Endovascular Treatment for Acute Mesenteric Ischemia

Abstract

The current standard care for acute mesenteric ischemia involves urgent revascularization and resection of the necrotic bowel. A dedicated protocol for early treatment and urgent revascularization is pivotal to improving diagnostic rate and patient survival. In this chapter, the critical components of diagnosis and treatment protocol are reviewed. Different treatment choices with endovascular approaches are discussed. After endovascular revascularization, a dedicated team consisting of surgeons and critical care specialists are needed to provide post-intervention care and second-look laparoscopy when necessary. In geographic regions where healthcare resources are lacking, a time-efficient strategy adopted by interventional radiologists or cardiologists should be considered to improve patient survival.

1. Introduction

1.1 How we begin our treatment protocol

On August 24, 2012, we started our first endovascular treatment for acute mesenteric ischemia. The patient received diagnosis of acute abdomen in the emergent department, and our general surgeon per- formed laparotomy, which found diffuse mesenteric necrosis. After emergent operation, the interven- tional cardiology team was consulted. Endovascular revascularization was performed by Dr. Mu-Yang Hsieh and Dr. Kuei-Chien Tsai. A coronary bare-metal stent was placed to revascularize SMA (superior mesenteric artery) (Integrity, bare-metal stent, 4.0 x 28 mm, Medtronics) (Figure 1).

Figure 1.

The angiography found acute superior mesenteric artery occlusion. The flow was re-established after thrombosuction, balloon angioplasty, and stenting with a bare-metal balloon expandable stent (case 1).

On August 17, 2012, Dr. Mu-Yang Hsieh initiated a draft for Acute Mesenteric Ischemia Protocol. Be- tween 2013 and 2014, interventional radiologist Dr. Chih-Hon Wu provided valuable revision sugges- tions. In the following years, another seven patients received emergent endocvascular revascularization for acute mesenteric ischemia.

1.1.1 The goal of the protocol

1. Initial goals: a definitive invasive angiography become a reasonable options for dignosis improvement. To have an in-hospital monitor program.

2. Intermediate goals: become a center for emergent treatment for acute mesenteric ischemia.

3. Longterm goals: to achieve better survival as reported from previous literatures. Make our one-year survival rate approximate 88%.

1.2 Statistics in our hospital

“Patients only have hours before irreversible gut ischemia ensues, followed by profound distributive shock, and death. (quoted from Moore and Ahn, Chapter 35).”

Bowel ischemia was diagnosed in around 0.1% of hospitalized patients [1]. But the mortality of acute mesenteric ischemia is quite high. In our hospital, about 95%mesenteric ischemia presented with acute abdomen.

Because the diagnosis of acute ischemic bowel is often difficult, we initiated a dedicated diagnosis pro- tocol to improve the patient outcomes. (Figure 2):

1. Emergent primary surgery with f/u angio: 4 patients, all received angio, with 2 SMA lesions fixed, survival 75% (3/4).

2. Emergent primary endovascular approach (with second look laparoscopy when indicated): 18 pa- tients, 5 failure, survival 0% (0/5), 13 success, survival 92.3% (12/13), 4 required laparoscopy/laparotomy.

3. Totally conservative management: 6 patients, survival 0% (0/6).

Figure 2.

Our registry 2012–2020, 28 patients in the registry. Survival is categorized by treatment modalities.

A filling defect (clot) was found in the SMA (Figure 3):

1. Early invasive endovascular approach: 8 patients, survival 75% (6/8).

2. Conservative medical management: 5 patients, survival 0% (0/5).

Figure 3.

The survival categoried by treatment methods after finding clot in the SMA.

2. Literature review

2.1 Review articles and guideline update

Since 2016, there are numerous literature reported that endovascular is better than open surgery [2, 3].

In 2017, a guideline suggested for patients with acute mesenteric ischemia, emergent surgical or endovascular intervention is reasonable.6.

