Dacron-woven pacemaker pouch. Influence on long-term pacemaker mobility. Pacemaker migration can interfere with correct pacing system function and patient comfort. A Dacron pouch has been developed which may prevent these problems. To assess the efficacy of the pouch, we measured various factors of pacemaker mobility in 100 patients after long-term follow-up. The patients were divided into three groups on the basis of their dictated operative reports: group 1, no pouch or anchoring stitch; group 2, pouch only; group 3, anchoring stitch to pacemaker header or pouch. The average age of the study population was 74.3 +/- 11 years. Total follow-up time was 42 +/- 28 months (group I, 53 +/- 32 months; group 2, 36 +/- 23 months; group 3, 34 +/- 25 months). There were no significant differences when pacemakers were measured for movement in the inferosuperior and lateromedial directions, nor was there any difference in the distance between the incision scar and the pacemaker header in any group. There was a significant difference between group 1 and groups 2 and 3 when the degree of tilt of the pacemaker off the chest wall was compared. This was 46 degrees +/- 34 degrees for group 1 and 27 degrees +/- 26 degrees and 26 degrees +/- 27 degrees for groups 2 and 3, respectively (p less than 0.02 for both). These data suggest that the Dacron pouch does not restrict pacemaker mobility parallel to the chest wall during long-term follow-up but does reduce the angle to which the pacemaker can be tilted relative to the chest wall. 