Wednesday, September 17, 2008
Consult with Surgeon #1
Today we met [face to face] with the Seattle Surgeon from whom we received our first surgical opinion. I expected it to be a routine, 10 minute chat in which we asked about experience, volume and outcomes and then said "see you later".
This was not the case.
I feel a sort of insane hilarity in writing this but it seems that either the surgical plan was incorrectly communicated in prior conversations with our cardiologist OR it has changed. Regardless, there were some significantly different elements to The Plan as we learned of it today. It was a very useful and informative meeting.
The Crib Notes Version of the Consult
Save the Valve
Open chest. Inspect aortic valve. IF valve appears acceptable perform a modified-Kono procedure to enlarge the aortic root and sub-valvar area and remove the obstructive tissue.
IF Valve appears floppy or patently insufficient after supportive sub-aortic tissue removed -----> PLAN B (valve replacement).
Perform a myectomy through the aortic valve to remove any remaining obstruction.
IF Valve OK: Off bypass. Observe valve performance.
IF gradient is satisfactory, valve motion acceptable, minimal regurg ---> Close.
IF gradient unsatisfactory ----> PLAN B (valve replacement).
Aortic valve replacement with mechanical valve and aortic root enlargement
Take down the modified kono [remove patches]. Insert single large patch across valve. Insert new mechanical valve. Off bypass. Close.
Start lifelong warfarin treatment.
------------ END CRIB NOTES -------------------
DISCUSSION FOR THE CHD INSIDERS or WANNABES or STUBBORNLY TRYING TO UNDERSTAND (like us)
Why not do a Ross-Kono procedure?
The R-K gained a lot of popularity in the 90's so we have some pretty good series data at this point. The data shows that over ten years the procedure has a 20% failure rate of the autograft in the aortic position. This is the average failure rate. We know that there is a higher failure rate in patients with risk factors of BAV and Coarctation. They are indicators of a Fibrillin disorder (a connective tissue disorder) which leads to a higher failure rate. Now, I don't know the rate offhand but even if we say that those patients are the 20% - that is too high. ..... I have three boys and if one of them had this condition I would not do a R-K procedure...
Another concern is sensitization/ development of antibodies due to the use of human donor tissue for the pulmonary graft. We try to keep options open in young children and we are having lots of problems in cases where children eventually need life saving heart transplant surgery because they have antibodies due to these grafts. This makes it very hard to find a good tissue match. In the US, bovine grafts are not FDA approved for use in initial pulmonary valve replacements but are approved for subsequent valve replacements. That means we would have to use a human tissue graft for a Ross-Kono pulmonary replacement.
Look, the R-K is a surgeon's procedure. Surgeons like it. Its about opening the whole heart up, fixing it and putting it back together. Its a great surgery - I enjoy doing it but I don't think its the right surgery in this situation.
SAM - Systolic Anterior Motion
A risk in cases of complex LVOT is SAM p where one of the mitral valve leaflets gets pulled into the valve due to the venturi effect. This leads to a significant obstruction. A modified Kono would open up the area and overcomes risk of this complication.
All the Kono procedures are high-risk for heart block. We see about 15% of patients develop heart block. Interestingly we have had a couple develop late onset (2 weeks out) heart block. In most cases it occurs post-op. Children then need to be fitted with a pacemaker. Its risky because the place where we make the incision is the electrical center of the heart but it is impossible to know exactly where it is so it is sometimes cut or damaged by scar tissue. We do our best to follow indications about position but its just a high risk in this procedure.
What about the bio-prosthetic valve we were expecting?
These Bio-p valves do not last long in young children with their fast metabolisms. Its not about outgrowing the valve in size but it degenerates. You would be lucky not to be back inside 5 years. We see it all the time. I would hope to get in a small-adult sized valve but he would need Coumadin therapy with it. I would have to see how big the valve could be but if he grows to his father's size (5 7") he may not need another valve for size - if we can get in a 21mm valve. I will just do my best but you can't be sure till you see it. Sometimes a large valve will impede the motion of the pulmonary valve and some kids can tolerate that and do very well but we just have to see.
Kono-procedure complicates subsequent valve replacements
A Kono procedure also makes it difficult to do valve replacements in future. Many surgeons can't/won't do it. Its a tricky surgery. You have to take down the Kono and resize and reshape the area with new patches [I didn't really follow the detailed explanation of the steps in the take-down and redo. Frankly, anything with Take-Down in it freaks me].
In usual Modified-Kono a L-shaped incision is made but in order to enable a translation to a Kono and Valve replacement in future he would use a straight incision that is appropriate to both surgeries. Also, he would use some techniques that would allow a Ross to be done in future [I may have this wrong].
The facility should do over 400 OHS this year. They are classed as a moderate sized institution. I have never lost a patient doing a Kono procedure but I can't promise that in writing. I do about 3 a year - not because of the complexity but because of the rarity of this condition in children. I have done about 40 of this procedure and related Ross procedures.
I have placed a call to Dr Lewin to talk about a lifetime on Coumadin/Warfarin. I am also interested in the issues of serial valve replacements with the Kono-take-down issues.
Meeting Dr K, 1pm Thursday.
Phone consult with Hanley, 9.30am Thursday.