A cross-species approach using an in vivo evaluation platform in mice demonstrates that sequence variation in human RABEP2 modulates ischemic stroke outcomes.

Ischemic stroke, caused by vessel blockage, results in cerebral infarction, the death of brain tissue. Previously, quantitative trait locus (QTL) mapping of cerebral infarct volume and collateral vessel number identified a single, strong genetic locus regulating both phenotypes. Additional studies identified RAB GTPase-binding effector protein 2 (Rabep2) as the casual gene. However, there is yet no evidence that variation in the human ortholog of this gene plays any role in ischemic stroke outcomes. We established an in vivo evaluation platform in mice by using adeno-associated virus (AAV) gene replacement and verified that both mouse and human RABEP2 rescue the mouse Rabep2 knockout ischemic stroke volume and collateral vessel phenotypes. Importantly, this cross-species complementation enabled us to experimentally investigate the functional effects of coding sequence variation in human RABEP2. We chose four coding variants from the human population that are predicted by multiple in silico algorithms to be damaging to RABEP2 function. In vitro and in vivo analyses verify that all four led to decreased collateral vessel connections and increased infarct volume. Thus, there are naturally occurring loss-of-function alleles. This cross-species approach will expand the number of targets for therapeutics development for ischemic stroke.

Vasostatin-2 associates with coronary collateral vessel formation in diabetic patients and promotes angiogenesis via angiotensin-converting enzyme 2.

AIMS: Members of the chromogranin family play a role in angiogenesis. One such biologically active peptide, generated through the processing of chromogranin A, is vasostatin-2. This study aimed at assessing the association of serum vasostatin-2 levels with coronary collateral vessels (CCV) in diabetic patients with chronic total occlusions (CTO) and the effects of vasostatin-2 on angiogenesis in diabetic mice with hindlimb or myocardial ischemia. METHODS AND RESULTS: Serum levels of vasostatin-2 in 452 diabetic CTO patients were evaluated. The status of CCV was categorized according to the Rentrop score. Vasostatin-2 recombinant protein or phosphate-buffered saline were then injected intraperitoneally in diabetic mouse models of hindlimb or myocardial ischemia, followed by laser Doppler imaging and molecular biology examinations. The effects of vasostatin-2 were also ascertained in endothelial cells and macrophages, with mechanisms clarified using ribonucleic acid (RNA) sequencing. Serum levels of vasostatin-2 were significantly different and progressively higher across Rentrop score 0, 1, 2, and 3 groups (P < .001), with significantly lower levels in patients with poor CCV (Rentrop score 0 and 1) than in those with good CCV (Rentrop score 2 and 3) (P < .05). Vasostatin-2 significantly promoted angiogenesis in diabetic mice with hindlimb or myocardial ischemia. RNA-seq analyzes verified an angiotensin-converting enzyme 2 (ACE2)-mediated vasostatin-2-induction of angiogenesis in ischemic tissues. CONCLUSION: Lower serum levels of vasostatin-2 are associated with poor CCV in diabetic CTO patients compared with patients with good CCV. Vasostatin-2 significantly promotes angiogenesis in diabetic mice with hindlimb or myocardial ischemia. Such effects are mediated by ACE2.

Spontaneous portosystemic shunt embolization in liver transplant recipients with recurrent hepatic encephalopathy.

INTRODUCTION AND OBJECTIVES: Spontaneous portosystemic shunts (SPSS) are a common cause of recurrent hepatic encephalopathy (HE). Shunt occlusion is an effective and safe procedure when performed in patients with cirrhosis and preserved liver function. We aimed to describe our experience with SPSS embolization after liver transplantation (LT). PATIENTS: We identified five patients who underwent SPSS embolization after LT. Clinical, biochemical and technical procedure data were collected. RESULTS: At presentation, all patients had developed graft cirrhosis and HE after LT. Median Model for End-stage Liver Disease (MELD) at embolization was 9 (range 7-12), median Child-Pugh was 8 (range 7-9). Splenorenal and mesocaval shunt were the most frequent types of SPSS found. Three patients have been completely free of HE. Of the two patients who had HE recurrence after embolization, one patient had two episodes of HE which was controlled well with medications. The other patient required three embolizations because of recurrent HE. Median follow-up was 4.4 years (range 1.0-5.0) and MELD score at last follow up was 13 (range 10-18) and median Child-Pugh score B, 7 points (range 5-12). CONCLUSIONS: SPSS can be considered as a cause of HE after LT. SPSS embolization is feasible and safe in LT recipients.

