Acute mesenteric ischaemia: a rare complication mimicking necrotising enterocolitis in a premature infant.

Acute mesenteric ischaemia (AMI) is a life-threatening gastrointestinal complication uncommonly described in premature infants. The diagnosis of AMI is challenging and may be delayed due to the limitation of accurate diagnostic imaging and non-specific clinical signs. Furthermore, AMI can be misdiagnosed as necrotising enterocolitis (NEC) due to the overlapping clinical and radiological features. Though known to be associated with high mortality rates, early recognition and intervention can improve the survival rates in infants with AMI. We describe a case of a premature infant who presented with an acute abdomen and haemodynamic collapse, initially treated for NEC but later diagnosed with AMI intraoperatively. Due to the extensive bowel necrosis, surgical intervention was rendered futile and the infant finally succumbed to the disease.

Mesenteric ischemia: Recognizing an uncommon disorder and distinguishing among its causes.

Mesenteric ischemia occurs because of inadequate intestinal blood flow. Its severity depends on the vessels involved and whether collateral blood vessels are available to prevent malperfusion. Mesenteric ischemia is an uncommon cause of abdominal pain, but it is associated with high mortality and often poses a diagnostic challenge to clinicians because its symptoms are nonspecific. Early recognition and treatment are imperative to improve patient outcomes.

Nonocclusive mesenteric ischemia after percutaneous kyphoplasty: A case report.

RATIONALE: Percutaneous kyphoplasty (PKP) is a minimally invasive technique employed for treating vertebral compression fractures. Although PKP is simple and relatively safe, severe complications are possible. Here, we report a new, severe complication linked to this procedure, namely nonocclusive mesenteric ischemia (NOMI). PATIENT CONCERNS: An 83-year-old female patient, previously in good health, fell backward, landing on her buttocks, and subsequently experienced persistent low-back pain that exacerbated during turning or sitting up. DIAGNOSES: Lumbar spine radiography revealed wedge deformity of the L1 vertebral body. Lumbar spine magnetic resonance imaging indicated a fresh compression fracture of the L1 vertebral body. INTERVENTIONS: On the 2nd day following the trauma, the patient underwent PKP under local anesthesia. Anesthesia was satisfactory, and the procedure progressed smoothly. OUTCOMES: The patient experienced mild discomfort in the right abdomen within the 1st hour to 3 days postoperatively, mild abdominal distension on the 4th day, and sudden severe abdominal pain on the 5th day. Immediate abdominal computed tomography revealed ischemic changes in the ascending colon and hepatic flexure, accompanied by hepatic portal venous gas. An hour later, abdominal pain spontaneously subsided. Approximately 5 hours later, an enhanced abdominal computed tomography revealed no filling defects in the mesenteric vasculature, absence of luminal narrowing or occlusion, enhanced intestinal walls, and a notable improvement in hepatic portal venous gas. Considering NOMI and ischemia related to superior mesenteric artery spasm, vasodilator therapy (papaverine hydrochloride) was initiated, leading to favorable outcomes. On day 17, pathological examination of the hepatic flexure revealed moderate, acute, and chronic mucosal inflammation, along with interstitial fibrous tissue proliferation, providing clear evidence supporting ischemic changes. She was discharged on day 18 after a successful recovery. LESSONS: The occurrence of NOMI after PKP is uncommon. Yet, once it happens, delayed diagnosis or misdiagnosis can lead to serious consequences such as intestinal necrosis and abdominal infection, even endangering the patient's life. We currently lack experience in preventing this complication, but timely diagnosis and appropriate intervention are effective measures in treating such complications.

Prognostic factor of patients with short bowel syndrome due to nonCrohn disease: A single institution observational study.

Short bowel syndrome (SBS) is a severely disabling and potentially life-threatening condition. Survival data for patients with SBS are limited. This study aimed to investigate prognostic factors in patients with SBS undergoing surgery. We reviewed the medical records of 27 consecutive patients with SBS who were treated at our hospital between January 2018 and December 2022. SBS was defined as a remaining small bowel length <200 cm, excluding patients with Crohn disease. Of the 27 patients identified, 17 were males and 10 were females, with a median age of 77 (46-90) years and a total observation time of 137 (2-1628) days. All patients underwent surgery and received parenteral nutrition (PN) and follow-up in our hospital. Superior mesenteric artery stenosis (44.4%) and nonocclusive mesenteric ischemia (25.9%) most commonly caused SBS. The median residual small bowel length and postoperative hospital stay were 50 (5-150) cm and 48 (2-104) days, respectively. Jejunostomy was performed in 17 (62.9%) patients, and 4 (14.8%) patients were weaned off their PN. Death occurred in 14 (51.8%), and the median survival time was 209 days. The survival outcome was compared between the survival (n = 13) and the death groups (n = 14). Jejunostomy and PN rates were significantly higher in the death group (P < .01, P = .03, respectively). SBS is associated with significantly higher mortality rates. Jejunostomy and long PN duration are significantly associated with death in patients with SBS.

