W32a Schild 40 Years of Experience Final Revised.ppt ... - SFAV

Changing Trends in Dialysis Access:
40 Years of Experience
A. Frederick Schild, M.D., F.A.C.S.
Asha R. Patel, B.S.
Joseph Fuller, B.S.
Patrick Collier, B.S.

History
• Hemodialysis was first carried out on
humans in Holland by Dr. Willem Kolff
during WWII.
• Soon afterward, Dr. Kolff came to the
United States to share his discoveries from
his experiments.
Uribarri J. Past, Present and Future of ESRD Therapy in the United States. Mount Sinai Journal of Medicine 66(1): 14-19,
Jan 1999.

Scribner Shunt
•The external
arteriovenous shunt
described by Quinton,
Dillard, and Scribner in
1960 led to the
establishment of chronic
hemodialysis.
Bennion RS and Wilson SE. Chapter 34: Hemodialysis and Vascular Access. Vascular Surgery: A Comprehensive Review. Sixth
Edition. Philadelphia, W.B. Saunders Company, 2002, Page 652.

Arteriovenous Fistula
• In 1966, Brescia, Cimino, and Appel
surgically created an anastamosis between
the radial artery and cephalic vein in the
wrist.
• Within a decade of its creation, the internal
arteriovenous fistula replaced the external
shunt as the preferred mode of vascular
access.
• Today, KDOQI recommends at least 66% of all
vascular access procedures be arteriovenous
fistulae.
Ronco, C and Levin NW (eds): Hemodialysis, Vascular Access, and Peritoneal Dialysis Access. Contrib Nephrol.
Basel, Karger, 2004, vol 142, pp 1-13.

AV Grafts
• Saphenous veins were also used in the
1970’s s and 1980’s, however, they tend
to have poor outcomes.
• PTFE grafts were introduced in 1973.
– Now it is the most commonly used
artificial material for vascular grafts in
hemodialysis.
Ronco, C and Levin NW (eds): Hemodialysis, Vascular Access, and Peritoneal Dialysis Access. Contrib Nephrol. Basel,
Karger, 2004, vol 142, pp 1-13.

Double-lumen lumen Catheter
• In 1980, a double-lumen lumen cuffed catheter was
designed to be placed in the internal jugular
vein and into the superior vena cava.
• Although the catheter has evolved into a better
and safer design, a great risk of complications
of central vein stenosis and infection still exist.
Ronco, C and Levin NW (eds): Hemodialysis, Vascular Access, and Peritoneal Dialysis Access. Contrib Nephrol. Basel,
Karger, 2004, vol 142, pp 1-13.

Conduits for Access
• Over the years, I have had the experience
of using a multitude of conduits for access
such as:
– Scribner’s s Shunt
– Bovine Grafts
– Autologous Fistulae
– Umbilical Vein Grafts
– PTFE
– Polyetherurethaneurea Grafts.

Vascular Access Requires a
Multidisciplinary Approach

American Medical News
April 21, 2003
•“Patients with chronic illnesses must
navigate a complex regimen of multiple
physicians and medications. Coordination of
the medical team supports patients by
improving care and avoiding
hospitalizations.”
•Therefore, a structured and well organized
multidisciplinary team approach appears to
be the most practical and efficient way to
achieve quality care for ESRD patients.

The Multidisciplinary Approach
• Patients who have earlier access to surgeons
– Higher incidence of an AVF because veins are
not destroyed
– Decreased use of temporary catheters
• Complications are identified and corrected in a
timely fashion, including:
– Increased long-term patency
– Less hospitalizations
– Less repeat surgery

Participating Specialties
• Primary Care Physicians
• Nephrologists
• Interventional Nephrologists
• Interventional Radiologists
• Anesthesiologists
• Surgeons
• Nurse Coordinator

Epidemiology
• At the present time, there are
approximately 300,000 patients on
hemodialysis in the United States.
• The number of vascular access procedures
is nearing 500,000 per year.
• ESRD is growing by approximately 15%
each year (doubling in 4-64
6 years).
• Total annual costs are projected to exceed
$28 billion by 2010.

Technique for Large Aperture
Anastomosis

Immediately Post-Operative AVF

Advantages of AVF
• Reduced infections!
• In our recent study we evaluated 1574
vascular access procedures for infection.
• There were 132 patients operated upon
for access infection.
• Of the 132 patients, only one (1) patient
had an AVF (0.75%).

Disadvantages of AVF
• It has been shown that 30-50% of all AV
fistulae fail to mature.
• A recent retrospective study by Schild, et
al compared 1700 consecutive procedures.
– At 10 years there were no statistically
significant differences between the patency of
grafts and fistulae.

