[Endovascular stent implantation as a treatment for iliac artery disease]. / Endovasculaire stentplaatsing als behandeling bij iliacaal vaatlijden.

A stent is an endovascular prosthesis that may be used in the treatment of intermittent claudication caused by lesions of the A. iliaca communis and the A. iliaca externa in which earlier balloon dilatation has proved insufficiently effective. The expansion is caused by inflation of an angioplasty balloon (plastic remodelling: Palmaz stent) or by self-expansion due to elastic transformation as in the Wail stent or to thermic memory metal, as in the Memotherm stent. Evaluation of the literature shows that stent placement is a safe method of treatment. The proportion of initial technical success appears to be higher than that of balloon angioplasty, especially in the treatment of total occlusions. The haemodynamic situation immediately after treatment also appears to be better in case of stent placement. Long-term comparison of the clinical efficacy is not well possible because the published studies differ with regard to patient population, definition of indication and criteria of success.

Impact of different hemodynamic criteria for stent placement after suboptimal iliac angioplasty. Dutch Iliac Stent Trial Study Group.

PURPOSE: To investigate the consequences of different hemodynamic criteria as indications for stent placement after suboptimal iliac angioplasty. MATERIALS AND METHODS: One hundred thirty-six patients with intermittent claudication, on the basis of atherosclerotic disease of the iliac artery, underwent angioplasty. Intraarterial systolic and mean pressures were simultaneously recorded above and below the lesion, with and without vasodilation, and before and after percutaneous angioplasty. These data were used to estimate what proportion of the study population would be eligible for stent placement according to different criteria reported in the literature. Subsequently, the authors compared peak systolic velocity (PSV) ratios during follow-up in their patients, with and without indication for stent placement according to two different criteria. RESULTS: Applying the different thresholds reported in the literature to the patient group shows that stent placement would be indicated in anywhere from 4% to 87% of cases. No difference was observed when PSV ratios were compared in patients with a residual mean pressure gradient of > or = 5 and < or = 10 mm Hg with patients with a residual mean pressure gradient of less than 5 mm Hg. CONCLUSIONS: Application of the various published thresholds as indications for secondary stent placement leads to a wide range in proportion of cases requiring stent placement. Lesions with a residual mean pressure gradient of > 5 and < 10 mm Hg fare as well as lesions with a residual mean pressure gradient of less than 5 mm Hg. The optimal criterion is still not clear.

Randomised comparison of primary stent placement versus primary angioplasty followed by selective stent placement in patients with iliac-artery occlusive disease. Dutch Iliac Stent Trial Study Group.

BACKGROUND: Percutaneous transluminal angioplasty (PTA) is a safe, simple, and successful treatment for intermittent claudication caused by iliac-artery occlusive disease. Primary stent placement has been proposed as more effective than PTA. We compared the technical results and clinical outcomes of two treatment strategies-primary placement of a stent across the stenotic segment of the iliac artery, or primary PTA followed by selective stent placement when haemodynamic results were inadequate. METHODS: We randomly assigned 279 patients with intermittent claudication, recruited from departments of vascular surgery, either to direct stent placement (group I, n=143) or primary angioplasty (group II, n=136), with subsequent stent placement in case of a residual mean pressure gradient greater than 10 mm Hg across the treated site. The main inclusion criterion was intermittent claudication on the basis of iliac-artery stenosis of more than 50%, proven by angiography. All patients had a clinical assessment before intervention and at 3, 12, and 24 months. Clinical success was defined as improvement of at least one clinical category. Secondary endpoints were initial technical results, procedural complications, cumulative patency as assessed by duplex ultrasonography, and quality of life. FINDINGS: In group II, selective stent placement was done in 59 (43%) of the 136 patients. The mean follow-up was 9.3 months (range 3-24). Initial haemodynamic success and complication rates were 119 (81%) of 149 limbs and 6 (4%) of 143 limbs (group I) versus 103 (82%) of 126 limbs and 10 (7%) of 136 limbs (group II), respectively. Clinical success rates at 2 years were 29 (78%) of 37 patients and 26 (77%) of 34 patients in groups I and II, respectively (p=0.6); however, 43% and 35% of the patients, respectively, still had symptoms. Quality of life improved significantly after intervention (p<0.05) but we found no difference between the groups during follow-up. 2-year cumulative patency rates were similar at 71% versus 70% (p=0.2), respectively, as were reintervention rates at 7% versus 4%, respectively (95% CI -2% to 9%). INTERPRETATION: There were no substantial differences in technical results and clinical outcomes of the two treatment strategies both at short-term and long-term follow-up. Since angioplasty followed by selective stent placement is less expensive than direct placement of a stent, the former seems to be the treatment of choice for lifestyle-limiting intermittent claudication caused by iliac artery occlusive disease.

