Thirty-Nine Percent of Patients with a Ruptured Abdominal Aortic Aneurysm (AAA) Have an Incidentally Detected AAA Prior to Rupture.

BACKGROUND: Abdominal aortic aneurysm (AAA) screening has been offered to 65-year-old men living in Oslo, Norway, since May 2011. A significant number of AAA-related deaths occurred in individuals who are not eligible for screening. The primary aim of this study was to describe the group of patients admitted to Oslo University Hospital with a ruptured AAA after the implementation of the local AAA screening project. The following parameters were investigated: AAA detection before rupture, surveillance status, eligibility for screening, and comorbidities. We also sought to compare outcomes (repair rates and 30-day mortality) between patients with and without an incidentally detected AAA prior to rupture. METHODS: This cohort study included patients admitted acutely to Oslo University Hospital due to a symptomatic or ruptured AAA in the period January 2011 to December 2022. Data on demographics, prior AAA detection, surveillance status, treatment, and mortality were collected retrospectively through electronic medical records. RESULTS: We identified 200 patients with a symptomatic or ruptured AAA, among which 79 (40%) had an AAA detected before rupture-one (1%) through screening and 78 (39%) incidentally. Up to 30% of the incidentally detected AAAs were not under any surveillance. Six patients were found eligible for screening: one had attended, three were non-attenders, and two had not been invited. Patients with an incidentally detected AAA before rupture had a more advanced age and a significantly higher degree of comorbidities than patients without a previously detected AAA, and the repair rates in these groups were 56% and 84%, respectively (P < 0.001). Adjusted for comorbidities and risk factors, the odds ratio for repair among patients with incidentally detected AAA was 0.56 (P = 0.292). The 30-day mortality was not significantly different between the two groups (P = 0.097). CONCLUSIONS: Most patients with a ruptured AAA were not eligible for screening, but 39% of the patients had an incidentally detected AAA prior to rupture. Standardized reporting and follow-up of incidentally detected AAAs is thus identified as an additional measure to organized screening in the effort to reduce AAA-related mortality.

Hemodynamic effects of supplemental oxygen versus air in simulated blood loss in healthy volunteers: a randomized, controlled, double-blind, crossover trial.

BACKGROUND: Trauma patients frequently receive supplemental oxygen, but its hemodynamic effects in blood loss are poorly understood. We studied the effects of oxygen on the hemodynamic response and tolerance to simulated blood loss in healthy volunteers. METHODS: Fifteen healthy volunteers were exposed to simulated blood loss by lower body negative pressure (LBNP) on two separate visits at least 24 h apart. They were randomized to inhale 100% oxygen or medical air on visit 1, while inhaling the other on visit 2. To simulate progressive blood loss LBNP was increased every 3 min in levels of 10 mmHg from 0 to 80 mmHg or until hemodynamic decompensation. Oxygen and air were delivered on a reservoired face mask at 15 L/min. The effect of oxygen compared to air on the changes in cardiac output, stroke volume and middle cerebral artery blood velocity (MCAV) was examined with mixed regression to account for repeated measurements within subjects. The effect of oxygen compared to air on the tolerance to blood loss was measured as the time to hemodynamic decompensation in a shared frailty model. Cardiac output was the primary outcome variable. RESULTS: Oxygen had no statistically significant effect on the changes in cardiac output (0.031 L/min/LBNP level, 95% confidence interval (CI): - 0.015 to 0.077, P = 0.188), stroke volume (0.39 mL/LBNP level, 95% CI: - 0.39 to 1.2, P = 0.383), or MCAV (0.25 cm/s/LBNP level, 95% CI: - 0.11 to 0.61, P = 0.176). Four subjects exhibited hemodynamic decompensation when inhaling oxygen compared to 10 when inhaling air (proportional hazard ratio 0.24, 95% CI: 0.065 to 0.85, P = 0.027). CONCLUSIONS: We found no effect of oxygen compared to air on the changes in cardiac output, stroke volume or MCAV during simulated blood loss in healthy volunteers. However, oxygen had a favorable effect on the tolerance to simulated blood loss with fewer hemodynamic decompensations. Our findings suggest that supplemental oxygen does not adversely affect the hemodynamic response to simulated blood loss. Trial registration This trial was registered in ClinicalTrials.gov (NCT05150418) December 9, 2021.

