Page 9 - Carotid and peripheral vascular interventions textbook

CHAPTER 14 • ENDOVASCULAR TREATMENT OF CENTRAL VENOUS DISEASE

STEP-BY-STEP TECHNIQUE and AV shunt vein is occasionally necessary to facilitate
wire crossing and to achieve continuous monitoring of
PERIPROCEDURAL MEDICATION the stent implants in central veins. In tortuosity vessel

and occlusion, stents also can be placed over a guide wire
The purpose of antithrombotic therapy for CVD forming a loop through (‘body-f ossing’ technique or
angioplasty with or without stenting is to prevent stent through-and-through technique) the AV shunt vein and
thrombosis and/or in-stent restenosis. Regardless of rising femoral vein in order to provide support for the transvenous
rates of venous angioplasty and stent implantation, few segment and possibly prevent stent embolization into the
studies have been conducted to predict the best antithrombotic pulmonary circulation.
therapy regimen (47). Most current practices, based on If patients don’t have an AV shunt vein, upper extremity
previous experience in managing CVD, rely on data venography can be performed by using hand contrast
reported from arterial stent implantation. For patients injection into the venous system via an 18- to 20-gauge
undergoing planned SVC, brachiocephalic or subclavian needle or angiocath in the superf cial veins on the dorsum
venous intervention, we usually give 81 mg to 325 mg of of the hand. With this technique, cephalic or basilic vein
aspirin and clopidogrel 75 mg daily prior to the procedure can be located and punctured using a 4F-micropuncture
for 5-7 days. In case of untreated patients, a loading dose of set or a radial set (as used for percutaneous coronary
clopidogrel 300-600 mg (4-8 tablets) and 81 mg of aspirin intervention). Using a doppler ultrasound guidance is
are usually given before the procedure. Unfractionated also helpful for getting vascular access of a non-palpable
heparin 50-70 units/kg with target activated clotting time superf cial vein.
(ACT) 250-300 sec is administered. The use of thrombolytic
agents or glycoprotein IIb/IIa agents for central vein DIAGNOSTIC CENTRAL VENOGRAPHY

obstruction is unnecessary and not recommended as an
initial treatment. Less data is available for the application A diagnostic venogram can be performed through
of thrombolytic agents during central venous thrombosis a venous access from the common femoral vein or the
(48). Therefore, it is not recommended as an initial treatment arm or using a 6-Fr Judkins right (JR) or multipurpose
regimen. Catheter-based thrombolysis is effective for (MP) catheter which is cannulated into the brachiocephalic
the treatment of central vein blockage secondary to acute or subclavian vein. Digital subtraction central venography
thrombosis, particularly in combination with a staged is well visualized in the anteroposterior (AP) projection.
surgical correction for the anatomical etiology for venous For a short stenotic lesion, imaging evaluation is
constriction for the case of Paget-Schroetter syndrome. mainly performed by venography via the dialysis access
(49,50). and advancing a catheter up to the lesion to obtain
imaging. Diagnostic DSA from the outf ow vein of the AV
VASCULAR ACCESS access to the SVC is achieved (Fig. 14-5). This diagnostic
imaging is used to def ne anatomy, pathology of CVD
Non-invasive pre-procedural imaging such as CTV and collateral pathways. After venography, simple
or MRV, if available, is helpful to make a plan and choose endovascular intervention can be performed through
an appropriate vascular access. A venous access can be this arm access. 435
obtained using surface or anatomic landmarks or imaging In case of central venous occlusion, following primary
guidance, usually doppler ultrasound. In short lesions of identif cation of the distal end of the lesion from the arm
the central veins, preferred access is usually from the arm access, a second common femoral vein access usually
using the AV shunt vein. Percutaneous needle entry to the is required and inserted with a 6-Fr JR4 or MP catheter
AV f stulas or grafts is straightforward, because these shunt advanced up to the brachiocephalic occlusion lesion.
veins usually are engorged and felt of palpable thrill. In Further venography by synchronous contrast injection
some cases, when large balloons or stent devices are used, from both ends of the lesion is performed once more to
transfemoral venous access can be used to avoid injury of delineate the position and length of the occluded segment
the AV shunt veins. In case of subclavian or brachiocephalic and to characterize collaterals and the point at which the
vein occlusion, two-way approach via common femoral central vein segment becomes patent again (Fig. 14-6).