Isolated femoropopliteal bypass graft for limb salvage after failed tibial reconstruction: a viable alternative to amputation.
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PURPOSE: Femoropopliteal bypass grafting procedures performed to isolated popliteal arteries after failure of a previous tibial reconstruction were studied. The results were compared with those of a study of primary isolated femoropopliteal bypass grafts (IFPBs). METHODS: IFPBs were only constructed if the uninvolved or patent popliteal segment measured at least 7 cm in length and had at least one major collateral supplying the calf. When IFPB was performed for ischemic lesions, these lesions were usually limited to the digits or small portions of the foot. Forty-seven polytetrafluoroethylene grafts and three autogenous reversed saphenous vein grafts were used. RESULTS: Ankle brachial pressure index (ABI) increased after bypass grafting by a mean of 0.46. Three-year primary life table patency and limb-salvage rates for primary IFPBs were 73% and 86%, respectively. All eight IFPBs performed after failed tibial bypass grafts remained patent for 2 to 44 months, with patients having viable, healed feet. CONCLUSION: In the presence of a suitable popliteal artery and limited tissue necrosis, IFPB can have acceptable patency and limb-salvage rates, even when a polytetrafluoroethylene graft is used. Secondary IFPB can be used to achieve limb salvage after failed tibial bypass grafting. (+info)
Surgical transluminal iliac angioplasty with selective stenting: long-term results assessed by means of duplex scanning.
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PURPOSE: The safety of iliac angioplasty and selective stenting performed in the operating room by vascular surgeons was evaluated, and the short- and long-term results were assessed by means of serial duplex scanning. METHODS: Between 1989 and 1996, 281 iliac stenotic or occlusive lesions in 235 consecutive patients with chronic limb ischemia were treated by means of percutaneous transluminal angioplasty (PTA) alone (n = 214) or PTA with stent (n = 67, 23.8%). There were 260 primary lesions and 21 restenosis after a first PTA, which were analyzed separately. Stents were implanted in selected cases, either primarily in totally occluded arteries or after suboptimum results of PTA (ie, residual stenosis or a dissection). Data were collected prospectively and analyzed retrospectively. Results were reported in an intention-to-treat basis. Clinical results and patency were evaluated by means of symptom assessment, ankle brachial pressure index, and duplex scanning at discharge and 1, 3, 6, and every 12 months after angioplasty. To identify factors that may affect outcome, 12 clinical and radiological variables, including the four categories of lesions defined by the Standards of Practice Committee of the Society of Cardiovascular and Interventional Radiology, were analyzed separately. The statistical significances of life-table analysis of patency were determined by means of the log-rank test. RESULTS: There were no postoperative deaths or amputations. Local, general, and vascular complications occurred in 2.1%, 1.3% and 4.7% of cases, respectively (total, 8.1%). The mean follow-up period was 29.6 months. The cumulative patency rates +/- SE of the 260 PTAs (including 55 PTAs plus stents) were 92.9% +/- 1.5% at 1 month, 86. 5% +/- 1.7% at 1 year, 81.2% +/- 2.3% at 2 years, 78.8% +/- 2.9% at 3 years, and 75.4% +/- 3.5% at 5 and 6 years. The two-year patency rate of 21 redo PTAs (including 11 PTAs plus stents) was 79.1% +/- 18.2%. Of 12 predictable variables studied in the first PTA group, only the category of the lesion was predictive of long-term patency. The two-year patency rate was 84% +/- 3% for 199 category 1 lesions and 69.7% +/- 6.5% for 61 category 2, 3, and 4 lesions together (P =. 02). There was no difference of patency in the stented and nonstented group. CONCLUSION: Iliac PTA alone or with the use of a stent (in cases of occlusion and/or suboptimal results of PTA) offers an excellent long-term patency rate. Categorization of lesions remains useful in predicting long-term outcome. PTA can be performed safely by vascular surgeons in the operating room and should be considered to be the primary treatment for localized iliac occlusive disease. (+info)
Ankle-arm index as a predictor of cardiovascular disease and mortality in the Cardiovascular Health Study. The Cardiovascular Health Study Group.
