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Open Access, Volume 2
Acute thrombectomy for saddle pulmonary embolus: Case
presentaon and review of management
Case Report
www.jcimcr.org
Journal of
Clinical Images and Medical Case Reports
Received: Feb 11, 2021
Accepted: Mar 09, 2021
Published: Mar 11, 2021
Archived: www.jcimcr.org
Copyright: © Shukla R (2021).
*Corresponding Author: Rajeev Shukla
Department of Cardiothoracic Surgery, Monash Medi-
cal Centre, Clayton, VIC Australia.
Email: drshuklara@gmail.com
Abstract
Pulmonary embolism is the third leading cause of cardiovascular
death aer myocardial infarcon and stroke [1,2,4,5]. Ancoagulaon is
the primary choice of treatment for the majority of paents presenng
with acute pulmonary embolism [2,4]. However, a greater risk of mor-
tality in paents with right ventricular (RV) dysfuncon may open the
door to more aggressive treatment modalies [2]. We present the case
of a paent who was diagnosed with a post-operave saddle pulmonary
embolus that failed inial treatment with ancoagulaon and required
emergency thrombectomy to prevent mortality. A brief overview of treat-
ment opons is highlighted.
Keywords: Pulmonary embolism management, Pulmonary embolism
guidelines, Saddle pulmonary embolism, Catheter based intervenon.
Rajeev Shukla1,2*; Adrian Pakavakis4; Prasanth Sadasivan Nair1; Anna Shukla3; Julian A Smith1; Prashant Joshi1
1Department of Cardiothoracic Surgery, Monash Medical Centre, Clayton, VIC Australia.
2Department of Surgery, University of Melbourne, Melbourne, VIC Australia.
3School of Health Sciences, University of Melbourne, Melbourne, VIC Australia.
4Department of Intensive Care Medicine, Monash Medical Centre, Clayton, VIC Australia.
ISSN 2766-7820
Introducon
Pulmonary embolism (PE) has a variable presentaon ranging
from incidental discovery in asymptomac paents to severe hae-
modynamically instability, which therefore makes the diagnosis
clinically challenging [1,2,3]. Mortality rates three months aer PE
are linked to the size of the embolus and the degree of RV strain
and have been reported as high as 17% [3]. The mortality rates of
paents presenng in cardiogenic shock can be as high as 30% [6].
PE is a preventable disease; with early recognion and the inia-
on of appropriate treatment, mortality can be prevented and as-
sociated morbidity signicantly improved. Treatment modalies
are iniated with the aid of risk stracaon and deviaon from
this can result in potenally dire consequences.
Case presentaon
A 46-year-old man was admied for management of an acute
exacerbaon of Crohn’s disease. His medical history included
deep vein thrombosis six weeks earlier with obstrucve thrombus
in one of the commitant peroneal veins in the midcalf extending
to 10 cm but with no extension above the knee. During the hos-
pital admission the paent required a semi-elecve laparoscopic
total colectomy. Aer an inial uncomplicated recovery, the pa-
ent developed sudden onset hypoxia (SaO2 70% RA), sinus tachy-
cardia (HR 135) and hypotension (BP 90/70 mmHg) on the sec-
ond post-operave day. The paent required low dose inotropic
support with noradrenaline to maintain haemodynamic stability.
Electrocardiography demonstrated sinus tachycardia with S1Q3T3
features. A transthoracic echocardiogram (TTE) demonstrated a
www.jcimcr.org Page 2
Citaon: Shukla R, Pakavakis A, Nair PS, Shukla A, Smith JA, Joshi P. Acute thrombectomy for saddle pulmonary embolus: case
presentaon and review of management. J Clin Images Med Case Rep. 2021; 2(2): 1023.
