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.     

Sequential in-situ saphenous vein bypass. Early results and technique

This report summarizes early results with saphenous vein bypass (SVB) utilizing both sequential and in-situ techniques (SIS SVB) in eight limbs requiring limb salvage. SIS SVB was performed to a variety of vessel combinations using "Y" graft, continuous, or vein extension techniques achieving early patency in all limbs, despite pedal arch disease. Postoperatively, there was a significant increase in ankle/brachial Doppler indices (ABI) (P less than 0.001) at dorsal pedal (0.23-0.88) and at posterior tibial (0.32-0.91). Successful isolated popliteal grafting was confirmed by return of phasic Doppler wave forms. All but one limb healed with minimal tissue loss within 1 month of bypass. Preoperative high resolution angiography and clinical Doppler evaluation of saphenous vein anatomy are mandatory to determine candidacy for SIS SVB.     

Selective stripping operation based on Doppler ultrasonic findings for primary varicose veins of the lower extremities

In 337 limbs (208 patients) with primary varicose veins, Doppler ultrasound was used to detect reverse flow in the saphenous veins caused by manual compression of the calf. According to the extent of reverse flow in the saphenous trunks, varicosities of the long saphenous vein were classified into five types and the short saphenous vein, into four types. Two hundred five (66.3%) of 309 limbs with varicosities of the long saphenous vein had reverse flow in the entire saphenous trunk from the groin to the ankle. In varicosities of the short saphenous vein, 37 (52.9%) of 70 limbs showed reverse flow from the popliteal fossa to the ankle. The other limbs demonstrated reverse flow only in some segments of the saphenous veins. On the basis of these Doppler ultrasonic findings, selective stripping operations were performed on 80 limbs, in which only the segments with venous reverse flow were selectively removed. Postoperative plethysmographic measurement of the venous reflux volume and follow-up studies showed that results of the selective stripping operations were as satisfactory as those of the standard stripping operations (189 limbs) in which the entire saphenous vein was removed. Furthermore, the selective stripping operation was advantageous in reducing the incidence of nerve injury.     

Valvular incompetence in superficial, deep and perforator veins of limbs with varicose veins

Venous valvular incompetence was investigated with Doppler technique in 296 limbs with untreated primary varicose veins. Partial or complete insufficiency of the long saphenous vein was found in 95%. Six patterns of incompetence of this vein could be distinguished. Insufficiency of the short saphenous vein was present in 15% of the limbs and perforator incompetence in 45%. Femoral and/or popliteal vein reflux was found in 20% of the limbs. In eight limbs (2.7%) with verified primary deep venous insufficiency there was a moderate or severe degree of femoral and popliteal venous reflux. Skin changes secondary to the venous disease were present in 18% of the limbs, mainly those with incompetence of perforator and long saphenous veins. Doppler investigation of varicose limbs give valuable information and can be recommended as a standard pre-treatment test.     

电凝术治疗下肢静脉曲张168例中长期随访报告

目的总结电凝术治疗下肢静脉曲张的疗效。方法2000年4月～2007年4月电凝法治疗下肢静脉曲张168例238条肢体。经踝大隐静脉主干顺行插入电凝器至大隐静脉根部,高位结扎后用电凝针及电凝器分别电凝静脉曲张团块及大隐静脉主干。结果术后住院时间1～2d,无切口感染。踝周溃疡4周内全部愈合。近期并发症：局部皮肤Ⅰ度灼伤1例1条肢体,Ⅱ度灼伤1例1条肢体;浅静脉炎痛2例2条肢体;踝周麻感10例14条肢体。随访148例208条肢体,时间2～9年,平均6.6年,复发率3.4%（7/208）;下肢酸胀感缓解率95.3%（162/170）;皮炎及湿疹缓解85.7%（12/14）;踝周色素沉着缓解率41.7%（15/36）;胫前及踝周水肿缓解率为36.4%（16/44）。结论电凝术创伤小,术后恢复快,复发率低,疗效可靠,是治疗下肢静脉曲张的理想方法。     

