Arteriosclerotic Artery Research Articles

A thermodynamic framework for unified continuum models for the healing of damaged soft biological tissue

When they are damaged or injured, soft biological tissues are able to self-repair and heal. Mechanics is critical during the healing process, as the damaged extracellular matrix (ECM) tends to be replaced with a new undamaged ECM supporting homeostatic stresses. Computational modeling has been commonly used to simulate the healing process. However, there is a pressing need to have a unified thermodynamics theory for healing. From the viewpoint of continuum damage mechanics, some key parameters related to healing processes, for instance, the volume fraction of newly grown soft tissue and the growth deformation, can be regarded as internal variables and have related evolution equations. This paper is aiming to establish this unified framework inspired by thermodynamics for continuum damage models for healing of soft biological tissues, in which we introduce for the first time the coupled description of damage/healing and growth/remodeling based on thermodynamic considerations. Therefore, this new model is more concise and offers a universal approach to simulate the healing process. Three numerical examples are provided to demonstrate the effectiveness of the proposed model, which are in good agreement with the existing works, including an application for balloon angioplasty in an arteriosclerotic artery with a fiber cap.

ナノテクノロジーとＤＤＳ ナノ診断・ナノ治療が開く新しい薬物治療

Restenosis after coronary intervention still remains a serious problem in clinical cardiology. Recent advances in nanotechnology have enabled us to selectively deliver an antiproliferative drug to the balloon-injured artery. Here we report our results with NK911 that is a doxorubicin containing nanocapsule and is characterized to selectively accumulate in vascular lesions with increased permeability. We first confirmed by Evans-blue staining that in the rat carotid artery, vascular permeability was markedly increased at least for one week after balloon injury. We then examined the inhibitory effect of NK911 on the restenotic changes 4 weeks after the injury either in the normal artery (single injury protocol) and in the arteriosclerotic artery that had been induced by a previous balloon injury (double injury protocol). NK911 was intravenously administered only three times (immediately after, and 3 and 6 days after the injury) at three different doses (0.1, 1.0 and 10 mg/kg). Corresponding doses of doxooruhicin alone (0.016, 0.16, 1.6 mg/kg) were also administered in the same manner. In both protocols. NK911 dose-dependently suppressed neointimal formation (P<0.001, n=6 each). Immunohistochemical examination demonstrated that the inhibitory effect of NK911 was mainly due to suppression of vascular smooth muscle proliferation. Measurement of vascular concentrations of doxorubicin demonstrated that NK911 effectively delivered the drug to the balloon-injured carotid arteries. Finally, NK911 was well tolerated without any systemic adverse effects. Thus, the treatment with nanocapsules containing antiproliferative agents may be a novel and promising strategy for the prevention of restenosis after balloon angioplasty.

Laser angioplasty: results of a prospective, multicenter study at 3-year follow-up.

A prospective multicenter trial was initiated to evaluate the efficacy and safety of laser angioplasty. Laser recanalization was performed in 338 patients with arteriosclerotic femoropopliteal artery occlusions (average length, 8.5 cm). Neodymium-yttrium-aluminum-garnet lasers were used in combination with sapphire probe catheters. The initial recanalization rate was 85%. Complications were observed in 14% of the patients. Emergency surgery was required in 1.5%. The cumulative long-term patency rate of the successfully recanalized arteries was 80%, 70%, 62%, and 57% at 6 months, 1 year, and 2 and 3 years, respectively. The patency rates were not affected by the length of the occlusion and the long-term medication (platelet inhibition vs anticoagulation), but patients with a normal runoff had significantly better patency rates than those with reduced runoff (63% vs 52%, P less than .01). The study has shown that laser-assisted angioplasty is safe and at least as effective as conventional angioplasty.

38 大動脈および下肢動脈疾患に併存した冠動脈病変

38 大動脈および下肢動脈疾患に併存した冠動脈病変

SURGICAL RESULTS ON ACUTE ARTERIAL OCCLUSION OF THE EXTREMITIES WITH SPEICAL REFERENCE TO ARTERIOSCLEROTIC THROMBOSIS

The results of surgical treatment of acute arterial occlusion depend in its etiology. During a period of 15 years, from 1972 until 1987, arterial reconstrucitons for acute arterial occlusion were performed in 28 patients. Of these, occlusion was caused by embolism in 14 patients and by arteriosclerotic thrombosis in 14. In 14 ischemic limbs of the patients with embolism, simple embolectomy was performed with the Forgaty catheter. In patients with acute thrombosis of the arteriosclerotic artery, arterial bypass grafting or thromboendarterectomy was performed.Hospital death for embolectomy alone (0%) was lower than that for arteriosclerotic thrombosis (42%). Death was attributed to cardiac failure in 3 patients, panperitonitis in 2 patients and revascularization syndrome in 1 patient.The patency rate during hospitalization, including patients with a patent reconstructive tract at the time of death, was 100% in patients with embolism and 72% in those with arteriosclerotic thrombosis. Of the seven patients with arteriosclerotic thrombosis who were discharged from our clinic with limb salvage after operation, reconstructive tracts were patient in two and occluded in the others.The operative procedure should be tailored to the etiology of acute arterial occlusion.

Prognosis in arteriosclerotic renovascular hypertension.

1. A comparison has been made of surgical and medical treatment in patients with arteriosclerotic renal artery stenosis and hypertension. 2. Immediate post-operative blood pressure was often normal, but frequently rose again later. After the sixth year only about 25% of surgical patients were normotensive without drug treatment. 3. Nephrectomy and vascular reconstruction gave similar results. 4. We presently believe that post-operative anticoagulant therapy is indicated in patients undergoing surgery for arteriosclerotic renal artery stenosis.

INTRA-ABDOMINAL APOPLEXY

This report will describe in detail only 1 case. However, since the pathologic process involved has been recorded in the literature only rarely, 12 previously reported cases will be tabulated and brief allusion made to them. In referring to intra-abdominal apoplexy, the subject of this report, Graham commented: This is probably a much more important matter than would seem to be the case from the small amount of discussion which it has received in the literature. Of interest also in this connection is the similarity of the symptoms produced by retroperitoneal hemorrhage to those of an acute surgical intra-abdominal lesion, a point which has been emphasized by Warren H. Cole. Thompson and Dunphy stated: Intra-abdominal apoplexy is the spontaneous rupture of an arterio-sclerotic artery of one of the abdominal viscera. In this region it is the counterpart of cerebral hemorrhage, but, whereas the latter condition is common, intra-abdominal apoplexy is