Effect of ischemia-reperfusion on outcomes after open mesenteric bypass for chronic mesenteric ischemia.

OBJECTIVE: Significant physiologic perturbations can occur in patients with chronic mesenteric ischemia (CMI) undergoing open mesenteric bypass (OMB). These events have frequently been attributed to ischemia-reperfusion events and have been directly implicated in the occurrence of multiple organ dysfunction (MOD). Scoring systems (MOD score [MODS] and sequential organ failure assessment [SOFA]) have been derived within the critical care field to provide a composite metric for these pathophysiologic changes. The purpose of the present study was to describe the early pathophysiologic changes that occur after OMB for CMI and determine whether these are predictive of the outcomes. METHODS: Patients with CMI who had undergone elective OMB from 2002 to 2018 at a single institution were reviewed. Changes in the hemodynamic, pulmonary, hepatic, renal, and hematologic parameters in the first 96 hours postoperatively were analyzed. The MODSs and SOFA scores were calculated. Cox regression was used to determine the association of the MODSs and SOFA scores with the outcomes. RESULTS: The use of OMB was analyzed for 72 patients (age, 66 ± 11 years; 68% women; body mass index, 23.8 ± 6 kg/m2; 48 ± 34-lb weight loss in 59%). Previous mesenteric stent placement or bypass had been performed in 39% [stenting in 21; bypass in 8; (one patient had both)]. An antegrade configuration (93%) was most common (retrograde configuration, 7%), with revascularization of the superior mesenteric artery/celiac vessels in 85% (superior mesenteric artery only in 15%). Postoperative pathophysiologic and metabolic changes were common, and the mean MODSs and SOFA scores were 3.6 ± 2.4 (range, 1-10) and 4.0 ± 2.7 (range, 1-13), respectively. The median length of stay was 14 days (interquartile range, 9-21). The 30-day mortality was 4% (n = 3) and in-hospital morbidity was 53% (n = 38; gastrointestinal, 25%; infectious, 22%; cardiac, 18%; pulmonary, 18%; renal, 11%). The clinical follow-up period was 16 ± 20 months. The MODSs and SOFA scores correlated linearly with overall mortality (MODS: odds ratio [OR], 1.4; 95% confidence interval [CI], 1.2-1.7; P < .01; SOFA score: OR, 1.4; 95% CI, 1.2-1.7; P < .01 per unit), with a score of ≥5 the inflection point most predictive of mortality (MODS: OR, 3.9; 95% CI, 1.6-9.9; P ≤ .01; SOFA score: OR, 2.8; 95% CI, 1.2-6.6; P = .02). The 1- and 3-year primary bypass patency and freedom from reintervention was 91% ± 5% and 83% ± 7%, respectively, with no association with the MODSs or SOFA scores. The 1- and 3-year survival was 86% ± 4% and 71% ± 6% with significantly worse outcomes for patients with higher MODSs and/or SOFA scores. CONCLUSIONS: Most CMI patients undergoing OMB will experience significant metabolic derangements resulting from sequelae of the ischemia-reperfusion phenomenon postoperatively. These can be objectively assessed in the early postoperative period using simply applied scoring systems to reliably predict the early and long-term outcomes. A derivation of the MODS and/or SOFA score after OMB for CMI can identify the most vulnerable patients at the greatest risk of mortality.

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.

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.

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.

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.

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.

Is Mesenteric Ischemia In COVID-19 Patients A Surprise?

