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Biomedical subjects

I Henry

Publications and source records attributed to I Henry.

At least 19 recordsLinked to original sources
PubMed2006

Carotid angioplasty and stenting under protection. Techniques, results and limitations.

A carotid stenosis is responsible for about 30% of strokes occurring. Carotid endarterectomy (CEA) is considered to be the gold standard treatment of a carotid stenosis. Carotid angioplasty and stenting (CAS) is emerging as a new alternative treatment for a carotid artery stenosis, but the risk of neurological complications and brain embolism remains the major drawback to this procedure. Therefore, in order to reduce the risks, we need: 1) good indications, good patient and lesion selection; 2) correct techniques; 3) brain protection devices (cerebral protection devices should be routinely used and are mandatory for any procedure); 4) 3 types of protection devices are available, but filters are the most commonly used (all protection devices have limitations and cannot prevent from all embolic events; however, neurological complications can be reduced by 60%); 5) a good choice of the stent and correct implantation (all stents are not equivalent and have different geometrical effects); 6) pharmacological adjuncts; 7) a good team. Recent studies have shown that CAS has superior short-term outcomes than CEA in high surgical risk patients, but there are enough reported data to conclude that CAS is also not inferior to CEA in low-risk patients. CAS under protection is the standard of care and is maybe becoming the gold standard treatment of a carotid stenosis at least in some subgroups of patients.

Angiography↗
PubMed2005

Angioplasty and stenting of extracranial vertebral artery stenosis.

Percutaneous angioplasty and stent placement seem a useful technique for the treatment of vertebro-basilar insufficiency and the first treatment to be proposed. This technique appears safe and effective for alleviating symptoms and improving blood flow to the cerebral circulation, with a low complications rate and good long-term results. However, this procedure needs experienced interventionists to choose the stent and have appropriate placement of the stent in the ostium of the vertebral artery (VA). The tortuosity of the VA may be technically challenging. The new coronary stents seem to be well suited to treat atherosclerotic lesions of the origin and of the proximal VA. A large variability of restenosis risk has been reported. Drug eluting stents may be the solution. Prospective randomized studies are needed to demonstrate the clinical effectiveness of VA stenting in stroke prevention, its durability, and to define more clearly its indications.

Angiography↗
PubMed2004

Percutaneous transluminal angioplasty using a new peripheral cutting balloon for stenosis of arch vessels in aorto arteritis.

Percutaneous transluminal angioplasty (PTA) with or without stenting of steno-occlusions in the supra-aortic arch vessels in aortoarteritis is associated with higher residual stenosis and restenosis, particularly in those with diffuse disease. The use of the new peripheral cutting balloon (Boston Scientific Interventional Technologies, San Diego, CA, USA) in these lesions in aortoarteritis has not been described. We report here the first 2 cases of stand alone cutting angioplasty for 2 patients (3 arteries). One patient presented with a critical stenosis of the common carotid artery. We obtained a good immediate result but a restenosis appeared at 6 months, easily treated by a new angioplasty with cutting balloon and stent implantation. The second patient had an occlusion of the subclavian artery associated with a severe ostial vertebral artery stenosis. The immediate result was excellent and the 6-month clinical and angiographic control showed no restenosis.

Adult↗
PubMed2002

The pNNx files: re-examining a widely used heart rate variability measure.

OBJECTIVE: To re-examine the standard pNN50 heart rate variability (HRV) statistic by determining how other thresholds compare with the commonly adopted 50 ms threshold in distinguishing physiological and pathological groups. DESIGN: Retrospective analysis of Holter monitor databases. SUBJECTS: Comparison of HRV data between 72 healthy subjects and 43 with congestive heart failure (CHF); between sleeping and waking states in the 72 healthy subjects; and between 20 young and 20 healthy elderly subjects. MAIN OUTCOME MEASURES: Probability values for discriminating between groups using a family of pNN values ranging from pNN4 to pNN100. RESULTS: For all three comparisons, pNN values substantially less than 50 ms consistently provided better separation between groups. For the normal versus CHF groups, p < 10(-13) for pNN12 versus p < 10(-4) for pNN50; for the sleeping versus awake groups, p < 10(-21) for pNN12 versus p < 10(-10) for pNN50; and for the young versus elderly groups, p < 10(-6) for pNN28 versus p < 10(-4) for pNN50. In addition, for the subgroups of elderly healthy subjects versus younger patients with CHF, p < 0.007 for pNN20 versus p < 0.17 for pNN50; and for the subgroup of New York Heart Association functional class I-II CHF versus class III-IV, p < 0.04 for pNN10 versus p < 0.13 for pNN50. CONCLUSIONS: pNN50 is only one member of a general pNNx family of HRV statistics. Enhanced discrimination between a variety of normal and pathological conditions is obtained by using pNN thresholds as low as 20 ms or less rather than the standard 50 ms threshold.

