1) Conservative management is generally the initial treatment for spontaneous isolated superior mesenteric artery dissection (SIDSMA), with 85-87% of patients receiving conservative care. 2) Complete or partial remodeling of the artery occurs in 49-51% of conservatively treated patients within 2 years, though endovascular stenting may increase remodeling rates to 88%. 3) Endovascular stenting results in better outcomes than conservative care for symptomatic patients, with lower recurrent symptom and mortality rates.

1. Comparison of Superior Mesenteric Artery Remodeling and Clinical
Outcomes between Conservative or Endovascular Treatment in
Spontaneous Isolated Superior Mesenteric Artery Dissection
I Hui Wu, MD., PhD.
Chairman, Department of Trauma Surgery
Clinical Surgical Professor
Cardiovascular Center, Surgical Department
National Taiwan University Hospital

2. Spontaneous isolated dissection of the superior mesenteric artery (SIDSMA)
Spontaneous isolated dissection of the celiac artery (SIDCA)
A rare condition
• Incidence: 0.06-0.09%
• Lack of reliable laboratory findings
• Most cases have been reported in Asian countries
• Unknown etiology
• Mechanical stress at the anterior wall of SMA near the convex curvature
• Hypertension
• Genetic factor: heterogeneity of a chromosome locus at 5q13-14, found
to be linked to familial ascending aortic aneurysms and dissection
J Wang et a;J Vasc Surg 2018;68:1228-40
SH Heo et al. J Vasc Surg 2017;65:1142-51
JY Luan et al; J Vasc Surg 2016;63:530-6

3. • Symptoms
• Asymptomatic to acute peritonitis
• Acute abdominal pain: 78-91%
• Self remission within one week
• recurrent abdominal pain: usually 6 months after acute
onset
• Male, Asian, smokers, Hypertension, middle age
J Wang et a;J Vasc Surg 2018;68:1228-40
SH Heo et al. J Vasc Surg 2017;65:1142-51
H Kim, et al; Eur J Vasc Endovasc Surg (2018) 55, 132-137
Spontaneous isolated dissection of the superior mesenteric artery (SIDSMA)
Spontaneous isolated dissection of the celiac artery (SIDCA)

4. • Classification
• Clinical
• Symptomatic
• Asymptomatic
• Morphological
• Only for SIDSMA
J Wang et a;J Vasc Surg 2018;68:1228-40
SH Heo et al. J Vasc Surg 2017;65:1142-51
H Kim, et al; Eur J Vasc Endovasc Surg (2018) 55, 132-137
Spontaneous isolated dissection of the superior mesenteric artery (SIDSMA)
Spontaneous isolated dissection of the celiac artery (SIDCA)

5. Sakamoto 2007
Yun 2009
Luan 2013
Li 2014 Heo 2017
Morphologic classification of SIDSMA
• None of these classifications
can predict the clinical course
• Symptoms
• stenosis of the true lumen
• the length of dissection

6. Conservative treatment
• Bowel rest, hydration, analgesia, blood pressure control
• Antithrombotic or antiplatelet agents
• Controversial
Endovascular stenting
Open surgical repair
Treatment options for SIDCA and SIDSMA

7. Initial conservative treatment is safe
Antithrombotic therapy,
no benefits either clinical or morphologic outcomes
Loeffler JW, et al. J Vasc Surg 2017;66:202-8, Heo SH, et al. J Vasc Surg
2017;65:114-51 Jiarong Wang J Vasc Surg 2018;68:1228-40
None of them required secondary intervention
Meta-analysis, 200 pts
Jiarong Wang J Vasc Surg 2018;68:1228-40
Asymptomatic for SIDCA and SIDSMA

8. Symptomatic for SIDCA and SIDSMA
Conservative management still remained the most common initial treatment

9. Symptomatic for SIDCA and SIDSMA
Conservative management still remained the most common initial treatment
Wang JR, et al.
J Vasc Surg 2018;68:1228-40
Zhu et al.
J Endovasc Therapy 2018 ;25:640-48
Patient number 904 514
Conservative number 774(85.6%) 447 (87%)
Secondary intervention 8-12% 11.2-14.3%
All-cause mortality 1-2% at 28 months N/A
Complete or partial remodeling 49-51% N/A
Antithrombotic agents N/A No difference in conversion rate

