Case
Case 1; A 54 year-old female was admitted due to shortness of breath and
persistent LVAD low flow alarm. Her initial surgery(HeartMate 3
insertion with mitral and tricuspid valve repair) was 2 years and 6
months prior to this presentation. The LVAD pump flow was 1.4L/minute
with 5400 rpm on admission, which was significantly lower than the
baseline(i.e. 4.0L/minute with 5400 rpm). An echocardiography revealed
that the aortic valve was open with every beat with a dilated left
ventricle. While lactate dehydrogenase(LDH) level was slightly
elevated(256U/l), serum haptoglobin(145mg/dl) and indirect
bilirubin(0.2mg/dl) were within normal range. A computed tomography
angiography(CTA) showed significant outflow graft narrowing at the
vicinity of the LVAD pump(Figure 1A,1B).
Case 2; A 38 year-old male presented with shortness of breath, abdominal
distension, nausea and vomiting. He had had the initial HeartMate 3
implantation and mitral valve repair 1 year and 6 months before. His
pump flow was slightly lower than his baseline, specifically 4.0L/minute
with 6200 rpm on admission and 5.1L/minute with 6200 rpm as baseline. An
echocardiography demonstrated that the aortic valve was open with every
beat. Lab data showed that lactate dehydrogenase(LDH) level was
elevated(425U/l), serum haptoglobin was low(36 mg/dl) and indirect
bilirubin was elevated(3.1mg/dl). An outflow graft angiography was
performed, which showed an apparent outflow graft twisting at the
proximal portion of the outflow graft(Figure 1C) with a significant
pressure gradient about 100mmHg at the twisting by a pull back pressure
measurement(Figure 1D,1E).
Both cases were taken to the operating room with a diagnosis of outflow
graft twisting/kinking. A subcostal approach was utilized to access
directly to the proximal portion of the outflow graft. A reverse-J shape
incision was made in the subcostal area and the outflow graft was
exposed enough to access to the connection between the outflow graft and
the device body. A Rultract retractor (Rultract Inc., Ohio) was used to
lift the rib to obtain a reasonable exposure (Figure 2A). The bend
relief was identified, the plastic frames of the bend relief were
partially removed, and the bend relief was longitudinally opened to
exposed the outflow graft. It was found that the outflow graft was
twisted about 3-4 cm from the device connector (Figure 2B). While the
bend relief was stuck to the surrounding tissue, the bend relief was
detached from the connector using the HeartMate accessory instrument.
Then, the connector was rotated in a direction for untwisting the
outflow graft. A curved-up Rongeur forceps was helpful to rotate. In
both cases, it required to rotate in a counter clockwise fashion in 120
degree to fix the twisting(Figure 2C,2D). Hemodynamics and LVAD
parameters were immediately improved. We did not place an outflow graft
clip given the risks to injure the surrounding structures during a
dissection with a relatively limited exposure. The opening of the bend
relief was covered with a Gore-Tex soft tissue patch(WL Gore & Assoc
Inc, Flagstaff, Ariz). After decent hemostasis, the incision was closed
in layers in the routine fashion. The postoperative course was
uneventful. No recurrent issue has been noted for 4 months of the follow
up period.