Adult↗
PubMed2001

Protected renal stenting with the PercuSurge GuardWire device: a pilot study.

PURPOSE: To evaluate the feasibility and safety of renal artery angioplasty and stenting utilizing a distal protection device to reduce the risk of intraprocedural atheroembolism. METHODS: Twenty-eight hypertensive patients (18 men; mean age 71.3 +/- 8.6 years, range 49-87) with atherosclerotic renal artery stenosis (4 bilateral) underwent angioplasty and stenting with distal protection in 32 renal arteries (29 ostial lesions). The lesion was crossed with a GuardWire temporary occlusion balloon, which was inflated to provide parenchymal protection. Generated debris was aspirated and analyzed. Blood pressure and serum creatinine levels were followed. RESULTS: Immediate technical success was 100%. All lesions were stented, either directly (14 ostial lesions), after predilation (15 ostial lesions), or owing to suboptimal angioplasty (3 nonostial lesions). Visible debris was aspirated from all patients. Mean particle number and diameter were 98.1 +/- 60.0 per procedure (range 13-208) and 201.2 +/- 76.0 microm (range 38-6206), respectively. Mean renal artery occlusion time was 6.55 +/- 2.46 min (range 2.29-13.21). Mean follow-up was 6.7 +/- 2.9 months (range 2-17). Systolic and diastolic blood pressure declined from 167.0 +/- 15.2 and 103.0 +/- 12.0 mm Hg, respectively, to 154.7 +/- 12.3 and 93.2 +/- 6.8 mm Hg after the procedure. The mean creatinine level dropped from 1.34 +/- 0.35 mg/dL preprocedurally to 1.22 +/- 0.36 mg/dL at 24 hours and remained constant. At 6-month follow-up, renal function did not deteriorate in any patient, whereas 5 patients with baseline renal insufficiency improved after the procedure. CONCLUSIONS: These preliminary results suggest the feasibility and safety of distal balloon occlusion during renal interventions to protect against atheroembolism. This technique's beneficial effects should be evaluated by randomized studies.

Aged↗
PubMed2000

State of the art: which stent for which lesion in peripheral interventions?

Applications of endovascular procedures have been expanded dramatically throughout the human body for both occlusive and aneurysmal disease; arteries at the aortoiliac and femoropopliteal levels are no exception. Currently, interventional procedures are the 1st treatment option for most patients who have peripheral artery disease. Although balloon angioplasty alone offers good immediate and long-term results, the addition of stents has been proposed to improve the procedural success of angioplasty and extend its application to more patients with vascular disease. Stenting, however, is controversial. Its use is considered acceptable in the aortoiliac vessels but is more in dispute for the femoropopliteal vessels. Moreover, the rapid development of endovascular stents for peripheral applications has made stent selection a complicated task for clinical practitioners. Many factors influence the type of stent selected; therefore, knowledge of the stents available--including various designs and individual properties--is mandatory. Appropriate selection depends on adequate preprocedural evaluation of the lesion; the choice of approach; the choice of primary versus selective stent placement; the location and characteristics of the lesion; the availability of stents in the intervention suite; and the experience of the operator Several stents are now available, but they are not equivalent; it is important to select the stent that is best suited to the lesion. On the basis of our experience using different types of stents, as well as our review of the world medical literature, we summarize the properties of various stents and specific indications for their application. This report is intended for use as a practical guide to stent selection.

Angioplasty, Balloon↗
PubMed2000

Angioplasty and stenting of the extracranial carotid arteries.

