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294
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M. E. Rackson
Providing access for stone removal
before PNL
Renal calculus disease requires the most specific approach to PCN. The particular calyx that must be punctured varies with the size, location, and number of stones;
more than one tract may be necessary. It is of paramount
importance to discuss the case with the referring urologist
to agree on the optimum approach as well as a backup
plan. After the system has been accessed and the tract is
dilated to 28 to 32 Fr, the urologist will insert a large-bore
rigid working sheath into the tract. An endoscope will be
placed through this sheath to visualize and extract the
stones. If the angle between the endoscope and the stones
is too acute or the tract is too long, the likely outcome is
hours of operative frustration and an unsuccessful stone
retrieval. Complications such as parenchymal damage
due to overtorquing the kidney or renal pelvic lacerations
and bleeding are also possible.
The other issue to decide at the initial consultation
with the referring urologist is whether the urologist
should place a retrograde ureteral occlusion balloon
prior to PCN. This balloon can be used to distend the
renal pelvis and calyces, facilitating PCN manipulations
in nonobstructed systems or collecting systems with a
large stone burden. Of course, this step entails an additional procedure for the patient.
After the collecting system is accessed, a catheter
should be manipulated down the ureter and into the
bladder to ensure that access to the collecting system will
not be lost during manipulations involving tract dilation,
sheath, or endoscope insertion. Either a 5 Fr catheter
that accepts a 0.038-inch guidewire can be placed into the
bladder with an 8 Fr PCN left alongside it for drainage,
or a nephroureteral stent can be inserted. If the radiologist performs the tract dilation, preferably with a balloon
catheter rather than serial dilators, a 28 Fr Foley is left in
the collecting system and the patient is transferred to the
operating room. In some institutions, the entire procedure, including stone extraction, is performed in the
interventional suite, although to do so is usually impractical because the second stage of the procedure ties up
the suite for several hours and most interventional suites
do not have the proper drainage systems to deal with the
large amount of irrigation fluid used in nephrolithotomy
procedures.
Access sites for various stones
Pelvic and posterior lower/midpole calculi are the simplest stones to access because the puncture is through a
posterior or midpole calyx. For a pelvic stone, the puncture can be through any calyx that provides a good path to
the stone. For a posterior or midpole calyx, direct puncture into the stone-bearing calyx should be performed.
The complex cases are those where staghorn calculi,
7,24–26
27
upper pole calculi, anterior calculi, or multiple calculi are
present. Staghorn calculi are difficult because there may
be branches into multiple calyces, which are difficult for
the urologist to access from one puncture site. The largest stone containing posterior lower pole calyx should be
punctured. Residual fragments may require a second
puncture or a “Y” tract from the first puncture.
Upper pole stones are likely to be located above the
costal margin, increasing the chances of pneumothorax
or liver or spleen puncture with a puncture above the
12th rib. If no infundibular stenosis is present and the
stone is small, a posterior lower pole calyx can be punctured and a flexible endoscope can be directed upward
into the calyx. If the stone is large or there is an infundibular stenosis, a direct puncture into the upper pole
calyx will be necessary.
Anterior calyceal stones, multiple calculi, and other
complex situations require careful analysis and will be
challenging even to experienced operators. Puncture
into a posterior upper pole calyx generally provides access into all calyceal stone sites. Many other approaches
are possible, however, and the access site must be tailored
to the individual situation. The reader is referred to an
advanced text for additional reading on this subject.
28
■ Troubleshooting
Most problems with nephrostomy tubes ultimately require a tube change in the department and cannot be
resolved at the bedside or over the telephone. The most
common problems are occlusion of the tube, which requires a tube change, and inadvertent removal or dislodgement of the tube, which requires that the tube be
reinserted or repositioned. At the least, the tube needs
to be evaluated by a contrast nephrostogram or “tube
check.” The following are commonly encountered problems.
• The PCN tube is not draining: The tube is either
occluded or dislodged. The tubes are made of kinkresistant material; so external kinking of the tube
occurs infrequently. The tube may not even be a
PCN but is an NU tube that is draining the urine
antegrade (see next item).
