Many factors contribute to the occlusion of arteriovenous endovascular fistulas for hemodialysis, mainly venous stenosis and subsequent thrombosis. Very few patients may also have no stenosis but have an occluded endovascular fistula due to excessive post-hemodialysis compression, hypotension, hypovolemia, compression during sleep, and hypercoagulable state. Once the endovascular fistula appears to have a murmur that disappears and a tremor that cannot be palpated locally, it should be treated as soon as possible, even if it is found in the latter part of the night, and needs to be rushed to the hospital where it is located.
The methods of emergency treatment are: ultrasound examination and physical examination by a specialized doctor to confirm the diagnosis of internal fistula occlusion, local puncture with urokinase thrombolysis, and interventional treatment if necessary. The aim is to resolve the stenosis of the anastomosis and to deal with the thrombus. For stenosis, a balloon can be used to dilate the radial artery by puncturing it proximally to the side of the fistula, introducing a catheter sheath and imaging the situation. If the anastomosis or venous outflow tract is narrowed and occluded, the catheter guide wire technique is used to pass through the narrowed and occluded segment and then dilate with a balloon catheter. If endovascular function is restored, urokinase is slowly pushed through the catheter sheath. In addition to local catheter contact thrombolysis under intervention, a more direct approach, mechanical thrombectomy, can also be used. A nickel-titanium alloy mesh basket is used to rotate the thrombus to crush it and aspirate it out via the catheter sheath, supplemented with urokinase lysis.
The human body has a limited number of extremity vessels that can be used to create a hemodialysis endovascular fistula. If an endovascular fistula becomes occluded, it should not be easily abandoned, and a new fistula in the opposite limb may temporarily solve the problem of vascular access for dialysis, but in the long run, it wastes valuable vascular reserves and has endless consequences. Finding ways to extend the life of a hemodialysis fistula as long as possible is a long-term measure.