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PubMed1996

Effect of E5510 on anastomotic intimal hyperplasia and platelet aggregation in dogs.

We examined the effect of an antiplatelet agent, E5510, which inhibits both platelet aggregation and release of platelet-derived growth factor (PDGF), on anastomotic intimal hyperplasia and platelet aggregation. Twenty Beagle dogs underwent infrarenal aortic reconstruction with an expanded polytetrafluoroethylene (ePTFE) graft 5 mm in diameter and 3 cm long. The dogs were divided into three groups: placebo (control group, 7 dogs), E5510 1 mg/day (1-mg group, 6 dogs), and E5510 4 mg/day (4-mg group, 7 dogs). E5510 was administered orally 2 h before operation and once daily for 3 months after operation. Grafts were harvested 3 months after operation. All 13 grafts in the treated groups remained patent without evidence of intimal hyperplasia, whereas only 4 of 7 grafts (57%) remained patent in the control group, including 1 graft with > 50% stenosis. Three occluded grafts showed severe intimal hyperplasia at the anastomoses. The platelet aggregation ratio (PAR) with collagen (100 micrograms/ml) before drug administration at 3 months in the 4-mg group was significantly lower than that in the control and 1-mg groups. PAR after drug administration at 3 months in the 1- and 4-mg groups was significantly lower than that in the control group. Intimal thickness at the distal anastomosis was 817 +/- 190 microns in the control group, 240 +/- 80 microns in the 1-mg group, and 197 +/- 28 microns in the 4-mg group. Intimal thickness in the control group was significantly greater than that in the 1- and 4-mg groups. Smooth muscle cell (SMC) values in the intima at the distal anastomosis were 65.6 +/- 4.4% extinction (%E) in the control group, 47.6 +/- 3.4%E in the 1-mg group, and 51.3 +/- 3.5%E in the 4-mg group. SMC value in the control group was significantly greater than that in the 1- and 4-mg groups. E5510 inhibited PAR and reduced the degree of anastomotic intimal hyperplasia.

Anastomosis, Surgical↗
PubMed2002

Endogenous nitric oxide synthase inhibitors in endothelial cells, endothelin-1 within the vessel wall, and intimal hyperplasia in perimenopausal human uterine arteries.

The present experiments were designed to investigate the ability to produce nitric oxide, concentrations of N(G)-monomethyl-L-arginine (L-NMMA), and asymmetric N(G), N(G)-dimethyl-L-arginine (ADMA) in endothelial cells, endothelin-1 within the vessel wall, and the degree of intimal hyperplasia (intima/media ratio) in perimenopausal human uterine arteries. According to the tentative classification based on basal cyclic GMP levels, 16 arteries could be grouped into groups I and II consisting of eight each. Net production of the nucleotide was significantly higher in group I than that in group II. Concentration of L-NMMA plus ADMA and endothelin-1 content were significantly higher in group II. All specimens from group I were histologically normal, whereas mild to severe intimal hyperplasia was observed in group II specimens. Although considerable individual variations were detectable in the intima/media ratio, L-NMMA plus ADMA and endothelin-1 (n = 35 each), there were significant and positive correlations between three parameters, indicating that intimal hyperplasia became greater as L-NMMA plus ADMA and endothelin-1 were increased. These results suggest that endogenous nitric oxide synthase inhibitors in endothelial cells and endothelin-1 within the vessel wall are important markers of intimal hyperplasia.

Adult↗
PubMed2002

Polypoid mucosa with eosinophilia and glandular hyperplasia in chronic sinusitis: a histopathological and immunohistochemical study.