large saddle PE (Figure 1), dilated and severely hypokinec right
ventricle, dilated inferior vena cava (IVC) with no collapse during
respiraon and moderate pulmonary hypertension (PA systolic
pressure 50 mmHg). An urgent computed tomography pulmonary
angiogram (CTPA) was obtained and revealed a massive saddle
pulmonary embolus (Figure 2) extending from the main pulmo-
nary trunk across the bifurcaon of the pulmonary trunk into
both right and le main pulmonary arteries (Figure 3). Inially
the paent was commenced on a therapeuc heparin infusion,
however, connued haemodynamic instability warranted acute
surgical pulmonary embolectomy. The paent was urgently trans-
ferred to the operang theatre where arterial and central venous
lines were inserted. Following the inducon of general anaes-
thesia the paent was intubated and venlated. The surgical ap-
proach required median sternotomy and subsequent administra-
on of heparin for preparaon of cardiopulmonary bypass, which
was achieved by placing cannulae in the ascending aorta and both
cavae. A dose of antegrade cold blood cardioplegia was delivered
on applying the cross clamp across the aorta, which achieved in-
stantaneous electromechanical arrest. A vercal pulmonary arte-
riotomy was performed revealing a large thrombus extending into
the le and right pulmonary arteries (Figure 4). The enre throm-
bus was carefully removed en-bloc (Figure 5 and 6). On comple-
on of the embolectomy, the pulmonary artery was closed in two
layers of 5-0 prolene. Intraatrial and intraventricular extension of
the thrombus was excluded by perfoming a small right atriotomy,
which was subsequently closed in two layers of 5-0 prolene. The
paent was weaned from cardiopulmonary bypass and heparin
reversed with protamine. Roune closure of the sternum and
so ssues completed the surgery. The paent was transferred
to the intensive care unit in a haemodynamically stable condion
on a low dose of noradrenaline. The post bypass transoesopha-
geal echocardiogram showed improved contraclity of the right
ventricle with overall reducon in diameter. The paent was ex-
tubated on day 1 and made an unevenul recovery. The paent
subsequently had an inferior vena cava lter inserted two days
aer embolectomy and was ancoagulated with warfarin. An ul-
trasound during this procedure revealed a le iliac vein clot which
was presumed to be the source of the pulmonary embolus. Re-
peat TTE one week post embolectomy revealed normal RV ejec-
on fracon with upper normal RV size. The IVC was mildly di-
lated with sasfactory inspiratory collapse. Pulmonary artery (PA)
pressures were unobtainable. The paent was discharged from
hospital thirteen days following embolectomy. Three months post
discharge the paent suered a small intracranial bleed without-
neurological injury. At seven years, the paent is alive and doing
well with no residual cardiac dysfuncon.
Discussion
The annual incidence of pulmonary embolism has been report-
ed to be between 39-115/100,000 populaon globally and is the
third leading cause of cardiovascular mortality behind myocardial
infarcon and stroke [1,2,4,5]. Diagnosis can oen be challenging
due to the spectrum of presentaons ranging from asymptomac
to cardiovascular collapse and death [1-3]. Health organisaons
world-wide have begun to adopt muldisciplinary pulmonary em-
bolism response teams (PERTs) who are tasked with convening in
real-me to aid clinical decision regarding management - taking
into account risk factors and risk stracaon scores, such as the
pulmonary embolism severity index (PESI) to assess risk of early
mortality [1,2,5]. The PESI score straes paents into 5 levels of
risk from very low to very high. It has been extensively validated
and shown to be reliable in idenfying paents at low risk of ear-
ly mortality [1,5]. The AHA and ESC guidelines both support the
use of risk stracaon scores such as PESI or Geneva Pulmonary
Embolism Score to help categorise paents into levels of risk and
determine the need for further invesgaons and the nal treat-
ment pathway [5,8]. However, it is important to note that dier-
ent risk stracaon models assess dierent aspects of risk. The
AHA/ESC categorise paents into high, intermediate and low risk
of mortality resulng from PE in 30 days. In comparison the PESI
scheme predicts the mortality in 30 days due to any cause [2,5].
Hence risk stracaon should aid in clinical decision making but
not be used to dene absolute treatment modalies. ESC guide-
lines recommend early use of echocardiography even in paents
determined as low-risk PE due to the signicant increase in mor-
tality in the presence of RV dysfuncon [5].
Figure 1: Transthoracic echocardiogram image demonstrang large
saddle pulmonary embolus.
Figure 2: Axial CTPAdemonstrang saddle pulmonary embolus
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Figure 3: Axial and coronal CT imagesdemonstrang extension of pul-
monary embolus into le and right pulmonary arteries
Treatment
The treatment phases for acute PE can be divided into (1) hae-
modynamic and respiratory support and (2) intervenon of acute
pulmonary embolism.
(1) Haemodynamic and respiratory support
Severe PE compromises both circulaon and gaseous exchange
and presents as hypoxaemia and RV failure. The venlaon and
perfusion mismatch that is observed in such cases requires care-
ful, deliberate intervenons to prevent further haemodynamic
deterioraon. RV dilataon occurs as a result of PA obstrucon
causing a sudden rise in PA pressures. The developing RV failure
further compromises forward ow from RV to LA and consequent-
ly a fall in cardiac output. The complex physiological changes re-
quire judicious and careful iniaon of all supporve interven-
ons. Supplemental oxygen is preferred via non-invasive routes
in the rst instance. Mechanical venlaon should be reserved
for paents who are unable to tolerate non-invasive oxygenaon
and the use of anaesthec inducon agents which can cause hy-
potension should be avoided. Posive-pressure venlaon should
be selected at the lowest tolerable pressures to prevent further
reducon in venous return. Volume replacement should be giv-
en judiciously in order to prevent over distenon of a failing RV,
thereby compromising cardiac output. Such replacement should
Figure 4: Pulmonary arteriotomy revealing large thrombus.
Figure 5: Removal of large thrombus.
