Late last year, Holyoke Medical Center became one of the first campuses in Western Mass. to make dialysis patients’ lives a lot easier.
Through a recent innovation known as subcutaneous access, dialysis patients now have a fourth — and very efficient — choice for cleansing their blood of waste products. While dialysis via fistulas, grafts, or catheterization remain the usual options at many hospitals, dialysis by the newer, subcutaneous access method is becoming an increasingly popular method at Holyoke Medical Center.
“It’s a nice alternative to catheters,” said Dr. John Horky, an interventional radiologist who performs the implant procedure of these devices at Holyoke Medical Center. “Patients like it because it’s not obtrusive and not uncomfortable.”
Dr. Jonathan Slater, a physician at Pioneer Valley Nephrology who conducts dialysis on many of the patients who use this new method, said that Horky has helped these patients immensely by bringing it to Holyoke Medical Center.
“Dr. Horky brings a tremendous amount of knowledge and skill to implanting the devices,” Slater said. “I would say he has the most experience with it in the area.”
The difference between this newer method and older ones involves understanding the difference in flow rates (how quickly the blood is removed and returned to the body during dialysis), and how doctors get access to the bloodstream. Dialysis using fistulas has become the preferred method for long-term dialysis over the years, as they usually last longer than other access methods and are less prone to infection or clotting problems.
A fistula is a surgical connection between a vein and an artery, usually done in the forearm, that allows for adequate blood flow during dialysis. Two needles are inserted into the fistula during dialysis, one for withdrawing blood and another for returning it to the body.
While fistulas allow for a good flow rate, they have several problems, Horky said. First, it takes a few months — or longer — for the fistula to develop to the point where dialysis can be performed. In addition, not all patients can use fistulas: some may have veins that are too small or have other conditions which make them ineligible for the procedure.
Similar to fistulas are grafts, which indirectly connect the artery to the vein through a synthetic tube. While these can usually be used more quickly than a fistula, they have an increased potential for infection and clotting and usually do not last as long as a fistula. The least effective method, which is meant as a temporary technique, is catheterization.
While catheters allow for immediate dialysis and easy replacement, they have high infection rates, lower flow rates, and possible lifestyle restrictions. Swimming or bathing are not allowed when a catheter is implanted. The subcutaneous implant access method combines the best of all the above procedures while limiting the potential problems. This method allows for high flow rates and decreased clotting and infection, and can be discreetly covered by clothing.
The way this method works is that two ‘buttonhole’ access devices are implanted, usually in the chest, and are connected to hollow, flexible catheters that are in turn hooked up to large veins. When dialysis is needed, doctors simply insert needles into the buttonholes and remove and return the blood through them. The subcutaneous devices open only when the needle is inserted, and close immediately after its removal. The buttonhole scar tract in the skin covering these insertion areas acts similarly to the opening made by a pierced ear.
This allows for an almost pain-free needle insertion after a short time, according to Vasca Inc., the company which makes the LifeSite hemodialysis access system employed at Holyoke Medical Center. This increased flow rate and fewer problems with infection add up to increased overall efficiency.
“It provides another option, and we get very good blood flow rates compared to catheters,” said Slater.
The new technology reduces costs and increases performance in an area that hasn’t seen significant changes in 30 years, according to Vasca officials.
This new technology also is beginning to expand in its popularity for several other reasons.
“They provide immediate access for dialysis and have just been approved for chronic dialysis patients,” said Horky. “They were originally just bridge devices to those waiting for fistulas, but now can be used for chronic patients on a long-term basis.”