Shifting paradigms in the treatment of lower extremity vascular disease: a report of 1000 percutaneous interventions

OBJECTIVES

Catheter-based revascularization has emerged as an alternative to surgical bypass for lower extremity vascular disease and is a frequently used tool in the armamentarium of the vascular surgeon. In this study we report contemporary outcomes of 1000 percutaneous infra-inguinal interventions performed by a single vascular surgery division.

METHODS

We evaluated a prospectively maintained database of 1000 consecutive percutaneous infra-inguinal interventions between 2001 and 2006 performed for claudication (46.3%) or limb-threatening ischemia (52.7%; rest pain in 27.7% and tissue loss in 72.3%). Treatments included angioplasty with or without stenting, laser angioplasty, and atherectomy of the femoral, popliteal, and tibial vessels.

RESULTS

Mean age was 71.4 years and 57.3% were male; comorbidities included hypertension (84%), coronary artery disease (51%), diabetes (58%), tobacco use (52%), and chronic renal insufficiency (39%). Overall 30-day mortality was 0.5%. Two-year primary and secondary patencies and rate of amputation were 62.4%, 79.3%, and 0.5%, respectively, for patients with claudication. Two-year primary and secondary patencies and limb salvage rates were 37.4%, 55.4%, and 79.3% for patients with limb-threatening ischemia. By multivariable Cox PH modeling, limb-threat as procedural indication (P < 0.0001), diabetes (P = 0.003), hypercholesterolemia (P = 0.001), coronary artery disease (P = 0.047), and Transatlantic Inter-Society Consensus D lesion complexity (P = 0.050) were independent predictors of recurrent disease. For patients that developed recurrent disease, 7.5% required no further intervention, 60.3% underwent successful percutaneous reintervention, 11.7% underwent bypass and 20.5% underwent amputation. Patency rates were identical for the initial procedure and subsequent reinterventions (P = 0.97).

CONCLUSION

Percutaneous therapy for peripheral vascular disease is associated with minimal mortality and can achieve 2-year secondary patency rates of nearly 80% in patients with claudication. Although patency is diminished in patients with limb-threat, limb-salvage rates remain reasonable at close to 80% at 2 years. Percutaneous infra-inguinal revascularization carries a low risk of morbidity and mortality, and should be considered first-line therapy in patients with chronic lower extremity ischemia.

Abdominal aortic aneurysm in women: Prevalence, risk factors, and implications for screening

OBJECTIVE

Accurate data regarding the prevalence and associated risk factors for aneurysmal disease is essential when determining the appropriateness of screening for abdominal aortic aneurysms (AAA). Although women are poorly represented in most large studies of AAA prevalence, the US Preventative Services Task Force recently recommended against primary screening for AAA in women. The purpose of this analysis was to define the prevalence and risk factors associated with the development of AAA in women.

METHODS

A free duplex ultrasound screening was offered to men and women with cardiovascular risk factors or a family history of AAA. Patients were recruited through advertising at local screening centers and screenings were performed between 2004 and 2006. Demographic information and cardiovascular and aneurysmal disease risk factors were obtained for each patient through a questionnaire. A total of 17,540 subjects were screened for AAA, including 10,012 women (mean age 69.6 years) and 7528 men (mean age 70.0 years). Univariate and multivariable logistic regression analysis was performed on the subset of women that were screened to determine risk factors for and prevalence of AAA.

RESULTS

Seventy-four aneurysms were detected in women (including four aneurysms >5 cm diameter and 70 aneurysms 3 to 5 cm diameter) while 291 were detected in men, resulting in prevalence rates of 0.7% and 3.9%, respectively. Increasing age (odds ratio [OR]= 4.57, 95% confidence interval [CI] 1.98 to 10.54, P < .0001), history of tobacco use (OR = 3.29, 95% CI 1.86 to 5.80, P < .0001), and cardiovascular disease (OR= 3.57, 95% CI 2.19 to 5.84, P < .0001) were independently associated with AAA in women on univariate and multivariable analysis. Women with multiple atherosclerotic risk factors were more commonly found to have AAAs and had a prevalence rate of AAA as high as 6.4%.

CONCLUSION

Although the medical literature suggests a low prevalence rate of AAA in women in the general population, specific risk factors are associated with the development of AAA, and subgroups of women can be identified that are at a substantially increased risk of aneurysmal disease. In particular, elevated rates of AAA were found among women of advanced age (> or =65 years) with a history of smoking or heart disease. These data support the notion that women with such risk factors should be considered for AAA screening.

Simulation improves resident performance in catheter-based intervention: results of a randomized, controlled study

OBJECTIVES

Surgical simulation has been shown to enhance the training of general surgery residents. Since catheter-based techniques have become an important part of the vascular surgeon's armamentarium, we explored whether simulation might impact the acquisition of catheter skills by surgical residents.

METHODS

Twenty general surgery residents received didactic training in the techniques of catheter intervention. Residents were then randomized with 10 receiving additional training with the Procedicus, computer-based, haptic simulator. All 20 residents then participated in 2 consecutive mentored catheter-based interventions for lower extremity occlusive disease in an OR/angiography suite. Resident performance was graded by attending surgeons blinded to the resident's training status, using 18 procedural steps as well as a global rating scale.

