Shear stress and pathophysiological PI3K involvement in vascular malformations.

Molecular characterization of vascular anomalies has revealed that affected endothelial cells (ECs) harbor gain-of-function (GOF) mutations in the gene encoding the catalytic α subunit of PI3Kα (PIK3CA). These PIK3CA mutations are known to cause solid cancers when occurring in other tissues. PIK3CA-related vascular anomalies, or "PIKopathies," range from simple, i.e., restricted to a particular form of malformation, to complex, i.e., presenting with a range of hyperplasia phenotypes, including the PIK3CA-related overgrowth spectrum. Interestingly, development of PIKopathies is affected by fluid shear stress (FSS), a physiological stimulus caused by blood or lymph flow. These findings implicate PI3K in mediating physiological EC responses to FSS conditions characteristic of lymphatic and capillary vessel beds. Consistent with this hypothesis, increased PI3K signaling also contributes to cerebral cavernous malformations, a vascular disorder that affects low-perfused brain venous capillaries. Because the GOF activity of PI3K and its signaling partners are excellent drug targets, understanding PIK3CA's role in the development of vascular anomalies may inform therapeutic strategies to normalize EC responses in the diseased state. This Review focuses on PIK3CA's role in mediating EC responses to FSS and discusses current understanding of PIK3CA dysregulation in a range of vascular anomalies that particularly affect low-perfused regions of the vasculature. We also discuss recent surprising findings linking increased PI3K signaling to fast-flow arteriovenous malformations in hereditary hemorrhagic telangiectasias.

Comprehensive Analyses of Coagulation Parameters in Patients with Vascular Anomalies.

BACKGROUND: Vascular anomalies comprise a diverse group of rare diseases with altered blood flow and are often associated with coagulation disorders. The most common example is a localized intravascular coagulopathy in venous malformations leading to elevated D-dimers. In severe cases, this may progress to a disseminated intravascular coagulopathy with subsequent consumption of fibrinogen and thrombocytes predisposing to serious bleeding. A separate coagulopathy is the Kasabach-Merritt phenomenon in kaposiform hemangioendothelioma characterized by platelet trapping leading to thrombocytopenia and eventually consumptive coagulopathy. Our previous work showed impaired von Willebrand factor and platelet aggregometry due to abnormal blood flow, i.e., in ventricular assist devices or extracorporeal membrane oxygenation. With altered blood flow also present in vascular anomalies, we hypothesized that, in particular, the von Willebrand factor parameters and the platelet function may be similarly impacted. METHODS: We prospectively recruited 73 patients with different vascular anomaly entities and analyzed their coagulation parameters. RESULTS: Acquired von Willebrand syndrome was observed in both of our patients with Kasabach-Merritt phenomenon. In six out of nine patients with complex lymphatic anomalies, both the vWF antigen and activity were upregulated. Platelet aggregometry was impaired in both patients with Kasabach-Merritt phenomenon and in seven out of eight patients with an arteriovenous malformation. CONCLUSIONS: The analysis of coagulation parameters in our patients with vascular anomalies advanced our understanding of the underlying pathophysiologies of the observed coagulopathies. This may lead to new treatment options for the, in part, life-threatening bleeding risks in these patients in the future.

Efficacy and safety of oral sirolimus for high-flow vascular malformations in real clinical practice.

BACKGROUND: Vascular malformations are a complex pathology with few treatment options. In previously published studies, oral sirolimus (rapamycin) has shown promising results in the treatment of low-flow vascular malformations, but its usefulness in high-flow vascular malformations is controversial. AIM: To evaluate the efficacy and safety of sirolimus for the treatment of high-flow vascular malformations in real-life practice. METHODS: In a unit specializing in vascular anomalies, patients treated with oral sirolimus for high-flow vascular malformations were located by consulting the drug dispensations. Reviewing the electronic medical records, data on patient demographics, vascular malformation characteristics, treatments, toxicity and clinical course were collected and statistically analysed. RESULTS: Nine patients with vascular malformations were included: eight had arteriovenous malformation and one had arteriovenous fistula. Six of these malformations were isolated while three were part of a syndrome. Sirolimus was initiated at a dosage of 1-4 mg/day to be taken as a single dose. Partial response was observed in eight of the nine patients (88.9%) with high-flow vascular malformation, while worsening was observed in the remaining patient. The treatment was well tolerated and at the most recent follow-up, five patients remained on treatment with oral sirolimus. CONCLUSION: Our results show that oral sirolimus is a well-tolerated therapeutic option, with an excellent safety profile, which can be useful in the long-term stabilization of patients with high-flow vascular malformations. Single-daily dosage may improve long-term adherence to treatment without worsening its effectiveness.

