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PubMed1996

Intravascular imaging of serial changes of disease in saphenous vein grafts after coronary artery bypass grafting.

To clarify the structural changes of saphenous vein grafts after coronary artery bypass grafting, intravascular ultrasound and angioscopic images were obtained from 23 grafts in vivo and 5 grafts and 3 new veins in vitro; the images were compared with histologic findings. Intravascular ultrasound demonstrated a single-layered appearance at new veins and all of the angiographically normal grafts within 6 months after surgery. A triple-layered appearance that might be related to the remarkably proliferative and degenerated intima was revealed histologically at 73.3% of the normal sites of grafts between 5 and 10 years after operation. In 83.3% of the stenoses at several years after operation, angioscopy showed yellow atheromatous plaques, often with a friable surface; a heterogeneous, lucent echo pattern was revealed on intravascular ultrasound. Thus intravascular ultrasound and angioscopy may be used to identify the morphologic changes of graft at different points after implantation more precisely than conventional angiography.

Angioscopy↗
PubMed2003

Plaque disruption and thrombus in Ambrose's angiographic coronary lesion types.

Lesion eccentricity with irregularities on coronary angiography is associated with ruptured plaques and thrombus based on postmortem and clinical angiographic studies. However, the predictive value of such angiographic markers of plaque disruption and thrombus remains to be determined in vivo. The purpose of this study was to establish whether Ambrose's angiographic coronary lesion types and other angiographic criteria predict the presence of disrupted plaques and thrombus using intracoronary angioscopy. Angioscopy was performed before angioplasty in 60 patients with various coronary syndromes and culprit lesions that were not totally occlusive. Lesions were classified angiographically according to Ambrose's criteria as concentric, type I and II eccentric, and multiple irregularities, or as complex or noncomplex, and then compared with the corresponding angioscopic findings. Disruption and/or thrombus were seen in 17 of 19 type II eccentric lesions and 21 of 23 angiographically complex lesions and had the highest positive predictive value to detect complicated atherosclerotic plaques (type II eccentric lesions: positive predictive value 89%, 95% confidence intervals 67% to 99%; complex lesions: 91%, 95% confidence intervals 72% to 99%). We conclude that Ambrose's type II eccentric stenoses and angiographically complex lesions are strongly associated with disrupted plaques and/or thrombus as assessed by angioscopy in patients and represent unstable plaque substrates.

Angioplasty, Balloon, Coronary↗
PubMed1995

Time course and mechanism of early luminal diameter loss after percutaneous transluminal coronary angioplasty.

To assess the time course and mechanism of early minimal luminal diameter (MLD) loss, serial angiographic observations were performed. Seventy-four patients (with 74 severe narrowings [ > or = 70%]) with acute ischemic syndromes who had an early loss in MLD of > 0.3 mm at 24 hours after percutaneous transluminal coronary angioplasty (PTCA) also underwent 1 hour post-PTCA angiography. In 12 consecutive patients with early loss 1 hour after PTCA, angioscopy was also performed to assess the mechanism of early loss. The percent diameter stenosis for the 74 lesions was 16.8 +/- 8.4% immediately after PTCA, 35.1 +/- 14.2% 1 hour after PTCA (p < 0.002 vs immediately after), and 41.4 +/- 13.2% at 24 hours (p < 0.10 vs 1 hour after). The MLD also showed similar differences: 2.6 +/- 0.3 mm immediately after to 2.0 +/- 0.4 mm 1 hour after(p < 0.002) to 1.8 +/- 0.4 mm 24 hours after PTCA (p < 0.10 vs 1 hour). In 60 patients (81%), the > 0.3 mm loss was detected 1 hour after PTCA. These 60 patients had no further decreases in MLD at 24 hours (1.9 +/- 0.4 vs 1.8 +/- 0.4 mm at 1 and 24 hours, respectively, p = NS). Adequate angioscopic images available in 11 patients showed that red thrombus was present in 1, minor or multiple dissection in 5, and neither thrombus nor dissection in 5 other patients (consistent with early wall recoil). Thus, in narrowings demonstrating early loss in MLD at 24 hours, 81% showed that the early loss occurred within 1 hour after PTCA. Early loss is not related to thrombus but usually to dissection or recoil.

