Reduced calf muscle pump function is not explained by handgrip strength measurements.

OBJECTIVE: Reduced calf muscle pump function (CPF) is an independent risk factor for venous thromboembolism and mortality. We aimed to evaluate the relationship between handgrip strength (HGS) and CPF. METHODS: Patients referred to the Gonda Vascular Laboratory for noninvasive venous studies were identified and consented. Patients underwent standard venous air plethysmography protocol. CPF (ejection fraction) was measured in each lower extremity of ambulatory patients by comparing refill volume after ankle flexes and passive refill volumes. The cutoff for reduced CPF (rCPF) was defined as an ejection fraction of <45%. Maximum HGS bilaterally was obtained (three trials per hand) using a dynamometer. HGS and CPF were compared (right hand to calf, left hand to calf) and the correlation between the measures was evaluated. RESULTS: 115 patients (mean age, 59.2 ± 17.4 years; 67 females, mean body mass index, 30.83 ± 6.46) were consented and assessed for HGS and CPF. rCPF was observed in 53 right legs (46%) and 67 left legs (58%). CPF was reduced bilaterally in 45 (39%) and unilaterally in 30 (26%) patients. HGS was reduced bilaterally in 74 (64.3%), unilaterally in 23 (20%), and normal in 18 (15.7%) patients. Comparing each hand/calf pair, no significant correlations were seen between HGS and CPF. The Spearman's rank correlation coefficients test yielded values of 0.16 for the right side and 0.10 for the left side. CONCLUSIONS: There is no significant correlation between HGS and CPF, demonstrating that HGS measurements are not an acceptable surrogate for rCPF, indicating different pathophysiological mechanisms for each process.

Artificial intelligence of arterial Doppler waveforms to predict major adverse outcomes among patients with diabetes mellitus.

OBJECTIVE: Patients with diabetes mellitus (DM) are at increased risk for peripheral artery disease (PAD) and its complications. Arterial calcification and non-compressibility may limit test interpretation in this population. Developing tools capable of identifying PAD and predicting major adverse cardiac event (MACE) and limb event (MALE) outcomes among patients with DM would be clinically useful. Deep neural network analysis of resting Doppler arterial waveforms was used to detect PAD among patients with DM and to identify those at greatest risk for major adverse outcome events. METHODS: Consecutive patients with DM undergoing lower limb arterial testing (April 1, 2015-December 30, 2020) were randomly allocated to training, validation, and testing subsets (60%, 20%, and 20%). Deep neural networks were trained on resting posterior tibial arterial Doppler waveforms to predict all-cause mortality, MACE, and MALE at 5 years using quartiles based on the distribution of the prediction score. RESULTS: Among 11,384 total patients, 4211 patients with DM met study criteria (mean age, 68.6 ± 11.9 years; 32.0% female). After allocating the training and validation subsets, the final test subset included 856 patients. During follow-up, there were 262 deaths, 319 MACE, and 99 MALE. Patients in the upper quartile of prediction based on deep neural network analysis of the posterior tibial artery waveform provided independent prediction of death (hazard ratio [HR], 3.58; 95% confidence interval [CI], 2.31-5.56), MACE (HR, 2.06; 95% CI, 1.49-2.91), and MALE (HR, 13.50; 95% CI, 5.83-31.27). CONCLUSIONS: An artificial intelligence enabled analysis of a resting Doppler arterial waveform permits identification of major adverse outcomes including all-cause mortality, MACE, and MALE among patients with DM.

Major adverse events associated with inducible cardiac ischemia during treadmill exercise testing for peripheral artery disease.

