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Dietrich Baumgart

Publications and source records attributed to Dietrich Baumgart.

At least 19 recordsLinked to original sources
PubMed2006

Frequency and outcomes of acute renal failure following thoracic aortic stent-graft placement.

We assessed the incidence, correlates, and outcomes of acute renal failure (ARF) after thoracic aortic stent-graft placement. Postprocedural ARF is an inherent complication of catheter-based interventional procedures that use intra-arterial contrast agents and has adverse effects on short- and long-term outcomes. However, few data exist on the incidence, predictors, and outcomes of ARF after thoracic aortic stent-graft placement. We analyzed data of 97 patients (64.4 +/- 11.6 years of age; 73% men) who underwent thoracic aortic stent-graft placement from July 1999 to October 2005. Postprocedural ARF was defined as an increase > or = 25% and/or > or = 0.5 mg/dl in preprocedural serum creatinine at 48 hours after the procedure. Baseline estimated glomerular filtration rate was 65 +/- 24 ml/min/1.73 m2. Chronic kidney disease (glomerular filtration rate < or = 60 ml/min/1.73 m2) at baseline was present in 45% of patients. During the stent-graft procedure, patients received 307 +/- 188 ml of nonionic contrast medium. Postprocedural ARF occurred in 33 patients (34%), and 3 required dialysis. Multivariable analysis identified American Society of Anesthesiologists class > 3 (odds ratio 5.53, 95% confidence interval 1.71 to 17.85, p = 0.004) and duration of the stent-graft procedure (odds ratio 1.01, 95% confidence interval 1.001 to 1.014, p = 0.022) as independent predictors of postprocedural ARF. Compared with patients without ARF, those with ARF had markedly higher 30-day (18.2 +/- 6.7% vs 1.6 +/- 1.6%, p = 0.0022) and 1-year (35.2 +/- 8.6% vs 10.1 +/- 3.9%, p = 0.001) mortality. In conclusion, postprocedural ARF is a frequent complication of thoracic aortic stent-graft placement and has a significant adverse effect on 30-day and 1-year survival. Baseline factors identified in our study as associated with increased risk of ARF may facilitate a comprehensive informed consent process by way of patient education. In addition, identification of an at-risk subset may allow modification of reversible periprocedural factors that may help decrease postprocedural ARF.

Acute Kidney Injury↗
PubMed2006

Underlying aortic pathology and clinical health status determine success of endovascular stent-grafting for descending thoracic aortic disease.

Despite advances in medical and surgical treatment, acute as well as chronic diseases of the thoracic aorta are still associated with a high mortality. For the descending thoracic aorta, endovascular stent-graft placement competes with surgical therapy for clinical outcome. From July 1999 till December 2004, a total of 84 patients (64 +/- 14 years) with aortic disease of the descending thoracic aorta were treated. Nine patients had acute (AAD) and 35 chronic aortic dissection (AD), 16 had thoracic aortic aneurysms (TAA), 21 had penetrating aortic ulcer (PAU), and 3 patients had traumatic dissection (trans). Initial clinical status was assessed using the American Society of Anesthesiologists (ASA) classification. Fifty-three patients were in class 2, 16 in class 3, 8 in class 4, and 7 in class 5. Stent-graft placement was performed in the cardiac catheterization laboratory with the patient under general anesthesia. Technical success was obtained in 81/84 patients (96%). Within 30 days, seven patients (8%) died, four of them due to aortic rupture. In 14 patients, additional stent-grafts had to be implanted due to type I endovascular leakage (n = 5) or additional entry site adding up to a total of 107 implanted stent-grafts. During a follow-up period of 21 +/- 18 months, 17 additional patients died (22%). In 10 patients, death was disease- or procedure-related (13%). This long-term mortality depended on the underlying disease and was highest in the group with TAA (45%) followed by AAD (38%) and AD (18%). Patients in ASA class 4 and 5 had a significantly worse outcome. No aortic-related death occurred among patients with PAU or traumatic transsections. Overall, there was only one transient neurological deficit. Endovascular stent-graft placement has acceptable results in the treatment of patients with disease of the descending thoracic aorta. The outcome strongly depends on the underlying aortic pathology and the clinical health status of the patients. Randomized trials are necessary in order to establish the exact value of this new therapeutic option.