In the absence of RCTs, evidence is based on prospective registries. In the case of embolic occlusion, open and endovascular revascularizations seem to do equally well, whereas, with thrombotic occlusion, endovascular therapy is associated with lower mortality and bowel resection rates. The principles of damage control surgery are important to follow when treating these frail patients. This concept focuses on saving life by restoring normal physiology as quickly as possible, thus avoiding unnecessary time-consuming procedures. Although laparotomy is not mandatory after endovascular therapy in these patients with acute bowel ischaemia, it is often necessary to inspect the bowel. In this setting, second-look laparotomy is also indicated after open revascularization. Intra-arterial catheter thrombolysis of the superior mesenteric artery has been reported with good results. Severe bleeding complications were uncommon, except when intestinal mucosal gangrene was present [4].

See Figures 3–5.

Figure 4.

The internal research board certification.

Figure 5.

Guideline update in 2017 [4].

2.2 Incidence

Acute mesenteric ischemia is one etiology among many causes of acute abdominal pain (< 1/1000) [5].

2.3 Mortality

In reported literatures, the mortality is around 60–80% among patients with acute mesenteric ischemia [5, 6, 7, 8].

2.4 Types of acute mesenteric ischemia

• embolism

• thrombosis

• non-occlusive mesenteric ischemia

• venous thrombosis

Current report addresses that non-occlusive mesenteric ischemia will lead to a worse prognosis.

2.5 Endovascular treatment- cost-effective study

2.5.1 Endovascular interventions decrease the length of hospitalization and are cost-effective in acute mesenteric ischemia

Dr. Erben reported in 2018 that endovascular revascularization for acute mesenteric ischemia is cost-saving, with a lower rate of in-hospital mortality [9].

2.5.2 Endovascular treatment for acute thromboembolic occlusion of the superior Mesen-teric artery and the outcome comparison between endovascular and open Surgi-cal treatments: A retrospective study

Similar good endovascular treatment results were also obtained in a cohort of Chinese population. A table comparing endovascular versus open surgery groups offer a good perspective on this topic (Table 1) [10].

Variable	Endovascular group (n = 18)	Open surgery group (n = 12)	p	t
Symptom onset to treatment (h)	20.8 ± 15.2	25.8 ± 11.3	0.35	−0.96
Laparotomy required (%/n)	33.33 (6)	58.33 (7)	0.26
Time to laparotomy (h)	26.3 ± 16.8	18.0 ± 7.7	0.26	1.18
Bowel resection (cm)	88 ± 44	253 ± 103	0.01	3.85
Thirty-day mortality (%/n)	16.7 (3)	33.3 (4)	0.68

Table 1.

Therapeutic efficacy between endovascular and open surgery groups [10].

Abbreviations: CA, celiac artery; CT; computed tomography; IMA, inferior mesenteric artery; MI, myocardial infarction; SMA, superior mesenteric artery.

Source: From Kirkpatrick ID, et al.: Biphasic CT with mesenteric CT angiography in the evaluation of acute mesenteric ischemia: initial experience. Radiology. 2003; 229(1):9 l-98.

2.6 Contemporary management of acute mesenteric ischemia in the Endovascular era

Dr. Lim et al. reported in 2019 that for acute mesenteric ischemia, both open surgery and endovascular revascularization are viable options in the modern era [11].

See: Tables 2 and 3.

Findings	Acute MI, n = 26	Control, n = 36	Sensitivity (%)	Specificity (%)
Pneumatosis intestinalis	11	0	42	100
SMA or combined CA and IMA occlusion	5	0	19	100
Arterial embolism	3	0	12	100
SMA or portal venous gas	3	0	12	100
Focal lack of bowel wall enhancement	11	1	42	97
Free intraperitoneal air	5	2	19	94
SMA or portal venous thrombosis	4	2	15	94
Solid organ infarction	4	2	15	94
Bowel obstruction	3	2	12	94
Bowel dilatation	17	6	65	93
Mucosal enhancement	12	7	46	81
Bowel wall thickening	22	10	85	72
Mesenteric stranding	23	14	88	61
Ascites	19	24	73	33

Table 2.

