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Endovascular angioplasty and stenting have become a treatment of choice for severely symptomatic left iliac veins under external, arterial compression. Patency rates of stented iliac veins based on ultrasonographic (US) findings were estimated. Retrospective analyses of gender, age, deep venous thrombosis (DVT) prior to stenting, stent location at common and/or external iliac veins, and patency rates from 1 month to 5 years were performed. Patients treated were mostly women (72 of 79, 91%), aged 51 ± 16 (25-89) years. Patency rates were 96% at 1 month, 89% at 1 year, and 85% at 3 to 5 years, best for common iliac, 95%, than for external iliac vein stents, subgroup with prior DVT, with secondary patency rates of 75%. US demonstrated acceptable patency rates for iliac vein stenting showing good performance for common iliac vein stents but a decreased performance with stent extending to the external iliac vein or stents placed in patients with prior iliac DVT.

Objective —Ulnar nerve compression, the Guyon's canal syndrome, is more unusual than carpal tunnel disorders. An exceptional case of a patient with vascular and neurogenic signs and symptoms is described. Patient Presentation —A 26-year-old female physiotherapist presented with neurogenic and arteriovenous signs and symptoms involving the right hand. The patient described fourth finger and wrist pain with flexion, and pain and itching extending to arm and forearm. Sensations worsened when exposed to air conditioning. Enlarged vessels were noted in the medial aspect of the fourth digit; trauma occurred 8 years earlier during attempts to open a nail polish container. Methods —Color flow, duplex-Doppler ultrasonography (US) of the subclavian to digital vessels was performed using 3- to 13-MHz transducers. Interpretation focused on flow waveforms obtained with the hand open and closed, having the left extremity as reference. Thermography was performed with camera Flir 15, room temperature at 21°C (70°F) and relative humidity at 48%. Results —Right subclavian to digital arteries had high diastolic flow with opened hand. Hand closure interrupted diastolic flow except in the ulnar circulation to the fourth digit. Common digital arteries feeding digits 3–4 and 4–5 had significantly more diastolic flow than the artery feeding digits 2–3. Diastolic flow through a dilated ulnar artery despite hand closure was associated to a millimetric arteriovenous fistula in the fourth finger. Hyperthermia saturating at 35°C (95°F) showed channel-like images over the ulnar nerve and artery and fourth digit, compared with 20°C (68°F) for digit 2. Conclusions —US and thermography demonstrated high flow and hyperthermia associated with a fourth digit fistula and abnormal vessels, and ulnar artery dilatation likely associated with ulnar nerve injury. A coadjuvant diagnosis of Guyon's canal syndrome at the wrist was raised.

Objective—To demonstrate differences in saphenous reflux detection performed with the use of a simplified protocol with the patient in the supine or reverse Trendelenburg positions (nonstanding) co...

ObjectivesWe sought to (1) to determine prevalence of high brachial artery bifurcation, forearm cephalic-arm cephalic connection, forearm cephalic-arm basilic vein alternate connection, and levels ...

Objective The small saphenous vein (SSV) often is a forgotten source of venous valvular insufficiency signs and symptoms or is a “victim” of unwillingness to treat. Either way, ultrasound (US) frequently focuses on the great saphenous vein without an equivalent thorough evaluation of the SSV. We investigated the prevalence and patterns of SSV reflux during a voluntary service to the community of Santiago de Guayaquil in Ecuador. Methods Patients were screened for SSV reflux while standing. A portable laptop scanner was used to examine the SSV at the proximal, mid, and distal calf (positions A, B, and C) in 410 legs of 205 subjects. Although all patients were C1 – C6 according to the clinical CEAP (i.e., clinical severity, etiology or cause, anatomy, and pathophysiology) classification, 14% of the legs were C0. Forward and reverse flows were noted after a variety of manual compressions. Only severe reflux lasting longer than 4 seconds is reported herein. Results The prevalence of SSV abnormalities was 17% (69/410). Reflux was noted in 54 (13%) of the extremities whereas in 15 (4%), the SSV did not have reflux but was intertwined with the pathways of varicose veins. The diameters of the refluxing veins were related to the location and extent of reflux. The most common pattern was reflux in the A, B, and C positions (n = 17) of SSV averaging 4.6 (A) to 4.4 mm (C) in diameter. Reflux was noted in the AB, A, and B positions in 10, 11, and 12 SSV, respectively; diameters of these veins averaged 4.1 (A) to 3.7 mm (B), 4.1 mm (A), and 3.4 mm (B). SSV reflux in the B and C and C only positions were least common (n = 4), noted in veins averaging 2.5 mm in diameter. Varicose veins interconnected with short SSV segments were noted in all three positions (A, B, and C) in seven legs whereas in eight legs the varicosities were segmental, most commonly in the B position (n = 6). Conclusions The prevalence of SSV abnormalities was significant. SSV reflux or connection to varicose veins was noted in close to one of five legs. The SSV should be evaluated at least at the proximal and mid calf to avoid missing significant reflux.

Purpose Patients with chronic venous insufficiency have been successfully treated with foam sclerotherapy. Reports of cerebral and respiratory symptoms after the foam procedure have been related to an open foramen ovale (PFO) between the right and left sides of the heart. This work evaluated the value of ultrasonography to demonstrate that bubbles may traverse a PFO and may be detected at the middle cerebral artery. Methods Patients describing cerebral or respiratory symptoms or suspected of having a PFO entered this study. Cerebral symptoms included visual disturbance, lightheadedness, dizziness and migraine. Respiratory problems included cough. A total of 20 patients had transthoracic echocardiography (TTE), and 12 had transcranial Doppler (TCD) of the middle cerebral artery. Results TTE detected bubbles in the left heart in 13 (65%) of 20 patients. The 12 TCDs were performed in nine patients with positive and three with negative TTE evaluation; five TCDs were positive for emboli at the middle cerebral artery. All five patients had positive transthoracic echocardiography. Conclusions This single-institution evaluation for quality control demonstrated that 1) patients with cerebral or respiratory symptoms after foam sclerotherapy may have PFO; and 2) patients with patent PFO may embolize the gas particles to the brain. Therefore, patients with known PFO must be evaluated before foam injection, and patients that are candidates for this treatment may have to be screened for PFO.

Introduction —Transcranial Doppler (TCD) has been used to document blood flow indicative of patients who are clinically brain dead. Limitations of TCD include signal loss in the absence of an adequate acoustic window, or extensive craniotomies that interfere with TCD insonation. Additionally, when compared with duplex ultrasonography of extracranial carotid and vertebral arteries, TCD is more technically difficult to master, with limited availability in many institutions. Objective —We sought to evaluate the use of carotid and vertebral artery ultrasound resistive indices in patients with clinically diagnosed brain death. Methods —Standard carotid and vertebral duplex ultrasound protocol was used to evaluate extracranial arteries in 2 groups: I: 8 control subjects, mean age of 49 years, without evidence of carotid or vertebral atherosclerosis, and II: 8 patients, mean age of 48 years, diagnosed with brain death confirmed by electroencephalography. All patients had insignificant (< 50% stenosis) carotid and vertebral atherosclerosis. T-test was used to compare common carotid, internal carotid (ICA), external carotid, and vertebral (VERT) artery resistive indices between Groups I and II. Results —Common carotid (0.74 ± 0.04 vs. 0.88 ± 0.08), ICA (0.60 ± 0.06 vs. 1.00 ± 0.00), and VERT (0.61 ± 0.05 vs. 1.00 ± 0.00) artery resistive indices were significantly lower in normal subjects than in brain death patients ( p < 0.05). Both ICA and VERT waveforms in brain death patients demonstrated the oscillatory, “to-and-fro,” pattern already established with TCD. Conclusion —Extracranial ICA and VERT waveforms in patients diagnosed with clinical brain death have the same resistive indices and waveform patterns that have been used to identify brain death intracranially with TCD. Because standard duplex ultrasonography is the most commonly used noninvasive modality for cerebrovascular evaluation, we believe this method may be easier to understand and more readily available for the initial diagnosis of cerebral brain death.

