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

OBJECTIVE: Retrograde 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. METHODS: We 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. RESULTS: Between 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%. CONCLUSIONS: ROMS 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.

Percutaneous Mechanical Thrombectomy Using the AcoStream Thrombus Aspiration System for Acute Superior Mesenteric Artery Embolism.

BACKGROUND: This study was performed to summarize our experience in treating acute superior mesenteric artery embolism (SMAE) by percutaneous mechanical thrombectomy (PMT). METHODS: Between January 2023 and October 2023, 18 patients presenting with acute mesenteric ischemia were admitted to our center, including 11 cases of SMAE, 3 cases of superior mesenteric artery thrombosis, and 4 cases of superior mesenteric vein thrombosis. We retrospectively reviewed 8 patients (4 males and 4 females; range, 51-79 years; mean, 62.50 ± 9.67 years) who underwent treatment of acute SMAE using the AcoStream system. The patients had no obvious evidence of intestinal necrosis as shown by peritoneal puncture or computed tomography. Thrombectomy was performed on the superior mesenteric artery (SMA) using an 8F AcoStream thrombus aspiration system (Acotec, China). The demographics, risk factors, therapeutic effect, complications, mortality, and follow-up of the study population were assessed. RESULTS: The technical success rate was 100%. After 1-3 passes (2.38 ± 0.92) and aspiration thrombectomy, complete thrombus removal was achieved in 7 (87.50%) patients. One patient received an adjunctive catheter-directed thrombolysis due to partial thrombus removal. Thrombolysis was conducted for 2 days, resulting in complete resolution of the thrombus. The other 7 patients did not receive adjunctive endovascular intervention due to complete thrombus removal and no residual stenosis. No distal embolization or device-related complications were noted during the procedure. After the procedure, sufficient clinical improvement was seen in 6 patients within 1-2 days. Two patients showed no significant improvement of their symptoms. Laparotomy was performed on day 1 and day 2 after thrombectomy in patients 3 and 7, respectively. Intestinal necrosis was diagnosed operatively and intestinal resection was performed. All patients were discharged 6-15 days (9.50 ± 3.07) after admission without perioperative complication or death. The mean follow-up period was 5.00 ± 3.30 months (range, 1-10 months), and the follow-up rate was 100%. During the follow-up, all patients remained symptom-free. Computed tomography angiography images showed good flow in the trunk and branches of the SMA in all patients. CONCLUSIONS: PMT using the AcoStream system is a minimally invasive, safe, and effective technique for acute SMAE. Early application of PMT can achieve immediate revascularization of the SMA and have the potential advantage of avoiding laparotomy or reducing the extension of enterectomy, as it could theoretically restore intestinal perfusion in less time than open revascularization. If the symptoms do not improve after PMT, exploratory laparotomy should be scheduled as soon as possible. Further studies are necessary on this field to confirm these findings.

Comparative outcomes of open mesenteric bypass after a failed endovascular or open mesenteric revascularization for chronic mesenteric ischemia.