10. Symptomatic for SIDCA and SIDSMA
Conservative management still remained the most common initial treatment
Wang JR, et al.
J Vasc Surg 2018;68:1228-40
Zhu et al.
J Endovasc Therapy 2018 ;25:640-48
Patient number 904 514
Conservative number 774(85.6%) 447 (87%)
Secondary intervention 8-12% 11.2-14.3%
All-cause mortality 1-2% at 28 months N/A
Complete or partial remodeling 49-51% N/A
Antithrombotic agents N/A No difference in conversion rate

11. Symptomatic for SIDCA and SIDSMA
Conservative management still remained the most common initial treatment
Wang JR, et al.
J Vasc Surg 2018;68:1228-40
Zhu et al.
J Endovasc Therapy 2018 ;25:640-48
Patient number 904 514
Conservative number 774(85.6%) 447 (87%)
Secondary intervention 8-12% 11.2-14.3%
All-cause mortality 1-2% at 28 months N/A
Complete or partial remodeling 49-51% N/A
Antithrombotic agents N/A No difference in conversion rate

12. Symptomatic for SIDCA and SIDSMA
Conservative management still remained the most common initial treatment
Wang JR, et al.
J Vasc Surg 2018;68:1228-40
Zhu et al.
J Endovasc Therapy 2018 ;25:640-48
Patient number 904 514
Conservative number 774(85.6%) 447 (87%)
Secondary intervention 8-12% 11.2-14.3%
All-cause mortality 1-2% at 28 months N/A
Complete or partial remodeling 49-51% N/A
Antithrombotic agents N/A No difference in conversion rate

13. Endovascular intervention
 Persistent symptoms, dissection progression, bowel gangrene, and aneurysmal degeneration
 16.2%-33.6% as the initial treatment
 93.5-95.7%: symptom relief
 2/97 (2%): required re-intervention due to ISR
Open surgery
 Bowel infarction or necrosis, peritonitis, or aneurysm rupture
 3.2%-5.1% as the initial treatment
 3/34 (8.8%) required re-intervention due to graft thrombosis
Wang JR, et al. J Vasc Surg 2018;68:1228-40
Symptomatic for SIDCA and SIDSMA
Luan JY, et al. . J Vasc Surg 2016;63:530-6

14. Proportion achieved complete remodeling after conservative treatment
Morphologic changes of lesion vessels
 SIDCA > SIDSMA
 Complete remodeling: (64% VS. 25%, P<0.05)
 Symptomatic > Asymptomatic (OR, 3.95; 95% CI, 1.31-11.85)
 Complete remodeling
 Mean time: 16 ± 16 months(range, 3-63 months) after initial
pain relief
 61% within 12 months
 81% within 24 months
 Dissection progression or aneurysmal formation: 3%
Wang JR, et al. J Vasc Surg 2018;68:1228-40
Heo SH, et al. J Vasc Surg 2017;65:1142-51

15. Proportion achieved complete remodeling after endovascular treatment
• Single center, 2011-2016, 128 pts
• SMA stent: 87.5%
• SMA remodeling
• SIDSMA stenting group vs non-stent group: 88.3% vs 6.3%
• Primary stent patency rate: 99.1%
• Recurrent symptom
• Stent group vs non-stent group: 0.9% vs 25%
• Survival
• Stents group vs non-stent group: 95.8% vs 62.5% at three years
Morphologic changes of lesion vessels
Qiu CY, et al. Eur J Vasc Endovasc Surg 2019; 58:88-95

16. Proportion achieved complete remodeling after endovascular treatment
• Single center, 2011-2016, 128 pts
• SMA stent: 87.5%
• SMA remodeling
• SIDSMA stenting group vs non-stent group: 88.3% vs 6.3%
• Primary stent patency rate: 99.1%
• Recurrent symptom
• Stent group vs non-stent group: 0.9% vs 25%
• Survival
• Stents group vs non-stent group: 95.8% vs 62.5% at three years
Morphologic changes of lesion vessels
Qiu CY, et al. Eur J Vasc Endovasc Surg 2019; 58:88-95

