D-dimer and inflammatory markers as predictors of functional decline in men and women with and without peripheral arterial disease.

OBJECTIVES: To determine whether higher circulating levels of inflammatory and thrombotic markers are associated with greater decline in lower extremity performance. DESIGN: Prospective cohort. SETTING: Academic medical center. PARTICIPANTS: Three hundred thirty-seven men and women with lower extremity peripheral arterial disease (PAD) and 215 without PAD. MEASUREMENTS: Objective measures of leg function, including the 6-minute walk and Short Physical Performance Battery (SPPB), were obtained at baseline and annually for 3 years. D-dimer, high-sensitivity C-reactive protein, serum amyloid A, and fibrinogen levels were measured at baseline. Participants were categorized into one of three groups, ranging from low to high levels of inflammation, depending on the number of individual blood factors in the lowest and highest tertiles for each corresponding blood factor. RESULTS: Adjusting for age, sex, race, ankle brachial index, comorbidities, and other confounders, greater inflammation was associated with greater decline in the SPPB (P=.008). Results were similar when repeated in participants with and without PAD separately (P for trend=.04 for participants with PAD and .07 for participants without PAD). In fully adjusted analyses, there were no significant associations between inflammation group and decline in 6-minute walk performance. CONCLUSION: Higher baseline levels of inflammatory markers and D-dimer were associated with greater decline in the SPPB at 3-year follow-up in persons with and without PAD.

The ankle brachial index is associated with leg function and physical activity: the Walking and Leg Circulation Study.

BACKGROUND: The ankle brachial index (ABI) is a noninvasive, reliable measure of lower-extremity ischemia. However, the relationship between ABI and lower-extremity function has not been well studied. OBJECTIVE: To describe the association between the ABI and lower-extremity function. DESIGN: Cross-sectional study. SETTING: 3 academic medical centers in the Chicago area. PARTICIPANTS: 740 men and women (460 with peripheral arterial disease). MEASUREMENTS: Accelerometer-measured physical activity over 7 days, 6-minute walk, 4-m walking velocity, standing balance, and ABI. RESULTS: 33% of participants with peripheral arterial disease had intermittent claudication. Fewer than 40% of participants with an ABI less than 0.40 walked continuously for 6 minutes compared with more than 95% of participants with an ABI between 1.00 and 1.50. Compared with an ABI of 1.10 to 1.50, an ABI less than 0.50 was associated with shorter distance walked in 6 minutes (beta-regression coefficient = -523 ft [95% CI, -592 to -454 ft]; P < 0.001), less physical activity (beta = -514.8 activity units [CI, -657 to -373 activity units]; P < 0.001), slower 4-m walking velocity (beta = -0.21 m/s [CI, -0.27 to -0.15 m/s]; P < 0.001), and less likelihood of maintaining a tandem stand for 10 seconds (odds ratio, 0.37 [CI, 0.18 to 0.76]; P = 0.007), after adjustment for typical confounders. Associations between ABI and function were stronger than associations between leg symptoms and function. CONCLUSIONS: The ABI, a noninvasive test that can be performed in a medical office, is more closely associated with leg function in persons with peripheral arterial disease than is intermittent claudication or other leg symptoms. These data support the use of the ABI to identify abnormal lower-extremity function.

Inflammatory and thrombotic blood markers and walking-related disability in men and women with and without peripheral arterial disease.

OBJECTIVES: To determine whether higher circulating levels of thrombotic and inflammatory markers are associated with greater disability. DESIGN: Cross-sectional. SETTING: Academic medical center. PARTICIPANTS: A total of 346 men and women with peripheral arterial disease (PAD) and 203 without PAD. MEASUREMENTS: Disability measures were the Walking Impairment Questionnaire (WIQ) distance, speed, and stair-climbing scores and the 36-item Short-Form (SF-36) physical functioning score. The SF-36 and WIQ are scored on a 0 to 100 scale (100=best). RESULTS: In persons with PAD, higher D-dimer levels were associated with lower WIQ speed scores (P<.001), lower stair-climbing scores (P<.04), and poorer SF-36 physical functioning scores (P<.01), adjusting for known and potential confounders. In participants without PAD, higher D-dimer levels were associated with lower WIQ distance scores (P<.03), lower speed scores (P<.05), and poorer SF-36 physical functioning scores (P<.02). Higher high-sensitivity C-reactive protein (hsCRP) levels were associated with lower WIQ distance (P<.02) and speed scores (P<.001) in persons without PAD. Most of these associations were attenuated after additional adjustment for objectively measured functional limitations. CONCLUSION: Higher circulating D-dimer and hsCRP levels are associated with greater disability in walking and physical functioning in individuals with and without PAD. Physiological changes that result in walking disability may mediate these associations.