INTRODUCTION: Clinical practice guidelines have recommended an endovascular-first approach (ENDO) for the management of patients with chronic mesenteric ischemia (CMI), whereas an open mesenteric bypass (OMB) is proposed for subjects deemed to be poor ENDO candidates. However, the impact of a previous failed endovascular or open mesenteric reconstruction on a subsequent OMB is unknown. Accordingly, this study was designed to examine the results of a remedial OMB (R-OMB) after a failed ENDO or a primary OMB (P-OMB) for patients with recurrent CMI. METHODS: All patients who underwent an OMB from 2002 to 2022 at the University of Florida were reviewed. Outcomes after an R-OMB (ie, history of a failed ENDO or P-OMB) and P-OMB were compared. The primary end point was 30-day mortality, whereas secondary outcomes included complications, reintervention, and survival. The Kaplan-Meier methodology was used to estimate freedom from reintervention and all-cause mortality, whereas multivariable Cox proportional hazards modeling identified predictors of death. RESULTS: A total of 145 OMB procedures (R-OMB, n = 48 [33%]; P-OMB, n = 97 [67%]) were analyzed. A majority of R-OMB operations were performed for a failed stent (prior ENDO, n = 39 [81%]; prior OMB, n = 9 [19%]). R-OMB patients were generally younger (66 ± 9 years vs P-OMB, 69 ± 11 years; P = .09) and had lower incidence of smoking exposure (29% vs P-OMB, 48%; P = .07); however, there were no other differences in demographics or comorbidities. R-OMB was associated with less intraoperative transfusion (0.6 units vs P-OMB, 1.4 units; P = .01), but there were no differences in conduit choice or bypass configuration.The overall 30-day mortality and complication rates were 7% (n = 10/145) and 53% (n = 77/145), respectively, with no difference between the groups. Notably, R-OMB had decreased cardiac (6% vs P-OMB, 21%; P < .01) and bleeding complication rates (2% vs P-OMB, 15%; P = .01). The freedom from reintervention (1 and 5 years: R-OMB: 95% ± 4%, 83% ± 9% vs P-OMB: 97% ± 2%, 93% ± 5%, respectively; log-rank P = .21) and survival (1 and 5 years: R-OMB: 82% ± 6%, 68% ± 9% vs P-OMB: 84% ± 4%, 66% ± 7%; P = .91) were similar. Independent predictors of all-cause mortality included new postoperative hemodialysis requirement (hazard ratio [HR], 7.4, 95% confidence interval [CI], 3.1-17.3; P < .001), pulmonary (HR, 2.7, 95% CI, 1.4-5.3; P = .004) and cardiac (HR, 2.4, 95% CI, 1.1-5.1; P = .04) complications, and female sex (HR, 2.1, 95% CI, 1.03-4.8; P = .04). Notably, R-OMB was not a predictor of death. CONCLUSIONS: The perioperative and longer-term outcomes for a remedial OMB after a failed intraluminal stent or previous open bypass appear to be comparable to a P-OMB. These findings support the recently updated clinical practice guideline recommendations for an endovascular-first approach to treating recurrent CMI due to the significant perioperative complication risk of OMB. However, among the subset of patients deemed ineligible for endoluminal reconstruction after failed mesenteric revascularization, R-OMB results appear to be acceptable and highlight the utility of this strategy in selected patients.

Postoperative new-onset atrial fibrillation causing acute embolic occlusion of the superior mesenteric artery: A case report.

RATIONALE: Postoperative atrial fibrillation following noncardiac surgery increases mortality, length of hospital stay, and medical expenses; moreover, compared to nonvalvular atrial fibrillation, it poses a similar risk of thromboembolic complications. In this report, we discuss our decision-making process for diagnosis and treatment in case with unexpected postoperative new-onset atrial fibrillation causing acute mesenteric ischemia. PATIENT CONCERNS: A 78-year-old male patient received varicose vein stripping and ligation in his right leg. The patient was previously healthy with no known comorbidities. The next day after surgery, he complained of sudden epigastric pain unresponsive to conservative treatment, and new-onset atrial fibrillation was observed on electrocardiography. DIAGNOSES: An abdominal computed tomography scan revealed acute embolic occlusion of the superior mesenteric artery. INTERVENTIONS: Emergent surgical embolectomy was performed successfully. The time to operation from the recognition of abdominal pain was 6 h. Surgical critical care was performed for life-threatening ischemic reperfusion injury. OUTCOMES: The patient was discharged from the hospital on the 40th postoperative day. LESSONS: Atypical postoperative abdominal pain unresponsive to conservative treatment should be considered a surgical emergency, and a high level of clinical suspicion for acute mesenteric ischemia is required. Preoperative electrocardiography and postoperative telemetry might be helpful in some asymptomatic patients.

Chronic mesenteric ischemia: Diagnosis and management.

