Premature peripheral vascular disease: clinical profile and abnormal lipid peroxidation

The aim of this study was to determine any biochemical differences between early-onset peripheral vascular disease and typical onset atherosclerosis, and age-matched controls. A subset of patients present at a young age ( < 50 years) with peripheral vascular disease which pursues an aggressive course. As lipid oxidation seems important in atherosclerosis, total lipid peroxides, oxidized subfractions, and Trolox equivalent antioxidant capacity (TEAC) were studied in patients with premature peripheral vascular disease. Charts were reviewed of patients operated on for vascular occlusive disease over a 5-year period. Patients with early-onset peripheral vascular disease (group I) were evaluated for biochemical abnormalities and compared with typical onset atherosclerotics (group II) and age-matched controls (group III). Sixteen patients with early-onset peripheral vascular disease underwent biochemical evaluation. Conventional lipid profiles did not differ statistically from those of age-matched controls, except for mild elevations in LDL and VLDL in patients with vascular occlusive disease (207 and 195 mg/dl in groups I and 11 versus 157 mg/dl in group III). Total oxidative potential was significantly elevated (P = 0.006) 3.04, 2.15 and 2.04 nmol/ml in groups I, II and III, respectively. Levels of oxidized LDL and VLDL were even more significantly elevated (P = 0.0009) for premature peripheral vascular disease, (1.2, 0.58 and 0.47 nmol/ml in groups I-II). TEAC values did not differ significantly between groups (0.83, 0.82, 0.82 nmol/ml) and did not correlate with total lipid peroxide values for individual patients. In conclusion, lipid peroxides were significantly elevated in patients with premature peripheral vascular disease, the most marked changes being seen in oxidized LDL and VLDL subfractions. Lipid peroxides were elevated when standard lipid profiles were only mildly abnormal. The poor long-term prognosis in these patients suggests the need for aggressive evaluation and treatment of lipid abnormalities.

Conservative management of residual and recurrent lesions after carotid endarterectomy: long-term results

PURPOSE

To document the natural history of residual and recurrent carotid stenoses that are initially treated without surgery, and to identify risk factors for recurrent stenosis.

METHODS

Review of data from a prospective carotid database with clinical and duplex follow-up. Analysis of rate of restenosis and rate of late reoperation by life table. Risk factor analysis by chi 2 and LEE-DESU statistics.

RESULTS

Three hundred forty-eight patients were available for follow-up, with 12 residual lesions (3.7%) and 22 recurrent lesions (6.6%). Rate of recurrent stenosis by life table analysis was 8.7% and 13% at 3 and 5 years. Restenosis was associated with smoking (p = 0.04) and contralateral progression. Only 21% of patients were underwent an operation within 5 years (p = 0.007) of restenosis developing, but eventually 10 of 22 patients required reoperation at long-term follow-up, eight for symptoms and two for progressive proximal stenoses. The late stroke rate was increased in patients who had residual or recurrent lesions compared with those who had normal duplex study results (18% vs 6%; p = 0.16) and was related to the ipsilateral artery.

CONCLUSIONS

Recurrent lesions that remain asymptomatic can be managed without operation with likelihood of success in the near term (5 years). However, these patients are at increased risk of late stroke, and almost half will eventually require operation. Therefore, in good-risk patients operation for asymptomatic restenosis should be considered.

Screening for asymptomatic deep vein thrombosis in surgical intensive care patients

PURPOSE

To identify the presence of occult deep vein thrombosis (DVT) in surgical intensive care unit (SICU) patients and to avoid unnecessary screening, we reviewed our experience with routine duplex screening for DVT in SICU patients.

METHODS

Over a 24-month period, all patients who were admitted to an SICU with an anticipated length of stay greater than 36 hours were studied to determine the prevalence of risk factors for asymptomatic proximal DVT. Risk factors, demographics, and operative data were collected and analyzed with multilinear regression, t tests and chi 2 analysis.

RESULTS

There was a 7.5% prevalence of major DVT in the 294 patients studied. APACHE II scores (14.5 +/- 6.24 vs 10.3 +/- 3.15; p < 0.0001) and emergent procedures (45.5% vs 23.2%; p > 0.0344) were associated with DVT by multifactorial analysis. Age was significant by univariate analysis. An algorithm based on the presence of any one of the three risk factors identified (APACHE II score 12 or more; emergent procedures; or age 65 or greater) could be used to limit screening by 30% while achieving a 95.5% sensitivity for identification of proximal DVT.

