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.     

Bovine endometrial retinol-binding protein secretion, messenger ribonucleic acid expression, and cellular localization during the estrous cycle and early pregnancy

OBJECTIVES: We assessed the safety and efficacy of stent placement in patients with poorly controlled hypertension and renal artery stenoses, which are difficult to treat with balloon angioplasty alone. BACKGROUND: Preliminary experience with stent placement suggests improved results over balloon angioplasty alone in patients with atherosclerotic renal artery stenosis. METHODS: Balloon-expandable stents were placed in 100 consecutive patients (133 renal arteries) with hypertension and renal artery stenosis. Sixty-seven of the patients had unilateral renal artery stenosis treated and 33 had bilateral renal artery stenoses treated with stents placed in both renal arteries. RESULTS: Angiographic success, as determined by quantitative angiography, was obtained in 132 (99%) of 133 lesions. Early clinical success was achieved in 76% of the patients. Six months after stent placement, the systolic blood pressure was reduced from 173 +/- 25 to 147 +/- 23 mm Hg (p < 0.001); the diastolic pressure from 88 +/- 17 to 76 +/- 12 mm Hg (p < 0.001); and the mean number of antihypertensive medications per patient from 2.6 +/- 1 to 2.0 +/- 0.9 (p < 0.001). Angiographic follow-up at a mean of 8.7 +/- 5.0 months in 67 patients revealed restenosis (>50% diameter narrowing) in 15 (19%) of 80 stented vessels. CONCLUSIONS: Renal artery stenting is an effective treatment for renovascular hypertension, with a low angiographic restenosis rate. Stent placement appears to be a very attractive therapy in patients with lesions difficult to treat with balloon angioplasty such as renal aorto-ostial lesions and restenotic lesions, as well as after a suboptimal balloon angioplasty result.     

Extending the C2 domain family: C2s in PKCs delta, epsilon, eta, theta, phospholipases, GAPs, and perforin

Percutaneous balloon angioplasty and endovascular stent placement are becoming common techniques intended to reduce the need for surgical bypass procedures that may be more expensive or have higher morbidity rates. Prophylactic antibiotics are not currently used before stent placement in most centers even when implanted via the femoral route. Infectious complications have been rare. In the case presented here an infected common iliac pseudoaneurysm occurred after percutaneous balloon angioplasty and stent placement. The literature is reviewed.     

Dietary and non-dietary factors associated with iron status in a cohort of Danish adults followed for six years

PURPOSE: Suboptimal distal coronary flow reserve after successful balloon angioplasty has been attributed to angiographically unrecognized inadequate lumen expansion, and adjunct coronary stenting has been shown to improve coronary flow reserve. The aim of this study was to investigate whether myocardial fractional flow reserve (FFRmyo) would increase further after coronary stenting compared with balloon angioplasty alone in the same patient group. METHODS: FFRmyo and quantitative coronary angiography were obtained before and after pre-stent balloon dilation, and again after stent placement in 11 patients (7 left anterior descending artery, 3 right coronary artery and 1 left circumflex artery). FFRmyo was calculated as the ratio of Pd/Pa during intracoronary adenosine 5'-triphosphate (50 micrograms and 20 micrograms in the left and right coronary arteries, respectively)-induced maximum hyperemia, where Pd represents mean distal coronary pressure measured by a 2.1 Fr infusion catheter and Pa represents mean aortic pressure measured by the guiding catheter. RESULTS: Percent diameter stenosis significantly decreased after balloon angioplasty (74% +/- 15% vs 37% +/- 17%, p < 0.001), and decreased further after stent placement (18% +/- 10%, p < 0.001 vs baseline and balloon angioplasty). FFRmyo after coronary stenting (0.85 +/- 0.09) was significantly higher than that at baseline (0.51 +/- 0.16, p < 0.001) and after balloon angioplasty (0.77 +/- 0.11, p < 0.05). There was a significant correlation between angiographic variables and FFRmyo. The increase in lumen dimensions after coronary stenting was followed by a further significant improvement of FFRmyo. CONCLUSION: These results suggest that coronary stenting may provide a more favorable functional status and lumen geometry of residual coronary stenosis compared with balloon angioplasty alone.     

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.     

What is a migraine, anyway, and when is it gone?