Association Between Portosystemic Shunts and Increased Complications and Mortality in Patients With Cirrhosis.

BACKGROUND & AIMS: Spontaneous portosystemic shunts (SPSS) have been associated with hepatic encephalopathy (HE). Little is known about their prevalence among patients with cirrhosis or clinical effects. We investigated the prevalence and characteristics of SPSS in patients with cirrhosis and their outcomes. METHODS: We performed a retrospective study of 1729 patients with cirrhosis who underwent abdominal computed tomography or magnetic resonance imaging analysis from 2010 through 2015 at 14 centers in Canada and Europe. We collected data on demographic features, etiology of liver disease, comorbidities, complications, treatments, laboratory and clinical parameters, Model for End-Stage Liver Disease (MELD) score, and endoscopy findings. Abdominal images were reviewed by a radiologist (or a hepatologist trained by a radiologist) and searched for the presence of SPSS, defined as spontaneous communications between the portal venous system or splanchnic veins and the systemic venous system, excluding gastroesophageal varices. Patients were assigned to groups with large SPSS (L-SPSS, ≥8 mm), small SPSS (S-SPSS, <8 mm), or without SPSS (W-SPSS). The main outcomes were the incidence of complications of cirrhosis and mortality according to the presence of SPSS. Secondary measurements were the prevalence of SPSS in patients with cirrhosis and their radiologic features. RESULTS: L-SPSS were identified in 488 (28%) patients, S-SPSS in 548 (32%) patients, and no shunt (W-SPSS) in 693 (40%) patients. The most common L-SPSS was splenorenal (46% of L-SPSS). The presence and size of SPSS increased with liver dysfunction: among patients with MELD scores of 6-9, 14% had L-SPSS and 28% had S-SPSS; among patients with MELD scores of 10-13, 30% had L-SPSS and 34% had S-SPSS; among patients with MELD scores of 14 or higher, 40% had L-SPSS and 32% had S-SPSS (P < .001 for multiple comparison among MELD groups). HE was reported in 48% of patients with L-SPSS, 34% of patients with S-SPSS, and 20% of patients W-SPSS (P < .001 for multiple comparison among SPSS groups). Recurrent or persistent HE was reported in 52% of patients with L-SPSS, 44% of patients with S-SPSS, and 37% of patients W-SPSS (P = .007 for multiple comparison among SPSS groups). Patients with SPSS also had a larger number of portal hypertension-related complications (bleeding or ascites) than those W-SPSS. Quality of life and transplantation-free survival were lower in patients with SPSS vs without. SPSS were an independent factor associated with death or liver transplantation (hazard ratio, 1.26; 95% confidence interval, 1.06-1.49) (P = .008) in multivariate analysis. When patients were stratified by MELD score, SPSS were associated with HE independently of liver function: among patients with MELD scores of 6-9, HE was reported in 23% with L-SPSS, 12% with S-SPSS, and 5% with W-SPSS (P < .001 for multiple comparison among SPSS groups); among those with MELD scores of 10-13, HE was reported in 48% with L-SPSS, 33% with S-SPSS, and 23% with W-SPSS (P < .001 for multiple comparison among SPSS groups); among patients with MELD scores of 14 or more, HE was reported in 59% with L-SPSS, 57% with S-SPSS, and 48% with W-SPSS (P = .043 for multiple comparison among SPSS groups). Patients with SPSS and MELD scores of 6-9 were at higher risk for ascites (40.5% vs 23%; P < .001) and bleeding (15% vs 9%; P = .038) than patients W-SPSS and had lower odds of transplant-free survival (hazard ratio 1.71; 95% confidence interval, 1.16-2.51) (P = .006). CONCLUSIONS: In a retrospective analysis of almost 2000 patients, we found 60% to have SPSS; prevalence increases with deterioration of liver function. SPSS increase risk for HE and with a chronic course. In patients with preserved liver function, SPSS increase risk for complications and death. ClinicalTrials.gov ID NCT02692430.

The comparative analysis of non-thrombotic internal jugular vein stenosis and cerebral venous sinus stenosis.

