Superior Mesenteric Artery Stenting Research Articles

Balloon Angioplasty and Stenting of Superior Mesenteric Artery in Chronic Intestinal Ischemia Associated with Decompensated Chronic Heart Failure (Clinical Case Report)

INTRODUCTION: Chronic intestinal ischemic syndrome (CIIS) is a pathology associated with chronic circulatory insufficiency in the visceral branches of the abdominal aorta. Duplex ultrasound can be used as the first imaging method to identify mesenteric artery stenosis. In general clinical practice, the diagnosis of CIIS is relatively rare. Expansion of application of percutaneous endovascular angioplasty and stenting of mesenteric arteries in recent years has significantly increased the effectiveness of treating patients with atherosclerotic lesion of the visceral arteries and CIIS. AIM: To demonstrate a clinical case of use of X-ray endovascular technologies in CIIS in a patient of cardiology profile. A clinical case of a patient with CIIS and severe decompensated polymorbidity is presented. Due to severity of the condition and impossibility of full examination for this reason, the patient was not included in the waiting list for heart transplantation despite the existence of indications for it. He was admitted to hospital for urgent indications. Ultrasound data revealed stenosis of the superior mesenteric artery. Balloon angioplasty and stenting of the superior mesenteric artery were successful. After discharge, the patient’s condition was satisfactory. CONCLUSION: The case demonstrates that effective treatment of even one of many comorbid diseases in a severe polymorbidity patient can improve his general condition, reduce load on the cardiovascular system and reverse edematous-ascitic syndrome.

S5128 Resolution of Gastric Ischemia Following Superior Mesenteric Artery Stenting in a Patient With Stage IV Pancreatic Adenocarcinoma

S5128 Resolution of Gastric Ischemia Following Superior Mesenteric Artery Stenting in a Patient With Stage IV Pancreatic Adenocarcinoma

Midterm Outcome of Branch Vessel Stenting for Superior Mesenteric Artery Malperfusion Complicating with Acute Aortic Dissection.

To investigate the midterm stent patency and patient prognosis after stenting for superior mesenteric artery malperfusion complicating with acute aortic dissection. Thirteen patients who underwent branch vessel stenting for superior mesenteric artery malperfusion between 2011 and 2021 in six institutions were retrospectively reviewed. By comparing pre- and postoperative computed tomography scans in the same plane, the length of the stent implanted in the superior mesenteric artery and the stent-to-vessel diameter ratio were measured. The technical and clinical success of stenting, midterm patient prognosis, and stent patency were evaluated. Superior mesenteric artery stenting was technically successful in 12 patients (92.3%). The mean length of the stents implanted in the superior mesenteric artery was 61.3 ± 39.4 mm (range, 14-127 mm). The mean proximal and distal stent-to-vessel diameter ratios were 1.02 ± 0.16 and 1.30 ± 0.42, respectively. A weak correlation was found between the length of the stents implanted in the superior mesenteric artery and the distal stent-to-vessel diameter ratio (R2 = 0.34). Two major complications occurred, one of which resulted in death within 30 days, and 12 (92.3%) were clinically successful. Of these 12 patients, no recurrent intestinal ischemia occurred during the follow-up duration (mean, 45.2 months). Partial occlusion of the stent distal edge without intestinal ischemia was observed in one patient (distal stent-to-vessel diameter ratio = 2.33) 42 months after stenting. The overall survival rate and primary stent patency rate were 84.6% and 91.7%, respectively. Midterm stent patency and survival after superior mesenteric artery stenting for malperfusion were acceptable.

A decade's experience with retrograde open mesenteric stenting for acute mesenteric ischemia