CONCLUSION

Absence of all three risk factors indicates a very low risk for DVT (1.1%). Screening of SICU patients is indicated because of a high prevalence of asymptomatic disease. Patients who have proximal DVT require active therapy and not prophylaxis. Costs and resources may be contained by using the above risk factors as a filter for duplex screening.

Research and clinical issues in chronic venous disease

The purpose of this study was to summarize the current issues in chronic venous disease by reviewing of the literature relating to the condition. The review was conducted by members of the Committee on Research of the American Venous Forum and includes the Committee's venous disease and current/future directions. Progress in the understanding and management of chronic venous problems has lagged behind that in arterial disease, despite the large number of patients affected. The complex pathophysiology of venous problems, lack of accepted evaluation standards and lack of prosthetic conduits are some of the factors which contribute to this. New information in these areas has laid the foundation for advances in both operations and non-operative therapy. In conclusion, many opportunities for clinical and basic research in the area of chronic venous disease are available. Application of basic science techniques, including those of molecular biology, will lead to new insights into pathophysiology of chronic venous syndrome. Developments in technology, classification and basic science suggest multiple new potentials therapeutic approaches in the next decade.

Completion angiography, is it really necessary?

BACKGROUND

Routine completion imaging after carotid endarterectomy (CEA) has been advocated by many investigators to detect and repair unsuspected defects with the goal of reducing perioperative morbidity and residual disease. However, completion imaging has been performed rarely in our practice. Our carotid registry was interrogated to determine whether omitting routine completion imaging adversely affected outcome.

METHODS

A retrospective review of 229 consecutive CEAs performed by one vascular surgeon during 1988 to 1996 was completed. Duplex follow-up was used to identify persistent residual defects, which were classified as 50% to 74%, 75% to 99%, and occlusion in the common (CCA), internal (ICA), and external (ECA) arteries and was available in 192 cases.

RESULTS

During the study period, eight completion angiograms were performed (3.5%) and 5 arteries were reopened. Combined stroke and death rate was 3.1% (7 of 229). Duplex follow-up, available on 192 patients, showed residual lesions in 29 patients (15%), but only 7 (3.6%) involving the internal or common carotid.

CONCLUSION

Routine completion imaging is not required to achieve acceptable morbidity and mortality and minimize residual problems after CEA. Attention to operative details with selective imaging will give excellent results.

Nicotine and its metabolite cotinine are mitogenic for human vascular smooth muscle cells

PURPOSE

Intimal hyperplasia caused by smooth muscle cell (SMC) proliferation is the major cause of infrainguinal graft failure within the first 12 months. Tobacco smoking is associated with a twofold increase in graft failure within the first year of extremity bypass surgery, but the mechanism is not clearly understood. This study evaluated the effect of nicotine and its major stable metabolite cotinine on vascular SMC proliferation in vitro.

METHODS

SMC were harvested from human arteries and grown in culture with standard methods. Cells were seeded at a density of 1.8 x 10(4) cells/well in 24 multiwell dishes and cell cycle-synchronized. Subsequently the SMC were incubated with media containing 0.1% or 15% fetal bovine serum and nicotine or cotinine at concentrations ranging from 10(-9) mol/L to 10(-6) mol/L. Control samples were incubated with corresponding media but without the drugs. SMC proliferation was determined at 4 days with a cell counter. DNA synthesis was assessed at 24 hours with 3H-thymidine uptake. The results were expressed as a percentage change compared with the control samples (mean +/- SEM). Results were analyzed by analysis of variance and t tests.

RESULTS

In the presence of serum both nicotine and cotinine at concentrations of 10(-7) and 10(-8) mol/L were mitogenic for SMC in vitro (p < 0.05). A weak mitogenic effect was observed at a low serum concentration for cotinine but not nicotine. Cotinine at a concentration of 10(-9) mol/L, a level seen among passive smokers, was a statistically significant stimulus for DNA synthesis in both minimum serum and serum-supplemented media. At high concentrations both substances were toxic for the cells.

CONCLUSION

We have demonstrated a potential role for nicotine and cotinine in the development of intimal hyperplasia and ultimately failure of the vascular reconstruction.