Chronic mesenteric ischemia (CMI) is an uncommon, potentially underdiagnosed clinical condition. Although there is a high prevalence of mesenteric artery stenoses (MAS), an abundant collateral network in the mesenteric circulation mitigates occurrence of ischemia. The most common etiology of CMI is atherosclerosis. CMI is a clinical diagnosis, based upon typical and atypical symptoms and consistent anatomic findings. Typical symptoms of CMI are postprandial abdominal pain, unintended weight loss and food avoidance. The main modalities to diagnose MAS are duplex ultrasound, CT angiography or MR angiography, although high resolution CTA is preferred. Endovascular therapy with balloon expandable stents has become the preferred treatment for MAS.

Transcollateral Recanalization of an Occluded Superior Mesenteric Artery.

OBJECTIVE: To report the technique of transcollateral retrograde recanalization of a superior mesenteric artery flush occlusion. METHODS: The technique of a patient undergoing transcollateral retrograde recanalization for acute symptomatic superior mesenteric artery flush occlusion was reviewed and presented. Other adjunctive methods to facilitate the endovascular treatment of the superior mesenteric artery total occlusion lesion were also compared and discussed. RESULTS: The patient was a 47-year-old woman, acute onset of symptomatic chronic mesenteric ischemia with flush occlusion of the superior mesenteric artery which was unable to be revascularized in a routine operation. A collateral was found to connect celiac artery and superior mesenteric artery (gastroduodenal arch). The guidewire was retrograde crossed the occluded lesion via this collateral and recaptured by the catheter from the same single brachial sheath followed by balloon angioplasty and stent implantation. The patient recovered well and the symptoms completely disappeared after the procedure. CONCLUSION: The technique of retrograde recanalization through collateral pathway is an applicable alternative option for patients with superior mesenteric artery flush occlusion who have failed attempts by conventional antegrade approaches.

Midterm results after covered stenting of the superior mesenteric artery.

OBJECTIVE: Despite the continuing controversy of covered stents (CS) vs bare metal stents, the use of CS in mesenteric occlusive disease (MOD) has been recommended by expert centers. The aim of this study was to report midterm results with CS of the superior mesenteric artery. METHODS: Between January 2014 and October 2019, patients with MOD with a severe atheromatous stenosis or occlusion of the superior mesenteric artery treated by mesenteric CS were included. Clinical presentation included both acute mesenteric ischemia (AMI), chronic mesenteric ischemia, and asymptomatic patients planned for major surgery. Demographics, procedure details, and follow-up data were prospectively collected and retrospectively reviewed. Study end points included primary patency, primary assisted patency, and secondary patency. RESULTS: During the study period, 86 patients (mean age, 70 ± 9 years; 57% males) were included. Clinical presentation was AMI (n = 42 [49%]), chronic mesenteric ischemia (n = 31 [36%]), and asymptomatic (n = 13 [15%]). The technical success rate was 97%. A total of 96 stents were implanted, including 86 proximal CS (Advanta V12, n = 73; Lifestream, n = 13). The mean length and mean diameter of the CS were 31.5 ± 6.3 mm and 6.9 ± 0.5 mm, respectively. Additional distal bare metal stents were used in 10 patients (12%) to overcome a kinking (n = 9) or a dissection (n = 1) downstream of the CS. All postoperative deaths occurred in patients with AMI (n = 11, 13%). During a median follow-up of 15.6 months (95% confidence interval [CI], 15.6 ± 3.6 months), 12 patients (14%) underwent reinterventions for either stent misplacement (n = 3), stent recoil (n = 3), stent thrombosis (n = 2), de novo stenosis at the distal edge of the CS (n = 2), or gastric ischemia (n = 1). At 1 year, overall the primary patency, primary assisted patency, and secondary patency rates were 83% (95% CI, 83% ± 9%), 99% (95% CI, 99% ± 3%), and 99% (95% CI, 99% ± 3%), respectively. At 2 years, the overall primary patency, primary assisted patency, and secondary patency rates were 76% (95% CI, 76% ± 13%), 95% (95% CI, 95% ± 8%) and 95% (95% CI, 95% ± 8%), respectively. CONCLUSIONS: Mesenteric CS provide very satisfactory midterm results in patients with MOD, with an excellent primary assisted patency rate at 2 years, at the price of a significant reintervention rate.