Scoping Review of Clinical Presentations and Outcomes in Patients with Concomitant COVID-19 Infection and Acute Mesenteric Ischaemia.

OBJECTIVES: COVID-19 infection confers an increased risk of coagulation dysfunction (1) predisposing to thromboembolism in many anatomical sites including the gastrointestinal tract (GIT) (2). This study investigates the clinical presentation and outcome in patients presenting with concurrent COVID-19 infection and gastrointestinal tract ischaemia. Furthermore, differentiation and comparisons are drawn between those with arterial and venous aetiology for mesenteric ischaemia. METHODS: A systematic search was undertaken on EMBASE, PubMed, and MEDLINE. Two independent reviewers screened titles, abstracts, and full-text articles according to the inclusion criteria and extracted relevant data. Data analyses were conducted using Excel®. RESULTS: Forty-one studies were included in the data analyses, yielding 44 patients. Twenty-six patients had mesenteric arterial occlusion, sixteen patients had mesenteric venous occlusion, and two patients had both arterial and venous mesenteric occlusion. All patients had concurrent COVID-19 infection. The survival rate in patients with arterial aetiology was 38.5% in contrast to 68.8% in patients with venous aetiology. Twelve patients (29.3%) experienced respiratory symptoms in the community before the onset of gastrointestinal symptoms, and five (12.2%) developed gastrointestinal symptoms during their inpatient stay for COVID-19 pneumonitis. CONCLUSIONS: Acute mesenteric ischaemia presents a clinical challenge to diagnose due to its non-specific symptoms. Concurrent COVID-19 infection with its predominant respiratory symptoms adds a further challenge in recognising the non-specific symptoms of mesenteric ischaemia. Our study draws attention to the increased thromboembolic risk posed by COVID-19 infection and the need for a high index of suspicion to aid prompt diagnosis and management of acute mesenteric ischaemia, even in the post-pandemic era.

A visceral organ function-focused therapeutic strategy using a 6-hour time window for patients with acute type a aortic dissection complicated by mesenteric malperfusion.

BACKGROUND: Acute type A aortic dissection (ATAAD) complicated by mesenteric malperfusion is a critical and complicated condition. The optimal treatment strategy remains controversial, debate exists as to whether aortic dissection or mesenteric malperfusion should be addressed first, and the exact time window for mesenteric ischemia intervention is still unclear. To solve this problem, we developed a new concept based on the pathophysiological mechanism of mesenteric ischemia, using a 6-hour time window to divide newly admitted patients by the time from onset to admission, applying different treatment protocols to improve the clinical outcomes of patients with ATAAD complicated by mesenteric malperfusion. METHODS: This was a retrospective study that covered a five-year period. From July 2018 to December 2020(phase I), all patients underwent emergency open surgery. From January 2021 to June 2023(phase II), patients with an onset within 6 h all underwent open surgical repair, followed by immediately postoperative examination if the malperfusion is suspected, while the restoration of mesenteric perfusion and visceral organ function was performed first, followed by open repair, in patients with an onset beyond 6 h. RESULTS: There were no significant differences in baseline and surgical data. In phase I, eleven patients with mesenteric malperfusion underwent open surgery, while in phase II, our novel strategy was applied, with sixteen patients with an onset greater than 6 h and eleven patients with an onset less than 6 h. During the waiting period, none died of aortic rupture, but four patients died of organ failure, twelve patients had organ function improvement and underwent surgery successfully survived. The overall mortality rate decreased with the use of this novel strategy (54.55% vs. 18.52%, p = 0.047). Furthermore, the surgical mortality rate between the two periods showed even stronger statistical significance (54.55% vs. 4.35%, p = 0.022). Moreover, the proportions of patients with sepsis and multiorgan failure also showed differences. CONCLUSIONS: Our novel strategy for patients with ATAAD complicated by mesenteric malperfusion not only improves the surgical success rate but also reduces the overall mortality rate.

