Lower Extremity Revascularization Procedures Research Articles

A Role for Embolic Protection in the Management of Acute Limb Ischemia

Distal embolization is a complication during lower-extremity revascularization procedures that may occur when intervening on acute or subacute lesions. Several studies have demonstrated the safety and feasibility of using embolic protection devices (EPD) and some interventionalists have adapted this technology for use in infrainguinal revascularization procedures. At present, there are no randomized trials to indicate the benefit, safety, and cost-effectiveness of EPD for this application and its use in the United States is considered off-label. However, based on our experience and a review of the published literature, we consider the use of EPD in acute lower-extremity ischemia a reasonable strategy.

Screening for peripheral artery disease in dialysis patients: an opportunity for early disease detection and timely initiation of appropriate therapeutic measures

Otsubo et al. [1] in this issue of International Urology and Nephrology report that peripheral arterial disease (PAD) is an independent predictor of mortality in hemodialysis patients. In univariate analysis, the presence of PAD was associated with a 67% increase in long-term mortality risk in patients undergoing maintenance hemodialysis compared with the absence of PAD (odds ratio [OR], 1.67; 95% confidence interval [CI], 1.18–2.28; P = 0.004) [1]. The relation between PAD and mortality persisted even after adjustment for age, gender, duration of dialysis, diabetes mellitus and smoking (OR, 1.575; 95% CI, 1.038–2.381; P = 0.033) [1]. These findings support the results of earlier studies showing that PAD is common in dialysis patients and that it is associated with increased cardiovascular morbidity and mortality rates in this population [2–4]. This Editorial discusses some additional aspects that may be of interest. There is a strong two-way correlation between impaired renal function and PAD. A recent comprehensive review demonstrated that 27–36% of patients with PAD also have concomitant impaired renal function [5]. The presence of impaired renal function in these individuals is associated not only with higher morbidity and mortality rates but also with the occurrence of cardiovascular events (stroke, myocardial infarction, and cardiovascular death) [5]. Furthermore, impaired renal function negatively affects survival, limb salvage and graft patency rates when these individuals undergo lower extremity revascularization procedures [5]. Conversely, patients on chronic dialysis have high atherosclerosis and arteriosclerosis rates [6]; the increased arterial stiffness is responsible for the high prevalence of carotid artery stenosis, myocardial infarction, PAD, and stroke in this population [6]. PAD is an atherosclerotic occlusive disease with/without vascular calcifications in the intima of lower extremity arteries [7–9]. The symptoms of PAD include intermittent claudication, which progresses to ischemic leg pain, critical limb ischemia, and finally, tissue necrosis requiring amputation. The prevalence of PAD is high among patients K. I. Paraskevas (&) A. Nikolaou Department of Vascular Surgery, ‘‘Red Cross’’ Hospital, 24, Al. Papagou street, Athens, Greece e-mail: paraskevask@hotmail.com

Evaluating Changes in Regional Tissue Perfusion Following Percutaneous Lower Extremity Revascularization Procedures with a Hyperspectral Image-based Tissue Oxygenation Mapping System

To establish the feasibility of using applied imaging spectroscopy to replace or supplement existing adjuncts in the evaluation of patients with chronic limb ischemia undergoing percutaneous revascularizations. This is an ongoing prospective study of a commercially available hyperspectral imaging (HSI) camera, enrolling patients undergoing endovascular procedures for chronic limb ischemia. Images of the dorsal surface of the foot are obtained across various wavelengths of light before and after intervention. Spectroscopic data are used to measure capillary oxyhemoglobin, deoxyhemoglobin, and oxygen saturation (StO2) values. These data are displayed as interactive digital color maps, demonstrating heterogeneous perfusion throughout the entire foot and allowing morphologic and quantitative analysis. Periprocedural changes are compared against existing noninvasive tests. Revascularized patients are re-imaged at regular intervals for up to one year post-procedure. Of 25 enrolled patients having lower extremity limbs amenable to endovascular treatment (Rutherford grades 1-4), 15 subjects (17 limbs) completed their pre- and post-procedure visits. Of these, 11 subjects (13 limbs) also completed their six week and three month visits. All limbs demonstrated a post-procedural change in their HSI profile. There was a statistically significant increase in StO2 following revascularization that persists at three months (from 32% ± 2% to 41% ± 9%, P = .01). The increase corresponds with an increase in the ankle-brachial index (ABI), which also persists at three months (0.75 ± 0.06 to 0.94 ± 0.05, P = .02). The increase in StO2 predominantly resulted from 32% average decrease in Hb-Deoxy (60 ± 4 to 41 ± 4, P = .004). Total hemoglobin in tissue also decreased following treatment (90 ± 7 to 70 ± 6, P = .04). HSI is an effective noninvasive imaging modality in the assessment of peripheral perfusion after percutaneous lower extremity revascularization procedures. The ease of use, precision of regionally discrete data, and strong correlation with widely-accepted noninvasive measures such as ABI suggests that HSI will be a valuable addition to the vascular lab.