Clinical characteristics associated with pain in patients with peripheral vascular malformations.

OBJECTIVE: Vascular malformations (VM) can negatively impact the patient's quality of life (QoL). Pain is a common problem in these patients. The aim of this study was to investigate risk factors associated with pain and to assess how pain affects QoL. METHODS: This prospective cross-sectional study was conducted in a tertiary vascular anomaly expertise center. Between June and December 2020, all patients from our local database (334 adults and 189 children) with peripheral VMs were invited to complete the Outcome Measures for VAscular MAlformations questionnaire to evaluate the presence, frequency, and intensity of pain. Additionally, patients were asked to complete several Patient-Reported Outcome Measurement Information System scales to evaluate their QoL. Risk factors associated with pain were identified in bivariate analysis and multivariable logistic regression. QoL domains were compared between patients who experienced pain and patients who did not. RESULTS: A total of 164 patients completed the questionnaire about pain and 133 patients completed all QoL questionnaires. Approximately one-half of the patients (52%) reported pain in the past four weeks and 57% of these patients reported pain daily or several times a week. Female sex (P = .009), lesions located in the upper extremity (P < .001) or lower extremity (P < .001), and intramuscular/intraosseous lesions (P = .004) were independently associated with the presence of pain. The following QoL domains were diminished in patients who experienced pain in comparison with patients who did not: pain interference (P < .001), physical functioning (P < .001), and social participation (P < .001) in adults, and pain interference (P = .001), mobility (P = .001), and anxiety (P = .024) in children. CONCLUSIONS: Pain is a frequently reported complaint in patients with VMs and is present in approximately one-half of the patients. Patients with lesions located in the upper or lower extremity, intramuscular/intraosseous lesions, and female patients are more likely to experience pain. The presence of pain negatively impacted patients' QoL. Although VM are a benign condition and expectative management is frequently applied, our study shows that pain is a serious concern and needs to be actively assessed. Pain is a sign of various etiologies and should be examined to properly treat the pain.

Malformação venolinfática em borda lateral de língua: relato de caso / Venolymphatic malformation in lateral edge of the tongue: case report

Resumo As malformações vasculares são anomalias que podem acometer veias, vasos linfáticos e artérias de forma isolada ou mista. Quando se apresentam de forma mista, com componentes venosos e linfáticos, são denominadas malformação venolinfática ou linfático-venosa, de acordo com sua constituição predominante. Embora seja um distúrbio benigno de bom prognóstico, é localmente invasivo, podendo levar a deformidade e havendo, ainda, a propensão de recorrência local. O presente artigo traz um caso de malformação venolinfática com localização incomum em borda lateral de língua, abordando-se a conduta clínica e o referencial teórico vigente.

Abstract Vascular malformations are vascular anomalies that can affect veins, lymphatic vessels, and/or arteries in isolated or mixed form. When they present in the mixed form with venous and lymphatic involvement, they are called venolymphatic or lymphatic-venous malformations, depending on their predominant component. Although these are benign disorders with good prognosis, they are locally invasive and may lead to deformity, while there is also a propensity for local recurrence. This article presents a case of venolymphatic malformation with unusual localization on the lateral border of the tongue, addressing the clinical conduct and the current theoretical framework.

Renal Artery Reconstruction for Refractory Hypertension Caused by Congenital Renal Artery Deficiency.

