A total of 20 patients with SMA embolisms were included in this study. Patient characteristics, clinical features and outcomes are listed in Table 1. The median age of the patients was 80 years (range 69-100 years), and the female-to-male ratio was 9:11. All patients had comorbidities (11 patients had arrhythmias such as atrial fibrillation). The obstructed regions of the SMA were proximal to the bifurcation of the ICA in 16 cases. Nine cases had PI based on the CT findings. There were 2 cases that underwent surgery, 12 cases who had EI, 4 cases who had heparin treatment and 2 cases who had BSC for the initial treatment. Two surgical cases required small bowel resection and the length of the remnant small bowel was 70 and 100 cm. One patient who underwent EI (case 15) required small bowel resection due to recurrence of SMA embolism on the 17th day after EI, and the remnant small bowel was 200 cm. EI was approached from the femoral artery. One case (Case 7) underwent stent placement and 11 cases underwent mechanical thrombectomy. All 12 patients had concomitant intra-arterial injection of urokinase. Fifteen patients survived, and five patients died in the hospital. In the survivors, two patients needed parenteral nutrition because of the development of short bowel syndrome (case9, 15).
Table 1
Case
|
Age
|
Sex
|
Shock
|
peritoneal irritation sign
|
Comorbidity
|
Time to diagnosis (hr)
|
Obstructed region*
|
Pneumatosis intestinalis
|
Treatment
|
Remnant small intestine (cm)
|
Nutrition
|
Hospitalization (day)
|
Outcome
|
1
|
86
|
F
|
-
|
-
|
DM, CKD (HD), HT
|
5
|
Proximal
|
○
|
BSC
|
|
-
|
3
|
Died
|
2
|
95
|
F
|
○
|
-
|
Arrhythmia (PM)
|
14
|
Proximal
|
○
|
BSC
|
|
-
|
2
|
Died
|
3
|
92
|
F
|
-
|
-
|
HT
|
4
|
Proximal
|
○
|
EI
|
|
-
|
2
|
Died
|
4
|
80
|
M
|
-
|
-
|
Af, CVD, HT, CKD, LC
|
10
|
Proximal
|
○
|
EI
|
|
-
|
3
|
Died
|
5
|
71
|
M
|
○
|
-
|
Af
|
6
|
Proximal
|
○
|
EI
|
|
-
|
2
|
Died
|
6
|
72
|
M
|
-
|
-
|
Af
|
13
|
Proximal
|
○
|
EI
|
|
Oral
|
9
|
Survived
|
7
|
86
|
F
|
-
|
-
|
Af, DM, prostatic cancer
|
27
|
Proximal
|
○
|
EI
|
|
Oral
|
42
|
Survived
|
8
|
100
|
M
|
-
|
-
|
HT, IHD
|
4
|
Proximal
|
○
|
OPE
|
70
|
Oral
|
26
|
Survived
|
9
|
91
|
F
|
-
|
-
|
Af
|
36
|
Proximal
|
○
|
OPE
|
100
|
TPN
|
66
|
Survived
|
10
|
86
|
M
|
-
|
○
|
HT, CVD
|
6
|
Proximal
|
-
|
EI
|
|
Oral
|
12
|
Survived
|
11
|
65
|
M
|
-
|
○
|
Af
|
17
|
Proximal
|
-
|
EI
|
|
Oral
|
8
|
Survived
|
12
|
72
|
M
|
-
|
-
|
HT
|
5
|
Proximal
|
-
|
EI
|
|
Oral
|
19
|
Survived
|
13
|
59
|
F
|
-
|
-
|
DM, HT, CVD
|
5
|
Proximal
|
-
|
EI
|
|
Oral
|
30
|
Survived
|
14
|
72
|
F
|
-
|
-
|
HT, IHD
|
10
|
Proximal
|
-
|
EI
|
|
Oral
|
38
|
Survived
|
15
|
85
|
M
|
-
|
-
|
HT, CVD, HL
|
4
|
Proximal
|
-
|
EI→OPE**
|
200
|
PPN
|
53
|
Survived
|
16
|
69
|
M
|
-
|
-
|
Af, HT
|
36
|
Proximal
|
-
|
Heparin
|
|
Oral
|
7
|
Survived
|
17
|
70
|
M
|
-
|
-
|
Af, DM
|
4
|
Distal
|
-
|
EI
|
|
Oral
|
16
|
Survived
|
18
|
83
|
M
|
-
|
-
|
CKD, VHD, LC
|
28
|
Distal
|
-
|
Heparin
|
|
Oral
|
24
|
Survived
|
19
|
80
|
F
|
-
|
○
|
Af, HT, DM
|
29
|
Distal
|
-
|
Heparin
|
|
Oral
|
7
|
Survived
|
20
|
77
|
F
|
-
|
-
|
Af
|
10
|
Distal
|
-
|
Heparin
|
|
Oral
|
11
|
Survived
|
Abbreviations: HT, hypertension; CVD, cerebrovascular disease; Af, atrial fibrillation; CKD, chronic kidney disease; LC, liver cirrhosis; DM, diabetes mellitus; IHD, ischemic heart disease; PM, pacemaker insertion; HD, hemodialysis; VHD, valvular heart disease; HL, hyperlipemia; EI, endovascular intervention; Heparin, heparin medication; OPE, operation; BSC, best supportive care; TPN, total parenteral nutrition; PPN, peripheral parenteral nutrition; F: female; M: male. |
* column indicates whether the obstructed region of the superior mesenteric artery is proximal or distal to the ileocecal artery. |
** indicates that operation was performed because of the relapsed SMA embolism on the 17th day after EI. |
All three deaths, excluding the patient who received BSC, received EI. They had intestinal necrosis after EI, but did not seek further treatment. To assess the risk factors for mortality in the patients who received EI, we compared the clinical features (age, sex, time to diagnosis, vital signs, peritoneal irritation sign), CT findings (obstructed region in the SMA, PI, ascitic fluid), and blood test results (WBC, Plt, D-dimer, CK, LDH, CRP, lactate) between the survivor group and the nonsurvivor group (Table 2). The rate of PI in the nonsurvivor group was significantly higher than that in the survivor group (100% vs 22.2%, P=0.046).
