Analysis of 1,338 Patients with Acute Lower Limb Deep Venous Thrombosis (DVT) Supports the Inadequacy of the Term "Proximal DVT".

OBJECTIVE/BACKGROUND: For decades acute lower limb deep venous thrombosis (DVT) has been subdivided into distal DVT (isolated to the calf veins) and proximal DVT (extending above calf vein level). The aim of this study was to analyse the anatomical site and extent of thrombus in a large cohort of patients with acute DVT. METHODS: A retrospective analysis of all patients aged >18 years, presenting with unilateral DVT according to duplex ultrasound investigation was performed at the University Hospital of Antwerp, Belgium (1994-2012). The anatomical site and extent of thrombus was registered and subdivided into five segments: calf veins (segment 1), popliteal vein (segment 2), femoral vein (segment 3), common femoral vein (segment 4), and iliac veins, with or without inferior vena cava (segment 5). RESULTS: The median age of the 1,338 patients (50% male) included was 62 years (range 18-98 years). Left sided DVT was predominant (57%). DVT was limited to one segment in 443 patients, of whom 370 had DVT isolated to the calf veins (28% of total cohort). In 968 patients with what was previously called "proximal DVT", the median number of affected segments was three (range 1-5 segments). In this group iliofemoral DVT (at least involving segment four and/or five) was present in 506 patients (38% of total cohort), whereas the remaining patients had femoropopliteal DVT (at least in segment two and/or three but not in four or five). Iliofemoral DVT without thrombus in segments one and two was present in 160 patients (12% of total cohort). CONCLUSION: This study illustrates the large diversity of thrombus distribution in patients previously described as having "proximal DVT". Therefore, this term should be abandoned and replaced with iliofemoral and femoropopliteal DVT. Patients with iliofemoral DVT (38%) could be considered for early clot removal; 12% of all patients with DVT would be ideal candidates for such intervention.

Invasive treatment of deep venous disease. A UIP consensus.

Deep venous disease includes primary and/or secondary pathological changes in the deep venous system. These may consist of valve insufficiency, complete or incomplete vein obliteration and/or functional impairment.

Spontaneous onset of bacterial cellulitis in lower limbs with chronic obstructive venous disease.

BACKGROUND: Cellulitis, often recurrent is a common complication of severe chronic venous disease (CVD) when dermatitis or ulcer is present. The skin breakdown obviously provides easy entry for bacteria but other factors such as oedema and lymphatic dysfunction likely play a role in pathogenesis as well. An iliac obstructive lesion is commonly present and correction with stent(s) often heals dermatitis/ulcer and relieves cellulitis. The current manuscript focuses on a relatively infrequent "spontaneous" variety of cellulitis which also occurs in obstructive venous disease in the absence of overt skin breakdown. Stenting results are of particular interest in this subset because its therapeutic efficacy can be related to factors other than healing of dermatitis/ulceration (portal of entry). MATERIAL AND METHODS: One thousand and nine limbs underwent iliac vein stenting for symptomatic CVD over a 7 year period; 29 limbs that were stented to treat spontaneous recurrent cellulitis of two or more prior attacks and 16 additional limbs with only one prior episode (stented for other indications) are analysed. Eighty two percent of the limbs had obvious swelling and the remainder had none at the time of stenting when cellulitis was inactive. Iliac vein outflow obstruction was found by intravascular ultrasound (IVUS) and all limbs were stented. RESULTS: Median age was 54 and male to female ratio 1:2. Aetiology of iliac obstruction was post-thrombotic in 33% and non-thrombotic in 67%. Preoperatively, lymphatic abnormalities were present in 17 (38%) of the limbs: no activity in 7, delayed flow in 8 and pooling of isotope in the lower leg in 2 limbs. Swelling and pain improved significantly after stent placement. Cumulative freedom from recurrent attacks of cellulitis was 76% at 3 years. CONCLUSION: Iliac vein outflow obstruction may underlie CVD limbs afflicted with cellulitis. IVUS examination is recommended if cellulitis is recurrent and conventional therapy had failed. Correction of outflow obstruction by venous stent placement appears to yield moderate freedom from repeat infections in the near term.