Important CT image findings for acute mesenteric ischemia [11].

Abbreviations: CA, celiac artery; CT; computed tomography; IMA, inferior mesenteric artery; MI, myocardial infarction; SMA, superior mesenteric artery.

Source: From Kirkpatrick ID, et al.: Biphasic CT with mesenteric CT angiography in the evaluation of acute mesenteric ischemia: initial experience. Radiology. 2003; 229 (1):9 l-98.

Author (Year)	Data Source	Morbidity	Mortality
Schermerhorn et al. (2009)	Nationwide Inpatient Sample	Length of stay: 9 days vs. 14 days	In-hospital: 16% vs. 39%
		Bowel resection: 28% vs. 37%
		Acute kidney injury: 11.4% vs. 18.4%
		Cardiac complication: 2.1% vs. 7.2%
		Respiratory complication: 1.1% vs. 5.7%
Block et al. (2010)	Swedish Vascular Registry	Laparotomy: 55% vs. 100%	30-day: 28% vs. 42%
		Bowel resection: 19% vs. 63%
		Second-look operation: 31% vs. 67%	1 year: 39% vs. 58%
		Short bowel syndrome: 27% vs. 55%
Arthur et al. (2011)	Single-Center Chart Review	Laparotomy: 69% vs. 100%	36% vs. 50%
		Bowel resection: 52 cm vs. 160 cm
Beaulieu et al. (2014)	Nationwide Inpatient Sample	Length of stay: 12.9 vs. 17.1 days	In-hospital: 24.9% vs. 39.3%
		Bowel resection: 14.4% vs. 33.4%
		TPN support: 13.7% vs. 24.4%
Branco et al. (2015)	Nasional Surgical Quality Improvement Program	Transfusion: 3.7% vs. 19.3%	Odds ratio 0.4 (CI 0.2–0.9)
		Pneumonia: 22.2% vs. 27.8%
		Sepsis: 25.9% vs. 35.5%
Arya et al. (2016)	Single-Center Chart Review	Bowel resection: 36.4% vs. 43.5%	30-day: 45.4% vs. 34.8%
		Sepsis: 45.4% vs. 22.7%
		Re-exploration: 63.6% vs. 56.5%
		Major morbidity: 63.6% vs. 69.6%

Table 3.

Summary of recent literatures (results are endovascular versus open revascularization, respectively) [ 11].

Abbreviations: CI, confidence interval; TPN, total parenteral nutrition.

2.7 Clinical problems

• For the suspected case of acute mesenteric ischemia, is following serum lactate level useful to confirm acute mesenteric ischemia?

  It is not helpful to wait for evidence of increasing serum lactate levels to proceed with further testing; ideally, in fact, intervention would occur in patients with acute mesenteric ischemia before lactic acidosis develops, with the goal of saving additional intestine from full-thickness injury [5].

  When the clinical suspicion of acute mesenteric ischemia is high, we should proceed with CT angiography. And in cases with equivocal CT findings, invasive angiography should be considered.

• In the early phase of abdominal pain, is serum amylase or lipase diagnostic? In the first eight patients of our case series, amylase and lipase is not useful.

• In the first CT study, for patients with no bowel necrosis but still have equivocal CT findings of acute mesenteric ischemia, the best diagnostic method is invasive angiography.

2.8 Primary stenting for acute mesenteric ischemia

Only a few report focused on primary stenting for acute mesenteric ischemia. Dr. Forbrig reported in 2017 with a case series of 19 consecutive patients and demonstrated that endovascular revascularization has high clinical success rates [12].

2.9 Methodology: using Stentriever

Besides balloon angioplasty and stenting, for large thrombus burden, Dr. Miura reported in 2017 that using a stent retriever achieved rapid and good revascularization in a patient with SMA embolism [13].

2.10 Filter protection

Dr. Mendes reported in 2018 that using a distal protection device can redude the event of distal em- bolization [14].