Renovascular hypertension is a common cause of secondary hypertension. According to the epidemiological survey, the prevalence of renovascular hypertension accounts for 1-5% of the population with hypertension. Most of the cases are associated with atherosclerosis and Fibromuscular Dysplasia (FMD). Owing to the lack of standard treatment, they will eventually develop into chronic kidney disease, which significantly affects the patient's quality of life. Hypertension is considered a prerequisite for renal artery surgery; renal function research is used to guide the treatment of unilateral lesions because endovascular intervention can only slightly improve hypertension and renal function. We advocate open surgery for patients with congenital dysplasia of renal vascular hypertension, in which the most common surgical operations are aortorenal artery bypass, renal artery endarterectomy, and renal artery replantation. This paper reports a rare case of renovascular hypertension. The patient was a 13-year-old female, and the operation was risky and complicated. He was diagnosed with a congenital absence of the right renal artery. The right renal function was recovered, and the blood pressure was well controlled after the Aorta-Right Renal Artery Bypass.

Involvement of Microglia in the Pathophysiology of Intracranial Aneurysms and Vascular Malformations-A Short Overview.

Aneurysms and vascular malformations of the brain represent an important source of intracranial hemorrhage and subsequent mortality and morbidity. We are only beginning to discern the involvement of microglia, the resident immune cell of the central nervous system, in these pathologies and their outcomes. Recent evidence suggests that activated proinflammatory microglia are implicated in the expansion of brain injury following subarachnoid hemorrhage (SAH) in both the acute and chronic phases, being also a main actor in vasospasm, considerably the most severe complication of SAH. On the other hand, anti-inflammatory microglia may be involved in the resolution of cerebral injury and hemorrhage. These immune cells have also been observed in high numbers in brain arteriovenous malformations (bAVM) and cerebral cavernomas (CCM), although their roles in these lesions are currently incompletely ascertained. The following review aims to shed a light on the most significant findings related to microglia and their roles in intracranial aneurysms and vascular malformations, as well as possibly establish the course for future research.

Venous malformations.

The often inexorable growth and expansion of congenital vascular malformations can result in substantial morbidity and, in some cases, premature death of these patients. Despite this, patients suffering from such lesions are often erroneously diagnosed and/or inadequately treated, due to a lack of expertise among primary care practitioners as well as specialists. Venous malformations are the most common type of congenital vascular malformations. Over the last two decades management of these lesions has significantly improved, predominantly due to the introduction and implementation of multidisciplinary team concept as well as improvement in diagnostic and treatment modalities. Relatively recently genetic studies are providing more insights into underlying pathophysiological mechanisms responsible for the development and progression of venous malformations and pharmacotherapy is becoming extensively evaluated for safety and efficacy in the treatment of these often challenging vascular lesions.

Single Center Experience of Sirolimus Therapy in Head and Neck Low-flow Vascular Malformations.

OBJECTIVE: Recently, studies have shown that sirolimus is clinically efficacious in the treatment of some low-flow vascular malformations (LFVM). This study aimed to assess the efficacy and safety of sirolimus in treating complex head and neck (H&N) LFVM that were challenging and/or refractory to standard treatment. METHODS: Each patient had baseline and 6-months assessments consisting of clinical history and examination, quality of life (QoL) questionnaires, laboratory investigations, MRI and medical photography. Patients were followed up 1-week and then 1-monthly for 6-months. Wilcoxon signed-rank test was used to compare pre-and 6-months treatment in all 8 domains of RAND 36-Item Short Form Health Survey (SF-36), hospital anxiety and depression scale (HADS), and visual analog score for pain (VAS-P). P < 0.05 was considered significant. RESULTS: Seven patients (median age 43 years, range 23-65 years) were recruited. Six patients completed the six-months course of therapy with 1 patient withdrawing due to intolerable side effects. All six patients reported reduction of swelling with and without other symptom improvement related to the vascular malformations while on treatment. However, at 1-month review after discontinuation of sirolimus, 5 patients reported return of initial symptoms. Overall, patients demonstrated an improvement in QoL six-months treatment but there was no statistical significance (P > 0.05) in all 8 domains of SF-36, HADS and VAS-P. Five patients demonstrated a minimum 10% decrease in lesion size six-months treatment (median 21%, range 13-40%). A Wilcoxon signed-rank test showed that sirolimus treatment did elicit a statistically significant change in lesion size in either direction (Z = -1.992, P = 0.046). The most common side effects found were dyslipidaemia (n-4) and mouth ulcers (n = 2). CONCLUSION: In our preliminary experience, sirolimus is effective and safe in treating patients with complex H&N LFVM. This provides an alternative treatment where standard treatment is challenging and/or refractory.