Repeat axillofemoral grafting as treatment for axillofemoral graft occlusion.

BACKGROUND: Patency of failed axillofemoral (ax-fem) grafts following thrombectomy is so poor, aortofemoral grafts are recommended as treatment for ax-fem graft thrombosis. In patients who are not candidates for aortic grafting, repeat ax-fem grafting is an alternative to thrombectomy. This report compares our experience treating ax-fem graft thrombosis with replacement or revision vs thrombectomy. METHODS: Patients treated with ax-fem grafts from October 1985 to April 2001 were identified, and those who underwent reoperation for thrombosis were reviewed. Limb salvage and patency of revision procedures (thrombectomy vs repeat ax-fem grafting) were determined using Kaplan-Meier curves. RESULTS: Three hundred thirty-five patients underwent ax-fem grafting, and 39 (11.6%) of the 335 required reoperation for graft failure. Twenty-five of these 39 patients had 51 operations for graft thrombosis: 42 graft replacements and/or anastomotic revision(s), and 9 thrombectomies. At 18 months, mean +/- SD patency following thrombectomy was 11% +/- 10%, while that for graft replacement or anastomotic revision was 54% +/- 8% (P<.001). Limb salvage at 18 months following revision for thrombosis was 88% +/- 5%. CONCLUSIONS: The large majority of ax-fem grafts do not require reoperation. For failure due to thrombosis, repeat ax-fem grafting provides excellent limb salvage. Axillofemoral graft replacement and/or anastomotic revision has superior patency to thrombectomy.

Iatrogenic arterial injury is an increasingly important cause of arterial trauma.

BACKGROUND: Iatrogenic arterial injuries (IAI) may result from any invasive diagnostic or therapeutic procedure. The relative occurrence and severity of IAI compared with those of penetrating and blunt vascular trauma is unknown. A review of arterial trauma at a university hospital level 1 trauma center, with a focus on iatrogenic injury, forms the basis of this report. METHODS: Patients treated for arterial trauma from January 1994 through October 2002 were identified from prospectively maintained registries. Record review included injury etiology, type of repair, 30-day all-cause mortality, and permanent morbidity. Permanent morbidity was defined as amputation or loss of extremity function. RESULTS: In all, 252 patients required treatment, 85 (33.7%) from IAI, 86 (34.1 %) from penetrating trauma, and 81 (32.1%) from blunt trauma. During the study period, the number of IAIs per year increased. Femoral artery injury from percutaneous intervention (50, 58.8%) was the most frequent IAI; intraoperative injury (including 14 tumor resections and 5 orthopedic procedures) was next most frequent (23, 27.1%). Three patients (3.5%) with IAI had permanent morbidity. The 30-day all-cause mortality was 7.1% (6) for patients with IAI. CONCLUSIONS: Iatrogenic arterial injury is increasingly frequent and caused one third of the arterial trauma at our level 1 trauma center. These data suggest education and training regarding IAI deserves equal priority with the study of penetrating vascular trauma.

Homocysteine and arterial disease. Experimental mechanisms.

Hyperhomocysteinemia (hH(e)) in the general population is associated with incidence and progression of arterial occlusive disease, although the underlying mechanisms are not well defined. Current research supports a role for homocysteine (H(e))-mediated endothelial damage and endothelial dysfunction. This mechanism appears to be a key factor in subsequent impaired endothelial-dependent vasoreactivity and decreased endothelium thromboresistance. These consequences may predispose hyperhomocysteinemic vessels to the development of increased atherogenesis. Additional mechanisms of H(e)-mediated vascular pathology, including protein homocysteinylation and vascular smooth muscle cell proliferation may also play a role. Continued investigation into the mechanisms contributing to H(e) toxicity will provide further insight into the processes by which hH(e) may increase atherosclerosis.

