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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3627_Библиотеки_им_академика_М_И_Перельмана
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52
https://t.me/med1917
RadCases.thieme.com RadCases Interventional Radiology
■
Imaging Findings
A
(A) Selected image from a noncontrast CT scan. Massive left-sided hydronephrosis is identied. (B) Spot lm obtained during percutaneous nephrostomy
tube insertion. There is an angiographic catheter within the collecting system. The renal pelvis shows signicant dilatation. Note that the calyceal shape
is normal. A stenotic proximal ureter is identied (arrow). (C) Spot lm after successful catheterization of the ureter. Note that the distal ureter is normal.
■ Dierential Diagnosis
• Ureteropelvic junction (UPJ) obstruction: There is
massive dilation of the renal pelvis, the shape of the
calyces is normal, and the distal ureter is normal.
• Obstructive hydronephrosis: There is no identiable
obstruction. The only dilated segment in the collecting
system is the renal pelvis.
• Renal cyst communicating with the collecting system:
These are usually peripheral and connect with a calyx.
■ Essential Facts
• UPJ obstruction is a congenital abnormality that often
presents in adulthood.
• The condition may go unnoticed until a cross-sectional
imaging study is done.
• Classically, the renal pelvis is massively dilated but the
calyces retain their normal shape.
• There are multiple treatment options.
• Robotic surgery and laparoscopy have become quite
popular in the management of this condition.
B C
Pearls and Pitfalls
Look for crossing vessels in axial imaging (accessory
renal artery) because these may be the cause of the
obstruction.
The concept of a crossing vessel as a cause of UPJ
obstruction is debated.
A crossing vessel should be identied because it may
lead to bleeding problems during correction.
Case 27
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A
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■ Clinical Presentation
A 62-year-old woman with end-stage renal disease is referred to interventional radiology for arteriovenous stula declotting.
A stula has never been used.
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■
Imaging Findings
A B
C
(A) Selected image from a stulogram with non-ionic contrast. The inner cannula of a micropuncture sheath was placed within the outow vein under
ultrasound guidance. The image shows severe stenosis at the arteriovenous anastomosis, severe narrowing of the entire outow vein, and reux into
the distal brachial artery. (B) Spot lm during angioplasty of the outow vein using a 0.018-inch, 4-mm balloon. (C) Spot lm from a carbon dioxide
stulogram obtained 2 weeks later, showing a patent outow vein.
■ Dierential Diagnosis
• Nonmaturing arteriovenous (AV) stula: Images show
a brotic, nonmature outow vein with a very small
caliber. There is no identiable thrombus.
• Clotted arteriovenous stula: The stula is nonfunctional,
but there is no thrombus. There is not enough space
within the small brotic vein to harbor a thrombus.
Pearls and Pitfalls
Evaluate the patient carefully; decide if intervention
may oer salvage.
Choose the best access and devices to be used because
these veins are sensitive to trauma.
If patient is not on dialysis at the time of intervention,
use CO
as the contrast agent.
2
Embolization of collaterals is another useful technique
to improve maturation.
■ Essential Facts
• About 30% of patients in the United States start
hemodialysis with an autogenous AV stula.
• An autogenous stula fails to mature in 30 % of
patients.
• The management of a nonmaturing AV stula is
problematic.
• Intervention to assist in AV stula maturation is
successful in 70 to 80% of cases.
Patient may need two to three interventions before the
AV stula is ready to be used.
CO
should be used carefully; there is a possibility of
2
reux of CO
into the central arteries.
2
Non-ionic iodinated contrast should be avoided because
it may precipitate the need for dialysis.
Case 28
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A
■ Clinical Presentation
A 63-year-old man with end-stage renal disease presents with right arm swelling and pain.
B
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RadCases.thieme.com RadCases Interventional Radiology
■
Imaging Findings
A
(A) Selected spot lms obtained during a declot procedure. The angiographic catheter is within the distal brachial artery. Minimal ow into the outow vein
is identied. (B) Selected spot lms obtained during a declot procedure. The angiographic catheter has been retracted into the outow vein. Venogram
shows thrombus within the lumen of the outow vein. (C) Selected spot lms obtained during a declot procedure. Film obtained after successful
declot. Catheter is within the brachial artery. Contrast injection shows a patent distal brachial artery, arteriovenous (AV) anastomosis, and outow vein.
(D) Selected spot lms obtained during a declot procedure. Image shows a late phase of the stulogram demonstrating the central veins. Central veins are
patent. Access to the AV stula to perform the declotting was obtained via the right internal jugular vein (arrow).