• The NU tube is not draining: The tube is either
occluded or the urine is draining antegrade into the
bladder. If the tube check demonstrates that the
tube is patent and the patient is urinating without
difficulty, then the external portion of the tube can
be capped off because the external drainage bag is
unnecessary.
• The NU tube is draining externally, but the patient
is not urinating: Either the internal ureteral portion
of the stent is occluded while the PCN external por-
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295
tion is patent, or there is a bladder outlet obstruction
with reflux or urine from the bladder up and out of
the external portion of the tube. This situation could
apply to a patient who has either one or two NU
tubes. The tube also could be dislodged, but this is
less likely to happen because long NU tubes are
anchored more firmly than short PCN tubes.
• Urine is leaking around the tube: The tube is either
occluded or dislodged, and urine is leaking alongside the tube through the tract to soak the dressing
or clothing. The external portion of the tube also
could be cracked or punctured. In this situation, the
skin around the tube should be dry. Another possibility is that the pigtail retention suture on the Meditech tube was not cut short enough, thereby exiting
the hub of the tube and getting caught in the Luer
lock between the PCN tube and the connecting tube
to the drainage bag, which will cause a urine leak.
• The tube is completely or partially dislodged: If the
tube is partially dislodged, injecting the tube usually
will opacify the tract and the collecting system. The
tube should be removed carefully over a guidewire
and replaced with a 5 Fr catheter. Further contrast
injections should opacify the tract. Then the catheter can be advanced back into the collecting system
over a floppy-tipped guidewire (Bentson) or a hydrophilic guidewire (Glidewire) and the tube replaced. If the tube has been removed completely, the
chance of reinserting it through the same tract is
best if urine is still leaking out of the tract. Local
anesthesia should not be administered because to do
so will cause the soft tissue to swell and compress the
tract. The key to recannulating the tract is to opacify
it with a contrast injection at the dermatotomy site
through a vessel dilator, short directional catheter, or
Christmas tree adapter, followed by advancement of
the catheter over a guidewire back into the collecting system. Failure will necessitate a new puncture,
which may convert an outpatient to an inpatient or
at least require a longer period of observation before
discharge.
• Bloody drainage is extremely common. Even a singlestick atraumatic nephrostomy procedure can cause
pink urine, which usually clears within hours. Grossly
bloody urine often is seen after procedures requiring
multiple punctures. If blood pulses out of the tract
while the tract is being dilated, a large catheter should
be inserted to tamponade the tract. The blood generally clears in a few days, particularly with repeated
flushing of the tube to ensure that it does not clot. If
the urine fails to clear or the hematocrit drops, the
tube should be exchanged for a larger tube to tamponade the tract. Larger tubes usually control the
bleeding, although sometimes a segmental renal artery needs to be embolized.
29,30
■ Outpatients
We routinely perform the following procedures on outpatients: PCN and NU tube changes and conversion of PCN
to NU or double J stents. We also schedule initial PCN
procedures on selected outpatients with the provision
that the patient will be admitted if a complication occurs
or if the patient is too drowsy to go home.
31
Routine tube changes can be performed every 3
months. The patient should be encouraged to drink a lot
of fluids to dilute the urine, which will help prevent tube
occlusion by urine sediment. Most nephrostomy tubes do
not need to be flushed routinely.
All outpatients should have the phone number and
names of the physicians and nurses in the interventional
radiology department where the tube was placed. They
should be encouraged to call if they experience any signs
of blockage of the tube or infection such as fever, chills,
flank pain, or leakage around the tube. Patients with
capped tubes should reattach them to external drainage
bags until they arrive in the department for a tube
change and possible antibiotic therapy.
Patients with skin infections around the tube also
should contact the department. Many skin infections will
resolve within 48 hr with increased home care. Those that
do not resolve will need formal evaluation and possible
antibiotic therapy.
32,33
REFERENCES
1. Lang EK, Price ET. Redefinitions of indications for percutaneous
nephrostomy. Radiology 1983;147:419–426.