Internal jugular vein (IJV) stenosis and cerebral venous sinus (CVS) stenosis belong to cerebral venous outflow insufficiency. This study aimed to analyze the similarities and differences between IJV stenosis and CVS stenosis. Patients with either IJV stenosis or CVS stenosis confirmed by contrast-enhanced magnetic resonance venography between October 2017 and July 2018 were enrolled in this retrospective study. The similarities and differences between IJV stenosis and CVS stenosis on the aspects of clinical and imaging features were compared. A total of 82 eligible patients entered into the final analysis. The similarities of the two subsets of cerebral venous outflow insufficiency mainly included headache, head noises or tinnitus, visual disorders, and sleeping disorders, as well as cloud-like white matter hyperintensity in T2WI and FLAIR sequences of MRI. However, there were differences in between, the ratio of patients with higher intracranial pressure (ICP) was common in CVS stenosis (p < 0.001). Namely, higher ratios of papilledema (p = 0.001) and visual damage (p = 0.029), as well as poor Frisen papilledema grade scores were more commonly observed in CVS stenosis (p = 0.004), while abnormal collateral-vessels appeared more frequently in IJV stenosis (100.00%) than CVS stenosis (28.57%). Continuous head noises, tinnitus and cloud-like white matter hyperintensity in MRI are the features of both IJV stenosis and CVS stenosis. Whereas, severe headache, visual damage, papilledema, and intracranial hypertension (IH) were more common in CVS stenosis, and the appearance of collateral-vessels is a key feature of IJV stenosis.

Pericytes in the Gut.

This review chapter describes the current knowledge about the nature of pericytes in the gut, their interaction with endothelial cells in blood vessels, and their pathophysiological functions in the setting of chronic liver disease. In particular, it focuses on the role of these vascular cell types and related molecular signaling pathways in pathological angiogenesis associated with liver disease and in the establishment of the gut-vascular barrier and the potential implications in liver disease through the gut-liver axis.

Development of Hemorrhage-prone Anastomoses in Asymptomatic Moyamoya Disease-A Comparative Study with Japan Adult Moyamoya Trial.

OBJECTIVE: Present study was aimed to precisely evaluate the angio-architectures in patients with asymptomatic moyamoya disease (MMD) by comparing with those with hemorrhagic stroke. METHODS: This study used the data set of cerebral angiography in Asymptomatic Moyamoya Registry (AMORE) Study and Japan Adult Moyamoya (JAM) Trial at enrollment. The development of 3 subtypes of collateral vessels, including lenticulostriate, thalamic, and choroidal anastomosis, was evaluated on cerebral angiography. Suzuki's angiographical stage and posterior cerebral artery (PCA) involvement were also assessed. These findings were compared between asymptomatic (AMORE) and hemorrhagic (JAM) groups. RESULTS: This study included 55 hemispheres of 35 patients in asymptomatic group and 75 hemispheres of 75 patients in hemorrhagic group. In asymptomatic group, thalamic anastomosis was less developed than in hemorrhagic group (P = .011), but there were no significant differences in the development of lenticulostriate and choroidal anastomosis between the 2 groups (P = .077 and P = .26, respectively). Suzuki's stage was more progressed and the prevalence of PCA involvement was significantly higher in hemorrhagic group than in asymptomatic group (P = .0033 and P = .016, respectively). CONCLUSIONS: This study reveals no significant differences in the development of choroidal anastomoses between asymptomatic and hemorrhagic-onset MMD. On the other hand, disease stage and PCA involvement were less advanced in asymptomatic MMD than in hemorrhagic-onset MMD. These findings strongly suggest a certain subgroup of asymptomatic patients with MMD is at potential risk for hemorrhagic stroke.

Risk factors for exacerbation of gastroesophageal varices and portosystemic encephalopathy during treatment with nucleos(t)ide analogs for hepatitis B virus-related cirrhosis.

