Effectiveness of Repetitive Hyperbaric Oxygen Therapy for Chronic Limb-Threatening Ischemia.

BACKGROUND: Lower extremity artery disease is strongly associated with morbidity and is typically addressed through revascularization interventions. We assessed the clinical outcomes of patients with chronic limb-threatening ischemia (CLTI) without revascularization who did and did not undergo repetitive hyperbaric oxygen therapy (HBOT). METHODS: Between April 2002 and March 2017, the records of 58 patients with CLTI (Rutherford classification 4 in 19% and 5 in 81%) were evaluated retrospectively. HBOT was performed at 2.8 atm of oxygen (HBOT group). The control group included those who could not continue HBOT and historical controls. Patients in poor general health or with an indication for revascularization therapy were excluded. We examined major adverse events (MAEs) and limb salvage rates. Independent predictors and risk stratification were analyzed using a multivariate regression analysis. RESULTS: The mean age was 71±13 years. Of all patients, 67% had diabetes and 43% were undergoing hemodialysis. The mean follow-up period was 4.3±0.8 years. The overall survival rate was 84.5% and 81.0% at 1 and 3 years, respectively. The Cox regression analysis indicated that high body mass index (odds ratio [OR]: 0.86; 95% confidence interval [CI]: 0.76-0.97; p=0.01), well-nourished (OR: 1.21; 95% CI: 1.01-1.45), and HBOT (OR: 0.05; 95% CI: 0.01-0.26; p<0.001) independently predicted absence of MAEs. For major limb amputation, the ankle-brachial index (OR: 0.2; 95% CI: 0.05-0.86; p=0.03) and HBOT (OR: 0.04; 95% CI: 0.004-0.32; p=0.003) were independent predictors. CONCLUSIONS: Repetitive, stand-alone HBOT was associated with MAE-free survival and limb salvage in patients with CLTI.

Imaging Angiogenesis Using 99mTc-Macroaggregated Albumin Scintigraphy in Patients with Peripheral Artery Disease.

UNLABELLED: One problem of vascular angiogenesis therapy is the lack of reliable methods for evaluating blood flow in the microcirculation. We aimed to assess whether (99m)Tc-macroaggregated albumin perfusion scintigraphy ((99m)Tc-MAA) predicts quantitated blood flow after therapeutic angiogenesis in patients with peripheral artery disease. METHODS: Forty-six patients with peripheral artery disease were treated with bone marrow mononuclear cell implantation (BMCI). Before and 4 wk after BMCI, blood flow was evaluated via transcutaneous oxygen tension (TcPO2), ankle-brachial index, intravenous (99m)Tc-tetrofosmin perfusion scintigraphy ((99m)Tc-TF), and intraaortic (99m)Tc-MAA. RESULTS: Four weeks after BMCI, TcPO2 improved significantly (20.4 ± 14.4 to 36.0 ± 20.0 mm Hg, P < 0.01), but ankle-brachial index did not (0.65 ± 0.30 to 0.76 ± 0.24, P = 0.07). Improvement in (99m)Tc-TF count (0.60 ± 0.23 to 0.77 ± 0.29 count ratio/pixel, P < 0.01) and (99m)Tc-MAA count (5.21 ± 3.56 to 10.33 ± 7.18 count ratio/pixel, P = 0.02) was observed in the foot region but not the lower limb region, using both methods. When these data were normalized by subtracting the pixel count of the untreated side, the improvements in (99m)Tc-TF count (-0.04 ± 0.26 to 0.08 ± 0.32 count ratio/pixel, P = 0.04) and (99m)Tc-MAA count (1.49 ± 3.64 to 5.59 ± 4.84 count ratio/pixel, P = 0.03) in the foot remained significant. (99m)Tc-MAA indicated that the newly developed arteries were approximately 25 µm in diameter. CONCLUSION: BMCI induced angiogenesis in the foot, which was detected using (99m)Tc-TF and (99m)Tc-MAA. (99m)Tc-MAA is a useful method to quantitate blood flow, estimate vascular size, and evaluate flow distribution after therapeutic angiogenesis.

Low-energy extracorporeal shock wave therapy improves microcirculation blood flow of ischemic limbs in patients with peripheral arterial disease: pilot study.