BACKGROUND: The coexistence of coronary artery disease and peripheral artery disease (PAD) is well-established. Whether myocardial ischemia by electrocardiography during treadmill testing to evaluate PAD severity is associated with adverse cardiac and limb events has not been established. The aim of the current study is to assess the risk of major adverse cardiac events (MACE), major adverse limb events (MALE), and all-cause mortality in patients with evidence of myocardial ischemia on ECG compared with those without ischemia in patients undergoing treadmill testing for PAD evaluation. METHODS: Patients undergoing treadmill exercise ankle-brachial index (ABI) evaluation (January 1, 2003, to December 31, 2006) were identified using the Mayo Clinic Gonda Vascular Laboratory database. Patients with ischemia by electrocardiogram (ECG) were age and sex matched to patients without ischemia. Outcomes were compared by ECG category. RESULTS: Of 4128 patients who underwent treadmill exercise, 170 (4.1%) had inducible myocardial ischemia by ECG. These were matched with 340 patients without ischemia. The positive ECG group had a higher percentage of diabetes mellitus (31.2% vs 21.8%; P = .02), carotid artery disease (22.4% vs 13.2%; P = .009), exercise-induced angina (14.1% vs 2.9%; P < .0001), and dyspnea (60.6% vs 35.6%; P < .0001). While the resting ABI was similar, the postexercise ABI was lower in the positive ECG group (0.5 vs 0.7; P = .04). After a median follow-up of 8 years, MACE were significantly greater in the positive ECG group (62.4% vs 46.5%; P < .001). MALE were significantly less frequent (17.1% vs 23.2%; P = .02), without an increased risk of amputation. In multivariable analysis, inducible ischemia was associated with higher incidence of MACE (hazard ratio, 1.65; 95% confidence interval, 1.25-2.16; P < .001) and lower incidence of MALE (hazard ratio, 0.51; 95% confidence interval, 0.31-0.84; P < .05). CONCLUSIONS: ECG monitoring during vascular treadmill testing identified a subset of patients with more frequent MACE but less MALE.

Compression therapy after invasive treatment of superficial veins of the lower extremities: Clinical practice guidelines of the American Venous Forum, Society for Vascular Surgery, American College of Phlebology, Society for Vascular Medicine, and International Union of Phlebology.

Guideline 1.1: Compression after thermal ablation or stripping of the saphenous veins. When possible, we suggest compression (elastic stockings or wraps) should be used after surgical or thermal procedures to eliminate varicose veins. [GRADE - 2; LEVEL OF EVIDENCE - C] Guideline 1.2: Dose of compression after thermal ablation or stripping of the varicose veins. If compression dressings are to be used postprocedurally in patients undergoing ablation or surgical procedures on the saphenous veins, those providing pressures >20 mm Hg together with eccentric pads placed directly over the vein ablated or operated on provide the greatest reduction in postoperative pain.[GRADE - 2; LEVEL OF EVIDENCE - B] Guideline 2.1: Duration of compression therapy after thermal ablation or stripping of the saphenous veins. In the absence of convincing evidence, we recommend best clinical judgment to determine the duration of compression therapy after treatment. [BEST PRACTICE] Guideline 3.1: Compression therapy after sclerotherapy. We suggest compression therapy immediately after treatment of superficial veins with sclerotherapy to improve outcomes of sclerotherapy. [GRADE - 2; LEVEL OF EVIDENCE - C] Guideline 3.2: Duration of compression therapy after sclerotherapy. In the absence of convincing evidence, we recommend best clinical judgment to determine the duration of compression therapy after sclerotherapy. [BEST PRACTICE] Guideline 4.1: Compression after superficial vein treatment in patients with a venous leg ulcer. In a patient with a venous leg ulcer, we recommend compression therapy over no compression therapy to increase venous leg ulcer healing rate and to decrease the risk of ulcer recurrence. [GRADE - 1; LEVEL OF EVIDENCE - B] Guideline 4.2: Compression after superficial vein treatment in patients with a mixed arterial and venous leg ulcer. In a patient with a venous leg ulcer and underlying arterial disease, we suggest limiting the use of compression to patients with ankle-brachial index exceeding 0.5 or if absolute ankle pressure is >60 mm Hg. [GRADE - 2; LEVEL OF EVIDENCE - C].

Association of Ankle-Brachial Indices With Limb Revascularization or Amputation in Patients With Peripheral Artery Disease.