RESULTS

There were no differences between the 2 resident groups with regard to demographics or scores on a visuospatial test administered at study outset. Overall, residents exposed to simulation scored higher than controls during the first angio/OR intervention: procedural steps (simulation/control) (50 +/- 6 vs. 33 +/- 9, P = 0.0015); global rating scale (30 +/- 7 vs. 19 +/- 5, P = 0.0052). The advantage provided by simulator training persisted with the second intervention (53 +/- 6 vs. 36 +/- 7, P = 0.0006); global rating scale (33 +/- 6 vs. 21 +/- 6, P = 0.0015). Moreover, simulation training, particularly for the second intervention, led to enhancement in almost all of the individual measures of performance.

CONCLUSION

Simulation is a valid tool for instructing surgical residents and fellows in basic endovascular techniques and should be incorporated into surgical training programs. Moreover, simulators may also benefit the large number of vascular surgeons who seek retraining in catheter-based intervention.

Safety and efficacy of carotid angioplasty and stenting in high-risk patients

Performance of carotid endarterectomy (CEA) may be associated with an increased risk in patients with significant comorbid medical conditions, neck irradiation, or previous CEA. This study compared the results of CEA with carotid angioplasty and stenting (CAS) in high-risk patients treated for carotid stenosis. Five hundred forty-five patients who underwent CEA and 148 patients who underwent CAS were evaluated. For patients undergoing CEA, general anesthesia was used in 91 per cent, electroencephalographic monitoring was used in 63 per cent, and shunting was performed in 19.8 per cent. Cerebral protection devices were used in 145/148 of CAS cases, and self-expanding stents were used in all cases. Evaluated end points included major cardiovascular events, and a composite of death, stroke, or myocardial infarction for the duration of the follow-up. Mean follow-up was 18 months for CAS and 23 months for CEA. Significant differences were present in patient age (CAS, 75 +/- 11.0 years vs CEA, 71 +/- 9 years, P = 0.012), however, there were no significant differences (P = NS) in gender or smoking history. The mean modified Goldman Score was significantly higher for CAS (21.1 +/- 14.8 [95% confidence interval = 18, 24]) than for CEA (6.3 +/- 6.8 [95% confidence interval = 5.7, 6.9]; P = 0.0001) patients. The incidence of periprocedural complications did not vary significantly between patients treated with CAS (CVA, 1.4%; myocardial infarction [MI], 1.4%; death, 0.7%; CVA/MI/death, 3.4%) compared with CEA (CVA, 1.8%; MI, 1.1%; death, 0.4%; CVA/MI/death, 4.0%). CAS is equivalent to CEA in safety and efficacy, even when performed in patients who may be at increased surgical risk.

Analysis of Outcomes Following Failed Endovascular Treatment of Chronic Limb Ischemia

Despite recent studies highlighting the advantages of endoluminal intervention in the management of chronic limb ischemia (CLI), outcomes following failed peripheral angioplasty remain less well described. We present a retrospective analysis of failed transluminal infrainguinal percutaneous arterial angioplasty with or without stenting (PTA/S) in patients with CLI. A database of patients undergoing infrainguinal PTA/S between 2002 and 2005 was maintained. Patients underwent duplex scanning follow-up at 2 weeks, 3 months, and every 6 months after the intervention. Angiograms were reviewed in all cases to assess lesion characteristics. Results were standardized to current Transatlantic Inter-Society Consensus (TASC) criteria. Kaplan-Meier survival analyses were performed to assess time-dependent outcomes. In total, our analysis involved 246 patients who underwent treatment for CLI using PTA/S. Eighteen percent of procedures (n = 46) were considered an intervention failure secondary to restenosis by duplex ultrasound, returning clinical symptoms, a nonhealing foot lesion, or the absence of a prior palpable pulse. Indications for the original procedure in patients whose PTA/S failed were tissue loss in 44%, claudication in 44%, and rest pain in 12%, while TASC lesion grades were A (0%), B (18%), C (18%), and D (64%). Of patients failing PTA/S, 4% failed in the first 30 days, 78% failed between 1 and 18 months, while 18% failed following 18 months, with a mean time to failure of 8.7 months. Also, 82% of PTA/S failures were candidates for a second endovascular procedure, 11% were suitable for only traditional open bypass, and 4% demonstrated progression of disease necessitating amputation. Of patients undergoing a second endovascular procedure, limb salvage rates were 86% at 12-month follow-up and there was a single periprocedural mortality and complication rate of 6.6%. Of patients requiring open surgical bypass after failed PTA/S, 20% (n = 1) required a major amputation and there were no mortalities. Failure of endoluminal therapy for treatment of lower extremity arterial occlusive disease is amenable to subsequent endovascular intervention for limb salvage with limited morbidity and mortality.

Percutaneous endovascular treatment of acute sequential systemic emboli

A 65-year-old woman was evaluated for acute right lower-extremity ischemia secondary to embolization from atrial fibrillation and subtherapeutic anticoagulation. Her symptoms quickly evolved in a dynamic fashion to involve multiple vascular beds, including a transient ischemic attack, abdominal pain secondary to mesenteric ischemia, and contralateral lower-extremity ischemia. Synchronous emboli were treated by using mechanical and pharmacologic thrombolysis via an endovascular approach under local anesthesia. This intervention allows prompt evaluation of multiple vascular beds with good short-term outcomes and minimal morbidity.

