Coronary artery perforation during percutaneous intervention: incidence and outcome.

OBJECTIVE: To examine the clinical outcome of percutaneous coronary intervention where the procedure was complicated by vessel perforation. SETTING: Tertiary referral centre. METHODS: The procedural records of 6245 patients undergoing coronary intervention were reviewed. In 52 patients (0.8%) the procedure was complicated by vessel perforation, ranging from wire exit to free flow of contrast into the pericardial space. The majority of lesions treated were complex (37% type B, 59% type C) and 9 of 52 (17%) were chronic occlusions. Ten patients (19%) received abciximab. Four underwent rotational atherectomy (8%). RESULTS: In 28 of 52 patients (54%) the perforation was benign and managed conservatively without the development of haemodynamically significant sequelae. In 24 of 52 (46%) a significant pericardial effusion ensued requiring drainage. Of these 24 procedures 6 had involved the treatment of a chronic occlusion (25%). Eight of the 24 patients were referred for emergency bypass surgery (33%), 3 of whom died. Of the remaining 16 not referred for surgery, 3 died. Of the 10 procedures complicated by vessel perforation where abciximab had been administered, 9 (90%) led to pericardial tamponade. Latterly 2 vessel perforations were successfully treated by the deployment of a covered stent. CONCLUSIONS: Coronary artery perforation with sequelae during intervention is rare--26 of 6245 (0.4%). This complication was seen in the treatment of chronic occlusions, which are therefore not risk-free procedures. The development of pericardial tamponade carries a high mortality. While prompt surgical intervention may be life saving, expertise in the use of covered stents may provide a valuable rescue option for this serious complication. Caution should be exercised where coronary perforation occurs and abciximab has been used.

The production of synthetic aggregate from a quarry waste using an innovative style rotary kiln.

The large volumes of wastes generated by industrialised society has led to efforts to find practical uses for these wastes, whilst also offsetting the consumption of natural resources. This paper describes the use of an innovative rotary kiln to produce synthetic aggregates from a variety of waste streams. The main waste used was a quarry fines which was blended with either paper sludge, clay, or a dredged harbour sediment. The different combinations were extruded and fired in the kiln to produce a material suitable for natural aggregate replacement. Two of the synthetic aggregates produced were tested by incorporation in to concrete as coarse aggregate replacement. The concrete 28-day compressive strengths achieved were above 40 N mm(-2) and compared favourably with control concretes made with natural aggregates and a commercially available lightweight aggregate (Lytag). Leaching tests have also been carried out to assess the potential environmental impact of utilisation. Although not finalised, these tests have also given favourable results.

Treatment of intractable angina in a nonagenarian patient by direct coronary stenting.

BACKGROUND: A 91-year-old man presented with a 6-month history of exertional angina. As he was already on maximally tolerated medical therapy, we decided to perform coronary angiography, which revealed severe stenosis of the distal main stem coronary artery, OUTCOME: The lesion was crossed with an intra-coronary wire, and a stent placed to cover the distal main stem lesion, without prior balloon dilatation. The result was satisfactory and he remains symptom-free at 6-month follow-up. CONCLUSION: Treatment of left main stem lesions with percutaneous intervention may be an acceptable alternative to surgery in high-risk elderly patients. Since percutaneous coronary angioplasty can be performed on very elderly patients with a high degree of success, the decision to investigate and treat should not be based solely on biological age.

A randomised trial of endoluminal reconstruction comparing the NIR stent and the Wallstent in angioplasty of long segment coronary disease: results of the RENEWAL Study.

