Transcript Carotid Endarterectomy

Procedures
Basic Format
Carotid Endarterectomy
Case Study Textbook # 1
Objectives
• Assess the anatomy, physiology, and
pathophysiology of the cerebral arterial
circulatory system.
• Analyze the diagnostic and surgical
interventions for a patient undergoing a
carotid endarterectomy.
• Plan the intraoperative course for a patient
undergoing_____________.
• Assemble supplies, equipment, and
instrumentation needed for the procedure.
Objectives
• Choose the appropriate patient position
• Identify the incision used for the procedure
• Analyze the procedural steps for carotid
endarterectomy.
• Describe the care of the specimen
• Discuss the postoperative considerations for a
patient undergoing _______________ .
Terms and Definitions
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Atheroclerosis
Atheroma
Stenosis
Ischemia vs infarction
Transient Ischemic Attack (TIA)
Definition/Purpose of Procedure
• Carotid endarterectomy
– Removal of an atheroma from an obstructed
carotid artery; the obstruction is usually at the
carotid artery bifurcation
– Procedure increases cerebral perfusion and
decreases risk of embolization and consequent
stroke
Relevant A & P
• Normal cerebral blood flow
Normal Anatomy
Pathophysiology: Atherosclerosis
• Progressive disease characterized by atheroma, which
affects the intimal and medial layers of large and midsize
arteries
• Caused by unknown precipitating factors that cause
lipoproteins and fibrous tissue to accumulate in the arterial
wall
• The most accepted theory: atherosclerosis begins with an
injury to or inflammation of endothelial cells lining the
artery.
• Endothelial damage promotes platelet adhesion and
aggregation, and attracts leukocytes to the area
• At the injury site: atherogenic lipoproteins collect in the
intimal lining of the artery
Pathophysiology: Atherosclerosis
• Macrophages migrate to the injured site as part of the
inflammatory process.
• Smooth muscle cells and connective tissue are stimulated to
proliferate abnormally as a result of contact with platelets,
cholesterol, and other blood components
• Early lesion looks like a yellowish fatty streak on the inner
lining of the artery
• It continues to grow as a fibrous plaque and protrudes into
the arterial lumen and is fixed to the inner wall of the intima
and eventually occludes the vessel and affects the vessels
ability to dilate in response to increased oxygen demands
Pathophysiology
• Transient cerebral ischemia
– TIA (Transient Ischemic Attack)
– Brief period of localized cerebral ischemia causing
neurological deficits lasting < 24 hrs; usually 1-2 hrs
– Warning signal of ischemic thrombocytic stroke
– Common S & S: contralateral weakness or numbness of
hand, forearm, corner of mouth (middle cerebral artery);
aphasia; visual disturbances such as blurring (posterior
cerebral artery)
Pathophysiology
• Thrombocytic CVA
– Occlusion of a large cerebral vessel by thrombus; often in
older persons who are resting or sleeping when BP is lower
– Thrombi tend to form in large arteries that bifurcate;
narrowed lumen as a result of atherosclerotic plaque
– Common locations: internal carotid artery, vertebral
arteries, junction of vertebral & basilar arteries
– Occurs rapidly, progresses slowly; begins as TIA and
worsens over 1-2 day period; stroke-in-evolution; when
maximum neurologic deficit has been reached (3 days),
called a completed stroke; damaged area is edematous,
necrotic
Diagnostics
• Exams
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CT
Transfemoral arteriography
Trancranial ultrasound doppler
MRI
PET
LP
• Preoperative Testing
– Ensure that if pt is on anticoagulant therapy (ASA or
Plavix, Trental, Coumadin, etc) it is discontinued a week
before surgery (or as directed)
– Blood work
– Routine; ECG, possible chest x-ray
Surgical Intervention:
Special Considerations
• Patient Factors
– Special consideration to compromised circulation&
general state of poor vascularization (often diabetic &
cigarette smokers= higher risk)
• Room Set-up
– Diagnostic arteriograms in the OR to view
• Grafting
– A Javid or Argyle shunt is frequently used for shunting
cerebral blood flow & MUST BE AVAILABLE
– If a graft is needed, a small portion of the saphenous
vein is obtained and trimmed to size
– Controversy exists r/t use of shunt
• Misc
Surgical Intervention: Anesthesia
• Method: General
– (cervical block may be used
which allows for observation
of neuro changes)
• Equipment
– Bair hugger unit & blanket
– ECG, BP, O2 Saturation
– EEG (electroencephalogram) to further monitor
cerebral perfusion
Surgical Intervention: Positioning
• Position during procedure
– Supine, head turned away from affected side about 45
degrees; neck slightly hyperextended w/roll between