2.11 Special scenario: bypass and its post-OP course

Dr. Morbi reported a patient with acute mesenteric ischemia and the patient received emergent by-pass surgery utilizing an aorto-SMA bypass, with good-quality long saphenous vein and segmental small bowel resection [15].

2.12 Special scenario: dissection

SMA (superior mesenteric artery) dissection has been reported extensively, and the most common problem is when performing open surgery, it is difficult to perform re-entry into the true lumen. The resolution is retrograde open mesenteric stenting (ROMS). The ROMS is performed by opening distal SMA true lumen with placement of a sheath, then proceeding with retrograde wiring and stenting [16].

2.12.1 Classification- SMA dissection

The proposed classification of SMA dissection (Figure 6).

Figure 6.

The classification of SMA dissection. Slide courtesy to Dr. 李栋林浙江大学医学院附属第一医院血管外科.

For SMA dissection, Dr. Loeffler reported in 2017, that if there was no evidence of bowel necrosis, even in symptomatic SMA dissection, regular medical treatment with follow-up may avoid the necessity of open surgery or endovascular stenting [17].

2.12.2 Endovascular treatment of spontaneous dissections of the superior mesenteric artery

Gobble et al. reported in 2009, included 9 patients (all isolated spontaneous SMA dissection). The treatment modality was variable, including expectant management (4 patients), anticoagulation (2 patients), and endovascular stent placement (3 patients). Among patients who received stenting, acute luminal gain is better [16].

Conservative management of symptomatic spontaneous isolated dissection of the superior mesenteric artery has been reported to be successful.^Cho2009

Systematic review and meta-analysis for patients with spontaneous isolated superior mesenteric artery dissection also suggested conservative treatment [17, 18, 19].^{Karaolanis2019}

2.13 Special scenario: combined celiac trunk and SMA disease

In our patient treated in December 2016, the patient had diffuse aorta atherosclerosis, with celiac trunk- hepatic artery and SMA ostial occlusion.

2.13.1 Chronic mesenteric ischemia involving both celiac trunk and SMA

For patients with chronic mesenteric ischemia due to occlusion of both celiac trunk and SMA, SMA revascularization alone may be adequate to improve symptoms [20].

2.14 Special scenario: ischemia: reperfusion syndrome

2.14.1 Reperfusion syndrome

Severe reperfusion syndrome after acute mesenteric ischemia revascularization has been reported. But optimal medical treatment has not been established ^{Robles−Martin2019.}

2.15 Recurrent superior mesenteric artery stent fracture

After successful stenting and salvage for acute mesenteric ischemia, stent fracture has been reported. This issue needs further study to establish the best treatment algorithm. Currently, we suggest following patients with abdominal contrast-enhanced CT to evaluate the patency of the stent ^{Robins 2019.}

3. Diagnosis of acute mesenteric ischemia

3.1 Initial phase- clinical challenges

The symptoms of acute mesenteric ischemia are described in most general text of most medical textbooks. We do not repeat the symptoms but wish to address the most common clinical challenges in the initial phase of diagnosis: after performing KUB plain film of CT angiography, it is still frequent to fail to proceed to invasive angiography due to multiple reasons: physicians do not familiar with invasive angiography, lack of staffs to perform emergent angiography, no bowel necrosis and surgeon wish to treat the patient conservatively. Following serum lactate level only detects the patients in irreversible bowel necrosis and is not beneficial providing chances of early salvage.

3.2 Computer tomography- CT

The axial, coronal, sagittal, and 3D reconstruction in advance is mandatory to be reviewed in the initial diagnostic phases. However, in patients with extensive aortic calcification and ostial calcification, care must be taken to interpret the lumen area and stenosis, because the lumen may be mis-interpretated as patent due to extensive ostial calficaition.

CT findings of bowel necrosis: no enhancement of bowel loop, pneumatosis intestinalis, aeroportia (Figure 7).

Figure 7.

