What Is the Clinical Utility of the Ankle-Brachial Index in Patients With Diabetic Foot Ulcers and Radiographic Arterial Calcification?

Toe brachial index and not ankle brachial index is appropriate in initial evaluation of peripheral arterial disease in type 2 diabetes

BACKGROUND

Non-invasive clinic-based tools for assessing PAD are not without limitations. Therefore, costly tests like Doppler study, CT angiography and MR angiography are often required to make a diagnosis. Ankle brachial index (ABI), commonly used for assessment of PAD, has high false positivity rates in sclerosed, calcified arteries which render them non-compressible. Toe brachial index (TBI) can be an alternative, as digital arteries are relatively unaffected by these changes.

AIM

To compare the reliability of ABI and TBI in diagnosing PAD in type 2 diabetes using CT angiography (CTA) as the reference.

METHODS

175 adults with T2D were selected. ABI &TBI were measured with an automated vascular Doppler XT 6 ports bilaterally for all subjects. For any subject, the limb with lower ABI and TBI was included for analysis. ABI < 0.9 & TBI < 0.6 were taken as evidence of PAD. CTA showing > 50% narrowing was taken as evidence of PAD.

RESULTS

24% of our study subjects had CTA confirmed PAD. ABI has low sensitivity of 35.29% (95% CI 0.21-0.52) compared to TBI being 82.35% (95% CI 0.66-0.92). The specificity however was similar. ABI < 0.9 was able to detect CTA confirmed PAD, but ABI > 0.9, including the so-called normal ABI (0.9-1.3) was unable to detect PAD. ROC showed ABI at 1.005 has sensitivity 64.71% (95% CI 0.48- 0.79) and specificity 61.7% (95% CI 0.53-0.69) and TBI at 0.6 has sensitivity 82.35% (95% CI 0.66-0.92) & specificity 92% (95% CI 0.87-0.96). Utilizing Cohen's Kappa, the reliability of ABI with respect to CTA showed fair agreement (K = 0.225, p = 0.001), whereas the reliability of TBI with respect to CTA showed substantial agreement (K = 0.759, p < 0.0001).

CONCLUSION

ABI < 0.9 detects PAD reliably, but presence of PAD in patients with ABI > 9.0 including the normal of ABI (0.9-1.3) can be confirmed with TBI, which correlated strongly with CTA. TBI is also non-inferior for PAD detection, when ABI < 0.9. TBI and not ABI can be utilized for initial assessment of PAD in subjects with T2D.

Use of consecutive transcutaneous oxygen measurement when assessing the need for revascularization and association with the outcomes of ischemic diabetic ulcers

This study compared the ankle-brachial index (ABI) with transcutaneous oxygen pressure (TcPO2 ) in assessing peripheral vascular disease (PVD) prevalence in 100 diabetic foot ulcer (DFU) patients. Patients were categorized into vascular or nonvascular reconstruction groups and underwent both ABI and TcPO2 measurements four times over 6 months. Predictive validity for PVD diagnosis was analysed using the area under the receiver-operating characteristic curve (AUC). The study found TcPO2 to be a superior predictor of PVD than ABI. Among the DFU patients, 51 with abnormal TcPO2 values underwent vascular reconstruction. Only TcPO2 values showed significant pretreatment differences between the groups and increased post-reconstruction. These values declined over a 6-month follow-up, whereas ABI values rose. For those with end-stage renal disease (ESRD), TcPO2 values saw a sharp decrease within 3 months. Pre-reconstruction TcPO2 was notably lower in amputation patients versus limb salvage surgery patients. In conclusion, TcPO2 is more effective than ABI for evaluating ischemic limb perfusion and revascularization necessity. It should be prioritized as the primary follow-up tool, especially for ESRD patients.

Contrast-free ultrasound imaging for blood flow assessment of the lower limb in patients with peripheral arterial disease: a feasibility study

