Techniques for EVAR Explants
Jonathan Eliason, University of Michigan
Vascular Annual Meeting 2013
Technical Aspects of Complex Open Vascular Surgery
•
Abdominal aortic aneurysms are preferentially treated
with EVAR in the modern era
•
Some hospitals in Michigan are treating over 90% of
AAAs with EVAR
•
While most of these operations are successful, a certain
subset of patients require explantation of endografts
– Infection
– Aneurysm expansion
• Documented endoleak
• Unknown cause (? Sub-clinical infection)
Focus
•
The goal of this talk is to discuss the technical
aspects of open aortic surgery unique to
explanting endografts
•
In this regard, the Michigan experience will be
reviewed, with a specific focus on select cases
Demographics
Table I. Patient demographics and preoperative variables
All
Endoleak
[N=39]
[N=27]
Males (%)
Age in years
BMI in kg/m2
ASA >3 at explantation (%)
Diabetes (%)
Hypertension (%)
Hyperlipidemia (%)
Coronary artery disease (%)
Prior MI (%)
Prior CABG/PCI (%)
Congestive heart failure (%)
Renal insufficiency (%)
Anticoagulation (%)
Ever Smoker (%)
Current Smoker (%)
EVAR at outside location (%)
25 (64.1)
71.9
27.1
22 (56.4)
8 (20.5)
38 (97.4)
30 (76.9)
23 (58.9)
13 (33.3)
19 (48.7)
6 (15.4)
7 (17.9)
3 (7.7)
32 (82)
8 (20.5)
26 (66.7)
14 (51.8)
73
28.2
14 (51.8)
7 (25.9)
26 (96.3)
21 (77.8)
14 (51.8)
7 (25.9)
11 (40.7)
4 (14.8)
5 (18.5)
3 (11.1)
23 (85.2)
5 (18.5)
16 (59.3)
Infection
[N=12]
11 (91.7)*
69.7
24.4*
8 (66.7)*
1 (8.3)
12 (100)
9 (75)
9 (75)
6 (50)
8 (66.7)
2 (16.7)
2 (16.7)
0
9 (75)
3 (25)
10 (83.3)
Indication for Operation
Table II. Primary indications for explantation of aortic endografts
Endoleak
Infection
N= 27 (23 elective, 4 emergent)
N=12 ( 7 elective, 5 emergent)
12 type 1A endoleaks
7 graft infections
1 type 1B endoleak
2 aorto-duodenal fistulae
8 type 2 endoleaks
1 type 3 endoleak
2 sac enlargements
(Purulence seen intraop)
4 endotension
1 rupture
1 rupture
Operative Variables
Table IV. Intraoperative and postoperative results
All
Endoleak
[N=39]
[N=27]
Intraoperative variables
Supraceliac clamping (%)
7 (18.4%)
1 (3.8%)
Intra-op blood loss (Litres)
4.5
3.7
Mean PRBCs transfused (units)
6.8
4.4
Mean FFPs transfused (units)
4.4
3
Renal bypass
4
2
Mesenteric bypass
2
0
Infection
[N=12]
p-value
6 (50%)
6.3
12.2
7.6
2
2
0.002
0.08
0.005
0.03
NS
0.09
Postoperative results
Re-exploration needed (%)
6 (15.4%)
1 (3.7%)
5 (41.7%)
0.007
DIC (%)
3 (7.9%)
0
3 (25%)
0.02
30-day morbidity (%)
24 (62.1%)
14 (51.8%)
10 (83%)
0.08
30-day major morbidity (%)
12 (30.8%)
3 (11.1%)
9 (75.0%)
0.001
30-day mortality (%)
2 (5%)
0
2 (17%)
0.09
ICU length of stay (in days)
6.7
5
10.4
NS
Hospital length of stay (in days)
13.9
11.8
18.7
NS
PRBC: Packed red blood cells; FFP: Fresh frozen plasma; DIC: Disseminated intravascular
coagulopathy; ICU: Intensive care unit
Operative Variables
Table IV. Intraoperative and postoperative results
All
Endoleak
[N=39]
[N=27]
Intraoperative variables
Supraceliac clamping (%)
7 (18.4%)
1 (3.8%)
Intra-op blood loss (Litres)
4.5
3.7
Mean PRBCs transfused (units)
6.8
4.4
Mean FFPs transfused (units)
4.4
3
Renal bypass
4
2
Mesenteric bypass
2
0
Infection
[N=12]
p-value
6 (50%)
6.3
12.2
7.6
2
2
0.002
0.08
0.005
0.03
NS
0.09
Postoperative results
Re-exploration needed (%)
6 (15.4%)
1 (3.7%)
5 (41.7%)
0.007
DIC (%)
3 (7.9%)
0
3 (25%)
0.02
30-day morbidity (%)
24 (62.1%)
14 (51.8%)
10 (83%)
0.08
30-day major morbidity (%)
12 (30.8%)
3 (11.1%)
9 (75.0%)
0.001
30-day mortality (%)
2 (5%)
0
2 (17%)
0.09
ICU length of stay (in days)
6.7
5
10.4
NS
Hospital length of stay (in days)
13.9
11.8
18.7
NS
PRBC: Packed red blood cells; FFP: Fresh frozen plasma; DIC: Disseminated intravascular
