Average Stenosis Research Articles

Physiological Significance of a Coronary Stenosis Assessed from Pulsatile Resistance Index at Baseline Flow

Coronary pressure and flow waveforms change in the presence of a stenosis. We exploited the pulsatile nature of these hemodynamic signals to assess functional coronary stenosis severity.In 29 patients, aortic pressure (Pa), and distal coronary pressure (Pd) and flow velocity (v) were recorded at rest and during maximal hyperemia in a diseased vessel. An index of the dynamic signal energy per cycle was defined as the root mean square of the recorded time‐varying signal after removing the mean. The Pulsatile Velocity Index (PVI) and respective Pulsatile Pressure Indices (PPIa and PPId) were calculated and a stenosis Pulsatile Resistance Index was derived as PRI = (PPId ‐ PPIa)/PVI. Average stenosis resistance SR = (Pa‐Pd)/v and fractional flow reserve (FFR) = Pd/Pa during maximal hyperemia served as gold standards.Hyperemic SR was a major determinant of PPId (p<0.0001), while PVI remained relatively unaffected (r = 0.3). PRI at rest was strongly correlated to both hyperemic SR (p<0.0005) and FFR (p<0.002), with separate relationships for left and right coronary arteries, reflecting different compression of intramural vessels.We conclude that the pulsatile energy of v, Pa and Pd can be utilized to characterize the functional significance of a coronary stenosis without inducing vasodilation. A practical advantage is that PRI is not affected by pressure drift.(Support: NHF grants 2000.090 and 2006B145)

Preliminary Experience With Cutting Balloon Angioplasty for Iliac Artery In-Stent Restenosis

To report our preliminary experience using cutting balloon angioplasty (CBA) in symptomatic iliac artery in-stent restenosis (ISR). Fourteen cases of hemodynamically significant iliac artery ISR (4 common and 10 external) were treated in 12 men (mean age 64 years, range 55-75). Of the 14 stents involved, 8 were balloon-expandable models and 6 were self-expanding. All patients had symptomatic deterioration of at least 1 clinical category over an average period of 50.2 months (range 6-120) post stenting. The mean length of ISR was 11.9 mm (range 2-48), and the average stenosis was 75.4% (range 52%-98%). Nine ISR lesions were focal (<10 mm), 4 were diffuse (>10 mm), and 1 extended outside the stent margins. CBA was performed after conventional angioplasty failure in 7 lesions and as a primary treatment method in 7 lesions. Single (9 focal lesions) or multiple overlapping (5 diffuse or proliferative lesions) inflations were performed using 6-x10-mm (1 lesion), 7-x10-mm (3 lesions), and 8-x10-mm (10 lesions) devices. There was 1 contained rupture treated with a covered stent. In the remainder of the cases, the cutting balloons allowed successful treatment without further stent implantation. During a mean follow-up of 23.6 months (range 12-60), no patient showed clinical deterioration, and no recurrent ISR was detected with color duplex. CBA shows high immediate technical and midterm clinical success in symptomatic iliac artery ISR.

Pedicle screw system in the treatment of unstable fractures of thoracolumbar

Objective To discuss pedicle screw system in the treatment of unstable thoracolumbar fraetures of the results of surgical treatment.Methods Pedicle screw system for thoracolumbar unstable fracture of 46 cases.Results 39 cases were followed up for an average of 17 months after the intervertebral space height and thoracolumbar physiological curvature satisfactory recovery.The average Cobb angle and the average spinal stenosis index has been markedly improved,Frankel raise a grade:three.Conclusion Posterior short section of the pediele screw system is the treatment of thoracic and lumbar fractures of the effective ways is satisfied with the reduction,reliable fixation. Key words: Fracture fixation; Fixtures; Thoracic vertebrae; Lumber vertebrae

Perkutane periphere Atherektomie bei arterieller Verschlußkrankheit: Angiographische und klinische Akut- und Langzeitergebnisse

