Permanent pacemaker insertion after CoreValve transcatheter aortic valve implantation: incidence and contributing factors (the UK CoreValve Collaborative).

BACKGROUND: Permanent pacemaker (PPM) requirement is a recognized complication of transcatheter aortic valve implantation. We assessed the UK incidence of permanent pacing within 30 days of CoreValve implantation and formulated an anatomic and electrophysiological model. METHODS AND RESULTS: Data from 270 patients at 10 centers in the United Kingdom were examined. Twenty-five patients (8%) had preexisting PPMs; 2 patients had incomplete data. The remaining 243 were 81.3±6.7 years of age; 50.6% were male. QRS duration increased from 105±23 to 135±29 milliseconds (P<0.01). Left bundle-branch block incidence was 13% at baseline and 61% after the procedure (P<0.001). Eighty-one patients (33.3%) required a PPM within 30 days. Rates of pacing according to preexisting ECG abnormalities were as follows: right bundle-branch block, 65.2%; left bundle-branch block, 43.75%; normal QRS, 27.6%. Among patients who required PPM implantation, the median time to insertion was 4.0 days (interquartile range, 2.0 to 7.75 days). Multivariable analysis revealed that periprocedural atrioventricular block (odds ratio, 6.29; 95% confidence interval, 3.55 to 11.15), balloon predilatation (odds ratio, 2.68; 95% confidence interval, 2.00 to 3.47), use of the larger (29 mm) CoreValve prosthesis (odds ratio, 2.50; 95% confidence interval, 1.22 to 5.11), interventricular septum diameter (odds ratio, 1.18; 95% confidence interval, 1.10 to 3.06), and prolonged QRS duration (odds ratio, 3.45; 95% confidence interval, 1.61 to 7.40) were independently associated with the need for PPM. CONCLUSION: One third of patients undergoing a CoreValve transcatheter aortic valve implantation procedure require a PPM within 30 days. Periprocedural atrioventricular block, balloon predilatation, use of the larger CoreValve prosthesis, increased interventricular septum diameter and prolonged QRS duration were associated with the need for PPM.

[Results of the French register of renal stenting: the Esternal study]. / Résultats du registre français du stenting rénal: étude Esternal.

Renal artery angioplasty using the same techniques employed for coronary arteries has developed considerably. A register was set up in France to evaluate the efficacy of this treatment for improving renal function and lowering blood pressure in cardiac patients. Between 2001 and 2005, 205 patients (234 lesions) were treated in 14 centres (mean age: 69.2 +/- 10.4 years, 59% male). All of the patients had hypertension and the majority of them (171) had renal failure (creatinine clearance<90 ml/min). Direct implantation of a stent was performed in 75.2% of the cases, successfully in 196 patients (96%) with 220 lesions (95.2%). The complications encountered were segmental renal infarction in two patients (0.9%), and four cases of minor vascular complications at the puncture site (2%). The mean value for pre-implantation creatinine clearance was 54.6 +/- 32.8 ml/min and 58.1 +/- 36.0 post- implantations. The duration of follow up was 5.9 +/- 2.7 months. Mortality was 3.5% (seven patients, of whom two died from renal causes). The mean systolic and diastolic blood pressure was 142.2 +/- 16.2 and 78.9 +/- 9.5 respectively versus 164.9 +/- 25.2 and 89.1 +/- 14.8 before treatment (p<0.0001). A non-significant improvement in creatinine clearance at six months was also observed in patients with renal failure prior to treatment: 48.7 +/- 17.1 ml/min vs. 69.2 +/- 160.3. Renal artery stenting in cardiac patients with renal artery stenosis is associated with a very high success rate, with few complications and an improvement in hypertension and renal function.

Percutaneous implantation of an aortic valve prosthesis.

Recently, percutaneous aortic valve implantation has become an alternative technique to surgical valve replacement in patient at high risk for surgery. Our animal experimentation evaluated the technical feasibility of aortic valve replacement using a bovine pericardium valve sutured on a self-expandable stent in a sheep model. Precise implantation with satisfactory attachment on the adjacent tissues and absence of migration was obtain in 8 out of 14 animals. This study confirmed the feasibility of the endovascular implantation of a pericardium valve sutured on a self-expandable stent in a sheep model.

Global experience in cervical carotid artery stent placement.

