Page 5 - Carotid and peripheral vascular interventions textbook
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                 traverses the junction of the clavicle and f rst rib and  RISK FACTORS FOR CVS ASSOCIATED

                 within the anterior-most part of the thoracic outlet.  WITH CENTRAL VENOUS CATHETER
                 Additional to extrinsic compression, repeated forces
                 in that region often result in f xed intrinsic trauma and       CVD is correlated with indwelling intravascular devices
                 extrinsic scar tissue development. Once primary thrombosis     including long-term hemodialysis catheter, pacemaker or
                 is identif ed, catheter-directed thrombolytic treatment   def brillator wires, as well as peripherally inserted central
                 is normally successful if initiated within 10-14 days of   catheter (PICC lines). Risk factors for CVD correlated
                 clot development, but frequently unmasks an underlying   with central venous catheter include:
                 lesion. Decompression of the venous thoracic outlet, using     •  Multiple central venous catheter implantations and
                 thorough external venolysis, resection of the costoclavicular     longer catheter dwell times (4,19)
                 ligament, partial anterior scalenectomy, and f rst rib excision   •  Subclavian location (4,19,27)
                 is essential. When bare metal stent (BMS) implantation is   •  Left sided catheterization (29,30)
                 conducted on central venous lesions, care should be given   •  Catheter infection (29,31)
                 to thoracic outlet syndrome, since they may contribute to   •  Larger caliber of central venous catheter (12-14 Fr) (32)
                 complications such as stent distortion and occlusion (24).   •  Catheter tip position in the proximal part of SVC (33)
                 Since the occurrence of this syndrome is very seldom and   •  Catheter composition induced inf ammation
                 is more frequent in young men in their 20 , so thoracic   (e.g., polyethylene and Tef on>polyurethane>
                 outlet syndrome is unlikely to contribute the pathogenesis   silicone) (17,34)
                 of CVD in dialysis patients.
                                                                 CLINICAL MANIFESTATION

                                                                     Central venous catheter implantation is the most
                     The incidence of CVD is undef ned and is probably   important CVD risk factor. CVD can be totally asymptomatic
                 underestimated because CVD can be asymptomatic. Serial   and can only be discovered by a venogram taken to prepare
                 or regular venograms also are not normally conducted   for AV access implantation (7,15). Following an ipsilateral
                 following central venous catheter implantation or removal.   AV access is created, CVD will probably become symptomatic
                 Most dialysis patients usually become symptomatic in    abruptly because of increased f ow. The symptoms rely
                 a short time following an ipsilateral AV access is formed   upon the particular location of stenosis. While subclavian
                 as the blood-f ow through the developing dialysis access   vein blockage is correlated with edema and venous
                 rises. The currently available prevalence is limited to the   hypertension of the related upper extremity and chest,
                 studies of symptomatic dialysis patients requiring imaging   brachiocephalic vein stenosis impedes blood-f ow from
                 studies. According to several studies, the occurrence of   the same side of the face as well as the upper extremity.
                 CVD has been published to range between 25% to 40 %   Bilateral brachiocephalic vein blockage or SVC blockage
                 (25,26). Previous implantation of pacemaker wires and   symptoms are described in Table 14-1.
                 central venous catheters has been robustly correlated
                 with CVD (18,19), with one study f nding that 27 %
                 of CVD patients already had central venous catheters    Table 14-1. Clinical manifestation of central   431
                 implanted (18). In asymptomatic patients, available     venous disease (CVD) (35)
                 studies have shown a relatively high occurrence of CVD
                                                                    • Upper extremity edema
                 in those patients with subclavian catheters (42-50%) in
                                                                    • Aneurysmal dilatation of the upper extremity veins and AVF
                 comparison with those with internal jugular catheter   • Progression of collaterals
                 (4,19,27). Since CVD or occlusions are not correlated   • Thrombosis of access
                 with any clinical f ndings and unable to identify any   • Venous thrombosis
                 predisposing factors, all patients who already have had   • Inadequate dialysis
                 previous subclavian vein catheters should be assessed to   • Recurrent infection
                                                                    • SVC syndrome
                 verify the subclavian vein’s patency prior to creation of
                 a permanent AV access (28).
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