the grey scale median is a quantitative way of assessing the degree of organisation of a deep vein thrombosis. This can be used to asses the suitability of patients for various treatment regimen. It is also a useful means of assessing the long-term implications of different therapies and could aid in determining the long-term outcome for the patient.

The value of computer analysis in predicting the long-term outcome of deep vein thrombosis.

BACKGROUND: The use of standardised computerised ultrasound images is an objective and quantitative method of determining the echogenicity of thrombus. This method had been applied to study the natural history of 100 acute thrombi over a period of one year to determine if early changes in echogenicity could indicate whether the thrombus would lyse, partially recanalise or remain occlusive. METHODS: A consecutive series of 100 above knee deep vein thromboses (DVT's) were analysed over a period of one year. The presence of a DVT was initially diagnosed by duplex scanning and the patients underwent follow-up scans at one week, one month, six months and at one year. A grey scale image of the thrombus was transferred to a computer at each examination and its grey scale median (GSM) was measured. The mean GSM's were calculated for each examination and compared. At one year the patients were divided into groups according to their final outcome (i.e. lysis, recanalisation or occlusion) and the mean GSM values from each group were compared. RESULTS: There were 100 proximal DVT's from 89 patients. At one year 14% of the patients had died and 23% were lost to follow-up. The mean GSM values increased over the one year period from 25.87+/-18.33 to a final value of 64+/-25.52 at one year. A total of 21 thrombi had fully resolved but there was no significant difference in their GSM values before resolution when compared to the other patients. Twenty-four patients had partially recanalised thrombi and 18 remained totally occluded. There was no significant difference in mean GSM values between these two groups until after six months when the permanently occluded venous segments had higher GSM values than those which partially recanalised. CONCLUSIONS: Measurement of GSM is an objective method of determining the degree of organisation of a thrombus and describes the subjective changes of individual thrombi. However, the organisation of a thrombus is a dynamic process and mean GSM values did not reflect these changes. Early changes in GSM could not predict the final outcome of the thrombus i.e. lysis, recanalisation or occlusion.

The value of duplex ultrasound in the follow-up of acute calf vein thrombosis.

Calf veins are one of the most common sites for deep vein thrombosis (DVT) but the management of patients with calf vein thrombosis differs. Many centres consider pharmacological treatment unnecessary and elect not to examine the calf veins with duplex ultrasound. Others advocate monitoring the thrombus with serial venous duplex scanning and commence treatment if there is evidence of propagation. In this laboratory duplex scanning of the calf veins is routinely carried out as part of the diagnostic procedure for DVT. A study was carried out where 50 patients with isolated calf vein thrombosis were followed over a one year period to determine the long term outcome in the calf veins. Note was made of the choice of treatment. A high percentage (85%) were treated with heparin/warfarin and only 15% received no pharmacological treatment. There was a propagation rate of 15%, one of which resulted in a fatal pulmonary embolus (PE). The DVT recurrence rate was 14% within the year. No long term effects such as valvular damage were noted during the follow-up period. The results suggest the need for better guidelines for the diagnosis and treatment of isolated calf vein thrombosis. Future studies with larger groups of patients need to be carried out to determine the significance of the recurrence rate and the long term effects. Duplex scanning enhances the diagnosis of calf vein thrombosis and should be used for closer observation of potential thrombus propagation.

Natural history of proximal deep vein thrombosis assessed by duplex ultrasound.

BACKGROUND: The late sequelae of an acute deep vein thrombosis (DVT) are difficult to predict. There are many retrospective studies which suggest that the post-phlebitic syndrome is associated with the development of valvular incompetence but these have lead to little understanding of the changes involved in the venous system following an acute thrombotic event. Duplex ultrasound imaging is an useful method to study changes in the venous system because it can locate a thrombus, assess the changes which occur over time and monitor the development of recanalization and reflux of blood flow. METHODS: In this study, 50 patients were followed by serial duplex ultrasound examination to determine if a more accurate prediction of patients at risk could be found. Rapid thrombolysis and extent of the thrombosis are both factors which influence the return of the vein to normal function. RESULTS: Complete thrombolysis within a short period of time occurred in 24% of patients resulting in preserved valvular function. After one year there were 34% with early post-phlebitic symptoms. All of these patients had veins which recanalized slowly and developed valvular incompetence with reflux. Veins remained occluded in 14% of patients and of these 8% had competent collateral channels. This appeared to be a better outcome because none of these patients had developed symptoms after one year. Recurrent DVT's occurred in 8% within the year. Of these, 4% presented with symptoms and 4% were without symptoms but thrombus was found by ultrasound examination. CONCLUSIONS: Serial duplex examination leads to better understanding of the natural history of an acute DVT. This may have clinical implications and lead to better management of acute DVT thereby reducing the long term risks of the post phlebitic limb.

Laser laparoscopy versus laparotomy in the treatment of infertility patients with severe endometriosis.

