Significant Increase In Perfusion Research Articles

Effects of L-Ornithine-L-Aspartate on Angiogenesis and Perfusion in Subacute Hind Limb Ischemia: Preliminary Study.

The current treatment options for peripheral arterial disease (PAD) are limited due to a lack of significant high-level evidence to inform clinical decisions and unfavorable outcomes in terms of cost-effectiveness and amputation rates. In order to suggest the use of the commercially available L-Ornithine-L-Aspartate (LOLA) for treating PAD, we induced hind limb ischemia (HLI) by unilaterally ligating the femoral artery in a rat model. The rats were randomly divided into three groups, with seven rats assigned to each group: group 1 (control), group 2 (sorbitol), and group 3 (LOLA). Intraperitoneal injections were administered five times on post-operative days (PODs) 3, 5, 7, 10, and 12. Perfusion imaging was conducted on PODs 7 and 14 and compared to pre-operative perfusion imaging. Immunohistochemistry staining and Western blotting were performed after the final perfusion imaging. Group 3 showed a significant increase in perfusion, high CD31-positive capillary lumen density, and substantial overexpression of VEGF in the ischemic limb during the subacute phase of HLI. In conclusion, this study provides the first documented evidence of angiogenesis and perfusion recovery in the subacute phase of the HLI model following the administration of LOLA. With LOLA readily available on the commercial market, the implementation of LOLA treatment for PAD in humans can be expedited compared to other therapies still in the developmental stage.

Perfusion increase in foot angiosomes: Comparison between direct and indirect revascularization of crural arteries.

In retrospective studies, wound healing and leg salvage have been better if revascularization is targeted to the crural artery supplying arterial flow to the wound angiosome. No data exist on how revascularization changes the blood flow in foot angiosomes. The aim of this study was to evaluate the change in perfusion after infrapopliteal artery revascularization in all foot angiosomes and to compare directly revascularized (DR) angiosomes to the indirectly revascularized (IR) angiosomes. In this prospective study, foot perfusion was measured with indocyanine green fluorescence imaging (ICG-FI) before and after either surgical or endovascular below-knee revascularization. According to angiograms, we divided the foot angiosomes into DR and IR angiosomes. Furthermore, in a subanalysis, the IR angiosomes were graded as IR_Coll+ angiosomes if there were strong collaterals arising from the artery which was revascularized, and as IR_Coll- angiosomes if strong collaterals were not seen. A total of 72 feet (28 bypass, 44 endovascular revascularizations) and 282 angiosomes were analyzed. Surgical and endovascular revascularization increased perfusion significantly in both DR and IR angiosomes. After bypass surgery, the increase in DR angiosomes was 55 U and 53 U in IR angiosomes; there were no significant difference in the perfusion increase between IR and DR angiosomes. After endovascular revascularization, perfusion increased significantly more, 40 U, in DR angiosomes compared to 26 U in IR angiosomes (p < 0.05). In the subanalysis of IR angiosomes, perfusion increased significantly after surgical bypass regardless of whether strong collaterals were present or not. After endovascular revascularization, however, a significant perfusion increase was noted in the IR_Coll+ but not in the IR_Coll- subgroup. Open revascularization increased perfusion equally in DR and IR angiosomes, whereas endovascular revascularization increased perfusion significantly more in DR than in IR angiosomes. Strong collateral network may help increase perfusion in IR angiosomes.

Evaluating time until ligation in a novel tourniquet – A crossover randomized-controlled trial

Introduction and aimSevere external hemorrhage is a significant reason for morbidity and mortality in adults; thus, the swift and correct application of a tourniquet by laypersons can be lifesaving. We conducted this randomized-controlled cross-over study to investigate the use of a novel tourniquet. MethodsParticipants were recruited at the Heidelberg University Hospital. Eligible participants were ≥ 18 years old with a medical background but without prior experience in applying a tourniquet. Participants were 1:1 randomized to the intervention group (PAX tourniquet) or the control group (SAM or CAT tourniquet). In the control group, participants underwent another randomization to either the SAM or CAT tourniquet without a predefined allocation ratio. Hyperspectral measurements were undertaken (i) before ligation, (ii) 30 s after ligation, and (iii) 30 s after the reopening of the tourniquet. The primary outcome was time until ligation before crossover between the respective groups. The analysis of secondary endpoints included all attempts to assess a possible learning effect, intraoperator variability, and hyperspectral measurements. Participants were crossed to the other study group after a brief wash-out phase. ResultsIn total, 50 participants were recruited, resulting in 100 attempts. A success rate of 98% was observed across the study population. Time until ligation was 49 s and 56 s (p = 0.572) in the intervention and control group, respectively. However, there was a significant difference between the PAX and SAM (54 vs 75 s; p = 0.037) and the SAM and CAT tourniquet (75 vs. 47 s; p = 0.015). Further, we observed a significant learning effect in participants allocated to the control group first, with a median reduction of 9 s in the time until ligation. Hyperspectral measurements showed a significant decrease in perfusion and tissue oxygenation after ligation. Further, a significant increase in perfusion and tissue oxygenation was found after reopening the tourniquet compared to the baseline measurement. ConclusionThe novel PAX tourniquet can be applied quickly and effectively by medical personnel without prior experience in applying a tourniquet.