2. Barbaric ZL. Percutaneous nephrostomy for urinar y tract obstruction. AJR, Am J Roentgenol 1984;143:803–809.
3. Reznek RK, Talner LB. Percutaneous nephrostomy. Radiol Clin
North Am 1984;22:393–406.
4. Keidan RD, Greenberg RE, Hoffman JP, et al. Is PCN for hydronephrosis appropriate in patients with advanced cancer? Am J Surg
1988;156:206–208.
5. Watkinson AF, A’Hern RP, Jones A, et al. Role of percutaneous
nephrostomy in malignant urinary tract obstruction. Clin Radiol
1993;47:32–35.
6. Yoder IC, Lindfors KK, Pfister RC. Diagnosis and treatment of
pyonephrosis. Radiol Clin North Am 1984;2:407–414.
7. Castaneda-Zuniga WR, Clayman R, Smith A, et al. Nephrostolithotomy: percutaneous technique for urinary calculus removal. AJR
Am J Roentgenol 1982;139:721–726.
8. Matalon TAS, Thompson MJ, Patel SK, et al. Percutaneous treatment of urine leaks in renal transplantation patients. Radiology
1990;174:1049–1051.
9. Bell DA, Rose SC, Starr NK, et al. Percutaneous nephrostomy for
nonoperative management of fungal urinary tract infections. J Vasc
Interv Radiol 1993;4:311–315.
10. Whitaker RH, Chir M. The Whitaker test. Urol Clin North Am
1979;6:529–539.
11. Naidich JB, Rackson ME, Mossey RT, et al. Non-dilated obstructive
uropathy: percutaneous nephrostomy performed for severe renal
failure. Radiology 1986;160:653–657.
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12. Lee WJ, Patel V, Patel S, et al. Emergency PCN: results and complications. J Vasc Interv Radiol 1994;5:135–139.
13. Babel SG, Winterkorn KG. Retrograde catheterization of the ureter
without cystoscopic assistance. Radiology 1993;187:547–549.
14. Clayman RV. Nephrolithotomy (nephrostolithotomy): concepts
and rationale. Semin Intervent Radiol 1984;1:75–78.
15. Dunnick NR, Carson CC III, Moore AV, et al. Percutaneous approach to nephrolithiasis. AJR Am J Roentgenol 1985;144:451–455.
16. Stables DP. Percutaneous nephrostomy: techniques, indications,
and results. Urol Clin North Am 1982;9:15–29.
17. Papanicolaou N. Renal anatomy relevant to percutaneous interventions. Semin Intervent Radiol 1995;12:163–172.
18. Lang EK. Percutaneous management of ureteral strictures. Semin
Interv Radiol 1987;4:79–89.
19. Cardella JF, Castaneda-Zuniga WR, Hunter DW. Long term ureteral
stenting: techniques and effectiveness. Radiology 1986;161:313–318.
20. Salzman B. Ureteral stents: indications, variations and complications. Urol Clin North Am 1988;15:481–491.
21. Rackson ME, Mitty HA, Dan SJ, et al. Elevated bladder pressure: a
cause of apparent ureteral stent failure. AJR Am J Roentgenol
1988;151:335–336.
22. de Baerre T, Denys A, Pappas P, et al. Ureteral stents: exchange
under fluoroscopic control as an effective alternative to cystoscopy.
Radiology 1994;190;887–889.
23. Mitty HA, Train JS, Dan SJ. Placement of ureteral stents by antegrade and retrograde techniques. Radiol Clin North Am 1986;24:
587–600.
24. Lee WJ, Smith AD, Cubelli V, et al. Percutaneous nephrolithotomy:
analysis of 500 consecutive cases. Urol Radiol 1986;8:61–66.
25. LeRoy AJ, May GR, Bender CE, et al. Percutaneous nephrostomy
for stone removal. Radiology 1984;151:607–612.
26. Clayman RV, Surya V, Miller RP, et al. Percutaneous nephrolithotomy: extraction of renal and ureteral calculi from 100 patients.
J Urol 1984;131:868–871.
27. Bjarnason H, Ferral H, Stackhouse DJ, et al. Complications related
to percutaneous nephrolithotomy. Semin Interv Radiol 1994;11:
213–225.