coagulopathy; ICU: Intensive care unit
Operative Variables
Table IV. Intraoperative and postoperative results
All
Endoleak
[N=39]
[N=27]
Intraoperative variables
Supraceliac clamping (%)
7 (18.4%)
1 (3.8%)
Intra-op blood loss (Litres)
4.5
3.7
Mean PRBCs transfused (units)
6.8
4.4
Mean FFPs transfused (units)
4.4
3
Renal bypass
4
2
Mesenteric bypass
2
0
Infection
[N=12]
p-value
6 (50%)
6.3
12.2
7.6
2
2
0.002
0.08
0.005
0.03
NS
0.09
Postoperative results
Re-exploration needed (%)
6 (15.4%)
1 (3.7%)
5 (41.7%)
0.007
DIC (%)
3 (7.9%)
0
3 (25%)
0.02
30-day morbidity (%)
24 (62.1%)
14 (51.8%)
10 (83%)
0.08
30-day major morbidity (%)
12 (30.8%)
3 (11.1%)
9 (75.0%)
0.001
30-day mortality (%)
2 (5%)
0
217%
(17%)
0.09
ICU length of stay (in days)
6.7
5
10.4
NS
Hospital length of stay (in days)
13.9
11.8
18.7
NS
PRBC: Packed red blood cells; FFP: Fresh frozen plasma; DIC: Disseminated intravascular
coagulopathy; ICU: Intensive care unit
Explant for Endoleak
•
68 y/o male
•
EVAR using the PowerLink device at OSH
•
History of Child’s B Cirrhosis
•
6cm AAA at initial treatment
•
Now 10cm
Previous coils for
Presumed Type II
endoleak
Operative Details
•
Review of CT suggested proximal aortic cuff,
with undersizing of endograft and Palmaz stent
above renal arteries
•
Midline incision
•
Wide exposure
•
Clamps
– Suprarenal
– External iliac and internal iliacs clamped
individually
Operative Details
•
Once heparinized renals occluded with tension
on Potts vessel loops and clamps placed, sac
opened
•
Kelly used to remove main body and iliac limbs
– Spread parallel to limbs to free up
•
Proximally found two aortic cuffs with a Palmaz
stent between. Stent quite incorporated by
aortic intima
•
Suprarenal clamp loosened as Palmaz pulled
free with unintentional endarterectomy due to
incorporation
Operative Details
•
Once graft removed, clamp moved infrarenally
•
Flow restored to renal arteries
•
18 x 9 mm nylon graft used for repair
•
Circumferential felt utilized for proximal and
distal anastomotic suture lines
•
EBL 5,000 for “straightforward” explant
More Complex
•
Preop Dx: Large left iliac artery aneurysm
proximal to a kidney transplant, moderate sized
AAA, polycystic liver and kidney disease
•
Previous left internal iliac artery coil
embolization with EVAR and left external iliac
extension using the Medtronic AneuRx system
performed at University of Michigan
L Renal Transplant
Operative Considerations
•
Baseline Cr 1.9
•
L CIA aneurysm now >10cm with type II
endoleak
•
AAA now >6cm and contiguous with L CIA
aneurysm
•
Large patulous abdominal wall
Operative Technique
•
Generous transverse skin incision above
umbilicus
•
Aorta exposed
•
L ex-vivo ax-fem bypass placed
•
Clamp placement as follows:
– L CIA aneurysm distally using soft-jaw clamp
– R CIA distally using small soft-jaw clamp
– 3 proximal aortic clamps (2 coarctation and 1
Crawford) placed in order to compress graft
Operative Technique
•
L Kidney perfused by ax-fem
•
Aortic graft transected with knife and heavy
wire cutter leaving partial proximal graft
•
Limbs transected as well leaving distal aspects
intact
•
22 x 11 Rifampin-bonded graft used
– Proximal anastomosis circumferential felt
reinforcement
– Distal anastomoses to graft limbs on L
– Back bleeding via ax-fem excellent
Operative Technique
•
Flow restored antegrade to left iliac
•
Ex-vivo ax fem clamped
•
Right iliac anastomosis to graft limb + iliac
•
Coagulopathy corrected after bilateral
antegrade flow restored
•
Ax-fem graft removed
•
Abdomen closed
Of Note
• EBL nearly 15 Liters
• Liberal cell-saver and
aggressive coagulopathy
correction when appropriate
• No adverse effect on renal
function
Graft components left in situ
When too hazardous to remove
Complex Scenario