Renal Function Impairment in Peripheral Arterial Disease: An Important Parameter that Should not Be Neglected

A considerable percentage of patients with peripheral arterial disease (PAD) have impaired renal function. We searched the literature (PubMed/Medline) to determine the clinical significance and assess the management of renal dysfunction in these patients. The results of our literature search suggest that impaired renal function is a frequent finding in patients with PAD. The presence of concomitant renal dysfunction in these patients is associated with higher morbidity and mortality rates, as well as the occurrence of cardiovascular events (stroke, myocardial infarction, and vascular death). Additionally, impaired renal function negatively affects survival, limb salvage, and graft patency rates when these patients undergo lower extremity revascularization procedures. The use of statins and angiotensin-converting enzyme (ACE) inhibitors is associated with improved renal function and reduced cardiovascular risk in patients with PAD. Based on current evidence, renal function should be assessed and regularly monitored in all patients with PAD. More importantly, initiation of appropriate treatment (e.g., statins and ACE inhibitors) should be implemented to preserve renal function and improve vascular morbidity and mortality in these patients.

Risk Factors for Failure of Lower-Extremity Revascularization Procedures: Are They Different for Bypass and Percutaneous Procedures?

Restenosis following lower-extremity revascularization remains a significant and costly public health burden. Technical advances in endovascular therapy afford us the choice of treating longer and more distal lesions, which were heretofore reserved for vein bypass surgery. While contemporary vascular surgeons are well-versed in both open and percutaneous techniques, predictive models of who is at risk for failure from a specific mode of therapy are lacking. Traditional Framingham cardiovascular risk factors have not been successful in discriminating risk for failure of peripheral bypass or angioplasty. At the heart of this is our inability to make sophisticated measurements necessary to resolve phenotypic profiles into those likely to experience restenosis versus those likely to enjoy long-term patency. In this article we outline the available literature in an epidemiological framework of the association of traditional cardiovascular risk factors, emerging risk factors, as well as novel biomarkers with failure of both endovascular and open lower-extremity reconstructive procedures.

Ileofemoral Malperfusion Complicating Type A Dissection: Revascularization Prevents Renal Failure

We report four cases of lower extremity malperfusion complicating acute type A dissection. Two patients were treated with acute type A dissection repair, followed by axillobifemoral bypass grafting when malperfusion persisted after aortic replacement and required dialysis. Two patients were managed with lower extremity revascularization procedures before acute type A dissection repair and had preserved renal function. Lower extremity revascularization before cardiopulmonary bypass minimizes ischemia and allows for controlled limb reperfusion under hypothermic conditions compared with delayed normothermic reperfusion when performed after acute type A dissection repair. This strategy may increase limb function salvage and decrease the incidence of dialysis after acute type A dissection repair in patients presenting with lower extremity malperfusion.

Biological Treatment of Vein Grafts and Stents in Lower-Extremity Arterial Reconstruction

Longevity of lower-extremity revascularization procedures has typically been limited because of restenosis of grafts, as well as stents and other percutaneous techniques. The ability to prevent or ameliorate neointimal hyperplasia and improve durability of lower-extremity arterial reconstruction is the focus of significant scientific and clinical research. The transcription factor decoy edifoligide was investigated as a potential inhibitor of neointimal hyperplasia, but the results of the pivotal clinical trial did not demonstrate significant improvement in graft reintervention, although secondary patency was improved. Similar to the coronary circulation, drug-eluting stents are a potential tool for prevention of restenosis after percutaneous arterial reconstruction. The SIROCCO study did not demonstrate improvement in superficial femoral artery stent patency with sirolimus-eluting stents. Studies are underway that are investigating paclitaxel-eluting stents for use in the superficial femoral artery. Other potential mediators of restenosis include absorbable drug-eluting stents and antibody-coated stents designed to promote endothelialization of the stent or graft surface. In addition, absorbable wraps eluting paclitaxel can be used at arterial and arteriovenous anastomoses to prevent restenosis. Clinical trials investigating these novel technologies are underway.

