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Dr Tapson: Dr Mayer, I remember
you publishing in the last couple of years a series of
cases that included a fairly high number of class IV patients.
Those patients would fit into the same category as those
with poor RV function. It sounds like you had a good outcome
with those individuals.
Dr Mayer: Yes, we have a
good outcome in NYHA class IV patients, if angiographic
findings and severity of pulmonary hypertension are proportional
and a complete removal of the obstructing material is
possible. I am in doubt about the surgi-cal indication
if there is only minor unilateral distal disease in the
angiography and very severe pulmonary hypertension com-bined
with poor right ventricular function. Those are the cases
with a very high risk. But if the disease is surgically
accessible, I really believe that every right ventricle
can recover.
Dr Tapson: What about cases
where you have concomitant left ventricular dysfunction
or concomitant COPD or other lung dis-ease? How does that
play in your decision to do surgery? I guess you have
to individualize these cases?
Dr Auger: That’s absolutely
correct. In days past these kinds of cases concerned us
a great deal. Let’s just take the case of patients with
severe COPD or emphysematous lung disease. This is where
CT scanning can be very helpful. If someone exhibits significant
occlusive vascular disease to the lower lobes and yet
much of the emphysematous lung is in the upper lobes,
these patients can be helped with a thromboendarterectomy
by improving perfusion to relatively normal lung tissue.
In the pa-tients with severe left ventricular dysfunction,
an endarterectomy can abruptly reduce right ventricular
afterload and consequent-ly increase left ventricular
preload, which can precipitate heart failure in the postoperative
period. These people are at particular-ly high risk and
do not generally do well following the operation.
Dr Tapson: Is there any
way to gauge what someone’s ultimate level of function
will be preoperatively or do you get really good results
in some sick people and maybe not so good results in some
people who do not have such significant obstruction? Can
you predict the outcome in any way?
Dr Mayer: Not for every
patient. For most of the patients we can predict the outcome
but there are still some patients in whom we are not able
to predict the operative and long-term outcome. It can
be very difficult to predict the outcome in the individual
case.
Dr McGregor: I agree with
that. The improvement in right ventricular function is
dramatic and early. By a week after surgery their EFs
increase 20 points. What is also interesting is that there
can be contin-uing improvement at 6 months and a year
when you repeat the test and it’s even better. So there’s
an early acute improvement and there may be ongoing more
gradual improvement. When you asked about COPD and patient
selection, I think one of the biggest problems we deal
with are the patients who have this disease who are missed
and have the possibility of getting surgery. When you
think that the prognosis of this dis-ease is so bad when
they get to class III or IV and the outcomes of surgery
are so good, the frustrating thing is that there are patients
sitting around major medical centers who are undiag-nosed.
I would say a third of the patients I see are labeled
as having asthma. We have to try and pick out the disease
and sec-ondly, if a group is going to do this surgery
regularly and estab-lish a program, they have to have
reproducible hemodynamic outcomes not only to confirm
operative mortality but the suc-cess of the surgery
Dr Fedullo: Even though
it appears that patients are being referred earlier, there
is still a large group of patients who are carried for
years with the diagnosis of asthma, for example. The patients
will say, “I’ve told the doctor, I’ve never wheezed, I
know what asthma is.” And yet they’ll be treated with
steroids for years until somebody finally stumbles upon
the diagnosis. Again, getting the word out to the general
community that this disease exists and can be confused
with other disease process-es is very important.
Dr McGregor: I presented
at an echo meeting recently and I really made the point
that anybody who has an echocardiogram, has elevated pressures,
and who does not have morphologic cardiac problems to
account for it should have a V/Q scan.
Dr Tapson: Chris is making
a crucial point. You first have to diagnose the pulmonary
hypertension. As we tell our patients, we have to figure
out the cause and the severity and that makes all the
difference in the world in terms of what we do. But you’ve
got to rule out curable causes of disease. It’s so rare
that we find a curable cause of pulmonary arterial hypertension.
And to find something surgically curable is crucial. I
would absolutely echo that, and no pun intended there,
that you’ve got to evaluate patients with abnormal pulmonary
artery pressures and exclude the possibility of acute,
subacute, or chronic pul-monary embolism.
Dr Auger: Many of us are
at centers focusing on pulmonary vas-cular disorders that
are busier than ever. We can all remember the days when
this disease was such an oddity; it was rare when we were
operating more than once or twice a month. Now many of
us are performing a dozen of these surgeries each month,
evaluating anywhere from 10 to 20 patients a month as
potential surgical candidates. However, it is still our
impression that there are many more folks out there where
the diagnosis has not been adequately explored.
Dr Tapson: When cases are
done, how often is reoperation done or how often is transplant
ultimately necessary in these cases? It’s amazing what
all of you have accomplished with this dis-ease over the
years, but there are some cases that will deterio-rate
no matter what you do.
