Page 8 - Carotid and peripheral vascular interventions textbook
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                    choices include PTA, implantation of bare metal stents      The contraindication of endovascular intervention of
                    (BMSs), and lately placement of covered stents (CSs).   CVD is the existence of large thrombus at the lesion except
                    The KDOQI guidelines recommended PTA, without or   when the thrombus is f rst be removed by thrombectomy or
                    with stent implantation as the favored CVD management     other means (14,42). Other contraindications are surgical
                    approach (39). However, for patients intractable to     revision<30 days before referral, infected access, pulmonary
                    endovascular treatment, surgical correction must be   hypertension, or the existence of a right-to-left intracardiac
                    considered. Similarly, in patients without a history of   shunt (43). Since progression of collaterals can be correlated
                    central venous catheterization, when treatment of the    with symptom resolution, endovascular treatment can
                    underlying disease is not possible or cannot resolve arm     be postponed in asymptomatic patients capable of
                    swelling, then PTA without or with additional stent    accomplishing adequate dialysis. Currently, the natural
                    implantation is indicated.                      history of stent implantation and angioplasty in those
                        When interventional management of CVD fails   elastic lesions are jeopardized by rapid and frequent
                    or is impossible, surgical evaluation is necessitated to   recurrence. Potentially an asymptomatic lesion may become
                    establish the most effective surgical method, along with   symptomatic following the intervention. Moreover, stenosis
                    the procedural risk, and life expectancy. Initially, all   has been demonstrated faster progress following intervention
                    venograms have to be re-assessed. If there is a functional   (44,45). Therefore, more elasticity with potentially for
                    arteriovenous AV access within the ipsilateral extremity to   severe recurrent neointimal hyperplasia should deter
                    the site of CVD, a ‘simple reduction’ process can reduce   intervention in mildly symptomatic or asymptomatic CVD.
                    the volume down to some levels that may be satisf ed by   Those patients need careful follow-up as deteriorating
                    collateral circulation while continuing to supply suff cient   symptoms will necessitate intervention.
                    blood-f ow for dialysis with alleviation of symptoms. If
                    not, then manage the CVD with extra-anatomic bypass,  PATIENT SELECTION
                    incorporating axillary to femoral vein bypass, subclavian
                    vein to external or internal jugular vein bypass, or jugular      When considering management of CVD, the clinical
                    vein turn down process. If an ipsilateral surgical bypass   presentation, location and type of AV access, previous AV
                    is impossible, further venography of the contralateral arm   accesses, future potential AV accesses, potential for kidney
                    should be performed to evaluate if a new access can be   transplantation, and life expectancy should be considered.
                    formed in another arm. After this, an ultimate treatment   CTV for the chest can help in assessing the feasibility of
                    access ligation may be considered, to alleviate local   intervention and delineate the CVD. When the access has
                    symptoms.                                       many other lesions, in older age with many other potential
                                                                    access sites, perhaps treatment is not needed, because
                    ENDOVASCULAR INTERVENTION                       a new AV access may be made and ligate the old access.
                                                                    Conversely, when a patient has one remaining access
                        Endovascular intervention is frequently used to   weak f ows without possibility of transplant, more
                    relieve symptoms and to improve the function of the   aggressive treatment can be considered. Central venous
                    hemodialysis access. The 2019 update KDOQI clinical   occlusions seldom result in access thrombosis since
         434        practice guideline for vascular access recommends that   most patients grow collateral circulation.

                    PTA, without or with stent implantation is considered       When a patient’s symptoms of facial/arm swelling
                    the preferential CVD approach (39).             are considerably acute, postponing for several weeks
                                                                    might permit growth of enough venous collaterals which
                    Indications for endovascular intervention       diminish symptoms with minimal dysfunction of access.
                        1. Symptomatic  CVD  with  edema  of  upper     When there is minimal elevated venous pressures, it is
                          extremity, face or chest wall             preferable to avoid intervention. Importantly, therapeutic
                        2. Inadequate dialysis secondary to CVD     intervention has been reported to be relatively worthless
                        3. CVD with thrombosis of AV access         for asymptomatic central venous lesions (46), so one
                        4. Cardiac  device-related  subclavian  stenosis    should avoid interventions for asymptomatic central
                          (40,41)                                   venous lesions.
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