Comparison of Computed Tomography Angiography to Contrast Arteriography for Patients Undergoing Evaluation for Lower Extremity Revascularization

In an effort to explore alternatives to contrast arteriography, we compared computed tomography angiography to contrast arteriography for defining anatomic features of patients undergoing lower extremity revascularization. From November 2003 to March 2004, 36 inpatients with chronic lower extremity ischemia underwent contrast arteriography and computed tomography angiography before undergoing lower extremity revascularization procedures. A Siemens 16 slice multiplanar computed tomography device with bolus tracking was used for these exams. The reports of these tests and images were compared prospectively, and the differences in the aorto-iliac segment, femoral-popliteal, and infrapopliteal segments were noted. The vessels were classified as mild disease (<50%), moderate disease (50%-70%), severe (71%-99%), and occluded. The studies and treatment plans based on these data were compared. The mean age was 76 +/- 12 years (SD). Indications for the procedures included gangrene (45%), ischemic ulcer (32%), rest pain (19%), and severe claudication (3%); 69% were diabetics. Accuracy of computed tomography angiography in the aorto-iliac, femoral-popliteal, and infrapopliteal segments was 100%, 81%, and 59%, respectively. Thirteen of 18 (72%) of these disagreements resulted in a different procedure than that suggested by computed tomography angiography. A review of the data obtained in this series indicated that computed tomography angiography appears to be unable to obtain adequate information in this highly selected population at our institution.

Duplex Arteriography for Lower Extremity Revascularization

Duplex arteriography may be a potential replacement of preoperative standard contrast arteriography for peripheral arterial imaging in lower extremity revascularization procedures. In patients with chronic or acute ischemia, a well-performed duplex arteriography offers several practical advantages over contrast arteriography: it is noninvasive; it does not require nephrotoxic agents; it is portable and can be done expeditiously; color flow and waveform analysis provide a better estimation of the hemodynamic significance of occlusive disease; it allows direct visualization of the entire artery and not only of the lumen thus enabling plaque characterization; with color flow and power Doppler techniques, it is possible to identify patent arteries subjected to very low flow states; and it can detect occluded arterial aneurysms thereby avoiding unnecessary attempts at thromboembolectomies. High-quality arterial ultrasonography performed by a highly skilled and well-trained vascular technologist may represent an alternative to conventional arteriography for patients in need of primary or secondary lower extremity revascularization.

Infra-inguinal revascularization surgical site infections: Australasian benchmark

Infra-inguinal revascularization surgery remains one of the most commonly performed major vascular procedures in contemporary practice. Surgical site infections (SSI) are a common cause of morbidity in this patient cohort and generate high rates of limb loss and mortality when vascular graft involvement occurs. An overall reduction in North American SSI has been attributed to the establishment of national benchmarks. A comparable Australasian benchmark does not exist. The purpose of the present study was to assess the methods used by Australasian vascular units to determine SSI rates and to instigate the development of an acceptable benchmark. A structured questionnaire pertaining to SSI after infra-inguinal revascularization surgery was sent to 26 Australasian vascular units. Data requested included the number and type of lower extremity revascularization procedures performed. Units were also asked to report the methods employed for defining and detecting wound infections and to document their SSI rate. The incidence of SSI causation by methicillin-resistant Staphylococcus aureus (MRSA) was also sought. The total number of revascularizations performed annually varied from 28 to 179 between units. The SSI rates ranged from 0 to 38%. The incidence of MRSA involvement varied from <1% to 56%. The SSI surveillance methodology varied considerably between units. The present study confirms the significant incidence of SSI after infra-inguinal revascularization surgery in contemporary vascular practice. Standardized definitions and surveillance protocols are required to facilitate inter- and intrahospital comparisons. A possible benchmark infection rate may be 10-20%.