Endovascular Treatment of Chronic and Acute on Chronic Mesenteric Ischaemia: Results From a National Cohort of 245 Cases.

OBJECTIVE: Endovascular treatment of chronic mesenteric ischaemia (CMI) is linked to low early morbidity and mortality but a higher risk of recurrence than open repair. Mid and long term outcomes after endovascular treatment remain to be proven in larger series. The aim of this study was to assess short and mid term outcome after first line endovascular revascularisation of CMI and acute on chronic mesenteric ischaemia (AoCMI). METHODS: This was a prospective population and registry based cohort study supplemented by a retrospective review of medical records and imaging files. A national cohort was created based on data extracted from the Danish National Registry for Vascular Surgery (Karbase) for all patients treated endovascularly for CMI or AoCMI between 2011 and 2015 in Denmark. Survival data, bowel resection, complications, re-intervention rate, and improvement of clinical symptoms were analysed, as were potential risk factors. RESULTS: In total, 245 patients had an endovascular intervention for CMI (n = 178; 72.6%) and AoCMI (n = 67; 27.3%). One and three year survival estimates were 85% (95% confidence interval [CI] 79 - 90) and 74% (95% CI 67 - 80) in the CMI-group, and 67% (95% CI 54 - 77) and 54% (95% CI 41 - 65) in the AoCMI group. The hazard ratio for death was 1.89 (95% CI 1.23 - 2.9) for AoCMI, relative to patients with CMI. Superior mesenteric artery (SMA) stenosis, rather then occlusion, significantly increased the success of SMA recanalisation: OR 19.4 (95% CI 6.2 - 61.4) and 9.3 (95% CI 1.6 - 53.6) in the CMI and AoCMI groups, respectively. The proportion of patients reporting clinical improvement was 71% (n = 127) in the CMI group and 59% (n = 39) in the AoCMI group. Five patients (3%) in the CMI and 30 (45%) in the AoCMI groups underwent bowel resection (p < .001), and the overall length of hospital stay (LoS) was a median of two days (interquartile range [IQR] 1 - 3 days) in the CMI group and seven days (IQR 3 - 23 days) in the AoCMI group. Within the first year, re-intervention was performed in 14 patients (5.7%). CONCLUSION: First line endovascular treatment of CMI carries a three year mortality rate of 25%, and low risk of re-occurrence of symptomatic ischaemia. Relative to CMI, patients suffering AoCMI have significantly higher morbidity and mortality, more bowel resections, and longer LoS.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Effects of preoperative visceral artery stenosis on target artery outcomes after fenestrated/branched endovascular aortic aneurysm repair.

OBJECTIVE: Target artery stenosis might affect the outcomes of fenestrated/branched endovascular aortic aneurysm repair (F-BEVAR). The aim of the present study was to assess the effects of preoperative stenosis of the celiac artery (CA) and superior mesenteric artery (SMA) on the target artery outcomes after F-BEVAR. METHODS: During a 4-year period, 287 consecutive patients, 204 men (71%) and 83 women (29%), had undergone F-BEVAR using fenestrated (83%), fenestrated-branched (4.5%), branched (3.5%), and off-the-shelf t-Branch (9%) devices (Cook Medical Inc, Bloomington, Ind). Preoperative SMA and CA significant stenosis was defined as a computed tomography angiography-based intraluminal diameter reduction >50%. The primary endpoints included primary patency, freedom from target vessel instability, and patient survival. RESULTS: The median patient age was 71 years (interquartile range, 67-77 years). Suprarenal (36%), juxtarenal (25%), and thoracoabdominal (39%) aortic aneurysms were treated. The technical success rate was 99%. The 30-day survival was 97%. Among 981 stented vessels, 179 (18%) were CAs and 270 (27.5%) were SMAs. Significant preoperative CA stenosis was identified in 39 patients (22%) and SMA stenosis in 24 (9%). The median follow-up was 29.9 months. The primary patency rates at 12, 36, and 60 months were 98%, 92%, and 92% for the CA and 99%, 98%, and 98% for the SMA, respectively. Primary patency was significantly lower in the patients with previous significant CA stenosis than in those without stenosis (83%, 83%, and 76% vs 100%, 100%, and 97% at 12, 36, and 60 months, respectively; P < .01). Freedom from celiac branch instability was also significantly lower among patients with significant stenosis (84%, 84%, and 76% vs 100%, 93%, and 93% at 12, 36, and 60 months; P < .01). The presence of significant SMA stenosis did not affect either primary patency or freedom from target vessel instability. The survival rates at 12, 36, and 60 months were significantly lower for the patients with CA stenosis than for those without stenosis (67%, 61%, and 55% vs 90%, 84%, and 82%, respectively; P < .01). Similarly, lower survival rates were observed for patients with significant SMA stenosis (70%, 60%, and 60% vs 87%, 79%, and 78% at 12, 36, and 60 months, respectively; P = .04). CONCLUSIONS: F-BEVAR was associated with overall primary patency rates >90% for the CA and SMA. Preoperative CA stenosis was associated with lower primary patency and freedom from target vessel instability. In contrast, neither SMA branch primary patency nor freedom from target vessel instability were affected by preoperative SMA stenosis. We found visceral artery stenosis was a marker of atherosclerosis burden associated with reduced mid- and long-term patient survival.

