Regional anesthesia: preferred technique for venodilatation in the creation of upper extremity arteriovenous fistulae.

Owing to the overall poor medical health of patients with end-stage renal disease, we have sought alternatives to the use of general anesthesia for access procedures. Furthermore, since local anesthesia (1) does not offer the motor block that is sometimes desired and (2) can be difficult to maintain when a large amount of vein needs to be transposed, we examined whether regional blocks can be useful for the creation of new arteriovenous fistulae (AVF). From August 2002 to January 2005, 41 patients scheduled for AVF placement underwent a regional block with the use of a lidocaine and ropivacaine mixture using a nerve stimulator. Either axillary, interscalene, or infraclavicular blocks or a combination was used. Intraoperative duplex ultrasonography was used to assess the degree of venodilatation of the basilic and cephalic veins before and after the block. The site of each measurement was marked on the skin and selected by a clearly identifiable branch point. Each measurement was recorded three times and was made in the (1) native state, (2) after application of a tourniquet with opening and closing of the hand for 15 seconds, and (3) after placement of the block. The average age of the patients was 65 +/- 14 years (SD), with ages ranging from 33 to 91 years, and the prevalence of diabetes mellitus was 50%. Complete brachial plexus block was achieved in 34 patients (83%). Sensory block was accomplished within 10 to 15 minutes and usually lasted 4 to 6 hours. Motor block was accomplished in 10 to 25 minutes. Venodilatation was not noted in patients whose blocks did not work (n = 7) or whose vein was found to be phlebitic on exploration (n = 3). The degree of venodilatation noted as a percentage increase after application of the tourniquet compared with the native state for these 34 patients (in whom the block worked) was 37% for the distal cephalic, 31% for the midcephalic, and 32% for the midbasilic vein. The degree of venodilatation noted as a percentage increase after placement of the block compared with after tourniquet application for these 34 patients was 42% for the distal cephalic, 19% for the midcephalic, and 26% for the midbasilic vein. No instances of systemic toxicity, hematomas, or nerve injury from the block were noted. Accesses placed included 20 radiocephalic AVF, 8 brachiobasilic AVF, 8 brachiocephalic AVF, 2 arteriovenous grafts, 2 radiobasilic AVF, and 1 brachial vein AVF.Regional block is a safe and, in our opinion, preferred technique for providing anesthesia for upper extremity vascular surgery. The venodilatation observed is augmented compared with that using a tourniquet and may allow more options for access placements.

Morbidity and mortality associated with brachial vein thrombosis.

We have noted a significant incidence of pulmonary embolism (PE) and mortality associated with upper extremity deep venous thrombosis (UEDVT). Since there is an association between site of lower extremity DVT (LEDVT) and PE, we hypothesized that there might also be a correlation between site of UEDVT and PE with associated mortality. To further elucidate this hypotheses, we analyzed the mortality and incidence of PE diagnosed with subclavian/axillary/internal jugular vein thrombosis during an 11-year period at our institution and compared the data to those of patients diagnosed with brachial DVT. We studied 598 patients diagnosed with acute internal jugular, subclavian, axillary, or brachial DVT by duplex scanning. The patients were divided into three groups based on the most proximal location of the thrombus: group I, UEDVT involving the subclavian or axillary veins (n = 467); group II, isolated internal jugular DVT (n = 80); group III, brachial DVT alone (n = 52). Mortality rates at 2 months were 29%, 25%, and 21% for each group, respectively. The number of patients diagnosed with PE by ventilation/perfusion scans in groups I, II, and III, respectively, were 5%, 6.25% and 11.5% (p = 0.13). Furthermore, stratification by risk factors failed to demonstrate factors associated with increased 2-month mortality. Contrary to the initial hypothesis of a relationship between the site of thrombosis and the incidence of PE and mortality, these data demonstrated no statistical differences in mortality or incidence of PE among the groups studied. Additionally, these data suggest that brachial vein thrombosis is a disease process related to comparable associated mortality and morbidity similar to other forms of UEDVT. Based on these data, we suggest that UEDVT may be thought of as a marker for the severity of systemic illness of the patient rather than just as a cause of venous thromboembolism.