Adult↗
PubMed2006

Endovascular stent-graft treatment of penetrating aortic ulcer: results over a median follow-up of 27 months.

BACKGROUND: Penetrating aortic ulcer (PAU) is increasingly acknowledged as a pathological variant of classic false-lumen aortic dissection with a high incidence of bleeding complications and rupture in up to 40% of patients. The objective of this study was to investigate the results of endovascular stent-graft placement for the treatment of patients with PAUs. METHODS: Between July 1999 and December 2004, endovascular stent-graft repair of PAU was performed in 22 patients (69.1 +/- 7.8 years, 16 men), 3 (14%) of whom had contained aortic rupture. Stent-graft placement was performed in the cardiac catheterization laboratory with the patient under general anesthesia, using a surgical access. RESULTS: Procedural success was achieved in all but 1 patient (technical success rate 96%). Postoperatively, 1 (5%) patient had minor stroke with transient amentia. There were no other inhospital complications or deaths. During a median follow-up of 27 (range 1-62) months, 1 patient underwent adjunctive stent-graft placement for type I endoleak. Three patients died unrelated to the aortic disease late during follow-up. Overall survival rates were 100% at 30 days, 100% at 1 year, 82.5% +/- 11.3% at 2 years, and 61.9% +/- 20.0% at 5 years. CONCLUSIONS: Endovascular stent-graft treatment is an effective treatment for patients with PAU and is associated with low procedural morbidity. Both acute and midterm mortality of this novel treatment concept appear to be favorable compared with the natural course of the disease.

Aged↗
PubMed2005

Endovascular stent-graft placement in aortic dissection: a meta-analysis.

AIMS: This article summarizes all available published data with respect to clinical success, complications, and outcomes of endovascular stent-graft placement among patients with descending aortic dissection (AD). METHODS AND RESULTS: We performed a meta-analysis of all published series on retrograde endovascular stent-graft placement encompassing >or=3 patients with AD. Thirty-nine studies, involving a total of 609 patients, were included. Procedural success was reported in 98.2+/-0.5% of patients. Major complications were reported in 11.1+/-1.4%, with the most dreaded neurologic complications in 2.9+/-0.7% patients. Periprocedural stroke was encountered more frequently than paraplegia (1.9+/-0.6% vs. 0.8+/-0.4%). Overall complications were significantly higher in patients undergoing stent-graft placement for acute AD than in patients with chronic AD (21.7+/-2.8% vs. 9.1+/-2.3%, P=0.005). The overall 30-day mortality was 5.3+/-0.9%, and was three-fold higher in patients with acute AD when compared with chronic AD (9.8+/-2.2% vs. 3.2+/-1.4%, P=0.015). In addition, 2.8+/-0.7% of patients died over a mean follow-up period of 19.5+/-7.1 months. Kaplan-Meier analysis yielded overall survival rates of 90.6+/-1.6% at 6 months, 89.9+/-1.7% at 1 year, and 88.8+/-1.9% at 2 years, respectively. CONCLUSION: Endovascular stent-graft placement in type B-AD is technically feasible with success rates of >95% in selected cohort. Although minimally invasive, major complications occurred in 14-18% of patients depending upon the acuity of presentation, with very low incidence of paraplegia. Both, acute and mid-term mortality of this novel treatment strategy appear to favourably compare with surgical treatment but further studies are necessary to compare stent-graft placement with medical treatment in uncomplicated AD.

Acute Disease↗
PubMed2005

Endovascular stent-graft treatment of aortic dissection: determinants of post-interventional outcome.

