Angioplasty and provisional stent treatment of common femoral artery lesions.

PURPOSE: Isolated atherosclerotic common femoral artery (CFA) disease is a rare cause of symptomatic peripheral arterial disease. Although surgical endarterectomy is considered the therapy of choice, little is known about outcomes of percutaneous treatment. MATERIALS AND METHODS: A prospectively maintained single-center database was retrospectively analyzed for outcomes of consecutive patients undergoing isolated percutaneous revascularization of CFA disease between 1996 and 2007. In all cases, the intended strategy was balloon angioplasty with provisional stent placement in case of poor angioplasty results. Among 516 consecutive procedures involving the CFA, 419 were excluded because of nonatherosclerotic disease (n = 156) or treatment of additional vascular segments during the same procedure (n = 263). Procedural success (ie,<30% residual stenosis), in-hospital vascular complications (major [requiring surgical or percutaneous treatment] or minor [treated conservatively]), and 12-month restenosis and target lesion revascularization (TLR) rates were assessed for the remaining 97 interventions. RESULTS: CFA bifurcation lesions were present in 40 cases (41.2%) and required treatment of the deep femoral artery in 25 (25.8%). Chronic total CFA occlusions accounted for 11 cases (11.3%). Balloon angioplasty was performed in 96 cases (98.9%), and provisional stent placement was necessary in 37 (38.1%). The procedure was successful in 89 cases (91.8%). Minor and major vascular complications at 30 days occurred in three (3.1%) and four (4.1%) cases, respectively. At 12 months, restenosis greater than 50% and TLR were observed in 19.5% and 14.1% of procedures, respectively. CONCLUSIONS: This series shows that isolated CFA lesions may be safely and efficaciously treated with angioplasty and provisional stent placement.

Endovascular treatment of common femoral artery disease: medium-term outcomes of 360 consecutive procedures.

OBJECTIVES: The purpose of this study was to evaluate the technical feasability, safety, and 1-year efficacy of the endovascular treatment of atherosclerotic common femoral artery (CFA) obstructions. BACKGROUND: Atherosclerotic CFA obstruction is a known cause of symptomatic peripheral arterial disease. Although surgical endarterectomy is considered the therapy of choice for this condition, little is known about the percutaneous options. METHODS: Using a prospectively maintained single-center database, we retrospectively analyzed the outcomes of 360 consecutive percutaneous interventions of the CFA for atherosclerotic disease and assessed procedural success, in-hospital complications, and 1-year patency and target lesion revascularization rates. RESULTS: Ninety-seven procedures (26.9%) were isolated CFA interventions, whereas 157 (43.6%) and 152 (42.2%) also involved inflow and outflow vessels, respectively. Bifurcation lesions were present in 140 cases (38.9%), and concomitant treatment of the profunda femoral artery was performed on 93 occasions (25.8%). Chronic total CFA occlusions were recanalized in 60 cases (16.7%). Balloon angioplasty was performed as the primary intervention in virtually all cases (98.6%), whereas stenting was needed for suboptimal angioplasty results in 133 procedures (36.9%). Failures-defined as a final angiographic result with a >30% residual stenosis-were observed on 26 occasions (7.2%). In-hospital major (i.e., requiring surgery) and minor (i.e., treated percutaneously or conservatively) complications occurred in 5 (1.4%) and 18 (5.0%) procedures, respectively. One-year follow-up data were available for 281 patients (87.5%). Restenosis >50% by duplex scanning and target lesion revascularization were observed in 74 of 268 (27.6%) and 64 of 322 (19.9%) procedures, respectively. CONCLUSIONS: This large series suggests that the percutaneous approach may be a valid alternative to surgery for CFA atherosclerotic obstructions.

Why can pulmonary vein stenoses created by radiofrequency catheter ablation worsen during and after follow-up? A potential explanation.