OBJECTIVE: To evaluate the histopathological and immunohistochemical characteristics of chronic sinusitis, with reference to the extent of sinus involvement. STUDY DESIGN: A nonrandomized, retrospective, controlled qualitative and quantitative study. METHODS: Twenty-nine adults with refractory chronic sinusitis underwent functional endoscopic sinus surgery. The score of computed tomography scans was used to determine the extent of disease. Six patients with normal sinus mucosae served as control subjects. Specimens underwent routine histological processing and hematoxylin-eosin and periodic acid-Schiff staining. Immunohistochemistry for T and B lymphocytes was applied. Low-magnification microscopy was designed to yield typical pathological features, and high magnification to count various inflammatory cells. RESULTS: Patients were divided into two groups according to their dominant pathological features: 16 had polypoid mucosa and eosinophilia, and 13 had glandular hyperplasia. The number of eosinophils, T and B lymphocytes in the lamina propria was significantly higher in patients with polypoid mucosa and eosinophilia, compared with those with glandular hyperplasia and with normal control subjects, whereas the difference between patients with glandular hyperplasia and control subjects was insignificant. Although the overall inflammatory reaction was relatively modest, nasal polyposis was more prevalent in patients with polypoid mucosa and eosinophilia; likewise, computed tomography revealed a significantly more extensive disease in these patients compared with the patients with glandular hyperplasia. CONCLUSION: Two pathophysiological pathways, inducing prolonged obstruction to the outflow of sinus secretion and ultimately causing chronic inflammation, are suggested: 1) swollen polypoid mucosa with activation of eosinophils that damage the epithelium and 2) continued increased mucus secretion originated from hyperplastic submucosal seromucous glands.

B-Lymphocytes↗
PubMed1995

Patient reactions to a program designed to facilitate patient participation in treatment decisions for benign prostatic hyperplasia.

Patients often want considerable information about their conditions, and enhanced patient participation might reduce unwanted practice variation and improve medical decisions. The authors assessed how men with benign prostatic hyperplasia reacted to an education program designed to facilitate participation in decisionmaking, and how strongly ratings of their symptom state and the prospect of complications predicted their treatment choice. A prospective cohort study was conducted in three hospital-based urology practices: two in prepaid group practices, and one Veterans Administration clinic. Four hundred twenty-one men with symptomatic benign prostatic hyperplasia without prior prostatectomy or benign prostatic hyperplasia complications were enrolled, and 373 provided usable ratings. Subjects participated in an interactive videodisc-based shared decisionmaking program about benign prostatic hyperplasia and its treatment options, prostatectomy, and "watchful waiting." They rated the length, clarity, balance, and value of the program and were followed for 3 months to determine if they underwent surgery. Patients rated the program as generally clear, informative, and balanced. Across all three sites, 77% of patients were very positive and 16% were generally positive about the program's usefulness in making a treatment decision. Logistic models predicting choice of surgical treatment documented the independent importance of negative ratings of the current symptom state (odds ratio 7.0, 95% confidence interval 2.9-16.6), as well as the prospect of postoperative sexual dysfunction (odds ratio 0.20, 95% confidence interval 0.08-0.48) in decisionmaking. Patients rated the Shared Decisionmaking Program very positively and made decisions consistent with their assessed preferences. These results suggest that patients can be helped to participate in treatment decisions, and support a randomized trial of the Shared Decisionmaking Program.

Aged↗
PubMed1991

Inhibition of subintimal hyperplasia of autologous vein bypass grafts by nimodipine in rats: a placebo-controlled study.

An arterial bypass may be required for the management of neoplastic or cerebrovascular disease. When an arterial graft is not suitable, autologous vein grafts are the most commonly used conduits; however, as many as 20% of the vein grafts used in vascular surgery may occlude as a result of subintimal hyperplasia. Although the mechanism initiating subintimal hyperplasia remains unclear, it is known that subintimal hyperplasia is dependent upon smooth muscle cell proliferation and migration from the media to the intimal layer. The present study focused on the prevention of smooth muscle cell proliferation using a calcium antagonist. Forty rats received an autologous vein bypass graft from the jugular vein to reconstruct the abdominal aorta. They were randomly divided into two groups of 20 rats each. Animals in the treated group received a calcium antagonist (nimodipine), and those in the control group received a placebo. Nine months after grafting, the group receiving the calcium antagonist presented no or only slight sub intimal hyperplasia as compared with the placebo-treated group (P less than 0.001). These data suggest that a calcium antagonist could be used for the prevention of venous graft disease.

Animals↗
PubMed2000

Effect of external stenting and systemic hypertension on intimal hyperplasia in rat vein grafts.