Long saphenous incompetence as a cause of venous ulceration

Four hundred and seventeen consecutive patients referred with significant chronic venous disorders of the lower limb have been studied. Two hundred and ninety-nine were considered to have uncomplicated primary varicose veins, with saphenous incompetence. The remaining 118 presented with past or current skin ulceration, prominent pain and swelling, or both. Ascending and descending venography and further Doppler studies revealed only 18 patients (17 with ulceration) with an incompetent long saphenous system and ankle perforators as the only identifiable abnormalities. In 12 of these, patients' dorsal foot vein pressures were measured at rest and the maximum fall demonstrable after exercise expressed as a percentage of this (12.9 per cent +/- 6.0). This test was repeated with a narrow tourniquet inflated to 160 mmHg, applied to the mid-thigh (35.6 per cent +/- 7.4) (P less than 0.05), and again after accurate groin ligation and stripping of the long saphenous vein to the knee (31.9 per cent +/- 10.7) (P less than 0.05). These results seem to validate the use of the foot pressure/tourniquet test in assessing the relevance of saphenofemoral incompetence, and suggest in a proportion of venous ulcers this is a princical factor.     

In situ vein bypasses to distal tibial and limited outflow tracts for limb salvage

To better define the limits of tibial reconstruction with saphenous vein bypass, we have analyzed our experience with the in situ vein valve incision technique in 83 cases of bypasses to the ankle or foot and 13 cases of bypasses to discontinuous tibial vessels. Bypasses to the ankle and foot had a 36-month cumulative patency rate of 70.4%. No statistical difference was noted with the use of small-caliber veins. The length of the bypass did not prejudice the long-term patency rate. Discontinuous tibial vessels can be used satisfactorily as an outflow tract for limb salvage.     

Manual high-dose regional intraoperative thrombolysis of lower extremity emboli after open repair of a ruptured abdominal aortic aneurysm

We describe a case of high-dose regional intraoperative thrombolysis subsequent to mechanical thrombectomy for the treatment of postoperative distal extremity embolization of the right lower limb owing to open repair of a ruptured abdominal aortic aneurysm. Mechanical thrombectomy was performed from the popliteal artery but residual embolic occlusion of all three tibial arteries remained. The limb was elevated, exsanguinated, and a blood cuff was placed below the knee and inflated to suprasystolic pressure to isolate the limb from systemic circulation. An 18-gauge infusion catheter was introduced to the exposed dorsalis pedis artery. Subsequently, the exposed great saphenous vein was cannulated and drained. A total of 100 mg of recombinant tissue-type plasminogen activator diluted in 500 mL of saline was infused into the anterior tibial artery with a slow hand infusion for 30 minutes. The infusion was continuously collected through the great saphenous cannulation and a closed loop was confirmed by angiogram. The limb was flushed with heparin and saline solution. Infusion catheter was extracted and the great saphenous vein was ligated. Blood cuff was removed, arterial flow was re-established, and a postprocedural arteriogram confirmed successful revascularization. This method may be an alternative to microtibial embolectomy at the foot ankle level after severe lower limb embolization after acute open repair of a ruptured abdominal aortic aneurysm.     

Relationship of venous reflux to the site of venous valvular incompetence: implications for venous reconstructive surgery

To evaluate the relationship of the site of venous valvular incompetence to the severity of venous reflux, legs of 71 patients with suspected chronic venous insufficiency were evaluated with Doppler ultrasonography and photoplethysmography. A venous recovery time (VRT) of less than 20 seconds after calf muscle exercise was considered indicative of significant reflux. Average VRTs were brief in 15 legs with stasis changes (10 +/- 7 seconds), longer in 42 legs with edema (26 +/- 23 seconds), and normal in 64 asymptomatic legs (37 +/- 24 seconds) and 16 legs with pain (53 +/- 19 seconds). Average VRTs in limbs with incompetent saphenous veins were abnormal. In limbs with competent superficial veins, only those with incompetent distal deep veins (popliteal and posterior tibial) had abnormal VRTs (14 +/- 10 seconds). VRTs in limbs with no detectable valvular incompetence and in those with incompetence limited to the proximal deep veins (common and superficial femoral) were normal (47 +/- 23 and 42 +/- 27 seconds, respectively). When superficial veins were incompetent, an ankle tourniquet normalized VRTs in 63% of legs with proximal deep venous incompetence and in only 33% of legs with distal deep venous incompetence. It is concluded that venous reflux is largely determined by saphenous and distal deep valvular function and that competence of the proximal valves has little effect. Decreased venous reflux would not be expected after proximal valvular reconstruction.     