AIMS: To investigate the results of endovascular stent-graft placement for the treatment of patients with type B aortic dissection (B-AD). METHODS AND RESULTS: A total of 38 patients (62+/-10 years, 32 male) with acute (n=10) and chronic (n=28) type B-AD were treated with endovascular stent-grafts. The implantation procedure was successful in all patients. Peri-procedural non-fatal complications occurred in four (11%) patients. Overall, 4/38 (11%) patients died during the in-hospital period. Patients undergoing stent-graft placement for acute AD had a significantly higher in-hospital mortality than patients with chronic AD (40 vs. 0%, P=0.001). During a median follow-up of 18 (1-57) months, there were six additional deaths. Overall survival rates were 97.4+/-2.6% at 30 days, 80.4+/-6.7% at 1 year, 73.2+/-7.8% at 2 years, and 54.9+/-16.9% at 4 years. Patients with a poor clinical health status (ASA class > 3) had a significantly reduced life expectancy compared with patients with only moderate co-morbidities (ASA class </= 3) (1-year survival rate 28.6+/-17.1 vs. 92.6+/-6.7%, P=0.0001). Multivariable analysis revealed that a poor clinical health status (ASA>3) pre-operatively (HR=29.5, 95% CI 1.5-581.9, P=0.026) and increased age (HR=1.1, 95% CI 0.9-1.2, P=0.084) were independent determinants of post-interventional mortality. CONCLUSION: Endovascular stent-graft treatment is a safe alternative for patients with AD. The pre-operative clinical health status of the patient is the most important determinant of post-interventional outcome. Careful patient selection is thus of particular importance.

Acute Disease↗
PubMed2005

Endovascular stent-graft placement for acute and contained rupture of the descending thoracic aorta.

OBJECTIVES: To identify determinants of postinterventional death after endovascular stent-graft placement for acute rupture of the descending thoracic aorta, an emerging therapeutic modality for this highly life-threatening condition. METHODS: Between July 1999 and November 2004, 17 patients (14 males; mean age, 65+/-16 (25-83) years) underwent stent-graft repair of the descending thoracic aorta for acute rupture from a thoracic aneurysm (TAA, n=6), acute aortic dissection (AAD, n=6), penetrating aortic ulcer (PAU, n=3), or blunt chest trauma (n=2). Immediate, 30-day, 1-year, and 3-year mortality was assessed. Twenty-one clinical and procedural variables were evaluated in a post-hoc analysis regarding their influence on mortality. Of these, four preprocedural factors with the greatest impact were used to construct a rupture score with a scale from 0 (no adverse prognostic factors present) to 4 (all four adverse factors present). RESULTS: Stent-graft placement was technically feasible in all patients. Complete exclusion of the ruptured aortic pathology could be achieved in only 11 (65%) patients, despite implantation of 1.6+/-0.9 stent-grafts per patient, with a median length of 130 mm. There was one procedure-related early complication (bleeding at the access site). One patient died immediately following the procedure because of progressive mediastinal hematoma, although the rupture site was effectively sealed. Overall survival rates were (76.5+/-10.3)% at 30 days and (52.9+/-12.1)% at 1 year and remained at (52.9+/-12.1)% at 3 years. The four most important preprocedural denominators of death were (1) TAA or AAD as the underlying etiology of aortic rupture (P=0.024), (2) maximum aortic diameter>5 cm (P=0.024), (3) presence of mediastinal hematoma (P=0.056), and (4) an estimated lesion length requiring >1 stent-graft to be covered (P=0.009). Furthermore, residual leakage at the conclusion of the procedure (P=0.009), postprocedural need for dialysis (P=0.004), and prolonged ventilation (P=0.043) were significantly associated with postprocedural death. Using a threshold of >or=3, the rupture score constructed on the basis of the four preprocedural denominators of death was found to be well suited to discriminate postprocedural death (1-year survival: (20.0+/-12.7)% in patients with a rupture score>or=3 vs. 100% in patients with a rupture score<3, P=0.001). CONCLUSION: Endovascular stent-graft placement in patients with acute aortic rupture was technically feasible, albeit still associated with high mortality. A simple risk score constructed in retrospect, on the basis of preprocedural prognostic factors, appeared to provide a useful separation of candidates who are likely to benefit from a straightforward endovascular procedure and should be tested prospectively in future studies.