Therapeutic consequences of variation in intraarterial pressure measurements after iliac angioplasty.

PURPOSE: To assess the accuracy of intraarterial measurement of transstenotic pressure gradients for the detection of hemodynamically suboptimal iliac angioplasty. METHODS: In 14 patients, referred for diagnostic angiography, mean pressure gradients in the aorta and iliac artery were obtained twice, using a double-sensor pressure catheter. Additional iliac measurements were performed during pharmacologically induced flow augmentation. Repeatability was assessed by calculation of the mean difference plus standard deviation (MD +/- SD) and repeatability coefficient (2 x SD). These results were extrapolated to 137 iliac angioplasty procedures with secondary stenting where there was a residual pressure gradient > 10 mmHg. RESULTS: MD +/- SD for repeated measurements at rest and during flow augmentation were 0 +/- 2 mmHg and 1 +/- 3 mmHg, respectively. Repeatability coefficients were 3 and 6 mmHg. Mean pressure gradients after hemodynamically insufficient angioplasty were 8 +/- 7 mmHg at rest and 17 +/- 5 mmHg following vasodilatation. Inaccurate pressure recordings may have led to inappropriate stent placement in less than 2.5%, and inappropriate denial of stent placement in less than 5% of the lesions. CONCLUSION: Variability of intraarterial pressure measurements has little consequence in the detection of hemodynamically significant stenosis after angioplasty.

Intraarterial pressure gradients after randomized angioplasty or stenting of iliac artery lesions. Dutch Iliac Stent Trial Study Group.

PURPOSE: To determine initial technical results of percutaneous transluminal angioplasty (PTA) and stent procedures in the iliac artery, mean intraarterial pressure gradients were recorded before and after each procedure. METHODS: We randomly assigned 213 patients with typical intermittent claudication to primary stent placement (n = 107) or primary PTA (n = 106), with subsequent stenting in the case of a residual mean pressure gradient of > 10 mmHg (n = 45). Eligibility criteria included angiographic iliac artery stenosis (> 50% diameter reduction) and/or a peak systolic velocity ratio > 2.5 on duplex examination. Mean intraarterial pressures were simultaneously recorded above and below the lesion, at rest and also during vasodilatation in the case of a resting gradient < or = 10 mmHg. RESULTS: Pressure gradients in the primary stent group were 14.9 +/- 10.4 mmHg before and 2.9 +/- 3.5 mmHg after stenting. Pressure gradients in the primary PTA group were 17.3 +/- 11.3 mmHg pre-PTA, 4.2 +/- 5.4 mmHg post-PTA, and 2.5 +/- 2.8 mmHg after selective stenting. Compared with primary stent placement, PTA plus selective stent placement avoided application of a stent in 63% (86/137) of cases, resulting in a considerable cost saving. CONCLUSION: Technical results of primary stenting and PTA plus selective stenting are similar in terms of residual pressure gradients.

Stent placement after iliac angioplasty: comparison of hemodynamic and angiographic criteria. Dutch Iliac Stent Trial Study Group.