Upper-extremity arterial injury

Current experience in the management of upper-extremity arterial injury in a Level I trauma center between 1992 and 1994 is reported. Arterial trauma was seen in 21 of 643 (3.3%) patients admitted with upper-extremity injury. The mechanism of injury was penetrating in 15 of 21 and blunt in 6 cases. Patient characteristics were: 18 of 21 male, mean age 28, left upper extremity 12 of 21, and 4 patients in shock. Preoperative angiography was performed in 12 of 21 cases (5 of 6 blunt and 7 of 15 penetrating). Involved arteries included: brachial (10), axillary (5), radial (3), and subclavian (3). Associated injuries were common: nerve (9), bone (7), and vein (5). Twenty patients were explored; 18 of 20 underwent arterial repair (16 graft, 2 primary repair), and two proximal arteries were ligated. One intimal flap in the subclavian artery was observed, with a good result. Nerves were repaired in four cases, all with transection, and in four cases there was neurologic deficit without focal transection and no repair was performed. One patient died before his nerve injury could be repaired. Most venous injuries (four of five) were ligated, and three patients with blunt arterial injury underwent forearm fasciotomy. Immediate limb salvage was 100 per cent; there was one in-hospital mortality (4.7%) from exsanguination, and there was one persistent clinically significant late motor nerve deficit. Mean follow-up was 94 days (range, 0-305 days). Upper-extremity arterial injury often can be managed without angiography, particularly in cases of penetrating trauma. Good results can be anticipated with prompt arterial and nerve repair combined with selective use of venous reconstruction and fasciotomy.

Nicotine and cotinine stimulate secretion of basic fibroblast growth factor and affect expression of matrix metalloproteinases in cultured human smooth muscle cells

PURPOSE

We have recently shown that nicotine and its metabolite cotinine are mitogenic for smooth muscle cells in vitro. In the present study, we examined the effect of nicotine and cotinine on the production of growth factors and the expression of matrix metallo-proteinases in smooth muscle cells.

METHODS

Smooth muscle cells were harvested from human arteries and grown in culture. Subconfluent cultures were incubated for 24 hours in M199 containing 0.1% fetal bovine serum with or without nicotine or cotinine at concentrations ranging from 10(-9) mol/L to 10(-6) mol/L. The supernatants and cell lysates were assayed by enzyme-linked immunosorbent assay for basic fibroblast growth factor (bFGF), tumor necrosis factor alpha (TNF-alpha), platelet-derived growth factor AB (PDGF-AB), and transforming growth factor beta (TGF-beta). Matrix metalloproteinase expression was determined in subconfluent cultures incubated in albumin with or without nicotine or cotinine at 10(-8) mol/L and 10(-7) mol/L for 6, 12, 18, 24 and 36 hours. Northern blot analyses were performed with human cDNA probes for collagenase-1, stromelysin-1, gelatinase A, gelatinase B, and triose phosphate isomerase. Blots were quantified by phosphor-imaging techniques.

RESULTS

Both nicotine and cotinine stimulated the production and secretion of bFGF in a dose-dependent manner. PDGF, TNF-alpha, and TGF-beta secretions were not significantly affected by nicotine or cotinine. Collagenase was up-regulated by nicotine at 18 and 24 hours (4.5-fold to 5.8-fold) and by cotinine at 18 hours (from 5.0-fold to 29-fold). Stromelysin-1 was up-regulated by nicotine and cotinine at 12 and 18 hours (1.5-fold to 7.0-fold). Gelatinase A generally peaked at 12 hours and was up-regulated by both agents (2.0-fold to 6.5-fold).

CONCLUSION

Nicotine and cotinine enhanced the production of bFGF, a major mitogen for smooth muscle cells, and up-regulated the expression of several matrix metalloproteinases that are critical in cell migration. These data demonstrate mechanisms by which smoking may contribute to the development of intimal hyperplasia, atherosclerosis, and aneurysms.

The thrombosed prosthetic graft is a risk for infection of an adjacent graft

BACKGROUND

A bland thrombosed graft may be more susceptible to the future risk of infection than a patent graft. Once infected, that graft can threaten other patent grafts. Therefore, the purpose of the following study was to assess the role a thrombosed graft might play in infection of contiguous patent bypasses.

METHODS

From 1990, a retrospective review was performed using the operative and medical records of cases in which a prosthetic graft infection was identified arising in association with an adjacent thrombosed graft.

