Nobuyoshi Azuma

Transfection of Human Hepatocyte Growth Factor Gene Ameliorates Secondary Lymphedema via Promotion of Lymphangiogenesis

Background— Lymphedema is a disorder of the lymphatic vascular system characterized by impaired lymphatic return and swelling of the extremities. Treatment for this disabling condition remains limited and largely ineffective. The goal of the present study was to investigate the therapeutic efficacy of hepatocyte growth factor (HGF) in animal models of lymphedema. Methods and Results— Immunofluorescent analysis demonstrated that canine primary lymphatic endothelial cells (cLECs) were positive for lymphatic-specific markers (vascular endothelial growth factor receptor-3, LYVE-1, podoplanin, and Prox1) and the HGF receptor c-Met. Treating cLECs with human recombinant HGF resulted in a dose-dependent increase in cell growth and migration and increased activity of extracellular signal-regulated kinase and Akt. In human LECs, c-Met also was expressed, and treatment with HGF increased cell growth and migration in a dose-dependent manner. Transfection of human HGF plasmid DNA in cLECs also increased the c-fos promoter activity. Furthermore, weekly HGF gene transfer in a rat tail lymphedema model by disruption of lymphatic vessels resulted in a decrease in lymphedema thickness. Although expression of the endothelial cell marker PECAM-1 was increased in both HGF- and vascular endothelial growth factor 165–injected groups, expression of LEC markers (LYVE-1 and Prox1) was increased only in the HGF-injected group. Conclusions— These data demonstrate that expression of HGF via plasmid transfer improves lymphedema via promotion of lymphangiogenesis. Further studies to determine the clinical utility of this approach would be of benefit to patients with lymphedema.

Factors related to postoperative delirium in patients with lower limb ischaemia: a prospective cohort study.

OBJECTIVES To preoperatively determine candidates at definitive risk of postoperative delirium (POD), we identified relevant factors in patients with arteriosclerosis obliterans who underwent bypass surgery. DESIGN A prospective cohort study. PATIENTS AND METHODS 299 patients (age ≥ 60 years) who underwent bypasses in 1995-2006 were enrolled. Cognitive impairment was assessed by the Revised Hasegawa Dementia Scale, the Confusion Assessment Method was also used, and severity was graded as Grade I-III (mild to severe) based on the Delirium Rating Scale. All patients were followed for 3 years. RESULTS POD occurred in 88 patients (29%), with a median age of 75 (10) years (IQR). Onset was 2 (1) days postoperatively, and a duration of 2 (2) days was observed. POD was hyperactive in 89% and was Grade I, II, and III in 11%, 68%, and 21% respectively. Multiple logistic regression analysis identified the following risk factors for POD: age ≥ 72 years (<0.0001), end-stage renal failure (0.001), multiple occlusive lesions (<0.0001), cognitive impairment (0.003), and critical limb ischaemia (0.034). The 3-year survival rate was similar when comparing POD and non-POD patients (84% vs. 88%, NS). CONCLUSIONS This study identified 5 risk factors for POD in patients undergoing bypasses for limb ischaemia. Long-term outcomes were similar when comparing the patients who experienced POD with those who did not.

Combined distal venous arterialization and free flap for patients with extensive tissue loss.

BACKGROUND We evaluated the mid-term outcome of distal venous arterialization (DVA) and the role of a combined free flap as a bridgehead for blood supply. METHODS In the past 5 years, nine patients with extensive tissue loss and lacking graftable distal arteries underwent DVA. These consisted of four primary DVAs, three combined DVA and free flap procedures, and two adjuvant DVAs for hemodynamically failed distal bypasses. After nine primary DVAs, three redo DVAs were performed for early failure. Etiologies were four Buerger disease and five arteriosclerosis obliterans, including three dialysis patients. RESULTS Among the nine DVA cases, there were five primary failures: two underwent amputation, two had successful redo DVA, and the remaining one did not require redo DVA. Primary patency, secondary patency, and limb salvage rates were 44.4%, 55.6%, and 77.8%, respectively. The postoperative period was 1-36 months (median 12). Angiography demonstrated DVA was effective in the early period, and development of collaterals or a capillary network from the free flap replaced the DVA function in the intermediate period. CONCLUSION DVA can be effective as a procedure for limb salvage in patients without graftable distal arteries, and a combined free flap is effective and functions as a bridgehead for blood supply to the ischemic zone.

