A mechanism of banding failure in excessively dilated fistulas

2018 ◽  
Vol 19 (1) ◽  
pp. 98-100 ◽  
Author(s):  
Alexandros Mallios ◽  
John Lucas ◽  
William Jennings
Keyword(s):  
Vessel Wall ◽  
Case Series ◽  
Successful Operation ◽  
Flow Reduction ◽  
Polypropylene Suture ◽  
Arteriovenous Fistulas ◽  
Flow Restriction ◽  
Second Procedure ◽  
Band Failure ◽  
Diameter Reduction

Introduction: We present an unreported cause of banding failure for flow restriction in dramatically enlarged arteriovenous fistulas (AVFs). Case series: Four patients operated in different institutions by two different surgeons experienced band failure within 6 months of the initially successful operation for AVF flow restriction. Prior to the initial banding procedure, each patient’s AVF was noted to have major dilatation of the post-anastomotic segment (>2 cm). All patients required a second operation for flow reduction with reconstruction of the AVF anastomosis to a tapered, smaller size. During this second procedure, the suture tie used for banding in each patient was found to have eroded a portion of the vessel wall and was extending into the fistula lumen. No thrombosis or bleeding was encountered and all AVFs have remained functional after revision. Conclusions: Identical findings in these four patients suggest that the extensive infolding and caliber diameter reduction created by banding these massively dilated fistulas, when combined with the pulsatility induced in the pre-banding segment, leads to a gradual incorporation of the suture tie into the vessel wall and finally within the lumen. We suggest erosion of banding material and failure of flow reduction may occur with any technique but may be more likely with a single polypropylene suture restricting very large AVF. We suggest such excessively dilated fistulas requiring flow reduction may be successfully treated by reconstruction of the AVF anastomosis to a much smaller size with tapering of the outflow vein to accommodate the revision.

scholarly journals Pulmonary arteriovenous malformation (PAVM) embolization: prediction of angiographically-confirmed recanalization according to PAVM Diameter changes on CT

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jihoon Hong ◽  
Sang Yub Lee ◽  
Jung Guen Cha ◽  
Jae-Kwang Lim ◽  
Jongmin Park ◽  
...  
Keyword(s):  
Arteriovenous Malformation ◽  
Case Series ◽  
Pulmonary Angiography ◽  
Endovascular Embolization ◽  
Pulmonary Arteriovenous Malformation ◽  
Conventional Angiography ◽  
Receiver Operating Characteristic Curves ◽  
Vein Diameter ◽  
Diameter Reduction

Abstract Background To assess pulmonary arteriovenous malformation (PAVM) recanalization after embolization based on PAVM diameter changes on computed tomography (CT), with pulmonary angiography used as a gold standard. Methods A retrospective review was done of patients from 2008 to 2019 with a PAVM treated with endovascular embolization. The treatment outcome was determined by conventional angiography. Follow-up pulmonary angiography was performed when recanalization was suspected on CT, or embolization of all lesions in multiple PAVM patients could not be completed in a single session. Patients who had no preprocedural or follow-up CT were excluded. Draining vein, feeding artery, and venous sac diameter were measured on CT, and diameter reduction rates were compared with the widely-used, binary 70 % criteria. Results Forty-one patients with 114 PAVMs were treated during the study period. Eight patients with 50 PAVMs met the inclusion criteria. Mean vein, artery, and venous sac diameter reduction rates were as follows: 59.2 ± 9.3 %, 47.5 ± 10.6 %, and 62.6 ± 13.2 %, respectively, in the occluded group and 5.4 ± 19.5 %, 11.3 ± 17.7 %, and 26.8 ± 14.2 %, respectively, in the recanalized group. The area under the receiver operating characteristic curves for PAVM recanalization for the draining vein was 1.00, showing a better result than the artery (0.97) and sac (0.99). Patients showed > 42 % draining vein diameter reduction in the occluded group and < 32 % in the recanalized group. The widely-used 70 % criteria showed low specificity for predicting recanalization (draining vein, 7.3 %; venous sac, 41.7 %) but 100 % sensitivity for both the draining vein and venous sac. Conclusions The widely-used 70 % binary criteria showed limited performance in predicting outcomes in this angiographically-confirmed case series. Further investigations are warranted to establish a strategy for detecting recanalization after PAVM embolization.

