Significant venous flow alterations following brain arteriovenous malformation Surgery: Assessment by transcranial colour duplex.

Brain arteriovenous malformation (bAVM) resection imposes several post-operative clinical challenges including intracranial haemorrhage (ICH). Daily non-invasive monitoring of haemodynamic measurements may be useful in predicting post-operative ICH. This prospective study used transcranial colour duplex (TCCD) and central aortic pressure (CAP) measurements to evaluate 15 bAVM patients pre-operatively and daily ≤ 14 days post-operatively. TCCD measurements of middle cerebral artery and veins included peak systolic (PSV), end diastolic (EDV), and pulsatility indices (PI). Parameters were compared with 7 craniotomy patients (non-bAVM craniotomy/surgical group). Normal reference values included 20 healthy volunteers. Significant middle cerebral vein MCV changes in bAVM patients occurred; Maximal PSV was significantly higher (median 47 cm/s) compared to non-bAVM craniotomy/surgical controls (median 17 cm/s, p = 0.0123); maximal PI was significantly higher (median 0.99, p = 0.005) compared to the non-bAVM craniotomy/surgical controls (median 0.49). In 8 of 15 patients, increased MCV velocity and pulsatility "stabilised" within 14 days post-operatively. Mean number of days for the 8 patients to reach stable state was 5.9 days, (range 0-9 days). To our knowledge, this is the first imaging study demonstrating significant venous changes post bAVM resection. Significant increased venous flow occurs in pial veins bilaterally. Increased pressure of venous flow is evidenced by a significant increase in diameter and pulsatility. Subsequently, haemorrhagic complications may be due distal constriction of the pial veins causing venous hypertension. The cause of the dilated vascular bed is unknown.

Correction: Obstructive Hydrocephalus Due to Unruptured Brain Arteriovenous Malformation: Demonstrating Transcranial Color Duplex Confirmation of Cerebral Venous Hemodynamic Alterations and Color Duplex Ultrasound Confirmation of Shunt Patency.

[This corrects the article DOI: 10.7759/cureus.6181.].

Obstructive Hydrocephalus Due to Unruptured Brain Arteriovenous Malformation: Demonstrating Transcranial Color Duplex Confirmation of Cerebral Venous Hemodynamic Alterations and Color Duplex Ultrasound Confirmation of Shunt Patency.

Given the rarity of arteriovenous malformations of the brain (bAVMs) with concomitant obstructive hydrocephalus, few papers have commented on the resultant hydrodynamic perturbations. To date, no study has specifically investigated the effect of ventricular shunting on intracranial venous parameters as measured by transcranial color duplex ultrasound (TCCD). This study investigates whether TCCD and color duplex ultrasound are useful modalities to elucidate the physiological and hemodynamic changes in a patient with bAVM following ventricular shunting. Using TCCD, this study demonstrates that preoperatively, there is a decrease in cerebral capacitance, manifesting in a decrease in cerebral inflow and reduced venous outflow. Following shunt insertion, intracranial compliance is increased, resulting in the dilatation of previously compressed capacitance vessels and restoration of venous compliance. Color duplex ultrasound (CDU) was a useful determinant of shunt patency in the neck. We report the first TCCD assessment of hemodynamic changes of the intracranial circulation in a patient with bAVM following ventricular-peritoneal shunting. The results lend conceptual support of a pressure gradient change with high pressure that occurs in the veins as compared to the subarachnoid space.

Improving the quality of the evidence - The necessity to lead by example.

Published systematic reviews and meta-analyses should comply with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, or PRISMA checklist. Variable reporting of systematic reviews has recently led to a number of publications demonstrating a lack of compliance with PRISMA. Poor reporting compliance can lower researchers' and clinicians' ability to detect bias in published research and can also lead to impaired clinical decision-making. The authors of this paper support the need for greater adherence to PRISMA standards when preparing systematic reviews and meta-analyses for publication and call on researchers who are drawing attention to this problem to lead by example.

