Outcomes and Influence of the Pedal Arch in Below-the-Knee Angioplasty in Patients with End-Stage Renal Disease and Critical Limb Ischemia

Avoiding the Deep Plantar Arterial Arch in Transmetatarsal Amputations: A Cadaver Study

BACKGROUND

The deep plantar arterial arch (DPAA) is formed by an anastomosis between the deep plantar artery and the lateral plantar artery. The potential risk of injury to the DPAA is concerning when performing transmetatarsal amputations, and care must be taken to preserve the anatomy. We sought to determine the positional anatomy of the DPAA based on anatomical landmarks that could be easily identified and palpated during transmetatarsal amputation.

METHODS

In an effort to improve our understanding of the positional relationship of the DPAA to the distal metatarsal parabola, dissections were performed on 45 cadaveric feet to measure the location of the DPAA with respect to the distal metatarsal epiphyses. Images of the dissected specimens were digitally acquired and saved for measurement using in-house-written software. The mean, SD, SEM, and 95% confidence interval were calculated for all of the measurement parameters and are reported on pooled data and by sex. An independent-samples t test was used to assess for sex differences. Interrater reliability of the measurements was estimated using the intraclass correlation coefficient.

RESULTS

The origin of the DPAA was located a mean ± SD of 35.6 ± 3.9 mm (95% confidence interval, 34.5-36.8 mm) proximal to the perpendicular line connecting the first and fifth metatarsal heads. The average interrater reliability across all of the measurements was 0.921.

CONCLUSIONS

This study provides the positional relationship of the DPAA with respect to the distal metatarsal parabola. This method is easily reproducible and may assist the foot and ankle surgeon with surgical planning and approach when performing partial pedal amputation.

Long-Term Outcomes of Extra-Anatomic Femoro-Tibial Bypass Reconstructions in Chronic Limb-Threating Ischemia

(1) Background: While tibial bypass surgery still plays a role in the treatment of patients with chronic limb-threatening ischemia and diabetic foot syndrome; only a few centers have recorded considerable numbers of these conditions. The current study aimed to determine contemporary practice with special focus on the performance of extra-anatomic grafting to the infrapopliteal arteries. (2) Methods: A retrospective, single-center study included patients with tibial bypass grafts from 1 January 2008 to 31 December 2019. Primary endpoints were complication rate, graft patency, amputation, overall survival, and major adverse cardiac (MACE) or limb event (MALE). The cohort was stratified by extra-anatomic vs. anatomic position. (3) Results: A total of 455 patients (31% female) with Rutherford stage 4 (12.5%) and 5/6 (69.5%) were included (thereof, 19.5% had high amputation risk according to the Wound Ischemia Foot Infection score). Autologous reconstruction was performed in 316 cases, and prosthetic reconstruction in 131 cases, with a total of 51 (11.2%) extra-anatomic grafts. Early occlusion rate was 9.0% with an in-hospital overall mortality of 2.8%. The in-hospital rate of MACE was 2.4% and of MALE, 1.5%. After one, three and five years, the primary patency of venous bypasses was 74.5%, 68.6% and 61.7%, respectively. For prosthetic grafts, this was 55.1%, 46.0%, and 38.3%, respectively (p < 0.001). The patency of extra-anatomic prosthetic grafts performed significantly better compared with anatomically positioned prosthetic grafts (log-rank p = 0.008). In multivariate analyses, diabetes (hazard ratio, HR 1.314, CI 1.023−1.688, p = 0.032), coronary artery disease (HR 1.343, CI 1.041−1.732, p = 0.023), and dialysis dependency (HR 2.678, CI 1.687−4.250, p < 0.001) were associated with lower odds of survival (4) Conclusion: In this large, single-center cohort, tibial bypass surgery demonstrated satisfactory results with overall low perioperative complication rates and long-term patency rates of 60% and 38%, respectively. Extra-anatomic bypasses represent a feasible alternative to venous grafts in terms of patency. A tailored, patient-centered approach considering predictors such as diabetes, dialysis dependency, and coronary artery disease along with prediction models may further improve the long-term results in the future.

The predictive value of microperfusion assessments for the follow-up of tibial bypass grafts

OBJECTIVE

We conducted a prospective evaluation of microperfusion parameters after tibial bypass surgery was performed. Differences between grafts with occlusions during follow-up and patent grafts were analyzed in relation to the pedal arch quality.