Multi-Slice Computed Tomographic Angiography for Stenosis Detection in Forearm Hemodialysis Arteriovenous Fistulas

2008 ◽  
Vol 9 (4) ◽  
pp. 278-284 ◽  
Author(s):  
P.P.G.M. Rooijens ◽  
G.P Serafino ◽  
D. Vroegindeweij ◽  
R. Dammers ◽  
T.I. Yo ◽  
...  
Keyword(s):  
High Specificity ◽  
Computed Tomographic Angiography ◽  
Observer Agreement ◽  
Predictive Values ◽  
Computed Tomographic ◽  
Arteriovenous Fistulas ◽  
Blinded Manner ◽  
Sensitivity Specificity ◽  
Tomographic Angiography ◽  
Diameter Reduction

Purpose A method of diagnosing the extent and severity of arteriovenous fistula (AVF) stenoses is multi-slice computed tomographic angiography (MS-CTA). The aim of this prospective study was to assess the accuracy of MS-CTA for the detection and grading of stenoses in AVF in comparison to digital subtraction angiography (DSA), which was used as the gold standard of reference. Methods Fifteen hemodialysis (HD) patients with dysfunctioning forearm AVF were included. These AVFs were evaluated by both DSA and MS-CTA and were read in a prospective, blinded manner by two radiologists experienced in vascular imaging. Results ROC analysis revealed areas under the curve of 0.90 ± 0.07 for observer I and 0.87 ± 0.08 for observer II at a stenosis cut-off level of ≥50% diameter reduction. The combined results for MS-CTA showed sensitivity, specificity and positive and negative predictive values of 82%, 98%, 82% and 98% for stenoses ≥50% and 71%, 99%, 77% and 98% for stenoses ≥75%. Inter-observer agreement for the detection of stenoses ≥50% diameter reduction was 0.70 and 1.0, for MS-CTA and DSA, respectively. Conclusion MS-CTA can provide good visualization of forearm HD access AVF and has moderate sensitivity, but high specificity for the detection of flow-limiting stenoses.

scholarly journals Clinical and angioarchitectural characteristics of spinal vascular malformations of the cervical spine

2020 ◽  
Vol 32 (5) ◽  
pp. 755-762 ◽  
Author(s):  
Waleed Brinjikji ◽  
Elisa Colombo ◽  
Giuseppe Lanzino
Keyword(s):  
Cervical Spine ◽  
Lower Extremity ◽  
Clinical Presentation ◽  
Vascular Malformations ◽  
Case Series ◽  
Acute Onset ◽  
Lower Extremity Weakness ◽  
Arteriovenous Fistulas ◽  
Spinal Vascular Malformations ◽  
Interventional Neuroradiologist

OBJECTIVEVascular malformations of the cervical spine are exceedingly rare. To date there have been no large case series describing the clinical presentation and angioarchitectural characteristics of cervical spine vascular malformations. The authors report their institutional case series on cervical spine vascular malformations diagnosed and treated at their institution.METHODSThe authors retrospectively reviewed all patients with spinal vascular malformations from their institution from January 2001 to December 2018. Patients with vascular malformations of the cervical spine were included. Lesions were characterized by their angioarchitectural characteristics by an interventional neuroradiologist and endovascular neurosurgeon. Data were collected on clinical presentation, imaging findings, treatment outcomes, and long-term follow-up. Descriptive statistics are reported.RESULTSOf a total of 213 patients with spinal vascular malformations, 27 (12.7%) had vascular malformations in the cervical spine. The mean patient age was 46.1 ± 21.9 years and 16 (59.3%) were male. The most common presentations were lower-extremity weakness (13 patients, 48.1%), tetraparesis (8 patients, 29.6%), and lower-extremity sensory dysfunction (7 patients, 25.9%). Nine patients (33.3%) presented with hemorrhage. Fifteen patients (55.6%) had modified Rankin Scale scores of 0–2 at the time of diagnosis. Regarding angioarchitectural characteristics, 8 patients (29.6%) had intramedullary arteriovenous malformations (AVMs), 5 (18.5%) had epidural arteriovenous fistulas (AVFs), 4 (14.8%) had paraspinal fistulas, 4 (14.8%) had mixed epidural/intradural fistulas, 3 (11.1%) had perimedullary AVMs, 2 (7.4%) had dural fistulas, and 1 patient (3.7%) had a perimedullary AVF.CONCLUSIONSThis retrospective study of 27 patients with cervical spine vascular malformations is the largest series to date on these lesions. The authors found substantial angioarchitectural heterogeneity with the most common types being intramedullary AVMs followed by epidural AVFs, paraspinal fistulas, and mixed intradural/extradural fistulas. Angioarchitecture dictated the clinical presentation as intradural shunts were more likely to present with hemorrhage and acute onset myelopathy, while dural and extradural shunts presented as either incidental lesions or gradually progressive congestive myelopathy.