ObjectiveRetrograde open mesenteric stenting (ROMS) is an alternative to mesenteric bypass in patients with acute mesenteric ischemia (AMI) with variable reported 30-day mortality rates. Large studies evaluating patient outcomes following ROMS are scarce. Our study aims to assess the results of this approach among patients presenting with AMI. MethodsWe reviewed all the patients with AMI who were treated with ROMS (2011-2022). Patient demographics, presentation, operative details, and outcomes were analyzed. Primary end points were in-hospital, 30-day, and 1-year mortality. Kaplan-Meier estimate for 1-year mortality and primary patency loss were generated. Secondary end points included postoperative 30-day complications. ResultsBetween 2011 and 2022, ROMS was attempted on a total of 42 patients. The median age was 70 ± 15 years and the majority of patients were female. Pain out of proportion to the physical examination was the most common presenting symptom (n = 18, 42.9%) followed by peritonitis (n = 14, 33.4%). All patients underwent preoperative intravenous contrast computed tomography imaging. In situ thrombosis was identified as the etiology of AMI in 36 patients (85.7%). Technical success was achieved in 40 patients (95.2%). Conventional, non-hybrid operating rooms were used for the majority of cases. Revascularization of all 40 patients involved angioplasty and stenting of superior mesenteric artery. A single stent was placed in 35 patients (87.5%) and the reminder had more than one stent. Eighty percent of patients required bowel resection. A second-look laparotomy was required in 34 patients (85.0%). The mean operative time, including both the general surgery and vascular surgery portions of the index procedure, was 192 ± 57 minutes. Sepsis was the most common complication observed within 30 days, occurring in 8 patients (20.0%). In terms of mortality, 13 patients (32.5%) died during their index hospitalization, and 9 died (22.5%) within 30 days. On Kaplan-Meier analysis, the 1-year overall patient survival rate was 58.6%, and the primary patency rate for stents was 51.4%. ConclusionsROMS has an excellent technical success rate in management of AMI with lower than traditionally reported mortality rates for AMI. The dual benefits of rapid revascularization and bowel evaluation should make this surgical modality an alternative approach for treatment of AMI.

Changing Nature of Endoleak in a Patient of Superior Mesenteric Artery Aneurysm Treated with Endovascular Stent Graft

AbstractA man in his early thirties with complaints of abdominal pain for 1 week was diagnosed with a fusiform, partially thrombosed aneurysm of the superior mesenteric artery (SMA), which was treated with an endovascular stent graft. Three months later, when the patient again presented with abdominal pain, there was an endoleak of type III as detected by computed tomography and digital subtraction angiography. This was treated by in-stent balloon angioplasty with complete resolution of the endoleak. The patient again presented 1 month later with abdominal pain, with a residual sac posterior to the stent, detected on digital subtraction angiography, which was confirmed to be type II endoleak as it was getting filled by one of the jejunal branches of SMA. This was treated by glue embolization of the patent component of the aneurysm after selectively cannulating the branch vessel. This case highlights changing nature of endoleak as a complication of SMA stenting.

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.

Aortic endarterectomy in patients with severe multivessel paravisceral and aortoiliac occlusive disease

ObjectiveAortic endarterectomy (AE), once a treatment of choice for aortoiliac occlusive disease, is now rarely performed in favor of endovascular procedures or open aortobifemoral bypass. However, in select patients with paravisceral or aortoiliac occlusive disease, AE remains a viable alternative for revascularization, either as a primary procedure or after prior interventions have failed. Here, we evaluated outcomes for an extended series of patients undergoing paravisceral or aortoiliac endarterectomy, demonstrating that these procedures can be an excellent alternative with acceptable morbidity and mortality in properly selected patients. MethodsA single institution retrospective review of 20 patients who underwent AE from 2017 to 2023 was performed. ResultsFive patients (25%) underwent paravisceral endarterectomy and 15 (75%) underwent aortoiliac endarterectomy. There were no perioperative mortalities. One paravisceral patient died 3 months postoperatively from complications of pneumonia. Three patients in the paravisceral group required reinterventions; one acutely due to thrombosis of the superior mesenteric artery (SMA) requiring extension of the endarterectomy and patch angioplasty on postoperative day 0, one due to stenosis at the distal edge of the endarterectomy 1 month postoperatively, successfully treated with SMA stenting, and one at 10-month follow-up due to SMA stenosis at the distal aspect of the endarterectomy, also successfully treated with SMA stenting. With these reinterventions, the 1-year primary patency in the paravisceral group was 40%, primary-assisted patency was 80%, and secondary patency was 100%. In the aortoiliac group, 1-year primary, primary-assisted, and secondary patency were 91%, 91%, and 100%, respectively. One patient developed iliac thrombosis 10 days postoperatively owing to an intimal flap distal to the endarterectomy site. She and one other patient, a young man with an undefined hypercoagulable disorder, ultimately required neoaortoiliac reconstructions at 18 and 32 months postoperatively, respectively (the latter in the setting of stopping anticoagulation). The remaining 13 patients experienced no complications. All patients had rapid resolution of clinical symptoms, and median postoperative ankle-brachial indexes of 1.06 on the right and 1.00 on the left, representing a median improvement from preoperative ankle-brachial indexes of +0.59 on the right and +0.56 on the left (P < .01 and P < .01). ConclusionsIn this series of 20 patients undergoing paravisceral and infrarenal aortoiliac endarterectomy, AE was associated with no perioperative mortality, relatively low and manageable morbidity, and excellent clinical outcomes in patients with both paravisceral and aortoiliac occlusive disease. SMA-related early reintervention was not uncommon in the paravisceral group, and attention should be given particularly to the distal endarterectomy site. AE remains a viable treatment for severe multivessel paravisceral or aortoiliac occlusive disease isolated to the aorta and common iliac arteries in select patients.