Nonocclusive mesenteric ischemia (NOMI) on Roux limb after biliary reconstruction successfully treated by interventional radiology (IVR).

Nonocclusive mesenteric ischemia (NOMI) is a life-threatening disorder. Early diagnosis is challenging because NOMI lacks specific symptoms. A 52-year-old man who received extended cholecystectomy with Roux-en-Y hepaticojejunostomy for gallbladder cancer (GBC) presented to our hospital with nausea and vomiting. Neither tender nor peritoneal irritation sign was present on abdominal examination. Blood test exhibited marked leukocytosis (WBC:19,800/mm3). A contrast-enhanced abdominal computed tomography (CT) scan revealed remarkable wall thickening and lower contrast enhancement effect localized to Roux limb. On hospital day 2, abdominal arterial angiography revealed angio-spasm at marginal artery and arterial recta between 2nd jejunal artery and 3rd jejunal artery, leading us to the diagnosis of NOMI. We then administered continuous catheter-directed infusion of papaverine hydrochloride until hospital day 7. Furthermore, the patient was anticoagulated with intravenous unfractionated heparin and antithrombin agents for increasing D-dimer level and decreasing antithrombin III level. On hospital day 8, diluted oral nutrition diet was initiated and gradually advanced as tolerated. On hospital day 21, the patient was confirmed of improved laboratory test data and discharged with eating a regular diet. We experienced a rare case of NOMI on Roux limb after 2 years of extended cholecystectomy with hepaticojejunostomy for GBC, promptly diagnosed and successfully treated by interventional radiology (IVR).

Giant cell arteritis causing mesenteric ischemia without cranial manifestations: Report of an unusual case.

ABSTRACT: Giant cell arteritis is a medium to large vessel vasculitis involving most commonly temporal arteries, vertebral and ophthalmic arteries. Giant cell arteritis causing mesenteric ischemia is not so frequent, more so if it occurs without cranial manifestations. Here we present an unusual case of a 26-year-old male patient presenting with subacute intestinal obstruction due to giant cell arteritis leading to mesenteric ischemia.

Predictive Factors of Intestinal Ischaemia in Adhesive Small Bowel Obstruction.

OBJECTIVE: To identify the predictive factors of intestinal ischaemia in adhesive small bowel obstruction (ASBO) and develop an intestinal ischaemia risk score. STUDY DESIGN: Observational study. Place and Duration of the Study: Department of General Surgery, Shandong Provincial Qianfoshan Hospital, Jinan, Shandong, China, from January 2017 to February 2022. METHODOLOGY: ASBO was determined by findings at laparotomy. The assessment of small bowel's viability was conducted through surgical inspection and subsequent histological examination of the surgical specimen. Univariate and multivariate analyses were conducted to ascertain the risk factors associated with intestinal ischaemia. RESULTS: In total, 79 patients were included. Factors entered into multivariate analysis associated with intestinal ischaemia were; rebound tenderness (odds ratio (OR): 7.8, 95% confidence interval (CI):1.7-35.3; p=0.008), procalcitonin (PCT) >0.5 ng/mL (OR: 11.7, 95% CI: 2.3-58.1; p=0.003), and reduced bowel wall enhancement on computerised tomography (CT) scan (OR: 12.2, 95% CI:2.4-61.5; p=0.003). Among patients with 0, 1, 2, and 3 factors, the rate of intestinal ischaemia increased from 0% to 49%, 72%, and 100%, respectively. According to the number of risk factors, the area under the receiver operating characteristic curve for the determination of intestinal ischaemia was 0.848 (95% CI: 0.764-0.932). CONCLUSION: Rebound tenderness, PCT levels >0.5 ng/mL, and reduced bowel wall enhancement are risk factors of intestinal ischemic injury that require surgery within the context of ASBO. These factors need to be closely monitored that could assist clinicians in avoiding unnecessary laparotomies and selecting patients eligible for surgery. KEY WORDS: Intestinal obstruction, Ischaemia, Adhesions.

Luminal Delivery of Pectin-Modified Oxygen Microbubbles Mitigates Rodent Experimental Intestinal Ischemia.