■ Dierential Diagnosis
• Thrombosed native arteriovenous (AV) stula: Images
A and B show the stula to be completely thrombosed.
B shows acute thrombus within the lumen of the outow
vein.
• Nonmaturing arteriovenous stula: There is no clinical
information, but this patient had a functional AV stula.
The lumen of the outow vein after declotting is of
functional caliber.
Pearls and Pitfalls
ü Ultrasound evaluation of the entire thrombosed stula
before the procedure is critical. Take 10 to 15 minutes to
scan the stula; identify the AV anastomosis, scan the
outow vein to measure the diameter, and determine
the extent of the thrombus.
ü After stula evaluation, decide the best possible access
for the procedure.
ü Access planning is probably the key to success in AV
stula declot procedures.
B
DC
ü Consider a transjugular access; it is useful for AV stula
■ Essential Facts
declot.
ü If the outow vein is aneurysmal and full of thrombus,
• Declotting of an AV stula can be problematic.
• The technical success rate for declotting procedures is
high, 70 to 95%.
• The only contraindication to AV stula declotting is
stula infection.
it may be better to avoid a declot because it will be
lengthy and likely unsuccessful.
Case 29
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A B
■ Clinical Presentation
A 65-year-old woman presents with a left neck mass.
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RadCases.thieme.com RadCases Interventional Radiology
■
Imaging Findings
A
C D
(A) Selected axial image from a contrast-enhanced CT scan of the neck showing a large, hypervascular soft tissue mass that displaces the internal and
external carotid arteries. (B) Selected image from a nonselective digital subtraction angiographic (DSA) arch arteriogram. The left hypervascular mass is
clearly demonstrated. No signs of vessel encasement are identied. (C) Selected image during a selective DSA arteriogram of the ascending pharyngeal
artery during embolization. (D) Selective left carotid arteriogram after embolization. There is signicant reduction of the hypervascular appearance of
the mass.
■ Dierential Diagnosis
• Paraganglioma: This is a soft tissue mass arising at
the carotid bifurcation. It displaces the vessels but does
not encase them. These are characteristic features of
paragangliomas.
• Parotid mass: The site corresponds, but the parotids are
normal in this case.
• Lymph nodes: Lymphadenopathy usually presents with
multiple masses.
Pearls and Pitfalls
ü Superselective embolization before surgery is
sometimes performed to decrease the risk of bleeding
during removal. This is not standard practice and its
utility is controversial.
ü The ascending pharyngeal artery has a characteristic
hook appearance (see Image C) and supplies most of the
blood ow to these tumors.
ü Preoperative embolization is usually performed
24 hours before surgery.
B
ü In some cases, the vascularity to these tumors is not
■ Essential Facts
• Carotid paragangliomas (chemodectoma, carotid body
tumor) are rare tumors.
• They represent 0.03% of all neoplasms.
• These tumors are more frequent in women and are
usually unilateral.
straightforward, and presurgical embolization is not
possible.
ü Risk of damage to the internal carotid artery during
embolization (dissection, stroke) has been described.
Case 30
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■ Clinical Presentation
A young man presents with left arm pain and swelling.
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RadCases.thieme.com RadCases Interventional Radiology
■
Imaging Findings
The brachial nerve is a well-dened structure anterior to the venous structures and anterior and lateral to the brachial artery (arrow).
■ Dierential Diagnosis
• Normal brachial nerve: It is important to know and
recognize a nerve by ultrasound, especially in the lower
extremities because these can be confused with small
thrombosed veins. Nerves are not compressible.
• Thrombosed brachial vein: This is the most important
dierential. The operator must know the structure and
follow it so it can be distinguished. In this case, two
normal venous structures are shown.
■ Essential Facts
• Identication of nerves by ultrasound is essential.
• These structures can be confused with thrombosed veins.
Pearls and Pitfalls
ü You should be alert to the presence of nerves in close
vicinity to normal veins.
ü Knowledge of nerve anatomy is crucial to perform
therapeutic nerve blocks.
ü Avoid these structures during peripherally inserted
central catheter (PICC line) insertion.
ü Vascular access through a nerve or in close vicinity to it
will cause severe arm pain.
ü Nerves can be mistaken for thrombosed veins. This is
particularly important in lower extremities. The patient
may be started on anticoagulants after a false diagnosis
of venous thrombosis.
Case 31
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A B
■ Clinical Presentation
An 82-year-old woman presents to the emergency department 4 days after a cardiac catheterization. The patient was on
apixaban for atrial brillation and restarted her medication 2 days after the cardiac catheterization.
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■ Further Work-up
C D
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