130 arteriosclerotic lesions--10 in the iliac, 109 in the superficial femoral, 10 in the popliteal and 1 in the anterior tibial artery--were treated by percutaneous atherectomy in 80 patients (62 men and 18 women: mean age 65 +/- 10 years). 23 of the lesions were concentric, 65 eccentric stenoses, while 42 were fully occlusive. 32 patients were in stage IIb (after Fontaine), 24 in stage IIa and 12 each in stage III or IV. Most of the stenoses were not suitable for conventional balloon dilatation because of their primary morphology. A good early angiographic result (residual stenosis less than 50%) was achieved in 94% of lesions. Mean stenosis degree was reduced from 85 +/- 12% to 12 +/- 10% (occlusions from 100% to 9 +/- 9%). The Doppler index increased from 0.6 +/- 0.18 to 0.85 +/- 0.15 (P less than 0.01). Follow-up angiography after 6 months in 104 lesions demonstrated an average stenosis degree of 33 +/- 25% (occlusions 44 +/- 28%). 26 of the 104 re-studied lesions fulfilled the criterion for re-stenosis (greater than 50%): six concentric ones and five eccentric ones, as well as 15 occlusions. These findings indicate that peripheral atherectomy can be employed with good short and long-term results even in morphologically unfavourable, markedly eccentric or calcified lesions and occlusions.

Coronary angioplasty with controlled longitudinal dissection. Initial clinical results using a new cutting balloon

A recently developed cutting balloon was used for coronary angioplasty in 21 patients (4 women, 17 men; mean age 57.6 [36-81] years) with coronary heart disease (angioplasty of the right coronary artery in 4, of the circumflex branch in 4, and of the anterior interventricular branch in 13 patients). The balloon contains 3-4 longitudinally arranged metal cutters to prevent uncontrolled vessel tears. An average stenosis reduction from 84 +/- 8.6% to 30 +/- 10.6% was achieved in ten patients. In the eleven others a second dilatation with a conventional balloon was necessary because of a residual stenosis of over 50% after the first dilatation with the cutting balloon. This reduced the original stenosis from 78.6 +/- 9.4% to 30.4 +/- 9.9%. Complete occlusion at the place of previous dilatation occurred in one patient 14 hours after the procedure, due to a dissection which required a stent implantation. These preliminary results suggest that the cutting balloon can achieve a stenosis reduction similar to that with a conventional balloon.

A 7-YEAR EXPERIENCE WITH BALLOON-MOUNTED CORONARY STENTS FOR THE TREATMENT OF SYMPTOMATIC VERTEBROBASILAR INTRACRANIAL ATHEROMATOUS DISEASE