INTRODUCTION: Ischemic gut injury is common in the intensive care unit, impairs gut barrier function, and contributes to multiorgan dysfunction. One novel intervention to mitigate ischemic gut injury is the direct luminal delivery of oxygen microbubbles (OMB). Formulations of OMB can be modified to control the rate of oxygen delivery. This project examined whether luminal delivery of pectin-modified OMB (OMBp5) can reduce ischemic gut injury in a rodent model. METHODS: The OMBp5 formulation was adapted to improve delivery of oxygen along the length of small intestine. Adult Sprague-Dawley rats (n = 24) were randomly allocated to three groups: sham-surgery (SS), intestinal ischemia (II), and intestinal ischemia plus luminal delivery of OMBp5 (II + O). Ischemia-reperfusion injury was induced by superior mesenteric artery occlusion for 45 min followed by reperfusion for 30 min. Outcome data included macroscopic score of mucosal injury, the histological score of gut injury, and plasma biomarkers of intestinal injury. RESULTS: Macroscopic, microscopic data, and intestinal injury biomarker results demonstrated minimal intestinal damage in the SS group and constant damage in the II group. II + O group had a significantly improved macroscopic score throughout the gut mucosa (P = 0.04) than the II. The mean histological score of gut injury for the II + O group was significantly improved on the II group (P ≤ 0.01) in the proximal intestine only, within 30 cm of delivery. No differences were observed in plasma biomarkers of intestinal injury following OMBp5 treatment. CONCLUSIONS: This proof-of-concept study has demonstrated that luminal OMBp5 decreases ischemic injury to the proximal small intestine. There is a need to improve oxygen delivery over the full length of the intestine. These findings support further studies with clinically relevant end points, such as systemic inflammation and vital organ dysfunction.

[Modern biochemical markers of acute mesenteric ischemia]. / Sovremennye biokhimicheskie markery ostroi mezenterial'noi ishemii.

OBJECTIVE: To analyze modern literature data on biochemical markers of critical mesenteric ischemia. MATERIAL AND METHODS: We analyzed the most promising, highly specific and sensitive biochemical markers of total and segmental intestinal damage following acute mesenteric ischemia. Analysis included domestic and foreign literature data between 2015 and 2023. RESULTS: We identified the most easy-to-use for any hospitals biochemical markers with at least 90% sensitivity and specificity for further practical research. CONCLUSION: Further prospective research will provide a new step in solving the problem of timely diagnosis of acute mesenteric circulatory disorders.

Successful Endovascular Treatment of Calcified Superior Mesenteric Artery Complicated by Intramural Hematoma in Chronic Mesenteric Ischemia.

BACKGROUND Chronic mesenteric ischemia (CMI) is defined as ischemic symptoms caused by insufficient supply of blood to the gastrointestinal tract. Patients diagnosed with advanced symptomatic CMI should be treated subsequently, as the transition from CMI to acute mesenteric ischemia can be unpredictable. However, there is little information regarding the management of potential procedural complications during endovascular therapy (EVT) for CMI. CASE REPORT A 70-year-old man was admitted to our hospital with recurrent abdominal pain just after hemodialysis. The angiogram showed significant stenosis with heavy calcification in the proximal of the superior mesenteric artery (SMA), leading to the diagnosis of CMI. To alleviate the symptom, EVT for the stenotic lesion of the SMA was indicated. During the procedure, a cutting balloon was inflated to facilitate vessel expansion in the target lesion. As a result, intravascular ultrasound (IVUS) imaging revealed dissection into the media with extension into the medial space without reentry and demonstrated a semilunar intramural hematoma. We were able to contain the intramural hematoma by covering the whole dissection in the SMA with implantation of self-expandable stents. CONCLUSIONS This case highlights the potential of EVT for heavy calcification of the SMA complicated by dissection without reentry. Intramural hematoma was observed with IVUS examination. We were able to contain the hematoma by the implantation of self-expandable stents over the whole length of the SMA dissection under IVUS-guided EVT.

Factors that may affect the outcome of acute occlusive mesenteric ischemia. A single-center study.