BACKGROUND: Because direct application of low-energy shock waves induces angiogenesis, we investigated the safety and efficacy of this new therapy to develop a noninvasive method of repeatable therapeutic angiogenesis for treating peripheral arterial disease (PAD). SUBJECTS AND METHODS: The subjects were 10 patients who had symptomatic PAD and limited ischemia in a below-the-knee artery. Low-energy shock waves were directly applied to the calf muscles 6 times every other day. Intracorporeal changes were evaluated with ultrasonography to determine adverse effects of therapy. To assess blood flow of the microcirculation, transcutaneous oxygen tension (TcPO2), skin perfusion pressure (SPP), and (99m)technetium-tetrofosmin ((99m)Tc-TF) scintigraphy were performed before and after therapy. The TcPO2 was measured while subjects inhaled pure oxygen (maximum TcPO2). The (99m)Tc-TF perfusion index was determined as a ratio of uptake in muscle to that in the brain (control) for quantitative analysis. RESULTS: No adverse effects were noted in any patient. Maximum TcPO2 values increased significantly on the calf (57.3±28.4 to 71.0±14.5 mm Hg, p=0.044) and the dorsum of the foot (52.2±21.8 to 76.1±17.9 mm Hg, p=0.012). The SPP tended to increase after therapy on the dorsum and plantar surfaces of the foot, but the differences were not significant. The (99m)Tc-TF perfusion index in the foot significantly increased (0.48±0.09 to 0.61±0.12, p=0.0013), but that in the leg did not change. CONCLUSION: We have demonstrated that low-energy shock wave therapy is safe and can restore blood flow in the microcirculation in patients with symptomatic PAD.

Therapeutic vascular angiogenesis for intractable macroangiopathy-related digital ulcer in patients with systemic sclerosis: a pilot study.

OBJECTIVE: SSc causes intractable ischaemic ulcers. To avoid major amputation, we examined the safety and efficacy of therapeutic vascular angiogenesis for digital ulcers due to SSc. METHODS: A single-centre, open-label pilot study was conducted in patients with an ischaemic digital ulcer [n = 40, mean age 65 years (s.d. 8), Rutherford class III-5 or III-6) due to lcSSc (n = 11) or arteriosclerosis obliterans (ASO; n = 29). Bone marrow mononuclear cells (0.4-5.1 × 10(10) cells in total) were administered into the ischaemic limbs. We evaluated short-term safety and efficacy by means of a pain scale, (99m)Tc-tetrofosmin scintigraphy and transcutaneous oxygen tension (TcPO2) before and 4 weeks after treatment. Also, the 2-year outcome was compared. RESULTS: There was a case of amputation in each group within 4 weeks after therapy. The pain scale significantly decreased in both groups [lcSSc 93 mm (s.d. 9) to 11 (s.d. 16), P < 0.01; ASO 77 mm (s.d. 22) to 16 (s.d. 13), P < 0.01] and TcPO2 significantly improved [lcSSc 9.0 mmHg (s.d. 9) to 35 (s.d. 14), P < 0.01; ASO 18 mmHg (s.d. 10) to 29 (s.d. 21), P < 0.05). At the 2-year follow-up, the limb amputation rate was 9.1% in lcSSc and 20.7% in ASO (P = 0.36), while the recurrence rate was 18.2% in lcSSc and 17.2% in ASO (P = 0.95). All-cause mortality was 27.3% in lcSSc and 17.2% in ASO (P = 0.65). CONCLUSION: In patients with lcSSc, bone marrow mononuclear cell implantation provides clinical benefit and is safe, without major adverse reactions, and may become an effective strategy. TRIAL REGISTRATION: UMIN-CTR, http://www.umin.ac.jp/ctr/index-j.htm, no. UMIN000004112.

Controlled-release basic fibroblast growth factor for peripheral artery disease: comparison with autologous bone marrow-derived stem cell transfer.

OBJECTIVE: We examined the safety and efficacy of controlled-release basic fibroblast growth factor (b-FGF) for peripheral artery disease (PAD), compared with autologous bone marrow mononuclear cell implantation (BMCI). BACKGROUND: We recently developed a b-FGF-incorporated biodegradable hydrogel that enables slow-releasing drug delivery system. METHODS: PAD patients were divided into a b-FGF group (n=10) and BMCI group (n=15). Injection of gelatin hydrogel containing 600 µg b-FGF or BMCI (0.4-5.1×10(10) cell) was performed. Visual analog pain scale (VAS), (99m)technetium-tetrofosmin (Tc-TF) scintigraphy, transcutaneous oxygen tension (TcPO(2)), and ankle-brachial index (ABI) were evaluated before and 4 weeks after each treatment, and 2-year prognosis was determined. RESULTS: VAS (b-FGF 67±15 to 4±5, p<0.01, BMCI 67±42 to 5±9 mm, p<0.01) and TcPO(2) (b-FGF 16±14 to 47±17, p<0.01, BMCI 13±13 to 37±21 mmHg, p<0.01) were significantly improved in both groups. Tc-TF and ABI were not changed. Prognosis was similar between the groups (b-FGF 91%, BMCI 80%, NS). CONCLUSION: Controlled-release b-FGF is as safe as BMCI, and its efficacy appears to be comparable. Thus, this therapy may be an alternative to BMCI.

