Discussion The patient woke up with no deficit, and was following commands. Here are some questions to consider: 1) Have you ever coiled an aneurysm with 3 separate compartments? 2) Who would have operated on this patient instead of coiling? 3) How do manage anticoagulation for ruptured versus ruptured aneurysms? 3) What initial coil would you have used? 4) Would you have continued to deploy the 6 mm coil into the suspected rupture site? 5) How often do you use general anesthesia for coiling and why? 6) Who would have tried to put more coils in? Please email your comments and I will post them anonymously here so we all can learn something. If you prefer to not have your comments posted, please let me know. Your Comments |
1) Have you ever coiled an aneurysm with 3
separate compartments?Yep. A few times. They really aren't more
difficult than single compartment ones, but you do have to decide how to attack
it. The two main approaches are big basket vs. peas-in-a-pod. If I can do it
as a single, lobulated compartment (big basket), that's easier, but it's really
only about 55:45 on the difficultometer. In this case, where you seem to have
an idea where the bleed happened, I would have done exactly what you did:
p-in-p.
2) Who would have operated on this patient instead of coiling?Our
main vascular neurosurgeon. None of the interventionalists would have agreed
with him.
3) How do you manage anticoagulation for ruptured versus
ruptured aneurysms?Nothing systemic until at least the first coil is
situated. In those cases, I've used the Kerber approach: have more drip with
heparinized saline going thru the Envoy (or whatever else you use). That way,
the heparin goes where you want it to go, get the same response, but in an
almost instantly reversible manner: turn it off if there's a problem, and the
few units that have gone systemic are a highly diluted factor in a few seconds.
When I *do* use heparin, e.g., in an unruptured aneurysm, I have drawn up 1 mg
protamine per 100 units of heparin. The anesthesia folks wield the protamine.
If nothing happens, like an intra-procedural rupture, we throw it away. If
there is a rupture, the protamine goes in over about a 5-7 second period. If
they get sick, too bad--they're asleep anyway.
3) What initial coil would you have used?I would
have started off with a Micrus Presidio coil to frame each lobule. There's so
much metal in them that a second coil would probably not have been necessary.
And all Presidio's are bioactive. In this setting, I would have used a 6 or 7
mm sphere.
4) Would you have continued to deploy the 6 mm coil into the
suspected rupture site?Sure. Why not? The radial force exerted by
even the 18-system coils is minuscule. I don't think that it's at all likely
that they would have resulted in a re-rupture. It might have been a problem to
persuade it not to prolapse into the parent artery, but other than that, I don't
see a serious downside.
BTW, I ~always~ oversize my coils unless it's impossible to keep it in the
aneurysm, which is rare. The reason I do that is to minimize the amount by
which the curved contour of the coil extends into the artery lumen. Consider:
the larger the coil diameter, the larger the radius of curvature, so the flatter
any length of thing is. For example, imagine a spherical 10 mm aneurysm with a
6 mm neck. A 10 mm coil will extend 1 mm into the parent artery. (Proof is
left as an exercise for tthe reader.) A 12 mm coil will extend in maybe only
abt 2/3 of a mm. In a small parent artery, like an a. comm., every couple
hundred microns counts, the more so when there's only one A1 segment.
5) How often do you use general anesthesia for
coiling and why?I use it exactly 100% of the time. Why? The last
time I lost a patient on the table was maybe 5 or 6 years ago. She died because
I re-ruptured her basilar apex aneurysm and she was wide awake, then in
desperate pain, which made it impossible for me to proceed until we got
anesthesia into the suite. By that time, the game was over. Since that time, I
had a patient with a torrential rupture of a previously unruptured basilar
aneurysm. Within 12 minutes the following happened:1) Blood pressure, which had
climbed dangerously, was rapidly brought under control, and the marked
bradycardia that you'd expect began to resolve as well; 2) a ventriculostomy got
inserted, and 3) I managed to place maybe 8 or 10 coils into the beast.
Rapidly. She woke up that night, intact except--mercifully--for some memory
problems. Even those have resolved completely. My NP asked me whether I thought
that it would be better if we could arrange for all SAHs to happen on the angio
table, since the outcome was remarkably good [read: lucky!!]. As an aside: in
item 1 above, the product of the patient's heart rate and mine remained roughly
constant.