28. Castaneda-Zuniga WR, Tadavarthy SM, Hunter DW, et al. Interventional uroradiology. In: Castaneda-Zuniga WR, Tadavarthy SM, eds.
Interventional radiology, 2nd ed, vol 2. Baltimore: Williams & Wilkins,
1992:777–989.
29. Ferral H, Stackhaus DJ, Bjarnason H, et al. Complications of percutaneous nephrostomy tube placement. Semin Interv Radiol 1994;
11:198–206.
30. Cope C. Zeit RM. Pseudoaneurvsms after nephrostomy. AJR Am J
Roentgenol 1982;139:255–261.
31. Cochran ST, Barbaric ZL, Lee JJ, et al. Percutaneous nephrostomy
tube placement: an outpatient procedure? Radiology 1991:179:
843–847.
32. Cronan JJ, Horn DL, Marcello A, et al. Antibiotics and nephrostomy
tube care: preliminary observations. Part II. Bacteriuria. Radiology
1989;172:1043–1045.
33. Nephrostomy catheter care. Informational pamphlet for patients distributed by SCVIR, Fairfax, VA, 1992.
A.KerrPelvic and Obstetric Hemorrh age
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25
Pelvic and Obstetric Hemorrhage
ANDREW KERR
Life-threatening pelvic hemorrhage may result from
blunt or penetrating trauma, pregnancy, malignancy, or
arterial venous malformation. The pelvis is supplied by
an extensive network of collateral vessels. Consequently,
surgical ligation of the hypogastric artery origins has
minimal effect on bleeding. Operative exposure and ligation of the bleeding distal hypogastric artery branches
are a technical nightmare.
toneum to find the hypogastric artery origins at laparotomy often exacerbates bleeding by removing compression of the bleeding site provided by adjacent anatomic
structures. Because of technical difficulties posed by the
surgical approach, angiographic embolization is the
treatment of choice for pelvic arterial hemorrhage. Embolic materials released into the internal iliac artery are
carried by the bloodstream to occlude the artery beyond
the larger collaterals. The arterial pressure at the
bleeding site then decreases sufficiently to permit hemostasis.
■ Trauma
1
Dissection of the retroperi-
Approach to the patient with pelvic fractures
and shock: Stop the bleeding!
The patient with life-threatening pelvic hemorrhage may
be in florid shock or may not appear to be seriously
injured at all when he or she is brought to the emergency department. Sometimes, flank and buttock hematomas are present. Displaced pelvic fractures may cause
obvious leg-length discrepancies,
visible. Blood pressure may be normal; baseline blood
2
or no injuries may be
pressure varies from individual to individual. An adult
can lose 30% of the blood volume acutely before systolic
pressure begins to drop (although it then drops rapidly).
Initially, the hematocrit is likely to be normal because it
takes hours of equilibration with extravascular fluids before the serum hematocrit reflects an acute blood loss.
Initially, the only abnormalities that may be observed are
tachycardia (pulse ⬎ 100/min), tachypnea, coolness of
the skin caused by peripheral vasoconstriction, a narrowed pulse pressure (actually an elevated diastolic pressure caused by catecholamine release), and low urine
output. If the trauma patient has signs of shock after
intravenous infusion of 2 L of fluid, it is most likely the
consequence of active internal bleeding.
mortality from pelvic fractures is 6 to 19%, and half of
these deaths are from hemorrhage and the others from
associated injuries. If tachycardia is attributed to pain
from pelvic fractures, the diagnosis of shock may not be
made until systolic blood pressure falls. The mortality
rate rises to 50% when hypotension is present.
tensive patients are treated with large volumes of intravenous crystalloid solution and packed red blood cells.
If platelets and plasma are not infused as well, a dilutional coagulopathy develops. If the intravenous solutions are not warmed, the patient may become hypothermic. Hypothermia interferes with normal coagulation.
Consequently, fluid resuscitation for hypotension may
worsen the bleeding. Patients who are hypotensive for
prolonged periods often develop multiple organ-system
failure and sepsis.
site of bleeding and to stop it before the patient’s condition deteriorates.