OBJECTIVE: Overdistention of vein grafts in arterial circulation and systemic hypertension are thought to be influential risk factors contributing to vein graft failures. This study tested the effects of external stenting in preventing systemic hypertension and overdistention of the rat vein graft in the long term. METHODS: Jugular vein grafts were interposed into the carotid artery of normotensive (n = 39) and two-kidney, one-clip hypertensive (n = 30) rats. Jugular vein grafts wrapped with 1.5-mm-diameter polyester stents were used in normotensive (n = 26) and hypertensive (n = 25) rats. The vein grafts were harvested at 1, 2, 4, 8, 12, and 24 weeks after the grafting procedure. The neointimal area and wall thickness were measured by computerized planimetry, and Ki-67 immunohistochemistry was used to detect replicative smooth muscle cells in the graft wall. RESULTS: In each group, intimal hyperplasia was apparent at 1 week and increased gradually to 24 weeks. The number of Ki-67-positive cells was most increased at 2 weeks after the grafting procedure and gradually decreased thereafter. The numbers of Ki-67-positive cells and the extent of intimal hyperplasia were not significantly different between normotensive and hypertensive rats. Both neointima formation and cell proliferation in the graft wall were significantly reduced by external stenting as compared with the results with unstented grafts. CONCLUSION: Systemic hypertension by itself is not a risk factor for intimal hyperplasia and experimental vein graft failure in the long term. External stenting is effective against intimal hyperplasia, and it is possible to reduce the subsequent atherosclerotic change of the vein graft wall and improve the long-term patency of the vein graft with external stenting.

Animals↗
PubMed1996

Vascular smooth muscle cells and neointimal hyperplasia in chronic transplant rejection.

Intimal hyperplasia is the characteristic pathological hallmark in the arterial tree of chronically rejecting solid organ grafts. Mechanisms underlying the development of this lesion are poorly understood. One strongly held hypothesis is that vascular smooth muscle cells (vs.mcs) migrate from the medial layer of arteries contained within the graft into the intima forming the "neointima" characteristic of intimal hyperplasia. This study investigated this theory in a rat aortic allograft model of intimal hyperplasia. It also examined the possibility, using a combination of immunocytochemistry and electron microscopy, that aortic vs.mcs may undergo a phenotypic change during this process. Intimal area in syngeneic grafts was 3509 +/- 4325 pixels (n = 5) compared with 240,896 +/- 87,042 in allogenic grafts (n = 9, P < 0.001) 12 weeks after transplantation. At that time medial nuclear density was markedly reduced in the same allografts compared with corresponding syngeneic grafts (0.83 +/- 0.14 versus 2.64 +/- 0.60, P < 0.001, respectively). The most striking finding was that there was strongly positive staining for alpha-actin cells in the neointima in association with an almost acellular medial layer. Immunocytochemical staining also demonstrated the presence of beta-actin cells in the neointima of allografts while electron microscopy showed these cells to be secretory in phenotype. These results support the hypothesis that vs.mcs form an important component of the lesion of intimal hyperplasia and also propose that a phenotypic change may occur in these cells once they are present in the neointima.

Actins↗
PubMed1996

A comparative study of risk factors for hyperplasia and cancer of the endometrium.

A cohort study has been carried out to investigate risk factors for cancer as well as hyperplasia of the endometrium. Over the 13 years for which we followed 25,000 women aged 40-65 (who took part in a population-based screening programme for breast cancer), 111 cases of endometrial cancer and 109 cases of endometrial hyperplasia were diagnosed. A comparison of the outcome between the two disease entities revealed that large body weight among postmenopausal women and the use of oestrogenic drugs at all ages were risk factors for both cancer and hyperplasia of the endometrium. However, reproductive histories and premenopausal steroid profiles differed. Steroid excretion determinations in urine samples collected years before diagnosis provided further evidence in favour of the hypothesis of unopposed action of oestrogens in the aetiology of endometrial cancer. In women who were to develop endometrial hyperplasia or cancer the obesity-oestrogen relationship was stronger than in those who remained free of endometrial disease during the period of follow-up. The possible significance of differences in aromatase activity among the obese is considered.

Adult↗
PubMed2001

Future concepts in the medical therapy of benign prostatic hyperplasia.

The standard medical therapy for symptomatic benign prostatic hyperplasia is still alpha-blockers and 5alpha-reductase inhibitors. Ongoing studies demonstrate the long-term safety and efficacy of these two classes of therapeutic approaches. Although there have been no new Food and Drug Administration approved medical therapies for the treatment of benign prostatic hyperplasia over the past year, interest in and the use of phytotherapeutic agents continues to increase. In this review, we will discuss the developments that have occurred over the past year in the medical management of benign prostatic hyperplasia. In addition, we present ongoing efforts at our center to obtain a better understanding of and manipulate the apoptotic pathway as it pertains to the pathophysiology of benign prostatic hyperplasia.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2003

Thermotherapy and thermoablation for benign prostatic hyperplasia.

