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454 M. A. Mauro and S. E. Black
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A B
FIGURE 35-13. Dialysis catheters. A: Radiograph of a dual-lumen dialysis catheter placed via the left internal jugular vein (IJV)
and tunneled over the clavicle onto the chest wall.
IJV.
Straight white arrows:
system placed via the right IJV and tunneled onto the chest wall. A, tip of arterial catheter at RA/SVC junction V, tip of venous
catheter 4 cm lower in the right atrium.
catheter within subcutaneous tunnel on the chest wall. B: Radiograph of the dual Tesio dialysis catheter
Curved arrows:
Straight black arrow:
sites of right IJV access.
tip of catheter in RA.
Straight arrows:
Curved black arrow:
parallel tunnels onto the chest wall.
access site in left
■ Catheter Management and Removal
In addition to device selection and insertion, the interventional radiologist must become familiar with postprocedural catheter care, patient follow-up, diagnosis,
and management of catheter-related complications and,
finally, device removal. A specialized nursing team for
patient education and supervision of routine catheter
care will help in significantly reducing the frequency of
catheter-related thrombosis and infections.
46
Adherence
to strict sterile techniques while accessing these devices,
routine dressing changes, and proper catheter heparinization cannot be overemphasized. Nurses who are specialized in infusion management also are trained in
catheter repair using commercially available repair kits.
Radiologists involved in this service should have these kits
available and become familiar with their use.
Device removal is the responsibility of the service that
initially places that device. Nontunnelled catheters are
simply removed following release of the tape or sutures.
Before a tunnelled catheter is removed, the catheter and
tunnel are thoroughly prepared and draped. The skin site
and the area around the cuff are infiltrated with a local
anesthetic. Gentle blunt dissection is performed around
the cuff using a hemostat. The catheter then is removed
with steady traction. The cuff usually is dislodged from the
subcutaneous tissues along with the catheter. If the cuff is
not dissected free, it may be left behind. The retained cuff
could be a continued nidus of infection in cases of sepsis
or a tunnel infection. In these cases, the cuff should be
removed. When the cuff is initially positioned within 1 to
2 cm from the exit site (as is our standard practice), it
usually can be dissected free and removed with the cathe-
ter. When the cuff is located some distance from the exit
site and requires removal, a separate incision over the cuff
parallel to the tunnel is required for its removal.
Removal of a subcutaneous port requires a sterile site
preparation analogous to its insertion. A surgical cutdown
also is used to provide the adequate tools. For removal,
the skin incision is made overlying the prior incision. Following dissection, a white sheath is identified surrounding the device and catheter, which will need to be incised
and dissected free. The port will easily slide from this
pocket. External pressure is applied for hemostasis. A twolayer closure is preferred. When needed, additional deep
sutures should be placed to eliminate only any dead space
that could lead to subsequent hematoma or seroma formation and an increased risk of infection.
■ Complications
Procedural complications
Access failure and catheter malposition constitute minor
procedural complications. Blinded percutaneous access
failure occurs in 5 to 8.9% of cases compared with less
than 2% when radiologic guidance techniques are
8,15,16,21,47
used.
to 2.5% incidence of catheter malposition immediately
following placement.
catheter malposition is immediately detected and corrected. A patient should not leave the suite with a malpositioned catheter.
Major procedural complications include hematomas,
pneumothorax, air embolism, and nerve injury.
Similarly, blind placement results in a 1.2
21,47,48
With radiologic guidance,
35
Hema-
Central Venous Access 455
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tomas typically result from an inadvertent arterial needle
puncture or bleeding within the subcutaneous tunnel or
pocket. The use of a 21-gauge needle, image guidance
(ultrasound, fluoroscopy), and a peripheral puncture has
virtually eliminated a significant hematoma resulting
from an inadvertent arterial puncture.
8,15,21
Contrast injection or careful observation of the 0.018-inch guidewire
will always confirm venous entry. Tunnel and subcutaneous pocket hematomas occur more commonly in patients
with a coagulopathy. Any coagulation and platelet abnormality should be corrected before tunneled or buried
devices areplaced. If necessary,a temporary nontunneled
device may be placed until the patient’s coagulation status
is normalized.