RESULTS

A total of 22 cases of prosthetic arterial bypass infection were treated at our institution from January 1990 through September 1995. Of these, 7 (32%) were identified by the operative report as arising in a thrombosed prosthetic graft and spreading to an attached or adjacent patent prosthetic graft. All patients had multiple bypasses prior to infection, mean 5.4 +/- .75 (range 3 to 8). All thrombosed infected grafts were infrainguinal polytetrafluoroethylene (PTFE) for limb salvage: 6 femoralpopliteal and 1 femorotibial. Mean interval time between placement of the primarily infected graft and removal was 14.6 +/- 6.7 months (range 1 to 53). The secondarily infected patent bypasses were inflow procedures to the same limb in 6 cases: 1 aortofemoral, 2 ileofemoral, 2 axillofemoral, and 1 femoral femoral graft. The thrombosed infrainguinal bypass was directly attached to the secondarily infected bypass in 5 cases and near but not attached in 1 case. One secondarily infected prosthetic graft was a femoraldistal bypass placed adjacent to the thrombosed graft. Four patients had above-knee amputations with a clinically bland graft divided at the time of amputation. In these 4 patients and 2 additional cases, wet gangrene or infection was present in the distal extremity prior to the development of prosthetic graft infection. At the point that infection became clinically apparent, the thrombosed graft was removed in all cases and the secondarily infected graft was removed in 4 of 7 cases. Overall mortality was 57%.

CONCLUSIONS

A thrombosed prosthetic graft near a patent prosthetic bypass may become secondarily infected and threaten the patent graft. We recommend total removal of any thrombosed prosthetic graft in proximity to a patent prosthetic bypass when the risk of infection is high or at the time of subsequent amputation for gangrene.

Is routine carotid ultrasound surveillance after carotid endarterectomy worthwhile?

BACKGROUND

Periodic ultrasound studies are routinely performed after carotid endarterectomy with the aim of detecting recurrent stenosis or progression of contralateral disease. The frequency with which these studies should be performed and their clinical utility is at present unclear. Our experience with ultrasound surveillance after carotid endarterectomy was reviewed.

METHODS

We performed a retrospective analysis of our carotid registry as a follow-up on patients who had undergone primary endarterectomy between 1982 and 1995. The database was searched for events referable to the contralateral carotid artery including incidence of contralateral endarterectomy, progression of contralateral stenosis, and development of new neurologic symptoms. Data was analyzed by life-table methodology.

RESULTS

A total of 562 patients underwent 660 endarterectomies during the study interval with a postoperative stroke rate of 3.6% and a mortality of 1.1%. Of these, 496 patients had data available on the contralateral artery. There were 384 patent, nonoperated contralateral arteries available for long-term clinical follow-up, of which 276 had serial Doppler examinations. At the time of initial presentation, 30% of patients (141 cases) had greater than 50% diameter stenosis in the contralateral artery including 45 occlusions. There were 67 contralateral endarterectomies performed within 6 months of the original surgery. An additional 15 endarterectomies were performed within 24 months of the original surgery and only 16 subsequent endarterectomies were performed up to the 8-year follow-up. Progression of contralateral stenosis from less than to greater than 50% occurred in 10.1% of the patient population. The rate of disease progression was 5.1% at 3 years, 17.8% at 5 years, and 30% at 7 years. Stroke-free survival in patients without progression was 94.7% at 3 years and 93.3% at 5 years.

CONCLUSIONS

Significant contralateral disease occurs in about one third of patients, most of whom are candidates for early contralateral endarterectomy. In patients who present with minimal contralateral disease, the incidence of progression is low over time. Follow-up duplex examinations on a biennial schedule is sufficient to detect clinically significant disease progression in these patients.

Extracranial internal carotid artery aneurysms: results of a surgical series with long-term follow-up

PURPOSE

The purpose of this study was to analyze mode of presentation, surgical treatment, and early and long-term results of a series of extracranial internal carotid artery aneurysms (EICAA).

METHODS

A retrospective analysis was performed on all cases treated for EICAA in a single institution from March 1974 to March 1995. Patient follow-up was obtained by a surveillance protocol, with duplex scanning performed 3 months after surgery and yearly thereafter.