PURPOSE OF REVIEW: From all the available thermoablative methods for the treatment of symptomatic benign prostatic hyperplasia, transurethral microwave thermotherapy is considered as standard in minimally invasive management. The literature is enriched by several new studies on transurethral microwave thermotherapy, and thus this review presents up-to-date information about thermotherapy. RECENT FINDINGS: New studies have provided significant information regarding differences in outcome for devices with different protocols and selection criteria, confirming the superiority of high-energy programmes. Furthermore, monitoring of the intraprostatic temperature promises better clinical results by means of individualization of the treatment. Long-term results have been available and allow the evaluation of the fundamental issue of treatment durability. Improvement after high-energy transurethral microwave thermotherapy remains durable for more than 2.5 years. Randomized studies comparing this treatment with other established therapies for benign prostatic hyperplasia, including medical treatment and transurethral resection of the prostate, have also contributed to an evaluation of the morbidity, and costs of treatment. Clinical outcomes with transurethral microwave thermotherapy are in the range of those obtained with transurethral resection of the prostate and are superior to those of medical management. Retreatment after transurethral resection of the prostate emerges because of complications following the procedure, whereas retreatment after transurethral microwave thermotherapy is as a result of treatment failure. In addition, the rate of failure of medical management is almost seven times higher than that for transurethral microwave thermotherapy. Thus, the latter seems to play a dominant role in the economic models used to assess the cost-efficiency of different treatment modalities for benign prostatic hyperplasia. SUMMARY: The recent innovations in high-energy transurethral microwave thermotherapy provide better and more durable clinical outcomes and lower morbidity, and strengthen its position as an established treatment for benign prostatic hyperplasia. However, there is always room for improvement, so further research on therapeutic protocols, treatment monitoring and selection criteria are to be welcomed.

Aged↗
PubMed2003

Are stents still a useful therapy for benign prostatic hyperplasia?

PURPOSE OF REVIEW: The use of an endoprosthesis to maintain lumenal patency is a well-established concept used in a variety of surgical settings, including cardiovascular and gastrointestinal pathologies. However, the utility of self-retaining endoprosthetics and their application in prostatic pathology and benign prostatic hyperplasia is not as clear. This report reviews recent developments in the management of symptomatic benign prostatic hyperplasia, particularly the current role of intraprostatic stenting in the advent of other minimally invasive therapies such as laser prostatectomy. RECENT FINDINGS: Over the past 5 years, urology has witnessed the proliferation of minimally invasive surgical therapies for benign prostatic hyperplasia. These interventions have enabled the urologist to treat a problem whose management was once limited to medical therapy, transurethral resection of the prostate, or open, relatively morbid surgery. The role of stents as an intermediary in cases of treatment failure, or as definitive therapy for benign prostatic hyperplasia and its associated problems is still not clear, when compared with newer, minimally invasive options. Current literature on stents is relatively sparse. However recent studies demonstrate that permanent and temporary prostatic urethral stenting are effective in relieving obstruction and urinary retention. Nevertheless larger controlled clinical studies are needed to demonstrate the real value of this intervention. SUMMARY: Prostatic stenting has a definite role in the management of benign prostatic hypertrophy, but stents must be used with caution because complications are still relatively common, and their true efficacy and utility in the urological setting has not been determined.

Aged↗
PubMed2004

A rational approach to benign prostatic hyperplasia evaluation: recent advances.

PURPOSE OF REVIEW: In this article we aim to outline the recent advances in the evaluation of a patient with symptoms suggestive of benign prostatic hyperplasia. We define the role of the clinical evaluation and techniques that are evolving for the appropriate management of a patient with benign prostatic hyperplasia. Both non-invasive and invasive investigation techniques are reviewed. RECENT FINDINGS: Initiating early and appropriate treatment is the primary aim of investigation for a patient with lower urinary tract symptoms. Both clinical history and examination and appropriate investigations are vital to establishing a diagnosis. Symptom scores, prostate specific antigen and prostate volume were found to closely relate in predicting the progression of benign prostatic hyperplasia and in recent years increased interest has centred on the progression of this disease principally related to the development of new pharmacotherapy. Despite these positive findings further research is needed to develop reliable tools to predict progression. Newer ultrasound techniques hold promise for the future. Conventional pressure flow studies have a defined role in excluding patients who are less likely to benefit from prostatic surgery by providing information on detrusor function; and non-invasive urodynamic techniques need further evaluation but appear to be promising. SUMMARY: The minimal initial evaluation of a patient with benign prostatic hyperplasia should include a thorough history, digital rectal and neurological examinations, symptom scoring (including quality of life and sexual score) and measurement of serum prostate specific antigen. Other methods should be reserved for more complex situations. Attempts should be made at identifying those patients in whom the disease process is likely to progress.