METHODS

Patients receiving tibial bypass grafts for chronic limb-threatening ischemia from 2019 to 2020 were included. Assessment of microcirculation (parameters: hemoglobin oxygen saturation [sO₂] and flow) was done by laser Doppler flowmetry and white light spectrometry (oxygen-to-see), supine and in elevation, whereas the macrocirculation was evaluated by the ankle-brachial index and duplex ultrasound examination. The quality of run-off was graded for each patient. Measurements were performed preoperatively, 1 day postoperatively, and after 6 months. Patients with graft occlusions during follow-up (OCCLUDED) and patients without occlusions (OPEN) were compared.

RESULTS

We included 42 patients (13 women, 29 men; mean age, 76.1 years; range, 60-89 years) were included. The patency of all grafts 1 day after the operation was confirmed by ultrasound examination. The overall analysis of the microcirculation showed significant changes in both the supine and elevated leg position between measurements taken preoperatively, 1 day after the operation, and after 6 months for the parameters sO₂ and FLOW (sO₂ supine, P = .001; sO₂ elevated, P < .001; FLOW supine, P < .001; FLOW elevated, P < .001). The comparison of the values 1 day after the operation yielded significantly decreased microperfusion parameters (both O₂ and FLOW) in the group that developed bypass occlusion in the later follow-up period (sO₂ supine: OCCLUDED, 35.7% [7.3-65.0] and OPEN, 48.7% [25.0-72.3] P = .011; FLOW supine: OCCLUDED, 27.7 A.U. [12.7-52.7] and OPEN, 57.3 A.U. [16.0-106.7], P = .008). No significant differences in the severity of the arch impairment was found between the OPEN and OCCLUDED groups (P = .651). Absolute values of the parameters sO₂ and flow showed no correlation with the pedal arch classification.

CONCLUSIONS

Significantly poorer microperfusion was detected postoperatively in patients with later occurrence of graft occlusions despite patent grafts on the first postoperative day. Microperfusion measurements might be a possible tool for the prediction of graft failure.

CIRSE Standards of Practice on Below-the-Knee Revascularisation

The CIRSE Standards of Practice Committee established a writing group that was tasked with producing up-to-date recommendations for performing below-the-knee revascularisation, taking into account data on novel techniques, devices, and long-term outcomes that have emerged over the last decade. CIRSE Standards of Practice documents are not clinical practice guidelines or systematic reviews of the literature. This document is not intended to impose a standard of clinical patient care but recommends a reasonable approach to and best practices for performing below-the-knee revascularisation.

Potential Target miR-455 Delaying Arterial Stenosis Progression Through PTEN

Background: Vascular smooth muscle cells (VSMC) underwent phenotypic switching upon stimulation signals, and this is the prerequisite for their proliferation and migration. Previous work revealed that miR-455 may be involved in vascular stenosis. Thus, this study aimed to explore potential targets and mechanisms underlying the dynamics of miR-455 in vascular stenosis.

Methods: miR-455 and PTEN expression levels were studied in normal and stenosis tissue, as well as in VSMC in proliferation model. Manipulating miR-455 expression levels was achieved by transfection of either miR-455 mimic or inhibitor, and its effect on cell proliferation was studied by CCK-8 assay. Its effect on gene expression was studied by RT-qPCR and western blot. The expression regulation mechanism was studied by luciferase reporter system. Finally, the effect of miR-455 on regulating vascular stenosis was studied using a rat balloon-injured carotid artery stenosis model.

Results: High expression levels of miR-455 were detected in both stenosis arterial tissues and VSMC proliferation models. In contrast, the expression levels of PTEN were downregulated in these systems. miR-455 transfected VSMC showed higher levels of proliferation and decreased levels of PTEN. Potential binding sites between miR-455 and PTEN 3′UTR were predicted and confirmed. NF-kB p65 was found to bind directly on miR-455 promoter region and regulate its transcription. The progression of arterial stenosis could be delayed by introducing miR-455 antagomir.

Conclusions: The p65/miR-455/PTEN signaling pathway plays a crucial role in regulating VSMC proliferation and vascular stenosis. This indicated that miR-455 is a novel target that would help improve treatment outcomes in patients suffering from vascular stenosis.