Image guidance also has reduced the pneumothorax
rate to less than 1%.
8,15,21
In addition, the pneumothorax
secondary to a 21-gauge needle is typically small and will
resolve spontaneously. If not, it is easy to place a small
catheter percutaneously in the apex through the second
anterior intercostal space and to place it to an underwater seal.
An air embolism may occur if the patient inspires when
the peel-away is open to the atmosphere. In a study of
percutaneously placed large-bore hemodialysis catheters,
air embolism occurred in 0.8% of cases, with no sequelae.
42
The air accumulates in the pulmonary outflow
tract and main pulmonary artery. Oxygen should be administered, and the patient should be observed. The air
will dissipate in several minutes.
Long-term complications
Long-term or delayed complications include mechanical,
thrombotic, and infectious complications. The interventional radiologist must be familiar with the detection and
management of these complications.
Mechanical complications
Delayed catheter migration into the internal jugular vein,
azygous vein, or contralateral innominate vein is caused
by head or arm motion and a short catheter. A forceful
injection of saline or placement of a guidewire or a transfemoral relocation can correct the malposition.
catheter migration recurs, the device should be exchanged for a longer catheter.
Catheter fragmentation is caused by the mechanical
stress on the catheter when it pierces the subclavius muscle and the costoclavicular ligament as it courses through
the clavicle/first rib space (“pinch-off” syndrome).
The fragment may lie anywhere from the subclavian vein
to the pulmonar y arteries. The average time between
insertion and fragmentation is 6.5 months.
mentation is discovered, the remaining device is removed
and the free fragment is retrieved by using conventional
36–38
23
When frag-
22,23,49
intravascular foreign-body retrieval techniques. This potential complication can be eliminated with venous entry
lateral to the clavicle/first rib space.
The repeated use of external catheters may cause fatigue and fracture of the hubs and external tubing. Repair kits are commercially available for their repair. A
severely damaged device must be replaced.
Thrombotic complications
Catheter-related thrombosis is a general term that may include thrombus within the catheter lumen and thrombus
within the vein and the fibrin sheath that surrounds the
catheter. The reported incidence varies greatly, depending on whether the diagnosis is made clinically or by
some diagnostic test. The incidence of catheter-related
thrombus varies from 3 to 70%.
malignancies or who are in hypercoagulable states and
those that are receiving caustic solutions (chemotherapy,
hyperalimentation) are particularly susceptible to thrombotic complications. Clinical signs and symptoms of
catheter-related thrombosis include ipsilateral swelling of
the neck and arm, venous distention, and nonspecific
pain in the neck and anterior chest wall.
The inability to aspirate blood is often the first indication of problems relating to thrombus or a fibrin sheath.
A fibrin sleeve develops around all catheters in place for
longer than a week.
50
When the sleeve reaches the tip of
the catheter, it will cause dysfunction. Contrast injection
will show a stream of contrast that tracks back along the
catheter and even extravasate from the venous entry site.
Passing a guidewire through the catheter breaking the
fibrin sleeve at the tip may restore function. Fibrin stripping using a transfemorally placed loop snare has been
used successfully in maintaining catheter function.
The snare is placed over the catheter, tightened, and
pulled down, stripping the sleeve. Simple catheter exchange over a guidewire through the same tunnel (for
tunnelled catheters) also will restore function and will
avoid a new puncture; the patient will be able to leave
immediately after the procedure. The relationships of
this fibrin sleeve and catheter thrombosis and infection
are not well understood. Inability to aspirate blood can
also occur when the catheter tip is against the vein wall,
If
a problem often corrected by a change in head or arm
position or a Valsalva maneuver.