•
66 year old female with Cook Zenith AAA
repair 7 years ago
•
Fevers, chills, abdominal pain
•
CT with PSA of aorta at suprarenal fixation site
and peri-graft enhancing fluid
•
PSA extends up to inferior border of celiac
artery
Principle Concerns
•
Need total graft explantation due to infection
•
Aortic pseudoaneurysm makes clamp location
and reconstructive plan complex
•
Patient acutely symptomatic
Operative Plan
•
L Ax-fem-fem bypass graft placed
– L axillary incision closed over drain
– Bilateral groin incisions partially closed, wound
vacs placed superficially
•
LE and pelvic perfusion now protected
•
Generous midline incision now made
•
Iliac exposures performed first
Operative Plan
•
Right hypogastric previously occluded
•
Right external iliac artery ligated with two 0silk ties
•
Left colon reflected and left common iliac
artery clamped distally
•
LE and pelvic perfusion now via ax-fem-fem
bypass and distal control now obtained
Operative Plan
•
Supraceliac aortic control obtained with
encircling using umbilical tape at this level
•
Critical branches now exposed
– Common hepatic artery and celiac origin encircled
– Kocher maneuver with right renal artery exposure
– SMA exposure just distal to middle colic to avoid
aortic PSA
– Plan to sacrifice L Renal Artery due to association
with PSA
Operative Plan
•
Supraceliac aorta clamped
•
7mm aorto-common hepatic graft placed (27
minute supra-celiac clamp time)
•
Pre-sewn bifurcated 7mm graft then sewn to
CHA graft creating a trifurcated graft
•
One limb passed through right retroperitoneum
and right aorto-renal performed. Prox A.
oversewn.
•
Another limb tunneled through Tx mesocolon
and end-to-side SMA anastomosis performed
Operative Plan
•
Aortic clamp placed below supra-celiac graft
•
Origin of celiac artery ligated and divided
between ties to provide exposure
•
Aorta oversewn at supraceliac location using 3
layer, felt-reinforced 3-0 Prolene horizontal
mattress type sutures.
•
Aneurysm and PSA now opened after depulsing the aneurysm
Operative Details
•
Massive bleeding when aneursym opened from
SMA proximally, L renal artery ostium,
multiple lumbar sites
•
Graft removed by individually grasping suprarenal struts with needle holder and disengaging
•
Difficult exposure of PSA dorsal to pancreas
•
Bleeding sites oversewn with multiple 3-0 and 40 Prolene sutures
•
Fatigue factor present
Operative Details
•
Once bleeding under moderate control:
– Reversal of anticoagulation
– Aggressive retroperitoneal pulse lavage
– Pedicled omental flap to fill retroperitoneal abscess
cavity
•
Abdomen closed
•
All branch bypass grafts were rifampin bonded
•
Anesthesia had been prepared for massive
bleeding and did well keeping up with 10L EBL
Post-operative CTA
• Patient survived
• Lived 18 months
• Returned to home
after 6 weeks in
rehabilitation facility
Pearls
•
Explants are complex operations even when
“straightforward”
•
Expect high blood loss regardless of indication for
reconstruction
•
Plan critical branch-revascularization in
the context of how much graft requires
excision
•
Aim for total graft excision with infection
•
EVAR explant for endoleak can leave
proximal and distal graft in place where
appropriate and suture new graft to
endograft/artery double layer
Pearls
•
If infection is suspected or known, utilize Rifampinbonded nylon grafts with adjunctive pedicled omental
flap
•
Consider extra-anatomic reconstruction for high
aortic involvement, aortoduodenal fistulae, graft
infection
Felt Appearance on CT
•
Temporary suprarenal clamping
facilitates graft removal
•
Multiple heavy and standard wire cutters may be
helpful for partial graft removal
•
Felt reinforcement can limit anastomotic bleeding