Outcomes of Lower Extremity Endovascular Revascularization: Potential Predictors and Prevention Strategies

Peripheral artery disease (PAD) is a manifestation of atherosclerosis, which may affect arteries of the lower extremities. The most dangerous PAD complication is chronic limb-threatening ischemia (CLTI). Without revascularization, CLTI often causes limb loss. However, neither open surgical revascularization nor endovascular treatment (EVT) ensure long-term success and freedom from restenosis and revascularization failure. In recent years, EVT has gained growing acceptance among all vascular specialties, becoming the primary approach of revascularization in patients with CLTI. In clinical practice, different clinical outcomes after EVT in patients with similar comorbidities undergoing the same procedure (in terms of revascularization technique and localization of the disease) cause unsolved issues that need to be addressed. Nowadays, risk management of revascularization failure is one of the major challenges in the vascular field. The aim of this literature review is to identify potential predictors for lower extremity endovascular revascularization outcomes and possible prevention strategies.

Indirect Endovascular Revascularization via Collaterals: A New Classification to Predict Wound Healing and Limb Salvage

BACKGROUND

In the setting of chronic limb ischemia, lower extremity (LE) wounds require revascularization of source arteries for wound healing and limb salvage. Direct revascularization of the source artery is preferred but cannot always be performed. Our objective was to analyze the influence of arterial-arterial connections on clinical outcomes after angiosome-directed endovascular revascularization.

METHODS

Consecutive LE wounds in patients with isolated infra-popliteal disease revascularized endovascularly from 2012 to 2016 within a single center were retrospectively reviewed. Treatment was classified as direct revascularization (DR) if the source artery supplying the wound angiosome was treated, indirect revascularization via collaterals (IR-C) if the source artery angiosome was revascularized by another major artery via arterial connections, or indirect revascularization (IR) if direct revascularization of the source artery angiosome was not possible. Demographics, comorbidities, and patient outcomes were collected.

RESULTS

Of 105 patients with 106 LE wounds, there were 35, 38, and 33 patients in the DR, IR-C, and IR groups, respectively. The mean age was 65.8 years old (standard deviation (SD) 11.9) with 81 males (77.1%) and 24 females (22.9%). Average follow-up was 21.0 months (SD 14.0). Overall wound healing rates were 80.0%, 92.1%, and 63.6% for DR, IR-C, and IR, respectively (P = 0.009). Significant differences were found between all 3 group comparisons, DR versus IR-C (P = 0.010), DR versus IR (P = 0.013), IR-C versus IR (P = 0.008). Overall major amputation-free survival was 85.7%, 89.5%, and 69.7% in DR, IR-C, and IR groups, respectively, with statistically significant differences between the IR-C and IR groups (P = 0.036).

CONCLUSIONS

Treating diseased infra-popliteal arteries and improving blood flow via arterial-arterial connections as per the angiosome model improved wound healing and amputation-free survival in this cohort. Although DR is still the gold standard, revascularization using IR-C may give superior healing results even in highly comorbid patients. This offers an additional avenue for treatment, especially when DR is not possible.

Assessment of the pedal arteries with Duplex Scanning

Vascular Doppler ultrasound is a noninvasive method that can help in diagnostic and therapeutic planning in case of pedal arterial obstructive disease. The dorsalis pedis artery is the direct continuation of the anterior tibial artery and follows a straight course along the dorsum of the foot, leading medially to the first intermetatarsal space, where it gives off its terminal branches. The posterior tibial artery forks distal to the medial malleolus and gives rise to the lateral plantar and medial plantar arteries. The medial plantar artery has a smaller caliber and runs medially in the sole of the foot, while the lateral plantar artery is of larger caliber, following a lateral course in the plantar region and forming the deep plantar arch, which anastomoses with the dorsalis pedis artery via the deep plantar artery. The arteries of the foot can be assessed noninvasively with Doppler, providing an adequate level of anatomical detail.

Implications of Renal Disease in Patients Undergoing Peripheral Arterial Interventions

Since the first peripheral endovascular intervention (PVI) in 1964, the procedure's technical aspects and indications have advanced significantly. Today, endovascular procedures span the spectrum of presentations from acute limb ischemia to critical limb ischemia and symptomatic limiting claudication. Goals of PVI remain restoring limb perfusion, minimizing rates of amputation and mortality, and sparing the need for the high-risk bypass surgery. Unfortunately, there are no large randomized controlled trials that address the optimal approach to peripheral arterial disease revascularization in chronic kidney disease (CKD) patients.