Analysis of anatomic factors and age in patients undergoing carotid angioplasty and stenting

Recent data suggest that patient age >80 years may be associated with increased risk of periprocedural complications from carotid angioplasty and stenting (CAS). In this study, we analyzed anatomic risk factors in patients undergoing CAS based on age >80 or <80 years. Our hypothesis was that patients >80 would have more challenging anatomy. Between February 2003 and August 2004, 82 patients underwent CAS. Images for 57 lesions were available for review. Eighteen patients were > or =80 years old and 39 were <80. Cerebral protection devices, including EPI Filterwire, Percusurge, Accunet, and Angioguard, were used in all but two cases; and self-expanding stents (Wallstent, NexStent, Acculink, Precise) were placed in all. Arterial anatomic characteristics were assigned a score based on complexity and associated procedural risk. Characteristics evaluated using angiographic images were aortic arch elongation classification, arch calcification, common carotid/innominate stenosis, common carotid tortuosity, internal carotid tortuosity, index lesion length, index lesion calcification, and index lesion stenosis. Statistical analysis was performed using Fisher's exact test. CAS was successfully completed in 98% of cases. The two patients in whom we could not perform CAS were 79 and 83 years old. The anatomic characteristics that were statistically significantly more complex/severe in patients > or =80 were arch calcification (p = 0.045), common carotid/innominate stenosis (p = 0.023), common carotid tortuosity (p = 0.049), and internal carotid tortuosity (p = 0.032). There was no statistically significant difference in arch elongation classification, lesion length, lesion calcification, or stenosis severity (p = nonsignificant). Overall, patients > or =80 years had an increased incidence of complex anatomic risk factors compared to younger patients (p < 0.001). Cerebrovascular accident without residual deficits occurred in two patients; both were >80 years old. Complex arterial anatomy is more often present in patients >80 years and may explain the increased complication rates associated with CAS. Pre- or intraoperative consideration of these characteristics may help provide better risk assessment in candidates for CAS.

Successful percutaneous treatment of gluteal claudication secondary to isolated bilateral hypogastric stenoses

We report an unusual case of bilateral buttock claudication at ambulation of less than two blocks in a 57-year-old man with normal lower-extremity segmental pressure on noninvasive exercise testing. He was found to have bilateral high-grade internal iliac artery stenoses on arteriography. Both sides were successfully treated in a staged fashion via a contralateral approach with percutaneous transluminal angioplasty and a balloon-expandable stent, with complete symptom resolution. A clinical vascular examination with normal findings of the common iliac, external iliac, and common and superficial femoral arteries eliminates significant vascular obstruction as a cause of claudication. However, internal iliac occlusive disease may be suspected when symptoms are limited to the gluteal musculature and other causes are eliminated. Percutaneous interventions can be of diagnostic and therapeutic value.

Plaque Excision for the Treatment of Infrainguinal Arterial Occlusive Disease

Lower extremity peripheral vascular disease has a broad spectrum of presentations, ranging from intermittent claudication, rest pain, to limb threatening tissue loss and gangrene. Over the last 10 to 15 years, short focal stenoses or occlusions have been treated using endovascular techniques, but conventional angioplasty and stenting is limited by high restenosis rates especially in longer lesions. Moreover, multilevel, complex disease is still generally considered best managed by surgical intervention. However, with the improvements in atherectomy technology, namely plaque excision and laser plaque ablation, the full spectrum of arterial occlusive lesions may now be addressed by percutaneous means with excellent limb salvage rates. Excisional atherectomy is currently exemplified by the SilverHawk Plaque Excision System, which is available in four sizes for the treatment of all infrainguinal vessels. As the apparatus is advanced, the rotational cutting blade excises a ribbon of plaque that is concurrently collected into a nosecone. Multiple passes are made, during which the blade is directed sequentially toward all quadrants of the vessel lumen. The stenotic lesion is grossly debulked by this technique with the proposed advantage of avoiding the arterial wall barotrauma that hampers the durability of angioplasty and stenting.

Integrating surgery and radiology in one suite: A multicenter study

PURPOSE

The study was performed to evaluate the performance of digital fixed-mounted angiographic C-arm systems in the operating room as used by surgeons, cardiologists, and interventional radiologists.

METHODS

An observational study in the operating room was performed, along with a structured questionnaire and semi-structured interviews. Twenty interventions were observed at 5 sites. Workflow was analyzed.

RESULTS

Integration of high-end angiographic imaging equipment in the operating room enables image-guided surgery with high-quality images, on-table quality assessment of surgical procedures, and "one-stop shopping" procedures. Integrated suites were run by surgery as well as radiology departments, and are used for a variety of procedures, including vascular, cardiothoracic, open surgical, percutaneous, and combined procedures. Operation of the angiographic system and its user interface design were not considered ideal for operating room use. Limited patient accessibility was observed, sometimes leading to uncomfortable positions for the operating physicians. Certain procedures, such as tibial artery surgery, were difficult to perform, owing to lack of accessories. Patient transfer was considered inadequate. Cleaning of the system was rated as poor. Operating room use puts an even higher demand on reliability of the system.