Effects of coronary flow reduction on capillary-myocardial exchange in dogs

1978 ◽  
Vol 234 (6) ◽  
pp. H679-H689 ◽  
Author(s):  
T. R. Harris ◽  
C. A. Gervin ◽  
D. Burks ◽  
P. Custer
Keyword(s):  
Small Molecules ◽  
Surface Area ◽  
Coronary Flow ◽  
Paired Comparison ◽  
Tritiated Water ◽  
Flow Reduction ◽  
Flow Restriction ◽  
Permeability Surface ◽  
Control Situations ◽  
Multiple Indicator

The effects of coronary flow reduction on tracer capillary permeability surface area (PS) and distribution volumes were studied in open-chest dog preparations. A mixture of 51Cr-labeled red blood cells, 125I-labeled albumin, [14C]sucrose, and tritiated water (3H2O) was introduced into a shunt connecting the carotid and left anterior descending coronary arteries. Sampling from the coronary sinus produced a multiple indicator curve from which [14C]sucrose PS and 3H2O volumes were computed. Curves were observed in control situations and after the cannula was partially clamped. In six dogs, cardiac lymph was collected and analyzed for total protein. Paired comparison of control and flow-restricted indicator curves showed that flow reduction decreased the absolute values of PS and tracer volumes. The ratio of sucrose volume to weight of perfused tissue increased with flow reduction. The ratio of sucrose PS to weight of perfused tissue increased with moderate flow reduction and decreased with severe flow reduction. The results suggest that flow reduction has two effects which competively affect exchange: 1) flow restriction reduces surface area by capillary derecruitment, and 2) the remaining functional capillaries appear to undergo an increase in permeability to small molecules.

Endovascular extraction of entrapped long-term central feeding catheter: Case series

2018 ◽  
Vol 20 (3) ◽  
pp. 329-332
Author(s):  
Marcin Michalak ◽  
Łukasz Januszkiewicz ◽  
Franciszek Majstrak ◽  
Monika Gawałko ◽  
Grzegorz Opolski ◽  
...  
Keyword(s):  
Vessel Wall ◽  
Balloon Dilatation ◽  
Case Series ◽  
High Volume ◽  
Central Venous Catheters ◽  
Catheter Removal ◽  
Central Venous ◽  
High Volume Center ◽  
Manual Traction

Long-term tunneled central venous catheters are widely used in several clinical indications, that is, hemodialysis, chemotherapy, and total parenteral nutrition. However, central venous catheters are associated with a number of complications, including catheter occlusion and sepsis, which may necessitate earlier catheter removal. In most cases manual traction is sufficient to remove the catheter. Nevertheless, in some cases severe adhesions, formed between the catheter and the vessel wall, complicate simple catheter removal. We present four cases of entrapped long-term central venous catheters and describe methods (e.g. endoluminal balloon dilatation and wire snare) performed by experienced cardiologists at high-volume center to remove them. We claim that permanent central venous catheters removal procedures may be unpredictable and hazardous. Therefore, entrapped central venous catheters should be extracted by experienced operators in specialized high-volume centers.

