Biomedical subjects

G Pasterkamp

Publications and source records attributed to G Pasterkamp.

At least 55 records · Page 3Linked to original sources

PubMed1999

Temporary luminal arteriotomy seal: III. Postmortem arteriosclerotic human coronary artery.

BACKGROUND: Recently, we described a temporary luminal arteriotomy seal that provided a bloodless arteriotomy without obstructing recipient artery blood flow during bypass grafting in nonarteriosclerotic porcine arteries. This postmortem study assessed the sealing properties in irregular arteriosclerotic human coronary arteries. METHODS: Three hearts were obtained from donated corpses within 24 hours of death. The coronary arteries were pressure-perfused at 60 mm Hg with citrated porcine blood. At 15 anastomosis sites in four different coronary arteries, an end-to-side anastomosis was created using a 200-microm-thick polyurethane seal. Adequacy of sealing was determined at perfusion pressures of 60, 40, and 20 mm Hg. RESULTS: After insertion, the arteriotomy was sealed instantaneously in 10 of 15 anastomoses. After repositioning, complete sealing with a bloodless operative field was obtained in all cases. Low intracoronary transmural pressure did not impede sealing. In 8 of 15 anastomoses, minor leakage without obscuring the arteriotomy edges was observed during anastomotic suturing. Histologic examination revealed no intimal tear or dissection caused by the anastomotic procedure. CONCLUSIONS: In postmortem-obtained arteriosclerotic human coronary arteries, the temporary luminal arteriotomy seal provided optimal visualization of the coronary anastomosis site in combination with persistent distal perfusion.

Aged↗

PubMed1999

Angioscopic complex lesions are predominantly compensatory enlarged: an angioscopy and intracoronary ultrasound study.

OBJECTIVES: Atherosclerotic remodeling of the coronary artery may lead to compensatory enlargement or to shrinkage. Post-mortem data suggest a relation between compensatory enlargement and histopathological markers of plaque vulnerability. In patients that required a coronary intervention, we investigated retrospectively the relation between the angioscopic appearance and the remodeling mode of the culprit lesion. METHODS: In 34 patients, coronary angioscopy and intracoronary ultrasound (ICUS) imaging was performed across the culprit lesion before the intervention. Only single de novo lesions were included. With angioscopy, lesions with a smooth surface without thrombus were classified as smooth, whereas lesions with an irregular surface with or without thrombus were classified as complex. With ICUS, remodeling of the culprit lesions was determined by the relative cross-sectional vessel area (lesion vessel area/reference vessel area) x 100%. Lesions were divided into three groups: compensatory enlargement (relative vessel area > or = 105%), no-remodeling (relative vessel area between 95 and 105%) and shrinkage (relative vessel area < or = 95%). RESULTS: In 22 patients good images were obtained with both imaging modalities. More complex lesions were compensatory enlarged compared to shrunken lesions, whereas more smooth lesions were shrunken compared to compensatory enlarged lesions, 8/9 versus 2/7 and 5/7 versus 1/9, respectively (p = 0.035). CONCLUSIONS: In patients selected for coronary intervention, angioscopic complex atherosclerotic lesions were found predominantly in compensatory enlarged arterial segments, whereas smooth lesions were found predominantly in shrunken arterial segments.

Adult↗

PubMed1999

Clinical implications of online and off-line interobserver variability in intracoronary ultrasound-guided interventions.