Eleven-Year Outcomes of a Screening Project for Abdominal Aortic Aneurysm (AAA) in 65-Year-Old Men.

Objective: Since 2011, the Department of Vascular Surgery at Oslo University Hospital has offered screening for abdominal aortic aneurysm (AAA) to 65-year-old men living in Oslo, Norway. The aim of this study was to evaluate the effect of the screening project on AAA-related mortality and rupture and repair rates in the screened population. Methods: This cohort study included men that participated in AAA screening at the Department of Vascular Surgery at Oslo University Hospital in the period May 2011 to September 2019. All men with screen-detected AAA (aortic diameter ≥30 mm) and subaneurysmal aortic dilatation (aortic diameter 25-29 mm) were included. A stratified (1:1 with the subaneurysm group), randomized selection of men with normal aortic diameter (<25 mm) upon screening was also included. The follow-up data on events (ruptures, repairs, and deaths) after screening were collected retrospectively from patient electronic medical records at Oslo University Hospital, the National Population Register and the Norwegian Cause of Death Registry (CoDR). Results: In total, 2048 men were included, with a median follow-up time of 7.1 years (IQR 3.8). Among men with screen-detected AAA, 0.6% died of AAA-related causes (0.9 AAA-related deaths per 1000 person-years). The rupture rate was 0.3% among men with screen-detected AAA or subaneurysmal aortic dilatation, giving an incidence of 0.5 ruptures per 1000 person-years. The overall repair rate in the AAA group was 20.6% (36.1 repairs per 1000 person-years) and 0.6% (0.9 repairs per 1000 person-years) in the subaneurysm group. Conclusion: In a population screened for AAA, the incidence of rupture and the AAA-related mortality was very low. Almost one-fifth of the participants with screen-detected AAA underwent elective repair, representing a group that might have presented with rupture if untreated. These results indicate that screening is valuable in preventing AAA rupture and AAA-related mortality.

Associations between cardiovascular risk factors, disease activity and cardiorespiratory fitness in patients with inflammatory joint disease: a cross-sectional analysis.

BACKGROUND: Inflammatory joint diseases (IJD) are accompanied by an increased risk of cardiovascular disease (CVD). Cardiorespiratory fitness (CRF) is a modifiable CVD risk factor and low levels of CRF associate with an elevated CVD risk. This study aimed to investigate the associations between CVD risk factors, disease activity and CRF in patients with IJD and to explore differences between patients with normal versus low levels of CRF. METHODS: CRF was measured as peak oxygen uptake (VO2peak) with a cardiopulmonary exercise test. Participants were also evaluated for: Body composition, blood pressure, blood lipids, inflammatory markers and disease activity. Patient-reported use of cigarettes/snuff, medication, disease duration, pain, fatigue, CVD history, habitual physical activity and exercise beliefs and self-efficacy were collected by questionnaire. Cross-sectional associations between CVD risk factors, disease-related factors and CRF were analyzed by multiple linear regression. CRF was categorized to normal CRF (VO2peak ≥ 80%) or low CRF (VO2peak < 80%) according to age- and gender-stratified reference data. Differences in demographic, CVD and disease-related factors between patients with normal versus low CRF were explored. RESULTS: In 60 Norwegian patients with IJD [34 females, age 59 years (IQR: 52-63)], mean VO2peak was 30.2 (± 6.9) mL/kg/min, corresponding to 83% (± 18) of normative reference values. Age (coefficient: - 0.18 years, p = 0.01) and fat mass (coefficient: - 0.67 %, p < 0.001) were inversely associated with CRF, while physical activity index (coefficient: 0.13 points, p = 0.05) was positively associated with CRF (R2 = 0.66). There were no significant associations between CRF, classical CVD risk factors and disease-related variables. Compared to patients with low CRF (n = 30), patients with normal CRF (n = 30) had higher peak oxygen uptake (+ 9.4 mL/kg/min, p < 0.001), high-density lipoprotein cholesterol (+ 0.5 mmol L-1, p < 0.001), and exercise self-efficacy (+ 6.9, p < 0.01) as well as lower fat mass (- 8.7%, p < 0.001), resting heart rate (- 8.0 beats/min, p < 0.01) and triglycerides (- 0.5 mmol L-1, p < 0.01). CONCLUSIONS: In this sample of IJD-patients, age, fatmass and physical activity level were associated with CRF. CRF was lower than reference values and patients with normal CRF presented with a more favorable health profile. There is a continued need for exercise interventions to improve CRF in patients with IJD. TRIAL REGISTRATION: NCT04922840.