BACKGROUND: The role of coronary stents in reducing the incidence of acute complications and late restenosis after angioplasty has been established in randomized studies focusing on simple, short coronary lesions. The development of long coronary stents has provided a safe and predictable means of treating long coronary lesions, but this carries with it a higher risk of restenosis. By comparing the outcome of treating long lesions with two different stent types, we aimed to assess the influence of stent design rather than the nature of long lesions per se on the relatively high restenosis rates in this subgroup. METHODS: This study was designed to assess procedural complications and 6-month restenosis rates in a randomized trial comparing a slotted tube stent with a self-expanding stent for the treatment of long coronary lesions. Randomization of vessels to either stent occurred after successful balloon angioplasty. Intravascular ultrasound (IVUS) was used to assess and optimize stent deployment. The patients were restudied angiographically and by IVUS at 6 months. RESULTS: A total of 82 patients (85 vessels) were recruited (slotted tube stent, n = 44 vessels; self-expanding stent, n = 41 vessels). Successful deployment occurred in 41 (100%) of 41 of the self-expanding stent group and 41 (93%) of 44 of the slotted tube stent group. There was no difference in lesion length between the two groups (slotted tube stent, 26.6 +/- 6.9 [SD] mm; self-expanding stent, 28.7 +/- 9.8 [SD] mm; P = .2), but the mean length of the self-expanding stent was greater than that of the slotted tube stent (41.6 +/- 18.8 [SD] mm vs 35.4 +/- 16.2 [SD] mm, respectively; P < .05). There was no significant difference in the rate of major events between the two groups at 6-month follow-up. The angiographic restenosis rate at follow-up was less in the slotted tube stent group, but this did not reach statistical significance (26% vs 46%, respectively; P = .1) and the target lesion revascularization rate was similar for both groups (7.9% vs 7.7%, respectively; P = .8). IVUS assessment of plaque/stent ratios suggested a greater plaque burden in the self-expanding stent compared with the slotted tube stent at follow-up (0.42 +/- 1.2 [SD] vs 0.3 +/- 0.08 [SD]), but this was not statistically significant (P = .1). CONCLUSIONS: Long stents can be safely and successfully deployed in long segment coronary disease, with an acceptable 6-month target lesion revascularization rate. Our results showed a trend toward lower angiographic restenosis and a lesser in-stent plaque burden at follow-up in the slotted tube stent compared with the self-expanding stent. This suggests that stent design may influence the restenotic process in long coronary lesions.

Development and validation of a Bayesian index for predicting major adverse cardiac events with percutaneous transluminal coronary angioplasty.

OBJECTIVE: To create a risk model for predicting major adverse complicating events of percutaneous transluminal coronary angioplasty (PTCA), and to test the accuracy of the model on a prospective cohort of patients SETTING: Tertiary cardiac centre METHODS: Available software can predict probabilities of events using Bayes's theorem. To establish the accuracy of these predictive tools, a Bayes table was created to evaluate major adverse complicating events (MACE)-death, emergency coronary artery bypass grafting (CABG), or Q wave infarct occurring during the in-patient episode-on the first 1500 patients in the department PTCA database (development group); the predictive value of this model was then tested with the subsequent 1000 patients (evaluation group). The following probabilities were assessed to determine their association with MACE: age, sex, left ventricular function, American Heart Association lesion morphology classification, cardiogenic shock, previous CABG, diabetes, hypertension, multivessel PTCA. MAIN OUTCOME MEASURES: To establish the discriminatory ability of the predictive index, calibration plots and receiver operating characteristic (ROC) curves were obtained to compare the development and evaluation groups. RESULTS: The ROC curve plotted to determine the discriminatory value of the Bayesian table created from the development group (n = 1500) in predicting MACE in the evaluation group (n = 1000) showed a moderately predictive area under the curve of 0.76 (SEM 0.07). This predictive accuracy was confirmed with separately constructed calibration plots. CONCLUSIONS: Accurate predictions of MACE can be identified in populations undergoing percutaneous intervention. The database used allows operators to obtain consent from patients appropriately from their own experience rather than from other published data. If a national PTCA database existed along similar lines, individual operators and interventional centres could compare themselves with nationally available data.

Intravascular ultrasound-guided stenting in long lesions: an insight into possible mechanisms of restenosis and comparison of angiographic and intravascular ultrasound data from the MUSIC and RENEWAL trials.

The high restenosis rates in long stents may be related to suboptimal stent deployment. In an attempt to understand the potential components associated with restenosis in long stents, this study compares angiographic and intravascular ultrasound (IVUS) data from the MUSIC and RENEWAL studies where IVUS was used to optimize stent deployment in short (< 15 mm) and long (> 20 mm) coronary lesions, respectively. The RENEWAL study, a randomized trial, compared the NIR stent and Wallstent in long (> 20 mm) coronary lesions and used on-line visual IVUS criteria to optimize stent expansion. Detailed analysis of IVUS data was performed off line. Angiographic and IVUS data from this study was compared to that from the MUSIC study. Initial stent deployment was deemed optimal by the operator after visual angiographic and IVUS assessment in 50 of 70 lesions. In the remaining 20 lesions further balloon inflations were required to optimize stent apposition that led to an average gain in minimal in-stent luminal area (MISA) of 15.9% (P < 0.01). Off-line IVUS data analysis showed that the number reaching "MUSIC criteria" for optimal stent deployment preredilatation was 8 (11.4%) of 70 and 14 (20%) of 70 postredilatation. The ratio of MISA/MRAprox (mean proximal reference area) was 0.69 in RENEWAL. At 6-month follow-up, the angiographic restenosis rate in RENEWAL was 36% and target lesion revascularization (TLR) rate was 7.8%, compared with MUSIC's 9.7% and 4.5%, respectively. In conclusion, angiographic assessment of stent deployment in long lesions is limited. On-line visual IVUS with further balloon inflations to improve stent apposition led to a significant gain in MISA, but the MISA/MRAprox ratio remained suboptimal. Therefore, suboptimal stent deployment due to constraint by lesion resistance may be an important mechanism underlying the high restenosis rates in long stents.