Importance: The prevalence and morbidity of peripheral artery disease (PAD) are high, with limb outcomes including revascularization and amputation. In community-dwelling patients with PAD, the role of noninvasive evaluation for risk assessment and rates of limb outcomes have not been established to date. Objective: To evaluate whether ankle-brachial indices are associated with limb outcomes in community-dwelling patients with PAD. Design, Setting, and Participants: A population-based, observational, test-based cohort study of patients was performed from January 1, 1998, to December 31, 2014. Data analysis was conducted from July 15 to December 15, 2017. Participants included a community-based cohort of 1413 patients with PAD from Olmsted County, Minnesota, identified by validated algorithms deployed to electronic health records. Automated algorithms identified limb outcomes used to build Cox proportional hazards regression models. Ankle-brachial indices and presence of poorly compressible arteries were electronically identified from digital data sets. Guideline-recommended management strategies within 6 months of diagnosis were also electronically retrieved, including therapy with statins, antiplatelet agents, angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, and smoking abstention. Main Outcomes and Measures: Ankle-brachial index (index ≤0.9 indicates PAD; <.05, severe PAD; and ≥1.40, poorly compressible arteries) and limb revascularization or amputation. Results: Of 1413 patients, 633 (44.8%) were women; mean (SD) age was 70.8 (13.3) years. A total of 283 patients (20.0%) had severe PAD (ankle-brachial indices <0.5) and 350 (24.8%) had poorly compressible arteries (ankle-brachial indices ≥1.4); 780 (55.2%) individuals with less than severe disease formed the reference group. Only 32 of 283 patients (11.3%) with severe disease and 68 of 350 patients (19.4%) with poorly compressible arteries were receiving 4 guideline-recommended management strategies. In the severe disease subgroup, the 1-year event rate for revascularization was 32.4% (90 events); in individuals with poorly compressible arteries, the 1-year amputation rate was 13.9% (47 events). In models adjusted for age, sex, and critical limb ischemia, poorly compressible arteries were associated with amputation (hazard ratio [HR], 3.12; 95% CI, 2.16-4.50; P < .001) but not revascularization (HR, 0.91; 95% CI, 0.69-1.20; P = .49). In contrast, severe disease was associated with revascularization (HR, 2.69; 95% CI, 2.15-3.37; P < .001) but not amputation (HR, 1.30; 95% CI, 0.82-2.07; P = .27). Conclusions and Relevance: Community-dwelling patients with severe PAD or poorly compressible arteries have high rates of revascularization or limb loss, respectively. Guideline-recommended management strategies for secondary risk prevention are underused in the community.

Program requirements for fellowship education in venous and lymphatic medicine.

Background In every field of medicine, comprehensive education should be delivered at the graduate level. Currently, no single specialty routinely provides a standardized comprehensive curriculum in venous and lymphatic disease. Method The American Board of Venous & Lymphatic Medicine formed a task force, made up of experts from the specialties of dermatology, family practice, interventional radiology, interventional cardiology, phlebology, vascular medicine, and vascular surgery, to develop a consensus document describing the program requirements for fellowship medical education in venous and lymphatic medicine. Result The Program Requirements for Fellowship Education in Venous and Lymphatic Medicine identify the knowledge and skills that physicians must master through the course of fellowship training in venous and lymphatic medicine. They also specify the requirements for venous and lymphatic training programs. The document is based on the Core Content for Training in Venous and Lymphatic Medicine and follows the ACGME format that all subspecialties in the United States use to specify the requirements for training program accreditation. The American Board of Venous & Lymphatic Medicine Board of Directors approved this document in May 2016. Conclusion The pathway to a vein practice is diverse, and there is no standardized format available for physician education and training. The Program Requirements for Fellowship Education in Venous and Lymphatic Medicine establishes educational standards for teaching programs in venous and lymphatic medicine and will facilitate graduation of physicians who have had comprehensive training in the field.

Digital obstructive arterial disease can be detected by laser Doppler measurements with high sensitivity and specificity.

OBJECTIVE: This study was conducted to determine the sensitivity and specificity of laser Doppler flowmetry (LDF) measurements for digital obstructive arterial disease (DOAD) using angiography as the reference standard and to compare the accuracy of different classical tests used to assess DOAD. Diagnosis of vascular abnormalities at the digital level is challenging. Angiography is the gold standard for assessment of DOAD but is invasive and expensive to perform. METHODS: We performed a retrospective analysis of consecutive patients referred at Mayo Clinic (Rochester, Minn) for upper extremity arterial assessment during a 27-month period. Finger-brachial index, skin blood flow (in arbitrary units [a.u.]), and skin temperature (in degrees Celsius) were recorded in each digit on the pulp at baseline and after a thermal challenge test (hand placed in a thermal box at 47.0°C for 15 minutes). Angiogram analysis was blinded and performed by a radiologist using a vascularization scale ranging from 0 (no vessel) to 4 (normal). The receiver operating characteristic curve was used to define a specific cutoff point to detect DOAD. Twenty-two patients had LDF measurements and complete angiograms. RESULTS: A total of 185 digits were analyzed because some patients had only analysis of one hand. The best area under the curve (AUC) was 0.98 (range, 0.94-0.99) for postwarming skin blood flow, with a cutoff point of ≤206 a.u. This AUC was statistically different from AUCs of all the other tests (P < .01). Sensitivity and specificity were 93% (95% confidence interval, 85%-97%) and 96% (95% confidence interval, 90%-99%), respectively. CONCLUSIONS: LDF combined with a thermal challenge is highly accurate, safe, and noninvasive means to detect DOAD.