Table 2
Comparison of outcomes after endovascular intervention
|
Survivor group
|
Non-survivor group
|
|
|
n=9
|
n=3
|
P value
|
Age, year
|
72 [70~85]
|
80 [75.5~86]
|
0.46
|
Male sex, n (%)
|
6 (66.7)
|
3 (66.7)
|
1
|
Time to diagnosis, hr
|
6 [5~13]
|
3 [5~8]
|
0.71
|
SBP, mmHg
|
149 [125~197]
|
152 [140~171]
|
0.93
|
Pulse, bpm
|
74.5 [55~94]
|
98 [86~122]
|
0.066
|
Shock, n (%)
|
0 (0)
|
1 (33.3)
|
0.25
|
Peritoneal irritation, n (%)
|
1 (11.1)
|
1 (33.3)
|
0.46
|
CT findings
|
|
|
|
Proximal obstruction*, n (%)
|
8 (88.9)
|
3 (100)
|
1
|
Pneumatosis intestinalis, n (%)
|
2 (22.2)
|
3 (100)
|
0.046
|
Ascitic fluid, n (%)
|
1 (11.1)
|
0 (0)
|
1
|
Blood test
|
|
|
|
WBC, /µL
|
14220 [13300~16130]
|
14590 [11910~15760]
|
1
|
Plt, ×104/µL
|
16.2 [13.7~21.8]
|
27.0 [25.5~27.65]
|
0.21
|
D-dimer, µg/mL
|
3.6 [2.2~6.1]
|
17.55 [13.0~22.1]
|
0.18
|
CK, IU/L
|
80 [50.0~107.0]
|
111 [90.5~120.5]
|
0.37
|
LDH, IU/L
|
315 [285~367]
|
349 [348~366.5]
|
0.48
|
CRP, mg/dL
|
0.87 [0.24~2.06]
|
0.21 [0.18~2.13]
|
0.73
|
Lactate, mg/dL
|
29.5 [24.5~37]
|
40 [31.5~48]
|
0.41
|
Note: Numerical data are indicated as medians. Values in parentheses are percentages, and values in brackets are IQR; first quartile~third quartile |
Abbreviations: SBP, systolic blood pressure; WBC, white blood cell; Plt, platelet; CK, creatine kinase; LDH, lactate dehydrogenase; CRP, C-reactive protein. |
* indicates that the superior mesenteric artery occlusion occurred proximal to the ileocecal artery bifurcation. |
All 20 patients were classified into 3 groups according to the obstructed region in the SMA and the existence of PI based on the CT findings; the findings of group A were that the obstructed region was proximal to the ICA bifurcation and that PI was present, the findings of group B were that the obstructed region was proximal to the ICA bifurcation and PI was not present and the findings of group C were that the obstructed region was distal to the ICA bifurcation and PI was not present. Table 3 shows the treatment and outcomes of each group. There were 9 cases in group A (Case1-9 in Table 1). The mortality rate in the cases that received BSC was 100% in group A. No deaths were found among the operated cases, but all the cases had short bowel syndrome. The mortality rate after EI was 60% (3 out of 5 cases), and 3 patients had died within 3 days after starting treatment. These patients needed surgical treatment because of their deteriorated general condition after EI. However, these patients and their families did not wish to receive treatment. There were 7 cases in group B (Case10-16 in Table 1). Six patients received EI, and one patient received heparin therapy. There were no deaths, and one patient had a recurrence of the SMA embolism 17 days after EI. He received a small bowel resection, which resulted in short bowel syndrome. There were 4 cases in group C (Cases 17-20 in Table 1). One patient received EI, and the others received heparin treatment. There were no deaths or recurrence of the SMA embolism.
Table 3
Treatment and outcome of the 3 groups classified by the obstructed region of superior mesenteric artery and the existence of pneumatosis intestinalis
Group
|
n
|
Occlusion location
|
PI
|
Initial treatment, n
|
Mortality, n (%)
|
A
|
9
|
Proximal
|
+
|
BSC, 2
|
2 (100)
|
OPE, 2
|
0 (0)
|
EI, 5
|
3 (60)
|
B
|
7
|
Proximal
|
-
|
EI, 6
|
0 (0)
|
Heparin, 1
|
0 (0)
|
C
|
4
|
Distal
|
-
|
EI, 1
|
0 (0)
|
Heparin, 3
|
0 (0)
|
Note: Group A included the patients with a superior mesenteric artery occlusion that was proximal to the ileocecal artery bifurcation and pneumatosis intestinalis, group B included the patients with a superior mesenteric artery occlusion that was proximal to the ileocecal artery bifurcation and no pneumatosis intestinalis and group C included the patients with a superior mesenteric artery occlusion that was distal to the ileocecal artery bifurcation and no pneumatosis intestinalis. |
Abbreviations: Proximal, obstruction that is proximal to the ileocecal artery bifurcation; Distal, obstruction that is distal to the ileocecal artery bifurcation; PI, pneumatosis intestinalis; BSC, best supportive care; EI, endovascular intervention; OPE, operation; Heparin, heparin medication. |