UNLABELLED: Intracoronary ultrasound (ICUS)-guided interventions imply online decision making. We investigated the on- and off-line interobserver variability in ICUS measurements and evaluated the clinical implication of the interobserver variability for ICUS-guided interventions in 40 lesions (38 patients). On the same recorded ICUS images, an online and an off-line observer independently selected and analyzed the proximal and distal reference images, the most severe stenosis image before intervention and the minimal lumen area (MLA) image after intervention. In addition, the off-line observer analyzed the online selected images. The interobserver variability (percentage difference between the two observers) of ICUS measurements was determined on images independently selected by both observers (Analysis A) and on images selected by the online observer (Analysis B). The balloon size was determined from ICUS measurements according to the CLOUT trial. After intervention, the CLOUT and MUSIC criteria for MLA by ICUS had to be fulfilled for PTCA and stent procedures, respectively. In Analysis A, the on- and off-line interobserver variability in diameter and area measurements was maximally 9% and 18%, respectively. In Analysis B, the on- and off-line interobserver variability was maximally 6% and 11%, respectively. The off-line observer would have chosen a balloon size differing by more than 0.25 mm in 25 % (10 of 40) and 12.5% (5 of 40) of the procedures in Analysis A and B, respectively. After PTCA or stenting, the off-line observer would have taken different procedural decisions in 19% or 15% and in 13% or 7% of the procedures in Analysis A and B, respectively. IN CONCLUSION: when the same location was selected, the on- and off-line interobserver variability was low. When different locations were selected, however, the interobserver variability resulted in different balloon sizing in 25 % of the cases. Interobserver variability may be a confounding factor in the analysis of ICUS-guided interventions.

Angioplasty, Balloon, Coronary↗

PubMed1999

Coronary artery disease: arterial remodelling and clinical presentation.

OBJECTIVE: To investigate the hypothesis that in coronary artery disease large plaques in compensatorily enlarged segments are associated with acute coronary syndromes, whereas smaller plaques in shrunken segments are associated with stable angina pectoris. METHODS: Patients selected for percutaneous transluminal coronary angioplasty (PTCA) were divided into two groups, one with stable angina pectoris (stable group, n = 37) and one with unstable angina or postmyocardial infarction angina of the infarct related artery (unstable group, n = 32). In both groups, remodelling at the culprit lesion site was determined by intravascular ultrasound before the intervention. Remodelling was calculated as relative vessel area: [vessel area culprit lesion site / mean vessel area of both proximal and distal reference sites] x 100%. Compensatory enlargement was defined as remodelling of >/= 105%, whereas shrinkage was defined as remodelling of </= 95%. RESULTS: In the unstable group, the vessel area at the culprit lesion site was larger than in the stable group, at mean (SD) 18.1 (5.3) v 14.6 (5.4) mm(2) (p = 0.008). Lumen areas were similar. Consequently, plaque area and percentage remodelling were larger in the unstable group than in the stable group: mean (SD) 14.8 (4.8) v 11.6 (4.9) mm(2) (p = 0.009) and 112 (31)% v 95 (17)% (p = 0.005), respectively. Significantly more culprit lesion sites were classified as shrunken in the stable group (21/37) than in the unstable group (8/32; p = 0.014). On the other hand, more lesion sites were classified as enlarged in the unstable group (16/23) than in the stable group (8/37; p = 0.022). CONCLUSIONS: In patients selected for PTCA, the mode of remodelling is related to clinical presentation.

Angina Pectoris↗

PubMed1999

Inflammation of the atherosclerotic cap and shoulder of the plaque is a common and locally observed feature in unruptured plaques of femoral and coronary arteries.

-Retrospectively, plaque rupture is often colocalized with inflammation of the cap and shoulder of the atherosclerotic plaque. Local inflammation is therefore considered a potential marker for plaque vulnerability. However, high specificity of inflammation for plaque rupture is a requisite for application of inflammation markers to detect rupture-prone lesions. The objective of the present study was to investigate the prevalence and distribution (local versus general) of inflammatory cells in nonruptured atherosclerotic plaques. The cap and shoulder of the plaque were stained for the presence of macrophages and T lymphocytes in 282 and 262 cross sections obtained from 74 coronary and 50 femoral arteries, respectively. From most cases, 2 atherosclerotic arteries were studied to gain insight into the local and systemic distribution of the inflammatory process. In 45% and 41% of all cross sections, staining for macrophages was observed in the femoral and coronary arteries, respectively. Rupture of the fibrous cap was observed in 2 femoral and 3 coronary artery segments and was always colocalized with inflammatory cells. At least 1 cross section stained positively for CD68 or acid phosphatase in 84% and 71% of all femoral and coronary arteries, respectively. Only 1 femoral and 6 coronary arteries revealed a positive stain for CD68 in all investigated segments. Inflammation of the cap and shoulder of the plaque is a common feature, locally observed, in atherosclerotic femoral and coronary arteries. The high prevalence of local inflammatory responses should be considered if they are used as a diagnostic target to detect vulnerable, rupture-prone lesions.