Acute Disease↗
PubMed2004

Spectrum of remodeling behavior observed with serial long-term (>/=12 months) follow-up intravascular ultrasound studies in left main coronary arteries.

Most intravascular ultrasound (IVUS) studies of arterial remodeling in native coronary arteries reported a remodeling index obtained at a single time point. We analyzed serial IVUS examinations, including the vessel cross-sectional area changes (remodeling behavior), of 60 hemodynamically nonstenotic left main lesions (baseline vs 18.4 +/- 9.4 months follow-up). Lumen reduction resulted from vessel reduction (sometimes despite plaque + media decrease), plaque + media increase (with or without vessel increase), or both. The percent annual changes in lumen area correlated strongly with changes in vessel (r = 0.84), but not with changes in plaque + media area. Plaques were classified as group A lesions, reflecting positive remodeling behavior (vessel changes >0), or group B lesions, reflecting negative (or intermediate) remodeling behavior (vessel changes <==0). Both groups did not differ significantly in demographics, laboratory data, and medications. Group A lesions (n = 40) more often showed plaque + media increase than group B lesions (32 of 40 [80%] vs 9 of 20 [45%]; p = 0.02). Group A lesions had, on average, mild annual lumen increase despite mild plaque + media increase, i.e, overcompensation of remodeling for plaque + media increase (vessel increase greater than plaque + media area increase, 19 of 40 [47%]). Conversely, group B lesions (n = 20) showed a significant lumen area reduction (-2.8 +/- 2.6 mm(2)/year) as a result of a decrease in vessel area only. Thus, serial long-term reduction of lumen size may result from vessel shrinkage (sometimes despite plaque decrease), plaque increase (with or without vessel increase), or both; overall, only the remodeling behavior has a significant relation to lumen changes. More than 30% of lesions show a negative remodeling behavior, which shows no relation to patient characteristics or initial plaque burden.

Aged↗
PubMed2004

Successful reduction of in-stent restenosis in long lesions using beta-radiation--subanalysis from the RENO registry.

PURPOSE: Long lesions remain a challenging task in interventional cardiology, with a high propensity of restenosis, especially within the stented segment. Although intracoronary gamma-radiation has been proved to reduce diffuse in-stent restenosis in long lesions, such an effect remains to be determined using beta-radiation. METHODS AND MATERIALS: Of 1098 consecutive patients at 46 European centers treated with localized beta-radiation ((90)Sr, Novoste Beta-Cath System), 139 patients (mean age 61.5 +/- 10.7 years, 84% male, 22% with diabetes mellitus) with lesions treated using a >40-mm source length underwent radiation using a single 60-mm source train (34%) or a stepping/pullback procedure with a 30-mm (12%) or 40-mm (87%) source length after conventional interventional procedures. The mean lesion length was 35.3 +/- 17.9 mm. RESULTS: Technical success was achieved in 96% of cases. Geographic miss was noted in 9 patients (6.5%). The reference (placebo) group was obtained from the Washington Hospital Center for In-Stent Restenosis Trial (WRIST) and the WRIST Trial for long lesions (LONG WRIST) studies by selecting the cases (94 patients) that required a dummy source length >/=13 seeds (or >51 mm in length). Statistically significant improvement was noted in late angiographic restenosis (34.7% vs. 76.5%, p <0.0001), target vessel revascularization (14.9% vs. 60.6), and major adverse cardiac events (i.e., death, myocardial infarction, or total vessel revascularization) (17.9% vs. 64.9%, p <0.0001) at 6 months in reference to the nonradiation group. CONCLUSION: This subanalysis from the Radiation in Europe with Novoste study confirms the safety and efficacy of beta-radiation combined with conventional interventional procedures in patients with diffuse, long, in-stent restenosis

Aged↗
PubMed2004

Intracoronary brachytherapy, a promising treatment option for diabetic patients: Results from a European multicenter registry (RENO).