Aim. The disease caused by the 2019 novel coronavirus is known predominantly for its respiratory outcomes; a subset of critically ill patients demonstrates clinically remarkable hypercoagulability in which thrombotic events range from acute pulmonary embolism in patients with COVID-19 pneumonia to extremity ischemia. Our observational study aimed to describe the incidence and characteristics, as well as clinical outcomes, of patients presenting and treated for mesenteric ischemia during the COVID-19 pandemic. Material and Methods. Between March 13 and May 13, 2020, 60 patients operated for emergency reasons were analyzed, and it was noticed that 5 of the 6 COVID-positive patients were operated due to mesenteric ischemia. Results. Five of sixty patients (83.3%) applied to our emergency clinic with COVID-19 positive and acute abdomen. Two of them (40%) did not have any comorbidities. All of them (%100) were male. There were no complications and only 1 death (20%). Mean leukocyte, neutrophil, and platelet levels were within the normal range, while the lymphocyte level was near the lower limit. C-Reactive Protein was above the limit in all patients. The mean levels of International Normalized Ratio, Platelet, and Activated Partial Thromboplastin Time were above the limits. While D-dimer levels were close to the upper limit; fibrinogen levels were above the normal limit for each patient. Conclusion. The presence of hypercoagulation status in critical COVID-19 patients should be observed closely, and anticoagulation therapy can be considered in selected patients. More clinical data are needed to examine the role of anticoagulation in COVID-19 treatment.

Normal Lactate and Unenhanced CT-Scan Result in Delayed Diagnosis of Acute Mesenteric Ischemia.

INTRODUCTION: To investigate the factors associated with a delayed diagnosis (DD) of acute mesenteric ischemia (AMI). METHODS: An observational cohort study from an intestinal failure center. The primary outcome was DD >24 hours. RESULTS: Between 2006 and 2015, 74 patients with AMI were included and 39 (53%) had a DD. Plasma lactate <2 mmol/L (odd ratio: 3.2; 95% confidence interval: 1.1-9.1; P = 0.03) and unenhanced computed tomography scan (odds ratio: 5.9; 95% confidence interval: 1.4-25.8; P = 0.01) were independently associated with DD. DISCUSSION: Suspicion of AMI should no longer be affected by normal plasma lactate levels and should prompt evaluation by a contrast-enhanced computed tomography-scan.

Improving midterm results justify the continued use of bare-metal stents for endovascular therapy for chronic mesenteric ischemia.

OBJECTIVE: The objective of this study was to evaluate the contemporary results of interventions in the celiac axis (CA) and superior mesenteric artery (SMA) for chronic mesenteric ischemia (CMI) and factors associated with patency and symptom-free survival. METHODS: A retrospective review of patients with CMI treated with angioplasty and stenting with bare-metal stents from 2003 to 2014 was conducted. Demographic, history, risk factor, preoperative testing, and technical variables were collected and subject to univariate analysis, with end points of patency loss. The patients were divided into early (2003-2008) and late (2009-2014) groups to compare early and contemporary results. Correlates of patency were then subject to further univariate and multivariable analysis. RESULTS: From 2003 to 2014, there were 150 patients (39 men, 111 women; age, 70.7 ± 11.1 years) with CMI who underwent interventions on the CA (56 vessels) and the SMA (133 vessels); 38 patients had both CA and SMA intervention. Primary patency for the CA was 86% (95% confidence interval [CI], 73-99) at 1 year and 66% (95% CI, 46-87) 3 years; for the SMA, primary patency was 81% (95% CI, 72-89) at 1 year and 69.0% (95% CI, 58-81) at 3 years. Increased age was associated with improved results in the SMA (hazard ratio [HR], 0.96; 95% CI, 0.92-1.00; P = .028). Chronic total occlusion in the SMA conferred worse patency compared with stenosis (HR, 2.38; 95% CI, 1.03-5.47; P = .042), and younger patients (<70 years) had a higher proportion of SMA occlusion (38.9% vs 22.8; P = .045). In the SMA, comparing early (2003-2008; 68 patients) vs late (2009-2014; 65 patients), primary patency was better in the late experience (3 years, 59% vs 77%; P = .016). The late cohort was older (early, 68.1 ± 12.5 years vs 72.5 ± 9.7 years; P = .024). The late cohort had a higher incidence of ostial flaring of the stent (early, 44.1%; late, 72.3%; P < .001). Multivariable analysis revealed only ostial flaring to be associated with improved patency in the SMA (HR, 0.29; 95% CI, 0.12-0.69; P = .006). CONCLUSIONS: Intervention for CMI has acceptable midterm results, and with experience and adoption of newer techniques, the results appear to be improving. Patients older than 70 years have better results than younger patients, and this may reflect a more malignant presentation in the younger patients. Ostial flaring proved to be the single factor on multivariate analysis associated with improved patency and was adopted in the late group. These data support the continued use of bare-metal stents in the treatment of CMI.

