Legal Medicine 42 (2020) 101636

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Legal Medicine
journal homepage: www.elsevier.com/locate/legalmed

Case Report

Major cerebral hypoperfusion on an internal carotid loop during an otologic
surgery: A case report

T

Florent Carsuzaaa, Xavier Dufoura,d, Tyffanie Houpertb, Jean-Claude Ferriéc, Michel Sapanetb,d,
⁎
Alexia Delbreilb,d,
a

Service ORL, chirurgie cervico-maxillo-faciale et audiophonologie, CHU de Poitiers, France
Institut médico-légal, CHU de Poitiers, France
c
Service de radiologie diagnostique et interventionnelle, CHU de Poitiers, France
d
Université de Poitiers, Faculté de médecine et de pharmacie, Poitiers, France
b

A R T I C LE I N FO

A B S T R A C T

Keywords:
Internal carotid artery
Loop
Kinking
Cerebral hypoperfusion

An aberrant course of the internal carotid artery, such as a carotid loop or kinking, is a rare type of malformation. These malformations are typically asymptomatic, their occurrence is unpredictable, and they can
exacerbate clinical disorders such as heart failure. We report the case of a seven-year-old child who died consecutively to cardiac arrest during otologic surgery for a cholesteatoma. After rapid and effective cardiorespiratory resuscitation, the child was transferred to a paediatric intensive care unit. In the following days,
pronounced cerebral hypoperfusion led to the death of the child. The autopsy revealed a right carotid loop and a
left carotid kink that presumably led to the cerebral hypoperfusion.

1. Background
The internal carotid arteries are a major source of blood supply to
the brain along with contributions from the vertebral arteries.
An aberrant course of the internal carotid artery is thought to occur
in 10% of the population; however, the incidence of variations that
cause symptomatic cerebrovascular insufficiency is less high [1]. These
aberrations include internal carotid loops and kinking.
2. Case report
We report the case of a seven-year-old child who had a congenital
cholesteatoma of the right middle ear. At five years of age, the child
underwent the first stage of surgery for exeresis of the cholesteatoma.
This initial surgery did not result in either cardiac or neurological
failure.
Secondarily, the child had a cholesteatoma recurrence in the right
middle ear. This required a second stage of surgery, which was performed under general anaesthesia.
After one hour of surgery, the child suffered cardiorespiratory arrest. Cardiopulmonary resuscitation was performed immediately (low
flow = 0 min) with cardiac massage and intravenous injection of
adrenaline, resulting in renewed heart activity with ventricular

⁎

tachycardia or fibrillation. The child was then subjected to an electric
shock, which resulted in the recovery of sinus rhythm after four minutes. Cardiac echocardiography was performed, and it revealed cardiogenic shock with myocardial stunning. The child was then transferred to the paediatric intensive care unit of the Poitiers university
hospital.
Cardiovascular examinations did not find any cardiac arrest aetiology. The child did not have any new episodes of heart failure, thus
allowing reduction of the doses of the inotropic treatment. The patient
then exhibited neurological symptoms (generalised tonic-clonic seizures and was irresponsive to nociceptive stimuli).
A CT scan and an MRI were performed, which revealed the presence
of ischemic lesions in the brain, predominantly in the right hemisphere,
linked with major cerebral hypoperfusion. A loop of the internal right
carotid and a kink in the left internal carotid were noted on the CT scan,
the MRI, and the carotid ultrasound imaging (Fig. 1). The neurological
status deteriorated with signs of increased intracranial pressure due to
cerebral oedema (anisocoria, bradycardia, and high blood pressure).
The child had reduced mobility of the limbs, was irresponsive to nociceptive stimuli, and exhibited fluctuating osteotendinous reflexes.
Electroencephalograms were generally slow, non-reactive, with signs of
greater distress predominating in the right side. At day 4 (D4), symptoms of brain death started to appear (hyperthermia, polyuria, fixed

Corresponding author at: Institut médico-légal – CHU de Poitiers, 2 rue de la Milétrie – CS 90577, 86021 Poitiers Cedex, France.
E-mail address: alexia.delbreil@chu-poitiers.fr (A. Delbreil).

https://doi.org/10.1016/j.legalmed.2019.101636
Received 6 May 2019; Received in revised form 1 August 2019; Accepted 21 September 2019
Available online 11 November 2019
1344-6223/ © 2019 Elsevier B.V. All rights reserved.

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F. Carsuzaa, et al.

Fig. 1. MRI imaging showing a loop of the right internal carotid and a kinking of the left internal carotid.

