European Journal of Cardio-Thoracic Surgery 2025, 67(6), ezaf135 ORIGINAL ARTICLE

https://doi.org/10.1093/ejcts/ezaf135 Advance Access publication 16 June 2025

Cite this article as: Bauer SJ, Sugimura Y, Schoettler FI, Immohr MB, Suzuki T, Mehdiani A et al. Iatrogenic aortic dissection in minimally invasive cardiac surgery for

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CONVENTIONAL
atrioventricular valves and atrial structures†. Eur J Cardiothorac Surg 2025; doi:10.1093/ejcts/ezaf135.

Iatrogenic aortic dissection in minimally invasive cardiac surgery

for atrioventricular valves and atrial structures†
Sebastian Johannes Bauer a,b, Yukiharu Sugimura a,b, Friederike Irmgard Schoettler b
,
Moritz Benjamin Immohr a,b, Tomoyuki Suzukib,c, Arash Mehdiani a,b, Hug Aubin a
,
Artur Lichtenberg a and Payam Akhyari a,b,�

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a
Department of Cardiac Surgery, Medical Faculty and University Hospital, Heinrich-Heine-University, Dusseldorf, Germany
b
Department of Thoracic and Cardiovascular Surgery, West German Heart and Vascular Center, University Hospital Essen, Essen, Germany
c
Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan

� Corresponding author. Department of Thoracic and Cardiovascular Surgery, West German Heart and Vascular Center, University Hospital Essen, Hufelandstrasse
55, 45147 Essen, Germany. Tel: þ49-(0)2017234919; fax: þ492017239474905; e-mail: payam.akhyari@uk-essen.de (P. Akhyari).

Received 27 October 2024; received in revised form 15 January 2025; accepted 30 March 2025

Abstract
OBJECTIVES: In the last decades, minimally invasive cardiac surgery has emerged as an alternative approach to conventional median
sternotomy. However, some reports state an increased risk of iatrogenic acute aortic dissection. Evidence remains limited regarding pre­
operative diagnostics for risk reduction and the appropriate adjustment of surgical procedures if acute aortic dissection is detected
intraoperatively.

†Presented at the 77th Annual Scientific Meeting of the Japanese Association for Thoracic Surgery (JATS), Kanazawa, Ishikawa, Japan, 2–4 November 2024.

© The Author(s) 2025. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery.
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2 S.J. Bauer et al. / European Journal of Cardio-Thoracic Surgery

METHODS: In this retrospective single-centre observational study, we analysed 1065 patients who underwent minimally invasive cardiac
surgery via right anterolateral thoracotomy for atrioventricular valves and atrial structures with femoral cannulation for cardiopulmonary
bypass from August 2009 to June 2021. Occurrence of iatrogenic acute aortic dissection was evaluated, along with patient profiles and
the primary composite outcome of major adverse cardiovascular events (non-fatal stroke, myocardial infarction or cardiovascular death).
An optimal perioperative strategy was subsequently described.
RESULTS: Intraoperative iatrogenic acute aortic dissection was observed in 8 patients (0.75%). It was identified at the start of cardiopul­
monary bypass in 4 patients (50.0%). All patients underwent conversion to full sternotomy; 7 patients underwent additional aortic surgery
with circulatory arrest thereafter. In-hospital mortality was 37.5% (n ¼ 3), including 1 intraoperative death. Non-fatal stroke was observed
in 12.5% (n ¼ 1). A preoperative computed tomography scan was missing in 3 patients with aortic calcification (n ¼ 1) and hostile periph­
eral arteries (n ¼ 2).
CONCLUSIONS: Intraoperative aortic dissection in minimally invasive cardiac surgery remains a rare complication. Frequent major ad­
verse cardiovascular events highlight the importance of preoperative imaging based procedure planning. Intraoperatively, early diagnosis
with standardized monitoring and time- and location-specific surgical adaptations might increase safety and outcomes.