Fetal Vascular Malperfusion Due To Long and Hypercoiled Umbilical Cords Resulting in Recurrent Second Trimester Pregnancy Loss: A Case Series and Literature Review

2020 ◽  
pp. 109352662096206
Author(s):  
Jonathan C Slack ◽  
Theonia K Boyd
Keyword(s):  
Umbilical Cord ◽  
Rare Event ◽  
Case Series ◽  
Second Trimester ◽  
Fetal Demise ◽  
Flow Restriction ◽  
Intrauterine Fetal Demise ◽  
Increased Risk ◽  
Second Trimester Pregnancy ◽  
Umbilical Cords

Background Intrauterine fetal demise due to fetal vascular malperfusion in mid-gestation is a rare occurrence. Abnormally long and hypercoiled umbilical cords are associated with an increased risk of umbilical cord blood flow restriction, which in turn can result in adverse perinatal and maternal outcomes. The factors that regulate umbilical cord development, specifically umbilical cord length and coiling, are poorly understood. Methods Maternal history, along with fetal and placental findings (post-mortem, pathological, and molecular), were reviewed for a series of 3 consecutive pregnancies that ended in second trimester intrauterine fetal demise. Results All 3 umbilical cords were exceptionally long and hypercoiled, and all placentas showed evidence of high-grade fetal vascular malperfusion. At fetopsy, all 3 fetuses were developmentally normal for gestational age and lacked congenital anomalies. Maternal medical history and antenatal testing (including an extensive work-up for maternal hypercoagulability syndromes) were normal and/or noncontributory. Conclusion Although excessively long and hypercoiled cords are generally thought of as sporadic, nongenetic events, rare examples of recurrent intrauterine fetal demise secondary to such exist have been reported. This intrafamilial clustering of a rare event is suggestive that at least a subset of hypercoiled, long umbilical cords may have an underlying genetic etiology.

scholarly journals Intracranial hemorrhage from dural arteriovenous fistulas: clinical features and outcome

2013 ◽  
Vol 34 (5) ◽  
pp. E15 ◽  
Author(s):  
David J. Daniels ◽  
Ananth K. Vellimana ◽  
Gregory J. Zipfel ◽  
Giuseppe Lanzino
Keyword(s):  
Clinical Features ◽  
Intracranial Hemorrhage ◽  
Case Series ◽  
Venous Drainage ◽  
Sudden Onset ◽  
Residual Symptoms ◽  
Arteriovenous Fistulas ◽  
Common Location ◽  
Dural Arteriovenous Fistulas

Object In this paper the authors' goal was to review the clinical features and outcome of patients with intracranial dural arteriovenous fistulas (DAVFs) who presented with hemorrhage. Methods A retrospective study of 28 patients with DAVFs who presented with intracranial hemorrhage to 2 separate institutions was performed. The information reviewed included clinical presentation, location and size of hemorrhage, angiographic features, treatment, and clinical and radiologically documented outcomes. Clinical and radiological follow-up were available in 27 of 28 patients (mean follow-up 17 months). Results The vast majority of patients were male (86%), and the most common presenting symptom was sudden-onset headache. All DAVFs had cortical venous drainage, and about one-third were associated with a venous varix. The most common location was tentorial (75%). Treatment ranged from endovascular (71%), surgical (43%), Gamma Knife surgery (4%), or a combination of modalities. The majority of fistulas (75%) were completely obliterated, and most patients experienced excellent clinical outcome (71%, modified Rankin Scale score of 0 or 1). There were no complications in this series. Conclusions Case series, including the current one, suggest that the vast majority of patients who present with intracranial hemorrhage from a DAVF are male. The most common location for DAVFs presenting with hemorrhage is tentorial. Excellent outcomes are achieved with individualized treatment, which includes various therapeutic strategies alone or in combination. Despite the hemorrhagic presentation, almost two-thirds of patients experience a full recovery with no or minimal residual symptoms.

VWF-Mediated Platelet Adhesion is Required for Deep Vein Thrombosis in a Flow Restriction Model.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 473-473
Author(s):  
Alexander Brill ◽  
Tobias Fuchs ