Reduced amputation rate with isovolemic hemodilution in critical limb ischemia patients

The Double Burden: Deciphering Chronic Limb-Threatening Ischemia in End-Stage Renal Disease

BACKGROUND

Chronic limb-threatening ischemia (CLTI) in patients with end-stage renal disease (ESRD) poses significant challenges in clinical management due to its unique pathology and poor treatment outcomes. This review calls for a tailored classification and risk assessment for these patients to guide better revascularization choices with early minor amputation as a first-line strategy in advanced stages.

METHODS

This review consolidates key findings from recent literature on CLTI in ESRD, focusing on disease mechanisms, treatment options, and patient outcomes. It evaluates the literature to clarify the decision-making process for managing CLTI in ESRD.

RESULTS

CLTI in ESRD patients often results in worse clinical outcomes, such as nonhealing wounds, increased limb loss, and higher mortality rates. While the literature reveals ongoing debates regarding the optimal revascularization method, recent retrospective studies and meta-analyses suggest potential benefits of endovascular treatment (EVT) over open bypass surgery (OB) in reducing mortality and wound complications, with comparable amputation-free survival rates.

CONCLUSIONS

The selection of revascularization methods in ESRD patients with CLTI is complex, necessitating individualized strategies. The importance of early detection and timely intervention is critical to decelerate disease progression and improve revascularization outcomes. There is a shift in these treatment strategies toward less invasive endovascular procedures, acknowledging the limitations these patients face with open revascularization surgeries. Considering early minor amputations after revascularization could prevent worse consequences, reflecting a shift in the approach to managing CLTI in ESRD patients.

Risk of amputation under diuretics in patients with or at risk of lower extremity arterial disease: A systematic review and meta-analysis

BACKGROUND

Recently, increased risk of amputation under sodium glucose cotransporter-2 inhibitors has been debated. Similar concerns have been raised with other "traditional" diuretics, more particularly in patients with or at risk of lower extremity arterial disease (LEAD).

AIM

To collect all available data on any potential risk of amputation associated with diuretics in patients with or at risk of LEAD. Additionally, we looked for other limb-related events in these patients.

METHODS

We searched in PubMed, Embase and Scopus databases up to February 2021 for references, using peripheral or lower extremity arterial disease, diuretics and amputation keywords, excluding case reports, experimental animal studies and non-English reports.

RESULTS

Among the 1376 hits identified in the databases, six studies were finally included in this review, including one cross-sectional and five longitudinal studies (total of 47,612 participants). One study was limited to thiazide diuretics, one focused on loop diuretics and the remainder mixed all diuretics. All studies reported a significant association between diuretic use and amputation risk in patients with or at high risk of LEAD. Despite some limitations in several studies, the meta-analysis showed an increased risk of amputation associated with diuretics (odds ratio: 1.75, 95% confidence interval: 1.53-1.99; P<0.001). Beyond amputation, patients with or at risk of LEAD under diuretics appeared to be at increased risk of other lower limb events, mostly in the presence of other comorbidities, including diabetes.

CONCLUSIONS

Although the amount of data in the literature is scarce, this first systematic review and meta-analysis favours an increased risk of amputation in patients with or at risk of LEAD under diuretics. Further prospective studies must be conducted to provide a better understanding of the mechanisms. Meanwhile, the use of diuretics in these patients should be parsimonious, considering alternatives whenever possible.

Effects of sarpogrelate on blood viscosity

The objective of the present study was to evaluate the effects and safety of sarpogrelate hydrochloride (sarpogrelate) in patients with elevated blood viscosity (BV), after 12 and 24 weeks of twice (BID) or thrice (TID) daily administrations of sarpogrelate (100 mg). The participants received oral sarpogrelate administration for 24 weeks and visited the hospital every 12 ± 2 week for blood viscosity measurements at shear rates of 5 and 300 s^-1. The BV measured at shear rate of 5 s^-1 in male patients decreased significantly from 18.91 cP at the baseline to 16.3 cP after 24 weeks of sarpogrelate administration (13.6 % drop, p < 0.001). The BV measured at 5 s^-1 in female decreased more significantly from 17.5 cP at the baseline to 13.4 cP after 24 weeks of sarpogrelate administration (23.0 % drop, p < 0.001). In summary, sarpogrelate may be considered as a possible therapeutic option for improving BV in patients with elevated blood viscosity. In particular, the reduction of the low-shear BV with the help of a viscosity-reducing drug such as sarpogrelate may be considered as a potentially new pharmacological tool for microvascular disease.