Objective: Endovascular placement of prosthetic valves is currently in clinical trials as treatment for lower extremity venous hypertension caused by valvular insufficiency. Femoropopliteal vein sizing is a critical factor in treatment planning. A wide diameter range could influence selection of an endoprosthesis. Quantitative data describing intrasubject vein diameter variation are scant. We measured vein diameters with ultrasound imaging to assess minimum-maximum diameter range under forced conditions of venoconstriction and venodilatation. Methods: Diameter of the common femoral vein (CFV), proximal femoral vein (PFV), mid-femoral vein (MFV), and distal femoral vein (DFV) in the thigh and the popliteal vein (PV) was measured in the morning under conditions of minimal venodilation and in the afternoon under conditions of stressed venodilatation that included activities of daily living and a 5-minute treadmill walk. Measurements were obtained twice on two different days in both extremities in 20 subjects with CEAP clinical classification C0 (n = 10), C3 (n = 7), C4 (n = 1), or C5 (n = 2). Results: Average vein diameter increased, from 11.2 ± 2.5 (SD) mm to 14.5 ± 2.3 mm at the CFV, from 6.9 ± 1.8 mm to 9.4 ± 1.9 mm at the PFV, from 6.9 ± 1.6 mm to 9.0 ± 1.8 mm at the MFV, from 7.3 ± 1.7 mm to 9.1 ± 1.5 mm at the DFV, and from 8.4 ± 1.4 mm to 9.7 ± 1.8 mm at the PV (P

Introduction Endoluminal stent grafts are replacing conventional abdominal aortic aneurysm (AAA) surgery in an increasing number of patients in an attempt to minimize morbidity and mortality. Long-term follow-up of endograft-treated AAA demands image-based surveillance to detect endoleak, graft migration, and morphology change in the excluded AAA. AAA diameter is a traditional but simplistic measurement that has inherent flaws and has been shown to be insensitive to changes in AAA sac morphology. Volume measurement, performed by CT data acquisition and computerized postprocessing, has been proposed as the most sensitive index of successful AAA stent graft exclusion. We evaluated two ultrasound (US) volume measuring techniques for AAA volume determination: Virtual Organ Computer-aided AnaLysis (VOCAL) and Multi-Plane Area Summation (MPAS). Methods US images of an endograft-treated AAA were obtained with a commercially available three-dimensional (3-D) scanner. A fast rotating motor inside the probe allowed registration of multiple two-dimensional (2-D) images in real time. Data from these images were assembled in a 3-D dataset. With VOCAL, the 3-D AAA boundaries were identified, and volume was calculated. The operator traced AAA boundaries in six virtual planes selected by the software. With MPAS, aneurysm boundaries were traced in 2-D virtual images perpendicular to the longitudinal axis of the aneurysm obtained every 1 mm. AAA area was calculated and multiplied by this 1-mm step to obtain incremental volumes that were summed to obtain the AAA volume. VOCAL and MPAS volumes were calculated 10 times each for one AAA scan. Results Average AAA volumes were 86.7 ± 3.7 cm3 with VOCAL and 87.6 ± 3.1 cm3 with MPAS. These averages were not statistically significantly different by t test ( p = 0.54). Standard deviation (SD) to average ratio was 4.3% for VOCAL and 3.5% for MPAS. Conclusion Volume of an endograft-treated AAA was successfully measured multiple times with two 3-D US techniques. Volumes obtained were comparable, demonstrating feasible reproducibility.

There is a major difference in thrombogenicity between lower extremity prosthetic and autologous vein bypass grafts, and arterial blood flow shear rate is known to influence thrombus formation. Despite this association, there has been little direct clinical observation of shear rates in bypass grafts. The authors developed a new noninvasive method to quantitate human arterial shear rate and used it in a pilot study to characterize differences in lower extremity bypasses. Shear rates were measured in 10 prosthetic and 14 autologous vein femoropopliteal bypass grafts. With CVI-M-mode color flow ultrasonography in resting supine patients, a velocity profile was recorded from a midgraft longitudinal section in the ultrasound beam direction. Shear rates were calculated by using a mathematical-graphic computer program at the anteromedial (near) and posterolateral (far) graft walls by averaging values immediately before and after peak systolic velocity (PSV). Comparison between prosthetic and autologous graft groups respectively revealed that differences in age (67 ± [S] vs 71 ± 10 yr), male gender (60% vs 43%), prevalence of hypertension (50% vs 71%), diabetes (40% vs 64%), smoking (50% vs 50%), hypercholesterolemia (30% vs 29%), coronary artery disease (60% vs 50%), and critical ischemia (60% vs 86%) did not reach statistical significance (p>0.19). Median PSVs were significantly less in prosthetic than in autologous vein bypasses (37 ± 13 vs 57 ±22 cm/s, p = 0.018). Prosthetic and autologous graft diameters were not statistically significantly different (6.3 ± 1.1 vs 5.6 ± 1.3 mm, p = 0. 18). Shear rates were significantly less in prosthetic than in autologous vein bypasses both at the near wall (382± 146 vs 698 +271 s-1, p=0.003) and at the far wall (551 ±235 vs 827 ±339 s-1, p=0.037). This mathematical model can be used to calculate shear rate from observed ultrasound flow patterns. Prosthetic bypass grafts had lower shear rates than autologous vein grafts.

Introduction Risk of cardiovascular diseases increases after menopause. Decrease in estrogen alters endothelium function, the first event in the atherosclerotic process. Endothelium function can be assessed by flow-mediated dilatation (FMD) during reactive hyperemia. We compared differences in brachial artery FMD in women before and after menopause. Methods Average ages of control (n = 35) and postmenopausal (n = 38) women were 34 ± 8 (SD) and 57 ± 7 years respectively. No subjects were on estrogen therapy or had known risk factors for cardiovascular disease. Brachial artery FMD was measured 5 cm above the cubital crease, using a 14 MHz transducer. B-mode images were selected during diastole using the flow waveform. Diameter measurements were performed before brachial artery occlusion and 60 seconds after release of a 5-min occlusion accomplished with pneumatic cuff inflation. FMD expressed the percentage change in diameter during reactive hyperemia versus baseline. Results Average FMD was 19 ± 6% (11 – 30%) for controls, decreasing significantly to 14 ± 6% (3–26%) post-menopause ( p < 0.001 by t-test). FMD was abnormally lower than 10% in 9 post-menopausal women, 7 older than 60 years, and 8 with menopause ≥10 years. Conclusions FMD decreased significantly post menopause and were abnormally low in older women with longer menopause. Changes in FMD with age, duration of menopause and relation of low FMD to risk development deserves further investigation to determine if FMD can be used as an independent risk factor.