The trauma patient with active hemorrhage usually
6
Therefore, it is essential to find the
3
The overall
4
Hypo-
5
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A. Kerr
arrives in the emergency department with little clinical
history but with many injuries. Complete evaluation of
the patient requires numerous diagnostic tests. If the
patient is to be saved, the sequence of tests must be
prioritized so that potentially lethal injuries are addressed first and less dangerous (although frequently
more obvious) injuries are evaluated later. The workup
must proceed rapidly despite the fact that the patient
may be hemodynamically unstable. Resuscitation and
evaluation must take place simultaneously. Suspending
the workup so that the patient can be “tuned-up” first
will delay the time when a surgical or interventional procedure can be performed to stop the bleeding. Often, it
is necessary to institute therapeutic procedures based on
a probable diagnosis before a complete clinical picture is
available.
7,8
Diagnostic peritoneal lavage
The pelvic fracture patient with a patent airway in whom
hemothorax, pneumothorax, cardiac contusion, and
pericardial tamponade have been ruled out who shows
signs of shock after vigorous intravenous fluid infusion is
presumed to be actively bleeding. Supraumbilical diagnostic peritoneal lavage then is performed. If gross
blood is found at lavage, it is likely that the bleeding
emanates from a ruptured intraperitoneal organ (usually
spleen or liver). The patient is taken for laparotomy. If
the lavage does not reveal gross blood or if the patient
remains unstable after laparotomy, ongoing retroperitoneal hemorrhage is probable. The patient then undergoes diagnostic pelvic angiography and possible emboli-
9
zation.
bones and is more fragile than the pelvic arteries (Fig.
25-2). The venous bed is a low-pressure, but high-capacity, structure. The pelvic veins are valveless and are therefore in open communication with the inferior vena cava,
and they are also in open communication with the portal
vein via the superior rectal vein. In dogs simultaneous
ligation of the lumbar arteries, inferior mesenteric artery, medial sacral artery, right and left hypogastric, external iliac, and profunda femoral arteries had no effect
on pelvic venous pressure.
14
Pelvic venous bleeding is
stopped by the tamponade (compression) effect of surrounding structures. An unstable pelvic fracture (particularly of the open-book type) can greatly increase the
potential volume of venous hemorrhage. A 3-cm diastasis
of the pubic symphysis will increase the potential volume
of the pelvis from the normal 4 L to 8 L.
15
Realigning
the fractured and displaced bones by placement of external fixators is an orthopedic procedure performed to
control venous bleeding. External fixation is helpful
when there is a diastasis of the pubic symphysis. It decreases the potential space in which bleeding can take
place and aids coagulation by preventing the fracture
fragments from moving in relation to each other.
Angiographic embolization and external fixation treat
different types of bleeding. External fixation controls
osseous and venous bleeding but not arterial bleeding.
Angiographic embolization controls arterial but not venous bleeding. At present, it is not possible to know
initially whether a pelvic fracture patient is bleeding primarily from an arterial or a venous source; thus, which
procedure should be performed first is a subject of controversy.
2
Angiography and embolization
Hemorrhage from branches of the internal iliac artery
requiring embolization occurs in 7 to 11% of patients
with pelvic fractures.
10
The most commonly injured arteries are the superior gluteal, iliolumbar, and lateral
sacral (associated with sacral fracture and sacroiliac joint
disruption), and the internal pudendal and the obturator arteries (associated with pubic ramus and acetabular
fractures) (Fig. 25-1).
11
Transcatheter embolization is
successful in treating pelvic arterial hemorrhage in 85 to
90% of cases.
6,12,13
There is great potential for cross-pelvic collateralization via anterior and posterior division
branches of the internal iliac arteries. Therefore,
selective injections of both internal iliac arteries should
be performed, and bilateral embolization is often necessary.