Adult↗
PubMed1997

Coronary angioscopy. Clinical applications.

Percutaneous coronary angioscopy is an invaluable alternative imaging modality that can not be used routinely in the interventional cardiac catheterization laboratory. The major value of angioscopy lies in its ability to determine safely, quickly, and accurately intraluminal morphologies before and after coronary interventions. The results from angioscopy can then be used to target more specific treatment strategies, given the vast array of interventional treatment strategies available. Percutaneous coronary angioscopy, however, requires meticulous attention for the proper preparation and use of the angioscope to minimize the potential risks associated with the imaging procedure.

Angioscopy↗
PubMed2003

Changes in coronary plaque color and morphology by lipid-lowering therapy with atorvastatin: serial evaluation by coronary angioscopy.

OBJECTIVES: Changes in coronary plaque color and morphology by statin therapy were evaluated using coronary angioscopy. BACKGROUND: Coronary plaque stabilization by statin therapy has not been clarified in humans. METHODS: Thirty-one patients with coronary artery disease were divided into either the comparison group (n = 16) or the atorvastatin group (n = 15). Before treatment and 12 months after, the color and complexity of 145 coronary plaques were determined according to angioscopic findings. The yellow score of the plaque was defined as 0 (white), 1 (light yellow), 2 (yellow), or 3 (dark yellow), and its disrupted score was defined as 0 (smooth surface) or 1 (irregular surface) and as 0 (without thrombus) or 1 (with thrombus). In each patient, the mean yellow score and mean disrupted score were calculated. RESULTS: Mean low-density lipoprotein cholesterol (LDL-C) decreased by 45% in the atorvastatin group, whereas an increase of 9% was seen in the comparison group. The mean yellow score decreased from 2.03 to 1.13 in the atorvastatin group, whereas it increased from 1.67 to 1.99 in the comparison group. There was a good correlation between the change in the mean yellow score and the change in LDL-C levels (r = 0.81, p < 0.0001). The change in the mean yellow score and mean disrupted score differed significantly between the two groups (p = 0.002 and p = 0.03, respectively). CONCLUSIONS: This is the first report clarifying detailed changes in coronary plaque by statin in humans. This study indicated that lipid-lowering therapy changes plaque color and morphology and should then lead to coronary plaque stabilization.

Aged↗
PubMed1983

In vivo coronary angioscopy.

The feasibility of in vivo coronary angioscopy was tested utilizing a 1.8 mm angioscope in vessels where blood had been replaced by optically clear liquids, including a new perfluorocarbon emulsion. After trials in postmortem canine and human coronary arteries, in vivo intraluminal visualization was accomplished in the dog with a catheterization technique and in patients during open heart surgery. The results demonstrate the feasibility and potential clinical usefulness of direct visualization of intravascular anatomy and disease, analogous to endoscopy of other organ systems.

Animals↗
PubMed2003

Endovascular assisted in situ bypass grafting: a simplified technique for saphenous vein side branch occlusion.

The in situ bypass procedure for lower extremity limb salvage requires a long continuous incision or multiple interrupted incisions over the greater saphenous vein to ligate the saphenous vein side branches. This can result in wound complications that frequently prolong hospital stay and threaten the graft. In an effort to reduce the incidence of wound complications, alternate methods of occluding the vein side branches have been used. One method is to deliver coils under angioscopic vision into the saphenous vein side branches. This report details a simplified technique that uses widely available catheter-based equipment to perform saphenous vein side branch occlusion under fluoroscopic guidance.

Embolization, Therapeutic↗
PubMed1995

The upper arm basilic-cephalic loop for distal bypass grafting: technical considerations and follow-up.

PURPOSE: The performance of a graft created from the upper arm basilic and cephalic veins in continuity was investigated. METHODS: Retrospective analysis of 50 patients, who underwent 54 distal reconstructions with an upper arm vein loop graft between February 1989 and October 1993 (male-to-female ratio of 30/20; mean age of 69.2 years, range 39 to 87; 74% had diabetes) was undertaken. Vein grafts were harvested through a near continuous incision, leaving a skin bridge in the cubita. Intraoperative angioscopy was used to exclude endoluminal disease and to directly observe valvulotomy of the nonreversed part of the graft. RESULTS: Operations were performed for limb salvage in 98.2% of 17 primary and 37 reoperative procedures. Eleven femoropopliteal, 33 femorotibial-pedal, seven popliteal-distal, and two outflow jump grafts were performed. The ipsilateral saphenous vein was unavailable because of previous infrainguinal bypass in 35, coronary artery bypass grafting in 14, and unsuitable quality in 5 cases. Thirty-eight grafts were used in continuity, and 16 grafts required repair or splicing with additional vein segments. Primary 30-day patency rate was 92.6% (n = 4 occlusions). No operative deaths occurred. The cumulative patency rate at 1 year was 74.4%, the limb salvage rate 90.7%. CONCLUSIONS: The upper arm vein loop is a durable graft with excellent short-term and midterm patency rates. Sufficient vein length can be obtained to reach the below-knee and midtibial levels. Angioscopic quality assessment is a valuable adjunct to exclude endoluminal disease most commonly occurring in the median cubital vein. Straightening the curve of the median cubital vein and valvulotomy do not influence patency rates. This is a valuable technique for vascular surgeons that enables rescue of ischemic limbs under otherwise difficult circumstances.

Adult↗
PubMed1994

Intraoperative imaging techniques in infrainguinal arterial bypass grafting: completion angiography versus vascular endoscopy.

This prospective study was designed to establish whether vascular endoscopy would provide more information on the graft lumen than standard completion angiography during infrainguinal bypass surgery. Ninety-nine patients with 102 infragenicular bypass grafts who underwent both angiography and angioscopy intraoperatively were evaluated. In 99 of the 102 patients the indication was critical limb ischaemia. Of the 102 bypass grafts, 81 were autogenous vein. Distally, 24 grafts were anastomosed to the below-knee popliteal segment, 64 extended to the crural and 14 to the pedal arteries. On completion of the distal anastomosis, grafts were first evaluated by angiography and then by angioscopy. The images obtained with the two monitoring modalities were compared by the operating surgeon and re-explorations were performed immediately if necessary. Completion angiography and angioscopy produced images of good quality in 96 and 97 cases, respectively. In 12 cases completion angiography showed abnormalities. Of these, five were located below the distal anastomosis and were not accessible to angioscopic examination. Conduit defects were found in seven instances. In one of them angioscopy showed the angiogram to be false-positive. Of the 90 grafts with normal completion angiograms, seven were found to show significant pathology on angioscopy. Compared to angioscopy, the sensitivity and specificity of angiography to detect abnormalities within the graft was 46% and 98%, respectively. Our results suggest that vascular endoscopy is superior to angiography for disclosing conduit defects, but that it does not provide adequate information about the distal arterial anatomy.

Aged↗
PubMed1988

Intraoperative assessment of in situ saphenous vein bypass grafts by vascular endoscopy.

Intraoperative vascular endoscopy was used in 20 femorocrural in situ saphenous vein bypass procedures in order to control valvular incompetence, to localize side branches and to assess the integrity of the distal anastomosis. We used an Olympus Fiberscope (PF-27L) with a diameter of 2.7 mm and a working length of 80 cm, which had fixed illuminating and viewing fibers and a steerable tip, Valvulotomy was performed according to the technique described by R. Leather using a valve-cutter. In 8 out of 20 patients, partly retained valve leaflets were found by intraluminal inspection and could be immediately corrected. The integrity of the distal anastomosis was verified angioscopically in 14 patients. In addition, venous side branches, which had to be ligated, were easily identified under direct vision and localized by transillumination of the endoscopic light through the skin. Vascular endoscopy seems to be a practicable and time saving method to control in situ vein bypass procedures. The steps of the procedure and early results after 20 bypasses for limb salvage are presented.

Anastomosis, Surgical↗
PubMed1997

An experimental study of intra aortic balloon pumping within the intact human aorta.