The best pregnancy rates reported in the literature for infertility patients with severe pelvic endometriosis (stage IV) have been attributed to surgical management. In the last few years, improved endoscopic instruments have allowed gynecologists to treat difficult conditions with the CO 2 laser via laparoscopy, with good results. To assess the usefulness of the CO 2 laser via laparoscopy in treating severe pelvic endometriosis, two groups of patients were studied. Thirteen patients were treated by laparotomy (group I) and 11 patients by laparoscopy (group II). Seven achieved pregnancy in group I (53.8%), and pregnancy occurred in 6 patients in group II (54.5%). This study suggests that the management of severe pelvic endometriosis in infertility patients via laparoscopy seems to yield similar pregnancy rates to those treated with laparotomy, with the advantages of faster recovery and fewer hospitalization days for those undergoing laparoscopic surgery.

Cardiac and peripheral arterial responses to isoprenaline challenge.

Changes in 1) heart rate, 2) brachial blood pressure, and 3) ankle systolic blood pressure, have been measured together with 4) diameter, 5) mean blood velocity, and 6) mean volume flow in the common femoral and posterior tibial arteries in normal volunteers following intravenous infusions of isoprenaline. A total of 70 studies in 15 normal volunteers were carried out using a sequence of three increasing doses of isoprenaline. Significant increases were observed in 1) heart rate, 2) brachial systolic blood pressure, and 3) femoral artery diameter, mean blood velocity and volume flow (p less than 0.001). Significant decreases were observed in 4) brachial diastolic pressure, and 5) ankle systolic pressure (p less than 0.001). In the posterior tibial artery, the diameter increased significantly at the highest isoprenaline dose but changes in velocity and volume were not significant. This investigation shows reproducible cardiovascular responses to intravenous isoprenaline in normal volunteers. Different responses were observed between the common femoral and posterior tibial arteries. Blood flow volume and velocity increased significantly in the femoral artery, whilst there was a trend towards an increase in volume blood flow with a decrease in velocity blood flow in the posterior tibial artery site. This difference between the two peripheral arteries is presumably due to a difference in the area of supply of the two arteries, the larger vessel predominately supplying muscle and the smaller vessel skin. Thus there may be either a different pattern of reflex outflow activity, and/or differences in the beta-adrenoceptor population of the sites supplied by the femoral and posterior tibial arteries.

Blood volume flow and sonagram disturbance in diseased common carotid arteries: one year follow-up.

A pulsed Doppler velocimeter with an adjustable range gated time system and a double transducer probe has been used to measure velocity and volume flow in follow-up studies of 100 patients with extra-cranial cerebro-vascular disease. The patient material was subgrouped according to whether the disease involved the carotid or vertebral arteries unilaterally or bilaterally. The results showed an unexpected and unexplained trend towards an improvement in mean volume blood flow in the common carotid arteries over the course of 1 year except in those patients who initially presented with four vessel disease in whom there was a trend towards deterioration. In contrast to this spectral analysis of the blood velocity flow showed evidence of deterioration with an increase in flow disturbance and damping. This deterioration was observed either in the vessel originally found with disease or by involvement of an additional vessel showing evidence of disease at the time of follow-up. The deterioration in sonagram appearance was statistically significant in the two and four vessel disease groups (0.025 greater than P greater than 0.01) the remaining two groups showed a similar trend towards deterioration but the numbers of patients in these two groups was probably too small to attain statistical significance.

Pulsed Doppler: a classification of results of diameter, velocity and volume flow measurement in diseased common carotid arteries.

Arterial diameter, mean velocity and mean volume flow was measured in 580 common carotid arteries of 290 patients. These patients were undergoing investigations for carotid artery disease and selection for arterial surgery. A pulsed Doppler velocimeter with an adjustable range gated time system and a double transducer probe was used. The results were classified using each of the parameters to determine which would give the most reliable method of subgrouping from normal range values through mild, moderate and severe reduction. Subgrouping by mean volume was found to be the most satisfactory method of expressing the results. Disturbance in the sonogram was observed in all examinations and the distribution of changes was not affected by the method of subgrouping used. The findings in this study suggest that interpretation of results from either diameter or velocity alone should be approached with caution.

Pulsed Doppler: determination of blood velocity and volume flow in normal and diseased common carotid arteries in man.

A pulsed Doppler velocimeter with an adjustable range gated time system and a double transducer probe has been used to measure volume blood flow in 50 normal and 50 diseased common carotid arteries. A significant difference in mean volume flow between normal and diseased arteries was found (P less than 0.0001). On-line audio-frequency display of velocity signals were evaluated in each of the arteries together with angiographic description of the diseased arteries. Disturbance of the velocity profile develops before significant changes in volume flow or angiogram occur. Volume flow results and angiogram appearance relate best when the angiogram description is either of minimal disease or severe disease. Determination of dynamic flow conditions from structural appearance of arteries are not consistently dependable.