Stenting Pseudoaneurysms, Across Elbow Joint, and in Cannulation

Stenting Pseudoaneurysms,
Across Elbow Joint, and
in Cannulation Zone
Thomas Vesely, M.D.
Saint Louis, Missouri
Dr. Vesely is a consultant
for W.L. Gore & Associates
Acute hematoma due to a
traumatic cannulation
at the dialysis center
arterial limb of
PTFE graft
Continued bleeding from
tear in graft
After placement of stent graft
Original
Lesion
Two month
follow-Up
Stents and Stent Grafts
Across Elbow Joint
Multiple fractures of metal stent
across elbow joint
Blood vessels undergo conformational changes
Different mechanical forces act upon stents
when placed in arteries and veins
no kink
kink
Stent design determines stent behavior
Images of stents and stent grafts
when subjected to
25% longitudinal compression
Stent design
determines flexibility
Elbow bent to greater than 90 degrees
Elbow bent to ~ 270 degrees
REVISE Clinical Trial
Viabahn Stent Graft Across Elbow Joint
3 months 6 months 12 months 24 months
18
17
17
12
Target Lesion
Primary Patency
72%
72%
56%
32%
Secondary Patency
95%
95%
95%
83%
# Across Elbow Joint
No stent fractures
Based upon the results of the REVISE study
the Viabahn stent graft is now
FDA approved for use across the elbow joint
Stent Grafts as Treatment for
Hemodialysis Access Pseudoaneurysms
Large pseudoaneurysm
arising from
arterial limb
of forearm PTFE graft
7mm x 100mm stent graft
Both ends of stent graft extend into
normal segments of hemodialysis graft
“ Sealing ” both ends using 7mm PTA balloon
Before
After
Used an 18g needle to aspirate ~25ml of
blood from the pseudoaneurysm sac.
Before
After
Rapidly enlarging
pseudoaneurysm
outflow stenosis
Outflow stenosis
causes increased
pressure within
graft causing
expansion of
pseudoaneurysm
Pre-Treatment
Post-Angioplasty
Post-Stent Graft
Pre-Treatment
Post-Stent Graft
Post-Aspiration
Prospective study of
24 pseudoaneurysms
treated with a stent graft
20 patients = PTFE graft
4 patients = fistula
12 patients had one pseudoaneurysm
12 patients had multiple pseudoaneurysms
All patients received Fluency stent grafts
1 stent graft = 9 patients
2 stent grafts = 11 patients
3 stent grafts = 4 patients
J Vasc Surg 2013; 57: 137-144
Assisted
Primary Patency
2 months
6 months
12 months
83%
54%
50%
Mean patency = 17.6 months
J Vasc Surg 2013; 57: 137-144
Complications
5 infections in 24 patients = 20.8%
5 stent graft infections
requiring removal of device
• 3 infections before 2 months
• 2 infections at 4 months
2 stent fractures
each treated with new stent
J Vasc Surg 2013; 57: 137-144
• 1 stent fracture at 36 months
• 1 stent fracture at 74 months
Thrombus aspirated from
36 of 100 hemodialysis grafts
had + blood cultures at 24 hours
Culture Results
Seminars in Dialysis 2015; 28:446-449
Staphylococcus epidermidis
27
Staphylococcus aureus
1
Staphylococcus hominis
4
Staphylococcus auricularis
1
Streptococcus viridans
2
Diphtheroids
2
Bacillus species
1
Mixed
2
J Vasc Intervent Radiol 2012; 23:69-74
Number of Graft Infections
by Indication and Location of Stent Graft
16% infections
Stents and Stent grafts
Across Cannulation Zone
Six weeks after insertion of stent graft
in needle cannulation
Enlarging pseudoaneurysm
at site of damaged venous stent
Damage to the stent in the venous limb
due to repeated needle cannulation
Stent graft looks chewed up
by rate of blood flow is good
Two year old brachiocephalic fistula
which was treated with multiple stent grafts
Stent graft damaged by repeated needle cannulation
Stent graft damaged by repeated needle cannulation
Angioplasty with
6mm diameter
balloon
Post-angioplasty
Conclusions
•
Stent grafts are not designed to be cannulated
•
Stent grafts work well for repair of acute vascular injuries
•
High risk of stent graft infection when deployed in
PTFE hemodialysis grafts
•
Stent design determines flexibility and
safety for deployment across elbow joint