AIM: The aim of this study was to determine the risk factors for worsening of gastroesophageal varices (GEVs) and development of portosystemic encephalopathy in patients with hepatitis B virus (HBV)-related cirrhosis during nucleos(t)ide analog (NA) treatment. METHODS: One hundred and thirty-seven patients with HBV-related cirrhosis were enrolled in this retrospective cohort study. Findings of portal hemodynamics with computed tomography, liver function, and endoscopic examinations during NA treatment were assessed. RESULTS: Among 137 patients, feeding vessels for GEVs (left gastric vein, posterior gastric vein, and short gastric vein) were present in 56 (41%) patients, and extrahepatic portosystemic shunt (paraesophageal vein, paraumbilicul vein, and splenorenal shunt) were present in 36 (26%) patients at the start of NA treatment. Although NA treatment was successful, significant improvements were not observed in portosystemic collateral vessels 3 years after NA treatment and GEVs were exacerbated in 48 (35%) patients. The cumulative 5- and 10-year exacerbation rate of GEVs was 27% and 50%, respectively. By multivariate analysis, the existence of feeding vessels for GEVs at the start of NA treatment was the independent predictive factor for the exacerbation of GEVs (P < 0.001). Eight patients who had extrahepatic portosystemic shunt at the start of NA treatment developed portosystemic encephalopathy during follow-up. The 3- and 5-year incidence of that was 5% and 8%, respectively. CONCLUSIONS: The presence of portosystemic collateral vessels at the start of NA treatment increases the risk of GEVs worsening and development of portosystemic encephalopathy in patients with HBV-related cirrhosis, despite improvement of liver function and success in reducing viral loads with NA treatment.

22q11.2 Deletion Status and Perioperative Outcomes for Tetralogy of Fallot with Pulmonary Atresia and Multiple Aortopulmonary Collateral Vessels.

Deletion of 22q11.2 (del22q11) is associated with adverse outcomes in patients with tetralogy of Fallot (TOF). We sought to investigate its contribution to perioperative outcome in patients with a severe form of TOF characterized by pulmonary atresia (PA) or severe pulmonary stenosis (PS) and major aortopulmonary collateral arteries (MAPCAS). We conducted a retrospective review of patients with TOF/MAPCAS who underwent staged surgical reconstruction between 1995 and 2006. Groups were compared according to 22q11.2 deletion status using t-tests or the Wilcoxon Rank sum test. We included 26 subjects, 24 of whom survived the initial operation. Of those, 21 subjects had known deletion status and constitute the group for this analysis [15 with no deletion present (ND) and 6 del22q11 subjects]. There was no difference with respect to occurrence of palliative procedure prior to initial operation, or to timing of closure of the ventricular septal defect (VSD). Other than higher prevalence of prematurity (50%) in the del22q11 group versus no prematurity in the ND, the groups were comparable in terms of pre-operative characteristics. The intra- and post-operative course outcomes (length of cardiopulmonary bypass, use of vasopressors, duration of intensive care and length of hospital stay, tube-feeding) were also comparable. Although the del22q11 had longer mechanical ventilation than the ND, this difference was not significant [68 h (range 4-251) vs. 45 h (range 3-1005), p = 0.81]. In this detailed comparison of a small patient cohort, 22q11.2 deletion syndrome was not associated with adverse perioperative outcomes in patients with TOF, PA, and MAPCAS when compared to those without 22q11.2 deletion syndrome. These results are relevant to prenatal and neonatal pre-operative counseling and planning.

Optimization of Vascular Casting for Three-Dimensional Fluorescence Cryo-Imaging of Collateral Vessels in the Ischemic Rat Hindlimb.

Development of collateral vessels, arteriogenesis, may protect against tissue ischemia, however, quantitative data on this process remain scarce. We have developed a technique for replicating the entire arterial network of ischemic rat hindlimbs in three dimensions (3D) based on vascular casting and automated sequential cryo-imaging. Various dilutions of Batson's No. 17 with methyl methacrylate were evaluated in healthy rats, with further protocol optimization in ischemic rats. Penetration of the resin into the vascular network greatly depended on dilution; the total length of casted vessels below 75 µm was 13-fold higher at 50% dilution compared with the 10% dilution. Dilutions of 25-30%, with transient clamping of the healthy iliac artery, were optimal for imaging the arterial network in unilateral ischemia. This protocol completely filled the lumina of small arterioles and collateral vessels. These appeared as thin anastomoses in healthy legs and increasingly larger vessels during ligation (median diameter 1 week: 63 µm, 4 weeks: 127 µm). The presented combination of quality casts with high-resolution cryo-imaging enables automated, detailed 3D analysis of collateral adaptation, which furthermore can be combined with co-registered 3D distributions of fluorescent molecular imaging markers reflecting biological activity or perfusion.