Femoral venous reflux abolished by greater saphenous vein stripping

Preoperative venous duplex scanning has revealed unexpected deep venous incompetence in patients with apparently only varicose veins. Acting on the hypothesis that the deep vein reflux was secondary to deep vein dilation caused by reflux volume, the following was done. Between July 1990 and April 1993, 29 limbs in 21 patients (16 females) were examined by color-flow duplex imaging to determine valve closure by the method of van Bemmelen. Instrumentation included high-resolution ATL-9 venous interrogation using a pneumatic cuff deflation stimulus of reflux in the standing, nonweight-bearing limb. All limbs showed greater saphenous vein reflux. Twenty-nine showed superficial femoral vein reflux and of these three showed popliteal vein reflux. Duplex testing was performed by a certified vascular technologist whose interpretation was blinded as to the results of clinical examination and grading of the severity of venous insufficiency. Surgery was performed on an outpatient basis under general anesthesia using groin-to-knee removal of the greater saphenous vein by the vein inversion technique of Van Der Strict. Stab avulsion of varicose tributary veins was accomplished during the same period of anesthesia. In 27 of 29 limbs with preoperative femoral reflux, that reflux was abolished by greater saphenous stripping. In patients with popliteal reflux both femoral and popliteal reflux was abolished. Improvement of deep venous hemodynamics by ablation of superficial reflux supports the reflux circuit theory of venous overload. Furthermore, preoperative evaluation of venous hemodynamics by duplex scanning appears to provide useful pre- and postoperative information regarding venous insufficiency in individual patients.Presented at the Twelfth Annual Meeting of the Southern California Vascular Surgical Society, Coronado, Calif, September 17–19, 1993.     

腘静脉肌袢成形术治疗下肢深静脉瓣膜功能不全

目的研究下肢腘静脉肌袢成形术治疗下肢深静脉瓣膜功能不全的临床疗效. 方法 1997年1月～2001年6月,选择经过彩色多谱勒、静脉造影确诊为原发性下肢深静脉瓣膜功能不全的27例(27条)下肢,病程2～32年,平均17.4年.均有浅静脉曲张;其中小腿沉重感25例;肿胀22例;足靴区色素沉着25例;单侧慢性溃疡19例;2例曾行单纯大隐静脉结扎剥脱术.静脉压静息直立时平均为(11.00±0.73) kPa, 活动后平均为(9.14±0.68) kPa.均行腘静脉肌袢成形术,同时行大隐静脉高位结扎抽剥术,有12例行腔镜下交通支结扎. 结果术后27条患肢静脉压活动后平均下降为(5.94±0.82) kPa.与术前活动后平均值比较,差异有统计学意义(P<0.01).近期疗效良好,小腿沉重感及肿胀完全或基本消失,溃疡创面在2周内愈合.术后22条患肢获2～6年随访,21条患肢疗效优良,无复发;1例随访3年时因肌袢粘连导致小腿深静脉血栓形成. 结论严格掌握适应证,规范手术操作,腘静脉肌袢成形术治疗下肢深静脉瓣膜功能不全,可获得满意效果.     

Arterial reconstruction of vessels in the foot and ankle.

OBJECTIVE: This study demonstrated that arterial reconstruction of vessels of the foot and ankle can preserve the majority of ischemic extremities with extensive tibial and peroneal occlusive disease and patent pedal arteries. SUMMARY BACKGROUND DATA: There are successful reports of bypass procedures to the ankle and foot, but despite this, these procedures have not gained widespread acceptance among surgeons performing infra-inguinal revascularization. Primary amputation is often offered for such patients. For this reason, the authors have reviewed their experience with bypasses to the foot and ankle. METHODS: A retrospective review was done of 75 arterial bypasses (5 bilateral), done since 1985, to the ankle and foot in 70 patients (38 males and 32 females). Fifty-four (77%) of the patients were diabetic. The age ranged from 55 to 95 years. Twenty-six (37%) were older than 80 years. The patients were selected for operative intervention because of severe tibioperoneal occlusive disease with ischemic rest pain or gangrene of the foot. Digital subtraction arteriography facilitated visualization of distal vessels. Operative principles included regional anesthesia, autogenous graft material, short bypass, non-traumatic vessel occlusion, selective operative arteriography, tension free ankle and foot skin closure, and concomitant conservative debridement of infected devitalized tissue. Incomplete pedal arch did not influence decision for operation. Indications for operation were: gangrene, 42 (56%); non-healing ulcer, 21 (28%); and rest pain, 12 (16%). Graft material was in situ greater saphenous vein, 40 (53%); translocated greater saphenous vein, 19 (25%); reversed greater saphenous vein, 11 (15%); and arm vein, lesser saphenous vein or vein patch, 5 (7%). Donor artery was popliteal, 30 (41%); common femoral, 26 (35%); and superficial femoral, 17 (23%). Recipient vessel was dorsalis pedis, 43 (57%); posterior tibial, 18 (24%); distal anterior tibial, 9 (12%); and distal peroneal, plantar or tibial endarterectomy, 5 (7%). RESULTS: There were four (5.7%) deaths and three (4.2%) graft failures within 30 days. Early graft failure led to transmetatarsal amputation (1), below knee amputation (1), and conversion of graft to femoral (1), popliteal bypass graft with limb salvage (1). In one patient, significant tissue necrosis with infection necessitated a below knee amputation within 30 days, despite a patent graft. Long-term follow-up revealed 10 graft failures, 4 major amputations, 3 graft revisions, and 15 deaths. Cumulative primary and secondary patency was 79.0% and 81.6% at 36 months. Limb salvage was 87.5% at 36 months. CONCLUSIONS: These results support an aggressive approach to limb salvage in patients with threatened limb loss, unreconstructable tibio-peroneal occlusive disease, and patent pedal arteries. Bypasses to the ankle and foot will maintain a functional extremity in the majority of these patients.     