Dr Mayer: I completely agree.
Fortunately we have only 1% of PTE reoperations (2 out
of 300 patients). In addition I did a lung transplantation
3 or 4 years after primary successful PTE. I don’t think
that lung transplantation is a good option for patients
if they really have CTEPH. However, there are very few
patients with primary pulmonary hypertension and in situ
thrombosis. We had two cases in the last 2 years in whom
we did not have the right diagnosis preoperatively and
both patients died. The diagnosis is very difficult if
they do have the combination of primary pulmonary hypertension
and in situ thrombosis. Lung transplantation is an option
for these rare cases.
Dr Fedullo: That has been
our experience too. I think some min-imum level of pulmonary
arterial pressure has to be reached postoperatively to
assure a good long-term hemodynamic out-come. Unless that
minimum level of pressure is reached, 4 to 5 years later
the patient may present with recurrent symptoms. When
we reevaluate those patients they have developed recur-rent
pulmonary hypertension that is not due to recurrent throm-boembolic
disease. They’ve progressed as a result of small-ves-sel
disease changes. My feeling is that patients who have
an incomplete hemodynamic outcome should probably be reevalu-ated
3 to 6 months after the surgical procedure. If the patient
still has pulmonary hypertension then we should strongly
con-sider medical therapy.
Dr Auger: Two comments,
one of which has to do with the rate of reoperation or
redo pulmonary thromboendarterectomies. The numbers that
have been discussed are consistent with our experience
as well—in the range of less than 1% of operated patients.
It also appears that if a patient experienced a suc-cessful
pulmonary thromboendarterectomy the first time and develops
recurrent, chronic thromboembolic disease, a second successful
thromboendarterectomy is possible. The second comment
relates to our experience with a cohort of patients who
do not achieve normalization of pulmonary artery pressures
postoperatively. Because of the availability of pulmonary
vasodilator therapies, we’re more aggressively treating
those patients who have a suboptimal hemodynamic response
from their pulmonary thromboendarterectomy. We have noted
that if the pulmonary vascular resistance achieved postoperatively
is in the range of 500 to 600, 4 or 5 years down the road
their pulmonary hypertension is typically worse. In many
cases, based on angiographic and other diagnostic studies,
it appears we’re not dealing with recurrent thromboemboic
disease but rather progression of small-vessel disease.
Dr McGregor: This reemphasizes
the point made earlier of why you need a pulmonary hypertension
clinic or center because patients move from the medical
site to the surgical site and back to the medical site.
This reemphasizes that you need to have multidisciplinary
care. Peter and Bill, educate me, what do you think is
the hemodynamic outcome in terms of mean PA pressure and
PVR that would indicate a good long-term out-come versus
naught?
Dr Fedullo: I feel absolutely
comfortable when the PVR is below 300 and I’m terribly
concerned when it is above 500 and uncertain when it is
between the two.
Dr McGregor: And mean PA?
Dr Fedullo: Above 40 I’m
concerned, below 30 I’m comfortable and between the two
I’m uncertain. These patients have to be evaluated sequentially.
If they have a mean PA pressure of 35 after operation,
they should undergo repeat right-heart catheter-ization
in 6 months or a year and if there is any evidence that
the pulmonary hypertension is progressing then at that
point I would initiate medical therapy.
Dr McGregor: And what about
PA pressure in the same situa-tion? If the PA pressure
is 35 at time of discharge?
Dr Fedullo: I would do exactly
the same thing.
Dr McGregor: So anybody
who has a mean PA pressure greater than 30 or PVR greater
than 300 you would recath them down the line?
Dr Fedullo: Yes.
Dr Auger: It’s important
to know the numbers we’re talking about. The number of
patients who are in the category that Peter is discussing
is in the range of 5% to 10% of those under-going surgery.
Dr Mayer: I agree that it’s
the same numbers, for sure less than 10% of the patients.
I think that a less invasive approach for quality control
and long-term assessment might be MR angiog-raphy and
evaluation of right ventricular function. It is a very
precise method and you don’t have to do a recatheterization.
Dr Tapson: One final question.
Any perioperative or postopera-tive care pearls in terms
of management, pressor therapy, any-thing else someone
feels strongly about? I visited the San Diego operation
before and Bill and Peter certainly have a superlative
operation, and it’s very clear that there is a substantial
amount of input from surgery and the pulmonary staff.
Dr Auger: It’s hard in a
moment or two to come up with a suc-cessful formula for
postoperative management of these patients. The two most
formidable problems we have, compris-ing 50% of our in-hospital
mortality, are persistent pulmonary hypertension with
RV dysfunction, and reperfusion lung injury. Meticulous
supportive care, particularly as it pertains to dealing
with reperfusion lung injury, is critical to getting these
patients discharged.
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