A Comparison of Magnetic Resonance Angiography, Contrast Arteriography, and Duplex Arteriography for Patients Undergoing Lower Extremity Revascularization

The objective of this study was to compare magnetic resonance angiography (MRA), contrast arteriography (CA), and duplex arteriography (DA) for defining anatomic features relevant to performing lower extremity revascularizations. From March 1, 2001 to August 1, 2001, 33 consecutive inpatients with chronic lower extremity ischemia underwent CA, MRA, and DA before undergoing lower extremity revascularization procedures. The reports of these tests were compared prospectively and the differences in the aortoiliac segment, femoral-popliteal, and infrapopliteal segments were noted. The vessels were classified as mild disease (<50%), moderate disease (50-70%), severe disease (71-99%), and occluded. These studies and treatment plans based on these data were compared. During this time period, 11 patients were not able to undergo MRA and therefore were excluded from the study. Thirty-three patients were included in this study. These patients underwent 35 procedures, as 2 patients underwent bilateral procedures. The mean age of the 33 patients was 76+/-10 years (SD). Indications for the procedures included gangrene (20), ischemic ulcer (8), rest pain (4), and severe claudication (1). Patients' medical history included diabetes mellitus (25), hypertension (20), and end-stage renal disease (5). No differences were noted between intraoperative findings and CA in this series. Two of the three differences between DA and CA were felt to be clinically significant whereas 9 of the 12 differences between MRA and CA were felt to be clinically significant. On the basis of these data in this series, MRA does not yet seem to be able to obtain adequate data on infrapopliteal segments, at least not for this highly selected population. When severe tibial calcification or very low flow states are identified, CA may be necessary for patients undergoing DA.

Magnetic resonance angiography versus duplex arteriography in patients undergoing lower extremity revascularization: which is the best replacement for contrast arteriography?

Objective In an effort to explore alternatives to contrast material–enhanced arteriography, we compared magnetic resonance angiography (MRA) and duplex arteriography (DA) with contrast arteriography (CA) for defining anatomic features in patients undergoing lower extremity revascularization. Methods From August 1, 2001, to August 1, 2002, 61 consecutive inpatients (64 limbs) with chronic lower extremity ischemia underwent CA, MRA, and DA before undergoing lower extremity revascularization procedures. The reports of these tests and images were compared prospectively, and the differences in the iliac, femoropopliteal, and infrapopliteal segments were noted. The vessels were classified as mildly diseased (<50%), moderately diseased (50%-70%), severely diseased (71%-99%), or occluded. The studies and treatment plans based on these data were compared. Results Mean patient age was 76 ± 10 years (SD). Indications for the procedures included gangrene (43%), ischemic ulcer (28%), rest pain (19%), severe claudication (9%), and failing bypass (1%). During this period 35 patients were ineligible for the protocol, because they could not undergo MRA (n = 27) or angiography (n = 8). Of the total 192 segments in the 64 patients (iliac, femoropopliteal, tibial), 17% were not able to be fully assessed with DA, and 7% with MRA. Disagreements with CA and DA were found in the iliac, femoropopliteal, and tibial segments in 0%, 7%, and 14% of cases, respectively, and between CA and MRA in 10%, 26%, and 42% of cases, respectively. Two of 9 differences (22%) between DA and CA were thought to be clinically significant, and 28 of 45 differences (62%) between MRA and CA were thought to be clinically significant. Conclusions A review of the data obtained in this series indicates that MRA does not yet seem to yield adequate data, at least in this highly selected population at our institution. When severe calcification is identified, CA may be necessary in patients undergoing DA.

Outcome of lower-extremity revascularization in patients younger than 40 years in a predominantly diabetic population.