Endovascular Treatment of Persistent Sciatic Artery Occlusion: Case Report and Literature Review.

Persistent sciatic artery (PSA) is a rare congenital anatomic variant of the lower limb vascular system with highly variable presentations. The management of lower limb ischemia due to PSA disease is not specifically recommended in guidelines, and surgical by-pass is usually the most described treatment. We reported a case of a 46-year-old patient with bilateral PSA and right chronic limb-threatening ischemia due to PSA occlusion at the PSA-popliteal junction which was successfully treated with percutaneous transluminal balloon angioplasty. In addition to this case report, a systematic review of the literature regarding the endovascular management of PSA stenosis and occlusion was conducted.

Internal Carotid Artery Agenesis in a Trauma Patient with Ipsilateral Neck GSWs.

A 38-year-old man presented to the emergency room in the trauma bay for multiple ballistic injuries to the right neck. He was hemodynamically stable, protecting his airway, and neurologically intact. Computed tomography angiography (CTA) revealed absent filling the right internal carotid artery from its origin to the circle of Willis, which was intact, as well as absent petrous carotid canal on the right. The patient was diagnosed with right internal carotid artery (ICA) agenesis and discharged in several days. This report demonstrates the importance of an in-depth knowledge of vascular embryology and anatomy. The patient has agreed to have images and case details published.

Non-Dolichoectatic Vertebral Artery Compression of the Medulla: A Comprehensive Literature Review.

OBJECTIVE: Vertebral artery compression of the medulla is a rare vascular finding that causes a variety of clinical presentations, from asymptomatic to neurological disability. This article presents the largest literature review to date on medullary compression of the vertebral arteries. METHODS: An English literature search was performed using the PubMed database and the keywords vertebral artery tortuosity, vertebral artery compression, and medullary compression. RESULTS: A comprehensive literature search yielded 68 patients (57% male) with medullary compression by an intracranial vertebral artery (ICVA). The left side of the medulla was compressed in 44, the right side in 19, and bilateral in 7. The most common clinical symptom was weakness - 26 patients (36%) - 6 had quadriparesis and 6 had hemiparesis. 21 patients reported imbalance; 12 various sensory symptoms; 4 patients were asymptomatic. CONCLUSIONS: Understanding the anatomy of the vasculature can help mitigate future debilitating stroke symptoms. Concrete guidelines for revascularization surgery in symptomatic patients may also be effective. Future studies are needed to further clarify the prevalence, natural history, vascular etiology, and treatment of this condition, including asymptomatic patients and the likelihood that they will develop further neurological signs and disability.

Development and Preliminary Validation of the Patient-Reported Outcome Measure for Vascular Malformation Questionnaire: A Prospective Cohort Study.

PURPOSE: To develop and validate the Patient-Reported Outcome Measure for Vascular Malformation (PROVAM) questionnaire to assess the health-related quality of life in patients with vascular malformations. MATERIALS AND METHODS: We developed and validated PROVAM using a mixed methods design during a prospective clinical trial at a vascular anomalies clinic. From July 2019 to February 2020, 108 consecutive patients completed 130 questionnaires. The 30-item instrument assessed the domains of pain, emotional/social well-being, functional impact, and treatment satisfaction. Two additional items assessed ease of understanding and relevance. The primary outcomes of instrument reliability and validity were evaluated across several indices. The secondary outcome of responsiveness evaluated total score changes for patients who completed questionnaires both before and after treatment. RESULTS: Instrument reliability, as measured by Cronbach alpha, was ≥0.79 for pain, emotional/social well-being, and functional impact domains. Primary domain structure was confirmed by factor analysis (P <. 001) and convergent construct validity for all but 1 Likert scale item. In the subgroup analysis of 13 participants who completed PROVAM before and after treatment, instrument responsiveness, as measured by the total score, showed a significant decrease (median, -10 points; interquartile range [IQR], -3 to -16; P = .04). Participants found the questions easy to understand (median, 5 points; IQR, 4-5 on a 5-point scale) and relevant (median score, 4; IQR, 3-5). CONCLUSIONS: Preliminary data support the reliability and validity of PROVAM in measuring the health-related quality of life in patients with vascular malformations.