OBJECTIVE: Intra-aortic balloon pumping is a therapeutic technique which carries a significant morbidity related to the interaction between the balloon catheter and the aorta. The aim of this study was to visualise directly the dynamic action of the balloon catheter within the cadaveric human aorta in an artificial circulation. METHODS: An artificial circulation was constructed using of PVC tubing, a filter and a roller pump. A series of five intact cadaveric human aortas were then individually studied by placing each in series within the circuit. A balloon catheter was advanced via the left common iliac artery into the descending aorta under direct angioscopic vision. Balloon pumping was then commenced. The circuit was perfused with normal saline at a flow rate of 3 l/min. Pump actions of 1:1 and 1:2 were simulated. Each aorta at the end of the experiment was subjected to histological examination. RESULTS: The balloon only appeared to make direct contact with the wall of the aorta during deflation when it was swept to one side by the circulating fluid. During maximal inflation the only points of contact were the tip of the catheter and the entry site. Side branches of the aorta were not occluded by the balloon. There was considerable atheromatous debris visualised within the lumen of the aorta. Atheromatous plaques were seen to fissure and disrupt by a pressure wave action and not by direct contact with the balloon. CONCLUSION: The balloon catheter moves relative to the wall of the aorta during inflation and deflation. Contact between the balloon and the aorta only occurs during deflation. Side branches of the aorta are not occluded by the catheter. Plaque disruption and embolus formation appear to result from pressure wave action rather than direct contact with the balloon. This may have implications for future balloon design. Further investigation of this poorly understood interaction between the balloon and the aortic wall is required.

Adult↗
PubMed1995

Infrainguinal arterial reconstruction with non-reversed autologous vein after angioscopy guided valvulotomy ex situ.

AIMS: The advantages of in situ autologous vein grafts for long infrainguinal arterial reconstructions are the tapered conduit, minimising size mismatch at proximal and distal anastomoses, and the possibility of using small sized veins with good results. Unfortunately, in about 30% of legs the ipsilateral saphenous vein is inadequate rendering in situ bypass grafting impossible. To profit from a valveless autologous vein graft in these cases we routinely performed ex situ valvulotomy after harvesting the contralateral saphenous vein or good quality segments of the ipsilateral saphenous vein. METHODS: The ex situ valvulotomy was performed under angioscopic guidance using a flushing-type Mill's valvulotome. RESULTS: Fifty non reversed grafts in 46 patients entered a prospective surveillance program. Primary and primary-assisted patency rates at 2 years were 68% and 82% respectively, early graft thrombosis 2%, late stenosis 8% and major amputation rate with a patent graft 6%. No technique related problems were noticed. CONCLUSION: Angioscopy guided valvulotomy was safe and simple and allowed good quality control of the veins. The presented results in this study are comparable to other recently reported series of in situ bypass. The clinical use of small flexible endoscopes allows a safe and atraumatic valvulotomy and simultaneous quality control of autologous vein grafts.

Adult↗
PubMed1996

A comparison of quality control methods applied to carotid endarterectomy.

OBJECTIVES: To compare the ability of continuous wave Doppler (CWD), B-mode ultrasound (BMU), angioscopy and transcranial Doppler (TCD) to detect technical error during carotid endarterectomy (CEA). DESIGN: A prospective, comparative study in 100 consecutive patients. SETTING: Leicester Royal Infirmary, Leicester, U.K. MATERIALS: Intraoperative TCD monitoring was performed using a SciMed PcDop 842 2 MHz TCD. An Olympus 2.8mm flexible angioscope was used to inspect the arterial lumen prior to restoration of bloodflow. After restoration of flow 10Mhz BMU images and 8Mhz CWD velocity spectra of carotid artery blood flow were obtained. CHIEF OUTCOME MEASURES: The detection of intimal flaps, thrombus, stenoses or other errors of surgical technique likely to result in perioperative morbidity. MAIN RESULTS: CWD and BMU images were technically inadequate in 9% and 24% of cases respectively and neither technique altered clinical management. Angioscopy demonstrated significant technical errors in 12 cases (four intimal flaps, thrombus in eight). TCD detected shunt malfunction in 13% of patients, emboli during dissection in 23% and early postoperative carotid artery thrombosis in three patients. CONCLUSIONS: A combination of TCD monitoring and completion angioscopy provided the maximum yield in terms of diagnosing technical error and establishing the cause of perioperative morbidity.