The CT found extensive air within the portal venous system.

4. Consultation

4.1 Consultation process

After our index case, an interventional cardiologist (Mu-Yang Hsieh) wrote a draft. The draft was reviewed and completed by an interventional radiologist (Chih-Horng Wu). The interventional radiologist trained the interventional cardiologist to perform selective bowel angiography to reduce time delay in the emergency scenario. The protocol was revised from the acute coronary syndrome protocol. For patients with evident bowel necrosis and peritoneal signs, direct consultation with a surgical team was mandatory (group 1 patients). The endovascular team was contacted after the surgical procedure. For patients with no evident bowel necrosis by CT, any team members can activate the protocol in the emergency department (group 2 patients). In suspected patients with possible CT findings (group 3 patients), the team votetd if proceeding with diagnostic angiography is beneficial to the patient Figures 8–10.

Figure 8.

During operation, direct manual examination after laparotomy confirms acute mesenteric ischemia with bowel necrosis.

Figure 9.

During emergent angiography, total occlusion SMA was confirmed. The occlusion was re- canalized with a 0.014-inch coronary wire, thrombosuction, and direct stenting. The abdominal pain completely resolved. No further surgical operation was needed.

Figure 10.

Severe ostial stenosis of SMA. Treated with bare-metal stenting. The abdominal pain com- pletely resolved.

4.2 Surgical consultation

When the patient developed peritoneal signs or when bowel necrosis was evident by CT, the patient will be sent to the operation room first, and open thrombectomy 及 retrograde open mesenteric stenting (ROMS) should be considered Oderich 2018Figure 11.

Figure 11.

The flow chart of consultation process according to CT imaging findings.

4.2.1 Experience in the Hsinchu

Since 2016, we performed emergent angiography for case 9 and case 10 before the emergent open laparotomy. Direct stenting was performed on SMA. The potential benefit is to shorten the ischemic time

(Figures 12 and 13).

Figure 12.

Case 10: revascularization first! It is better with improved flow to jejunum and proximal ileum than SMA proximal total occlusion. During bowel resection, resect the ileocecal junction to ascending colon for about100 cm, with 200 cm viable small bowel saved after the revascularization.

Figure 13.

Case illustration example. This illustration was made to make a thorough explanation to the patient and his family.

5. Critical statistics for patient explanation and the results pro- vided to the family for rapid briefing of acute mesenteric ischemia

Treatment results (historical results) were provided to the patient family at the emergency department.

• Angiographic (technical) success rate: 6/8 (75%)

• Survival at 30 days: 75%

• Survival at 7 days, In angiographic success patients: 100%

• Survival at 7 days, In angiographic failure patients: 0%

• Long-term follow-up survival at 2-year: 50% (due to multiple comorbidities) (Figure 14).

Figure 14.

The drawing of disease explanation. All the drawing was made in the emergency department.

Poster prepared and mounted in the emergency department and at the waiting area of intensive care units (Figure 15).

Figure 15.

The poster explaining the endovascular protocol for acute mesenteric ischemia. The poster was written in Chinese.

6. Angiography and treatment

Abdominal angiography was performed emergently in the cath room (cardiology department) angiography room (radiology department). The vascular access was set with a 6-Fr sheath. To perform diagnostic angiography, a 5-Fr diagnostic catheter (RC-1 or JR) was used. In our protocol, the flow was rated using the coronary grading system: TIMI (thrombolysis in myocardial infarction) flow scale. Mesenteric artery disease was defined if there was diameter stenosis over 50%, and mesenteric artery occlusion was defined if there was 100% stenosis with 0 TIMI flow.