Influence of end-stage renal disease on long-term survival after major amputation

Background: To analyze long-term outcomes and possible influencing factors in patients with endstage renal disease (ESRD) and critical limb ischemia (CLI) after major amputation compared to patients with normal renal function and non-dialysis-dependent chronic kidney disease. Patients and methods: Abstraction of single-center medical records of patients undergoing above knee (AKA) and below knee (BKA) amputation over a 10 years period (n = 436; 2009-2018). Excluded were amputations due to trauma or tumor. Patients were subdivided according to renal function in three categories: ESRD patients (n = 98), non-dialysis dependent chronic kidney disease (CKD, n = 98) and normal renal function (NF, n = 240). Predefined endpoints were survival and postoperative complications. Cox-regression models were built to analyze independent risk factors for outcome parameters. Results: In total, 298 AKA, 133 BKA and 5 knee joint exarticulations were performed. ESRD patients showed inferior in-hospital results as to death (ESRD 36.7 % vs. CKD 19.4 % and NF 20.0 %, P = .002). Similarly, long-term survival rates (6 months: ESRD 55.0 % vs. CKD 69.4 %, NF 67.9 % 1 year: ESRD 48.6 %, CKD 60.2 %, NF 60.8 % 5 years: ESRD 9.9 %, CKD 31.8 %, NF 37.1 %, P < .001) were significantly decreased for ESRD patients. Median postoperative survival was 10 months in ERSD, and 22 months in CKD and NF, respectively. Analysis of postoperative surgical complications revealed no differences between groups (ESRD 19.4 %, CKD 17.3 %, NF 17.0 %; P = 0.433). Cox regression analysis indicated that dialysis (HR 1.63; 95 % CI 1.22-2.16; P = .001), hypertension (HR 1.59; 95 % CI 0.99-2.54) and smoking (HR 1.22; 95 % CI 1.03-1.44; P = .022) was associated with increased risk of death during follow-up. Conclusions: Mortality after limb amputation in ERSD patients remains high. Survival of ERSD patients is lower in relation to chronic kidney disease and patients with normal renal function. Due to poor in hospital outcomes and absent long-term survival, benefit of primary amputation in ERSD seems scarce.

Far-infrared therapy improves ankle brachial index in hemodialysis patients with peripheral artery disease

Ankle brachial index (ABI) is a diagnostic tool for peripheral artery disease (PAD), which is an important issue in hemodialysis (HD) patients. We enrolled 198 maintenance HD patients in this study. PAD is defined as ABI ≤ 0.90. Only PAD patients received far-infrared (FIR) therapy using the WS TY101 FIR emitter for 40 min during each HD session, three times weekly for 6 months. The ABI was measured at the bilateral lower extremities for 4 times [pre-dialytic timing (0 min) and 40 min after the initiation of HD session at both day 0 and 6 months after the FIR therapy]. The primary outcome is the change in ABI. There were 51 out of 198 patients with PAD. In comparison with the period without FIR therapy in the 51 PAD patients, 6 months of FIR therapy significantly improved the ABI of the right/left side for 0 min (from 0.77 ± 0.19 to 0.81 ± 0.20, p = 0.027/0.79 ± 0.20 to 0.81 ± 0.17, p = 0.049), 40 min during HD (from 0.73 ± 0.23 to 0.83 ± 0.19, p < 0.001/from 0.77 ± 0.21 to 0.83 ± 0.18, p < 0.001), and the incremental change between 0 and 40 min (from - 0.04 ± 0.14 to 0.05 ± 0.13, p = 0.007/from - 0.05 ± 0.13 to 0.03 ± 0.11, p = 0.012), respectively. In conclusion, the application of FIR therapy for 40 min, three times weekly for 6 months, has improved the ABI of both lower extremities, thus providing a new strategy of PAD treatment in HD patients.

Modern endovascular methods in treatment of patients with the tibial arteries lesion: determinants and perspectives

Endovascular interventions have proved efficacy in the treatment of the shin arteries lesion management. Lots of published works witness on the significance and future perspective of the field. The article is focused on the analysis of studies for previous 5 years, on various treatment approaches, balloons and cytostatics coated stents usage. The ways for interventions relsults improvement are sketched on tibial arteries with drug eluting stents.

Open Versus Endovascular Revascularization of Below-Knee Arteries in Patients With End-Stage Renal Disease and Critical Limb Ischemia

Background:

Evaluation of below-the-knee open revascularization (OR) versus endovascular revascularization (EVT) in patients with end-stage renal disease and critical limb ischemia (CLI) was performed.

Patients and Methods:

Seventy-seven dialysis patients with CLI and infrapopliteal involvement from 2007 to 2017 were included. Thirty-five patients received OR and 42 patients were treated with EVT. Survival, amputation-free survival (AFS) and wound-healing were evaluated. Furthermore, both groups were analyzed for differences as to anatomic (lesion length, runoff, pedal arch classification) and clinical (VSG risk score, WIfI score) characteristics.

