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At least 505 records · Page 28Linked to original sources
PubMed2005

A randomized prospective study of valvulotome efficacy in in situ reconstructions.

OBJECTIVES: To compare the efficacy of valvulotomes during in situ bypass surgery. DESIGN: A randomized prospective blinded study. MATERIALS AND METHODS: Thirty PAD patients scheduled for infrainguinal greater saphenous vein bypass were randomized to use of adjustable or fixed valvulotomes for valve destruction. Valvulotomy was performed after construction of the proximal anastomosis. The efficacy of valve destruction was determined by angioscopy after completion of the distal anastomosis by a separate blinded examiner. RESULTS: A total of 123 valves were evaluated, 61 after use of an adjustable and 62 with a fixed valvulotome. There was no difference ( p = .88) in number of retained valves between the two groups ( n = 16, 17, respectively). The majority of incompletely destroyed valves were found in the proximal parts of the graft (46%, 13 out of 28). The primary patency at 30 days was 100 and 79%, respectively, p = .09). CONCLUSIONS: No significant difference in efficacy between valvulotomes was found. Both types tend to miss a large proportion of proximal valves.

Aged↗
PubMed2005

Incidence and natural history of proliferative sickle cell retinopathy: observations from a cohort study.

OBJECTIVE: To describe the incidence, prevalence, and natural history of proliferative sickle cell retinopathy (PSR). DESIGN: Prospective longitudinal study over 20 years. PARTICIPANTS: Newborn screening of 100000 consecutive deliveries from 1973 to 1981 identified 315 children with homozygous sickle cell (SS) disease and 201 with SS-hemoglobin C (SC) disease. By the age of 5 years, 307 SS patients and 166 SC patients were alive and living in Jamaica and were recruited for this ophthalmic study. METHODS: Description of retinal vascular changes on annual angiography and angioscopy. MAIN OUTCOME MEASURES: Incidence and prevalence of PSR and its behavior on follow-up. Progression of PSR was investigated using the number of eyes affected (none, one, both) and the interval until PSR onset. RESULTS: At last review in January 2000, PSR had developed in 59 patients (14 SS, 45 SC), unilaterally in 36 patients and bilaterally in 23. Incidence increased with age in both genotypes, with crude annual incidence rates of 0.5 cases (95% confidence interval [CI], 0.3-0.8) per 100 SS subjects and 2.5 cases (95% CI, 1.9-3.3) per 100 SC subjects. Prevalence was greater in SC disease, and by the ages of 24 to 26 years, PSR had occurred in 43% subjects with SC disease and in 14% subjects with SS disease. Patients with unilateral PSR had a 16% (11% SS, 17% SC) probability of regressing to no PSR and a 14% (16% SS, 13% SC) probability of progressing to bilateral PSR. Those with bilateral PSR had an 8% (8% SS, 8% SC) probability of regressing to unilateral PSR and a 1% (0 SS, 2% SC) probability of regressing to a PSR-free state. Irretrievable visual loss occurred in only 1 of 82 PSR-affected eyes, and 1 required detachment surgery and recovered normal visual acuity. CONCLUSIONS: Longitudinal observations over 20 years in a cohort of patients followed from birth confirms a greater incidence and severity of PSR in SC disease, and shows that spontaneous regression occurred in 32% of PSR-affected eyes. Permanent visual loss was uncommon in subjects observed up to the age of 26 years.

Adolescent↗
PubMed1997

Angioscopic evaluation of angiographically complex coronary lesions.