Balloon-mounted coronary stents (BMCS) have been adapted for use in the intracranial circulation for the treatment of symptomatic intracranial atheromatous disease (ICAD). We performed a retrospective analysis of our 7-year experience with these devices in an attempt to quantify the periprocedural risks and long-term outcomes in patients with symptomatic ICAD of the vertebrobasilar (VB) system treated with BMCS. A retrospective review of a prospectively maintained database was performed to determine the neurological and non-neurological periprocedural risks of BMCS treatment of ICAD. Patients were followed with serial transcranial Doppler (TCD) and, in some cases, angiographic imaging. The clinical status was determined based on clinic visits and by telephone interviews when possible. Over the 6-year period from March 1999 to May 2005, 44 patients (35 men, 9 women; average age, 64.8 yr) with 47 symptomatic atheromatous lesions of the VB system were treated with BMCS. In two patients, the BMSC could not be delivered across the target lesion. Treatment of the remaining 45 lesions was technically successful (95.7%). The periprocedural neurological morbidity and mortality was 26.1% (10 clinically evident strokes, 2 deaths). One additional patient experienced a periprocedural transient ischemic attack (TIA). Two patients died of non-neurological causes within 6 months (4.3%, myocardial infarction and cholecystitis). The average stenosis measured 82.5%, declining to 10.0% stenosis after BMCS. TCD examinations showed a preprocedural velocity of 127.7 cm/second (n = 43; standard deviation, 63.7 cm/s), which declined to 54.0 cm/s immediately after the procedure (n = 42; standard deviation, 22.7 cm/s). In patients with serial TCD evaluations, velocities were typically constant over years of follow-up (six patients with >5 yr of follow-up; average velocity, 52.2 cm/s). Angiographic follow-up was available for 11 patients. Three patients had stent occlusion (all symptomatic with TIAs), one patient had greater than 50% in-stent restenosis (ISR) (symptomatic with TIA) and seven had no significant (<50%) stenosis. The overall ISR/occlusion rate was 12.5% (4 out of 32 lesions with angiographic and/or TCD follow-up > 6 mo). Of the 42 patients who successfully underwent BMCS, clinical follow-up was available for 33 (78.6%, average follow-up period, 43.5 mo), three patients died before any follow-up could be performed, and seven were lost to follow-up. Of the patients with follow-up, five had recurrent vertebrobasilar ischemic symptoms (15%; four TIA, one stroke). Four out of five patients with recurrent symptoms had ISR or occlusion verified on conventional angiography. At the time of the last follow-up examination, seven patients of 44 patients who underwent attempted treatment were dead (modified Rankin Scale [mRS] score, 6); four had an mRS score of 3 to 5, 16 had an mRS score of 1 or 2, and 10 had an mRS score of 0. Percutaneous transluminal angioplasty and stenting using BMCS for the treatment of symptomatic VB ICAD can be carried out with high rates of technical success and excellent immediate angiographic results. However, the procedure carries with it a very high rate of periprocedural morbidity and mortality. Greater than 50% ISR or stent occlusion occurred in 12.5% of the patients and was associated with recurrent TIAs. In the absence of ISR/occlusion, patients who tolerated the initial procedure did well neurologically and did not typically experience recurrent ischemic symptoms.

Outcome of Endoscopic Treatment of Adult Postintubation Tracheal Stenosis

To assess the results of primary endoscopic treatment of adult postintubation tracheal stenosis, to identify predictors of a successful outcome, and better define the scope and limitations of minimally-invasive surgery for this condition. Sixty-two consecutive patients treated between April 2003 and 2006 with initial endoscopic surgery were prospectively studied. Patient and lesion characteristics, treatment details, complications, decannulation, and open surgery rates were recorded. Actuarial analysis and Cox regression were used to identify predictors of decannulation and freedom from external surgery. There were 34 male patients and the average age was 45 +/- 16 years. The average stenosis height was 18 mm (range: 5-55 mm), and 82% of lesions were Myer-Cotton grades III or IV. Lesion height and intubation-to-treatment latency independently predicted success of endoscopic surgery. Ninety-six percent of patients with lesions <30 mm in height were treated endoscopically, but the success rate fell to 20% for lesions longer than 30 mm. Patients with recalcitrant lesions underwent airway augmentation (n = 11) or resection (n = 3), with a 79% success rate. All patients were decannulated, but some, predominantly morbidly obese patients, required long-term stents for dynamic airway compromise. Ninety-eight percent of re-interventions occurred within 6 months. Minimally invasive treatment is effective in postintubation airway stenosis and obviates the need for open cervicomediastinal surgery in most patients. Patients with old and long lesions are less likely to be cured endoscopically. For most patients in this subgroup, endoscopic surgery makes airway augmentation a viable, less invasive alternative to resection. Patients were unlikely to require further therapy after 6 months of symptom-free follow-up.