Angioscopy↗
PubMed1997

Adjunctive Therapy with an Antithrombotic Drug Can Prevent Reocclusion and Induce Residual Thrombus Reduction After Percutaneous Transcatheter Angioplasty of the Thrombotic Lesions.

Acute reocclusion after successful angioplasty is a severe complication. The preventive effects of heparin, the synthetic antithrombin, argtroban, and the defibrinogenating agent batroxobin on reocclusion after balloon angioplasty of thrombotic occlusions were evaluated in canine iliac arteries. After the 2-hour-old thrombus was evaluated by angiography and angioscopy, percutaneous transcatheter angioplasty (PTA) was performed on the thrombotic stenosis. We used one of the three agents, heparin (100 U/kg), the antithrombin argatroban (0.3 mg/kg), or the defibrinogenating agent batroxobin (0.3 U/kg). Then angioscopy and angiography were performed before, just after, and 2 hours after PTA. After PTA, angiography revealed a marked reduction in percent stenosis in all groups (from 88 +/- 8% to 24 +/- 4% in the heparin group, from 79 +/- 7% to 26 + 11% in the argatroban group and from 89 +/- 12% to 32 +/- 7% in the batroxobin group). At 2 hours after PTA, angiography demonstrated a greater reduction in percent stenosis with argatroban (from 26 +/- 11% to 9 +/- 3%) and batroxobin (from 32 +/- 7% to 10 +/- 8%), and maintenance of percent stenosis reduced by PTA with heparin (from 24 +/- 5% to 28 +/- 9%) when compared with the significant reversal of percent obstruction in the control side. Angioscopic visualization also demonstrated a similar trend. These results show that these antithrombotic drugs have a preventive effect on reocclusion after balloon angioplasty for thrombotic obstruction.

Journal Article↗
PubMed2002

Present status of infrainguinal arterial bypass procedures following an all autogenous policy--long-term results of a single center.

OBJECTIVES: The direction of vein grafts for infrainguinal arterial reconstruction is controversial. Long-term results of a single center following an all autogenous tissue policy in infrainguinal arterial reconstruction are reported with special attention to possible advantages for the in situ and non-reversed bypass using angioscopy. METHODS: From 10/88 until 12/00 540 bypasses with autogenous veins were performed on 497 patients. Veins were used in a non-reversed or in-situ direction, valve disruption was performed under angioscopic control. All grafts were prospectively included in our data base and follow-up was scheduled in our vascular lab before discharge and after 3, 6, 9, 12, 24 etc. months. RESULTS: Primary patency of all bypasses after 108 months was 55.2%, primary assisted 76.9% (SE +/- 9.87), survival 58.4% (SE +/- 8.88) and limb salvage 81.3% (SE +/- 9.75). Perioperative mortality was 0.9% (5 pat). Patency rates (primary assisted patency) after 72 months were 81.7% (98.2%) for supragenicular, 61.5% (79.4%) for infragenicular and 56.6% (78.1%) for tibial anastomoses and for pedal reconstructions after 48 months 49.3% (68.6%). CONCLUSION: Reviewing the literature neither the in situ and non-reversed nor the reversed grafts yielded better long-term results. Absence of size mismatch may be an advantage in smaller veins. Angioscopy may detect unsuspected vein disease.

Aged↗
PubMed1999

A policy of quality control assessment helps to reduce the risk of intraoperative stroke during carotid endarterectomy.

