Page 8 - Carotid and peripheral vascular interventions textbook

CAROTID AND PERIPHERAL VASCULAR INTERVENTIONS: STEP-BY-STEP

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.