Treadmill Measured vs. Questionnaire Estimated Changes in Walking Ability in Patients With Peripheral Artery Disease

OBJECTIVE

Determining the maximum walking time (MWT) using the treadmill test is the gold standard method for evaluating walking capacity and treatment effect in patients with peripheral arterial disease (PAD). However, self reported functional disability is important when assessing quality of life. Changes in the Walking Estimated Limitation Calculated by History (WELCH) questionnaire scores were compared with the MWT.

METHODS

A cross sectional study was performed in patients with intermittent claudication. The treadmill test (3.2 km/h; 10% gradient) and WELCH questionnaire were administered to all patients for objective evaluation of walking capacity. Given the log normal distribution of these parameters in patients with PAD, a log transformation was applied to the WELCH score (LnW) and maximum walking time (LnT). The responsiveness of the WELCH score was determined using mean changes and correlation coefficients of LnW and LnT changes. The effect of time on the "estimated minus real" (E - R) changes (LnW - change minus LnT - change) was assessed after categorisation of patients into various test-retest intervals. Patients who underwent lower limb revascularisation between the two tests and those who underwent medical treatment only were analysed.

RESULTS

Correlation coefficients between LnW and LnT for tests 1 and 2 were r = 0.514 and r = 0.503, respectively (p < .001, for both). Correlation for LnW change vs. LnT change was 0.384 (p < .001). E - R was positive only early after surgery. E - R was negative for all test-retest intervals >1 year in revascularised and non-revascularised patients.

CONCLUSION

Changes in WELCH scores correlated with changes observed on the treadmill in patients with intermittent claudication. For long test-retest intervals, WELCH changes tended to overestimate the worsening of walking impairment as compared with the measured difference observed in both revascularised and non-revascularised patients. A shortlived "honeymoon" (overestimation of the benefit for the shortest test-retest interval) was observed only in revascularised patients.

Lower Rate of Restenosis and Reinterventions With Covered vs Bare Metal Stents Following Innominate Artery Stenting

Purpose: To determine any difference between bare metal stents (BMS) and balloon-expandable covered stents in the treatment of innominate artery atheromatous lesions. Materials and Methods: A multicenter retrospective study involving 13 university hospitals in France collected 93 patients (mean age 63.2±11.1 years; 57 men) treated over a 10-year period. All patients had systolic blood pressure asymmetry >15 mm Hg and were either asymptomatic (39, 42%) or had carotid (20, 22%), vertebrobasilar (24, 26%), and/or brachial (20, 22%) symptoms. Innominate artery stenosis ranged from 50% to 70% in 4 (4%) symptomatic cases and between 70% and 90% in 52 (56%) cases; 28 (30%) lesions were preocclusive and 8 (9%) were occluded. One (1%) severely symptomatic patient had a <50% stenosis. Demographic characteristics, operative indications, and procedure details were compared between the covered (36, 39%) and BMS (57, 61%) groups. Multivariate analysis was performed to determine relative risks of restenosis and reinterventions [reported with 95% confidence intervals (CI)]. Results: The endovascular procedures were performed mainly via retrograde carotid access (75, 81%). Perioperative strokes occurred in 4 (4.3%) patients. During the mean 34.5±31.2–month follow-up, 30 (32%) restenoses were detected and 13 (20%) reinterventions were performed. Relative risks were 6.9 (95% CI 2.2 to 22.2, p=0.001) for restenosis and 14.6 (95% CI 1.8 to 120.8, p=0.004) for reinterventions between BMS and covered stents. The severity of the treated lesions had no influence on the results. Conclusion: Patients treated with BMS for innominate artery stenosis have more frequent restenoses and reinterventions than patients treated with covered stents.

High prevalence of exercise-induced ischemia in the asymptomatic limb of patients with apparently strictly unilateral symptoms and unilateral peripheral artery disease

BACKGROUND:

The prevalence of exercise-induced ischemia in the asymptomatic limb of patients with unilateral claudication based on history and treadmill evaluation, and with unilateral ipsilateral peripheral artery disease (i.e ankle-to-brachial systolic pressure index <0.90) is unknown.

METHODS:

We detected exercise-induced ischemia in the asymptomatic limb of patients with apparently unilateral claudication. Among 6059 exercise-oximetry tests performed in 3407 nondiabetic and 961 diabetic patients. We estimated the intensity of ischemia in the both limb (buttocks and calves) using the lowest minimum value of the decrease from rest of oxygen pressure (DROP; limb changes minus chest changes from rest), with significant ischemia defined as DROP lower than -15 mmHg.

