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338 Vascular Surgery
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The patient was investigated at her primary healthcare centre with gastroscopy
and colon enema, with negative results. After 2 months, she had melaena again;
after further melaena 3 months later, she was referred to the hospital. On this occasion, she also had slight back pain and low-grade fewer.
Question 2
What is meant by herald bleeding?
A. Bleeding where the aetiology cannot be determined.
B. Small bleeding(s) before a large one from a major artery.
C. A “warning” bleeding before a fatal one.
D. A small haematemesis before melaena.
A gastroscopy showed a very distal duodenal “ulcer” with a green-coloured (bilestained) graft in the bottom (Fig. 37.1). A computed tomography (CT) scan showed
fluid around the proximal part of the graft, with some gas bubbles.
Question 3
How will you rule out the presence of an aortoenteric fistula?
A. Gastroscopy.
B. Computed tomography.
C. Magnetic resonance imaging.
D. Barium enema and or barium swallow and follow-through.
E. None of the above.
Fig. 37.1. Gastroduodenoscopy showing the Dacron graft in the bottom of an ulceration, the graft being bile
stained.
Aortoenteric Fistulas 339
Question 4
Which part of the bowel is involved in an aortoenteric fistula?
A. Duodenum.
B. Jejunum.
C. Ileum.
D. Appendix.
E. Any of the above could be involved.
Following a diagnosis of secondary aortoenteric fistula, and with the patient
being circulatory stable, an axillo-bifemoral Dacron graft was inserted. During the
same period of anaesthesia, the old aortic graft was extirpated. A duodenorrhaphy
was made, and the aortic stump, which was about 2 cm below the renal arteries, was
sutured and covered with omental tissue.
Question 5
Which treatment options are not to be recommended?
A. Stent grafting the anastomosis.
B. Wait and see if the patient starts bleeding again.
C. Extirpation of the aortic graft and then an axillofemoral reconstruction.
D. Axillofemoral reconstruction and then extirpation of the aortic graft.
E. In situ reconstruction with a new graft.
The patient recovered and she left hospital after 12 days. After 10 months, she
had melaena again and was admitted to hospital. Based on her previous history, a
CT scan was ordered, but she suddenly developed abdominal and back pain, large
gastrointestinal bleeding – both haematemesis and melaena – and went into shock.
She died before any treatment could be given. Autopsy showed a blow-out of the
aortic stump with a fistula to the duodenum and also bleeding into the retroperitoneal space.
Commentary
The term “aortoenteric fistula” means a communication between the aorta and
some part of the gastrointestinal tract. It is rarely primary; most often, it is seen secondary to reconstructive vascular surgery, that is, secondary aortoenteric fistula. In
the majority of cases, it is seen after aortic graft insertion. It has also been reported
after stent-grafting [1] and after simple aortic suture [2]. The majority (about 75 per
cent) of fistulas involve the duodenum, but any part of the gastrointestinal tract
may be involved. [Q4: E] A few patients have more than one fistula. In exceptional
340 Vascular Surgery
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cases, it can occur after other abdominal operations or radiation treatment. It is an
emergency situation and should always be suspected in patients with an aortic
reconstruction presenting with gastrointestinal bleeding. It can occur at any time
postoperatively, which means that the patient with an aortic graft is at risk for their
entire lifetime of developing a fistula. Thus, the true incidence of this condition
cannot be established until all patients in a risk population have died. The longest
interval reported is 18 years. Often, there is a delay of several years. [Q1: D] During a
period of 21 years in Sweden, there are indications that the incidence has decreased
to around 0.5 per cent after abdominal aortic operations [3].
Two factors have been considered to be of major aetiological importance:
mechanical stress from the pulsating graft, which is in continuous contact with
the intestine, and the presence of a low-grade infection. In patients with an aortoenteric fistula, there is often a history of complicated and troublesome
primary graft operation or infectious complications in the postoperative course.
The three most common findings at surgery are suture line contact with the
bowel, pseudoaneurysm rupturing into the intestine, and graft body erosion of
the intestine. To avoid complications, atraumatic surgical technique is important, avoiding bowel trauma and large haematomas. The surgeon should always
try to cover the graft to avoid direct contact between the graft and the bowel.
The main symptom is gastrointestinal haemorrhage, which can range from mild
melaena with anaemia to a profuse, immediately fatal haematemesis. Often, this
massive bleeding is preceded by small herald bleedings, which are an important
warning symptom. [Q2: C] About half of the patients also have septic symptoms of
varying severity. In some patients, septic symptoms dominate, and the bleeding
may even be occult.
There is often a long delay between onset of the symptoms and final diagnosis. In
some patients with a large initial bleeding, the diagnosis is established at autopsy.