We performed percutaneous transluminal angioplasty and stenting in patients with carotid artery stenosis to determine the efficacy of these techniques as an alternative to surgical endarterectomy. From April 1995 through July 1999, 315 carotid angioplasty procedures were performed (right, 151; left, 164) in 290 patients ranging in age from 40 to 93 years. Of these patients, 42% were symptomatic and 58% were asymptomatic. Twenty-five patients underwent bilateral procedures. The mean percentage of stenosis was 82.3%+/-8.7% SD. Angioplasty and stenting were performed without cerebral protection in 165 arteries and with protection in 150. Two methods of protection were used: the Theron technique and the PercuSurge Guardwire temporary occlusion and aspiration system. Balloon dilation and stent placement were successful in 289 patients; in the last patient, severe arterial tortuosity prevented catheterization and stenting. We observed 13 periprocedural neurologic complications due to ischemia (4.2%): 4 transient ischemic attacks (1.3%), 4 minor strokes (1.3%), and 5 major strokes (1.6%), including 1 death. At 6 months, 210 patients had a follow-up angiogram (155) or duplex ultrasound (55). There were 10 restenoses (4.7%), 1 of which was symptomatic and 2 of which showed mild compression of a Palmaz stent without marked stenosis. Primary and secondary 4-year patency rates were 96% and 99%, respectively. These results demonstrate acceptable mortality and morbidity rates related to carotid angioplasty and stenting. However, we found the risk of embolic stroke to be substantial. Cerebral protection may improve the results of carotid angioplasty and expand the indications for this procedure.

Aged↗
PubMed2000

Percutaneous endovascular treatment of peripheral aneurysms.

BACKGROUND: To evaluate the feasibility and efficacy of percutaneous endovascular treatment of peripheral aneurysms. METHODS: Forty-eight patients, M: 41, F: 7, mean age: 65.7 +/- 10.1 years (47-85 years), with 50 aneurysms were treated: 45 with covered stents (Cragg/Passager 22, Corvita 21, Wallgraft 1, Endotex 1) 4 with non-covered stents and 1 with stent graft. Twenty-six aneurysms located at the iliac artery, 12 at the femoral and 12 at the popliteal artery. Mean lesion length: 61.1 +/- 21.3 mm. Percutaneous approach used in all cases, femoral antegrade (n=24), retrograde (n=23), contralateral (n=2), popliteal (n=1). Stents used were 6-12 mm in diameter and 30-120 mm in length. Multiple stents used to cover all lesions in 20 cases. RESULTS: Immediate technical success was 96% (48/50). In 1 case of long, tortuous femoropopliteal aneurysm, it was impossible to cover the low part, due to rigidity of the device used, in 1 case of large iliac aneurysm there was incomplete immediate exclusion. No complication during the procedure. Four patients developed non-infectious fever/local pain. Eight thromboses occurred: 2 at iliac, 1 at femoral and 5 at the popliteal level. All other stents remained patent, the aneurysms completely excluded over a mean follow-up of 20.6 +/- 13.2 m, maximum 61 m. Primary patency: all lesions 82%, iliac 92%, femoropopliteal 78%. Secondary patency: all lesions 88%, iliac 96%, femoropopliteal 86%. CONCLUSION: Percutaneous endoluminal treatment of peripheral aneurysms seems safe and effective with high technical success and good long-term results, except for popliteal localization. It could be an alternative to surgery.

Aged↗
PubMed1999

[LagoZ and LagZ, 2 genes depleted of CpG dinucleotides, derived from the LacZ gene for the study of epigenetic control].

The methylation of 5'CpG 3' dinucleotides within genes creates potential targets for protein complexes that bind to methylated DNA sequences and to histone deacetylases (MBD-HDAC). This can lead to transcriptional repression by modification of chromatic. To test the importance of this repression in vivo and to determine when during development these epigenetic controls are placed on genes, two novel genes have been engineered by directed mutagenesis of the CpG-rich LacZ gene that are depleted of (LagZ) or completely lacking (LagoZ) CpG sequences. We report that the expression (transcriptional and translational) of the three genes is indistinguishable in transient assays in cleaving mouse embryos. Therefore, the complete absence of CpG sequences within three kilobases of coding sequence is compatible with its maintenance in the nucleus and with its expression. These molecules can now be used to study the ontogenesis of the CpG-dependent repressive system in intact organisms.

Acetylation↗
PubMed1999

Carotid stenting with cerebral protection: first clinical experience using the PercuSurge GuardWire system.