Venous flow restriction: the role of vein wall motion in venous admixture.

OBJECTIVE: There are wide differences in flow between vascular beds at rest, even more during stress. The hydrodynamic energy (Energy grade line or EGL) of venous outflows must also vary considerably between vascular beds. We explored the mechanism of venous admixture of differing energy flows using a mechanical model. MATERIALS AND METHODS: The model simulated two venous flows coalescing at a venous junction and then flowing through collapsible venous pumps. Flow rates and pressures were monitored when the venous pumps were full (steady state) and when they were compressed and allowed to refill inducing wall motion (pump flow). RESULTS: With increasing EGL differences between two coalescing venous flows, reduction or cessation (venous flow restriction) of the weaker flow occurred during steady state; higher base EGL of both flows ameliorated venous flow restriction and lower base EGL the opposite. Outflow obstruction favoured venous flow restriction. Pump action in the vicinity of the venous junction abolished venous flow restriction and maximized both venous flows. CONCLUSION: The model suggests a pivotal role for vein wall motion in venous admixture and regional perfusion. Observations in the model are explained on the basis of network flow principles and collapsible tube mechanics.

Reversal of abnormal lymphoscintigraphy after placement of venous stents for correction of associated venous obstruction.

PURPOSE: The purpose of this study was to report improvement or normalization of abnormal lymphoscintigraphy in swollen lower limbs after correction of associated venous stenosis by balloon dilatation and placement of venous stent of the iliac veins. MATERIAL: Twenty-six patients with lower-limb swelling underwent balloon dilatation and placement of venous stent of the iliac veins for correction of venous stenosis. Technetium 99M-sulfur colloid lymphoscintigraphy was also abnormal (8 absent, 18 reduced) before stent placement in all 26 limbs, suggesting combined venous/lymphatic etiology for the limb swelling. Median age was 53 years. Male-to-female ratio was 1:8 and left-to-right ratio, 3:1. Fifteen patients had limb pain associated with the swelling. Severity of venous stenosis was generally underestimated by preoperative transfemoral venography as compared with intravascular ultrasound, (mean, 50% versus 77%); in five limbs (19%), transfemoral venography altogether failed to identify the venous lesion evident on intravascular ultrasound. The etiology of venous obstruction was post-thrombotic in nine limbs and nonthrombotic (web, stricture, or May-Thurner syndrome) in 17 limbs. RESULTS: Poststent lymphoscintigraphy completely normalized in 10 limbs, improved but remained abnormal in 9, and remained unchanged in 7. Clinical follow-up (mean, 1 year) showed improvement in swelling in 16 of 26 limbs (P <.022), with complete resolution of swelling in six; degree of pain also improved (P <.02), with total relief of pain in 9 of 15 patients. There was also significant improvement in all categories of a quality of life questionnaire. CONCLUSION: These findings suggest that patients with a diagnosis of lymphedema made on the basis of lymphoscintigraphy alone and consigned to conservative therapy on that basis may benefit from additional venous investigations regardless of clinical presentation suggestive of lymphedema. This report supports the practice of aggressively searching for a venous basis of edema in these patients. Correction of the venous lesion may result in normalization or improvement of the lymphoscintigraphic abnormality and in any case may yield significant symptom relief, even in some limbs where the lymphoscintigraphic abnormality failed to improve after placement of venous stent.

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.

Transcommissural valvuloplasty: technique and results.

PURPOSE: The purpose of this study was to describe the technique of a variation of closed external venous valve repair (transcommissural valvuloplasty), its complication rate, and duplex scan durability. METHODS: The "blind" transcommissural valve repair of the vein was performed by placing transluminal sutures along the valve attachment lines, which simultaneously closed the valve attachment angle and also tightened the valve cusps. A total of 179 successfully repaired valve sites of 141 limbs in 129 patients were followed up 1 to 42 months through clinical observation and with duplex Doppler ultrasound scan. RESULTS: Postoperative complications (< 30 days) occurred in 12 (9%) of 141 limbs: superficial (1) and deep (1) wound infection, large wound hematoma (4), seroma (1), and deep vein thrombosis (5), with associated pulmonary embolus in one patient. Seventy-eight percent (reflux time

Ambulatory venous pressure revisited.

