Peripheral Vascular
Arteriosclerosis: Arterial wall thickening/hardening.
Atherosclerosis: Arteriosclerosis with plaque, causing narrowing.
Blood Pressure: Force exerted on arterial walls by the heart.
Claudication: Leg pain from poor circulation, often atherosclerosis.
Infarction: Artery blockage causing ischemia/tissue death.
Ischemia: Reduced blood supply to tissue.
Occlusion: Artery obstruction causing pain.
Aneurysm: Artery ballooning due to wall weakness.
Embolism: Circulating object lodged in a vessel.
Thrombus: Stationary embolism, like a clot.
Venous stasis: Blood pooling in veins.
Hemodialysis: Blood filtering outside the body.
Hemolysis: Rupturing of red blood cells.
Peripheral Vascular System: Blood vessels to/from the heart.
Hypovolemia: Drop in blood volume.
Hypoxia: Insufficient blood oxygen.
Angioplasty: Restoring blood flow endovascularly.
Arteriotomy: Incision into an artery.
Bifurcation: Artery/graft Y-shape.
Endarterectomy: Plaque removal from artery.
Hemodynamic: Cardiovascular pressure/flow/resistance.
In-situ: Normal position.
Intimal hyperplasia: Vessel's inner layer thickening.
Percutaneous: Insertion through the skin.
Stent: Dilation/support device in artery.
Umbilical tapes: Vessel retraction.
Vessel loop: Vessel retraction/occlusion.
Thrombus vs. Embolus
Thrombus is a blood clot.
Embolus is a fragment of blood clot traveling through the vein.
Peripheral Surgical Anatomy
Consists of:
Blood Vessels
Blood Pressure
Arterial System
Venous System
Blood Vessel Anatomy
Closed system of vessels that transport blood away from the heart to body tissues, and then back to the heart.
Arteries:
Transports oxygenated blood away from the heart.
Thicker muscle layer, helps to compensate for changes in BP and volume.
Aorta is the largest artery in the body
Arterioles:
Smaller arteries
Capillaries:
Smaller arterioles, no muscle fibers
Microscopic vessels
Exchanges nutrients and wastes between blood and tissue fluid
Venules:
Capillaries that have gone through exchanges and united
Unite to form progressively larger blood vessels called veins
Veins:
Designed to transport deoxygenated blood back to the heart.
Eventually will become the superior & inferior vena cava, which are the largest veins in the body
Artery Structure
Tunica Externa (Adventitia):
Outermost layer, consist of connective tissue
Attaches artery to surrounding tissue
Contains tiny vessels called Vasa Vasorum
Tunica Media:
Middle layer, thickest of the 3 layers
Consist of elastic fibers and smooth muscle fibers that completely encircle the artery
Vasoconstriction happens here
Tunica Intima:
Innermost tunic, consist of epithelium
Lining must be smooth so blood can flow without being damaged and clotting will be prevented
Vein Structure
Vein Structure:
3 layers like arteries, but thinner.
Thick tunica adventitia, thin tunica intima.
Larger lumen and valves to prevent reflux.
Valves prevent backflow, aided by muscle contraction.
Malfunction causes venous stasis/varicosity/thrombosis
Thin walls allow expansion; larger veins have constricting muscle fibers.
Tunica Adventitia is the thickest layer
Tunica Intima is much thinner than that of the artery
The lumen is larger than an artery
Veins must work against gravity for trip back to the heart
Vein valves prevent backflow; malfunction causes pooling (varicosity) and thrombosis.
Flow of blood against gravity depends on skeletal muscle contraction
Thin walled, which allows them to expand. Larger veins contain muscle fibers that allow them to constrict
Circulatory System
Divided into two pathways: pulmonary and systemic system.
Systemic Circulation (sends out oxygenated blood and returns deoxygenated blood to heart)
Carries the oxygenated blood from the heart to the rest of the body and picks up the carbon dioxide to recycle.
The left ventricle pumps the blood through ascending aorta to the body.
Deoxygenated blood returns by passing through the capillaries into the venous system to the left atrium through the vena cava.
Pulmonary circulation
Needed to recycle blood. Picks up excess carbon dioxide from the blood and makes it oxygenated again.
