Subclavian Artery Calcification: A Narrative Review

Systematic review and meta-analysis of Jueyin disease theory in the treatment of gangrene with traditional Chinese medicine formulations

OBJECTIVE

This review aims to systematically evaluate the application of Jueyin disease theory in the diagnosis and treatment of gangrene within the framework of traditional Chinese medicine (TCM). Through systematic review and meta-analysis, the efficacy of commonly used TCM formulations, including Wumei pill, Pulsatilla decoction, and Dang-Gui-Si-Ni decoction, is explored.

METHODS

A systematic search of PubMed, Web of Science, and CNKI was conducted, integrating meta-analysis and systematic review. Clinical trials and case reports based on Jueyin disease theory for gangrene treatment were included. Data extraction, quality assessment, and statistical analyses were performed.

RESULTS

A total of nine studies met the inclusion criteria. The meta-analysis indicated that TCM formulations significantly improved clinical outcomes, particularly in enhancing the ankle-brachial index (ABI) and maximum walking distance, with mean differences of 0.17 (95% CI, 0.11, 0.24; p < 0.01) and 293.22 (95% CI, 174.85, 411.60; p < 0.01), respectively. Sensitivity analysis and tests for publication bias confirmed the robustness and consistency of the findings. Sensitivity analysis and publication bias assessment confirmed the robustness and reliability of the results.

CONCLUSION

Jueyin disease theory and its related formulas (Wumei pill, Pulsatilla decoction, and Dang-Gui-Si-Ni decoction) demonstrate significant clinical value in traditional Chinese medicine (TCM) treatment of gangrene, effectively improving clinical symptoms and blood circulation. The findings provide scientific evidence for the modern application of Jueyin disease theory in TCM while acknowledging limitations such as small sample sizes and study heterogeneity, offering valuable insights for future research and clinical practice.

Investigating the efficacy of uncrosslinked porcine collagen coated vascular grafts for neointima formation and endothelialization

Introduction

This study evaluates the efficacy of uncrosslinked porcine collagen coated vascular grafts (UPCCVG) in facilitating neointima formation and endothelialization.

Methods

Prior to coating, the uncrosslinked porcine collagen underwent comprehensive characterization employing SDS-PAGE, image analysis, circular dichroism and immunogenicity. The PET substrate of the vascular graft was coated with collagen solution utilizing the dip-coating method. Water permeability, blood leakage resistance, radial compliance, hemolysis, cytotoxicity and cell proliferation of UPCCVG in vitro were studied. Subsequent in vivo evaluation involved the implantation of UPCCVG as a substitute for the porcine abdominal aorta. Digital subtraction angiography (DSA) was employed to evaluate UPCCVG patency post-implantation, while histology, immunohistochemistry, and scanning electron microscopy were utilized to assess neointima formation and endothelialization. The in vivo thrombosis of UPCCVG was analyzed simultaneously to further characterize its blood compatibility.

Results

The uncrosslinked collagen demonstrated high purity, maintaining its triple helix structure and molecular weight akin to the type I bovine collagen standard substrate, indicative of preserved biological activity and low immunogenicity. UPCCVG exhibited water permeability, blood leakage resistance, radial compliance and blood compatibility comparable to commercial grafts. DSA revealed satisfactory patency of UPCCVG without evidence of stenosis or swelling at the 3-week post-implantation mark. Histological analysis illustrated well-developed neointima with appropriate thickness and controlled proliferation. Immunohistochemistry confirmed the presence of endothelial cells (VWF positive) and smooth muscle cells (α-SMA positive) within the neointima, indicating successful endothelialization. Moreover, the morphology of the neointima surface closely resembled that of the natural artery tunica intima, oriented along the direction of blood flow.

Discussion

UPCCVG, composed of uncrosslinked porcine collagen, demonstrates promising potential in fostering neointima formation and endothelialization while mitigating intimal hyperplasia. This biocompatible uncrosslinked porcine collagen merits further investigation for its clinical applications in vascular reconstruction.