Elevated plasma homocysteine as risk factor for peripheral arterial disease--what is the evidence?

There is abundant evidence that elevated plasma homocysteine (HC) is independently associated with presence of atherosclerotic disease. There is credible evidence from a number of prospective studies that elevated HC is independently associated with progression of atherosclerotic disease. All studies to date agree that vitamin therapy, primarily folate, results in reliable decreases in HC, without recognized toxicity or side effects. Two small, randomized clinical trials have demonstrated clinically relevant benefit from folate treatment, which reduced HC in patients, compared to placebo. The results of multiple large scale clinical trials will be available within 2 to 5 years, and these have sufficient power to determine whether vitamin therapy intended to lower plasma HC will be established as the first effective therapy for atherosclerosis that does not involve expensive medication with toxic side effects and/or difficult changes in habits or lifestyle.

Outcomes after redo procedures for failed mesenteric revascularization.

This report examines results of mesenteric revascularization following a failed splanchnic revascularization. Patients undergoing repeat mesenteric revascularization from January 1985 to July 2002 were identified from a prospectively maintained registry. Data recorded included procedures performed, perioperative mortality, complications, and operative indications. Patients who had embolic events were excluded. Eighty-six patients underwent 105 mesenteric interventions in this time period; 22 patients underwent 33 repeat mesenteric revascularization procedures. There were 25 single-vessel bypasses, 3 multivessel reconstructions, 3 angioplasty procedures (1 open, 2 percutaneous), and 2 graft thrombectomies. Complications occurred in 33.3%. Perioperative mortality was 6.1%, all in patients with acute mesenteric ischemia. One- and 4-year primary patency for repeat mesenteric revascularization was 73.5% and 62.2%, respectively, and survival for repeat mesenteric revascularization was 85.9% and 75.5%, respectively. Patients surgically treated for mesenteric ischemia can require additional interventions. Repeat revascularization effectively prolongs survival when an earlier intervention fails.

Carotid surgery following previous carotid endarterectomy is safe and effective.

With the perceived high risk of repeat carotid surgery, carotid angioplasty and stenting have been advocated recently as the preferred treatment of recurrent carotid disease following carotid endarterectomy. An experience with the operative treatment of recurrent carotid disease to document the risks and benefits of this procedure is presented. A review of a prospectively acquired vascular registry over a 10-year period (Jan. 1990-Jan. 2000) was undertaken to identify patients undergoing repeat carotid surgery following previous carotid endarterectomy. All patients were treated with repeat carotid endarterectomy, carotid interposition graft, or subclavian-carotid bypass. The perioperative stroke and death rate, operative complications, life-table freedom from stroke, and rates of recurrent stenosis were documented. During the study period 56 patients underwent repeat carotid surgery, comprising 6% of all carotid operations during this period. The indication for operation was symptomatic disease recurrence in 41 cases (73%) and asymptomatic recurrent stenosis >/=80% in 15 cases (27%). The average interval from the prior carotid endarterectomy to the repeat operation was 78 months (range 3 weeks-297 months). The operations performed included repeat carotid endarterectomy with patch angioplasty in 31 cases (55%), interposition grafts in 19 cases (34%), and subclavian-carotid bypass in 6 cases (11%). There were three perioperative strokes with one resulting in death for a perioperative stroke and death rate of 5.4%. One minor transient cranial nerve (CN IX) injury occurred. Mean follow-up was 29 months (range, 1-116 months). Life-table freedom from stroke was 95% at 1 year and 90% at 5 years. Recurrent stenosis (>/=80%) developed in three patients (5.4%) during follow-up, including one internal carotid artery occlusion. Two patients (3.6%) underwent repeat surgery. Repeat surgery for recurrent cerebrovascular disease following carotid endarterectomy is safe and provides durable freedom from stroke. Most patients are candidates for repeat endarterectomy with patching, but interposition grafting is often required. These results strongly support the continued role of repeat carotid surgery in the treatment of recurrent carotid disease.

Functional decline in peripheral arterial disease: associations with the ankle brachial index and leg symptoms.