Treatment of luminal or vein thrombosis involves combinations of intracatheter thrombolytic therapy, anticoagulation, venous thrombolysis, and catheter removal. Luminal thrombotic occlusion is treated with a low-dose
thrombolytic regimen. A bolus is injected into the catheter
and aspirated after a30-min dwelltime. If this is unsuccessful, an infusion may be used for 6 to 12 hr.
restored in more than 95% of cases. Treatment of venous
thrombosis depends on the severityof symptoms,the need
50–52
Patients who have
5,42
53,54
Patency is
456 M. A. Mauro and S. E. Black
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for access, and the availability of other sites. In patients
with long-term need and limited access, heparinization
followed by coumadin is used with the catheter left in
place. For particularly symptomatic patients, venous
thrombolytic therapy with urokinase also will be
50,55,56
used.
Symptomatic patients withlong-term need but
with other available sites simply may be treated with catheter removal, new catheter placement, and anticoagulation. Signs of septic thrombophlebitis require immediate catheter removal and appropriate antibiotic
treatment. Long-term low-dose (1 mg daily) coumadin
and even full anticoagulation have been used to prevent
thrombosis.
57
Infectious complications
Catheter-related infections occur at the catheter exit site,
within the subcutaneous tunnel or pocket or systemically
as catheter related bacteremia (or sepsis).
infections often present with erythema and tenderness at
the exit sitein additionto an exudate. A tunnel or subcutaneous pocket infection is more serious and is characterized by erythema and tenderness along the tunnel or
over the pocket. Pus may be expressed from the tunnel by
“milking” the tract. Catheter-related bacteremias present
with fever and a leukocytosis and often are used as a diagnosis of exclusion in a patient with no other apparent
source of sepsis. Clinicalevidence implicatingthe catheter
as a source of sepsis includes (a) an exit-site or tunnel
infection caused by the same organism isolated from the
blood, (b) clinical sepsis refractory to antibiotics but resolves followingcatheter removal, (c) positive quantitative
catheter culture with isolation of the same organism from
bloodstream, and (d) a differential quantitative blood culture greater than 10-fold colony count of organisms isolated from blood obtained through the catheter and from
blood obtained from a peripheral site.
lated infections arise fromcontamination at the skin insertion site, colonization of the catheter hub, hematogenous
seeding of the catheter, and infusate contamination.
Catheter-related infections occur in 10 to 30% of patients
with a rate of 0.2 episodes per 100 days at risk.
rate compares favorably to surgical reports.
Local (exit site or subcutaneous) infections must be
detected early and aggressively treated to save the device.
Gram stain and culture of any drainage should be performed. Most (50–70%) of these infections are caused by
skin flora. Gram-positive organisms are effectively treated
with a 10- to 14-day course of intracath vancomycin hydrochloride.
42,50
Early erythema withdrainage may be treated
with oral antibiotics. If the condition does not improve or
worsens on therapy, the device is removed immediately
and new cultures are obtained. Even with treatment, the
device is salvaged in only 25% of patients with tunnel
infections and 70% with exit site infections.
58–60
58,61
Catheter-re-
50,59
Exit-site
42,59,60
58–60
This
Catheter-related bacteremias are treated with intravenous antibiotics according to culture and sensitivity studies. If, however, no improvement has occurred in 48 to 72
hr, the device must be removed. Even when the device is
salvaged, there is a 20% chance the bacteremia will recur
compared with a 3% risk of recurrence if the device is
removed.
58
■ Conclusion
The need for central venous access is expanding rapidly.
This service can be provided economically and expeditiously by an interventional radiologist. Most cases can be
completed within 45 to 60 min. The devices can be placed
safely, and the late infectious and thrombotic complications seen with these procedures are comparable to those
seen when the devices are placed within an operating
room. The skills and technology available to interventional radiologists place them in a unique position to
deliver this service.
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44. Ganaud B, Beraud JJ, Joyeux H, et al. Internal jugular vein cannulation using 2 silastic catheters: anew, simple andsafe long-termvascular access for extracorporeal treatment. Nephron 1986;43:133–138.
45. Canaud B, Beraud JJ, Joyeux H, et al. Internal jugular cannulation
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47. Takasugi JK, O’Connell TX. Prevention of complications in permanent central venous catheters. Surg Gynecol Obstet 1988;167:6–11.
