Growth rates of abdominal aortic aneurysms in Japanese patients observed in one institute.

AIM: The aim of this paper was to investigate the growth rate of abdominal aortic aneurysms (AAA) in Japanese patients. METHODS: We retrospectively studied patients conservatively followed with infrarenal AAA in terms of AAA diameter measured using computed tomography (CT) in our hospital between 1999 and 2009. The AAA surgery criterion in our institute was a diameter ≥ 5.0 cm or a growth rate ≥5 mm/year. We estimated operation-free ratios by initial AAA diameter and changes in AAA growth rates. Patients with an initial AAA diameter < 5.0 cm were divided into 2 groups. Patients with AAA that met the criteria for surgery were classified into the expansion group, and those remaining into the non-expansion group. Their AAA growth rates were compared. RESULTS: The group consisted of 124 patients (average age, 73.7±8.6 years (range 54-92)) who had at least 2 recorded AAA measurements. The average follow-up period was 3.0±2.2 years (range 0.3-10.2). There were no cases of rupture during follow-up. Twenty-six patients (21.0%) underwent surgery (open replacement [N.=20]; endovascular abdominal aneurysm repair [N.=6]). The growth rate determined from the initially measured diameter was significantly faster in AAAs measuring 5.0-5.4 cm than in AAAs measuring 4.5-4.9 cm (P=0.01). More than 90% of patients with an initial AAA diameter <5.0 cm were observed conservatively for 2 years or more. However, more than half of the patients with an initial AAA diameter ≥4.0 cm needed surgery within 5 years. The growth rates of AAAs for each size during growth were significantly faster when the AAA diameter was 4.5-4.9 cm than when it was 4.0-4.4 cm (P=0.006), and when the AAA diameter was 5.0-5.4 cm than when it was 4.5-4.9 cm (P = 0.009). The expansion and non-expansion groups consisted of 38 (34.2%) and 73 (75.8%) patients, respectively. The AAA growth rate in the expansion group was significantly faster than that in the non-expansion group (3.4±2.2 mm/year vs. 1.4±1.3 mm/year, P=0.0001). CONCLUSION: It may be considered that the appropriate indication for AAA repair is defined by a diameter of 5.0 cm for Japanese patients. Patients with AAA that is growing continuously by ≥3 mm/year and who have low operative risk may undergo surgery even if their AAA is <5.0 cm.

[Thoracoscopic surgery for intractable pneumothorax under epidural and local aesthesia].

Thoracoscopic surgery under epidural and local anesthesia for intractable pneumothorax were performed in 26 patients. A total of 29 thoracoscopic operation were performed in 26 patients. Twenty-three patients undervent only a single thoracoscopic operation, and 3 patients underwent twice thoracoscopic operations. We could control the air leak of intractable pneumothorax with the covering of polyglycolic acid sheets using aerosolized fibrin glue in 25 patients. In all patients postoperative course was uneventful and there was no operative death.

Transfection of human HGF plasmid DNA improves limb salvage in Buerger's disease patients with critical limb ischemia.

AIM: Hepatocyte growth factor is a potent angiogenic agent. This study investigated the efficacy and safety of intramuscular injection of naked plasmid DNA encoding the human hepatocyte growth factor gene in Japanese patients with Buerger's disease and critical limb ischemia. METHODS: An open-label clinical study was performed at eight hospitals in Japan from May 2004 to April 2008. Ten patients were enrolled. They had Buerger's disease with ischemic ulcers, were not candidates for revascularization, and were unresponsive to conventional drug therapy. Treatment consisted of 8 injections (total dose: 4 mg) of hepatocyte growth factor plasmid, which were administered into the calf muscles and/or distal thigh muscles of the ischemic limbs under ultrasound guidance. Administration was done twice at an interval of 4 weeks. If there was no improvement after 2 doses, a 3rd dose could be administered. The response to treatment was evaluated from the reduction of ischemic ulcer size. RESULTS: The size of ischemic ulcers showed a decrease in 6/9 (66.7%) patients and the ulcers healed completely in 5/9 (55.6%) patients after gene therapy. Major amputation was not required. There were no deaths and no major safety concerns. CONCLUSION: Hepatocyte growth factor gene therapy is safe and effective for critical limb ischemia in patients with Buerger's disease.

Expression and localization of vascular endothelial growth factor in normal abdominal aorta and abdominal aortic aneurysm.