The role of emergency presentation and revascularization in aneurysms of the peripancreatic arteries secondary to celiac trunk or superior mesenteric artery occlusion.

OBJECTIVE: The goal of this study was to analyze our 10-year experience in the treatment of aneurysms of the collateral circulation secondary to steno-occlusions of the celiac trunk (CT) or superior mesenteric artery (SMA). METHODS: In the last 10 years, 32 celiac-mesenteric aneurysms were detected (25 true aneurysms and seven pseudoaneurysms) in 25 patients with steno-occlusion of the CT or SMA. All cases were diagnosed and treated at our center, with either surgical or endovascular approach. As open surgery, we performed aneurysmectomy and revascularization; as endovascular treatment we performed both the embolization (or graft exclusion) of the aneurysm sac, and embolization of afferent and efferent arteries. RESULTS: Sixteen patients (64%) underwent endovascular treatment, accounting for 66% of aneurysms (21/32). Six patients (24%) and seven associated aneurysms (22%) underwent open surgery. Three asymptomatic patients (12%), representing a total of four aneurysms (12%), were not treated. For endovascular procedures, the technical success rate was 90%, with a 56% clinical success rate. For open surgery, clinical and technical success were achieved in five patients (83%) and six procedures (86%), respectively. Sixty-eight percent of patients (17/25) were treated in an emergency setting, using either endovascular (88%) or open (12%) approaches. Although technical success was achieved in more than 85% of these procedures for both approaches, clinical success was reached less frequently among patients with an acute presentation (P = .041). Regardless of the type of treatment, CT or SMA revascularization during the first procedure did not show an increased rate of clinical success (P = .531). However, we reported four cases of visceral ischemia after an endovascular approach without revascularization, with three open surgical corrections required. The mean follow-up was 41 months (range, 0-136 months). CONCLUSIONS: Neither of the approaches described qualifies as a standard optimal choice. We suggest a tailored therapeutic approach based on the clinical condition at the time of diagnosis and specific vascular anatomy.

Median arcuate ligament syndrome.

BACKGROUND: Median arcuate ligament syndrome (MALS) describes the clinical presentation associated with direct compression of the celiac artery by the median arcuate ligament. The poorly understood pathophysiologic mechanism, variable symptom severity, and unpredictable response to treatment make MALS a controversial diagnosis. METHODS: This review summarizes the literature pertaining to the pathophysiologic mechanism, presentation, diagnosis, and management of MALS. A suggested diagnostic workup and treatment algorithm are presented. RESULTS: Individuals with MALS present with signs and symptoms of foregut ischemia, including exercise-induced or postprandial epigastric pain, nausea, vomiting, and weight loss. Consideration of MALS in patients' diagnostic workup is typically delayed. Currently, no group consensus agreement as to the diagnostic criteria for MALS exists; duplex ultrasound, angiography, and gastric exercise tonometry are used in different combinations and with varying diagnostic values throughout the literature. Surgical management involves decompression of the median arcuate ligament's constriction of the celiac artery; robotic, laparoscopic, endoscopic retroperitoneal, and open surgical intervention can provide effective symptom relief, but long-term follow-up data (>5 years) are lacking. Patients treated nonoperatively appear to have worse outcomes. CONCLUSIONS: MALS is an important clinical entity with significant impact on affected individuals. Presenting symptoms, patient demographics, and radiologic signs are generally consistent, as is the short-to medium-term (<5 years) response to surgical intervention. Future prospective studies should directly compare long-term symptomatic and quality of life outcomes after nonoperative management with outcomes after open, laparoscopic, endoscopic retroperitoneal, and robotic celiac artery decompression to enable the development of evidence-based guidelines for the management of MALS.

Recanalization of superior mesenteric artery chronic total occlusion using hybrid algorithm and dissection reentry device.

