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Dialysis and fistula/graft declotting and interventions, involving angioplasty and vascular stenting or catheter-directed thrombolysis, can help improve blood flow by opening up narrow blood vessels.

What Are These Procedures?

Fistulas and grafts are artificially created blood vessel connections that assist with kidney dialysis. Minimally invasive declotting and intervention helps restore blood flow in patients with fistulas or grafts and decreased kidney function.

For dialysis, a machine and tubing divert blood from the body, then remove any waste and extra fluids before the blood is returned. Access to the blood vessels is created through:

  • A fistula, in which an artery and vein are surgically joined together to create a larger blood vessel with a higher flow.
  • A graft, which involves placing a soft plastic tube between the artery and vein. The result is an artificially constructed blood vessel that also has a high flow.

Like natural blood vessels, fistulas and grafts can become clogged or begin to narrow over time. Your doctor may recommend an image-guided procedure to reopen them, such as:

  • Catheter-directed thrombolysis, which injects a medicine into the artificial blood vessel to dissolve the clot.
  • Catheter-directed mechanical thrombectomy, which involves physically removing or breaking up the clot.
  • Angioplasty and vascular stenting, using a balloon to keep the fistula or graft and open. As with other stenting procedures, a small wire mesh tube may be inserted to prevent the artificial blood vessel from collapsing.

If a doctor recommends angioplasty and vascular stenting, a catheter with an inflatable balloon will be inserted through a small incision, where it’s guided to the fistula or graft, then to the blockage.

The balloon expands against the vein or artery wall, which helps increase blood flow. From here, a stent may be placed into the vessel if angioplasty did not fully correct the issue.

Involving X-ray imaging and contrast material, a catheter-directed thrombectomy or thrombolysis begins in much the same way. However, instead of inflating a balloon in the narrow or blocked blood vessel, a medication is delivered through the catheter to the clot. In the case of thrombectomy, a mechanical device passes into the vessel, where it physically breaks down the clot.

For these procedures, the patient lies on a radiographic table while one or two X-ray tubes take images, via fluoroscopy, which get displayed on a monitor in an adjacent room. Results help the radiologist observe and guide the procedure.

Once imaging has identified the precise location of the clot or narrowing, a catheter will be guided through the vessel. The balloon at the tip varies in size, depending on the blood vessel being imaged. A guide wire also assists with the placement of diagnostic and angioplasty balloon catheters.

If a stent is used, it’s collapsed before it expands in the blood vessel and may have a fabric covering. You may also be attached to an IV line, ultrasound or devices to monitor your heart rate and blood pressure.

Who Should Have This Procedure?

Doctors may recommend dialysis and fistula/graft declotting and interventions for patients with a narrow or clogged dialysis fistula or graft.

If the issue is not addressed, blood begins to coagulate in the artificial vessel. Instead of flowing freely, it takes on a gel-like consistency, creating a clot or thrombus.

Dialysis and fistula/graft declotting and interventions offer several benefits for patients. No surgical incision is required to insert the catheter nor are stitches needed. Patients rarely require general anesthesia; local is sufficient for most. Afterwards, individuals can usually resume their daily activities.

These procedures significantly improve blood circulation following a clot and reduce the need for more invasive surgery. Compared to an open surgical procedure, blood loss is minimal and a long hospital stay is not required.

Nevertheless, patients need to be aware of a few risks before undergoing these procedures:

  • Patients may experience an allergic reaction if contrast material is used.
  • Damage to the blood vessel, including potential tears, bleeding or bruising at the incision site, are minor possibilities. With angioplasty, severe bleeding may warrant a blood transfusion.
  • Fistulas and grafts may also be damaged during the procedure. If this occurs, a new point of access will need to be created.
  • If angioplasty is used, a future blockage or clot may still form in the artery or blood vessel. In these situations, you may need to undergo a second angioplasty.
  • Also related to angioplasty, the blood vessel may close suddenly. To treat this issue, a patient may be given medication to dissolve the clot, have to undergo angioplasty and stenting or emergency bypass surgery.
  • In very rare cases, patients may experience a heart attack or sudden cardiac death.
  • If an anticoagulant or thrombolytic agent is used, bleeding may begin elsewhere in the body, including the head region, increasing a patient’s stroke risk.
  • In certain cases, the substance blocking the artificial blood vessel may travel to another part of the vascular system. This may require a second thrombolysis procedure or surgery.


