Biomedical subjects

S X Salles-Cunha

Publications and source records attributed to S X Salles-Cunha.

At least 19 recordsLinked to original sources

PubMed2001

Femoral pseudoaneurysm thrombinjection.

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.

Adult↗

PubMed1999

Values and limitations of duplex ultrasonography as the sole imaging method of preoperative evaluation for popliteal and infrapopliteal bypasses.

The purpose of this study was to evaluate whether duplex ultrasound arterial mapping (DAM) can reliably replace standard arteriography (SA) in the preoperative assessment of candidates for popliteal and infrapopliteal bypasses. This is the report of a two-phase study undertaken at our institution from July 1997 to May 1998. Carefully performed DAM averted the need for preoperative SA (51 of 58 procedures). The results of this study can be used as an impetus to initiate larger, multicenter protocols to further evaluate this newer noninvasive approach for patients presenting with severe lower-limb ischemia.

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PubMed1999

Diameter-reflux relationship in perforating veins of patients with varicose veins.

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 (C(2)E(P)A(SP)P(R)). 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.

Female↗

PubMed1999

Carotid arterial ultrasound scan imaging: A direct approach to stenosis measurement.

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 <50% stenosis shown with USI, the prediction of <50% stenosis shown with XRI was 94% (253/269). For borderline stenosis in the 50% to 79% range with USI, the addition of velocity criteria to USI data improved both the PPV and the NPV. In the range of 70% to 79% stenosis with USI, the PPV improved from 82% (76/93) to 91% (53/58) for the subgroup with an EDV of more than 80 cm/s. For the range of 60% to 69% stenosis with USI, the PPV improved from 75% (71/95) to 95% (21/22) for the subgroup with an EDV of more than 80 cm/s. In the range of 50% to 59% stenosis with USI, the NPV improved from 69% (53/77) to 93% (14/15) for the subset with a peak systolic velocity of less than 100 cm/s. CONCLUSION: On the basis of the USI data alone, a prediction of arteriographic findings was possible at the 95% level for occlusion and severe stenosis and for ruling out hemodynamically significant stenosis. The addition of velocity data improved prediction in borderline degrees of stenosis. USI was effective for quantifying clinically significant degrees of stenosis.

Adult↗

PubMed1998

Lower extremity arterial evaluation: are segmental arterial blood pressures worthwhile?

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.

Adult↗

PubMed1998

Biplane color flow duplex intravenous intravascular ultrasound for arterial visualization.

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.

Animals↗

PubMed1996

Management of arterial occlusive disease following radiation therapy.

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 lower-extremity 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.

Aged↗

PubMed1995

Gender bias in use of venous ultrasonography for diagnosis of deep venous thrombosis.

PURPOSE: We observed that ultrasound examinations for deep venous thrombosis (DVT) were more frequently requested for women than for men in our vascular laboratory serving a general outpatient population and referral 774-bed hospital. Because existing literature presents conflicting information about sex differences in occurrence of DVT, we investigated correlation in our population with positive ultrasound study results and risk factors for DVT. METHODS: In 13 months, 2055 ultrasound examinations for DVT were requested. Of these, 300 patients (15%) were categorized in four subgroups: 75 ultrasonography-negative men, 75 ultrasonography-negative women, 75 ultrasonography (DVT)-positive men, and 75 ultrasonography (DVT)-positive women for risk factor analysis. RESULTS: Women comprised 64% (1311 of 2055) and men 36% (744 of 2055) of ultrasound examinations requested, but men had significantly higher incidence of DVT-positive ultrasonography results (101 of 744 [14%]) compared with women (118 of 1311 [9%]) (p = 0.002 by chi-square testing). There were no significant sex differences in conventional DVT risk factors and no difference in aggregate number of risk factors. The anatomic distribution of DVT was the same in men as in women. Among those having negative ultrasonography results, significantly more outpatient examinations were performed in women (p = 0.018 by t testing). CONCLUSIONS: Gender bias exists in use of ultrasonography for diagnosis of DVT. The greater incidence of women undergoing venous ultrasonography is not explained by higher prevalence of DVT risk factors or of higher occurrence of positive ultrasound examination results. Further investigation is needed to determine whether these differences indicate underuse of ultrasonography in men or overuse in women.

Bias↗

PubMed1995

Preoperative assessment of alternative veins.

Duplex ultrasonography, with or without color flow, has replaced phlebography as the technique of choice to select veins for autogenous bypass grafts. Although anatomic location and length are well-defined by ultrasound, evaluation of the venous wall itself is still imperfect. In situ diameters are less than those of arterialized veins. Ultrasonic search is most valuable in the examination of patients with good veins obscured by a layer of fat. Preoperative knowledge of variant anatomy and location of major veins and their branches facilitates bypass surgery. The preoperative vein mapping should be available in the operating room to guide the placement of incisions for unroofing and exploration directly over veins and vein segments that have a high likelihood of being usable. The finding of a useful vein when none is apparent on physical examination may enable the construction of an autogenous bypass in lieu of a less desirable prosthetic graft or leg amputation.

Blood Flow Velocity↗

PubMed1991

Percutaneous transluminal angioplasty of the lower extremities by the vascular surgeon.

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.

Aged↗

PubMed1990

Preoperative duplex scanning prior to infrainguinal revascularization.

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.

Arterial Occlusive Diseases↗

PubMed1990

Successful percutaneous angioplasty after failed femorodistal bypass.

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.

Aged↗

PubMed1989

Lateral plantar artery bypass grafting: defining the limits of foot revascularization.

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.

Adult↗

PubMed1989

Changes in peripheral hemodynamics after percutaneous transluminal angioplasty.

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.

Aged↗

PubMed1988

Bypass grafts to the ankle and foot.

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.

Aged↗

PubMed1986

Totally autogenous venovenous composite bypass grafts. Salvage of the almost irretrievable extremity.

When a suitable single length of saphenous or arm vein is unavailable, the elderly patient with a profoundly ischemic extremity, poor runoff, and a distal outflow vessel frequently undergoes amputation. Rather than performing primary amputation or resorting to nonautogenous conduites, we used 21 different combinations of available vein segments of ipsilateral or contralateral greater saphenous, lesser saphenous, cephalic, and basilic veins as composite autogenous bypass grafts. Fifty-four extremities, of which 21 (39%) had one or more failed previous bypasses, were revascularized. Tissue necrosis necessitated operation in 74% (40 instances) and rest pain in 19% (ten instances). All grafts extended below the knee, 22% (12 grafts) to the infrageniculate popliteal artery, 78% (42 grafts) to an infrapopliteal runoff vessel, and 28% (15 grafts) to the ankle or foot. The patency rate at one month was 81%. Thrombectomy alone or with local graft repair increased the one-month patency rate to 96%. At one year, the patency and limb salvage rates were 74% and 82%, respectively.

Aged↗

PubMed1986

Preoperative noninvasive assessment of arm veins to be used as bypass grafts in the lower extremities.

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.

Arm↗

PubMed1986

Arm veins for arterial revascularization of the leg: arteriographic and clinical observations.

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.

Aged↗