Purpose: Treatment of chronic venous valvular insufficiency requires understanding of the hemodynamics of perforating veins. To preserve normal veins or veins that can function normally once primary sources of valvular insufficiency are removed, a better understanding of the diameter-reflux relationship is desirable. We measured reflux and diameters in 500 perforating veins of patients with varicose veins (C2EPASPPR). Methods: Color flow duplex ultrasonography scanning was performed with the patient standing. Perforating veins were mapped medially in the thigh and medially, laterally, and posteriorly in the calf. Reflux was defined as reverse flow that lasted longer than 0.5 seconds. Diameters were measured on B-mode transverse projections at the crossing of the fascia. Competent versus incompetent vein diameters were compared by means of Student t test, one-way analysis of variance, and Bonferroni t test. Results: Diameters of competent and incompetent perforators averaged 2.5 ± 0.9 mm (n = 17) and 4.7 ± 1.9 mm (n = 17) at the medial thigh (P < .0002), 2.2 ± 0.8 mm (n = 179) and 3.7 ± 1.0 mm (n = 210) at the medial calf (P < .0001), 2.2 ± 0.6 mm (n = 13) and 3.5 ± 0.8 mm (n = 37) at the posterior calf (P < .0001), and 2.1 ± 0.8 mm (n = 9) and 3.3 ± 0.7 mm (n = 18) at the lateral calf (P < .003), respectively. Perforating vein diameters of 3.5 mm or larger in the calf and thigh were associated with reflux in more than 90% of the cases. Conclusion: An enlargement in the diameter of the perforating veins of 1 to 1.5 mm in the calf or 2 mm in the thigh of patients with varicose veins could be the difference between normal flow and reflux. Further studies are needed to confirm if elimination of reflux in patients with primary varicosity will transform incompetent perforators to competent ones. (J Vasc Surg 1999;30:867-75.)

Innovations in the management of venous disorders have included subfascial endoscopic perforator surgery (SEPS). Information on resource utilization of this procedure is limited. Comparison of sequential cohorts of patients treated for leg venous hypertension by SEPS versus open perforating vein ligation (OPL) was performed to quantify the impact on hospital resource utilization and length of stay. At the Jobst Vascular Center, the last OPL was performed in June 1995 and the first SEPS was performed in January 1994. The authors compared the last 34 consecutive OPL procedures with the first 33 consecutive SEPS operations. Both groups had similar clinical indications. Variables describing utilization of hospital resources were assessed from a computer database compiled at time of treatment and compared by use of t test and chi-square statistics. Charges were selected as representation of hospital resources. SEPS length of stay, 2.3 ±1.8 (sd) days was significantly less than OPL, 4.5 ±2.7 days (p < 0.001) with concomitant reduction in physician bedside visits, 4.8 ±3.9 for SEPS versus 8.0 ±5.3 for OPL (p = 0.007). Total hospital charges in dollars, adjusted for sequential annual increments, were similar: 8,093 +3,811 for OPL versus 7,278 ±1,716 for SEPS (p=0.27). When OPL and SEPS were compared respectively, there were no significant differences in patient age, 58 ±14 versus 53 ±12 years; gender distribution, 62% women versus 42%; active ulcer status, 88% versus 85%; advanced admission testing, 41% versus 58%; use of venography, 97% versus 88%; use of general anesthesia, both 82%; or concomitant vein stripping, 65% versus 58% (p >0.1). SEPS anesthesia time was longer, 136 ±10 versus 122 ±28 minutes (p = 0.01), but not clinically significant. SEPS reduced length of hospital stay and number of physician bedside visits compared with OPL. Total hospital charges may be further reduced as experience with this procedure accumulates.

Purpose: Management decisions regarding carotid artery disease are critically dependent on stenosis but have been made difficult because of conflicting methods used to determine such stenosis. The increasing use of duplex ultrasound scanning has conventionally depended on Doppler velocity measurement, an indirect method for calculating carotid stenosis. Recent technical advances have improved the quality of B-mode/color-flow ultrasound scan imaging (USI). We tested prospectively whether USI was clinically effective as the primary criterion for estimating carotid stenosis. Methods: Transverse and longitudinal USI, Doppler velocity, and arteriography data were obtained sequentially and independently for 713 carotid bifurcations. The internal carotid artery (ICA) residual lumen, the local outer diameter at the stenotic site, and the diameter distal to the bulb were measured in a representative USI longitudinal section. The peak systolic velocity and the end diastolic velocity (EDV) were measured at the stenosis. Local stenosis as determined with USI was compared with the x-ray arteriographic clinical radiology interpretation (XRI). As the primary method, radiologists compared the residual lumen with the distal ICA diameter, as recommended by the North American Symptomatic Carotid Endarterectomy Trial and the Asymptomatic Carotid Atherosclerosis Study. Analysis was by means of the USI positive predictive value (PPV) and negative predictive value (NPV) of the XRI findings, with the assumption that 80%, 70%, and 60% local stenosis with USI related to 70%, 60%, and 50% stenosis with XRI, respectively. Results: All 56 ICA occlusions as determined with USI were confirmed with XRI. When the USI showed 80% to 99% stenosis, the PPV of the XRI showing 70% to 99% stenosis was 94% (116/123). Two ICAs that were shown to be severely diseased with USI appeared to be occluded with XRI. For

Purpose: To describe a feasibility study in a sheep model using an intravascular ultrasound (IVUS) instrument in an intravenous position to produce color flow, B-mode images of arterial segments along with Doppler blood flow velocities. Methods: Four healthy adult male sheep were anesthetized for surgical exposure of the right external jugular vein. A 9.0F sheath was also introduced in the common femoral artery for arteriography and device insertion. A 7.5-MHz ultrasound probe with 1-cm graduation markers was passed into the jugular vein. B-mode and color flow pictures were captured at aortic branches in cross and longitudinal sections. Length measurements between aortic branches and Doppler spectral velocities were obtained. Guidewire, balloon, and stent maneuvers were monitored by the stationary intravenous IVUS probe. Results: High-quality visualization of the entire abdominal aorta and its branches was achieved in all animals. With the probe stationary in the vena cava, a 1.5-cm linear segment of the aorta could be continuously observed in both B-mode and color flow ultrasound scans. Insertion and implantation of a Palmaz balloon-expandable stent was guided by intravenous IVUS alone. Selective catheterization of the right renal artery was followed visually by moving the intravenous IVUS probe sequentially. Conclusions: Intravenous IVUS appears feasible as a guidance and monitoring tool for endovascular interventions. While conventional IVUS provides only cross-sectional images in B-mode, intravenous IVUS captures color flow and Doppler velocity data as well. These added ultrasound modalities may offer potential advantages for guidance of endovascular procedures and endoleak detection.

Purpose: Although much attention has been focused on lower extremity deep venous thrombosis (LEDVT), there is a relative paucity of data regarding the impact of upper extremity deep venous thrombosis (UEDVT) on morbidity and mortality rates. To increase our knowledge with the latter disease, we have reviewed our experience at our institution with 170 patients who had brachial, axillary, and subclavian vein thromboses. Methods: Over the past 5 years, UEDVT was diagnosed in 170 patients by duplex scanning. The indications for duplex examination were either upper extremity swelling (95%) or as part of the workup for pulmonary embolism (5%). There were 103 women (61%) and 67 men (39%), with ages ranging from 9 to 101 years (mean, 68 ± 17 years). The diagnosis was made in 152 patients (89%) while they were admitted to the hospital and in 18 patients (11%) in the outpatient clinic. Risk factors included presence of a central venous catheter or pacemaker in 110 patients (65%), malignancy in 63 patients (37%), concomitant LEDVT in 19 patients (11%), and history of LEDVT in 18 patients (11%). Fifty-six patients (33%) had multiple risk factors, whereas 36 patients (21%) had no obvious risk factor. Results: The 1-month and 3-month mortality rates for the entire study group were 16% and 34%, respectively. Patients who had concomitant LEDVT, were 75 years of age or older, and were not treated with anticoagulation medication had a significantly higher 1-month mortality rate. Patients whose diagnoses were made in the outpatient setting were statistically younger and had a lower 3-month mortality rate when compared with the patients whose diagnoses were made as inpatients. Pulmonary embolism was documented by ventilation/perfusion scan in 12 patients (7%). Although no patient in the group in which UEDVT was diagnosed on an outpatient basis was documented to have a pulmonary embolism and 12 patients (8%) in the inpatient group had pulmonary emboli, this difference was not statistically significant. Anticoagulation medication did not totally prevent pulmonary embolism in this review. All patients were followed-up for between 0 to 49 months (mean, 13 ± 1 months). No swelling of the affected arm was observed in 145 patients (94%); four patients complained of mild intermittent swelling (2%), and seven patients reported significant swelling (4%). Conclusions: Contrary to previous reports, these data suggest that UEDVT is associated with a low incidence of postthrombotic upper extremity swelling, but a significant incidence of pulmonary embolism and rate of mortality. This review suggests that UEDVT is at least as serious a disease entity as LEDVT and should be managed as aggressively as LEDVT. (J Vasc Surg 1997;26:853-60.)