CONCLUSION

Integration of digital angiographic systems into operating rooms has produced opportunities for new treatments and offers a superior solution for interdisciplinary work among surgeons, cardiologists, and radiologists. However, the context of use differs radically from that in the traditional radiologic examination room; the environment, users, and procedures are all different. Integration of imaging methods into the operating room can be more successful if special operating room conditions are taken into account by medical systems manufacturers.

Degree of carotid plaque calcification in relation to symptomatic outcome and plaque inflammation

OBJECTIVE

We undertook this study to quantitate differences in the degree of calcification between symptomatic and asymptomatic plaques removed at carotid endarterectomy (CEA) and to determine associated extent of plaque macrophage infiltration, a histopathologic feature of plaque instability.

METHODS

CEA plaques (n = 48) were imaged at 1.25-mm intervals with spiral computed tomography (CT; 10-15 images per plaque). Indications for CEA were transient ischemic attack (n = 16), stroke (n = 5), amaurosis (n = 4), and critical asymptomatic stenosis (n = 23). The percent area calcification for each plaque was determined in spiral CT serial sections and averaged for each plaque. In 31 of 48 plaques macrophage infiltration was quantitated in corresponding histologic sections with immunohistochemical techniques.

RESULTS

The mean (+/- SD) age of patients with symptomatic and asymptomatic plaques was 66 +/- 7 years vs 71 +/- 7 years, respectively, and degree of stenosis was 76% versus 82%, respectively (P =.05). Atherosclerosis risk factors were similar between groups. Percent plaque area calcification was twofold greater in asymptomatic versus symptomatic plaques (48% +/- 19% vs 24% +/- 20%, respectively; P <.05). At receiver operating characteristic curve analysis, 80% of symptomatic plaques were below and 87% of asymptomatic plaques were above a cutoff point of 30% plaque area calcification. Macrophage burden was greater in the symptomatic plaques than in the asymptomatic plaques (52% vs 23%; P <.03). A strong inverse relationship between the degree of plaque calcification and macrophage infiltration was found in critical carotid stenoses (r = -0.87; P <.001).

CONCLUSIONS

Symptomatic plaques are less calcified and more inflamed than asymptomatic plaques. Regardless of clinical outcome, a strong inverse correlation was found between the extent of carotid plaque calcification and the intensity of plaque fibrous cap inflammation as determined by the degree of macrophage infiltration. Carotid plaque calcification is associated with plaque stability, and is a potential spiral CT in vivo quantitative marker for cerebrovascular ischemic event risk.

Limb salvage after infrainguinal bypass graft failure

OBJECTIVE

The purpose of this study was to examine the outcome of patients in whom an infrainguinal bypass graft failed.

METHODS

This was a retrospective analysis of consecutive patients undergoing infrainguinal bypass grafting in a single institution over 8 years.

RESULTS

Six hundred thirty-one infrainguinal bypass grafts were placed in 578 limbs in 503 patients during the study period. The indication for surgery was limb-threatening ischemia in 533 patients (85%); nonautologous conduits were used in 259 patients (41%), and 144 (23%) were repeat operations. After a mean follow-up of 28 +/- 1 months (median, 23 months; range, 0-99 months), 167 grafts (26%) had failed secondarily. The rate of limb salvage in patients with graft failure was poor, only 50% +/- 5% at 2 years after failure. The 2-year limb salvage rate depended on the initial indication for bypass grafting: 100% in patients with claudication (n = 16), 55% +/- 8% in patients with rest pain (n = 49), and 34% +/- 6% in patients with tissue loss (n = 73; P <.001). The prospect for limb salvage also depended on the duration that the graft remained patent. Early graft failure (<30 days; n = 25) carried a poor prognosis, with 2-year limb salvage of only 25% +/- 10%; limb salvage was 53% +/- 5% after intermediate graft failure (<2 years, n = 110) and 79% +/- 10% after late failure (>2 years, n = 15; P =.04). Multivariate analysis revealed shorter patency interval before failure (P =.006), use of warfarin sodium (Coumadin) postoperatively (P =.006), and infrapopliteal distal anastomosis (P =.01) as significant predictors for ultimate limb loss.

CONCLUSION

The overall prognosis for limb salvage in patients with failed infrainguinal bypass grafts is poor, particularly in patients with grafts placed because of tissue loss and those with early graft failure.