Incidence of perioperative complications is increased and outcome is poor in young patients undergoing vascular surgery. We extensively reviewed results of lower-extremity procedures in this group of patients to further define the extent of short-term and long-term morbidity. Results from our vascular registry were retrospectively reviewed for 76 lower-extremity revascularization procedures performed between January 1990 and May 2000 in 51 patients younger than 40 years. This represents 1.88% of 4052 lower-extremity bypass procedures performed during this period. Perioperative cardiac complications, long-term survival, graft patency, and limb salvage were evaluated. Kaplan-Meier curves were generated, and their significance was determined with the Cox-Mantel test. Forty-nine percent of patients were male, and 51% were female; mean age at presentation was 35.9 years (range, 27.5-39.8 years). Preoperative morbidity included diabetes mellitus (96.1%), smoking (70.6%), hypertension (78.4%), coronary artery disease (37.3%), hyperlipidemia (33.3%), and renal dysfunction (52.9%). Overall rate for 30-day postoperative mortality was 0.0%, for myocardial infarction was 0.0%, and for congestive heart failure was 1.32%. Thirty-day graft failure was 11.1% (n = 9). At 1 year, primary patency was 71.0%, secondary patency was 82.5%, and limb salvage was 87.1%; and at 5 years these rates were 51.9%, 63.4%, and 77.2%, respectively. After the initial surgery 11.8% (n = 6) of patients required at least one additional ipsilateral revascularization procedure, 31.3% (n = 16) required a bypass graft in the contralateral limb, and 23.5% (n = 12) ultimately required amputation. In patients who required additional ipsilateral procedures, 1-year primary patency rate was 66.7%, secondary patency rate was 62.5%, and limb salvage rate was 77.8%, compared with 5-year rates of 44.4%, 41.7%, and 64.8%, respectively, representing a decrease in patency compared with primary revascularization procedures. Overall survival at 1 year was 88.2%, compared with 73.3% at 5 years. Patients with preexisting renal disease had significantly decreased survival at 5 years compared with those without renal dysfunction (64.5% vs 82.6%; P =.019). Our data suggest that age younger than 40 years is not associated with increased perioperative morbidity and mortality. However, these patients have a significant rate of early graft failure and dismal long-term survival, especially in patients with preexisting renal dysfunction. In addition, ipsilateral repeat operations have a marginal success rate.

Postoperative nausea and vomiting in regional anesthesia: a review.

ANESTHESIA has become remarkably safe, and while death and permanent damage have become rare occurrences, other sequelae of anesthesia are gaining more importance. Postoperative nausea and vomiting (PONV) still is the most troublesome adverse event encountered in the recovery room, despite advances in prevention and treatment. The incidence of PONV has remained high and has a major negative impact on patient satisfaction about the overall surgical experience. Furthermore, the ongoing trend toward ambulatory procedures has increased the focus on PONV as its occurrence may delay discharge or cause unanticipated hospital admission. General anesthesia has long been considered as causing a greater frequency and severity of PONV than regional anesthetic techniques. Recent studies investigating this time-honored dictum in a controlled manner mostly, but not unanimously, confirmed it. Accordingly, considerable effort has been invested to examine etiology, define patients at risk, and outline preventive and therapeutic strategies in patients undergoing general anesthesia. Reviews dealing with PONV have discussed almost exclusively general anesthesia and largely ignored regional anesthesia. This contrasts with the increasing popularity of regional anesthesia. A survey in Europe showed that one third of patients are undergoing regional anesthesia for their operative procedure. In France, the proportion of regional anesthesia increased from 15 to 25% of all anesthetics administered from 1980 to 1996. The number of local anesthetic and analgesic agents available for regional anesthesia has increased over the last two decades. Since the introduction of intrathecal and epidural morphine in 1979, a multitude of medications, such as synthetic opioids, 2-agonists, and cholinesterase inhibitors, have been introduced in an attempt to enhance the action of local anesthetics. The decision about their usefulness will not only rely on their effects on nerve blockade and pain relief, but also on their influence on side effects such as PONV. This review focuses on PONV in the setting of perioperative regional anesthesia. General aspects of PONV, such as physiology, patient, and perioperative factors involved are discussed. Few studies regarding these issues have been specifically devoted to regional anesthesia. Therefore, much information must be derived from investigations of general anesthesia. Specific regional anesthetic techniques and the influence of adjunctive medications on PONV are also presented. Combined general–regional anesthesia is purposefully excluded, avoiding the many variables introduced by general anesthesia. A final section is devoted to continuous peripheral nerve blocks and their possible impact on PONV.

Comparison of Magnetic Resonance Angiography (MRA) and Duplex Ultrasound Arterial Mapping (DUAM) prior to infrainguinal arterial reconstruction