Cerebral processing of sharp mechanical pain measured with arterial spin labeling.

IntroductionArterial spin labeling (ASL) is a functional neuroimaging technique that has been frequently used to investigate acute pain states. A major advantage of ASL as opposed to blood‐oxygen‐level‐dependent functional neuroimaging is its applicability for low‐frequency designs. As such, ASL represents an interesting option for studies in which repeating an experimental event would reduce its ecological validity. Whereas most ASL pain studies so far have used thermal stimuli, to our knowledge, no ASL study so far has investigated pain responses to sharp mechanical pain.MethodsAs a proof of concept, we investigated whether ASL has the sensitivity to detect brain activation within core areas of the nociceptive network in healthy controls following a single stimulation block based on 96 s of mechanical painful stimulation using a blunt blade.ResultsWe found significant increases in perfusion across many regions of the nociceptive network such as primary and secondary somatosensory cortices, premotor cortex, posterior insula, inferior parietal cortex, parietal operculum, temporal gyrus, temporo‐occipital lobe, putamen, and the cerebellum. Contrary to our hypothesis, we did not find any significant increase within ACC, thalamus, or PFC. Moreover, we were able to detect a significant positive correlation between pain intensity ratings and pain‐induced perfusion increase in the posterior insula.ConclusionWe demonstrate that ASL is suited to investigate acute pain in a single event paradigm, although to detect activation within some regions of the nociceptive network, the sensitivity of our paradigm seemed to be limited. Regarding the posterior insula, our paradigm was sensitive enough to detect a correlation between pain intensity ratings and pain‐induced perfusion increase. Previous experimental pain studies have proposed that intensity coding in this region may be restricted to thermal stimulation. Our result demonstrates that the posterior insula encodes intensity information for mechanical stimuli as well.

Cord Lining Mesenchymal Stem Cells Have a Modest Positive Effect on Angiogenesis in Hindlimb Ischemia

Purpose: We investigated the use of human Cord Lining Mesenchymal Stem Cells (CL-MSCs) (US Patent number 9,737,568), in a rabbit hindlimb ischemia model, and evaluated their potential in stimulating neovascularization. Allogenic human CL- MSCs could potentially be used to treat patients with lower limb ischemia and non-healing wounds.Methods: Twenty rabbits were divided into two separate groups. We created a hindlimb ischemia model surgically. At 21 and 49 days post-operatively, animals in the treatment group were injected with CL-MSCs (500,000 cells per 0.2 ml on each site) at 10 different sites (Quadriceps- 4 sites, Hamstrings- 4 sites and Calf-−2 sites) in the hindlimb muscles. The control group received only saline injection to the corresponding sites at the same time point as the treatment group. We then evaluated the effects of treatment on neovascularization by angiography, laser doppler perfusion imaging, as well as by histology. We evaluated the tissue samples for any signs of local immune reaction to the cell implantation. We also observed the rabbit clinically for any adverse effects after treatment.Results: We found a higher number of CD31 positive cells in the treatment group, with a greater number of capillaries found in the treated muscles. The Rectus Femoris demonstrated a median vessel count/muscle fiber of 0.121 for the treatment group, compared to 0.076 in the control group (median difference 0.04; 95% CI 0.001–0.11; p = 0.041). The Gastrocnemius demonstrated a median vessel count/muscle fiber of 0.175 for the treatment group, compared to 0.089 in the control group (median difference 0.087; 95% CI −0.006 to 0.234; p = 0.07). Blood perfusion quantification through Laser Doppler Perfusion Imaging (LDPI) also demonstrated a non-statistically significant increase in perfusion in favor of the treatment group. CL-MSCs demonstrated no toxicity associated morbidity and minimal local immune reaction to implantation.Conclusion: CL-MSCs have a positive effect on angiogenesis in a rabbit hindlimb ischemia model. This preliminary data is encouraging and paves the way for future large animal studies or for clinical trials.

Botulinum Toxin A and B Improve Perfusion, Increase Flap Survival, Cause Vasodilation, and Prevent Thrombosis: A Systematic Review and Meta-analysis of Controlled Animal Studies.