Chronic total occlusion (CTO) of mesenteric arteries with associated chronic mesenteric ischemia (CMI) is associated with high morbidity and mortality. Endovascular intervention has been associated with high technical success with high rates of freedom from symptoms and long-term patency. However, to achieve high procedural success, use of optimal vascular access and expertise in CTO hybrid algorithm including advanced dissection reentry strategies are essential. We present a case of CMI from severe celiac artery (CA) stenosis and CTO of superior mesenteric artery (SMA) and inferior mesenteric artery (IMA). After treatment of CA stenosis, we were unsuccessful in our first attempt at recanalization of SMA CTO. On second attempt, left brachial artery (BA) access was obtained and the hybrid algorithm along with use of Stingray Reentry balloon (Boston Scientific) for dissection reentry into true lumen was successful in recanalizing the SMA CTO with placement of balloon expandable covered stents (CS). To the best of our knowledge, this is the first case report utilizing Sting-ray Reentry balloon in the mesenteric arteries.

Endovascular Pressure Measurements to Assess the Functional Severity of Mesenteric Arterial Stenoses.

PURPOSE: To assess the ability of pressure measurements to discriminate clinically significant celiac artery (CA) or superior mesenteric artery (SMA) stenosis in patients with suspected chronic mesenteric ischemia (CMI). MATERIALS AND METHODS: Single-center, retrospective cohort study of 41 intra-arterial pressure measurements during mesenteric angiography with intended revascularization, performed in 37 patients (mean age 67.7 ± 10.8 years, 62% female) between April 2015 and May 2017. Simultaneous prestenotic and poststenotic pressure measurements had been obtained before and after intra-arterial administration of nitroglycerin. Revascularization was performed in 38 of 41 procedures. Definitive diagnosis of CMI was defined as patient-reported symptom relief or improvement after successful revascularization. RESULTS: Pressure gradients obtained after vasodilator administration were significantly higher in CAs and SMAs with ≥50% stenosis. Pressure ratios (pressure distal [Pd]/pressure aorta [Pa]) obtained after vasodilator administration were significantly higher in CAs with ≥50% stenosis. Subgroup analysis of 22 patients with a ≥50% stenosis of either CA or SMA showed significantly higher pressure gradients and Pd/Pa ratios after vasodilator administration in CMI patients (median pressure gradient: CMI [interquartile ratio] 36 [21-40] mm Hg versus no-CMI 20 [9-21] mm Hg, P = 0.041; Pd/Pa: CMI 0.703 [0.598-0.769] versus no-CMI 0.827 [0.818-0.906], P = .009). A ≤0.8 Pd/Pa cutoff value after administration of a vasodilator best identified a clinically relevant stenosis, with 86% sensitivity and 83% specificity. Complications related to the pressure measurements were not observed. CONCLUSIONS: Intra-arterial pressure measurements are feasible and safe. Low Pd/Pa ratios were associated with clinically relevant CA or SMA stenosis.

Evaluation of Technical Success, Efficacy, and Safety of Portomesenteric Venous Intervention following Nontransplant Hepatobiliary or Pancreatic Surgery.

PURPOSE: To evaluate technical success, efficacy and safety of portomesenteric venous (PMV) intervention for PMV stenosis or occlusion following nontransplant hepatobiliary or pancreatic (HPB) surgery. MATERIALS AND METHODS: A retrospective review identified 42 patients (mean age 60 y) with PMV stenosis (n = 33; 79%) or occlusion (n = 9; 21%) who underwent attempted PMV intervention following HPB surgery between June 1, 2011, and April 1, 2018. Main outcomes were technical success, primary patency rates, and complications. Technical success was compared by venous pathology and primary PMV patency based on anticoagulation status after the procedure using Fisher exact test. Rates of primary patency by stent group were estimated using Kaplan-Meier method. RESULTS: Technical success was 91% (n = 38/42) and significantly higher in patients with stenosis (n = 33/33; 100%) vs occlusion (n = 5/9; 56%) (P = .001). Primary presenting symptom resolved in 28 (87%) patients, including 6 (100%) patients with gastrointestinal bleeding. At mean imaging follow-up of 8.6 months ± 8.8, primary stent patency was 76%. There was no significant difference in primary stent patency based on anticoagulation status after the procedure (P = .48). There were 2 (4.8%) periprocedural complications. CONCLUSIONS: Portomesenteric venoplasty and stent placement following nontransplant HPB surgery is safe with a high rate of technical success if performed before chronic occlusion.

Acute mesenteric ischaemia: imaging and intervention.

Acute mesenteric ischaemia (AMI) is an abdominal emergency in which an acute reduction in mesenteric arterial supply threatens bowel viability and may result in bowel infarction, perforation, and death. Despite improvements in diagnosis and treatment over recent decades, mortality rates in AMI remain very high. This article discusses the aetiological classification, pathophysiology, and clinical aspects of AMI. The specific imaging characteristics of each aetiological type of AMI are detailed and the role of different imaging methods in the diagnosis of AMI is discussed. Surgery is the established treatment of choice for AMI, but there is increasing use of endovascular techniques in treating AMI in cases where there are no clinical features of peritonism or radiological evidence of irreversible ischaemia. This article reviews the evidence for different diagnostic and management strategies for patients with AMI and discusses the advantages and disadvantages of surgical and endovascular treatments. Endovascular techniques have been reported to have high technical success rates and favourable outcomes when compared to open surgery; however, patient selection bias and a paucity of data limit the conclusions that can be drawn.

Long-Term Outcomes of Mesenteric Stenting and Analysis of In-Stent Restenosis Duplex Velocity Criteria.

BACKGROUND: Endovascular therapy for chronic mesenteric ischemia (CMI) is the mainstay of treatment. Duplex velocity criteria within stented mesenteric vessels are not well established. We describe single-center outcomes of mesenteric stenting for CMI and analyze duplex velocities associated with in-stent restenosis (ISR). METHODS: We performed a single-center retrospective review of patients undergoing mesenteric stenting for CMI (2012-2018). Primary outcome was reintervention for recurrence of CMI symptoms. Secondary outcomes were occlusion or bypass grafting. Duplex velocities in those with recurrent symptoms, corresponding with clinically significant ISR, were identified. Receiver operating characteristic (ROC) curves were created to identify velocity thresholds for ISR. RESULTS: Mesenteric stents were placed in 61 patients (71 arteries). Mean age was 72 years (range, 49-92), and the majority were female (55%). Thirty-two (45%) celiac (CA) stents and 39 (55%) superior mesenteric artery (SMA) stents were placed. Ten patients had SMA and CA stents placed. Twenty-five stents were covered (35%). Freedom from reintervention at 1, 2, and 3 years was 83%, 73%, and 60%. Freedom from occlusion or bypass grafting at 1, 2, and 3 years was 100%, 86%, and 86%. No significant difference in patency was seen between covered and bare-metal stents (OR 0.45; 95% CI: 0.15-1.33; P = 0.1383). Median survival was 6.1 years. For CA stents, a peak systolic velocity (PSV) of 440 cm/s corresponded with clinically significant ISR with 100% sensitivity and 86% specificity. For SMA stents, a PSV of 341 cm/s corresponded with clinically significant ISR with only 80% sensitivity and 52% specificity. CONCLUSIONS: A PSV of 440 cm/s for CA stents was indicative of clinically significant ISR with excellent sensitivity and specificity. This should be used in conjunction with clinical findings to identify patients that may benefit from repeat intervention. A similar threshold could not be identified for SMA stents and warrants further collaborative investigation.

Using the OUTBACK Catheter to Overcome Aortic Reentry Issues in Retrograde Open Mesenteric Stenting.

BACKGROUND: The purpose of this study was to describe the use of the OUTBACK catheter to overcome aortic reentry issues in acute mesenteric ischemia (AMI) treated by retrograde open mesenteric stenting (ROMS). TECHNIQUE: The technique is demonstrated in two female patients presenting with late AMI related to flush occlusion of the superior mesenteric artery (SMA). In such cases of thrombotic AMI with clear preoperative evidence of intestinal necrosis, ROMS is the first-line revascularization technique in our intestinal stroke center. Following an open approach of the SMA through laparotomy, the SMA was punctured in a retrograde fashion. Retrograde mesenteric subintimal recanalization was initiated. In case of aortic reentry issue, the OUTBACK Elite (Cordis, Hialeah, Fl) catheter was advanced through the occlusion over a 0.014 guidewire. The aortic reentry was created by puncture of the aortic wall with the OUTBACK needle, positioned in the desired position. After low-profile balloon angioplasty of the reentry site and 0.035 guidewire exchange, ROMS was performed using balloon-expandable covered stent. CONCLUSIONS: The OUTBACK catheter appears to be a safe and effective tool to overcome aortic reentry issues in ROMS. This technical tip might therefore increase the technical success rate of challenging ROMS and decrease the need for bailout bypass in the septic context of AMI.

Outcomes Following Inferior Mesenteric Artery Reimplantation During Elective Aortic Aneurysm Surgery.

BACKGROUND: The role of inferior mesenteric artery (IMA) reimplantation during open aortic reconstruction is debated. We assessed outcomes after inferior mesenteric artery reimplantation (IMAR) for aortic aneurysmal disease to help shed light on this question. METHODS: A single-center retrospective review of all IMARs performed during open aortic surgery over a 10-year period between 2000 and 2009 was carried out. The primary outcome was patency, while secondary outcomes included colonic ischemia and overall survival. Analysis was performed using Cox models and Kaplan-Meier estimates. RESULTS: Of 840 patients who underwent elective abdominal aortic aneurysm (AAA) reconstructions during this period, 70 underwent IMAR. Indications for IMAR included intraoperative colonic ischemia (n = 24), poor back bleeding (n = 52), large IMA (n = 5), internal iliac disease (n = 5), and prior colon surgery (n = 1). Follow-up imaging studies were available in 35 of 70 patients (computed tomography in 30 [86%] and duplex in 5 [14%]). Patency was confirmed in 32 of 35 patients (91%) over a median follow-up of 98 months. Both losses in patency were at 4 months and did not require an operation. One patient underwent left colon resection on postoperative day 9 because of ischemia. (Patency could not be confirmed.) No statistically significant predictor of patency was noted. Incidence of colonic ischemia was 1.4% in patients undergoing IMAR. The overall mortality was 51% in patients undergoing IMAR over the median follow-up period. The overall 10-year survival was 30% in patients undergoing IMAR for aortic aneurysmal disease. The nature of aneurysm (juxtarenal or higher juxta renal abdominal aortic aneurysm [JRAAA]) was associated with mortality, with a hazard ratio of 1.8 (P = 0.08) approaching significance. Ten-year survival was worse if IMAR was performed for intraoperative colonic ischemia (26% vs 34%) or in JRAAA (19.0% vs 38%; P = 0.03). Age per year at the time of repair was the only statistically significant predictor of survival (P < 0.001). CONCLUSION: IMAR for AAA remains necessary for select patients. Reimplantation is associated with excellent long-term patency and low risk of colonic ischemia.

Percutaneous Mechanical Thrombectomy for Acute Superior Mesenteric Artery Embolism: Preliminary Experience in Five Cases.

BACKGROUND: This study was performed to summarize our experience in treating acute superior mesenteric artery embolism (SMAE) by percutaneous mechanical thrombectomy (PMT). METHODS: The clinical data of five patients with acute SMAE treated by PMT in our center from October 2015 to May 2018 were retrospectively analyzed. PMT was performed under local anesthesia. Access was established via the femoral artery or brachial artery. Thrombectomy was performed on the superior mesenteric artery using a 6F Rotarex catheter (Straub Medical, Wangs, Switzerland). RESULTS: Technical success of PMT was achieved in all five patients; emboli were completely removed in three patients and partially removed in two patients. No PMT-related complications were noted after surgery. Four patients were smoothly discharged from the hospital after their symptoms were relieved. One patient still had symptoms of intestinal ischemia after the operation, and massive small intestinal necrosis was found by exploratory laparotomy. Intestinal resection was performed, and the patient died 4 months later. CONCLUSIONS: PMT by the Rotarex system is a minimally invasive, safe, and effective technique in removing SMAE. Early application of PMT can avoid intestinal necrosis.