Absence of Preceding Intermittent Claudication and its Associated Clinical Freatures in Patients with Critical Limb Ischemia

AIM The current study investigated how prevalent the absence of a prior history of intermittent claudication would be in patients with critical limb ischemia (CLI) and examined the associated clinical features. METHODS We used a database of 559 Japanese CLI patients participating in a multicenter prospective study. A history of intermittent claudication prior to CLI onset was surveyed at registration. The 95% confidence interval (CI) of its prevalence was calculated using the Clopper-Pearson method. Logistic regression analysis was performed to assess the association between the clinical features and the absence of preceding intermittent claudication. RESULTS The study subjects were 73±10 years old and 67% were male. Tissue loss occurred in 82% of this population. The prevalence of the absence of prior intermittent claudication was 50% [95% CI: 46-55%]. In multivariate logistic regression analysis, a non-ambulatory status, diabetes mellitus, and regular dialysis were significantly and independently associated with the lack of a prior history of intermittent claudication (all p＜0.05). Indeed, the presence of these features was associated with a higher prevalence of the lack of the history. Regular dialysis, but not non-ambulatory status or diabetes mellitus, lost its statistical significance after further adjustment for the presence of isolated infrapopliteal lesions, whereas the presence of isolated infrapopliteal lesions itself was significantly associated with a lack of prior intermittent claudication. CONCLUSIONS The absence of a prior history of intermittent claudication was prevalent in CLI patients. Patients with a non-ambulatory status, diabetes mellitus, and regular dialysis were more likely to lack a prior history of intermittent claudication.

Surgical reconstruction versus peripheral intervention in patients with critical limb ischemia – a prospective multicenter registry in Japan: The SPINACH study design and rationale

Clinical evidence reflecting the recent development of treatments for patients with critical limb ischemia is mandatory to guide the decision-making process for the selection of revascularization procedures, including bypass or endovascular treatment. This paper describes the protocol for a clinical study that is designed and carried out by both vascular surgeons and interventional cardiologists collaboratively, and will investigate current treatment for critical limb ischemia in Japan. The registry aimed to recruit approximately 450 patients with critical limb ischemia, including approximately 150 patients who underwent bypass surgery and approximately 300 patients who underwent endovascular treatment in 23 institutions. The primary endpoint of this study is amputation-free survival at 36 months, and the secondary endpoints include major amputation, cardiovascular events, re-intervention, death, ulcer healing, and their composite outcomes. The SPINACH study aims to provide a suitable patient model for each revascularization procedure, bypass and endovascular treatment, and will expound on the role of each approach for critical limb ischemia treatment (Clinical trial registration UMIN000007050).

Clinical Results of Cystic Excision for Popliteal Artery Cystic Adventitial Disease: Long-term Benefits of Preserving the Intact Intima

Surgical treatment for popliteal artery cystic adventitial disease (PACAD) is still controversial. PACAD often occurs in young or middle-aged adults. Therefore, the maintenance of graft patency for very long periods is a concern if a prosthesis is used. Because the intima is intact in PACAD patients with popliteal artery stenosis, a treatment that preserves the healthy intima is ideal. We describe the cases of 3 patients who underwent cystic excision for PACAD with severe stenosis. No recurrence was observed for up to 11 years, and these long-term results revealed that cystic excision could be reconsidered as one of the first-line therapeutic methods.

Cyclic adenosine monophosphate response-element binding protein activation by mitogen-activated protein kinase-activated protein kinase 3 and four-and-a-half LIM domains 5 plays a key role for vein graft intimal hyperplasia

OBJECTIVE Intimal hyperplasia (IH) is the main cause of vein graft stenosis or failure after bypass surgery. Basic investigations are proceeding in an animal model of mechanically desquamated arteries, and numerous molecules for potential IH treatments have been identified; however, neither insights into the mechanism of IH nor substantially effective treatments for its suppression have been developed. The goals of the present study are to use human vein graft samples to identify therapeutic target genes that control IH and to investigate the therapeutic efficacy of these candidate molecules in animal models. METHODS Using microarray analysis of human vein graft samples, we identified two previously unrecognized IH-related genes, mitogen-activated protein kinase-activated protein kinase 3 (MAPKAPK3) and four-and-a-half LIM domains 5 (FHL5). RESULTS Transfer of either candidate gene resulted in significantly elevated vascular smooth muscle cell (VSMC) proliferation and migration. Interestingly, cotransfection of both genes increased VSMC proliferation in an additive manner. These genes activated cyclic adenosine monophosphate response-element (CRE) binding protein (CREB), but their mechanisms of activation were different. MAPKAPK3 phosphorylated CREB, but FHL5 bound directly to CREB. A CREB dominant-negative protein, KCREB, which blocks its ability to bind CRE, repressed VSMC proliferation and migration. In a wire-injury mouse model, gene transfer of KCREB plasmid significantly repressed IH. In this vessel tissue, CRE-activated gene expression was repressed. Furthermore, we confirmed the changes in MAPKAPK3 and FHL5 expression using vein graft samples from eight patients. CONCLUSIONS We successively identified two previously unrecognized IH activators, MAPKAPK3 and FHL5, using human vein graft samples. Gene transfer of KCREB repressed IH in an animal model. Inhibition of CREB function is a promising gene therapy strategy for IH.