Angiographic and clinical restenosis following the use of long coronary Wallstents.

This study assessed clinical and angiographic restenosis following the deployment of the long coronary Wallstent. Between May 1995 and June 1997, 182 Wallstents were deployed in 162 vessels in this unit. Forty-eight percent had an unstable coronary syndrome and 94% had AHA grade B or C lesions. The mean lesion length was 37 +/- 20 mm and the mean stent length was 48 +/- 20 mm. The procedural success rate was 99% and the primary success rate was 93%. Six in-patients suffered subacute stent thrombosis, the majority being in the era of anticoagulation rather than antiplatelet regimes. Seventy-three percent remained free of major adverse clinical events in the follow-up period, but 41% had angiographic restenosis. The Wallstent can be deployed in complex lesions with a high primary success rate and an acceptably low restenosis rate. The optimal management of in-stent restenosis remains to be defined.

Randomised trial of elective stenting after successful percutaneous transluminal coronary angioplasty of occluded coronary arteries.

BACKGROUND: The value of angioplasty in occluded coronary arteries is limited by a restenosis/reocclusion rate of 50-70%. In patients with subtotal occlusion, stent implantation has been shown to reduce clinical and angiographic restenosis. Retrospective observational studies have suggested that stenting could reduce restenosis in total occlusions. The value of sustained coronary patency on global and regional left ventricular function in this clinical setting has not been defined clearly. OBJECTIVES: To assess the medium term effect of elective intracoronary stent deployment after successful percutaneous transluminal coronary angioplasty (PTCA) of an occluded coronary artery. METHODS: Sixty patients with a total coronary occlusion successfully treated by PTCA were randomised to receive an intracoronary stent or no stent. Patients underwent clinical and angiographic follow up at six months. RESULTS: Thirty patients received a stent (group A) and 30 were treated by angioplasty alone (group B), all with initial success. One patient in group B required repeat angioplasty with stenting at 24 hours and one patient died after 10 days. Angiographic follow up was available for 57 patients. This showed a significantly reduced reocclusion rate in group A compared with group B (7% v 29%, p < 0.01) and a tendency to a reduced restenosis rate (22% v 40%, p = 0.105) in patients with no reocclusion. Left ventricular function, both global and regional, improved in group A. Only the regional left ventricular function in the area supplied by the target coronary artery improved in group B. Recurrence of symptoms and clinical events such as repeat angioplasty, coronary artery bypass grafting, death or myocardial infarction tended to be reduced in group A (4 (13%) v 9 (30%)). CONCLUSIONS: Intracoronary stent insertion is effective in reducing the rate of reocclusion and shows a trend towards reduced restenosis after opening of a total coronary occlusion by balloon angioplasty. Sustained patency of the target coronary artery is associated with improvement in global and regional left ventricular function.

Non-invasive cardiac investigations in patients awaiting renal transplantation.

Patients with chronic renal failure undergoing renal transplantation have a high prevalence of cardiovascular disease. Invasive investigation may identify those at risk of cardiac death during or after renal transplantation, but which patients should undergo cardiac catheterization is currently not clear. In 95 patients awaiting renal transplantation we assessed the ability of echocardiography and exercise electrocardiography to identify patients at risk of cardiac death. Echocardiography identified impaired left ventricular (LV) systolic function in 20%, severe in 8%. Of the patients with severe LV dysfunction, 25% died before transplantation. Of those undergoing exercise electrocardiography, 44% did not achieve 85% of maximum predicted heart rate. No coronary artery disease requiring intervention was identified by exercise testing. These findings indicate that echocardiography, but not exercise electrocardiography, should be part of the assessment for renal transplantation.

