Jong Lim Kim , Dae Chul Suh, Jin-Ho Shin, Dong Ho Hyun, Ha Young Lee,
Deok Hee Lee, Choong Gon Choi, Sang Joon Kim, Jong Sung Kim
Departments of Radiology and Research Institute of Radiology , Department of
Neurology, University of Ulsan, College of Medicine,
Asan Medical Center, Korea

· Carotid sinus reaction
Post- and peri-procedural hypotension (SBP <90 mmHg)
Bradycardia (HR <50 beats/sec)
Heart rate fluctuation (>20 beats/sec)
* Asystole (≥ 3 sec) and hypotension (SBP ≤ 90 mm Hg)
Leisch F, et al. Catheter Cardiovasc Interv . 2003
* Hypotension (SBP < 90 mm Hg) or bradycardia (HR < 60 beats/min)
Gupta R, et al. J Am Coll Cardiol. 2006

Carotid sinus reaction occurs frequently (40%) during carotid sinus stent
Bifurcation location of stenosis is the most important predictor of carotid sinus reaction
* Carotid sinus reaction
Asystole (≥ 3 sec)
Hypotension (SBP ≤ 90 mmHg)
* Carotid stenosis location
Bifurcation
Ostial
Isolated ICA
Leisch F, et al. Catheter Cardiovasc Interv . 2003

Hemodynamic disturbances was not related to carotid stenosis location
* Hemodynamic disturbances
Hypotension (SBP < 90 mmHg)
Bradycardia (HR < 50 beats/min)
Heart rate fluctuation (> 20 beats/min)
Hypertension (SBP > 160 mmHg)
* Carotid stenosis location
Apical
Body
Park ST, et al. Am J Neuroradiol. 2010

Apical type stenosis in the left carotid bulb
No carotid sinus reaction
Body type stenosis in the right carotid bulb
Marked carotid sinus reaction

(anatomy & physiology)
· Ill-defined dilatation at the origin of the internal carotid artery
D Heath. Thorax.
1983
· Monitoring and regulation of blood pressure
Michael Doumas, et al. Expert Opin. Ther. Targets.
2009

(Embryology)
Common carotid artery and proximal part of internal carotid artery
- Formed by remodeling of the third arch artery (yellow)
Baroreceptors (arrow) of the glossopharyngeal nerve
- Distributed in proximal portion of internal carotid artery (carotid sinus)
Yoko Kameda. Cell Tissue Res.
2009

· Originating from the glossopharyngeal (IX) nerve
· Located in loose tissue close to the ICA wall
Run parallel to or together with vagus nerve
· Ended in both carotid sinus & carotid body
Toorop RJ, et al. J Vasc Surg.
2009
IX, glossopharyngeal nerve
X, vagus nerve
P, pharyngeal branches
S, sympathetic trunk

· Major contributor to the homeostatic system of blood pressure control
Michael Doumas, et al. Expert Opin. Ther. Targets.
2009
· Afferent fibres from carotid sinus baroreceptors join the glossopharyngeal nerve and project to the nucleus tractus solitarii in the dorsal medulla, and in turn projects to efferent cardiovascular neurones in the medulla and spinal cord
Timmers HJ et al. J Physiol.
2003
Arterial baroreflex loops
Carotid sinus baroreceptors
→ glossopharyngeal nerve
→ medullary centres (nucleus tractus solitarii)
→ sympathetic and parasympathetic fibres to heart and blood vessels

Prospective analysis
2007.01 ~ 2009.6
95 patients who underwent carotid stenting
M : F = 82 : 12
Mean age : 69 years (38-89 years)
Symptomatic carotid stenosis ≥ 50% (NASCET criteria)

Transient sinus reaction : <3 hours
Delayed sinus reaction : 3~24 hours
Analyzed angiographic or neurointerventional findings
- Location of plaque : apical vs. body
- Length of maximum stenosis from the ICA ostium
- Lesion length
- Stenosis degree
- Calcification
- Balloon diameter
- Balloon pressure
- Stent length
- Residual stenosis
- Hyperperfusion
- Restenosis

Comparison of Significant Difference of Transient Sinus Reaction
Lesion type
Apical
Body
Lesion length
Length of maximum stenosis fr om the ICA ostium*
Stenosis degree
Calcification (yes)
Balloon diameter (mm)
<3hr SR(+)
7
16
16.77
7.74
75.87
6
5.23
<3hr SR(-)
49
23
18.30
12.79
74.04
15
5.37
P-valve
0.001
0.26
0.004
0.968
0.577
0.283
Balloon pressure (ATM)
Stent length
8.00
34.35
8.29
34.03
0.464
0.728
Residual stenosis 23.52
19.86
0.295
* Stepwise logistic regression to eliminate confounding factor reveals that length is true independent factor (P = 0.002)

< 3 h
SBP>160
3 - 24 h
1m
Event
6m
Hyperperfusion
Restenosis
Apical (n=56) Body (n=39)
0
6
1
12
7
5
1
2
3
8
5
0
P-valve
0.914
1
0.076
0.411
0.464
0.302

Age/sex
Location
Transient sinus reaction
Lesion type
Length of maximum stenosis from the ICA ostium* (mm)
M/63 right
+
Body
2.24

Age/sex
Location
Transient sinus reaction
Lesion type
Length of maximum stenosis from the ICA ostium* (mm)
M/77 right
-
Apical
14.53

Age/sex
Location
Transient sinus reaction
Lesion type
Length of maximum stenosis from the ICA ostium* (mm)
Hyperperfusion
M/85 right
-
Apical
16.67
+

1. Sinus reaction in carotid stenting is different in two distinct locations, body and apical portion of carotid bulb
2. Body lesion type was more vulnerable to sinus reaction than apical lesion type
① Related to anatomical baroreceptor disposition in carotid sinus
* Baroreceptors are located in the carotid sinus of carotid bulb
Such embryological implication appeared to affect carotid bulb lesion type
② Induced preventive effect for high blood pressure which might contribute to hyperperfusion syndrome
→ Less common to hyperperfusion syndrome
3. Apical lesion type had higher event rate than body lesion type
① Associated with more common periprocedural hypertension
→ Needs more careful management of blood pressure control for apical lesion type after carotid stenting