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Keywords: Minimally invasive cardiac surgery • Iatrogenic aortic dissection • Extracorporeal circulation • Cardiopulmonary bypass

who underwent MICS via a right anterolateral thoracotomy with

ABBREVIATIONS peripheral cannulation and who experienced intraoperative
IAAD at this long-standing, high-volume MICS centre.
cNIRS Cerebral near-infrared spectroscopy
CPB Cardiopulmonary bypass
CT-A Computed tomography angiography MATERIALS AND METHODS
FA Femoral artery
IAAD Iatrogenic acute aortic dissection Ethics committee approval
IQR Interquartile range
MACE Major adverse cardiovascular events This study was approved by the local ethics committee of the
MICS Minimally invasive cardiac surgery Medical Faculty of Heinrich-Heine-University, D€ usseldorf (Ref.
RA Radial artery 3650). Patient consent was waived due to the retrospective char­
RCA Right coronary artery acter of this study.
SA Subclavian artery
TEE Transoesophageal echocardiography
Study design and data collection
VCD Vascular closure device
This retrospective single-centre observational study aimed to
identify the prevalence of IAAD in MICS, quantify subsequent se­
INTRODUCTION verity and evaluate optimal operative management. From
August 2009 to June 2021, 1065 consecutive patients underwent
In the last decades, minimally invasive cardiac surgery (MICS) MICS for atrioventricular valves, atrial tumours or interatrial sep­
has emerged as an alternative approach to conventional median tum procedures at our institute. In patients with IAAD, the pri­
sternotomy, offering lower overall surgical trauma among other mary outcome was a composite of major adverse cardiovascular
advantages [1–3]. Despite all the benefits of MICS, iatrogenic events (MACE; non-fatal stroke, myocardial infarction and car­
acute aortic dissection (IAAD) remains a rare but life-threatening diovascular death). Preoperative, perioperative and postopera­
complication in cardiac surgery [4–7]. The incidence of IAAD tive data were collected retrospectively from the hospital’s data
may increase in MICS due to the femoral cannulation site for management and quality assurance system.
cardiopulmonary bypass (CPB), which has been described as an
independent risk factor by Williams et al. [4]. In addition, when
performing MICS, options for intraoperative monitoring of car­
Preoperative diagnostic protocol
diac function and visual assessment of the macroscopic features
Our standard preoperative diagnostic protocol has already been
of the heart and great vessels are limited. Due to the nature of
described in detail before [5–11]. Briefly, in addition to normal
the disease and its rare prevalence of 0.06%–0.29%, there is lim­
interview and preoperative physical assessment, preoperative
ited evidence on preoperative diagnostic methods for risk re­
computed tomography angiography (CT-A) of the aorta, sub­
duction [4]. Moreover, data on how to appropriately adjust the
clavian, axillary and iliac arteries was performed since July 2017
surgical procedure if IAAD is identified during surgery remain
as standard imaging for MICS to avoid risks of adverse events at
scarce [7, 9].
our institution [12].
Since August 2009, MICS via right anterolateral thoracotomy
has been performed as the standard procedure for all operations
on atrioventricular valves and atrial structures at the Department Intraoperative management and
of Cardiac Surgery at the University Hospital of D€ usseldorf. To surgical procedure
gain a better understanding of the causes and prevalence of
IAAD in the context of MICS—and to potentially improve surgical Arterial blood pressure was monitored via the right radial artery
management—we conducted a retrospective analysis of patients (RA), and transoesophageal echocardiography (TEE) assessed
 S.J. Bauer et al. / European Journal of Cardio-Thoracic Surgery 3

cardiac function. Cerebral near-infrared spectroscopy (cNIRS) (MICS Control: 19.3%; IAAD: 50.0%) and chronic obstructive pul­
monitored cerebral perfusion. MICS procedures were performed monary disease (MICS Control: 10.8%; IAAD: 37.5%).