AIM: The genesis of abdominal aortic aneurysms is associated with remodeling of the vascular wall by angiogenesis as well as proteolysis. Vascular endothelial growth factor (VEGF) is known to be a regulator of angiogenesis and to simultaneously stimulate elastolytic proteinases. We analyzed the expression and localization of VEGF in human abdominal aortic aneurysms compared to normal human aorta METHODS: Eighteen infrarenal aortic aneurysm samples were collected at the time of abdominal aortic aneurysm surgery, while nine normal aortic samples were obtained from autopsy specimens. Immunohistochemical staining was performed to detect VEGF. Immunoenzyme or immunofluorescent double staining was also used to identify those cells presenting VEGF. RESULTS: VEGF was expressed in 18 (100%) of the 18 abdominal aortic aneurysm samples, while 0 (0%) in the 9 normal abdominal aorta samples. Of the 18 samples of aneurysms, all 18 displayed positive VEGF immunostaining in macrophages, 12 in smooth muscle cells (SMCs), and 9 in endothelial cells (ECs). CONCLUSION: Our study clearly demonstrated the expression of VEGF in ECs, and SMCs, and macrophages of abdominal aortic aneurysms as well as its absence in those cells of normal abdominal aorta, suggesting that VEGF may play an important role in aneurysm formation via its direct and/or indirect actions.

Randomized, double-blind, placebo-controlled clinical trial of hepatocyte growth factor plasmid for critical limb ischemia.

Hepatocyte growth factor (HGF) is a potent angiogenic factor. The efficacy and safety of intramuscular injection of a naked plasmid encoding human HGF gene (beperminogene perplasmid, Collategene) was investigated in patients with critical limb ischemia (CLI) in a multicenter, randomized, double-blind, placebo-controlled trial. The randomization ratio for plasmid to placebo was 2:1. Injection sites were selected in each patient limb based on angiographic findings. Placebo or plasmid was injected on days 0 and 28. Evaluation of efficacy was carried out after 12 weeks. The primary end point was the improvement of rest pain in patients without ulcers (Rutherford 4) or the reduction of ulcer size in patients with ulcer(s) (Rutherford 5). Secondary end points were ankle-brachial pressure index, amputation, and quality of life (QOL). Forty-four patients were treated, and we performed interim analysis of efficacy in 40 patients. The overall improvement rate of the primary end point was 70.4% (19/27) in HGF group and 30.8% (4/13) in placebo group, showing a significant difference (P=0.014). In Rutherford 5 patients, HGF achieved a significantly higher improvement rate (100% [11/11]) than placebo (40% [2/5]; P=0.018). HGF plasmid also improved QOL. There were no major safety problems. HGF gene therapy is safe and effective for CLI.

Three-year cardiovascular events and disease progress in patients with peripheral arterial disease: results from the Japan Medication Therapy for Peripheral Arterial Disease (J-METHOD).

AIM: To investigate the current status of peripheral arterial disease (PAD) drug treatment in Japan, and the effects of drug treatment, risk factors, and complications on disease progress and onset of cardiovascular events in PAD patients. METHODS: In this prospective observational cohort study, 557 PAD patients were followed up for 3 years, and the current status of PAD treatment, risk factors, and cardiovascular events were monitored. RESULTS: Three drugs, i.e., beraprost sodium, cilostazol, and aspirin, were most frequently used. The patients who had undergone vascular reconstruction of the lower limbs before enrollment showed significant improvement in ABI. Among the patients who had not undergone vascular reconstruction before enrollment, there was a significant improvement in ABI after treatment with beraprost. During the observation period, cardiovascular deaths occurred in 35 patients (6.3%), heart diseases in 63 (11.3%), brain diseases in 39 (7.0%), and events in the lower limbs in 94 (16.9%). The factors affecting the increase of the cardiovascular events were explored by multivariate analysis (Cox regression analysis). As a result, age (75 years or older), ischemic heart disease and increase in severity on the Fontaine classification were identified as significant factors for cardiovascular deaths, whereas kidney disorders and increase in severity on the Fontaine classification were identified for heart diseases, the number of oral drugs for treating PAD was identified for brain diseases, and age (younger than 75 years), dialysis, ABI (less than 0.7) and aspirin were identified for the events in the lower limbs. CONCLUSION: As a result of the three-year follow-up on the Japanese PAD cohort, the current status of PAD treatment, risk factors, and cardiovascular events could be identified.

Prostaglandin receptors EP2 and IP are detectable in atherosclerotic arteries and plaques.

AIM: Prostaglandin (PG) receptor agonists are frequently used for the pharmacological treatment of arteriosclerosis obliterans (ASO). In particular, the PG receptors EP2 and IP stimulate vasodilation and inhibit platelet aggregation, biological processes thought to be protective against ASO and important for physiological homeostasis. However it is uncertain whether EP2 and IP exist in diseased arteries, or what their distribution within the artery might be. In this study, we analyzed the distribution of these PG receptors in patients with severe ASO to determine the potential application of stimulation of these receptors as targets for pharmacological treatment. METHODS: We collected segments of atherosclerotic femoral arteries during femoropopliteal bypass surgery and determined the expression levels of EP2 and IP receptors by western blotting. Immunofluorescence was used to observe receptor localization. RESULTS: Findings of western blotting showed an increased Cox-2 expression in patients with ASO. The EP2 as well as IP receptors were each induced approximately 3-fold in comparison to normal samples. The expression of these receptors was increased in the intimal layer as well as the medial layer; their expression was also detectable within the atherosclerotic plaque. CONCLUSION: We observed induction of the PG receptors EP2 and IP in atherosclerotic femoral arteries in the arterial intima, medial layer, as well as the associated atherosclerotic plaque. These results suggest that receptor-selective PG agonists specifically target atherosclerotic arteries and therefore, may find potential application in the pharmacological management of patients with ASO.

The education system to master endovascular aortic repair in Japan - the Japanese Committee for Stentgraft Management.

OBJECTIVE: The Japanese Committee for Stentgraft Management (JACSM) was established with the aim of ensuring the safe and proper reach of commercial stent grafts following their regulatory approval. This study examines the validity of the practice standards developed by JACSM. METHODS: JACSM comprises 10 associations related to endovascular treatment. Based on the practice standards developed by JACSM, the status of practising institutions, practising surgeons, supervising surgeons and the results of follow-up surveys were analysed. RESULTS: In the 2.5 years following the establishment of JACSM, 298 institutions have fulfilled the practice standards. The number of practising surgeons reached 493, and the number of supervising surgeons reached 177. There were 3089 registered cases up to June 2009. The present study analysed 1570 cases registered in the 2 years from July 2006 to June 2008. The hospital mortality rate was low (0.4%) in the follow-up surveys. CONCLUSIONS: Early results following the introduction of stent grafts were generally good. The procedure spread safely without the learning curve seen in the initial stages following introduction of new medical materials, indicating that the practice standards were appropriate.

Cell sheet injection as a technique of osteogenic supply.

We previously reported a new cell transplantation method utilizing injections of mesenchymal stem cell (MSC) sheets that have osteogenic potential. After subcutaneous transplantation without any scaffold, the sheet demonstrated in vivo bone formation. In the present study, we transplanted such sheets by injection into implanted ceramics and assessed whether the injectable MSC sheets could stimulate osteogenic integration of the ceramics. To fabricate MSC sheets, bone marrow cells cultured from femur shafts of 7-week-old rats were subcultured in regular 10-cm dishes containing dexamethasone and ascorbic acid phosphate until confluent. Each cell sheet was then lifted using a scraper. Porous ß-tricalcium phosphate (ß-TCP) disks (5 mm Φ×2 mm) were transplanted subcutaneously into the backs of the rats. Immediately following implantation, the sheets were injected around the disks via a 16G needle (immediate group). Cell sheets were also injected into the remaining implanted disks 1 week after disk implantation (1-wk group). Four weeks following sheet injection, radiography and histology revealed calcification and bone tissue around the harvested disks of the immediate group (eight disks exhibited bone formation/eight implanted disks), whereas calcification and bone tissue were observed in 50% of the samples in the 1-wk group (four disks exhibited bone formation/eight implanted disks). The present study indicates that injected cell sheets can supply osteogenic potential to implanted ceramics. Owing to the usage of a needle for cell sheet transplantation, such an injection method can be applied as a minimally invasive technique of osteogenic supply to implanted ceramics.

[Adequate size of elephant trunk in the procedure of total arch replacement for acute aortic dissection].

Total aortic arch replacement using the 'elephant trunk (ET)' procedure has commonly been applied to acute aortic dissection, but enlargement of a residual false lumen of the descending thoracic aorta sometimes occurs. We performed endovascular stent-grafting to close the entry as the second operation and obtained successful outcomes. From April 1997 to January 2004, we performed the modified ET procedure for acute aortic dissection in 29 patients and evaluated postoperative changes of the false lumen. In many cases of the residual false lumen, kinks and wrinkles were observed at the site of the ET grafts in the descending aorta. An adequate length of ET would be about 8 cm long to prevent kinking, and a diameter about 20 mm to prevent wrinkles.

Reduced vascular reserve measured by stressed single photon emission computed tomography carries a high risk for stroke in patients with carotid stenosis.