The Effect of 12-Week Treatment with Intermittent Negative Pressure on Blood Flow Velocity and Flowmotion, Measured with a Novel Doppler Device (Earlybird). Secondary Outcomes from a Randomized Sham-Controlled Trial in Patients with Peripheral Arterial Disease.

BACKGROUND: Treatment with intermittent negative pressure (INP) is proposed as an adjunct to standard care in patients with peripheral arterial disease (PAD). The aims of this study were to evaluate the applicability of a novel ultrasound Dopplerdevice (earlybird) to assess blood flow characteristics in patients with PAD during a treatment session with INP, and whether certain flowproperties could determine who could benefit from INP treatment. METHODS: Secondary outcomes of data from a randomized sham-controlled trial were explored. Patients were randomized to 12 weeks of treatment with 40 mm Hg or 10 mm Hg INP, for one hour twice daily. Earlybird blood flow velocity recordings were made before and after the 12-week treatmentperiod and consists of a 5-min recording in rest, 3-min during INP treatment and 5-min recording after ended INP test-treatment. Mean blood flow velocity (vmean), relative changes in flow and frequency spectrum by Fourier-transform of the respective bandwidths of endothelial, sympathetic, and myogenic functions, were analyzed for the different series of blood flow measurements. RESULTS: In total, 62 patients were eligible for analysis, where 32 patients were treated with 40 mm Hg INP. The acquired recordings were of good quality and were used for descriptive analyses of flow characteristics. An immediate increase in vmean during the negative pressure periods of the INP test-treatment was observed in the 40 mm Hg INP treatment group at both pre- and post-test. There was a significant difference between the treatment groups, with a difference between the medians of 13.7 (P < 0.001) at pre-test and 10.7 (P < 0.001) at posttest. This finding was confirmed with spectrum analysis by Fourier-transform of the bandwidth corresponding to INP treatment. The change in amplitude corresponding to myogenic function after 12-weeks of treatment, was significantly different in favor of the 40 mm Hg INP treatment group. We were not able to detect the specific flow characteristics indicating who would benefit INP-treatment. CONCLUSIONS: Earlybird is an applicable tool for assessing blood flow velocity in patients with PAD. Analysis of the flow velocity recordings shows that INP induces an immediate increase in blood flow velocities during INP. The positive effects of INP may be attributed to recruitment of arterioles, and thereby, increasing blood flow. In these analyses, no flow characteristics were determined which could predict who would benefit INP treatment.

Laparoscopic Surgery for Median Arcuate Ligament Syndrome (MALS): A Prospective Cohort of 52 Patients.

Background: The selection of patients with MALS for surgical treatment depends upon the reliability of the symptom interpretation and the diagnostic work-up. We aimed to follow up the results of the laparoscopic decompression of the patients with MALS. Patients and Methods: In a single-center, 52 consecutive MALS patients were followed-up, prospectively, after transperitoneal laparoscopic decompression. MALS was diagnosed with a computed tomography angiography (CTA) verified stenosis, ≥50% of the celiac artery (CA), and with duplex ultrasound, a peak systolic velocity (PSV) ≥2.0 m/s. Postoperative, CTA, and duplex ultrasound were performed, and the patients were followed-up at 3, 6, 12 months, and yearly after that. Results: Mean age of the patients was 47 ±21 years, and 65% were females. The patients had a mean weight loss of 8.4 ±7.2 kg. Fifty-one patients had the laparoscopic operation with a mean operation time of 102 ± 28 minutes. Forty-seven patients (90%) achieved relief from the symptoms either completely (67%) or partially (23%) at 3-6 months of follow-up. Significant improvement in postoperative PSV was found compared to the preoperative values, p<0.001. Five patients (10%) with no immediate effect of the operation, but two of them became free from symptoms during the mean study follow-up of 2.4 ± 2 years. Five patients (10%) had operative complications, including one trocar injury to the liver, one pneumothorax, and three cases of bleeding from the branches of CA. Two patients died of cancer disease during the study period. Only two patients (4%) had symptoms relapse, both later treated successfully. Conclusion: Laparoscopic transperitoneal decompression provides most of the patients a persistent relief from MALS symptoms.

