Keywords
aortic valve - extracorporeal circulation - transcatheter valve implantation
Introduction
Patients undergoing transcatheter aortic valve implantation (TAVI) present with multiple
comorbidities such as coronary artery disease, chronic obstructive pulmonary disease,
and impaired left ventricular function. These relevant comorbidities and application
of rapid ventricular pacing result in a high risk for hemodynamic deterioration during
valve implantation with potentially life-threatening situations. Lifesaving actions
might be associated with an inherent risk for adverse events. Venoarterial extracorporeal
membrane oxygenation (ECMO) offers the option for temporary cardiac support and can
be implanted in advance when hemodynamic problems are anticipated. In case of sudden
hemodynamic collapse, emergency implementation of ECMO support can be instituted during
the procedure via peripheral vessels.[1]
Case Description
A 71-year-old man with severe aortic valve stenosis was planned for TAVI due to a
reduced clinical condition and the presence of relevant comorbidities including reduced
left ventricular ejection fraction of 30%, coronary artery disease, chronic obstructive
pulmonary disease, kidney insufficiency, and history of abdominal surgery for colon
carcinoma. After routine preoperative workup, a transfemoral implantation of a CoreValve
(29 mm, Medtronic, Minneapolis, Minnesota, United States) was planned in general anesthesia.
At our institution, transfemoral TAVIs are routinely executed in general anesthesia
to facilitate transesophageal echocardiography for intraprocedural guidance and postprocedural
quality control. A 6-French (F) pigtail catheter was inserted via the left common
femoral artery for contrast media visualization of the aortic root, a pacemaker wire
was inserted via the left femoral vein for rapid ventricular pacing, and an 18-F sheath
was inserted via the right common femoral artery for balloon valvuloplasty and valve
implantation. After unproblematic balloon valvuloplasty, the CoreValve was advanced
into the desired position. Valve deployment was then started under fluoroscopic guidance;
after the release of about two-thirds, the valve threatened to slide into the ventricle
with subsequent drop of blood pressure. The valve was retracted into the delivery
catheter while cardiopulmonary resuscitation was started. Since the patient could
not be stabilized, ECMO cannulas were implanted into the vessels of the left groin
using the arterial (18-F cannula) and venous (22-F cannula) access of the previously
inserted pigtail catheter and pacemaker wire, respectively. Pericardial effusion and
rupture of the aortic root were excluded as potential triggers for the hemodynamic
impairment while the patient was stabilized under ECMO support. However, a pigtail
catheter was no more present for the injection of contrast media to guide the unfinished
CoreValve implantation. Therefore, a Y-connector (3/8″-3/8″-1/4″) was plugged into
the arterial line of the ECMO. An additional 18-F sheath was shortened and inserted
into the 1/4″ connector with subsequent deairing ([Figs. 1] and [2]). This sheath facilitated the introduction of a pigtail catheter for contrast media-guided
and uneventful implantation of the CoreValve prosthesis.
Fig. 1 Dummy model of intraoperative setting with arterial and venous extracorporeal membrane
oxygenation cannulas. A Y-connector (2) (3/8″-3/8″-1/4″) was plugged into the arterial
line (1) and an 18-F sheath (3) was joined to the 1/4″ connector using a connecting
tube (5) facilitating the insertion of a pigtail catheter (4). Venous line (6).
Fig. 2 Dummy model of all implemented and separated parts used for the arterial line. Arterial
cannula (1); Y-connector (2); 18-F sheath (3); pigtail catheter (4); and connecting
tubes (5).
After 30 minutes of reperfusion, the ECMO was successfully weaned, all insertion sites
were manually compressed to avoid further bleeding and the patient was transferred
to the intensive care unit. The patient's stay in the intensive care unit was 7 days
and finally was discharged after additional 22 days.
Discussion
In the present case report, we describe the advancement of a pigtail catheter through
an arterial extracorporeal membrane oxygenator cannula during a TAVI procedure. Insertion
of a Y-connector facilitated injection of contrast media into the aortic root for
exact positioning of the CoreValve after emergency establishment of ECMO support due
to hemodynamic collapse. Of note, the additional insertion of the pigtail catheter
through the 18-F arterial cannula did not markedly impair the ECMO flow. Additional
distal limb perfusion was not instituted after ECMO implantation since we decided
to restrict the use of extracorporeal circulation on the time in the hybrid operating
room. Luckily, the patient could be weaned from the ECMO in the operating room and
was transferred to the intensive care unit.
The EndoReturn Arterial Cannula (Edwards Lifesciences Co., Irvine, California, United
States) would have been an alternative to the custom-made additional port for the
pigtail catheter as described in the presented case. This cannula features a “side
arm” with a hemostasis valve that allows the passage of additional catheters. However,
our routine cannula for peripheral ECMO implantation was used in the emergency situation.
Additional costs would incur in routine use of the EndoReturn Arterial Cannula.
As we described an urgent ECMO implantation due to sudden hemodynamic collapse, Arlt
et al reported about a series of four TAVI patients with cardiopulmonary resuscitation
or hemodynamic instability with need for ECMO support, respectively. In two patients,
the transcatheter procedure was successfully continued; two further patients were
transferred for surgical aortic valve replacement of which one patient died 6 days
after the procedure due to multiorgan failure.[2]
ECMO support can also be instituted before beginning a TAVI procedure in case of conceivable
hemodynamic problems. Seco et al reported about eight patients with prophylactic ECMO
implantation in patients undergoing TAVI procedures. The decision for ECMO implementation
was made by the heart team due to hemodynamic instability after balloon aortic valvuloplasty,
general “borderline hemodynamics” before the definitive valve implantation, valve
malpositioning, or ventricular fibrillation. The authors finally present one patient
with a life-threatening bleeding but no mortality.[3]
In summary, the presented case report describes a safe technique of pigtail insertion
via an arterial ECMO cannula for contrast media injection during TAVI and can help
successfully finish TAVI procedures even after unplanned ECMO support.