Influence of phlebographic abnormalities on the natural history of venous ulceration

Eighty-five limbs in 73 patients with a healed venous ulcer were assessed by ascending and descending phlebography, foot volume plethysmography and transcutaneous oxygen measurements. Forty-four limbs had post-thrombotic changes on ascending phlebography. In 24 (28 per cent) these extended into the femoral vein, while in 20 (24 per cent) only the calf veins were involved. In the 41 limbs (48 per cent) with normal deep veins on ascending phlebography, 11 had evidence of localized incompetence of the calf communicating veins, 14 had either long saphenous incompetence, deep vein reflux to the level of the knee or below, or both of these abnormalities, and 16 limbs had no phlebographic abnormalities. However all limbs had a decreased half volume refilling time on foot volume plethysmography. Limbs with post-thrombotic changes extending into the femoral vein were associated with a significantly longer history of ulceration and more ulcer recurrences than limbs with calf vein damage (P less than 0.05 for each) and limbs with normal deep veins (P less than 0.01 for each). However, these limbs did not have lower transcutaneous oxygen ratios or longer times to achieve ulcer healing. Ascending phlebography identified a group of limbs with extensive post-thrombotic changes in which there was a higher incidence of ulcer breakdown, but this was not associated with a delay in ulcer healing.     

Prospective study of duplex scanning for venous reflux: Comparison of Valsalva and pneumatic cuff techniques in the reverse Trendelenburg and standing positions

Purpose: To achieve uniform testing of venous reflux between institutions, comparable methods of testing by duplex scanning are desired. This study directly examines differences of testing by two techniques, Valsalva and rapid cuff deflation, performed in two positions: 15-degree reverse Trendelenburg (RT-15) and standing.Methods: Duplex examination of 22 extremities in 19 patients with moderate to severe, class 2 and 3 chronic venous insufficiency symptoms were compared with duplex scanning of 21 limbs in 11 normal, healthy volunteers. Duration of retrograde flow and peak velocity were measured in 247 venous segments. All extremities were studied in four ways: RT-15 Valsalva, standing Valsalva, RT-15 cuff, and standing cuff. Reflux was defined as duration of retrograde flow or reflux time greater than 0.5 seconds. Six venous segments were examined: common femoral, superficial femoral, deep femoral, and greater saphenous in the upper thigh, popliteal, and posterior tibial (at the ankle).Results: The results of testing the Valsalva technique and the cuff in both the RT-15 and standing non-weight bearing positions indicate that the Valsalva method is best performed in the RT-15 position as opposed to standing, whereas the cuff technique is more effective in the standing position. In symptomatic limbs, the RT-15 Valsalva method showed similar proportion of reflux in the upper thigh when compared with the standing cuff method: common femoral (90% vs 67%), superficial femoral (81% vs 71%), greater saphenous (88% vs 59%), and deep femoral veins (30% vs 15%). In the popliteal vein the standing cuff test showed similar proportion of reflux (77%) as compared with the RT-15 Valsalva test (68%); however, a case-by-case analysis identified a large amount of variability between techniques, and inconsistencies could not be used to identify one technique as better than the other. Examination of the posterior tibial veins by all methods produced inconsistencies and a low yield of reflux in symptomatic limbs. In the common femoral vein, RT-15 Valsalva testing produced reflux times of up to 1.5 seconds in normal limbs, and represented "physiologic reflux." There was no recognizable effect of iliac vein valves on testing distal venous segments by Valsalva maneuver.Conclusions: Reflux in the upper thigh veins — common femoral, superficial femoral, deep femoral, and greater saphenous — is similarly demonstrated in both normal and symptomatic states by cuff deflation and RT-15 Valsalva techniques. In the popliteal vein, discrepancies between these two techniques are identified in patients with chronic venous insufficiency, and tibial vein reflux is not well demonstrated by either technique. Further investigation is needed to determine ideal techniques for identifying popliteal and tibial vein reflux. (J VASC SURG 1994;20:711-20.)     

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.     

The effect of pregnancy on the lower-limb venous system of women with varicose veins.

OBJECTIVES: to assess the effect of pregnancy on the lower-limb venous system of women with varicose veins. Design a longitudinal prospective study of 11 pregnant women, with varicose vein disease. METHODS: eleven pregnant women with varicose veins were recruited as part of a larger study. Veins were assessed in both lower limbs using colour-flow duplex scanning at a 75 degrees head-up tilt. The diameter and velocity and duration of reflux were measured in each vein at 12, 20, 26, 34, 38 weeks gestation and 6 weeks postpartum. RESULTS: eleven women had reflux and varicose veins demonstrated at first scan. All veins dilated with increasing gestation. This was maximal in the superficial system, reaching significance (p相似文献   

Mechanism of action of external compression on venous function.

Compression stockings and bandages have been shown to improve venous haemodynamics and may act by reducing venous reflux. The aim of this study was to assess the mechanism of action of compression therapy on venous function and to determine whether such treatment may correct valvular incompetence. Both lower limbs of 36 patients (median age 59 (interquartile range 45-65) years) were assessed by duplex ultrasonographic scanning. There were 17 limbs with popliteal vein reflux, 19 with long saphenous vein (LSV) reflux and 21 with short saphenous vein (SSV) reflux. A water-filled adjustable pressure cuff was applied around the knee and inflated gradually, while continuously assessing the veins for reflux using ultrasonographic imaging. The external pressure applied by the cuff was noted when reflux was abolished or when the vein was completely occluded. In four (24 per cent) of 17 popliteal veins, eight (42 per cent) of 19 LSVs and three (14 per cent) of 21 SSVs reflux was abolished before occlusion of the vein. The cuff pressures required to achieve restoration of valvular function were significantly lower than those required to occlude the veins. It is possible, in some refluxing veins, to correct valvular dysfunction by external compression therapy. Coaptation of valvular cuffs to restore valvular competence may be the mechanism of action of compression therapy in venous disease.     

Venous pump of the calf: A study of venous and muscular pressures

Purpose: Little data are available concerning the relation between the muscular pumping mechanism and the variation of superficial and deep venous pressure during normal action of the calf pump; therefore we undertook this study to determine the pressure values in three compartments of the calf and in the deep and the superficial venous system and to establish correlation between muscular and venous pressure.Methods: Nine healthy young women with a mean age of 23 years (range 19 to 28 years) were examined. In the same calf, a muscular catheter was placed in the deep posterior compartment (DPC), in the superficial posterior compartment (SPC), and in the anterior tibial compartment (ATC), and a vascular catheter was placed in the popliteal vein and in the greater saphenous vein (GSV). The five lines of pressure were simultaneously recorded in the following situations: at rest, during Valsalva maneuver, foot flexion, and foot extension. The situation was studied with the patient in the following positions: decubitus, sitting, standing, and squatting. A final continuous recording was carried out after the patient had been walking for 5 minutes.Results: Mean values with standard errors of muscular and venous pressure were established in each situation. At rest and during Valsalva maneuver, the muscular pressures did not vary, whereas venous pressures increased significantly when the patient was sitting and standing. On the other hand, squatting was associated with a rise in the muscular and vein pressures. Foot flexion entailed a significant increase in the ATC pressure and a rise in the GSV pressure, whereas foot extension caused the DPC pressure to rise without venous pressure modifications. Walking was associated with an alternating increase in the DPC, SPC, GSV and popliteal vein pressures when the foot was compressed to floor followed by a significant decrease when the foot pressure was released.Conclusions: The variations in the deep and superficial venous pressures when the patient is sitting and standing both at rest and during Valsalva maneuver are not associated with an increase in the muscular pressure. On the contrary, during foot movements, the ATC and the DPC are responsible for superficial vein pressure variations without modifications of the SPC pressure. (J VASC SURG 1994;20:728-35.)     