Patient-specific computational flow simulation reveals significant differences in paravisceral aortic hemodynamics between fenestrated and branched endovascular aneurysm repair

BackgroundEndovascular aneurysm repair with four-vessel fenestrated endovascular aneurysm repair (fEVAR) or branched endovascular aneurysm repair (bEVAR) currently represent the forefront of minimally invasive complex aortic aneurysm repair. This study sought to use patient-specific computational flow simulation (CFS) to assess differences in postoperative hemodynamic effects associated with fEVAR vs bEVAR. MethodsPatients from two institutions who underwent four-vessel fEVAR with the Cook Zenith Fenestrated platform and bEVAR with the Jotec E-xtra Design platform were retrospectively selected. Patients in both cohorts were treated for paravisceral and extent II, II, and V thoracoabdominal aortic aneurysms. Three-dimensional finite element volume meshes were created from preoperative and postoperative computed tomography scans. Boundary conditions were adjusted for body surface area, heart rate, and blood pressure. Pulsatile flow simulations were performed with equivalent boundary conditions between preoperative and postoperative states. Postoperative changes in hemodynamic parameters were compared between the fEVAR and bEVAR groups. ResultsPatient-specific CFS was performed on 20 patients (10 bEVAR, 10 fEVAR) with a total of 80 target vessels (40 renal, 20 celiac, 20 superior mesenteric artery stents). bEVAR was associated with a decrease in renal artery peak flow rate (−5.2% vs +2.0%; P < .0001) and peak pressure (−3.4 vs +0.1%; P < .0001) compared with fEVAR. Almost all renal arteries treated with bEVAR had a reduction in renal artery perfusion (n = 19 [95%]), compared with 35% (n = 7) treated with fEVAR. There were no significant differences in celiac or superior mesenteric artery perfusion metrics (P = .10-.27) between groups. Time-averaged wall shear stress in the paravisceral aorta and branches also varied significantly depending on endograft configuration, with bEVAR associated with large postoperative increases in renal artery (+47.5 vs +13.5%; P = .002) and aortic time-averaged wall shear stress (+200.1% vs −31.3%; P = .001) compared with fEVAR. Streamline analysis revealed areas of hemodynamic abnormalities associated with branched renal grafts which adopt a U-shaped geometry, which may explain the observed differences in postoperative changes in renal perfusion between bEVAR and fEVAR. ConclusionsbEVAR may be associated with subtle decreases in renal perfusion and a large increase in aortic wall shear stress compared with fEVAR. CFS is a novel tool for quantifying and visualizing the unique patient-specific hemodynamic effect of different complex EVAR strategies. Clinical RelevanceThis study used patient-specific CFS to compare postoperative hemodynamic effects of four-vessel fenestrated endovascular aneurysm repair (fEVAR) and branched endovascular aneurysm repair (bEVAR) in patients with complex aortic aneurysms. The findings indicate that bEVAR may result in subtle reductions in renal artery perfusion and a significant increase in aortic wall shear stress compared with fEVAR. These differences are clinically relevant, providing insights for clinicians choosing between these approaches. Understanding the patient-specific hemodynamic effects of complex EVAR strategies, as revealed by CFS, can aid in future personalized treatment decisions, and potentially reduce postoperative complications in aortic aneurysm repair.

Dual-Lumen Stenting of Dissected Superior Mesenteric Artery During Fenestrated Branched Endovascular Repair of a Post-dissection Thoracoabdominal Aortic Aneurysm.

