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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3597_Библиотеки_им_академика_М_И_Перельмана
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Arterial and Venous Access
A
1 cm
CFA
FV
2 cm
B
3 cm
Figure 2-14
held sterile covered transducer with needle guide for arterial access.
B, Ultrasound image of common femoral artery (CFA) and femoral vein (F V).
three fingers while you remove the needle from the skin and maintain
puncture site pressure. Pinch the guidewire firmly with the index
finger and thumb to avoid accidental wire removal as the needle is
taken off the guidewire from the artery. At this point, an assistant may
help to withdraw the needle over the wire and wipe the wire clean
with wet gauze.
Ultrasound visualization for femoral ar terial access. A, Hand-
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Arterial and Venous Access 75
SFA
PFA
FV
C
SFA
DFA
FV
D
Figure 2-14, cont’d
superficial femoral artery (SFA), and FV. D, Doppler color flow images of deep
femoral artery (DFA) and SFA (blue) and vein flow (red).
C, Ultrasound image of profunda femoral artery (PFA),
Advancement of the Sheath
After guidewire insertion into the artery, advance the sheath-dilator
assembly over the wire while holding the guidewire straight and
stable. Introduce the sheath-dilator assembly into the arter y by firmly
holding it close to the tip, making clockwise and counterclockwise
half-rotations, and applying firm advancing pressure. (Rotational
motion reduces forward friction.) The sheath should not be advanced
if significant resistance is encountered, which may occur through scar
tissue. In this case, serial dilators of bigger sizes are necessary before
the final sheath is positioned. The guidewire should be held straight
and taut because it may otherwise kink at the site of the sheath tip.
After the sheath is inserted completely, the operator holds the sheath
hub firmly in place and removes the dilator and guidewire together.
Aspirate 2 to 3 mL of blood from the side arm of the sheath and flush
the sheath with heparinized saline solution. The arterial pressure can
be checked immediately by connection of a pressure manifold to the
side arm of the sheath.
Percutaneous Femoral
Vein Puncture
The femoral arterial pulse is the landmark for the femoral vein. The
femoral vein is located approximately 1 cm medial to the femoral
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artery, and sometimes it is located partially behind the artery. The
procedure for femoral vein percutaneous entry involves the following
steps: (1) The femoral arterial pulse is located as described previously.
If arterial and venous puncture is planned, the area infiltrated by
lidocaine must be wide enough to provide adequate anesthesia to
both puncture sites. (2) The skin is entered 0.5 to 1 cm medial and 0.5
to 1 cm caudal (toward the foot) to the arterial entry site. Because vein
puncture may be successful only after several attempts, the skin incision may be made after the needle has been placed in the vein. (3)
Because venous pressure is low, a 10- or 20-mL syringe is attached to
the Seldinger needle and gently aspirated during needle advancement. The operator inserts the needle medially through the skin at a
30- to 45-degree angle to the horizontal plane while palpating the
femoral arterial pulse (remember: N-A-V = nerve, artery, vein, from
outside in; i.e., lateral to medial). Be sure not to press so hard on the
artery as to occlude the vein. If arterial pulsations are felt at the tip of
the needle, withdraw and redirect the needle at a slightly more medial
angle.
fills the syringe. Blood should come easily into the syringe on the
needle without application of much negative pressure. If the vein has
not been entered, flush and reintroduce the needle in a slightly more
lateral or medial direction. If the artery is entered and not used, the
needle is removed and firm manual pressure is applied over the artery
for several minutes. Another attempt to enter the vein can be made
after the bleeding has stopped. Several attempts may be necessary to
puncture the vein. Sometimes it may be necessary to direct the needle
close to the artery because the vein may be located partially under
the artery. Ultrasound imaging guidance can reduce the number of
venous puncture attempts.
puncture attempt should be used only if the needle tip did not puncture both walls of the artery and go into the vein behind it. Placing a
sheath through the artery into the vein may create an AV fistula or
cause uncontrolled bleeding from a large hole in the posterior wall of
the femoral artery. The remainder of the venous sheath placement is
completed in the same fashion as described for the femoral arterial
sheath insertion.
over the vein as described for femoral artery sheath removal, although
much less pressure is needed. After percutaneous femoral vein puncture, 5 to 10 minutes of compression is usually enough time to obtain
adequate hemostasis.