Hemi-body port-wine stains and progressive paresis due to territorial perineuriomas.

We present a case of a biopsy-proven intraneural perineurioma involving the left lumbosacral and brachial plexus with prominent hemi-body port wine stains in the associated dermatomes. The relationship between the two entities is not clear, but this case may provide a clue to understanding the etiological pathogenesis of intraneural perineurioma in the future.

A different way to look at varicose veins.

OBJECTIVE: The development of varicose veins is commonly attributed to vessel wall degeneration. The idea that varicose veins occur because of pathological processes, however, is challenged by certain observations. For example, their high prevalence (50% or greater) in many populations makes it statistically "normal" to have varicose veins; their well-established genetic predisposition raises the possibility that this high prevalence reflects a survival benefit. One way to explain this apparent contradiction is to theorize that varicose veins are produced by the same mechanism(s) that lead to the growth and remodeling of other types of blood vessels. If so, being "good" at forming varicose veins may also predispose to being "good" at forming various types of collateral blood vessels when necessary. METHODS: A selected literature review was conducted. Works chosen for review included those suggesting that: the process of varicose vein formation may share the same basic mechanisms as the formation of collateral veins, arteries, and lymphatic vessels; and clinical outcomes may be different between subjects with and without varicose veins. RESULTS: Evidence suggests that subjects who are "good" at forming varicose veins may also be "good" at forming various types of collateral vessels, and they may have better overall survival (with less cardiovascular morbidity) than those without varicose veins. CONCLUSIONS: Varicose veins may be "the price we pay" for an enhanced ability to form collateral vessels when necessary.

Outpatient vascular and interventional radiology practice from 2001-2008.

PURPOSE: To describe experience with an outpatient vascular interventional radiology (IR) practice with respect to number of patients seen, number of procedures performed, and number of imaging studies ordered in follow-up. MATERIALS AND METHODS: The outpatient vascular IR practice at the authors' institution was established in 2001 with two physicians spending one half-day per week; a third physician joined in 2004. A retrospective review was done of all patients seen by an interventional radiologist from 2001 to July 2008. The following data were collected for each physician per year: the number of new and established patients seen, the number and type of procedures performed, and the number and type of imaging studies ordered. Data are presented as mean ± standard deviation per physician per year and total number. RESULTS: In 2001, the average number of new patients seen was 61 ± 11 (total number = 122), which peaked in 2006 at 127 ± 28 (total number = 380). A similar trend occurred with the established patients. In 2001, the procedure performed with the greatest frequency was abdominal aortogram with stent placement, which started at 18 ± 2 (total number = 35) and peaked by 2006 at 37 ± 23 (total number = 122). The number of ancillary imaging studies ordered by each physician increased each year and by 2006 was nearly 93 ± 77 (total number = 278). CONCLUSIONS: A robust outpatient IR practice in vascular disease can be developed in 3-5 years with downstream imaging studies being ordered for the radiology department.

Increasing awareness about venous disease: The American Venous Forum expands the National Venous Screening Program.

OBJECTIVE: To evaluate the results of the expanded National Venous Screening Program (NVSP) as administered by the American Venous Forum. METHODS: Eighty-three physicians across 40 states participated in screening Americans for venous disease. The NVSP instrument included demographics, venous thromboembolism (VTE) risk assessment, quality-of-life (QOL) assessment, duplex ultrasound scan for reflux and obstruction, and clinical inspection. Participants received educational materials and a report card to give their physician. RESULTS: A total of 2234 individuals underwent screening (mean, 26 people/site; range, 4-42). Demographic data observed included mean age of 60 years (range, 17-93 years); 77% female; 80% Caucasian; mean BMI of 29 (range, 11-68); 40% current or previous smoker; and 24% taking antiplatelet therapy and 4% taking warfarin. If placed in a situation conducive for VTE, 40% of participants were low risk, 22% were moderate risk, 21% were high risk, and 17% were very high risk. On a venous QOL assessment, 17% had a combined total score for all 11 questions of "very limited" or "impossible to do." Reflux or obstruction was noted in 37% and 5% of participants, respectively. CEAP class 0 to 6 was 29%, 29%, 23%, 10%, 9%, 1.5%, 0.5%, respectively. DISCUSSION: Despite a dramatic expansion in the second annual NSVP (from 17 to 83 centers), the presence of venous disease observed in a larger screened population continues to be high. The NVSP represents one pathway to increasing public awareness about venous disease.