PURPOSE: To assess the effect of pneumoperitoneum on P(a-ET)CO2 gradient in children. METHODS: Sixty one ASA I and II children (10.7 +/- 3.0 yr, 38.4 +/- 14.2 kg, mean +/- SD), scheduled for visceral or urological laparoscopic procedures, were studied. They were anaesthetized, intubated, paralysed and their lungs ventilated with constant ventilator settings to obtain PETCO2 values between 4.3 and 4.8 kPa. Intra-abdominal pressure was maintained between 8 and 14 mmHg. The following measurements were performed at steady state, before the pneumoperitoneum (T1) and 15 min later (T2): heart rate, systolic and diastolic arterial pressure; peak airway and intra-abdominal pressure; PaCO2 corrected for the patient's temperature; PETCO2 drawn between the micropore filter and the ventilator tubes, corrected for BTPS conditions; P(a-ET)CO2. Values between -1.0 and +1.0 mmHg were considered nil; patient position (horizontal or head-down tilt): all patients were horizontal at T1. RESULTS: Arterial pressure, heart rate and peak airway pressure increased at T2: PaCO2 and PETCO2 increased by 14%. The incidence of negative gradients increased from 54 to 67% although mean P(a-ET)CO2 remained clinically unchanged. No difference was found in P(a-ET)CO2 gradient, whatever the position and intra-abdominal pressure. The 95% confidence intervals for P(a-ET)CO2 were [-5.6; +3.2] at T1 and [-8.8; +4.8] at T2. CONCLUSION: PETCO2 often overestimates PaCO2 during laparoscopy in children, by up to 8.8 mmHg. Arterial blood gas analysis should be performed during long procedures to avoid hyperventilation.     

The value of donor iliac artery pressure gradients in predicting the outcome of femorofemoral bypass

PURPOSE: This study tests the clinical value of femoral artery pressure measurements by analysis of the relationship between iliac artery pressure gradients (PGs) and both femorofemoral bypass graft patency and the hemodynamic changes produced in the donor and recipient limbs. METHODS: Systemic and donor femoral artery systolic and mean pressures were measured during surgery at rest and during papaverine-induced hyperemia before 94 femorofemoral bypasses. Ankle/brachial (A/B) pressure ratios and pulse volume recordings (PVRs) were measured before and early after surgery. Donor iliac artery stenosis was 25% +/- 23% (mean +/- 1 SD). Follow-up was 23+/- 20 months. RESULTS: Eight bypasses failed at 21 +/- 20 months. Patients with failed bypasses had a resting systolic and mean PG of 23 +/- 22 mm Hg and 5 +/- 7 mm Hg, respectively, compared with 10 +/- 11 mm Hg (p = 0.007) and 1 +/- 2 mm Hg (p = 0.001) for the 86 patent bypasses. Donor limb A/B ratios and PVRs decreased 9% +/- 5% and 15% +/- 14%, respectively, had a linear regression slope less than 0 (p < 0.05) with resting and hyperemic PGs, and correlated best with resting PGs (p < 0.05). Recipient limb A/B ratios and PVRs increased 86% +/- 48% and 191% +/- 111%, respectively, had a linear regression slope greater than 0 (p < 0.05) with all resting and hyperemic PGs, and correlated best with hyperemic systolic PGs (p < 0.05). However, all regressions had a large SD, wide 95% confidence limit, and a low correlation coefficient. Sensitivity-specificity receiver-operating characteristic curves for optimal PG criteria for both graft failure and donor limb hemodynamic impairment are weak, with an accuracy of 50% to 75%. Recommended criteria for not performing a femorofemoral bypass are a resting systolic PG of 28 mm Hg or greater or a resting mean PG of 6 mm Hg or greater. CONCLUSIONS: Although iliac artery PGs correlate with graft failure and both the degree of donor limb hemodynamic impairment and recipient limb improvement, the large variability in PGs between patients with similar outcomes and the low accuracy of optimal PG criteria indicate that they have limited clinical value in decision making.     