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through a right anterolateral mini-thoracotomy with peripheral
CPB via the femoral vessels, as previously described [5–12]. If Surgical characteristics and
femoral artery cannulation was unsuitable due to conditions
such as calcification, plaques or a small diameter (<6 mm), axil­
postoperative outcomes
lary cannulation was used. From September 2018, percutaneous
Of 1065 consecutive patients undergoing MICS, IAAD occurred
femoral cannulation with vascular closure devices (VCDs) was
in 8 patients (0.75%). Table 2 shows representative intra- and
introduced, guided by ultrasound [13]. Dilatation and subse­
postoperative parameters and results. After operations with a
quent cannulation were performed according to Seldinger only
median time of 367 min (circulatory arrest time; 24 min), in-
if both wires showed correct positioning upon TEE control.
hospital mortality was 37.5% (n ¼ 3), of whom one patient died
Cannula size (Fem-Flex, Edwards Lifesciences, USA) was based
intraoperatively (CPB time 562 min) due to severely impaired
on the diameter of the femoral artery as shown in the preopera­ cardiac function accompanied by refractory vasoplegic syn­
tive CT-A or at surgeon’s discretion in cases without preopera­ drome and additional neurological dysfunction. The neurologic­

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tive CT-imaging. If the total body surface area was >2.0 m2, an al impairment was presumably caused by prolonged cerebral
additional venous cannula was placed in the right jugular vein. hypoperfusion due to an initially undetected IAAD evolving
from the clamping site, leading to global cerebral oedema, with
Statistical analysis no chance of therapeutic success (Patient 1). The 2 remaining
patients who deceased in intensive care unit originally suffered
Statistical analysis was performed using IBM SPSS Statistics from retrograde IAAD during cannulation (Patient 2), and ante­
29.0.1.1 (IBM, USA). Descriptive and comparative analyses (χ2- grade IAAD caused by a suture for the tricuspid annuloplasty
test, Mann–Whitney U-test) were conducted. The Shapiro–Wilk (Patient 3). Another IAAD patient had non-fatal apoplexy post­
test assessed normality, and Fisher’s exact test was used for operatively (Patient 4), resulting in an overall incidence of the
expected values <5. Interval-scaled data are expressed as the primary outcome—MACE—among patients with IAAD of
median and interquartile range (IQR). 50.0% (n ¼ 4).

Representative perioperative clinical features

RESULTS
An overview of the perioperative features of 8 IAAD patients are
Patient baseline characteristics presented in Supplementary Material, Table S1. Seven patients
underwent mitral valve surgery, of whom 2 had additional tri­
The patient profiles and relevant comorbidities are shown in
cuspid valve repair. One patient underwent surgical atrial septal
Table 1. Most patients suffered from a vitium of the mitral valve
defect closure. IAAD was identified at various stages: at the start
(98.5% in all MICS). Baseline characteristics did not show signifi­ of CPB (n ¼ 4), at aortic declamping (n ¼ 2), during the
cant differences except for EuroSCORE II [MICS Control: 1.6
(IQR, 1.0–3.5) versus IAAD: 4.4 (IQR, 3.3–8.9)], smoking history