While being a relatively prevalent condition particularly among aging patients, peripheral arterial disease (PAD) of lower extremities commonly goes undetected or misdiagnosed due to its symptoms being nonspecific. Additionally, progression of PAD in the absence of timely intervention can lead to dire consequences. Therefore, development of non-invasive and affordable diagnostic approaches can be highly beneficial in detection and treatment planning for PAD patients. In this study, we present a contrast-free ultrasound-based quantitative blood flow imaging technique for PAD diagnosis. The method involves monitoring the variations of blood flow in the calf muscle in response to thigh-pressure-cuff-induced occlusion. Four quantitative metrics are introduced for analysis of these variations. These metrics include post-occlusion to baseline flow intensity variation (PBFIV), total response region (TRR), Lag0 response region (L0RR), and Lag4 (and more) response region (L4 + RR). We examine the feasibility of this method through an in vivo study consisting of 14 PAD patients with abnormal ankle-brachial index (ABI) and 8 healthy volunteers. Ultrasound data acquired from 13 legs in the patient group and 13 legs in the healthy group are analyzed. Out of the four utilized metrics, three exhibited significantly different distributions between the two groups (p-value < 0.05). More specifically, p-values of 0.0015 for PBFIV, 0.0183 for TRR, and 0.0048 for L0RR were obtained. The results of this feasibility study indicate the diagnostic potential of the proposed method for the detection of PAD.

Analysis of repeated lesions after diabetic forefoot amputation

AIM

This study was performed to analyze the clinical characteristics, related factors, and prognosis of repeated lesions after diabetic forefoot amputation.

METHODS

The medical records of 998 patients who underwent forefoot amputation because of their diabetic feet from March 2002 to February 2021 were retrospectively analyzed. Of the 508 selected patients with a follow-up period of at least 6 months, 288 had repeated lesions in the forefoot, and 220 did not have repeated lesions. The related factors of repeated lesions were compared and analyzed. Of the patients with repeated lesions, 142 and 104 on the ipsilateral and contralateral sides, respectively were also compared and examined.

RESULTS

Repeated lesions were statistically significant in diabetic polyneuropathy, vascular calcification, and dialysis. However, the anatomical positions of diabetic foot lesions, causes of lesions, anatomical amputation levels, number of surgeries, and management duration had no significant differences. Contralateral lesions occurred 8 months later than ipsilateral lesions, but reamputation above the Lisfranc joint was more frequent and prognosis was poorer.

CONCLUSIONS

Repeated lesions were affected by general conditions, and the contralateral side must be carefully examined after diabetic forefoot amputation.

Vascular Assessment in Patients With a Lower Limb Wound: A Correlational Study of Photoplethysmography and Laser Doppler Flowmetry Toe Pressure Techniques

BACKGROUND

Vascular assessment of the lower limbs is essential in patients with diabetes. In the presence of noncompressible arteries, the ankle brachial index (ABI) can either be inconclusive or provide false-positive results. Toe pressure measurement has been suggested as an alternative as a noninvasive method for detecting peripheral arterial disease (PAD). Toe pressure measurement can be performed either by photoplethysmography (PPG) or by Laser Doppler flowmetry (LDF). The aim of this study was to determine correlations between the two techniques in order to promote the use of PPG in clinical practice.

METHODS

This was a prospective correlational study of 108 consecutive recruited adult patients, with and without diabetes, with at least one lower limb wound from a University-affiliated hospital wound care clinic. Toe pressure measurements were both performed with PPG and LDF devices.

RESULTS

Mean toe pressure values for PPG and LDF were, respectively, 83.7 (SD 35.4) and 79.5 (SD 32.0) mmHg (with a paired t-test 3.969, P < 0.01). In patients with at least one lower limb wound, a strong linear relation was found between PPG and LDF toe pressure techniques with a Pearson's r correlation coefficient of 0.920 (P < 0.001).

CONCLUSIONS

PPG and LDF toe pressure techniques are equivalent in patients with at least one lower limb wound, irrespective of the presence of diabetes. Therefore, in the presence of an ABI with inconclusive results, such as in a patient with noncompressible vessels, both toe pressure techniques can be used for assessing the vascular supply of the lower limb with a wound.

Toe-brachial index is beyond a peripheral issue in patients with type 2 diabetes

BACKGROUND

Atherosclerosis is the leading cause of death in patients with diabetes. We aimed to evaluate the association between ankle-brachial index (ABI) and toe-brachial index (TBI) with carotid intima-media thickness (CIMT) in patients with type 2 diabetes (T2DM).

METHODS

This cross sectional study included 296 patients with T2DM who met the American Diabetes Association criteria for the assessment of peripheral arterial atherosclerosis. The ABI ≤ 0.9 and TBI ≤ 0.7 were considered as abnormal values. Linear and logistic regression analyses were performed to evaluate the association between TBI/ABI and CIMT.

RESULTS

Right CIMT was significantly greater in the low TBI group (p = 0.03) while, left CIMT did not show a significant difference. Each 0.1-unit decrease in TBI value was independently associated with 0.017 mm increase in the right CIMT (β ± SE; -0.017 ± 0.005, p = 0.002) and with odds of the presence of increased CIMT [odds ratio and 95% confidence interval: 1.21 (1.02, 1.44)] after adjustment with all traditional risk factors. There was not any significant association between ABI and increased CIMT.