BACKGROUND: Radiofrequency catheter ablation of excitation foci inside pulmonary veins (PV) generates stenoses that can become quite severe during or after the follow-up period. Since severe PV stenoses have most often disastrous consequences, it would be important to know the underlying mechanism of this temporal evolution. The present study proposes a potential explanation based on mechanical considerations. METHODS: we have used a mathematical-physical model to examine the cyclic increase in axial wall stress induced in the proximal (= upstream), non-stenosed segment of a stenosed pulmonary vein during the forward flow phases. In a representative example, the value of this increase at peak flow was calculated for diameter stenoses (DS) ranging from 1 to 99%. RESULTS: The increase becomes appreciable at a DS of roughly 30% and rise then strongly with further increasing DS value. At high DS values (e.g. > 90%) the increase is approximately twice the value of the axial stress present in the PV during the zero-flow phase. CONCLUSION: Since abnormal wall stresses are known to induce damages and abnormal biological processes (e.g., endothelium tears, elastic membrane fragmentations, matrix secretion, myofibroblast generation, etc) in the vessel wall, it seems plausible that the supplementary axial stress experienced cyclically by the stenotic and the proximal segments of the PV is responsible for the often observed progressive reduction of the vessel lumen after healing of the ablation injury. In the light of this model, the only potentially effective therapy in these cases would be to reduce the DS as strongly as possible. This implies most probably stenting or surgery.

Could increased axial wall stress be responsible for the development of atheroma in the proximal segment of myocardial bridges?

BACKGROUND: A recent model describing the mechanical interaction between a stenosis and the vessel wall has shown that axial wall stress can considerably increase in the region immediately proximal to the stenosis during the (forward) flow phases, so that abnormal biological processes and wall damages are likely to be induced in that region. Our objective was to examine what this model predicts when applied to myocardial bridges. METHOD: The model was adapted to the hemodynamic particularities of myocardial bridges and used to estimate by means of a numerical example the cyclic increase in axial wall stress in the vessel segment proximal to the bridge. The consistence of the results with reported observations on the presence of atheroma in the proximal, tunneled, and distal vessel segments of bridged coronary arteries was also examined. RESULTS: 1) Axial wall stress can markedly increase in the entrance region of the bridge during the cardiac cycle. 2) This is consistent with reported observations showing that this region is particularly prone to atherosclerosis. CONCLUSION: The proposed mechanical explanation of atherosclerosis in bridged coronary arteries indicates that angioplasty and other similar interventions will not stop the development of atherosclerosis at the bridge entrance and in the proximal epicardial segment if the decrease of the lumen of the tunneled segment during systole is not considerably reduced.

Thresholds and complications with right ventricular septal pacing compared to apical pacing.

BACKGROUND: Right ventricular septal pacing has been proposed as an alternative to apical pacing. However, data concerning thresholds and requirement for lead repositioning with this technique are scant. METHODS: We reviewed data at implantation and follow-up of 362 consecutive recipients of the same model of active fixation lead (Medtronic 5076-58, Minneapolis, MN, USA) to avoid differences due to lead characteristics. Patients were divided into two groups according to whether the lead was positioned on the interventricular septum (n = 157) or at the right ventricular apex (n = 205). Thresholds, lead impedance, and requirement for lead repositioning were compared between groups at implantation and follow-up. RESULTS: There were no differences between the septal and apical groups in sensing and pacing thresholds or lead impedance, either at implantation or during a 24-month follow-up. In the septal group, the lead had to be repositioned in four patients (2.5%) due to lead dislodgement in two patients, acute threshold rise in one patient, and pericardial effusion in another patient (the lead had unintentionally been positioned on the anterior free wall in these last two patients). In the apical group, the lead had to be repositioned in eight patients (3.9%, P = 0.56) due to lead dislodgement in three patients and acute threshold rise in five patients. CONCLUSIONS: Acute and chronic thresholds associated with septal pacing are similar to those observed with apical pacing, and risk of lead dislodgement is low. However, multiple radioscopic views must be used to avoid inadvertent positioning of the lead on the anterior free wall.

