Lumbar sympathectomy versus prostanoids for critical limb ischaemia due to non-reconstructable peripheral arterial disease

Endovascular and Surgical Venous Arterialization for No-Option Patients With Chronic Limb-Threatening Ischemia: A Systematic Review and Meta-Analysis

BACKGROUND

Chronic limb-threatening ischemia (CLTI) is known for its high rates of major amputation and mortality. Conventional revascularization techniques often fail in CLTI patients due to the heavily diseased arteries. Foot vein arterialization (FVA) has been proposed as an alternative technique to provide arterial blood to the foot by using the disease-free venous bed.

OBJECTIVES

This systematic review and meta-analysis aimed to determine outcomes of surgical FVA (sFVA) and percutaneous FVA (pFVA) at 6 and 12 months post-procedure.

DATA SOURCES

PubMed, Scopus, Web of Science, and the Cochrane Library databases were searched to identify papers reporting clinical outcomes of sFVA and pFVA published between January 1966 and March 2023.

METHODS

Databases were searched for eligible studies. A meta-analysis was performed to evaluate the limb salvage rate, overall survival rate, and wound healing rate at 6 and 12 months.

RESULTS

A total of 27 studies were included, with 753 patients and 793 limbs. Of the included studies, 16 analyzed the sFVA technique and 11 the pFVA technique. Of the included patients, 86.3% were Rutherford 5/6 in the sFVA group versus 98.4% in the pFVA group. The pooled limb salvage rate at 6 and 12 months was 78.1% and 74.1% in the sFVA group and 81.7% and 78.6% in the pFVA group, respectively. Wound healing rates were not reported in the sFVA group. In the pFVA group, the pooled wound healing rates were 48.1% and 64.5% at 6 and 12 months, respectively.

CONCLUSION

This study showed promising results after FVA among a large population of CLTI patients. In high-risk patients, pFVA is a feasible option with favorable limb salvage and wound healing rates.

An anatomical study of the tibial nerve branches innervating the posterior tibial artery

The arteries of the lower limbs are innervated by vascular branches (VBs) originating from the lumbar sympathetic trunk and branches of the spinal nerve. Although lumbar sympathectomy is used to treat nonreconstructive critical lower limb ischemia (CLLI), it has limited long-term effects. In addition, the anatomical structure of tibial nerve (TN) VBs remain incompletely understood. This study aimed to clarify their anatomy and better inform the surgical approach for nonreconstructive CLLI. Thirty-six adult cadavers were dissected under surgical microscopy to observe the patterns and origin points of VBs under direct vision. The calves were anatomically divided into five equal segments, and the number of VB origin points found in each was expressed as a proportion of the total found in the whole calf. Immunofluorescence staining was used to identify the sympathetic nerve fibers of the VBs. Our results showed that the TN gave off 3-4 VBs to innervate the posterior tibial artery (PTA), and the distances between VBs origin points and the medial tibial condyle were: 24.7 ± 16.3 mm, 91.7 ± 66.1 mm, 199.6 ± 52.0 mm, 231.7 ± 38.5 mm, respectively. They were mainly located in the first (40.46%) and fourth (31.68%) calf segments, and immunofluorescence staining showed that they contained tyrosine hydroxylase-positive sympathetic nerve fibers. These findings indicate that the TN gives off VBs to innervate the PTA and that these contain sympathetic nerve fibers. Therefore, these VBs may need to be cut to surgically treat nonreconstructable CLLI.

Lumbar sympathectomy versus prostanoids for critical limb ischaemia due to non-reconstructable peripheral arterial disease

BACKGROUND

Peripheral arterial disease (PAD) is a common circulatory problem that can lead to reduced blood flow to the limbs, which may result in critical limb ischaemia (CLI), a painful manifestation that occurs when a person is at rest. The mainstay of treatment for CLI is surgical or endovascular repair. However, when these means of treatment are not suitable, due to anatomical reasons or comorbidities, treatment for pain is limited. Lumbar sympathectomy and prostanoids have both been shown to reduce pain from CLI in people who suffer from non-reconstructable PAD, but there is currently insufficient evidence to determine if one treatment is superior. Due to the severity of the rest pain caused by CLI, and its impact on quality of life, it is important that people are receiving the best pain relief treatment available, therefore interest in this area of research is high.

OBJECTIVES

To compare the efficacy of lumbar sympathectomy with prostanoid infusion in improving symptoms and function and avoiding amputation in people with critical limb ischaemia (CLI) due to non-reconstructable peripheral arterial disease (PAD).

SEARCH METHODS

The Cochrane Vascular Information Specialist (CIS) searched the Specialised Register (last searched 29 March 2017) and CENTRAL (2017, Issue 2). The CIS also searched clinical trials databases for ongoing or unpublished studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs), with parallel treatment groups, that compared lumbar sympathectomy (surgical or chemical) with prostanoids (any type and dosage) in people with CLI due to non-reconstructable PAD.

