INTRAOPERATIVE RADIOFREQUENCY MICROBIPOLAR COAGULATION TO REPLACE INCISIONS OF MAZE-III PROCEDURE FOR CORRECTING ATRIAL-FIBRILLATION IN PATIENTS WITH RHEUMATIC VALVULAR DISEASE
Am. Patwardhan et al., INTRAOPERATIVE RADIOFREQUENCY MICROBIPOLAR COAGULATION TO REPLACE INCISIONS OF MAZE-III PROCEDURE FOR CORRECTING ATRIAL-FIBRILLATION IN PATIENTS WITH RHEUMATIC VALVULAR DISEASE, European journal of cardio-thoracic surgery, 12(4), 1997, pp. 627-633
Objective. Radiofrequency catheter ablation of atrial tachycardias and
flutter is an established technique. The same modality in the microbi
polar mode is effective in producing full thickness coagulation injury
. Cox's maze procedure is highly successful in curing atrial fibrillat
ion (AF) surgically. However, it consumes relatively long cross clamp
time and cardiopulmonary bypass time. In this study, radiofrequency mi
crobipolar coagulation was used as an adjunct to corrective valve surg
ery, as an intraoperative ablative modality to replace Cox's maze III
incisions, thus remarkably shortening the procedure. The results of th
is procedure are compared historically with those of 26 patients who u
nderwent corrective valve surgery alone. Methods: Radiofrequency micro
bipolar coagulation was used to produce conduction blocks along the Co
x's maze III incision lines as an adjunct to valve surgery in 18 patie
nts in atrial fibrillation undergoing surgery for rheumatic valvular d
isease. A bayonet type bipolar forceps with an active tip length of 7
mm drawing current from a microbipolar port of Valleylab Force 4 elect
rosurgical unit (Valleylab, Boulder, CO) was used for microbipolar coa
gulation. A 3-mm retinal handheld cryoprobe working on nitrous oxide g
as was used for cryoablation, Results: A total of 15 survivors in the
coagulation maze group were followed from 43 to 224 days (149.7 +/- 73
.1 mean +/-S.D.). Twelve of the 15 survivors (80%) converted to normal
sinus rhythm (70% confidence limit: 64.7-90.6%). Atrial transport fun
ction studies with pulsed wave doppler, showed presence of a wave in a
ll the 12 (100%) patients in tricuspid valve flow and in nine (75%) pa
tients in mitral valve flow. The procedure took 11.62 +/- 3.86 min of
elective cardioplegic arrest time for the left atrial portion and 18.7
1 +/- 4.25 min of cardiopulmonary bypass time during reperfusion for t
he right atrial portion. Of the 23 survivors out of 26 patients who un
derwent the valve procedure alone, only one patient (4.3%) converted t
o normal sinus rhythm (70% confidence limit: 0.6-14%). Conclusion: Thu
s, our modification considerably shortened the time taken for creating
the maze in comparison to the Cox's maze procedure and was effective
in restoring normal sinus rhythm in 80% of the patients. (C) 1997 Else
vier Science B.V.