Faculty Bibliography

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.

BACKGROUND: Carotid artery balloon angioplasty and stenting (CBAS) is emerging as an acceptable alternative to carotid endarterectomy in selected high-risk patients. Conversely, patients with pre-existing renal impairment, diabetes, or both may be harmed by the nephrotoxic contrast agents required during CBAS. We attempted to limit or eliminate the use of contrast material during CBAS. METHODS: Eighteen patients with severe carotid stenoses (>70%) underwent CBAS at our institution over the last 12 months with duplex scan-assisted CBAS. Of these, 12 were primary procedures, and 6 were performed for carotid re-stenosis. Fourteen patients (78%) were neurologically asymptomatic. The average age of these patients was 75 +/- 11 years (range, 44-92 years). Hypertension, chronic renal insufficiency (serum creatinine level > or =1.5 mg/dL), coronary artery disease, diabetes, and smoking were present in 89%, 67%, 59%, 33%, and 28% of patients, respectively. Preoperative duplex carotid mapping was performed in all cases. All procedures were performed with patients under local anesthesia and light sedation. RESULTS: An ATL HDI 5000 scanner with the SonoCT feature was used. The common femoral artery was cannulated with a single-entry needle under direct ultrasound visualization. Fluoroscopy was used to assist passage of the guidewire into the aorta and the common carotid artery. In only four cases (22%) was an aortic arch angiogram obtained. Selective catheterization of the internal and external carotid arteries was performed under ultrasound guidance. The distal cerebral protection device (17 cases) was placed under fluoroscopic guidance. Balloon width and length were chosen according to ultrasound measurements. Balloon and stent deployment were successfully achieved with ultrasound guidance alone in all cases. Appropriate stent apposition and resolution of the stenosis was confirmed by duplex scanning in all cases. Five patients (28%) were noted to have low (<100 mL/min) internal carotid artery volume flow after stent deployment (range, 20-88 mL/min; mean +/- SD, 50 +/- 25 mL/min). The internal carotid artery volume flow increased immediately after Filterwire retrieval in all cases and ranged from 136 to 400 mL/min (mean, 245 +/- 107 mL/min). This increase was statistically significant ( P < .02). No ipsilateral strokes or deaths occurred during follow-up from 1 to 12 months (mean follow-up, 5 months). CONCLUSIONS: Duplex scan-assisted CBAS is feasible and may reduce the need for intra-arterial contrast injection in selected patients deemed at high risk for renal failure from nephrotoxic contrast material. Additional advantages include direct visualization of the puncture site, precise position of the balloon and stent, and B-mode and hemodynamic confirmation of the adequacy of the technique.

BACKGROUND: The technique of balloon angioplasty of infrainguinal arteries requires standard arteriography and fluoroscopic guidance. We attempted to perform this procedure under duplex guidance to avoid the use of nephrotoxic contrast material and radiation exposure in patients with renal insufficiency. METHODS: Over 16 months, 28 patients (17 men) with serum creatinine levels of 1.5 mg/dL or more underwent 37 lower extremity duplex-guided balloon angioplasties at our institution. Ages ranged from 58 to 92 years (mean +/- SD, 74 +/- 9 years). Disabling claudication was the indication in 24 cases (65%), and critical ischemia, in 13 cases. Preoperative duplex arterial mapping showed severe superficial femoral artery and/or popliteal artery stenoses in all cases. No arterial occlusions were treated in this series. Seven procedures (19%) were performed for restenosis. The ipsilateral common femoral artery was cannulated in 32 cases (86%), and the contralateral common femoral artery, in 5 cases (14%), under direct duplex visualization. Contralateral common iliac artery cannulations were performed with the help of fluoroscopy. By using sonographic visualization, a guidewire was directed into the origin of the superficial femoral artery, across the diseased segment, and into the popliteal artery. The diseased segment was then balloon-dilated. Balloon diameter and length were chosen according to arterial measurements obtained by duplex scan. Plaque dissections and recoils causing stenosis of 30% or more, a peak systolic velocity ratio of 2 or more, or both were stented under duplex guidance. Arterial duplex examinations and ankle/brachial indexes were obtained before hospital discharge, within 1 month after the procedure, and every 3 months thereafter. RESULTS: Thirty-day survival was 100%. Local complications included one open exploration for expanding hematoma. Technical success was achieved in all cases. Placement of intraluminal stents was deemed appropriate in 23 (62%) of 37 cases. The 1-month patency and limb salvage rates were 100%. Preprocedure and postprocedure ankle/brachial indexes ranged from 0.3 to 0.9 (mean +/- SD, 0.64 +/- 0.16) and 0.64 to 1.2 (mean +/- SD, 0.92 +/- 0.15), respectively (P < .0001). CONCLUSIONS: Duplex-guided balloon angioplasty seems to be a safe and effective technique that allows renal patients to experience continued limb salvage and relief from claudication without the risk of developing dye-induced acute renal failure. Other advantages include direct visualization of the puncture site, accurate selection of the proper size of balloon and stent, confirmation of the adequacy of the technique by hemodynamic and imaging parameters, and avoidance of radiation. Although this technique holds considerable potential, longer follow-up will help to fully evaluate its broader applicability.