Acid Phosphatase↗

PubMed1998

Saline flush during excimer laser angioplasty: short and long term effects in the rabbit femoral artery.

BACKGROUND AND OBJECTIVE: In this study, the effect of flushing saline on arterial wall damage (medial ruptures and necrosis), intimal hyperplasia, and arterial remodeling was determined. During excimer laser coronary angioplasty saline is flushed to reduce the size of explosive water vapor bubbles formed by intraluminal delivery of excimer laser pulses in blood. METHODS: In the femoral artery of the rabbit, 600 excimer laser pulses (308 nm, 50 mJ/mm2 per pulse, 20 Hz) were delivered coaxially over a length of 20 mm in 10 bursts of 3 seconds each. In 24/48 procedures, saline was flushed (0.2 ml/s) via the guidewire channel. After 2 and 56 days, microscopic and angiographic results were compared. RESULTS: At 2 days, as compared to lasing in blood, saline flush had drastically reduced the incidence of dissections (2/12 vs. 11/12, P < 0.002), but had increased the extent of medial and adventitial necrosis. The latter is attributed to direct irradiation of the arterial wall. After 56 days, in the saline group, in the middle-distal part of treated segments, medial necrosis without intimal hyperplasia was observed. However, at the edges of these lesions, intimal hyperplasia and arterial shrinkage reduced the lumen. CONCLUSION: Flushing saline during coaxial excimer laser pulse delivery significantly reduced the incidence of vessel wall ruptures, and prevented intimal hyperplasia formation in part of the lesion. The histologic findings at 56 days are attributed to the optical window which the saline flush provides for direct ultraviolet light irradiation of the arterial wall.

Angiography↗

PubMed1998

Is plaque formation in the common carotid artery representative for plaque formation and luminal stenosis in other atherosclerotic peripheral arteries? A post mortem study.

The atherosclerotic carotid artery is easily accessible for non-invasive duplex investigation. The aim of the present post mortem study was to examine whether plaque accumulation and luminal stenosis in the common carotid artery is representative for atherosclerotic plaque accumulation and luminal stenosis in other peripheral arteries. A total of 3765 cross-sections were obtained at regular intervals from 240 arteries (24 individuals). Five types of peripheral arteries were investigated: common carotid, femoral, common iliac, external iliac and renal arteries. In each cross-section, the lumen area, vessel area, plaque area and maximal plaque thickness was measured. For each location, the percentage luminal stenosis and relative plaque area was calculated. Relative plaque area was defined as the percentage of the vessel area which was occupied by plaque. Weak correlations (r=0.41-0.59) were observed between percentage relative plaque area or maximal plaque thickness in the common carotid artery and percentage relative plaque area in other peripheral arteries. Neither plaque accumulation nor luminal stenosis in the common carotid artery correlated with the percentage luminal stenosis in other peripheral arteries (P > 0.05). We conclude that plaque area in the common carotid artery is weakly correlated with plaque area and not correlated with luminal stenosis in other peripheral arteries.

Aged↗

PubMed1998

Intravascular ultrasound elastography in human arteries: initial experience in vitro.

Intravascular elastography is a new technique to obtain the local mechanical properties of the vessel wall and its pathology using intravascular ultrasound (IVUS). Knowledge of these mechanical properties may be useful for guiding interventional procedures. An experimental set-up is described for assessment of the strain data of arteries. Using a 30-MHz IVUS catheter, radio frequency data are acquired with a custom-made high-performance data acquisition system. High-resolution, local tissue displacement estimation by cross-correlation is followed by computation of local strain. An algorithm that uses a priori knowledge of the correlation coefficient function was applied to filter the obtained strain data. With this experimental set-up, intravascular elastograms containing 400 angles/revolution with a radial resolution of 200 microns can be produced. The feasibility of intravascular elastography with this experimental set-up is demonstrated using two diseased human femoral arteries. Qualitative comparison of the elastograms with the echograms and the histology demonstrates the potential of intravascular elastography to obtain mechanical information from the vessel wall and from plaque.