External fixation
Venous bleeding is common after pelvic fractures. An
extensive venous plexus exists adjacent to the pelvic
■ Indications for Other Radiographic
Studies in the Pelvic Fracture Patient
Plain films
The only radiographs that an unstable blunt trauma patient should have are cervical spine, anteroposterior (AP)
chest, and AP abdomen.
of the potentially lethal injuries that can be visualized by
plain films. The patient may well have obvious extremity
fractures and facial lacerations. Evaluation and treatment
of these must wait until life-threatening injuries have
been treated or ruled out. Foley et al.
trauma patients who bled to death of ruptured spleens
while plain films were being obtained in the emergency
department.
Computed tomography scanning
Trauma patients with neurosurgical emergencies requiring immediate evacuation of intracranial hematomas
usually present with one or more of the following: hy-
3
These studies will identify most
16
reported on four
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Superior
Gluteal
FIGURE 25-1. Internal iliac artery branches vulnerable to pelvic fractures. The superior gluteal and internal pudendal arteries
are most commonly affected.
Internal
Pudendal
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thoracic aortography and pelvic angiography should be
performed.
10
Uroradiographic studies
A patient in shock must have a catheter to drain the
bladder and to measure urine output. Urethral injury in
females is rare. If a male with pelvic trauma is unable to
void, has blood at the meatus, has a prostate that is high
riding or is not palpable, or has a scrotal hematoma, he
may have sustained a urethral injury. To avoid converting
a partial urethral tear to a complete transection, urethrography should be performed before a Foley catheter
is placed.
thrography, cystography, or intravenous urography for
two reasons: First, time is better spent stopping the bleeding than performing studies to evaluate injuries that are
not life threatening; second, contrast that extravasates
from an injured bladder may render pelvic angiography
uninterpretable. Patients in shock who may have urethral
injury and have an easily palpable bladder should have a
suprapubic cystostomy placed at the bedside, which can
be performed quickly and without contrast and is therapeutic. Many of these patients will require elective repair
of urethral strictures after the urethral injury has
healed.
17
A patient in shock should not undergo ure-
18
FIGURE 25-2. Pelvic venous plexus and collateral pathways.
pertension (not shock), bradycardia (not tachycardia),
altered mental status (Glasgow coma scale of 8 or less),
a dilated pupil on the side of the intracranial bleeding,
and a peripheral neurological deficit on the side opposite the injury. For these patients, immediate computed
tomography (CT) scan of the head is indicated.
3
Chest and body CT scanning is appropriate for evaluation of the hemodynamically stable trauma patient but
in general should not be performed on the patient in
shock. Oral contrast should not be used when there is a
possibility that angiography may follow CT scanning. In
the unstable patient with pelvic fractures and when findings on the chest film suggest great vessel injury, both
■ Obstetric Hemorrhage
Bleeding in excess of 1 L occurs in 1 to 2% of deliver-
19
ies;
11 to 13% of pregnancy-related maternal deaths in
the United States are caused directly by hemorrhage,
averaging 53 maternal deaths from bleeding each year.
The pregnant uterus is extremely vascular. It is perfused
by the uterine branches of the internal iliac arteries as
well as by the ovarian arteries, which in most cases originate from the abdominal aorta (Fig. 25-3). The ovarian
arteries may arise from the renal, iliac, lumbar, or adrenal arteries.
21
The collateral blood supply to the uterus
is excellent. Fatal obstetric hemorrhage can take place
within minutes. Bilateral hypogastric artery ligation is
successful in curtailing hemorrhage only 50% of the
time. Bilateral uterine artery ligation is successful 95%
of the time.
19
Packing the uterus with gauze when coagulopathy is present and even hysterectomy occasionally fails to stop uterine hemorrhage. When medical
management fails, angiographic embolization in many
cases can obviate laparotomy and may preser ve fertility
by making hysterectomy unnecessary.
22–26
When a patient is considered at high risk for postpartum bleeding,
an angiographic catheter can be placed into the aorta
through a left axillary approach while a lead apron
shields the pelvis before the patient is taken to the operating room for cesarian section. Then intraoperative
20
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FIGURE 25-3. Arterial anatomy of the female reproductive organs.
embolization can be performed using C-arm fluoroscopy
if hemorrhage is severe.
the full-term uterus are extremely vascular structures,
embolization to stop bleeding from a postpartum uterus
or from an ectopic placenta frequently requires far
larger quantities of Gelfoam than needed to control
posttraumatic hemorrhage. Obstetric hemorrhage may
be caused by bleeding from the placental implantation
site, by trauma during delivery, or by the HELLP
(hemolysis, elevated liver enzymes, and low platelet
count) syndrome.
