Dialysis Access & Management
Dialysis programs are often used to aid patients suffering from kidney failure. To create optimal care for these patients, they need procedures performed on their veins, arteries, and accesses. Our physician specializes in the following procedures:
- Dialysis Access Procedures – thrombectomy, fistulagrams, fistula maturation and the Miller Procedure
- Central line placements (powerports, PICCS, groshongs, dialysis/pheresis catheters)
- Venograms, Venous angioplasty/stents
Dialysis Access Procedures
Angioplasty and Stenting in Dialysis
Angioplasty and vascular stenting are minimally invasive procedures performed to improve blood flow in the body’s arteries and veins.
In the angioplasty procedure, imaging techniques are used to guide a balloon-tipped catheter, a long, thin plastic tube, into an artery or vein and advance it to where the vessel is narrow or blocked. The balloon is inflated to open the vessel, then deflated and removed.
A balloon catheter is a long, thin plastic tube with a tiny balloon at its tip. A stent is a small, wire mesh tube. Balloons and stents come in varying sizes to match the size of the diseased artery.
In vascular stenting, which may be performed with angioplasty, a small wire mesh tube, called a stent, is permanently placed in the newly opened artery or vein to help it remain open. There are two types of stents: bare stents (wire mesh) and covered stents (also commonly called stent grafts).
Stents are specially designed mesh, metal tubes that are inserted into the body in a collapsed state on a catheter and then expanded inside the vessel to prop the walls open. In some cases the stent may have a synthetic fabric covering.
Angioplasty and angioplasty with vascular stenting are commonly used to treat conditions that involve a narrowing or blockage of arteries or veins throughout the body, including:
Renal Vascular Hypertension
Renal Vascular Hypertension is high blood pressure caused by a narrowing of the kidney arteries. Angioplasty with stenting is a commonly used method to open one or both of the arteries that supply blood to the kidneys. Treating renal arterial narrowing is also performed in some patients to protect or improve the renal function.
Narrowing in Dialysis Fistula or Grafts
It is very common to see narrowing involving the dialysis fistula or graft. When there is decreased flow in the graft or fistula that is not adequate for dialysis, angioplasty is generally the first line of treatment. Stenting or stent-grafting may also be needed in some cases.
In these procedures, X-ray imaging equipment, a balloon catheter, sheath, stent, and guide wire are used.
The equipment typically used for this examination consists of a radiographic table, an X-ray tube and a television-like monitor that is located in the examining room or in a nearby room. A guide wire is a thin wire used to guide the placement of the diagnostic catheter, angioplasty balloon catheter, and the vascular stent. A sheath is a vascular tube placed into the access artery, such as the femoral artery in the groin, which allows catheter exchanges easily during these complex procedures.
This procedure is often done on an outpatient basis.Back To Top
Declot Procedure For Dialysis Patients: Thrombectomy
The most common problem experienced with dialysis access devices is clotting, or thrombosis. Blood clots can form in temporary access catheters, fistulas, and grafts. Clotting can decrease or stop blood flow and make dialysis impossible.
Clotting is a more common problem for grafts than for fistula. (Blood is stimulated to clot by artificial substances; blood vessel walls contain substances that help to prevent clotting.) It is usually possible to tell by examining a fistula or graft if there is good flow through it. Good flow is turbulent and often produces a rhythmic buzz or thrill. The access should be checked frequently. If it appears that the device has stopped working, notify your dialysis doctor or your surgeon. Removing the clot is known as a thrombectomy.
In some cases it is possible to use thrombolytic agents to dissolve the clot.
Prevention and Surveillance
In order to decrease the incidence of thrombosis, and other access-related complications, the Kidney Dialysis Outcomes Quality Initiative (KDOQI) guidelines for vascular access surveillance were developed.
A routine vascular access surveillance program, combined with early diagnosis and repair of stenoses, can decrease the incidence of vascular access thrombosis and prolong graft longevity. Several studies have demonstrated an increase in graft survival when elective treatment, using either endovascular or surgical techniques, is performed prior to graft thrombosis.
Other advantages of good surveillance include:
- Reduced morbidity
- Efficient, continuous, uninterrupted hemodialysis
- Less need for temporary hemodialysis catheters
- Fewer hospital days for access-related problems
- Increased graft longevity
- Reduced rate of graft replacement
- Improved quality of life
Defining and Detecting Maturation
Fistula maturation requires adequate arterial inflow, adequate venous outflow, and the ability of the vein to dilate to increase blood flow enough to allow repetitive cannulation for dialysis. Preoperative venous, as well as arterial, imaging can reduce the number of non-maturing fistulas. Careful postoperative evaluation is also essential. A fistula should be examined at approximately four weeks following creation. Ultrasound can determine vein diameter, areas of stenosis, significant accessory veins, and blood flow.
Following duplex ultrasound, the next step for a non-matured fistula is a contrast fistulogram. Intervention usually consists of balloon angioplasty of all significant stenoses as well as obliteration of significant accessory venous branches.Back To Top
Dialysis-associated steal syndrome (DASS) is defined as a clinical condition caused by arterial insufficiency distal to the dialysis access owing to diversion of blood into the fistula or graft. It is usually asymptomatic, not requiring treatment.
Symptomatic steal occurs in patients who are unable to develop collateral or direct flow to offset steal.
Diagnosis of DASS requires three criteria to be fulfilled: (1) symptoms highly suggestive of DASS; (2) absent forearm pulses; and (3) radiographic criteria.
Treatment options include sacrifice of the access, flow reduction procedure (banding), percutaneous transluminal angioplasty (PTA) of arterial stenosis, embolization, and various revascularization surgeries.Back To Top