scalpulas; arms tucked to sides using sheet
• Supplies and equipment
– Small sandbag or rolled towel is placed under the
shoulders to hyperextend the neck
– Rest head on donut or rolled stockinette
– Arm sleds to tuck and protect arms
• Special considerations: high risk areas
– Ulnar nerves
– If a saphenous vein patch graft is to be used, the affected
leg should be bent at knee and externally rotated
Surgical Intervention: Skin Prep
• Method of hair removal: clipper or wet shave of
leg if needed
• Anatomic perimeters
– From face to axillary lines; from lower ear of affected
side, across midline of neck, to just below clavicle
– If saphenous vein graft is to be used, also prep affected
limb
• Solution options
– Betadine (or Duraprep) or Hibiclens
Surgical Intervention: Draping/Incision
• Types of drapes: towels, laparotomy, pedi, or thyroid
sheet; ¾ sheet available; may use split sheet
• Order of draping
– Square draping with towels and thyroid or pedi sheet
– ¾ drape over feet
– If saphenous vein used, place ¾ sheet under affected leg &
over unaffected leg; 6 in stockinette should be rolled over
the foot up to the area of the incision. A folded towel is
secured over the groin; the lap, thyroid, or pedi sheet should
be folded under the top of pubis
• Special considerations
• State/Describe incision
– Incise the neck longitudinally at sternocleidomastoid muscle
Surgical Intervention: Supplies
• General: lap pack or basic (thyroid drape or split),
gowns/gloves, adaptic/4x4’s, lap sponges, Raytex,
ESU pencil, variety of syringes & hypodermic
needles
• Specific
– Suture & Blades: 6-0; 7-0 Prolene; 3-0, 4-0 Silk ties,
18 in.; # 11, # 10 knife blades, # 15 avail
– Medications on field (name & purpose)
• Heparinized NS (IV Bag) irrigation—always have available;
antibiotic irrigation, Xylocaine 1% for carotid body irrigation
– Catheters & Drains: typically ½ inch penrose; may use
Jackson-Pratt
Surgical Intervention: Supplies
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Vessel loops or umbilical tape
Suture boots
Hemostatics: Surgical, Avitene, Gelfoam
Hemoclips (sm & med)
20-cc syringe, heparin needle or Angiocath
cannula for intra-arterial irrigation
• Javid or Argyle shunts (available)
• Vascular patch/PFTE (Teflon) (available)
• IV saline for Heparin; Bag-o-jet
Surgical Intervention: Instruments
• General: Minor set, Basin set
• Specific
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Carotid Set
Javid shunt clamps
Hemoclip applicators (short, med, lg)
Potts & DeMartel scissors
Vascular clamps
Small nasal or neuro elevator (Penfield or Freer-type)
Yankauer suction
Instruments
Surgical Intervention: Equipment
• General: ESU, Suction,
• Specific
– Electroencephalogram (EEG)—may be used especially
if no shunt used (General Anesthesia)
Surgical Intervention:
Procedure Highlights
• Neck is incised
• Common, external, and internal carotid
arteries are mobilized and clamped
• Common carotid artery is incised
• The plaque is removed
• The artery is closed
• The wound is closed
Neck is incised
Common, external, and internal carotid arteries are
mobilized and clamped
Common carotid artery is incised
The plaque is removed
The artery is closed
The wound is closed
Surgical Intervention: Procedure Steps
• A longitudinal incision is made over the area of the
carotid bifurcation; Weitlaner (dull) may be placed
for exposure (have a variety available; sm rakes, US
Army)
– STSR has ready a # 10 blade w/#3 Knife handle. Place 2
folded sponges on opposite sides if the operative site.
Use a magnetic pad over chest to secure instruments.
• With Metz scissors, the soft tissue is dissected for
exposure of the carotid artery and its bifurcation.
• A moistened umbilical tape or vessel loop is passed
around the vessel for traction and ease of handling.
Heparin is administered systemically (per
anesthesiologist).
Surgical Intervention: Procedure Steps
• The common, internal, & external carotid arteries
are dissected free and isolated w/vessel loops.
– STSR had ready small or med Metz & sm or med
Debakey forceps
• Clamps are applied first to the internal carotid,
then to the external carotid, then to the common
carotid artery.
– STSR has ready angled vascular and bulldog vascular
clamps for occlusion. The internal and external
carotids may be occluded w/vessel loops. NOTE TIME
of heparin administration and vessel occlusion.
Restrictive Devices applied to common, external, &
internal carotid arteries; See line of arteriotomy
Surgical Intervention: Procedure Steps
• An arteriotomy is made over the stenotic area: the
lateral portion of the distal common artery and,
with the use of Potts (angulated) coronary scissors,
is extended into the internal carotid artery. The
full content of the occluding plaque is exposed.