Coronary angioscopy (CA) provides direct visualization of the endoluminal surface of coronary vessels. The usefulness of CA during coronary angioplasty of angiographically complex lesions remains to be established. This study was designed to determine the value of CA to elucidate the underlying substrate of angiographically complex lesions. Forty-seven consecutive patients with angiographically complex lesions were studied with CA before coronary intervention. Mean age of the group was 59 +/- 9 years; six patients were women. Forty (85%) patients had unstable angina. Complex angiographic lesions included coronary occlusions (n = 23) (14 with Thrombolysis in Myocardial Infarction coronary flow grade 0 and nine with flow grade 1), lesions with intraluminal filling defects suggestive of thrombus or ulceration (n = 8), and lesions that were highly eccentric (n = 16). Items analyzed with CA included red thrombus (lining or protruding) and plaque color (yellow, white, or mixed). In all patients, CA visualized the protruding material causing the angiographic appearance. At this site CA detected red thrombus in 34 (72%) patients (14 protruding, 20 lining) and atherosclerotic plaque in 45 (96%) patients. At the site of the angiographically complex lesion, plaque was classified as predominantly yellow in 24 patients, mixed in 12, and white in nine. The incidence of thrombus on CA was higher for occluded vessels (91%) or lesions with intraluminal filling defects or ulceration (87%) than in eccentric lesions (37%) (p < 0.05). However, plaque coloration was not significantly different among these three angiographic subgroups. Initial procedural success (without stent requirement) was lower in lesions showing protruding thrombus on CA (64% vs 91 %, p < 0.05). Thus most angiographically complex lesions contain thrombus. On CA red thrombus was more frequently identified on occluded vessels and lesions with filling defects or ulceration than in eccentric lesions. Yellow or mixed plaques are common in these patients, suggesting lipid-laden plaques as the underlying pathologic substrate of angiographically complex lesions.

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PubMed1997

Angioscopic assessment of coronary lesions underlying thrombus.

This study examines the characteristics of coronary lesions in which thrombus is found as assessed by angioscopy before percutaneous transluminal coronary angioplasty in patients with various coronary syndromes. Our findings demonstrate that the plaque underlying intracoronary thrombus is usually yellow and/or disrupted, and support in vitro observations that lipid-rich plaques are highly thrombogenic and that disruption of these plaques is associated with in situ thrombosis.

Angioscopy↗
PubMed1999

Detecting and differentiating white from red coronary thrombus by angiography in angina pectoris and in acute myocardial infarction.

To determine the ability to detect thrombus by angiography, angioscopy was performed before angiography in patients undergoing interventional procedures and the data collected in a blinded fashion. These data demonstrated that the sensitivity of angiography to detect white thrombus was 50% and the specificity was 95%, whereas the sensitivity and specificity to detect red thrombus was 100%, respectively; the positive and negative predictive value of detecting thrombus in general was 89% and 83%, respectively.

Aged↗
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

Effects of surgical manipulation on coronary stents: should surgical strategy be altered?

BACKGROUND: Coronary artery bypass grafting is usually indicated for those patients who undergo open heart surgical procedures who have previously undergone percutaneous transluminal coronary angioplasty regardless of the absence of stenosis. Occasionally, however, if the treated artery has remained patent for many years and there is a shortage of conduit material or the patient is undergoing a complex operation, the branch is left ungrafted. With the gaining popularity of coronary stent placement, patients with these devices are undergoing open heart operations with increasing frequency. METHODS: To determine whether normal surgical manipulation during open heart surgical procedures results in obliteration of the Palmaz-Schatz stents previously deployed in the epicardial arteries, we developed an experimental model using ten isolated adult pig hearts. This allowed us to perform stent deployment and surgical manipulation and to apply direct pressure on the stented areas, with each heart evaluated by angioscopy and angiography and, finally, stent explantation. RESULTS: Retraction of the heart resulted in severe deformity of all left anterior descending artery stents, mild deformity of those in the circumflex artery, and mild or no deformity of those in the right coronary artery. However, direct pressure over the stented epicardial arteries (enough to retract the heart) resulted in complete obliteration of every intracoronary stent. CONCLUSIONS: The findings from this study indicate that once the need for surgical revascularization arises, a previously stented coronary artery should be bypassed even if the angiographic findings are normal, because of the likelihood that manipulation during an open heart operation will result in significant deformity or obliteration of the stent.

Angioscopy↗
PubMed2000

The use of arm vein in lower-extremity revascularization: results of 520 procedures performed in eight years.

