[Two false myths of the 20th century vascular surgery]. / Dva mylné mýty flebologické chirurgie 20. století.

Two myths or dogmas have influenced the therapeutic proceeding of phlebological surgeons in the second half of the 20th century, and both did not stopped to wield their influence up to the present time. The first one is the Cockett's theory of the incompetent calf perforators (blow-out syndrome), the second one is the assertion that femoral vein incompetence invariably causes the most serious stage of chronic venous insufficiency. The incorrectness of the theory of incompetent calf perforators was documented by venous pressure measurements, including direct pressure and electromagnetic flow measurements in the incompetent calf perforators themselves, as well as by plethysmographic results after surgical procedures eliminating the saphenous reflux. The pressure measurements showed that incompetent calf perforators did not cause ambulatory venous hypertension in the superficial veins of the gaiter area; directly the opposite happened: the high hydrostatic pressure measured in the quiet standing position in the incompetent calf perforator decreased profoundly during calf pump activity, as soon as the saphenous reflux was interrupted by digital compression. As to the femoral vein incompetence, no direct evidence has so far been presented which would confirm its hemodynamic significance. On the contrary, plethysmographic findings in patients displaying both saphenous and femoral vein incompetence showed that saphenous reflux was the factor which was responsible for the hemodynamic derangement, whereas femoral vein incompetence was hemodynamically irrelevant.

Possible impact of hemodynamic factors on the development of recurrent reflux in primary varicose veins.

Definition of reflux as a centrifugal flow within an incompetent vein connecting both poles of the ambulatory pressure gradient and causing ambulatory venous hypertension is presented. Recurrent reflux occurs also after correctly performed crossectomy and stripping. Growth of new vessels (neo-angiogenesis) or dilatation of pre-existing venous channels (vascular remodelling) has been claimed to be the main cause of recurrences in these instances. Attempts to blockade the development of recurrent reflux in the groin by inserting mechanical barriers over the ligated saphenofemoral junction failed to prevent recurrences. The synergistic effect of two hemodynamic factors - pressure difference between the femoral vein and the saphenous remnant in the thigh on one side, and the propensity to restore centrifugal flow on the other side - may play a crucial role in the development of recurrent reflux. Pressure gradient apparently triggers the event. Restoration of centrifugal flow might be the pre-programmed phenomenon that improves compromised blood supply in arterial occlusions, but evokes recurrent reflux in incompetent superficial veins. In this way, it can be explained why recurrent reflux can occur after any therapeutic procedure.

Venous pressure gradients in the lower extremity and the hemodynamic consequences.

Pressure differences play an important role in the hemodynamics of both arterial and venous circulation. Venous ambulatory pressure gradient of about 35 mm Hg arises during the activity of the calf muscle venous pump between the veins in the thigh and the lower leg; this is the initiator launching venous reflux in varicose vein patients. The hemodynamic consequence of venous reflux is interference with the physiological decrease in venous pressure in the lower leg and foot and the occurrence of ambulatory venous hypertension, the degree of which depends on the magnitude of refluxing blood. Pressure difference occurring between the femoral vein and the remnant of great saphenous vein after high ligation or crossectomy during calf pump activity may be the activator of the process leading to the building of new venous communicating channels, the consequence of which is recurrent reflux. Neovascularization is apparently triggered by this hemodynamic factor, not by the surgical procedure itself, because neovascularization does not occur after harvesting of the great saphenous vein in the groin in people without varicose veins. Venous pressure potentials developing in the lower leg during the calf pump activity force the blood to flow from deep into superficial veins during muscle contraction and in the opposite direction during muscle relaxation. An untoward event caused by venous pressure difference is presented - spontaneous bypassing of a competent valve in the saphenous remnant after crossectomy, which converted a favourable hemodynamic situation into a harmful one. Possible explanation of this undesirable event is offered.

Conception of the venous hemodynamics in the lower extremity.