Effects of beta3-integrin blockade (c7E3) on the response to angioplasty and intra-arterial stenting in atherosclerotic nonhuman primates

Because the beta3-antagonist abciximab (c7E3 Fab) has significantly improved late outcomes after coronary angioplasty, the beta3 integrins have been implicated in the arterial response to injury. However, the mechanisms underlying this benefit are unknown. The observation that c7E3 binds beta3 integrins on vascular cells (alphavbeta3) with affinity equal to that for the platelet glycoprotein IIb/IIIa integrin has led to the hypothesis that c7E3 may act directly on the artery wall to prevent restenosis after angioplasty. To test this hypothesis, we studied the effects of c7E3 on structural changes within the artery wall after angioplasty or stent angioplasty in 23 male cynomolgus monkeys with established atherosclerosis. Animals were randomly assigned to receive either a bolus of c7E3 (0.4 mg/kg IV, n=11) followed by a 48-hour infusion (0. 2 microg. kg-1. min-1) or an equal volume of vehicle (n=12). Animals received weight-adjusted aspirin and heparin and then underwent unilateral iliac artery experimental angioplasty and subclavian artery stent angioplasty (Palmaz). Iliac artery lumen diameter (LD) was determined by angiography at baseline (LDPre), after angioplasty (LDPost), and 35 days later (LDDay35). Arteries were then fixed by perfusion and removed for analysis. Lumen, intima, media, and external elastic lamina (EEL) areas were measured in iliac artery cross sections. Values from each injured iliac artery were normalized to the contralateral uninjured iliac artery to control for interanimal variability in baseline artery size and atherosclerosis extent. Intimal area was also measured in subclavian stent cross sections. c7E3 blocked platelet aggregation and prolonged the bleeding time from 2.8+/-1.1 to 19.8+/-2.5 minutes, P<0.001. Experimental angioplasty increased LDPost an average of 28%, and the initial gain was similar in both groups (P=NS). Despite an anti-platelet effect, c7E3 did not inhibit iliac lumen narrowing (LDDay35-LDPost: c7E3, -0.69+/-0.17 versus vehicle, -0.99+/-.17 mm, P=0.35); intimal hyperplasia (neointima area: c7E3, 1.12+/-.28 versus vehicle, 1.22+/-.20 mm2, P=0.77); or decrease in artery wall size (EEL area [percent of uninjured control]: c7E3, 101+/-7% versus vehicle, 121+/-7%). Stent intimal hyperplasia was also unaltered by c7E3 treatment (neointimal area: c7E3, 1.09+/-0.16 versus vehicle, 1. 28+/-0.11 mm2, P=0.36). These results suggest that the benefits of c7E3 treatment in coronary angioplasty were not from inhibition of intimal hyperplasia or improved artery wall remodeling. Alternative mechanisms should be explored to explain improved late outcomes after angioplasty in patients treated with c7E3.     

Cytogenetic analysis of several pseudomyxoma peritonei lesions originating from a mucinous cystadenoma of the appendix

BACKGROUND: Reports of endovascular stent infection have recently been described. The purpose of this study was to determine if intravascular metallic stents in a swine model could become infected following a bacterial challenge given remote from the time of stent placement. METHODS: Balloon expandable metallic stents (Palmaz) were implanted in the iliac arteries of 14 swine. An angioplasty, without stent placement, was also performed in the contralateral iliac artery. An intravenous bacterial challenge with Staphylococcus aureus was given 4 weeks after stent placement. Euthanasia was performed 72 hours after the bacterial challenge. At the time of euthanasia, the iliac artery/stent complex and the contralateral angioplastied iliac artery were harvested and sent for microbiologic and pathologic analysis. RESULTS: Seven of the 14 stent/artery complexes were culture positive for S aureus whereas only one of the 14 angioplastied arteries was positive for S aureus (P = 0.03). On histologic examination, 6 of the 14 stent/artery complexes had evidence of acute inflammatory changes in the arterial wall. This compares with only 1 of 14 angioplastied arteries having evidence of inflammatory infiltrate in the arterial wall (P = 0.07). All 6 of the stent/artery complexes with inflammatory infiltrate were culture positive. CONCLUSION: In the swine model, intravascular metallic stents have the potential to become infected when a bacterial challenge is given 4 weeks after stent placement. Further studies evaluating the incidence of stent infections in humans are needed.     