OBJECTIVES: A pilot study in our unit suggested that a combination of transcranial Doppler (TCD) plus completion angioscopy reduced incidence of intra-operative stroke (i.e. patients recovering from anaesthesia with a new deficit) during carotid endarterectomy (CEA). The aim of the current study was to see whether routine implementation of this policy was both feasible and associated with a continued reduction in the rate of intraoperative stroke (IOS). MATERIALS AND METHODS: Prospective study in 252 consecutive patients undergoing carotid endarterectomy between March 1995 and December 1996. RESULTS: Continuous TCD monitoring was possible in 229 patients (91%), while 238 patients (94%) underwent angioscopic examination. Overall, angioscopy identified an intimal flap requiring correction in six patients (2.5%), whilst intraluminal thrombus was removed in a further six patients (2.5%). No patient in this series recovered from anaesthesia with an IOS, but the rate of postoperative stroke was 2.8%. CONCLUSIONS: Our policy of TCD plus angioscopy has continued to contribute towards a sustained reduction in the risk of IOS following CEA, but requires access to reliable equipment and technical support. However, a policy of intraoperative quality control assessment may not necessarily alter the rate of postoperative stroke.

Aged↗
PubMed1999

Semi-closed femoropopliteal thromboendarterectomy: a prospective study.

OBJECTIVE: to study the primary patency rates of angioscopically controlled thromboendarterectomies of the superficial femoral artery. DESIGN: prospective open study. METHODS: between 1990 and 1995, femoropopliteal thromboendarterectomies were performed in 63 patients (41 male, 22 female). Postoperative follow up was performed at 3- to 6-month intervals using non-invasive pressure measurements plus IVDSA at 1 year. RESULTS: eight patients were not evaluable, leaving 55 patients eligible for follow-up analysis. Postoperative complications (arteriovenous fistulas, false aneurysms) were observed in 5.4% of patients. Immediate perioperative occlusions occurred in 7.3%, early occlusions in 21.8% and late occlusions in 16.4% of all cases. The mean follow-up was approximately 57 months. The mean primary patency rate at 5 years was 44.5% (28 patients with the superficial femoral artery still open). Six patients died during the follow-up period. CONCLUSIONS: in contrast to the very positive reports found in recent literature, this prospective study shows a lower five-year patency rate for semi-closed femoropopliteal thromboendarterectomy than for bypass grafting. Thromboendarterectomy cannot be considered as a standard procedure in revascularisation of the femoropopliteal region.

Aged↗
PubMed1999

Intraoperative assessment of technical perfection in carotid endarterectomy: a prospective analysis of 1305 completion procedures. Collaborators of the EVEREST study group. Eversion versus standard carotid endartectomy.

OBJECTIVE: to define the incidence of technical defects and the impact of technical errors on ipsilateral carotid occlusion, ipsilateral stroke, and early restenosis rates, we analysed 1305 patients undergoing carotid completion procedures. DESIGN: prospective multicentre study. PATIENTS AND METHODS: adequacy of CEA was assessed intraoperatively by angiography in 1004 (77%), by angioscopy in 299 (22%), and by duplex scan in two patients (1%). Arteriograms and angioscopic findings were interpreted at the time of the procedure by the operating surgeon, who also established the need for immediate surgical revision. RESULTS: perioperatively, 13 major strokes (0.9%, all ipsilateral) and six deaths (0.4%) were recorded. Overall, 112 defects (9%) were identified intraoperatively: 81 (72%) were located in the common carotid artery (CCA) or internal carotid artery (ICA), and 31 (28%) in the external carotid artery. In 48 patients (4%) the defects were revised. Logistic regression analysis revealed that carotid plaque extension >2 cm on the ICA was a positive independent predictor of CEA defects (odds ratio (OR) 1.5p=0.03). A significant association was found between the incidence of revised defects of the CCA and ICA and perioperative ipsilateral stroke (OR 11.5p=0.0002). In contrast, patients with minor non-revised defects had an ipsilateral stroke rate comparable to that of patients with no defects (p=0.4). No significant association was found between revised or non-revised defects and occurrence of restenosis/occlusion at 6-month follow-up. CONCLUSIONS: the incidence of major technical defects during CEA is low, yet the perioperative neurological prognosis of patients with major defects warranting revision is poor. Completion angiography or angioscopy and possible correction of defects did not protect per se from an unfavourable early outcome after CEA. Therefore, surgical excellence is mandatory to achieve satisfactory results after CEA.

Adult↗