Figure 6: Large pulmonary embolus removed en-bloc.
www.jcimcr.org Page 4
be guided by invasive CVP monitoring or TTE. Inotropic use has
been shown to be eecve in the haemodynamically unstable pa-
ent by improving coronary perfusion [5].
(2) Intervenon of acute pulmonary embolism
Ancoagulaon: Both the ESC and AHA recommend that in the
absence of absolute contraindicaon, therapeuc ancoagulaon
with low molecular weight heparin (LMWH) or fondaparinux is
commenced while concomitantly performing appropriate inves-
gaons for all risk categories of PE. AHA also recommend the
use of unfraconated heparin (UFH), however, the ESC guidelines
tend not to prefer UFH due to it carrying a higher risk of bleed-
ing and heparin-induced thrombocytopaenia. ESC recommend
reserving UFH use to paents with severe renal impairment (CrCl
<30 ml/min), severe obesity or imminent haemodynamic decom-
pensaon requiring reperfusion intervenon [5,8].
Thrombolysis: The ESC and AHA recommend thrombolysis
for intermediate and high risk PE. Studies have shown a faster
improvement in RV funcon, reducon in PA pressure and pul-
monary obstrucon when thrombolysis is commenced within 48
hours of onset of symptoms, although intermediate-risk paents
experienced a higher risk of severe extracranial and intracranial
bleeding. An overall reducon in mortality rates of 50-60% have
been reported for the laer category of paents. Early thromboly-
sis and its eect on long term sequalae of acute PE such as chronic
pulmonary hypertension remain unknown, and results from the
PEITHO trial conrm no role for thrombolysis for intermediate PE
for the purpose of prevenng long term sequalae [5,8].
Catheter Based Intervenons: These intervenons are pro-
posed for paents who are categorised as high or intermediate
risk PE with absolute or relave contraindicaons to systemic
thrombolysis, failed thrombolysis or at risk of signicant clinical
deterioraon prior to the thrombolyc eect [1,5,7,8]. Two types
of intervenon exist:
Embolectomy – Involves a catheter being navigated to the site
of clot burden and retrieval of the clot by aspiraon. Studies have
shown these intervenons to signicantly reduced RV/LV pres-
sure rao but only produce modest reducon in PA pressure. No
intracerebral bleeding events have been reported [7].
Catheter directed thrombolysis – Involves the delivery of
thrombolycs locally to the site of clot burden, thereby excluding
the use of systemic thrombolycs. This can be achieved by use
of a low-power, high-frequency ultrasound catheter. The ULTIMA
trial demonstrated improvement in RV funcon and PA pressure
in the short-term, however, the long-term benet remains un-
clear. Bleeding rates are higher than those observed by systemic
ancoagulaon but lower than systemic thrombolysis [5,7,8].
The AHA and ESC recommend the use of catheter based in-
tervenons in high risk paents in whom thrombolysis has failed
or is contraindicated. Given the lack of prospecve, randomised
trials examining catheter-based intervenons, Theroux et al pro-
pose that paents in the high and intermediate risk PE category
be considered on a case-by-case basis with discussion at the PERT
team level [5,7,8].
Surgical embolectomy: is reserved for paents in the high or
intermediate risk PE categories with absolute contraindicaons to
thrombolysis or at risk of rapid clinical deterioraon prior to the
eect of systemic thrombolysis or as a rescue intervenon where
thrombolysis has failed. Studies have shown that prompt surgical
intervenon signicantly improves RV funcon and PA pressure
with a lower risk of major bleeding when compared with throm-
bolysis. No dierence in 30 day mortality was found between sur-
gical embolectomy and thrombolysis (13% and 15%), however,
stroke and re-intervenon rates within 30 days was higher with
thrombolysis [5,7,8].
Conclusion
We present the case of a 46-year-old man who had success-
ful emergency surgical embolectomy for a high risk saddle pul-
monary embolism. RV dysfuncon and PA pressure returned to
normal post procedure. The paent is alive at 7 years and his
echocardiogram at 5 years post embolectomy remains stable with
mildly dilated right ventricle and normal right ventricular func-
on. Both the AHA and ESC guidelines make recommendaons
aimed at improving the morbidity and mortality of paents pre-
senng with acute, high and intermediate risk PE, which include
the early involvement of the PERT team to aid real-me clinical
assessment and decision for treatment opons and the early use
of echocardiography to assess RV dysfuncon – even in low risk
PE [1,2,5]. Thrombolysis, catheter based and surgical interven-
ons for treatment of acute PE are endorsed by AHA and ESC.
Both catheter-based and surgical intervenons require special-
ist experse and therefore outcomes are variable and reecve
of this [5,7,8]. In our centre we oer both services, however, we
have demonstrated that with early surgical intervenon by an ex-
perienced team, excellent outcomes can be achieved without the
risk of stroke, bleeding or re-intervenon that is inherent with
thrombolyc intervenons.
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