Prospective evaluation of combined upper and lower extremity DVT.

The clinical importance of upper extremity deep venous thrombosis (UEDVT) has been increasingly demonstrated in recent literature. Not only has the risk of pulmonary embolism from isolated upper extremity DVT been demonstrated, but a significant associated mortality has been encountered. Examination of this group of patients has demonstrated the existence of combined upper and lower extremity deep venous thrombosis (DVT) in some patients who exhibit an even higher associated mortality. As a result of this information, it has become the standard practice at this institution to search for lower extremity DVTs in patients found to have acute thrombosis of upper extremity veins. Since January 1999, there have been a total of 227 patients diagnosed with acute UEDVT. Within this group, 211 (93%) patients had lower extremity studies; 45 of these 211 (21%) had acute lower extremity DVTs by duplex examination in addition to the upper extremity DVTs. Overall, there were 145 women, 66 men, and the average age was 70 +/-1.2 (SEM); 22 of these patients had bilateral lower extremity thrombosis (LEDVT), and 8 patients were found to have chronic thrombosis of lower extremity veins. Of the patients with bilateral upper extremity DVTs, there were 3 with bilateral LE acute DVTs. Finally, 8 of the remaining 166 patients (5%) with originally negative lower extremity studies were found to develop a thrombosis at a later date. These data serve to confirm previous studies, on a larger scale, that there should be a high index of suspicion in patients with UEDVT of a coexistent LEDVT.

Impact of duplex arteriography in the evaluation of acute lower limb ischemia from thrombosed popliteal aneurysms.

Acute limb-threatening ischemia from thrombosis may be the initial presentation of popliteal artery aneurysms (PAA) and is associated with amputation rates of 20-30%. Since contrast angiography may miss the diagnosis, the authors suspect that thrombosis of PAA may be an underappreciated cause of acute ischemia. Routine use of duplex arteriography (DA) may aid in the diagnosis and may help identify the outflow vessels with improved results. One hundred and nine patients (group 1) from 1994 to 1997 and 201 patients from 1998 to 2001 (group 2) presenting with acute limb-threatening ischemia were studied. None of the group 1 patients underwent preoperative DA and no diagnosis of acute popliteal artery aneurysm thrombosis was made. Ten patients with acute ischemia due to thrombosed popliteal artery aneurysms were identified in group 2 when preoperative DA was routinely performed. Urgent revascularization based on the results from DA was performed with use of autogenous saphenous vein in all patients. Six patients had functioning bypasses with a mean follow-up of 15.6 months. There were 3 deaths, 2 within 30 days and 1 after 2(1/2) years with functioning grafts. One patient was lost to follow-up. No major amputations were performed. Incidence of thrombosed popliteal artery aneurysms as the cause of acute limb-threatening ischemia is probably underestimated. Routine use of DA may provide the diagnosis and identifies the available outflow vessels. Contrary to previously published reports, urgent revascularization of an acutely ischemic extremity from thrombosed popliteal aneurysm can provide excellent rates of limb salvage.

Mini skin incision for carotid endarterectomy (CEA): a new and safe alternative to the standard approach.