Objective: the purpose of this study is to compare Magnetic Resonance Angiography (MRA) to Duplex Ultrasound Arterial Mapping (DUAM) and intraoperative findings to determine the clinical, accuracy of MRA for planning lower extremity revascularization procedures. Methods: forty-two patients who underwent lower extremity revascularization procedures had both MRA and DUAM evaluations. These data were analyzed retrospectively and two distinct endpoints were considered. First, we compared the MRA and DUAM findings for aorto-iliac, femoral-popliteal and infra-popliteal segments to intraoperative findings and evaluated the degree to which they agreed. Second, if there was a disagreement between imaging modalities, it was established whether a change in operative procedure would have resulted. Results: MRA and DUAM findings agreed in 26 of 31 cases (83%) of aorto-iliac segments, in 25 of 31 cases (81%) of femoral-popliteal segments, and in 16 of 21 cases (76%) of infra-popliteal segments. In total, DUAM agreed with intraoperative findings in 98% of cases while MRA agreed in 82% (p<.001). Disagreement between intraoperative findings and DUAM lead to an alternate surgical procedure in only one case (2%) while disagreement with MRA lead to a different procedure in 38% of cases (p<.001). Conclusions: these data show that MRA is not yet adequate to replace conventional angiography and is less accurate that DUAM. Further improvements are necessary before MRA can be used as the sole modality for formulation of a pre-operative plan for lower extremity revascularization.Eur J Vasc Endovasc Surg 25, 139–146 (2003)

Risk Factors Associated with Infection of Lower Extremity Revascularization: Analysis Of 365 Procedures Performed at a Teaching Hospital

Infection of arterial reconstructions is associated with high rates of mortality and limb loss despite optimal treatment. Lower extremity revascularization procedures performed at a teaching hospital were reviewed to identify risk factors associated with wound infection. Medical records, postoperative infection surveillance forms, and a computerized vascular registry for lower extremity revascularizations involving a common femoral or more distal artery during a 3-year period were reviewed. There were 335 bypass operations (184 femoral-distal, 36 popliteal-distal, 17 aortofemoral, 13 femorofemoral, 11 axillofemoral, 74 graft revisions) and 30 other vascular procedures (arterial thrombectomy or endarterectomy). Factors analyzed included age, gender, diabetes mellitus, dialysis dependence, malnutrition, obesity, ipsilateral foot ulcer or gangrene, separate admissions within the month preceding surgery, length of hospital stay before surgery, length of operation, wound hematoma requiring reoperation, vein or prosthetic grafts, or redo surgery. Risk factors commonly thought to increase wound infection following lower extremity revascularizations, such as diabetes, obesity, renal failure, redo surgery, and prosthetic grafts, did not predict this complication in this series. Given the correlation of operative time with infection, efforts to minimize operative time by "double-teaming" staff participation in teaching cases may decrease infection rates, although this is speculative. Vascular services should institute strategies to ensure that appropriate prophylactic antibiotics are administered in a timely fashion before lower extremity revascularizations.

Comparative decades of experience with glutaraldehyde-tanned human umbilical cord vein graft for lower limb revascularization: An analysis of 1275 cases

Purpose: Biological material has been used as an alternative to autogenous vein since the first lower extremity revascularization procedures were performed. Our experience with glutaraldehyde-tanned human umbilical cord vein graft (UVg), which spanned a period of 28 years, forms the basis of this report, with an emphasis on comparative results between the two decades from 1975 to 1985 and from 1990 to 2000. Methods: Between 1990 and 2000, 283 lower extremity bypass grafting procedures were performed in 230 patients (264 limbs), with UVg used as the predominant, or sole, graft material. Our experience with 907 reconstructions in the decade from 1975 to 1985 has been previously documented and now serves as a baseline comparison with the past decade of experience with UVg. Each reconstruction was classified on the basis of the distal anastomotic site with or without distal arteriovenous fistulas (dAVFs). The primary and secondary graft patency rates were determined for each category as was cumulative palliation, which combines the end points of graft failure, amputation, and death Results: The results from the second decade (1990 to 2000) showed a continuation of improving patency rates for UVg grafts in lower extremity revascularization. Comparison results of complications showed no changes in the low incidence rates of infection, stenosis, dissection, and pseudoaneurysm. The original series results showed a 2.9% requirement for aneurysm surgery, with an incidence rate of biodegradation of 57% (36% aneurysms, 21% dilation), whereas the current series results have shown no aneurysms to date. The comparative 6-year secondary patency rates for past and current popliteal and crural bypass grafts (with or without dAVF) were: popliteal, 53% versus 67%, P <.05; and crural, 26% without dAVF versus 47% with dAVF, P <.05. The limb salvage rates for the two series at 6 years showed no significant changes between the decades and the types of bypass grafts. Thrombolysis was performed during the decade from 1990 to 2000 in 27 UVg cases, with lysis achieved in 23 cases (85%) and limb salvage achieved in 20 cases (74%). Since 1996, associated endovascular procedures (fluoroscopy, angioplasty) have assumed increasing importance in the reduction of perioperative graft closure and in the enhancement of patency Conclusion: Our continuing experience with UVg confirms that favorable results can be obtained with this biologic alternative to autologous vein for lower limb revascularization. Concern regarding biodegradation and aneurysm formation even after 5 years are unfounded at this time. Improved patency and limb salvage rates can be achieved in concert with lower nonthrombotic failure rates, increasing performance of associated endovascular procedures, use of tourniquets, and the addition of dAVF for crural bypass grafting. Prospective randomized studies are still necessary for the assessment of the comparative role of all graft materials, a project that continues to evade our specialty. (J Vasc Surg 2002;35:64-71.)