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50. Lowell JA, Bothe A Jr. Venous access preoperative, operative, and
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51. Haire WD, Lieberman RP, Lund GB, et al. Thrombotic complications of silicone rubber catheters during autologous marrow and
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54. Hosal VL, Ause RG,Hoskins PA. Fibrin sleeve formation on indwelling subclavian central venous catheters. Arch Surg 1971;102:353–
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A.C. Roberts and J. E. SilberzweigHemodialysis Access Management
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36
■■■
Hemodialysis Access Management
ANNE C. ROBERTS AND JAMES E. SILBERZWEIG
Dialysis is defined as the removal of blood elements by
diffusion through a semipermeable membrane. The purpose of dialysis is to remove metabolic waste products and
maintain fluid and electrolyte balance. The hemodialysis
machine functions as an “artificial kidney.” Blood is
drawn from the patient at a rate of 300 to 500 mL per
minute, passed through the dialysis machine, and then
returned to the patient. Patients with end-stage renal
disease typically require hemodialysis three times per
week for 3 to 4 hours. The rapid circulation of blood
between patient and hemodialysis machine requires a
conduit that is durable, has a low infection rate, and is
easily accessible. Peritoneal dialysis is an alternative form
of dialysis in which dialysate is instilled into the peritoneal cavity, periodically drained, and replaced with fresh
solution via a catheter. The peritoneal membrane acts as
the dialyzing surface in peritoneal dialysis.
Alternatives for access to the patient’s blood circulation for hemodialysis include the use of a central venous
catheter, a surgically created arteriovenous fistula, or a
prosthetic graft interposed between an artery and vein.
Central venous catheters have one lumen for drawing
blood from the patient into the hemodialysis machine
(arterial ) and one lumen for blood return to the patient
from the hemodialysis machine (venous ). Access to a
prosthetic graft or the venous outflow of a surgically created fistula is made with two 14- to 16-gauge needles.
Renal transplantation is the treatment of choice for
many patients with end-stage-renal disease. Because of
limited organ availability, however, dialysis is the primary
therapy for most of these patients. More than 280,000
persons in the United States require chronic dialysis.
1
For
these patients, functioning dialysis accessis their“lifeline,”
and maintenance of this access is critical. Hemodialysis
access maintenance represents one of the most challenging problems for interventional radiologists. Thrombosis
is the most common cause of hemodialysis access graft loss
and usually is related to stenoses in the venous outflow.
The goal of hemodialysis access maintenance is to detect
and treat access dysfunction prior to access thrombosis
and to salvage thrombosed grafts.
■ Arteriovenous Graft
Most patients requiring chronic hemodialysis have an upper-extremity arteriovenous graft (AVG) constructed of
6-mm-diameter polytetrafluoroethylene (PTFE) tubular
graft material. Typical upper-extremity grafts include a
loop graft with anastomoses at the brachial artery and
basilic vein or cephalic vein and a straight graft with anastomoses at the distal radial artery and the basilic or cephalic
vein near the antecubital fossa. The graft is tunneled subcutaneously and is easily accessible by percutaneous needle puncture. A lower-extremity loop graft extending
from the common or superficial femoral artery to the
saphenous vein is constructed when upper-extremity
veins are no longer usable for graft construction. The
most common complication associated with PTFE hemodialysis access grafts is the development of stenosis at the
venous anastomosis or venous outflow of the graft resulting in graft thrombosis. Patency rates at 1 year range from
55 to 75%,
estimated to be less than 2 years.
2,4,5
and the life span of the average graft is
6
459
460 A. C. Roberts and J. E. Silberzweig
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■ Brescia–Cimino Fistula
The preferred access for hemodialysis is an endogenous
arteriovenous fistula because it provides the greatest
chance for long-term function. A Brescia–Cimino arteriovenous fistula is usually constructed with a side-to-side
anastomosis of the cephalic vein and radial artery at the
wrist. A fistula also can be placed at the antecubital fossa
with an anastomosis of the brachial artery and cephalic
vein. Brescia–Cimino fistulas are less likely to thrombose
than a PTFE graft because a fistula has a single anastomosis with multiple potential areas of venous outflow.