17. Proportion achieved complete remodeling after endovascular treatment
• Single center, 2011-2016, 128 pts
• SMA stent: 87.5%
• SMA remodeling
• SIDSMA stenting group vs non-stent group: 88.3% vs 6.3%
• Primary stent patency rate: 99.1%
• Recurrent symptom
• Stent group vs non-stent group: 0.9% vs 25%
• Survival
• Stents group vs non-stent group: 95.8% vs 62.5% at three years
Morphologic changes of lesion vessels
Qiu CY, et al. Eur J Vasc Endovasc Surg 2019; 58:88-95

18. Proportion achieved complete remodeling after endovascular treatment
• Single center, 2011-2016, 128 pts
• SMA stent: 87.5%
• SMA remodeling
• SIDSMA stenting group vs non-stent group: 88.3% vs 6.3%
• Primary stent patency rate: 99.1%
• Recurrent symptom
• Stent group vs non-stent group: 0.9% vs 25%
• Survival
• Stents group vs non-stent group: 95.8% vs 62.5% at three years
Morphologic changes of lesion vessels
Qiu CY, et al. Eur J Vasc Endovasc Surg 2019; 58:88-95

19. Proportion achieved complete remodeling after endovascular treatment
• Single center, 2011-2016, 128 pts
• SMA stent: 87.5%
• SMA remodeling
• SIDSMA stenting group vs non-stent group: 88.3% vs 6.3%
• Primary stent patency rate: 99.1%
• Recurrent symptom
• Stent group vs non-stent group: 0.9% vs 25%
• Survival
• Stents group vs non-stent group: 95.8% vs 62.5% at three years
Morphologic changes of lesion vessels
Qiu CY, et al. Eur J Vasc Endovasc Surg 2019; 58:88-95

20. Proportion achieved complete remodeling after endovascular treatment
• Single center, 2011-2016, 128 pts
• SMA stent: 87.5%
• SMA remodeling
• SIDSMA stenting group vs non-stent group: 88.3% vs 6.3%
• Primary stent patency rate: 99.1%
• Recurrent symptom
• Stent group vs non-stent group: 0.9% vs 25%
• Survival
• Stents group vs non-stent group: 95.8% vs 62.5% at three years
Morphologic changes of lesion vessels
Qiu CY, et al. Eur J Vasc Endovasc Surg 2019; 58:88-95

21. 2007/01-2019/08, NTUH
• Intimal flap at SMA with/without false lumen thrombosis
• Concomitant aortic and SMA dissection excluded
29.41%
treatment with the preexisting medications
• Food withdrawal
• Hydration
• Analgesia
• Blood pressure control
• Consider pre-existing comorbidities to
add on antithrombotic agent
70.59%
> 2 days
progressive SMA dissection
• Brachial or femoral approach
• Self-expandable bare metal stents
• Proximal/Distal landing zone >1cm
• 3–5 mm beyond the orifice of the SMA into the aorta
• Stent size: distal 5 mm, proximal 8 mm
SAPT/DAPT
3- and 6-month intervals and annually
3- and 6-month intervals and annually
54.17% 41.67% 4.1%
Conservative 67.65% (23/34)

23. Total lumen diameter
True lumen diameter
False lumen diameter

24. No aneurysmal change
EVT was the only significant factor for SMA
remodeling
No peri-procedure complication

26. At a median follow-up of 23.3 months (range: 9.6–55.2):
• No SMA aneurysm formation
• No recurrent symptoms requiring admission
• No stent occlusion
• No new dissection
• Survival 96% (1 mortality in conservative group at 4 year unrelated to SMA dissection)
 70% symptomatic, mostly abdominal pain
 30% (45% in all symptomatic patients) need intervention: persistent abdominal pain
 From qualitative result (remodeling or not) to quantitative data:
 Endovascular SMA stent significantly promote SMA remodeling with no peri-procedure complication,
especially in patients with Yun’s IIb classification morphology
 At near 2 years: no aneurysmal change, no recurrent symptoms, good survival
More patients and Longer follow up to see clinical outcome, Timing for intervention

27. Thanks for your attention !!