BACKGROUND: Acute mesenteric ischemia is a rare but lethal disease. Acute occlusive mesenteric ischemia consists of mesenteric artery embolism, mesenteric artery thrombosis, and mesenteric vein thrombosis. This study aimed to investigate the factors that may affect the outcome of acute occlusive mesenteric ischemia. METHODS: Data from acute occlusive mesenteric ischemia patients admitted between May 2016 and May 2022 were reviewed retrospectively. Patients were divided into 2 groups according to whether complications(Clavien‒Dindo ≥ 2) occurred within 6 months of the first admission. Demographics, symptoms, signs, laboratory results, computed tomography angiography features, management and outcomes were analyzed. RESULTS: 59 patients were enrolled in this study. Complications(Clavien‒Dindo ≥ 2) occurred within 6 months of the first admission in 17 patients. Transmural intestinal necrosis, peritonitis, white blood cell count, percentage of neutrophils, percentage of lymphocytes, neutrophil-to-lymphocyte ratio, lactate dehydrogenase, creatine kinase isoenzyme, cardiac troponin I, laparoscopic exploration rate, open embolectomy rate, enterostomy rate, length of necrotic small bowel, length of healthy small bowel, surgical time and intraoperative blood loss differed significantly between groups. Creatine kinase isoenzyme (OR = 1.415, 95% CI: 1.060-1.888) and surgical time (OR = 1.014, 95% CI: 1.001-1.026) were independent risk factors associated with complications(Clavien‒Dindo ≥ 2). CONCLUSIONS: Our analysis suggests that acute occlusive mesenteric ischemia patients with a creatine kinase isoenzyme level greater than 2.22 ng/mL or a surgical time longer than 156 min are more likely to experience complications'(Clavien‒Dindo ≥ 2) occurrence within 6 months of the first admission.

Mesenteric Vein Thrombosis following Sleeve Gastrectomy: A Case Report and Review of the Literature.

INTRODUCTION: Acute mesenteric ischemia (AMI) is a rare but lethal disease. Mesenteric vein thrombosis (VAMI) is a subtype of AMI. Morbid obesity is usually accompanied by hypertension, hyperlipidemia, or diabetes mellitus, which are risk factors associated with AMI. CASE PRESENTATION: We present a 28-year-old man with VAMI post-laparoscopic sleeve gastrectomy. He was first misdiagnosed with intestinal obstruction. Superior VAMI was confirmed after computed tomography angiography. Laparotomy, resection of the necrotic small bowel, and ostomy were performed immediately. CONCLUSION: Patients with morbid obesity accompanied by hypertension, hyperlipidemia, or diabetes mellitus have a high risk of AMI. Abdominal pain with sudden onset should be considered AMI. Anticoagulation therapy post-sleeve gastrectomy might help reduce the incidence of AMI.

[Surgical strategies and efficacy analysis for aortic dissection complicating intractable mesenteric artery ischemia].

Objective: To explore the surgical strategies and clinical efficacy for aortic dissection combined with refractory superior mesenteric artery (SMA) ischemia. Methods: This is a retrospective case series study. Clinical data of 24 patients with aortic dissection and refractory SMA ischemia admitted to the Department of Vascular Surgery, Zhongshan Hospital, Fudan University from August 2010 to August 2020 were retrospectively collected. Of the 24 patients, 21 were males and 3 were females, with an age of (50.3±9.9) years (range: 44 to 72 years).Among them, 9 cases were Stanford type A aortic dissection, and 15 cases were type B. All patients underwent CT angiography upon admission, and based on imaging characteristics, they were classified into three types. Type Ⅰ: severe stenosis/occlusion of the SMA true lumen only; Type Ⅱ: stenosis of the true lumens in the descending aorta and SMA (isolated type); Type Ⅲ: stenosis of the true lumens in the thoracoabdominal aorta and SMA (continuation type). Surgical procedures, complications, mortality, and reintervention rates were recorded. Results: Among the 24 patients, 17 (70.8%) were classified as Type Ⅰ, 4 (16.7%) as Type Ⅱ, and 3 (12.5%) as Type Ⅲ. Fourteen cases of Type Ⅰ underwent thoracic endovascular aortic repair combined with SMA stent implantation. Additionally, 3 Type Ⅰ and 1 Type Ⅱ patients underwent only SMA reconstruction (with one case of chronic TAAD treated with iliac artery-SMA bypass surgery). Moreover, 3 Type Ⅱ and 3 Type Ⅲ patients underwent descending aorta combined with SMA stent implantation. There were 5 patients (20.8%) who underwent small bowel resection, either in the same sitting or in a staged procedure. During hospitalization, 4 patients died, resulting in a mortality rate of 16.7%. Among these cases, two patients succumbed to severe intestinal ischemia resulting in multiple organ dysfunction syndrome. The follow-up duration was (46±9) months (range: 13 to 72 months). During the follow-up, 2 patients died, unrelated to intestinal ischemia. The 5-year freedom from reintervention survival rate was 86.1%, and the 5-year cumulative survival rate was 82.6%. Conclusions: Patients with aortic dissection and refractory SMA ischemia have a high perioperative mortality. However, implementing appropriate surgical strategies according to different clinical scenarios can reduce mortality and alleviate intestinal ischemia.