PURPOSE: The purpose of this study was to describe a method for measuring the deep venous pressure changes in the lower extremity and compare it with those obtained in the dorsal foot vein. METHODS: After cannulation of the posterior tibial vein, a catheter with a pressure transducer in its tip was inserted and placed at the knee joint level. The dorsal foot vein was also cannulated. Pressures were recorded simultaneously at both sites during toe stands and repeated with the probe in the upper, middle, and lower calf. RESULTS: The study was performed in 45 patients with signs and symptoms of chronic venous insufficiency. Duplex Doppler scanning and ascending and descending venography performed before pressure measurements revealed saphenous vein incompetence in 11 lower extremities, incompetent perforators in 11 extremities (eight were combined with saphenous incompetence), and marked compression of popliteal vein with plantar flexion in 28 extremities. No significant deep axial reflux was observed on duplex Doppler examination or descending venography. No morphologic outflow obstruction was detected. The mean deep pressure at the knee joint level fell during toe stands, -15% +/- 27 (SD), and the mean dorsal foot vein pressure drop was even more marked, -75% +/- 22 (SD). Although the exercise pressure in the dorsal foot vein decreased in all patients (range, 13-90% drop), the popliteal vein pressure increased (4-72%) in nine limbs, decreased only marginally if at all in 15 limbs (0-15%), and fell more markedly in 21 extremities (22-65%). Deep vein recovery time was considerably shorter overall as compared with the findings by the dorsal vein measurement. In the comparison of limbs with and without superficial reflux, the recovery times in the deep system were significantly shorter in limbs with superficial incompetence. CONCLUSION: Ambulatory dorsal foot venous pressure is not always accurate in detecting changes in the pressure of the tibial and popliteal veins. Although dorsal foot venous pressure may be normal, deep venous pressure may decrease to a lesser degree or even increase.

Venous valve station changes in "primary" and postthrombotic reflux: an analysis of 149 cases.

The purpose of this study was to analyze valve station changes noted during venous valve reconstruction and the associated outcome. One hundred and forty-nine valve reconstructions were available for analysis at the time of surgical exploration; the venous valve was graded according to valve station changes (VS grades) from zero through six. Ascending venography was analyzed by a similar grading system and the two methods were compared. The results of this analysis showed that valve station wall changes are frequently present in patients with deep venous reflux and pose technical challenges during valve reconstruction; the outcome, however, appears unaffected. Grade 0 to 1 valve station changes are predominantly due to "primary" reflux, with an occasional instance of postthrombotic etiology. Grade 2 or 3 valve station changes are roughly evenly divided between phlebosclerosis of primary reflux and postthrombotic etiologies. The mechanism of onset of reflux with preservation of valve cusps in the latter group of postthrombotic cases is probably different from currently accepted theories of evolution of postthrombotic changes. Postthrombotic valve damage is variable, and the valve station anatomy may be sufficiently preserved in some patients to allow direct valve repair.

Balloon dilation and stenting of chronic iliac vein obstruction: technical aspects and early clinical outcome.

PURPOSE: To describe the technical aspects of percutaneous balloon dilation and stenting for the treatment of venous outflow obstruction in chronic venous insufficiency. METHODS: Between March 1997 and December 1998, 94 consecutive patients (median age 48 years, range 14 to 80) with suspected iliac vein obstruction in 102 limbs were studied prospectively with the intent to treat any venous occlusion or stenosis verified during femoral vein cannulation. Data from the history, clinical examination, procedure, and follow-up were recorded. Preoperative indicators of obstruction were venographic evidence of occlusion, stenosis, or pelvic collateral vessels; increased arm-foot venous pressure differential; and abnormal hyperemia-induced venous pressure elevation. RESULTS: Cannulation and technical success rates were 98% and 97%, respectively, with 118 Wallstents deployed in 77 veins. Primary, assisted primary, and secondary patency rates at 1 year were 82%, 91%, and 92%, respectively. Clinical improvement in pain and swelling was significant. CONCLUSIONS: Stenting of benign iliac vein obstruction is a safe method with good short-term results. Venous lesions should always be stented; when treating iliocaval junction lesions, stents should be inserted well into the inferior vena cava. Absence of collateral vessels does not exclude the existence of significant obstruction, and their presence may indicate an obstruction not visualized. No gold standard for accurate pre- or intraoperative patient selection is currently available.