Deoxygenated blood in right ventricle is pumped through pulmonary arteries to the lungs
Pulmonary arteries are the only arteries that carry deoxygenated blood
Pulmonary veins are the only veins that carry oxygenated blood
Blood is oxygenated in capillaries of the alveoli (lungs) and returns to left ventricle through pulmonary veins
Blood Pressure
Arterial Blood Pressure (B/P): Depends on:
Blood Volume- adults (5 liters)
Loss of Volume- decrease B/P
Increase in B/P
Strength of ventricular contraction
Cardiac Output/Stroke Volume- the amount of blood ejected from the left ventricle during one ventricular contraction
If the amount ejected rises, the B/P rises
As blood leaves the heart, the pressure decreases the farther it travels from the heart
As the heart beats faster, there is less time for the ventricle to refill for the next contraction
Higher than venous pressure
Systole:
Upper number, occurs during contraction of the ventricles
B/P rises because of resistance in arteries
Diastole:
Lower number, occurs during the relaxation phase of the heart
Pressure progressively falls because of lesser resistance distally
Beyond capillaries, the pressure is almost nonexistent or ()
Normal BP affected by:
Gender- adult females generally higher than males
Age- gradual rise in BP from childhood to adulthood
Wt.- BP rises in individuals with a high body mass index, regardless of age
Exercise- BP rises with strenuous activity and returns to baseline at rest
Diurnal (daily) fluctuation- BP tends to rise during the day and lower in the morning
Elasticity of the arterial wall, blood volume
Blood Pressure cont.
Central Venous Pressure (CVP):
Pressure in the right atrium
Increased if heart is weak, causing blood to back up in the venous system
Low CVP means good heart and vascular function
Peripheral Resistance:
Friction between the blood and walls of the blood vessels produces force, which hinders blood flow
Blood pressure must overcome this to continue flowing
Resistance is greater in smaller vessels
Depends on viscosity (thickness of blood)
Arterial System
Right Common Carotid Artery
Right Subclavian Artery
Brachocephalic Artery
Renal Arteries
Brachial Artery
Vertebral Arteries
Left Common Carotid Artery
Left Subclavian Artery
Thoracic Aorta
Abdominal Aorta
Common Iliac Arteries
Femoral Arteries
Radial Artery
Dorsalis Pedis Artery
Popliteal Arteries
Posterior Tibial Artery
Aorta
The aorta, which originates in the left ventricle, is divided into three regions:
Ascending Aorta:
First region
Rises a few cm above the left ventricle
Rt. & Lt. coronary arteries branch off to supply blood to the myocardium
Aortic Arch:
Second region
Curves over the heart and downward, behind heart making a U shape
Branches into 3 major arteries:
Brachiocephalic- supplies blood to the head and right arm
Left Common Carotid Artery- extends into the neck
Left Subclavian Artery- supplies blood to the left shoulder and upper arm
Descending Aorta:
Third region
Travels downward to the heart through the thoracic & abdominal cavity
Called the Thoracic Aorta above the diaphragm and the Abdominal Aorta below the diaphragm
Thoracic and Head Arteries
Subclavian: arm and shoulder
Common carotid: neck, face, & brain
External Carotid- skull & face
Internal Carotid- Brain
Vertebral: upper spinal cord, brainstem, cerebellum, & posterior part of brain
Lumbar: spinal cord & meninges
Vertebral Arteries
Arise from the right & left Subclavian arteries
Each extends up the neck, through the cervical vertebrae, and enters the cranium
Lumbar arteries supply the spinal cord and meninges
Circle of Willis:
On the undersurface of the brainstem
The two vertebral arteries unite
Branches from the internal carotids and basilar artery form several anastomoses to create a circle of arteries at the base of the brain
Anatomic structure where intracranial aneurysms arise. Area involved with Cerebral aneurysm clipping
Abdominal Arteries
Descending Aorta
Celiac artery (trunk)
Gastric arteries (left and right)
Common hepatic artery
Splenic artery
Phrenic artery
Mesenteric arteries
Ovarian/Gonadal arteries
Renal arteries
Upper and Lower Extremity Arteries
Upper Extremity
Brachial
Ulnar
Radial
Axillary arteries
Lower Extremity
Iliac arteries
Internal and external iliac arteries
Femoral arteries
Popliteal arteries
Tibial arteries
Peroneal arteries
Dorsalis pedis arteries
Smaller arteries in the foot and phalanges
Venous System
Veins drain blood from the organs and other parts of the body and carry it to the vena cava
Delivers blood back to the heart’s right atrium
Vena Cava is the body’s main vein and the largest
Chronic Venous Insufficiency is not life threatening. It is caused by incompetent valves.