Utility of the surface ECG before VDD pacemaker implantation.

BACKGROUND: VDD pacemakers may be implanted in the setting of atrioventricular block with preserved sinus function. Their main advantage over DDD pacemakers is use of a single lead. However, low-amplitude atrial electrograms (EGMs) recorded from the free-floating atrial electrode may lead to undersensing. There is currently no way of predicting EGM amplitude prior to implantation and to thus identify candidates who may be safely implanted with a VDD pacemaker. AIM: We sought to investigate whether the P-wave amplitude measured on the standard surface ECG correlates with the atrial EGM amplitude measured by the single-pass lead at implantation. METHODS: Data on 122 patients implanted with a VDD pacemaker at our institution were reviewed. Atrial EGM amplitudes measured at implantation by the single-pass lead were correlated with the maximal P-wave amplitude on the surface ECG recorded just prior to implantation. RESULTS: There was a highly significant correlation between the maximal P-wave amplitude on the surface ECG and the atrial EGM (Pearson's correlation 0.313, P<0.001). Multivariate analysis showed that maximal P-wave amplitude was independently associated with atrial EGM amplitude (p=0.003). For the overall population, an EGM amplitude of <0.9 mV was present in only 11/122 (9%) cases. An atrial EGM amplitude of <0.9 mV was found in 10/69 (14%) of patients with a maximal surface P-wave < or =0.1 mV but only in 1/53 (2%) of those with >0.1 mV (p=0.023). CONCLUSION: Low-amplitude atrial EGMs at implantation are found in a minority of patients with single-pass leads. However, patients with a maximal surface P-wave amplitude of >0.1 mV are especially unlikely to have a low atrial EGM amplitude and may be good candidates for a VDD pacemaker.

Prospective study of axillary vein puncture with or without contrast venography for pacemaker and defibrillator lead implantation.

Axillary vein puncture may be used to implant pacemaker (PM) or cardioverter defibrillator leads, though usually requires venography. We prospectively compared punctures guided by venography versus a new radiological landmark. In 232 patients, the puncture was guided by injecting diluted contrast material via an ipsilateral peripheral vein (group A, n = 142), or without venography using the intersection of the lateral borders of the second and third rib as a radiological landmark, followed by contrast injection in case of failure (group B, n = 90). We implantated 1-3 leads per patient. In group A, implantation was successful in 135 patients (95%) and in group B in 55 patients (61%, P < 0.001 vs group A). Subsequent contrast injection allowed successful implantations in 34 of 35 patients, with an success rate of 97% for the overall study population of 224 patients. Venous access was achieved after a mean of 10.4 +/- 3.2 minutes of skin incision in group A versus 9.4 +/- 3.0 minutes in group B (ns). Pneumothorax occurred in two patients (1% overall). Thus non-contrast guided puncture using a new radiological landmark was successful in a majority of patients. This technique may be useful in absence of ipsilateral peripheral vein access, or presence of contrast allergy.

Residual stenosis poststenting and subsequent decrease in the proximal reference diameter are correlated: excessive axial wall stress is a plausible explanation.

PURPOSE: To test the hypothesis that edge restenosis in stented lesions might be due to an increase in axial wall stress in the adjacent proximal vessel segment by examining whether the proximal reference diameters of conventionally stented lesions are reduced at follow-up and whether this reduction depends on the degree of residual stenosis poststenting. METHODS: The literature published in the past 5 years dealing with restenosis following implantation of standard stents was screened for the availability of (1) reference vessel diameters poststenting, (2) mean residual stenosis poststenting, and (3) mean reference vessel diameters at follow-up in the same patients or groups of patients. Data collected from 11 publications were pooled and used to compute the change in reference segment diameter over time. These differences were compared to the residual stenosis poststenting by nonlinear regression. RESULTS: The reduction in the mean reference diameters over time and the mean residual stenosis poststenting appear to be strongly correlated (r2 = 0.838), which supports the idea that the evolution of a stenosis adjacent to a stent margin depends on the severity of the residual stenosis. CONCLUSIONS: This finding indicates that edge restenosis might be due to excessive axial wall stress. It may also explain, at least partly, why edge restenosis is observed with catheter-based brachytherapy and radioactive or drug-eluting stents.