CONTEXT: Among individuals with lower-extremity peripheral arterial disease (PAD), specific leg symptoms and the ankle brachial index (ABI) are cross-sectionally related to the degree of functional impairment. However, relations between these clinical characteristics and objectively measured functional decline are unknown. OBJECTIVE: To define whether PAD, ABI, and specific leg symptoms predict functional decline at 2-year follow-up. DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study among 676 consecutively identified individuals (aged > or =55 years) with and without PAD (n = 417 and n = 259, respectively), with baseline functional assessments occurring between October 1, 1998, and January 31, 2000, and follow-up assessments scheduled 1 and 2 years thereafter. PAD was defined as ABI less than 0.90, and participants with PAD were categorized at baseline into 1 of 5 mutually exclusive symptom groups. MAIN OUTCOME MEASURES: Mean annual changes in 6-minute walk performance and in usual-paced and fast-paced 4-m walking velocity, adjusted for age, sex, race, prior-year functioning, comorbid diseases, body mass index, pack-years of cigarette smoking, and patterns of missing data. RESULTS: Lower baseline ABI values were associated with greater mean (95% confidence interval) annual decline in 6-minute walk performance (-73.0 [-142 to -4.2] ft for ABI <0.50 vs -58.8 [-83.5 to -34.0] ft for ABI 0.50 to <0.90 vs -12.6 [-40.3 to 15.1] ft for ABI 0.90-1.50, P =.02). Compared with participants without PAD, PAD participants with leg pain on exertion and rest at baseline had greater mean annual decline in 6-minute walk performance (-111 [-173 to -50.0] ft vs -8.67 [-36.9 to 19.5] ft, P =.004), usual-pace 4-meter walking velocity (-0.06 [-0.09 to -0.02] m/sec vs -0.01 (-0.03 to 0.003] m/sec, P =.02), and fastest-pace 4-meter walking velocity (-0.07 [-0.11 to -0.03] m/sec vs -0.02 [-0.04 to -0.006] m/sec, P =.046). Compared with participants without PAD, asymptomatic PAD was associated with greater mean annual decline in 6-minute walk performance (-76.8 (-135 to -18.6] ft vs -8.67 (-36.9 to 19.5] ft, P =.04) and an increased odds ratio for becoming unable to walk for 6 minutes continuously (3.63; 95% confidence interval, 1.58-8.36; P =.002). CONCLUSIONS: Baseline ABI and the nature of leg symptoms predict the degree of functional decline at 2-year follow-up. Previously reported lack of worsening in claudication symptoms over time in patients with PAD may be more related to declining functional performance to than lack of disease progression.

Duplex scan characteristics of bypass grafts to mesenteric arteries.

BACKGROUND: Mesenteric bypass grafts may be followed postoperatively with duplex scanning. It is unknown, however, if duplex-derived velocity measurements vary over time or if the type of procedure (antegrade vs retrograde) and the caliber of graft affect velocity measurements. The purpose of this study was to characterize duplex findings in mesenteric bypass grafts with respect to the type of revascularization, graft caliber, and changes over time. This study also sought to identify duplex characteristics that could predict subsequent graft failure. METHODS: Duplex examinations of mesenteric bypass grafts were reviewed. Peak systolic velocities (PSV) from the inflow artery, proximal anastomosis, mid graft, distal anastomosis, and outflow arteries were analyzed with respect to timing of the examination (index study vs follow-up exam), inflow source, distal target, and graft diameter. The results were compared with analysis of variance (P < .05). Univariate and multivariate analyses were used to determine any association with mid-graft PSV. RESULTS: Fasting postoperative duplex scans were reviewed from 43 mesenteric bypass grafts in 38 patients (28 superior mesenteric artery [SMA] alone, 3 celiac alone, 5 celiac and SMA, 2 SMA and renal). A total of 167 duplex exams were analyzed (mean of 4.5 studies per patient; range, 1 to 14). Inflow artery velocities were significantly lower in antegrade vs retrograde configurations (93 +/- 73 cm/s vs 154 +/- 73 cm/s, P < .05); however, proximal and mid-graft PSVs were not significantly different between the two groups. In addition, no effect was noted on mid-graft PSV when distal targets were compared (SMA vs celiac, 149 +/- 42 cm/s vs 160 +/- 78 cm/s, P = NS). An association between smaller graft diameter and higher mid-graft PSV was seen with univariate analysis (P = .03), with a trend toward significance with multivariate analysis (P = .06). In 18 bypass grafts where a follow-up examination was available >1 year (mean 38 +/- 25 months) after the index postoperative exam, velocity did not significantly change over time. No duplex scan characteristics were predictive of graft thrombosis. CONCLUSION: This is the first study, to our knowledge, to fully characterize duplex-derived flow velocities in mesenteric artery bypass grafts. Although surveillance duplex scans after mesenteric bypass procedures may be affected by graft diameter, they are not significantly affected by the choice of inflow artery. These data can serve as standards for postoperative surveillance of mesenteric bypass grafts.

Prospective evaluation of the relationship between C-reactive protein, D-dimer and progression of peripheral arterial disease.

OBJECTIVE: Elevated levels of C-reactive protein (CRP) and D-dimer (DD) have been associated with the presence and progression of various forms of atherosclerotic disease, particularly coronary heart disease. We hypothesize that there is a relationship between elevated levels of baseline CRP and DD and progression of peripheral arterial disease (PAD) in patients with symptomatic PAD. The current study is a prospective evaluation of this hypothesis. METHODS: Between 1996 and 2003, 384 subjects were enrolled in a National Institutes of Health-sponsored blinded, prospective trial evaluating the effects of multiple atherosclerotic risk factors on progression of symptomatic PAD. Baseline levels of CRP and D-dimer were obtained in 332 subjects. Subjects were followed every 6 months with clinical history and exam, ankle-brachial pressure index (ABI), and carotid artery duplex scanning (CDS). The primary study end point was a composite of ABI progression, CDS progression, stroke, myocardial infarction, amputation, and death from cardiovascular disease. Secondary end points included each of the components of the primary end point. The relationship between time to the various endpoints and baseline CRP and DD levels was examined by life-table analysis and Cox proportional hazards analysis. RESULTS: Adequate baseline samples for CRP and DD were available in 332 subjects (mean age, 67 years; 57.8% men) with mean follow-up of 38.4 months (range, 1 to 99 months). Mean baseline levels (+/- SD) for CRP were 0.8 +/- 1.14 (range, 0.03 to 13.0), and mean DD levels were 227.4 +/- 303.3 (range, 1.9 to 2744.8). Progression, as defined by the primary end point, occurred in 48.5% of subjects. Subjects with elevated CRP (highest tertile) were no more likely to have any of the progression end points than those with the lowest values (lowest tertile) (P = NS, log-rank test, for all comparisons). By univariate analysis, subjects with elevated DD (highest tertile) were significantly more likely to die from any cause compared with subjects with the lowest DD values (lowest tertile) (P = .03, log-rank test). They were, however, no more likely to reach any of the other progression end points, including the primary end point (P = NS, log-rank test for all other comparisons). Multivariate analysis showed that DD level was a significant independent variable associated with occurrence of myocardial infarction (hazard ratio, 2.3; P = .02). CONCLUSIONS: In subjects with symptomatic PAD, elevated baseline DD, a marker of thrombotic activity, was significantly associated with the occurrence of myocardial infarction. This study did not confirm a relationship between progression of PAD and baseline DD or CRP during the first 3 years. Baseline DD and CRP do not provide useful risk stratification in patients at high risk for progression of symptomatic PAD. Future studies should evaluate serial levels of these markers to assess their utility in predicting progression of symptomatic PAD.

Prospective randomized multicenter trial of fibrin sealant versus thrombin-soaked gelatin sponge for suture- or needle-hole bleeding from polytetrafluoroethylene femoral artery grafts.