Manometric study of the effects of experimental fundoplication in rats

BACKGROUND: The manometric effects of surgical repair of gastroesophageal reflux remain largely unknown, making the interpretation of the changes in the esophagogastric high pressure zone after fundoplication difficult. AIM: To measure in a murine model the transdiaphragmatic pressure gradients, intraabdominal esophageal length, and lower esophageal sphincter pressure and length after Nissen fundoplication. MATERIAL AND METHODS: Adult Wistar rats were divided into two groups Control group (n = 10): in which measurements were made after laparotomy and intraabdominal esophageal dissection. Nissen Group (n = 15): in which measurements were made at baseline, after fundoplication and 1 week after surgery. We considered the following variables: end-inspiratory and end-expiratory transdiaphragmatic gradient (TDIG and TDEG respectively), lower esophageal sphincter pressure (LESP) length (LESL), and length of the intraabdominal segment of the esophagus (LIAS). RESULTS: The LIAS increased significantly after esophagogastric dissection in the control group (11.38 +/- 3.22 mm vs 16.02 +/- mm, p < 0.05). No differences between pre- and postoperative status were found in TDIG, TDEG, LESP and LESL in the control group. However, LESP increased significantly after fundoplication (14.22 +/- 13.3 vs 32.96 +/- 7.8 mmHg, p < 0.05) and these differences were still present one week later (30.72 +/- 6.73 mmHg, p < 0.05). LESL was also increased (1.91 +/- 1.76 mm vs 7.68 +/- 1.83 mm) after fundoplication (p < 0.05), and reached 7.02 +/- 2.18 mm (p < 0.05) 1 week later. No differences were found in pre- and postoperative TDIG, TDEG and LIAS in the Nissen Group. CONCLUSION: In this murine experimental model, intraabdominal esophageal dissection increased the length of the intraabdominal esophagus without modifying the esophagogastric high pressure zone, while Nissen fundoplication increased lower esophageal sphincter pressure and length, without modifying the length of the intraabdominal esophagus or the transdiaphragmatic pressure gradients.     

Balloon valvuloplasty for the treatment of pulmonary stenosis in dogs

OBJECTIVE: To measure the effect of hypertension on neointima formation after balloon injury of rat aorta and its association with the local angiotensin converting enzyme (ACE) concentration. Balloon angioplasty of the thoracic aorta using a 2 French Fogarty catheter was performed in spontaneously hypertensive rats (SHR) and normotensive Sprague-Dawley (SD) rats. RESULTS: The injured aortic wall of SHR had already significantly higher ACE concentrations than did the uninjured aortic wall of normotensive SD rats (media: 729 +/- 37 dpm/mm2 in SHR versus 496 +/- 38 dpm/mm2 in SD rats, P < 0.01; intima: 83 +/- 5 dpm/mm2 versus 68 +/- 6 dpm/mm2 in SD rats, P < 0.01). Fourteen days after injury of the aorta the hypertensive rats had significantly higher neointima: media ratios than did the normotensive rats (0.83 +/- 0.09 versus 068 +/- 0.01, P < 0.01). This was associated with a significant increase in vascular media and neointima ACE concentrations in SHR (media 965 +/- 25 dpm/mm2, neointima 614 +/- 48 dpm/mm2) compared with those in normotensive SD rats after balloon angioplasty (media 669 +/- 23 dpm/mm2, neointima 287 +/- 33 dpm/mm2, P < 0.01). ACE inhibitor treatment with 10 mg/kg body weight lisinopril daily for 14 days by gavage reduced neointima proliferation in hypertensive and normotensive rats (neointima: media ratio: 0.35 +/- 0.02 for SHR, P < 0.01, versus untreated SHR with balloon injury; 0.28 +/- 0.01 for SD, P < 0.01, versus untreated SD rats with balloon injury). This was associated with significant vascular media ACE inhibition (SHR 149 +/- 9 dpm/mm2; SD rats 118 +/- 7 dpm/mm2; P < 0.01 versus untreated controls with balloon injury) and neointima ACE inhibition (SHR 73 +/- 4 dpm/mm2, SD rats 63 +/- 7 dpm/mm2, P < 0.01, versus untreated controls with balloon injury), but also lowered the blood pressure in SHR significantly (to 148 +/- 5 mmHg, P < 0.01, versus untreated SHR with balloon injury). When this drop in blood pressure was prevented by feeding the rats a high-salt diet (SHR with ACE inhibitor plus high salt-diet group blood pressure 193 +/- 3 mmHg, P = 0.57, versus untreated SHR) hypertension per se without the local ACE increase (ACE concentration in SHR with ACE inhibitor high-salt diet rats' media 167 +/- 10 dpm/mm2 and neointima 81 +/- 9 dpm/mm2) had only a mild effect on neointima formation after balloon angioplasty (neointima: media ratio 0.4 +/- 0.01 for SHR with ACE inhibitor plus high-salt diet versus 0.35 +/- 0.02 for SHR with ACE inhibitor plus normal-salt diet P < 0.05). Treatment with 10 mg/kg body weight angiotensin II subtype 1 receptor antagonist losartan potassium daily for 14 days by gavage was associated with a reduction in neointima formation similar to that observed with the ACE inhibitor both for SHR and for SD rats (neointima: media ratio 0.32 +/- 0.04 for SHR with losartan, 0.27 +/- 0.03 for SD rats with losartan; P < 0.01, versus untreated controls with balloon injury) suggesting that ACE inhibitor prevented neointima formation, at least in part by, reducing the local production of angiotensin II. CONCLUSION: Neointima formation after balloon angioplasty in SHR is increased compared with that in normotensive SD rats. This is due mainly to there being a higher degree of activation of the renin-angiotensin system in the aorta of the SHR before and after balloon injury compared with that in normotensive SD rats measured in terms of the increased vascular ACE concentrations. Blood pressure alone had only a moderate effect on neointima formation.     

The relation between multiple sleep latency test findings and the frequency of apneic events in REM and non-REM sleep

OBJECTIVES: The purpose of this prospective study was to evaluate the immediate results and the 6-month angiographic recurrent restenosis rate after balloon angioplasty for in-stent restenosis. BACKGROUND: Despite excellent immediate and mid-term results, 20% to 30% of patients with coronary stent implantation will present an angiographic restenosis and may require additional treatment. The optimal treatment for in-stent restenosis is still unclear. METHODS: Quantitative coronary angiography (QCA) analyses were performed before and after stent implantation, before and after balloon angioplasty for in-stent restenosis and on a 6-month systematic coronary angiogram to assess the recurrent angiographic restenosis rate. RESULTS: Balloon angioplasty was performed in 52 patients presenting in-stent restenosis. In-stent restenosis was either diffuse (> or =10 mm) inside the stent (71%) or focal (29%). Mean stent length was 16+/-7 mm. Balloon diameter of 2.98+/-0.37 mm and maximal inflation pressure of 10+/-3 atm were used for balloon angioplasty. Angiographic success rate was 100% without any complication. Acute gain was lower after balloon angioplasty for in-stent restenosis than after stent implantation: 1.19+/-0.60 mm vs. 1.75+/-0.68 mm (p=0.0002). At 6-month follow-up, 60% of patients were asymptomatic and no patient died. Eighteen patients (35%) had repeat target vessel revascularization. Angiographic restenosis rate was 54%. Recurrent restenosis rate was higher when in-stent restenosis was diffuse: 63% vs. 31% when focal, p=0.046. CONCLUSIONS: Although balloon angioplasty for in-stent restenosis can be safely and successfully performed, it leads to less immediate stenosis improvement than at time of stent implantation and carries a high recurrent angiographic restenosis rate at 6 months, in particular in diffuse in-stent restenosis lesions.     

Intraoperative endovascular angioplasty and stenting of iliac artery: an adjunct to femoro-popliteal bypass

BACKGROUND: With the rapid development of endovascular techniques, the management strategy of patients with multilevel atherosclerotic arterial occlusive disease is also evolving. Iliac artery stenting is a means whereby multiple bypass operations can be avoided in such patients. The early results of preoperative iliac artery stenting seem promising but the role of intraoperative iliac artery angioplasty and stenting is less clear. STUDY DESIGN: This study was undertaken to evaluate our early results of a combined endovascular and operative approach to patients with multilevel atherosclerotic arterial occlusive disease. Between June 1995 and March 1997, primary intraoperative iliac artery balloon angioplasty and stent placement were performed on 13 affected limbs of 12 patients undergoing an infrainguinal bypass operation. Indications for operation, patient demographics, and risk factors were noted. The outcome of surgery and the patency rates of bypass graft and stent were also recorded. RESULTS: The initial technical success of primary iliac artery angioplasty and stenting was 93%. An improvement of the ankle-brachial index by a mean value of 0.38 was attained after operation (p < 0.001). Clinical success, based on the criteria suggested by the Society for Vascular Surgery/International Society for Cardiovascular Surgery, was achieved in all patients. There was no operative or hospital mortality. Postoperative morbidity rate was 8% (n = 1). The cumulative 1-year patency rates of iliac stent and infra-inguinal bypass grafts were 100% and 85%, respectively. The limb loss rate was 7%. CONCLUSIONS: The technique of intraoperative angioplasty and stenting can be easily mastered by an experienced and skilled vascular surgeon, using a portable C-arm fluoroscopic unit, in the operation theater. A combined endovascular and operative approach optimizes the therapeutic option to this selected group of patients.     