Long-segment aortic branch dissections have been considered a relative contraindication for fenestrated-branched endovascular aneurysm repair (FB-EVAR). This case report describes a technique of dual-lumen stenting of a fully-dissected superior mesenteric artery (SMA) to preserve patency of the true and false lumens during FB-EVAR. A 67-year-old man presented with a 6.0 cm extent III chronic post-dissection thoracoabdominal aortic aneurysm. The patient had highly-complex anatomy including dissection of the entire SMA. The true and false lumens of the dissected SMA were noted to be supplying different branches, requiring preservation of both lumens. The patient underwent a staged physician-modified FB-EVAR. A modified endograft containing 5 fenestrations and 1 branch cuff was introduced and the celiac, true-lumen SMA, and 3 renal arteries were sequentially catheterized using staggered deployment of the modified endograft. The false lumen SMA stent was catheterized via the branch cuff. Molded parallel grafting ("eye-of-the-tiger") technique was used to achieve double D configuration between the true and false lumens of the SMA. This case demonstrates feasibility of dual-lumen stenting to incorporate dissected target vessels during FB-EVAR while preserving flow to both the true and false lumens and the second-order branches they supply. We report a novel technique that allows incorporation of branch vessels affected by long segment dissection during fenestrated branched endovascular aortic repairs. This has potential advantage of preserving flow to all secondary branches of the dissected target vessels, while reducing the risk of type Ic endoleak.

Changes in renal-mesenteric duplex ultrasound velocities after fenestrated and branched endovascular aortic aneurysm repair

ObjectiveStenting of renal and mesenteric vessels may result in changes in velocity measurements due to arterial compliance, potentially giving rise to confusion about the presence of stenosis during follow-up. The aim of our study was to compare preoperative and postoperative changes in peak systolic velocity (PSV, cm/s) after placement of the celiac axis (CA), superior mesenteric artery (SMA) and renal artery (RAs) bridging stent grafts during fenestrated-branched endovascular aortic repair (FB-EVAR) for treatment of complex abdominal aortic aneurysms (AAA) and thoracoabdominal aortic aneurysms. MethodsPatients were enrolled in a prospective, nonrandomized single-center study to evaluate FB-EVAR for treatment of complex AAA and thoracoabdominal aortic aneurysms between 2013 and 2020. Duplex ultrasound examination of renal-mesenteric vessels were obtained prospectively preoperatively and at 6 to 8 weeks after the procedure. Duplex ultrasound examination was performed by a single vascular laboratory team using a predefined protocol including PSV measurements obtained with <60° angles. All renal-mesenteric vessels incorporated by bridging stent grafts using fenestrations or directional branches were analyzed. Target vessels with significant stenosis in the preoperative exam were excluded from the analysis. The end point was variations in PSV poststent placement at the origin, proximal, and mid segments of the target vessels for fenestrations and branches. ResultsThere were 419 patients (292 male; mean age, 74 ± 8 years) treated by FB-EVAR with 1411 renal-mesenteric targeted vessels, including 260 CAs, 409 SMAs, and 742 RAs. No significant variances in the mean PSVs of all segments of the CA, SMA, and RAs at 6 to 8 weeks after surgery were found as compared with the preoperative values (CA, 135 cm/s vs 141 cm/s [P = .06]; SMA, 128 cm/s vs 125 cm/s [P = .62]; RAs, 90 cm/s vs 83 cm/s [P = .65]). Compared with baseline preoperative values, the PSV of the targeted vessels showed no significant differences in the origin and proximal segment of all vessels. However, the PSV increased significantly in the mid segment of all target vessels after stent placement. ConclusionsStent placement in nonstenotic renal and mesenteric vessels during FB-EVAR is not associated with a significant increase in PSVs at the origin and proximal segments of the target vessels. Although there is a modest but significant increase in velocity measurements in the mid segment of the stented vessel, this difference is not clinically significant. Furthermore, PSVs in stented renal and mesenteric arteries were well below the threshold for significant stenosis in native vessels. These values provide a baseline or benchmark for expected PSVs after renal-mesenteric stenting during FB-EVAR.