Vascular Calcifications are Associated with Increased Mortality in Patients with Acute Mesenteric Ischemia.

BACKGROUND: Vascular calcifications have been identified as predictors of mortality in several cardiovascular diseases but have not been investigated in context of acute mesenteric ischemia. The aim of this study was to investigate the impact of vascular calcifications in patients with acute mesenteric ischemia. METHODS: Patients admitted for an acute mesenteric ischemia were retrospectively included. The presence of calcifications in the visceral aorta, the celiac trunk, the superior mesenteric artery, and the renal arteries was assessed on computed tomography scan images at the arterial phase. The calcification volumes were measured using the software Aquarius iNtuition Edition®. RESULTS: The all-cause mortality was 55 out of 86 patients (63.9%) for a median follow-up of 3.5 days (1-243). The survival rate of patients with calcification in the superior mesenteric artery was significantly lower than that of those without calcification (22% vs. 55.6%, P = 0.019). Patients who died had significantly a higher frequency of calcifications in the superior mesenteric artery, the visceral aorta, the celiac trunk, and the renal arteries. CONCLUSIONS: The presence of vascular calcifications in the superior mesenteric artery is associated with increased mortality in patients diagnosed with acute mesenteric ischemia. Further studies are required to identify the mechanisms underlying this association.

Distal Superior Mesenteric Artery Endarterectomy Remains an Excellent Option for Mesenteric Revascularization in the Endovascular Era.

BACKGROUND: Endovascular treatment of mesenteric lesions has become increasingly prevalent. Mesenteric bypass, however, remains the optimal treatment in the cases of chronic mesenteric ischemia (CMI) in young, medically fit patients given its durability. Endarterectomy has gone by the wayside, but in certain situations, this technique remains surgically relevant and should still be used. Herein, we present 2 cases of distal superior mesenteric artery (SMA) endarterectomy for mesenteric revascularization. METHODS/RESULTS: Case 1 is a 40-year-old male with history of antithrombin III deficiency, myocardial infarction, bilateral pulmonary embolism, acute aortic thrombus, and mesenteric ischemia status after placement of a proximal SMA stent and was transferred to our institution because of concern for ischemic bowel. Intraoperative angiography showed mid to distal SMA chronic thromboembolism with narrow lumen of recanalization and distal flow. No intervention was performed at that time. He developed worsening abdominal pain and weight loss over several months which required initiation of total parenteral nutrition, complicated by line-associated sepsis. Subsequent distal SMA endarterectomy was performed. He recovered well and had improved enteral intake at 1-month follow-up, and radiographic imaging at 2 months showed patent vessels. Case 2 is a 50-year-old female with extensive smoking history and hyperlipidemia and gastroesophageal reflux who presented with postprandial abdominal pain and a forty-pound weight loss over the past year. Attempted angiographic cannulation with a stent was not successful because of flush occlusion of the SMA approximately 1 centimeter distal to the ostium that was unable to be crossed. Computed tomography angiography confirmed that the SMA origin was free of atherosclerotic disease with a distal focal segment of occlusion. She underwent successful endarterectomy of this occlusion. The postoperative course was uneventful, and at 1-month follow-up, she reported continued improvement in pain and appetite. CONCLUSIONS: SMA endarterectomy can be successfully performed on mid to distal lesions of the SMA. This operation should remain a viable option in the management of CMI.