Contradictory reports on the significance of several hemodynamic phenomena, such as femoral vein incompetence and incompetent calf perforators, impede orientation in venous hemodynamics. Venous pressure difference arising between the popliteal and the posterior tibial vein during the activity of the calf muscle venous pump was reported for the first time about 50 years ago, but regrettably, this important discovery continues to be unrespected. The venous pressure difference has since been termed ambulatory pressure gradient and seems to be the key factor triggering the venous reflux in the lower limb as well as the process leading to varicose vein recurrence. On the other hand, simultaneous recordings of the mean venous pressure in the posterior tibial and long saphenous veins demonstrated that the pressure curves have been identical at rest, during ambulation, and in the recovery period, a finding typical of conjoined vessels. Bidirectional flow within calf perforators taking place both in healthy subjects and in patients with varicose veins enables a quick equilibration of pressure changes between deep and superficial veins of the lower leg. Reflux disturbing the venous hemodynamics is in various degrees dependent on the quantity of retrograde flow; abolition of reflux restores normal venous hemodynamics. Reflux in superficial veins, if large enough, may cause the most severe form of chronic venous insufficiency. Femoral vein incompetence and incompetent calf perforators per se do not produce ambulatory venous hypertension and do not cause hemodynamic disturbance. This study discusses the controversial issues, tries to define and appraise the principal hemodynamic phenomena (ambulatory venous hypertension, ambulatory pressure gradient, venous reflux, superficial and deep vein incompetence, incompetent perforators), mentions a possible relation between deep vein incompetence and varicose veins, and attempts to present, based on proved facts, a comprehensive picture of the venous hemodynamics in the lower extremity.

Impact of the calf perforators on the venous hemodynamics in primary varicose veins.

The hemodynamic significance of the calf perforating veins continues to be the point of controversy. The conception that incompetent perforating veins cause hemodynamic disturbance and are responsible for the formation of leg ulceration has still many adherents prefering perforator surgery, whereas others reject any causal relation between large, incompetent perforators and severe forms of chronic venous insufficiency. In this study well documented facts concerning the impact of the calf perforators on the venous hemodynamics are reviewed. There is a bidirectional flow within calf perforators in healthy subjects enabling a quick equilibration of pressure changes produced during calf muscle contractions and relaxations, so that recordings of the mean pressure display identical values in superficial and deep veins of the lower leg, a feature typical of conjoined vessels. In cases with saphenous reflux, the bidirectional flow within calf perforators has a distinct inward vector directed to the deep veins; this inward component is the more pronounced, the larger the saphenous reflux is. Incompetent calf perforators do not cause ambulatory venous hypertension, exactly the opposite happens: the high hydrostatic pressure found in the quiet standing position drops significantly during ambulation, as soon as the saphenous reflux is interrupted. In primary varicose veins calf perforators can not become the source of reflux because they are situated at the lower pole of the ambulatory pressure gradient, which occurs between thigh and lower leg veins during ambulation. The size of the calf perforators is determined by the amount of saphenous reflux. When the saphenous reflux is abolished (e.g. by high ligation), the enlarged calf perforators diminish.

[Historical review of opinions on the nature of varicose veins and leg ulcers and their treatment]. / Historický prehled názoru na povahu a lécení varixu a bércových vredu.

The development and changes of opinions concerning the nature and treatment od varicose veins and varicose ulcers are summarized in this article covering a long period from the Greek antiquity till the 20th century. Whereas in the ancient times (Hippokrates, Celsus, Galen) the meanings did not contradict the contemporaneous knowledge, curious opinions dominated from the 11th till the half of the 19th century, obviously influenced by the humoral theory of Avicenna. The official teaching claimed that black bile and other bad humours collected in varicose veins. Bandaging was thought to push back these humours into the body and cause madness or other serious illness and, therefore, was refused. On the contrary, ulcers were considered to be a favourable condition because their function was to drain the bad humours. The fundamentals of modern surgical treatment of varicose veins were presented by Madelung, Trendelenburg and Babcock at the end of the 19th and the beginning of the 20th century. Trendelenburg deserves acknoledgement of having introduced physiological and pathophysiological reasoning into the field of phlebology. The conception of the role of incompetent calf perforators for the development of leg ulcers advocated by Cockett and others represents a derailment on the way of evidence based medicine. The substance of this theory, although supported by most autors till the present time, have been repeatedly confuted by exact hemodynamic measurements. Evidence based medicine whose basement was laid by Trendelenburg more than 100 years ago cuts a difficult way through the field of phlebology.

The venous reflux.

Venous reflux is the most common cause of venous hemodynamic disorders. In this paper 2 issues are discussed: how and where does reflux arise and what are the hemodynamic consequences of retrograde flow. Pressure gradient and incompetent vein connecting both poles of the gradient are the prerequisite for venous reflux to arise. Ambulatory pressure gradient occurs during the activity of the calf muscle venous pump between deep veins of the thigh and the lower leg. Thus the incompetent reflux-carrying vein must connect the popliteal, femoral, profunda femoris, or iliac vein with 1 of the deep veins of the lower leg. Reflux can be considered as shunting of blood from thigh veins into the lower leg veins. The most frequently found incompetent veins are the long and short saphenous veins and perforators communicating with deep veins of the thigh. On the other hand, calf perforators emptying into the deep veins of the lower leg, where the lower pole of the pressure gradient is located, cannot be the feeding source of reflux. A physiological bidirectional flow takes place in calf perforators connecting superficial and deep veins of the lower leg and making them conjoined vessels. Venous reflux produces ambulatory venous hypertension. The quantity of reflux volume and not the localization of retrograde flow in superficial or deep veins is the most important hemodynamic factor. Reflux in superficial veins, when large enough, can cause the most serious symptoms of chronic venous insufficiency including leg ulcers. Plethysmographic findings have shown that incompetence of the femoral and calf perforating veins is hemodynamically unimportant. Large incompetent calf perforators are not the cause of venous abnormality but are the consequence of saphenous retrograde flow.