Despite advances in the interventional treatment of coronary disease, diabetics still have double the case fatality rate as nondiabetics. The purpose of this analysis from the Radiation in Europe With Novoste (RENO) registry was to assess the clinical and angiographic 6-month outcome of diabetic patients in comparison to nondiabetic patients after localized beta-radiation. A total of 1,098 patients (83.8% with in-stent restenosis) treated with the Novoste Beta-Cath system in Europe were enrolled in the RENO registry. Diabetes was, irrespective of the type of lesion treated, no significant risk factor for major adverse cardiac events or target vessel revascularization. Individuals with diabetes (n = 256) and without diabetes (n = 833) displayed no significant differences concerning clinical or angiographic endpoints. Vascular brachytherapy appears to be the first technique to even out the increased risk of diabetic patients undergoing percutaneous coronary interventions in the routine clinical setting. Thus, intracoronary brachytherapy represents a promising treatment option for diabetic patients.

Brachytherapy↗
PubMed2004

The EchoMap System: online integration of intracoronary ultrasound and Doppler images into angiographic images during cardiac catheterization. Influence on radiation exposure and procedure parameters.

The EchoMap system allows online integration of intravascular ultrasound (IVUS) and intracoronary Doppler (ICD) images into angiographic images during catheterization, providing exact localization of the IVUS transducer and the ICD wire tip position. Although this is a major advance, the use of the system could lead to more angiographic documentation sequences and enhanced radiation exposure. We investigated the influence of system use on radiation and procedure parameters. During a 22-month period, 794 patients underwent coronary angiography with simultaneous performance of IVUS and/or ICD. The EchoMap system was applied in 392 patients ("EchoMap group"), the remaining 402 patients formed the "No-EchoMap group." Multivariate regression analysis showed no independent association between the use of EchoMap and fluoroscopy time (14.7 +/- 8.5 minutes in the EchoMap group vs 14.5 +/- 10 minutes in the No-EchoMap group, P = NS) or dose area product (7589 +/- 4916 in the EchoMap group vs 7031 +/- 5434 cGy x cm(2), P = NS). EchoMap use was significantly associated with a moderate increase in contrast media amount (392 +/- 162 in the EchoMap vs 356 +/- 155 mL in the No-EchoMap group, P = 0.001). In conclusion, the use of the EchoMap system had no significant influence on radiation exposure during cardiac catheterization, whereas it was associated with a moderate increase in contrast media amount.

Cardiac Catheterization↗
PubMed2004

Aortoesophageal fistula secondary to stent-graft repair of the thoracic aorta.

PURPOSE: To report the incidence and management of aortoesophageal fistula (AEF) secondary to endovascular stent-graft repair of the descending thoracic aorta. METHODS: A retrospective review was conducted of patients treated at our facility between July 1999 and June 2003. During this interval, 60 patients (46 men; average age 66+/-10 years) underwent thoracic aortic stent-graft placement for a variety of pathologies. RESULTS: AEF occurred in 3 (5%) patients. One 62-year-old man presented with recurrent back pain and fever and died suddenly due to fatal exsanguination; the AEF was revealed at necropsy. The other 2 patients (both women) presented with hematemesis after endovascular repair of thoracic aortic aneurysms. AEF was detected by esophagogastroduodenoscopy. Both patients were treated conservatively, as open surgical repair was refused because of their general condition. Both patients developed severe mediastinitis and died after 5 weeks and 10 months, respectively. CONCLUSIONS: Aortoesophageal fistula is, in our experience, a catastrophic complication of endovascular stent-graft placement. Treatment options are very limited, as these patients are usually not candidates for open surgery. Outcome under conservative management is, however, almost invariably fatal.

Aged↗
PubMed2004

Identification of syndrome X using intravascular ultrasound imaging and Doppler flow mapping.