RESULTS

Twenty-four EICAA in 20 patients were treated over a 21-year period. The cause was fibromuscular dysplasia in 12 cases (50%), nonspecific "atherosclerosis" in nine (37.5%), previous carotid artery surgery in two (8.3%), and trauma in one case (4.1%). Neurologic symptoms were present in a total of nine cases (37.5%) and were hemispheric in seven (29.1%) and nonhemispheric in two (8.3%). Operative techniques were performed with patients receiving general anesthetic and included aneurysm excision with internal carotid artery reanastomosis (8 cases [33.3%]) or reimplantation onto the external carotid artery (1 case [4.1%]); interposition graft (10 cases [41.6%]), 7 veins, 3 polytetrafluoroethylene) or simple aneurysmectomy and closure of the wall defect either with (3 cases [12.5%]) or without (2 cases [8.3%]) a patch. Elective surgery was performed in 22 cases, with a 0% mortality rate and 4.5% stroke rate. Emergency operations were performed in two cases of ruptured aneurysms (one spontaneous and one iatrogenic); one patient (50%) died. Cranial nerve morbidity occurred in five cases (20.8%). Mean follow-up was 96.7 +/- 88.15 months (range 4 to 240 months) and included 2 of 7 (28%) complications in saphenous vein grafts, 1 (4.1%) late transient ischemic attack, and a recurrent aneurysm after 19 years.

CONCLUSIONS

Symptoms and potential complications caused by EICAA suggest a broad surgical indication. EICAA can be treated safely because of the good early and long-term results.

Use of dermagraft, a cultured human dermis, to treat diabetic foot ulcers

OBJECTIVE

To assess the effect of a tissue-engineered human dermis (Dermagraft) in healing diabetic foot ulcers.

RESEARCH DESIGN AND METHODS

This controlled prospective multicenter randomized single-blinded pilot study evaluated healing over a 12-week period in 50 patients with diabetic foot ulcers. These patients were randomized into four groups (three different dosage regimens of Dermagraft and one control group). All patients received identical care except for the use of Dermagraft tissue. Ulcer healing was assessed by percentage of wounds achieving complete or 50% closure, time to complete or 50% closure, and volume and area measurements.

RESULTS

Ulcers treated with the highest dosage of Dermagraft, one piece applied weekly for 8 weeks (group A), healed significantly more often than those treated with conventional wound closure methods; 50% (6 of 12) of the Dermagraft-treated and 8% (1 of 13) of the control ulcers healed completely (P = 0.03). The percentage of wounds achieving 50% closure was also significantly higher (75 vs. 23%; P = 0.018), and the time to complete or 50% closure was faster (P = 0.056). The group A regimen was more effective than other treatment regimens. All three were better than the control, however, and a dose-response was observed. There were no safety concerns. After a mean of 14 months of follow-up (range 11-22 months), there were no recurrences in the Dermagraft-healed ulcers.

CONCLUSIONS

Dermagraft was associated with more complete and rapid healing in diabetic foot ulcers. The recurrence data may indicate an improved quality of wound healing.

Lesion width as a discriminator of plaque characteristics

This study evaluated the relative ability of two techniques to quantify carotid atheroma. Diameter stenosis and lesion width were used to predict clinical significance and morphologic characteristics of 54 carotid endarterectomy specimens. Diameter stenosis was a better predictor of symptoms than lesion width (P=0.03 versus P=0.085). Both parameters were predictive of complex atheroma (diameter stenosis P=0.000; lesion width P=0.03). However, use of lesion width allowed finer definition of categories permitting more precise subclassification of plaque. This resulted in a better correlation of symptoms to complexity when lesion width was used as the discriminating variable (lesion width P=0.04; diameter stenosis P=0.121). Lesion width is a valuable parameter for the classification of carotid atheroma, correlating with symptoms and plaque complexity. Lesion width should be evaluated in future studies of carotid atheroma. The discriminative ability of lesion width as detected by high-resolution ultrasonography needs to be evaluated.

Long-term follow-up of patients with early atherosclerosis

PURPOSE

Patients with premature peripheral vascular disease may respond differently than their older counterparts. To determine the impact of early onset of atherosclerosis on outcome, we decided to compare a group of these patients with a group of patients with typical onset of atherosclerosis with regard to early complications, indications for intervention, site of disease at initial presentation (aortoiliac, infrainguinal, or cerebrovascular), and long-term outcomes (secondary revascularization, amputation, and death).

