Effects of a microprocessor-controlled ankle-foot unit on energy expenditure, quality of life, and postural stability in persons with transtibial amputation: An unblinded, randomized, controlled, cross-over study.

BACKGROUND: Microprocessor-controlled prostheses are designed to improve mobility and quality of life through better balance and energy restoration in persons with transtibial amputation. Quasi-active microprocessor-controlled ankles (MPA) adapt to variable terrain by ankle angle adjustment. OBJECTIVES: To compare energy expenditure, balance, quality of life, and satisfaction of Proprio-foot® (a quasi-active MPA model) with standard prescribed ankle prosthesis (prescribed ankle-foot units [PA]) (standard energy storage and return prosthesis). STUDY DESIGN: Multicenter, unblinded, randomized, controlled, cross-over study. METHODS: Energy expenditure (primary outcome) was assessed by oxygen uptake (VO2) measured at the maximum level reached with the 2 prostheses during treadmill walking at progressively increasing incline and speed. Balance was assessed by stabilometry in different static positions. Quality of life and satisfaction were assessed by "Short Form 36" questionnaire (0-100) and by Evaluation de la Satisfaction envers une Aide Technique (0-5) questionnaires after wearing each of the 2 prostheses for 34 days. RESULTS: Forty-five patients tested the 2 prostheses. No statistical difference in VO2 was observed. Significant improvement of balance was observed both during standing on an incline or decline with MPA and PA (p < 0.01). Short Form 36 questionnaire physical scores and Short Form 36 questionnaire mental scores were 68.5 ± 19.5 vs. 62.1 ± 19.6 (p < 0.01) and 72.0 ± 20.8 vs. 66.2 ± 20.9 (p < 0.01) in MPA and PA, respectively. Evaluation de la Satisfaction envers une Aide Technique score on the device was not statistically significant between the 2 groups (MPA 4.4 ± 0.5 vs. PA 4.3 ± 0.5, p = 0.360). CONCLUSION: Proprio-foot® improved balance, quality of life, and patient satisfaction despite no reduction or increase in energy expenditure in comparison with standard energy storage and return prosthesis.

Ankle brachial index is equally predictive of exercise-induced limb ischemia in diabetic and non-diabetic patients with walking limitation.

BACKGROUND: In diabetic patients, arterial stiffness may impair compressibility of vessels and result in higher ankle to brachial index (ABI) than in non-diabetic subjects. METHODS: We studied 1972 non-diabetic and 601 diabetic patients, with suspected peripheral artery disease, Exercise transcutaneous oxygen pressure (Ex-tcpO2), expressed in DROP index (limb tcpO2 change minus chest tcpO2 change), is insensitive to arterial stiffness and can estimate exercise-induced regional blood flow impairment (RBFI). A minimal DROP <-15 mm Hg indicates the presence of RBFI (positive test). ABI was simplified to a category variable (ABIc) by rounding ABI to the closest first decimal. RESULTS: In the ABIc range 0.4 to 1.1 linear regression for mean DROP values were: y = 34 x - 53; (R2 = 0.211) and y = 33 x - 52; (R2 = 0.186) in diabetic and Non-diabetic patients, respectively. Both Db and non-D patients showed a high proportion of positive Ex-tcpO2 tests for ABIc in the normal range (ABIc: 1.0 and over) from 27.1 to up to 58%. More than half of patients with borderline ABI (ABIc = 0.9) had RBFI during exercise. it was 65.6% in diabetic and 58.5% non-diabetic patients. CONCLUSIONS: Resting ABI was not a better predictor of exercise-induced RBFI in non-Db than in Diabetic patients. Our results highlights the interest of still measuring resting-ABI in diabetic patients to argue for the vascular origin of exertional limb pain, but also of performing exercise tests in patients with walking impairment.

Transcutaneous Exercise Oximetry for Patients With Claudication　- A Retrospective Review of Approximately 5,000 Consecutive Tests Over 15 Years.

BACKGROUND: Exercise transcutaneous oximetry (Ex-tcPO2) is used to argue for the vascular origin of lower limb pain, especially at the proximal level, where the diagnosis of peripheral artery disease can be difficult. This study analyzed the principal indications, mean results, and limitations of Ex-tcPO2, as well as the relationship between the annual number of Ex-tcPO2 tests and internal iliac artery (IIA) revascularizations.Methods and Results:Data from our first 15 years' experience (3,631 patients, 5,080 tests) with Ex-tcPO2 were analyzed retrospectively using the minimal value of the decrease from rest of oxygen pressure (DROPmin). We had 99.7% of expected DROPminresults. The proportion of tests showing isolated proximal unilateral or bilateral ischemia ranged from ~5% to ~20%. A gradual increase with time was observed in both the annual number of Ex-tcPO2 tests (from 0 to ~500 per year) and the annual number of IIA revascularizations performed (from 0 up to 18 per year). At least 85% of patients (77/91) showed function improvement after IIA revascularization. CONCLUSIONS: Ex-tcPO2 (using DROPmin) provides an objective argument for exercise-induced ischemia, bilaterally at the distal and/or proximal level. Using Ex-tcPO2 has improved our diagnostic performance and markedly changed our therapeutic decisions, specifically for proximal claudication. The increased number of Ex-tcPO2 tests is associated with an increased number of IIA revascularizations, although a causal relationship was not proven.