New distal embolic protection device the FiberNet® 3 dimensional filter: First carotid human study

Evaluate the performance and safety of the FiberNet Embolic Protection System during carotid artery intervention. Carotid Angioplasty and Stenting (CAS) can be proposed to treat the majority of carotid stenoses. Brain embolization takes place and routine use of Embolic Protection Devices (EPD) is warranted. Many EPDs have significant limitations, which may be addressed by a new EPD, the FiberNet (Lumen Biomedical, Plymouth, MN). The system consists of a 3-dimensional expandable filter made of fibers, which expand radially, mounted onto a 0.014'' wire and retrieval catheter. FiberNet can capture particles as small as 40 microm without compromising flow. 35 lesions treated in 34 patients. Male 67.6%. Age: 71.4 +/- 8.8 (50-85). Average stenosis 84.5% +/- 7.9 (70-99). 29.4% were symptomatic. Technical success: 34/35 (97%). No stroke or death within 30 days. Neurological events: two permanent amaurosis, one amaurosis fugax. All samples visually contained significant amounts of emboli. The mean surface area of debris caught was 63.8 mm(2) (37.7-107.5). Comparisons were made with other EPDs. The mean surface area of debris caught was 12.2 mm(2) (2.7-34.3). No changes were noted in CT/MRI at 30-day post procedure. The first human use of this new novel EPD in carotid artery stenting is encouraging. The FiberNet was easy to use and confirmed the ability to capture particles less than 100 microm. The feasibility of the FiberNet has been demonstrated. Additional patients will demonstrate the overall safety and efficacy of this new EPD device.

Left Ventricular Hypertrophy in Patients with Renal Artery Stenosis

Left ventricular hypertrophy (LVH) has been shown to be 3 times more prevalent in patients with renal artery stenosis (RAS) compared to essential hypertension, but factors that predict LVH in this population are not known. We identified 66 patients with unilateral renal artery stenosis and an interpretable electrocardiogram (ECG). LVH by either Cornell voltage-duration product or Sokolow-Lyon voltage criteria was present in 18 of the 66 patients (27%). The mean intra-aortic blood pressure was 100 +/- 14 mm Hg in patients with LVH, and 104 +/- 23 mm Hg in those without LVH (P = 0.37). The average stenosis by quantitative computerized angiography was 68 +/- 17% in patients with LVH, and 64 +/- 13% in those without LVH (P = 0.34). The mean translesional pressure gradient was 11 +/- 15 mm Hg in patients with LVH, and 13 +/- 20 mm Hg in those without LVH (P = 0.60). Using linear regression models, there was no correlation between intra-aortic blood pressure, percentage of stenosis, or translesional pressure gradient and either Cornell voltage-duration product or Sokolow-Lyon voltage criteria. In summary, LVH using ECG criteria was present in 27% of patients with unilateral RAS but was not associated with blood pressure at the time of the procedure or severity of renal artery stenosis.

Impact of Cuffed, Expanded Polytetrafluoroethylene Dialysis Grafts on Graft Outlet Stenosis

The objective of this study was to determine prospectively the difference between the graft outlet strictures of a polytetrafluoroethylene (ePTFE) graft with a cuff at the graft-vein anastomosis (Venaflo; Bard industries, Tempe, Ariz.) and that of the regular ePTFE graft (Stretch Gore-Tex; Gore, Flagstaff, Ariz.) placed for hemodialysis access. Between January and April 2005, 36 consecutive patients (average age: 63.3 years) underwent ePTFE graft implantation (36 implantations) for hemodialysis at the Vascular Surgery Section of Chang Gung Memorial Hospital. The patients of the study cohort were randomly assigned to two groups based on the graft used: cuffed graft group (Venaflo graft) and non-cuffed standard graft group (Gore-Tex graft). Each patient underwent antegrade venography at the 3-month follow-up to demonstrate the graft outlet stricture. Results of the graft outlet angiography analysis were examined, and all medical records were reviewed at end of the study. The degree of the graft outlet stenosis was compared between the two groups. Average stenosis of the cuffed graft group and non-cuffed (standard) graft group were 22.76 +/- 26.37%% and 44.95 +/- 27.48%%, respectively; the difference between the two groups was statistically significant (P < 0.05). The graft outlet stricture of cuffed ePTFE grafts for hemodialysis 3 months after implantation was less severe than that for the standard ePTFE graft. The correlation between the stricture level and dialysis graft patency requires further clarification.