Improving limb salvage in critical ischemia with intermittent pneumatic compression: a controlled study with 18-month follow-up.

BACKGROUND: Intermittent pneumatic compression (IPC) is an effective method of leg inflow enhancement and amelioration of claudication in patients with peripheral arterial disease. This study evaluated the clinical efficacy of IPC in patients with chronic critical limb ischemia, tissue loss, and nonhealing wounds of the foot after limited foot surgery (toe or transmetatarsal amputation) on whom additional arterial revascularization had been exhausted. METHODS: Performed in a community and multidisciplinary health care clinic (1998 through 2004), this retrospective study comprises 2 groups. Group 1 (IPC group) consisted of 24 consecutive patients, median age 70 years (interquartile range [IQR], 68.7-71.3) years, who received IPC for tissue loss and nonhealing amputation wounds of the foot attributable to critical limb ischemia in addition to wound care. Group 2 (control group) consisted of 24 consecutive patients, median age 69 years (IQR, 65.7-70.3 years), who received wound care for tissue loss and nonhealing amputation wounds of the foot due to critical limb ischemia, without use of IPC. Stringent exclusion criteria applied. Group allocation of patients depended solely on their willingness to undergo IPC therapy. Vascular assessment included determination of the resting ankle-brachial pressure index, transcutaneous oximetry (TcPO(2)), duplex graft surveillance, and foot radiography. Outcome was considered favorable if complete healing and limb salvage occurred, and adverse if the patient had to undergo a below knee amputation subsequent to failure of wound healing. Follow-up was 18 months. Wound care consisted of weekly débridement and biologic dressings. IPC was delivered at an inflation pressure of 85 to 95 mm Hg, applied for 2 seconds with rapid rise (0.2 seconds), 3 cycles per minute; three 2-hourly sessions per day were requested. Compliance was closely monitored. RESULTS: Baseline differences in demography, cardiovascular risk factors (diabetes mellitus, smoking, hypertension, dyslipidemia, renal impairment), and severity of peripheral arterial disease (ankle-brachial indices, TcPO(2), prior arterial reconstruction) were not significant. The types of local foot amputation that occurred in the two groups were not significantly different. In the control group, foot wounds failed to heal in 20 patients (83%) and they underwent a below knee amputation; the remaining four (17%, 95% confidence interval [CI], 0.59%-32.7%) had complete healing and limb salvage. In the IPC group, 14 patients (58%, 95% CI, 37.1%-79.6%) had complete foot wound healing and limb salvage, and 10 (42%) underwent below knee amputation for nonhealing foot wounds. Wound healing and limb salvage were significantly better in the IPC group (P < .01, chi(2)). Compared with the IPC group, the odds ratio of limb loss in the control group was 7.0. On study completion, TcPO(2) on sitting was higher in the IPC group than in the control group (P = .0038). CONCLUSION: IPC used as an adjunct to wound care in patients with chronic critical limb ischemia and nonhealing amputation wounds/tissue loss improves the likelihood of wound healing and limb salvage when established treatment alternatives in current practice are lacking. This controlled study adds to the momentum of IPC clinical efficacy in critical limb ischemia set by previously published case series, compelling the pursuit of large scale multicentric level 1 studies to substantiate its actual clinical role, relative indications, and to enhance our insight into the pertinent physiologic mechanisms.

Controversies in vascular screening art versus science.

Whether or not to screen asymptomatic members of the general public for various forms of vascular disease is a controversial issue with huge medical, social, and financial ramifications. This article reviews several criteria for determining the appropriateness of vascular screening, including: (1) is it possible to detect occult vascular disease ;early'?; (2) what should we screen for, and how should we do it?; (3) who should be screened?; and (4) what standards for vascular screening should be set? While some of these controversies may ultimately be resolvable using an evidence-based approach, it is apparent that there are issues which will not be amenable to strict scientific analysis. Individualized approaches to screening will therefore remain the rule for the foreseeable future.