The cardinal importance of a high degree of clinical suspicion for obtaining a
correct diagnosis must be emphasised. Unfortunately, there is no specific diagnostic
test. At gastroduodenoscopy, it is important to scrutinise the whole duodenum
down to the ligament of Treitz. Observation of a bile-stained graft is obviously
pathognomonic. Endoscopy is also important to reveal other sources of bleeding.
CT, magnetic resonance and angiography may be helpful in showing pseudoaneurysm or fluid outside the graft, sometimes with gas in it. Conventional radiological methods for gastrointestinal examination are rarely helpful. One great problem
is that the absence of abnormalities does not exclude the diagnosis. Exploratory
laparotomy is indicated in patients with massive bleeding or where diagnostic
efforts have been negative and the patient is still bleeding. [Q3: E]
The management is difficult. Total removal of all old graft material and revascularisation seems to give the best results [4]. Just closing the fistula locally always
leads to recurrence and the mortality is close to 100 per cent and cannot be recommended [5]. It seems optimal to start with an extra-anatomical revascularisation of
the extremities and thereafter removal of the graft. Some authors recommend a
delay of a few days between the two procedures [6]; this is possible when the haemorrhage is under control. In emergency situations, an abdominal exploration with
closure of the fistula and graft removal is vital, but this may lead to delayed revascularisation with profound limb ischaemia. When the graft is removed, the problem is
how to deal with the aortic stump, which must be closed, preferably with double
sutures. This may, however, not be possible if the distance to the renal arteries is too
short. The stump is preferably covered with some vascularised tissue, and most fre-
Aortoenteric Fistulas 341
Table 37.1. Surgical treatment options for aortoenteric fistula
Extra-anatomic bypass with resection of the infected prosthesis
Staged
Simultaneous
Resection with in situ reconstruction
Antibiotic (rifampicin)-soaked graft with omental wrap
Homograft
Autologous vein
quently an omental pedicle has been used. Some authors advocate removal of the
graft and an in situ reconstruction with expanded polytetrafluoroethylene (ePTFE)
graft or an antibiotic-bonded Dacron graft (often with rifampicin) [7, 8] or in situ
autologous vein [2, 9] Table 37.1 summarises the treatment options for the surgical
management of aortoenteric fistula. [Q5: B]
The prognosis is poor, with a high postoperative mortality, often several complications should the patient survive, and a risk of aortic stump blow-out, which very
few patients survive. Results have improved over recent years, but aortoenteric
fistula is still a very serious and challenging complication. The 5-year survival rate is
50–60 per cent [3, 7].
References
1. Norgren L, Jernby B, Engellau L. Aortoenteric fistula caused by a ruptured stent-graft: a case report. J
Endovasc Surg 1998;5:269–72.
2. Moore RD, Tittley JG. Laparoscopic aortic injury leading to delayed aortoenteric fistula: an alternative
technique for repair. Ann Vasc Surg 1999;13:586–9.
3. Bergqvist D, Björkman H, Bolin T, Dalman P, Elfström J, Forsberg O. Secondary aortoenteric fistulae –
changes from 1973 to 1993. Eur J Vasc Endovasc Surg 1996;11:425–8.
4. Nagy SW, Marshall JB. Aortoenteric fistulas. Recognizing a potentially catastrophic cause of gastroin-
testinal bleeding. Postgrad Med 1993;93:211–12, 215–16, 219–22.
5. Müller BT, Abbara S, Hennes N, Sandmann W. Diagnosis and therapy of second aortoenteric fistulas:
results of 16 patients. Chirurg 1999;70:415–21.
6. Geroulakos G, Lumley JS, Wright JG. Factors influencing the long-term results of abdominal aortic
aneurysm repair. Eur J Vasc Endovasc Surg 1997;13:3–8.
7. Hayes PD, Nasim A, London NJ, Sayers RD, Barrie WW, Bell PR, Naylor AR. In situ replacement of
infected aortic grafts with rifampicin-bonded prostheses: the Leicester experience (1992 to 1998). J
Vasc Surg 1999;30:92–8.
8. Young RM, Chery KJ, Jr, David PM, Gloviczki P, Bower TC, Panneton JM, Hallet JW, Jr. The results of
in situ prosthetic replacement for infected aortic grafts. Am J Surg 1999;178:136–40.
9. Franke S, Voit R. The superficial femoral vein as arterial substitute in infections of the aortoiliac
region. Ann Vasc Surg 1997;11:406–12.
38. The Optimal Conduit for Hemodialysis
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Access
Frank T. Padberg Jr, Robert W. Zickler and
Joseph M. Caruso
A 42-year-old type 1 diabetic of normal weight has recently progressed to chronic
renal disease. Insulin-dependent diabetes mellitus (DM) has been managed by
the same primary care physician for the preceding 12 years; glucose control has
never been a problem in this cooperative and well-educated individual. The renal
failure was initially managed with appropriate adjustments to diet and medications; the presumptive diagnosis is diabetic nephropathy. Recent laboratory tests
demonstrate a creatinine of 4.1, a blood urea nitrogen of 94, a potassium of 4.8,
mild proteinuria, and a creatinine clearance of 20 ml/min.
