Discussion
While the role of PFO in refractory hypoxemia and cryptogenic stroke in
patients with COVID-19 may have often been overlooked throughout the
pandemic, there is currently no evidence-based recommendation regarding
the management of these patients.1, 3-5, 13 To our
knowledge, this report highlights the first case of PFO closure in a
COVID-19 patient using NobleStitch.
While COVID-19 can often present with thromboinflammation and a
hypercoagulable state, right-to-left shunting through a PFO further
increases the risk for paradoxical embolism, possibly due to the
increased right atrial pressure.3, 5, 14 This is a
predicament in patients with a PFO in the setting of COVID-19 pneumonia,
where increased right-sided pressures induce vascular damage, further
activating the coagulation system and exacerbating the risk for
paradoxical embolism.1, 4, 5 Moreover, the increased
pulmonary pressures in these patients may be responsible for the
refractory hypoxemia that is seen.3, 4 Surgical
correction may not only improve oxygenation and right-to-left shunting
in these patients, but it can also help prevent cryptogenic
strokes.1, 4, 13
The NobleStitch provides a novel way of closing a PFO which represents a
significant source of embolic stroke and refractory
hypoxemia.8 Guided by transesophageal echocardiography
(Video 1), this technique effectively closes the PFO by applying sutures
through the septum primum and septum secundum, subsequently creating a
knot between the two sutures and removing excess suture material,
thereby avoiding many risks that accompany septal
occluders.8 Hypercoagulable patients such as those
with COVID-19 may be at increased risk of thrombotic complications with
permanent implants with a large device burden. Additionally, these
permanent devices can eventually hinder left-sided heart procedures in
younger patients who might benefit from such interventions later on in
the future.9
Thus far, NobleStitch has shown promising results in terms of
effectiveness, safety, and longevity.9, 10, 15 To
improve patient selectivity, a retrospective observational study of 247
patients who underwent PFO closure with NobleStitch suggested new
predictors of residual shunting after intervention. This study revealed
improved outcomes with a preoperative PFO < 5mm in width and
absence of a spontaneous right to left shunt, indicators that were both
met in our patient.10 Another prospective
single-center study with a six month follow up period (n=116)
investigated factors that may have contributed to residual intracardiac
shunting \(\geq 2\ (20\%,\ n=23),\ \)revealing partial stitch
detachment (n=12), atrial septal tear (n=3), and KwiKnot embolization
(n=2) as the main causes of right-to-left shunting at follow
up.11 Although NobleStitch is not without
complications, it has clear advantages over commonly used device PFO
closures.8, 9, 11
This case highlights how the NobleStitch procedure may be used to close
a PFO in a COVID-19 patient on VV-ECMO with refractory hypoxemia and
cryptogenic stroke. Particularly useful in younger patients, this
deviceless system overcomes many of the complications associated with
traditional PFO closure devices.8 Given the ubiquity
of COVID-19 and its complications, early detection and treatment of PFO
in patients with severe COVID-19 are critical for timely recovery and
prevention of serious sequelae.4 Furthermore, given
the hypercoagulable state with severe COVID-19, choosing a deviceless
method to close the PFO may avert clot formation, future strokes, and
the need for anticoagulation. This case highlights that the NobleStitch
device shows promise in avoiding severe neurologic sequelae of
cryptogenic stroke. Notably, PFO closure with NobleStitch is a
relatively noninvasive cardiac intervention with a low device burden,
allowing for future surgical intervention, especially in younger
patients.