Experience with UAE

A consensus statement was developed by a panel comprised of interventional radiologists on the Society of Interventional Radiology (SIR) Uterine Artery Embolization Task Force and members of the SIR Standards Division. This statement recommended the following: “To ensure patient safety and a successful outcome, UAE should be performed by physicians trained to properly select and evaluate patients for treatment, technically skilled to perform the procedure, and capable of periprocedural patient management and follow-up.” For interventional radiologists that are transitioning their practice in to the OBL environment, 2 important factors to consider are: patient selection and post-procedural care.

Embolization experience, particularly fibroid embolization experience, is an important technical pre-requisite for performing UAE in the OBL setting. Experience is manifested in different ways. An example of this can be knowing which patient can be safely performed in the OBL, and who is probably best handled in the hospital setting. The ideal patient for treating symptomatic fibroids in the OBL setting has the following characteristics:

Non-obese (BMI <40) woman with no significant medical history.

Multiple, small-medium size fibroids (<7cm and FIGO 2-5) and overall uterine size <16 weeks.

No Adenomyosis.

No interest in future fertility.

Patients with significant medical co-morbidities (e.g. poorly controlled hypertension, Ehlers-Danlos, marked obesity with potential airway issue, renal insufficiency) are probably best handled in the hospital setting.

Patient Evaluation

Patient evaluation in the office consists of a through history and review of pelvic imaging. While pelvic ultrasound has already been obtained in most patients that are seen in the office, I believe it is not adequate to rely on ultrasound alone.

Magnetic resonance imaging (MRI) is the best imaging modality to diagnose, map, and characterize fibroids. MRI can also diagnose other benign (e.g. adenomyosis) or malignant concurrent pelvic pathology, which may also be contributing to symptoms. This will change technique (e.g. embolic size, angiographic endpoint in the case of adenomyosis) or even preclude UAE in case of suspected malignancy (unless for palliative purposes). Twenty-two percent of patients studied in a trial by Omary et al had their clinical management changed following MRI evaluation (i.e. not relying on pelvic ultrasound alone). ^,

Following the initial MR localizing sequence, we obtain 4 fast spin echo series in our patients: sagittal T1, sagittal T2, axial T2, and coronal T2 planes. We will display the coronal T2 images in the angiographic suite to compare with the selective internal iliac angiograms to search for “bare areas” that will require investigation for ovarian arterial collaterals. The patient’s symptoms should be correlated with the imaging findings to insure concordance between the two. When there is not, the UAE should not be performed and an alternative treatment option should be investigated.

Post-Procedural Care

Post-procedural care actually begins in the pre-procedural office consultation. Patients and their family members need assurances that the physician performing the UAE procedure in the office is not compromising the quality of care. Each of our physicians gives out their mobile phone number to their patients. This is reassuring to the patient, as it provides improved and direct communication with the patient’s physician. Inaccessibility in the post-procedural period may lead to costly and unnecessary trips to the Emergency Department and reduced patient satisfaction.

We encourage patients to come to the pre-procedural office consult with someone; preferably the person that will be with the patient following discharge. Setting expectations for what to expect throughout the day of the procedure, as well as during their recovery, is crucial to patient satisfaction and the overall success of the procedure. Post-procedural pain is expected as over 90% of patients who undergo UAE report pain afterwards. In 2002, Worthington-Kirsch et al. demonstrated the post-UAE pain curve which shows a rapid rise in pain immediately following the procedure which plateaus over several hours, before significantly falling to a reasonable level by 24 hours post UAE.

Since that time, there has been significant improvement with dedicated pain protocols that has eliminated or significantly curtailed this immediate peak and plateau. With a specific pain protocol in place, the likelihood of severe pain is significantly diminished. Despite these measures, there will still be patients that will need to come back to the office for several hours of conservative measures (e.g. intravenous fluids, narcotics). Fortunately, in our experience, once these patients are discharged from the office, they have not returned until it was time for their routine follow up.

“Pain protocols” are varied and have evolved over the years. Originally, the protocol may have consisted of fentanyl and midazolam during the procedure, 23-hour admission for a patient-controlled analgesia (PCA) pump, and several days of an oral narcotic and nonsteroidal anti-inflammatory medication upon discharge. To perform UAE in the OBL setting, it is recommended that a more specific pain regimen be in place. These can vary across practices; however, certain tenets can help formulate the specific one that is developed.

Due to the consistent pattern of post-procedural pain seen after UFE, a strategy that effectively controls pain for the first 24 hours is the goal. The evolution of a specific pain protocol was one of the driving forces that allowed the performance of UFE to transition from the hospital outpatient setting to the OBL. ^,

Opioids

The pain protocol should begin prior to the UFE procedure. Opioids have been frequently used alone, or more commonly, in combination with nonsteroidal anti-inflammatory drugs (NSAIDs) in the management of postprocedural pain. The combination is synergistic and decreases the amount of narcotic use when compared to using opioids alone. Our Center’s combination consists of intravenous ketorolac and an intravenous narcotic (e.g. hydromorphone) prior to discharge and oral oxycodone and meloxicam on discharge. Fibroid infarction from the embolization appears to release inflammatory mediators. In some patients, this results in a post-embolization syndrome consisting of pain, malaise, nausea/vomiting, and a low-grade fever. This responds very well to conservative measures (e.g. fluids, pain/anti-inflammatory medication, anti-emetics) and will resolve over 7-14 days.