Arterial and Venous Access
If the vein has been entered, venous (nonpulsatile) dark blood
A vein that has been entered mistakenly during a femoral artery
After the catheterization is completed, finger pressure is applied
Note for Accessing Both Femoral Artery and Vein
For cases in which right and left heart catheterization is planned, the
method of vascular access can be modified from the standard
approach described previously. In some laboratories, venous access
is performed first, but instead of proceeding to insert a sheath after
the wire is introduced, the wire remains in the vein until the artery has
been punctured and the artery guidewire is in place. The insertion of
sheaths then follows after skin nicks are made. The sheaths are inserted
over each wire sequentially, usually vein, then artery. The advantage
of this minor change is the elimination of the chance to puncture the
venous plastic sheath while searching with the needle for the nearby
artery.
Patient Awareness
For both radial and femoral access, three steps may be associated with
pain and vagal reaction: (1) initial administration of lidocaine, (2)
arterial needle insertion, and (3) sheath assembly advancement. The
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operator should monitor the heart rate and feel the strength of the
arterial pulse to detect early vagal responses. A vasovagal reaction of
hypotension can occur with no change in heart rate, most commonly
in elderly patients.
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Arterial and Venous Access 77
Hemostasis After Catheter and
Sheath Removal
After catheterization has been completed, the patient’s blood pressure
is monitored and the catheter is removed. The sheath is aspirated and
flushed to clear any thrombi. The patient is transferred to the holding
area on a stretcher. If heparin has been given during the procedure,
an activated clotting time (ACT) is obtained. Protocols vary, but the
sheath is generally not removed until the ACT falls below 200. To
remove the sheath, the operator places his or her fingers over the
femoral artery. Because the actual puncture site is more cranial
(toward the patient’s head) than the skin incision, the operator’s
fingers should be placed over the femoral artery above the skin puncture site. The operator applies gentle pressure and removes the sheath
from the leg, taking care not to crush the sheath and “strip” clot into
the distal artery. When a small spurt of blood purges the arterial site
of retained thrombi, the operator should apply firm downward pressure. Firm three-finger pressure should control most femoral bleeding.
A rolled gauze pack may be placed over the artery to the groin and
pressure applied with the palm of the hand. Standing on a short stool
at bedside permits the operator’s upper body weight to be used for
pressure application.
Manual pressure is held firmly for approximately 5 minutes per
sheath size; therefore, 25 minutes for 5 F and 30 minutes for 6 F. In
patients receiving antiplatelet treatment (e.g., aspirin or clopidogrel),
longer puncture site compression may be necessary. Compression
time should be divided into four periods: full pressure, three-quarters
pressure, half pressure, and one-quarter pressure over the prescribed
duration. During pressure application, pedal pulses should be intermittently evaluated and the entire leg should be uncovered to identify
duskiness of the extremity. A diminished pulse is acceptable during
brief full-pressure application, but distal pulses should not be obliterated completely at any time during manual compression. If the pedal
pulse is absent during compression, the pressure over the artery
should be decreased slightly periodically to allow distal circulation.
Complete artery occlusion prevents clotting factors and platelets from
being deposited at the arterial wall puncture site and in extreme cases
can lead to thrombotic events, particularly in lower extremity bypass
grafts. In patients with low cardiac output, mitral stenosis, or cardiomyopathy with a small pulse pressure, the femoral artery can easily
be obliterated. In these patients, distal pulses should be checked more
often and less pressure should be applied to the groin.
Hematoma Monitoring and Groin Dressings
After an appropriate time for manual pressure, the operator’s hand is
removed slowly and the area is inspected for hematoma or bleeding.
Hemostasis may be difficult to secure in obese, hypertensive, or elderly
female patients or in patients with aortic insufficiency. Likewise,
patients with a coagulopathy or who are receiving anticoagulant or
antiplatelet agents may take longer for hemostasis. In all such patients,
an extended monitoring period is prudent. In larger patients, greater
than 500 mL of blood can be lost in a thigh or pannus before the
patient or nurse identifies the problem.
After hemostasis is obtained, clean the puncture area with an
antiseptic solution and apply a small clear sterile dressing (e.g., Opsite,
Tegaderm). This permits visualization of the entry site and surrounding
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tissues. One should not use gauze under the plastic dressing because
this forms a culture media if left in place after discharge. Likewise,
large pressure dressings or sandbags should not be used, because they
are ineffective in preventing bleeding and obscure the puncture site
so that early hematoma formation may be missed.
should ensure arterial hemostasis first and then remove the venous
sheath to decrease the risk of AV fistula formation. In addition, preservation of venous access for the first 15 minutes of arterial compression may provide a useful access to treat a vagal reaction should
the peripheral IV line be inadequate for large volume resuscitation.