Redo infrainguinal bypass: factors predicting patency and limb salvage

The increased complexity of redo infrainguinal bypass procedures can result in prolonged operative time and increased morbidity. This review was undertaken to compare outcomes from primary and redo bypass procedures and to identify factors predictive of graft failure and limb loss after redo bypass. All infrainguinal bypasses ( n = 468) from 1995 to 1999 were reviewed. A total of 367 primary bypasses in 317 patients were compared to 101 redo grafts in 84 patients with previously failed bypasses. Risk factors and types of procedures were compared using Student's t-test and the chi(2) test. Patency and limb salvage were compared using life-table analysis. Patients requiring redo bypasses were less likely to have diabetes and end-stage renal disease. Two-year patency (66 +/- 4% primary vs. 55 +/- 7% redo, p = 0.13) and limb salvage (75 +/- 3% primary vs. 72 +/- 6% secondary, p = 0.43) were comparable between primary and redo bypass groups. Female gender was predictive of redo graft failure (2-year patency 73 +/- 8% male vs. 39 +/- 9% female, p = 0.01). Clinical indications that predicted failure of a redo bypass included thrombosis of an autologous graft (1-year patency 71 +/- 7% previous prosthetic vs. 49 +/- 10% previous autologous, p = 0.004), thrombosis of an infrageniculate bypass (2-year patency 65 +/- 10% suprageniculate vs. 46 +/- 9% infrageniculate, p = 0.044), and a limb salvage indication for the primary operation (2-year patency 86 +/- 9% claudication vs. 44 +/- 8% limb salvage, p = 0.008). When a primary bypass fails despite the use of optimal conduit (autologous vein) and an infrageniculate target vessel, the redo bypass has a higher risk of failure, particularly in female patients. Nonetheless, patency and limb salvage rates justify an attempt at revascularization after failed primary bypass.

Current status of intravascular stents as delivery devices to prevent restenosis

The acute technical success of percutaneous transluminal angioplasty (PTA) has been improved with the use of intravascular stents. However, stent placement has led to the development of an increased myointimal hyperplastic response leading to late reduction in vessel lumen. Restenosis (> or =50% reduction in reference lumen diameter) rates for coronary angioplasty and stenting are reported between 20% and 50% at 1 year. Several studies are currently evaluating novel delivery of antiproliferative agents to prevent neointimal hyperplasia. The authors review the mechanism of neointimal hyperplasia as it relates to stent placement and discuss recent and ongoing trials evaluating intravascular brachytherapy and drug-eluting stent technology in the inhibition of restenotic lesions.

Long-term outcome of infrainguinal bypass grafting in patients with serologically proven hypercoagulability

OBJECTIVE

The purpose of this study was to test the hypothesis that the long-term outcome of infrainguinal bypass grafting in patients with congenital or acquired hypercoagulability is inferior to the results in patients without documented clotting disorders.

METHODS

The study was a retrospective analysis of consecutive patients from January 1994 to January 2001.

RESULTS

Five hundred eighty-two infrainguinal bypass grafts were created in 456 patients. Indication for surgery was limb-threatening ischemia in 84%; prosthetic conduits were implanted in 38%. Seventy-four grafts were created in 57 patients with one or more serologically proven hypercoagulable states, including heparin-induced platelet aggregation (n = 37), anticardiolipin antibodies (n = 11), lupus anticoagulant (n = 8), protein C or S deficiency (n = 7), antithrombin III deficiency (n = 3), and factor V Leiden mutation (n = 1). Patients with hypercoagulability were younger (63 +/- 2 years versus 69 +/- 1 years; P =.007), more likely to have undergone prior revascularization attempts (38% versus 21%; P =.003), and more likely to have chronic anticoagulation therapy after surgery (46% versus 25%; P =.001). After 5 years (median follow-up, 19 months), patients with hypercoagulability had poorer primary patency (28% +/- 7% versus 35% +/- 5%; P =.004), primary assisted patency (37% +/- 7% versus 45% +/- 6%; P =.0001), secondary patency (41% +/- 7% versus 53% +/- 6%; P =.0001), limb salvage (55% +/- 8% versus 67% +/- 6%; P =.009), and survival (61% +/- 8% versus 74% +/- 4%; P =.02) rates. Multivariate analysis identified only prosthetic conduit choice (P =.0001), hypercoagulability (P =.0003), and limb salvage indication (P =.01) as independent predictors of graft failure.

CONCLUSION

Patients with serologically proven hypercoagulability have inferior long-term patency, limb salvage, and survival rates after infrainguinal bypass. The high prevalence rate (13%) of diverse hypercoagulable states in this patient population supports serologic screening, especially in referral practices.

Long-term results of infrageniculate bypass grafting using all-autogenous composite vein

Infrageniculate (below-knee) bypass using all-autogenous composite vein requires multiple incisions, venovenostomy, and prolonged operating time. The purpose of this study was to evaluate the long-term results of this procedure, with comparisons to grafts created from single-segment greater saphenous vein (GSV) or polytetrafluoroethylene (PTFE). A total of 362 consecutive infrainguinal bypass grafts with infrageniculate distal target arteries were created in 283 patients in a single institution between January 1995 and December 2000. Comorbid conditions were common, including diabetes (58%), coronary artery disease (56%), prior lower extremity revascularization (41%), end-stage renal failure (20%), and prior coronary artery bypass grafting (18%). The indication for revascularization was limb salvage in 93% of cases. The grafts were constructed from single segments of GSV (n = 239), from two or more vein segments resulting in an all-autogenous composite graft (n = 61), or from PTFE (n = 62). All-autogenous composite grafts were constructed using segments of ipsilateral or contralateral GSV (n = 49), upper extremity vein (n = 23), superficial femoral vein (n = 7), or lesser saphenous vein (n = 5). Infrageniculate all-autogenous composite vein grafts exhibited similar long-term results to those of GSV grafts, and far superior results to those of PTFE grafts. For patients with available autogenous segments, the all-autogenous composite vein graft is the conduit of choice.