DATA COLLECTION AND ANALYSIS

Three review authors independently selected trials, extracted data and assessed risk of bias. Any disagreements were resolved by discussion. We performed fixed-effect model meta-analyses, when there was no overt sign of heterogeneity, with risk ratios (RRs) and 95% confidence intervals (CIs). We graded the quality of evidence according to GRADE.

MAIN RESULTS

We included a single study in this review comparing lumbar sympathectomy with prostanoids for the treatment of CLI in people with non-reconstructable PAD. The single study included 200 participants with Buerger's disease, a form of PAD, 100 in each treatment group, but only 162 were actually included in the analyses. The study compared an open surgical technique for lumbar sympathectomy with the prostanoid, iloprost, and followed participants for 24 weeks.Risk of bias was low for most evaluated domains. Due to the nature of the treatment, blinding of the participants and those providing the treatment would be impossible as a surgical procedure was compared with intravenous injections. It was not mentioned if blinded assessors evaluated the study outcomes, therefore, we judged subjective outcomes (i.e. pain reduction) to be at unclear risk of detection bias and objective outcomes (i.e. ulcer healing, amputation and mortality) at low risk of detection bias. We also rated the risk of attrition bias as unclear; 38 out of 200 (19%) participants were not included in the analysis without clear explanation (16 of 100 in the iloprost arm and 22 of 100 in the sympathectomy arm). The quality of evidence was low due to serious imprecision because the study numbers were low and there was only one study included.The single included study reported on the outcome of complete healing without pain or major amputation, which fell under three separate outcomes for our review: relief of rest pain, complete ulcer healing and avoidance of major amputation. We chose to keep the outcome as a singularly reported outcome in order to not introduce bias into the outcomes, which may have been the case if reported separately. The limited evidence suggests participants who received prostaglandins had improved complete ulcer healing without rest pain or major amputation when compared with those who received lumbar sympathectomy (RR 1.63, 95% CI 1.30 to 2.05), but as it was the only included study, we rated the data as low-quality and could not draw any overall conclusions. The study authors stated that more participants who received prostaglandins reported adverse effects, such as headache, flushing, nausea and abdominal discomfort, but only one participant experienced severe enough adverse effects to drop out. Five participants who underwent lumbar sympathectomy reported minor wound infection (low-quality evidence). There was no reported mortality in either of the treatment groups (low-quality evidence).The included study did not report on claudication distances, quality of life or functional status, ankle brachial pressure index (ABPI), tissue oxygenation or toe pressures, or progression to minor amputation, complications or provide any cost-effectiveness data.

AUTHORS' CONCLUSIONS

Low-quality evidence from a single study in a select group of participants (people with Buerger's disease) suggests that prostaglandins are superior to open surgical lumbar sympathectomy for complete ulcer healing without rest pain or major amputation, but possibly incur more adverse effects. Further studies are needed to better understand if prostaglandins truly are more efficacious than open surgical lumbar sympathectomy and if there are any concerns with adverse effects. It would be of great importance for future studies to include other forms of PAD (as Buerger's disease is a select type of PAD), other methods of sympathectomy as well as data on quality of life, complications and cost-effectiveness.

Prostanoids for critical limb ischaemia

BACKGROUND

Peripheral arterial occlusive disease (PAOD) is a common cause of morbidity and mortality due to cardiovascular disease in the general population. Although numerous treatments have been adopted for patients at different disease stages, no option other than amputation is available for patients presenting with critical limb ischaemia (CLI) unsuitable for rescue or reconstructive intervention. In this regard, prostanoids have been proposed as a therapeutic alternative, with the aim of increasing blood supply to the limb with occluded arteries through their vasodilatory, antithrombotic, and anti-inflammatory effects. This is an update of a review first published in 2010.

OBJECTIVES

To determine the effectiveness and safety of prostanoids in patients with CLI unsuitable for rescue or reconstructive intervention.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Specialised Register (January 2017) and the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 1). In addition, we searched trials registries (January 2017) and contacted pharmaceutical manufacturers, in our efforts to identify unpublished data and ongoing trials.

SELECTION CRITERIA

Randomised controlled trials describing the efficacy and safety of prostanoids compared with placebo or other pharmacological control treatments for patients presenting with CLI without chance of rescue or reconstructive intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed trials for eligibility and methodological quality, and extracted data. We resolved disagreements by consensus or by consultation with a third review author.