Algorithms↗

PubMed1998

Relation of arterial geometry to luminal narrowing and histologic markers for plaque vulnerability: the remodeling paradox.

OBJECTIVE: To relate local arterial geometry with markers that are thought to be related to plaque rupture. BACKGROUND: Plaque rupture often occurs at sites with minor luminal stenosis and has retrospectively been characterized by colocalization of inflammatory cells. Recent studies have demonstrated that luminal narrowing is related with the mode of atherosclerotic arterial remodeling. METHODS: We obtained 1,521 cross section slices at regular intervals from 50 atherosclerotic femoral arteries. Per artery, the slices with the largest and smallest lumen area, vessel area and plaque area were selected for staining on the presence of macrophages (CD68), T-lymphocytes (CD45RO), smooth muscle cells (alpha-actin) and collagen. RESULTS: Inflammation of the cap or shoulder of the plaque was observed in 33% of all cross sections. Significantly more CD68 and CD45RO positive cells, more atheroma, less collagen and less alpha-actin positive staining was observed in cross sections with the largest plaque area and largest vessel area vs. cross sections with the smallest plaque area and smallest vessel area, respectively. No difference in the number of inflammatory cells was observed between cross sections with the largest and smallest lumen area. CONCLUSION: Intraindividually, pathohistologic markers previously reported to be related to plaque vulnerability were associated with a larger plaque area and vessel area. In addition, inflammation of the cap and shoulder of the plaque was a common finding in the atherosclerotic femoral artery.

Actins↗

PubMed1998

Intravascular ultrasound elastography: assessment and imaging of elastic properties of diseased arteries and vulnerable plaque.

OBJECTIVE: Intravascular elastography is concerned with methods for measuring the local elastic properties using intravascular ultrasound (IVUS). The elastic properties of the vessel wall and atheroma can be measured through the strain. Knowledge of these mechanical properties is useful for guiding interventional procedures (balloon dilatation, ablation) and detection of plaque vulnerability. METHODS: Elastograms and palpograms (images of strain) were constructed using the relative local displacements between IVUS images acquired at two levels of intravascular pressure with a 30-MHz echo catheter. These displacements were estimated from the time shift between gated radio-frequency echo signals using cross-correlation algorithms with interpolation around the peak. RESULTS: Experiments on gel-based phantoms mimicking atherosclerotic vessels demonstrated the capability of elastography to identify soft and hard plaques independently of the echogenicity contrast. In vitro experiments on human arteries have demonstrated the potential of intravascular elastography to identify different plaque types based on the mechanical properties. These plaques could not be identified using the IVUS image alone. Regions with elevated mechanical stress could also be detected. These stress concentrations are related to plaque fracture. CONCLUSION: Intravascular elastography provides information that is frequently unavailable or inconclusive from the IVUS image and therefore may assist in the diagnosis and treatment of atherosclerotic disease.

Algorithms↗

PubMed1998

Intravascular ultrasound predictors of restenosis after balloon angioplasty of the femoropopliteal artery.

OBJECTIVES: To determine intravascular ultrasound parameters related to restenosis following percutaneous transluminal balloon angioplasty (PTA) of the femoropopliteal artery. DESIGN: Prospective study. MATERIALS AND METHODS: Patients were studies with intravascular ultrasound before and after angiographic successful PTA (n = 114). Intravascular ultrasound cross-sections obtained with 1 cm interval in the dilated segment were analysed. A distinction was made between anatomic (duplex scanning) and clinical (Rutherford criteria) restenosis assessed within 1 month and at 6 months after PTA. RESULTS: Intravascular ultrasound predictors of 1 month anatomic outcome were lumen area stenosis after PTA, lumen area increase, plaque area decrease, and area stenosis decrease; predictor of 6 months anatomic outcome was area stenosis after PTA. Multivariate analysis revealed that area stenosis after PTA was the only independent predictor of both 1 and 6 months anatomic outcome. Intravascular ultrasound predictors of 1 month clinical outcome were the presence of hard lesion and the mean arc of hard lesion. Multivariate analysis revealed that the mean arc of hard lesion was the only independent predictor of 1 month clinical outcome. No predictors for 6 months clinical outcome were found. CONCLUSIONS: Intravascular ultrasound can elucidate parameters predictive of restonosis after PTA. The strongest intravascular ultrasound parameter predictive of anatomic restenosis was a large area stenosis after PTA.