Retrograde Superior Mesenteric Artery Stenting via Jejunal Arterial Access: How I Do It

Retrograde Superior Mesenteric Artery Stenting via Jejunal Arterial Access: How I Do It

Reversal of Bowel Wall Pneumatosis After Superior Mesenteric Artery Stenting

Reversal of Bowel Wall Pneumatosis After Superior Mesenteric Artery Stenting

Midterm Clinical Outcomes of Retrograde Open Mesenteric Stenting for Mesenteric Ischemia

Retrograde open mesenteric stenting (ROMS) has become a mainstay in treatment of mesenteric ischemia; however, follow-up in contemporary studies is limited. A single-center retrospective review of patients undergoing ROMS from 2007 to 2020 was conducted. Demographics, presentation, and procedural details were reviewed. End points were morbidity and mortality, technical success, primary patency, reinterventions, and freedom from clinical recurrence. ROMS was performed in 34 patients, 19 female (56%). Mean age was 71±10years. Eighteen patients (53%) presented with acute mesenteric ischemia (AMI), 11 (32%) with acute-on-chronic, and 5 (15%) with chronic mesenteric ischemia. Etiology was chronic atherosclerosis with/without in-situ thrombosis in 28 patients (82%), superior mesenteric artery dissection in 3, and 1 each with embolic, vasculitic, and nonocclusive ischemia. Four patients (12%) had prior mesenteric procedures (3 Celiac/1 superior mesenteric artery stent) and 1 had unsuccessful transbrachial stenting attempt. Technical success, defined as successful stenting through a retrograde approach was attained in 31 patients (91%), with the 3 remaining patients treated with transbrachial stenting in 2 and iliomesenteric bypass in 1. Covered stents were used in 21 patients (64%) with or without stent extension with bare-metal stents. Eight patients (23%) required thromboembolectomy and 9 (26%) underwent patch angioplasty. Thirty-day mortality rate was 35%, all in patients with AMI (10) or acute-on-chronic (2). Eighteen patients (53%) underwent bowel resection, all presenting acutely. Early reinterventions within the first 30days were required in 5 patients (15%), including 2 redo ROMS with thrombectomy and endarterectomy, 2 percutaneous stent extensions, and 1 aortic septum fenestration with coiling of a jejunal branch pseudoaneurysm. With a median follow-up of 3.7 (interquartile range: 0.8-5.0) years, in patients surviving discharge, 5 required reintervention yielding freedom from reintervention rates of 87% at 1year and 71% at 3years. All postdischarge reinterventions were endovascular with no conversion to bypass. The overall 1-year and 3-year primary patency rates were 70% and 61% (primary-assisted patency at 1 and 3years was 87% and secondary patency at 1 and 3years was 97%). The freedom from symptom recurrence was 95% at 1 and 3years. ROMS carries high rates of technical success in patients with mesenteric ischemia, despite a high chronic atherosclerotic burden. Although mid-term patency rates are acceptable, AMI is still associated with high early morbidity and mortality, with high rates of associated bowel resection. ROMS is a valuable tool in the armamentarium of vascular surgeons.

Anatomic characteristics associated with superior mesenteric artery stent graft placement during fenestrated para/suprarenal aneurysm repair

ObjectiveAccording to the instructions for use, fenestrated endovascular aortic aneurysm repair (FEVAR) with the Zenith fenestrated endograft (ZFEN; Cook Medical, Bloomington, Ind) requires ≥4 mm of nonaneurysmal infrarenal neck length, and superior mesenteric artery (SMA) stenting is optional. In the present study, we evaluated the outcomes of FEVAR with SMA stent grafting relative to SMA scallops or unstented fenestrations and their anatomic differences. MethodsWe performed a single-institution retrospective analysis of patients who had undergone FEVAR with an SMA scallop or large fenestration with and without SMA stent grafting from June 2012 to May 2020 after institutional review board approval. ResultsOf the 203 aneurysms repaired with ZFENs, 127 were included in our analysis. Of these 127 aneurysms, 55 had stent grafted SMA fenestrations, 38 unstented SMA fenestrations, and 34 SMA scallops. Technical success was achieved in all patients. The operative times were longer (335.5 ± 16.4 minutes vs 265.0 ± 12.8 minutes vs 269.0 ± 12.7 minutes; P < .001) and the transfusion rates were higher (33% vs 8% vs 18%; P = .01) in the SMA stent graft group. However, the fluoroscopy time (65.4 ± 3.76 minutes vs 58.3 ± 3.94 minutes vs 51.4 ± 4.75 minutes; P = .05) and contrast volume (92.2 ± 5.17 mL vs 87.1 ± 6.73 mL vs 93.1 ± 5.89 mL; P = .84) were not significantly different. Anatomically, the patients who had undergone FEVAR with a ZFEN and SMA stent grafting had had shorter infrarenal neck (1.73 ± 1.18 mm vs 4.92 ± 1.16 mm vs 6.28 ± 1.42 mm; P = .03) and infra-SMA neck (10.3 ± 1.39 mm vs 23.9 ± 1.24 mm vs 26.8 ± 1.67 mm; P < .001) lengths. In the SMA stent graft group, one patient had developed small bowel necrosis after embolization of an intraoperatively perforated jejunal branch and two had developed colonic ischemia of unclear etiology with patent SMA stent grafts found on imaging. Endograft migration and SMA occlusion with bowel ischemia occurred in one patient in the SMA fenestration group. Overall mortality (24% vs 21% vs 18%; P = .82) and 30-day mortality (5% vs 3% vs 3%; P = .80) were comparable between the three groups. In addition, the incidence of type III endoleak (5% vs 3% vs 3%; P = .45) and the need for reintervention (20% vs 18% vs 12%; P = .60) were similar across all three groups. The mean follow-up duration was longer for the SMA scallop group, which can be attributed to 82% of these occurring in the first one half of the study period. ConclusionsDespite the added technical complexity, SMA stenting enabled FEVAR in patients with pararenal and suprarenal aneurysms with high rates of technical success and no increased risk of mortality, major adverse events, type III endoleaks, or reintervention.