Wallenberg Syndrome Secondary to Vertebrobasilar Aneurysm Associated With Subclavian Steal Syndrome

Wallenberg syndrome, also known as lateral medullary syndrome, is a rare condition affecting the vertebrobasilar circulation, causing symptoms such as vertigo, nystagmus, dysarthria, and hemifacial weakness. Typically linked to ischemic strokes, it can also arise from vertebrobasilar aneurysms. In rare cases, subclavian steal syndrome (SSS), involving retrograde flow in the vertebral artery due to subclavian stenosis, complicates the picture, as observed in this case of a 66-year-old woman with both conditions and a vertebrobasilar aneurysm. This study was conducted at the Neurosurgery Department of Centro Médico Nacional 20 de Noviembre, Mexico City. The patient, a 66-year-old woman with hypertension and chronic smoking, presented with vertigo, diplopia, and quadriparesis. Imaging revealed a vertebrobasilar aneurysm and SSS. Despite recommendations for further invasive studies, the patient declined angiography and therapeutic interventions, opting for voluntary discharge without treatment. This case underscores the rare association of Wallenberg syndrome with a vertebrobasilar aneurysm and SSS. Hemodynamic stress from retrograde vertebral artery flow likely contributed to aneurysm formation. Advanced imaging is vital for diagnosis, and while the patient refused treatment, multidisciplinary management, including future innovations such as three-dimensional printing and endovascular techniques, holds promise for improving outcomes in such complex cases.

A Case of Pontine Infarction due to Subclavian Steal Phenomenon Enhanced by an Arteriovenous Shunt for Hemodialysis

We present a case of pontine infarction caused by subclavian steal phenomenon (SSP) due to subclavian artery stenosis (SAS) and an arteriovenous shunt in the forearm in a 74-year-old man with hemodialysis and stenting for SAS with improvement of SSP. He developed dysarthria during dialysis. He was admitted to our hospital and diagnosed with a pontine infarction. As the basilar artery appeared to be occluded on magnetic resonance angiography, an emergency diagnostic angiography was performed. Aortagram showed severe stenosis of the left subclavian artery. Right vertebral artery (VA) angiogram revealed retrograde arterial blood flow from the right VA to the left VA via the VA union, which suggested SSP. In addition, the steal was augmented by an ipsilateral hemodialysis arteriovenous shunt. Percutaneous subclavian artery stenting was performed 12 days later, and there was no recurrence of symptoms in the follow-up period. To our knowledge, this study is the first to report a patient with SSP who developed a pontine infarction due to SAS and an arteriovenous shunt during hemodialysis and who underwent subclavian artery stenting and had a good outcome.

Uncommon Presentation of Recurrent Lung Adenocarcinoma: A Finger Ulcer Induced by Subclavian Artery Invasion Successfully Healed With Viabahn VBX Treatment

Recurrence of a lung tumor invading the subclavian artery, causing stenosis and leading to finger ulcers as the initial symptom, is rare. We employed endovascular techniques, inserting a Viabahn® VBX covered stent (W. L. Gore & Associates, Flagstaff, Arizona) to aid in ulcer healing and improve the patient's quality of life. The patient, a 73-year-old male, had a history of lung adenocarcinoma resection two years prior but had not undergone follow-up examinations or cancer-specific treatments. Clinical examination revealed an invasion of the right subclavian artery by the recurrent tumor, resulting in severe stenosis and ischemic symptoms in the right upper limb. Given the patient's advanced cancer stage and the decline of further tumor-specific treatments, an endovascular intervention using a Viabahn VBX covered stent was performed to improve blood flow and promote ulcer healing. The stent demonstrated exceptional stability and patency during the six-month follow-up, greatly improving the patient's quality of life. This case highlights the importance of recognizing atypical symptoms as potential indicators of tumor recurrence or progression and demonstrates the promising role of covered stents in managing vascular complications in selected patients with advanced-stage malignancies.