Lower Extremity Revascularization without Preoperative Contrast Arteriography: Experience with Duplex Ultrasound Arterial Mapping in 485 Cases

This study reviews our experience with duplex ultrasound arterial mapping (DUAM) for preoperative evaluation in 466 patients (262 men) who underwent 485 lower extremity revascularization procedures from January 1, 1998 to May 30, 2001. Preoperative imaging consisted of DUAM alone in 449 procedures and DUAM and contrast angiography (CA) in 36. An attempt to image from the distal aorta to the pedal arteries was made in all the patients. The selection of optimal inflow and outflow bypasses anastomotic sites was based on a schematic drawing following DUAM examination. Inflow disease was also assessed by intraoperative pressure gradient (IPG) between the distal anastomosis and radial arteries, and completion arteriography of the runoff vessels was obtained, which was correlated with the preoperative findings. Indications for surgery were severe claudication in 91 (19%) limbs, tissue loss in 197 (40%), rest pain in 113 (23%), acute ischemia in 46 (10%), popliteal aneurysm in 18 (4%), superficial femoral artery aneurysm in 1, abdominal aortic aneurysm with claudication in 1, and failing graft in 18 (4%). Age ranged from 30 to 97 years (mean 72 +/- 12 (SD) years) and risk factors such as diabetes, hypertension, use of tobacco, coronary artery disease, and end-stage renal disease were present in 45%, 45%, 44%, 44%, and 13% of the patients, respectively. One hundred twenty-one (25%) limbs had at least 1 previous ipsilateral revascularization. The mean DUAM time was 66 +/- 20 (SD) min (30-150 min). Additional preoperative imaging was deemed necessary in 36 cases due to extensive ulcers, edema, severe arterial wall calcification, and very poor runoff. The distal anastomosis was to the popliteal artery in 173 cases and to the tibial and pedal arteries in 255. Inflow procedures to the femoral arteries, embolectomy, thrombectomy, balloon angioplasty, and patch angioplasty accounted for the remaining 57 cases. Overall, 6-, 12-, and -24- month secondary patency rates were 86%, 80%, and 66%, respectively. This early experience shows that high-quality arterial ultrasonography performed by a highly skilled vascular technologist may represent an alternative to conventional arteriography for patients in need of lower extremity revascularization. Because of limitations inherent to the technique and very poor runoff observed on ultrasonographic examination, additional preoperative imaging procedure's are needed for certain patients.

A comparative study of alternative conduits for lower extremity revascularization: All-autogenous conduit versus prosthetic grafts