Aged↗

PubMed1998

Shrinkage of human coronary arteries is an important determinant of de novo atherosclerotic luminal stenosis: an in vivo intravascular ultrasound study.

OBJECTIVE: To assess the occurrence of arterial remodelling types and its relation with the severity of luminal stenosis in atherosclerotic coronary arteries. PATIENTS AND METHODS: Twenty one de novo coronary lesions of 20 patients, who were scheduled for percutaneous transluminal coronary angioplasty (PTCA), were investigated with intravascular ultrasound before PTCA. Local arterial remodelling at the lesion site was studied by measuring the cross sectional area circumscribed by the external elastic lamina (EEL) relative to the reference site: (EEL area lesion/reference EEL area) x 100%. Three groups were defined. Group A: relative EEL area of less than 95% (shrinkage), group B: relative EEL area between 95% and 105% (no remodelling), group C: relative increase in EEL area of more than 105% (compensatory enlargement). RESULTS: All three types of remodelling were observed at the lesion site: group A (shrinkage) n = 8, group B (no remodelling) n = 5, group C (compensatory enlargement) n = 8. The mean (SD) relative EEL area at the lesion site in group A and C was 83(9)% and 132(30)%, respectively. In group A, 33% of the luminal area stenosis at the lesion site was caused by shrinkage of the artery. In contrast, group C showed that 87% of the plaque area did not contribute to luminal area stenosis because of compensatory arterial enlargement. CONCLUSIONS: These results show that both compensatory enlargement and paradoxical shrinkage occurs in the atherosclerotic coronary artery. Next to plaque accumulation, the type of atherosclerotic remodelling is an important determinant of luminal narrowing.

Adult↗

PubMed1998

The relation between de novo atherosclerosis remodeling and angioplasty-induced remodeling in an atherosclerotic Yucatan micropig model.

Geometric remodeling in de novo atherosclerosis and in restenosis after balloon angioplasty constitutes a change in total arterial circumference that, together with plaque growth or neointima formation, determines the lumen of the artery. The heterogeneous nature of arterial obstructions raises the question of whether early and late outcomes (restenosis) of angioplasty are affected by the degree and direction of de novo atherosclerotic remodeling. This study was designed to assess the relationship between atherosclerotic remodeling and the degree and mechanism of restenosis after balloon angioplasty. Atherosclerosis was induced in 27 peripheral arteries of 18 Yucatan micropigs by a combination of denudation and atherogenic diet. Balloon angioplasty was performed, with serial intravascular ultrasound and quantitative angiography before and after intervention and at 42 days' follow-up. We used the relative media-bounded area (MBA), defined as the MBA of the treated site divided by the MBA of the reference, before angioplasty as a measure of remodeling in de novo atherosclerosis and late MBA loss as a measure of remodeling after balloon angioplasty. Relative MBA before angioplasty was not correlated with angiographic and echographic acute gain after balloon angioplasty (r=.22, P=.28 and r=.14, P=.48) or with late lumen loss (r=-.05, P=.81 and r=.19, P=.33). No correlation was found between relative MBA and late MBA loss (r=.14 and P=.48). In the atherosclerotic Yucatan micropig, remodeling during de novo atherosclerosis has no relevance for acute gain and late lumen loss after balloon angioplasty. Both the direction and the extent of remodeling after balloon angioplasty are not related to the direction and extent of remodeling during de novo atherosclerosis.

Angiography↗

PubMed1997

Prediction of restenosis after coronary balloon angioplasty. Results of PICTURE (Post-IntraCoronary Treatment Ultrasound Result Evaluation), a prospective multicenter intracoronary ultrasound imaging study.