BACKGROUND: The purpose of this study was to assess the morphological changes and physiological function of coronary arteries in patients presenting with chest pain but having normal coronary angiograms, using intravascular ultrasound imaging (IVUS) and intracoronary Doppler (ICD) flow measurements, in order to elucidate the mechanism of syndrome X. METHODS: A total of 126 patients [67 males, 59 females, mean age (53.1 +/- 13.0) years] who experienced chest pain but had normal coronary angiograms were included in this study. ICD flow measurements of the left anterior descending coronary artery (LAD) were performed using a Cardiometrics FloMap II system. Coronary flow velocity reserve (CFVR) was defined as the ratio of the average peak velocity during hyperemia to that at baseline, induced by an intracoronary bolus injection of 18 microg adenosine. A 3.2F or 2.9 F 30 MHz mechanical rotating ultrasound catheter (CVIS, Boston Scientific) or a 3.0 F 20 MHz electronic ultrasound catheter (Endosonics) was used for IVUS. RESULTS: The mean CFVR value of the LAD was 2.71 +/- 0.74. Reduction of CFVR (< 3.0) was found in 82 of 126 (65.1%) patients. IVUS images of the LAD were available for 109 patients. Plaque formation was detected in 76/109 (69.7%) patients. Based on the presence or absence of plaque formation as well as the reduction or non-reduction of CFVR, patients were divided into four groups: Group I (n = 10), normal IVUS findings and normal CFVR; Group II (n = 23), normal IVUS findings with reduction in CFVR; Group III (n = 29), IVUS evidence of plaque formation but normal CFVR; and Group IV (n = 47), IVUS evidence of plaque formation with reduction in CFVR. CONCLUSION: This study shows the important clinical value of a combination of IVUS and ICD in diagnosing patients with angiographically normal coronary arteries. Only 10% of patients studied (Group I) were found to be truly free of coronary disease, while 20% of patients (Group II) would be diagnosed as suffering from syndrome X.

Adult↗
PubMed2004

Impact of gender on femoral access complications secondary to application of a collagen-based vascular closure device.

BACKGROUND: Vascular complications at the femoral access site continue to be a significant problem after cardiac catheterization procedures. It was the aim of the present study to assess the impact of gender on the incidence of severe femoral access complications following the application of a collagen-based vascular closure device after transfemoral catheterization procedures. METHODS: A total of 1,294 consecutive patients (977 male, 317 female) underwent closure of femoral access sites with 8F collagen-based vascular closure devices (Angioseal) immediately after diagnostic or interventional coronary catheterization procedures, independently of the coagulation status. All patients were closely monitored for the occurrence of complications during the following 24 hours. RESULTS: Between male and female patients, there was no difference in the technical performance of the device with successful deployment being achieved in 96.7% and 95.9%, respectively (p=0.60). Severe access complications were found to be significantly higher in female versus male patients (1.6% vs. 0.2%; Odds ratio 7.7, 95% confidence interval 1.5-40.1; p=0.015), although similar accomplishment of an immediate hemostasis was seen in 92.8% and 92.4% of male and female patients (p=0.98). CONCLUSION: Women show a significantly increased risk of developing severe femoral access complications secondary to the application of a collagen-based vascular closure device, although the overall incidence of these complications is relatively low. We speculate that the increased risk in women may be related to smaller arterial dimensions, which could be evaluated by femoral angiography prior to deployment of a closure device.

Adult↗
PubMed2003

Relation between progression and regression of atherosclerotic left main coronary artery disease and serum cholesterol levels as assessed with serial long-term (> or =12 months) follow-up intravascular ultrasound.

BACKGROUND: The relation between serum lipids and risk of coronary events has been established, but there are no data demonstrating directly the relation between serum low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol versus serial changes in coronary plaque dimensions. METHODS AND RESULTS: We performed standard analyses of serial intravascular ultrasound (IVUS) studies of 60 left main coronary arteries obtained 18.3+/-9.4 months apart to evaluate progression and regression of mild atherosclerotic plaques in relation to serum cholesterol levels. Overall, there was (1) a positive linear relation between LDL cholesterol and the annual changes in plaque plus media (P&M) cross-sectional area (CSA) (r=0.41, P<0.0001) with (2) an LDL value of 75 mg/dL as the cutoff when regression analysis predicted on average no annual P&M CSA increase; (3) an inverse relation between HDL cholesterol and annual changes in P&M CSA (r=-0.30, P<0.02); (4) an inverse relation between LDL cholesterol and annual changes in lumen CSA (r=-0.32, P<0.01); and (5) no relation between LDL and HDL cholesterol and the annual changes in total arterial CSA (remodeling). Despite similar baseline IVUS characteristics, patients with an LDL cholesterol level > or =120 mg/dL showed more annual P&M CSA progression and lumen reduction than patients with lower LDL cholesterol. CONCLUSIONS: There is a positive linear relation between LDL cholesterol and annual changes in plaque size, with an LDL value of 75 mg/dL predicting, on average, no plaque progression. HDL cholesterol shows an inverse relation with annual changes in plaque size.