PURPOSE: The absence of an adequate ipsilateral saphenous vein in patients requiring lower-extremity revascularization poses a difficult clinical dilemma. This study examined the results of the use of autogenous arm vein bypass grafts in these patients. METHODS: Five hundred twenty lower-extremity revascularization procedures performed between 1990 and 1998 were followed prospectively with a computerized vascular registry. The arm vein conduit was prepared by using intraoperative angioscopy for valve lysis and identification of luminal abnormalities in 44.8% of cases. RESULTS: Seventy-two (13. 8%) femoropopliteal, 174 (33.5%) femorotibial, 29 (5.6%) femoropedal, 101 (19.4%) popliteo-tibial/pedal, and 144 (27.7%) extension "jump" graft bypass procedures were performed for limb salvage (98.2%) or disabling claudication (1.8%). The average age of patients was 68.5 years (range, 32 to 91 years); 63.1% of patients were men, and 36.9% of patients were women. Eighty-five percent of patients had diabetes mellitus, and 77% of patients had a recent history of smoking. The grafts were composed of a single arm vein segment in 363 cases (69. 8%) and of spliced composite vein with venovenostomy in 157 cases (30.2%). The mean follow-up period was 24.9 months (range, 1 month to 7.4 years). Overall patency and limb salvage rates for all graft types were: primary patency, 30-day = 97.0% +/- 0.7%, 1-year = 80.2% +/- 2.1%, 3-year = 68.9% +/- 3.6%, 5-year = 54.5% +/- 6.6%; secondary patency, 30-day = 97.0% +/- 0.7%, 1-year = 80.7% +/- 2.1%, 3-year = 70.3% +/- 3.4%, 5-year = 57.5% +/- 6.2%; limb salvage, 30-day = 97.6% +/- 0.7%, 1-year = 89.8% +/- 1.7%, 3-year = 82.1% +/- 3.3%, 5-year = 71.5% +/- 6.9%. Secondary patency and limb salvage rates were greatest at 5 years for femoropopliteal grafts (69.8% +/- 12.8%, 80.7% +/- 11.8%), as compared with femorotibial (59.6% +/- 10. 3%, 72.7% +/- 10.5%), femoropedal (54.9% +/- 25.7%, 56.8% +/- 26.9%, ) and popliteo-tibial/pedal grafts (39.0% +/- 7.3%, 47.6% +/- 15.4%). The patency rate of composite vein grafts was equal to that of single-vein conduits. The overall survival rate was 54% at 4 years. CONCLUSION: Autogenous arm vein has been used successfully in a wide variety of lower-extremity revascularization procedures and has achieved excellent long- and short-term patency and limb salvage rates, higher than those generally reported for prosthetic or cryopreserved grafts. Its durability and easy accessibility make it an alternative conduit of choice when an adequate saphenous vein is not available.

Adult↗
PubMed1995

An angioscopic method for intraluminal aortic evaluation and stent placement.

PURPOSE: The purpose of this study was to develop an angioscopic technique to visualize the endoluminal surface of the aorta and to guide vascular stent placement. METHODS: A fiberoptic angioscope, fitted with a balloon at its tip, was passed via a carotid arteriotomy into the abdominal aorta of seven anesthetized pigs. Saline solution inflation of the balloon allowed for blood displacement and clear visualization of the endoluminal anatomy. After the left renal artery orifice had been identified with angioscopy, a catheter was inserted via a left femoral sheath to cannulate the orifice under direct visualization. The position of the catheter was verified angiographically. A vascular stent was loaded onto an angioplasty balloon, inserted through a right femoral arteriotomy, positioned by use of angioscopic visualization, and deployed immediately below the left renal artery orifice. RESULTS: The aortic trifurcation and the lumbar and renal artery orifices were clearly visualized in every animal. Vascular stents were placed in seven animals within an average of 3.14 +/- 1.14 mm (mean +/- SEM, range 0 to 8 mm) below the inferior rim of the left renal artery orifice. No stents were positioned above a renal artery orifice or obstructed blood flow. CONCLUSIONS: This angioscopic technique permitted detailed evaluation of aortic endoluminal anatomy and precise implantation of vascular stents. Direct endovascular visualization may facilitate other endovascular procedures, including endovascular grafting.

Angioscopy↗
PubMed1994

Early results of endovascular-assisted in situ saphenous vein bypass grafting.