Question 1
At this juncture the physician’s most appropriate course of action is:
A. Refer the individual to a surgeon for hemoaccess.
B. Refer the individual to a nephrologist to refine diagnosis and initiate specialty
care. It is not time to initiate dialysis.
C. Refer the individual to a nephrologist who will refine diagnosis, and determine if
there is a reversible cause for the renal insufficiency.
D. Refer the individual to a nephrologist who will evaluate the etiology of the renal
insufficiency and determine if there is a reversible cause. If not, a surgeon
skilled in the construction of durable hemoaccess should be consulted.
E. Refer the individual to a nephrologist to commence dialysis with a central
venous catheter.
Question 2
A nephrology work-up finds no reversible cause and the patient’s immune status
precludes any further consideration of transplantation. The patient is referred for
345
346 Vascular Surgery
construction of a hemoaccess. The most appropriate action is to perform a clinical
vascular examination with specific attention to:
A. The pedal pulses and examination of the foot; extensive arterial occlusive
disease is common in diabetic patients and infection would complicate any
hemoaccess procedure.
B. The radial pulses and superficial venous anatomy. Book the operating room and
proceed to construct an access in the upper extremity, guided by your clinical
examination.
C. The radial pulses and superficial venous anatomy supplemented by a duplex
ultrasound (DU) study. Book the operating room and proceed to construct an
access in the upper extremity guided by these findings.
D. Immediate hemoaccess placement. Simultaneous placement of an arteriovenous
fistula and a central venous catheter.
Question 3
Preoperative duplex ultrasound examination should include all except one of the
following:
A. Both upper extremities.
B. Size and location of the arteries.
C. Location of the brachial bifurcation.
D. Assessment of the axillary and subclavian veins.
E. At least one lower extremity.
F. Size and location of the superficial veins.
G. Evaluation of the superficial veins for evidence of prior scarring.
The patient is right hand dominant. Non-invasive examination demonstrated the
findings given in the caption to Fig. 38.1.
Question 4
Which procedure would be the best option for this individual?
A. Left brachial to basilic transposition arteriovenous fistula in the arm.
B. Right radial to basilic transposition arteriovenous fistula in the forearm.
C. Left brachial to median antecubital vein forearm loop graft (PTFE).
D. Left internal jugular tunneled, cuffed dual lumen hemodialysis catheter.
E. Left radial to cephalic arteriovenous fistula.
The Optimal Conduit for Hemodialysis Access 347
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Fig. 38.1.
following findings.
Right:
upper arm to their junctions with the axillary and brachial veins respectively; however, both superficial forearm
veins demonstrate post-thrombotic changes in the forearm. The brachial artery (diameter 4.2 mm) bifurcates
into a radial (diameter 2.8 mm) and ulnar (diameter 2.7 mm) artery 3 cm below the antecubital crease; the
palmar arches are intact. The deep venous structures are normal from the forearm veins through visualization of
the axillary and subclavian veins.
Left:
just below the elbow continuing into its junction with the brachial vein at mid-humerus. The cephalic vein
(diameter 3.5 mm) has a normal luminal surface, is superficial, communicates with the proximal basilic at the
antecubital junction, and remains patent into its junction with the axillary vein. The brachial artery (diameter 4.2
mm) bifurcates into a radial (diameter 2.8 mm) and ulnar (diameter 2.7 mm) artery at mid-humerus; the palmar
arches are intact. The deep venous structures are normal from the forearm veins through visualization of the
axillary and subclavian veins.
Duplex ultrasound: The patient is right hand dominant. Non-invasive examination demonstrated the
Cephalic (diameter 3.3 mm) and basilic (diameter 3.5 mm) veins course through both the forearm and
The basilic vein is post-thrombotic and thickened in the forearm; it has a normal 3.5-mm diameter lumen
348 Vascular Surgery
Question 5
Which of the following best describes when this new hemoaccess is considered
mature enough to begin puncture for hemodialysis?
A. The wound is securely healed, the sutures have been removed, and there is a pal-
pable thrill.
B. The wound is securely healed, the sutures have been removed, and there is a pal-
pable thrill. At 2 weeks, a duplex examination demonstrates unobstructed flow,
but the walls of the conduit appear to be relatively thin.
C. The wound is securely healed, the sutures have been removed, and there is a pal-
pable thrill. At 8 weeks, a duplex examination demonstrated that there was
unobstructed flow and the walls of the conduit have thickened measurably.
D. The wound is securely healed, the sutures have been removed, and there is a pal-
pable thrill. At 6 weeks, a duplex examination demonstrates an equal volume of
flow through both the fistula vein and a large branch vein at the site of the thrill.