Three-dimensional ultrasound volume and conventional ultrasound diameter changes are equally good markers of endoleak in follow-up after endovascular aneurysm repair.

INTRODUCTION: The main disadvantages of computed tomography angiography (CTA) in follow-up after endovascular aneurysm repair are the risks of contrast-induced renal impairment and radiation-induced cancer. Three-dimensional ultrasound is a new technique for volume estimation of the aneurysm sac. Some studies have reported promising results. The aim of this study was to evaluate the accuracy and precision of three-dimensional ultrasound aneurysm sac-volume estimates, and to explore whether volume and/or diameter changes on ultrasound can be used as markers of endoleak. METHODS: A single-center diagnostic accuracy study was performed. A total of 92 patients planned for endovascular aneurysm repair were prospectively and consecutively enrolled (2013-2016). Aneurysm sac diameter and volume were measured using CTA, conventional ultrasound, and three-dimensional ultrasound preoperatively and 1, 6, 12, and 24 months postoperatively. Three-dimensional ultrasound was performed with a commercially available electromechanical transducer. Patients with endoleak were observed 5 years after endovascular aneurysm repair. RESULTS: A total of 79 men and 13 women were included. Mean age was 74 years (57-92 years). Median follow-up was 24 months. Endoleak cases were observed for up to 55 months. Diameter measurements on conventional ultrasound correlated well with CT diameters (r = 0.9, P < .05, n = 347), and Bland-Altman analyses showed an upper limit of agreement of +0.5 cm and a lower limit of agreement of -0.8 cm. The mean difference was -0.13 cm ± 0.36 cm. Three-dimensional ultrasound volumes had a correlation with CTA diameters of r = 0.8 (P < .05, n = 347) and with three-dimensional CT volumes of r = 0.8 (P < .05, n = 155). Receiver operating characteristic analyses showed that the diameter and volume changes that led to reintervention were most accurate at 24-month follow-up, with area-under-the-curve percentage changes of 0.98 (two-dimensional ultrasound), 0.97 (three-dimensional ultrasound), and 0.97 (two-dimensional CT). DISCUSSION: Both diameter and volume changes can be used as markers for endoleak with excellent areas under the curve on receiver operating characteristic analyses. However, three-dimensional ultrasound volumes did not add any further diagnostic information. Conventional 2D diameter measurements were as accurate as volume changes as markers of endoleak. CONCLUSIONS: Type II endoleaks can safely be followed up using a simple diameter measurement on conventional ultrasound.

A randomized controlled trial of treatment with intermittent negative pressure for intermittent claudication.

OBJECTIVE: We investigated the effects of lower extremity intermittent negative pressure (INP) treatment for 1 hour two times daily for 12 weeks on the walking distance of patients with intermittent claudication (IC). METHODS: Patients with IC were randomized to treatment with -40 mm Hg INP (treatment group) or -10 mm Hg INP (sham control group). Pain-free walking distance (PWD) and maximal walking distance (MWD) on a treadmill, resting and postexercise ankle-brachial index, resting and postischemic blood flow (plethysmography), and quality of life (EQ-5D-5L and Vascuqol-6) were measured at baseline and after 12 weeks of treatment. RESULTS: A total of 72 patients were randomized, and 63 had data available for the intention-to-treat analyses. The between-group comparisons showed a significant change in the PWD, favoring the treatment group over the sham control group (estimated treatment effect, 50 m; 95% confidence interval [CI], 11-89; P = .014). The PWD had increased by 68 m (P < .001) in the treatment group and 18 m (P = .064) in the sham control group. No significant difference was found in the change in the MWD between the two groups (estimated treatment effect, 42 m; 95% CI, -14 to 97; P = .139). The MWD had increased by 62 m (P = .006) in the treatment group and 20 m (P = .265) in the sham control group. For patients with a baseline PWD of <200 m (n = 56), significant changes had occurred in both PWD and MWD between the two groups, favoring the treatment group (estimated treatment effect, 42 m; 95% CI, 2-83; P = .042; and estimated treatment effect, 62 m; 95% CI, 5-118; P = .032; respectively). Both overall and for the group of patients with a PWD <200 m, no significant differences were found in the changes in the resting and postexercise ankle-brachial index, resting and postischemic blood flow, or quality of life parameters between the two groups. CONCLUSIONS: Treatment with -40 mm Hg INP increased the PWD compared with sham treatment in patients with IC. For the patients with a baseline PWD of <200 m, an increase was found in both PWD and MWD compared with sham treatment.