Results:

Amputation-free survival (1-year AFS: OR 54.5% vs 47.6% in EVT, 2-year AFS OR 38.3% vs 23.9% EVT, P = .201) did not significantly differ between OR and EVT nor did the wound healing rate (29% OR vs 31% EVT, P = .532). Overall survival was noticeably poor (1-year survival: 66.7% in OR and 49% in EVT, 2-year survival OR 47.4% vs EVT 27.7%; P = .088); evaluation of peripheral runoff (Rutherford score 6.9 OR vs 7.1 EVT, P = .499) and pedal arch classification as well as WIfI or VSG risk score (9.8 OR vs 9.6 EVT, P = .673) could not detect significant differences as to both the groups. Treated median lesion length was significantly increased in OR patients (OR 26 cm vs EVT 7 cm, P < .001), whereas the incidence of major adverse cardiac events was higher in EVT patients (67% in EVT vs 40% OR, P = .023).

Conclusion:

OR and EVT showed comparable outcomes as to AFS and wound healing. Poor overall survival remains the determining factor in patients with ESRD having CLI. Both groups differ in terms of anatomic features as lesion length and severity of comorbidities; considering the comparable long-term outcomes, decision-making should be based on these premises; individually applied, each method can contribute to limb salvage, although the overall survival remains limited.

Hemodialysis patients have worse outcomes after infrageniculate revascularization procedures

BACKGROUND

Hemodialysis (HD) has been shown to be an independent predictor of poor outcomes after femoropopliteal revascularization procedures in patients with chronic limb-threatening ischemia. However, HD patients tend to have isolated infrageniculate disease, an anatomic risk factor for inferior patency. We aimed to compare outcomes for HD versus non-HD patients after infrageniculate open lower extremity bypass (LEB) and endovascular peripheral vascular interventions (PVIs).

METHODS

Data from the Society for Vascular Surgery Vascular Quality Initiative database (2008-2014) were analyzed. All patients undergoing infrageniculate LEB or PVI for rest pain or tissue loss were included. One-year primary patency (PP), secondary patency (SP), and major amputation outcomes were analyzed for HD versus non-HD patients stratified by treatment approach using both univariable and multivariable analyses.

RESULTS

A total of 1688 patients were included, including 348 patients undergoing LEB (HD = 44 versus non-HD = 304) and 1340 patients undergoing PVI (HD = 223 versus non-HD = 1117). Patients on HD more frequently underwent revascularization for tissue loss (89% versus 77%, P < 0.001) and had ≥2 comorbidities (91% versus 76%, P < 0.001). Among patients undergoing LEB, 1-y PP (66% versus 69%) and SP (71% versus 78%) were similar for HD versus non-HD (P ≥ 0.25) groups, but major amputations occurred more frequently in the HD group (27% versus 14%; P = 0.03). Among patients undergoing PVI, 1-y PP (70% versus 78%) and SP (82% versus 90%) were lower and the frequency of major amputations was higher (27% versus 10%) for HD patients (all, P ≤ 0.02). After correcting for baseline differences between the groups, outcomes were similar for HD versus non-HD patients undergoing LEB (P ≥ 0.21) but persistently worse for HD patients undergoing PVI (all, P ≤ 0.006).

CONCLUSIONS

HD is an independent predictor of poor patency and higher risk of major amputation after infrageniculate endovascular revascularization procedures for the treatment of chronic limb-threatening ischemia. The use of endovascular interventions in these higher risk patients is not associated with improved limb salvage outcomes and may be an inappropriate use of healthcare resources.

Patency of the arterial pedal-plantar arch in patients with chronic kidney disease or diabetes mellitus

BACKGROUND

Patency of the pedal-plantar arch limits risk of amputation in peripheral artery disease (PAD). We examined patients without chronic kidney disease (CKD)/diabetes mellits (DM) [PAD-control], those with DM without CKD, and those with CKD without DM.

METHOD

Uni- and multivariate logistic regression was used to assess association of CKD with loss of patency of the pedal-plantar arch and presence of tibial or peroneal vessel occlusion. Multivariate models adjusted for age, sex, hypertension, hyperlipidemia and smoking.

