An 81-year-old lady presented to clinic in March with a 2-month history
of a pulsatile left neck mass, with associated dysphagia, and weight
loss. There was mild pain with no overlying skin changes. Of note, she
had a background of previous multiple strokes and of a left CEA
performed in 2014 to treat a symptomatic carotid artery stenosis. She
was known to have an occluded left common carotid artery as far as the
circle of Willis in her CT angiogram and duplex ultrasound in late 2019
when she presented with left hemispheric stroke. On examination there
was a palpable tender pulsatile mass measuring 2.5x 3cm. She complained
of associated compressive symptoms of dysphagia that was contributing to
malnutrition.
A duplex US was performed which demonstrated a vascularized mass with
difficulty delineating the wall. It was decided at this point to perform
a CT angiogram which demonstrated a left carotid pseudoaneurysm
measuring 3.3x 3.5cm with patch disruption. The previously occluded left
carotid system was now patent from the origin of the common carotid
artery to the circle of Willis, with occluded external carotid artery.
The diameter of the internal carotid artery was 5mm. her inflammatory
markers were slightly elevated.
Our approach was to improve her general condition and optimize her for
surgical intervention. We adopted the hybrid approach to treat this
pseudoaneurysm. This was done with a trans-cervical carotid artery
stenting followed simultaneously by open carotid pseudoaneurysm repair
using interposition vein bypass. The patient was positioned supine with
right tilted extended neck in a hybrid operating theatre. A
transcervical carotid artery stent approach was accessed initially by
doing small vertical proximal carotid cutdown at base the neck and
inserting a 7 French hydrophilic sheath into the proximal left common
carotid artery (CCA). The direct angiography revealed left carotid patch
pseudoaneurysm with continuity of left internal carotid artery (ICA)
intracranially. A bolus 5,000 intravenous unfractionated heparin was
given. We placed two of covered self-expandable Viabhan stents from the
common carotid artery as far as the ICA (W. L. Gore & Associates,
Arizona, USA) to temporarily seal the pseudoaneurysm. We performed
negative suction while we deployed the stents using suction syringe from
sheath sideway combined with left proximal CCA clamping. The negative
suction technique was used in order to reduce improve the retrograde
flow from the ICA and reduce the distal embolization while stents
deployment (see Fig 1). We removed the 7fr sheath with purse string
monofilament stitch to repair the carotid puncture site. At that time
the left great saphenous vein was harvested from the right groin. We
then started the open exploration of the carotid pseudoaneurysm. The
initial carotid vertical incision was extended cranially until the
mastoid process over the left carotid pseudoaneurysm. Dissection was
performed carefully avoiding nerve injury. The pseudoaneurysm was
exposed and revealed a disrupted Dacron graft with combined pus and
blood clots noted. The bare metal stents inserted were visible at this
point with no active bleeding (see Fig 2). Distal ICA control was
achieved (see Fig 3). We routinely use the ICA stump pressure combined
with retrograde ICA blood backflow to check the intracranial circulation
prior to and after CCA clamping. Also, the patient has intact right
carotid arterial tree and circle of Willis with no obvious contralateral
ICA stenosis. the stump pressure was 52 mmHg with good ICA blood
backflow after CCA clamping. We decided to avoid using the carotid shunt
in addition to maintaining the systolic blood pressure between (160-180
mmHg). The affected arterial segment was then excised along with the
previously inserted stents with good ICA arterial backflow seen (see Fig
4, 6). In situ End-to-end anastomosis was performed between the CCA and
the proximal end of the vein bypass followed by ICA anastomosis with
distal end of the harvested vein (see Fig 5). A sternocleidomastoid
muscle flap was used to cover the interposition vein bypass as a
secondary prevention of graft infection with good hemostasis.
Surprisingly, there were no organism grown in the tissue and the Dacron
patch culture that has been sent intraoperatively. Postoperatively, the
patient recovered well and required 24 hours monitoring in high
dependency unit.
Dual anti-platelet was started as well as antibiotics with a plan to
complete 48 hours course. She continued to receive multidisciplinary
input from physiotherapy, occupational therapy, and dietician to enhance
recovery. A repeat CT angiogram showed a widely patent graft and left
ICA. She had no residual symptoms or dysphagia on her 6 weeks routine
follow up course with patent interposition carotid bypass on the duplex
scan.
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