Determining optimal atrial sensitivity settings for single lead VDD pacing: the importance of the P wave histogram.

In order to provide atrioventricular synchrony, VDD pacing systems require reliable atrial sensing. Variations in atrial signals with exercise and daily activities may lead to undersensing, with loss of physiological pacing. The aim of this study was to determine, for a single lead VDD pacing system, the maximal variation in atrial signals in order to facilitate optimal programming of atrial sensitivity. Fifteen patients underwent implantation of a Vitatron Saphir VDD pacemaker with a Vitatron Brilliant electrode. At a mean (+/-SD) follow-up of 67.3 +/- 38.8 days, resting P wave amplitude was compared with the P wave amplitude histogram obtained from the pacemaker, which recorded atrial signals over the preceding 30 days. Resting P wave amplitude was also compared with P wave amplitudes during variations in posture, respiration, and during exercise. P wave amplitude showed great variation with changes in posture and respiration, but there was no consistent increase or reduction. During exercise, the mean P wave amplitude fell by 36.6% +/- 31.3% compared with the resting value (P < 0.05). During daily activities, 22.6% of P wave amplitudes recorded on the P wave histogram were < 0.5 mV. The smallest P wave amplitudes were detected by the P wave histogram in 11 (79%) of 14 patients. These data suggest that atrial sensitivity may need to be programmed higher than that indicated by single readings or exercise. The P wave amplitude histogram is the most reliable indicator of the smallest atrial signal and should be used to optimize atrial sensitivity settings.

Transradial artery coronary angiography and intervention in patients with severe peripheral vascular disease.

BACKGROUND: Traditionally, cardiac catheterization in patients with severe aorto-iliac disease has been performed using a brachial arteriotomy. This approach is associated with significant vascular and neuronal complications and requires considerable training to achieve an adequate level of expertise. Improvement and miniaturization of catheter equipment now allows the radial artery to be used for coronary investigation and intervention. The lack of important structures close to the radial artery, a good collateral ulnar artery circulation and its superficial position suggests that these procedures should have a low complication rate. The purpose of this study was to assess the efficacy and safety of percutaneous transradial diagnostic and interventional coronary catheterization in patients with severe peripheral vascular disease. PATIENTS AND METHODS: We undertook a non-randomized prospective analysis of 75 patients who had transradial artery diagnostic and interventional coronary catheterization in whom femoral angiography was impossible or relatively contraindicated (22 patients with severe claudication and absent femoral pulses, 24 patients with previous aorto-iliac surgery or intervention, 20 patients with a failed femoral approach, 9 patients with an aortic aneurysm). Three patients had an absent ulnar artery and were excluded. RESULTS: Radial artery cannulation was successful in 73/75 (97%) cases. Seventy-one (95%) patients had a successful diagnostic study. There was a high incidence of 3 vessel disease (73%), and the majority of patients (64%) were referred for coronary bypass surgery. Twelve patients underwent successful follow-on intervention including the insertion of 9 intracoronary stents. Adequate haemostasis was achieved within 20 min after diagnostic angiography and 60 min after interventional procedures. One patient had a forearm haematoma with paraesthesia of the hand which settled with conservative treatment. At 4-6 weeks, all patients had normal hand sensation and function (100%) with a palpable pulse present in 59/62 (96%). All patients undergoing diagnostic angiography were discharged on the same day, and patients undergoing intervention were discharged the following day. CONCLUSIONS: Transradial coronary investigation and intervention can be performed with a high degree of success and a low complication rate with early mobilization and discharge in patients with severe peripheral vascular disease. We suggest that the percutaneous transradial technique should be considered as an alternative to the Sones' technique in these patients.

Platelet activation in acute myocardial infarction and unstable angina is inhibited by nitric oxide donors.