PURPOSE: Patients requiring surgery are naturally attracted to shorter incisions because they tend to cause less pain and are esthetically more appeasing. To substantially shorten the length of standard skin incisions (4 to 7 inches) for carotid endarterectomy (CEA), we used preoperative duplex scanning to outline the carotid bifurcation as well as to determine the extent of disease in both the internal and common carotid arteries. METHODS: During the last 21 months, 265 consecutive primary CEAs were performed in 253 patients (mean age 72 +/- 10 years) at a single institution. Of these, 142 were men (56%). Hypertension, coronary artery disease, diabetes mellitus, smoking, and chronic renal failure were present in 81%, 44%, 43%, 28%, and 19% of the patients, respectively. Neurologically asymptomatic patients accounted for 71% of the cases. All patients received general anesthesia. Duplex-assisted skin markings of the diseased carotid artery were performed after proper patient positioning on the operating table. Synthetic patches were routinely used, and intraluminal shunts were deemed necessary by low stump pressures in 64 cases (24%). Completion duplex scanning was performed in all cases. RESULTS: The length of the longitudinal skin incision varied from 0.8 to 3.5 inches (average 1.4 +/- 0.5 inches). It was < or = 1 inch in 56 cases (21%), 1.1 to 1.5 inches in 110 (42%), 1.6 to 2 inches in 85 (32%), and 2.1 to 3.5 inches in the remaining 14 cases (5%). Intraluminal shunts were required in 9 (16%), 18 (16%), 29 (34%), and 8 (57%) of the cases, respectively. Incisions were longer in cases requiring an indwelling shunt (1.6 +/- 0.6 inches vs 1.4 +/- 0.4 inches) (P < .0001). The average patch length was 1.3 +/- 0.3 inches (range, 0.7 to 2.6 inches). The skin incision averaged 1.54 +/- 0.45 inches for the first 133 cases and 1.35 +/- 0.45 inches for the remaining 132 cases (P < .0001). Technical defects occurred in 10 cases (3.8%). The overall incidence of ipsilateral stroke and death was 1.9% and 0%. There were no technical defects or strokes in patients with the shortest incisions (< or = 1 inch). Overall, there were three transitory peripheral nerve injuries (1.1%). A comparative analysis with 265 consecutive CEAs performed immediately before this series without duplex-assisted skin markings revealed no significant differences in age (71 +/- 11 years), incidence of neurologically symptomatic patients (26%), sex (60% men), shunt use (24%), and major technical defects (3%). Also, postoperative transitory peripheral nerve injury (0.8%), stroke (0%), and death (0%) were not significantly different from the duplex-assisted group. It is of interest to note that none of the former cases was performed with a skin incision < or = 2 inches. CONCLUSION: Most CEAs (95%) can safely be performed with < or = 2-inch skin incisions. Pre-CEA duplex-assisted skin marking is a novel approach that confirms the side of the operation, localizes the disease, and minimizes the magnitude of the operation via shorter, more esthetically pleasing incisions.

A 10-year experience with complementary distal arteriovenous fistula and deep vein interposition for infrapopliteal prosthetic bypasses.

Since up to 20% of patients undergoing lower extremity revascularization do not have an adequate venous conduit, some authors have explored the use of prosthetic grafts with adjunctive techniques for lower extremity revascularization. However, the long-term graft patency of those procedures has not been well documented. The purpose of this study was to examine the long-term patency of polytetrafluoroethylene (PTFE) bypass with adjunctive arteriovenous fistula and venous interposition (AVF/VI) for infrapopliteal revascularization. Over a 10-year period, 246 lower extremity reconstructions were performed in 176 (71.5% men) patients with critical ischemia in whom a totally autogenous vein bypass was not feasible. Seventy-six limbs had undergone 1 or more failed ipsilateral infrainguinal bypasses. Indications for surgery were chronic critical limb-threatening ischemia (86%) (rest pain, ischemic ulcer, or gangrene) or acute ischemia (14%). Ages ranged from 46 to 91 years (mean 74 +/-0.6 [SD] years). Risk factors such as diabetes, hypertension, coronary artery disease, end-stage renal disease, and use of tobacco were present in 49%, 49%, 52%, 8%, and 67% of the patients, respectively. During the follow-up, 112 cases (45%) required reinterventions. Twenty-seven patients (15%) required bypass revision twice. During the follow up, 56 limbs (23%) were amputated (above-the-knee amputation 25 (10%); below-the-knee amputation 31 (13%). To date, 150 (85%) patients of a total of 176 are deceased. The primary graft patency rates were as follows: at 1 year, 51%; at 2 years, 41%; 3 years, 35%; and 5 years, 24%. Limb salvage rates were as follows: 1 year, 79%; 2 years, 76%; 3 years 76%; and 5 years, 74%. Patient survival rates were as follows: 1 year, 69%; 2 years, 60%; 3 years, 54%; and 5 years, 40%. Amputation-free patient survival rates were as follows: 1 year, 66%; 2 years, 57%, 3 years, 51%, and 5 years, 30%. This technique appears to offer reasonable patency and limb salvage rates in patients in whom autogenous bypass grafts are not feasible.