PURPOSE: This study evaluated an endovascular technique for occlusion of arteriovenous fistula when performing saphenous vein in situ bypass grafting. METHODS: In 31 limbs femoropopliteal (17) or femorotibial (14) in situ bypass grafting was performed for claudication/aneurysm (4), rest pain (6), or tissue loss (21). A valvulotome was used for valve lysis. Saphenous vein branches were identified with angioscopy in 16 limbs or with fluoroscopy in the remainder. An electronically steerable endovascular catheter was used to deliver platinum coils into the venous tributaries to occlude them. RESULTS: The maximal number of coils placed in any limb was nine. Most operations were performed with only a groin incision (length = 9.8 +/- 1.6 cm) and a distal incision (length = 16.8 +/- 6.5 cm). Wound complications occurred in four limbs, whereas four limbs developed localized superficial thrombophlebitis. The postoperative ankle-brachial index increased to a mean of 0.91 +/- 0.12. Postoperative duplex imaging revealed a missed arteriovenous fistula in 12 limbs. Two were surgically ligated, whereas the remainder were embolized in the radiology suite. Postoperative length of hospitalization was 4 +/- 2 days in uncomplicated cases. Follow-up revealed five graft occlusions. Occlusion occurred at 12 hours, 2 weeks, and 6, 14, and 15 months after operation. Although there were no perioperative deaths, two patients have died of unrelated causes. CONCLUSION: This endovascular technique of arteriovenous fistula embolization decreased the length of the surgical wounds, and patients were discharged 4 +/- 2 days in uncomplicated cases. The ultimate test of its efficacy, however, will be long-term functional results.

Adult↗
PubMed1994

Randomized prospective study of angioscopically assisted in situ saphenous vein grafting.

PURPOSE: A study was conducted to test the hypothesis that angioscopically assisted valve lysis and vein branch identification during in situ saphenous vein bypass would reduce technical causes of graft failure, local operative morbidity, and hospital stay. METHODS: Patients requiring primary bypass to an infrageniculate artery were randomly assigned to undergo in situ saphenous vein bypass with valvulotomy and branch identification either under angioscopic visualization with use of short intermittent incisions (scope) or under direct vision with use of a continuous incision (no scope). Data on operative details, morbidity, hospital length of stay, and graft patency were collected prospectively and compared. RESULTS: Fifty-nine patients were enrolled (32 scope, 27 no scope). There were no significant differences between study groups in the incidence of diabetes, claudication versus critical ischemia indications for surgery, or popliteal versus infrapopliteal location of distal anastomoses. Rates of wound complications (9.3% and 3.7%), early graft occlusion (6.2% and 7.4%), and mean postoperative hospital stay (8.0 and 8.6 days) were statistically similar for the scope and no scope groups, respectively. Differences in cumulative secondary patency rates at 48 months (79% scope, 91% no scope) were also insignificant. CONCLUSIONS: Use of angioscopy to assist with preparation of the in situ vein for infrageniculate grafting appears to have no impact on local operative morbidity, hospital length of stay, or midterm graft patency.

Aged↗
PubMed2003

Ultrasonographic analysis of arteriosclerotic plaques in the internal carotid artery.

OBJECTIVES: The aim of this study was to investigate whether ultrasonography can characterise plaque morphology and surfaces independent of the observer. METHODS: Computer-assisted image analysis of the grey scales of B-mode scans from 15 patients with stenoses of the internal carotid artery was performed and compared with the histopathological reports. In vitro angioscopy, was used to visualise the plaque surfaces of the thromboendarterectomy specimens. RESULT: Assessment of the internal plaque structure by ultrasound showed close agreement between the two observers (P<0.01) without correlation with the histopathological results. Ultrasonography was able to characterise the plaque surfaces in 93% of cases. CONCLUSION: This investigation showed that standardised computer-assisted analysis of the internal plaque structure correlates less closely than histological investigation, but agrees closely with the surface structure of the plaque. The exclusive use of digital image processing and standardisation of the investigative technique are expected to provide even better results.

Aged↗
PubMed2005

Causes of telengiectasias, reticular veins, and varicose veins.

Study of surgical specimens and direct observation by angioscopy has revealed that the varicose venous wall, the valvular annulus, and the valves themselves undergo profound changes. Morphologic investigations have shown dilation of the valve annulus, bulging valve leaflets, commissural dilation, leaflet stretching, and eventually complete destruction of the valves. The venous wall has been seen to undergo changes of thickening in some segments and thinning in others. Our investigations show that inflammation and subsequent remodeling of the venous valves and wall are the fundamental mechanisms underlying the observed lesions. Hemodynamic forces, such as blood pressure changes in the wall and sheer stress, as well as varying planes of laminar and turbulent flow, induce activation of leukocytes and endothelial cells. Integrins appear to act as intermediaries and expression of adhesion molecules has been observed. Breakdown of extracellular matrix of the media and adventitia through activation of matrix metalloproteases (MMP) has been observed. In particular, expressions of MMP-1, MMP-2, MMP-9, and tissue inhibitor of metalloproteinase have been studied. Telangiectasias, reticular veins, and true varicose veins appear to be a consequence of the changes induced by venous hypertension and sheer stress.