OBJECTIVE: We evaluated the safety and efficacy of the fibrin sealant Beriplast P (FSBP; Aventis-Behring) for hemostasis in anastomosis of polytetrafluoroethylene (PTFE) grafts to the femoral artery. METHODS: In a single-blinded randomized prospective multicenter clinical trial, FSBP was compared with thrombin-soaked gelatin sponge (TSG) for efficacy in stopping bleeding from needle or suture holes in PTFE grafts after anastomosis to the femoral artery. Patients were randomized to FSBP application, which requires a 3-minute period of arterial clamping to enable the fibrin clot to adhere, or to TSG application, which requires pressure from gauze sponges, after completion of the femoral artery anastomosis. The primary end point was hemostasis, defined as absence of any detectable bleeding as judged by the operating surgeon, by 4 minutes after randomization. Secondary end points included actual time from randomization to hemostasis, time to beginning of wound closure, measured blood loss (weighed sponges), incidence of recurrent bleeding, stay in the intensive care unit, and hospital length of stay. Data were analyzed with the intention-to-treat method. RESULTS: Two hundred thirty-five subjects were enrolled at 26 medical centers; 34 were subsequently excluded from the study. Of the 201 randomized subjects, 100 received FSBP and 99 received TSG. Hemostasis was achieved by 4 minutes in 64 subjects (63%) in the FSBP group and 40 subjects (40%) in the TSG group (P =.0018). In the FSBP group, compared with the TSG group, time to hemostasis was shorter (median, 4.0 minutes; 95% confidence interval [CI], 3.8-4.18 minutes vs median, 5.6 minutes, 95% CI, 4.5-7.0; P =.008), blood loss was less (mean, 4.0 +/- 29.7 g vs mean, 15.6 +/- 28.4 g; P <.0001), and time to wound closure was shorter (median, 15 minutes; 95% CI, 10.47-18.67 minutes vs median, 22.8 minutes; 95% CI, 18.67-30.67; P =.005). There were no differences in recurrent bleeding or any other adverse events. There was no significant difference in ICU stay, but hospital length of stay was shorter in the FSBP group compared with the TSG group, and the difference approached significance (median, 6.5 days; 95% CI, 5.00-7.00 days vs median, 7.0 days; 95% CI,. 6.00-8.00 days; P =.0565). CONCLUSION: FSBP is more effective than TSG for achieving hemostasis of needle or suture hole bleeding from PTFE femoral artery grafts.

Comparison of procedural outcomes after lower extremity reversed vein grafting and secondary surgical revision.

OBJECTIVE: Many lower extremity vein graft procedures require revision. Although morbidity associated with revision procedures is assumed minimal, this has not been previously quantified and may be underestimated. In this study, patient outcome after initial vein graft procedures and revisions are compared. METHODS: Records for all patients undergoing vein graft revision from January 1995 to August 2002 were reviewed for operation time, estimated blood loss, blood transfusion, hospital length of stay, perioperative complications, and functional status at discharge and at 2-month follow-up. Revisions were compared with the original operation and by revision type. RESULTS: One hundred sixty-five vein graft revisions were performed in 137 patients. In comparison with the initial bypass procedure, mean operation time (3.35 +/- 1.41 hours vs 2.58 +/- 1.04 hours; P <.001), estimated blood loss (272.4 +/- 249.9 mL vs 174.8 +/- 140.8 mL; P <.001), hospital length of stay (10.15 +/- 4.85 days vs 7.05 +/- 5.14; P <.001), and overall complication rate (35.8% vs 22.4%; P =.015) were significantly less for revision procedures. Revision of more than one site on the graft resulted in longer operation time (P =.003) and estimated blood loss (P <.001), but similar complication rates (P = NS), compared with revision at only one site. Revisions that involved only the graft resulted in decreased hospital length of stay compared with revisions involving extension to native inflow or outflow vessels (P <.02). Return to preoperative ambulatory status at discharge was 71% after initial operation, and was 92% after revision (P <.001). Return to independent living at discharge was 66% after the initial operation, and was 80% after revision (P <.01). CONCLUSIONS: Operative revisions were better tolerated than initial vein graft procedures, but are still major procedures. Hospital length of stay is longer for patients undergoing proximal or distal extension of the graft to native vessels and in patients who are not ambulatory and living independently at discharge. Patients undergoing vein graft revision should be counseled about potential morbidity.

Risk factors for autogenous infrainguinal bypass occlusion in patients with prosthetic inflow grafts.

