Pacemaker Help

AB87

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Not Too Sure About this one... I've onlt Done a few of These, Any Help Would Be Helpful

PREOPERATIVE DIAGNOSES:
1 Congenital heart block, status post pacemaker placement.
2 Lead fracture (right ventricular).
POSTOPERATIVE DIAGNOSES:
1 Congenital heart block, status post pacemaker placement.
2 Lead fracture (right ventricular).

NAME OF OPERATION: Pacemaker system replacement (left ventricular
lead by way of left thoracotomy and generator change by way of
abdominal pocket).



Following induction of anesthesia, the
child was sterilely prepped and draped and given IV antibiotics. The
pacemaker was not pacing at this time. The underlying heart rate and
blood pressure were within safe limits. We positioned the patient
with the left side about 35 degrees up. The left side had been
previously marked. We sterilely prepped and draped and administered
IV antibiotics. After an appropriate surgical time-out, we made a
short lateral thoracotomy incision over the fifth intercostal space
and carried it down into the pleural cavity and placed a rib
retractor. This strictly lateral rather than posterolateral approach
was excellent for visualization of the leftward aspect of the
pericardial cavity, and a very convenient place just anterior to the
phrenic nerve was chosen for entry into the pericardium. We did this
with cautery and scissors and did encounter some adhesions, but not
dense adhesions, to the left ventricle. We dissected anteriorly to
confirm that we were at the left ventricular free wall by noting the
position of the left anterior descending artery. We tested the
general area using a wand in the unipolar sense and found these
surfaces to be adequate for lead placement. Then, using 5-0 Prolene,
we anchored in place two Medtronic steroid-eluting leads that were
configured to a common cable in order to utilize bipolar pacing. This
was a Medtronic model #4968-35, 35 cm long, lead. The leads were
separated by about a centimeter. The R-wave amplitude was 10.1 mV,
with a pacing threshold of 0.5 volts in the bipolar sense, with an
impedance of 1431 ohms, which was felt to be quite acceptable. Once
connected later to the device, the pacing threshold was 0.75 volts
with an R-wave amplitude of 15.7 mV. With these acceptable lead
characteristics, we now made a midline epigastric incision, which
functionally was actually quite close to the umbilicus due to the very
narrow costal margin. This was adjacent to the leftward pacemaker
pocket. We entered the pocket without difficulty and extracted the
generator and disconnected it from the nonfunctional right ventricular
lead and capped the latter using two 0 silk ties. We irrigated the
pocket with antibiotic saline solution. We then used a <Schnitt>
clamp and a tunneler instrument to form a tunnel between the pocket
and the left chest cavity staying immediately under the rib cage and
using direct palpation. We then used the tunneler to bring the lead
in through into the pocket. We chose a 35 cm length to assure
reasonable redundancy at both ends. We connected the lead to a new
Medtronic generator, model #ADSR01, placed it in the pocket and used
the telemetry wand to measure final characteristics, as described
above. We irrigated further with antibiotic saline solution. We
closed a small midline epigastric fascial defect with two
figure-of-eight 0 Vicryl stitches. By palpation, this seemed secure.
We then closed the pocket and the wound in layers with running
absorbable suture. We then turned our attention back to the
thoracotomy. We removed our previously placed 4 x 4 packing to
retract the lung posteriorly. Then, we irrigated with antibiotic
saline solution, then placed an 8 French pigtail catheter and secured
it to the skin and set it to suction. Hemostasis was good. We
reinflated the lungs, then closed the chest in layers with three
interrupted 0 Vicryl pericostal sutures, followed by closure of the
soft-tissue layers with running absorbable suture, with antibiotic
irrigation at each level. We instilled 4 cc of Marcaine into the
wounds. We placed Steri-Strips and dry dressings. The child
tolerated the procedure well and was extubated and taken back to the
cardiac ICU for further care.
 
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