Cerebrovascular Disease and Intracranial Artery Stenosis in Patients with Symptomatic Peripheral Artery Disease

BACKGROUND Patients with symptomatic peripheral artery disease (PAD) have an elevated prevalence of internal carotid artery (ICA) stenosis and cerebral infarction, although the correlations between the severity of PAD and cerebral infarction, cerebral white matter lesion (WML), or intracranial or extracranial artery stenosis are unclear. METHODS We evaluated the prevalence of cardiovascular risk factors, cerebral infarction, and WML on magnetic resonance imaging and intracranial and extracranial carotid artery stenoses on magnetic resonance angiography in patients with symptomatic PAD (n = 136; males/females [M/F] 109/27) and a control group comprised of patients without PAD (n = 92; M/F 57/35). PAD was classified by Fontaine stage (stage II, n = 46; stage III, n = 20; stage IV, n = 70). Cerebral infarctions were classified into symptomatic or asymptomatic groups. WMLs were evaluated according to Fazekas stage. Artery stenosis was classified as normal (no stenosis), mild (stenosis <50%), moderate (stenosis ≥ 50%), severe (tight stenosis), and obstruction on magnetic resonance angiography. RESULTS Diabetes mellitus (DM), dyslipidemia, coronary artery disease (CAD), and chronic kidney disease (CKD), as well as symptomatic cerebral infarction and WML, were more frequent in patients with Fontaine III/IV PAD than without PAD. The prevalence rates of cerebral infarction and WML in patients with Fontaine stage II PAD were between those of the control and Fontaine III/IV PAD patients. Supraclinoid and cervical ICA stenoses (>50%) were more frequent in patients with Fontaine stage IV PAD than without PAD. CONCLUSIONS Our results indicate that patients with advanced PAD have an increased prevalence of symptomatic cerebral infarction, WML, and intracranial and cervical ICA stenosis as well as DM, CAD, and CKD.

Recent Progress of Bypass Surgery to the Dialysis-Dependent Patients with Critical Limb Ischemia

According to expansion of dialysis-dependent population, more than half of patients with critical ischemic limbs are dialysis-dependent in Japan. Although patients with end-staged renal disease are well-known as poor life prognosis, well-managed dialysis patients in Japan can survive much longer compared to dialysis patients in the United States and Europe. Therefore, some dialysis patients can enjoy the long-term benefits of bypass surgery. To decide the indication of bypass surgery, patient’s general condition, nutrition status, and vein availability are more important rather than arterial disease anatomy. Ultrasound guided nerve block anesthesia blocking both sciatic and femoral nerve is contributing greatly to quick postoperative recovery of high risk patients. Preoperative ultrasound examination also contribute to not only vein mapping but also find out the graftable segment of artery. The selection of distal target should be decided based on the degree of arterial disease (luminal surface as well as wall calcification), and arterial run-off. Several tips regarding anastomosis to heavily calcified artery have been established including how to create bloodless operative field without arterial clamps. Adequate wound management after bypass surgery is also important. Detection of deep infection such as osteomyelitis and the adequate treatment may avoid major amputation of salvageable limbs. In the era of endovascular treatment, the evidences guiding how to select dialysis patients suitable for bypass surgery are awaiting. (This is a translation of Jpn J Vasc Surg 2017; 26: 33–39.)

Effect of a Low-Intensity Pulsed Ultrasound Device, SX-1001, on Clinical Symptoms in Buerger Disease With Limb Ischemia.

Buerger disease is a rare disease of unknown etiology and cannot be treated by bypass surgery or percutaneous re-endovascularization. Although the need for effective limb ischemia prevention strategies is increasingly being recognized, effective preventative strategies are insufficient. The aim of this study using a new pulsed ultrasound device, SX-1001, is to determine whether treatment using SX-1001 can mitigate rest pain and improve blood supply to ischemic legs in patients with Buerger disease. This study is a multicenter, double-blinded, parallel randomized clinical trial testing the efficacy and safety of SX-1001. Treatment using SX-1001 is expected to result in reduction of the visual analog scale score for pain in Buerger disease patients who have Fontaine stage III. A total of 44 patients from 20 hospitals in Japan will be enrolled. The primary endpoint of the trial is a change in rest pain intensity on the visual analog scale score from baseline to 24 weeks. This trial will be the first to show the safety and efficacy of low-intensity pulsed ultrasound using SX-1001 for clinical symptoms in patients with Buerger disease. Low-intensity pulsed ultrasound may be a new therapy for limb ischemia. Ethical approval has been obtained from each of the participating institutes. Study findings will be disseminated through peer-reviewed journals and at scientific conferences.This study is registered at UMIN Clinical Trial Registry (UMIN000014757).