The purpose of this article is to review and update the current status of carotid artery stent placement in the world. Surveys to major interventional centers in Europe, North and South America, and Asia were initially completed in June 1997. Subsequent information from these 24 centers in addition to 12 new centers has been obtained to update the information. The survey asked the various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 5,210 procedures involving 4,757 patients. There was a technical success of 98.4% with 5,129 carotid arteries treated. Complications that occurred during the carotid stent placement or within a 30-day period following placement were recorded. Overall, there were 134 transient ischemic attacks (TIAs) for a rate of 2.82%. Based on the total patient population, there were 129 minor strokes with a rate of occurrence of 2.72%. The total number of major strokes was 71 for a rate of 1.49%. There were 41 deaths within a 30-day postprocedure period resulting in a mortality rate of 0.86%. The combined minor and major strokes and procedure-related death rate was 5.07%. Restenosis rates of carotid stenting have been 1.99% and 3.46% at 6 and 12 months, respectively. The rate of neurologic events after stent placement has been 1.42% at 6-12-month follow-up. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative for vascular surgery, especially for patients that are high risk for standard carotid endarterectomy. The periprocedure risks for major and minor strokes and death are generally acceptable at this early stage of development and have not changed significantly since the first survey results. Cathet. Cardiovasc. Intervent. 50:160-167, 2000.

In-stent restenosis: long-term outcome and predictors of subsequent target lesion revascularization after repeat balloon angioplasty.

OBJECTIVES: We sought to evaluate the long-term clinical outcome of patients undergoing successful balloon angioplasty for in-stent restenosis, and to determine correlates of the need for subsequent target lesion revascularization (TLR). BACKGROUND: In-stent restenosis can be safely treated by repeat percutaneous intervention. Reported subsequent TLR rates have varied from 20% to 80% and seem related to the type of restenotic lesion. METHODS: The study population comprised 234 patients with follow-up data who were successfully treated with repeat balloon angioplasty for in-stent restenosis in 257 lesions between May 1995 and January 1998 at our institution. RESULTS: Clinical follow-up was available at 459 (286 to 693) days after the repeat procedure. Event-free survival was 78.5% and 74.6% at 12 and 24 months, respectively. Recurrent events occurred in 58 patients (24.8%), including 6 deaths (2.6%), 4 myocardial infarction (1.7%) and repeat target vessel revascularization in 50 patients (21.4%). Independent predictors of repeat TLR were time to in-stent restenosis <90 days (Hazard ratio 4.67, p < 0.001), minimal luminal diameter after repeat procedure (Hazard ratio 0.38, p = 0.034) and the angiographic pattern of in-stent restenosis (Hazard ratio 1.65, p = 0.036). CONCLUSIONS: Balloon angioplasty is an effective means of treating in-stent restenosis. The long-term results are acceptable particularly for focal restenotic lesions. Further restenosis is more common in patients with early initial recurrence, more proliferative lesions and a poorer angiographic result from repeat angioplasty.

Coronary stenting in diabetics: immediate and mid-term clinical outcome.

Balloon angioplasty in diabetics is associated with acceptable immediate results but with high rates of restenosis, target vessel revascularization, and late mortality. The impact of coronary stenting on the outcome of these patients remains controversial. We reported the immediate and mid-term clinical outcome of 272 consecutive diabetic patients, representing 12.5% of the population undergoing coronary stenting between May 1995 and April 1997. Diabetes mellitus was insulin-requiring in 58 patients and non-insulin-requiring in 214. Stenting performed on large vessels (mean diameter >/=3 mm) was successful in 99.2% of nondiabetic patients and in all cases in diabetics. During in-hospital stay, the complications rate, including mortality, nonfatal myocardial infarction, emergency coronary bypass surgery, and stent subacute thrombosis, was similar in nondiabetic patients, insulin-requiring, and non-insulin-requiring diabetics (2.55%, 0%, and 2.0%, respectively). No complication occurred in the insulin-requiring group. One patient (0.5%) died from myocardial infarction and another (0.5%) presented a nonfatal myocardial infarction (subacute stent thrombosis) in the non-insulin-requiring group. The clinical follow-up (mean length 13 +/- 8 months) was obtained in 93% and 97% of the insulin-requiring and non-insulin-requiring diabetics, respectively. Overall mortality was significantly higher in insulin-requiring patients (9.3% vs. 2.4%). Nonfatal myocardial infarction and target lesion revascularization rates were similar in the two groups (0% vs. 0.5% and 8.2% vs. 10.5%). These results suggest that coronary stenting in diabetics could be performed with acceptable immediate and mid-term results. Cathet. Cardiovasc. Intervent. 47:279-284, 1999.