Purpose: The advent of endovascular grafting has created detailed imaging requirements for which intravascular ultrasound (IVUS) may be useful. Since intra-arterial IVUS imaging uses space within endovascular graft delivery systems and risks embolism, we investigated the use of intravenous IVUS imaging of arterial vasculature and endovascular grafts, a technique that appears not to have been previously described. Methods: IVUS catheters with 12.5- and 20-MHz transducers were inserted through the common femoral artery and vein of mature sheep. Transcutaneous images were also obtained with a 5-MHz linear transducer. B-mode images of the aortoiliac arterial segments and diameter measurements were recorded from both access vessels using anatomic landmarks for site localization. To assess device visualization from the intravenous image source, studies were done in vessels containing previously placed endovascular stent-grafts. Results: In this feasibility study, comparison among intravenous IVUS, arterial IVUS, and external ultrasound indicated equal diameter precision and ability to recognize arterial structures. Comparison of arterial diameter, whether obtained from an arterial, venous, or transcutaneous source, showed similar values. Conclusions: We conclude that it is probable for such techniques to be usefully applied to human aortoiliac arterial segments and that further investigation of arterial visualization from adjacent venous structures is warranted.

Clinically significant arterial occlusive disease developed in 26 patients at between 5 months and 44 years (mean(s.d.) 10.7(12.0) years) following radiation therapy. Therapeutic radiation was associated with lesions of the carotid artery (nine patients), subclavian-axillary arteries (seven) and the abdominal aorta and its branches (10). Clinical presentations included transient ischemic attack, stroke, vertebrobasilar insufficiency, carotid bruit, upper- or lowerextremity ischemia and renovascular hypertension. Surgery for cerebrovascular insufficiency included carotid endarterectomy with vein patch, interposition grafting or subclavian-to-carotid bypass. Carotid or subclavian-to-axillary bypass was performed for upper-extremity ischemia. A combination of endarterectomy and Dacron or saphenous vein grafts was used for infrarenal reconstruction. Tunnels were placed orthotopically. Musculocutaneous flaps assisted in healing selected wounds. Ureteral catheters were useful adjuncts in abdominal vascular reconstructions. There were no operative deaths, strokes or amputations. One patient had recurrent transient ischemic attacks following subclavian-to-carotid bypass. The mean(s.d.) postoperative follow-up was 48.1(39.6) months. Patients presenting with end-organ ischemia following radiation therapy can be managed successfully with aggressive surgical revascularization using a broad spectrum of reconstructive techniques.

Purpose: Autogenous vein bypass grafts to infrapopliteal outflow sites have patency and limb salvage rates significantly superior to those obtained with prosthetic grafts. However, when infrageniculate bypass is required for limb-threatening ischemia in the patient lacking suitable autogenous veins, nonautogenous reconstruction or primary amputation are the only other alternatives. Methods: During a 2-year period we implanted 25 cryopreserved allograft saphenous vein bypass grafts in 24 patients (median age 76 years) with tissue necrosis (20 patients), rest pain (4 patients), or acute ischemia (1 patient); 16 patients were men and 8 were women. As many as six previous revascularizations were performed in 79%; two grafts extended to the infrageniculate popliteal artery; 23 grafts extended to a paramalleolar vessel. Results: Secondary patency at 1 month was 87%, but only 36% at 1 year. Use of warfarin (Coumadin) failed to improve the patency rate (five of nine occlusions treated with Coumadin versus eight of 16 not treated with Coumadin). Only eight of 24 patients are alive with open grafts; nine patients have died. Conclusions: Unheralded occlusions more typical of prosthetic graft failure tempered the initial enthusiasm and effectiveness of vein allografts. All autogenous options must be exhausted to complete distal, secondary revascularization before resorting to nonautogenous conduits. Use of allograft veins must be viewed with continued skepticism. (J VASC SURG 1993;18:553-60.)

Introduction: Pelvic varicose veins, one of the main causes of chronic pelvic pain and dyspareunia, are an important source of reflux for lower limb varicose veins, especially in recurrent cases. Color Doppler ultrasound of the lower limbs and transvaginal ultrasound are the noninvasive diagnostic methods most commonly used to assess pelvic venous insufficiency, whereas phlebography is still considered as the gold standard. Objectives: To determine the prevalence of lower limb varicose veins originating from the pelvis in a group of female patients and to determine the agreement between results obtained via color Doppler ultrasound of the lower limbs, transvaginal ultrasound, and phlebography. Methods: The sample comprised female patients referred to a vascular laboratory for lower limb screening. Patients diagnosed with deep venous thrombosis were excluded. Data analysis included kappa coefficient of agreement, McNemar's test, sensitivity and specificity values. Results: Of a total of 1,020 patients, 124 (12.2%) had findings compatible with reflux of pelvic origin. Among these patients, 51 (41.2%) were recurrent cases. A total of 249 were submitted to transvaginal ultrasound. There was significant agreement between lower limb ultrasonographic findings and transvaginal findings. Phlebography was performed in 54 patients. The comparison between transvaginal ultrasound and phlebography was associated with a 96.2% sensitivity and 100% specificity. Conclusions: The authors draw attention to the relatively high prevalence of lower limb varicose veins originating from the pelvis, suggesting an important but underdiagnosed cause of recurrent varicose veins. Introdução: AS VARIZES Pélvicas, uma das principais causas de dor pélvica crônica e dispareunia, são uma importante fonte de refluxo para as varizes dos membros inferiores, especialmente em casos recorrentes. O Doppler colorido dos membros inferiores e o ultrassom transvaginal são os métodos diagnósticos não-invasivos mais comumente usados para avaliar a insuficiência venosa pélvica, enquanto a flebografia ainda é considerada como o padrão-ouro. Objetivos: Determinar a prevalência de varizes dos membros inferiores originadas na pélvis em um grupo de pacientes do sexo feminino e determinar a concordância entre os resultados obtidos por Doppler colorido dos membros inferiores, ultrassom transvaginal e flebografia. Métodos: A AMOstra incluiu pacientes do sexo feminino encaminhadas para o laboratório vascular para triagem dos membros inferiores. As pacientes diagnosticadas com trombose venosa profunda foram excluídas. A análise dos dados incluiu o coeficiente de concordância kappa, o teste de McNemar e os valores de sensibilidade e especificidade. Resultados: De um total de 1.020 pacientes, 124 (12.2%) tiveram achados compatíveis com refluxo de origem pélvica. Entre essas pacientes, 51 (41.2%) eram casos recorrentes. Um total de 249 foram submetidas a ultrassom transvaginal. Houve concordância significativa entre os achados ultrassonográficos dos membros inferiores e os achados transvaginais. A flebografia foi realizada em 54 pacientes. A comparação entre o ultrassom transvaginal e a flebografia foi associada a 96.2% de sensibilidade e 100% de especificidade. Conclusões: OS AUTores chamam a atenção para a prevalência relativamente alta de varizes dos membros inferiores originadas na pélvis, sugerindo uma importante, embora subdiagnosticada, causa de varizes recorrentes.