The incidence of deep vein thrombosis in Japanese patients undergoing endoscopic submucosal dissection.

BACKGROUND: Endoscopic submucosal dissection (ESD) is more invasive than other common endoscopic procedures and may increase the risk for deep vein thrombosis (DVT)/pulmonary embolism. The incidence of DVT/pulmonary embolism after ESD has not been adequately studied. OBJECTIVE: To evaluate DVT incidence and disease-specific features of D-dimer levels in ESD patients. DESIGN: Prospective cohort study. SETTING: Single academic center. PATIENTS: This study involved 60 patients with superficial gastric neoplasms indicated for ESD. INTERVENTION: For all patients who underwent ESD, ultrasonography of the lower limbs was performed to detect DVT the day after ESD. D-dimer levels were measured 3 times: before ESD, immediately after ESD, and the day after ESD. MAIN OUTCOME MEASUREMENTS: DVT incidence after ESD. RESULTS: The DVT incidence was 10.0% (6/60). At all 3 time points, D-dimer measurements were higher in patients with DVT than in patients without DVT. According to receiver operating characteristic curve analysis, the resulting cut-off value of the D-dimer level the day after ESD was 1.9 µg/mL (sensitivity 83.3%; specificity 79.6%) for ESD patients, with superior association to pre-ESD or immediately after ESD. In univariate analyses, high D-dimer levels the day after ESD and the presence of comorbidities were significantly associated with DVT development. LIMITATIONS: Single center and small number of patients. CONCLUSION: ESD procedures have a moderate risk for venous thromboembolism. In patients undergoing ESD, D-dimer levels, especially on the day after ESD, may have specific features associated with DVT development.

Prediction of limb salvage after therapeutic angiogenesis by autologous bone marrow cell implantation in patients with critical limb ischemia.

PURPOSE: Despite advances in therapeutic angiogenesis by bone marrow cell implantation (BMCI), limb amputation remains a major unfavorable outcome in patients with critical limb ischemia (CLI). We sought to identify predictor(s) of limb salvage in CLI patients who received BMCI. MATERIALS AND METHODS: Nineteen patients with CLI who treated by BMCI were divided into two groups; four patients with above-the-ankle amputation by 12 weeks after BMCI (amputation group) and the remaining 15 patients without (salvage group). We performed several blood-flow examinations before BMCI. Ankle-brachial index (ABI) was measured with the standard method. Transcutaneous oxygen tension (TcPO2) was measured at the dorsum of the foot, in the absence (baseline) and presence (maximum TcPO2) of oxygen inhalation. (99m)technetium-tetrofosmin ((99m)Tc-TF) perfusion index was determined at the foot and lower leg as the ratio of brain. RESULTS: Maximum TcPO2 (p = 0.031) and (99m)Tc-TF perfusion index in the foot (p = 0.0068) was significantly higher in the salvage group than in the amputation group. Receiver operating characteristic (ROC) curve analysis identified maximum TcPO2 and (99m)Tc-TF perfusion index in the foot as having high predictive accuracy for limb salvage. CONCLUSION: Maximum TcPO2 and (99m)Tc-TF perfusion index in the foot are promising predictors of limb salvage after BMCI in CLI.

Therapeutic angiogenesis by controlled-release fibroblast growth factor in a patient with Churg-Strauss syndrome complicated by an intractable ischemic leg ulcer.

Churg-Strauss syndrome (CSS) causes necrotizing vasculitis affecting small- to medium-sized arteries, mainly in the lungs, gastrointestinal system, heart, kidneys, and skin. Skin lesions sometimes ulcerate because of severe ischemia and become intractable when complicated by bacterial infection. We report a rare case of CSS, characterized by a nonhealing ischemic skin ulcer of the right calf with bacterial infection resistant to antibiotics. After sterile maggot debridement therapy, 2 skin autografts failed. Subsequently, a slow-release formula of basic fibroblast growth factor incorporated in biodegradable gelatin hydrogel was administered into the calf muscles to induce vascular regeneration. The ulcer eventually healed with no recurrence. This report describes the use of controlled-release basic fibroblast growth factor for an ischemic leg ulcer in a patient with CSS, suggesting a possible therapeutic role of this novel neovascularization therapy in treating severe skin lesions complicating autoimmune vasculitis syndromes.

Chronic direct stimulation of adenylyl cyclase induces cardiac desensitization to catecholamine and beta-adrenergic receptor downregulation in rabbits.

Chronic stimulation of beta-adrenergic receptors (betaARs) induces betaAR downregulation. However, it is not known whether continuous activation of adenylyl cyclase without direct stimulation of betaARs leads to receptor downregulation. This study investigated the effects of chronic stimulation of adenylyl cyclase with colforsin, on hemodynamic variables, and on myocardial betaAR density. In all, 55 rabbits received intravenous colforsin (1.6 microg/kg/min, n = 20), isoproterenol (ISO; 0.4 microg/kg/min, n = 16), or saline (n = 19) for two weeks. After chronic drug administration, responses of systolic (Delta% peak LV +dP/dt) and diastolic function (Delta% peak LV -dP/dt), and heart rate (Delta% heart rate), to acute administration of ISO (0.05 to 0.2 microg/kg/min) or colforsin (5 to 20 nmol/kg/min) were decreased compared to those before chronic administration. betaAR density in the colforsin group (69.8 +/- 13.8 fmol/ml protein) was less than that in the saline group (79.8 +/- 15.0 fmol/ml protein, P < 0.05), but was greater than that in the ISO group (56.3 +/- 8.4 fmol/ml protein, P < 0.05). Thus, chronic direct stimulation of adenylyl cyclase elicited systolic and diastolic functional desensitization to betaAR stimulation or adenylyl cyclase stimulation, and myocardial betaAR downregulation.

Type 5 adenylyl cyclase disruption alters not only sympathetic but also parasympathetic and calcium-mediated cardiac regulation.

In a genetically engineered mouse line with disruption of type 5 adenylyl cyclase (AC5-/-), a major cardiac isoform, there was no compensatory increase in other isoforms of AC in the heart. Both basal and isoproterenol (ISO)-stimulated AC activities were decreased by 30% to 40% in cardiac membranes. The reduced AC activity did not affect cardiac function (left ventricular ejection fraction [LVEF]) at baseline. However, increases in LVEF after ISO were significantly attenuated in AC5-/- (P<0.05, n=11). Paradoxically, conscious AC5-/- mice had a higher heart rate compared with wild-type (WT) mice (613+/-8 versus 523+/-11 bpm, P<0.01, n=14 to 15). Muscarinic agonists decreased AC activity, LVEF, and heart rate more in WT than in AC5-/-. In addition, baroreflex-mediated, ie, neuronally regulated, bradycardia after phenylephrine was also attenuated in AC5-/-. The carbachol-activated outward potassium current (at -40 mV) normalized to cell capacitance in AC5-/- (2.6+/-0.4 pA/pF, n=16) was similar to WT (2.9+/-0.3 pA/pF, n=27), but calcium (Ca2+)-mediated inhibition of AC activity and Ca2+ channel function were diminished in AC5-/-. Thus, AC5-/- attenuates sympathetic responsiveness and also impairs parasympathetic and Ca2+-mediated regulation of the heart, indicating that those actions are not only regulated at the level of the receptor and G-protein but also at the level of type 5 AC.

Gender differences on the effects of aging on cardiac and peripheral adrenergic stimulation in old conscious monkeys.

We examined the effects of gender and aging on cardiac and peripheral hemodynamic responses to beta-adrenergic receptor (beta-AR) stimulation in young (male = 5.9 +/- 0.4 yr old and female = 6.5 +/- 0.7 yr old) and old (male = 19.8 +/- 0.7 yr old and female = 21.2 +/- 0.2 yr old) conscious monkeys (Macaca fascicularis), chronically instrumented for measurements of left ventricular (LV) and arterial pressures as well as cardiac output. Baseline LV pressure, the first derivative of LV pressure (LV dP/dt), cardiac index, mean arterial pressure, total peripheral resistance (TPR), and heart rate in conscious monkeys were not different among the four groups. Increases in LV dP/dt in response to 0.1 microg/kg isoproterenol (Iso) were diminished (P < 0.05) in old males (+99 +/- 11%) compared with young males (+194 +/- 18%). In addition, the inotropic responses to norepinephrine (NE) and forskolin (FSK) were significantly depressed (P < 0.05) in old males. Iso-induced reductions of TPR were less (P < 0.05) in old males (-28 +/- 2%) than in young males (-49 +/- 2%). The changes of TPR in response to NE and FSK were also significantly attenuated (P < 0.05) in old males. However, the LV dP/dt responses to BAY y 5959 (15 microg. kg-1. min-1), a Ca2+ channel promotor independent of beta-AR signaling, were not significantly different between old and young males. In contrast to results in male monkeys, LV dP/dt and TPR responses to Iso, NE, and FSK in old females were similar to those observed in young females. Thus both cardiac contractile and peripheral vascular dynamic responses to beta-AR stimulation are preserved in old female but not old male monkeys. This may explain, in part, the reduced cardiovascular risk in the older female population.