PTFE-Covered Self-Expanding Nitinol Stents for the Treatment of Severe Iliac and Femoral Artery Stenoses and Occlusions:Final Results From a Prospective Study

To evaluate the technical performance, safety, and 1-year clinical efficacy of polytetrafluoroethylene (PTFE)-covered nitinol stents in the treatment of atherosclerotic iliac and superficial femoral artery (SFA) disease. The multicenter, prospective, nonrandomized COVENT study involved 98 patients (70 men; mean age 64+/-10 years) who received PTFE-covered nitinol stents in 107 arteries (60 iliac and 47 SFAs) after predilation. The average lesion length was 50 mm in the SFA and 45 mm in the iliac arteries. Postdilation was performed when necessary. Duplex ultrasound and ankle-brachial index (ABI) were performed at discharge and at 1, 6, and 12 months in follow-up. In total, 130 stents were placed successfully in 97 (99%) of 98 patients. One stent was misplaced during deployment and required subsequent surgical removal. The average stenosis grade was reduced from 98% to 6% in the SFAs and from 96% to 4% in the iliac arteries after covered stent placement. There was a significant rise of the mean ABI from 0.64 at baseline to 0.97 and 0.95 at 1 and 12 months, respectively (p<0.001). There were 7 primary covered stent occlusions (6.5% of 107 stented lesions: 3 not treated, 2 bypassed, 2 dilated or stented) and 5 (4.7%) recurrent in-stent occlusions (1 bypassed, 2 dilated, 2 untreated) during the 1-year follow-up. Primary patency rates were 92% at 6 months and 89.8% at 12 months for the entire cohort. Secondary patency rates were 98% and 95.6%, respectively. No statistically significant differences were observed in the primary patency rates for the SFAs (89.3% at both 6 and 12 months) versus the iliac arteries (94.3% at 6 months and 90.7% at 12 months). Primary implantation of PTFE-covered nitinol stents in the iliac and superficial femoral arteries is technically feasible, safe, and effective, with excellent 1-year patency.

Percutaneous Peripheral Atherectomy of Femoropopliteal Stenoses Using a New-Generation Device:Six-Month Results From a Single-Center Experience

To report the early and 6-month results after atherectomy of femoropopliteal lesions using a new atherectomy device compatible with a 7-F sheath. Fifty-two patients (36 men; mean age 67+/-7 years) with stable, chronic lower limb occlusive disease were enrolled prospectively in a study of percutaneous directional atherectomy using the SilverHawk Atherectomy Catheter. The 71 femoropopliteal stenoses were grouped for analysis according to pathology: 30 (42%) primary stenoses, 27 (38%) native vessel restenoses, and 14 (20%) in-stent restenoses. The overall average stenosis length was 48+/-64 mm (range 10-300). There were more diabetics in the primary lesion cohort, whereas the lesion length of the in-stent restenoses was nearly twice as long as the other groups. After atherectomy alone, residual stenosis was < or =50% in 68 (96%) lesions and < or =30% in 54 (76%). Additional balloon angioplasty was used in 41 (58%) lesions, primarily to smooth the arterial contour; stents were implanted in 4 (6%) arteries. Acute results after atherectomy and additional therapy were identical for the 3 groups (mean residual stenosis 15% in primary lesions, 8% in restenoses, and 14% in in-stent lesions). At the beginning of the study, 5 cases of tissue embolism were successfully treated with aspiration (device modification solved this problem). Restenosis rates after 6 months were not significantly lower in primary lesions (27%) compared with the other groups (41% for restenoses and 36% for in-stent restenoses). Reintervention after 6 months was also lowest for primary lesions (20% versus 37% for restenoses and 29% for in-stent lesions; p=NS). The ankle-brachial index was significantly improved after 6 months in all groups. At the 6-month follow-up, >80% of all patients were symptom free or had no lifestyle-limiting claudication. Short and medium-length femoropopliteal lesions can be treated successfully and safely in most cases with this new atherectomy catheter. Technical and 6-month clinical outcomes seem to favor primary lesions compared with restenoses.