PURPOSE: To study the feasibility and safety of carotid angioplasty and stenting using a new cerebral protection device that temporarily occludes the distal internal carotid artery (ICA). METHODS: Forty-eight high-risk patients (39 men, mean age 69.1 +/- 8 years, range 54 to 86) with 53 ICA stenoses underwent percutaneous angioplasty and stenting via the femoral approach under cerebral protection afforded by a 0.014-inch GuardWire balloon occlusion device. Mean stenosis was 82.1% +/- 9.65% (range 70 to 96) and mean lesion length was 16.0 +/- 7.5 mm (range 6 to 50). Thirty-three (62%) lesions were calcified, and 38 (72%) were ulcerated. Thirty-two (60%) of the lesions were asymptomatic. With the occlusion balloon inflated in the distal ICA, the lesion was dilated and stented. The area was cleaned by aspiration and flushed via an aspiration catheter advanced over the wire. Blood samples were collected from the external carotid artery (ECA) and analyzed to measure the size and number of particles collected. Computed tomography and neurological examinations were performed the day after the procedure. RESULTS: Immediate technical success was achieved in all patients with the implantation of 38 Palmaz stents, 8 Expander stents, and 11 Wallstents. Carotid occlusion was well tolerated in all patients but 1 who had multiple, severe carotid lesions and poor collateralization. Mean cerebral flow occlusion time was 346 +/- 153 seconds during predilation and 303 +/- 143 seconds during stent placement. Total mean flow occlusion time was 542 +/- 243 seconds. One immediate neurological complication (transient amaurosis) occurred in a patient who had an anastomosis between the external carotid (EC) and ICA territories. Debris was removed in all patients with a mean 0.8-mm diameter catheter. CONCLUSION: Cerebral protection with the GuardWire device is easy, safe, and effective in protecting the brain from cerebral embolism. Larger studies are warranted.

Aged↗
PubMed1999

Percutaneous transluminal angioplasty of the subclavian arteries.

PURPOSE: To review the feasibility, risks, and long-term results of subclavian artery angioplasty with and without Palmaz stent placement. METHODS: Over a 9-year period, 113 patients (67 males; mean age 63 +/- 13 years) underwent percutaneous balloon angioplasty of subclavian occlusive lesions for a variety of indications: vertebrobasilar insufficiency (n = 70), upper limb ischemia (n = 50), coronary steal syndrome (n = 6), or anticipated coronary artery bypass grafting using the internal mammary artery in 12 asymptomatic patients. There were 94 (83%) stenoses and 19 (17%) occlusions with a mean percent stenosis of 80.1% +/- 7.4% (range 70 to 100). Mean lesion length was 24 +/- 8 mm (range 10 to 50). Beginning in 1989, stents were implanted for suboptimal dilation; in 1995, stenting became routine. RESULTS: Overall, 103 (91%) of 113 lesions were successfully treated; 10 (53%) occlusions could not be recanalized. Fifty-one stents were implanted in 46 patients. There were 3 (2.6%) procedural complications: a transient ischemic attack, one major (fatal) stroke, and an arterial thrombosis 24 hours after the procedure (treated medically) (0.9% major stroke and death rate). During a mean 4.3-year follow-up (range to 10), 16 (15.5%) restenoses were treated with angioplasty (n = 4), stenting (n = 7), or surgery (n = 5). Primary and secondary patencies for all treated lesions (n = 113) at 8 years were 75% and 81%, respectively; in patients without initial stent placement, the rates were 69% and 76%, while in those with stents, the rates rose slightly to 87% and 94% at 2.5 years (NS). Patency rates for all 103 recanalized lesions were 83% and 90% at 8 years (81% and 90% without stent and 87% and 94% with stent at 2.5 years, respectively [NS]). CONCLUSIONS: Balloon angioplasty with or without stenting is safe and effective for treating subclavian artery occlusive diseases with good long-term patency. Recanalization of occlusions is more difficult to achieve. Stents (implanted only for suboptimal dilation) do not seem to improve long-term patency.

Adult↗
PubMed1999

Stents in the treatment of renal artery stenosis: long-term follow-up.

PURPOSE: To evaluate the role of percutaneous stenting in the treatment of renal arterial lesions after failure of balloon angioplasty. METHODS: Two hundred ten patients (139 males; mean age 67.7 +/- 9.9 years, range 27 to 87) had 259 balloon-expandable stents (165 Palmaz and 94 Renal Bridge stents) implanted in 244 renal artery stenoses (171 ostial and 73 nonostial lesions). The patients were suffering from intractable hypertension (n = 210) and/or renal dysfunction (n = 48). The majority of the lesions (n = 234) were atheromatous in origin. Stents were implanted for suboptimal balloon dilation (n = 182, 75%), restenotic lesions (n = 27, 11%), or dissection (n = 9, 4%); 26 (11%) ostial lesions were stented primarily. Mean lesion length was 11.9 +/- 4.4 mm (range 5 to 30) and mean percent stenosis was 81.9% +/- 8.25% (range 70 to 100). RESULTS: Immediate technical success was 99% (241 of 244). Three (1.2%) major complications included one intraprocedural stent thrombosis, one arterial perforation manifesting as a perirenal hematoma 24 hours after the procedure, and one renal arterial rupture. Follow-up over a mean 25.4 +/- 22.8 months (range 1 to 96) in 185 eligible patients (209 arteries) found 24 cases of restenosis (11.4%). Primary and secondary patencies for all lesions at 60 months were 79% and 98%, respectively, with no significant differences between ostial and nonostial lesions or stent types. Hypertension was reversed in 35 (19%), improved in 112 (61%), and remained unchanged in 37 (20%). Renal function was improved in 29% (14 of 48), unchanged in 67% (32 of 48), and worse in 4% (2 of 48). CONCLUSIONS: Renal artery stenting is safe, effective, and may be an alternative to surgery, particularly in ostial lesions. Our experience shows reduction in the restenosis rate compared to conventional angioplasty. All ostial stenoses should be stented.

