[Surgery for deep venous reflux in the lower limb].

UNLABELLED: Surgery for deep venous reflux (DVR) in the lower limb had displayed, for various reasons a much more limited development than arterial surgery including endovascular techniques. Importance and frequency of DVR in chronic venous disease and particularly in chronic venous insufficiency (CVI) has been fully identified only in the last 20 Years, thanks to the development of duplex-scanning. Despite its effectiveness, deep reconstructive surgery remains controversial which probably explains why this specific surgery is performed by few units worldwide. Furthermore as deep reconstructive surgery is usually combined with superficial and perforator surgery, assessment of its specific benefit is difficult. In patients with severe CVI, venous valvular reflux involves deep vein as an isolated abnormality in less than 10%, but is associated with superficial reflux or/and perforator incompetence in 46%. The most common etiology in DVR is post-thrombotic syndrome accounting for an estimated 60-85% of patients with CVI. Primary reflux is the result of structural abnormalities in the vein wall and the valve itself. A very rare cause of reflux is the absence of valves secondary to agenesis. Surgical techniques for treating DVR can be classified into two groups: those that do and those that do not involve phlebotomy. The first group includes internal valvuloplasty, transposition, transplantation, neo valve and cryopreserved allograft. The second group involves wrapping, Psathakis II procedure, external valvuloplasty (transmural and transcommissural) angioscopy assisted or not, external valve construction and percutaneous placed devices. There are some clinical features that enable distinguishing superficial venous insufficiency from deep venous insufficiency but they are not reliable enough as both are frequently combined. In addition primary reflux is difficult to identify from secondary deep reflux.

INVESTIGATIONS: Duplex scanning provides both hemodynamic and anatomic information. Photoplethysmography as air plethysmography can help when superficial and deep venous reflux are combined to identify the predominant pathological component. It would seem logical to go beyond these investigations only in those patients in whom surgery for DVR may be considered. That means that the decision to continue investigations is dominated by the clinical context and absence of contraindication (uncorrectable coagulation disorder, ineffective calf pump). When surgery is considered, complementary investigations must be carried out: ambulatory venous pressure measurement and venography including ascending and descending phlebography. The goal of DVR surgery is to correct the reflux related to deep venous insufficiency at the subinguinal. But it must be kept in mind that DVR is frequently combined with superficial and perforator reflux, consequently all these mechanisms have to be corrected in order to reduce the permanent increased venous pressure. As mentioned previously, surgery results for DVR are somewhat difficult to assess as superficial venous surgery and/or perforator surgery have often been performed in combination with DVR surgery. Valvuloplasty is the most frequent procedure used for primary deep reflux. On the whole, valvuloplasty is credited with achieving a good result in 70% of cases in terms of clinical outcome defined as a freedom of ulcer recurrence and the reduction of pain, valve competence and hemodynamic improvement over a follow-up period of more than 5 years. In all series, a good correlation was observed between these three criteria. External transmural valvuloplasty does not seem to be as reliable as internal valvuloplasty in providing long-term valve competence or ulcer free-survival. In PTS, long-term results are available for transposition and transplantation. In terms of clinical result and valve competence, a meta-analysis demonstrates that a good result is achieved in 50% of cases over a follow-up period of more than 5 years, with a poor correlation between clinical and hemodynamic outcome. Results with others techniques including Psathakis II technique, neovalve and cryopreserved valves are less satisfactory. DVR surgery indications for reflux rely on clinical severity, hemodynamics and imaging: most of the authors recommend surgery in patients severe disease graded C4 and C 5-6. When superficial and perforator reflux are associated, they must be treated, for some Authors as a first step, for others shortly before DVR surgery in the same hospitalization stay. Contraindications as previously stipulated have to be kept in mind. Hemodynamics and imaging criteria: only reflux graded 3-4 according to Kistner are usually treated with DVR surgery. It is generally recognized that, to be significantly abnormal, venous refill time must be less than 12 s, and the difference between pressure at rest and after standardized exercise in the standing position must be less than 40%. The decision to operate should be based on the clinical status of the patient, not the non-invasive data, since the patient's symptoms and signs may not correlate with the laboratory findings. Indications according to etiology: the indications for surgery can be simplified according to the clinical, hemodynamic and imaging criteria described above. In primary reflux, reconstructive surgery is recommended after failure of conservative treatment and in young and active patients reluctant to wear permanent compression. Valvuloplasty is the most suitable technique, with Kistner, Perrin and Sottiurai favoring internal valvuloplasty and Raju transcommissural external valvuloplasty. In PTS, obstruction may be associated with reflux; most of the authors agree that when significant obstruction is localized above the inguinal ligament, obstruction must be treated first. Secondary deep venous reflux, mainly post-thrombotic syndrome may be treated only after failure of conservative treatment as the results achieved by subfascial endoscopic perforator surgery associated or not with superficial venous surgery are not convincing. It is recommended that this procedure might be carried out in combination with deep reconstructive surgery. The techniques to be used, given that valvuloplasty is rarely feasible, in order of recommendation, are: transposition, transplantation, neovalve and cryopreserved allograft. Patients must be informed that in PTS surgery for reflux has a relatively high failure rate.

CONCLUSION: as large randomized control trials comparing conservative treatment and DVR surgery for DVR shall or should be difficult to conduct we must rely on the outcome of present series treated by DVR surgery. Analysis of those series provides recommendation grade C. Better results are obtained in the treatment of primary reflux compared with secondary reflux. Such surgery is not however, often indicated, and the procedure must be performed on specialized and high-trained centers.