A systematic review and meta-analysis of case-control animal model studies will help clarify the vascular effects of botulinum toxin (BTX). Preferred Reporting Items of Systematic reviews and Meta-Analyses guidelines were used to identify all animal case-control studies published before September 13, 2020, evaluating the vascular effects of BTX. Primary parameters included the following: perfusion, flap survival, arterial and venous dilation, and arterial and venous thrombosis. Thirty-six studies with 1032 animals met the systematic review inclusion criteria. Twenty-nine studies had quantifiable data for statistical analysis. Statistically significant increases in perfusion with BTX over saline were detected within 1 day and sustained up to 8 weeks. The following represent weighted mean data from the meta-analysis. The administration of BTX has a 26% increase in both random pattern and pedicled flap survival area over controls. Botulinum toxin causes vasodilation. Botulinum toxin increases vessel diameter in arteries by 40% and in veins by 46% compared with saline controls. The administration of BTX reduces thrombosis by 85% in arteries and by 79% in veins compared with saline controls. Vascular effects were consistent across both BTX-A and BTX-B serotypes, multiple animal species, and various doses. No clear relationships between vascular effects and BTX pretreatment time were identified. Perivascular BTX administration intraoperatively or as a chemical delay pretreatment several days before surgery in multiple animal species and models shows multiple changes to the vascular system. Extrapolation of lessons learned from this systematic review and meta-analysis of animal models could expand research and clinical use of BTX in human vascular disease and surgery.

Эффективность комбинированной терапии негонококковых уретритов у мужчин

To carry out a comparative assessment of the efficiency of combination therapy for non-gonococcal urethritis (NGU) in men.a total of 124 patients with NGU and laboratory-confirmed urogenital infection were included in the study. The diagnostic methods included microscopy of urethral smear, real-time polymerase chain reaction (PCR) for the detection of uropathogens and laser Doppler flowmetry for evaluating the urethral microcirculation. All patients were randomized into three groups matched for age, clinical manifestations, and disease duration. Patients of the group 1 received targeted antibiotic therapy. In the group 2, local peloid therapy was added, while patients in group 3 additionally received vibromagnetotherapy. The control group consisted of 22 patients aged 18 to 55 years. The study included 2 visits, at the baseline and 4 weeks after the end of treatment.After the treatment, the frequency of microbiological cure was 89%. In the group 3, more pronounced improvement in main symptoms of NGU was observed. The analysis of microcirculation after treatment in the groups 2 and 3 showed a significant increase in perfusion and modulation of urethral blood flow and a decrease in venous congestion after combined therapy.The combined treatment, including antibiotic, peloid therapy, and vibromagnetotherapy, promotes more pronounced clinical improvement, restoration of urethral microcirculation and relief of inflammatory process in patients with NGU and can be recommended for routine clinical practice.

Evaluation of the Effect of Hyperbaric Oxygen Therapy on Tissue Perfusion in Patients with Delayed Severe Frostbite by MR Perfusion Imaging; Case Report

Introduction: In the cold damage of the extremity, frostbite is an emergency that can cause limb loss. Since frostbite cases did not occur very frequently and large randomized clinical trials were not sufficient, high-level treatment protocols could not be established. Nowadays, positive results have been obtained in case series in which hyperbaric oxygen (HBO) treatment is applied in frostbite.(1,2 In this case; perfusion magnetic resonance images (MRI) were evaluated before and after HBO treatment in the patient who developed significant edema in both lower limbs, necrosis in the foot and fingers due to frostbites. Methods: A 25-year-old male patient was brought to the hospital emergency department 6 days after contact with cold, a heavy snowfall while he was a shepherd. On physical examination of the patient, both lower extremities were cold, there was standing tension and edema, necrosis of the feet and fingers. In the Doppler USG, the blood flow in all vascular structures was triphasic and no obstruction was detected. Hyperbaric oxygen therapy was started on the second day of his inpatient medical treatment. Foot perfusion MRI was performed prior to HBO therapy.A significant increase in perfusion was observed in both feet. Patient underwent HBO therapy at 2.4 atmospheric pressure and perfusion MRI was performed 30 minutes after the first HBO treatment. After HBO treatment, both foot perfusion MRI areas were significantly reduced, compared with post-treatment. Necrotic tissues were debrided on the sole of the foot with medical treatment and 20 sessions of HBO treatment was completed. After 30 days from the beginning of the treatment, the third and fourth fingers of the left foot were amputated to the second and third fingers of the right foot. Results: Cold-induced frostbites and other localized injuries are common among soldiers, but can also be seen in laborers working outside, elderly and homeless people. Pathophysiology of frostbite-related injuries; is similar to ischemia reperfusion injury. The intra- and extracellular ice crystals formed after frostbite, cause endothelial damage in the arterioles and prolongs vasoconstriction and lead to necrosis. (3,4) This patient had complete skin involvement, subdermal plexus damage, hemorrhagic bullae and necrosis due to freezing. Although no vascular occlusion was detected, intense perfusion was observed in both feet. After HBO treatment, perfusion decrease was found in perfusion MRI. With HBO therapy, tissue oxygen pressure increased to over 400 mmHg, reducing neutrophil adhesion and contributing to normalization of vascular permeability.(5,6) Conclusion: In this case, it was observed that HBO therapy at 2.4 atmospheric pressure for 120 min significantly decreased the increase in reperfusion after frostbite. These results suggest that HBO treatment will reduce ischemia-reperfusion injury in the pathophysiology of frostbite and help medical treatment.Figure-3A, Perfusion MRI before HBO treatment. B, Perfusion MRI after HBO treatment.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Disclosure: Nothing to disclose

Hypnosis Influence on the Perfusion in Perforator Flaps in Early Postoperative Period: A Series of 18 Cases.

