arteriovenous shunting
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2021 ◽  
Vol 14 (12) ◽  
pp. e246758
Author(s):  
Evan M Luther ◽  
Fatima Chagani ◽  
Hunter King ◽  
Robert Starke

Acquired unruptured dural arteriovenous fistulas (DAVFs) have been described; however, ruptured de novo DAVFs remain exceedingly rare. We describe the case of a man in his 40s who presented with a recurrent intraparenchymal haemorrhage several years after angiographic cure of an intracranial arteriovenous malformation (AVM). Repeat angiography identified a new Cognard type IV DAVF anterior to the prior craniotomy. He underwent preoperative embolisation followed by craniotomy to completely obliterate the fistulous point. This case illustrates the need for close monitoring of AVM patients, even after complete obliteration, as local recrudescence of arteriovenous shunting can occur even in adulthood.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 121-121
Author(s):  
Liza Afzali-Hashemi ◽  
Lena Vaclavu ◽  
John C Wood ◽  
Aart J Nederveen ◽  
Henk J.M.M. Mutsaerts ◽  
...  

Abstract Introduction Silent cerebral infarcts (SCI) are common in patients with sickle cell disease (SCD) and thought to be caused by a mismatch between oxygen delivery and consumption. The mechanism underlying insufficient oxygen utilization is related to severity of anemia, and paradoxically, to the elevated cerebral blood flow (CBF) observed in SCD patients. CBF is elevated as a compensatory mechanism to maintain oxygen delivery, but high CBF levels can result in rapid transit of blood through the brain capillaries, limiting offloading of oxygen to the tissue; a process called arteriovenous shunting. One way to assess functional arteriovenous shunting is to use noncontrast perfusion MRI techniques in which we can assess the signal intensity of an endogenous blood tracer when it reaches the sagittal sinus. This venous signal (VS) reflects the amount of labeled blood that has not exchanged with the brain parenchyma. Under normal physiological conditions, the VS intensity will increase approximately proportionally with CBF as we expect only some of the water to exchange with tissue as it flows by. However, it is unknown whether functional shunting scales with CBF only, or whether other hemodynamic processes play a role in patients with SCD. We hypothesize that, under pathophysiological conditions such as in SCD patients, more labeled blood may pass unexchanged through the capillaries, which results in higher VS. In the present study, we investigated functional shunting by quantifying VS and assessed its association with hemodynamic, demographic and laboratory parameters in both pediatric and adult SCD patients, and controls. In addition, VS-CBF relationship was studied by further increasing CBF after a vasodilatory challenge. Methods We included 28 children (mean age 12.7 ± 2.3, 9 F) and 38 adults (mean age 32.1 ± 11.2, 14 F) with SCD (HbSS and HbS), and 10 healthy race-matched adult controls (mean age 36.4 ± 15.9, 4 F). For the CBF and VS measurements, pseudo-continuous arterial spin labelling (pCASL) data were acquired using 3T MRI. We segmented the ASL blood pool in the sagittal sinus to determine a common region of interest for each group. We used these images as masks to calculate average VS. Notably, for the comparison between children and adults the ratio between VS to gray matter CBF was used (VGR) instead of the VS, to take into account higher CBF in children. To get more insight into the oxygen utilization, oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO 2) were calculated. In adult participants acetazolamide (ACZ) was used as a vasodilatory challenge. The hematologic laboratory parameters hemoglobin (Hb) and LDH were used as markers of anemia and hemolysis, respectively. Results VS as a marker of cerebral shunting was higher in both adult and pediatric patients with SCD as compared to controls (p<0.01) and increased after ACZ administration in all groups (p<0.01) (Fig. 1A). VS was significantly associated with CBF both before (R 2=0.59, p<0.001) and after ACZ administration (R 2=0.57, p<0.001) in all groups (Fig. 1B). To test the impact of demographics and hematological parameters on the presence of shunting, VS was corrected for CBF (VS CBF) and the residuals were used in multiple linear regression analysis against age, sex, blood flow velocity in the brain feeding arteries, participant groups, hydroxyurea, Hb and LDH. Cerebral shunting, reflected by VS CBF showed significant association with Hb (Fig. 1C). In addition, we added OEF, CMRO 2 and ACZ condition as additional parameters in adults and used a linear mixed model to accommodate the repeated measures dependencies. A negative association between the level of cerebral shunting (VS CBF) and CMRO 2 was found (β=-0.79, p<0.001) in all groups (Fig. 1C), and in adult patients with SCD, CMRO 2, Hb (β=-14.2 p<0.001) and LDH (β=0.13, p=0.002) were significant predictors of VS CBF. Conclusion Our results show that the VS in the sagittal sinus on ASL images can be used to assess functional arteriovenous shunting in the brain. Given its negative association with CMRO 2 in combination with the negative association with hemoglobin and positive correlation with LDH, this functional shunting seems to reflect pathophysiologic shunting related to higher disease severity. Future studies will focus on the relation between functional shunting and the prevalence of SCI, investigating its link to aberrant capillary oxygen exchange in SCD. Figure 1 Figure 1. Disclosures Vaclavu: Philips Healthcare: Research Funding. Biemond: GBT: Honoraria, Research Funding, Speakers Bureau; Novo Nordisk: Honoraria; Novartis: Honoraria, Research Funding, Speakers Bureau; Celgene: Honoraria; Sanquin: Research Funding.