Development of collateral vessels: A new paradigm in CAM angiogenesis model.

The chorioallantoic membrane (CAM) assay is one of the most widely used models to study angiogenesis. In this study, collateral vessel development is reported in CAM assay useful in analysis of angiogenesis. Four days old white Leghorn fertilized chicken eggs were inoculated with vehicle, standard or test angiogenesis inhibitor using standard protocol. Central vessel growth was seen tapering down and collateral vessels were developed from the lower side of the chorioallantoic membrane moving upward in 12 days old standard or test treated CAMs. In the absence of the central vessel, collateral blood supply helped in survival of embryos. Hence, development of collateral vessels was used for ranking of blood vessels and angiogenesis in addition to well-known standard parameters related to central vessel. The finding could differentiate molecules inhibiting angiogenesis with or without collateralization which is crucial in anti-angiogenic therapy used for cardiovascular diseases and cancer. This study proposes a new avenue to distinguish pro-angiogenic molecules from anti-angiogenic ones as well as anti-angiogenic molecules which may or may not support alternative vascularization pathway that would have great impact on future angiogenic and anti-angiogenic therapy.

Computed tomographic characteristics of collateral venous pathways in dogs with caudal vena cava obstruction.

Collateral venous pathways develop in dogs with obstruction or increased blood flow resistance at any level of the caudal vena cava in order to maintain venous drainage to the right atrium. The purpose of this retrospective study was to describe the sites, causes of obstruction, and configurations of venous collateral pathways for a group of dogs with caudal vena cava obstruction. Computed tomography databases from two veterinary hospitals were searched for dogs with a diagnosis of caudal vena cava obstruction and multidetector row computed tomographic angiographic (CTA) scans that included the entire caudal vena cava. Images for each included dog were retrieved and collateral venous pathways were characterized using image postprocessing and a classification system previously reported for humans. A total of nine dogs met inclusion criteria and four major collateral venous pathways were identified: deep (n = 2), portal (n = 2), intermediate (n = 7), and superficial (n = 5). More than one collateral venous pathway was present in 5 dogs. An alternative pathway consisting of renal subcapsular collateral veins, arising mainly from the caudal pole of both kidneys, was found in three dogs. In conclusion, findings indicated that collateral venous pathway patterns similar to those described in humans are also present in dogs with caudal vena cava obstruction. These collateral pathways need to be distinguished from other vascular anomalies in dogs. Postprocessing of multidetector-row CTA images allowed delineation of the course of these complicated venous pathways and may be a helpful adjunct for treatment planning in future cases.

Recanalization of port-superior mesenteric vein thrombosis with long-term anticoagulant therapy after failed early anticoagulant therapy.

BACKGROUND: Anticoagulant therapy with heparin is the first-line treatment for acute mesenteric vein thrombosis and is effective in improving outcomes. Conversely, patients with failed early anticoagulant therapy occasionally develop bowel infarction requiring surgery. The efficacy of long-term anticoagulant therapy on recanalizing mesenteric vein thrombosis in patients with failed early anticoagulant therapy remains unclear. Herein, we report a patient who achieved recanalization of port-superior mesenteric vein thrombosis treated with anticoagulant therapy for 10 years after failed early anticoagulant therapy, followed by bowel resection. CASE PRESENTATION: A 38-year-old male patient visited an outpatient clinic due to acute exacerbation of abdominal pain that had persisted for a month. He was diagnosed with port-superior mesenteric vein thrombosis on contrast-enhanced computed tomography (CT) scan and was transferred to our institution. Although he presented with abdominal pain, his respiration and circulation were stable upon hospital arrival. Anticoagulant therapy with heparin was started, and the patient was admitted to the intensive care unit. However, the patient's abdominal pain worsened, and he began to develop signs of peritonitis. Repeat CT scan revealed bowel infarction. Thus, the patient underwent bowel resection 6 h after admission. The initial surgery was completed with open abdomen management. Bowel anastomosis was performed on the second-look surgery on the first postoperative day. Finally, the abdomen was closed on the third postoperative day after confirming the absence of bowel ischemia progression. The patient had prolonged impaired bowel function with paralytic ileus, but was discharged on the 60th postoperative day. He was then diagnosed with protein C and S deficiency based on the tests performed. Anticoagulant therapy with warfarin was initiated. He also received anticoagulant therapy in the outpatient setting. The patient's port-superior mesenteric vein thrombosis had improved gradually with warfarin during the follow-up period. At 10 years after surgery, total occlusion of the port-superior mesenteric vein was recanalized with improvement of the portal collateral vessels. In addition, no gastric or esophageal varices were observed. CONCLUSIONS: Long-term anticoagulation therapy could affect the recanalization of extensive thrombus in multiple segments in patients with mesenteric venous thrombosis.

Collateral vessels on preoperative enhanced computed tomography for predicting pathological grade of clear cell renal cell carcinoma: A retrospective study.

OBJECTIVES: To retrospectively evaluate the association between the presence of collateral vessels and grade of clear cell renal cell carcinoma (ccRCC) and whether the presence of collateral vessels could serve as a predictor to differentiate high- and low-grade ccRCC. MATERIALS AND METHODS: From May 2018 to September 2022, a total of 160 ccRCC patients with pathological diagnosis were enrolled in this study. Patients were divided into a high-grade group and a low-grade group according to World Health Organization/International Society of Urological Pathology (WHO/ISUP) grading system. The significant variables were extracted based on the univariate analyses using Student t test, Mann-Whitney U test, Chi-square test or Fisher's exact test. Multivariate logistic regression analyses were performed to determine independent factors among extracted variables. We calculated the sensitivity, specificity and their 95% confidence intervals (CI) of collateral vessels for predicting high WHO/ISUP grade to quantify its predictive performance. Furthermore, to investigate the additional predictive contribution of collateral vessels, a primary model and a control model were constructed to predict WHO/ISUP grade. The primary model included all extracted significant variables and the control model included significant variables except collateral vessels. RESULTS: The proportion of ccRCC patients with collateral vessels was significantly larger in high-grade ccRCC than those in low-grade ccRCC (87.5 % vs. 26.8 %, P < 0.001). Multivariate logistic regression analyses showed that the presence of collateral vessels was an independent predictor for high WHO/ISUP grade (P < 0.001). The sensitivity and specificity of the presence of collateral vessels for differentiating high- and low-grade ccRCC were 87.5 % (95 % CI 0.753-0.941) and 73.2 % (95 % CI 0.643-0.806) respectively. Including collateral vessels in predictive model improves predictive performance for WHO/ISUP grade, increasing the area under the curve (AUC) value from 0.889 to 0.914. CONCLUSION: The presence of collateral vessels has high sensitivity and specificity for differentiating high- and low-grade ccRCC and can improve the predictive performance for high WHO/ISUP grade.

Differences in collateral vessel formation after experimental retinal vein occlusion in spontaneously hypertensive rats and wild-type rats.

Objective: Retinal vein occlusion (RVO) can lead to visual impairment, but the development of collateral vessels can sometimes mitigate significant damage. This study aimed to investigate the relationship between collateral vessels and hypertension, the most common underlying condition associated with RVO, by comparing spontaneously hypertensive rats (SHRs) and wild-type Wister rats (WWRs). We also examined the differences between WWRs and SHRs in terms of sphingosine 1-phosphate receptor 1 (S1PR1) expression and its product nitric oxide synthase 3 (NOS3) expression, which are involved in the formation of collateral vessels after vascular occlusion. Methods: Laser photocoagulation (PC) was used to occlude one randomly selected retinal vein in WWRs and SHRs, and the area surrounding the occluded vessel was examined using optical coherence tomography angiography. If reperfusion of the occluded vessel occurred within 2 weeks, the vessel was re-occluded repeatedly by PC. The number of eyes with successfully occluded vessels accompanied by collateral vessels was recorded. Then, WWRs and SHRs were divided into the following four groups: 1) control (no treatment), 2) vehicle (20% DMSO), 3) S1PR1 agonist (2 mg/mL SEW2871), and 4) S1PR1 antagonist (0.25 mg/mL VPC 23019) groups. The drugs were administered intravitreally in all groups except the control. The number of laser shots required for successful RVO was recorded. Histological evaluation and quantitative real-time PCR of S1PR1 and NOS3 were performed to elucidate the mechanisms underlying collateral vessel formation. Results: The proportion of eyes achieving successful vein occlusion was lower in SHRs (4/12 eyes, 33.3%) than in WWRs (8/10 eyes, 80%, p = 0.043). NOS3 expression at 6 h after PC was significantly higher in WWRs than in SHRs (p = 0.021). In WWRs treated with SEW2871, vein occlusion failed in 7 of 10 eyes (70%). The expression of NOS3 was significantly higher in the SEW2871 treatment group than in the untreated group (p < 0.001). Furthermore, NOS3 expression was significantly higher after SEW2871 treatment in WWRs than in SHRs (p = 0.011). Conclusion: In hypertensive environments, collateral vessels are less likely to develop, and S1PR1 may be involved in this phenomenon.