Vena Cava is divided into the:
Superior Vena Cava (SVC):
Receives deoxygenated blood from the head, neck, shoulders, and arms
Inferior Vena Cava (IVC):
Receives blood from the lower part of the body. Some veins, like the Brachiocephalic, drain directly into the SVC. Others drain into a second vein, which may merge with still another vein, before draining into the vena cava.
Veins of the Head and Neck Principal Veins
Internal Jugular:
Drains most of the blood from the brain
Merges into the subclavian vein, which in turn becomes the brachiocephalic vein
In right sided heart failure, blood backs up from the heart and causes jugular vein distention
External Jugular:
The more superficial of the jugular veins
Drains blood from the scalp, facial muscles, and other superficial structures
Drains into the subclavian vein
Vertebral:
Drains the cervical vertebrae, spinal cord, and some of the muscles of the neck
Azygos:
Located in the right side of the thoracic vertebral column
Drains itself towards the superior vena cava
Connects the systems of the superior vena cava and inferior vena cava and can provide an alternative path for blood to the rt. Atrium when either the vena cava are blocked
Venous System of Upper Extremity
Brachiocephalic:
Returns blood to the superior vena cava
Known as the Innominate vein
At the level of the joint
Longer on the right
Subclavian:
Paired large vein
Empties blood from the upper extremities and carry it back to the heart
Diameter the size of the smallest finger
Originates at the outer border of the first rib
Connect to the internal jugular to form the brachiocephalic vein
Axillary:
Large vein
Conveys blood from the later aspect of the thorax, axilla, and upper limbs toward the heart
Cephalic:
Known as the antecubital vein
Located in the lateral side of the arm from the shoulder to the hand
Joins the axillary vein and becomes the subclavian vein
Commonly used for blood samples and to add fluids to the body
Median Cubital:
Most common site for drawing blood
Passes across the anterior aspect of the elbow
Basilic:
large vein that drains the dorsum of the hand
Radial
Drains blood from hand and forearm
Venous System of Pelvis and Lower Extremity
Iliac Veins:
Common iliac drains blood from pelvis and lower limbs merging with IVC at 5th lumbar
External and internal iliac merge with each other and carry blood away from the reproductive, urinary, and digestive organs and become the common iliac vein
Femoral:
A continuation of the popliteal vein
Considered a deep vein
Located in the upper thigh
Instead of draining deoxygenated blood from specific parts of the body, it receives blood from several significant branches
Eventually transports blood to the inferior vena cava
Because of its size and importance, problems with the femoral vein could potentially be fatal
Popliteal:
Continues upward into the thigh, behind the knee
Becomes the femoral vein
Greater Saphenous:
Longest vein in the body
Frequently harvested for CABG
Receives blood from the foot, ankle, leg and thigh
Anterior & Posterior Tibial:
Drain blood from the deep veins of the foot
Unite at the knee to form the popliteal vein
Hepatic Portal Circulation
Veins of the abdominal organs, digestive organs and spleen don’t empty into the inferior vena cava
Send blood through the hepatic portal vein
Allows the liver to modify the blood by removing excess glucose and toxins
Blood flows out of the microscopic capillaries of the liver, into the IVC and back to the heart
Decompression of the portal circulation can be accomplished by splenorenal shunt, portocaval anastomosis, mesocaval shunt
Splenorenal shunt: splenic vein detached from portal vein. Reattached to left renal vein. Relieves pressure from portal vein.
Portocaval shunt: connection made between portal vein and vena cava to bypass liver due to severe liver problems.
Mesocaval shunt: side of superior mesenteric vein anastomosed to proximal end of vena cava to help control portal hypertension.