The objectives of this chapter are to review applications and describe protocols of duplex ultrasound arterial mapping (DUAM) of the upper extremities. A literature search revealed multiple arterial applications of duplex ultrasound in the upper extremity. Situations in which ultrasound may replace arteriography or other techniques actually employed are also mentioned.The examples cited expand the role of the noninvasive vascular laboratory to many medical specialties, including vascular surgery, vascular medicine, radiology, neurology, nephrology, orthopedics, plastic surgery, emergency medicine, trauma, and physiology.

The clinical experience with periprocedural duplex ultrasound detailed in this chapter is based on over 2,000 lower extremity open and endovascular arterial revascularization procedures. The topics discussed include goals of testing, detailed protocols of duplex ultrasound arterial mapping (DUAM), rationale of preoperative DUAM for revascularization decision making, and comparison of DUAM with other imaging modalities such as contrast arteriography (XRA), magnetic resonance angiography (MRA), and computed tomography arteriography (CTA). The limitations and pitfalls of duplex arterial testing are discussed as well as the learning curve for this diagnostic technique including necessary components to be followed during the training phase for replacing other imaging modalities with DUAM.

As vascular surgeons, we performed 376 percutaneous transluminal angioplasties as follows: aorta and iliac arteries (148), infrainguinal arteries (191), and bypass grafts (21). Sixteen procedures were attempted but not completed. Neodymium-yttrium-aluminum-garnet laser thermoprobe was successfully used prior to balloon dilatations in 49 procedures. In contrast to our experience with operative intervention, percutaneous transluminal angioplasty was performed more frequently for claudication (75%), nondiabetics (72%), and women (45%). Median age was 71 years. Percutaneous transluminal angioplasty either preceded or followed proximal or distal open reconstruction in 58 extremities. Primary patency rates for iliac percutaneous transluminal angioplasties were: 94% at one month, 93% at six months, and 88% at one year. For infrainguinal percutaneous transluminal angioplasties they were 95%, 82%, and 70% at 1, 6, and 12 months, respectively. Repeat percutaneous transluminal angioplasty increased the one-year patency rates to 92% and 86% for iliac and infrainguinal percutaneous transluminal angioplasties, respectively. Preliminary data indicate that the six-month secondary patency rates were 82% for laser-assisted percutaneous transluminal angioplasty and 65% for percutaneous transluminal angioplasty of distal bypass grafts. The implementation of balloon angioplasty was facilitated by our 21 years of experience with arteriography. Percutaneous transluminal angioplasty has become a valuable adjunct to the practice of vascular surgery by expanding the therapeutic options for managing peripheral vascular occlusive disease.

Although balloon angioplasty for the management of failing bypass grafts has been well documented, little mention has been made of its use in treating the occlusive lesion within the native artery after a failed bypass graft. We report our experience with five patients in whom successful balloon angioplasty was carried out subsequent to failure of a femoral popliteal bypass graft. Increasingly aggressive percutaneous therapy of arterial occlusive disease may now be expanded to include a unique group of patients with chronically failed bypass grafts and occlusive disease within the native artery conducive to percutaneous transluminal angioplasty. This group of patients would previously have been relegated to repeat bypass grafts with its inherently inferior patency and recognized added technical demands. Percutaneous balloon angioplasty appears to be a plausible alternative in selected cases for repeat lower extremity revascularization.

Chronic venous insufficiency (CVI) with the resultant clinical sequelae significantly reduces quality of life. Most elderly patients with CVI are treated nonoperatively owing to concerns of increased operative risk and therefore suffer more advanced disease. Radiofrequency ablation (RFA) has emerged as a minimally invasive procedure to treat patients with superficial venous insufficiency (SVI) due to great saphenous vein (GSV) incompetence. The purpose of this study was to review our experience using RFA of the GSV to treat CVI due to superficial disease in elderly patients compared to younger patients in terms of procedure-related morbidity and severity of disease at time of treatment. RFA treatment of the GSV was performed in 490 extremities of 421 patients with SVI between March 2001 and December 2002. Indications, medical history, and outcome (operative complications and hospital stay) were compared between 2 groups: Group I: 41 extremities of 35 patients, 70 years if age or older (mean 75 ±4); and Group II: 449 limbs of 386 patients younger than 70 years (mean 47 ±11). The incidence of skin pigmentation and healed/nonhealed ulcers (CEAP 4–6) was significantly higher in the elderly than in the younger group (41% vs 16%, p

The authors have noted a significant incidence of pulmonary embolism and mortality associated with upper extremity deep venous thrombosis (UEDVT). Since there is an association between the site of lower extremity DVT (LEDVT) and pulmonary embolism, they hypothesized that there might also be a correlation between the site of UEDVT and the incidence of pulmonary embolism (PE) and associated mortality. To further elucidate this hypothesis, they analyzed the mortality rate and incidence of PE diagnosed with subclavian/axillary or internal jugular vein thrombosis during a 5-year period at their institution. Two hundred and ten patients were diagnosed with acute internal jugular and/or subclavian/axillary DVT during a 5-year period by duplex scanning. The indications for the duplex examination were upper extremity swelling in 187 (89%) or as part of the work-up for pulmonary embolism in 23 (11%). There were 126 women (60%) and 84, men (40%). The mean age was 67 ±18 years (range 1–101 years). The patients were divided into 3 groups based on the location of the thrombus: Group I — UEDVT involving the subclavian and/or axillary veins (n = 128); Group II — internal jugular vein thrombosis alone (n = 21); and Group III — concomitant subclavian/axillary and internal jugular vein DVT (n = 61). Risk factors were presence of central venous catheter or pacemaker in 127 patients (60%), malignancy in 78 patients (37%), concomitant lower extremity deep venous thrombosis (LEDVT) in 40 patients (19%), and history of LEDVT in 6 patients (3%). Eighty (38%) patients had more than 1 risk factor. The mean follow-up period was 13 ±1 months (range 0–49 months). Mortality rates at 1, 3, and 12 months were 13%, 31%, and 40% for Group I; 14%, 33%, and 42% for Group II; and 23%, 44%, and 59% for Group III. The mortality rate in Group I was statistically significantly higher for patients =75 years old, patients not treated with anticoagulation, and patients who underwent placement of a central venous line. The same risk factors did not achieve statistical significance in the 2 other groups. The number of patients diagnosed with pulmonary embolism by ventilation/perfusion scans in Groups I, II, and III that could be attributed to the UEDVT solely was 8 (4%), 1 (0.5%), and 3 (2.4%), respectively. Contrary to the initial hypothesis of a relationship between the site of thrombosis and the incidence of pulmonary embolism and mortality, these data showed no statistical differences in mortality rate or incidence of pulmonary embolism among the 3 groups studied. These data also suggest that internal jugular vein thrombosis is a disease process associated with mortality and morbidity rates comparable to those of subclavian/ axillary vein thrombosis.