Critical Left Subclavian Artery Stenosis With Retrograde Vertebral Flow: A Case Report and Literature Review

Subclavian artery stenosis is a rare condition associated with significant morbidity and mortality, making prompt recognition and treatment essential. We present a case of left-sided subclavian artery occlusion with neurological symptoms, including vertigo, unsteady gait, and left upper extremity pain and paresthesia. The patient's symptoms had been progressing over several months. Her risk factors included age, hyperlipidemia, and poorly controlled blood pressure with resultant arteriosclerosis throughout her vasculature. An arteriogram demonstrated critical stenosis of the left subclavian with retrograde flow through the left vertebral artery. Aspirin and clopidogrel were initiated prior to successful balloon angioplasty and stenting. After stent placement, the patient had minimal residual subclavian stenosis and anterograde vertebral artery flow. In this case report, we discuss clinical presentation, typical examination and imaging findings, and treatment options for subclavian stenosis including medical management and revascularization procedures.

Peripheral Arterial Disease: A Narrative Review

Peripheral arterial disease (PAD) describes the partial or complete occlusion of blood flow in the distal arteries of the body. A decreased arterial patency may occur due to a reduction in the elasticity or diameter of the vessel. The goal of interventions is to decrease incidence and reduce complications by identifying and minimizing the primary causes. This paper discusses PAD affecting the aortoiliac, common femoral, and femoropopliteal arteries. In a significant portion of the population, PAD may lack usual symptoms such as limb pain, claudication, and diminished pulses. Imaging techniques become crucial to ensuring timely diagnosis, monitoring treatment effectiveness, and preventing recurrence. Duplex ultrasound (DUS) is a cheap and non-invasive preliminary technique to detect atherosclerotic plaques and grade arterial stenosis. Magnetic resonance angiography (MRA) provides the added advantage of minimizing artifacts. Digital subtraction angiography (DSA) remains the gold standard for grading the degree of stenosis but is only employed second-line to DUS or MRA due to the high dose of nephrotoxic contrast. Computed tomography angiography (CTA) is able to overcome the anatomical limitations of DUS and MRA and proves to be a suitable alternative to DSA in patients with renal disease. Preventative measures involve monitoring blood pressure, cholesterol levels, and tobacco usage. First-line treatment options include endovascular procedures as well as surgical interventions in cases of significant arterial involvement. Endovascular treatments involve the use of balloon angioplasty, drug-coated balloons, and drug-coated stents, to name a few, that serve as minimally invasive techniques to manage PAD. Surgical procedures, although more complex, are considered gold-standard treatment options for long and intricate lesions. Endovascular methods are generally preferred over surgical options as the complication risk is severely reduced and the rates of reintervention are comparable to surgical options.

Cross-sectional analysis of potential risk factors of the pineal gland calcification

The Pineal gland (PG) is the site of production of melatonin as an important central hormone in the body. It is not known yet whether PG calcification (PGC) is an age-associated physiological process or a pathologic condition caused by lifestyle-factors and metabolic-dysregulations.Here, we performed a cross-sectional analysis on 586 patients referred to have Computed Tomographic (CT) scans (above 15 years old), in the Ali Ebne Abi Taleb hospital radiology center in 2017-2018. Based on the CT-scans of the brain, the presence of PGC was recorded and a score of scale 0 to 6 (PGC_score) was calculated for its intensity based on the volume and the Hounsfield units of the calcified pineal. Logistic and ordered logistic regression tests were employed to determine potential risk factor of PGC and higher PGC_score, respectively, testing the factors age, sex, history of cardiovascular and metabolic diseases, smoking and opioid use. We found male sex (OR: 2.30 (95% CI:1.39-3.82) and smoking cigarettes (OR: 4.47 (95% CI:1.01-19.78)) as the main potential risk factors for the pineal gland calcification. For PGC_score, we found age to be dose-dependently associated with PGC_score only in patients aged below 63 (p-trend < 0.001). Stratifying for age, in patients < 63 years old, we found age, male sex (positive association) and dyslipidemia (negative association) as the main significantly associated factors of PGC_score. On the contrary, in patients aged >  = 63, cigarette smoking was the only significantly associated factor of higher PGC_score.In conclusion, our results indicate that at ages below 63, age, male sex and blood lipid are the main associated factors of higher PGC, but at ages above that, the lifestyle factor smoking is significantly associated with higher pineal gland calcification.