A critical experiential teaching strategy: student and faculty participation in an AIDS walk

The authors report their experience in the placement of a new Nitinol stent. Thirty eight stents were placed in 28 iliac arteries, 3 superficial femoral arteries, 1 popliteal artery, 2 subclavian arteries, and 2 veins of hemodialysis fistulae. The primary success rate was 100%, but several angioplasty balloons have been ruptured due to the specific configuration of the stent. The mean follow-up period was 6 months. Memotherm placement is an easy procedure, but the specific structure of the device makes the manipulation of the angioplasty balloons delicate, especially in tortuous vessels.     

Physicians and surgeons during the French intervention and the Second Empire

Little is known about the frequency of adverse events in the year following stent placement in patients treated with aspirin and ticlopidine, without warfarin. We analyzed the first such 234 consecutive patients treated at our hospital between October 1994 and December 1995. Their mean age was 62+/-12 years; 40% had had a prior myocardial infarction, 22% had undergone coronary artery bypass surgery, and 65% had multivessel disease. The indication for stent placement was dissection or abrupt closure in 24% of patients and suboptimal balloon angioplasty results in 14%; placement was elective in 62% of patients. Three hundred forty-five coronary segments were treated in the 234 patients; 305 stents (1.3 stents/patient) were placed. Palmaz-Schatz coronary stents (75%), Gianturco-Roubin stents (21%), and Johnson & Johnson biliary stents (4%) were used. Mean nominal stent size was 3.4+/-0.4 mm. High-pressure inflations (> or = 14 atm, mean 17+/-2) were performed in all patients. The mean residual stenosis was 3+/-5% by visual estimate. Intravascular ultrasound was utilized to facilitate stent placement in 53% of patients. Mean follow-up was 1.6+/-0.5 years. There were no deaths, Q-wave myocardial infarctions, coronary artery bypass operations, or repeat angioplasty procedures required during the remainder of the hospitalization or in 30 days after stent placement; stent thrombosis did not occur. Kaplan-Meier analysis of adverse events in the 6 months following the procedure revealed a mortality rate of 0.9%; the rate of myocardial infarction (Q-wave or non-Q-wave) was 1.3%. Bypass surgery was performed in 0.9% and angioplasty for in-stent restenosis was performed in 9.5% of patients. Any 1 of these events occurred in 11.7% of patients in the 6 months after the procedure. The corresponding event rates at 1 year were 1.3%, 2.2%, 3.5%, and 12.2%, respectively; any 1 of these events occurred in 16.5% of patients. In patients receiving intracoronary stents of varying designs followed by high-pressure postdeployment inflations in whom an excellent visual angiographic result is achieved, antithrombotic therapy with aspirin and ticlopidine is associated with a very low frequency of adverse cardiovascular events in the 12 months following the procedure regardless of the indication for stent placement.     

Stent placement compared with balloon angioplasty for obstructed coronary bypass grafts. Saphenous Vein De Novo Trial Investigators