Objectives Carotid duplex scanning is the standard test for documenting carotid disease. Carotid endarterectomy effectively reduces stroke in selected patients with carotid artery disease. Data from large national randomized trials suggest that the benefits of CEA may be gender dependent. Because many diagnoses are made and treatment is based on the results of carotid duplex ultrasound scanning alone, it is important to determine whether different diagnostic thresholds should be used in men and women. The purpose of this study was 2-fold: to examine whether there is an overall gender difference in carotid velocity at similar arteriographic stenoses, and to determine whether there are significant differences at clinically relevant thresholds of disease. Methods A database of 938 carotid arteriogram entries was established prospectively, with accompanying measurements of peak systolic velocity (PSV) and end-diastolic velocity (EDV). The percent of internal carotid artery stenosis seen on arteriograms was calculated according to criteria from the North American Symptomatic Carotid Endarterectomy Trial. Analyses were made in 536 carotid arteries in men and 402 carotid arteries in women. In addition, the single most diseased artery per patient was analyzed by gender. PSV and EDV were averaged for data subsets according to 10% intervals of internal carotid artery stenoses. Velocity for each interval was compared between men and women with the Student t test. Receiver operator characteristic curves were developed to define optimal duplex criteria for 60% and 70% stenosis. Results For all intervals, PSV and EDV averaged 9% and 6% higher, respectively, in women than in men. Significant gender differences existed between PSV and EDV for 60% and 70% stenosis (P = .03). When a single vessel per patient was analyzed these observations persisted, but lost significance for PSV at 60% stenosis (P = .18). Receiver operator characteristic curves at 90% sensitivity demonstrated that optimal PSV for 60% stenosis was 160 cm/s and 180 cm/s, and for 70% stenosis was 185 cm/s and 202 cm/s, in male and female patients, respectively. Conclusions Women have higher carotid blood flow velocity than men do. Gender differences exist, and are notably different at clinically relevant thresholds for intervention. These data indicate that different criteria should be used for interpreting carotid velocity profiles in women than in men, and have potentially important implications for patient care.

In the past decade, expected in-hospital length of stay (LOS) after carotid endarterectomy (CEA) has decreased from 4 days to 1. Long LOS is associated with known complications and factors affecting severity of the patient's condition. Factors affecting an intermediate stay of 2 to 4 days need further clarification. The vascular registry at Jobst Vascular Center includes data on manifestation of disease; cardiovascular history; operation and discharge dates; surgeon; surgical details such as patching, shunting, and completion arteriography; and complications. Univariate chi-square and ANOVA and multivariate logistic regression were applied to analyze 635 CEAs performed in 1998, 1999, and 2000. Statistical significance was at a p value less than 0.05 (two-sided). Overall morbidity rate was 8.2% with three (0.5%) inhospital neurologic complications and one death for a 0.16% mortality rate. Fifty-eight percent of the patients were discharged in 1 day. Patients staying 1 day were 3 years younger. Female gender and prior cerebrovascular accident were factors extending LOS to 2 and 3 days. History of angina, heart failure, valve disease, and vein patch or no patch contributed to LOS of 3 or 4 days. Completion arteriography had an association with LOS of 2 days. The relative percentage of patients with complications increased with LOS. No significant relationship was found for symptoms, smoking, myocardial infarction, atrial fibrillation, cardiac revascularization, or surgeon. Insulin-treated diabetes mellitus, cardiac risk factors, cerebrovascular accident, and vein patch or no patch correlated with prolonged hospitalization. Factors were identified that may alter a clinical pathway designed for discharge 1 day after CEA. Focused management of patients with cardiac and cerebrovascular accident history or requiring vein patch and a better understanding of CEA in women may further increase the percentage of patients discharged 1 day after CEA.

Shear has been implicated in the etiology of atherosclerosis, thrombosis and graft stenosis. We measured shear rate noninvasively in infrainguinal bypasses. Velocity profiles were recorded from 35 femoropopliteal and 40 tibial grafts. Flow rate (Q), systolic shear rate (SSR), diameter, and bluntness factor (BF) were measured at midgraft using ultrasound (US). Mean shear rate (MSR) was calculated from flow and diameter. SSR, 671 +/- 260 (SD) vs. 659 +/- 304 s(-1) (p = 0.85), and MSR, 168 +/- 84 vs. 193 +/- 110 s(-1) (p = 0.26), were similar for popliteal and tibial bypasses, but differences in Q, 126 +/- 57 vs. 104 +/- 38 mL/min, were borderline significant (p = 0.058). Popliteal grafts had larger diameters, 5.2 +/- 1.1 mm vs. 4.7 +/- 0.8 mm (p = 0.048), and BF, 3.4 +/- 0.9 vs. 2.8 +/- 0.7 (p = 0.0014). Shear rates were obtained noninvasively in humans. Larger diameters in popliteal vs. tibial bypasses did not result in lower shear rates and were compensated for by larger bluntness factors. Velocity profile bluntness cannot be ignored in shear rate analysis.

Background: The risk of pseudoaneurysm (PSA) increases with the number of catheterizations performed for cardiovascular diagnosis and therapy. Thrombin injection, or “thrombinjection,” is an alternative to ultrasound-guided compression or surgical repair. Thrombinjection is effective and economical, but the specter of systemic arterial thrombosis hinders its wide application. We report cautionary steps taken prior to injection and lessons learned during our first 20 cases. Methods and Results: Thrombinjection was performed under ultrasound (US) guidance in 12 women and 8 men with PSA after femoral catheterization. PSA varied in size from 17 to 39 mm with neck openings from 1.5 to 3.9 mm. Under local anesthesia and US longitudinal view, a 20-gauge US needle tip was placed in the PSA away from the neck. With 12 cases under 600 units, 100 to 2,300 units of thrombin (1,000 U/mL) were injected slowly. Slow injection, positioning of the ball of thrombus formed at the needle tip, probe compression, and combined or interchangeable use of US color flow and B-mode were the essential techniques utilized. All PSA thrombosed successfully on the first treatment. One patient had fever and another returned for compression treatment of a second, not recurrent, PSA. Conclusions: Successful thrombinjection was accomplished by focusing on common femoral artery PSA with small neck openings, avoiding arteriovenous fistulas, and using standard thrombin concentration, US needle, state of the art ultrasonography, slow injection, thrombus ball positioning, and adjunctive probe compression.

Shear rate has been linked to various arterial wall properties and diseases such as cell function, neointimal hyperplasia, post-stenotic dilation and progression of atherosclerotic plaque. An accurate noninvasive method of measuring blood flow near the arterial wall is needed to allow the study of wall shear rate in humans to progress. Current clinical vascular laboratories are limited to using the Hagen-Poiseuille formulation based on steady laminar flow through a rigid- walled tube, which is not realized in vivo. This project used data collected with an ultrasound scanner to approximate the magnitude of wall shear rate in two dimensions using the formal definition of the velocity gradient in a radial direction. Blood flow was measured in the common carotid artery of 20 subjects in both longitudinal and transverse directions. The results showed that the wall shear rate was a factor of approximately 1.5 to 2 times greater than the value calculated using the Hagen-Poiseuille formulation. A comparison of the longitudinal and transverse estimation methods showed very similar values for all of the calculated quantities. This comparison contributed to the conclusion that this image-based technique provides a more accurate assessment of wall shear rate, with the significant addition of a second dimension for analysis.