dilated pupils, non-spontaneous ventilation, and an abnormal heart
rate). After a thorough assessment of their prognosis by the medical
team, the decision was made to stop all resuscitation therapeutics. The
young patient died on the fifth-day post-surgery (D5).
Due to the child’s death in the absence of a particular medical history, and in light of the fact that they had undergone a surgical procedure, a formal investigation was initiated, and post-mortem CT scan
and a medicolegal autopsy were performed. These found stigmata of
middle ear surgery, without haemorrhaging or an inflammatory state. A
loop of the internal right carotid and a kink in the left internal carotid
were noted (Fig. 2). There were no dysmorphic features or macroscopic
malformations of the organs.
The anatomopathological examination found signs of cerebral hypoperfusion (anoxia) with smoothed circumvolutions, ischaemic neurons with nuclear pyknosis, and congestive meninges. The internal right
carotid artery formed a complete loop, without artery crushing, and the
internal left carotid formed an incomplete loop without artery crushing
(kinking). All of the layers of the wall of the arteries were respected.
The various organs exhibited moderate levels of oedema.
The toxicological examination found traces of the resuscitation
treatments.
A genetic analysis was performed in an attempt to identify a genetic
mutation responsible for congenital heart arrhythmia (e.g., Brugada
syndrome, congenital QT syndrome). Analysis of 51 genes failed to find
a causal mutation.
Input was sought from several medical experts (an anaesthesiologist
and an ENT surgeon). The principal conclusions were that this death
was due to major cerebral hypoperfusion linked with the cardiac arrest
(quickly resuscitated) associated with perioperative hypoperfusion.
Indeed, when an otologic surgery is performed, blood pressure is typically reduced to limit bleeding. This was associated with a cervical
rotation in order to facilitate the surgical procedure. These factors,
associated with the internal carotid artery malformations, resulted in
perioperative cerebral hypoperfusion.

Fig. 2. Internal carotid malformations during autopsy. a: Loop of the right internal carotid artery. b: Kinking of the left internal carotid artery.

atherosclerosis, they occur more frequently in the elderly.
The internal carotid artery is derived from a coiled third aortic arch
and the dorsal aortic root. Congenital tortuosity arises when uncoiling
fails to take place at the embryonic stage.
It is more frequent in men (3:2), and 71% of cases occur bilaterally
[1]. They mostly form at the intersection between the internal carotid
artery and the XIIth cranial nerve.

3. Discussion
The incidence of tortuosities of the internal carotid artery ranges
from 10 to 40%; however, the incidence of variations that cause
symptomatic cerebrovascular insufficiency is between 4 and 16% [1,2].
Carotid loops or kinks constitute one type of such malformations. As a
result of the loss of arterial wall elasticity due to hypertension or
2

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F. Carsuzaa, et al.

combination of the kinking and the cervical rotation to the left.
This cerebral hypoperfusion had not been noted two years prior,
during the first surgery. The first assumption to explain this new event
is a structural modification of these malformations during the child’s
development (the first surgery was performed two years prior and the
internal carotid artery loop may have become more compressed over
time). The second assumption is that the cervical rotation was associated with a backward arching of the neck.

The formation of a kink, which is the most frequently reported type
of carotid abnormalities has been described as an acute angulation of
the internal carotid artery and classified according to the severity of the
angle between the two segments forming the kink [3]. Carotid kinking
is present in 38% of the individuals with no history of atherosclerotic
disease, diabetes, or hypertension [4].
Carotid loops are reported less frequently and they constitute a 360°
loop of the internal carotid artery.
These anomalies can be associated with atherosclerotic stenosis and
may be complicated by carotid dissection or aneurysmal dilatation.
Coiling of the carotid artery can produce luminal narrowing, which can
lead to turbulent blood flow and subsequent intimal ulceration and
embolization. It is known to cause various adverse effects, including
syncope, blackout, dizziness, and vertigo; it can also result in episodes
of cerebrovascular insufficiency related to head positions [5].
When one of these anomalies is diagnosed, vascular imaging is necessary to determine whether there is merely looping or kinking
without blood flow obstruction, or a complex malformation with obstruction of the blood flow.
The main treatment consists of surgery whereby resection of the
redundant internal carotid artery is performed with reimplantation and
thromboendarterectomy of any associated plaque.
To perform an otologic surgery properly, the operating position
requires a contralateral cervical hyper-rotation. It may be stabilised by
gelosis or sheets. An initial surgery for exeresis of a cholesteatoma can
take up to three or four hours, and this position is conserved throughout
the entire surgery, and the head cannot be moved because the surgery is
performed under a microscope.
During an otologic surgery, reduced bleeding is necessary to identify
anatomical landmarks. This is why anaesthesia for otologic surgery
requires arterial hypotension. This objective is achieved by injection of
adrenaline and use of a proclive position (permitting reduction of venous pressure at the operating site) under anaesthesia that is maintained with halogen derivatives (isoflurane or sevoflurane).
In this particular case, the surgery was performed on the right ear.
During the surgical procedure, the head was turned to the left for
greater comfort. The cerebral hypoperfusion may be explained by a
reduction in the flow rate of the right carotid artery by a combination of
the loop of the right carotid artery and the cervical rotation to the left.
Another possible explanation could be a reduction in the flow rate of
the left carotid artery due to stenosis of the left carotid artery by a

4. Conclusion
The presented case shows that internal carotid loops or kinks can
exacerbate clinical disorders, particularly heart failure.
The medical experts did not consider that the outcome in this case
was due to medical malpractice. The relevant guidelines regarding good
practice for anaesthesia, operating position, and the surgical procedures
were followed. These malformations, which were fully asymptomatic in
addition to being unpredictable in a young child, could not have been
foreseen at the start of the surgery and it was not possible to adjust the
surgery to account for these malformations.
Declaration of Competing Interest
The authors declare that they have no known competing financial
interests or personal relationships that could have appeared to influence the work reported in this paper.
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