Impact of Patient and Procedural Factors on Outcomes Following Mesenteric Bypass.

BACKGROUND: Mesenteric bypass (MB) for patients with acute (AMI) and chronic mesenteric ischemia (CMI) is associated with cardiovascular (CV) and pulmonary morbidity. METHODS: Patients with AMI and CMI from 2008 to 2019 were identified to determine independent predictors of CV (cardiac arrest, MI, DVT, and stroke) and pulmonary (pneumonia and ventilator time>48 h) morbidities in patients undergoing MB. RESULTS: 377 patients were identified. Patients with AMI had higher rates of preoperative SIRS/sepsis (28 vs 12%, P < .0001), were more likely to be ASA class 4/5 (55 vs 42%, P = .005), were more likely to require bowel resection (19 vs 3%, P < .0001), and were more likely to have vein utilized as their bypass conduit (30 vs 14%, P < .0001). There were no differences in use of aortic or iliac inflow (P = .707) nor in return to the OR (24 vs 19%, P = .282). Both postoperative sepsis (12 vs 2.6%, P = .003) and mortality (31.4% vs 9.8%, P < .0001) were significantly increased in patients with AMI. After adjusting for both patient and procedural factors, multivariable logistic regression (MLR) identified international normalized ratio (INR) (OR 3.16; 95% CI 1.56-6.40, P = .001) and chronic heart failure (CHF) (OR 5.88; 95% CI 1.15-29.97, P = .033) to be independent predictors of pulmonary morbidity, while preoperative sepsis (OR 1.96; 95% CI 1.45-2.66, P < .0001) alone was predictive of CV morbidity in all patients undergoing MB. DISCUSSION: Mesenteric bypass for mesenteric ischemia leads to high rates of morbidity and mortality, whether done in an acute or chronic setting. Preoperative sepsis, independent of AMI or CMI, predicts CV morbidity, regardless of bypass configuration or conduit, while elevated INR or underlying CHF carries a higher risk of pulmonary morbidity.

Raising Systemic Blood Pressure to Delay Irreversible Intestinal Ischemia in a Swine Model of Proximal Superior Mesenteric ArteryOcclusion.

INTRODUCTION: Acute proximal superior mesenteric artery (SMA) occlusion is highly lethal, and adjuncts are needed to mitigate ischemic injury until definitive therapy. We hypothesized that raising mean arterial pressure (MAP) >90 mmHg with norepinephrine may delay irreversible bowel ischemia by increasing gastroduodenal artery (GDA) flow despite possible pressor-induced vasospasm. METHODS: 12 anesthetized swine underwent laparotomy, GDA flow probe placement, and proximal SMA exposure and clamping. Animals were randomized between conventional therapy (CT) versus targeted MAP >90 mmHg (MAP push; MP) where norepinephrine was titrated after 45 min of SMA occlusion. Animals were followed until bowel death or 4 h. Kaplan-Meier bowel survival, mean normalized GDA flow, and histology were compared. RESULTS: 12 swine (mean 57.8 ± 7.6 kgs) were included, six per group. Baseline weight, HR, MAP and GDA flows were not different. Within 5 min following SMA clamping, all 12 animals had an increase in MAP without other intervention from 81.7 to 105.5 mmHg (29.1%, P < 0.01) with a concomitant 74.9% increase in GDA flow as compared to baseline (P < 0.01). Beyond 45 min postclamp, MAP was greater in the MP group as intended, as were GDA flows. Median time to irreversibly ischemic bowel was 31% longer for MAP push animals (CT: 178 versus MP: 233 min, P = 0.006), Hazard Ratio of CT 8.85 (95% CI: 1.86-42.06); 3/6 MP animals versus 0/6 CT animals with bowel survived to predetermined end point. CONCLUSIONS: In this swine model of acute complete proximal SMA occlusion, increasing MAP >90 mmHg with norepinephrine was associated with an increase in macrovascular blood flow through the GDA and bowel survival. Norepinephrine was not associated with worse bowel survival and a MAP push may increase the time window where ischemic bowel can be salvaged.