Table 2: Surgical characteristics and postoperative outcomes

Table 1: Baseline characteristics
MICS IAAD
n ¼ 1065 n¼8
MICS IAAD
n ¼ 1065 n¼8 Operation time, min (median; 232 (198–270) 367 (307–527)
IQR, 25th–75th)
Age, years (median; IQR, 25th–75th) 67 (56–75) 73 (70–75) CPB time, min (median; 160 (132–192) 257 (208–336)
Male, % (n) 52.5 (559) 62.5 (5) IQR, 25th–75th)
Weight, kg (median; IQR, 25th–75th) 75 (66–87) 74 (63–81) Aortic cross-clamp time, min 88 (72–112) 144 (99–184)
Height, cm (median; IQR, 25th–75th) 172 (164–179) 171 (155–180) (median; IQR)
BMI, m/kg2 (median; IQR, 25th–75th) 25.0 (22.7–28.1) 25.5 (22.4–28.0) Circulatory arrest time, min 24 (19–29)
EuroSCORE II (median; IQR, 1.6 (1.0–3.5) 4.4 (3.3–8.9) (median; IQR)
25th–75th) In-hospital mortality, % (n) 3.4 (35) 37.5 (3)
Nicotine abuse, % 19.3 (206) 50.0 (4) Stroke, % (n) 1.3 (13) 12.5 (1)
Creatinine, mg/dl (median; IQR, 1.0 (0.8–1.2) 1.0 (0.7–1.8) Dialysis, % (n) 3.9 (40) 25.0 (2)
25th–75th) Temporary MCS, % (n) 4.3 (44) 37.5 (3)
Diabetes, % (n) 11.1 (118) 12.5 (1) Revision surgery
Arterial hypertension, % (n) 66.1 (704) 87.5 (7) Valvular cause, % (n) 2.6 (26) 12.5 (1)
LVEF, % (median; IQR, 25th–75th) 57 (50–61) 60 (48–61) Haematothorax, % (n) 4.7 (48) 12.5 (1)
Coronary artery disease, % (n) 23.8 (253) 50.0 (4) Pacemaker implantation, % (n) 2.1 (21) 0 (0)
Peripheral artery disease, % (n) 3.1 (33) 12.5 (1) Duration of hospital stay
Chronic obstructive pulmonary 10.8 (115) 37.5 (3) ICU, h (median; IQR) 48 (24–72) 228 (42–636)
disease, % (n) IMC, h (median; IQR) 72 (48–120) 168 (48–342)
Pulmonary hypertension, % (n) 36.2 (385) 12.5 (1) Total, d (median; IQR) 14 (11–19) 22 (14–30)
Mitral valve procedures, % (n) 98.5 (1049) 87.5 (7)
Results are shown as median þ interquartile range (IQR, 25th–75th).
Results are shown as median þ interquartile range (IQR). CPB: cardiopulmonary bypass; IAAD: iatrogenic acute aortic dissection;
BMI: body mass index; IAAD: iatrogenic acute aortic dissection; LVEF: left ICU: intensive care unit; IMC: intermediate care unit; MCS: mechanical cir­
ventricular ejection fraction; MICS: minimally invasive cardiac surgery. culatory support; MICS: minimally invasive cardiac surgery.
4 S.J. Bauer et al. / European Journal of Cardio-Thoracic Surgery

procedure (n ¼ 1) and after removing the aortic vent (n ¼ 1). postoperative CT-A thereafter. The further treatment should
While patients with cannulation-associated IAAD exhibited then be discussed interdisciplinary within an aortic board.
retrograde dissection, with the initial tear in the descending If IAAD arises at a later stage intraoperatively, weaning from
aorta followed by proximal propagation, other patients had CPB is typically not an option. Ensuring adequate cerebral perfu­
IAAD entries at the surgical sites that then spread distally. All sion becomes the top priority. The right SA may serve as an al­
patients were converted to full sternotomy of whom 7 under­ ternative cannulation site, and a second arterial line should be
went additional supracoronary replacement of the ascending placed concurrently to ensure accurate monitoring and exclude
aorta and hemiarch replacement under circulatory arrest. In 2 measurement errors. Median sternotomy should then be per­
patients (Patients 7 and 8), mitral valve replacement was pre­ formed, followed by an extension of the planned procedure to
ferred to mitral valve repair in the given situation. In patient 3, include aortic surgery.
we avoided aortic surgery because of the already long time of If IAAD is identified following the completion of the primary
CPB. Venoarterial extracorporeal membrane oxygenation was cardiac procedure, the management approach aligns closely with
implanted as a ‘bridge to decision’ for a 2nd operation. IAAD that employed when IAAD occurs intraoperatively. Once again,
was immediately detected after its occurrence in 7 patients, ensuring adequate cerebral perfusion remains the foremost pri­