OBJECTIVE: In patients with prosthetic inflow (PI) grafts the proximal anastomosis of autogenous infrainguinal bypass (AIB) can be placed on the PI or on a distal native vessel in the groin. This study was performed to determine the effect of placement of an AIB proximal anastomotic site in a patient with ipsilateral PI. METHODS: Patients undergoing AIB and PI between January 1990 and July 2002 were included in the study. They were classified into two groups on the basis of location of the proximal anastomosis. In group 1 the AIB proximal anastomosis was placed on the PI in the groin, whereas in group 2 the AIB proximal anastomosis was placed on a distal native groin artery. Patency, limb salvage, and patient survival in the two groups were calculated with the Kaplan-Meier method. The Cox proportional hazards model was used to determine independent risk factors affecting AIB patency. RESULTS: Two hundred twenty-nine patients underwent AIB and PI. In group 1, 23 AIBs became thrombosed concurrent with 26 PI occlusions, and in group 2, 7 AIBs became thrombosed concurrent with 36 PI occlusions (P <.001). Five-year assisted primary patency, limb salvage, and patient survival in groups 1 and 2 were 50% and 75% (P <.001, log-rank test), 78% and 90% (P =.005, log-rank test), and 56% and 69% (P = NS, log-rank test), respectively. Factors independently associated with AIB occlusion are hypertension (hazard ratio [HR], 3.41; 95% confidence interval [CI], 1.65-7.05; P =.001), postoperative warfarin sodium therapy (HR, 1.86; 95% CI, 1.07-3.23; P =.03), continued smoking (HR, 1.72; 95% CI, 0.93-3.18; P =.08), AIB arising from PI (HR, 2.38; 95% CI, 1.35-4.18; P =.003), and PI occlusion (HR, 3.70; 95% CI, 2.15-6.36; P <.001). CONCLUSION: A proximal AIB anastomosis located directly on the PI is an independent risk factor for decreased AIB patency of equal or greater importance than current smoking, hypertension, or PI occlusion. The proximal anastomosis of an AIB in a patient with an ipsilateral PI should be placed on a distal native artery.

Long-term outcome of revised lower-extremity bypass grafts.

PURPOSE: Reversed lower-extremity vein grafts (LEVGs) frequently require operative revisions to maintain patency. Identifying grafts that are at risk, however, requires an intensive duplex scanning-based surveillance program. Excellent 5-year graft patency and limb-salvage rates have previously been reported in patients undergoing graft revisions, but results beyond 5 years are essentially unknown, a factor that is of importance in an increasingly aging population. This study was performed to determine the results of surgical revisions of LEVGs after a follow-up as long as 10 years. METHODS: All patients undergoing placement of a LEVG were observed in a program of duplex scanning-based surveillance as long as the patient remained a candidate for graft revision. Grafts were considered for revision on the basis of the presence of focal areas of increased velocity, a prestenotic to intrastenotic velocity ratio more than 3.0, or uniformly low velocities throughout the graft. All lesions were confirmed with preoperative arteriography before revision. Assisted primary patency, limb-salvage, and survival rates were determined by means of Kaplan-Meier analysis in all patients who underwent LEVG revision from January 1990 to December 2000. RESULTS: A total of 1498 LEVG procedures were performed during the study period. A total of 330 surgical graft revisions were performed on 259 extremities in 245 patients. The median follow-up period was 38 months. The assisted primary patency rate of all grafts, the limb-salvage rate for patients undergoing surgery for limb-salvage indications, and the survival rate of all patients were 87.4%, 88.7%, and 72.4%, respectively, 5 years after the original bypass grafting procedure, 85.7%, 83.4%, and 67.8%, respectively, 7 years after the original bypass grafting procedure, and 80.4%, 75.4%, and 53.4%, respectively, 10 years after the original bypass grafting procedure. A total of 180 revisions (55%) were performed during the first year, 110 (33%) between the first year and the fifth year, and 40 revisions (12%) were performed on grafts older than 5 years. LEVGs revised within the first year after bypass grafting had lesions within the graft in 78%, in the native arterial inflow in 10%, and in the native arterial outflow in 12%. This differed significantly from the location of lesions in revisions performed between 1 and 5 years and after 5 years (graft, 63% and 62%; inflow, 20% and 19%; outflow, 17% and 19%; P >.05, Chi-square). CONCLUSION: Excellent assisted primary patency and limb-salvage rates can be achieved for as long as 10 years in LEVGs that require revision, with only a 7% drop in overall patency and limb-salvage rates between the fifth and 10th years. Although most revisions were required within the first year, 34% were performed between the first year and the fifth year, and 11% after 5 years. These data support the growing body of evidence that favors an aggressive regimen of duplex scanning surveillance of LEVGs for the life of the graft. Revised grafts have excellent patency through 10 years.