Recanalization and Stenting of the Celiac and the Superior Mesenteric Artery Supported by Use of a Steerable Introducer Sheath: Report on 2 Years' Experience.

PURPOSE: To compare technical parameters and success of recanalization of celiac (CA) or superior mesenteric artery (SMA) with usage of steerable vs not steerable introducer sheaths. METHODS: A retrospective analysis was performed on all consecutive patients who underwent recanalization with stent implantation of CA or SMA between 2015 and 2019. Data regarding technical success (successful stent placement with restoration of sufficient blood flow by the first attempt without changing kind of introducer sheath or access site), indication for treatment, vascular access, kind of introducer sheath, fluoroscopy time and radiation dose were collected. Preinterventional CT were analyzed to classify the difficulty of catheterization of target vessels. Technical parameters were compared with independent t-test (p ≤ 0.05). RESULTS: 66 patients underwent recanalization of CA or SMA. Usage of steerable introducer sheaths was associated with higher technical success compared to not steerable introducer sheaths with transfemoral approach respectively of 8/8 vs 15/19 for the CA and 11/11 vs 17/20 for the SMA. Steerable introducer sheaths were used in recanalization considered more technically difficult compared to not steerable introducer sheaths (58% vs 33%). Usage of steerable introducer sheath showed a statistically significant reduction of radiation dose in the recanalization of the SMA (respectively 32035 ± 15716 cGy cm2 vs 60102 ± 28432 cGy cm2; p = 0.005). CONCLUSION: Even if used in more difficult interventions, steerable introducer sheaths showed a higher technical success compared to not steerable introducer sheaths with transfemoral access.

Primary Conservative Therapy for Symptomatic Isolated Mesenteric Artery Dissection with Severely Compressed True Lumen or Large Dissecting Aneurysm.

PURPOSE: To investigate the safety and effectiveness of primary conservative therapy for patients with symptomatic isolated mesenteric artery dissection (IMAD) with a severely compressed true lumen and/or a large dissecting aneurysm. MATERIALS AND METHODS: A total of 35 consecutive patients (all men; median age, 53 y) with symptomatic IMAD with a severely compressed true lumen and/or a large dissecting aneurysm but without intestinal necrosis or arterial rupture who were treated with primary conservative therapy between November 2018 and February 2020 were assessed. A severely compressed true lumen was defined as luminal stenosis > 70%. A large dissecting aneurysm was defined as dissecting aneurysm diameter ≥ 1.5 times larger than the normal mesenteric artery diameter. RESULTS: There was a strong positive relationship among abdominal pain, degree of luminal stenosis, and length of dissection (R = 0.811; P < .001). Conservative treatment was successful in all patients. Abdominal pain was eliminated within 4.7 d ± 4.8 (range, 2-31 d) in all patients, within 3.6 d ± 1.2 (range, 2-6) in the 31 patients with minor or moderate abdominal pain, and within 13.3 d ± 11.9 (range, 6-31 d) in the 4 patients with severe abdominal pain. Complete or partial remodeling of the mesenteric artery was achieved in 6 (17.1%) and 29 (82.9%) patients, respectively, during 8.6 mo ± 4.3 of follow-up. CONCLUSIONS: Primary conservative therapy can be used safely and effectively in patients with symptomatic IMAD with a severely compressed true lumen and/or a large dissecting aneurysm but without intestinal necrosis or arterial rupture.

Clinical Features and Factors Affecting Postoperative Mortality for Obstructive Acute Mesenteric Ischemia in China: A Hospital- Based Survey.