BACKGROUND: Treatment of stenosis in saphenous-vein grafts after coronary-artery bypass surgery is a difficult challenge. The purpose of this study was to compare the effects of stent placement with those of balloon angioplasty on clinical and angiographic outcomes in patients with obstructive disease of saphenous-vein grafts. METHODS: A total of 220 patients with new lesions in aortocoronary-venous bypass grafts were randomly assigned to placement of Palmaz-Schatz stents or standard balloon angioplasty. Coronary angiography was performed during the index procedure and six months later. RESULTS: As compared with the patients assigned to angioplasty, those assigned to stenting had a higher rate of procedural efficacy, defined as a reduction in stenosis to less than 50 percent of the vessel diameter without a major cardiac complication (92 percent vs. 69 percent, P<0.001), but they had more frequent hemorrhagic complications (17 percent vs. 5 percent, P<0.01). Patients in the stent group had a larger mean (+/-SD) increase in luminal diameter immediately after the procedure (1.92+/-0.30 mm, as compared with 1.21+/-0.37 mm in the angioplasty group; P<0.001) and a greater mean net gain in luminal diameter at six months (0.85+/-0.96 vs. 0.54+/-0.91 mm, P=0.002). Restenosis occurred in 37 percent of the patients in the stent group and in 46 percent of the patients in the angioplasty group (P=0.24). The outcome in terms of freedom from death, myocardial infarction, repeated bypass surgery, or revascularization of the target lesion was significantly better in the stent group (73 percent vs. 58 percent, P = 0.03). CONCLUSIONS: As compared with balloon angioplasty, stenting of selected venous bypass-graft lesions resulted in superior procedural outcomes, a larger gain in luminal diameter, and a reduction in major cardiac events. However, there was no significant benefit in the rate of angiographic restenosis, which was the primary end point of the study.     

Measurement of the vascular mass of the human radial artery by ultrasonics

OBJECTIVE: To determine the reproducibility of radial artery mass (RAM), in hypertensive patients. DESIGN AND METHODS: In 49 patients, RAM was measured using a high resolution echotracking device (Nius-02) which allows noninvasive measurement of diameter and wall thickness of the radial artery. RAM was validated in vitro by comparing weight of arterial segments to ultrasonographic measurement and determined as RAM = r (pi Re2-pi Ri2) where r is the arterial wall density (1.06 g/cm3), and Re and Ri are values of internal and external radii, respectively. Repeatability coefficient (RC2 = SDi2/n) was 1.3 mg. RESULTS: Blood pressure was (mean +/- SD) 146 +/- 19/85 +/- 15 mmHg, radial arterial diameter was 2,449 +/- 376 microns, radial wall thickness was 302 +/- 68 microns, RAM was 28 +/- 9 mg (range 13-43 mg). CONCLUSION: These results indicate that radial artery mass can be measured using a high resolution echotracking device.     

Enhanced involvement of endothelin in the haemodynamic sequelae of endotoxaemia in conscious, hypertensive, transgenic ((mRen-2)27) rats

1. Age-matched (3-4 months old) male, heterozygous, hypertensive, transgenic ((mRen-2)27) rats (abbreviated to TG rats) and the normotensive control animals (homozygous, Hannover Sprague-Dawley rats (abbreviated to SD rats), were chronically instrumented for the assessment of regional haemodynamic responses to continuous lipopolysaccharide (LPS) infusion (150 microg kg(-1) h(-1), i.v.) 2. The early (1-2 h) hypotension in SD rats (-11+/-3 mmHg; n=7) was significantly less than that in TG rats (-35+/-3 mmHg; n=8), but by 24 h mean arterial blood pressure (MAP) in both strains of rat was not different from the pre-LPS value (SD rats: baseline, 108+/-3 mmHg; 24 h LPS, 112+/-4 mmHg; TG rats: baseline, 171+/-2 mmHg; 24 h LPS, 169+/-3 mmHg). At this stage in the SD rats there was a renal vasodilatation (delta vascular conductance, 29+/-10 [kHz mmHg(-1)]10(3)) but not in TG rats (delta vascular conductance 2+/-3[kHz mmHg(-1)]10(3)). 3. Co-infusion of LPS and the non-selective endothelin receptor antagonist, SB 209670 (600 microg kg(-1) bolus, 600 microg kg(-1) h(-1)) between 24 and 31 h in SD rats caused a fall in MAP of 16+/-2 mmHg accompanied by hindquarters vasodilatation (delta vascular conductance 11+/-3 (kHz mmHg(-1))10(3)). In TG rats, under the same conditions, the fall in MAP was -60+/-6 mmHg, and there were renal, mesenteric and hindquarters vasodilatations (delta vascular conductance, 23+/-5, 32+/-7, and 14+/-4 (kHz mmHg(-1))10(3), respectively). All effects, except the hindquarters vasodilatation, were greater in TG than in SD rats. 4. In TG rats infused with LPS alone for 31 h, between 24 and 31 h the fall in MAP was -17+/-4 mmHg, and the changes in renal, mesenteric and hindquarters vascular conductances were 5+/-3, -4+/-5, and 12+/-4 (kHz mmHg(-1)10(3), respectively. 5. Administration of the angiotensin (AT1)-receptor antagonist, losartan (10 mg kg(-1), i.v.) following co-infusion of LPS and SB 209670 between 24 and 31 h caused similar falls in MAP in SD and TG rats (-12+/-3 and -14+/-4 mmHg, respectively). 6. These results, together with previous findings, are consistent with a relative enhancement of the contribution of endothelin to the maintenance of cardiovascular status in endotoxaemic TG rats, particularly through a mesenteric vasoconstrictor action.     