Neointimal hyperplasia in balloon-injured rat carotid arteries: the influence of hyperhomocysteinemia.

PURPOSE: Hyperhomocyst(e)inemia (hH[e]) is a risk factor for atherosclerosis. Neointimal hyperplasia (NH) after vessel injury can contribute to atherosclerosis. In this study, we investigated the effects of hH(e) on NH formation after arterial balloon injury in rats. METHODS: Lewis rats that were given a hH(e)-inducing (high methionine, low folate) or normal diet for 150 days underwent common carotid artery (CCA) balloon injury. Two and 4 weeks after injury, CCAs were formalin perfusion-fixed, sectioned, and stained for elastin. Neointimal index (NI, percent lumen occlusion) and neointima (N) and media (M) area were measured by using computer-interfaced microscopy. RESULTS: Plasma homocyst(e)ine (H[e]) levels were elevated in rats given the study diet compared with rats given the normal diet at days 40 and 90 (69 +/- 8 and 73 +/- 9 micromol/L vs 4 +/- 0.4 and 4 +/- 0.6 micromol/L, P <.001). After balloon injury, the CCA NI and N/M ratio, but not the M area, were increased by hH(e) compared with normal plasma H(e) (2 weeks [n = 6,7]: NI = 7.3 +/- 1.7 vs 2.9 +/- 0.7, P =.002, and N/M = 0.31 +/- 0.08 vs 0.08 +/- 0.02, P <.001; 4 weeks [n = 4,7]: NI = 13.1 +/- 2.2 vs 6.3 +/- 1.3, P =.002, and N/M = 0.36 +/- 0.08 vs 0.17 +/- 0.03, P <.001). CONCLUSION: hH(e) accelerates NH in a rat CCA balloon-injury model. The effect of hH(e) on NH may contribute to increased atherosclerosis in humans with hH(e).

Choice of autogenous conduit for lower extremity vein graft revisions.

BACKGROUND: Surgical revision to repair stenosis is necessary in about 20% of lower extremity vein grafts (LEVGs). Alternate conduit, especially arm vein, is often necessary to achieve a policy of all-autogenous revisions. Although basilic vein harvest necessitates deep exposure in proximity to major nerves, it typically uses a large vein unaffected by prior intravenous lines and as such appears ideally suited for revisions in which a segmental interposition conduit is needed for revision within the graft or for extension to a more proximal inflow or distal outflow site. In this report, we describe our experience with the use of the basilic vein for LEVG revisions compared with other sources of autogenous conduit. METHODS: All patients who underwent LEVG were placed in a duplex scan surveillance program. LEVGs that developed a focal area of increased velocity or uniformly low velocities throughout the graft with appropriate lesions confirmed with angiography were candidates for revision. All patients who underwent graft revision with basilic vein segments from January 1, 1990, to September 1, 2001, were identified, and their courses were reviewed for subsequent adverse events (further revision or occlusion) and complications of harvest. These revisions were compared with revisions in which cephalic and saphenous vein were used. RESULTS: One hundred thirty basilic veins were used to revise 122 LEVGs. The mean follow-up period after revision was 28 +/- 27 months. Ninety-three grafts (71%) remained patent with no further revision, and 37 grafts (29%) either needed additional revisions (22 grafts) or were occluded (15 grafts). Only four of these adverse events (11%) were directly attributed to the basilic vein segment. Ten of 43 grafts revised with cephalic vein (23%) were either revised or occluded, of which three were related to the cephalic vein segment (P = not significant, compared with basilic vein). Twenty-four of 81 grafts revised with saphenous vein (30%) were either revised or occluded, of which 11 were attributed to the saphenous vein segment (P <.01, compared with basilic vein). Two patients (1.5%) had complications from basilic vein harvest (one hematoma, one arterial injury). No neurologic injuries resulted from basilic vein harvest. CONCLUSION: The basilic vein is a reliable and durable conduit when used to segmentally revise LEVGs. Stenoses rarely occur within interposed basilic vein segments, and excellent freedom from subsequent revision or occlusion is possible. We conclude the basilic vein can be safely harvested with minimal complications and is ideally suited for use as a short segment interposition graft for LEVG revision.