Lower Extremity Intermittent Negative Pressure for Intermittent Claudication. Follow-Up after 24 Weeks of Treatment.

BACKGROUND: Treatment with lower extremity intermittent negative pressure (INP) of -40 mm Hg for one hour twice daily for 12 weeks, increases walking capacity in patients with intermittent claudication (IC). However, the effects of INP treatment beyond 12 weeks have not been elucidated. The aim of the present study was to investigate the clinical effects of INP treatment after 24 weeks in patients with IC. METHODS: This was a follow-up study after a randomized sham-controlled trial, where patients randomized to the active treatment group were offered to continue treatment for 12 additional weeks (24 weeks in total). Treatment with -40 mm Hg INP was applied in a pressure chamber sealed around the lower leg, and the patients were instructed to treat themselves at home one hour in the morning and one hour in the evening. Pain free walking distance (PWD), maximal walking distance (MWD), resting ankle-brachial index (ABI) and post exercise ABI were measured at baseline, after 12 and 24 weeks. RESULTS: Ten out of 32 patients (31%) from the active treatment group in the initial trial were included in this follow-up study. At baseline, PWD was (mean ±SD) 151 ± 91 m and MWD was 362 ±159 m. There was a significant increase in both PWD and MWD after 24 weeks of treatment, compared to baseline (ANOVA; P= 0.006 and P= 0.012, respectively). Post hoc tests revealed that PWD increased significantly from baseline to 12 weeks (mean 81 m; 95% CI [6, 156]; P = 0.032), and that MWD increased significantly from 12 to 24 weeks (mean 145 m; 95% CI [22, 268]; P = 0.018). There were no significant changes in resting ABI or post exercise ABI during the 24-week treatment period (ANOVA; P= 0.157 and P= 0.450, respectively). CONCLUSION: Both PWD and MWD improved after treatment with - 40 mm Hg INP for one hour twice daily for 24 weeks, compared to baseline. The main improvement in PWD occurred during the first 12 weeks of treatment, whereas the main improvement in MWD occurred between 12 and 24 weeks of treatment.

Histological Analysis of a Long Term Patent Subintimal Canal in the Superficial Femoral Artery.

INTRODUCTION: Subintimal angioplasty (SIA) was introduced in the late 1980s and is a supplement to bypass surgery. Adaptation of the technique has been hampered by high rates of early intervention to maintain patency, but the long term assisted patency is good. REPORT: The superficial femoral and popliteal artery containing a patent subintimal canal were explanted from a patient who died in the authors' ward. Histological analysis indicated that the lumen was created in the medial layer of the vessel wall. A collagen rich neointima and fragmented internal elastic lamina were observed, presumably as a result of activated smooth muscle cells. The luminal surface was partly covered by a single layer of CD31, von Willebrand factor, and partly CD144 positive cells. An early atherosclerotic lesion was observed distally in the subintimal canal. DISCUSSION: Remodelling and neo-cellularisation of the vascular wall after SIA are described. Notably, hallmarks of early and late stage atherosclerotic disease were evident throughout the subintimal canal. These observations require confirmation in a larger number of specimens but underscore the need for surveillance after SIA.

Effects of Krill Oil and Race Distance on Serum Choline and Choline Metabolites in Triathletes: A Field Study.