Carbon dioxide as a contrast agent to guide vascular interventional procedures

OBJECTIVE: The purpose of this study was to assess the value and limitations of carbon dioxide (CO2) as a contrast agent to guide vascular interventional procedures. SUBJECTS AND METHODS: Twenty-two adults underwent 26 vascular interventional procedures (21 arterial, five venous). We aimed to use only CO2 if possible because these patients had renal insufficiency (n = 21; mean creatinine level, 2.8 mg/dl) or were allergic to contrast material (n = 1). Arterial procedures performed included renal angioplasty or stent (n = 6), iliac angioplasty or stent (n = 5), infrainguinal angioplasty (n = 5), arterial bypass graft angioplasty (n = 3), and thrombolysis (n = 2). Venous procedures included transjugular intrahepatic portosystemic shunt recanalization (n = 3), angioplasty of the venous anastomosis of a thigh dialysis graft (n = 1), and angioplasty of the inferior vena cava (n = 1). RESULTS: Twenty-five of the 26 procedures were successfully performed. Of the 26 procedures, eight required no iodinated contrast material and 11 required less than or equal to 20 ml of contrast material. CO2 proved to be inadequate for the remaining seven procedures. Iliac artery angioplasty or stent placement required an average of 9 ml of iodinated contrast material; infrainguinal angioplasty required an average of 22 ml of iodinated contrast material. CONCLUSION: CO2 can be successfully used as a contrast agent in a variety of vascular interventional procedures. Such procedures can usually be performed in the iliac and infrainguinal arteries using minimal supplemental iodinated contrast material. However, CO2 failed to provide satisfactory guidance in half of the intraabdominal procedures in our study.     

Efficacy of benazepril monotherapy in moderate essential hypertension studied by automatic ambulatory blood pressure monitoring

Authors examined the effects of benazepril, regarding the length of effectiveness by ambulatory blood pressure monitoring (ABPM), drug tolerable, and the compliance of patients in mild to moderate essential hypertension. 14 patients were treated with benazepril monotherapy. Six of them were newly diagnosed, and the rest had already been treated for hypertension. At the start, after six and 12 weeks, 24-hour monitoring was performed. Casual blood pressure (BP) measurements and detection of side-effects were also performed at 3rd and 9th-week. Prior the study the average daytime BP measured by ABPM was 149.1 +/- 7.7/96.6 +/- 4.7 mmHg. 10 mg of benazepril was first administered in the morning. By the end of the sixth week the average BP was significantly decreased (daily average: 139.1 +/- 9.9/88.2 +/- 7.6 mmHg). The daytime diastolic average BP of 8 patients was lower than 90 mmHg and the other's daily dose was raised to 20 mg. During the 12th-week we found optimal tension in 11 patients, while in two others there was also a significant decrease. The daily average BP was 134.7 +/- 7.5/85.6 +/- 6.6 mmHg. In comparison the data at the beginning of the study here was significant decrease in the 24-hour, daytime and night-time BP, in the hypertension time-index and the hyperbaric impact, both in systolic and diastolic levels. During the 12th-week period the diurnal index was unchanged. The early morning BP decreased by the end of the 3rd month from 148.6 +/- 14.1/98.5 +/- 11.7 mmHg to 135.2 +/- 13.5/93.4 +/- 11.2 mmHg. Sustained side-effect did not occur. The patient's compliance to benazepril was excellent. Authors conclude that benazepril monotherapy lowered in 92.8%, and normalized in 78.5% the blood pressure of patients suffering from mild to moderate essential hypertension. The unchanged diurnal index, and the decrease in the early morning blood pressure suggest the 24-hour effect of benazepril.