The use of arm vein in lower-extremity revascularization: results of 520 procedures performed in eight years.
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PURPOSE: The absence of an adequate ipsilateral saphenous vein in patients requiring lower-extremity revascularization poses a difficult clinical dilemma. This study examined the results of the use of autogenous arm vein bypass grafts in these patients. METHODS: Five hundred twenty lower-extremity revascularization procedures performed between 1990 and 1998 were followed prospectively with a computerized vascular registry. The arm vein conduit was prepared by using intraoperative angioscopy for valve lysis and identification of luminal abnormalities in 44.8% of cases. RESULTS: Seventy-two (13. 8%) femoropopliteal, 174 (33.5%) femorotibial, 29 (5.6%) femoropedal, 101 (19.4%) popliteo-tibial/pedal, and 144 (27.7%) extension "jump" graft bypass procedures were performed for limb salvage (98.2%) or disabling claudication (1.8%). The average age of patients was 68.5 years (range, 32 to 91 years); 63.1% of patients were men, and 36.9% of patients were women. Eighty-five percent of patients had diabetes mellitus, and 77% of patients had a recent history of smoking. The grafts were composed of a single arm vein segment in 363 cases (69. 8%) and of spliced composite vein with venovenostomy in 157 cases (30.2%). The mean follow-up period was 24.9 months (range, 1 month to 7.4 years). Overall patency and limb salvage rates for all graft types were: primary patency, 30-day = 97.0% +/- 0.7%, 1-year = 80.2% +/- 2.1%, 3-year = 68.9% +/- 3.6%, 5-year = 54.5% +/- 6.6%; secondary patency, 30-day = 97.0% +/- 0.7%, 1-year = 80.7% +/- 2.1%, 3-year = 70.3% +/- 3.4%, 5-year = 57.5% +/- 6.2%; limb salvage, 30-day = 97.6% +/- 0.7%, 1-year = 89.8% +/- 1.7%, 3-year = 82.1% +/- 3.3%, 5-year = 71.5% +/- 6.9%. Secondary patency and limb salvage rates were greatest at 5 years for femoropopliteal grafts (69.8% +/- 12.8%, 80.7% +/- 11.8%), as compared with femorotibial (59.6% +/- 10. 3%, 72.7% +/- 10.5%), femoropedal (54.9% +/- 25.7%, 56.8% +/- 26.9%, ) and popliteo-tibial/pedal grafts (39.0% +/- 7.3%, 47.6% +/- 15.4%). The patency rate of composite vein grafts was equal to that of single-vein conduits. The overall survival rate was 54% at 4 years. CONCLUSION: Autogenous arm vein has been used successfully in a wide variety of lower-extremity revascularization procedures and has achieved excellent long- and short-term patency and limb salvage rates, higher than those generally reported for prosthetic or cryopreserved grafts. Its durability and easy accessibility make it an alternative conduit of choice when an adequate saphenous vein is not available. (+info)
Changes in the practice of angioaccess surgery: impact of dialysis outcome and quality initiative recommendations.