RESULTS:

We found 152 tests performed in 142 nondiabetic patients and 40 tests performed in 38 diabetic patients. The asymptomatic limb showed significant ischemia in 46.7% and 37.5% of the tests. Strictly unilateral exercise-induced claudication with apparently unilateral peripheral artery disease was rare (<4% of all tests). However, among these highly selected tests, significant ischemia was found in the asymptomatic limb in more than one-third of cases.

CONCLUSION:

The asymptomatic limb of patients with peripheral artery disease should not be considered a normal limb.

Microvascular Response to the Roos Test Has Excellent Feasibility and Good Reliability in Patients With Suspected Thoracic Outlet Syndrome

Background: Exercise oximetry allows operator-independent recordings of microvascular blood flow impairments during exercise and can be used during upper arm provocative maneuvers.

Objective: To study the test-retest reliability of upper-limb oximetry during the Roos test in patients with suspected thoracic outlet syndrome (TOS).

Materials and Methods: Forty-two patients (28 men, 14 women; mean age: 40.8 years) were examined via transcutaneous oxygen pressure (TcpO2) recordings during two consecutive Roos tests in the standing position. The minimal decrease from rest of oxygen pressure (DROPmin) value was recorded after each maneuver was performed on both arms. The area under the receiver operating characteristic (ROC) curve defined the DROPmin diagnostic performance in the presence of symptoms during the tests. The Mann–Whitney U-test was used to compare the DROPmin in the symptomatic vs. asymptomatic arms. The test-retest reliability was analyzed with Bland-Altman representations. The results are presented as means ± standard deviations (SD) or medians [25–75 percentiles].

Results: The symptoms by history were different from the symptoms expressed during the Roos maneuvers in one-third of the patients. The DROPmin measurements were −19 [−36; −7] mmHg and −8 [−16; −5] mmHg in the symptomatic (n = 108) and asymptomatic (n = 60) arms, respectively. When TOS observed on ultrasound imaging was the endpoint, the area under the ROC curve (AUC) was 0.725 ± 0.058, with an optimal cutoff point of −15 mmHg. This value provided 67% sensitivity and 78% specificity for the presence TOS via ultrasound. When symptoms occurring during the test represented the endpoint, the AUC was 0.698 ± 0.04, with a cutoff point of −10 mmHg. This provided 62% sensitivity and 66% specificity for the presence of pain in the ipsilateral arm during the test. The test-retest reliability of DROPmin proved to be good but not perfect, partly because of unreliability of the provocation maneuvers.

Conclusion: To the best of our knowledge, this study is the first to investigate microvascular responses during the Roos maneuver in patients with suspected TOS. The presence of symptoms was significantly associated with ischemia. TcpO2 facilitated the recording of both macrovascular and microvascular responses to the Roos test. The Roos maneuver should probably be performed at least twice in patients with suspected TOS.

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.

Exercise transcutaneous oximetry significantly modifies the diagnostic hypotheses and impacts scheduled investigations or treatments of patients with exertional limb pain

INTRODUCTION

In lower extremity peripheral artery disease (PAD), transcutaneous oximetry at exercise (Ex-TcpO2) has been largely validated in research practice, but evidence of routine practice in various vascular laboratories is missing. We hypothesized that Ex-TcPO2 would change the diagnosis hypotheses, investigations and treatments for patients referred for exertional limb pain.

MATERIAL & METHODS

A multicenter prospective trial was conducted in nine different referral centers. Investigators performed Ex-TcpO2 and recorded investigations and treatments already scheduled for the patient. We encoded referral physician's diagnostic hypothesis. Before Ex-TcpO2, vascular physicians were asked to give their diagnosis hypotheses. A minimal decrease from rest of oxygen pressure (DROP)<minus 15mmHg defined the presence of exercise-induced ischemia on the area of interest. After Ex-TcPO2, we recorded post-test diagnostic hypothesis and investigations and treatments to be cancelled or performed. We compared the diagnosis hypotheses, scheduled investigations and treatments, before and after the Ex-TcpO2.

RESULTS

We included 603 patients (485 males: 80.4%), aged 64.7±9.8years. The post-test diagnosis hypothesis differed in 266 patients (44.1%; p<0.0001) and in 96 patients (15.9%) from the pre-test hypothesis of referring and vascular physician, respectively. This led to the recommendation to cancel 27 scheduled investigations or treatments of a total cost of ~130,000 euros.

DISCUSSION

Ex-TcPO2 in patients with exertional limb pain is applicable in various vascular institutions, and significantly modifies the diagnostic hypotheses and impacts scheduled investigations or treatments of patients with exertional limb pain.

