Expression of Cathepsins B, D, and G in Extracranial Arterio-Venous Malformation

Objectives: We have previously identified a population of cells that expressed stemness-associated markers in extracranial arterio-venous malformation (AVM) and demonstrated expression of cathepsins B, D, and G on embryonic stem cell (ESC)-like populations in other vascular anomalies. This study investigated the expression of cathepsins B, D, and G, and their localization in relation to this primitive population in extracranial AVM.

Methods: Immunohistochemical staining was performed on AVM tissue samples from 13 patients to demonstrate expression of cathepsins B, D, and G. Western blotting was performed on four AVM tissue samples and three AVM-derived primary cell lines to confirm protein expression of cathepsins B and D proteins. RT-qPCR was performed on three AVM-derived primary cell lines to demonstrate transcript expression of cathepsins B, D, and G. Enzymatic activity assays were performed on three AVM-derived primary cell lines to investigate if cathepsins B and D were active. Localization of the cathepsins was investigated using immunofluorescence dual-staining of the cathepsins with the ESC markers OCT4 and SOX2, and mast cells marker chymase on two of the 13 AVM tissue samples.

Results: Immunohistochemical staining demonstrated expression of cathepsins B, D, and G in all 13 AVM tissue samples. Western blotting showed expression of cathepsins B and D proteins in all four AVM tissue samples and all three AVM-derived primary cell lines. RT-qPCR demonstrated transcripts of cathepsins B, D, and G in all three AVM-derived primary cell lines. Enzymatic activity assays showed that cathepsins B and D were active. Immunofluorescence staining showed expression of cathepsins B and D on the OCT4+/SOX2+ endothelium and media of the lesional vessels and cells within the stroma in AVM nidus. Cathepsin G was expressed on the chymase+ phenotypic mast cells.

Conclusions: This study demonstrated the novel finding of the expression of cathepsins B, D, and G in AVM. Cathepsins B and D were expressed by the primitive population, and cathepsin G was localized to mast cells, within the AVM nidus.

Current concepts and perspectives on brain arteriovenous malformations: A review of pathogenesis and multidisciplinary treatment

Brain arteriovenous malformations (bAVMs) are unusual vascular pathologies characterized by the abnormal aggregation of dilated arteries and veins in the brain parenchyma and for which the absence of a normal vascular structure and capillary bed leads to direct connections between arteries and veins. Although bAVMs have long been believed to be congenital anomalies that develop during the prenatal period, current studies show that inflammation is associated with AVM genesis, growth, and rupture. Interventional treatment options include microsurgery, stereotactic radiosurgery, and endovascular embolization, and management often comprises a multidisciplinary combination of these modalities. The appropriate selection of patients with brain arteriovenous malformations for interventional treatment requires balancing the risk of treatment complications against the risk of hemorrhaging during the natural course of the pathology; however, no definitive guidelines have been established for the management of brain arteriovenous malformations. In this paper, we comprehensively review the current basic and clinical studies on bAVMs and discuss the contemporary status of multidisciplinary management of bAVMs.

Arteriovenous Malformation of the Lip: A Rare Case Report

Vascular malformation (VM) consists of a group of tumors that emerge from vascular origin caused by vascular angiovascular or lymphoproliferation. Arteriovenous malformations (AVMs) contribute high-flow, creating direct vein artery contact without regular capillary network. AVMs are present at birth or in congenital. Acquired AVMs occur later in life due to hormonal changes or trauma, and acquired AVMs in oral cavity are very rare. AVMs are persistent and progressive in nature when present, can represent a lethal, causing significant blood loss, and an incomplete resection frequently leads to a recurrence of the lesion. We present a rare case of a congenital AVM diagnosed on retinue dental checkup using color doppler ultrasonography (USG) in a 62-year-old man from South India.

Mutations in Chromatin Modifier and Ephrin Signaling Genes in Vein of Galen Malformation

Normal vascular development includes the formation and specification of arteries, veins, and intervening capillaries. Vein of Galen malformations (VOGMs) are among the most common and severe neonatal brain arterio-venous malformations, shunting arterial blood into the brain's deep venous system through aberrant direct connections. Exome sequencing of 55 VOGM probands, including 52 parent-offspring trios, revealed enrichment of rare damaging de novo mutations in chromatin modifier genes that play essential roles in brain and vascular development. Other VOGM probands harbored rare inherited damaging mutations in Ephrin signaling genes, including a genome-wide significant mutation burden in EPHB4. Inherited mutations showed incomplete penetrance and variable expressivity, with mutation carriers often exhibiting cutaneous vascular abnormalities, suggesting a two-hit mechanism. The identified mutations collectively account for ∼30% of studied VOGM cases. These findings provide insight into disease biology and may have clinical implications for risk assessment.

Focal visual status epilepticus

Epileptic visual auras are elementary to complex and sometimes occur as colourful visual phenomena located close to or within the central part of the contralateral hemi-field. They typically last from seconds to a few minutes, which discriminates them from the usually longer-lasting visual auras (5-30 minutes) of patients suffering from migraine. We present an adult patient with occipital lobe epilepsy whose visual aura under epilepsy monitoring lasted for more than 30 minutes with almost no propagation, demonstrating a rare, but remarkable, sustained local epileptic network activity associated with resection of an occipital arterio-venous malformation.