RESULTS

A total of 419 patients were included [age 75.2 ± 10.3 years, 288 (69%) male]. CKD nearly doubled the unadjusted odds ratio (OR) for loss of patency of the pedal-plantar arch. After adjustment, association remained significant for severe CKD [estimated glomerular filtration rate (eGFR) ≤ 29 ml/min compared with eGFR ≥ 60 ml/min, adjusted (adj.) OR 8.24 (95% confidence interval {CI} 0.99-68.36, p = 0.05)]. CKD was not related to risk of tibial or peroneal artery occlusion [PAD-control versus CKD, adj. OR 1.09 (95% CI 0.49-2.44, p = 0.83)] in contrast to DM [PAD-control versus DM, adj. OR 2.41 (95% CI 1.23-4.72, p = 0.01), CKD versus DM, adj. OR 2.21 (95% CI 0.93-5.22); p = 0.07)].

CONCLUSIONS

Below the knee (BTK) vascular pattern differs in patients with either DM or CKD alone. Severe CKD is a risk factor for loss of patency of the pedal-plantar arch.

Pilot Assessment of the Angiosome Concept by Intra-operative Fluorescence Angiography After Tibial Bypass Surgery

OBJECTIVES

The "angiosome" concept as a model for decision making in revascularisation of patients with critical limb ischaemia (CLI) has been subject to lively discussion in recent years. The aim of this prospective pilot study was to use intra-operative fluorescence angiography to provide further data on the angiosome concept on the level of microcirculation after tibial bypass surgery.

DESIGN, MATERIALS, AND METHODS

This was a prospective analysis of 40 patients presenting with CLI Rutherford stage IV to VI before and after tibial bypass surgery. The macrocirculation was measured by the ankle brachial index. Skin microcirculation was assessed by intra-operative fluorescence angiography. The alteration of microcirculation was compared in direct and indirect revascularised angiosomes. Clinical follow-up investigations were performed and the wound healing rate was compared between the different revascularisation methods.

RESULTS

Cumulated microcirculation parameters showed a significant improvement after surgery (ingress, ingress rate p<.001). Likewise, general microcirculatory improvement was observed in each foot angiosome after revascularisation, regardless of the tibial artery revascularised. Furthermore, a comparison of the direct (DR) and the indirect revascularised (IR) angiosomes did not show a significant difference concerning the improvement of microcirculation (difference DR-IR, ingress: 1.69, 95% CI 71.73-75.11; ingress rate: 0.08, 95% CI -12.91 to 13.07). The wound healing rate was similar in both groups, although the time to wound healing was faster by on average 2.5 months in the DR group (p=.083).

CONCLUSION

Microcirculatory improvement was seen over the whole foot after tibial bypass. Therefore, fluorescence angiography is a promising tool to evaluate the angiosome concept in future larger studies. Clinicaltrials.gov: NCT03012750.

Prevalence of Tibial Artery and Pedal Arch Patency by Angiography in Patients With Critical Limb Ischemia and Noncompressible Ankle Brachial Index

Background—

Approximately 20% of patients undergoing ankle brachial index testing for critical limb ischemia have noncompressible vessels because of tibial artery calcification. This represents a clinical challenge in determining tibial artery patency. We sought to identify the prevalence of tibial artery and pedal arch patency by angiography in these patients.

Methods and Results—

One hundred twenty-five limbs (of 89 patients) with critical limb ischemia and ankle brachial index ≥1.4 who underwent lower extremity angiograms within 1 year were included. Reviewers of angiography were blinded to results of physiological testing. Tibial artery vessels were classified as completely occluded, significantly stenosed (≥50%), or patent (<50% stenosis). The sensitivity of toe brachial index and pulse volume recording to predict tibial artery disease was also determined. Of 125 limbs with noncompressible ankle brachial index, 72 (57.6%) anterior tibial and 80 (64%) posterior tibial arteries were occluded. Another 23 (18.4%) anterior tibial and 13 (10.4%) posterior tibial arteries had ≥50% stenosis. Pulse volume recording was moderate to severely dampened in 54 of 119 (45.4%) limbs. Toe brachial index <0.7 was found in 75 of 83 (90.4%) limbs. Moderate to severe pulse volume recording dampening was 43.6% sensitive, whereas toe brachial index <0.7 was 89.7% sensitive in diagnosing occluded or significantly stenotic tibial artery disease. The pedal arch was absent or incomplete in 86 of 103 (83.5%) limbs.

Conclusions—

Among patients with critical limb ischemia and noncompressible ankle brachial index results, the prevalence of occlusive tibial and pedal arch disease is very high. Toe brachial index <0.7 is more sensitive in diagnosing occluded and significantly stenotic tibial artery disease in these patients compared with ankle pulse volume recording.