Simultaneous pain intensity rating and quantification of ischemia throughout exercise and recovery in proximal versus distal arterial claudication.

Data on simultaneous hemodynamic changes and pain rating estimation in arterial claudication while walking are lacking. This study was conducted to determine if a difference in transcutaneous oxygen pressure (tc pO2) exists between proximal and distal localization at pain appearance (PAINapp), maximal pain (PAINmax) and pain relief (PAINrel) in proximal or distal claudication and if a relationship exists between tc pO2 changes and pain intensity. We analyzed the pain rating (Visual Analog Scale (VAS)) to lower limb ischemia, measured with the decrease from rest of oxygen pressure (DROP) tc pO2 index during constant-load treadmill tests in patients with calf ( n = 41) or buttock ( n = 19) claudication. Calves versus buttocks results were analyzed with ANOVA tests. The R2 correlation coefficient between individual VAS versus DROP was calculated. Ischemia intensity versus pain rating changes were correlated. Significant ischemia was required for pain appearance, but pain disappeared despite the persistence of ischemia. We observed no statistical difference for DROP at PAINapp, PAINmax or PAINrel between proximal or distal claudication. A significant correlation between pain rating versus DROP was found: from PAINapp to PAINmax, R2 = 0.750 (calves) and 0.829 (buttocks), and from PAINmax to PAINrel, R2 = 0.608 (calves) and 0.560 (buttocks); p<0.05. Pain appeared after a significant decrease of hemodynamic parameters but disappeared while parameters were not normalized. No difference in pain rating was found in proximal versus distal claudication.

Exercise Transcutaneous Oximetry of the Buttocks　- External Validation With Computed Tomography Angiography.

BACKGROUND: Exercise transcutaneous oximetry (Ex-tcPO2) is a non-invasive test for exercise-induced buttock ischemia. Prior study defined Ex-tcPO2 normal/abnormal cut-offs against arteriography but no external validation was available. The aims of this study were therefore to (1) determine the diagnostic performance of Ex-tcPO2 against CTA; (2) determine the cut-off point for detection of stenosis >75% in arteries toward the hypogastric circulation; and (3) determine the effect of chest profile classification on the diagnostic performance of Ex-tcPO2.Methods and Results:A total of 207 patients referred for Ex-tcPO2 were analyzed. DROP during Ex-tcPO2 was compared with the CTA results. Chest-tcPO2 changes were automatically classified into pre-defined profiles representing normal or abnormal responses. Using DROP <-15 mmHg as a cut-off, Ex-tcPO2 had 80.2% sensitivity, 72.3% specificity, 43.1% PPV, 93.3% NPV and 73.9% accuracy, to detect 1 stenosis >75% in arteries toward the hypogastric circulation. Optimal DROP to detect stenosis was: -15 mmHg. The overall diagnostic performance of Ex-tcPO2 was independent of chest profile classification. CONCLUSIONS: Ex-tcPO2 has satisfactory diagnostic performance to detect arterial stenoses towards the hypogastric circulation. Abnormal chest-tcPO2 profile does not impair the overall diagnostic performance of the test.

High prevalence of known and unknown pulmonary diseases in patients with claudication during exercise oximetry: A retrospective analysis.

The prevalence of pulmonary disease in patients with peripheral artery disease (PAD) has not been extensively studied. Recent evidence has shown that ∼20% of the patients have an atypical chest transcutaneous oxygen pressure (TcpO2) pattern during exercise, which suggests walking-induced hypoxemia. The main objectives of this study were to: (1) describe in a retrospective way the characteristics of the patients suffering from claudication, who attended a treadmill testing in our laboratory, (2) assess the prevalence of known or unknown pulmonary disease. The second aim of this study was to evaluate the impact of the therapeutic interventions on the walking capacities, after treatment, of the eventually detected pulmonary disorders.We retrospectively analyzed 1482 exercise TcpO2 test results. Patients that had no history of pulmonary disease, but either reported severe dyspnea or showed atypical profiles on their chest exercise-TcpO2, were advised to refer to the department of pneumology for additional investigations.In addition to the 166 patients with a history of pulmonary disease, 158 patients were suspected of unknown pulmonary disease from the result of their TcpO2 test. Many patients (n = 99/158, 62.7%) did not attend a pulmonologist visit. A pulmonary disease was established in 55 (93.2%) of the other 59 patients. Obstructive sleep apnea syndrome (OSAS) was the one and only diagnosis retained in 42/59 patients (71.2%). Among the 47 patients who had a second evaluation of their walking capacity on treadmill, 38 had treatment of the pulmonary disease found, vascular surgery treatment or a severe restricted diet, 9 had no treatment. Only the "treated" group showed a significant improvement in the maximal walking distance on treadmill between the 2 evaluations, 313 ±â€Š251 m to 433 ±â€Š317 m (P = 0.03).This retrospective pilot study underlines the high prevalence of both known and unknown pulmonary disease in patients whose primary complaint was lower limb claudication. Systematic screening and treatment of pulmonary disease in patients with claudication might be justified, to improve walking ability of such patients and possibly reduce or delay the requirement for revascularization. Prospective studies are required to confirm these preliminary results.