[Does saphenous vein saving surgery have a role in the therapy of primary varices?]. / Má saphenous vein saving surgery své místo v terapii primárních varixu?

Venous grafts retrieved from long saphenous veins are the best conduits for vascular and coronary reconstructions. The demand for such grafts rise continuously with the development of vascular and coronary surgery. Surgeons were soon confronted with the problem whether the saphenous trunk in patients with varicose veins may be used for grafting or not. Saphenous vein saving surgery means intentional renouncement of removing the saphenous trunk during varicose vein surgery and saving it for a possible graft in the future. Opinions whether such procedures are substantiated differ widely and concern both the suitability of such grafts and the fact that lowering the radicality of varicose vein surgery increases the probability of varicose vein recurrence. The saphenous trunk in primary varicose veins is not diffusely degenerated, it usually shows only a few local bulges and is basically compatible for the use as a vascular or coronary artery conduit; it does not dilate aneurysmatically when transplanted into the arterial circulation. Crossectomy disconnects saphenofemoral junction, the most frequent source of reflux, abolishes even the most serious venous derangement and restores normal venous hemodynamics; stripping brings about no further immediate amelioration. Recurrence of varicose veins is more frequent when crossectomy alone is performed in comparison with crossectomy and stripping, but nor crossectomy combined with stripping is able to reliably prevent recurrence, because the distinct tendency to recur is a characteristic feature of varicose disease. Saphenous vein saving surgery can be efficiently supplemented by sclerotherapy during follow-up. The excellent hemodynamic improvement achieved immediately after crossectomy can be preserved for many years during follow-up by repeated applications of sclerotherapeutic agents. In this way necessary conditions for a rapid and mostly a definitive healing of varicose ulcers can be established. In addition, preservation of a possible graft for arterial reconstructions is relevant in elderly patients.

[Hemodynamic basis for the development of varicose ulcers and their therapy]. / Hemodynamické predpoklady vzniku varikózních vredu a terapeutické moznosti.

The prevalence of leg ulcers is about 1%, approximately 75% of them are of venous origin. The precondition for the development of venous ulcers is ambulatory venous hypertension. It is assumed than a linear correlation exists between the severity of ambulatory venous hypertension and the incidence of venous ulcers. Venous ulcers caused by superficial vein reflux are called varicose ulcers and are more frequent than postthrombotic ones. Crossectomy removes the hemodynamic disorder responsible for the development of varicose ulcers and creates conditions for a quick and mostly definitive ulcer healing. In cases with simultaneous reflux in the saphenous and femoral veins the saphenous reflux is responsible for the severity of venous disorder, whereas femoral reflux is hemodynamically unimportant. Selective abolition of saphenous reflux restores normal hemodynamic conditions in such cases. Compressive therapy continues to be the most frequently used therapeutic procedure in the treatment of venous ulcers; it must be considered as a symptomatic measure, because it is not able to substantially affect the underlying venous disorder in spite of the fact that the correctly lying bandage positively influences venous hemodynamics. The diagnostic procedure in patients with leg ulcers should screen out cases with varicose ulcers; abolition of superficial vein reflux can deliver these patients from their annoying disease.

[Evaluation of the hemodynamic significance of femoral vein insufficiency]. / Zhodnocení hemodynamického významu insuficience v. femoralis.

Deep vein incompetence is generally regarded as the main cause of severe chronic venous insufficiency, without specifying which deep vein segments are really meant. Opinions concerning hemodynamic significance of femoral vein incompetence differ considerably. Femoral vein incompetence can be part of a postthrombotic syndrome, it can occur as a primary incompetence described by Kistner or as a secondary incompetence due to vein dilatation. Therapeutic possibilities and outcome of valvuloplasty and valve transplantation described in the literature are presented. The results of valve transplantation into the popliteal vein in postthrombotic patients were disappointing. In primary varicose veins the saphenous incompetence is often accompanied by femoral vein reflux which mostly disappears after removal of incompetent saphenous vein; the possible mechanism causing this phenomenon is discussed. In cases with combined saphenous and femoral vein reflux the most important factor causing venous derangement is the saphenous reflux, not the femoral vein incompetence; therefore, the first therapeutic step in such cases must be the abolition of saphenous reflux. The question whether femoral vein incompetence deteriorates the natural course of primary varicose veins can't so far be answered conclusively, but the first reports concerning this issue show that it could be answered yes.