6) Who would have tried to put more coils in?Probably
most people, but I'm not one of them. When there's no more filling,
particularly in a small aneurysm, I stop
1) Yes, but
the nipple bleed was left without entering, and
thrombosed because the other compartments were filled. I'm too
frightened to intentionally stress a recently bled nipple.
2) The termination type of A-comm aneurysm is tougher to fully
obliterate than other A-comms. Today this aneurysm should first be
coiled, and operated if that is not successful. I have a short series
of coiling this aneurysm after regrowth from clipping. The jet of
filling of the termination type makes regrowth a good possibility
whether coiled or clippedn, especially since we can see the
triangular neck base.
3) I always worry about the thrombo-embolic risks of all the
catheterizations. I use a flush of 3000 IU/500 ml saline for all
angiography. I will give a bolus of 5000 IU heparin at the moment
that we agree that we are continuing with micro-catheters, and check
the ACT after that. I remember that "Heparin stops clotting; it
doesn't cause bleeding". To me the risk is rupture of the aneurysm
while we work, versus thromboemboli occurring while we use multiple
co-axial systems to get there. A rupture can still be big trouble
even with no heparin.
4) I would have chosen a coil for the larger sac and not the nipple
that likely ruptured.
5) Coiling should be only do with GA. We learned in the early 1990s
that moving the head a bit here and there made our understanding of
what we did quite poor, and we didn't quite fit coils well enough
into the sac. As well, with a bit of movement, a coil or micro-guide
might not be where we think it is. Very dangerous.
6) Its hard to judge the sense of balancing the risks of doing more
versus less. I predict that this aneurysm will re-develop in a big
way because it is a termination type aneurysm and has the A1 jet of
flow go right into the remaining untreated neck, and branches are
perpendicular. I've asked ISAT to divide their A-comm cases into
termination versus non-termination to see the differences in results
(I'm still waiting). It is actually an easy-enough designation, as
the termination type usually has what we see here: one A1 supplies
both pericallosals with the other A1 hypoplastic. All that is needed
is to see which cases have a balanced ACA supply versus the pattern
that we see her.
Termination type of A-comm
aneurysms are tough. This aneurysm has a pear-shape with a tapered neck region,
that still fills after coiling (the double density triangle on your
post-coiling films. For this type of aneurysm I often use a basal view (submental
vertex), as it is the only view that I know that shows the neck to best
advantage. It is tough though to keep a patient's head back enough (and
the I-I angled over the belly). The 3D DSA images are lovely. They can also be
done with CTA. In fact, in 1993 when the imaging research team that I
joined began the 3D DSA project (supported by Siemens), the stated
goal was to produce CTA from a C-Arm of an angiography unit. Once this was
successfully done by the graduate student. I pushed that we use a different
name, as CTA means a different technology. Since the head researcher did
his PhD on creating a micro-CT scanner and to do micro-CTA, he knew then
that CTA was a great advance well ahead of DSA. The success of 3D DSA (the
team called it "CRA" in the literature) is a testament to that. Many
however doing 3D DSA every day are often not also doing cross sectional
imaging and don't realize that 3D DSA was developed to approach the
quality of CTA, and not the other way around
Follow-Up
The patient did very well post coiling and was extubated right away neurologically intact. Over the next few days, her TCD velocities went up a bit and she became mildly confused, so I re-angioed her which was normal. Her confusion resolved, but she transiently developed a mild left CN VI palsy which also got better. (Anybody know why that occurred?) Ill be seeing her back in 6 months for a repeat angio.
Regarding the procedure itself, I actually did try to avoid the rupture site, but the first coil just had a mind of its own and wanted to go there. I figured after the first 5 or so cm of coil went into it without rupturing it I was homefree and placed the rest of the coil into the rupture site. I know some folks don't use systemic heparin, but I just don't feel comfortable doing that. So, on ruptured aneurysms, I get the ACT to 200 until I get the first coil in, then bump it to 250. For unruptured, I go right to 250. For all cases, I use 5k units/liter of saline flush.