CONCLUSIONS

Beyond a suitable tool for the diagnosis of peripheral artery disease in patients with T2DM, TBI can be applied for prediction of subclinical carotid atherosclerosis.

The Influence of Arterial Calcification on Clinical Outcomes in Patients with Diabetic Foot Ulcer Complicated by Osteomyelitis Treated by Surgery

The aim of our study was to analyze the influence of radiographic arterial calcification (RAC) on clinical outcomes and wound healing in patients with diabetic foot ulcers complicated by osteomyelitis treated by surgery. We analyzed retrospectively the clinical records of 102 patients with diabetic foot osteomyelitis who underwent surgery at a specialized diabetic foot unit between January 2014 and December 2016. The clinical data of evolution until its complete epithelialization and a follow-up 1 year were reviewed, and after reviewing the radiological images, patients were classified into 2 groups: those with RAC and those without RAC. We analyzed several clinical features in both groups. The presence of RAC was associated with a greater time of healing (10.68 ± 7.24 vs 8.11 ± 4.50 weeks; P = .029) and shorter time to recurrence and reulceration (13.30 ± 9.25 vs 18.81 ± 11.63 weeks; P = .036). However, this association was not found for patients with mild and moderate peripheral artery disease (PAD), whose time of healing was 8.97 ± 4.51 weeks compared to 9.16 ± 6.39 weeks for patients without PAD; P = .864. The time of healing of diabetic foot ulcers complicated by osteomyelitis treated by surgery can be negatively affected by the presence of RAC even more than by the presence of mild and moderate ischemia. The presence of RAC may offer clinical guidance at the level of primary care though this would need thorough validation in future studies.

Specialised wound care clinics in Spain: distribution and characteristics

OBJECTIVE

To determine the number of specialised wound care units/clinics (SWCUs) in Spain, at present, and to describe their most important characteristics.

METHOD

This was an observational study with a descriptive-analytical, cross-sectional, multicentre approach, where the studied population consisted of SWCUs in Spain. A specific data-collection questionnaire was designed using a modified Delphi method, consisting of four rounds, with the collaboration of 10 wound experts. The final questionnaire included 49 items distributed across four dimensions/areas with a content validity index (CVI-Total for pertinence=0.96 and CVI-Total for relevance=0.94.

RESULTS

A total of 42 SWCUs were included in the study. Most SWCUs were based in hospitals (n=15, 35.7%) or healthcare centres, covering a specific healthcare area (n=17, 40.5%). SWCU coordinators were primarily nurses (n=33, 78.6%). Staff members' professions in SWCUs included registered nurses (n=38 units, 92.7%), nursing assistants (n=8 units, 19.5%), podiatrists (n=8 units, 19.5%), vascular surgeons (n=7 units, 17%), osteopaths (n=2 units, 4.8%) and medical doctors from different specialties (n=3 units, 7.2%). For wound aetiology, the most prevalent wounds managed were diabetic foot ulcers (n=38 units, 90.5%), followed by venous leg ulcers (n=36 units, 85.7%) and arterial ischaemic ulcers (n=36 units, 85.7%). A statistically significant association was found between the number of staff members in a SWCU and the existence of resistance/opposition barriers when developing a SWCU (Chi-square test, p=0.049; Cramér's V=0.34; 34%), as well as between resistance/opposition barriers when developing a SWCU and a nurse as coordinator of a SWCU (MacNemar test, p=0.007, Cramér's V=0.35; 35%).

CONCLUSION

The typical SWCU implemented in Spain is located in a hospital or integrated in a healthcare structure that offers coverage to a whole health area and providing services for people with hard-to-heal wounds (wound management and prevention) and health professionals (advice, consultancy and training/education). Despite the growing number of SWCUs in Spain, the future of this new organisational model is uncertain, as there can be barriers to creating them and some deficiencies, such as low staff numbers, which need to be addressed.