Author(s):  
M Ashour ◽  
O Fortin ◽  
G Sébire ◽  
C Saint-Martin ◽  
C Poulin ◽  
...  

Background: Hirayama Disease (HD) is a rare disorder consisting of insidious onset of unilateral weakness and atrophy of the forearm and intrinsic hand muscles. Vein of Galen aneurysmal malformations (VGAMs) are rare congenital cerebral vascular malformations, consisting of high-flow arteriovenous shunting between a persistent median prosencephalic vein and arterial feeders. Methods: 14 years old boy known for VGAM presented with left-sided HD. His cervical MRI revealed enlarged epidural with anterior, left-ward displacement of the posterior dura and spinal cord. He underwent surgical treatment by laminotomies, along with tenting of an autologous duroplasty to the overlying laminae. Results: We decided to combine epidural venous plexus coagulation with posterior duraplasty and dural fixation using tenting suture which led to a favorable clinical outcome has not been previously proposed in the literature. We hypothesize that in this context, an abnormal vasculature could also predispose to posterior epidural venous plexus engorgement, anterior dural displacement in cervical flexion, and microvascular changes in the anterior spinal arterial circulation, leading to the progressive anterior horn cell ischemia that lead to the clinical phenotype of HD. Conclusions: The association between HD and VGAM in this patient may provide clues with regard to the pathophysiology of HD.


Author(s):  
Yuta Sudo ◽  
Hiroshi Inagaki

Abstract Background Primary plasma cell leukaemia is rarely associated with high-output heart failure, and the underlying mechanism is not well understood. We encountered a rare case of high-output heart failure caused by primary plasma cell leukaemia. Its underlying mechanism was clarified through imaging studies. Case Summary A 49-year-old man with no specific medical history was admitted to our hospital because of heart failure that did not improve with diuretic therapy. His condition was diagnosed as high-output heart failure and primary plasma cell leukaemia after admission. Extensive bone involvement in primary plasma cell leukaemia and arteriovenous shunts in the same lesion were suspected after various imaging studies. The first cycle of chemotherapy with bortezomib, adriamycin, and dexamethasone led to remission of primary plasma cell leukaemia and improved heart failure symptoms. The patient received further chemotherapy in addition to autologous peripheral blood stem cell transplantation and maintenance therapy and had no recurrence of pPCL or heart failure for 1 year to date. Discussion : Primary plasma cell leukaemia can be associated with high-output heart failure, which is caused by arteriovenous shunting at the lesion site with diffuse bone involvement. Imaging studies may lead to the early diagnosis of aetiology and treatment of patients with high-output heart failure associated with primary plasma cell leukaemia.