Arterial and Venous Access
If the femoral artery and vein are used in the procedure, one
Mechanical Compression and
Vascular Closure Devices
Femo-Stop Pressure System
The Femo-Stop (Fig. 2-15) is an air-filled clear plastic compression
bubble that molds to skin contours. It is held in place by straps passing
around the hips. The amount of applied pressure is controlled with a
sphygmomanometer gauge. The clear plastic dome allows the operator to see the puncture site. The Femo-Stop is used most often for
patients in whom prolonged compression is anticipated or whose
bleeding persists despite prolonged manual compression. The duration of Femo-Stop compression and time until removal of the device
vary depending on the patient and staff protocols. In some hospitals,
the time from application to removal may be less than 30 minutes. In
other patients in whom hemostasis is required, the device may be left
at lower pressures for a longer duration. During the entire time of
placement, direct visualization and monitoring should be performed
by a trained individual.
Arterial Closure Devices
Several different types of VCDs are currently available. All VCDs have
demonstrated rapid hemostasis and a decreased time to ambulation
when compared with manual compression, but none have been
shown to decrease vascular complications in randomized controlled
trials. These devices may be especially helpful in patients who have
back pain or cannot lie flat. Active closure methods include suture
type (Perclose, Abbott Vascular, Redwood City, CA), extravascular
collagen implant (Angio-Seal, St. Jude Medical, St. Paul, MN), and
surgical staple/clip technology (StarClose, Abbott Vascular, Redwood
City, CA; EVS-Angiolink, Medtronic, Inc., Minneapolis, MN). AngioSeal theoretically has a higher risk of thromboembolic events because
of the intravascular collagen anchor. The suture-mediated devices use
primary healing (end-to-end anastomosis at the arteriotomy site) but
have the highest rate of device and operator failure due to the learning
curve associated with their use. Because VCDs do not ensure freedom
from bleeding or vascular complications, diligent monitoring is still
essential. The advantages and disadvantages of the various arterial
closure devices are summarized in Table 2-2.
All VCDs should be used with caution in patients with peripheral
vascular disease or with a high (above upper third of the femoral head)
or low (at or below the femoral bifurcation) arterial puncture. Caution
is also needed in patients with scar tissue at the site of prior femoral
artery procedures. Femoral angiography with an ipsilateral oblique
angle (i.e., right anterior oblique [RAO] for right femoral artery, left
anterior oblique [LAO] for left femoral artery) lays out the bifurcation,
although the sheath entry site is often obscured. On the other hand,
the contralateral oblique angle nicely demonstrates the sheath entry
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Arterial and Venous Access 79
A
B
Figure 2-15
(1) examine the puncture site carefully, (2) note and mark edges of any
hematoma, and (3) record patient’s current blood pressure. A and B, Step
1: Position belt. The belt should be aligned with the puncture site equally
across both hips. Step 2: Center the dome and adjust the belt. The dome
should be centered over the arterial puncture site above and slightly toward
the midline of the skin incision. The sheath valve should be below the rim
of the pressure dome. Attach the belt to ensure a snug fit. The center arch
bar should be perpendicular to the body. Step 3: Connect the dome pressure
pump. Step 4: For a venous sheath, inflate dome to 20 or 30 mm Hg and
remove the sheath. To minimize formation of arteriovenous fistula, obtain
arterial hemostasis before the venous sheath is removed. Step 5: For the
arterial sheath, pressurize the dome to 60 to 80 mm Hg, remove the
sheath, and increase the pressure in the dome to 10 to 20 mm Hg above
systolic arterial pressure. Step 6: Maintain full compression for 3 minutes.
Then, reduce pressure in the dome by 10 to 20 mm Hg ever y few minutes
until 0 mm Hg is reached. Check arterial pulse. Observe for bleeding. After
hemostasis is obtained, remove Femo-Stop and dress wound. (Cour tesy St.
Jude Medical, Inc.)