Peripheral Arterial Disease Located in the Feet of Patients With Diabetes and Foot Ulceration Demands a New Approach to the Assessment of Ischemia

Peripheral arterial disease (PAD) is common below the knee in diabetes but arteries in the foot are controversially said to be spared of occlusive disease. This is relevant to the convenient site of vascular assessment that is recommended in guidelines. Should assessment be distal at toe/forefoot to detect foot disease or only proximal to detect disease at ankle level? The objective was to determine frequency of PAD at foot and ankle level. This was a cross-sectional observational study, evaluating arterial disease proximally by palpation of pedal pulses and Ankle Brachial Index (ABI), and distally by Toe Brachial Index (TBI), and forefoot transcutaneous oxygen tension (tcpO₂), in consecutive patients presenting with foot ulceration. We assessed 301 limbs in 154 patients: 59% of limbs were ulcerated. PAD in the foot was detected in 70% and 74% of limbs by TBI and forefoot tcpO₂, respectively, but PAD at ankle level only in 51% and 34% by pulse palpation and ABI, respectively. In limbs with "normal" ABI, PAD was present in the foot in 70% as indicated by low TBI, and in 73% by low tcpO₂, with 70% to 64% having associated ulceration, respectively. When compared with arterial waveforms, as a measure of PAD, TBI gave an excellent AUC (area under the curve of the receiver operating characteristic curve) of 0.81 (95% confidence interval: 0.73-0.89), but ABI gave a poor AUC of 0.65 (95% confidence interval: 0.55-0.76). In conclusion, arterial disease is important in the foot and can be detected by TBI, which should be performed even when ABI is normal. Guidelines that recommend TBI only if ABI is artificially raised need updating.

Association of Circulating Osteopontin Levels With Lower Extremity Arterial Disease in Subjects With Type 2 Diabetes Mellitus: A Cross-Sectional Observational Study

Osteopontin (OPN) is involved in the atherosclerotic and inflammatory process. In this article, we examined the relationship between circulating OPN levels with lower extremity arterial disease (LEAD) in individuals with type 2 diabetes mellitus (T2DM). Seventy individuals with T2DM and 66 individuals without T2DM were recruited. Diagnosis of LEAD was based on the absence of triphasic waveform on the pedal arteries. Plasma OPN levels were determined by Luminex Multiplex immunoassay. LEAD was present in 34 (48.6%) patients with T2DM. In the diabetes cohort, individuals with LEAD had higher plasma OPN concentrations than those without LEAD (geometric mean [95% confidence intervals]; 43.4 [37.5-50.4] vs 26.1 [22.9-29.8] ng/mL, respectively, P < .001). Multivariable analysis showed that presence of LEAD independently associated with higher OPN levels in subjects with T2DM, with marginal statistical significance ( P = .049). In both cohorts, plasma OPN concentrations were negatively associated with ankle-brachial index values ( P < .05). In the total sample, there was a gradual increase of OPN levels across subgroups with triphasic, biphasic, and monophasic/blunted waveforms ( P < .001). In conclusion, plasma OPN levels are associated with the presence and severity of LEAD in subjects with T2DM. Further studies are needed to investigate the role of OPN in the pathogenesis and progression of LEAD.

Clinical significance of mirror lesions in lower extremity arterial disease

OBJECTIVE

The aim of this study was to investigate the clinical relevance of bilateral peripheral arterial disease (PAD) patterns.

BACKGROUND

No prior study has evaluated the clinical significance of symmetrical lesion patterns, particularly the coexistence of same-level significant plaques in both lower extremities ("mirror lesions").

METHODS

We conducted a single-facility, primary data analysis involving 225 patients with symptomatic PAD.

RESULTS

Eighty-two percent of the patients had bilateral lesions: 14.2% had femoropopliteal, 38.7% had infrapopliteal, and 27.1% had both femoropopliteal and infrapopliteal lesions. The lesions were found in the exact same arteries bilaterally in 24.9% of the patients, while 26.7% had a local mirror pattern limited to the femoropopliteal (13.7%) or infrapopliteal (12.9%) arteries. Having a lesion in an artery was a risk factor for occlusive disease of the corresponding artery on the other side. Patients presenting with critical limb ischemia (CLI) had a history of resting pain (17%), ulceration/gangrene (13%), or prior amputation (26%) of the contralateral limb. Patients with significant bilateral disease had unilateral false-negative ABI results in 11.6% of the cases. The arterial Doppler study results were unilaterally false-negative in 19.6% and bilaterally false-negative in 2.8% of the patients.

CONCLUSIONS

Patients with known peripheral arterial disease need to have both limbs fully evaluated and monitored, even in cases with negative screening results. Mirror angiographic imaging is common and often accompanied by symptoms of claudication. Unilateral ischemia is a strong risk factor for contralateral disease. Patients with CLI are at high risk for occlusive lesions of the nonindex limb.

