Work-up and Follow-up after Embolization 43
4 Work-up and Follow-up after Embolization
Jim A. Reekers
natively another embolization material should be used, such as occlusion balloon or glue.
Before starting any elective embolization it is important to talk to the patient and obtain informed consent. In talking to the patient, emphasis should not only be on the advantages but also on the risks and complications of embolization therapy. Alter- native therapeutic options should be discussed. In both emergency and elective embolization there is no scientific proof that antibiotics should be given prior to embolization. Always work as a team with the referring physician, to have a back-up plan for possible procedure failure or complications.
Needless to say, embolization should only be per- formed with ample experience and support. Optimal angiographic facilities and all necessary materials should be at hand.
4.2
Work-up for Emergency Embolization
Requests for emergency embolization are usually unexpected and often occur after hours, therefore logistical support must be optimized to provide trained personal who are available on a 24 h basis.
In case of an emergency there is usually not much time for full diagnostic work-up. Undoubtedly a CT scan can be very helpful to guide the interven- tion. In traumatic bleeding essentials like hemody- namic monitoring and live-support should be avail- able. Some basic lab data should also be recorded (Table 4.1). Furthermore, typed and cross match packed red blood cells should be obtained imme- diately. Fresh frozen plasma and platelets also may be required to correct coagulopathies that develop in severe hemorrhagic shock. Intravenous access and fluid resuscitation are standard. However, this practice has become controversial. For many years, aggressive fluid administration has been advocated to normalize hypotension associated with severe hemorrhagic shock. Recent studies of urban patients
CONTENTS
4.1 General Work-up 43
4.2 Work-up for Emergency Embolization 43 4.3 Semi-Emergency 44
4.4 Elective Embolization 44 4.5 Follow-up 45
References 46
4.1
General Work-up
It is important to become familiar with all aspects of the patient’s clinical history, as this will ultimately help to determine the appropriateness of the planned intervention and will also help optimize and guide the catheter-based intervention. For example, one should know if the patient is using anti-coagulant medication or other medication, which might alter the clinical presentation of hemorrhaging patient or influence the efficacy of the embolization pro- cedure. It is important to be informed about the patient’s medical history and medication. A history of contrast allergy is important, as these patients should be pre-treated with corticosteroids. Since B-blockers might fully mask the hyperdynamic response of hypovolemic shock, appropriate pre- cautions should be taken in patients with elevated creatinine who are using Metformin before contrast medium is given. Patients with renal insufficiency should be pre-treated with hydration, alkaliniza- tion and N-acetyl cysteine (600 mg dosing every 6 h, preferably twice before the intervention). Oral anti-coagulants can reduce the prothrombotic effect of coil embolization and, whenever possible, should be stopped or reversed before embolization, or alter-
J. A. Reekers, MD, PhD
Academic Medical Centre, University of Amsterdam, Depart- ment of Radiology, G1-207, Meibergdreef 9, 1105 AZ, Amster- dam, The Netherlands
44 J. A. Reekers
with penetrating trauma have shown that mortal- ity increases with these interventions; these find- ings call these practices into question. Reversal of hypotension prior to the achievement of hemostasis may increase hemorrhage, dislodge partially formed clots, and dilute existing clotting factors. Findings from animal studies of uncontrolled hemorrhage support these postulates. These provocative results raise the possibility that moderate hypotension may be physiologically protective and should be permit- ted, if present, until hemorrhage is controlled.
For a hemodynamically unstable patient with, for example a pelvic bleeding, timely embolization may be the patient’s only chance for survival. Although some of the literature may disagree, it has been our experience that any delay in embolization therapy to allow the application of external or internal pelvic fixators can result in deadly delays. Patients with acute hemodynamic instability do not die in the angio suit, as modern anesthesia can almost always keep them alive during the procedure. They die, however, from the sustained shock and blood transfusions which will lead to multi-organ failure (MOF) days after the initial procedure. There is a direct relation between the amount of blood trans- fusions and the chance to leave the hospital alive. On the other hand, recently available Velcro-type pelvic binders offer a rapid and effective alternative to time consuming orthopedic fixation procedure in pelvic fractures and may allow stabilization of the patient without delaying indicated angiographic emboli- zation procedures. It is therefore paramount to get the patient to the angiography suite as promptly as possible. It has been the experience in some major trauma centers that an angiography suite next to the trauma bay is a very helpful arrangement. It is important for the interventionist to be present at the emergency department when the patient gets in and to start the preparation for the embolization proce- dure.
4.3
Semi-Emergency
If there is an acute indication for embolization therapy, but if the patient is hemodynamic stable, a spiral CT can be very beneficial to help planning the intervention. A pseudoaneurysm of a visceral vessel certainly will target the intervention. A retroperito- neal hematoma will suggest potential bleeding sites.
Active extravasation can also sometimes be visual-
ized on CT, especially newer multi-detector scan- ners, allowing the angiographer to zoom in on the likely site of major bleeding without a proceeding exhaustive angiographic search. In hemodynami- cally unstable patients, a focused ultrasound exami- nation of the abdomen while the patient is being prepared for the angiogram can sometimes localize a pelvic or intra-abdominal fluid collection and help guide the intervention. Therefore, we believe that cross-sectional imaging in some form should be per- formed as a work-up whenever possible.
Other forms of bleeding localization can also be used. In a patient with GI bleeding who was first seen by an endoscopist, as is usually the case, application of a clip to the bleeding site can guide a possible sub- sequent catheter intervention. Having a good under- standing with the endoscopist on this is important.