Aged↗
PubMed2004

Enhanced detection of atypical hyperplasia in endometrial polyps by PTEN expression.

Endometrial hyperplasia is difficult to recognize within endometrial polyps because of the background of randomly distributed irregular glands. The loss of expression of the PTEN oncogene is characteristic of endometrial cancers and clinically significant hyperplasia. Using immunohistochemical staining for the PTEN protein, we studied 12 endometrial polyps that were noted to contain foci of complex hyperplasia or glandular crowding. Loss of PTEN staining was found in 3 cases, suggesting a precancerous lesion. Moreover, 2 of these cases were originally classified as complex hyperplasia without atypia and 1 as merely glandular crowding. Thus, in selected cases, the loss of PTEN expression in an area of glandular crowding can highlight biologically significant lesions and afford a more definitive diagnosis.

Endometrial Hyperplasia↗
PubMed2006

Bacillary angiomatosis associated with pseudoepitheliomatous hyperplasia.

Bacillary angiomatosis is an opportunistic bacterial infection caused by either Bartonella henselae or B. quintana. The classic histologic presentation of bacillary angiomatosis involves three components: a lobular proliferation of capillaries with enlarged endothelial cells, neutrophilic debris, and clumps of finely granular material identified as bacteria with staining techniques. Pseudoepitheliomatous hyperplasia is a histologic reaction pattern characterized by epithelial proliferation in response to a variety of stimuli, including mycobacterial, fungal, and bacterial infections. We describe a case of bacillary angiomatosis associated with pseudoepitheliomatous hyperplasia in an immunocompromised patient with Acquired Immunodeficiency Syndrome. Histologic examination of a finger lesion demonstrated a capillary proliferation with neutrophilic debris and characteristic amorphous granular deposits. Warthin-Starry and Giemsa staining revealed clumps of coccobacilli. Cervical lymph node tissue also revealed organisms identified as Bartonella with PCR techniques. Stains and cultures for acid fast bacilli, fungus, and bacteria were negative. To our knowledge, there has been only one other report of bacillary angiomatosis presenting with pseudoepitheliomatous hyperplasia. We conclude that the differential diagnosis of entities associated with pseudoepitheliomatous hyperplasia should be expanded to include bacillary angiomatosis.

AIDS-Related Opportunistic Infections↗
PubMed2006

To what extent do real life practice studies differ from randomized controlled trials in lower urinary tract symptoms/benign prostatic hyperplasia?

PURPOSE OF THE REVIEW: To compare the real-life practice studies and randomized controlled trials on benign prostatic hyperplasia in order to understand the applications of the data from the two types of study. RECENT FINDINGS: Until recently, much of the available information on benign prostatic hyperplasia has come from randomized controlled trials conducted by secondary care urologists on selected populations of patients, who are likely to represent the more symptomatic among the cohort of men with lower urinary tract symptoms in the community. The strict inclusion criteria in these trials led to uncertainty about the applicability of the results to community populations. Moreover, as patients in randomized controlled trials are specially recruited, rather than being drawn from a general population of men with lower urinary tract symptoms, the calculations of incidence and prevalence rates may not be possible. In the last few years, there have been a few important real-life practice studies such as the Triumph project, the Quadraet study and the ALF-ONE study, which have provided very useful data regarding the incidence and prevalence of lower urinary tract symptoms/benign prostatic hyperplasia, the incidence of acute urinary retention, the impact of therapy on the risk of surgery related to benign prostatic hyperplasia and the predictors of disease progression during treatment with alpha-blocker. SUMMARY: As the results from randomized controlled trials cannot always be generalized to daily urological practice, it is important to complement them with data made available by the real-life practice studies. In order to do that, the salient features in the methodology of both types of study must be understood.