Mitochondrial complex I defect resulting from exercise-induced lower limb ischemia in patients with peripheral arterial disease

This study aims to compare the structural and mitochondrial alterations between muscle segments affected by exercise-induced ischemia and segments of the same muscle without ischemia, in the same subject. In a prospective analysis, 34 patients presenting either peripheral arterial disease or chronic coronary syndrome without any evidence of peripheral arterial disease were eligible for inclusion based on findings indicating a need for either a femoro-popliteal bypass or a saphenous harvesting for coronary bypass. Before surgery, we assessed the level of exercise-induced ischemia in proximal and distal sections of the thigh by the measurement of transcutaneous oxygen pressure during an exercise treadmill test. Distal and proximal biopsies of the sartorius muscle were procured during vascular surgical procedures to assess mitochondrial function and morphometric parameters of the sartorius myofibers. Comparisons were made between the distal and proximal biopsies, with respect to these parameters. Thirteen of the study patients that initially presented with peripheral arterial disease had evidence of an isolated distal thigh exercise-induced ischemia, associated with a 35% decrease in the mitochondrial complex I enzymatic activity in the distal muscle biopsy. This defect was also associated with a decreased expression of the manganese superoxide dismutase enzyme and with alterations of the shapes of the myofibers. No functional or structural alterations were observed in the patients with coronary syndrome. We validated a specific model ischemia in peripheral arterial disease characterized by muscular alterations. This "Distal-Proximal-Sartorius Model" would be promising to explore the physiopathological consequences specific to chronic ischemia. NEW & NOTEWORTHY We compared proximal versus distal biopsies of the sartorius muscle in patients with superficial femoral artery stenosis or occlusion and proof of, distal only, regional blood flow impairment with exercise oximetry. We identified a decrease in the mitochondrial complex I enzymatic activity and antioxidant system impairment at the distal level only. We validate a model to explore the physiopathological consequences of chronic muscle ischemia.

Frequency of the Pectoralis Minor Compression Syndrome in Patients Treated for Thoracic Outlet Syndrome

BACKGROUND

Pectoralis minor compression syndrome (PMCS) is a compression of the neurovascular structures in the subpectoral tunnel and remains underestimated in the management of patients with thoracic outlet syndrome (TOS). Its underdiagnosis may be responsible for incomplete or failed treatment. The aim of the study was to evaluate the frequency of PMCS in our experience.

METHODS

We retrospectively reviewed all patients treated for TOS in our department. We selected those in whom PMCS was diagnosed with a systematic dynamic arteriography. Surgery was performed using the Roos axillary approach when a first rib resection was associated or an elective approach when a first rib resection was not associated.

RESULTS

From January 2004 to December 2014, 374 surgeries for TOS were performed in 279 patients, which included 90 men (sex ratio = 0.48) with a mean age of 40.1 ± 10 years old. Among these patients, 63 (22.5%) underwent 82 interventions (21.9%) for PMCS, including 26 men (sex ratio = 0.70, P < 0.05) with a mean age of 37.9 ± 9.4 years old. Tenotomy of the pectoralis minor muscle was performed using axillary approach if it was associated with a first rib resection in 74 cases (90.2%) or through an elective approach in 8 cases (9.8%) if it was isolated. Four (4.9%) postoperative complications were found (1 hematoma [1.2%], 1 hemothorax [1.2%], 1 scapula alata [1.2%], and 1 subclavian vein thrombosis [1.2%]), all after an axillary approach. In 63 cases (79.7%), preoperative symptoms were resolved. In 14 cases (17.7%), symptom resolution was incomplete, and 2 patients (2.6%) had recurrent symptoms.

CONCLUSIONS

Evaluation of PMCS in TOS is justified by its frequency and the simplicity and low morbidity of the surgical procedure.

Hypogammaglobulinemia and risk of severe infection in kidney transplant recipients

BACKGROUND

Recent data have outlined a link between hypogammaglobulinemia (HGG) and infection risk and suggested that HGG correction may decrease post-transplant infections.

METHODS

We analyzed the risk factors of HGG and the relationship between HGG and the risk of severe infection in a cohort of 318 kidney transplant recipients (KTR) who were transplanted between 2003 and 2013. Immunoglobulin (Ig) concentration was measured prospectively at day 15 (D15), month 6 (M6), month 12 (M12), and month 24 (M24) post transplant.