Digestive System Veins:
Splenic:
Drains blood from the spleen, stomach fundus, and part of the pancreas
Superior Mesenteric:
Drains blood from the small intestine (jejunum and ileum)
Combines with the splenic vein to form the hepatic portal vein
Inferior Mesenteric:
Drains blood from the large intestine
Terminates when reaching the splenic vein
Hepatic Portal:
Transports blood high in glucose concentration and amino acids from the small intestine to the liver
Hepatic:
Blood vessels that drain de-oxygenated blood from the liver and blood cleaned by the liver (from stomach, pancreas, small intestine, and colon) into the IVC
Pathology
Arterial Embolism
Usually in an extremity
Travels through vascular system until they become lodged
Blocks flow of organs or extremity
Morbidity is high, reflecting the underlying overall medical condition of the patient
Lodge at bifurcations and anatomical narrowing sites
80% affect lower limbs
90% have underlying heart disease
Overall medical condition needs treatment
High doses of anticoagulant therapy and enzymatic drugs are considered in high risk patients
Surgery is last resort
Evaluation of the effectiveness of limb loss is determined quickly to reduce risk of limb loss
Embolectomy: Use of a Fogarty catheter
Aneurysm:
portion of artery is weak and distended. Often lined with atherosclerotic plaque that delaminates and causes blood to seep out between wall layers
Intimal Hyperplasia
Tunica intima layer is thickened
Can occur in artery or vein
Athersclerosis
Obstructive arterial disease that causes stiffening and loss of elasticity in the artery wall
Arterial Disease
Chronic Arterial Insufficiency:
Atherosclerosis is 1 of the leading causes of death and disability. Occurs because of calcium and cholesterol in the wall of the artery. The walls get thicker and hardens, reducing the elasticity of the artery
Arterial Insufficiency Cerebrovascular Disease: CVA is a leading cause of death in the US.
May present as a TIA or major stroke- TIA usually resolves in 24 hours and may be caused by debris or thromboembolism from carotid artery or vertebral basilar system
Vascular lesions in carotid artery occur primarily at the bifurcation of the common carotid artery into the internal and external
Arterial Insufficiency Peripheral Vascular Disease
Most noticeable symptom in aortoiliac vessels and distal arteries is claudication. Severe pain in calf muscles during walking but subsides with rest.
Referred to as a function ischemia, blood flow is adequate with rest but not with exercise
The 2nd symptom- rest pain is located in foot- disease has progressed, body can no longer meet the O2 needs of distal tissues. Unless, the disease is corrected, nonhealing ulcers and gangrene can develop
Diagnostic Procedures
Arterial Plethysmography
Pulse volume recorder used to measure the arterial pulse waveform.
3 BP cuffs are placed on the leg and arm then inflated to 65. Each cuff produces a waveform, which is compared with the waveforms from the other 2 cuffs. Reduced waveform in one area may indicate reduced blood flow at that point
Doppler Scanning
Intensifies the sound of the blood flowing through a vessel. The pitch, rhythm, and quality of the sound reflect the pressure, volume and flow rate.
Can provide information in 3 forms: audible signal, visible graph and a spectral analysis that appears on the screen
Angiography
Contrast media is used through a catheter into the arterial or venous system and x-rays are taken of the movement of the dye
Shows location of a stenosis or occluded vessel
Venogram- shows venous abnormalities in extremities, vena cava, hepatic and renal systems
Intravascular Ultrasonography
Maps the lumen of a vessel, by placing a flexible catheter into the vessel. Ultrasonic energy is generated and interrupted by the transducer and the lumen of the vessel can be mapped (including density, accumulation of plaque and wall thickness and a visual image is produced.
MRI/MRA
Provides detailed and 3D images of the anatomy for evaluation
PET Scan
Diagnostic test that examines blood flow and metabolic function of the heart and brain.
Arteriosclerosis Obliterans
Generalized disease
Atheroma formation (build up of fat and lipids)
Main areas:
Abdominal aortic bifurcation
Distal superficial femoral artery
Medical management is preferred when no claudication is present
Associated with smoking, hypertension, obesity, diabetes, high cholesterol
Abdominal Aortic Aneurysm
Affects more than aorta
Many important arteries arise from the abdominal aorta (Renals)
Most arise just inferior of Renal arteries & terminate at the bifurcation
Some may include the renal arteries & some may extend beyond the common iliacs
Operative mortality is very low (2-3%) for elective procedure
Emergency (ruptured AAA) have 80% mortality
Signs and Symptoms
Severe abdominal pain
Severe back pain
Pulsatile abdomen
Aneurysm is suspected when a patient comes to emergency room
Asymptomatic AAA can be found by accident when a patient is seeking other health care treatment
Most common cause of Aortic Aneurysm is atherosclerosis.