Choline is an essential nutrient that has been implicated in athletic performance due to its role in maintaining normal muscle function. The concentration of free choline in serum may decrease during long-distance high-intensity exercise, yet few nutritional strategies to counteract this potentially performance-depleting loss in choline have been investigated outside the laboratory. This exploratory field study was performed to investigate if pre-race supplementation with phosphatidylcholine from krill oil can counteract the expected drop in choline and some of its metabolites during triathlon competitions. Forty-seven triathletes, 12 females and 35 males ranging in age from 25 to 61 years, were recruited from participants in the Ironman-distance Norseman Xtreme triathlon and the Sprint/Olympic-distance Oslo Triathlon. Twenty-four athletes were randomly allocated to the krill oil group, receiving 4 g of SuperbaBoost™ krill oil daily for 5 weeks prior to the race, and 23 athletes were randomly allocated to the placebo group, receiving 4 g of mixed vegetable oil daily. Blood samples were obtained before the race, immediately after completion of the race, and the day after the race for analysis of choline and its metabolites. The results showed that serum choline concentrations significantly decreased from pre-race to race finish in all races, with a more pronounced decrease observed in the Ironman-distance Norseman Xtreme triathlon (34% decrease) relative to the Sprint/Olympic-distance Oslo Triathlon (15% decrease). A reduction in betaine was also observed, while dimethylglycine (DMG) concentrations remained stable across all time points. Significantly higher concentrations of choline (9.4% on average) and DMG (21.4% on average) were observed in the krill oil compared to the placebo group, and the krill oil group showed a significantly greater increase in serum choline following race completion. In conclusion, krill oil may help to prevent that circulating choline concentrations become limiting during endurance competitions.

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.

Contrast-enhanced ultrasound detects type II endoleaks during follow-up for endovascular aneurysm repair.

OBJECTIVE: Repeated computed tomography angiography (CTA) can be used during follow-up visits for endovascular aneurysm repair (EVAR) but leads to accumulated radiation exposure and may cause renal impairment. Therefore, the use of contrast-enhanced ultrasound (CEUS) has increased, and its ability to detect endoleaks has been promising. The aim of this study was to investigate the diagnostic accuracy of CEUS vs CTA for endoleak detection during EVAR follow-up. METHODS: Ninety-two patients with planned EVAR for abdominal aortic aneurysm were prospectively, consecutively enrolled. In total, 233 paired CTA and CEUS procedures were performed within the same day. Follow-up visits occurred 1 month, 6 months, 12 months, and 24 months postoperatively. RESULTS: Of 48 endoleaks discovered by CTA, 39 were also detected on CEUS, giving an overall sensitivity of 81.3% and specificity of 98.9%. All undetected endoleaks were minor, without clinical importance, and occurred in patients with high body mass index. CONCLUSIONS: In this study, CEUS was accurate for detecting type II endoleaks during follow-up visits for EVAR. Sensitivity was lower in obese patients. Doppler ultrasound has low sensitivity and seems to be unsuitable for the detection of endoleaks.

Gastroscopy assisted laser Doppler flowmetry and visible light spectroscopy in patients with chronic mesenteric ischemia.

Mucosal pathology due to chronic mesenteric ischemia (CMI) is rarely seen during upper endoscopy. Combining Laser Doppler Flowmetry (LDF) and Visible Light Spectroscopy (VLS) may aid in detection of CMI at an early stage. We aimed to investigate the utility of LDF and VLS in detecting microcirculatory changes in patients with CMI during upper endoscopy. In a single center, prospective study, 104 patients were evaluated for mesenteric ischemia during a 24 months period. Patients with a consensus diagnosis of CMI (n = 40) were examined with LDF and VLS. Thirty-two were successfully treated and had a definitive diagnosis of CMI. Results were compared with controls (n = 38) with normal intestinal circulation evaluated with duplex ultrasonography (DUS). Treatment response was evaluated clinically and with DUS at 1 month and with VLS and LDF at 3 months. A significant reduction in mucosal capillary hemoglobin oxygen saturation (SO2) was found in CMI patients compared to controls before treatment: mean ± SD: 67 ± 9%, 81 ± 4%, respectively (p < .001). A significant reduction was also seen for the relative hemoglobin (rHb) amount, flow and velocity (p < .001). The sensitivity of SO2 measured by VLS for diagnosing CMI was 94% and the specificity 72% (cut-off 78%), calculated with ROC curve analysis. A combination of SO2 and rHb increased the test sensitivity and specificity to 97% and 79%, respectively. Conclusion: CMI patients have significantly reduced microcirculation in the stomach and duodenum compared to controls. The results suggest that VLS should be included when performing an upper endoscopy in patients with suspected CMI.