Definition of venous reflux in lower-extremity veins

PURPOSE: This prospective study was designed to determine the upper limits of normal for duration and maximum velocity of retrograde flow (RF) in lower extremity veins. METHODS: Eighty limbs in 40 healthy subjects and 60 limbs in 45 patients with chronic venous disease were examined with duplex scanning in the standing and supine positions. Each limb was assessed for reflux at 16 venous sites, including the common femoral, deep femoral, and proximal and distal femoral veins; proximal and distal popliteal veins; gastrocnemial vein; anterior and posterior tibial veins; peroneal vein; greater saphenous vein, at the saphenofemoral junction, thigh, upper calf, and lower calf; and lesser saphenous vein, at the saphenopopliteal junction and mid-calf. Perforator veins along the course of these veins were also assessed. In the healthy volunteers, 1553 vein segments were assessed, including 480 superficial vein segments, 800 deep vein segments, and 273 perforator vein segments; and in the patients, 1272 vein segments were assessed, including 360 superficial vein segments, 600 deep vein segments, and 312 perforator vein segments. Detection and measurement of reflux were performed at duplex scanning. Standard pneumatic cuff compression pressure was used to elicit reflux. Duration of RF and peak vein velocity were measured immediately after release of compression. RESULTS: Duration of RF in the superficial veins ranged from 0 to 2400 ms (mean, 210 ms), and was less than 500 ms in 96.7% of these veins. In the perforator veins, regardless of location, outward flow ranged from 0 to 760 ms (mean, 170 ms), and was less than 350 ms in 97% of these veins. In the deep veins, RF ranged from 0 to 2600 ms. Mean RF in the deep femoral veins and calf veins was 190 ms, and was less than 500 ms in 97.6% of these veins. In the femoropopliteal veins, mean RF was 390 ms, and ranged from 510 to 2600 ms in 21 of 400 segments; however, RF was less than 990 ms in 99% of these veins. Duration of RF was significantly longer in all three veins systems in patients (P <.0001 for all comparisons). With a cutoff value of more than 1000 ms rather than more than 500 ms, prevalence of abnormal RF in the femoropopliteal veins was significantly reduced, from 29% to 18% (P =.002). Thirty-seven vein segments (2.4%) had RF greater than 500 ms in the supine position, compared with less than 500 ms in 22 of these vein segments (59%) in the standing position. Of the 48 vein segments (3.1%) with RF greater than 500 ms in the standing position, RF was less than 500 ms in 6 of these vein segments (13%) in the supine position. Similar observations were noted in patient veins. There was no association between RF and peak vein velocity. Peak vein velocity had no significance in determining reflux. CONCLUSIONS: The cutoff value for reflux in the superficial and deep calf veins is greater than 500 ms. However, the reflux cutoff value for the femoropopliteal veins should be greater than 1000 ms. Outward flow in the perforating veins should be considered abnormal at greater than 350 ms. Reflux testing should be performed with the patient standing.     

Role of venous elasticity in the development of varicose veins

A reduction in the 'elasticity' of the venous system has been proposed as a precursor of venous insufficiency, but the concept remains controversial. This study was designed to develop a method of assessing venous elasticity, and to use this method to investigate the aetiology of varicose veins. Simultaneous measurements of calf volume (determined using strain gauge plethysmography) and venous pressure (obtained via a dorsal foot vein) were made during venous occlusion plethysmography. The elastic modulus, K, defined as stress/strain when the veins are full, was calculated from the pressure/volume relationship. The elastic modulus was determined in 19 normal legs, 33 legs with superficial venous insufficiency, 16 legs with deep venous insufficiency, and 18 legs of a high risk group of volunteers or patients without varicose veins but with a strong history of factors associated with their development. The results showed a clear difference in elasticity between normal limbs and limbs with varicose veins, and also between normal limbs and high risk limbs. These results support the hypothesis that reduced elasticity has a role in the development of varicose veins and precedes the onset of valvular incompetence.