Faculty Bibliography

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.

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.

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.

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.

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.

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.

PURPOSE: Thromboembolic complications after carotid endarterectomy are frequently associated with technical defects. We analyzed the effect of intraoperative duplex scanning in detection of significant but clinically unsuspected technical defects and residual common carotid artery (CCA) disease as a potential source of postoperative transitory ischemic attack (TIA) and stroke. METHODS: From April 2000 to April 2003, 650 consecutive primary carotid endarterectomy procedures were performed in 590 patients at a single institution by two vascular surgeons. Patients included 335 men (57%) and 255 women (43%). Indications for surgery were asymptomatic internal carotid artery (ICA) stenosis (>or=70%) in 464 patients (71%). All procedures were performed with the patient under general anesthesia, with synthetic patch angioplasty in 644 (99.1%). Major technical defects at intraoperative duplex scanning (>30% luminal internal carotid artery stenosis, free-floating clot, dissection, arterial disruption with pseudoaneurysm) were repaired. CCA residual disease was reported as wall thickness (0.7-4.8 mm; mean, 1.7 +/- 0.7) and percent stenosis (16%-67%; mean, 32% +/- 8%) in all cases. Postoperative 30-day TIA, stroke, and death rates were analyzed. RESULTS: There were no clinically detectable postoperative thromboembolic events in this series. All 15 major defects (2.3%) identified with duplex scanning were successfully revised. These included 7 intimal flaps, 4 free-floating clots, 2 ICA stenoses, 1 ICA pseudoaneurysm, and 1 retrograde CCA dissection. Diameter reduction ranged from 40% to 90% (mean, 67 +/- 16%), and peak systolic velocity ranged from 69 to 497 cm/s (mean, 250 +/- 121 cm/s). Thirty-one patients (5%) with the highest residual wall thickness (>3mm) in the CCA and 19 (3%) with the highest CCA residual diameter reduction (>50%) did not have postoperative stroke or TIA. Overall postoperative stroke and mortality rates were 0.3% and 0.5%, respectively; combined stroke and mortality rate was 0.8%. One stroke was caused by hyperperfusion, and the other occurred as an extension of a previous cerebral infarct. No patients had TIAs. Two deaths were caused by myocardial infarction, and one death by respiratory insufficiency. CONCLUSION: We believe intraoperative duplex scanning had a major role in these improved results, because it enabled detection of clinically unsuspected significant lesions. Residual disease in the CCA does not seem to be a harbinger of stroke or TIA.

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.

BACKGROUND: We have previously demonstrated that programmed cell death, proteolytic activity, and inflammatory infiltrate in the aneurysmal wall may have a role in the pathogenesis of popliteal artery aneurysms (PAA). This investigation examines the expression of a cell death-promoting molecule, a cysteine protease, YAMA/CPP-32 in a series of PAA specimens. METHODS: Twenty PAA specimens were obtained from patients undergoing elective surgical repair. Normal controls were popliteal arteries obtained from patients without PAA who were undergoing infrainguinal bypass surgery (n = 8). Standard histochemistry techniques were used to assess inflammatory infiltrates in PAA. Expression of apoptosis-promoting molecule, CPP-32, vascular smooth muscle cells (VSMC), macrophages, and T lymphocytes was detected by immunohistochemistry. RESULTS: There is a conspicuous disruption and fragmentation of elastic lamellae and increased inflammatory infiltrate in the PAA as compared with normal arteries. As compared with normal popliteal artery tissues, the PAA demonstrated large number of cells immunopositive for CPP-32 (60.45 +/- 4.25% P < 0.05). This study revealed significantly increased expression of CPP-32 in the T-cell population of the PAA as compared with the other cells (P < 0.01). Dual immunolabeling and investigation of serial sections demonstrated that co-expression of CPP-32 was maximum in the CD8+ subset (37 +/- 3.3% of the total CPP-32 immunoreactive cells identified). CONCLUSIONS: The data emphasize that the inflammatory infiltrate in the PAA walls has a significant role in the pathogenesis of this vascular disorder. Cells expressing death-promoting molecules are present in large numbers and are predominantly T lymphocytes in PAA. In addition to compromising the mechanical integrity of the vessel wall, apoptosis in the inflammatory infiltrate may contribute to the production of cytokines, activation of other signaling molecules such as stress proteins that could eventually favor PAA development.

Contrast arteriography (CA) is the gold standard preoperative imaging modality for patients with chronic and acute lower limb ischemia. We have previously shown that high-quality DUAM can safely replace CA in patients with chronic ischemia. The goal of this study was to investigate whether DUAM can also be used effectively in the setting of acute ischemia. From January 1998 to February 2001, 68 patients were admitted to our institution with 87 instances of acute lower limb(s) ischemia and underwent 87 operations. There were 34 men and 34 women whose age ranged from 51 to 95 years (mean 72 +/- 12.5). There were 44 cases of acute arterial occlusions and 43 cases of bypass graft thromboses. In the former group the most proximal occluded site based upon duplex was the aorta in 1 case, common iliac in 4 cases, external iliac in 15 cases, and infrainguinal arteries in 24 cases. In the latter group, there were 4 suprainguinal grafts, 24 bypasses to the popliteal artery, and 15 bypasses to infrapopliteal arteries. All patients had DUAM as their initial diagnostic study. The duplex protocol varied according to the pulse exam. In patients with a good femoral pulse but absent popliteal pulse, attempts were made to visualize the ipsilateral femoral-popliteal segment and the proximal third of the infrapopliteal arteries. This was extended to the pedal arteries in cases of proximal occlusion. When the femoral pulse was absent the protocol included visualization of the distal aorta, bilateral iliac, and common femoral arteries. This exam was extended into the deep and superficial femoral-popliteal segments in cases of proximal occlusion. None of these cases had preoperative or prebypass CA. Intraoperative arterial pressures to confirm the adequacy of the inflow tract and completion arteriography to assess the runoff were performed in 78% of the cases at the end of the procedure. This initial experience suggests that high-quality DUAM may replace CA in patients with lower limb ischemia. DUAM provides a reliable assessment of the inflow and outflow arteries even in very low-flow situations. In addition, DUAM can identify the cause of the arterial occlusion, thereby making therapy more effective and less time consuming.