Angioscopy↗
PubMed2000

Morphological analysis of atherosclerotic plaque retrieved by coronary atherectomy.

The development of atherectomy catheters and their use in clinical practice during percutaneous revascularization procedures permitted the analysis of the pathophysiology of obstructive coronary disease in vivo. The various clinical presentations of coronary disease are related to distinct morphological aspects of the culprit coronary stenosis as assessed by angiography, angioscopy or intravascular ultrasound imaging. Analysis of plaque fragments revealed the underlying histopathology. Restenotic lesions following various mechanical interventions have been studied in detail both in native coronary arteries and in bypass conduits. The biological reaction to implantation of endovascular stents involves inflammation around the stent wires as well as smooth muscle cell proliferation. Specific processes such as nitric oxide production or the activity of intramural proteases can be characterized and contribute to identify targets for future pharmacological therapy.

Angina Pectoris↗
PubMed2000

Arm vein conduit is superior to composite prosthetic-autogenous grafts in lower extremity revascularization.

PURPOSE: Various alternative conduits have been used for lower extremity revascularization when an adequate ipsilateral greater saphenous vein is absent. This study compared the effectiveness of all-autogenous multisegment arm vein bypass grafts with that of composite grafts composed of combined prosthetic and autogenous conduits. METHODS: One hundred fifty-three lower extremity revascularization procedures performed between 1990 and 1998 were followed up prospectively using a computerized vascular registry. The grafts were composed of spliced arm vein segments with venovenostomy in 122 and of composite prosthetic-autogenous conduit in 31. Arm vein conduit was prepared by means of intraoperative angioscopy for valve lysis and identification of luminal abnormalities in 47.7% of cases. RESULTS: Bypass graft configurations were as follows: femoropopliteal (12 arm vein, 2 composite); femorotibial (75 arm vein, 23 composite); femoropedal (14 arm vein, 6 composite), and popliteo-tibial/pedal (21 arm vein, 0 composite). The indication for surgery was limb salvage in 98% and disabling claudication in 2% of cases. The mean follow-up was 25.1 months (range, 1 month to 7.9 years). Overall survival at 4 years was 51%. Overall patency and limb salvage rates were as follows: primary patency, at 1 year-arm vein, 76.9% +/- 4.8%; composite, 59. 5% +/- 9.6% (P =.02); at 3 years-arm vein, 70.0% +/- 8.0%; composite, 43.7% +/- 12.4% (P <.01); and at 5 years-arm vein, 53.8% +/- 8.7%; composite, 0%; secondary patency, at 1 year-arm vein, 77.5% +/- 4. 6%; composite, 59.8% +/- 9.5% (P =.02); at 3 years-arm vein, 70.7% +/- 7.5%, composite, 44.9% +/- 13.1% (P <.01); at 5 years-arm vein, 57.7% +/- 8.0%; composite, 0%; limb salvage, at 1 year-arm vein, 89. 3% +/- 3.7%; composite, 73.9% +/- 8.9% (P <.01); at 3 years-arm vein, 80.5% +/- 7.0%; composite, 49.6% +/- 14.3% (P <.01); at 5 years-arm vein, 76.3% +/- 9.9%; composite, 0%. CONCLUSION: In this study, multisegment autogenous arm vein was used successfully in a wide variety of lower extremity revascularization procedures and achieved good long-term patency and limb salvage rates, well in excess of those achieved with composite prosthetic-autogenous grafts. The use of autogenous conduit appears to offer superior results to composite conduit in lower extremity revascularization. The superior durability of arm vein makes it one of the alternative conduits of choice when an adequate greater saphenous vein is not available.

Aged↗
PubMed1992

Clinical experience of laser angioplasty with angioscopic guidance.

Since 1986, intraoperative angioscopic observations have been followed by the study of laser angioplasty experimentally and clinically. The healing process of the lased arterial wall initially was evaluated angioscopically in the canine model. The lased area was observed as a crater covered with char soon after laser irradiation. One week after laser irradiation, subintimal bleeding around the crater and a small fresh thrombus on the crater were seen in some cases. Four weeks after laser irradiation, the crater was covered with new endothelium. In this experimental study angioscopy provides information which cannot be obtained by other means.

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