Effect of ultrasonography in the assessment of carotid artery stenosis.

Although ultrasonography (US) advantageously portrays lumen and wall thickness, velocity criteria have been used primarily to interpret carotid artery stenosis. The relationship of US and velocity measurements was investigated. Peak-systolic and end-diastolic velocities (PSV, EDV) increase exponentially as the lumen of the internal carotid artery narrows and the percent stenosis (%S) increases. We tested the consistency of the, relationship between carotid velocities and US %S in two distinct data sets. One data set was used to obtain regression equations relating velocity parameters and %S based on US. Validation of these equations was conducted using a separate, independent data set. US measurements were classified in 12 %S intervals, PSV, EDV, the ratio of the internal carotid artery to the common carotid artery PSV, and %S were entered consecutively until 10 records for each %S interval were obtained. Regression equations obtained in the first data set were used to predict %S in the second data set. Predicted %S was then compared with actual US %S. The highest correlation in the first data set (r = .89) was between %S and the natural logarithm (In) of PSV. This In PSV -%S equation was then applied to a second data set of an additional 120 carotid duplex images. In the second data set, actual %S and PSV-predicted %S differed by >10% in 38 cases (32%). When all velocity-%S regression equations were used for comparison, differences between actual and at least one velocity-predicted %S were >10% in 19% of the arteries. Conversely, actual %S matched at least one prediction of %S based on velocity data in 81% of the cases. US %S differed significantly from single velocity-based estimates of %S in at least one-third of the cases. On the other hand, four of five US measurements were confirmed by at least one velocity parameter. Emphasis on US, in addition to velocity data, is recommended for the interpretation of duplex US carotid examinations.

Decreased production of nitric oxide by peripheral blood mononuclear cells of patients with peripheral vascular disease.

Although prior studies have implicated nitric oxide (NO), a molecular messenger, in the development and progression of atherosclerosis, most of these studies have centered on atherosclerotic plaques. The current investigation determines whether a correlation exists between the presence of altered levels of NO production by peripheral blood mononuclear cells (PBMCs) and atherosclerotic disease. Venous blood was collected from 8 surgical patients having severe peripheral vascular disease and 8 healthy controls. PBMCs were separated by gradient centrifugation, diluted to 10(5) cells per mL, and cultured. Lipopolysaccharide (LPS), at doses of 10, 25, and 50 ng/mL, was used to stimulate NO production. Total nitric oxide assay was performed to determine the levels of NO produced by PBMCs at 24 and 48 hours. When stimulated by LPS there was an increase in NO production in the PBMCs cultured from control as well as patient samples, as compared to basal NO levels. However, the data demonstrate a significant decrease in the nitric oxide production in the patients with atherosclerosis as compared to that in the control group (p < 0.05). The differential production of nitric oxide by PBMCs of patients with atherosclerotic disease and healthy controls not only suggests that it has a role in the pathogenesis of this disease but also underlines its systemic nature. Blood cells circulating in the body with altered levels of NO production could have profound effects in the microvascular environment mediating molecular pathways and signaling cascades that activate and augment atherosclerosis.