– STSR has ready a # 11 knife blade w/# 7 knife handle
• FOR SHUNT: a piece of tubing (polyethelene or
Silastic) with a suture tied around its center or
commercially prepared shunt device is inserted
into the common carotid artery and the internal
carotid artery to maintain cerebral blood flow & is
held w/vessel loops or shunt clamps
Shunt
in
Place:
Argyle
shunt
is held
in
place
with
vessel
loops
or
tapes
(LT)
Surgical Intervention: Procedure Steps
• The plaque is dissected free from the arterial wall,
beginning in the distal common carotid artery and
moving into the external & internal carotids.
STSR passes blunt dissector.
– A Freer elevator or # 4 Penfield dissector is used to
elevate the plaque. Remaining pieces are removed with
Debakey forceps and mosquito clamp. Have available
Tenotomy scissors.
• The endpoint is determined for the plaque in the
distal internal carotid artery. The arteries are
irrigated with heparinized saline to wash away any
stray media or fibrin strands; to clean the intima.
Surgical Intervention: Procedure Steps
• The arteriotomy is closed w/fine vascular sutures:
(6-0 & 7-0 Prolene). A synthetic (polyester or
PTFE) or autologous (vein) patch graft may be
used to restore the arterial lumen if it is too small.
– Before complete closure, blood flow is temporarily
restored thru the arteries to wash away any free
plaques, air, or thrombi. For this to be done, the
occluding clamps are opened and closed individually,
with flushing any debris away from the internal carotid
artery. Surgeon checks for leaks and may repair using
additional suture &/or use topical agents such as
Surgicel.
Surgical Intervention: Procedure Steps
• Before closure is completed, the shunt clamp or
vessel loop on the internal carotid artery is released
and the shunt removed. The external carotid
occluding clamp is removed, followed by the
common carotid artery clamp, and last, the internal
carotid artery clamp
• Additional interrupted sutures to control leakage
• A drain is placed and secured
– ½ inch Penrose is common—ensure it is secured w/
safety pin. With this drain, apply bulky 4 x4 dressings
for fluid absorption
• Wound is closed w/absorbable suture (4-0 Vicryl or
Dexon) or staples
Counts
• Initial: Sponges, Sharps
• First closing
• Final closing
– Sponges
– Sharps
Dressing, Casting, Immobilizers, Etc.
• Types & sizes
– 4x4 ‘s
• Type of tape or method of securing
– Surgeon pref: silk, cotton, etc.
Specimen & Care
• Identified as atherosclerotic plaque
• Handled: routine
Postoperative Care
• Destination
– PACU: Pt’s neurological status is carefully monitored
for postop changes
– Flexion and turning pt’s head are avoided to decrease
risk of kinking artery, bleeding, or thrombosis; elevate
HOB 20 degrees
• Expected prognosis (Good, Depends on other
chronic disease processes eg: HTN, recent MI,
Organ dysfunction)
– Discharge first postop day usually
Postoperative Care
• Potential complications
– Hemorrhage
– Infection
– Other: Stroke, Embolus, MI, Cranial nerve
injury, Hematoma
• Surgical wound classification: I
• Type of surgery: ablative
Resources
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L & B pp. 1308-1319; pp. 808-0810
Fuller p 530
STST: Procedure 23-6; pages 959-963
Alexander’s pp. 1106-1109
MAVCC Unit 13
Complete Review of Surgical Technology by
Boegi, Rogers, McGuiness
• Taber’s 19th edition
• AST Exemplar (handout)
• www.allrefer.com
Which medication is commonly given IV about 3-5
minutes prior to cross-clamping the artery during
arteriotomy?
a. Epinephrine
b. Protamine sulfate
c. Papaverine
d. heparin
The removal of plaque and removal of the lining of an artery
is called a(n):
a. Profundoplasty
b. Endarterectomy
c. Phlebography
d. Arteriovenous Fistula formation
The scissors used for intravascular access during an
endarterectomy are called:
a. Jameson
b. Metzenbaum
c. Tenotomy
d. Potts
_________________ is the medication used to reverse the initial
anticoagulant therapy during vascular surgery:
a. Sodium bicarbonate
b. Heparin sodium
c. Vitamin K
d. Protamine sulfate
The retraction of fine sutures during vascular surgery is
accomplished by the use of:
a. Senn retractors
b. Vessel loops
c. Malleable ribbon retractors
d. Penrose drain
The procedure which may require the temporary use if an
intraoperative bypass shunt is a (n):
A. Femoral – Popliteal Bypass Graft
B. Abdominal Aortic Aneurysmectomy
C. Carotid Endarterectomy
D. Aortic-Artery Bypass Graft