Use of the Femo -Stop pressure system. Before proceeding,
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Arterial and Venous Access
Ipsilateral
Access <90 Days
Sheath Sizes
(French [F])
6 and 8 1 cm higher
possible
thromboembolic
complications,
infection related to
Intraarterial component,
wick
5 to 8 No restrictions
steep learning cur ve,
device failure may
require surgical repair
long track
record
Secure closure,
suture mediated
Collagen and
present
1997 to
Suture mediated Secure closure Intraarterial component,
present
Vascular Closure Devices
Table 2-2
MN)
Device On the Market Mechanism Advantages Disadvantages
Angio -Seal (St. Jude Medical, Inc., St. Paul,
Perclose (Abbott Vascular, Redwood City, CA) 1997 to
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established
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Arterial and Venous Access 81
5 and 6 Not fully
needed to prevent
device failure
Adequate skin tract
component
Nitinol clip No intraar terial
5 to 7 No restrictions
injection of sealant
Possible intraarterial
component,
potential use
in PVD
PEG hydrogel plug No intraarterial
present
2005 to
CA)
StarClose (Abbott Vascular, Redwood City,
present
2007 to
Mynx (AccessClosure, Inc., Santa Clara, CA)
PEG, Polyethylene glycol; PVD, peripheral vascular disease.
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site but obscures the bifurcation (Fig. 2-16). The ipsilateral oblique
angle is generally preferred and then the sheath is gently pulled medially (“wiggled”) to determine its entry point. For patient comfort,
femoral angiograms can be done with a 50/50 contrast mixture.
Arterial and Venous Access
Postcatheterization Patient Instructions
and Discharge
Depending on the catheter and sheath size, and whether or not a VCD
was used, the patient is kept at bed rest for 2 to 4 hours after femoral
artery puncture. In the recovery area, the patient is instructed to (1)
keep the head down, (2) hold the groin site when coughing, (3) keep
the punctured leg straight, (4) stay in bed, (5) drink fluids, and (6) call
a nurse for assistance if there is any bleeding, leg numbness, leg pain,
or chest pain. Following bed rest, the patient can sit up in bed for 30
minutes and can then walk with nursing assistance. At this point, the
groin is rechecked and if there is no sign of hematoma or bleeding,
the discharge process can continue.
Percutaneous Brachial
Artery Approach
The percutaneous brachial arterial entry, which replaced the brachial
artery cutdown, should be reserved for patients in whom neither the
radial nor femoral artery can be used for access. Although similar to
femoral arterial puncture, there are several important differences. The
brachial artery is smaller (3 to 5 mm in diameter) than the femoral
artery. Because of the relatively loose subcutaneous tissues, the course
of the brachial artery may change considerably. Spasm can occur
easily with considerable decrease in pulse amplitude, making the
puncture more difficult. The artery is more mobile than the femoral
artery. Care should be taken to puncture the artery successfully on the
first attempt. Because of the smaller space in the arm, uncontrolled
hematoma formation here can readily cause compartment syndrome
with ischemia of the forearm and hand. The median nerve lies immediately medial to the artery. Accidental touching of the median nerve
causes a peculiar electrical shock sensation in the hand.
The operator should check the brachial and radial pulses before
attempting brachial arterial puncture. Both pulses should be strong
and equal in both arms. In patients in whom femoral access is not
possible because of severe atherosclerosis, vascular surgery, or the
presence of an IABP or LV support device, the same type of atherosclerotic disease may exist in the subclavian arterial system. The
subclavian-axillary artery system should be auscultated carefully for
bruits above and below the clavicle.
Anesthesia Administration
The maximum point of brachial arterial pulse is located approximately
1 cm above the elbow crease. With a 25-gauge needle, infiltrate the
skin and subcutaneous tissue with 2 to 3 mL of 1% lidocaine. Injection
of excessive amounts of local anesthetic may make palpation of the
artery difficult or obscure the pulse completely.
Puncture of the Artery and Introduction of
the Guidewire
Similar to the radial artery entry technique, a micropuncture needle
with a 0.018-inch guidewire is used to enter the brachial artery.
The through-and-through puncture with an angiocath needle is not
recommended in this location. To facilitate the arterial puncture, the
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Arterial and Venous Access 83
A
B
Figure 2-16
femoral bifurcation is obscured, although the insertion of the sheath can
be visualized. B, Right anterior oblique (RAO) projection. The bifurcation of
the femoral artery is now visible (arrow). The sheath inser tion site is made
visible by gently pulling the sheath medially during the angiogram.
Femoral angiograms. A, Anteroposterior projection. The
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