METHOD

All patients younger than 50 years old requiring operative intervention between 1987 and 1992 were retrospectively compared with a group of patients greater than 60 years old, randomly selected from patients who underwent operation during the same time period. Patients were evaluated and compared for indications, risk factors, and early and late outcomes.

RESULTS

Patients with early onset atherosclerosis at the aortoiliac or infrainguinal level had a higher late amputation rate (17% versus 3.9%, p = 0.02) and poorer overall outcome than their older cohorts. Patients with cerebrovascular disease in both cohorts had similarly good prognoses.

CONCLUSION

Aortoiliac or infrainguinal disease diagnosed in patients less than 50 years of age portends a poorer outcome than does similar disease in an older patient population.

External carotid endarterectomy with internal carotid artery transposition flap angioplasty for symptomatic internal carotid artery occlusion

The external carotid artery is an important collateral pathway for cerebral perfusion when the internal carotid artery is occluded. After internal carotid artery occlusion, there is a definite risk of ipsilateral neurological events. The authors retrospectively examined their experience with endarterectomy of the external carotid artery for symptomatic internal carotid artery occlusion. Results based on the authors' experience and on historical data show external carotid endarterectomy to be a safe procedure. Obliteration of the cul-de-sac appears to be a very important factor in the prevention of reocclusion or recurrence of symptoms after external carotid endarterectomy. Use of the internal carotid artery stump for patching of the endarterectomized external carotid artery is both safe and effective in treating symptomatic internal carotid artery occlusion.

Vascular reactivity in patients with peripheral vascular disease

Noninvasive techniques have been used to demonstrate a specific pattern of impaired vasoactive response in the normal brachial artery of patients with clinical atherosclerosis. This is a physiologic reflection of the systemic nature of atherosclerosis and may be useful as a marker for identifying patients with preclinical atherosclerotic disease.

Risk factors for stroke after cardiac surgery: Buffalo Cardiac-Cerebral Study Group

PURPOSE

The purpose of this study was to identify risk factors for stroke in patients undergoing heart surgery.

METHODS

A retrospective chart review of patients who underwent cardiac surgery in three hospitals of the State University of New York at Buffalo system over a 36-month period was completed. Demographics and risk factors were recorded, and stroke and death were determined by chart review. Carotid artery stenosis was determined by duplex examination. Data were analyzed by chi-squared and multiple logistic regression.

RESULTS

One thousand one hundred seventy-nine cases were analyzed, with a mortality rate of 2.3%, stroke rate of 1.6%, and combined stroke/death rate of 3.1%. Four variables were found to be associated with an increased risk of stroke: carotid artery stenosis greater than 50%, redo heart surgery, valve surgery, and prior stroke. Five variables were associated with increased mortality rates:; carotid artery stenosis greater than 50%, redo surgery, peripheral vascular disease, longer pump time, and hypercholesterolemia. Carotid artery stenosis greater than 50% was present in 14.7% of cases. Carotid artery stenosis greater than 75% was not itself associated with increased stroke risk. Most strokes occurred more than 24 hours after surgery. Stroke distribution did not correlate with site of carotid artery stenosis greater than 50%.

CONCLUSIONS

Most neurologic events after heart surgery occur in a subset of patients who can be defined before operation. Whereas carotid artery stenosis greater than 50% is a strong risk factor, the role of prophylactic endarterectomy is unclear. Future studies should focus on this high-risk subgroup. A prospective study of prophylactic carotid endarterectomy in patients undergoing coronary artery bypass grafting is needed.

Promotion and acceleration of diabetic ulcer healing by arginine-glycine-aspartic acid (RGD) peptide matrix. RGD Study Group

OBJECTIVE

To determine the effectiveness and safety of arginine-glycine-aspartic acid (RGD) peptide matrix in the treatment of diabetic foot ulcers.

RESEARCH DESIGN AND METHODS

This randomized placebo-controlled investigator- and patient-blinded prospective multicenter investigation was conducted at three institutional and three private U.S. clinics providing ambulatory care. Sixty-five diabetic patients with chronic full-thickness neurotrophic foot ulcers were enrolled. Six discontinued the study because of adverse events. RGD peptide matrix (Argidene Gel; formerly Telio-Derm Gel) was applied topically twice weekly for up to 10 weeks in patients who otherwise received standard care. Control group patients received topical saline as a placebo plus standard care. The primary method of assessment was the incidence and rate of ulcer closure. All patients enrolled were included in the data analysis.