Use of internal bioabsorbable PLGA "finger-type" stents in a rabbit tracheal reconstruction model.

To design and develop a biodegradable tracheal stent that can be used internally to stabilize and support surgically reconstructed airways. In vitro mechanical and degradative properties of 80:20 poly(D,L-lactide-co-glycolide) (PLGA) "finger-like" stents were determined. The stents were then tested in vivo in rabbits that underwent anterior patch tracheoplasties with fascia lata grafts. Comparisons were made between a control group and an internal stent group for stridor development, overall group mortality, reconstructed airway lumen size, and histological findings. Twenty-five New Zealand white rabbits. The average dry modulus for the internal stents was 6800 kPa. All of the internal stents cracked by 4 weeks in buffer solution. Significant mass loss was not noted in vitro until after 5 weeks in buffer solution. By 14 weeks, the stents were nearly 100% degraded. The attrition rate for the control group was 23% compared with 17% for the experimental group. The stridor rate for the control group was also higher at 38% compared with 17% for the stented group. The stented rabbits had a significantly smaller average stenosis (23%) across the entire reconstruction site than the control group (34%) (P<.05). Biodegradable PLGA stents degrade in a predictable fashion and have a statistically significant effect in augmenting anterior patch tracheoplasties with fascia lata grafts in rabbits.

Clinical failure after percutaneous transluminal angioplasty of the superficial femoral and popliteal arteries.

Anatomic patency after percutaneous transluminal angioplasty (PTA) of the superficial femoral and popliteal arteries does not guarantee clinical success. The aim of this report is to determine the causes of clinical failure after PTA. The records of all patients who have undergone PTA of the femoropopliteal arterial segment by our vascular group were retrospectively reviewed. Only patients with complete records and at least one postprocedure clinical and anatomic assessment within the same 30-day time interval were included. Success was defined according to the Society for Vascular Surgery/International Society for Cardiovascular Surgery Ad Hoc Subcommittee on Reporting Standards for Endovascular Procedures. Anatomic cumulative patency and clinical success were calculated according to life table analysis on an intent-to-treat basis. We identified 85 patients who met inclusion criteria. We treated 112 lesions with an average stenosis of 80% +/- 16% and lesion length of 2.3 +/- 1.8 cm. Technical failure occurred in six (5.4%) of 112 lesions. Cumulative clinical success was 69% at 1 year, 54% at 2 years, 49% at 3 years, and 40% at 4 years. Anatomic patency was 74% at 1 year, 62% at 2 years, 57% at 3 years, and 52% at 4 years. There were 45 clinical failures; of these, twenty-seven (60%) occurred in conjunction with anatomic failure. Anatomic failure was due to restenosis in 12 patients (44%), occlusion in eight patients (30%), and restenosis with progression of disease in six patients (22%). Anatomic failure at the time of the procedure occurred in one patient (4%). Clinical failure occurred despite anatomic patency in the remaining 18 patients (40%). Etiology for clinical failure in this latter group included progression of disease within the treated vessel in 12 patients (67%), iliac disease in three patients (17%), tibial disease in two patients (11%), and bypass graft failure in one patient (5%). Fifty percent of all 45 clinical failures were successfully treated with supplemental percutaneous procedures. A PTA is an acceptable therapeutic option for the treatment of focal occlusive disease of the femoropopliteal arterial segment. Most clinical failures were due to anatomic failure, but a significant number occurred despite patency at the PTA site. Although primary clinical success rates were inferior to surgical bypass graft, supplemental PTA was possible in 50% of patients. Repeat percutaneous treatment may extend the interval of clinical success and may obviate the need for surgical bypass graft.