Angiographic access site complications in the era of arterial closure devices

Coronary and peripheral angiography is associated with a low but significant risk of access site complications. While percutaneous devices have been shown to permit more rapid puncture site closure, previous reports have suggested the incidence and severity of complications associated with these devices are greater than with manual compression. This study compares access site complications with and without closure devices in the current era. The authors conducted a retrospective review of patients with access site complications after coronary or peripheral angiography between 1998 and 2000. Forty-five complications requiring vascular surgical consultation were identified in the 4,800 procedures performed during this time period. Fourteen complications occurred in 1,536 procedures (0.9%) using suture-mediated or collagen devices and 31 occurred in 3,264 procedures without devices (0.9%). The types of procedures and catheter sizes (mean 7 Fr) used were not different in the 2 groups. Other than complications involving a retained device, there was no difference between device and manual compression with respect to incidence or types of complication,requirement for operation, type of operation, or outcome. Access site complications identified included pseudoaneurysm (n = 22; 49%), bleeding or hematoma (n = 8;18%), arteriovenous fistula (n=5;11%), arterial thrombosis (n = 4;9%), infection (n = 4;9%), and retained device (n = 2;4%). Twenty-four patients (71% vs 45%; p = NS) required operative intervention including pseudoaneurysm repair, hematoma drainage, and thrombectomy. Eleven patients (26%) underwent successful ultra-sound-guided pseudoaneurysm compression and 9 patients (21%) required no intervention. These data demonstrate that closure devices facilitate arterial puncture site repair without an increase in access site complications. These devices can be safely utilized when rapid hemostasis is desired after coronary or peripheral angiography.

Routine early postoperative duplex scanning is unnecessary following uncomplicated carotid endarterectomy

Although early postoperative duplex scanning has become routine after carotid endarterectomy (CEA), it is unclear whether the results of these scans alter clinical management. The purpose of this study was to critically examine the usefulness of early postoperative duplex scans in evaluating the ipsilateral carotid artery (for technical perfection) as well as the contralateral carotid artery (for potential velocity changes after improvements in ipsilateral flow). Consecutive patients undergoing CEA between January 1995 and June 1999 in a tertiary hospital setting were studied. Patients underwent early postoperative duplex scanning according to the discretion of the operating surgeon and the availability of the patient. In 212 patients 236 CEAs were performed with selective use of patch closure (49%), intraluminal shunting (19%), and intraoperative completion imaging studies (14%). Neurologic complications included 3 transient ischemic attacks (TIAs) (1.3%), 3 nondisabling strokes (1.3%), and 3 disabling strokes (1.3%). There was 1 30-day death from myocardial infarction. Patients were followed up for a median of 18 months (range 0-72 months). Sixty-five percent of patients undergoing uncomplicated CEA (147/227) underwent early duplex surveillance within 6 months of operation. Unsuspected sonographic abnormalities were discovered in 8 patients (5%), including 7 cases of mild internal carotid artery (ICA) stenosis (>50% by velocity criteria) and 1 case of common carotid artery (CCA) stenosis (intimal flap). None of the patients with ICA stenosis developed symptoms or required operation at any time. The CCA intimal flap was electively repaired without complication. Postoperative changes in velocity in the contralateral ICA were found in 8/48 (17%) cases. There were 3 cases of increased velocity, upgrading 1 from 0-49% to 50-79% stenosis and upgrading 2 from 50-79% to 80-99% stenosis. The latter patients both underwent uneventful contralateral CEA. There were 6 cases of decreased velocity, resulting in downgrading of stenoses from 50-79% to 0-49% (n=5) or from 80-99% to 50-79% (n=1). Only the latter patient underwent contralateral CEA; the remainder have been followed up without intervention. Early scanning appeared to offer no clinical benefit; survival and neurologic outcome were the same in the 135 patients scanned within the first 6 months as in the 68 patients whose first postoperative scan occurred later (4-year neurologic event rate 0% in both groups; patient survival with early duplex 98 +/- 1.5%, without early duplex 96 +/- 2.6%; = NS). Early ipsilateral duplex abnormalities following CEA are infrequent in asymptomatic patients and, even if found, rarely alter management. Patients with bilateral stenosis being considered for contralateral CEA should undergo repeat duplex scanning after the first operation, because of the significant rate (19%) of contralateral velocity changes induced by ipsilateral CEA.

Conduit choice for above-knee femoropopliteal bypass grafting in patients with limb-threatening ischemia

Many surgeons consider PTFE to be the conduit of choice for above-knee femoropopliteal bypass grafting, since PTFE is relatively easy to implant and spares autogenous saphenous vein (ASV) for subsequent peripheral or coronary artery bypass grafting (CABG). This practice has recently been challenged, as some studies have suggested that ASV may exhibit superior patency in certain patient subgroups. The purpose of this retrospective study was to examine the contemporary outcome of above-knee femoropopliteal bypass grafting in patients with limb-threatening ischemia. Between January 1995 and December 2000, 159 above-knee femoropopliteal bypass grafts were created for limb-threatening ischemia (rest pain or tissue loss). There was a high incidence of comorbid illness, including open foot wounds at the time of operation (62%), hypertension (58%), coronary artery disease (53%), diabetes mellitus (36%), cerebrovascular disease (23%), prior contralateral bypass or amputation (21%), disadvantaged or "blind" outflow (19%), prior ipsilateral bypass (14%), prior CABG (11%) end-stage renal failure (7%). The use of PTFE predominated (n = 11), with a minority of grafts comprising single-segment ipsilateral or contralateral ASV (n = 18). Although the small number of patients undergoing ASV grafting limited the statistical power of comparison, our results suggest that above-knee ASV performs better than PTFE in patients with limb-threatening ischemia.