Platelet activation and thrombus formation within the coronary artery are major factors in acute myocardial infarction (AMI) and unstable angina (UA), and continuing platelet activation is associated with an adverse prognosis. We assessed platelet activation by using flow cytometry to measure platelet surface expression of P-selectin and glycoprotein IIb/IIIa in 20 patients with AMI and 20 with UA, all of whom were treated with aspirin. Platelet studies were repeated after the infusion of a nitric oxide donor (glyceryl trinitrate or S-nitrosoglutathione) that produced a fall in mean arterial pressure of no more than 10 mm Hg. P-selectin was expressed on 2.5% (range, 1.4% to 6.3%) of platelets from AMI and 2.3% (range, 1.6% to 3.3%) from UA subjects compared with 1.0% (range, 0.6% to 1.9%) of platelets from 20 control volunteers without angina (P < .001). Glycoprotein IIb/IIIa expression was 101.6 +/- 2.7 arbitrary units of relative fluorescence in AMI and 100.2 +/- 3.3 in UA compared with 87.8 +/- 2.5 in control subjects (P < .01). In both AMI and UA, S-nitrosoglutathione reduced P-selectin (P < .001) and glycoprotein IIb/IIIa (P < .05) expression, as did glyceryl trinitrate (P < .02 and P < .01, respectively). In 3 of 20 patients receiving glyceryl trinitrate the lowest dose was not tolerated due to headache or hypotension. These findings show that platelet activation persists in AMI and UA despite aspirin treatment and that this can be inhibited by using glyceryl trinitrate or S-nitrosoglutathione. S-nitrosoglutathione is better tolerated at the doses required.

Comparison of clinical outcome after elective and "bail out" coronary stent insertion.

BACKGROUND: Coronary stents may be used electively during percutaneous transluminal coronary angioplasty (PTCA) or as a "bail-out" device to treat abrupt or threatened vessel closure following PTCA. OBJECTIVE: To compare the clinical outcome of elective and "bail-out" coronary stent insertion. DESIGN: A retrospective analysis of all patients receiving coronary stents. SETTING: Tertiary referral center performing over 400 PTCA procedures a year. PATIENTS: Fifty-six patients (42 male), mean age 57 (range = 32 to 78) years received 67 Palmaz-Schatz coronary stents. Forty-nine stents were deployed as "bail-out" in 41 patients (abrupt vessel closure in 15 and threatened vessel closure in 26) and 18 stents were deployed electively in 15 patients. MAIN OUTCOME MEASURES: Myocardial infarction, repeat angiography, coronary artery bypass graft surgery and death. RESULTS: Stents were successfully deployed in 56/62 (90.3%) patients. In-hospital events were significantly more common in the "bail-out" group compared to the elective group. The in-hospital events, comparing the "bail-out" group versus the elective group, were as follows: Death 2/41 (4.9%) vs 0/15 (0%), coronary artery bypass graft surgery (CABG) 8/41 (19.5%) vs 0/15 (0%), stent thrombosis 3/41 (7.3%) vs 0/15 (0%), and myocardial infarction 6/41 (14.6%) vs 1/15 (6.7%) respectively. After discharge no patient died or had CABG. One patient in the "bail-out" group had a myocardial infarct (late stent thrombosis). Two patients from each group had repeat angiography because of recurrent angina in the 6 month follow up period. CONCLUSION: "Bail-out" stenting has an increased incidence of in-hospital complications compared to elective procedures. If these short-term problems can be overcome however, the clinical events in the first 6 months after leaving hospital are low and similar to patients under-going elective procedures.

Inhibition of platelet activity by S-nitrosoglutathione during coronary angioplasty.

Platelet activation is associated with acute vessel occlusion and chronic restenosis after percutaneous transluminal coronary angioplasty (PTCA). Organic nitrates, which act by releasing the vasodilator and anti-platelet agent nitric oxide (NO), have a predominantly vasodilator action and cause hypotension at doses required to inhibit platelet activation. S-nitrosoglutathione (GSNO) is an NO donor with a preferential action on platelets. We investigated platelet activation in patients undergoing PTCA and the effect of GSNO. Blood was sampled from the coronary sinus to measure platelet surface expression of P-selectin and glycoprotein IIb/IIIa as indices of platelet activation. In 7 control patients, PTCA caused a rise in platelet surface expression of P-selectin and glycoprotein IIb/IIIa, which was maximal 5 minutes after PTCA, indicating increased platelet activation despite treatment with aspirin, glyceryl trinitrate, and heparin. 6 patients received an intracoronary infusion of GSNO, starting 10 min before PTCA. GSNO significantly inhibited the PTCA-induced increase in platelet surface expression of P-selectin and glycoprotein IIb/IIIa without altering blood pressure. These findings show that platelets are activated following PTCA and that GSNO can prevent this activation.

Use of an intracoronary stent to control intrapericardial bleeding during coronary artery rupture complicating coronary angioplasty.