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PURPOSE: Recommendations recently published by the National Kidney Foundation-Dialysis Outcome and Quality Initiative (DOQI) included an appeal for increased use of native arteriovenous fistulas (NAVFs) to improve overall patency and contain angioaccess costs. We evaluated the impact of the DOQI recommendations on angioaccess surgery and its outcome at our institution. METHODS: From June 1996 to April 1999, 483 angioaccess procedures were performed on 247 patients. There were 133 men and 114 women, with an average age ranging from 28 to 95 years (mean age, 69 +/- 0.59 years). Risk factors included smoking in 143 patients (58%), diabetes mellitus in 135 patients (55%), hypertension in 150 patients (61%), and coronary artery disease in 98 patients (40%). The patients were divided in two groups. Group I (pre-DOQI) included patients who had angioaccess procedures between June 1996 and November 1997, and group II (post-DOQI) included patients who had angioaccess procedures between December 1997 and April 1999. The types of procedures performed included placement of arteriovenous grafts (AVGs) in 122 patients (25%), creation of NAVFs in 99 patients (20%), revision of AVGs in 123 patients (25%), and temporary access procedures in 135 patients (28%). Forty-seven of the NAVF procedures were radial-cephalic fistulas (47%), 22 were brachial-cephalic fistulas (23%), and 30 were brachial-basilic fistulas (30%). Patients underwent serial ultrasonography scanning and physical examinations; the mean follow-up period was 9 months. Choice of angioaccess procedures and patency rates before and after implementation of the DOQI recommendations were compared. RESULTS: There was a significant increase in the use of NAVFs after implementing DOQI recommendations (5% vs 68%, P <.001). The 1-year primary patency rate of AVGs was less than that of arteriovenous fistulas (54% vs 85%, P <.001). During the study period, the percentage of AVGs placed at our institution that required revision (59%; 72 of 123) was higher than that of NAVFs that required revision (4%; 4 of 99; P <.001). There was no significant difference in the maturation rates of radial-cephalic fistulas (75%), brachial-cephalic fistulas (91%), and brachial-basilic fistulas (87%). CONCLUSION: By adopting the DOQI recommendations, we used NAVFs more often. This resulted in superior patency rates, compared with synthetic grafts. The liberal use of preoperative duplex venous mapping further increased NAVF use, surpassing the DOQI expectations for primary arteriovenous fistulas. Additionally, fewer revisions were required. (+info)
Human arm movements described by a low-dimensional superposition of principal components.
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A new method for analyzing kinematic patterns during smooth movements is proposed. Subjects are asked to move the end of a two-joint manipulandum to copy a smooth initial target path. On subsequent trials the target path is the subject's actual movement from the preceding trial. Using Principal Components Analysis, it is shown that the trajectories have very low dimension and that they converge toward a linear superposition of the first few principal components. We show similar results for handwriting on an electronic pen tablet. We hypothesize that the low dimensionality and convergence are attributable to combined properties of the internal controller and the musculoskeletal system. The low dimensionality may allow for efficient descriptions of a large class of arm movements. (+info)
Saccade-related activity in the parietal reach region.
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In previous experiments, we showed that cells in the parietal reach region (PRR) in monkey posterior parietal cortex code intended reaching movements in an eye-centered frame of reference. These cells are more active when an arm compared with an eye movement is being planned. Despite this clear preference for arm movements, we now report that PRR neurons also fire around the time of a saccade. Of 206 cells tested, 29% had perisaccadic activity in a delayed-saccade task. Two findings indicate that saccade-related activity does not reflect saccade planning or execution. First, activity is often peri- or postsaccadic but seldom presaccadic. Second, cells with saccade-related activity were no more likely to show strong saccadic delay period activity than cells without saccade-related activity. These findings indicate that PRR cells do not take part in saccade planning. Instead, the saccade-related activity in PRR may reflect cross-coupling between reach and saccade pathways that may be used to facilitate eye-hand coordination. Alternatively, saccade-related activity may reflect eye position information that could be used to maintain an eye-centered representation of intended reach targets across eye movements. (+info)
Value of somatosensory and motor evoked potentials in predicting arm recovery after a stroke.