Evolution of spontaneous portosystemic shunts over time and following aetiological intervention in patients with cirrhosis.

Background & Aims: Spontaneous portosystemic shunts (SPSS) develop frequently in cirrhosis. Changes over time and the effect of aetiological interventions on SPSS are unknown, so we aimed to explore the effect of these variables on SPSS evolution. Methods: Patients with cirrhosis from the Baveno VI-SPSS cohort were selected provided a follow-up abdominal CT or MRI scan was available. Clinical and laboratory data were collected at baseline and follow-up. Imaging tests were reviewed to evaluate changes in the presence and size of SPSS (large (L)-SPSS was ≥8 mm) over time. Regarding alcohol- or HCV-related cirrhosis, two populations were defined: cured patients (abstinent from alcohol or successful HCV therapy), and non-cured patients. Results: A total of 617 patients were included. At baseline SPSS distribution was 22% L-SPSS, 30% small (S)-SPSS, and 48% without (W)-SPSS. During follow-up (median follow-up of 63 months), SPSS distribution worsened: L-SPSS 26%, S-SPSS 32%, and W-SPSS 42% (p <0.001). Patients with worse liver function during follow-up showed a simultaneous aggravation in SPSS distribution. Non-cured patients (n = 191) experienced a significant worsening in liver function, more episodes of liver decompensation and lower transplant-free survival compared to cured patients (n = 191). However, no differences were observed regarding SPSS distribution at inclusion and at follow-up, with both groups showing a trend to worsening. Total shunt diameter increased more in non-cured (52%) than in cured patients (28%). However, total shunt area (TSA) significantly increased only in non-cured patients (74 to 122 mm2, p <0.001). Conclusions: The presence of SPSS in cirrhosis increases over time and parallels liver function deterioration. Aetiological intervention in these patients reduces liver-related complications, but SPSS persist although progression is decreased. Impact and implications: There is no information regarding the evolution of spontaneous portosystemic shunts (SPSS) during the course of cirrhosis, and especially after disease regression with aetiological interventions, such as HCV treatment with direct-acting antivirals or alcohol abstinence. These results are relevant for clinicians dealing with patients with cirrhosis and portal hypertension because they have important implications for the management of cirrhosis with SPSS after disease regression. From a practical point of view, physicians should be aware that in advanced cirrhosis with portal hypertension, after aetiological intervention, SPSS mostly persist despite liver function improvement, and complications related to SPSS may still develop.

Hemodynamic Evaluation of Coronary Artery Lesions after Kawasaki Disease: Comparison of Fractional Flow Reserve during Cardiac Catheterization with Myocardial Flow Reserve during 13N-Ammonia PET.

Coronary artery lesions (CALs) after Kawasaki disease present complex coronary hemodynamics. We investigated the relationship between coronary fractional flow reserve (FFR), myocardial flow reserve (MFR), and myocardial blood flow volume fraction (MBF) and their clinical usefulness in CALs after Kawasaki disease. Nineteen patients (18 men, 1 woman) who underwent cardiac catheterization and 13N-ammonia positron emission tomography, with 24 coronary artery branches, were included. Five branches had inconsistent FFR and MFR values, two had normal FFR but abnormal MFR, and three had abnormal FFR and normal MFR. The abnormal MFR group had significantly higher MBF at rest than the normal group (0.86 ± 0.13 vs. 1.08 ± 0.09, p = 0.001). The abnormal FFR group had significantly lower MBF at adenosine loading than the normal group (2.23 ± 0.23 vs. 1.88 ± 0.29, p = 0.021). The three branches with abnormal FFR only had stenotic lesions, but the MFR may have been normal because blood was supplied by collateral vessels. Combining FFR, MFR, and MBF will enable a more accurate assessment of peripheral coronary circulation and stenotic lesions in CALs and help determine treatment strategy and timing of intervention.