Abdominal aortic aneurysms are operated on at 6cm or greater less than 6cm it can be done endovascularly. 2-3% percent morbidity
Arterial Disease (Aneurysms)
Aneurysmal disease: most common cause of atherosclerotic degeneration of the arterial wall
True aneurysm: dilation of all layers of the artery wall. Most frequently found in the abdominal aorta, but also in thoracic aorta, iliac, femoral and popliteal arteries. Men are affected more
Dissecting aneurysm: tear in the artery wall allowing blood between the layers of the vessel wall (involves the circumference of the artery)
False aneurysm: disruption through all the layers of a vessel wall with the escaping blood being contained by perivascular tissues. May result from trauma, infection, or disruption of a suture line
AAA account for 75% of all aneurysms. Occur just below the renal arteries and external to bifurcation of the common iliac. Ultrasound can be used to detect involvement of the renal arteries, stenosis and additional aneurysm.
Arterial Occlusion
May occur anywhere in body
May be complete or partial
Surgical procedure depends on site of occlusion
May be related to other locations or combination ex. Aorta, Carotids, Iliac, Femoral, Popliteal, etc.
Arteriotomy- # 7 knife handle, # 11 blade, Potts scissors. Clamping order prior to an arteriotomy (heparinize patient, apply proximal clamp(s), apply distal clamp, incise vessel)
Instrumentation for Vascular Surgery
Major Set
Peripheral Vascular Set
Carotid Set
AV Shunt Set
Additional surgeon specialty sets
Self retaining retractors (Weitlaner, Gelpi)
Hemoclips
Diethrich Coronary Artery Set (includes: Bulldog clamps, dilators)
Castroviejo needle holders
DeBakey forceps
Tunnelers
Tenotomy scissors
Potts-Smith scissors
Metzenbaum scissors
DeBakey clamps
Cooley clamps
Satinsky clamps
Fogarty clamps
Freer elevator or penfield
Supplies
Vessel Loops- used to retract blood vessels
Umbilical Tapes
Suture Booties, Rubber Shods- ends of mosquitos are covered and used to tag delicate suture
Pledgets- used to reinforce grafts
Hemoclips
30 & 60 cc syringes
Heparinized saline
Doppler and ultrasounic gel
Fogarty Catheters- to remove thrombus or embolus
Grafts
Shunts- Javid shunt used to keep continuous blood flow in a carotid endarterectomy
Stents
Cell saver
Fogarty inserts
Grafts
Synthetic:
Knitted Polyester (Dacron):
Rapid tissue ingrowth, porous
Requires pre-clotting
Use above the knee because it will kink at the knee
Knitted Velour (Dacron)
Preclotted to minimize bleeding
Woven Polyester (Dacron)
Leak proof
Does not need to be pre-clotted
Polytetrafluoroethylene (PTFE, Gortex)
Can be taken across the knee joint without risk of kinking
Less satisfactory for more distal bypasses
May have rigid rings built in for wall protection
In situ:
Patient’s own vein
Valves must be “stripped” away to prevent the valves from dictating the venous flow direction
Suture
3-0 to 7-0 Based on size of vessel
Non-absorbable, monofilament
Double armed
Silk is common for free ties
Aorta:
3-0, 4-0
Femoral:
5-0, 6-0
Popliteal
5-0, 6-0, 7-0
Carotid:
6-0, 7-0
Pledgets are supplied on suture or you may have to load it
Polypropylene, Dacron, Polyester, PTFE
Moisten surgeon’s hands with saline when tying knots
Practical Considerations
Do not try to remove suture knots, just discard or let surgeon use nerve hook
Leaks in grafts are closed with single armed suture or you may be asked to cut off double armed suture needle. Pledgets may also be used to help seal the leak
Be prepared to handle small delicate needles
Wet white towel or lap to cover instruments to prevent suture catching
Suture on exchange basis (not always able to do)
Always wet the surgeons hands when tying fine prolene suture.