Lower sensitivity of ankle-brachial index measurements among people suffering with diabetes-associated vascular disorders: A systematic review

Diabetes mellitus is a systemic disease affecting microvascular and macrovascular systems and is considered as the strongest risk factor for peripheral arterial disease. Although the prevalence of the peripheral arterial disease is high among people living with diabetes, its severity is not accurately detected with the prevalent diagnostic methodologies. The ankle-brachial index measurement is a simple, objective, and reliable tool for diagnosis of peripheral arterial disease. However, it is of limited value in the diagnosis of peripheral arterial disease among diabetic patients due to its low sensitivity among diabetic individuals. Diabetes mellitus results in atherosclerosis and calcification of peripheral arterial walls leading to false normal ankle-brachial index values. Therefore, healthcare practitioners should be careful not to misinterpret ankle-brachial index results among diabetic patients. A literature search was conducted using the keywords “ankle-brachial index,” “interpretation,” “limitations,” “diabetic foot,” and “peripheral arterial disease” on different medical search engines. The results were manually scanned and then further reviewed to select the articles related to our topic of discussion. This article will review the use of ankle-brachial index measurement among diabetic patients, its limitations and its prognostic value. In Conclusion, Ankle-brachial index can be used for diagnosis of peripheral arterial disease with some precautions (e.g. raising the threshold of diagnosis or using the lowest systolic pressure value measured at the ankle) and can also be a prognostic indicator for cardiovascular morbidity and mortality.

A retrospective study of ABI and TBI during the healing of ulcer among diabetic patients

OBJECTIVE

To assess the role of ABI and TBI in the detection of ulcer wounds among diabetic patients.

METHODS

A retrospective approach is used to enroll 192 diabetic patients to detect their ulcer wounds using ABI and TBI index. HbA1c and lipid profile were other important variables in determining the efficacy of screening test. Frequency analysis and Pearson Correlation were used to analyze the data through SPSS.

FINDINGS

The results have shown that 57.1% male and 42.9% female were treated in <0.60 ABI group; 67.4% male and 32.6% female were treated in 0.60-0.90 ABI group; 65.9% male and 34.1% female were treated in 0.90-1.30 ABI group; and 63.8% male and 36.2% female were treated in >1.30 ABI group. The correlation showed insignificant association between ABI and ulcer outcomes, but significant association between TBI and ulcer outcomes at 5% level of significance.

CONCLUSION

The study concluded that ABI should be based on standardized normal values to be used as an effective biomarker in screening diabetic foot ulcer patients.

Laser speckle flowgraphy can also be used to show dynamic changes in the blood flow of the skin of the foot after surgical revascularization

Objectives

Laser speckle flowgraphy is a new method that enables the rapid evaluation of foot blood flow without contact with the skin. We used laser speckle flowgraphy to evaluate foot blood flow in peripheral arterial disease patients before and after surgical revascularization.

Materials and methods

A prospective single-center study. Thirty-one patients with 33 limbs that underwent surgical revascularization for peripheral arterial disease were included. Pre- and postoperative foot blood flows were measured on the plantar surface via laser speckle flowgraphy and skin perfusion pressure. The laser speckle flowgraphy device was used to visualize the blood flow distribution of the target skin and processed the pulse wave velocity of synchronized heart beats. The mean blood flow, which was expressed as the area of the pulse wave as the beat strength of skin perfusion on laser speckle flowgraphy converted into a numerical value, was assessed as dynamic changes following surgery. Beat strength of skin perfusion was also investigated in non-peripheral arterial disease controls (23 patients/46 limbs).

Results

The suitability of beat strength of skin perfusion in non-peripheral arterial disease controls was achieved; the beat strength of skin perfusion value was significantly higher in every area of interest in non-peripheral arterial disease controls compared to that in peripheral arterial disease limbs at the preoperative stage (105.8 ± 8.2 vs. 26.3 ± 8.2; P < 0.01). Although the pulse wave before surgery was visually flat in peripheral arterial disease patients, the pulse wave was remarkably and immediately improved through surgical revascularization. Beat strength of skin perfusion showed a dynamic change in foot blood flow (26.3 ± 8.2 at preoperation, 98.5 ± 6.7 immediately after surgery, 107.6 ± 5.7 at seven days after surgery, P < 0.01 for each compared to preoperation) that correlated with an improvement in skin perfusion pressure.

Conclusions

Laser speckle flowgraphy is a noninvasive, contact-free modality that is easy to implement, and beat strength of skin perfusion is a useful indicator of foot circulation during the perioperative period. Further analysis with a larger number of cases is necessary to establish appropriate clinical use.