Adult↗
PubMed1998

Identification of constitutional WT1 mutations, in patients with isolated diffuse mesangial sclerosis, and analysis of genotype/phenotype correlations by use of a computerized mutation database.

Constitutional mutations of the WT1 gene, encoding a zinc-finger transcription factor involved in renal and gonadal development, are found in most patients with Denys-Drash syndrome (DDS), or diffuse mesangial sclerosis (DMS) associated with pseudohermaphroditism and/or Wilms tumor (WT). Most mutations in DDS patients lie in exon 8 or exon 9, encoding zinc finger 2 or zinc finger 3, respectively, with a hot spot (R394W) in exon 9. We analyzed a series of 24 patients, 10 with isolated DMS (IDMS), 10 with DDS, and 4 with urogenital abnormalities and/or WT. We report WT1 heterozygous mutations in 16 patients, 4 of whom presented with IDMS. One male and two female IDMS patients with WT1 mutations underwent normal puberty. Two mutations associated with IDMS are different from those described in DDS patients. No WT1 mutations were detected in the six other IDMS patients, suggesting genetic heterogeneity of this disease. We analyzed genotype/phenotype correlations, on the basis of the constitution of a WT1 mutation database of 84 germ-line mutations, to compare the distribution and type of mutations, according to the different symptoms. This demonstrated (1) the association between mutations in exons 8 and 9 and DMS; (2) among patients with DMS, a higher frequency of exon 8 mutations among 46, XY patients with female phenotype than among 46,XY patients with sexual ambiguity or male phenotype; and (3) statistically significant evidence that mutations in exons 8 and 9 preferentially affect amino acids with different functions.

Amino Acid Sequence↗
PubMed1998

Wilms' tumor and gonadal dysgenesis in a child with the 2q37.1 deletion syndrome.

Here we report Wilms' tumor, gonadal dysgenesis and a bifid uterus in an 18-month-old female with a terminal deletion of the long arm of chromosome 2 [46,XX,del(2)(q37.1)]. Since Wilms' tumor has been previously reported in the 2q37 deletion syndrome, the present observation raises the question of whether a tumor susceptibility gene maps to chromosome 2q37 and suggests giving consideration to the possible occurrence of Wilms' tumor in the course of disease.

Abnormalities, Multiple↗
PubMed1998

The Hydrolyser thrombectomy catheter: a single-center experience.

PURPOSE: To present a single-center experience with a mechanical hydrodynamic thrombectomy system (Hydrolyser) in native arteries, veins, and bypass grafts. METHODS: The Hydrolyser is a 7F, double lumen, over-the-wire thrombectomy catheter. The device was used in 41 patients (22 males; mean age 68 years, range 40 to 90), with recent thromboses (aged 1 to 30 days, mean 8.7+/-8.5), measuring from 4 to 35 cm long (mean 17.7+/-9.5). The occlusions were located in native lower limb arteries (n = 28), bypass grafts (n = 8), superior venae cavae (n = 2), axillary vein (n = 1), and pulmonary arteries (n = 2). RESULTS: Immediate technical success (residual clot < 50% of lumen diameter) was achieved in 34 patients (83%): 22/28 native arteries (78%), 7/8 bypass grafts (87%), and all pulmonary arteries, superior venae cavae, and the axillary vein. The 7 failed patients were treated surgically (bypass graft or Fogarty balloon). Adjunctive procedureswere used to maximize luminal diameter: angioplasty (n = 29, with 13 immediate stent implantations), thromboaspiration (n = 17), and thrombolysis (n = 10). One case of distal embolism was the only complication (treated by thromboaspiration). At 30 days, 30 (73%) vessels remained patent. CONCLUSIONS: The Hydrolyser system is a promising concept for percutaneous thrombectomy. It is a quick, reliable, efficient device that may offer an alternative to thrombolysis and surgical thrombectomy.

Adult↗