After an arteriovenous fistula is created, thepatient cannot undergo dialysis using this access until fistula maturation occurs. Maturation involves vein-wall thickening and
dilatation, which facilitates vein puncture with large-bore
needles and accommodates arterial blood flow required
for dialysis. The maturation process typically takes 1 to 4
months. Fistulas are ideally placed several months prior to
anticipated use to ensure adequate maturation.
Unfortunately, Brescia–Cimino fistulas have a high
early failure rate, usually as a result of inadequate venous
size or runoff. When the fistula is established and used
successfully for hemodialysis, late failure is rare. In about
20 to 30% of cases, the fistula will never mature.
2–4
problem.
9
Occasionally, no underlying anatomic lesion
can be found. It has been postulated that these grafts may
have thrombosed due to excessive postdialysis graft compression at the needle puncture sites, hypotension, hypovolemia, compression of the graft due to sleeping position, or a hypercoagulable state.
10
The development of venous stenoses appears to be
caused by neointimal hyperplasia. The cause of this hyperplasia is not well understood. A variety of theories
have been proposed to explain the development of
neointimal hyperplasia. One mechanism of hyperplasia is
a response to turbulent blood flow and vibration resulting from placement of the graft.
11
Other factors such as
the transition between the relatively noncompliant graft
material and the compliant vein,
stretching of the vein at the anastomosis,
12
or angulation and
13
may be important. Whatever the cause, these stenoses inevitably recur
after intervention because the underlying pathophysiology is unchanged. This is the cause for the ongoing
requirement for repeated angioplasty and thrombolysis
of the dialysis grafts. Until the pathophysiology of intimal
hyperplasia is understood and techniques are developed
to prevent intimal hyperplasia, there will be a need for
the mechanical treatment of venous stenoses.
■ Causes of Graft Dysfunction
Thrombosis is the most common cause of hemodialysis
access graft loss and usually is related to stenoses in the
venous outflow. If thrombosis occurs in the first few weeks
after placing the access, there is often a technical problem related to the graft. Technical problems include graft
kinking, narrow arterial or venous anastomoses, or preexisting arterial inflow or venous outflow disease (Fig.
7
36-1).
nous outflow stenosis after graft insertion.
Occasionally, there is rapid development of ve-
8
Thrombosis
that occurs after 2 to 3 months is usually due to the
development of stenosis in the venous outflow. Arterial
inflow stenosis may occur, but it is a much less frequent
FIGURE 36-1. Kinking of this newly placed hemodialysis graft
near the venous anastomosis (
sion.
arrow
) required surgical revi-
■ Treatment of the Poorly
Functioning Graft
The sites available for hemodialysis access are limited;
therefore, it is important to extend the life of each access
for as long as possible. Treatment of grafts prior to thrombosis is more cost- and time-effective than treatment of
thrombosed grafts. Long-term patency of grafts is improved if stenoses are treated prior to thrombosis as
opposed to undertaking angioplasty or surgical revision
after thrombosis has occurred; however, this requires
identifying functioning grafts that are at risk for thrombosis. If the developing stenosis can be identified and
treated with angioplasty, the risk and cost of thrombolysis
can be avoided.
A number of signs may identify developing graft
stenoses, including elevated venous pressure,
with needle placement, increased bleeding following
needle removal, extremity edema, dilatation of collateral
veins over the upper extremity or chest,
of the normal graft thrill to a pulse.
refers to the pressure measured by the dialysis machine
as blood is returned to the patient. Venous return pressure greater than 150 mm Hg at a blood flow of 200 mL
per minute is indicative of a venous outflow stenosis.
Recent studies showed that Doppler ultrasound may be
useful in the evaluation for stenoses.