RESULTS

The percentage of patients whose ulcers healed completely in the RGD peptide matrix group (35%; 14 of 40 patients) was over fourfold greater (P = 0.02) than that in the placebo group (8%; 2 of 25 patients). By the study end point (either day of healing or week 10), 30 of 40 (75%) RGD peptide matrix patients had achieved > 50% ulcer closure compared with 12 of 25 (48%) placebo patients (P = 0.03). RGD peptide matrix also significantly (P = 0.03) increased the rate of ulcer closure over the 10 weeks of the study.

CONCLUSIONS

RGD peptide matrix treatment promoted and accelerated the healing of chronic diabetic foot ulcers to a significant degree.

Carotid endarterectomy for non-hemispheric ischaemia: long-term follow-up

Earlier results reported by the authors suggest that carotid endarterectomy can relieve symptoms of non-hemispheric ischemia in patients who present with hemodynamically significant carotid stenosis. Long-term follow-up of a subgroup of these patients is described. Some 61 patients with non-hemispheric ischemia who underwent carotid endarterectomy were reviewed. Indications for surgery and postoperative results (stroke, death, symptom relief) were determined by office visit or phone interview. Results in these patients were compared with those of an entire patient population who underwent endarterectomy performed by the authors. Mean (s.d.) follow-up was available for 42.3 (31.7) months. Perioperative stroke rate (4.9%), survival (85.3 and 64.9% at 3 and 5 years respectively) and stroke-free survival (77.1 and 63.4% at 3 and 5 years respectively) were not different from that entire cohort of 553 patients. During follow-up, 11 patients (18%) developed recurrent symptoms of non-hemispheric ischemia. Carotid endarterectomy is successful in providing long-term relief of symptoms of non-hemispheric ischemia in most patients with significant carotid bifurcation stenosis. Results in such patients are similar to those seen in patients with symptoms of anterior cerebral ischemia or with symptom-free stenoses.

Morphology of small aneurysms: definition and impact on risk of rupture

BACKGROUND

Parietal characteristics of small aortic aneurysms predictive of increased risk of rupture are unknown.

METHODS

Prospective morphologic evaluation was performed in 135 consecutive cases of small (< 5 cm) abdominal aortic aneurysm. Twelve cases (9%) were found to be ruptured and sent for emergency surgery. The remaining 123 patients were evaluated with ultrasonography, angiography, and intraoperatively during elective surgery. Ninety-six (78%) also underwent computerized tomography (CT) scanning. The evaluation assessed the thickness of the endoluminal thrombus and arterial wall as well as the presence of saccular outpouchings ("blisters"). Also noted were any areas of impending rupture, defined as discontinuity of the arterial wall with only a thrombus preventing rupture.

RESULTS

Blisters were discovered intraoperatively in 12 aneurysms. Digital subtraction angiography (DSA) revealed 3 (25%) of these preoperatively. Eleven of the patients with blisters were examined preoperatively with CT scanning, which detected 3 blisters (27%). Both endoluminal thrombus and wall thickness were measurable by CT scan but not ultrasonography. The incidence of impending rupture was significantly greater in patients with blisters than in those without (71% versus 29%, P = 0.0001). The incidence of impending rupture was similar whether the amount of endoluminal thrombus was more or less than 2 cm (57% versus 40%, P = 0.386). Rupture was no more frequent when aneurysmal walls were thicker or thinner than 0.3 cm (14% versus 20%, P = 0.719). In an analysis using logistic regression, the presence of a blister was the only independent morphologic predictor of impending rupture (P = 0.001, Wald = 15).

CONCLUSION

In patients with small aneurysms, increased attention should be directed to the preoperative detection of blisters.