The effects of sympathetic activity induced by ice water on blood flow and brachial artery flow-mediated dilatation response in healthy volunteers.

OBJECTIVE: To investigate the association between sympathetic activity, reactive hyperemia and brachial artery flow-mediated dilation (FMD). BACKGROUND: It is claimed that major surgery has an impact on endothelial function, as observed by post-operative reduced brachial artery FMD response. However, another explanation for the observed reduced FMD response post-operatively may be sympathetic stress-induced reduction in blood flow. METHODS: Seventeen healthy volunteers with a median age (25th-75th percentiles) of 23.5 (23-24.8) years were recruited. Participants' brachial blood flow and FMD response were measured (i) during normal non-stress conditions (Normal1); (ii) during exposure to ice water; and (iii) afterwards, under normal non-stress conditions (Normal2). We continuously measured arterial blood pressure (Finometer), heart rate (ECG), skin blood flow of the index finger (laser Doppler), and brachial artery blood flow and diameter (Ultrasound Doppler). Measurements were taken at baseline; before a 5-min suprasystolic forearm occlusion; and following a 3-min post-occlusion, to measure reactive hyperemia and FMD. RESULTS: Median (25th-75th percentiles) FMD response after exposure to ice water was reduced compared to non-stress conditions [4.9 (2.9-8.4) % during ice water vs. 9.7 (7.6-12.2) % Normal1 and 9.7 (6.4-10.3) % Normal2, P < 0.001]. Blood flow 60 s after cuff-deflation during ice water exposure was significantly reduced to 328 (289-421) mL compared to non-stress conditions (both P < 0.05). No differences were observed between Normal1 [446 (359-506) mL] and Normal2 [455 (365-515) mL] (both P > 0.05). Heart rate significantly increased during ice water exposure [67 (59-69) beats/min)] compared to 55 (49-60) beats/min during Normal1 and 54 (47-60) beats/min during Normal2 (both P < 0.05). MAP did not change during Normal1 [72 (64-84)] or during Normal2 [71 (65-81) mm Hg] (both P > 0.05), but increased to 86 (75-98) mm Hg during ice water exposure (P < 0.05). CONCLUSIONS: Increased sympathetic activity resulted in decreased blood flow and brachial artery FMD response in healthy volunteers, independent of endothelial dysfunction. Future studies should adjust for blood flow when interpreting the FMD response.

Recellularization of Decellularized Venous Grafts Using Peripheral Blood: A Critical Evaluation.

Vascular disease is a major cause of death worldwide, and the growing need for replacement vessels is not fully met by autologous grafts or completely synthetic alternatives. Tissue engineering has emerged as a compelling strategy for the creation of blood vessels for reconstructive surgeries. One promising method to obtain a suitable vessel scaffold is decellularization of donor vascular tissue followed by recellularization with autologous cells. To prevent thrombosis of vascular grafts, a confluent and functional autologous endothelium is required, and researchers are still looking for the optimal cell source and recellularization procedure. Recellularization of a decellularized scaffold with only a small volume of whole blood was recently put forward as a feasible option. Here we show that, in contrast to the published results, this method fails to re-endothelialize decellularized veins. Only occasional nucleated cells were seen on the luminal surface of the scaffolds. Instead, we saw fibrin threads, platelets and scattered erythrocytes. Molecular remnants of the endothelial cells were still attached to the scaffold, which explains in part why earlier results were misinterpreted. Decellularized vascular tissues may still be the best scaffolds available for vascular tissue engineering. However, for the establishment of an adequate autologous endothelial lining, methods other than exposure to autologous whole blood need to be developed.

Reduced reactive hyperemia may explain impaired flow-mediated dilation after on-pump cardiac surgery.