Outcome 14 to 18 years after percutaneous transluminal coronary angioplasty

Outcome 14 to 18 years after percutaneous transluminal coronary angioplasty

An Improvement of Cerebral Hemodynamics following Percutaneous Transluminal Angioplasty in Patients with Atherosclerotic Arterial Stenosis

The purpose of this study was to evaluate changes in cerebral hemodynamics following percutaneous transluminal angioplasty (PTA) in patients with atherosclerotic cerebral arterial stenosis. PTA was performed on the patients under the condition that the arterial stenosis ratio was 70% or more and regional cerebrovascular reserve (rCVR) had decreased to 10% or less. Resting regional cerebral blood flow (rCBF) and rCVR responding to acetazolamide loading were measured by (133)Xe single photon emission tomography (SPECT) just prior to and 1 month after PTA. The average stenosis ratio was significantly improved from 77% to 36% one month after PTA. There were 185 preoperative normal rCBF and normal rCVR regions, 176 region (95%) of which retained their normal rCBF and normal rCVR postoperatively. In 9 regions (5%) only rCVR worsened. Preoperatively, there were 59 normal rCBF and decreased rCVR regions. Forty-five (76%) regions later showed normalized rCVR. Six regions (10%) remained decreased rCVR regions; no region did not worsen during the course of this study. Twenty-nine regions of both preoperative resting rCBF and rCVR decreased regions. Postoperatively, 18 regions (62%) normalized in regards to both rCVR and resting rCBF; in 4 regions (14%), only the resting rCBF was normalized. In the 24 decreased rCBF and normal rCVR regions, there were no hemodynamic alterations after PTA. Regions with decreasing rCVR are at high risk of future brain infarction. This study indicates that the risk of cerebral infarction was avoided by PTA in the low rCVR regions.

Natural history of stenosis from intracranial atherosclerosis by serial angiography.

Knowledge of the natural history of stenoses due to intracranial atherosclerosis may be useful for evaluating possible treatments such as angioplasty. We retrospectively reviewed records over a 7-year period to identify patients with intracranial atherosclerotic stenoses and serial angiograms. Quantitative measurements of stenoses were made in a blinded manner, and clinical outcomes were reviewed. We identified 21 patients with 45 intracranial stenoses who underwent repeat angiography at an average interval of 26.7 months. The average stenosis for all intracranial lesions was 43.9% initially and 51.8% on follow-up (P=.032). The average stenosis in the intracranial internal carotid artery (ICA) was stable (51.2% versus 52.6%). The average stenosis in the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) progressed from 32.4% to 49.7% (P=.037). Based on a minimum 10% change, 20% of intracranial ICA lesions progressed compared with 61% of ACA, MCA, and PCA lesions. Regression occurred in 14% of the intracranial ICA group and 28% of the ACA-MCA-PCA group. Cerebrovascular events were infrequent during this period, with 4 transient ischemic attacks and 1 intracerebral hemorrhage. Intracranial atherosclerotic stenoses are dynamic lesions demonstrating both progression and regression.

Percutaneous Transluminal Coronary Angioplasty Versus Medical Therapy for Stable Angina Pectoris: Outcomes for Patients With Double-Vessel Versus Single-Vessel Coronary Artery Disease in a Veterans Affairs Cooperative Randomized Trial