Risk factors for mortality in patients with upper extremity and internal jugular deep venous thrombosis.

OBJECTIVE: To elucidate the natural history of upper extremity deep venous thrombosis (UEDVT), we examined factors that may contribute to the high mortality associated with UEDVT. METHODS: Five hundred forty-six patients were diagnosed with acute internal jugular/subclavian/axillary deep venous thrombosis from January 1992 to June 2003 by duplex scanning at our institution. There were 329 women (60%). The mean age +/- SD was 68 +/- 17 years (range, 1-101 years). Risk factors for UEDVT were the presence of a central venous catheter or pacemaker in 327 patients (60%) and a history of malignancy in 119 patients (22%). Risk factors for mortality within 2 months of the diagnosis of UEDVT that were analyzed included age, sex, presence of a central venous catheter or pacemaker, history of malignancy, location of UEDVT, concomitant lower extremity deep venous thrombosis, systemic anticoagulation, placement of a superior vena caval filter, and pulmonary embolism. RESULTS: The overall mortality rate at 2 months was 29.6%. The number of patients diagnosed with pulmonary embolism by positive ventilation/perfusion scan or computed tomographic scan was 26 (5%). The presence of a central venous catheter or pacemaker ( P < .001), concomitant lower extremity deep venous thrombosis ( P = .04), not undergoing systemic anticoagulation ( P = .002), and the placement of a superior vena caval filter ( P = .02) were associated with mortality within 2 months of the diagnosis of UEDVT by univariate analysis. Pulmonary embolism ( P = .42), sex ( P = .65), and a history of malignancy ( P = .96) were not. CONCLUSIONS: These data suggest that the high associated mortality of UEDVT may be due to the underlying characteristics of the patients' disease process and may not be a direct consequence of the UEDVT itself.

Duplex arteriography prior to femoral-popliteal reconstruction in claudicants: a proposal for a new shortened protocol.

The standard preoperative duplex arteriography (DA) from the aorta to the pedal vessels is time consuming and may be unnecessary in patients presenting with calf claudication alone. The feasibility of a shortened protocol was evaluated. Of 286 femoral-popliteal reconstruction based on DA during the last 4A years, 79 (28%) were primary operations for calf claudication. Eliminating the aortoiliac portion of the test except for the distal external iliac artery and limiting the scanning of the infrapopliteal vessels to one or two arteries in the leg would significantly shorten the exam. To confirm the adequacy of the inflow tract, we relied on the common femoral artery Doppler waveform analysis and the intraoperative graft pressure upon completion of the bypass. Of the 79 primary femoral-popliteal bypasses, 53 (67%) had triphasic common femoral artery waveform and the remaining 26 had monophasic or biphasic waveforms. Three (6%) of the 53 femoral-popliteal bypasses in the former group had significant pressure gradients measured intraoperatively and were treated with iliac angioplasties and stents for unsuspected stenoses in 2 cases and a covered stent for a common iliac aneurysm in 1 case. Three, two, and one infrapopliteal vessel runoff was observed in 24 (45%), 16 (30%), and 9 (17%) extremities, respectively. Four patients (8%) had significant stenoses (>50%) or occlusion of all three infrapopliteal arteries. Eighty-one percent of the patients would have completed the short protocol had we scanned the peroneal artery initially. An additional 8% would have required scanning of a second vessel (anterior tibial) and only 11%, scanning of all three infrapopliteal vessels. The time interval for completion of short-protocol DA was significantly less than the time for the standard DA (16.2 A+/- 5.2A min vs. 35.1 A+/- 10.6 min) ( p < 0.01). We believe that the proposed short DA protocol combined with intraoperative graft pressure measurements can be used in 94% of the patients who have a patent popliteal artery (>/= 7 cm). It is a totally noninvasive approach that is particularly suitable for vascular technologists and surgeons who wish to start utilizing DA instead of contrast arteriography prior to infrainguinal reconstructions. However, the short protocol does not avert the need for completion arteriography of the inflow arteries and readiness to perform endovascular procedures to correct lesions not suspected by common femoral artery waveform analysis.