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while some delay in IAAD recognition occurred in 1 patient ority, which may necessitate establishing an alternative arterial
cannulation site. In both scenarios, the surgical plan should be
(Patient 1). In this patient, several attempts of aortic clamping
expanded to include aortic surgery to effectively address the in­
were performed due to inefficient cardiac arrest after cardiople­
timal defect and prevent further complications (Fig. 1).
gia administration. IAAD was then detected at an advanced stage
after the cardiac procedure, in which the neurological sign of
cerebral malperfusion, i.e. pupillary dilatation, was already DISCUSSION
observed. Another patient (Patient 5) showed visible macroscop­
ic IAAD with persistent bleeding at the former aortic vent site, The main findings of this study are as follows: (i) the incidence of
presumably caused by a tear during the insertion of the aortic IAAD in MICS was 0.75%, with these patients exhibiting higher
vent. However, the tear was still covered while the vent preoperative risk scores compared to controls [MICS Control:
remained in place. IAAD was then detected after the removal of 1.6 (IQR, 1.0–3.5) versus IAAD: 4.4 (IQR, 3.3–8.9)]; (ii) in-hospital
the vent. Four patients required recannulation of the right sub­ mortality and the incidence of MACE in patients with IAAD
clavian artery (SA) after IAAD occurred at CPB initiation (Patients remained high at 37.5% and 50%, respectively; (iii) half of the
2, 6, 7 and 8). Three patients had an intima tear at the right cor­ IAAD cases were identified at the initiation of CPB and (iv) a
onary artery (RCA) ostium, necessitating coronary artery bypass time-optimized operative strategy was conceptualized to im­
grafting. Regarding preoperative diagnostics, preoperative CT-A prove patient outcomes in the event of IAAD.
was missing in 3 patients who had (i) significant aortic calcifica­ The incidence of IAAD was reported to be 0.06% to 0.29% in
tion at the clamping site causing an intima tear (Patient 1) or (ii) the pre-MICS era [4, 14]. Femoral cannulation has been identi­
hostile peripheral arteries (Patients 2 and 6), which presumably fied as a significant risk factor for IAAD, along with advanced
predisposed the intima to a guidewire-associated tear during age (>60 years) and the presence of peripheral vascular disease
cannulation. Among them, 2 patients (Patients 1 and 2) did not [4, 15]. However, it remains uncertain whether peripheral cannu­
survive. The remaining patient who died (Patient 3) demon­ lation represents the cause or consequence of IAAD, as it may
strated an ascending aorta injury with a dissection entry site also serve as an alternative site for cannulation [4]. According to
near the right coronary cusp, which also involved the RCA, Ram et al. [16], occurrence of IAAD is 10 times more likely, if
necessitating an RCA bypass. This injury was likely caused by a femoral or iliac arteries are the site of cannulation, when com­
suture placed for the tricuspid annuloplasty ring near the septal pared to cannulation of the ascending aorta. In recent years,
or anterior leaflet of the tricuspid valve. with the trend towards miniaturization of access and reduction
of invasiveness [2], MICS is also performed in older and presum­
ably more frail patients [17]. While results of MICS in older pa­
Phase-specific adjustment of the surgical plan tient groups are promising [11], careful patient selection and
interdisciplinary decision-making within a heart team remain
The results and detailed analysis of patients who experienced intra­ mandatory [18]. However, if selected for MICS, peripheral vascu­
operative IAAD have guided the development of a standardized lar cannulation is the standard approach.
operative protocol to address this rare but yet potentially fatal Preoperatively, risk factors for IAAD including vascular frailty
complication (Fig. 1). Given the critical importance of both cerebral should be carefully evaluated. In this cohort, 4 patients had hos­
and systemic perfusion, early diagnosis of an aortic dissection must tile femoral arteries, 3 had iliac artery kinking, and 1 had under­
be prioritized in this context. To facilitate this, continuous TEE gone femoral artery Iintervention 4 months earlier. There is no
monitoring should be complemented by intraoperative cNIRS and fully established method to objectify iliac or femoral kinking,
a right-sided RA pressure line. Particular focus should be given on but a ratio between the length of the descending thoraco-
key procedural stages, including the initiation of CPB, aortic suture abdominal aorta and a straight line from the level of access to
placement, and cross-clamping, as well as declamping. the level of the aortic arch could be a potential approach [19]. In
If an aortic dissection is detected at the very beginning of case of calcification, CT scoring tools could objectify the grade
surgery, weaning from CPB is a viable option. Subsequently, if of calcification as shown by Buijs et al. [20] in the abdominal
adequate cerebral perfusion is confirmed, discontinuation of the aorta. Conclusively, as atherosclerosis has also been identified as
surgery is reasonable, as retrograde dissection is most likely a major risk factor for intraoperative IAAD in previous studies
the underlying cause (at this phase of surgery still Stanford [15, 21, 22], preoperative CT-A seems to be essential in MICS. In
Type B Aortic Dissection). Patients should undergo immediate fact, 66.7% of the deceased patients in this study did not
 S.J. Bauer et al. / European Journal of Cardio-Thoracic Surgery 5