Retrograde Superior Mesenteric Artery Stenting in Case of SMA Shuttering.

This case describes a patient who underwent endovascular repair for an extent V thoracoabdominal aneurysm with planned coverage of the celiac artery. Following deployment of the stent graft, the superior mesenteric artery was shuttered, and the patient subsequently developed signs and symptoms of bowel ischemia. The patient underwent successful retrograde open superior mesenteric artery stenting with resolution of her symptoms. Although retrograde open mesenteric artery stenting (ROMS) has been primarily shown to be effective in acute mesenteric ischemia, this case demonstrates that ROMS can be used as a salvage option for shuttering during endovascular procedures.

A PRIMARY EMPYEMA OF UNKNOWN DURATION DUE TO ANAEROBIC GRAM-NEGATIVE BACILLUS HAFNIA ALVEI

TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: Empyema is the presence of pus or bacteria in the pleural space. Incidence is increasing gradually with higher rates in the elderly with a greater prevalence in males [1]. Empyema is a fatal infection with a mortality rate of 20% [2]. Anaerobic Enterobacteriaceae accounting for less than 6% of empyema cases, are an infrequent cause [1]. CASE PRESENTATION: An 80-year-old male with a history of coronary disease, hypertension, hyperlipidemia, peripheral vascular disease, moderate aortic stenosis, a former smoker was seen at the pulmonary clinic for intermittent dyspnea with right-sided abdominal fullness of unknown duration and no symptoms of infection. He had significant asbestos exposure from his shipyard work. Around six months back, he underwent superior mesenteric artery (SMA) stenting for chronic abdominal angina. He was taking a super enzyme supplement to enhance his digestion. Chest x-ray review revealed right-sided effusion, which was also present before SMA stenting (Figure A1-2). A diagnostic thoracentesis showed brownish-green fluid with analysis indicative of empyema (Figure B). His blood work was normal. He was admitted, and a pigtail catheter was inserted into the right pleural space with purulent fluid drainage. He also underwent fibrinolysis. The pleural fluid culture grew Hafnia alvei sensitive to quinolones, aminoglycoside, and carbapenems (Amp C resistance pattern). At discharge, computed tomography and x-ray of the chest revealed empyema resolution, and the chest tube was removed (Figure C1-2). The initial antibiotic ertapenem was transitioned to levofloxacin for one month at discharge. At four weeks after discharge, his symptoms had entirely resolved DISCUSSION: H. alvei is a gram-negative facultative motile anaerobe of the Enterobacteriaceae family, a commensal in the gastrointestinal (GI) tract of humans and animals. It colonizes the oropharynx in humans [3]. It produces a cytolytic toxin, a virulent factor, causing acute gastroenteritis. It is a rare cause of nosocomial and community-acquired infection with a preference for biliary tree infection and has lower mortality [4-5]. In patients with multiple comorbidities and immunosuppressed, it causes extraintestinal diseases such as endophthalmitis, bronchopneumonia, gastroenteritis, and meningitis [5]. The infection source is the GI tract via gut translocation or oropharynx venous drainage draining into the heart and forced into the visceral pleura or alveolar capillary bed [5-6]. In our patient, another source could be the contaminated supplement (it contains Ox bile) CONCLUSIONS: In primary empyema of remote duration and an infrequent cause, a possible source could be the GI tract or the oropharynx. Clinicians should be aware of supplement contents that could be a source of infection REFERENCE #1: Godfrey MS, Bramley KT, Detterbeck F. Medical and Surgical Management of Empyema. Semin Respir Crit Care Med. 2019;40(3):361-74 REFERENCE #2: Corcoran JP, Wrightson JM, Belcher E, DeCamp MM, Feller-Kopman D, Rahman NM. Pleural infection: past, present, and future directions. Lancet Respir Med. 2015;3(7):563-77 REFERENCE #3: Fazal BA, Justman JE, Turett GS, Telzak EE. Community-acquired Hafnia alvei infection. Clin Infect Dis. 1997;24(3):527-8 DISCLOSURES: No relevant relationships by Phillip Beck, source=Web Response no disclosure on file for Wilson Grace; No relevant relationships by Ethan Karle, source=Web Response No relevant relationships by AARON MILLER, source=Web Response No relevant relationships by Shakuntala Patil, source=Web Response No relevant relationships by SACHIN PATIL, source=Web Response No relevant relationships by ANTONY RAWINDRARAJ, source=Web Response