Purpose: In the absence of an adequate ipsilateral greater saphenous vein, various alternative conduits have been used for the performance of lower extremity revascularization. In this study we compared the effectiveness of all-autogenous arm vein bypass grafts with that of prosthetic grafts. Methods: Seven hundred forty lower extremity revascularization procedures (506 arm vein, 234 prosthetic) performed between 1990 and 1999 were followed prospectively by means of a computerized vascular registry. Results: Bypass graft configurations were femoro-above-knee-popliteal (26 arm vein, 100 prosthetic); femoro-below-knee-popliteal (38 arm vein, 29 prosthetic); femorotibial (174 arm vein, 55 prosthetic); femoropedal (23 arm vein, 2 prosthetic); popliteotibial/pedal (101 arm vein, 1 prosthetic); and extension “jump” grafts (144 arm vein, 47 prosthetic). The indications for surgery were limb salvage (98.0% arm vein, 89.7% prosthetic) and disabling claudication (2.0% arm vein, 10.3% prosthetic). The mean follow-up was 23.4 months (range, 1 month–7.4 years). Overall patient survival at 4 years was 54% (arm vein) and 69% (prosthetic). Cumulative patency varied with graft configuration. The 1-year primary patency rates for femorotibial grafts were 81.6% ± 3.6% (arm vein) and 58.0% ± 8.4% (prosthetic); the 3-year rates were 68.3% ± 6.1% (arm vein) and 41.1% ± 9.8% (prosthetic) (P <.01). The 1-year limb salvage rates for femorotibial grafts were 91.1% ± 2.8% (arm vein) and 69.1% ± 8.8% (prosthetic); the 3-year rates were 81.4% ± 5.6% (arm vein) and 63.2% ± 10.3% (prosthetic) (P =.02). The 1-year primary patency rates for femoro-below-knee-popliteal grafts were 92.9% ± 5.1% (arm vein) and 83.4% ± 8.0% (prosthetic); the 3-year rates were 72.8% ± 10.1% (arm vein) and 55.5% ± 12.1% (prosthetic) (P =.05). The 1-year limb salvage rates for femoro-below-knee-popliteal grafts were 100% (arm vein) and 91.3% ± 7.0% (prosthetic); the 3-year rates were 94.7% ± 7.3% (arm vein) and 75.3% ± 14.6% (prosthetic) (P = NS). Conclusion: In this study autogenous arm vein grafts demonstrated increased patency and limb salvage, compared with prosthetic grafts. These increases achieved statistical significance in the femoro-below-knee-popliteal and femorotibial configurations. An effort to use an all-autogenous vein conduit is justified on the basis of these results; however, if no autogenous vein is available, prosthetic grafts provide a reasonable alternative to primary amputation. (J Vasc Surg 2000;32:1080-90.)

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

Purpose: Various alternative conduits have been used for lower extremity revascularization when an adequate ipsilateral greater saphenous vein is absent. This study compared the effectiveness of all-autogenous multisegment arm vein bypass grafts with that of composite grafts composed of combined prosthetic and autogenous conduits.Methods: One hundred fifty-three lower extremity revascularization procedures performed between 1990 and 1998 were followed up prospectively using a computerized vascular registry. The grafts were composed of spliced arm vein segments with venovenostomy in 122 and of composite prosthetic-autogenous conduit in 31. Arm vein conduit was prepared by means of intraoperative angioscopy for valve lysis and identification of luminal abnormalities in 47.7% of cases.Results: Bypass graft configurations were as follows: femoropopliteal (12 arm vein, 2 composite); femorotibial (75 arm vein, 23 composite); femoropedal (14 arm vein, 6 composite), and popliteo-tibial/pedal (21 arm vein, 0 composite). The indication for surgery was limb salvage in 98% and disabling claudication in 2% of cases. The mean follow-up was 25.1 months (range, 1 month to 7.9 years). Overall survival at 4 years was 51%. Overall patency and limb salvage rates were as follows: primary patency, at 1 year—arm vein, 76.9% ± 4.8%; composite, 59.5% ± 9.6% (P = .02); at 3 years—arm vein, 70.0% ± 8.0%; composite, 43.7% ± 12.4% (P < .01); and at 5 years—arm vein, 53.8% ± 8.7%; composite, 0%; secondary patency, at 1 year—arm vein, 77.5% ± 4.6%; composite, 59.8% ± 9.5% (P = .02); at 3 years—arm vein, 70.7% ± 7.5%, composite, 44.9% ± 13.1% (P < .01); at 5 years—arm vein, 57.7% ± 8.0%; composite, 0%; limb salvage, at 1 year—arm vein, 89.3% ± 3.7%; composite, 73.9% ± 8.9% (P < .01); at 3 years—arm vein, 80.5% ± 7.0%; composite, 49.6% ± 14.3% (P < .01); at 5 years—arm vein, 76.3% ± 9.9%; composite, 0%.Conclusion: In this study, multisegment autogenous arm vein was used successfully in a wide variety of lower extremity revascularization procedures and achieved good longterm patency and limb salvage rates, well in excess of those achieved with composite prosthetic-autogenous grafts. The use of autogenous conduit appears to offer superior results to composite conduit in lower extremity revascularization. The superior durability of arm vein makes it one of the alternative conduits of choice when an adequate greater saphenous vein is not available.