Introduction:In practice worldwide, there are experiences affecting different body functions via central control mechanisms with the help of psychotherapy methods. In plastic and reconstructive surgery, there is the experience of applying hypnosis, with the main goal of eliminating pain. The aim of this research is to study the impact of hypnosis on the perfusion level in perforator flaps in the early postoperative period, which could enhance flap survival.Patients and Methods:For studying the impact of hypnosis on blood circulation in perforator flaps, the analysis of a 18 cases has been conducted. All patients had hypnosis sessions on the second day after the reconstruction, and some had additional sessions on the third and fifth days. In the state of trance, the patient was given specially organized instructions aimed at improvement of perforator flap perfusion. Monitoring of microcirculation in the flap during hypnosis sessions was carried out using a Moor VMS-LDF1 Laser Doppler Perfusion and Temperature Monitor.Results:When applying hypnosis, the vast majority of patients had significant increases in perfusion as well as flap surface temperature rise. Most of the patients had significant increases in perfusion during the second part of the hypnosis session in synchrony with hypnosis instruction translation aimed at increasing perfusion.Conclusions:The results of our research cannot be distributed widely in medical practice, but, despite that, they illustrate the central nervous system influence on perforator flap perfusion. Including hypnosis in a medical protocol can contribute to increasing the effectiveness of flap surgery.

Accelerated Early Oxygen Kinetics in the Medial Gastrocnemius of PAD Patients During Light‐Intensity Plantar Flexion

Peripheral arterial disease (PAD) is a systemic vascular disease characterized by impaired skeletal muscle perfusion and mitochondrial respiration. Symptoms most often manifest during moderate‐intensity exercise, such as brisk walking. While the effect of PAD on oxygen transport after the onset of symptoms is well established, the contributions of convective and diffusive oxygen transport to early‐phase muscular work are less clear.PurposeThe aim of this study was to determine if oxygen transport kinetics are altered in the affected muscles of PAD patients during early stage, pre‐symptomatic exercise.MethodsTo answer this question, 5 patients with bilateral PAD and 5 healthy age‐matched controls performed graded dynamic plantar flexion exercise in the bore of a 3T MRI scanner. Exercise began at a workload of 2 kg and increased by 2 kg every 2 minutes for a total of 10 minutes, or until fatigue. Within each 2‐minute stage, subjects performed plantar flexion at a cadence of 30 contractions per minute for a total of 110 seconds. During the final 10 seconds of each stage, a custom fMRI sequence was used to simultaneously examine perfusion, T2* relaxation time (an index of tissue oxygenation), and venous oxygen saturation (SvO2) in the medial gastrocnemius. This imaging protocol consisted of a gradient‐recalled‐echo sequence interleaved into the post labeling delay of a pulsed‐arterial‐spin‐labeling sequence (acquisition time=3.2 seconds). Heart rate and blood pressure were also collected during the final minute of each stage using an automated MRI‐compatible brachial blood pressure cuff.ResultsAs has been reported elsewhere, the peak mean arterial pressure response was augmented in PAD patients (+14.34 mmHg, P=0.03). For fMRI data, multi‐factorial analyses of variance with repeated measures indicated significant group by time interactions for perfusion (F(1,8)=10.671, P=0.01) and T2* relaxation time (F(1,8)=5.285, P=0.05). After eliminating a matched‐pair due to the presence of an outlier, results also indicated a trend towards a significant group by time interaction for SvO2 (F(1,6)=5.629, P=0.055). These interactions can be explained by an initial attenuation in T2* in the PAD group compared to controls at 2 kg (mean diff=1.6±0.7 AU, P=0.05); which was followed by a significant increase in perfusion at 4 kg in the PAD group but not controls (mean diff=17.8±5.4 AU, P=0.01). SvO2 also tended to be lower at 4 kg in the PAD group compared to the control group (mean diff=13.2±5.5%, respectively, P=0.055).ConclusionsOur results indicate that oxygen transport kinetics are accelerated during the early phases of pre‐symptomatic plantar flexion exercise in PAD patients. We postulate that this may be a compensatory mechanism to the reduced total perfusion and mitochondrial capacity previously reported in PAD patients, and may also be partially mediated by the augmented pressor response to exercise.Support or Funding InformationThis research was supported NIH P01 HL134609 (PI‐Sinoway).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