Humans↗
PubMed2006

Loss of nuclear expression of parafibromin distinguishes parathyroid carcinomas and hyperparathyroidism-jaw tumor (HPT-JT) syndrome-related adenomas from sporadic parathyroid adenomas and hyperplasias.

Parathyroid carcinoma is notoriously difficult to diagnose with confidence in borderline cases. Commonly there is a long lag time between diagnosis and clinical evidence of malignant behavior even in histopathologically straightforward lesions. There is therefore a need for a novel adjunctive marker to assist in the diagnosis of carcinoma. Parafibromin is the protein encoded by the putative tumor suppressor gene HRPT2. Mutations predicted to inactivate parafibromin were first detected in the germline of patients with hyperparathyroidism-jaw tumor (HPT-JT) syndrome. Subsequently, somatic mutations have been identified in the majority of sporadic carcinomas. We performed immunohistochemistry for parafibromin on 115 parathyroid tissues comprising 4 HPT-JT-related tumors (3 adenomas and 1 carcinoma), 11 sporadic parathyroid carcinomas, 79 sporadic adenomas, 3 multiple endocrine neoplasia 2A-related adenomas, 2 sporadic primary hyperplasias, 2 multiple endocrine neoplasia (MEN)-1-related hyperplasias, 6 secondary hyperplasias, 4 tertiary hyperplasias, and 4 normal parathyroid glands. There was complete absence of nuclear staining in 3 of 4 (75%) HPT-JT-related tumors and 8 of 11 (73%) sporadic parathyroid carcinomas and focal weak staining in 1 of 4 HPT-JT tumors and 2 of 11 sporadic parathyroid carcinomas. Only 1 parathyroid carcinoma exhibited diffuse strong nuclear expression of parafibromin. In contrast, 98 of 100 non-HPT-JT-related benign parathyroids showed diffuse strong nuclear positivity and 2 of 100 showed weak positive staining. We conclude that, in the correct clinical and pathologic context, complete absence of nuclear staining for parafibromin is diagnostic of parathyroid carcinoma or an HPT-JT-related tumor.

Biomarkers, Tumor↗
PubMed2005

Thymic hyperplasia in thyroid cancer patients.

OBJECTIVE: Although there is a well-recognized association between thymic hyperplasia and benign thyroid disorders, the prevalence of thymic hyperplasia in patients with malignant thyroid diseases has not been previously reported. We performed this study to determine the prevalence and morphologic features of thymic hyperplasia on CT scans of thyroid cancer patients. CONCLUSIONS: Thymic hyperplasia is commonly observed on CT scans of thyroid cancer patients and almost always demonstrates a characteristic pyramidal configuration. This characteristic appearance should not be mistaken for metastatic disease.

Adult↗
PubMed2006

Intramural stress increases exponentially with stent diameter: a stress threshold for neointimal hyperplasia.

PURPOSE: Techniques designed to increase initial luminal diameter during stent implantation may ultimately lead to early restenosis by causing substantial vessel wall trauma and promoting neointimal hyperplasia. The purpose of this study was to evaluate the impact of stent oversizing on resultant arterial wall stress concentrations and examine the concept of a "stress threshold" for neointimal hyperplasia development. MATERIALS AND METHODS: A previously described three-dimensional large-strain hyperelastic numeric model was used to examine the nonlinear isotropic behavior of a 6-mm-diameter artery during stent deployment. An in situ axial prestretch of 10% and a mean arterial pressure of 100 mm Hg (13.3 kPa) were applied before stepwise expansion of a simulated Palmaz-Schatz stent to a diameter 30% greater than that of the native artery. The variation of arterial wall von Mises stresses with percentage diameter inflation was then compared with the known distribution of stent-induced neointimal hyperplasia. RESULTS: The order in which location-specific peak stresses exceeded a predetermined stress threshold was constant: the stent ends surpassed the threshold first, followed by the stent cross-links, then the stent struts, and finally the bare area between the stent struts. These locations corresponded in order to the most common locations of intimal proliferation after stent deployment. An exponential relationship between peak stress concentration and percent stent inflation was formulated. CONCLUSIONS: Stent-induced intramural stress injury beyond a certain threshold may cause early restenosis by triggering neointimal hyperplasia. Maximum stress concentrations increase exponentially with stent deployment diameter, highlighting the importance of minimal stent overexpansion and novel stent designs that specifically address peak stress reduction.

Computer Simulation↗