6.1 Endovascular treatment

Thrombosuction, balloon angioplasty, and stenting were performed sequentially or by the discretion of the interventional cardiologist. First, the femoral sheath was changed to a 7-Fr sheath (10 cm), and a guiding catheter (7-Fr JR4 or IMA) was used according to the angle between of SMA ostium and aorta after reviewing the sagittal view on the CT. For ostial lesion, a guide catheter with side hole was used. We usually give a bolus of heparin (3000–5000 U) to achieve activated clotting time of at least 250 seconds. A workhorse 0.014-inch soft coronary wire was used to cross the lesion. With a dedicated coronary thrombosuction catheter, distal contrast injection can be done to confirm that true lumen was reached in cases with SMA occlusion. Thrombosuction was performed (Thrombuster, Terumo, Tokyo, Japan). Balloon angioplasty was done after successful establishment of antegrade flow. Ifpersistentt recoil or restenosis had been noted, the operator could perform bail-out stenting (usually with a coronary bare-metal stent. Thrombolytic agent was not used in our protocol because it was declined by our team (GI man). Because the National Health Insurance did not cover distal protection device in the treatment of acute mesenteric ischemia, the distal protection device was not used.

6.2 Procedure details

6.2.1 Percutaneous endovascular intervention

A coronary system with 0.014-inch wire, balloon, and stents are used in our protocol. Usually, the vascular access is at the common femoral artery (7 Fr sheath). We used a JR4 diagnostic coronary catheter with 0.035-inch wire (Terumo GlideWire) to perform diagnostic angiography. During the intervention, a 0.014-inch coronary wire with length of 180 cm is used (Sion, BMW-U2).

6.2.2 Guiding catheter choices

The angle between SMA ostium and aorta can help to choose the suitable guide sheath or guiding catheter to engage SMA. The choices included angled sheath (6 or 7 Fr), IMA, or JR4 guide catheters.

6.2.3 Thrombosuction

Thrombosuction: we used coronary system, Thrombuster (6 Fr), or Export catheter.

6.2.4 Balloon angioplasty

Most commonly used balloons: Trek, Maverick, and Sapphire, with 6–8 atm.

6.2.5 Bail-out stenting

Bail-out stenting should be considered: when thrombosuction, or balloon angioplasty failed, stenting may still be tried.

Before performing bail-out stenting, we should always use thrombosuction catheter to perform distal injection in order to confirm the adequate distal landing zone.

Rotational Thrombectomy Device can be considered and has reported successful to salvage patients with acute mesenteric ischemia in a single center study [21].

7. Surgery

7.1 Inportant notices for surgeons

1. Surgery and revascularization are both mandatory to provide optimal survival chances in patients with extensive bowel necrosis.

2. For patients who received stenting to SMA before surgery, care must be taken not to manipulate the SMA forcefully to avoid inadvertent crush of the stent.

8. Post-stenting care

ICU care after the endovascular procedure is mandatory. The electrolyte, urine output, and arterial pressure are to be monitored. An infection specialist is consulted at the discretion of the critical care specialist. The general surgeon will check the abdominal physical exams to detect changes in peritoneal signs. As- pirin (100 mg) and clopidogrel (75 mg) are initiated if no bleeding is noted after overnight observation. For patients with atrial fibrillation, an oral anticoagulant is started at the discretion of the operator and the caring cardiologist.

8.1 Definition of treatment success

Important definition: [22].

• Primary clinical success was defined as complete resolution of symptoms.

• Partial clinical success was defined as resolution of some or most of the symptoms, but persistence of some symptoms after the procedure.

• Primary clinical failure was defined as the lack of any or minimal symptom relief.

• Technical success: the successful revascularization of all arteries that were treated in which there was less than a 30% residual diameter stenosis.

• Partial technical success per patient (who had multiple mesenteric arteries treated) was defined as at least one mesenteric artery treated successfully.

• Technical failure was defined as the inability to treat at least one mesenteric artery per patient

8.2 Antibiotics

Oral digestive decontamination: PO gentamicin 80 mg/day, PO metronidazole 1.5 g/day [23].

What Is the Role of Empiric Treatment for Suspected Invasive Candidiasis in Nonneutropenic Patients in the Intensive Care Unit?