Results of stenting of unprotected left main coronary artery stenosis in patients at high surgical risk.

From March 1994 to September 1996, 39 patients underwent stenting of the unprotected left main coronary artery because of high surgical risk. Stenting appeared to improve clinical outcome, but there was a significant mortality rate at long-term follow-up.

[Implantation of coronary stents in diabetic patients. Short- and medium-term clinical results]. / Implantation d'endoprothèses coronaires chez les patients diabétiques. Résultats cliniques à court et moyen terme.

Coronary balloon angioplasty is associated with a high incidence of restenosis in diabetics and of revascularisation of the culprit lesion and increased long-term mortality. The authors report the short and medium-term results of coronary stenting in diabetics. Between May 1995 and April 1997, 2,182 patients underwent coronary stenting. This population included 272 diabetics : 58 insulin-dependent and 214 non-insulin dependent (oral antidiabetics). Stents were implanted in vessels with mean diameters of 3 mm and over. During the hospital period, the complication rate (mortality, non-fatal myocardial infarction, emergency coronary bypass surgery, subacute thrombosis of the stent) was comparable in non-diabetics, insulin-dependent and non-insulin-dependent diabetics (2.55, 0 and 2.0% respectively). One patient (0.5%) died and another (0.5%) had non-fatal myocardial infarction (thrombosis of the stent) in the non-insulin-dependent group. No complications were observed in the insulin-dependent diabetic group. The mean clinical follow-up of 13 months (3-26 months) was respected in 93 and 97% of diabetics. The non-fatal myocardial infarction rate and revascularisation of the culprit lesion were comparable in the insulin and non-insulin-dependent groups (0 versus 0.5% and 8.2 versus 10.5% respectively) but global mortality was higher in the insulin-dependent diabetics (9.3 versus 2.4%).

Current global status of carotid artery stent placement.

Our purpose was to review the current status of carotid artery stent placement throughout the world. Surveys were sent to major interventional centers in Europe, North and South America, and Asia. Information from peer-reviewed journals was also included and supplemented the survey. The survey asked various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. Of the centers which were sent surveys, 24 responded. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 2,048 cases, with a technical success of 98.6%. Complications that occurred during carotid stent placement or within a 30-day period following placement were recorded. Overall, there were 63 minor strokes, with a rate of occurrence of 3.08%. The total number of major strokes was 27, for a rate of 1.32%. There were 28 deaths within a 30-day postprocedure period, resulting in a mortality rate of 1.37%. Restenosis rates of carotid stenting have been 4.80% at 6 mo. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative to vascular surgery, especially for patients that are at high risk for standard carotid endarterectomy. The periprocedural risks for major and minor strokes and death are generally acceptable at this early stage of development.

Use of stents covered with polytetrafluoroethylene in experimental abdominal aortic aneurysm.

PURPOSE: To establish the effectiveness of covered stents in the treatment of aortic aneurysms, to investigate the histopathologic healing patterns of the device, and to determine the long-term endurance and integrity of modified polytetrafluoroethylene (PTFE). MATERIALS AND METHODS: Experimental aneurysms were created in dogs by enlarging the aortic lumen with a patch of abdominal fascia. After 5 months, eight animals underwent an endoluminal bypass. The bypass device consisted of a 6-cm-long stent covered with thin PTFE. After surgery, the animals were killed at 3, 6, and 12 months in groups of three, three, and two, respectively. Specimens were processed for luminal surface studies and cross-sectional histologic study. Explanted PTFE material was analyzed for its physical characteristics and performance and was compared with retained control samples. RESULTS: Before the animals were killed, aortography showed patent bypass conduits in all animals, although two of eight had leaks into the aneurysmal sac. Endothelialized neointima largely covered the luminal surface of the PTFE stent. The percentage of prosthetic surface covered by tissue did not change from 3 months to 1 year. Physical testing of the explanted PTFE material showed no structural deterioration and no change in the internodal distance. Thickness and axial tensile strength varied 12% and 17% from controls, respectively. CONCLUSION: Thin-walled PTFE seems to have physicochemical characteristics that make this material adequate for endovascular use. Though limited, this study supports the establishment of preliminary clinical evaluation of metallic stents combined with PTFE for the treatment of abdominal aortic aneurysm.

Influence of anatomic distribution of atherosclerosis on the outcome of revascularization with iliac stent placement.