Purpose: Physiologic observations with blood flow waveform analysis and pressure measurements can document the severity of lower extremity arterial disease. Segmental blood pressures (SEGPs) taken at the thigh, calf, and ankle are commonly used, but their utility has seldom been studied. We quantified improvements in accuracy compared with arteriography when ankle pressures alone (ABI) or SEGP data were added to velocity waveforms obtained by Doppler ultrasound. Methods: Continuous-wave Doppler velocity waveforms were recorded at common femoral (CFA), popliteal (POP), and dorsal pedal and posterior tibial (TIB) arterial levels. Systolic SEGP data were obtained with appropriately sized upper thigh, upper calf, and ankle cuffs. Waveforms, waveforms plus ABI, and waveforms plus SEGP data from 81 patients were randomly interpreted by 14 technologists or physicians from four institutions blinded to clinical and arteriographic data. Arteriograms were assigned negative or significant, severe (≥75% diameter stenosis) values for four segments: iliofemoral (CFA), superficial femoral (SFA), popliteal (POP), and infrapopliteal (TIB) arteries. A total of 9072 segmental interpretations were analyzed. Results: Compared with arteriography, the accuracy of waveform analysis was 83% for severe disease at and proximal to the CFA, 79% for SFA disease, 64% for POP disease, and 73% for TIB disease. Adding ABI improved the accuracy significantly (p < 0.01) to 88% (CFA), 86% (SFA), 70% (POP), and 85% (TIB). Accuracy was inferior when SEGP data replaced ABI: 86% (CFA), 85% (SFA), 70% (POP), and 80% (TIB). Conclusions: ABIs significantly improved Doppler waveform accuracy at all levels. Compared with ABI, the addition of segmental pressure to waveform data failed to improve accuracy. Pressure measurements above the ankle may lack cost effectiveness and clinical utility. (J Vasc Surg 1998;27:831-9.)

Shear rate has been linked to endothelial and smooth muscle cell function, neointimal hyperplasia, poststenotic dilation and progression of atherosclerotic plaque. In vivo studies of shear rate have been limited in humans due to the lack of a truly accurate noninvasive method of measuring blood flow. In clinical vascular laboratories, the primary method of wall shear rate estimation is the scaled ratio between the center line systolic velocity and the local arterial radius. The present study compares this method with the shear rate calculated directly from data collected using a Doppler ultrasound scanner. Blood flow in the superficial femoral artery of 20 subjects was measured during three stages of distal resistance. Analysis and display programs were written for use with the MATLAB image processing software package. The experimental values of shear rate were calculated using the formal definition and then compared to the standard estimate. In all three states of distal resistance, the experimental values were significantly higher than the estimated values by a factor of approximately 1.57. These results led to the conclusion that the direct method of measuring shear rate is more precise and should replace the estimation model in the clinical laboratory.

Arterial occlusive disease has been successfully evaluated with ultrasonography prior to infrainguinal revascularization; this technique contributes to design of operation and, in the case of a bypass, to the selection of a venous conduit. Techniques of black-and-white and color sonoangiography of the peripheral arteries and veins comprise imaging and blood velocimetry. Velocity and flow measurements and other data in the literature that compare ultrasound and radiologic techniques indicate that sonoangiography is already the "practical standard" for vein selection and will have a growing role in preparation for infrainguinal revascularization.

Two types of crossed-coil nuclear magnetic resonance (NMR) blood flowmeter detectors have been developed for the noninvasive measurement of blood flow. The first is a cylindrical coil configuration suitable for limb blood measurement. A cylindrical flowmeter (12.5 cm internal diam) operating at a nuclear resonance frequency of 3.2 MHz has been applied to measurement of flow in the forearm. The second type is the flat crossed-coil detector, which retains many of the operational advantages of the cylindrical detector, but is suitable for blood flow measurement of almost any surface of the body. Three flat crossed-coil detectors are described, operating at NMR frequencies of 9, 21.4, and 75 MHz. Two types of intermediate frequency signal processors have been used in the NMR receivers, a simple diode type, and a synchronous detector. The synchronous detector is preferred for its ease of operation and superior stability. Modular detection systems containing transmitter, receiver, post-detector signal conditioning, and power supply have been designed for all of the flat crossed-coil detectors. A self-contained synchronous detector module is included in the 21.4 and 75 MHz systems.

Transcutaneous electromagnetic (EM) flowmetry measures, noninvasively, the induced voltage generated by the flow of blood through a region immersed in a magnetic field. Steady magnetic fields of less than 0.5 tesla (T) have been used to measure pulsatile popliteal, brachial, and bilateral common carotid blood flow in normal subjects, in patients with arteriovascular disease, and in subjects with arteriovenous fistula (AVF) surgically created for hemodialysis. In these studies, field magnitude and time of exposure were below the limits suggested by two exposure guidelines available. Flow rate was calculated from the measured voltages and geometrical and electrical parameters using equations developed for three-media (body segment-vessel-blood) cylindrical models, based on electromagnetic theory. The 68 measurements reported here are in the expected range.

We measured ankle/arm pressure indexes and blood flow rates before and after performing percutaneous transluminal angioplasty in 36 extremities. Flow rates through the leg were determined with a magnetic resonance blood flow scanner. All patients had claudication; one had gangrene, another had an ulcer, and two complained of rest pain. The median age was 65 years, and 72% were men. There were 25 dilations of the iliac artery, 12 of the superficial femoral artery, and eight of the popliteal arteries; nine patients had two arterial segments dilated. Nineteen legs had ankle/arm pressure indexes before percutaneous transluminal angioplasty of less than 0.80 (range 0.51 to 0.75); their flow rates averaged 40 ± 20 (SD) ml/min. After percutaneous transluminal angioplasty flow and pressure increased significantly in 14 of these 19 legs, and three had no hemodynamic improvement; in one leg only pressure and in another only flow increased significantly. The remaining 17 extremities had ankle/arm pressure indexes before percutaneous transluminal angioplasty ranging from 0.81 to 1.09; their flow rates averaged 53 ± 27 (SD) ml/min. Abnormal flow rates were detected in 15 of these 17 extremities. With near-normal ankle/arm pressure indexes no significant increase in pressure was anticipated. Flow rates augmented to 75 ± 28 (SD) ml/min after percutaneous transluminal angioplasty; a significant increase in flow was noted in 12 legs (71%). For patients with ankle/arm indexes before percutaneous transluminal angioplasty. of less than 0.80, either pressure or flow measurements should corroborate the benefits of the operation, whereas if the ankle arm index is greater than 0.80, flow measurements are most likely to substantiate changes in peripheral hemodynamics. (J Vasc Surg 1989;10:338–42.)

The results of 160 infrainguinal bypasses with arm vein grafts were analyzed. Seventy-three arteriograms were reviewed to identify early and late graft defects; arteriographic findings paralleled those described for saphenous vein grafts. Intimal fibrosis during the first postoperative year, observed in 16 grafts, was the most common defect. Aneurysmosis and elongation were rare, resulting in two graft replacements. Patency and limb salvage rates were calculated for 88 single-length femorodistal bypass grafts; the other 72 were inflow (eight) or outflow (22) jump grafts, sequential (eight) and composite autogenous vein grafts (34). The primary and secondary patency rates for single-length grafts were 74% and 80% at 1 year and 51% and 57% at 5 years, respectively. The limb salvage rate at 5 years was 82%. The survival rate for all patients was 44% at 5 years. These findings reconfirm our use of arm veins as bypass grafts when the saphenous vein is unavailable. (J VASC SURG 1986;4:416-27.)

Static and alternating magnetic fields are employed in blood flowmeters using nuclear magnetic resonance (NMR) principles and electromagnetic induction by a moving conductor (TEM). Both techniques require high steady magnetic fields, obtained either from permanent magnets or from electromagnets. A relatively homogeneous magnetic field is needed for NMR, but, though important for calibration, homogeneity is not critical for TEM. NMR is more complex than TEM since it requires radio-frequency and audio-frequency magnetic fields. However, the TEM method requires surface electrodes in contact with the skin, or needle electrodes placed subcutaneously, whereas NMR is contactless. The NMR flowmeter can be calibrated directly, but appropriate and approximate models must be assumed and then solved by computer to quantify blood flow by the TEM flowmeter. Flow in individual vessels is measured a priori in the TEM flowmeter by virtue of the assumed models. To measure flow in individual vessels by NMR, a scanning or ranging method is required, which logically leads to blood flow imaging. The levels of steady, radio-frequency, and audio-frequency magnetic fields used in the two types of flowmeters are low enough so as not to cause any apparent stimulus to human volunteers and patients tested.