ЛАЗЕРНАЯ ДОППЛЕРОВСКАЯ ФЛОУМЕТРИЯ В ДИАГНОСТИКЕ ТКАНЕВОЙ МИКРОЦИРКУЛЯЦИИ У ПРЕДСТАВИТЕЛЕЙ ЛЕГКОЙ АТЛЕТИКИ

Aim. The article deals with establishing functional peculiarities of tissue microcirculation in athletes during the different stages of the training cycle. Materials and methods. We examined 10 track-and-field athletes aged 19–22 (middle- and long-distance running) involved in aerobic trainings. All athletes possess the rank of Candidate for Master of Sport and the average training experience of 8 years. We studied tissue microhemodynamics with the help of laser doppler flowmetry using LAKK-01 (Lazma, Russia) laser analyzer of blood microcirculation. Results. At the preparatory period, we registered a low level of perfusion (3.38 ± 0.21 p.u.) and shunt blood flow (1.27 ± 0.08) and a high level of reserve capillary blood flow (525 ± 55 %) in comparison with the control group. At the beginning of the competitive period, we revealed a significant increase in perfusion (by 81 %) and a decrease in reserve blood flow (by 32 %) and neurogenic (by 16.7 %) and myogenic (by 15.4 %) tone of microvessels in comparison with the preparatory period. Prolonged competitive activities contributed to the increase in neurogenic (by 21.3 %) and myogenic (by 38.4 %) tone, shunt blood flow and T1/2 (by 22 seconds on the average). Conclusions. We established that regular physical loads result in a decrease in the number of functionally active capillaries at rest. The main blood flow passes through nutritive capillaries. At the beginning of the competitive activity, there is an increase in perfusion. As loads increase during the competitive period, microvessel stiffness increases. This contributes to a decrease of their sensitivity to vasodilating factors.

ЛАЗЕРНАЯ ДОППЛЕРОВСКАЯ ФЛОУМЕТРИЯ В ДИАГНОСТИКЕ ТКАНЕВОЙ МИКРОЦИРКУЛЯЦИИ У ПРЕДСТАВИТЕЛЕЙ ЛЕГКОЙ АТЛЕТИКИ

Aim. The article deals with establishing functional peculiarities of tissue microcirculation in athletes during the different stages of the training cycle. Materials and methods. We examined 10 track-and-field athletes aged 19–22 (middle- and long-distance running) involved in aerobic trainings. All athletes possess the rank of Candidate for Master of Sport and the average training experience of 8 years. We studied tissue microhemodynamics with the help of laser doppler flowmetry using LAKK-01 (Lazma, Russia) laser analyzer of blood microcirculation. Results. At the preparatory period, we registered a low level of perfusion (3.38 ± 0.21 p.u.) and shunt blood flow (1.27 ± 0.08) and a high level of reserve capillary blood flow (525 ± 55 %) in comparison with the control group. At the beginning of the competitive period, we revealed a significant increase in perfusion (by 81 %) and a decrease in reserve blood flow (by 32 %) and neurogenic (by 16.7 %) and myogenic (by 15.4 %) tone of microvessels in comparison with the preparatory period. Prolonged competitive activities contributed to the increase in neurogenic (by 21.3 %) and myogenic (by 38.4 %) tone, shunt blood flow and T1/2 (by 22 seconds on the average). Conclusions. We established that regular physical loads result in a decrease in the number of functionally active capillaries at rest. The main blood flow passes through nutritive capillaries. At the beginning of the competitive activity, there is an increase in perfusion. As loads increase during the competitive period, microvessel stiffness increases. This contributes to a decrease of their sensitivity to vasodilating factors.

The clinical utility of extracorporeal shock wave therapy for burn pruritus: A prospective, randomized, single-blind study

PurposesTo investigate the effect and mechanisms of extracorporeal shock wave therapy (ESWT) on burn scar pruritus. MethodsForty-six patients participated (experimental group, n=23; sham stimulation group, n=23). Patients had complaints of severe pruritus ranging from 5 to 10 on the visual analog scale. The experimental group received 1000–2000 shock waves for each treatment with 100 impulses/cm2, each with low-energy flux density (0.05–0.20mJ/mm2) and a 1-week interval between treatments for 3 weeks. The numerical rating scale (NRS), 5D-Itch Scale, and Leuven Itch Scale were evaluated immediately before ESWT and after the third session. Laser Doppler blood perfusion imaging (LDI) was performed immediately before ESWT and after the first and third sessions. ResultsIn the experimental group, mean NRS scores were 6.30±1.29 before therapy and 3.57±2.09 after the third session, and the difference was significant (p<0.001). NRS scores in the experimental group after the third ESWT were significantly decreased compared to those of the sham stimulation group (p=0.009). The duration, severity, and consequences scores of pruritus on the Leuven Itch Scale after the third ESWT were significantly decreased in the experimental group compared with the sham stimulation group (p=0.033, p=0.007, and p=0.009, respectively). The direction score on the 5-D Itch Scale after the third ESWT was significantly decreased in the experimental group compared to the sham stimulation group (p=0.033). After the first ESWT session and after 3 sessions, the burn area had a significant increase in perfusion according to LDI, compared with the scores before treatment in the experimental group (p=0.023 and p=0.013, respectively). ConclusionESWT is a non-invasive modality that significantly reduced burn-associated pruritus.