PURPOSE: The study aimed to report the clinical manifestation and identify the risk factors for postoperative mortality in patients who were diagnosed with obstructive acute mesenteric ischemia (AMI) based on a survey of a hospital in western China. PATIENTS AND METHODS: We reviewed clinical data of 108 patients with obstructive AMI at West China Hospital, Sichuan University, from 2011 to 2017. Clinical characteristic was described and compared. Factors affecting postoperative survival were analyzed. RESULTS: A total of 108 obstructive AMI cases were included in this study, with an overall average age of 57.1 years, including 58 arterial occlusive mesenteric ischemia (AOMI) and 50 mesenteric venous thrombosis (MVT). AOMI patients were older and had a significantly higher frequency of these comorbidities, including heart disease, hypertension, and diabetes. In comparison, MVT had a significantly higher proportion of male patients and a higher frequency of liver disease. A total of 77 patients underwent laparotomy, and the 30-day postoperative mortality rate was 29.9%. Multivariate logistic regression analysis showed that the time interval from admission to surgery (adjust OR 1.19; 95% CI [1.07-1.34], P = 0.005), platelet count (adjust OR = 0.98; 95% CI [0.97-0.99], P = 0.008) and AOMI (adjust OR = 5.55; 95% CI [1.36-22.55], P = 0.017) were independent predictors of 30-day mortality after exploratory laparotomy for obstructive AMI. Further analysis of the 45 AOMI showed that the time interval from admission to surgery (adjustOR 1.22; 95% CI [1.01-1.47], P = 0.036) and platelet count (adjustOR = 0.98; 95% CI [0.97-0.99], P = 0.020) were independent risk factors for 30-day postoperative mortality of AOMI. CONCLUSION: Early identification of AOMI, improving the efficiency of enhanced CT examination, strengthening doctor-patient communication, active laparotomy, and optimize platelet management may also help reduce the overall short-term mortality of obstructive AMI. Building the multidisciplinary team model of diagnostic imaging, vascular intervention, and surgical treatment to manage obstructive AMI may be urgently needed in western China.

Perioperative Microcirculatory Changes Detected with Gastroscopy Assisted Laser Doppler Flowmetry and Visible Light Spectroscopy in Patients with Median Arcuate Ligament Syndrome.

PURPOSE: Physiological tests may aid in diagnosing median arcuate ligament syndrome (MALS). MALS is a symptomatic compression of the celiac artery causing symptoms similar to chronic mesenteric ischemia (CMI) of atherosclerotic etiology. Simultaneous use of visible light spectroscopy (VLS) and laser doppler flowmetry (LDF) during upper endoscopy may detect microcirculatory changes in these patients. PATIENTS AND METHODS: In a single-center, prospective comparative cohort, 25 patients were evaluated for MALS. Patients with a consensus diagnosis of MALS (n=15) underwent a gastroscopy assisted, transmucosal microcirculatory assessment with LDF and VLS. Results were compared to individuals with normal intestinal circulation (n=38) evaluated with duplex ultrasonography, and to patients with chronic mesenteric ischemia (n=32). Treatment response was evaluated clinically at 1, 3, 6, and 12 months, and with ultrasound, VLS and LDF at three months. Health-related quality of life (QoL) was assessed with Euroqol (EQ-5D-5L), preoperatively, and 12 months postoperatively. RESULTS: Preoperative mean transmucosal oxygen saturation was significantly lower in patients with MALS (SO2 76±6), as compared to healthy individuals (SO2 81±4), p=0.02. An overall significant improvement in SO2 after surgical decompression of the celiac artery was found (SO2 81±3.7, p=0.05). Eleven (92%) patients with clinical improvement after laparoscopic decompression had a definitive diagnosis of MALS. Median follow-up was 18 months (4-24 months). Four of the five dimensions investigated with EQ-5D-5L improved. CONCLUSION: VLS detected a significantly lower baseline transmucosal SO2 in patients with MALS as compared to control subjects with normal intestinal circulation. An improvement in SO2 after laparoscopic decompression was found, supporting a possible ischemic etiology in our patient population.