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OBJECTIVES: Prediction of motor recovery in the arm in patients with stroke is generally based on clinical examination. However, neurophysiological measures may also have a predictive value. The aims of this study were to assess the role of somatosensory (SSEPs) and motor (MEPs) evoked potentials in the prediction of arm motor recovery and to determine whether these measures added further predictive information to that gained from clinical examination. METHODS: Sixty four patients who had had a stroke and presented with obvious motor deficit of the arm were examined in terms of three clinical variables (motor performance, muscle tone, and overall disability) and for SSEPs and MEPs. Clinical and neurophysiological examinations were done at entry to the study (2 to 5 weeks poststroke), and at about 2 months after stroke. Further clinical follow up was conducted at 6 and 12 months after stroke. RESULTS: Neurophysiological measures made in the acute phase were of little use alone in predicting motor recovery of the arm at 2, 6, and 12 months after stroke. At 2 months, the absence of SSEPs and MEPs indicated a very poor outcome. Conversely, if the responses were preserved, a great variation in motor outcome was found. Multiple regression analysis showed that the addition of SSEPs and MEPs to the clinical examination increased the possibility of predicting arm recovery in the long term. In the acute phase, the combination of the motor score and SSEPs were best able to predict outcome. The long term outcome based on variables taken at 2 months, was best predicted through incorporating the three clinical measures and MEPs. CONCLUSIONS: Neurophysiological measures alone are of limited value in predicting long term outcome. However, predictive accuracy is substantially improved through the combined use of both of these measures and clinical variables. (+info)
Motor disorder in Huntington's disease begins as a dysfunction in error feedback control.
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A steady progression of motor dysfunction takes place in Huntington's disease (HD). The origin of this disturbance with relation to the motor control process is not understood. Here we studied reaching movements in asymptomatic HD gene-carriers (AGCs) and subjects with manifest HD. We found that movement jerkiness, which characterizes the smoothness and efficiency of motion, was a sensitive indicator of presymptomatic HD progression. A large fraction of AGCs displayed elevated jerk even when more than seven years remained until predicted disease onset. Movement termination was disturbed much more than initiation and was highly variable from trial to trial. Analysis of this variability revealed that the sensitivity of end-movement jerk to subtle, self-generated early-movement errors was greater in HD subjects than in controls. Additionally, we found that HD corrective responses to externally-generated force pulses were greatly disturbed, indicating that HD subjects display aberrant responses to both external and self-generated errors. Because feedback corrections are driven by error and are delayed such that they predominantly affect movement termination, these findings suggest that a dysfunction in error correction characterizes the motor control deficit in early HD. This dysfunction may be observed years before clinical disease onset and grows worse as the disease progresses. (+info)
Cutaneous Scedosporium apiospermum infection in an immunocompromised patient.
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Scedosporium apiospermum infection occurred in the left forearm of a patient who was taking oral prednisolone for pulmonary fibrosis. The infection appeared to follow a scratch from a blackcurrant bush. This is the first reported case in the United Kingdom of a cutaneous infection from Scedosporium apiospermum in an immunocompromised patient. (+info)
Objective measurement of functional upper-extremity movement using accelerometer recordings transformed with a threshold filter.
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BACKGROUND AND PURPOSE: The consensus is that the most important outcome for rehabilitation is functional activity in the life situation. Constraint-Induced Movement Therapy, a new treatment that transfers in-clinic gains to the life situation, demands objective measurement of real-world movement. However, direct, objective, and accurate measures of arm use in the real world are not available. Previous attempts to use accelerometry to measure extremity movement have failed because of unacceptable variability. This problem has been addressed here by use of a threshold filter. METHODS: Nine stroke patients and 1 healthy individual wearing accelerometers were videotaped while they carried out their usual activities at home or in the clinic; the duration of their arm, torso, and ambulatory movements was judged by 2 observation teams. In addition, 11 college students performed 5 standardized activities of daily living for varying durations in the laboratory. The accelerometer data were transformed; the raw value recorded for a given epoch was set to a constant if it exceeded a low threshold. RESULTS: The threshold-filtered recordings measured the duration of movement accurately and with very little variability. Correlations between the threshold-filtered recordings and the observer ratings of the duration of arm, torso, and ambulatory movements were 0.93, 0.93 and 0.99, respectively; the corresponding correlations for the raw values were -0.17, 0.34, and 0.85. CONCLUSIONS: These results present initial evidence for the validity of threshold-filtered accelerometer recordings for objectively measuring the amount of real-world upper-extremity movement as an index of treatment outcome for rehabilitation patients. (+info)