Long-term results justify autogenous infrainguinal bypass grafting in patients with end-stage renal failure

INTRODUCTION

Infrainguinal bypass grafting for limb-threatening ischemia in patients with end-stage renal disease is generally thought to be associated with increased operative risk and poor long-term outcome. This retrospective study was undertaken to examine the modern-era, long-term results of infrainguinal bypass grafting in dialysis-dependent patients.

METHODS

Over the past 5 years in a single institution, 425 lower extremities (368 consecutive patients) were revascularized for the indication of limb salvage. Sixty-four patients (82 limbs) were dialysis-dependent at the time of revascularization, and this group was analyzed separately. They exhibited statistically significant higher incidences of diabetes (83% vs 56%; P <.001), hypertension (91% vs 74%; P <.001), and more distal vascular disease, which required a greater proportion of proximal anastomoses at the popliteal level (24% vs 11%; P <.01) and distal anastomoses at the infrapopliteal level (75% vs 65%; P <.05).

RESULTS

Despite the higher prevalence of comorbid conditions and distal disease in patients with renal failure, their perioperative 30-day mortality rate remained low (4.9%) and was not significantly different from that in patients with functioning kidneys (2.9%; P = not significant). After a median follow-up of 11 months (range, 0-60 months), the 3-year autogenous conduit secondary graft patency in patients with renal failure was no different than in patients with functioning kidneys (67% +/- 9% vs 64% +/- 5%; P = not significant). Nonautogenous conduits in dialysis-dependent patients exhibited a significantly poorer outcome with only 27% +/- 12% remaining secondarily patent at 2 years. As expected, both limb salvage and patient survival were significantly less in patients with renal faiture, although both exceeded 50% at 3 years (limb salvage 59% +/- 8% vs 68% +/- 5%; P <.05; patient survival 60% +/- 8% vs 86% +/- 4%; P <.001). The often-quoted phenomenon of limb loss, despite a patent bypass graft, occurred infrequently in this study (n = 3 of 82 limbs).

CONCLUSION

Infrainguinal revascularization can be performed in dialysis-dependent patients with acceptable perioperative and long-term results, especially in patients in whom adequate autologous conduit is available.

Patency and limb salvage after infrainguinal bypass with severely compromised ("blind") outflow

HYPOTHESIS

Infrainguinal graft patency and limb salvage are adversely affected by severely compromised outflow.

DESIGN

Retrospective review of all infrainguinal bypass procedures performed at a single institution during a 5-year period.

SETTING

University teaching hospital.

PATIENTS

Two hundred seventy-four patients underwent infrainguinal bypass for limb salvage (351 grafts in 307 limbs).

INTERVENTIONS

All infrainguinal bypasses originated from a femoral artery. The distal anastomosis in 279 grafts was located in an artery with at least 1 patent outflow vessel with anatomically normal end-artery runoff (Society for Vascular Surgery/International Society for Cardiovascular Surgery ad hoc committee runoff score, 1-9). The distal anastomosis of 72 grafts was located in an artery with only collateral outflow ("blind bypass"; runoff score, 10).

MAIN OUTCOME MEASURES

Perioperative morbidity and mortality, primary-assisted and secondary graft patency, limb salvage, and survival.

RESULTS

All data are presented as mean +/- SEM. Patients undergoing blind bypass were older (age, 70 +/- 2 vs. 66 +/- 1 years; P <.05) and had a higher incidence of hypertension (90% vs 70%; P <.05) and end-stage renal disease (24% vs. 13%; P <.05). Comparing patients undergoing blind bypass to bypass with at least 1 patent outflow vessel, there were no differences in the use of nonautogenous conduits (50% vs 59%; P =.21) or postoperative warfarin (30% vs 32%; P =.69), or in perioperative mortality rates (2.7% vs 3.2%; P =.79). After a median follow-up of 13 months (range, 0-60 months), 2-year secondary graft patency for the entire group was 63% +/- 4%. The secondary patency rate of blind bypass grafts was no different from that of grafts with at least 1 patent outflow vessel (67% +/- 7% vs. 64% +/- 4%; P was not significant). However, the 2-year limb salvage rate in limbs with blind outflow was significantly worse than in limbs with at least 1 patent outflow vessel (67% +/- 7% vs. 76% +/- 3%; P =.04).

CONCLUSION

Acceptable long-term patency rates can be achieved in infrainguinal bypass grafts with blind outflow, although blind outflow remains a marker for subsequent limb loss in the chronically ischemic leg.

Angioplasty does not affect subsequent operative renal artery revascularization

BACKGROUND

Although increased application of percutaneous renal artery angioplasty and stenting has facilitated nonoperative renal revascularization, patient outcomes after failed angioplasty are not established.

METHODS

Renal artery revascularization was performed in 31 patients (38 arteries) from 1993 to 1999. Twenty patients underwent primary surgical repair, and 11 patients underwent secondary reconstruction after angioplasty (n = 7) or angioplasty and stenting (n = 4). Before operation, all patients had severe hypertension (blood pressure 166+/-5.2/92 +/- 2.7 mm Hg) that required an average of 3.0 +/- 0.2 medications for control. In addition, 12 patients (primary 45% vs secondary 27%; P = NS) had evidence of renal insufficiency (creatinine > or =1.7 mg/dL).

RESULTS

There was no difference between primary and secondary procedures in the length of hospital stay (12+/- 1.4 vs. 12+/-3.2 days; P = NS), major morbidity (10% vs. 18%; P = NS) or perioperative mortality (overall mortality 2 of 31; primary 5% vs secondary 9%; P = NS). The majority of patients demonstrated improvement or cure of hypertension (primary 94% vs secondary 90%; P = NS) and stable or decreased creatinine (primary 74% vs secondary 82%; P = not significant). Overall survival (mean follow-up 22+/-3.5 months) was 89%+/-5.7%.

CONCLUSIONS

Although this surgical series does not address the true outcomes of renal artery angioplasty, the results suggest that renal artery angioplasty does not prejudice subsequent surgical outcomes in patients who are carefully followed after angioplasty.

Estimating the contemporary in-hospital costs of carotid endarterectomy

Carotid endarterectomy (CEA) is the treatment of choice for symptomatic carotid stenosis and selective asymptomatic lesions. Alternative approaches have recently been championed under the guise of increased efficacy and decreased cost. The purpose of this study was to determine the results and in-hospital costs of CEA in a university hospital in the modern era. A retrospective chart review was undertaken for all patients undergoing CEA between January 1995 and December 1997. This corresponded to the implementation of a clinical path and extended efforts toward cost reduction. Patients undergoing combined CEA and cardiopulmonary bypass were excluded (n = 3). Cost was analyzed by the hospital Office of Program Planning using TSI (Transition Systems, Inc.) software. Direct costs are related to the utilization of clinical resources and are therefore manageable by clinicians (bed, room, supplies, nursing staff, OR staff, radiology, pharmacy, etc.). Total costs additionally include administration and overhead costs not directly chargeable to patient accounts. The results of this study showed that CEA can be safely performed with brief hospital stays and reasonable hospital costs. Results of alternative interventions for the treatment of carotid stenosis should be compared to these contemporary data.

Effective hemodynamic diameter: an intrinsic property of vein grafts with predictive value for patency

INTRODUCTION

Conduit size and quality are major determinants of the long-term success of infrainguinal autologous vein grafting. However, accurate measurement of the internal diameter of vein grafts is difficult given their variable wall thickness and taper. The purpose of this study was to define the "effective" internal diameter of a vein graft according to its hemodynamic properties and to determine its significance for graft patency.

METHODS

Sixty infrainguinal bypass grafts performed on 57 patients were evaluated intraoperatively. Proximal and distal graft pressure and blood flow (Q(meas)) were measured with fluid-filled catheter transduction and ultrasonic transit-time flowimetry, respectively, after unclamping. Waveforms were recorded digitally at 200 Hz under baseline conditions and after stimulation with 60 mg of papaverine. According to Fourier transformation of the measured pressure gradient (DeltaP), the Womersley solution for fluid flow in a straight rigid tube was used to calculate theoretical flow waveforms (Q(calc)) for a range of graft diameters. The theoretical waveforms were then compared with the measured flow waveforms and the best-fit diameter chosen as the "effective hemodynamic diameter" (EHD). Only grafts in which the correlation coefficient of Q(calc) versus Q(meas) was more than 0.90 were accepted (n = 47) to assure validity of the hemodynamic model. After a mean follow-up of 12.5 months (range, 0.1-43.9 months), patency was determined by the life table method. Hemodynamic and clinical variables were tabulated, and their effect on patency determined the use of univariate and multivariate Cox regression.

RESULTS

Mean EHD was 4.1 +/- 0.1 mm with a range of 2.5 to 5.7 mm. Administration of papaverine caused profound changes in DeltaP (+78% +/- 17%) and Q(meas) (+71% +/- 12%) as expected, but had no effect on EHD (+0.05% +/- 0.1%). Univariate regression identified five variables associated with decreased secondary patency (P <.10): low EHD, conduit source other than the greater saphenous vein, high baseline DeltaP(mean), female sex, and redo operation. Of these, only low EHD was significant after multivariate analysis (P =.03). Patency of small diameter grafts (EHD < 3.6 mm; n = 11) was compared with patency of larger grafts (EHD > 3.6 mm; n = 36) to test a frequently espoused clinical guideline. Grafts with an EHD less than 3.6 mm exhibited significantly lower secondary patency compared with larger grafts (P =.0001). The positive and negative predictive values for an EHD less than 3.6 mm for secondary graft failure for grafts with at least 1 year follow-up were 86% and 88%, respectively.

CONCLUSION

An EHD is a unique parameter that quantifies conduit size and has a significant impact on vein graft patency. An EHD less than 3.6 mm portends graft failure.