Vertebral Artery Stenosis: A Narrative Review

Vertebral artery stenosis (VAS) is the cause of approximately 20% of ischemic strokes in the posterior circulation. There are several causes of vertebral artery stenosis, including atherosclerosis, calcification, dissections, fibromuscular dysplasia, giant cell arteritis, neurofibromatosis type 1, and bony compressions. The most common cause of VAS is atherosclerosis which is derived from the macrophage-induced oxidation of low-density lipoproteins (LDLs), alongside the accumulation of cholesterol. Calcification of the vertebral artery occurs when there is excess calcium and phosphate deposition in the vessel. Dissection of the vertebral artery can lead to the formation of a hematoma causing stenosis of the vertebral artery. Fibromuscular dysplasia can result in stenosis due to the deposition of collagen fibers in the tunica media, intima, or adventitia. Giant cell arteritis, an autoimmune disorder, causes inflammation of the internal elastic membrane resulting in eventual stenosis of the artery. Neurofibromatosis type 1, an autosomal dominant disorder, results in the stenosis of the vertebral artery due to the altered function of neurofibromin. Mechanical compression of the vertebral artery by bone can also cause stenosis of the vertebral artery. Digital subtraction angiography (DSA) is considered the current gold standard in diagnosing vertebral artery stenosis; however, its associated morbidity and mortality have led to increased use of non-invasive techniques such as duplex ultrasonography (DUS), computed tomography angiography (CTA), and magnetic resonance angiography (MRA). Currently, asymptomatic and symptomatic vertebral artery stenoses are treated by risk factor modification and medical treatment. However, it is recommended that surgical (endarterectomy, reconstruction, and decompression) and endovascular (balloon coronary, bare-metal, and drug-eluting stents) treatments are also used for symptomatic vertebral artery stenosis.

Incidence of steal syndrome following arteriovenous fistula and arteriovenous graft

BACKGROUND

Renal failure is one of the dangerous chronic diseases that different solutions are used for dialysis in these patients. Arteriovenous graft (AVG) and arteriovenous fistula (AVF) are two communication methods for dialysis in these patients, associated with pain, sensory and Pulse disturbances, and even limb necrosis. Using cubital AVF and AVG for hemodialysis is a critical issue in vascular surgery. Arterial steal syndrome is an essential medical condition requiring surgical interventions. In this research project, we decided to measure the incidence of steal syndrome among AVF and AVG patients and compare them with each other.

METHODS

This cohort study was performed in Al-Zahra Hospital, Isfahan, Iran, from 2018 to 2020. Two hundred one patients undergoing AVF or AVG were included, and patients were followed for six months. The frequency of pain symptoms, anesthesia and pulse disorders, necrosis of the limbs, and the frequency of steal syndrome were assessed.

RESULTS

Among the studied patients, 2 cases in the AVF group and 10 cases in the AVG group had steal syndrome, and there was a significant difference between the two groups based on the frequency of steal syndrome (P=0.007). Also, there was a considerable difference between the two groups based on the pulse disorder (P<0.05), but there was no significant difference between the two groups in terms of symptoms of sensory impairment, pain, and evidence of necrosis (P>0.05).

CONCLUSION

AVF technique is better than AVG in creating symptoms of steal syndrome, and also, the number of symptoms such as pulse disorder was relatively less seen in the AVF method.