The role of perfusion and diffusion MRI in the assessment of patients affected by probable idiopathic normal pressure hydrocephalus. A cohort-prospective preliminary study

BackgroundInvasive tests measuring resistance to cerebral spinal fluid (CSF) outflow and the effect of temporary drainage of CSF are used to select candidates affected by idiopathic normal pressure hydrocephalus (iNPH) for shunt surgery. Neither test, however, completely excludes patients from treatment. Perfusion and diffusion magnetic resonance imaging (MRI) are non-invasive techniques that might be of value in selecting patients for surgical treatment and understanding brain changes in iNPH patients. The aim of this study was to understand the role of perfusion and diffusion MRI in selecting candidates for shunt surgery and to investigate the relationship between cerebral perfusion and possible microstructural changes in brain tissue before and after invasive tests, and after ventricular-peritoneal (VP) shunt implantation, to better clarify pathophysiological mechanisms underlying iNPH.MethodsTwenty-three consecutive patients with probable iNPH were included in this study. Patients underwent a clinical and neuroradiological evaluation before and after invasive tests, and after surgery. Only patients who showed a positive result in at least one of the invasive tests were submitted for VP shunt implantation. Perfusion and diffusion magnetic resonance imaging (MRI) was performed before and after invasive tests and after shunt surgery.ResultsThirteen patients underwent surgery and all showed clinical improvement after VP shunt implantation and a significant increase in perfusion in both periventricular white matter (PVWM) and basal ganglia (BG) regions. The 10 patients that did not have surgery showed after invasive tests, a significant reduction in perfusion in both PVWM and BG regions. Comparing the changes in perfusion with those of diffusion in positive patients we found a significant positive correlation in BG and a significant inverse correlation in PVWM area.ConclusionsPerfusion MRI is a non-invasive technique that could be useful together with invasive tests in selecting patients for surgical treatment. Furthermore, the relationship between perfusion and diffusion data could better clarify pathophysiological mechanisms underlying iNPH. In PVWM area we suggest that interstitial edema could reduce microvascular blood flow and interfere with the blood supply to these regions. In BG regions we suggest that a chronic hypoxic insult caused by blood hypo-perfusion produces a chronic cytotoxic edema. Both in PVWM and in BG regions, pathophysiological mechanisms could be modified after VP-shunt implantation.

Abstract P4-02-02: Increased tumor perfusion following treatment with trastuzumab as measured by contrast-enhanced ultrasound

Abstract Introduction: The primary purpose of this study is to determine if the order of dosing in standard-of-care (SOC) combination therapy for HER2+ breast cancer has an effect on the perfusion characteristics within the tumor. Improving the intratumoral delivery of cytotoxic systemic therapy is a significant challenge in advancing cancer treatment. Knowledge of the vascular changes following SOC treatments could enable optimizing their order and timing, potentially leading to significantly improved response. Currently, one SOC regimen for HER2+ breast cancer treatment is doxorubicin administered for 3-4 cycles prior to trastuzumab. Our goal is to quantitatively map the changes in perfusion in response to different combinations of trastuzumab plus doxorubicin treatment through imaging in a murine model of HER2+ breast cancer. Experimental Design: BT474 breast cancer cells (1×107) were subcutaneously implanted into mice (n = 12) and randomly assigned into three treatment groups: two doses of trastuzumab (10 mg/kg) followed by doxorubicin (1.5 mg/kg), doxorubicin prior to trastuzumab (same total drug dosage as group 1), and saline. After tumors reached ~225 mm3, animals were imaged with contrast-enhanced ultrasound (CEUS) (VisualSonics Vevo 770, Definity microbubbles) before treatment (day 0), and on days 1, 3, 4, and 7. Treatment occurred on days 0, 3 and 4. Percent change (from baseline, day 0 scans) of the CEUS signal intensity quantified from the functional vasculature (surrogate for vessel perfusion) following contrast injection were measured for each animal for each day. Tumors were extracted on day 7, and sectioned, paraffin-embedded, and stained with CD31, alpha-SMA and H&amp;E. Results: Tumors treated with trastuzumab initially exhibited a significant increase in CEUS signal intensity (from the functional vasculature) on day 1 compared to tumors initially treated with doxorubicin (p &amp;lt; 0.01). Additionally, compared to the control tumors, tumors treated with trastuzumab prior to doxorubicin revealed a significant increase in perfusion (change in signal intensity of functional vasculature) of contrast agent on days 3 (p = 0.01), 4 (p = 0.001) and day 7 (p &amp;lt; 0.01). There were no significant differences in the doxorubicin treated first group and the controls on any of the days (p &amp;gt; 0.25). Qualitative differences were noted between control and treated groups for alpha-SMA, no apparent differences were noted in microvessel density. Conclusion: Trastuzumab significantly improves a tumor's vascular perfusion in this HER2+ breast cancer model. Doxorubicin dosing prior to treatment with trastuzumab may potentially be hindering the intratumoral delivery of the subsequently delivered, targeted therapy. Improving the tumor's functional vasculature by altering the order of dosing of these combination therapies by giving trastuzumab prior to cytotoxic therapy has potential to enhance both the delivery and the effectiveness of these combination therapies. These data indicate a potential pathway to optimize therapeutic efficacy for individual HER2+ breast cancer patients. Citation Format: Sorace AG, Barnes SL, Quarles CC, McIntyre JO, Yankeelov TE. Increased tumor perfusion following treatment with trastuzumab as measured by contrast-enhanced ultrasound [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-02-02.