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.

BACKGROUND: The published results of carotid endarterectomy (CEA) in chronic renal insufficiency (CRI) patients are contradictory, mostly because of the relatively small number of patients in these studies. To better assess the neurologic complications and mortality, we reviewed a recent and substantially larger series of CRI patients who underwent CEAs. METHODS: From March 2000 to March 2003, 675 consecutive primary CEAs were performed in 609 patients (346 men, 57%) under general anesthesia. Asymptomatic carotid artery stenosis accounted for 71% of cases. CRI (serum creatinine level > or = 1.5 mg/dL) was detected in 166 patients (27%) who underwent 184 CEAs. The remaining 443 patients (73%) had 491 CEAs. RESULTS: Patients with CRI were different in age (76 +/- 8 years vs 72 +/- 9 years, P < .001), male gender (73% vs 51%, P < .001), coronary artery disease (50% vs 28%, P < .001), and diabetes mellitus incidence (38% vs 27%, P < .02). No significant difference in stroke rates was observed between the CRI patients and the control group (1.2% vs 0.5%). The mortality rate for CRI patients was 3%, whereas it was 0% for the control group ( P < .002). The 143 CRI patients with serum creatinine levels from 1.5 to 2.9 mg/dL had a 0.7% mortality rate, whereas it was 17% for 23 patients with serum creatinine levels of 3 mg/dL or more ( P < .001). The stroke rate for the former group was 0.7% and 4.3% for the latter group (NS). Asymptomatic (16) and symptomatic (7) patients with serum creatinine levels of 3 mg/dL or more had mortality rates of 13% and 28%, respectively, with P = .6. CONCLUSION: The high mortality rate observed in patients with serum creatinine levels of 3 mg/dL or more after CEA calls for a nonoperative approach in the management of asymptomatic patients.