PURPOSE: To determine the influence of clinical and angiographic variables, including the anatomic disease pattern, on the outcome of iliac stent placement. PATIENTS AND METHODS: The 455 patients of the study population were divided in three groups according to the anatomic distribution of their peripheral atherosclerosis lesions. Pattern type 1 (focal aortoiliac and/or common iliac lesion) included 180 patients (39.6%), type 2 (external iliac lesion) comprised 58 patients (12.8%), and type 3 (multilevel lesions) included 217 patients (47.7%). RESULTS: Complete relief of symptoms immediately after revascularization was observed in 88.3% and 85.4% of patients with pattern type 1 and 2, respectively, compared to 60.1% with type 3 (P < .05). The persistence of clinical benefit at 36-month follow-up was 91.6%, 97.9%, and 60.8% in disease patterns 1, 2, and 3, respectively. The overall 1-year mortality rate was 3% with type 1 lesions, 5.7% with type 2, and 9.7% with type 3. On multivariate logistic regression, the presence of a disease pattern type 3 was the most powerful indicator (P < .001) of early unsatisfactory clinical outcome in iliac stent placement. Unexpectedly, female gender was predictive of unsatisfactory clinical outcome (P < .01) and higher periprocedural complications (P < .001) following iliac stent revascularization. CONCLUSIONS: Pattern type classification helps identify patients at higher risk for cardiovascular morbidity and mortality. Ideal candidates for iliac stent placement are patients with pattern type 1 or 2 disease.

Use of a balloon-expandable intravascular graft in the management of type B aortic dissection in an animal model.

PURPOSE: To evaluate obliteration of an experimental aortic dissection with a balloon-expandable intravascular stent. MATERIALS AND METHODS: Fourteen adult dogs were divided into two groups. In group 1 (n = 6), a thoracoabdominal aortic dissection was surgically created to observe the natural course of this lesion. In group 2 (n = 8), a balloon-expandable intraluminal vascular graft was introduced via the femoral artery in a dissected aorta to try to obliterate the dissection. Angiography was performed postoperatively and again 6 weeks later before the aortae were explanted for pathologic evaluation. RESULTS: In group 1, postoperative aortography depicted evidence of aortic dissection in all animals. Autopsy revealed persisting dissection with reentry tear near the celiac axis in five animals. In group 2, placement of a stent at only entry and reentry sites resulted in partial obliteration of the dissection (n = 3). When the entire length of dissected aorta was treated, the dissection was completely obliterated (n = 4). CONCLUSION: An aortic dissection can be obliterated with a balloon-expandable stent if the entire dissected aorta is treated.

Use of endovascular stents for acute aortic dissection: an experimental study.

This study was designed to evaluate the potential obliteration of an experimental aortic dissection using an intravascular stent introduced via the femoral artery. Twenty-two adult dogs were divided into four groups: in group A (n = 6) a thoracoabdominal aortic dissection was surgically created to observe the natural course of this lesion; in group B (n = 6) a nitinol coil graft was introduced into the aorta via the femoral artery; in group C (n = 3) a nitinol coil graft was introduced via the femoral artery into a dissected aorta in an attempt to obliterate the dissection; and in group D (n = 7) an expandable intraluminal vascular graft (Palmaz stent) was introduced via the femoral artery into a dissected aorta in an attempt to obliterate the dissection. Arteriographic evaluation was performed postoperatively and again 6 weeks later before the aortas were explanted. Gross and light microscopic examinations were performed on all explanted aortas. In group A dissection was achieved and a postoperative aortogram demonstrated evidence of aortic dissection in all animals. Autopsy revealed persistence of dissection with a reentry tear near the celiac axis in five animals. In group B there was incomplete expansion of the nitinol coil graft in five dogs, resulting in aortic thrombosis in one. In group C the nitinol coil graft failed to obliterate the aortic dissection in all animals and resulted in aortic thrombosis in two. In group D placement of a balloon-expandable intraluminal stent solely at entry and reentry sites resulted in only partial obliteration of the dissection (n = 3), but when the entire length of the dissected aorta was treated, the dissection was completely obliterated (n = 3).

Vascular occlusion with a balloon-expandable stent occluder.