Surgical Management of Intramuscular Venous Malformations.

BACKGROUND: Intramuscular venous malformations, often erroneously called "intramuscular hemangiomas," present to pediatric orthopaedic surgeons either as a differential diagnosis of tumor or as a cause of muscle pain. Treatment options include injection sclerotherapy or surgery. There is some literature to indicate that sclerotherapy can reduce pain, but little evidence on the effectiveness of surgery. The primary aim of this study was to evaluate the efficacy of surgical resection for intramuscular venous malformations, with a secondary aim to evaluate the natural history and presentation of intramuscular venous malformations to improve clinician understanding of this condition. METHODS: A retrospective chart analysis was performed of cases identified from a vascular anomalies database from January 2004 and December 2018. Primary outcome was change in preoperative and postoperative pain. Natural history of the lesion was assessed, including age when the lesion was first noticed, when it became painful, and when it required treatment. RESULTS: Fifty-four cases were identified in the study period of which 40 underwent surgery. Pain improved in 36 of 39 patients (92.3%) who had pain before surgery and 29 (74.4%) were pain free after surgery. All 13 patients who required whole muscle excision to resect the lesion experienced an improvement in pain and 10 (76.9%) were pain free. A history of previous intervention, with surgery or sclerotherapy showed a trend towards less successful surgical outcomes. Patients presented across a wide age range from infancy to adulthood, but the most common presentation was pain with exercise between 9 and 16 years of age, with presence of a mass in about half of cases. CONCLUSIONS: Surgery, when performed by a surgeon with appropriate experience, is an effective first-line treatment for painful intramuscular venous malformations, offering pain relief in the majority of cases. Magnetic resonance imaging and ultrasound are diagnostic in most cases. The majority of lesions are resectable, meaning they can be removed with a margin leaving a functional limb. Sometimes resection of a whole muscle is required. LEVEL OF EVIDENCE: Level IV-case series.

Surgical ligation of a portosystemic shunt for the treatment of type II Abernethy malformation in 12 children.

OBJECTIVE: This study aimed to investigate the feasibility and effectiveness of surgical ligation in the treatment of a congenital extrahepatic portosystemic shunt (Abernethy malformation) in children. METHODS: Twelve children (aged 10 days to 13.3 years; six boys and six girls) with Abernethy malformation were admitted to the Capital Institute of Pediatrics (Beijing, China) from May 2014 to November 2019 owing to hyperammonemia. Among them, nine suffered from hematochezia, two had elevated liver transaminase levels or jaundice, and one had hypoxemia. Their surgical procedures and outcomes were retrospectively analyzed. Portal pressure measurement and angiography of the portal vein were performed before and after the occlusion of the portosystemic shunt during the surgery. Six patients underwent a single-stage ligation of the portosystemic shunt, five underwent a two-stage ligation of the portosystemic shunt, and one was treated with a partial ligation of the portosystemic shunt. RESULTS: Each of the operations was successfully completed with an operative time ranging from 60 to 240 minutes and with an intraoperative blood loss ranging from 50 to 200 mL. Three children had a blood transfusion. The postoperative portal pressure was significantly higher than that before the surgery in all children. The patients were followed for 5 to 70 months. The symptoms of hematochezia were relieved in nine patients after the surgery. The levels of blood bilirubin and transaminase returned to normal after the surgery in two patients. The oxygen saturation returned to normal in one patient. The level of blood ammonia was normal after the surgery in all patients. CONCLUSIONS: The surgical ligation of the portosystemic shunt was an effective method to treat a type II Abernethy malformation. According to the portal pressure after the occlusion of the portosystemic shunt, a single or staged procedure was selected.