BACKGROUND: Intracoronary ultrasound (ICUS) imaging is potentially suitable to identify lesions at high risk of restenosis after percutaneous transluminal coronary angioplasty (PTCA), but it has not been studied systematically. METHODS AND RESULTS: We recruited 200 patients in whom ICUS studies were performed after successful PTCA and related their ICUS parameters to 6-month follow-up quantitative coronary angiography. This was performed in 164 patients (82%), yielding 170 lesions for analysis. The overall incidence of a > or = 50% diameter stenosis at follow-up (categorical restenosis) was 29.4%. Quantitative ICUS parameters were weakly but significantly related to follow-up minimal luminal diameter on quantitative coronary angiography (lumen area: R2 = .36, P = .0001; vessel area: R2 = .29, P = .0002; plaque area: R2 = -.18, P = .021; percent obstruction: R2 = -.15, P = .05), but categorical restenosis was not significantly related to these parameters (P = .63, .77, .38, and .08, respectively). There were no significant predictors of restenosis in ICUS parameters of plaque morphology: eccentric versus concentric (P = 1.0), plaque type (hard, soft, or calcific, P = .98), or the number of calcified quadrants (P = .41). There were no significant predictors of restenosis in two predefined types of vessel-wall disruptions: (1) rupture: presence (P = .79), depth (partial versus complete, P = .85), or extent in quadrants (P = .6), and (2) dissection: presence (P = .31), depth (P = .82), or extent (P = .38). CONCLUSIONS: Qualitative ICUS parameters after PTCA did not predict restenosis. A larger lumen and vessel area and a smaller plaque area by ICUS were associated with a larger angiographic minimal lumen diameter at follow-up, but these parameters were not significantly related to categorical restenosis.

Aged↗

PubMed1997

Impact of local atherosclerotic remodeling on the calculation of percent luminal narrowing.

The choice of the reference site in order to calculate percent luminal narrowing mainly depends on which diagnostic tool is used for examination. In intravascular ultrasound or histology, the local area encompassed by the internal elastic lamina (IEL) area is used as a reference. However, the local IEL area, and thereby the reference value, may have been altered by atherosclerotic remodeling. In the present study we examined the impact of local arterial remodeling on the calculation of luminal narrowing. Forty-five human femoral arteries were analyzed, 32 postmortem and 20 in vivo, by intravascular ultrasound. Cross sections were examined every 0.5 cm over an arterial segment length of 10 to 15 cm. In each cross section we measured the lumen area and the IEL area. Two reference areas were used to calculate percent luminal narrowing: (1) the lumen area in the cross section that contained the least amount of plaque (distant reference); and (2) the local IEL area (local reference). In each cross section, the IEL area was expressed as percent of the IEL area in the cross section that contained the least amount of plaque (relative IEL area). Using the distant reference, we found that less luminal narrowing was observed for cross sections with a relative IEL area > 100% (indicating compensatory enlargement) than for those with a relative IEL area < 100% (indicating shrinkage), whereas percent luminal narrowing calculated using the local reference hardly differed between cross section with a relative IEL area > 100% and < 100%. Thus, arterial wall remodeling makes the local IEL area an unreliable reference for calculation of percent luminal narrowing. The calculated percent luminal narrowing using a distant, nondiseased reference site reflects the actual change of the luminal area more accurately.

Aged↗

PubMed1997

Arterial remodeling after balloon angioplasty of the coronary artery: an intravascular ultrasound study. PICTURE Investigators. PostTreatment IntraCoronary Transluminal Ultrasound Result Evaluation.