Coronary artery rupture is a rare complication of percutaneous transvenous coronary angioplasty (PTCA) usually requiring urgent cardiac surgery and often resulting in a poor outcome including death. We report, for the first time, the use of an intracoronary stent to control intrapericardial bleeding following the development of a coronary artery rupture during PTCA. Cardiac surgery was avoided and the patient was discharged well 1 week after the procedure.

Bail-out coronary stenting in an extremely tortuous right coronary artery with the Palmaz-Schatz stent and Teleguide sheath.

Significant vessel tortuosity is a relative contraindication to the use of the Palmaz-Schatz coronary stent for fear of stent displacement during delivery. We describe a patient with unstable angina in whom conventional coronary angioplasty in an extremely tortuous right coronary artery resulted in an occlusive dissection. Emergency bypass surgery was avoided by the successful placement of a protected Palmaz-Schatz stent using a 5F Teleguide sheath.

The long-term safety and tolerability of transdermal glyceryl trinitrate, when used with a patch-free interval in patients with stable angina.

The safety and tolerability of intermittent (16 hours on/8 hours off) nitrate patch therapy (0.2, 0.4 or 0.6 mg/hr: dose adjusted as required) was studied for a median duration of 356 days in 106 patients (mean age 60.9 +/- 8.6 years) with angina pectoris. Most patients (82%) were on existing beta-blocker and/or calcium antagonist therapy. Safety, tolerability and efficacy data were obtained by means of patient diary cards and regular clinic visits. Almost 90 treatment years revealed no significant or serious adverse events, and there were no changes in haematology or biochemistry associated with intermittent nitrate patch therapy. The most frequently reported side-effects were headache, skin reactions and dizziness (53%, 20% and 8% of patients respectively). Treatment resulted in a sustained reduction in the frequency and severity of angina attacks, reduced sublingual GTN consumption, an improvement in general wellbeing and a rise in the proportion of patients in whom angina was controlled.

Early mobilisation after percutaneous cardiac catheterisation using collagen plug (VasoSeal) haemostasis.

OBJECTIVE: To assess the efficacy and safety of a haemostatic bovine collagen plug (VasoSeal) in reducing patient immobilisation after cardiac catheterisation from a percutaneous femoral arterial approach. DESIGN: A non-randomised, prospective analysis of a new biodegradable haemostatic agent on an intention to treat basis. SETTING: The catheterisation suite of a regional cardiothoracic unit. PATIENTS: A series of 63 patients having various diagnostic investigations and therapeutic interventions agreed to participate in this study. INTERVENTIONS: Cardiac catheterisation was performed from a percutaneous femoral artery approach. Patients taking aspirin and those who required formal anticoagulation were not excluded. Patients were measured for the appropriate sized collagen delivery system at the beginning of the procedure. At the end of the procedure two bovine collagen plugs were applied to the surface of the femoral artery through the channel created by the application device. MAIN OUTCOME MEASURES: Incidence of successful delivery, insertion time, immediate outcome, inpatient complications, success of mobilisation of the patient at one and two hours after the procedure, and whether these variables relate to individual patient characteristics. RESULTS: Successful placement of the device was achieved in 57 of 63 consecutive patients (90.5%). The mean (SD) insertion time was 86 (24) seconds. Six (9.5%) patients did not receive the haemostat because of femoral artery perforation by the tissue dilator (n = 3), inability to compress the femoral artery proximal to the site of delivery (n = 1), pre-existing haematoma (n = 1), or patient withdrawal from the study (n = 1). Uncomplicated mobilisation within two hours of investigation was possible in 54 of 57 (94.7%) patients receiving this device. A sizeable haematoma (> 5 x 5 cm) prevented early mobilisation in the remaining three patients. Mobilisation was uncomplicated in 32 of 34 (94.1%) patients mobilised at two hours and 22 of 23 (95.6%) at one hour (NS). One patient who was mobilised early without complication later developed evidence of claudication in the treated leg. Femoral arteriography showed a smooth intraluminal filling defect attached to the wall of the femoral artery at the puncture site. This obstruction, presumed to be a collagen plug, was treated successfully with angioplasty. Sheath size, arterial pressure, the use of aspirin, heparin or warfarin, and body mass index did not influence patient outcome. The pattern of complications did not relate to a learning curve experience. CONCLUSIONS: The bovine collagen haemostat is a relatively safe and effective device that allows far earlier patient mobilisation than conventional haemostasis after diagnostic and therapeutic interventions from a percutaneous femoral artery approach. These results have important implications for patients undergoing investigation in mobile x ray units or in hospital based day case units.