Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3834_Библиотеки_им_академика_М_И_Перельмана

0/1 is mainly seen in primary DVR, while grade 4/5 is usually present in secondary DVR.Grade 2/3 can be seen in primary or secondary DVR [20]. However, it must be borne in mind that while valve station changes do affect reconstruction technique, they do not affect clinical outcomes. Dr. O’Donnell’s group has reported on the signi­cant role that DVR plays in the progression of CVI.Clinical severity increases with an increase in DVR (higher CEAP clinical class correlates with worsening axial reux) [21]. This has been supported by other studies [22, 23]. Additional pathophysiological factors contributing to DVR have also been explored. Sarin etal. elucidated the role of ow in medial calf vein perforators with distal compression during the relaxation phase as a contributor to the severity of venous disease [24].

Based on studies by Masuda et al. and Araki et al., the standing cuff deation technique appears to be a superior method when compared to other techniques, including Valsalva maneu­ver [29, 30]. The most common criteria used for dening reux are derived from data published by multiple groups [28, 31, 32] including Labropoulous etal. and have since been incor­porated into the clinical practice guidelines of the Society for Vascular Surgery and the American Venous Forum [33, 34]. Per the guide- lines, DVR is dened as reux lasting for 500ms or more in the deep veins below the knee and the deep femoral vein and lasting for 1000 ms or more in the femoral and popliteal veins. The current role of descending phlebog­raphy in assessing reux is deemed only of his­torical importance now with duplex technology having supplanted it [35, 36].

In addition to venous duplex, other methods that help shed light on DVR include air plethys­mography (APG) and ambulatory venous pressure (AVP). APG helps determine a variety of param­eters that quantify calf pump function in addition to determining the venous lling index, a highly sensitive indicator of severe venous disease and reux in general [22]. AVP was once the tradi­tional gold standard for assessing DVR.However, AVP is impacted by other factors including calf pump function [37] and is therefore more of a global index of calf function than a specic mea­sure of DVR.It cannot be used to evaluate suc­cess of treatment thereof, as normalization occurs in only a fraction of treated limbs despite good clinical outcome [14]. The presence of medial calf perforator vein ow with distal compression dur­ing relaxation phase is also an indicator of more severe venous disease including DVR, as noted previously [24]. Diagnosis of concomitant deep venous obstruction should focus on determining etiology of obstruction, in addition to determining ow patterns in and out of the affected segment. Such testing includes multiple studies including noninvasive testing (venous duplex ultrasound (DUS), air plethysmography (APG), and com­puterized tomographic venogram [CTV]/mag­netic resonance venogram [MRV] and invasive testing (ascending venogram and intravascular ultrasound). DUS serves as a screening tool and helps determine the extent of stenosis or occlu-

sion based on luminal diameters, besides provid­ing reux data. Normal luminal diameter cutoffs used for the common femoral vein (CFV), the external iliac vein (EIV), and the common iliac vein (CIV) are 12 mm, 14 mm, and 16 mm, respectively (Table 3.1). The corresponding areas used for the three segments are 125mm2, 150mm2, and 200mm2, respectively. Air pleth­ysmography provides information on calf pump function, the competence of which serves as one of the factors determining development of chronic venous insufciency. CTV/MRV helps illuminate venous anatomy and provides information on compression/occlusion and collateral circulation. Ascending venography provides data on ow pat­terns and may be helpful, especially in patients with prior deep vein thrombosis.

DVR, as noted previously, can exist in isolation or coexist with supercial venous reux (SVR) and/or deep venous obstruction (DVO). Treatment should be tailored accordingly.

Valvuloplasty techniques include internal valvu­loplasty, external valvuloplasty, and external banding (Figs.3.2, 3.3, 3.4, and 3.5). Internal val- vuloplasty involves the use of a venotomy at the level of commissure [longitudinal transcommis-

and thereby restore valvular competence. External valvuloplasty involves suture of valve attachment lines from the outside to facilitate competence of the valve cusps without the use of a venotomy. This can be accomplished using an external commissural suture, an external/internal suture, or an angioscopically directed external suture [41–45]. The advantage of external valvu­loplasty is that it enables repair of multiple valves at the same operation. External banding involves the use of a PTFE, Dacron, or fascia-based sleeve to create a band around the incompetent valve that is tightened until competence is attained.

Valve transplantation involves harvesting a 2–3cm segment of axillary/brachial vein with a competent valve and transplanting it to the femoral vein (after resection of appropriate segment of femoral vein) just below its conu­ence with the profunda vein. This transplant

Taheri etal. whose clinical success fell from 75% at 5years to 55% at 10years [53]. Eklof etal. have suggested that the popliteal vein recipient site is per­haps the better option, given the better size match of the axillary vein to the popliteal vein than to the femoral vein. The authors also feel that a competent valve at the popliteal level safeguards against both femoral and profunda femoral vein reux into the calf [55]. Bry etal. reported on results in 15 patients undergoing axillary-to-popliteal vein valve trans­plantation and observed a 93% symptom improve­ment and a 62% cumulative ulcer-free survival on late follow-up [mean 5.3years] [56].

Wallstents (Boston Scientic, Marlborough, MA) of the diseased segments. Careful attention must be paid during IVUS interrogation since at times larger caliber stents may have to be used. To provide addi­tional radial strength across the iliocaval conuence which is a choke point, a 25mm Gianturco Z stent (Cook Medical, Bloomington, IN) is deployed using a 14mm Cook Shuttle sheath (Cook Medical, Bloomington, IN). The majority of this stent is within the Wallstent with just a few mm extending beyond the edge of the Wallstent. Post dilation of the entire stent stack is then carried out using the previously used angioplasty balloon. Completion IVUS interrogation is then carried out to ensure that all areas of disease have been successfully treated and that there is good stent apposition. A comple­tion venogram is then performed to ensure adequacy of ow through the reconstructed segments.