PURPOSE: To evaluate the effectiveness of a new vascular occlusion device. MATERIALS AND METHODS: The device was created by coating a balloon-expandable stent with a silicone sleeve that tapers to a blind-ended nozzle at its leading end. Once crimp-mounted on an angioplasty balloon catheter, the device is introduced over a guide wire through a small end hole in the nozzle. RESULTS: The device was tested for stability and occlusive ability. No migration was measured over a pulsatile pulse range of 50-300 mm Hg, and mean flow rate in the occluded vessel was reduced from 443 mL/min +/- 99 (standard deviation) to 1.9 mL/min +/- 2.7. Subsequently, 12 arteries were occluded in three dogs, and immediate vascular occlusion was achieved in all vessels. An arteriovenous fistula was created in another six dogs and was successfully occluded with the device. Follow-up arteriography at 3 months demonstrated persistent occlusion with no migration of the device. CONCLUSION: This new occlusive device offers immediate vascular occlusion with excellent stability.

[History of the treatment of varices]. / Aperçu historique du traitement des varices.

Diseases of the vein and particularly varicose veins have been recognized since antiquity. The Ebers papyrus, dated 1550 b.c., mentions serpent-shaped dilatation of the lower limbs. The Acropolis tablet of the IVth century b.c. concerning Dr Amynos allows us to visualize an enlarged lower limb clearly showing a varicosity. From 460-377 b.c., Hippocrates noted that a loose tourniquet leads to haemorrhages but that when the tourniquet is tight gangrene ensues and finally that standing up can exaggerate leg ulcerations. Of course much progress has been made since Hippocrates. The school at Alexandria, with Herophilus and Erasistrates speak of vascular ligatures. Their work was unfortunately lost in the fire of the Alexandria library in 391 a.d. Galien himself described varicose vein ligatures in 200 a.d. Leonardo de Vinci's magnificent anatomic studies of veins are widely known. In 1525, Ambroise Paré described leg bandaging for ulcers beginning from the foot up to the knee. In 1585, Fabrice d'Acquapendente described venous valves. In 1676, Wiseman invented the first supportive stockings made of leather and in 1854, Unna described in Vienna the supportive boot which now carries his name. Shortly thereafter new medical and surgical techniques were developed for the treatment of varicose veins. Pravaz, in 1860, invented a syringe which now carries his name and initiated sclerotherapy. At the end of the XIXth century, Trendelenburg performed the first ligatures of the greater saphenous veins. In 1905, and 1906, Keller and Mayo performed the first ablation of the greater saphenous vein and in 1906, Carrel reported the first venous transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Stenting of the iliac arteries with the Palmaz stent: experience from a multicenter trial.

Balloon-expandable, intraluminal stenting of the iliac arteries with the Palmaz stent was the subject of a multicenter study for 4 years. A total of 486 patients underwent 587 procedures. Four hundred and five patients had unilateral and 81 had bilateral iliac stent placements. Follow-up ranged from 1 to 48 months (mean 13.3 +/- 11 months). Sustained clinical benefit of the treated patients was obtained in 90.9% at 1 year, 84.1% at 2 years, and 68.6% at 43 months. Angiographic patency rate was 92%. Diabetes mellitus and poor runoff had significant negative influence on the clinical outcome. The 10% incidence of procedural complications was not altered by operator experience.

Intraluminal bypass of abdominal aortic aneurysm: feasibility study.

This study evaluated the feasibility of treatment of abdominal aortic aneurysm (AAA) by means of intraluminal bypass. Artificial aortic aneurysms with fusiform Dacron conduits were created at surgery , a weft-knit Dacron tube with balloon-expandable stents attached at both ends was inserted transfemorally through a 14-F introducer sheath and expanded at the aneurysmal level by means of inflation of a coaxial balloon. The transluminal bypass successfully excluded the aneurysmal lumen immediately after placement. In two dogs, a postplacement aortogram revealed torsion of the graft that caused early occlusion. The six other dogs had a patent bypass at 6 months follow-up. Four of these dogs had evidence of kinking of the graft as a result of shrinkage of the prosthetic aneurysm. Histopathologic studies revealed that endothelialization was complete on the stents and partial on the graft surface. It is concluded that transluminal bypass of AAA is feasible in the dog model.

Aortic bifurcation stenosis: treatment with intravascular stents.

Balloon-expandable intravascular stents were employed to correct atherosclerotic stenosis of the aortic bifurcation. The devices were placed in the proximal iliac arteries with the cephalic end of the stents contacting in the midline. This arrangement provided an adequate lumen for the distal portion of the aortic wall and the proximal iliac arteries. Six of seven patients who received this form of treatment had hemodynamic and clinical improvement of their vascular insufficiency at an average follow-up of 1 year.