E. Two weeks.
Your initial hemoaccess has functioned well for 6.4 years, but the hemodialysis
staff has noted increasing difficulty obtaining adequate flows for the external
machine circuit; arterial pressures were low at 70 mm Hg and venous pressures elevated to 350 mm Hg. You are asked to consider revision or a new hemoaccess.
A new duplex examination demonstrates progressive stenosis of the distal radial
artery, and multiple sites of localized thrombosis extending into the upper arm
cephalic vein. With the exception of the appropriate postoperative changes, the
remainder of the examination is unchanged from that described in Fig. 38.1.
Question 6
Which is the best option to maintain hemodialysis?
A. Right radial to basilic transposition arteriovenous fistula in the forearm.
B. Right forearm loop graft (PTFE).
C. Left forearm loop graft (PTFE).
D. Left radial (antecubital) to basilic transposition arteriovenous fistula in the arm.
E. Left internal jugular tunneled, cuffed dual lumen hemodialysis catheter.
A new hemoaccess is constructed and an excellent thrill achieved. During initial
maturation, hemodialysis is continued via the original left arm hemoaccess.
Fortunately, the original left hemoaccess provides sufficient flow for adequate interval hemodialysis, but 6 weeks later has spontaneously thrombosed. Dialysis using
the new hemoaccess is successful and the hemoaccess functions well for thrice
weekly puncture.
Two years later you are again contacted to evaluate this individual. One year previously, an uneventful coronary bypass was performed. Subsequently, following an
The Optimal Conduit for Hemodialysis Access 349
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Fig. 38.2.
The chest X-ray was taken at the time of the referral for arm edema.
episode of syncope, and tachyarrhythmia, a permanent defibrillator was installed on
the left anterior chest wall 2 months ago (Fig. 38.2).
The patient is complaining of an obviously swollen left arm.
Question 7
What is wrong?
A. The patient’s heart failure has worsened from a combination of a fixed heart rate
and the increased output demanded for the hemoaccess.
B. Edema is a result of lymphatic disturbance from defibrillator implantation.
C. The patient is hypercoagulable and has thrombosis of the superior vena cava
(SVC).
D. Unilateral swelling results from continuously increasing flow in the hemoaccess
and enlargement of the arterial anastomosis.
E. The transvenous electrodes have induced a stenosis or obstruction of the left
subclavian vein.
Question 8
The best treatment for this condition is?
A. Begin strong diuresis to counter the right heart failure.
B. Place the arm in a sling and elevate it to reduce the existing edema from the
operation. The patient is reassured that edema following pacemaker insertion of
these devices is usually self-limited and will soon resolve.
350 Vascular Surgery
C. The defibrillator is removed and replaced in the right subclavian vein.
D. A fistulagram/venogram is performed. This will determine the etiology of the
edema and may offer an opportunity for interventional therapy.
E. A hypercoagulable work-up is obtained.
All of the interventions aimed at reducing the left arm edema are unsuccessful,
and the patient is discharged home. After multiple attempts, the dialysis staff reluctantly admit they are no longer able to reliably cannulate the left arm arteriovenous
fistula (AVF). You are again asked to consider revision or a new hemoaccess.
A new duplex ultrasound is obtained. The appropriate postoperative findings are
noted; otherwise, the relevant arm anatomy is unchanged from the initial survey as
shown in Fig. 38.1.
Question 9
The optimal hemoaccess for this individual now is:
A. Right forearm loop graft (PTFE). Ligation of left hemoaccess.
B. Left internal jugular tunneled, cuffed dual lumen hemodialysis catheter.
Ligation of left hemoaccess.
C. Right internal jugular tunneled, cuffed dual lumen hemodialysis catheter.
Ligation of left hemoaccess.
D. Left femoral to femoral loop graft (PTFE). Ligation of left hemoaccess.
E. Left femoral tunneled, cuffed dual lumen hemodialysis catheter.
F. Right brachial-cephalic transposition.
The left arm symptoms resolve, and the new access functions well for 2.6 additional years. However, dilation begins to appear in two sites most commonly used
for the tri-weekly puncture for hemodialysis. Duplex examination of the larger discerns the presence of a large pseudoaneurysm with a 0.6-mm neck communicating
with the lumen of hemoaccess. The individual reports several recent episodes of
prolonged difficulty achieving hemostasis after removal of the access needles.
During duplex interrogation, a thrombotic plug is dislodged. Pulsatile bleeding
ensues, which is controlled with 30–45 minutes of direct compression.
Question 10
The best treatment option at this time is:
A. Ligation of the hemoaccess.
B. Revision by primary closure of the pseudoaneurysm.
C. Revision with placement of an interposition, prosthetic segment.
D. Removal of the hemoaccess.
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