19,20
Angiographic evaluation of a hemodialysis access graft
should include the arterial anastomosis, graft, venous
8,14
15
and conversion
16,17
Venous pressure
difficulty
18
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461
anastomosis, and the entire venous outflow. This can be
done easily by using a dialysis needle, which can be left in
place following a dialysis session or using standard Seldinger technique. If a stenosis is identified, angioplasty can
be performed immediately and the patient discharged
following completion of the procedure (Fig. 36-2).
Early correction of venous stenoses prolongs access
viability. A recent study followed up on 106 grafts suspected on clinical examination to have a venous steno-
21
sis.
The grafts were studied angiographically, and any
venous stenosis was treated with balloon angioplasty. The
technical success for angioplasty was 98%. The primary
patency at 1 year was 23% for PTFE grafts. Repeated
angioplasty improved the patency rate to 68% at 1 year
and 51% at 2 years (primary assisted patency rate). A
combination of thrombolysis and repeated angioplasty
improved patency further, with secondary patency rates
at 1 year of 82% and at 2 years of 65%.
21
Recurrence of stenoses should not be considered a
failure of the procedure but rather an expression of the
underlying pathophysiology. Redilatations allow easy and
safe maintenance for months and even years.
17
Gaining
added months of patency through redilatations could be
of great value for dialysis patients. In contrast to a surgical
graft revision, loss of central veins does not occur with
angioplasty. Because angioplasty and surgical techniques
may have similar secondary patency, the loss of future
access sites becomes an important issue.
The treatment of a poorly functioning Brescia–Cimino
fistula is less likely to involve thrombolysis and more likely
to require angioplasty of a venous stenosis. In patients
with Brescia–Cimino fistulas, most stenoses occur in the
anastomotic and postanastomotic area before the puncture area for dialysis.
22
These fistulas are difficult to evaluate because of the number of outflow veins that become
opacified with angiographic evaluation. This is particularly apparent when a stenosis in the main outflow and
development of collateral veins occur. The collateral
veins may overlie and obscure the venous stenosis, and
angiography in multiple projections may be required to
demonstrate an abnormality.
■ The Thrombosed Graft
The traditional therapy for failing hemodialysis access
has been surgical thrombectomy with or without revision
of the venous anastomosis. Thrombectomy alone is usually not successful because thrombectomy does not address the cause of graft failure, and replacement is not a
realistic option because the possible access sites would be
exhausted rapidly.
During the past 10 to 15 years, percutaneous techniques have become widely used for dialysis access salvage. Graft thrombolysis and balloon angioplasty of stenoses are the essence of percutaneous therapy for clotted
hemodialysis access grafts. The thrombolysis portion of
the procedure can be performed by several methods,
including a combination of clot-dissolving medications
and mechanical “declotting” devices.
A hemodialysis graft has unique characteristics that
make it particularly amenable to percutaneous therapy.
The graft is easy to access percutaneously, contains fresh
clot responsive to thrombolytic agents, and is a closed
system with only a single inflow and outflow, keeping the
thrombolytic agent from diffusing into the systemic circulation.
The percutaneous approach to a thrombosed dialysis
graft allows not only for thrombolysis but also for angiographic evaluation of the graft. The entire graft, including the arterial inflow and the complete venous outflow,
can be evaluated easily. The venous anastomotic stenosis
that is often encountered can be treated with balloon
angioplasty.
The percutaneous graft declotting and angioplasty procedure is performed in a single session and usually is
performed on an outpatient basis. Following the conclusion of the procedure, the patient can be discharged to a
dialysis unit or home. The graft is functional for dialysis
immediately following percutaneous therapy, unlike after
surgical revision or new graft insertion. This is crucial
because successful percutaneous therapy obviates the
need for the insertion of a temporary central venous
hemodialysis catheter. Avoidance of the use of temporary
A B
FIGURE 36-2. Arteriovenous shunt stenosis. Venous anastomotic stenosis. (A). Before the 7-mm
balloon angioplasty. (B). After angioplasty.
462 A. C. Roberts and J. E. Silberzweig
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jugular or femoral central venous dialysis catheters decreases expenses and eliminates the risk of complications
from these catheters, such as central venous stenosis and
infection.