26,27
Because the placenta and
Bleeding from the site of
placental implantation
The arterial flow to the placenta at term is approximately
600 mL/min.
the vessels connecting the uterus to the placenta are torn.
Approximately 500 mL of blood is usually lost at this time.
Contractions of the uterus occlude the disrupted vessels.
If part of the placenta remains adherent to the uterus,
bleeding will continue until the residual placenta is removed. If the uterus does not contract after delivery
20
When the placenta is expelled at delivery,
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A. Kerr
(atonic uterus), bleeding will persist. Atonic uterus usually
responds to administration of oxytocin or, if this fails, to
prostaglandin (15-methyl prostaglandin F
).19If the pla-
2a
centa attaches to the myometrium instead of to the endometrial decidua, it is called placenta accreta; if it invades
deeply into the myometrium, placenta increta; and if it
extends through the uterus and sometimes into adjacent
organs, termed placenta percreta. Massive postpartum hemorrhage is probable in these situations because the abnormal placenta will not separate from the uterus at delivery.
If the placenta separates from the uterus before labor
begins (placental abruption), severe bleeding may occur
and frequently is exacerbated by a coagulopathy caused
by substances released by the placenta. Placental abruption associated with fetal distress or with continuing hemorrhage is treated by delivery of the fetus. If the placenta
is near or covers the cervix (placenta previa), massive
bleeding is likely to occur when labor begins. Placenta
previa is detected by prenatal ultrasound. The patient is
then delivered by cesarean section before labor begins.
In ectopic pregnancy, the placenta attaches and develops outside the uterus. Most commonly, the fetus develops in a fallopian tube (tubal pregnancy). Less commonly,
the fetus may develop in the peritoneal cavity (abdominal
pregnancy) or in the uterine cervix (cer vical pregnancy).
The ectopicgestation will establish bloodvessels to nearby
structures. These abnormal placental attachments may
separate partially, causing massive hemorrhage. When an
advanced abdominal or cervical pregnancy is removed at
laparotomy, massive hemorrhage frequently occurs when
the placenta is dissected from its abnormal insertion site.
When preoperative embolization of the placenta is performed, operative blood loss is usually minimal. Gelfoam
embolization should be performed less than 24 h before
surgery because the vessels perfusing the ectopic gestation recanalize rapidly.
27,28
oping during pregnancy. When seizures are also present,
the condition is termed eclampsia. Approximately 10% of
severely preeclamptic patients and 30 to 50% of eclamptic patients develop the HELLP syndrome. The cause of
these disorders is unknown, but current research suggests
that it may be an as yet unidentified toxic substance
produced by the placenta. The placental toxin theory is
supported by the fact that the disease resolves only after
delivery of the fetus and placenta. Further, recovery has
been more rapid in some patients treated with postpartum uterine curettage, plasma exchange, or steroids.
Patients with the HELLP syndrome develop disseminated
intravascular coagulation (DIC). Liver infarction and intrahepatic hematoma formation are also common. After
infarction, the affected portions of the liver sometimes
rupture following minimal trauma or during labor. Liver
rupture in the presence of coagulopathy is associated
with massive intraperitoneal hemorrhage. If hepatic infarction or subcapsular hemorrhage is not associated with
rupture of the liver capsule, the patient may be treated
without surgery. Patients with intraperitoneal hemorrhage from liver rupture are treated with surgical packing
at the rupture site and drainage of the intraperitoneal
hemorrhage; this controls the bleeding in most cases.
One study reported an 82% survival rate following this
procedure.
31
Transcatheter hepatic artery embolization
is an alternative to laparotomy for treatment of intraperitoneal hemorrhage from liver rupture in postpartum patients who have the HELLP syndrome. Arteriography
usually demonstrates an avascular area with stretching of
adjacent hepatic artery branches and small pseudoaneu-
32,33
rysms.