PURPOSE: To assess the diagnostic value of angiography as a guideline for selective stent placement after percutaneous transluminal angioplasty (PTA) of the iliac artery. MATERIALS AND METHODS: Seventy-nine patients (100 iliac artery lesions) with intermittent claudication were treated with PTA and stent placement if they had a residual intraarterial mean pressure gradient of more than 10 mm Hg across the PTA site. Pre- and post-PTA angiograms were used to determine if stent placement was necessary for improvement of the initial result of PTA. Interobserver agreement was determined by using kappa statistics. Pearson correlation coefficients for the percentage of residual stenosis and the pressure gradient after angioplasty were calculated. Sensitivity and specificity of angiography with regard to secondary stent placement were calculated. RESULTS: Observer agreement on stenosis grade before angioplasty was good (mean kappa, 0.65). Agreement on angioplasty results was fair (mean kappa, 0.45). Agreement on selective stent placement on the basis of angiographic criteria was poor to fair (kappa = 0.21-0.62). Correlation between percentage stenosis and pressure gradient was low (Pearson coefficient, 0.01-0.17). The sensitivity and specificity of angiography were 45% and 63%, respectively. CONCLUSION: Angiography is inadequate for determination of a suboptimal angioplasty result. The decision to perform selective stent placement should be made on the basis of hemodynamic measurements.

Management outcome and follow-up of fetal tachycardia.

OBJECTIVES: The aim of this study was to evaluate fetal tachycardia and the efficacy of maternally administered antiarrhythmic agents and the effect of this therapy on delivery and postpartum management. BACKGROUND: Sustained fetal tachycardia is a potentially life-threatening condition in which pharmacologic therapy is reported to be effective. There is ongoing discussion about optimal management. METHODS: A group of 51 patients with M-mode echocardiographically documented fetal tachycardia was studied retrospectively. RESULTS: Thirty-three fetuses had supraventricular tachycardia; 15 had atrial flutter; 1 had two episodes of both; and 2 had ventricular tachycardia. Fetal hydrops was seen in 22 patients. Thirty-four fetuses received maternal therapy with either digoxin or flecainide as the first administered drug (additional drugs were given in 12). Drug treatment was successful in establishing acceptable rhythm control in 82% (84% without, 80% with hydrops). In the latter group the median number of drugs and number of days to conversion were higher. Three patients with fetal hydrops died. In 50% of cases, tachycardia reappeared at delivery: 9 neonates presented with atrial flutter, 14 with supraventricular tachycardia and 1 with ventricular tachycardia. Seventy-eight percent of the group had pharmacologic therapy by 1 month of age and 14% by 3 years. CONCLUSIONS: Fetal tachycardia can be treated adequately in the majority of patients, even in the presence of hydrops, and therefore emergency delivery might not be indicated. Digoxin and flecainide were drugs of first choice and produced no serious adverse effects in this series of patients. The majority of patients do not require prolonged therapy.

Fetal arrhythmias.

The increased awareness of fetal arrhythmias by obstetricians and the development of sophisticated fetal echocardiography have established the basis for identification and treatment of these arrhythmias. The development of fetal hydrops is a recognized link to the severity of the arrhythmia. Fetal tachycardias have been diagnosed relatively early in gestation. They may be differentiated into sinus tachycardia, supraventricular tachycardia, atrial flutter or fibrillation, and ventricular tachycardia. The need for prenatal treatment is widely accepted and various modes of therapy are advocated. Oral maternal antiarrhythmic medication is often used, is considered convenient and safe, and provides adequate conversion. The drugs of choice at various centers have included digoxin, flecainide, amiodarone, and a host of combinations, as well as sotalol, which is gaining popularity. At birth, reentry mechanisms are often documented, with frequent relapses of tachycardia, warranting postpartum continuation of treatment. Fetal bradycardias consist of sinus bradycardia (generally related to obstetric pathology) and atrioventricular block. Atrioventricular block may occur secondary to severe congenital heart disease in the fetus or as an isolated phenomenon. The development of isolated total atrioventricular block has been seen to occur from a gestational age of 18 weeks up to term. It is invariably accompanied by the presence of SS-A and SS-B autoantibodies in the mother. Passage of these antibodies across the placenta causes inflammatory disease of fetal atrioventricular node tissue, resulting in fibrosis and atrioventricular block.(ABSTRACT TRUNCATED AT 250 WORDS)