AORTIC SURGERY
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Figure 1: Graphic explanation of the standard intraoperative approach to the treatment of IAAD in the setting of MICS. cNIRS: cerebral near-infrared spectroscopy;
CPB: cardiopulmonary bypass; IAAD: iatrogenic acute aortic dissection; MICS: minimally invasive cardiac surgery; RA: radial artery; SA: subclavian artery; TEE: trans­
oesophageal echocardiography.

undergo preoperative CT-A, but intraoperative findings and post­ macroscopic view of the ascending aorta may not be accessible
operative CT-A have demonstrated aortic calcification at the to the surgical team. Thus, in addition to evaluation of the
clamping site or hostile peripheral arteries. However, besides vas­ descending aorta in TEE during initiation of CPB, routine intrao­
cular frailty evaluated through CT-A [12], optimal cannulation type perative monitoring of cerebral perfusion, i.e. arterial pressure
(cut-down versus percutaneous) should also be discussed line in the right RA and the use of cNIRS, appears indispensable
preoperatively. for proper risk management, especially for MICS. However,
If conventional cut-down technique is performed for femoral these values should be viewed as monitoring parameters rather
canulation, lymphatic fistulas and wound healing disorders seem than absolute values at a single timepoint. Therefore, as a pre­
to be the major complications [13, 23, 24]. In the case of femoral caution, cNIRS measurement should be initiated prior to the
access with a VCD, it is predominantly vascular injuries. Yet, start of anaesthesia, before oxygen administration, and used as a
retrospective studies show the same absolute number of vascular reference for cerebral oxygen saturation measurement.
complications [13, 23, 24]. In 2018, our centre implemented per­ Regarding the operative strategies for IAAD in the context of
cutaneous access for peripheral cannulation as part of our pro­ MICS, our standard protocol is presented in Fig. 1. An earlier re­
cedural advancements. Since then, 2 patients have experienced port described an excellent approach to IAAD management
early IAAD after percutaneous cannulation (Supplementary when median sternotomy is the primary approach, resulting in a
Material, Table S1). Nevertheless, CT-A was introduced as a mortality rate of 6.7% [25]. Major steps included the immediate
standard preoperative diagnostic tool at the same time. If signifi­ involvement of a second attending surgeon, securing true lumen
cant femoral calcification was seen in CT-A, cannulation was per­ perfusion and initiation of systemic cooling as well as immediate
formed in cut-down technique. Moreover, as pronounced iliac repair including hemiarch or total arch replacement, while care­
kinking may represent an additional risk factor when repeated fully monitoring for malperfusion [25]. In the setting of MICS,
introduction of guide wire is planned, e.g. for percutaneous can­ the initial response may vary depending on the time at which an
nulation with endovascular suture based VCDs, the SA served as aortic dissection occurs, especially in the case of retrograde dis­
an alternative cannulation site [12]. section that does not spread beyond the left SA (Stanford Type
Besides precise operative planning and preventive measures, B Aortic Dissection) at the beginning of surgery. CPB weaning
early diagnosis of intraoperative IAAD is crucial for immediate should be attempted to quickly restore physiologic antegrade
management. In our study, one of the first manifestations of blood flow as opposed to retrograde perfusion through the FA.
IAAD was a sudden drop in blood pressure in the right RA and a In case of cessation of false lumen perfusion in the thoracic
decrease in cerebral oxygen saturation detected by cNIRS. aorta after CPB weaning, it is still debatable whether the surgical
Statistically, most IAADs occur directly after CPB starts when procedure should be discontinued and a conservative observa­
thoracotomy has sometimes not been performed, meaning the tion with delayed secondary surgery should be preferred over
6 S.J. Bauer et al. / European Journal of Cardio-Thoracic Surgery