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Peripheral arterial disease (PAD) in the legs, measured noninvasively by the ankle-arm index (AAI) is associated with clinically manifest cardiovascular disease (CVD) and its risk factors. To determine risk of total mortality, coronary heart disease, or stroke mortality and incident versus recurrent CVD associated with a low AAI, we examined the relationship of the AAI to subsequent CVD events in 5888 older adults with and without CVD. The AAI was measured in 5888 participants >/=65 years old at the baseline examination of the Cardiovascular Health Study. All participants had a detailed assessment of prevalent CVD and were contacted every 6 months for total mortality and CVD events (including CVD mortality, fatal and nonfatal myocardial infarction, congestive heart failure, angina, stroke, and hospitalized PAD). The crude mortality rate at 6 years was highest (32.3%) in those participants with prevalent CVD and a low AAI (P<0.9), and it was lowest in those with neither of these findings (8.7%, P<0.01). Similar patterns emerged from analysis of recurrent CVD and incident CVD. The risk for incident congestive heart failure (relative risk [RR]=1.61) and for total mortality (RR=1.62) in those without CVD at baseline but with a low AAI remained significantly elevated after adjustment for cardiovascular risk factors. Hospitalized PAD events occurred months to years after the AAI was measured, with an adjusted RR of 5.55 (95% CI, 3.08 to 9.98) in those at risk for incident events. A statistically significant decline in survival was seen at each 0.1 decrement in the AAI. An AAI of <0.9 is an independent risk factor for incident CVD, recurrent CVD, and mortality in this group of older adults in the Cardiovascular Health Study. (+info)
Ropivacaine or 2% mepivacaine for lower limb peripheral nerve blocks. Study Group on Orthopedic Anesthesia of the Italian Society of Anesthesia, Analgesia, and Intensive Care.
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BACKGROUND: Intra- and postoperative clinical properties of sciatic-femoral nerve block performed with either ropivacaine at different concentrations or mepivacaine have been evaluated in a multicenter, randomized, blinded study. METHODS: Adult patients scheduled for foot and ankle surgery were randomized to receive combined sciatic-femoral nerve block with 225 mg of either 0.5% (n = 83), 0.75% (n = 87), or 1% (n = 86) ropivacaine, or with 500 mg of 2% mepivacaine (n = 84). A thigh tourniquet was used in all patients. Onset time, adequacy of surgical anesthesia, time to offset of nerve block, and time until first postoperative requirement for pain medication were evaluated by a blinded observer. RESULTS: The adequacy of nerve block was similar in the four treatment groups (the ratios between adequate:inadequate: failed blocks were 74:9:0 with 0.5% ropivacaine, 74:13:0 with 0.75% ropivacaine, 78:8:0 with 1% ropivacaine, and 72:12:0 with 2% mepivacaine). The onset of the block was slower with 0.5% ropivacaine than with other anesthetic solutions (P < 0.001). Regardless of the concentration, ropivacaine produced a longer motor blockade (10.5+/-3.8 h, 10.3+/-4.3 h, and 10.2+/-5.1 h with 0.5%, 0.75%, and 1% ropivacaine, respectively) than with mepivacaine (4.3+/-2.6 h; P < 0.001). The duration of postoperative analgesia was shorter after mepivacaine (5.1+/-2.7 h) than after ropivacaine (12.2+/-4.1 h, 14.3+/-5 h, and 14.5+/-3.4 h, with 0.5%, 0.75%, or 1% ropivacaine, respectively; P < 0.001). Pain relief after 0.5% ropivacaine was 14% shorter than 0.75% or 1% ropivacaine (P < 0.05). During the first 24 h after surgery, 30-37% of patients receiving ropivacaine required no analgesics compared with 10% of those receiving mepivacaine (P < 0.001). CONCLUSIONS: This study suggests that 0.75% ropivacaine is the most suitable choice of local anesthetic for combined sciatic-femoral nerve block, providing an onset similar to mepivacaine and prolonged postoperative analgesia. (+info)
Volume of ankle dorsiflexors and plantar flexors determined with stereological techniques.
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The validity of the methods used for determination of muscle mass has not been evaluated previously. We determined muscle mass by estimating muscle volume with assumption-free stereological techniques applied to magnetic resonance imaging (MRI) in 18 healthy untrained subjects (6 women, 12 men) aged 41 yr (29-64 yr; median, range). Muscle mass was also estimated by measuring leg circumference and cross-sectional muscle areas (CSA) from MRIs at three predetermined levels. Power [peak torque (PT)] of the ankle dorsiflexors and plantar flexors was estimated by using isokinetic dynamometry. Dorsiflexor volume (r2 = 0.76, P < 5 x 10(-6)) and CSA (r2 = 0.73, P < 5 x 10(-5)) were related to PT, whereas circumference was not (r2 = 0.17, not significant). Correspondingly, a relationship to plantar PT was established for plantar flexor volume (r2 = 0.69, P < 5 x 10(-5)) and CSA (r2 = 0.46, P < 5 x 10(-3)) but not leg circumference (r2 = 0.15, not significant). SDs of the residuals were smaller for the relationship between dorsiflexor PT and volume than between PT and CSA (0.42 vs. 0.45) for plantar flexors (1.5 vs. 2.0). By using the Cavalieri method, six MRI sections and 15 min of point counting are sufficient to obtain a valid estimate of the volume of the muscles of the lower leg. (+info)
Lower limb deep venous flow in patients with peripheral vascular disease.