• Advantages:
AV Grafts
– Newer grafts can be cannulated within 24-72
hours, decreasing double-lumen lumen cuffed catheter
time.
– AV graft revisions have better results than
revised AV fistulae.
– In certain populations grafts are a better
alternative to fistulae.
• Disadvantages:
– Higher infection rate
– Higher rate of thrombosis

Complications of Vascular Access:
Central Vein Stenosis

Seroma

Access Thrombectomy
• Thrombosis is the most common complication of
vascular access.
• AV grafts have higher incidence of clotting than
AV fistulae, but have longer post revision
patency.
• Methods of access thrombectomy:
– Endovascular with angioplasty and stent
– Surgical revision
• Both methods must focus on removal of arterial
plug.

Failure of AVFs to Mature:
University of Miami Study

Methods
• 373 patients underwent construction of
AVF as permanent primary access.
• Our criteria and KDOQI requires the vein
and artery to be at least 2.5 mm in
diameter.
• Pre-operative vein mapping was
performed.
• From, this population, 291 patients had
complete follow-up data for at least three
months

Definition of Failure
• All early AVF occlusions were considered
failures.
• After construction, if the AVF did not
clinically mature within 3 months, it was
considered a failure.
• Additional failures were identified when
cannulation in the dialysis center could not
be accomplished.

Conclusions
• In our series we placed more AVF in Males
than in Females; despite the fact that
Males and Females present for dialysis at
the same frequency.
• Overall Failure Rate was 31.3%
– Females 41.2%
– Males 27.2%

Conclusions
• Increasing co-morbidity did not result in
major changes in failure rate.
• The brachiocephalic position matured at
a higher frequency than the
radiocephalic.

Questions for Discussion
• In light of published AVF Failure Rates
ranging from 20% to 50% are we
submitting patients to an unnecessary
second operation (AVF then prosthetic
access)?
• Should KDOQI Guidelines be revisited in
terms of developing more focused criteria
for AVF or should we be more meticulous
in our pre-operative work-up?

Infections associated with
vascular access procedures:
University of Miami Study

Infections in Vascular Access
• Infection is the second most common
complication in vascular access.
• Death secondary to infection in dialysis
patients is estimated at 36%.

Methods
• We reviewed the medical records of 1574
consecutive vascular procedures
performed on 850 patients, over a 60
month period.
• Infection was diagnosed when there were
local signs of inflammation or purulence
requiring intravenous antibiotics and
removal of the access.

Methods
• 132 procedures (8%) were performed for
infection in 87 patients.
– 86 infected grafts
– 1 infected AVF
• This occurred two years following access surgery
which was complicated by a pseudo-aneurysm with
skin erosion.

Results
• There were multiple organisms cultured as the
cause of infection.
• The two most common were:
– S. aureus (26%)
– MRSA (21%)
• Overall Operative Infection Rate was 0.51% (n
= 1574) .
– Fistulas had no operative infections (n = 521).
– Operative graft infection rate of 0.86% (n = 921).

Conclusions
• Infections attributable to access
operations had a low prevalence.
• The largest number of infections occurred
in patients undergoing routine dialysis.
– Dialysis centers were responsible for 50% of
all infections identified.
• This data suggests close observation in
the dialysis center is strongly advised.

Conclusions
• We found 30 grafts (23%) that were non-
functional and dormant for long periods of
time that ultimately became infected.
• There should be a high index of suspicion
for thrombosed grafts as a source of
bacteremia even in the absence of local
signs of infections.

Conclusions
• When a graft was removed, it had been
our policy to leave a graft stump at the
arterial anastomosis when the artery
was very small and no vein was
available for a patch.
• 17% of these operations for infection
were performed because these stumps
became infected.

Recommendations
• It is recommended when infection is
identified in non-functional grafts they be
removed immediately.
• Delay due to antibiotic therapy is not
warranted as the presence of a foreign
body will not allow complete eradication of
infection with antibiotics alone.

Complications of Infection

Complications of Infection

Future Developments
• New studies are being conducted to alter the
genes in the vein at the venous anastomosis to
prevent neointimal hyperplasia.
• There is a new graft manufactured by Atrium
Medical Corp. in which cannulation can be
achieved within 24-72 hours.
• This early cannulation prevents prolonged
double-lumen lumen cuffed catheter use, leading to
lower rates of stenosis and infection.
– Current clinical trials have shown much success

Final Conclusions
• Vascular Access procedures are
becoming the most common surgery
performed in the United States and
around the world.
• Vascular Access should be a
multidisciplinary effort.

Final Conclusions
• Vascular Access surgery encompasses
many difficult problems and should
only be performed by those dedicated
to its success.
• A greater effort should be made to
create more arteriovenous fistulae
than prosthetic grafts to comply with
KDOQI guidelines.

THANK YOU