Hemodilution on microvascular oxygen delivery potential of the blood during coronary bypass surgery

PURPOSE

The hematocrit-to-whole blood viscosity ratio (Hct/WBV) reflects the blood O₂ delivery potential (O₂-DP). WBV is variable to the dynamic vascular shear rate (SR), 1-5/s at microcirculation and 300/s at larger vessels. To estimate the impact of hemodilution on the blood O₂-DP to the myocardium, we analyzed the hemodilution-induced change of Hct/WBV at SR 5/s (Hct/WBV₅) during off-pump coronary bypass (OPCAB) surgery.

METHODS

During OPCAB surgery (n = 21), 10% acute normovolemic hemodilution (HD 10%) was applied. Arterial blood samples were taken: one before and two after HD 10%. One of which after HD 10% underwent an additional 33% in vitro hemodilution (reaching 40% hemodilution in total, HD 40%). WBV of all blood samples was determined using a scan-capillary tube viscometer (Hemovister^™). The changes of Hct/WBV₅ were analyzed as a primary measure of the study and compared with those of Hct/WBV at SR 300/s (Hct/WBV₃₀₀).

RESULTS

Median[IQR] of Hct/WBV₅ [3.5 (2.8-4.2)%/cPoise] was significantly increased by HD 10 and HD 40% [3.6 (3.2-4.6)%/cPoise and 4.2 (3.3-5.2)%/cPoise, respectively, all P < 0.001], but the degrees of changes after HD 10 and HD 40% were not different. Median[IQR] of Hct/WBV₃₀₀ [10.3(8.6‒10.8)%/cPoise] was not changed by HD 10% [10.3(9.1-11.1)%/cPoise], but it was significantly decreased by HD 40% [8.4(7.4‒9.2)%/cPoise, P < 0.001].

CONCLUSION

The increased Hct/WBV₅ suggests that 10-40% hemodilution improves the blood O₂-DP to the myocardium during OPCAB surgery. The SR-specific discrepancy in Hct/WBV changes advocates using microvascular WBV and Hct/WBV to evaluate the blood O₂-DP changes to the myocardium. Further study is warranted to assess the actual changes in myocardial O₂ delivery.

[Chronic spinal stimulation in treatment of lower limb critical ischaemia syndrome]

Obliterating peripheral artery disease is a commonly occurring pathological condition, most often resulting from an atherosclerotic lesion of vessels with progressive narrowing of their lumens. The consequences of decompensation of chronic arterial insufficiency such as ischaemic pain, claudication, and trophic impairments are in some instances difficult to treat, despite using multicomponent medicamentous therapy and/or performing revascularizing interventions. This article describes a clinical case report regarding the use of spinal stimulation in a patient presenting with stage IV chronic lower limb ischaemia according to the Fontaine classification. This is accompanied and followed by depicting the dynamics of the laboratory, instrumental, and clinical parameters over a two-year follow-up period. In order to explain the choice of the intervention and the causes of the described picture, discussed are the existing theories of the mechanisms of action of spinal stimulation. To this is added a literature review of using this method in treatment of lower limb critical ischaemia when performing reconstructive angiosurgical treatment is unavailable. Mention is also made of the incidence and types of probable complications, as well as possibilities and limitations of the method.

Relation of Preprocedural Hemoglobin Level to Outcomes After Percutaneous Coronary Intervention

Adverse effects have been reported in patients with preprocedural anemia after percutaneous coronary intervention (PCI), but data regarding the relation between elevated hemoglobin (Hb) level and post-PCI prognosis remain limited. This study assessed the impact of elevated Hb on major adverse cardiac and cerebrovascular event (MACCE) at 12 months, a composite of all-cause mortality, nonfatal myocardial infarction, and ischemic stroke after PCI. We pooled patient-level data from four Korean multicenter drug-eluting stent registries from 2010 to 2016. In total, 5,107 patients were divided into 5 categories according to the baseline Hb level (<10, 10 to 12.9, 13 to 14.9, 15 to 16.9 and ≥17 g/dl). Patients with higher Hb levels were significantly younger, predominantly male, current smokers with higher body mass index, and more frequent dyslipidemia. Hypertension, diabetes, chronic kidney disease, and cerebrovascular accident were more prevalent in lower Hb groups. Categorically, a U-shaped curvilinear relation was observed between baseline Hb and clinical outcomes showing significantly higher MACCE rate in <10g/dl (hazard ratio [HR], 4.62 [2.81 to 7.68]) and ≥17 g/dl (HR, 4.06 [1.57 to 10.5]) groups compared with the reference group (13 to 14.9 g/dl), especially in men. In nonanemic patients (Hb ≥13 g/dl), adjusted HRs of MACCE, mortality, and stroke were significantly higher in ≥17 g/dl group than in the reference group. Furthermore, ≥17 g/dl was an independent predictor for MACCE and all-cause mortality after PCI. In conclusion, not only low Hb but also elevated Hb of ≥17 g/dl was significantly associated with higher MACCE rates and all-cause mortality after PCI. An appropriate treatment strategy for patients with high Hb level should be identified through future studies.