Preoperative noninvasive imaging of the veins of the upper extremities has been included in the protocol to select an autogenous vein for a distal bypass in the lower extremity. Arm veins are sought as bypass grafts when the saphenous vein is absent or not usable. Duplex ultrasound provided images of the cephalic and basilic veins in 10 patients in whom visual inspection failed to reveal usable grafts. All arm veins implanted were at least 2 mm (range 2 to 6 mm) in internal diameter determined by ultrasound and were, on the average, 2 mm larger when unroofed. This noninvasive technique has decreased the number of fruitless surgical explorations to obtain a suitable arm vein and has increased the use of arm veins by revealing veins previously not anticipated by physical examination, which virtually eliminated the use of nonautogenous conduits in our practice.

Nuclear Magnetic Resonance (NMR) permits the noninvasive measurement of blood flow signals unimpaired by clothes, bandages, casts, etc. The cylindrical crossed-coil NMR blood flowmeter was used to measure blood flow through a cross-section of the human forearm. Two calibration procedures are described: one for pulsatile flows and the other for flows with a high non-pulsatile component. Flow measurements from normal arms, from limbs with arterial obstruction, arteriovenous hemodialysis fistulas or other conditions are reported. An application of the flow scanning technique for separation of flow signals from individual arteries (e.g., ulnar and radial) is described. The flat crossed-coil NMR flowmeter was applied to detect blood flow from individual arteries (e.g., brachial, popliteal, etc.). Applications of a ranging technique developed to detect signals at predetermined depths are described.

Two hundred forty-three bypasses to paramalleolar arteries were performed in 224 extremities of 208 patients since 1971; 166 were implanted in men (68%) and 77 in women (32%). The median age was 73 years. Gangrene (61%), nonhealing ulcer (15%), rest pain (22%), and trauma (2%) were the indications for bypass. Usual risk factors were noted: diabetes (65%), smoking (51%), heart disease (46%), and hypertension (45%). The extent of occlusive disease dictated three graft configurations: long grafts originating in arteries proximal to the adductor tendon (n = 111), short grafts originating at or below the popliteal artery (n = 88), and jump grafts originating near the distal end of a previous femorodistal bypass (n = 44). The association between diabetes (incidence 80%) and gangrene (75%) in patients with short grafts was statistically significant (p less than 0.01). The 2-year secondary patency rate of long in situ grafts was 92% compared with 72% for other autogenous vein long grafts. The limb salvage rate for all autogenous vein long grafts was 90% at 3 years. The secondary patency rate at 3 years for short grafts was 81% and the limb salvage rate was 80%. There were four amputations with patent grafts. Primary and secondary patency rates of jump grafts were similar (53%), whereas the limb salvage rate was 89% at 2 years. Patency and limb salvage rates of rarely employed nonautogenous conduits were less than 35% at 1 year (long grafts). Bypass grafts to the ankle and foot are effective and durable and should be performed with autogenous vein.

We placed 20 bypass grafts to the lateral plantar artery in 18 extremities to salvage feet with wet (12) or dry (six) gangrene; 15 grafts were implanted in men (75%), and five were implanted in women (25%). The median age was 65 years. All except two patients had diabetes; eight were treated with insulin. One patient had Buerger's disease, and another had vasculitis with chronic lymphocytic leukemia. History of smoking (65%), hypertension (53%), heart disease (71%), and osteomyelitis in the foot (35%), were noted. Cultures were positive in 15 gangrenous feet, 11 with gram-negative bacilli. Four long femoroplantar bypasses were placed. Ten short grafts were placed from the popliteal artery, and six jump grafts were placed distal to a femoropopliteal or tibial bypass. Hospital stay ranged from 8 to 38 days (median 16 days), and there were two in-hospital deaths. Transmetatarsal or button toe amputations were performed in nine feet. There were two below-knee amputations, one with a patent graft, for a foot salvage rate of 89% at 2 months. In four instances the gangrenous ulcers took longer than 6 months to heal; all other wounds healed within 6 months. The primary and secondary patency rates were 85% at 1 month, and 73% at 3 months and thereafter. Four of five graft failures occurred in the two legs with repeat bypass graftings. All patients with successful revascularization are able to walk, and seven returned to work full time.

A miniature probe has been developed which combines the isothermal and hydrogen clearance methods for measurement of local tissue flow. In vitro testing demonstrated the stability and reproducibility of the results with each system. In vivo tests in the brain, spinal cord, and kidney of the cat showed that changes in the isothermal measurement correlated well with changes in the hydrogen clearance measurement. The hydrogen clearance system produced measurements in close agreement with literature values. A comparison between measurements in kidney tissue and renal artery flow measured with an electromagnetic flowmeter was linear up to a renal flow rate of 130 ml/ 100 g/min. Above that level measurements in the system were constant. The use of the isothermal system for continuous measurement with intermittent calibration using the hydrogen clearance system provides a method for quantitatively monitoring changes in local tissue flow.

ObjectiveThis clinical study evaluated prospectively adverse events immediately following ultrasound-guided foam sclerotherapy (UGFS) for the treatment of lower extremity venous valvular insufficiency. Incidence of side effects associated with carbon dioxide (CO2) foam was compared with a historical control using air-based foam. The literature on the subject was reviewed.MethodsVital signs were monitored during and immediately after UGFS, and adverse events were recorded for 24 hours following the procedure. The air-based foam group had 49 patients: 44 women and 5 men. The CO2-based foam group had 128 patients: 115 women and 13 men. CEAP class was C2EpAsPr, describing varicose veins, primary etiology, and saphenous reflux. UGFS followed thermal ablation of the great saphenous vein. Foam was prepared using the three-way tap technique to mix gas with 1% polidocanol in a 4:1 ratio. Segments of the great and small saphenous veins and their tributaries were treated with UGFS. Foam volumes injected were 27 ± 10 (SD) (6-46 range) and 25 ± 12 (6-57 range) mL for air- and CO2-based foams respectively (P = .39). Incidence of adverse events was compared by χ2 statistics. Vital signs were compared by paired t test.ResultsDuring the procedure, the average heart rate decreased by less than 5 bpm for both groups (P < .001), and blood pressure decreased by less than 3 mm Hg in the CO2 group (P < .02). Respiratory rate, electrocardiogram, and pulse oxymetry did not change significantly in both air- and CO2-foam series (P > .05). Visual disturbances were experienced by 3.1% (4/128) and 8.2% (4/49) patients in the CO2 and air groups respectively (P = .15). Respiratory difficulties or circumoral paresthesia each occurred in 0.8% (n = 1) of the CO2 patients. Incidence of chest tightness (3.1% vs 18%), dry cough (1.6% vs 16%), or dizziness (3.1% vs 12%) were significantly lower in the CO2 vs air groups (P < .02). Nausea occurred in 2% and 4% of the CO2 and air-based foam groups (P = .53). Overall, the proportion of patients describing side effects decreased from 39% (19/49) to 11% (14/128) as CO2 replaced air for foam preparation (P < .001). Similar findings were described in the literature of air-based foam but data on the use of physiological gas were rare.ConclusionsSide effects decreased significantly if CO2 rather than air was employed to make the sclerosing foam for chemical ablation of superficial veins of the lower extremity.