1. Intraoperative radiofrequency maze ablation for atrial fibrillation: the Berlin modification 
Miralem Pasic, MD, PhD, Peter Bergs, MD, Peter Müller, MD, Michael Hofmann, MD, Onnen Grauhan, MD, Hermann Kuppe, MD, Roland Hetzer, MD, PhD 
The Annals of Thoracic Surgery 
Volume 72, Issue 5, Pages (November 2001)
DOI: /S (01)

2. Fig. 1
The left atrial part of the standard Cox-maze III procedure encompasses excision of the left atrial appendage, multiple incisions with isolation of the pulmonary veins and consecutive continuous sutures of the left atrial incisions, cryoablation of the dissected coronary sinus and mitral annulus. (The illustration is slightly modified and reprinted with permission from the American College of Cardiology [Journal of the American College of Cardiology 1998;32:1040–7.])
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

3. Fig. 2
In the modified method (the Berlin modification), the incisions and sutures of the standard maze technique are replaced by radiofrequency ablation lines (dashed lines). The line directions are slightly changed. The right and left pulmonary veins are isolated separately using two ablation lines instead of one encircling line as used in the standard maze procedure. The left appendage is not excised.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

4. Fig. 3
A flexible surgical radiofrequency probe (Thermaline, Boston Scientific, San Jose, CA) can be bent manually to adjust it to the anatomy of the left atrium. The probe has seven coagulation electrodes at its distal part; six of them are 12.5 mm in length each and the tip electrode is only 8 mm long. There is a 2-mm distance between each electrode. Any combination of the electrodes can be selected for ablation.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

5. Fig. 4
Dashed lines show the position of the radiofrequency maze lines of the Berlin modification in comparison to the standard surgical maze lines. (A) The first line completes the isolation of the ostia of the right pulmonary veins, (B) and the second maze line isolated the ostia of the left pulmonary veins. The pulmonary veins isolation lines are performed about 10 mm away from the ostia of the pulmonary veins. (C) The third maze line connects the encircling line around the ostia of the left pulmonary veins (the isolation line of the left pulmonary veins) and the middle of the posterior part of the mitral valve annulus. (D) The fourth maze line is a connecting line between the two lines that isolate the ostia of the pulmonary veins. The line lies on the roof of the left atrium.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

6. Fig. 5
Postoperative freedom from atrial fibrillation (% of patients). (OP. = operation.)
The Annals of Thoracic Surgery  , DOI: ( /S (01) )