8.2.1 Invasive candidiasis

Preferred empiric therapy for suspected candidiasis in non-neutropenic patients in the intensive care unit (ICU) is an echinocandin (caspofungin: loading dose of 70 mg, then 50 mg daily; micafungin: 100 mg daily; anidulafungin: loading dose of 200 mg, then 100 mg daily) (strong recommendation; moderate-quality evidence) [24].

8.3 ICU care

• Mandatory medical protocol: blood volume resuscitation, with mean arterial pressure > 65 mmHg, urine output >0.5 ml/kg/hour.

• Curative unfractionated heparin therapy with aPTT 50–70 seconds.

• IV proton pump inhibitors: IV pantoprazole 80 mg/day

• Oxygen therapy

• Food resting, PN if prolonged >5 days.

• Antibiotics: empirical, not prophylaxis. Tazocin and possible Candida coverage (no evidence of presence)

Important findings: In some patients with SMA and celiac trunk 100% occlusion, the patients can present with acute mesenteric ischemia.

Tables 4 and 5.

No	Age	Sex	Comirbidities	CHADS2-VASc	Shock	Resting dyspnea	Food avoidance	Diarrhea	Nausea/vomiting	Ileus, diffuse	Ileus, localized	Lactate (mmol/L)
1	79	Female	Cirrhosis, gout	2	+	+	—	—	—	—	+	8.8
2	61	Male	PAOD, ESRD, DM, dyslipidemia, smoking	2	+	—	—	+	+	—	+	2.5
3	74	Female	HTN, dyslipidemia, gout	2	—	—	—	+	—	—	+	1.7
4	72	Female	DM, HTN	3	−+	—	—	—	+	—	7.4
5	63	Female	Afib, VHD, mechanical valve, CVA, DM, HTN, dyslipidemia	5	—	+	—	—	—	—	+	2.4
6	74	Female	CAD, old MI, PAOD, ESRD, DM, HTN, dyslipidemia	4	+	+	—	—	—	—	+	5
7	86	Male	CAD, Afib, VHD, DM, HTN	3	—	—	—	—	—	—	+	2.6
8	80	Female	CAD, ESRD, DM, HTN	4	—	—	+	—	—	—	+	1

Table 4.

Demographics, clinical characteristics, and presentation of acute abdominal pain of the study participants.

Category	No	Culprint vessel	Lesion	Diameter (mm)	Length (mm)	Calcification	Time from ER to angiography	Treatment	Stenting	Angio / Clinical success	Laparotomy required	Angio to Discharge (days)	F/U durations (days)	Survival at 30 days	Outcome at 12 montsh
1	1	SMA	100% occlusion, main trunk	4	28	Minimal	24.5	Aspiration/stenting	BMS	Yes/Yes	Yes (after stenting)	45	33	Yes	Moratlity
1	6	SMA	50% stenosis, ostium	4	5	Moderate	12.1	Direct stenging	BMS	Yes/Yes	Yes (before stenting)	21	166	Yes	Moratlity
2	4	SMA	100% occlusion, main trunk	2.5	40	Minimal	16.3	Aspiration only	NA	No/No	No	NA	1	No	Mortality
2	5	SMA	100% occlusion, main trunk	4	30	Minimal	3.4	Aspiration/stenting	BMS	Yes/Yes	No	2	341	Yes	Survival
2	7	SMA	100% occlusion, main trunk	4.5	50	Minimal	5.5	Aspiration/stenting	BMS	Yes/Yes	No	3	187	Yes	Survival
3	2	SMA & celiac trunk	100% occlusion, from ostium	3	NA	Severe	11.9	Wiring only	NA	No/No	No	NA	1	No	Mortality
3	3	IMA	80% stenosis, ostium	3	15	Minimal	22.2	Direct stenting	BMS	Yes/Yes	No	2	465	Yes	Survival
3	8	SMA	90% stenosis, ostium	4.5	8	Moderate	9	Direct stenting	BMS	Yes/Yes	No	2	90	Yes	Survival

Table 5.

Procedure details and outcomes, by group.