Before hepatic artery embolization, arterial
portography should be performed to show that there is
adequate perfusion of the liver by the portal vein. Care
must be taken during embolization to place the catheter
distal to the cystic artery origin to avoid gallbladder infarction.
30
Traumatic obstetric hemorrhage
Significant bleeding may occur from lacerations of the
vagina caused by forceps delivery or by episiotomy. The
uterus may bleed after spontaneous rupture during delivery or after cesarean section. The hemorrhage may be
per the vagina, or it may be into the retroperitoneum
and consequently not visible. Intractable bleeding usually is treated by hypogastric artery ligation, uterine artery ligation, or hysterectomy. Successful treatment of
these injuries by angiographic embolization has been
reported.
29
Intraperitoneal hemorrhage associated
with the HELLP syndrome
Preeclampsia, which occurs in 7% of pregnancies, is defined as hypertension associated with proteinuria devel-
■ Pelvic Malignancy
Successful control of pelvic hemorrhage has been reported in patients with intractable bleeding from primary carcinoma of the cervix, uterus, and bladder as
well as invasion of these organs by metastases. Bleeding
from pelvic malignancy can be fatal; however, the rate
of bleeding is often too slow to be demonstrated angiographically. The tumor usually can be well delineated
angiographically, by CT scan, or magnetic resonance imaging. If continuing pelvic hemorrhage is clinically evident from a known pelvic tumor, angiographic demonstration of the bleeding site is not required before
embolization.
Embolization of pelvic malignancy is a palliative proce-
dure that does not eradicate the tumor. Bilateral emboli-
Pelvic and Obstetric Hemorrhage 303
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zation of the anterior divisions of the internal iliac arteries is necessary to minimize the risk of rebleeding. When
an appropriate embolic agent is used, infarction of normal structures is unlikely because the collateral blood
supply remains from the superior hemorrhoidal, iliac
circumflex, gonadal, and profunda femoral arteries.
When embolization is performed for traumatic or obstetrical bleeding, a temporar y occluding agent such as
Gelfoam can be used because rapid healing is to be expected at the bleeding site. Unfortunately, pelvic malignancy will persist after embolization. Consequently, a permanent embolic agent must be used. Polyvinyl alcohol
(PVA) 250-590 micron is the embolic agent of choice
because it is permanent, it will occlude distal vessels, and
yet it is not so small as to block the precapillary collateral
34,35
plexus.
■ Uterine Fibroids
Uterine fibroids are present in 20 to 40% of women older
than 35 years of age. The standard treatment for sympto-
matic patients (bleeding, pain) is hysterectomy or
myomectomy. Since 1995 interventional radiologists have
reported successful treatment of fibroid related symptoms by transcatheter embolization of the uterine arteries
36
bilaterally (Fig. 25-4).
This causes infarction of fibroids
but not of normal uterine tissue.
The procedure is performed using particulate polyvinyl alcohol, (500–710 microns). Technical success is
achieved in over 95% of patients. Early and midtern
follow up demonstrates that 80–94% of patients have
moderate or marked improvement in symptoms, and
over 90% of these patients have significant reduction in
fibroid and uterine size.
37–39
Complication rates appear
low. The effect on fertility is not yet known.
■ Pelvic Vascular Malformations
Vascular malformations are abnormal communications
between arteries and veins. They are low-resistance pathways for arterial blood (high pressure) to enter the venous system (low pressure) without first perfusing nor-
A
D
B
FIGURE 25-4. Bilateral uterine artery embolization.
A: Pelvic arteriogram demonstrates bilateral large tor-
tuous uterine arteries feeding hypervascular uterine
fibroid. B: The left uterine artery has been selectively
catheterized from the contralateral femoral approach.
C: Superselective catheterization of the left uterine
artery using a coaxial microcatheter system, prior to
particulate PVA embolization. D: The right uterine artery has been catheterized. Note the marked hypervascularity of the uterine fibroid. E: Following emboli-
zation, there is marked decreased vascularity and
E
marked arterial stasis.
C
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