MATERIALS AND METHODS
The institutional review board at our institution gave full approval and waiver of informed consent for our retrospective study and had previously approved our treatment protocol.
Written patient informed consent was obtained from each patient prior to treatment.
Clinical indication for treatment was type Ia,
type II or type Ia-II with evidence an increase of the aneurysm sac’s diameter of at least 25 % during post-EVAR follow-up.
The treatment was considered technically feasible,
when the inferior vena cava was found to be adjacent and adherent to the aneurysm sac.
In addition,
there must be sufficient space between the aneurysm wall and the endograft wall.
In fact,
in the absence of such space would run the risk of perforating the prosthesis wall causes the lesion with fistula formation and bleeding.
(Fig 1)
Fourteen patients (6 males,
8 females; mean age:71.6 ± 7.9 years; range: 57-83) with type Ia,
type II or type Ia-II endoleak were treated by transcaval embolization between January 2006 and January 2007 at our Department.
After EVAR treatment with different endografts types.
These Patients were followed by Computed Tomography angiography (CTA) at minimum intervals of one week,
1,
6 and 12 months,
and yearly thereafter.
Nine patients were treated and followed at our institution while the other five were treated at other hospitals but the follow-up were performed at our institution.
When an endoleak was detected CTA was performed at 6-month intervals to detect eventual changes in the dimensions of the aneurysm sac.
The mean increase of aneurysm sac diameter was 26.8 ± 1.3 % (14.7 ± 1.5 mm)
over a mean period of 8.6 ± 3.1 months after EVAR .
Two patients presented a type Ia endoleak,
10 with type II endoleak and 2 with type I-II associated endoleak and a significant increase in aneurysm sac diameter.
Technique
In the first 4 patients treated,
all with a type II endoleak,
TCEE was selected as an
alternative method after an unsuccessful attempt of intra arterial retrograde catheterization of the feeding artery.
In the first patient treated for a type Ia endoleak,
TCEE was selected as the deployment of an extension cuff was unfeasible due to the short infrarenal neck.
In all patients treated in our institution,
was not possible to treat endoleak at the time of implantation.
After our initial experience with TCEE,
this was chosen as the primary approach in
the successive patients treated for a type I a,
II or type Ia-II endoleak.
All procedures were performed in a dedicated angiography suite under moderate
sedation.
The common femoral vein was punctured under local anesthesia using lidocaine and a standard 0.035” J tipped 180 cm long
hydrophilic guidewire (Radiofocus,
Terumo,
Tokyo,
Japan) was advanced into the
inferior vena cava (IVC).
A 12F introducer sheath 40cm long was placed and advanced into the IVC to give stability and allow a safe puncture.
Transcaval puncture of the aneurysm sac was performed with the same technique for all patients,
using an Angiodinamics TIPS puncture set (Angiodynamics,
Queensbury NY,
US).
The 8 French transjugular curved catheter and the 5F curved guiding cannula was advanced trought the introducer sheath over the guidewire.
The system was oriented to the stent graft so that the curved guiding cannula resting against the vena cava wall.
The orientation of the system was verified on multiple fluoroscopic projections to clarify landmarks wich are the vertebrae and if present the aorta wall calcification.
The Colapinto needle assembly with the 5F curved guiding cannula was advanced through the system and finnaly the aneurysm sac was punctured according to the landmarks gathered from the pre-procedural CT scan.(fig 2-3)
The 5 Fr cannula with its chatether was introduced under fluoroscopic guidance
through the Colapinto needle.
The flexible puncture needle was removed,
and a 0.035” standard J tipped 180cm long hydrophilic guidewire was slowly advanced into the aneurysm sac until a low resistance path was engaged.
(Fig 4)
This was considered as an indirect sign of the passage of the guidewire into an unthrombosed area,
suggestive of the site of the endoleak.
The caftheter was then advanced over the guidewire into the area of the presumed endoleak.
The backflow of blood through the catheter,
after removal of the guidewire,
confirmed its position within the endoleak.
The contrast media was manually injected low pressure to visualize the presence of intrasac flow and,
in case of type II endoleaks,
an eventual back-flow into lumbar arteries.
(Fig.5-6)
Intrasac pressure was also evaluated during the procedure to confirm the drop of intrasac pressure after embolisation.
When a type Ia endoleak was suspected,
the passage of the guidewire through the proximal sealing zone into the aorta was assessed.
(Fig7)
When such a communication was found,
the guiding catheter was advance into
the sealing zone and contrast media was gently injected to visualize the endoleak.
(Fig.
8)
Type Ia endoleaks were embolised using 7-15 platinum fibered coils (Target,
Boston Scientific,.Natick MA,
US),
with diameters ranging between 6-9 mm,
and 1.8 ± 1.0 ml (range 1-3) of human thrombin (Tissucol,
Baxter SpA,Italia) (Fig 9).
Type II endoleaks were embolised using a combination of 7-15 platinum fibered coils,
with a diameter ranging between 6-9 mm,
and 1ml of Glubran 2 acrylic glue (GEM,
Viareggio,Italy) mixed to Lipiodol using a 1:3 volume ratio,
in order to allow its fluoroscopic visualization (fig 10,11).
Type Ia-II endoleaks were embolised using 17-23 platinum fibered coils (Target,
Boston Scientific,.Natick MA,
US),
with diameters ranging between 6-9 mm,
and
1,5 ml of Glubran 2 acrylic glue (GEM,
Viareggio,Italy) mixed to Lipiodol.
The complete exclusion of the endoleak was confirmed by the persistence of contrast
medium within the aneurysm sac (Fig.
11),
the absence of intrasac flow and the drop
of intrasac pressure measured with a continuous in-line hemodynamic monitoring
performed by the ACIST System (Bracco,
Italy).
The Mean fluoroscopy time was 15.4 ± 4.1(range: 10-22).
Patients were discharged 24 hours post-procedurally,
after a CTA examination had
been performed.
(fig 12-13)
FOLLOW-UP
Follow-up was performed by Computed Tomography angiography (CTA) at 1,
3,
6
and 12 months post-procedurally.