■ Patient Selection
Usually, thrombosis of a recently (within a few weeks)
constructed graft is due to a surgical technical problem.
Sometimes thrombolysis is performed to identify the
cause of the problem, which may allow a focused surgical
repair. There is some increased risk of bleeding from
recent anastomotic sites; however, if this does occur, it is
usually controlled easily with manual pressure. Balloon
angioplasty of the anastomosis of a recently placed graft,
however, is at increased risk for rupture and should be
avoided.
Some patients should not undergo thrombolysis. Criteria that would exclude a patient with a thrombosed dialysis graft are the same for other thrombolytic procedures.
Absolute contraindications to thrombolysis are active gastrointestinal bleeding and recent neurologic processes,
including intracranial bleeding, stroke, or neurologic
surgery. Relative contraindications include major surgery
or organ biopsy within 2 weeks; recent serious trauma;
preexisting coagulation defects; uncontrolled, severe hypertension; pregnancy or the immediate postpartum period. The use of a mechanical thrombectomy device may
be ideal for patients at increased risk for bleeding.
A contraindication to percutaneous graft thrombolysis
is the presence of a graft infection. Lysis of infected clot
may precipitate bacteremia and lethal sepsis.
23
Also an
infected clot is relatively resistant to thrombolysis. Determining the presence of infection in a graft is often difficult. The classic signs of infection, such as redness, tenderness, warmth, swelling, and fever, are often blunted in
patients with uremia. Purulent discharge or skin breakdown around the graft are obvious signs of infection, but
these sign are uncommon. Needle aspiration of the graft
clot for Gram stain and culture or of perigraft fluid collections found on ultrasound evaluation may be helpful
in diagnosing graft infections.
24
Infection of the graft
mandates treatment with antibiotics and referral for surgical removal of the graft.
Grafts that have undergone attempts at access just
prior to the thrombolytic procedure are more likely to
develop bleeding from the puncture sites during the
thrombolytic procedure. It is worthwhile to develop a
policy with the referring dialysis center so that if a patient
presents with a pulseless graft, no attempts will be made
to cannulate the graft, and the patient is immediately
referred for percutaneous recanalization. Bleeding occasionally develops from puncture sites that are several days
old, particularly if the puncture was traumatic. Usually
bleeding is not a serious problem. Bleeding can be managed by manual compression over the site and by rapid
relief of the outflow stenosis by angioplasty that will decrease the pressure within the graft. On occasion, it is not
possible to control the bleeding site while continuing to
recanalize the graft. In this situation, surgical therapy
may be required.
■ Graft Recanalization Technique
Graft access
The crossed-catheter technique is the basis of the approach to the thrombosed graft (Fig. 36-3 and Table
25–27
36-1).
and venous ends of the graft simultaneously. A standard
single-wall entry needle or a Micropuncture Introducer
set (Cook, Bloomington, IN, U.S.A.) is used to access the
graft. The first puncture is made in the graft at the junction of the proximal and middle third of the graft (the
arterial end of the graft) directed toward the venous end
of the graft. The graft can be accessed most successfully
if it is fixed between the thumb and index finger and held
firmly while the puncture is being made. As the graft wall
is punctured, there is a “popping” sensation. This sensa-
Graft
FIGURE 36-3. Initial catheter access for declotting of an up-
per-extremity hemodialysis loop graft using the crossed catheter technique.
This approach allows access to both the arterial
Vein
Catheter
Artery
Catheter
Hemodialysis Access Management 463
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TABLE 36-1. Hemodialysis Graft Declotting Procedure
1. Obtain antegrade access to the graft near the arterial
anastomosis.
2. Cross the venous anastomosis with diagnostic catheter.
3. Obtain pullback venogram of central veins and graft outflow.
4. Angioplasty/stent central venous stenosis/occlusion.
5. Obtain retrograde access to the graft near the venous
anastomosis.
6. Insert infusion catheters and inject thrombolytic agent or perform
mechanical thrombectomy.