2021 ◽  
pp. 197140092110428
Author(s):  
Nimisha Parikh ◽  
Richard Williamson ◽  
Matthew Kulzer ◽  
Albert Sohn ◽  
Warren M Chang ◽  
...  

Cavernous malformations are angiographically occult vascular malformations. They are often associated with a developmental venous anomaly through poorly understood mechanisms. We present an unusual case of a gradually enlarging cavernous malformation associated with a developmental venous anomaly with arteriovenous shunting, suggesting venous hypertension or reflux as a potential cause of progressive growth.


2021 ◽  
Vol 10 (27) ◽  
pp. 2042-2043
Author(s):  
Debasish Das ◽  
Debasis Acharya ◽  
Jogendra Singh ◽  
Subhas Pramanik

Transradial intervention usually does not mandate history of arm or forearm injury; we report a case of traumatic AV fistula with focal narrowing of brachial artery for which right transradial angiogram could not be performed and coronary angiogram was accomplished from left transradial access. This rare case teaches us the fact that planning a transradial intervention also requires a history of trauma or surgical intervention to arm or forearm to avoid inadvertent complications during transradial access. Communication between an artery and a vein is known as arteriovenous fistula (AVF) which may be congenital, acquired or surgically created. Acquired arteriovenous fistula is most commonly due to traumatic injury. Following vascular injury, a hematoma develops locally, local healing and fibrosis leads to adhesion between artery and vein creating an arteriovenous fistula.1 Large arteriovenous fistula results in high output cardiac failure and rarely accounts for chronic ischaemia.2 Degree of arteriovenous shunting decides the timeframe of clinical presentation which is often subtle with delay in diagnosis. We report a case of post traumatic brachial AV fistula presenting with feeble pulse, difficult radial puncture and right transradial access failure with switch over to right transfemoral access for accomplishing coronary intervention.


Author(s):  
Roberto R. Rubio ◽  
Ricky Chae ◽  
Todd Dubnicoff ◽  
Ethan Winkler ◽  
Adib A. Abla

Abstract Objectives Dural arteriovenous fistulas (DAVFs) at the cervicomedullary junction are uncommon and often accompanied by subarachnoid hemorrhage (SAH). We aim to illustrate in detail the microsurgical procedure for treating a DAVF located at the cervicomedullary junction. Design We present a two-dimensional operative video that includes clinical history, preoperative imaging, surgical strategy, still images with labels, clinical course, and postoperative imaging. Setting The microsurgery was performed at an academic medical center. Participant The patient is a 55-year-old female who presented with SAH, acute onset headache, nausea, and vomiting. Angiography demonstrated right vertebral artery vasospasm and a persistent arteriovenous shunt at the cervicomedullary junction supplied by small perforating arteries of the right vertebrobasilar junction (Fig. 1). Main Outcome Measures The patient was placed in the park-bench position with the head turned to the contralateral side. A hockey stick incision was made, followed by a right-side far-lateral transcondylar approach. Indocynanine green videoangiography was performed to help identify the areas of arteriovenous shunting. Multiple clips were placed to interrupt vessels that corresponded to arterial feeders at the level of the C1 and C2 nerve root sleeves (Fig. 2). The dura was closed in a water tight fashion and the posterior fossa was reconstructed with a titanium mesh. Results Postoperative imaging showed no evidence of continued arteriovenous shunting. The patient was discharged in good clinical condition with an uneventful postoperative course. Conclusion A deep understanding of the microsurgical vascular anatomy is necessary for successful occlusion of a cervicomedullary DAVF.The link to the video can be found at: https://youtu.be/-LfOcNB05BY.


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