GUIDELINES [ back to index ]
24. Management of central venous obstruction (2)
*1 Surgical evaluation
• When interventional treatment of central venous obstruction is impossible or fails (in approximately 30 % of cases), thorough assessment of the patient is necessary to define the most effective surgical method to guarantee long-term vascular access for haemodialysis 1. Surgical evaluation has to focus on the general risk (in terms of the ASA Physical Status Classification System, see this algorithm, *2) and life expectancy as well as on the patient’s vascular pathology.
• All angiograms have to be re-evaluated. If an ipsilateral surgical bypass is impossible due to brachiocephalic vein obstruction, additional venography of the contralateral arm should be performed to assess whether a new peripheral access can be performed on that arm or a cross-over bypass graft inserted2 3 4.
• In case of bilateral obstruction of mediastinal veins, including the superior vena cava, colour-coded duplex-ultrasonography of ilio-caval veins is indicated in the planning of arterio-venous thigh access.
*2 Identify risk
• The American Society of Anesthesiologists (ASA) has proposed a classification system for risk stratification of surgical patients. It is based on clinical and laboratory findings and has been shown to be one of the best indicators for perioperative morbidity and mortality in a variety of clinical settings. Patients are classified into six groups:
ASA I: A normal healthy patient
ASA II: A patient with mild systemic disease
ASA III A patient with severe systemic disease
ASA IV: A patient with severe systemic disease that is a constant threat to life
ASA V: A moribund patient who is not expected to survive without the operation
ASA VI: A declared brain-dead patient whose organs are being removed for donor purposes
• Using this definition, patients on chronic renal replacement therapy have to be classified as ASA III or ASA IV. Otherwise healthy patients in the pre-dialysis state (end-stage renal disease or end-stage chronic allograft rejection) with only mild symptoms may be classified as ASA II.
*3 ASA II
• In those rare ASA II patients, with relatively low operative morbidity/mortality and relatively high life expectancy on chronic haemodialysis, every effort should be made to save a functioning access and preserve the contralateral arm for later accesses.
• When only the subclavian vein is occluded, a veno-venous bypass to the ipsilateral internal jugular vein can be performed 2 5. When the brachiocephalic vein is occluded, cephalic or axillary vein-to-superior vena cava bypass can be considered even if the contralateral central arm veins are open. However, it is questionable, whether such invasive surgery is justified whilst other more simple peripheral access is possible in the contralateral limb. In patients with chronic occlusion of the superior vena cava, cephalic or axillary vein-to-right atrial bypass have been performed ( see this algorithm, *10) in order to postpone the need for thigh access ( see this algorithm, *6) with its consequent risk of losing the last venous territory.
*4 ASA III
• Due to the higher operative risk in ASA III patients, median sternotomy or right thoracotomy for caval or atrial anastomosis should be avoided. When only the subclavian vein is occluded, a veno-venous bypass to the ipsilateral internal jugular vein should be performed 2 5. In cases of occlusion of the brachiocephalic vein, cross-over bypass to the contralateral internal jugular vein can be considered 2 6, although bearing in mind that a peripheral new access in the other arm is likely to be more durable than extra-anatomic veno-venous bypass. Cross-over bypass to a patent axillary vein (with the risk of subsequent stenosis of the vein) has to be avoided, as long as peripheral access on the contralateral arm is possible 4. Contralateral central arm veins have to be spared until ipsilateral access is no longer possible.
*5 ASA IV
• In patients with high operative risk and reduced life expectancy (ASA IV), ligation of the access is an effective option to treat disabling arm swelling. Creation of a new access in the other arm or thigh should be performed prior to ligation of the fistula in the swollen arm in order to have a matured access at the time of abandonment of the old one.
*6 Axillary-to-superior caval vein bypass
• In case of thrombosis of the subclavian and jugular vein, a bypass from the axillary to the superior caval vein is possible but requires thoracotomy. This should only be performed it there is no other option elsewhere.
*7 Access ligation and thigh access
• For details see “Placement of Graft” *9.
*8 Axillary vein-to-right atrial bypass
• There are only a few case reports in the literature of axillary vein-to-right atrial bypass in haemodialysis patients with complete occlusion of the superior vena cava. Patency rates published are better than those for central venous bypasses in non-haemodialysis patients. It is believed that the high flow rates provided by the arterio-venous accesses prevent thrombus formation in veno-venous bypasses 8 9.
• In case of superior vena cava occlusion and no other possibility of creating a peripheral vascular access, a subclavian artery to right atrium haemodialysis bridge graft has been successfully performed 10.
*9 Axillary-to-internal jugular vein bypass
• Criado et al. successfully performed the axillary-to-internal jugular vein bypass in two patients 11. As no thoracotomy is required, this procedure is well suitable for ASA III patients.
• It is also possible to perform a jugular vein transposition onto the subclavian or axillary vein.
• Axillary vein obstruction can be treated with a brachio-jugular PTFE-graft 5, although long-term outcome is likely to be poor.
*10 Axillary-to-internal jugular vein cross-over bypass
• In the case of thrombosis of the ipsilateral jugular vein, the bypass can be sutured to the contralateral internal jugular vein.