Medical adjunctive therapy for patients with chronic limb-threatening ischemia: a systematic review

INTRODUCTION

The aim of this article is to systematically review the literature on medical adjunctive therapy for patients with chronic limb-threatening ischemia (CLTI).

EVIDENCE ACQUISITION

MEDLINE, Embase, and Cochrane Database of Systematic Reviews were searched for studies published between January 1st, 2009, and June 1st, 2019. Articles that studied medical treatment of CLTI patients and reported clinical outcomes were eligible. Main exclusion criteria were case reports <20 patients, incorrect publication type, and CLTI caused by Buerger disease. The primary end point was major amputation (above the ankle) in studies with a follow-up of ≥6 months. Secondary end points were other clinical end points such as death and wound healing. Study quality was assessed according to the Downs and Black checklist.

EVIDENCE SYNTHESIS

Included were 42 articles: four focused on antiplatelet therapy, five on antihypertensive medication, 6 on lipid-lowering therapy, 16 on stem cell therapy, three on growth factors, five on prostanoids, and one study each on cilostazol, glucose-lowering therapy, spinal cord stimulation, sulodexide, and hemodilution. Calcium channel blockers, iloprost, cilostazol, and hemodilution showed significant improvement of limb salvage, but data are limited. Stem cell therapy showed no significant improvement of limb salvage but could potentially improve wound healing. Antiplatelets, antihypertensives, and statins showed significantly lower cardiovascular events rates but not evident lower major amputation rates. The quality of the studies was fair to good.

CONCLUSIONS

Certain medical therapies serve to improve limb salvage next to revascularization in CLTI patients, whereas others are important in secondary prevention. Because high quality evidence is limited, further research is needed.

Trends of the treatment of Critical Limb Ischemia during the last two decades

In this review 14 studies were identified reporting the treatment strategy in 4891 patients with Critical Limb Ischemia (CLI) with the aim to investigate if the strategy of treatment of the first episode of CLI has changed during the last 15-20 years. A computer research has been performed on PubMed and Scopus databases on November 2016. The used terms for the investigation about studies evaluating the strategy of treatment of CLI at the first-time presentation, have been "critical leg ischemia", "critical limb ischemia", "critical lower limb ischemia" along with the terms "placebo", "medical treatment" and/or "conservative" revascularisation, surgical revascularisation, endovascular revascularisation, hybrid revascularisation and primary amputation. Studies were included if they were either retrospective or prospective and reporting the rate of patients who underwent to any form of revascularization, conservative treatment and primary amputation. The one-year limb and life survival rates have been reported as major outcomes. The pooled rate of revascularization was 72.5% (95% CI 80-64.96) of which 54.5%, surgical, 38.3% endovascular and 7.1% hybrid. The bivariate regression of revascularisation procedures has been with not significant increase, from 68% in 1993 to 88% in 2015. The endovascular procedures have shown a significant increase of the trend, from 2% to more the 50% (p 0.007), while surgical and hybrid procedures have not. The pooled rate of conservative treatment was 18% (95% CI 11.6-24.5%) with a not significant increasing trend and primary amputation pooled rate was 8.7% (95% CI 12.0-5,4) with a significant decreasing trend (p 0.009). The one-year limb survival rate was 75,4% (95% CI 81.5-69.3%) and the life survival was 76%. (95% CI 85.4-66.1%) both with a not significant increasing trend. In conclusion, this review highlights how the treatment strategy of the first CLI manifestation has changed over the last 15-20 years. It has shown an increase of the rate of revascularization procedures, particularly for endovascular and a significant reduction of the rate of primary amputations. The rate of patients treated conservatively appears to be unchanged and maybe influencing the rate of limb and life survival, that have remained unchanged.