S3018 Superior Mesenteric Artery Thrombosis Associated With Antiphospholipid Syndrome and COVID-19

Introduction: Mesenteric artery thrombosis and antiphospholipid syndrome (APS) is a rare combination but must be suspected in patients with high clinical suspicion. Treatment options of mesenteric ischemia include open surgical or endovascular revascularization. Medical therapy can be given in patients with incomplete duodenal obstruction, multiple comorbidities and moderate symptoms. Here we present a case of rethrombosis of superior mesenteric artery (SMA) in a patient with APS, history of SMA thrombosis with stent placement and COVID 19 while being on direct oral anticoagulant (DOAC). Case Description/Methods: 56 year old male with PMH of APS, peripheral arterial disease, deep vein thrombosis (DVT) s/p inferior vena cava filter, chronic mesenteric ischemia s/p small bowel resection complicated by SMA thrombosis treated with stent placement, left atrial thrombosis (was on xarelto) presented with intermittent abdominal pain in the lLUQ for last 2 weeks, aggravated 20 min after eating and radiated to the flanks, associated with non bloody non bilious vomiting and chills. He also tested PCR positive for COVID but was asymptomatic.. On admission, vitals were normal. Lipase was moderately elevated but criteria for pancreatitis were not met. CT scan with oral and IV contrast showed occluded superior mesenteric artery stent with distal reconstitution of the vessel via collaterals from celiac and inferior mesenteric artery suggesting chronicity of the occlusion. Invasive radiology was also consulted, but considering developed collaterals and no bowel ischemia, no intervention was attempted. Xarelto was discontinued. Patient was started on heparin drip and then bridged to warfarin before discharge. Discussion: DOAC for patients with APS can lead to increased risk of thrombotic events as per European wide review. Our patient has multiple etiologies for development of restenosis including Covid 19, APS, left atrial thrombosis and the use of direct acting anticoagulation. Our case is compelling because of rethrombosis of SMA while being on DOAC in APS and COVID 19 itself is a thrombophilic condition, which might be contributing to the cause.Figure 1.: CT Abdomen Pelvis with oral and IV contrast showing filling defect in Superior Mesenteric Artery

Early outcomes associated with use of the Zenith TX2 Dissection Endovascular Graft for the treatment of Stanford type B aortic dissection

ObjectiveTo evaluate short term outcomes related to the use of the Zenith TX2 Dissection Endovascular Graft (ZDEG) and the Zenith Dissection Bare stent (ZDES) for the treatment of Stanford type B aortic dissections. MethodsThis retrospective multicenter case cohort study collated data from 10 European institutions for patients with both complicated and uncomplicated type B aortic dissection treated with ZDEG and ZDES between 2011 and 2018. The primary end point was mortality at 30 and 90 days. Secondary end points included complications related to TEVAR, such as, type Ia endoleak, stroke, paraparesis, paraplegia, and retrograde type A dissection (RTAD). Statistical analysis was carried out using the t test, or one-way analysis of variance and the χ2 or Fisher exact tests. ResultsWe treated 120 patients (87 male; mean age, 62.7 ± 12.2years) either in the acute 76 (63.3%), subacute 16 (13.3%), or chronic 28 (23.3%) phase. Seven patients (5.8%) died within 30 days after the index procedure and two (1.7%) between 30 and 90 days. There was one instance of postoperative RTAD in a patient treated for rupture. Stroke and paraplegia occurred in three (2.5%) and five (4.2%), patients, respectively. Eight patients (6.7%) had a type Ia endoleak in the perioperative period. There were no instances of paraplegia, no permanent dialysis, and no requirement for adjunctive superior mesenteric or celiac artery stenting in the 33 patients (27.5%) who were treated by concurrent placement of ZDES distal to the ZDEG. The length and distal oversizing of ZDEG components used was less in this group. ConclusionsThe present series demonstrates a low (<1%) RTAD rate and favorable morbidity and mortality. The lower rate of paraplegia, dialysis, and visceral artery stenting in the cohort that had adjunctive use of ZDES is compelling and merits further assessment.