Lower extremity deep venous thrombosis: vascular laboratory quality assurance without correlation between ultrasound and venography.

Venography is rarely available for comparison with ultrasonography (US) as a means for quality assurance (QA) in the detection of lower extremity venous thrombosis. New QA methods must be implemented. We compared results of multiple serial studies performed in the same extremity as a QA indicator. From a 3-year sample of close to 9,000 venous tests, we obtained a subset of 44 patients who had 331 tests in 71 lower extremities throughout the years. A positive or negative study preceded or followed by another positive or negative study was considered as a confirmed study. A negative or positive study not preceded or followed by a negative or positive study was considered as unconfirmed. Explanations were then sought to explain unconfirmed results. There were 169 (51%) and 124 (37%) confirmed positive and negative studies, respectively, and 13 (4%) and 25 (8%) unconfirmed positive and negative studies, respectively. Of the 13 unconfirmed positive tests, 2 were preceded by negative tests, 3 were preceded and followed by negative tests, and 8 were followed by negative tests. Of these 13 tests, 4 documented extensive venous thrombosis. Of the 25 unconfirmed negative tests, 11 followed treatment for venous thrombosis, 6 had recurrent thrombosis with intermittent lysis, and 8 were followed by positive tests. Considering the low probability of extensive thrombosis being a false-positive test, positive predictive value was 95% (173/182). Excluding 11 negative tests following treatment for venous thrombosis, negative predictive value was 90% (124/138) and accuracy was 93% (297/320). US versus US and literature US versus venography comparisons of these statistics were similar.

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.

Deep venous thrombosis after radiofrequency ablation of greater saphenous vein: a word of caution.

PURPOSE: Radiofrequency ablation (RFA) of the greater saphenous vein (GSV; "closure") is a relatively new option for treatment of venous reflux. However, our initial enthusiasm for this minimally invasive technique has been tempered by our preliminary experience with its potentially lethal complication, deep venous thrombosis (DVT). METHODS: Seventy-three lower extremities were treated in 66 patients with GSV reflux, between April 2003 and February 2004. There were 48 (73%) female patients and 18 (27%) male patients, with ages ranging from 26 to 88 years (mean, 62 +/- 14 years). RFA was combined with stab avulsion of varicosities in 55 (75%) patients and subfascial ligation of perforator veins in 6 (8%) patients. An ATL HDI 5000 scanner with linear 7-4 MHz probe and the SonoCT feature was used for GSV mapping and procedure guidance in all procedures. GSV diameter determined the size of the RFA catheter used. Veins less than 8 mm in diameter were treated with a 6F catheter (n = 54); an 8F catheter was used for veins greater than 8 mm in diameter (n = 19). The GSV was cannulated at the knee level. The tip of the catheter was positioned within 1 cm of the origin of the inferior epigastric vein (first GSV tributary). All procedures were carried out according to manufacturer guidelines. RESULTS: All patients underwent venous duplex ultrasound scanning 2 to 30 days (mean, 10 +/- 6 days) after the procedure. The duplex scans documented occlusion of the GSV in 70 limbs (96%). In addition, DVT was found in 12 limbs (16%). Eleven patients (92%) had an extension of the occlusive clot filling the treated proximal GSV segment, with a floating tail beyond the patent inferior epigastric vein into the common femoral vein. Another patient developed acute occlusive clots in the calf muscle (gastrocnemius) veins. Eight patients were readmitted and received anticoagulation therapy. Four patients were treated with enoxaparin on an ambulatory basis. None of these patients had pulmonary embolism. Initially 3 patients with floating common femoral vein clots underwent inferior vena cava filter placement. Of the 19 limbs treated with the 8F RFA catheter, GSV clot extension developed in 5 (26%), compared with 7 of 54 (13%) limbs treated with the 6F RFA catheter (P =.3). No difference was found between the occurrence of DVT in patients who underwent the combined procedure (RFA and varicose vein excision) compared with patients who underwent GSV RFA alone (P =.7). No statistically significant differences were found in age or gender of patients with or without postoperative DVT (P = NS). CONCLUSION: Patients who underwent combined GSV RFA and varicose vein excision did not demonstrate a higher occurrence of postoperative DVT compared with patients who underwent RFA alone. Early postoperative duplex scans are essential, and should be mandatory in all patients undergoing RFA of the GSV.

