An Extensive Unprovoked Left Lower Extremity Deep Vein Thrombosis Secondary to an Anatomical Anomaly: A Case of May-Thurner Syndrome

ADAMTS13 inhibits H2O2-induced human venous endothelial cell injury to attenuate deep-vein thrombosis by blocking the p38/ERK signaling pathway

Deep vein thrombosis (DVT) is a common complication in hematologic malignancies and immunologic disorders. Endothelial cell injury and dysfunction comprise the critical contributor for the development of DVT. A disintegrin and metalloproteinase with thrombospondin motifs 13 (ADAMTS13), a plasma metalloprotease that cleaves von Willebrand factor, acts as a critical regulator in normal hemostasis. This study was aimed to explore the role of ADAMTS13 in endothelial cell injury during DVT and the possible mechanism. First, human umbilical vein endothelial cells (HUVECs) were exposed to hydrogen peroxide (H2O2). Then, the mRNA and protein expressions of ADAMTS13 were evaluated with the reverse transcription-quantitative polymerase chain reaction and western blot. After treatment with recombinant ADAMTS13 (rADAMTS13; rA13), the viability and apoptosis of H2O2-induced HUVECs were assessed by cell counting kit-8 assay and terminal-deoxynucleoitidyl transferase-mediated nick end labeling staining. In addition, the levels of prostaglandin F1-alpha, endothelin-1, and reactive oxygen species were detected using the enzyme-linked immunosorbent assay and dichloro-dihydro-fluorescein diacetate assay. The expressions of proteins related to p38/extracellular signal-regulated kinase (ERK) signaling pathway were estimated with the western blot. Then, p79350 (p38 agonist) was used to pretreat cells to analyze the regulatory effects of rA13 on p38/ERK signaling in H2O2-induced HUVEC injury. The results revealed that ADAMTS13 expression was significantly downregulated in H2O2-induced HUVECs. The reduced viability and increased apoptosis of HUVECs induced by H2O2 were revived by ADAMTS13. ADAMTS13 also suppressed the oxidative stress in HUVECs after H2O2 treatment. Besides, ADAMTS13 was found to block p38/ERK signaling pathway, and p79350 reversed the impacts of ADAMTS13 on the damage of HUVECs induced by H2O2. To sum up, ADAMTS13 could alleviate H2O2-induced HUVEC injury through the inhibition of p38/ERK signaling pathway.

Iliofemoral Vein Stenting in a Patient with Pelvic Metastasis

We report a case of an 81-year-old woman with extensive pelvic lymphadenopathy that caused severe stenosis and occlusion of the right common and external iliac veins and proximal common femoral vein. Pelvic lymphadenopathy resulted from the recurrence of a previous right ovarian epithelial tumor. The patient had severe right lower extremity edema, consistent with severe venous insufficiency. She was treated with high-pressure balloon angioplasty (12-14 mm in diameter) and four self-expanding stents (14-10 mm diameter, 80-40 mm length). The postoperative response was dramatic to a near-complete resolution of the edema. The venous clinical severity scores were 10 and 2 at presentation and 6 months after the follow-up, respectively. Balloon angioplasty and stenting are safe and effective methods for providing symptomatic relief for lower extremity venous insufficiency in patients with extensive and unresectable pelvic masses.

Deep Vein Thrombosis Due to Fecal Impaction

BACKGROUND

Deep vein thrombosis (DVT) can occasionally be secondary to mechanical compressions, such as in May-Thurner syndrome. To our knowledge, no cases of DVT associated with mechanical compression by fecal impaction in a pediatric patient have been previously reported.

CASE PRESENTATION

An 18-year-old developmentally delayed female presented to the emergency department with swelling involving her left lower extremity. Cross-sectional imaging revealed a significant stool burden in the rectosigmoid colon compressing the left external iliac vein and causing secondary thrombosis. Thrombectomy successfully alleviated the clot burden.

CONCLUSION

This case underscores the potentially serious implications of severe fecal impaction in the pediatric and adolescent populations.

Lumbosacral exostosis as a rare cause of iliac vein compression and significant limb swelling

A 67-year-old woman presented to our vein clinic for chronic left lower extremity edema, pain, and varicosities. After failed conservative management, a computed tomography scan revealed central venous stenosis secondary to compression of the left common iliac vein by a large osteophyte along the anterolateral aspect of the L5-S1 disk space. An anterior osteophytectomy was performed, followed by iliac venous stenting at a 1-month interval. The patient had resolution of symptoms and remains symptom free at 15 months of follow-up. This report describes a spinal exostosis causing symptomatic venous compression successfully relieved by surgical decompression.

Sudden death due to pulmonary embolism after minor ankle surgery

Venous thromboembolism prophylaxis guidelines are clear for major orthopaedic surgeries, but data regarding ankle surgery are insufficient. Death from pulmonary embolism (PE) after ankle surgery is rare with the frequency of less than 0.037%. ¹ We present a case of a fatal PE after ankle surgery to raise awareness about this rare but potentially fatal complication. Our patient had a left ankle fracture status postsurgical fixation and was discharged without venous thromboembolism (VTE) prophylaxis. Twenty days later, she presented with a sudden onset of dyspnoea and palpitations and was diagnosed to have extensive right-sided PE. Intravenous heparin and thrombolytics were given, but she had multiple pulseless electrical activity arrests, developed disseminated intravascular coagulation and died. Our case depicts an unusual complication of ankle surgery and highlights the importance of considering VTE as one of the complications. Medical personnel should evaluate the need for VTE prophylaxis after ankle surgery on a case to case basis.