Defining Duplex Ultrasound Criteria for In-Stent Restenosis of the Superior Mesenteric Artery

This study sought to define duplex ultrasound (DUS) velocity criteria predicting ≥70% stenosis in superior mesenteric artery (SMA) stents by correlating in-stent peak systolic velocity (PSV) with computed tomographic angiography (CTA) measurements of percent stenosis. A retrospective review of 109 patients undergoing SMA stenting between 2003 and 2018 was conducted at a single institution. Thirty-seven surveillance duplex ultrasound studies were found to have a CTA performed within 30 days of study completion. Bare metal (n = 20) and covered stents (n = 17) were included. Velocities were paired to in-stent restenosis (ISR) measured by mean vessel diameter reduction on SMA centerline reconstructions from CTA. Receiver operating characteristic (ROC) curves was generated and logistic regression models for ≥70% ISR probability were used to define velocity criteria in the stented SMA. At a PSV of 300 cm/sec, the sensitivity is 100% and specificity 80% for a ≥70% in-stent SMA stenosis. At a PSV of 400 cm/sec, the sensitivity and positive predictive value (PPV) is 63% and the specificity and negative predictive value (NPV) is 90%. A PSV of 450 cm/sec was consistent with the highest specificity (100%) and PPV (100%) but lower sensitivity (50%) and NPV (87.9%). One patient with a PSV of 441 cm/sec on surveillance DUS died from complications of acute-on-chronic mesenteric ischemia. A PSV of 400 cm/sec on mesenteric DUS can predict ≥70% ISR with high sensitivity and should be considered as a diagnostic threshold for SMA in-stent restenosis.

Multicentre Evaluation of an Extra Low Dose Protocol to Reduce Radiation Exposure in Superior Mesenteric Artery Stenting

Radiation dose in mesenteric stenting (MS) remains under evaluated. Yet, MS can lead to high levels of radiation mainly because lateral angulation is needed. The aim of this study was to evaluate the efficacy of an extra low dose protocol (ELDP) to reduce radiation exposure in MS. From November 2017 to November 2019, all patients presenting with either acute or chronic atherosclerotic mesenteric ischaemia treated by antegrade MS using either fixed or mobile imaging systems in three university hospitals were included. In November 2018, an ELDP including ≤3 frames/s fluoroscopy and digital subtraction angiography (DSA) was introduced. Prospectively enrolled ELDP patients (Nov 2018-Nov 2019) were compared with retrospectively captured patients (Historical group, Nov 2017-Nov 2018). Radiation data including dose area product (DAP), cumulative air kerma (CAK), and fluoroscopy time (FT) were analysed. Overall, 46 patients (median age 73 years [63-72], 59% males) were included (ELDP group, n=21; Historical group, n=25). Thirty-three patients (72%) underwent MS in a hybrid room. Median DAP (ELDP group, 10 [4.7-26] Gy.cm2vs. Historical group, 45 [24-88] Gy.cm2, p=.002), median CAK (ELDP group, 170 [58-260] vs. Historical group, 262 [152-460], p=.037), and median number of DSA runs (ELDP group, 4 [1.5-5] vs. Historical group, 5.5 [3.7-5], p=.030) were statistically significantly lower in patients receiving the ELDP, whereas median FT (ELDP group, 16min [11-23] vs. Historical group, 14min [9-25], p=.71) and technical success (ELDP group, 95%; Historical group, 92%, p=.65) were not statistically significantly different between groups. MS exposes both patients and physicians to a high ionising radiation dose. Awareness of radiation safety and seeking dose reduction is paramount in these highly irradiating procedures. The use of ELDP significantly reduces radiation without compromising technical success.