Endovascular surgery in the treatment of chronic primary and post-thrombotic iliac vein obstruction.

OBJECTIVES: To compare the results and complications of endovascular surgery in limbs with post-thrombotic and non-thrombotic disease and to detail some technical aspects of the procedure. DESIGN: A single centre, prospective study. MATERIALS AND METHODS: Between March 1997 and August 1999, 139 consecutive lower extremities with chronic iliac venous obstruction (61 limbs with primary disease [MTS] and 78 with post-thrombotic disease [PTS]) were treated by balloon dilation and stenting. History, clinical examination, procedure and follow-up data were recorded. RESULTS: Mortality was zero. Non-thrombotic complication rate was only 3%. Postoperative (8%, 6/78) and late occlusion (3%, 2/69) occurred only in post-thrombotic limbs. Primary, primary-assisted and secondary cumulative patency rates of the stented area at 2 years were 52%, 88% and 90%, respectively, in the PTS group as compared to 60%, 100% and 100% in the MTS group. Clinical improvement in pain and swelling was significant in both groups. Half of active venous ulcers healed after the procedure. CONCLUSIONS: Chronic iliac vein obstruction appears to be a symptomatic lesion that can be treated safely and effectively by endovascular surgery regardless of aetiology. Generous use of IVUS is suggested in both diagnosis and treatment since phlebography is unreliable. The clinical improvement was significant in both groups; however, more excessive neointimal hyperplasia and a higher early and late occlusion rate were observed in post-thrombotic disease. Stenting after balloon dilation is advised in all venoplasties; stents should be inserted well into the IVC when treating iliocaval junction stenosis. A wide-diameter (16 mm) stent is recommended. The stent should cover the entire lesion as outlined by the IVUS.

Popliteal vein entrapment: a benign venographic feature or a pathologic entity?

PURPOSE: Asymptomatic morphologic popliteal vein entrapment is frequently found in the healthy population (27%). In our institution, popliteal vein compression on plantar flexion was observed in 42% of all ascending venograms. Some authorities consider the lesion benign, without pathologic significance. This study examines the pathophysiologic importance in select patients, describes treatment with surgery, and suggests a diagnostic tool. METHOD: Thirty severely symptomatic patients with venographic evidence of popliteal entrapment were selected to have popliteal vein release after a process of elimination (ie, other causes of chronic venous insufficiency [CVI] were ruled out by means of comprehensive hemodynamic and morphologic studies). In the last nine limbs, popliteal vein pressure was also measured by means of the introduction of a 2F transducer tip catheter. Patients were clinically and hemodynamically assessed before and after surgery, and anatomical anomalies encountered during surgery were recorded. RESULTS: Popliteal vein release was performed without mortality or serious morbidity. Anomalies of the medial head of the gastrocnemius muscle caused entrapment in 60% of the patients; anatomic course venous anomalies were infrequent (7% of the patients). Significant relief of pain and swelling occurred in the patients who had surgery. Stasis ulceration/dermatitis resolved in 82% of patients. Popliteal venous pressures had normalized in the six patients who were studied postoperatively. CONCLUSION: Popliteal vein entrapment should be included in the differential diagnosis of CVI in patients in whom other, more common etiologies have been excluded on the basis of comprehensive investigations. Popliteal vein compression can be demonstrated venographically in a large proportion of patients with CVI, but the lesion is likely pathological only in a small fraction of these patients. A technique for popliteal venous pressure measurement is described; it shows promise as a test for functional assessment of entrapment. Immediate results of popliteal vein release surgery are encouraging; long-term follow-up is necessary to judge the efficacy of surgical lysis of entrapment in symptomatic patients who fail to improve with conservative treatment measures.