Acetominophen

Using acetaminophen (1000 mg either iv or po) also has been shown to be an important component of the pain protocol. Bilhim and Pisco reported a mean pain of 2.5 out of 10 in the first 8 hours where pain is typically the highest. They reported no readmissions for pain control using this protocol.

Steroids

Glucocorticoids are potent anti-inflammatory agents. It is believed that by decreasing inflammatory mediators following ischemia that the pain should be more manageable. Kim et al demonstrated that the single (10 mg) dose administration of dexamethasone prior to the embolization was effective in reducing pain and inflammation (as measured by reductions in C-reactive protein, interleukin-6, and cortisol during the first 24 hours following embolization). Unless contraindicated (e.g. diabetic patients), we use a single 10 mg dose of dexamethasone prior to the procedure.

Other Medications

There may be value in an acid-suppressing agent (ex. omeprazole 20 mg) to reduce the gastric side effects from the NSAID that is used. Other medications that we use include an anxiolytic (e.g. lorazepam), an antihistamine (e.g. Diphenhydramine 25-50 mg), and a stool softener (e.g. docusate).

Superior Hypogastric Nerve Block (SHNB)

Rasuli et al reported on performing SHNB for pain control in outpatient fibroid embolization. Under fluoroscopic guidance a needle is placed into the hypogastric nerve ganglia at the beginning of the UFE procedure. Bupivicaine is typically the agent used in this setting and some investigators have added steroids to prolong the analgesic effect. A systematic review of published series on SHNB was published by Musa et al. Fifteen studies with a total of 488 patients were reviewed. Technical success was 98.8%, same day admission 97.9%, readmission rate of 6.9%, minor adverse events in 17% (most commonly emesis), and major adverse events (e.g. systemic toxicity, seizure-like activity, significant bleeding) in 0.4%. Mean fluoroscopy time was 13.3 minutes. Mean procedure time (SHNB + UFE) was 106 minutes.

SHNB is a safe and effective procedure that can significantly reduce pain and analgesic use. However, the severe risks discovered in performing SHNB are particularly relevant in the OBL setting where there is much less support immediately available. The most severe potential complication is cardiac arrest and/or seizure from the intravenous injection of bupivacaine. Immediate resuscitation measures along with a lipid emulsion (which is thought to bind the lipophilic bupivacaine preventing its binding to cardiac or neural receptors) are instituted. Obese patients with large fibroids may make performing SHNB challenging. This is also a risk for bowel transgression. These risks, along with the unfamiliarity and/or lack of experience with SHNB by many interventional radiologists, should give one pause before performing SHNB in the OBL setting.

Intra-Arterial Lidocaine

Based on the years of experience with hepatic chemoembolization, intra-arterial lidocaine was administered pre-embolization in a study by Keyoung in an effort to reduce post-procedural pain in UAE procedures. However, this caused significant uterine artery vasospasm and concomitant under-embolization which led to treatment failures from incomplete fibroid infarction. Noel-Lamy et al used preservative free intraarterial lidocaine immediately post-embolization and showed both reduction in pain scores and complete fibroid infarction.

Epidural or Spinal Anesthesia

Both spinal and epidural anesthesia have been shown to be effective for reducing pain, reducing medication requirements, and improved overall patient satisfaction.

However, this must be weighed against a significant increase in cost, availability of anesthesia in the OBL, and other solutions which are easier to implement in the OBL and appear equally as effective.

Fentanyl Patch

These patches are not approved for opioid-naïve patients and their use would be considered off-label in patients post fibroid embolization. They deliver a slow and differing amount of fentanyl into the blood stream; often up to 72 hours. Song et al studied 42 embolization patients for fibroids or adenomyosis. Half of these patients received an opioid/NSAID combination and the other half that same combination plus a fentanyl patch. They concluded that pain scores were significantly lower 6 hours post embolization in the group receiving the fentanyl patch. However, there are concerns for side effects (e.g. respiratory depression), potential for abuse, and accidental overdose in children exposed to these patches. With the slow, variable, and relatively long duration of drug delivery along with other concerns about this medication, its utility in the OBL appears to be limited.

Summary

Over the past 25 years, the safety of uterine artery embolization (UAE) and the progressive improvement in managing the associated post-procedural pain has enabled the treatment of fibroids and adenomyosis to transition from an inpatient to an outpatient setting. More recently, patients are finding the same (or better) care in the OBLs that are dedicating the care specifically around these patients. Those centers performing UAE should have physicians that see these patients in the office and set the appropriate expectations for the patient and their family members. Magnetic resonance imaging is the modality of choice to correlate the patient’s symptoms to ensure that the patient is a candidate for embolization, and that they are also suitable for the OBL. Correlating this MRI during the procedure to plan the appropriate embolization is important.

Finally, while no consensus guidelines exist to date, it is clear that having a defined pain protocol in place is necessary to successfully perform UAE in the OBL setting. Knowing the options and medical literature to support them, the interventional radiologist can design a pain protocol to provide adequate and safe pain control for their patients. They will also have the knowledge to handle the small percentage of patients that still experience significant pain despite these efforts. Hospitals are very costly, inefficient, difficult to navigate, and are often not the best recovery environment. As medical costs continue to shift to the patient, patients are increasingly demanding more value for their healthcare dollar. This is an opportunity for OBLs to provide better care, more efficiently than the hospital with a much lower cost, and a significantly increased patient experience. Performed in this manner, UFE can clearly be a part of the armamentarium of office based procedures.