proceeding with surgery and extending the operation to additional FUNDING

aortic surgery [26–30]. However, if a still Stanford Type B aortic dis­
section is diagnosed at the earliest time possible (TEE plane in the There is no commercial funding in the context of this publication.
midoesophageal descending aorta view during the start of CPB),
we recommend discontinuing the surgical procedure with postop­ Conflict of interest: The authors have no financial interests or
erative CT-A to rule out peripheral or abdominal malperfusion. In affiliations with organizations that could be seen as a real or per­
our study, there were no patients with isolated Stanford Type B ceived conflict of interest related to this publication.
aortic dissection at the time of diagnosis, as the first predominant
manifestation was a sudden drop in blood pressure in the right RA.
If IAAD occurs during cardiac procedures, a second arterial cannu­
ACKNOWLEDGEMENTS
lation, e.g. on the right SA, should be immediately considered to
The authors appreciate the work of the members of the MICs team
maintain sufficient cerebral perfusion. Alternatively, central cannu­
at the Medical Faculty and University Hospital Dusseldorf. Figure 1
lation may also be feasible as shown by Ramaprabhu et al. [31], but
and the Graphical Abstract were created with Biorender.com.
it must be considered that manipulation of the dissected aorta
Writefull for Word (Version 2025.8.0) was used for language editing.

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could potentially cause aortic rupture or propagation of the dissec­
tion, as the intimal tear might be fairly close at the site of the cardi­
oplegic cannula or the aortic cross-clamp [32–34]. Also, accurately DATA AVAILABILITY
identifying the true lumen can pose a significant challenge.
Nevertheless, we believe that a proper intraoperative judgement All data available are included in the manuscript.
according to the standard protocol introduced here will improve
the clinical outcomes of IAAD in MICS.
There are several limitations to this study. First, this manuscript Author contributions
deals with a retrospective observational study based on a limited
cohort size of patients affected by IAAD in a single centre. Sebastian Johannes Bauer: Conceptualization; Data curation; Formal ana­
Potential systematic measurement errors and also unidentified lysis; Investigation; Methodology; Software; Visualization; Writing—original
bias can affect the outcomes. Second, there are also patients who draft; Writing—review & editing. Yukiharu Sugimura: Formal analysis;
Software; Supervision; Writing—review & editing. Friederike Irmgard
did not undergo MICS despite undergoing an mitral procedure or
Schoettler: Data curation; Formal analysis; Writing—review & editing. Moritz
surgery for atrial structures. These patients are not mentioned in Benjamin Immohr: Formal analysis; Investigation; Software; Supervision;
this manuscript as this work is based on a database including Writing—original draft; Writing—review & editing. Tomoyuki Suzuki: Data
MICS procedures exclusively. In general, patients did not undergo curation; Writing—original draft; Writing—review & editing. Arash Mehdiani:
MICS in cases of emergency surgery (e.g. for endocarditis), ana­ Supervision; Visualization; Writing—review & editing. Hug Aubin:
Supervision; Validation; Visualization. Artur Lichtenberg: Supervision;
tomical variations that posed challenges (e.g. severe pectus exca­
Writing—original draft; Writing—review & editing. Payam Akhyari:
vatum), or when femoral and axillary artery quality was deemed Supervision; Writing—original draft; Writing—review & editing.
unsuitable for peripheral cannulation [12]. Third, our analysis does
not cover long-term results. Due to the nature of the disease and
the rare incidence, randomized controlled trials appear difficult to Reviewer information
implement. However, prospective multicentre studies could pro­
vide further insights in this field. Reviewer information European Journal of Cardio-Thoracic Surgery thanks
Diana Reser, Sven Peterss and the other, anonymous reviewer(s) for their
contribution to the peer review process of this article.
CONCLUSION

In our retrospective study of 1065 MICS patients, IAAD occurred

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European Journal of Cardio-Thoracic Surgery, 2025, 67, ezaf135
https://doi.org/10.1093/ejcts/ezaf135
Original article