Role of duplex arteriography as the sole preoperative imaging modality prior to lower extremity revascularization surgery in diabetic and renal patients.

The limitations and complications associated with contrast angiography (CA) prior to lower extremity revascularization have led to an increased interest in duplex arteriography (DA) as a potential replacement. We report our experience with DA in patients with diabetes and/or chronic renal insufficiency (CRI) that would particularly benefit from a noninvasive approach to preoperative evaluation of the arterial tree. From January 1998 to November 2000, DA was performed in 145 patients with diabetes mellitus and/or CRI prior to 180 arterial reconstructions. One hundred twenty-one procedures were performed on 91 patients with diabetes alone, 41 on 33 patients with diabetes and CRI, and 18 on 15 patients with CRI alone. Patient ages ranged from 36 to 98 years (mean 72 +/- 12 years). Indications for surgery were severe claudication in 33 (18%), rest pain in 37 (21%), nonhealing ischemic ulcers in 52 (29%), and limb gangrene in 58 (32%). Optimal inflow and outflow anastomotic sites were selected according to a diagram based on DA that included arterial tree imaging from mid-aorta to the pedal vessels. Preoperative contrast arteriography was performed in 16 cases (9%) because of extremely poor runoff based on DA and limited visualization of outflow vessels. The distal anastomosis was to the popliteal artery in 89 cases (49%) and to the tibial and pedal arteries in 91 (51%). Intraoperative findings confirmed the preoperative DA results with the exception of one (0.6%) where the distal anastomosis was placed proximal to a significant stenosis requiring an extension graft. The use of DA presents a safe and reliable option to prebypass CA for many patients with diabetes or CRI. The ease of use and favorable patient outcomes achieved by this imaging modality may rival the use of CA for these patients.

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.

Endovascular management of axillofemoral bypass graft stump syndrome.

OBJECTIVE: Upper extremity embolic complications of occluded axillofemoral bypass grafts are infrequent. However, traditional management of dissection of axillary anastomosis for removal of the stump can be challenging. We report two patients with critical upper extremity ischemia secondary to stump syndrome and its successful management with endovascular techniques. METHODS: One hundred fifty-two patients underwent axillofemoral bypass grafting over 10 years from 1991-2001. Two patients from this series had acute ischemia involving the ipsilateral upper extremity of occluded axillofemoral bypass graft. Duplex ultrasound scans revealed occlusion of the axillofemoral bypass graft and acute occlusion of ipsilateral upper extremity arteries. Both patients underwent brachial artery exploration and embolectomy. Completion angiograms revealed persistent axillofemoral bypass graft stump as the source of embolus. The stump was obliterated with a 10-mm/40-mm Wallgraft introduced through the same arteriotomy made for brachial embolectomy. Transesophageal echocardiography and magnetic resonance angiography of the arch and great vessels were performed to exclude other sources of origin for the embolus. RESULTS: Both patients remained symptom-free and with patent stent grafts, as seen on duplex scans at 3, 6, and 9 months of follow-up. CONCLUSIONS: Upper extremity embolism is a rare complication after occlusion of axillofemoral bypass grafts. The endovascular approach to obliterate the stump of occluded axillofemoral bypass grafts is minimally invasive and an effective alternative treatment of this rare condition.