Cholesterol↗
PubMed2003

Preintervention arterial remodeling affects vessel stretch and plaque extrusion during coronary stent deployment as demonstrated by three-dimensional intravascular ultrasound.

The mechanisms of lumen enlargement during stent implantation may be significantly affected by arterial remodeling. To assess effects of lesion remodeling, we performed 3-dimensional intravascular ultrasound (IVUS) analyses in 55 coronary lesions before and after deployment of balloon-expandable stents. Standard quantitative analysis was performed, and arterial remodeling was assessed by the remodeling index (target site divided by mean of proximal and distal reference segment vessel areas), which classified lesions into group A (remodeling index < or =1, negative or intermediate remodeling, n = 40) or group B (remodeling index >1, positive remodeling, n = 15) lesions. Characteristics of the 55 patients and the interventional procedures were similar in the 2 groups. IVUS demonstrated that stenting resulted in increased lumen and vessel dimensions and in a reduced plaque size (p < or =0.001 each) in both group A and group B lesions. The extent of lumen increase inside the stents was almost identical, but resulted from different mechanisms: (1) vessel stretch was greater in group A (p <0.002 at minimum lumen site); (2) plaque compression (or embolization) tended to be greater in group B (p = 0.05, along entire stented segment); (3) plaque redistribution within the stent was observed in both groups (p <0.005 both); and (4) significant (p <0.01) plaque extrusion into the distal reference segment was found in group B only. Thus, the remodeling pattern of coronary lesions has a significant impact on the mechanisms of lumen enlargement during stent deployment. Lesions with positive remodeling show more plaque extrusion into the distal reference and less stent-induced vessel stretch than those with negative remodeling.

Aged↗
PubMed2003

Impact of moderate lesion calcium on mechanisms of coronary stenting as assessed with three-dimensional intravascular ultrasound in vivo.

Axial plaque redistribution is an important mechanism of lumen enlargement after stenting of noncalcified lesions. To assess effects of lesion calcification on mechanisms of coronary stenting, we analyzed 55 lesions with noncircumferential calcification with 3-dimensional intravascular ultrasound (IVUS) (standard qualitative and quantitative analyses) before and after implantation of balloon-expandable stents. Thirty-two plaques (58%) showed arcs of calcium <120 degrees of vessel circumference (group A), whereas 23 lesions (42%) contained arcs of calcium > or =120 degrees of vessel circumference (group B). In the entire cohort of 55 lesions, as well as groups A and B, which were studied separately, both single-slice IVUS analysis (performed at minimum lumen site before intervention) and mean stented segment IVUS analysis showed an increase in lumen and vessel area and a decrease in plaque area (p <0.001). The magnitude of lumen and vessel increase and of plaque decrease was similar in both groups. Group A lesions showed significant plaque extrusion into the distal reference segment that was not observed in group B (increase in plaque area of 1.3 +/- 1.9 vs 0.1 +/- 2.0 mm(2), p <0.04). Stenting did not alter plaque area of the proximal reference segment in either group. In addition, there was an increase in vessel area of the distal reference of both groups, indicating that stent-induced vessel expansion observed within the lesion also affected the distal reference. Thus, longitudinal plaque redistribution and vessel expansion contribute to increased lumen dimensions during stenting of lesions with varying amounts of calcium; however, marked plaque extrusion was found only in lesions with a calcium arc of <120 degrees.

Aged↗