Anesthesia management of a patient with a femoral neck fracture and hered-itary hemorrhagic telangiectasia

BACKGROUND

The hereditary hemorrhagic telangiectasia (HHT) or Osler-Weber-Rendu syndrome is an autosomal dominant genetic disorder affecting the small blood vessels due to mutations in specific genes that lead to angiogenesis errors. HHT represents a clinical entity with great clinical interest as severe, unpredicted, and life-threatening bleeding, sepsis, ischemia, and hemodynamic failure might occur. Literature regarding anesthesia and perioperative management of such patients is limited, with no published papers for orthopedic surgery in patients with HHT.

CASE REPORT

An 82-year-old HHT female patient with femoral neck fracture was scheduled for hemiarthroplasty. Computerized tomography scan revealed an arteriovenous malformation (AVM) in the right lung. The nature of surgery in association with AVM presence suggested the use of regional anesthesia (RA) as the optimal choice. Midazolam (2 mg) was administered as premedication. Perioperatively, Levobupivacaine hydrochloride (15 mg) was administered in the subarachnoid space, at the L4-L5 lumbar intervertebral space, using a 29 Gauge needle. The patient was in lateral position with close monitoring of her blood pressure, electrocardiogram, oxygen saturation, and urine output. Two units of blood were transfused perioperatively. Her recovery was uneventful and she was discharged after ten days.

CONCLUSION

Patients with HHT require careful preoperative evaluation to identify and appreciate possible symptoms as well as to assess their pulmonary and cardiac function accurately. Meticulous preoperative planning is required to minimize perioperative risks and additionally close perioperative monitoring is essential. RA was preferred to general anesthesia as positive pressure ventilation could lead to hypoxia, AVM rupture, embolism, and hemodynamic collapse, while RA offers absence of respiratory stress, excellent muscle relaxation, and decreases blood loss, lowers probability of venal thrombosis and pulmonary embolism, and assists to better perioperative management of analgesia, thus contributing to positive outcome of surgery. Hippokratia 2016, 20(4): 303-305.

Cerebral vascular malformations: Time-resolved CT angiography compared to DSA

PURPOSE

The purpose of this article is to prospectively test the hypothesis that time-resolved CT angiography (TRCTA) on a Toshiba 320-slice CT scanner enables the same characterization of cerebral vascular malformation (CVM) including arteriovenous malformation (AVM), dural arteriovenous fistula (DAVF), pial arteriovenous fistula (PAVF) and developmental venous anomaly (DVA) compared to digital subtraction angiography (DSA).

MATERIALS AND METHODS

Eighteen (eight males, 10 females) consecutive patients (11 AVM, four DAVF, one PAVF, and two DVA) underwent 19 TRCTA (Aquillion one, Toshiba) for suspected CVM diagnosed on routine CT or MRI. One patient with a dural AVF underwent TRCTA and DSA twice before and after treatment. Of the 18 patients, 13 were followed with DSA (Artis, Siemens) within two months of TRCTA. Twenty-three sequential volume acquisitions of the whole head were acquired after injection of 50 ml contrast at the rate of 4 ml/sec. Two patients with DVA did not undergo DSA. Two TRCTA were not assessed because of technical problems.TRCTAs were independently reviewed by two neuroradiologists and DSA by two other neuroradiologists and graded according to the Spetzler-Martin classification, Borden classification, overall diagnostic quality, and level of confidence. Weighted kappa coefficients (k) were calculated to compare reader's assessment of DSA vs TRCTA.

RESULTS

There was excellent (k = 0.83 and 1) to good (k = 0.56, 0.61, 0.65 and 0.67) agreement between the different possible pairs of neuroradiologists for the assessment of vascular malformations.

CONCLUSION

TRCTA may be a sufficient noninvasive substitute for conventional DSA in certain clinical situations.

Periodontal manifestations and management of a patient with AV malformation

Arterio-venous malformation (AVM) is an abnormal communication between an artery and a vein. The incidence of its occurrence in oral and maxillofacial region is rare, and if present, the most common sign is gingival bleeding. A 12-year-old female patient presented with an extra oral swelling in relation with upper lip. Intra oral examination showed non tender gingival swelling with spontaneous bleeding associated with maxillary arch. On initiation of phase I therapy using hand instruments, spontaneous brisk bleeding was encountered which was difficult to control. Because of severe nature of hemorrhage encountered, some type of vascular abnormality was suspected. Ultrasonography followed by angiography confirmed AVM in relation with upper lip. Embolization of lesion was followed by gingivectomy procedure and no recurrence was reported during one year of follow-up. Thus, proper recognition and therapeutic intervention is essential to avoid serious complications and potentially tragic outcome in such situations.

Rehabilitation following surgery for reconstruction of a foot defect

Background

This report illustrates the use of pressure for scar management to aid in foot re-shaping following a surgical intervention to repair an arterio-venous (AV) malformation.

Methods

This report describes the rehabilitation of a 13-year-old girl after surgical reconstruction of a defect in her left foot following the removal of an AV malformation. Early surgical attempts to repair the problem resulted in complications that required the amputation of toes 2, 3, and 4, and the use of a split thickness skin graft to cover the plantar surface of the medial longitudinal arch on the left foot. Following surgery, the patient had an antalgic gait pattern with decreased weight bearing on the left. The graft obliterated the left medial longitudinal arch and the patient would only weight bear on the heel. The patient had decreased metatarsal joint mobility on the affected side and no movement in the remaining toes. Left talocrural joint active range-of-motion (AROM) was within normal limits and gross ankle muscle force production was assessed to have a grade of 3/5.

Results

Treatment included reshaping the left foot using a pressure garment and orthotic, followed by interventions to address range-of-motion and muscle force production deficiencies. All treatment objectives were achieved and all patient goals were achieved.

Conclusions

Pressure was effective in re-shaping the foot to promote normal gait mechanics.