OBJECTIVE: Balloon angioplasties of stenotic or occluded infrapopliteal arteries may be helpful in selected high-risk patients threatened with limb loss. Thus far, these procedures have demanded fluoroscopy and the injection of potentially nephrotoxic contrast material. Herein, we proposed a new alternative to avoid the harmful effects of radiation exposure and the risk of acute renal failure. METHODS: Over the last 16 months, 30 patients (57% male) aged 74 +/- 9 years (mean +/- SD) had a total of 52 attempted balloon angioplasties of the infrapopliteal arteries in 32 limbs under duplex guidance. Indications for the procedure were critical ischemia in 20 limbs (63%), including rest pain, ischemic ulcers, and gangrene in 4 (13%), 10 (31%), and 6 (19%) limbs, respectively. Severe disabling claudication was an indication in the remaining 12 limbs (37%). All patients had concomitantly performed balloon angioplasties of the superficial femoral and popliteal arteries (28 cases) or the popliteal artery alone (4 cases). Balloon angioplasty of the infrapopliteal arteries was performed as an adjunct to improve runoff. Hypertension, diabetes, renal insufficiency, smoking, and coronary artery disease were present in 77%, 73%, 50%, 47%, and 37% of cases, respectively. There were 42 cases (81%) with infrapopliteal arterial stenoses (25 tibioperoneal trunks, 9 peroneal arteries, 4 anterior tibial arteries, and 4 posterior tibial arteries) in 26 limbs. The remaining 10 cases (19%) had infrapopliteal arterial occlusions (4 tibioperoneal trunks, 5 peroneal arteries, and 1 anterior tibial artery) in 6 limbs. All these cases were combined with more proximal endovascular procedures (21 femoropopliteal stenoses and 11 femoropopliteal occlusions). All patients had preprocedure duplex arterial mapping and ankle/brachial index (ABI) measurement. Local anesthesia with light sedation was used in all cases. The common femoral artery was cannulated under direct duplex visualization. Still under duplex guidance, a guidewire was directed into the proximal superficial femoral artery and distally, beyond the infrapopliteal diseased segment. The diseased segment was then balloon-dilated. Balloon diameter and length were chosen according to the arterial measurements obtained by duplex guidance. Completion duplex examinations were performed and postprocedure ABIs were obtained in all cases. RESULTS: Although the overall technical success was 94% (49/52 cases), it was 95% for those with stenoses (40/42 cases) and 90% for those with occlusions (9/10 cases; P < .5). Intraoperative thrombosis occurred in three infrapopliteal cases (two tibioperoneal trunks and one peroneal artery) and in one popliteal artery. All four cases were successfully managed with intra-arterial infusion of thrombolytic agents under duplex guidance. Overall, the preprocedure and postprocedure ABIs ranged from 0.4 to 0.8 (mean +/- SD, 0.58 +/- 0.15) and 0.7 to 1.1 (mean +/- SD, 0.9 +/- 0.16), respectively (P < .0001). Twenty-two (88%) of 25 patients experienced a significant (> 0.15) postoperative ABI increase. Overall 30-day survival and limb salvage rates were 100%. CONCLUSIONS: The proposed technique eliminates the need for radiation exposure and the use of contrast material, and it seems to be an effective alternative approach for the treatment of infrapopliteal occlusive disease. Additional advantages include accurate selection of the proper size of balloon and confirmation of the adequacy of the technique by hemodynamic and imaging parameters.

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.

The clinical significance of lower extremity deep vein thrombus (DVT) propagation in the setting of anticoagulation therapy remains unclear. The purpose of this study is to compare results of thrombus outcome found with repeat duplex ultrasonography to the incidence of pulmonary embolism and mortality. During a recent 18-month period, 457 patients were diagnosed with lower extremity DVT with duplex ultrasonography and their data were retrospectively analyzed. Repeat examinations were available for review in 118 patients (51 men, 67 women). Results of repeat duplex exams were divided into 4 groups: resolved, improved, unchanged, or extended proximally. All patients received heparin and warfarin therapy. Ventilation-perfusion (V/ Q) scans were obtained only for signs and symptoms of pulmonary embolism (n=30). Mortality, the prevalence of high-probability V/ Q scans, frequency of intracaval filter insertion, gender, mean age, mean prothrombin time (PT), mean partial thromboplastin time (PTT), mean number of repeat ultrasounds per patient, and mean time over which the repeat ultrasounds took place were compared among the 4 groups. Patients who had proximal extension of DVT (19%) on repeat duplex ultrasound had an increased prevalence of pulmonary embolism (p<0.05). Also, patients whose DVT resolved were younger (p<0.05). There was no difference among the 4 groups in mortality, placement of Greenfield filters, mean PT, mean PTT, mean number of ultrasound exams per patient, or mean follow-up time over which the exams took place. Proximal extension of DVT documented by repeat duplex ultrasound is a significant risk factor for pulmonary embolism. Repeat duplex ultrasound can identify a group of patients who may benefit from insertion of an intracaval filter device.

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.

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.