Prior to dialysis and fistula/graft declotting and interventions, your doctor will provide preparation instructions. Before the procedure, patients are encouraged to:

  • Discuss any existing medical conditions, recent illnesses or any known allergies to contrast material, general or local anesthesia.
  • Disclose if you are or think you may be pregnant.
  • List all medications and supplements you currently take. Many patients are advised to stop using NSAIDs, aspirin and blood thinners before the procedure, or may need to change their medication schedule.

Dialysis and fistula/graft declotting and interventions are performed on an outpatient basis. Some individuals may be admitted to the hospital afterward.

As the procedure begins, you will be placed on a radiographic table and connected to monitors for your heart rate, blood pressure, pulse and oxygen level. You may also be given a sedative or general anesthesia.

At this point, the area where the radiologist will insert the catheter is sterilized and numbed with a local anesthetic before a surgical drape is placed on top. From here, the radiologist will make a small incision in the skin.

If you’re undergoing angioplasty and vascular stenting:

  • A short tube or sheath is inserted into the fistula or graft.
  • Using X-ray technology, the catheter is inserted into the sheath, until it reaches the blockage. At this stage, you will be injected with a contrast material to better identify the blockage.
  • After the guide wire is moved to the location, a balloon-tipped catheter is inflated for a brief period. Depending on the procedure, this may be done multiple times or in different locations.
  • The radiologist takes another set of X-rays to assess the blood flow through the unblocked vessel. This step may be done multiple times until the vessel is open completely or the blood flow is satisfactory. Once it reaches this level, the catheter and guide wire are withdrawn.
  • If your doctor recommends a stent, the small wire tube will be inserted into the vessel and expanded with a balloon. After the stent is supporting the vessel, the balloon will be removed.
  • The sheath will then be taken out of the incision site. The radiologist or technician will also check the fistula or graft for bleeding and swelling and may recommend your blood pressure and heart rate be monitored.

Following any angioplasty procedure, patients must avoid exercise and heavy lifting for at least 24 hours and quit smoking. You’ll also asked to monitor bleeding at the catheter site. If bleeding begins, lie down, apply pressure and seek medical attention. Report any change in color, pain or a warm feeling around the incision site.

Your doctor may have you change medications following the angioplasty and stenting, although this is often temporary. You may also be asked to take a blood thinner or aspirin to reduce the occurrence of clots, as your body repairs itself. Lastly, your doctor may request additional blood work to monitor the medication’s effects.

If you were given a stent, you will need to notify any medical professionals of its placement, should you have to undergo an MRI in the future. It’s recommended patients avoid having an MRI done in the weeks following the stent’s introduction.

If your doctor recommends catheter thrombolysis, the catheter will be inserted in a similar manner. However, after this point:

  • Your radiologist determines if a clot-dissolving medication will be inserted through the catheter or a medical device to break up the clot. In certain instances, both may be recommended.
  • If medication is used, the catheter will release the substance over several minutes.
  • Following these steps, the catheter is removed and pressure applied to the incision site to stop any bleeding. A closure device may be added to seal the small hole made in the artery.
  • Following the procedure, patients will be asked to monitor their pain level. You may be given pain medication orally or through IV if it becomes too uncomfortable.

Following either type of dialysis and fistula/graft declotting and interventions, the radiologist will inform you if the blood vessel was successfully opened. You may also be asked to schedule a follow-up visit, which could entail additional imaging or blood work. During this session, patients are encouraged to discuss any side effects or other changes.
Has your doctor recommended a dialysis and fistula/graft declotting and intervention? Contact us to make an appointment today!