There has been a fair amount of interest in the world of uterine artery embolization (UAE) over recent data presented by Dr Jean-Pierre Pelage, of the Department Of Radiology Hospital Ambroise Pare, Boulogne, France, and Dr James Spies of Georgetown University Hospital in Washington. It is usual practice for a contrast enhanced MRI to be performed post procedurally at three to six months to assess fibroid infarction. However, over the last year, Pelage and Spies have been presenting data on MRI performed 24-48 hours after UAE and comparing it with magnetic resonance imaging (MRI) performed at three to six months. Their research advocates the use of contrast-enhanced MRI to understand potential failures after embolization.
The data, when put together allows the following observations:
In many cases (especially with Contour-SE), contrast-enhanced MRI 24-48 hrs after UAE shows significant continued perfusion of fibroids.
There is no 'late infarction' after UAE - what is infarcted or alive at 24-48 hours after UAE is infarcted or alive in three months, six months, and ongoing.
Short-term or even mid-term symptom improvement can occur even in patients with subtotal fibroid infarction.
There is no data that would allow the use of post-UAE MRI to predict medium to long term outcomes.
There can be little doubt that this is an excellent research tool. However, the data and what it means in practice has not been greeted with unanimous delight amongst some interventional radiologists who specialize in UAE. There is concern that their colleagues in general practice may be seriously considering the routine performance of immediate postoperative MRI.
"I think that this is a bad idea, since we really don't know what the results mean in terms of practice" said Dr Robert Worthington-Kirsch of Philadelphia, PA when interviewed by Interventional News. "Apparently some IRs have at least discussed starting to routinely get early (within a week of UAE) MRIs based on this data. I think that this is admirable in a research setting, but should not be done in a general clinical practice."
Pelage stated, however, that far from becoming widespread, his center is in fact the only one to perform early post embolization MRI at 24 hours. Most centers cannot afford to perform early post embolization MRI because of reimbursement issues. Pelage went on to explain that he has been performing 24-hour post embolization MRIs since late 2001, in selected patients with potential failure because of anatomical (additional ovarian artery supply) or technical (unilateral embolization, spasm) problems at the time of embolization. The data from this has already been presented at the RSNA, the SIR and the CIRSE. Pelage has also used this protocol in the evaluation of new embolization products, which has proved to be particularly useful in understanding the problems associated with spherical PVA.
Worthington-Kirsch states that he is not troubled with the data presented by Pelage and Spies per se, but how he sees it may be misused or misinterpreted. His concerns fall into two categories; firstly the risks implied in immediate re-embolization and secondly, the cost implications for an unproven practice. "Of course, if an MRI shows complete fibroid infarction, that is reassuring to all. But what of the patient who has residual fibroid perfusion after UAE? The worst thing (in my opinion) would be for the IR to return the patient to the angio suite and attempt to re-embolize. This is a recipe for potential disaster - uterine infarction, non-target embolization, puncture site complications, needless embolization of the ovarian arteries with risk of ovarian compromise, etc".
Pelage is in complete agreement with this and categorically states that his research has never advocated immediate re-embolization.
"I treat patients not pictures," he says. "We have never said that immediate re-embolization should be done just because there are viable fibroids on the MRI. All we do is inform the patient and the referring gynecologist about the results of the 24-hour MRI and tell them that recurrence may happen". However, this is what Worthington-Kirsch takes issue with. "Does the IR tell the patient 'Well, we didn't kill all your fibroids, so your symptoms may come back?' Since at least some component of symptom relief is subjective, this is a recipe for an unhappy patient and referring physician - or perhaps more worryingly - a jubilant referring physician who now has more ammunition with which to dissuade patients from a valuable procedure." Pelage, however, is adamant that sharing the results of early MRI is best practice. "It makes a big difference in the follow-up when you, as a clinician, can predict and explain clinical recurrence before it actually occurs" he says. "We only re-embolize in cases of clinical failure or recurrence".
Worthington-Kirsch also believes that he cannot cost-justify routine post-operative MRIs within his own practice. He obtains routine follow-up with ultrasound and feels this is sufficient. Only if the patient develops any problems after UAE (recurrence of heavy bleeding, recurrent bulk symptoms, symptoms of fibroid slough), does he order an MRI to evaluate the situation.
Pelage's position is very different. "Should we perform early post-embolization MRI routinely?" Pelage asks. "My answer is probably yes in the future." As his data shows, what is infarcted immediately after the procedure does not alter with time. "With this kind of practice, we may even consider skipping the usual three, six or 12 month post embolization MRI" he concludes. It appears that although Worthington-Kirsch's fears that Pelage and Spies data may be misused by less canny clinicians, this is not what their research advocates. However, for most centers performing UAE, early MRI, simply through its cost implications and problems with reimbursement, may remain in the future for some time yet.
|