Ascertaining the Value of Noninvasive Measures Obtained Using Color Duplex Ultrasound and Central Aortic Pressure Monitoring During the Management of Cerebral Arteriovenous Malformation Resection: Protocol for a Prospective, Case Control Pilot Study.

BACKGROUND: Dramatic hemodynamic changes occur upon removal of an arteriovenous malformation of the brain (bAVM) with a number of potentially serious perioperative complications, such as intracranial hemorrhage and venous occlusive hypertensive syndrome. As these complications largely occur in the postoperative inpatient period, a rapid, repeatable noninvasive investigation to serially monitor relevant intracranial hemodynamics may be of benefit. Though, transcranial Doppler (TCD) and transcranial color duplex (TCCD) are techniques used and available to provide hemodynamic measurements postoperatively, the time course of hemodynamic sequences following bAVM resection remains uncertain. OBJECTIVE: This is a prospective, case control pilot study conducted in participants having elective bAVM resection surgery. METHODS: Each participant will undergo a preoperative color duplex ultrasound (CDU) of the bilateral extracranial carotid arteries, a CDU of the circle of Willis including the bAVM vessels, and a central aortic pressure measurement, repeated daily, postoperatively, for a 2-week period. RESULTS: Patient accrual has commenced with anticipation of first results in 2018. CONCLUSIONS: This protocol aims to strengthen the work of previous authors by providing documentation of the time course of hemodynamic changes following bAVM resection. The protocol is designed to determine whether noninvasive technology, including CDU imaging of the extracranial carotid and intracranial arteries in the form of TCCD along with central aortic pressure measurements, can determine whether there are any hemodynamically significant prognostic markers that may provide insight into the process of vessel remodeling, including insight into venous changes following bAVM resection.

Cerebral hemodynamics and the role of transcranial Doppler applications in the assessment and management of cerebral arteriovenous malformations.

Dramatic hemodynamic changes occur following resection of brain arteriovenous malformations (AVM). Transcranial Doppler (TCD) records non-invasive velocity and pulsatility parameters. We undertook a systematic review to assess AVM hemodynamics including the time course of changes in velocity and pulsatility in patients undergoing AVM resection. The review employed the Embase and Medline databases. A search strategy was designed. An initial title search for clinical series on AVM and TCD was performed followed by a search for reports on AVM and TCD. A total of 283 publications were selected. Full text analysis produced 54 studies with extractable data regarding AVM, velocity and pulsatility. Two TCD techniques were utilized: conventional "blind" TCD (blind TCD); and transcranial color duplex Doppler (TCCD). Of these, 23 publications reported on blind TCD and seven on TCCD. The presence of high velocity and low pulsatility within AVM feeding arteries preoperatively followed by a postoperative decrease in velocity and subsequent increase in pulsatility of feeding arteries is established. The time sequence of hemodynamic changes following AVM resection using TCD remains uncertain, confounded by variations in methodology and timing of perioperative measurements. Of the two techniques, TCCD reported qualitative aspects including improved differentiation of feeding arteries from draining veins. However, there are a limited number of studies supporting this conclusion. Furthermore, none report reproducible changes with time from treatment. TCCD appears to be a useful technique to analyze the hemodynamic changes occurring following treatment of AVM, however little data is available. This is a field of research that is appropriate to pursue.

Buerger's disease (thromboangiitis obliterans): clinical features and assessment by colour duplex ultrasound.

Buerger's disease is a progressive, nonatherosclerotic, segmental inflammatory vasoocclusive disease of unknown aetiology1-9, affecting the small and medium sized arteries, veins and nerves and is often bilateral5-7. The normal structure of the vessel wall is usually preserved, including the internal elastic lamina and media. Buerger's disease predominantly affects male cigarette smokers1-3,8 with 11%-23% of disease distribution in females6-7. Buerger's disease remains largely a clinicopathologic entity highlighting the importance of the sonographer's role to obtain a comprehensive clinical history and clinical examination. The combination of clinical assessment and the distinctive appearance of vessels affected by Bueger's disease on colour duplex ultrasound provide a useful tool for correct diagnosis.