Carotid exploration for acute postoperative thrombosis

To determine the incidence of carotid reoperation and to document operative findings and clinical results, the records of patients requiring early reoperation (after less than 24 hours) during a 10-year period were analyzed with respect to operative findings, clinical outcome, and arterial patency. Endarterectomy was performed in 920 patients, with 27 strokes (3%) and 10 deaths (1%). Early re-exploration was required for 27 patients (3%) for either expanding hematoma (6 patients) or suspected thrombosis associated with a new neurologic deficit (21 patients). Two patients bled from the arteriotomy and 4 bled from surrounding tissues. Exploration for new postoperative neurologic events confirmed thrombosis in 19 cases (91%). Two patients with patent arteries and normal operative arteriograms were felt to have distal embolization, and the arteriotomy was not opened. Causes of thrombosis were intimal flap in 6 patients and closure stenosis in 11; the cause was unknown in 2 cases. All arteries were repaired over a shunt with a patch. Follow-up studies were available for 16 arteries, all of which remained patent. Of patients explored for hemorrhage, there was one death (from myocardial infarction), no neurologic events, and no late infections. Of 21 patients who underwent a second operation for neurologic deficits, 2 died, 8 were unchanged, 2 had minor residual deficit, and 9 had completely resolved deficits. Severe contralateral disease was more common among patients with residual deficits (10 of 12) compared with patients without residual deficits (0 of 9; chi-square = 8.23, P < 0.005). Carotid re-exploration is most commonly undertaken for a new neurologic deficit, usually associated with thrombosis at the operative site. Thrombosis is more often due to arterial narrowing than to an intimal defect. Prompt repair will restore patency and result in improvement in 50% of cases. Neurologic recovery is related to the status of the contralateral artery.

Evaluation and treatment of carotid stenosis in open-heart surgery patients

Indications for identification and treatment of extracranial carotid artery disease in candidates for open-heart surgery (OHS) remain unsettled. We evaluated the efficacy of OPG-GEE screening and our nonrandomized use of carotid endarterectomy in 2312 OHS patients from 1975 to 1989. Data was analyzed using the chi 2 squared and Fisher's exact tests. OPG was performed in 1602/2312 (69%) of the patients. OPG was positive in 122/1602 patients (7.6%) and negative in 1480/1602 (92.4%) patients. Of the patients with positive OPG, 31 patients had insignificant carotid bifurcation disease, 32 patients had total internal carotid artery occlusion, and 59 patients had operable carotid bifurcation lesions. Selective use of angiography identified an additional 8 patients with operable carotid bifurcation lesions (total 67, 33 symptomatic and 34 asymptomatic). Overall stroke rate for 2312 patients was 40/2312 (1.7%) [30 day mortality rate 60/2312 (3.2%)]. Stroke incidence was significantly increased (P < 0.01) in patients with a positive OPG, 8/122 (6.60%) vs those with negative OPG (23/1480, 1.6%). However, it was most marked in patients with operable bifurcation lesions (6/67, 9.0%). Stroke was not increased in patients with carotid occlusion or positive OPG without significant carotid bifurcation disease (2/63, 3.20%). Carotid endarterectomy in patients with operable bifurcation lesions was associated with a decreased (P < 0.05) stroke rate after OHS (1/44, 2.30% vs 5/23, 21.7%). Our data suggests identification of significant carotid disease and carotid endarterectomy will decrease stroke after OHS.

Long-term cryopreservation of autologous veins in rabbits

This study was undertaken to determine the effect of long-term cryopreservation on graft ultrastructure and endothelial cell viability in an animal model. The jugular veins from 12 New Zealand White rabbits were excised with a 'no-touch' technique and divided into four groups: control group (fresh veins); group 1, veins cryopreserved for 1 month; group 2, veins cryopreserved for 2 months; and group 3, veins cryopreserved for 3 months. Cryopreservation was accomplished by rapid freezing (-5 degrees C s-1 to -196 degrees C) in a solution of 17.5% dimethylsulphoxide and 20% fetal bovine serum and by storage in liquid nitrogen. Veins were then implanted as a carotid autograft (three grafts/group). At the time of graft implantation a segment of the paired matched vein was perfusion-fixed and evaluated by scanning and transmission electron microscopy, whereas the remainder were subjected to endothelial cell culture techniques to determine cell viability. Autografts were removed 1 month after implantation and subjected to similar evaluations. Histological changes seen in cryopreserved veins were dependent on preservation time and included focal endothelial cell blebbing, cytoplasmic vacuolization and disruption of cell-to-cell contacts. Smooth muscle cells showed mitochondrial swelling. Patency was identical in all groups (66.6%). Explants at 1 month were similar in histological appearance to fresh veins with a smooth endothelial cell lining arranged longitudinally and intact cell junctions. Endothelial cells could be cultured from fresh veins and 1-month-old explants but not from the cryopreserved graft surface before implantation. the present technique of cryopreservation leads to some damage of graft architecture and loss of endothelial cell viability.(ABSTRACT TRUNCATED AT 250 WORDS)