MAIN RESULTS

For this update, 15 additional studies fulfilled selection criteria. We included in this review 33 randomised controlled trials with 4477 participants; 21 compared different prostanoids versus placebo, seven compared prostanoids versus other agents, and five conducted head-to-head comparisons using two different prostanoids.We found low-quality evidence that suggests no clear difference in the incidence of cardiovascular mortality between patients receiving prostanoids and those given placebo (risk ratio (RR) 0.81, 95% confidence interval (CI) 0.41 to 1.58). We found high-quality evidence showing that prostanoids have no effect on the incidence of total amputations when compared with placebo (RR 0.97, 95% CI 0.86 to 1.09). Adverse events were more frequent with prostanoids than with placebo (RR 2.11, 95% CI 1.79 to 2.50; moderate-quality evidence). The most commonly reported adverse events were headache, nausea, vomiting, diarrhoea, flushing, and hypotension. We found moderate-quality evidence showing that prostanoids reduced rest-pain (RR 1.30, 95% CI 1.06 to 1.59) and promoted ulcer healing (RR 1.24, 95% CI 1.04 to 1.48) when compared with placebo, although these small beneficial effects were diluted when we performed a sensitivity analysis that excluded studies at high risk of bias. Additionally, we found evidence of low to very low quality suggesting the effects of prostanoids versus other active agents or versus other prostanoids because studies conducting these comparisons were few and we judged them to be at high risk of bias. None of the included studies assessed quality of life.

AUTHORS' CONCLUSIONS

We found high-quality evidence showing that prostanoids have no effect on the incidence of total amputations when compared against placebo. Moderate-quality evidence showed small beneficial effects of prostanoids for rest-pain relief and ulcer healing when compared with placebo. Additionally, moderate-quality evidence showed a greater incidence of adverse effects with the use of prostanoids, and low-quality evidence suggests that prostanoids have no effect on cardiovascular mortality when compared with placebo. None of the included studies reported quality of life measurements. The balance between benefits and harms associated with use of prostanoids in patients with critical limb ischaemia with no chance of reconstructive intervention is uncertain; therefore careful assessment of therapeutic alternatives should be considered. Main reasons for downgrading the quality of evidence were high risk of attrition bias and imprecision of effect estimates.

Lumbar sympathectomy techniques for critical lower limb ischaemia due to non-reconstructable peripheral arterial disease

BACKGROUND

Critical lower limb ischaemia (CLI) is a manifestation of peripheral arterial disease (PAD) that is seen in patients with typical chronic ischaemic rest pain or patients with ischaemic skin lesions - ulcers or gangrene - for longer than 2 weeks. Critical lower limb ischaemia is the most severe form of PAD, and interventions to improve arterial perfusion become necessary. Although surgical bypass has been the gold standard for revascularisation, the extent or the site of disease may be such that the artery cannot be reconstructed or bypassed. These patients require other modalities of treatment, for example, vasodilatation by drugs or lumbar sympathectomy to relieve pain at rest and to avoid amputations. A systematic review of randomised controlled trials is required to evaluate the effects of lumbar sympathectomy in treating patients with CLI due to non-reconstructable PAD.

OBJECTIVES

The objective of this review is to assess the effects of lumbar sympathectomy by open, laparoscopic and percutaneous methods compared with no treatment or compared with any other method of lumbar sympathectomy in patients with CLI due to non-reconstructable PAD.

SEARCH METHODS

The Cochrane Vascular Information Specialist (CIS) searched the Specialised Register (January 2016) and the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 12). In addition, the CIS searched clinical trials databases for details of ongoing and unpublished studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing any of the treatment modalities of lumbar sympathectomy, such as open, laparoscopic and chemical percutaneous methods, with no treatment or with any other method of lumbar sympathectomy for CLI due to non-reconstructable PAD were eligible. To decrease the bias of including participants that may be incorrectly diagnosed with CLI, review authors defined CLI as persistently recurring ischaemic rest pain requiring regular analgesia for more than two weeks, or ulceration or gangrene of the foot or toes, attributable to objectively proven arterial occlusive disease by measurement of ankle pressure of < 50 mmHg or toe pressure < 30 mmHg. We defined non-reconstructable PAD as a resting ankle brachial index (ABI) < 0.9 when no reasonable open surgical or endovascular revascularisation treatment option is available, as determined by individual trial vascular specialists.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies identified for potential inclusion in the review. We planned to conduct data collection and analysis in accordance with the Cochrane Handbook for Systematic Review of Interventions.

MAIN RESULTS

We identified no studies that met the predefined inclusion criteria. To decrease the bias of including participants who may be incorrectly diagnosed with CLI, we based our inclusion criteria on objective tests, as described above. The randomised trials identified by the literature search were performed before such objective criteria for selection were applied and therefore were not eligible for inclusion in the review.

AUTHORS' CONCLUSIONS

We identified no RCTs assessing effects of lumbar sympathectomy by open, laparoscopic and percutaneous methods compared with no treatment or compared with any other method of lumbar sympathectomy in patients with CLI due to non-reconstructable PAD. High-quality studies are needed.