Thoracic aortic plaques, transoesophageal echocardiography and coronary artery disease.

BACKGROUND: The purpose of this study was to assess whether the detection of atherosclerotic aortic plaques by transoesophageal echocardiography (TEE) could be used as a marker of coronary artery disease (CAD), relying on their number, cross-sectional surface, depth and localisation. METHODS: The thoracic aortas of 102 consecutive patients (77 men, mean age 67 +/- 12 years) undergoing elective cardiac surgery were assessed by TEE. Atherosclerotic plaques were defined as > or = 5 mm thick focal hyperechogenic zones of the aortic intima and/or lumen irregularities with mobile structures or ulcerations. All patients had undergone prior coronary angiography. RESULTS: Thoracic aortic plaques were present in 73 patients, 66 of whom had CAD. The presence of aortic plaques detected by TEE identified significant coronary artery disease with a sensitivity of 90% and a specificity of 76%. The maximum transverse cross-sectional plaque area, the maximum plaque depth and the total plaque number all correlated significantly with the presence of CAD, but not with its severity. Multivariate regression analysis showed that aortic plaques, hypertension and hypercholesterolaemia were significant predictors of CAD, but aortic plaques were the most significant predictor regardless of age and sex. CONCLUSIONS: This study suggests that detection of atherosclerotic aortic plaques is a useful marker of significant coronary artery disease. Absence of plaques in the patients aged over 70 identified a subgroup with a very low probability of CAD.

In-hospital complications of percutaneous intraaortic balloon counterpulsation.

Complications related to intraaortic balloon counterpulsation pumping (IABP) remain a problem despite the development of small caliber balloon catheter shafts and introducer sheaths. The authors report their experience in counterpulsation-related complications of 201 consecutive patients who underwent 212 percutaneous counterpulsation balloon insertions from June 1989 to June 1996 by use of balloons with 8-9.5 French shafts. Of these, 82% were men and 36 (18%) were women, with a mean age of 61 +/-12 years. Indications for counterpulsation were acute myocardial infarction (AMI) (67%), severe left ventricular failure without AMI (20%), dilated cardiomyopathy (4%), unstable angina (3%), high-risk supported percutaneous coronary angioplasty (2%), and others (4%). IABP was instituted at the bedside in the intensive care unit in 82 patients (39%) and in the catheterization laboratory in 130 (61%). Median duration of counterpulsation was 48 hours (range 30 minutes to 25 days) with successful weaning from counterpulsation in 70% (148 of 212) of procedures. Overall in-hospital mortality rate was 45% (90 of 201). The overall complication rate was 22/212 (10.4%). Major complications were present in 10/212 procedures (4.7%): 6 patients with limb ischemia (1 death directly attributed to this complication, 1 with associated septicemia and limb amputation, 3 requiring surgical thromboembolectomy, and 1 with persistent limb ischemia treated medically until his death caused by intractable left ventricular failure), 2 with important bleeding (1 fatal despite vascular surgical repair and 1 requiring blood transfusion) and 2 with balloon rupture requiring vascular surgery. Minor complications were present in 12 procedures (5.7%), 6 with limb ischemia, 3 with local bleeding, and 3 with catheter dysfunction. All of these resolved after balloon removal and required no further intervention. When limb ischemia did develop it occurred after a median delay of 24 hours following balloon insertion (range 2 to 98 hours). The only predictor of limb ischemia among baseline clinical and procedure-related variables was an age greater than 60 years. Compared with previous recent studies, the rate of complications observed in this study performed with small balloon catheters was acceptably low. Limb ischemia was the most frequent complication, often occurred early, and required further intervention in half the cases.