Keywords
pulmonary embolism - chronic thromboembolic pulmonary hypertension - pulmonary endarterectomy
Case Description
A 21-year-old male patient (marathon runner) with progressive dyspnea over 8 weeks
was admitted to hospital on an emergency basis. The initial examination at admission
revealed cardiopulmonary dysfunction with normal blood pressure, tachycardia (112
bpm) and hypoxia (po
2 50.1 mm Hg), and an elevation of D-dimeres (5.5 mg/L). Echocardiography, chest computed
tomographic scan, and a duplex sonography of the lower extremity veins showed a massive,
bilateral pulmonary embolism with right ventricular dysfunction (right ventricular
systolic pressure: 90 mm Hg) and a concomitant popliteal vein thrombosis. Screening
for thrombophilia was negative.
The patient was treated systemically with heparin and 120 mg of recombinant tissue
plasminogen activator (rt-PA), that is, recombinant tissue plasminogen activator (Alteplase)
intravenously followed by catheter-based thrombus fragmentation. As the patient remained
in critical clinical condition, he was transferred to a cardiac surgical center and
underwent emergent bilateral pulmonary embolectomy, right ventricular thrombectomy,
and persistent foramen ovale (PFO) closure. Because of tearing, the right pulmonary
artery was reconstructed by a bovine pericardial patch. Postoperatively, the patient
was anticoagulated orally with phenprocoumon.
Although the patient's clinical condition improved, he never reached his former physical
capacity. Therefore, he consulted several pulmonologists and cardiologists for further
evaluation of his dyspnea. Pulmonary function tests and blood gas analysis were normal.
Echocardiography showed progressive right ventricular dysfunction, and multiple mismatched
pulmonary perfusion defects were detected by VQ scan. Chronic thromboembolic pulmonary
hypertension (CTEPH) was suspected 2 years after the initial event.
At admission in our clinic, the patient was in WHO functional class II. Echocardiography
and magnetic resonance imaging (MRI) showed right ventricular dysfunction (tricuspid
annular plane systolic excursion [TAPSE]: 13 mm, right ventricular ejection fraction
[RVEF]: 37%). In addition, peripheral perfusion defects were detected by VQ scan.
Besides, a right pulmonary artery stenosis was found by MRI ([Fig. 1]). Right heart catheterization revealed borderline pulmonary hypertension at rest,
pathological increase of pulmonary artery pressure at exercise, and a pressure gradient
between central and peripheral right pulmonary artery ([Table 1]). Biplanar digital subtraction angiography showed bilateral pulmonary segmental
artery stenoses and occlusions. Indication for surgery was based on the patient's
individual loss of quality of life, pulmonary hemodynamics at exercise, and pulmonary
artery obstructions at angiography.
Table 1
Right heart catheter before 3 months and 1 year after PEA
|
Right heart catheter
|
Pre-op
|
Post-op 3 mo
|
Post-op 12 mo
|
|
At rest
|
150 W
|
At rest
|
150 W
|
At rest
|
125 W
|
|
PAmean
|
20
|
37
|
15
|
33
|
14
|
31
|
|
CI
|
3.4
|
6
|
3.45
|
11.2
|
3.2
|
8.8
|
|
PVR
|
90
|
234
|
94
|
86.6
|
107
|
88.03
|
|
Gradient
|
10
|
40
|
0
|
4
|
–
|
–
|
Notes: All pressures were measured proximally to the stenosis. (PAmean = mean pressure
in the pulmonary artery in mm Hg; CI = cardiac index in L/min/m2; PVR = pulmonary vascular resistance in dyn*sec/cm[5]; gradient = pressure gradient central and peripheral of the stenosis of the right
pulmonary artery in mm Hg).
Fig. 1 Cardiac magnetic resonance imaging showing the central stenosis of the right pulmonary
artery after the first operation.
Surgery was performed under extracorporeal circulation and two phases of deep hypothermic
circulatory arrest (17 and 15 minutes). A complete endarterectomy of both pulmonary
arteries was achieved and the central right pulmonary artery was reconstructed, using
an autologous pericardial patch. The patient was extubated on postoperative day 1
and discharged from the hospital on the 14th day after an uneventful postoperative
course. An oral anticoagulation with phenprocoumon was recommended for life time.
The patient was reevaluated after 3 months. He was in good clinical condition with
normal physical capacity, corresponding to WHO functional class I. The right heart
catheterization showed normal pulmonary hemodynamics at rest and at exercise. There
was no pressure gradient between the central and the peripheral right pulmonary artery
at rest, and 4 mm Hg at exercise ([Table 1]).
One year after the surgery, his physical capacity had further improved. MRI showed
a normal dimension and function of the right ventricle (RVEF: 61%). Pulmonary hemodynamics
were normal at right heart catheterization ([Table 1]). Spiroergometry revealed a maximum work load of 200 W for 12 minutes with a maximum
oxygen uptake of 45.9 mL/min/kg.
Discussion
The actual case report describes a patient, who developed CTEPH in combination with
a hemodynamically relevant stenosis of the central right pulmonary artery after thrombolysis
and surgical embolectomy. The pathogenesis of the causal popliteal vein thrombosis
of the patient could not be clarified and no coagulation abnormalities were found.
Within the respective literature, you will find few references describing pulmonary
embolism after prolonged running. The pulmonary artery stenosis was interpreted as
a consequence of the first operation.
Assessing the presented case, the patient was treated according to current guidelines,
which divide patients with pulmonary embolism into two major subgroups: high-risk
and non–high-risk patients, describing the early mortality rate. Thrombolysis was
unsuccessful probably due to the organization of the thrombotic material and recurrent
episodes of acute embolism.
Interventional catheter-based fragmentation did not improve pulmonary hemodynamics.
In literature, conclusive results of this procedure are still missing. Surgical embolectomy
was then indicated.[1]
[2]
[3]
One to five percent of patients with acute pulmonary embolism develop CTEPH.[4] Patients with persisting or recurrent dyspnea and acute pulmonary embolism in their
medical history are screened with echocardiography and VQ scanning of the lungs. Right
heart dysfunction and mismatched perfusion defects are suspicious of CTEPH. These
patients should be transferred to an expert center to ensure the correct diagnosis
by right heart catheterization and pulmonary angiography. An experienced interdisciplinary
team should assess the operability. Using extracorporeal circulation and deep hypothermic
circulatory arrest, pulmonary endarterectomy is the therapy of choice for patients
with CTEPH, and it is a safe, standardized, and often curative treatment.[5] Even patients in WHO functional class II should be evaluated, depending on their
individual loss of quality of life, although they might not have CTEPH by definition
(mean pressure in the pulmonary artery ≥ 25 mm Hg).[4]
The patient was presented in WHO functional class II, but his individual loss of quality
of life was distinct. Right-heart catheter showed borderline pulmonary hypertension
at rest with pathological increase under work. Furthermore, there was a postoperative
hemodynamically relevant stenosis of the right pulmonary artery after acute pulmonary
embolectomy. The decision for surgery was made on individual basis regarding the explicit
wish of the patient to have this surgery performed. A complete normalization of pulmonary
hemodynamics and physical capacity on a long-term basis could be achieved by pulmonary
endarterectomy with patch reconstruction of the right pulmonary artery.