Pulmonary Perfusion Changes as Assessed by Contrast-Enhanced Dual-Energy Computed Tomography after Endoscopic Lung Volume Reduction by Coils

Background: Endoscopic lung volume reduction by coils (LVRC) is a recent treatment approach for severe emphysema. Furthermore, dual-energy computed tomography (DECT) now offers a combined assessment of lung morphology and pulmonary perfusion. Objectives: The aim of our study was to assess the impact of LVRC on pulmonary perfusion with DECT. Methods: Seventeen patients (64.8 ± 6.7 years) underwent LVRC. DECT was performed prior to and after LVRC. For each patient, lung volumes and emphysema quantification were automatically calculated. Then, 6 regions of interest (ROIs) on the iodine perfusion map were drawn in the anterior, mid, and posterior right and left lungs at 4 defined levels. The ROI values were averaged to obtain lung perfusion as assessed by the lung's iodine concentration (C_Lung, μg·cm^-3). The C_Lung values were normalized using the left atrial iodine concentration (C_LA) to take into account differences between successive DECT scans. Results: The 6-min walk distance (6MWD) improved significantly after the procedure (p = 0.0002). No lung volume changes were observed between successive DECT scans for any of the patients (p = 0.32), attesting the same suspended inspiration. After LVRC, the emphysema index was significantly reduced in the treated lung (p = 0.0014). Lung perfusion increased significantly adjacent to the treated areas (C_Lung/C_LA from 3.4 ± 1.7 to 5.6 ± 2.2, p < 0.001) and in the ipsilateral untreated areas (from 4.1 ± 1.4 to 6.6 ± 1.7, p < 0.001), corresponding to a mean 65 and 61% increase in perfusion, respectively. No significant difference was observed in the contralateral upper and lower areas (from 4.4 ± 1.9 to 4.8 ± 2.1, p = 0.273, and from 4.9 ± 2.0 to 5.2 ± 1.7, p = 0.412, respectively). A significant correlation between increased 6MWD and increased perfusion was found (p = 0.0027, R² = 0.3850). Conclusions: Quantitative analysis based on DECT acquisition revealed that LVRC results in a significant increase in perfusion in the coil-free areas adjacent to the treated ones, as well as in the ipsilateral untreated areas. This suggests a possible role for LVRC in the improvement of the ventilation/perfusion relationship.

Comparison of Laser Doppler and Laser-Assisted Indocyanine Green Angiography Prediction of Flap Survival in a Novel Modification of the McFarlane Flap

The McFarlane rat ischemic dorsal skin flap model has been commonly used for clinical vector studies, as well as the testing of noninvasive diagnostics. However, variability of this model secondary to flap contact with the wound bed has led many to question its validity. Here we present a novel modification to the McFarlane skin flap using sterile silicone. We also use this model to test the prognostic efficacy of laser-assisted indocyanine green (ICG) angiography and laser Doppler imaging (LDI). A 3 × 9-cm dorsal skin flap with a cranially based pedicle was created, centered 1 cm distal to the scapulae. The flap was undermined, and in one of the 2 groups, a sterile silicone sheet was placed onto the wound bed. All flaps were then reapproximated with sutures 1-cm intervals. Clinical assessment and perfusion imaging was performed immediately postoperative, and at 24, 48, and 72 hours postsurgery. Postoperative day 7 clinical assessment was obtained before euthanasia. A comparative study using silicone blocked versus unblocked models (n = 6 per group) showed that, clinically, both models had equivalent flap survival [8.5 (0.913) vs 9.5 (1.01) cm]. However, a statistically significant increase in perfusion in the mid-third of unblocked models was observed on POD3 [20.28% (2.7%) vs blocked 13.45% (2.5%), P < 0.05], with a similar increase in the distal third on POD7 [18.73% (2.064%) vs 10.91% (4.19%), P < 0.05]. A prognostic study comparing LDI and ICG angiography prediction of POD7 survival at early time points (n = 10) found that LDI underpredicted flap survival at early time points [84.2% (12.03%) on POD0, 87.35% (16.11%) on POD1]. In contrast, ICG was more proficient [100.1% (10.1%) on POD0]. We present a modification of the McFarlane skin flap model that results in similar clinical results, but with a noted reduction in perfusion inconsistencies noted in unblocked models. The ICG angiography is superior to LDI in predicting POD7 flap necrosis within the first 48 hours postinjury. Future work will focus on histologic validation of our model, and vector efficacy testing.