Vessel loops should always be moist to prevent dragging on vessels
Tables for vascular procedures are never broken down until the patient is out of the room.
Drugs
Heparin – prevents clotting (given intravenously before cross clamping to prevent clotting, also used to irrigate/flush the vessel with an olive tip or Christmas tree). Side effects of thrombolytics is hemorrhage
Papaverine - dilates the muscle wall of a vessel, used as a topical
Local Anesthetics available for postop pain
Antibiotic solutions (Surgeons choice)
Hemostatic agents (Surgeons choice)
Protamine Sulfate- to reverse heparin- must be given slowly or it may cause dyspnea, hypertension or bradycardia
Topical hemostatic agents
Gelfoam, thrombin (
Dextran- used parenterally to expand blood plasma volume
Hypaque- contrast medium used in radiographic procedures (arteriography)
Renografin- used when patient is allergic to iodine
The activated clotting time (ACT) normally determines the need for more heparin or the need for reversal of heparin
Vitamin K is essential for clotting process
Vascular Clamping vs. Unclamping
Clamping:
Clamp proximal first then distal (ICA, CCA, ECA)
Reduces pressure on diseased or obstructed area
Backflow Testing:
Clamp is removed to check for suture line leakage (ICA, ECA, CCA)
Repair stitch is used (usually one size smaller)
Unclamping:
Open distal first then proximal (CCA, ECA, ICA)
Reduces pressure on suture line
In Situ Procedure
The autogenous graft that is left in place after removal of internal valves and anastomosed to the arterial system
Extends the length of the procedure
No tissue reaction
Choice for distal leg
Resists infection better than any other graft material
Saphenous vein is used
Procedures
Angioplasty:
Treats symptomatic atherosclerosis
Conservative treatment to restore lumen vessel
Balloon dilatation
Percutaneous Transluminal Angioplasty
Best for short areas of disease (90% success rate)
Crucial element is correct balloon sizing
Requires detailed angiography
Femoral artery approach most often used
Balloon is inflated with diluted contrast media
Abdominal Aortic Aneurysm (AAA):
Also called Triple A, performed to treat aortoiliac occlusive disease, commonly caused by athersclerosis
Weakened area in the arterial wall
Incision is from xiphoid process to pubis
Most likely to use a bifurcated graft
Cell saver is commonly used
Proximal anastomosis is first, usually with a 4-0 double armed needle
Aortofemoral bypass- a graft is implanted between aorta and femoral arteries to bypass the iliac arteries and restore circulation
Prime consideration for ruptured AAA is hemorrhage control
Technique
A laparotomy is preformed through a long midline incision (from xiphoid process to pubis), and the aorta is exposed
If doing a femoral bypass then groin incisions are made to expose the femoral arteries
Pt. is heparinized and aorta is clamped below the renal arteries. Aorta is normally clamped with a Satinsky clamp
11 blade on a long handle is used to incise aorta. Long Potts are used to extend incision. Plaque is dissected
The distal portion of aorta is oversewn with 3-0 or 4-0 prolene double armed suture
Proximal end of bifurcated graft is anastomosed to the distal aorta
Bilateral subcutaneous tunnels are made in the retroperitoneal tissue to the groin
Bilateral arteriotomies are made in the femoral arteries, and the graft limbs are anastomsed to each artery with 5-0 or 6-0 prolene suture
Helpful hints
When doing an open AAA, cell saver is used. If any type of hemostatic agent is used, the cell saver can no longer be used. Always mention to surgeon before passing this to the surgeon.
Wet surgeons' hands when they are tying fine prolene suture, to allow suture to slide freely and not get caught.
Cell saver should not be used if patient has cancer
Supplies to have- different sizes of Dacron bifurcated grafts, doppler, and cellsaver
Endovascular AAA procedure
The aneurysm is approached through the femoral artery under fluoroscopy
Prep is done the same as an open AAA, incase of need to open. Left arm is tucked to allow c-arm access
18 gauge arterial entry needle is inserted
A guidewire is advanced
Sheath is inserted and catheters are inserted. Radiopaque dye is injected. The aneurysm is measured and grafts are chosen
Multi sectional grafts stents are introduced into the aorta and femoral artery. Graft is deployed.
Balloons are advanced to be inflated