7. Angioplasty venous anastomotic stenosis/occlusion.
8. Remove residual clot at the arterial anastomosis by passing a
deflated Fogarty or occlusion balloon catheter through the graft
into the inflow artery. Inflate the balloon with contrast and pull
back into the graft.
9. Macerate residual clot with the angioplasty balloon.
10. Perform completion angiogram of the inflow artery, graft, and
outflow veins.
11. Exchange vascular sheaths for temporary hemodialysis
catheters and transfer patient to hemodialysis unit.
12. Remove catheters after hemodialysis.
tion can be blunted in an older graft because scar tissue
builds up around the graft after many punctures. The
graft is thrombosed; thus, there will be no pulse within
the graft and usually no return of blood when the lumen
is entered. When the graft is entered, the guidewire usually passes easily through the lumen, even in the presence
of clot. In some cases, a small amount of dark blood
returns through the needle.
If the wire does not pass easily and coils in the soft
tissues, as seen on fluoroscopy, the needle should be
repositioned until it is within the graft lumen. If the
patient complains of pain when the wire is advanced, this
is an indication that the guidewire is not within the graft.
On the other hand, the patient may not complain of pain
when the wire is in the soft tissues, and so fluoroscopy and
“feel” are extremely important. When the puncture is
difficult, it is tempting to inject contrast to determine
whether the graft has been entered. This temptation
should be resisted. If the needle is not in the graft and
contrast is injected into the soft tissues, the appearance
may be misleading. At first, it may appear that the graft
has been entered, as the injection continues, it will become evident that the contrast is not within the graft. At
this point, however, the graft is often obscured and will
remain obscured for the remainder of the procedure.
Although it can be difficult to do so, it is best to rely on
observing the wire following the course of the graft as
evidence of correct placement of the needle within the
graft.
After the guidewire has been placed correctly into the
graft, avascular sheath is placed over the guidewire,which
then must be passed through the venous anastomosis and
into the venous outflow. If difficulty is encountered in
passing the venous anastomosis or the stenosis that is
often in the same vicinity, an angled Glidewire (Terumo,
Boston Scientific, Natick, MA, U.S.A.) may be useful. It is
crucial to confirm passage of the wire into the venous
outflow before proceeding. If the venous outflow stenosis
cannot be passed, thrombolysis should not be performed.
If venous outflow is not reestablished and blood flow is
reestablished, bleeding will occur from previous puncture
sites or from around the catheters. If the venous anastomosis cannot be crossed, surgical thrombectomy and revision of the venous anastomosis are the most appropriate
therapy.
When the guidewire can be passed beyond the venous
anastomosis, a catheter is placed into the outflow vein. An
outflow venogram then is performed to evaluate for any
central venous stenosis and the presence of thrombus
within the outflow vein.
The second vascular sheath in the cross-catheter technique is placed by puncturing the graft at the junction of
the middle one third and the distal one third of the graft
(the venous end of the graft). The guidewire is directed
toward the arterial end of the graft. The catheter and wire
manipulations at the arterial end of the graft should be
done gently. Vigorous movement of the wire or forceful
contrast injections can cause embolization of clot from
the arterial anastomosis into the artery (Fig. 36-4).
■ Thrombolysis/Thrombectomy
Thrombolysis
The tissue plasminogen activator (tPA) (Activase, Genentech, South San Fransisco, CA, USA; Retauase, Centoeor,
Malvern, PA, USA) has become the thrombolytic agent of
choice following the recall of Urokinase in 1999.
Several methods to deliver the thrombolytic agent are
available, including endhole, coaxial, and multi-sidehole
catheter infusions and forced intrathrombic injections
(pulse-spray) with use of tip-occluded multi-sidehole and
multislit-type catheters. Prolonged thrombolytic infusion,
FIGURE 36-4. Arterial embolus. A rare complication of hemodialysis declotting is arterial embolization. The embolus to the
bifurcation of the brachial artery (
moved with the use of a Fogarty balloon catheter.
arrow
) was successfully re-
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