Multiprobe devices for exercise transcutaneous oxymetry in patients complaining claudication: interest and limits of unusual probe positions.

BACKGROUND: Exercise transcutaneous oximetry (PtcO2) can argue for a vascular origin of exercise-related pain in atypical unusual localizations, such as lumbar, thigh or foot pain. We used five probes as a standard for treadmill PtcO2 tests. Recent commercially available devices now include up to eight probes. We aimed at analyzing the potential interest of positioning a 6th probe on the area of unusual localization during exercise PtcO2 tests. METHODS: We retrospectively analyzed our data with a 6-probes device, using as a standard: one probe on the chest, one on each buttock and one on each calf. The sixth probe was positioned either: in the lumbar median position (N.=342), on the anterior lower part of the thigh (N.=391) or on the dorsum of the foot (N.=155) in patients complaining exercise-induced pain including the back, thigh or foot respectively. Results on the sixth probe at the limb were compared to result of the standard adjacent probe. A positive test (abnormal result) was defined as a minimal value of the DROP-index lower than minus 15 mmHg. RESULTS: Prevalence of positive results on the 6th probe with negative results on the adjacent standard probe was 2.3% at the lumbar site, 3.8% at the thigh and 12.3% at the foot level. CONCLUSIONS: Atypical localizations are rarely but sometimes associated to isolated positive exercise PtcO2 results and may justify the use of more than five probes in some patients, specifically for foot pain.

Comparison of two devices for measuring exercise transcutaneous oxygen pressures in patients with claudication.

BACKGROUND: We aimed at estimating the agreement between the Medicap" (photo-optical) and Radiometer• (electrochemical) sensors during exercise transcutaneous oxygen pressure ( tcp02) tests. Our hypothesis was that although absolute starting values (tcp02rest: mean over 2 minutes) might)e different, tcpOTchanges over time and the minimal value of the decrease from rest of oxygen pressure (DROPmin) results at exercise shall be concordant between the two systems. taneously, one of each system on the chest, on each buttock and on each calf. RESULTS: Seventeen Medicap" probes disconnected during the tests. tcp02rest and DROPmin values were higher with Medicap• than with Radiometer•, by 13.7 ± 17.1mmHg and 3.4 ± 11.7 mmHg, respectively. Despite the differences in absolute starting values, changes over time were similar between the two systems. The concordance between the two systems was approximately 70% for classification of test results from DROPmin. CONCLUSIONS: Photo-optical sensors are promising alternatives to electro-chemical sensors for exercise oximetry, provided that miniaturization and weight reduction of the new sensors are possible. PATIENTS AND METHODS: Forty seven patients with arterial claudication ( 65 ± 7 years) performed a treadmill test with 5 probes each of the electro-chemical and photo-optical devices simul-

Time and reliability issues associated with automatic vs. manual measurements of Ankle to Brachial pressure Index (ABI) following heavy load exercise.

OBJECTIVES: Ankle to brachial index after heavy load exercise is the most accurate way of diagnosing minor arterial lesions in athletes, such as endofibrosis. The reliability and practical aspects of ankle to brachial index measurements after heavy-load exercise have not been studied. The purpose of this study was to analyze the interest of oscillometric automatic vs. manual Doppler measurements, for the calculation of ankle to brachial index, after heavy-load exercise in athletes. DESIGN: Prospective single-center study. METHODS: Fifteen healthy trained athletes performed an incremental test twice. Ankle to brachial index measurements were performed at Rest, as soon as possible after exercise (Rec-0), and then started at the 3rd minute of recovery (Rec-3), by two operators using each one of the two ankle to brachial index measurement methods. RESULTS: Mean times for automatic vs. manual ankle to brachial availability were 99 ± 18 s vs. 113 ± 25 s (p = 0.005) and 44 ± 25 s vs. 53 ± 12 s (p = 0.001) respectively at Rec-0 and Rec-3. Ankle to brachial index values from the two methods were highly correlated (r = 0.89). Mean absolute differences of automatic vs. manual ankle to brachial values from test-retest were 0.04 ± 0.05 vs. 0.08 ± 0.08 (p > 0.05) and 0.07 ± 0.05 vs. 0.09 ± 0.10 (p > 0.05) at Rest and Rec-0. CONCLUSIONS: Automatic method allows obtaining faster and simultaneously post-exercise ankle to brachial index measurement compare to the manual Doppler. This time issue does not result in a significant change in absolute ankle to brachial index values, nor in the absolute differences of these in test-retest. Nevertheless, the test-retest variability of post-exercise ankle to brachial index results seems smaller with the automatic than the manual method.