[Principles of surgical treatment of varicose veins with regard to new findings on venous hemodynamics]. / Principy chirurgického lécení varixu konfrontované s novými poznatky o zilní hemodynamice.

Pressure changes occurring during the activity of the calf muscle venous pump are the driving force of venous hemodynamics in the lower extremity. An ambulatory pressure gradient arises between the veins of the thigh and the lower leg as a consequence of pumping up the blood from the deep veins of the lower leg, where the venous pressure decreases, into the popliteal and femoral vein, where no pressure decrease occurs. Therefore, venous reflux can only take place in an incompetent vein connecting the femoral, profunda femoris, popliteal or iliac vein with one of the deep veins of the lower leg. Calf perforators represent the so called re-entry points and can't become the source of reflux. Venous reflex disturbs venous hemodynamics to a various degree dependent on the magnitude of reflux volume. When strong enough, it can produce the graviest form of chronic venous insufficiency even if localised in superficial veins. The magnitude of reflux volume, not the localisation of reflux in deep or superficial veins is the most important hemodynamic factor causing venous disturbance. The goal of varicose vein surgery is to remove reflux and visible varicose veins with the aim to achieve the most favorable hemodynamic and cosmetic results. Crossectomy is a very important step, because it is able to repair even the most pronounced hemodynamic disorder and restore normal hemodynamic conditions. If stripping of the incompetent saphenous trunk on the thigh is not performed in addition to crossectomy, the saphenous trunk continues to be patent and incompetent after surgery in most patients and provokes recurrent reflux. But nor can crossectomy combined with stripping avert the risk of recurrence definitively, because varicose veins are a dynamic disease with distinct tendency to recurrence. Correctly performed operation can reduce the recurrence rate and postpone its occurrence. A hemodynamic factor--the ambulatory pressure gradient--triggers probably the process leading to recurrence. When varicose veins recur, the recurrent reflux volume remains significantly lower for many years of follow-up as compared with the situation before surgery. External banding of incompetent valve in the long saphenous vein and the CHIVA-method are less efficient in comparison with standard surgery (crossectomy plus stripping). Sclerotherapy is a useful supplement to surgery during follow-up, as it is able to improve significantly the hemodynamic situation. This improvement is only transitory, but sclerotherapy can be repeated and the improvement re-established, if necessary, during follow-up.

Ambulatory pressure gradient in the veins of the lower extremity.

BACKGROUND: Neovascularization is an important cause of venous reflux recurrence after high ligation of the long saphenous vein. The pathogenesis of this phenomenon is so far obscure. It is possible that a hemodynamic factor--a pressure gradient between the femoral vein and the residual long saphenous vein--could be the trigger initiating the process of neovascularization. PATIENTS AND METHODS: Venous pressure measurements on eight patients with primary varicose veins were performed in the erect position in the insufficient long saphenous vein on the thigh. Mean pressures in the quiet standing position and ambulatory pressures were considered. By interrupting the saphenous reflux either distally or proximally to the point of measurement the pressure conditions either in the femoral or in the crural veins were simulated. RESULTS: With the tourniquet placed distally to the point of measurement, the venous pressure in the upper interrupted segment of the long saphenous vein (equivalent to the pressure in the femoral vein) remained uninfluenced during ambulation. In contrast, by interrupting the reflux proximally to the point of measurement, a marked decrease of the ambulatory pressure in the lower part of the long saphenous vein (equivalent to the pressure in the crural veins) was noted. CONCLUSIONS: A pressure difference occurs between the veins of the thigh and the lower leg during the activation of the muscle venous pump. This fact may explain the tendency of recurrencies of varicose veins after high ligation of the long saphenous vein as well as the initiation of reflux.

[Insufficiency of crural perforators: myths, dogma and reality]. / Insuficientní bércové perforátory: mýtus, dogma a skutecnost.

The author evaluates critically ideas on the importance of insufficient crural perforators in the pathogenesis of primary varicosities, incl. states with chronic venous insufficiency. Based on published facts assessed by phlebodynamometry, assessment of the blood flow, duplex sonography and plethysmography, the author provides evidence that impaired venous circulation is due to reflux in the insufficient saphenous vein. Conversely insufficient crural perforators do not cause venous disorders but are due to reflux in the insufficient saphenous vein.