OBJECTIVE: Before balloon dilation, failure of compensatory enlargement and even arterial shrinkage are frequently observed at the lesion site in response to plaque accumulation. Balloon angioplasty may be regarded as artificial remodeling to enlarge the artery. The prevalence of the different types of arterial wall remodeling after applied stretch by balloon angioplasty is unknown. METHODS AND RESULTS: In 181 patients an intravascular ultrasound study was performed after coronary balloon angioplasty (n = 200 lesions). The vessel area was measured at a proximal and distal reference site and at the lesion site. Subsequently, the relative vessel area [(Vessel area lesion site)/Vessel area reference site) x 100] was calculated. Lesions were classified in three groups on the basis of their relative vessel areas: > or =105%, <105% but >95%, and < or =95%. A relative vessel area > or =105%, indicating enlargement compared with the reference site, was observed in 84 (44%) lesions. A relative vessel area <105% but >95% was observed in 43 (22%) lesions. A relative vessel area < or =95%, indicating "shrinkage" compared with the reference site, was observed in 66 (34%) lesions. CONCLUSIONS: After balloon angioplasty, the vessel area was found to be smaller compared with the reference site in 34% of the lesions. This small vessel area at the lesion site compared with a reference site may be a reflection of insufficient stretch by balloon angioplasty.

Angioplasty, Balloon, Coronary↗

PubMed1997

Remodeling of the atherosclerotic arterial wall: a determinant of luminal narrowing in human coronary arteries.

BACKGROUND: The type of remodeling of the human femoral artery (enlargement or shrinkage) is related to the percentage luminal stenosis. OBJECTIVE: To assess how local changes in vessel size, together with plaque load, determine luminal narrowing in atherosclerotic human coronary arteries. METHODS: We obtained 576 segments of 28 coronary arteries from 10 patients who had died from noncardiac causes. The lumen area and area circumscribed by the internal elastic lamina (IEL) area, a measure of local vessel size in each histologic cross-section were measured, and the mean lumen diameter and mean IEL diameter were calculated. To correct for arterial tapering, expected reference diameter values were calculated at the same location using linear regression of all data points along the artery. The IEL diameter and lumen diameter were expressed as percentages of the calculated IEL diameter and lumen diameter at the same location (percentage lumen diameter stenosis and relative IEL diameter, respectively). RESULTS: We found a negative relation between the relative IEL diameter and the percentage lumen diameter stenosis. On average, a narrower than expected lumen diameter was accompanied by a smaller than expected IEL diameter. A larger than expected lumen diameter was accompanied by a larger than expected IEL diameter. This relation was found for the left anterior descending, circumflex, and right coronary arteries (y = -0.60x + 105.33, r = 0.48; y = -0.45x + 100.69, r = 0.84; and y = -0.39x + 101.84, r = 0.61, respectively, all P < 0.05). CONCLUSIONS: Local luminal narrowing was correlated with a decrease in vessel size. Local remodeling of the artery is one of the determinants of luminal narrowing in the atherosclerotic human coronary artery.

Coronary Artery Disease↗

PubMed1997

Renal artery origins: location and distribution in the transverse plane at CT.

PURPOSE: To determine the in situ location and distribution of the renal artery origins in the transverse plane with computed tomography (CT). MATERIALS AND METHODS: CT scans of the paired main renal arteries in 200 patients (89 men, 111 women) were retrospectively reviewed. The locations of the renal artery origins, defined on the basis of their optimal profile angles, and the angle between them were measured. The degree of aortic atherosclerosis was graded in 119 of the 200 patients. RESULTS: The origins of 400 paired main renal arteries were identified. A statistically significant difference was found between the average best profile angle on the right (24 degrees [range, 26 degrees-70 degrees]) and that on the left (5 degrees [range, -75 degrees to 38 degrees]) (P < .001). Truly laterally located renal arteries were seen on the right in 11 (5%) of 200 right renal arteries and on the left in 56 (28%) of 200 left renal arteries. One hundred eighty-six (93%) of 200 right ostia and only 40 (20%) of 200 left ostia were in an anterolateral location. One hundred four (52%) of 200 left ostia and three (2%) of 200 right ostia were in a posterolateral location. The prevalence of truly opposite renal arteries was 17%. The average profile angle between the renal artery origins was 161 degrees (range, 72 degrees-225 degrees) and was significantly larger in women (P = .001). No relationship was found between ostial location and patient age or atherosclerotic grade. CONCLUSION: In the transverse plane, the location of the origin of the right renal artery tended to be anterolateral and of the left renal artery tended to be posterolateral or lateral. The variation in location and distribution width was great.

Aortic Diseases↗