Vascular Surgery
Lec : 1
Obstructive Arterial diseases :- is generally divided to 3 kinds
1.Acute occlussion :- also called Embolic occlusion
which arise either from
A.
Cardiac Emboli :- Large emboli , represent 80% , usually
obstruct big arteries e.g Femoral artery,the source is usually
from the left atrium in paitents with cardiac arrhythmias
especially atrial fibrillation or from mural thrombus after
myocardial infarction.
B. Atheroemboli :- are small and obstruct small arteries of
hands and feet , they arise either from clots inside an
aneurysm or from atheromatus plaque which detach from
atheroseclerotic lesion of big arteries.
C.Fs :- sudden onset , the limb distal to obstruction become
cold , pulsless , parasthetic , paretic i.eloss of movement ,
painful and pale.
O/E : The involved part is normal in size in comparison to
other limb , no muscle wasting , no hair loss , normal skin
texture with absence of pulse while the pulse in non-involved
limb is irreguler due to cardiac dysrrythmia ….aftre 6 to 12
hours the involved limb become tender , hard and swollen
due to edema of ischemic muscles and with passage of time
gangrene will develop if it is not Rxed urgently and properly.
Chronic Occlusion : - caused by atheroseclerotic diseases
which may involve any segment of arterial system, this
produce gradul reduction in vessel diameter which will
reduce blood flow to limb distal to site of obstruction , here
when the vessel diameter is reduced gradually by 50% the
surface area avialable for blood flow is reduced by 75% and
the paitent start to complain from intermetant claudication
which cramp-like pain felt in the muscles distal to site of
arterial narrowing , it is characterised by :-
1.brought on by walking
step.
st
2.not present on taking the 1
3.relieved by standing still.
The distance the pt. can walk is called the claudication
distance which is nearly similar , claudication mostly involve
calf muscles but it can also affect the thigh or buttok.
Pt. present with coldness in the involved limb with
reduction in pulse volume distal to site of obstruction and
muscle wasting , hair loss will develop , arterial bruit can be
felt proximal to site of obstruction , with the progress of
disease, extensive collateral vesseles will develop between
area proximal and distal to site of obstruction.
When the stenosis increase more pt. will complain from
Rest Pain which occur when the limb put in supine or
elevation position since the blood flow through the stenosed
segment depends on gravity effect in standing position , the
pain is felt in the foot and it is worse at night and relieved by
standing and if pt. is not Rxed ulceration and gangrene will
develop.
O/E : the involved limb shows features of chronic ischemia
mntioned previously , the other limb also shows reduction in
the pulse volume, muscle wasting , change in color and
temperature since the athroseclerosis is generalised process.
3. Acute on chronic obstruction:- may develop at site of
atheroseclerotic narrowing which may be obstructed
suddenly by an embolus , this will produce mixed features of
acute and chronic disease.
Investigations:-
1.General investigation :- include complete blood count , lipid
profile , renal functions tests , ECG and Echo to assess cardiac
function , CXR and Pulmonary function test to assess
respiratory function.
2. Dopplar study :- simply it is Ultrasound study of arterial
and venous system , it can show the direction of blood flow ,
the site and length of obstruction and/or narrowing and it is
helpful in acute condition when a quick evaluation is needed
while in chronic conditions it gives clue for the next step and
the need for angiography ,Dopplar study also can be used
The Ankle- Brachial Pressuer Index (ABPI) which is the ratio of
systolic pressuer at the ankle to the systolic pressuer in the
arm , Resting ABPI is about 1
When become < 0.9 indicate some degree of arterial
obstruction and when it is below 0.3 suggest imminent
necrosis
3. Duplex imaging study:- is B-mode U/S with color coding
can shows image of blood flow in the vessel in different
colors according to change in the direction and velocity of
blood flow i.e at narrowd segments , also it can shows the
phases of arterial pulse since the normal arterial wave is
triphasic and with narrowing of the artery it become biphasic
and then uniphasic.
4. Angiography :- can give clear cut Dx. For the site of
obstruction and /or narrowing , show the site of collateral
vesseles and the possibility to do surgery, there are 2 kinds of
angiography
a. the classical angio :-done by injecting radiopaque solution
into the arterial system by percutanous catheter inserted to
the vascular Tree through Common Femoral artery at the
groin
b. the new modality CT angio:- is done by new CT Scan
machine which can give from 64 to 256 images per second,
these high no. of images will give accurate pictuer of vascular
tree with contrast material given intravenously.
Mx :-
1.In acute conditions :- usually the Pt. come to emergency
department with acute symtoms of pain , cold limb and
pallor , the initial steps to Rx such cases are :-
1.optimize the intravascular volume by intravenous fluid
infusion because in some cases dehydration increase the
ischemic features
2. I.v heparin given as 7500 U loading dose followed by 5000
U infusion every 6 hours .(1+2) will increase flow through the
narrow vesseles and open the collaterals improving distal
perfusion
3. optimize cardiac conditions e.g Rx heart failure ,
dysrrthymia etc.
4. Surgery :- In acute conditions we do Embolectomy usually
under local anasthesia given in the upper thigh , common
Femoral A. is explored , small arteriotomy is done and the
embolus is drawn out by especially degined cathetre called
Fogarty catheter followed by irrigation of the vascular tree
with heparin/saline solution and then arteriotomy is closed ,
anthor proceduer may be added sometimes called Faciotomy
which means incision of the facial layers which envelop the
muscles of leg as the reperfusion of ischemic muscles will
make them swallon and edematus and the tight facial layers
will compress the edematus muscles inducing ischemic
muscle necrosis ,therefore ; these facial layers must be
incised to allow enough space for the reperfusion of swallon
muscles.this phenomena is known as Compartment
Syndrome.
Mx chronic obstruction
1. stop smoking , exercise and achieve ideal body weight
2. control serum lipid level and blood sugur for diabetic pt.s
3. pt.s with high blood viscosity venesection may be
requiered
4. some arteriodilator drugs may be used e.g Deltiazim ,
Trental (pentoxphyllin) but they are of limited value.
5.Surgery :- In chronic conditions the atheroseclerotic
plauque usually adherant to vessel wall and cannot be
removed by Fogarty Cathetre , here the mx done by
a.percutanous transluminal angioplasty and stenting which is
successful for short segment(1-3)cm stenosis in the Ialiac
artery and to lessor extent for Femoral and Axillary arteries ,
it is done by ballon inflation through the narrowed segment
ofatheroseclerotic artery to dilate it and to put metal stent to
keep the vessel patent.
b.arterial bypass procedure using a graft (either Saphenous
vein or synthetic) , it will be anastamosed to an artery
proximal to the site of obstruction and then to the vessel
distal to obstruction providing an extra channel for blood
flow to the limb distal to obstruction ,the long term graft
patency is related to
1. quality of inflow and outflow vessel
2.graft lengh
3. graft type as autologus Saphenous VG has better long term
patency than synthetic graft.