AIM: A few studies have observed reduced vascular reserve measured by single photon emission computed tomography (SPECT) to be a risk factor for stroke in patients with carotid artery occlusion, but stenosis has been excluded from these former studies. This study has evaluated the prognosis of reduced vascular reserve in patients with stenosis, and the effect of carotid endarterectomy (CEA) on these patients. METHODS: Forty patients diagnosed as having >70% stenosis of the carotid artery at the University of Tokyo Hospital, between 2001 and 2004, underwent acetazolamide-stress SPECT test first. A resting SPECT study was performed on a different day from the stressed SPECT study. The patients were grouped as having reduced vascular reserve or normal vascular reserve from the SPECT results. Analysis of risk factors and the stroke-free curve analysis for reduced vascular reserve was performed. RESULTS: Of the 40 patients, 24 (60%) had reduced vascular reserve and 18 underwent CEA. The mean follow-up period was 21.5+/-15.5 months (mean+/-SD). Four strokes occurred during follow-up: in 1 patient with CEA and 3 without CEA. All stroke patients had reduced vascular reserve. The patients with reduced vascular reserve without any surgery had a significantly lower stroke-free rate compared with those with normal vascular reserve or reduced vascular reserve, but also receiving CEA. CONCLUSIONS: We propose performing SPECT tests in patients with severe carotid stenosis regardless of symptoms, and performing CEA on those with a reduction in vascular reserve.

Carotid endarterectomy may reduce the high stroke rate for patients with the disease of abdominal aorta and peripheral arteries.

AIM: The prevalence of carotid stenosis is reported to be high among patients with arteriosclerosis, but the hazards of carotid stenosis and the benefits of carotid endarterectomy (CEA) on long-term event-free survival are still unknown. The aim of this prospective study was to screen preoperative patients with arterial disease for carotid stenosis, and to determine whether CEA had any effect on stroke during the postoperative follow-up period. METHODS: From 1999 to 2003, 406 consecutive preoperative patients with arterial disease underwent routine carotid duplex scan. Patients with known carotid stenosis and those due to undergo operation in emergency were excluded from the study. CEA was performed before or simultaneously with vascular surgery if necessary. The prevalence and risk factors for carotid stenosis were studied, and the patients were followed up for stroke or death. RESULTS: Among the 406 patients examined, 19.4% had greater than 50% stenosis and 11.3% had greater than 70% stenosis. The risk factors for carotid stenosis were having occlusive arterial disease (P=0.0001), and history of stroke (P=0.0038). Long-term follow-up study revealed that patients with greater than 70% carotid stenosis without CEA had a higher tendency for stroke or death, but the stroke rate in patients with severe stenosis who underwent CEA remained low, as in patients with less than 70% stenosis. CONCLUSIONS: Patients with greater than 70% carotid stenosis, diagnosed before arterial operation who did not undergo CEA, had a higher risk for stroke during the postoperative follow-up period. However, their risk could be reduced by performing CEA before or simultaneously with scheduled vascular surgery.

Long-term results of combined iliac endovascular intervention and infrainguinal surgical revascularization for treatment of multilevel arterial occlusive disease.

AIM: The purpose of this study was to investigate the long-term results of combined iliac endovascular intervention and infrainguinal surgical revascularization. METHODS: A retrospective review of 39 infrainguinal bypasses combined with iliac endovascular intervention in 35 patients over a 16-year period was performed (Combined group). These results were compared to those of 43 infrainguinal bypasses performed with suprainguinal bypass operation in 39 patients (Surgical group), who had iliac lesions not amenable to angioplasty/stenting. There was no significant difference in the preoperative limb ischemic symptoms between them. RESULTS: Although the proportion of patients with coronary artery disease in the Combined group was significantly higher than that in the Surgical group, there was a trend toward lower morbidity/mortality in the Combined group compared with the Surgical group (8.6% vs 15.4%; P=0.3706). No significant differences in the rates of clinical and hemodynamic improvement and limb salvage rate were observed between the two groups. The primary patency rate of infrainguinal bypass at 1, 3, and 5 years was 83.2%, 80%, and 71.2% in the Combined group, and 97.1%, 89.9%, and 80.5% in the Surgical group, respectively. The secondary patency rate at 1, 3, and 5 years was 91.9%, 91.9%, and 76.3% in the Combined group, and 97.1%, 89.9%, and 84.6% in the Surgical group, respectively. Importantly, there was no significant difference in the primary/secondary patency rates between the two groups (Kaplan-Meier, log-rank test, primary patency, P=0.116; secondary patency, P=0.4407). CONCLUSIONS: Infrainguinal surgical reconstruction combined with iliac endovascular procedure may reduce operative risk, and further, long-term patency is comparable to that in the Surgical group.