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PURPOSE: A prospective controlled study was undertaken to determine how peripheral vascular disease (PVD) influences flow in the deep veins of the leg. METHODS: Eighty-nine patients with peripheral vascular disease and 35 age-matched control subjects were studied. The popliteal vein diameter and flow velocity were measured at rest by means of color duplex ultrasound scanning, and these measurements were compared with the ankle-brachial pressure index. For 23 subjects, measurements were also performed during reactive hyperemia and then repeated after venous return from the foot was prevented by an ankle cuff. RESULTS: There was a significant correlation between the ankle-brachial pressure index and the popliteal vein diameter (r = 0.35, P <.001) but a negative correlation between the ankle-brachial pressure index and venous flow velocity among patients with PVD (r = -0.24, P =.002). In PVD patients the diameter decreased further in reactive hyperemia, whereas it increased in control subjects ( P <.001). Preventing venous return from the foot in PVD patients led to diameter increase at rest and abolished the reduction in diameter caused by reactive hyperemia. Despite the reduction in diameter during reactive hyperemia, flow velocity increased less in patients with PVD than it did in control subjects (P =.01). CONCLUSION: Chronic tissue ischemia results in constriction of the popliteal vein. This appears to be an active process related to the washout of humoral factors from ischemic tissues distally, which leads to an increase in flow velocity. The latter may confer some protection against the deep vein thrombosis that would otherwise tend to occur with low venous flow rates. (+info)
Modulation of stretch reflexes during imposed walking movements of the human ankle.
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Our overall objectives were to examine the role of peripheral afferents from the ankle in modulating stretch reflexes during imposed walking movements and to assess the mechanical consequences of this reflex activity. Specifically we sought to define the changes in the electromyographic (EMG) and mechanical responses to a stretch as a function of the phase of the step cycle. We recorded the ankle position of a normal subject walking on a treadmill at 3 km/h and used a hydraulic actuator to impose the same movements on supine subjects generating a constant level of ankle torque. Small pulse displacements, superimposed on the simulated walking movement, evoked stretch reflexes at different phases of the cycle. Three major findings resulted: 1) soleus reflex EMG responses were influenced strongly by imposed walking movements. The response amplitude was substantially smaller than that observed during steady-state conditions and was modulated throughout the step cycle. This modulation was qualitatively similar to that observed during active walking. Because central factors were held constant during the imposed walking experiments, we conclude that peripheral mechanisms were capable of both reducing the amplitude of the reflex EMG and producing its modulation throughout the movement. 2) Pulse disturbances applied from early to midstance of the imposed walking cycle generated large reflex torques, suggesting that the stretch reflex could help to resist unexpected perturbations during this phase of walking. In contrast, pulses applied during late stance and swing phase generated little reflex torque. 3) Reflex EMG and reflex torque were modulated differently throughout the imposed walking cycle. In fact, at the time when the reflex EMG response was largest, the corresponding reflex torque was negligible. Thus movement not only changes the reflex EMG but greatly modifies the mechanical output that results. (+info)
The influence of experience on the reproducibility of the ankle-brachial systolic pressure ratio in peripheral arterial occlusive disease.
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OBJECTIVES: to estimate the intra-observer variability of the measurement of the ankle-brachial systolic pressure index (ABPI) and to compare the reproducibility of the measurements by experienced vascular laboratory assistants and by less-experienced general practice personnel. DESIGN: repeated measurement of ABPI by general practitioners (GPs), GP-assistants and vascular laboratory assistants using a pocket Doppler device and a random-zero sphygmomanometer. METHODS AND MATERIALS: ABPI was measured in six patients with various degrees of PAOD by two experienced observers (vascular laboratory assistants) and by 24 less-experienced observers (18 practice assistants, six GPs). RESULTS: the total number of measurements was 354. The overall intra-observer variability estimate was 11.8% ABPI. The intra-observer variability was 7.3% in the experienced observers and 12.0% in the less-experienced observers. The difference of variability between experienced and less-experienced observers was significant. CONCLUSIONS: the ABPI is suitable in follow-up studies where repeated measurements are needed. Differences between measurements can be minimised by performing repeated measurements or by using more experienced observers. (+info)