Bach1 Represses Wnt/β-Catenin Signaling and Angiogenesis.

Wnt/β-catenin signaling has an important role in the angiogenic activity of endothelial cells (ECs). Bach1 is a transcription factor and is expressed in ECs, but whether Bach1 regulates angiogenesis is unknown. This study evaluated the role of Bach1 in angiogenesis and Wnt/β-catenin signaling. Hind-limb ischemia was surgically induced in Bach1(-/-) mice and their wild-type littermates and in C57BL/6J mice treated with adenoviruses coding for Bach1 or GFP. Lack of Bach1 expression was associated with significant increases in perfusion and vascular density and in the expression of proangiogenic cytokines in the ischemic hindlimb of mice, with enhancement of the angiogenic activity of ECs (eg, tube formation, migration, and proliferation). Bach1 overexpression impaired angiogenesis in mice with hind-limb ischemia and inhibited Wnt3a-stimulated angiogenic response and the expression of Wnt/β-catenin target genes, such as interleukin-8 and vascular endothelial growth factor, in human umbilical vein ECs. Interleukin-8 and vascular endothelial growth factor were responsible for the antiangiogenic response of Bach1. Immunoprecipitation and GST pull-down assessments indicated that Bach1 binds directly to TCF4 and reduces the interaction of β-catenin with TCF4. Bach1 overexpression reduces the interaction between p300/CBP and β-catenin, as well as β-catenin acetylation, and chromatin immunoprecipitation experiments confirmed that Bach1 occupies the TCF4-binding site of the interleukin-8 promoter and recruits histone deacetylase 1 to the interleukin-8 promoter in human umbilical vein ECs. Bach1 suppresses angiogenesis after ischemic injury and impairs Wnt/β-catenin signaling by disrupting the interaction between β-catenin and TCF4 and by recruiting histone deacetylase 1 to the promoter of TCF4-targeted genes.

351. Gene Electrotransfer of pVEGF in a Porcine Model to Induce Angiogenesis and Improve Cardiac Function

Nonviral gene therapy is an attractive method for treating cardiovascular disease; however, achieving appropriate gene expression levels is often problematic. Gene electro transfer (GET) can be safely used to enhance expression. We have previously reported on establishing GET protocols to safely and effectively delivering plasmids encoding luciferase, green fluorescent protein or VEGFA directly to the heart in a porcine model. In the current study, we tested whether gene delivery of VEGF via GET could induce angiogenesis and improve cardiac function in a porcine ischemic model. Domestic farm pigs were anesthetized and intubated followed by median sternotomy to expose the heart. The left anterior descending coronary artery was partially tied off to induce localized ischemia. Animals received no treatment, injection of pVEGF or injection of pVEGF with electro transfer. Treatment was performed at four sites surrounding the ischemic region on the border of viable and ischemic myocardium. A SPY Intraoperative Perfusion Assessment System was utilized to determine the area of ischemia and quantify the approximate reduction in perfusion and to identify the area of ischemia before treatment. The animals were followed for seven weeks. Ultrasound evaluation and arteriograms were performed prior to surgery, post treatment, 2 weeks post treatment and 7 weeks post treatment. Arteriograms suggest the growth of blood vessels as early as 2 weeks. Spy analysis revealed significant increase in perfusion within the ischemic zone in animals treated with pVEGF +GET compared to controls. Echography showed improved cardiac output was significantly greater (p<0.03) 14 days post-infarct in GET treated animals compared to values immediately after surgery. Based on these results, gene delivery to the heart can be successfully accomplished using in vivo GET and evidence suggests the potential for a therapeutic effect.

Assessment of free microvascular flap perfusion by intraoperative fluorescence angiography in craniomaxillofacial surgery

Microsurgical tissue transfer represents a standard technique for reconstruction in craniomaxillofacial surgery. The transferred tissue is anastomosed to vessels of varying diameters and different physiological conditions. The aim of this study was to evaluate the blood flow in free flaps at their origin and compare this with the flow after reperfusion.In 24 patients undergoing microsurgical procedures (13 radial forearm free flaps (RFFF) and 11 parascapular/scapular free flaps (PSFF)), blood flow was evaluated by intraoperative fluorescence angiography after flap raising and again after reperfusion in the neck area (Flow800, Carl Zeiss AG, Oberkochen, Germany). Flow is expressed by the blood flow index (BFI), maximum intensity (MaxInt) and half-time to MaxInt (t1/2) and was measured in the flap pedicle itself, as well as in the supplying vessels.Following anastomosis of the free flaps in the head and neck area, both the arterial and the venous BFI and MaxInt significantly increased, whereas t1/2 decreased significantly. There was no significant difference in the perfusion parameters between RFFF and PSFF.Intraoperative fluorescence angiography is a reliable method for assessing the perfusion of free microvascular flaps. In the head and neck area, free flaps undergo a significant increase in perfusion but show no differences between varying flap types.