Similarly, in patients presenting with hemoptysis, bronchoscopy can be of great help to determine the bleeding site, along with a cross-sectional imaging study. Again, blood, plasma and at least two large caliber running intravenous lines should always be available. In addition, we have also found that, in these semi-acute patients, professional monitoring by an anesthesiologist is highly advantageous.
4.4
Elective Embolization
Elective embolization can be performed for many indications as will be presented in other chapters in this book. Different indications have different appropriateness criteria and require different work- up and preparations (Table 4.2). For example, prepa- ration for a uterine fibroids embolization procedure varies greatly from preparation for a varicocele embolization. Work-up and preparation includes a focused history with physical examination, evalu- ation by an appropriate allied clinical specialist (for example, a gynecologist in the case of uterine
Table 4.1. Basic data that should be recorded before emergent embolization
•
Medication history•
Prothrombin time, activated partial thromboplastin time, and platelets count•
Hemoglobin/hematocrit•
Arterial blood gases, base deficit, and lactate levels (reflect acid-base and perfusion status)Work-up and Follow-up after Embolization 45
fibroid embolization), and a proper imaging and laboratory evaluation. Patient education is a crucial part of the preparation procedure, as some of these elective embolization procedures can result in sig- nificant complications. The patient needs to be well informed of the indications, alternatives, and the risk of complications.
4.5 Follow-up
The follow-up should be focused on the possible complications and clinical outcome (Table 4.3). In the acute and immediate post-procedural phase, special attention should be directed to the early detection of sequelae of non-target embolization, which can often result in major complications. It is a good practice to routinely conduct a telephone interview with the patient no later than a week after the procedure. Modern interventionists are clini- cal providers and an interventional clinic follow- up at an appropriate period of time following a major embolization procedure is not an option but a required minimal standard of practice.
After embolization of a uterine fibroid clinical follow-up might be sufficient. However, to pre- vent an early recurrence, early MR controls might be necessary. Pain control following embolization
of a congenital vascular malformation can often be effectively accomplished done with oral anal- gesics, such as acetaminophen or non-steroidal anti-inflammatory drugs. However, in the case of embolization of a solid organ or tumor, special care should be taken to the management of post- embolization pain that can be severe. In some instances, for example uterine fibroids or kidney tumor embolization, opiates or epidural anesthesia may be required. The interventionist should always check the patient personally as post-embolization pain can sometimes be unpredictable, and may be the source of significant anxiety and negative per- ception by the patient. Fever, usually below 38.5°C but sometimes as high as 39°C, and nausea are also often seen after embolization due to tissue necrosis.
Fever above 39°C is suspect for infection or abscess formation. CT scan guided percutaneous sampling and drainage might be mandatory in some of these cases. Surgical consultation for debridement and drainage may also be needed in extreme cases.
Wide spectrum empirical antibiotic therapy should be started whenever infection is suspected. In some embolization applications, like embolization of the splenic artery, there is a higher predilection to abscess formation, which can be treated with anti- biotics and percutaneous drainage. It is mandatory to document all of the details surrounding post- operative adverse effect and their management in the medical record.
Table 4.2. Preparation for elective embolization
Application Work-up Procedural risks
Vascular malformation MRI/MRA Necrosis
Uterine fibroids MRI/MRA, US Septicemia/pain and fever
Spermatic vein US Recurrence
Endoleaks Spiral CT, MRI, angiography, duplex US Recurrence/non-target embolization Primary liver tumors CT, angiography Necrosis/fever/sepsis/recurrence Metastatic renal cell tumor CT, angiography Necrosis/fever/pain
Benign bone tumors CT Pain/recurrence
Tumor in general CT/MR Necrosis/fever/pain
Table 4.3. Complications of therapeutic embolization
Complication Referral Management
Tissue necrosis Plastic surgeon Skin grafts/skin transplants
Bowl/parenchyma ischemia/necrosis Surgeon CT scan/laparotomy
Sepsis Interventional radiologist or surgeon Antibiotics/drainage
Severe pain Interventional radiologist NAIDS/morphine
46 J. A. Reekers
Take Home Points:
• Work-up and follow-up of embolization patients should be specifically tailored to the patient, and the indication for intervention.
• Vital information can be obtained from the patient’s medical history.
• The doctor who performs the embolization pro- cedure should be responsible for the follow-up.
• Proper pain management is important after embolization.
• Proper medical documentation is very impor- tant.
• A team approach is important.
References
Agnew SG (1994) Hemodynamically unstable pelvic fractures.
Orthop Clin North Am 25:715–721
Beers MH, Berkow R (eds) (1999) Hemostasis and coagulation disorders. In: Beers MH, Berkow R (eds) The Merck manual of diagnosis and therapy, 17th edn. Merck, USA
Ben Menachem Y, Coldwell DM, Young JW, Burgess AR (1991) Hemorrhage associated with pelvic fractures: causes, diagnosis, and emergent management. Am J Roentgenol 157:1005–1014
Moore H, List A, Holden A, Osborne T (2000) Therapeutic embolization for acute haemorrhage in the abdomen and pelvis. Australas Radiol 44:161–168
Simons ME (2001) Peripheral vascular malformations: diag- nosis and percutaneous management Can Assoc Radiol J 52:242–251
Spies JB, Pelage JP (eds) (2004) Uterine artery embolization and gynecologic embolotherapy. Lippencott, USA
Wilkins RA, Viamonte M (eds) (1982) Interventional radiol- ogy. Blackwell, Oxford
