Ngoh Chin Liew
Current Position
Professor of Surgery
University Putra Malaysia
Access Session

Topic: Avoiding complications during salvage of renal access dysfunction and thrombosis


Salvage of renal access thrombosis enables return to dialysis without the need of an intervening central venous catheter and construction of a new renal access. This includes the use of endovascular procedure or open surgery or both and has good success rate and patency.
Common complications reported include primary access failure, recurrent thrombosis, bleeding, sepsis, proximal embolization and limb ischemia. Many of these complications are potentially avoidable.
Primary failure is largely due to case selection. Three instances should alert the interventionalist and surgeon to the risk of primary failure: tandem central vein stenosis or occlusion, recent intervention with re-thrombosis and long segmental occlusion with poor runoffs.
Early re-thrombosis occurs when unsuspected tandem stenotic lesions, such as downstream and upstream stenosis that are missed or failure to fully efface a stenosis. Often an upstream stenosis, when corrected, unmasked an in-situ juxta-anastomotic or anastomotic lesion. Complete imaging of the circuit prevents such complication.
Bleeding occurs due to rupture of a fibrotic stenosis that could not be fully effaced. Such lesion often necessitated the use of cutting balloons, high pressure balloons and balloons that exceeded the normal diameter. In controlled rupture, stents or stent grafts should be available to seal the anticipated tear.
Sepsis from endovascular intervention arises from failure to recognize the presence of infected haematoma in the renal access. Thrombosed fistula, especially those with venous aneurysm might be infected and underlying suppurative phlebitis could lead to metastatic infection.
Proximal embolization leads to pulmonary embolism. Fortunately, most of the emboli are small and non-obstructing and may not cause haemodynamtic instability. Larger thrombus, especially those in a venous aneurysm, when dislodged, could lead to severe consequences.
Limb ischaemia is reported to be occurring in up to 10% of patients but may remain largely undiagnosed. The presence of thrombus in a juxta-anastomotic venous segment should lead to gentle and cautious imaging techniques, especially when crossing the lesion retrogradely into the anastomosis.