Clinical Characteristics of the Patient With Unmeasurable Ankle-Brachial Index in Endovascular Treatment.

Introduction Ankle-brachial index (ABI) is an important indicator to diagnose lower extremity arterial disease (LEAD). However, patients with unmeasurable ABI are sometimes excluded from the analysis and their clinical characteristics are poorly understood. Methods One hundred twenty-two consecutive Japanese subjects (mean age, 72 years), who underwent successful endovascular treatment (EVT) for lower extremity arteries at our hospital were retrospectively studied. Results Of the 122 patients, 23 (19%) patients presented an unmeasurable ABI before EVT. Five of 23 (22%) had still an unmeasurable ABI one day after EVT. Comorbidities including hypertension, diabetes, dyslipidemia, hemodialysis, smoking, ischemic heart disease, atrial fibrillation, and past-EVT history were not different between ABI measurable and unmeasurable patients. However, patients with unmeasurable ABI presented a significantly higher degree of Rutherford category and a smaller number of tibial vessel runoff than patients with measurable ABI before EVT (p<0.05 and p<0.01, respectively). There was no difference in the lesion site between the two groups. The event rate including all-cause mortality, re-EVT, lower limb amputation, and bypass surgery did not differ between two groups four years after EVT. ABI after four years of initial EVT did not differ between pre-EVT measurable and unmeasurable patients (0.96 vs. 0.84, p=0.48). Conclusions Patients with unmeasurable ABI before EVT were characterized by higher degree of Rutherford categorization and a small number of tibial vessel runoff, but there was no significant difference in outcomes during the follow-up period.

Determinants of cerebral collateral circulation in acute ischemic stroke due to large vessel occlusion.

Introduction: Cerebral collateral circulation has a central role in ischemic stroke pathophysiology, and it is considered to correlate with infarct size, the success of reperfusion therapies, and clinical outcomes. Our aim was to study the factors influencing the development of collaterals in patients with acute ischemic stroke eligible for endovascular treatment. Materials and methods: We enrolled patients with acute ischemic stroke and large vessel occlusion of anterior circulation potentially eligible for endovascular treatment. Included patients performed multiphase CT angiography to assess collaterals that were graded by the Menon Grading Score. We investigated the associations between clinical factors and collaterals and tested independent associations with logistic (good vs. poor collaterals) and ordinal (collateral grade grouped, Menon 0-2, 3, 4-5) regression analysis adjusting for age, sex, stroke severity, and onset to CT time (OCTT). Results: We included 520 patients, the mean age was 75 (±13.6) years, 215 (41%) were men, and the median (IQR) NIHSS was 17 (11-22). Good collaterals were present in 323 (62%) patients and were associated with lower NIHSS (median 16 vs. 18; p < 0.001) and left hemisphere involvement (60% vs. 45%; p < 0.001), whereas previous stroke/TIA was more frequent in patients with poor collaterals (17 vs. 26%; p = 0.014). These results were confirmed in both logistic and ordinal regression analyses where good collaterals were associated with lower NIHSS (OR = 0.94; 95% CI = 0.91-0.96; cOR = 0.95; 95% CI = 0.92-0.97, respectively) and left hemisphere stroke (OR = 2.24; 95% CI = 1.52-3.28; cOR = 2.11; 95% CI = 1.46-3.05, respectively), while previous stroke/TIA was associated with poor collaterals (OR = 0.57; 95% CI = 0.36-0.90; cOR = 0.61; 95% CI = 0.40-0.94, respectively). Vascular risk factors, demographics, and pre-stroke treatments did not influence the collateral score. Discussion: The results of our study suggest that risk factors and demographics do not influence the development of collateral circles, except for a negative relation with previous ischemic events. We confirm an already reported observation of a possible protective effect of collaterals on tissue damage assuming NIHSS as its surrogate. The association between left hemispheric stroke and better collaterals deserves to be further explored. Further efforts are needed to identify the factors that favor the development of collaterals.