In previous studies, Flow Mediated Dilation (FMD) was used to study the effect of cardiac surgery on endothelial function. This study investigated the effect of on-pump cardiac surgery on FMD and reactive hyperemia. The FMD-response and reactive hyperemia were measured in 25 patients the morning before- and the first morning after cardiac surgery. Brachial artery diameter and blood flow were measured with ultrasound at baseline before 5 min occlusion of the blood flow to the forearm, and continuously for 3 min after release of the occlusion. An exponential wash-out model was fitted to the blood flow over time. Nineteen patients remained for final data analysis. Data are mean ± SEM The FMD response was reduced after surgery from 3.3 ± 0.5% to 1.4 ± 0.6% (P = 0.02). Max blood flow after cuff release was reduced from 342 ± 30 mL preoperatively to 305 ± 30 mL postoperatively (P < 0.00) and fell toward baseline significantly quicker; preoperative half-life was 36 ± 2.4 sec. versus 29 ± 1.9 sec postoperatively (P < 0.00). Resting blood flow was reduced from 84 ± 9 mL/min to 66 ± 9 mL/min, (P < 0.00). Brachial artery baseline diameter was unaffected by coronary artery bypass surgery (P = 0.3). The observed reduction in brachial artery FMD after surgery, by previous authors taken to represent endothelial dysfunction, may at least partly be due to reduced hyperemic flow postoperatively. In studies where FMD is measured on multiple occasions, flow data should also be included. Reduced postoperative blood flow to the arm may indicate regional differences in vascular resistance after cardiac surgery.

Hemodynamic Responses to Resistance Exercise in Patients with Coronary Artery Disease.

PURPOSE: Investigate hemodynamic responses of resistance exercise (RE) with moderate load (i.e., international guidelines for RE of patients) versus RE with high load in patients with coronary artery disease (CAD). METHODS: Medically stable male (n = 11) and female patients (n = 4) treated with PCI or percutaneous coronary intervention, or coronary artery bypass surgery a minimum of 6 months before this study, performed three sets of 15RM and 4RM RE in a randomized order on separate days. Beat-to-beat systolic (SBP), diastolic (DBP) blood pressure, heart rate (HR), stroke volume (SV), cardiac output (CO), and systemic vascular resistance (SVR) were monitored at preexercise, and continuously during RE. RESULTS: Compared with preexercise, SBP and DBP (mean of three sets) increased by 12% to 13% (both; P < 0.001) and 35% to 40% after 15RM RE (both; P < 0.001). 15RM SBP and DBP were higher than 4RM SBP and DBP (both; P < 0.001). The SBP of the fourth repetition of 15 RM RE was similar to the SBP of the fourth repetition of 4RM RE. Compared with preexercise, SV increased moderately after 4RM and 15 RM RE, respectively (both, P < 0.001). HR increased more after 15RM compared with 4RM RE (P < 0.05); thus, higher CO after 15RM (compared with 4RM RE; P < 0.05) was mainly caused by higher HR. SVR decreased by 15% (P < 0.001) and 50% (P < 0.01) after 4RM and 15RM RE. CONCLUSIONS: SBP and DBP increased significantly more during moderate load RE; thus, the magnitude of the external load is not the prime determinant of the pressure response during RE. If management of blood pressure is of concern, high load/low rep RE is preferable to medium load/high rep RE.

Cardiac function assessed by exercise echocardiography on the first morning after coronary artery bypass grafting.

Cardiac surgery patients are urged to resume light physical activity on the first postoperative day, even if cardiac function may not have recovered fully after the operation. To elucidate the postoperative recovery process, we examined cardiac surgery patients with exercise echocardiography before and on the first day after the operation. Patients undergoing on-pump coronary artery bypass grafting were examined with echocardiography during semirecumbent cycle exercise. Patients exercised for five minutes at 10 W intensity and five minutes at 30 W intensity in bed with the upper body supported to approximately 30°. Fourteen patients were studied. Mitral annulus excursion and pulsed wave Doppler from the left ventricular outflow tract indicated postoperatively reduced cardiac stroke volume. Early diastolic tissue velocities of the mitral annulus were reduced, and early trans-mitral flow velocity was increased. The ratio between early mitral flow velocity and early diastolic mitral tissue velocity was increased postoperatively, indicating impaired left ventricular relaxation and increased left atrial pressure. Postoperative systolic mitral annulus tissue velocities were similar to preoperative velocities, indicating maintained systolic function. Postoperative exercise was associated with improvements in myocardial function indices and cardiac stroke volume similar to preoperative improvements. There were no signs of further deterioration in myocardial function during 30 W exercise. In summary, reduced left ventricular diastolic function after surgery resulted in reduced cardiac stroke volume, increased left atrial pressure and a higher rate of perceived exertion on the first postoperative day.