Persistent sciatic artery in a patient with extracranial internal carotid artery aneurysm and infrarenal abdominal aortic aneurysm. A case report.

A rare case of a persistent sciatic artery (PSA) in a patient with aneurysms of the internal carotid artery and abdominal aorta is presented. A 70-year-old man was referred with intermittent claudication of the right lower extremity. Angiography and computed tomography demonstrated that this symptom was due to occlusion of the PSA. On preoperative examinations, aneurysms of the extracranial internal carotid artery and abdominal aorta were incidentally discovered, and then surgically treated prior to the management of PSA. Systemic examinations must be performed in patients with PSA in order to scrutinize associated anomalies or vascular disease.

DNA methylation-associated inactivation of TGFbeta-related genes DRM/Gremlin, RUNX3, and HPP1 in human cancers.

The transforming growth factor beta (TGFbeta)-signalling pathway is deregulated in many cancers. We examined the role of gene silencing via aberrant methylation of DRM/Gremlin and HPP1, which inhibit TGFbeta signalling, and RUNX3, which facilitates TGFbeta-signalling, of all genes that are thought to be tumour suppressors, are aberrantly expressed, and are thus thought to have important role in human cancers. We examined DRM/Gremlin mRNA expression in 44 cell lines and the promoter methylation status of DRM/Gremlin, HPP1, and RUNX3 in 44 cell lines and 511 primary tumours. The loss of DRM/Gremlin mRNA expression in human cancer cell lines is associated with DNA methylation, and treatment with the methylation inhibitor-reactivated mRNA expression (n=13). Methylation percentages of the three genes ranged from 0-83% in adult tumours and 0-50% in paediatric tumours. Methylation of DRM/Gremlin was more frequent in lung tumours in smokers, and methylation of all three genes was inversely correlated with prognosis in patients with bladder or prostate cancer. Our results provide strong evidence that these TGFbeta-related genes are frequently deregulated through aberrant methylation in many human malignancies.

Aberrant methylation of SPARC in human lung cancers.

SPARC (secreted protein acidic and rich in cysteine) is an extracellular Ca2+-binding matricellular glycoprotein associated with the regulation of cell adhesion and growth. We investigated loss of expression of SPARC gene and promoter methylation in lung cancers and correlated the data with clinicopathological features. We observed loss of SPARC expression in 12 of 20 (60%) lung cancer cell lines. Treatment of expression-negative cell lines with a demethylating agent restored expression in all cases. Methylation frequencies of SPARC gene were 55% in 20 lung cancer cell lines. Primary tumours had methylation at a rate of 69% (119 of 173), while nonmalignant lung tissues (n=60) had very low rates (3%). In lung adenocarcinomas, SPARC methylation correlated with a negative prognosis (P=0.0021; relative risk 4.65, 95% confidence interval 1.75-12.35, multivariate Cox's proportional-hazard model). Immunostaining revealed protein expression in bronchial epithelium (weak intensity) and in juxtatumoral stromal tissues (strong intensity) accompanied by frequent loss in cancer cells that correlated with the presence of methylation (P<0.001). Our findings are of biological interest and potentially of clinical importance in human lung cancers.

Laser Doppler skin perfusion pressure in the assessment of Raynaud's phenomenon.

OBJECTIVES: In the assessment of Raynaud's phenomenon, objective evaluation of digital microcirculatory flow is important, and so we investigated whether the measurement of laser Doppler skin perfusion pressure could be of use. MATERIALS AND METHODS: Ten fingers of five patients with secondary Raynaud's phenomenon due to systemic sclerosis, 22 fingers of 11 patients with primary Raynaud's phenomenon and 10 fingers of five control patients were examined. Skin perfusion pressure was measured on the third finger of both hands at rest, and then again 3 min after local cold exposure. RESULTS: Laser Doppler skin perfusion pressure at rest in patients with secondary Raynaud's phenomenon was significantly lower than that in patients with primary Raynaud's phenomenon and the control patients (p<0.05). Skin perfusion pressure decreased significantly in both patient groups upon local cold exposure (p=0.005). There were significant differences in perfusion pressure after cold exposure among both groups (p<0.05). CONCLUSIONS: The low skin perfusion pressure at rest in patients with secondary Raynaud's phenomenon suggested the presence of obstructive arterial lesions. The marked pressure decrease in all Raynaud's patients after local cold exposure might be due to vasospasm of the microvasculature in the digits. These results indicate that the measurement of laser Doppler skin perfusion pressure is valuable in the diagnosis of Raynaud's phenomenon.