Objectives. This study sought to assess outcomes of men with double-vessel coronary artery disease randomly assigned to treatment by percutaneous transluminal coronary angioplasty (PTCA) or medical therapy, compared with previously reported outcomes for men with single-vessel disease.Background. We previously reported that PTCA provides better symptom relief and treadmill performance than medical therapy for men with stable angina pectoris due to single-vessel disease. Whether this advantage applies to patients with double-vessel disease is unknown.Methods. Male patients (n = 328) with stable angina pectoris and ischemia on treadmill testing were randomly assigned to PTCA or medical therapy; 101 patients had double-vessel disease, and 227 had single-vessel disease. Symptoms, treadmill performance, quality of life score, coronary stenosis and myocardial perfusion were compared at baseline and at 6 months. Patients were followed up for up to 6 years and underwent additional treadmill testing 2 to 3 years after randomization.Results. PTCA-treated and medically treated patients with double-vessel disease experienced comparable improvement in exercise duration (+1.2 vs. +1.3 min, respectively, p = 0.89), freedom from angina (53% and 36%, respectively, p = 0.09) and improvement of overall quality of life score (+1.3 vs. +4.4, respectively, p = 0.32) at 6 months compared with baseline. This contrasts with greater advantages favoring PTCA by these criteria in patients with single-vessel disease (p = 0.0001 to 0.02). Trends present at 6 months persisted at late follow-up. Patients undergoing double-vessel dilation had less complete initial revascularization (45% vs. 83%) and greater average stenosis of worst lesions at 6 months (74% vs. 56%). Likewise, patients with double-vessel disease showed less improved myocardial perfusion imaging (59% vs. 75%).Conclusions. PTCA is beneficial in male patients with double-vessel disease; however, we cannot demonstrate the same advantage over medical therapy seen in similar patients with single-vessel disease. Less complete revascularization and greater restenosis for patients having multiple dilations would account for these findings. Alternatively, a type 2 error might be operative. Technical advances since completion of this trial might improve these outcomes. These findings warrant further investigation in a larger trial.(J Am Coll Cardiol 1997;29:1505–11)

Intrarenale Duplexsonographie zur Erfassung von Flußänderungen nach renaler PTA

Changes of the intrarenal Doppler signal were analysed before and after renal balloon dilatation to assess the technical success of PTRA. In 33 patients, intrarenal Doppler signal was depicted before and after renal PTA. Doppler flow curve was analysed by using the acceleration index (AI), acceleration time index (AT) and resistance index (RI); for all indices side ratios (AI-R, AT-R and RI-R) were calculated. Balloon dilatation was angiographically successful in all cases. Average stenosis graded 71% before and 21% after PTA. By definition of limits for all indices used, a single patient was graded as non-stenotic before balloon dilatation by application of AI/AI-R and no patient was graded nonstenotic by AI/RI-R. After renal PTA, all indices significantly changed towards normal findings and by application of both AI/AI-R and AI/RI-R, only a single patient was graded stenotic after PTA. Intrarenal Doppler signal analysis reliably allows to detect flow changes following renal PTA in patients with renal artery stenosis. It may therefore be used as a noninvasive method to monitor flow improvement after renal PTA and during follow-up.

Iliac Artery Stent Placement with the Palmaz Stent: Follow-up Study

The long-term efficacy of iliac artery stent placement with the Palmaz stent was evaluated for treatment of limb ischemia. Iliac stent implantation for limb ischemia was performed on 108 limbs in 83 patients. Eighty patients (96.4%) were followed up clinically from 1 to 70 months (mean, 25.8 months), and 30 patients (37.5%) were followed up with angiography from 1 to 48 months (mean, 10.4 months). Patients were classified into six categories by using an ischemic ranking profile. Clinical success was defined as a minimum one-category improvement from preprocedure ranking. The clinical success rate was 98.9% immediately after the procedure and 86.2% at 48 months. Long-term success was statistically more common in patients with higher preprocedure and lower postprocedure ischemic ranking, and in patients without diabetes. Arteriography demonstrated a primary patency rate of 87.5% at latest follow-up, with five occlusions (12.5%) and only two (5.0%) restenoses. Average stenosis was 17.8% at 6 months and 24.7% at 2 years. Stent restenosis was statistically more common with a higher postprocedure pressure gradient. The complication rate was 9.7%, and 30-day mortality was 1.2%. Long-term clinical and angiographic follow-up demonstrates iliac artery stent placement with the Palmaz stent is safe and efficacious for treatment of limb ischemia.