RESULTS

The prevalence of IgG HGG was 56% and 36.8% at D15 and M6, respectively. Age was the sole identified risk factors for D15 IgG HGG (odds ratio [OR] 1.02, P = 0.019). Risk factors for M6 IgG HGG were the presence of D15 IgG HGG (OR 6.41, P < 0.001) and treatment of acute rejection (OR 2.63, P = 0.014). Most infections occurred between D15 and M6 post transplant. Only age (hazard ratio 1.03, P < 0.001) was identified as a risk factor of infection between D15 and M6 post transplant. Survival free of infection (overall infections and bacterial or viral infections) did not differ significantly between patients with or without D15 IgG HGG. Only septicemia occurring between M6 and M12 post transplant was more frequently observed in patients with HGG. The low prevalence of severe HGG (<400 mg/dL) did not allow conclusions on the infectious risk associated with this patient subgroup.

CONCLUSIONS

This study does not support the existence of a strong link between post-transplant HGG and the risk of severe infections in KTR. Correction of HGG to minimize the risk of severe infections in KTR is thus questionable and needs to be reevaluated in prospective studies.

Pain description in patients with isolated proximal (without distal) exercise-related lower limb arterial ischemia

Among the last 250 claudicants referred to the laboratory for transcutaneous oxygen pressure recording at exercise, we analyzed the symptoms reported by the 36 patients who showed isolated proximal (without distal) ischemia. Among the symptomatic proximal sites cited by these patients, the hip and thigh represent 60%, whereas the buttock is cited in fewer than 25% of cases. Buttock symptoms are reported in only 31% of symptomatic patients. ‘Buttock’ claudication is probably not the dominant symptom in isolated proximal vascular ischemia. Assessing proximal lower limb ischemia through the sole detection of ‘buttock pain’ could contribute to the underestimation of proximal vascular ischemia.

Evaluation of the Vascular Surgical Complications of Renal Transplantation

BACKGROUND

Renal transplantation is the treatment of choice of end-stage renal failure. However, vascular surgical complications can compromise the functional prognosis of the transplant or even be life threatening in the short term. Since few data are available in the literature, the objective of this study was to evaluate the vascular surgical complications of renal transplantation.

METHODS

In a retrospective and monocentric study, the records of all the patients receiving a kidney transplant between January 2008 and December 2014 were reviewed. The demographic data and the follow-up of the patients who presented a vascular surgical complication in relation to their transplant were collected. Minor, intermediate, or major vascular complications were defined according to the need for monitoring, reoperation, or the risk of transplant loss or a life-threatening situation. Predictive factors of vascular complications were also looked for.

RESULTS

Mean age was 50.9 ± 15.0 years, and 312 kidney transplants were carried out (205 men). Fifty vascular surgical complications (16.0%) were found. Among them, 23 vascular complications (7.4%) were major, including 6 (1.9%) which required transplantectomy, after 4 arterial thromboses (1.3%), 1 early venous thrombosis (0.3%), and 1 injury of the inferior vena cava (0.3%). Twelve complications (3.8%) were minor. Surgical revision was necessary in 76% of the vascular complications (n = 38). The average follow-up of the transplanted population was 37.4 ± 24.0 month, 268 kidney transplants (85.8%) were functional and 21 patients (6.7%) returned to dialysis. Surgical complications were more frequent when the recipient had hypertension (P = 0.02, OR = 2.5; 95% CI [1.1-6.1]), in case of right kidney transplant (P = 0.0004, OR = 3.1; 95% CI [1.6-5.8]) and when the kidney hilum consisted of at least arteries (P = 0.02, OR = 10.0; 95% CI [1.3-34]). Male gender (P = 0.03, OR = 0.5; 95% CI [0.3-0.9]) as well as the choice of the common iliac arterial (P = 0.001, OR = 0.4; 95% IC [0.2-0.7]) and venous (P = 0.002, OR = 0.3; 95% IC [0.2-0.8]) axes to carry out the vascular anastomoses appeared as protective factors.

CONCLUSIONS

The vascular surgical complications of kidney transplantation, especially thromboses, can be serious and lead to transplant loss. The expertise of vascular surgeons finds its place here and makes it possible to maintain low rates of vascular complications and loss of transplants.

Endovascular treatment of iatrogenic aortic graft injury after sternal puncture

We report the case of a 71-year old woman who had previously undergone supra-aortic trunk transposition via a median sternotomy, along with endovascular thoracic aortic stent-graft repair. During the diagnostic sternal puncture for a recently discovered acute lymphoblastic leukaemia, an accidental graft injury occurred. For this patient, who was not a surgical candidate, endovascular treatment with a covered stent (endograft) was performed, with uneventful postoperative follow-up. This case report illustrates the limitations of sternal puncture in patients with a previous sternotomy, and discusses the possibility of endovascular treatment in the event of aortic graft injury, given easy accessibility and favourable aortic neck anatomy.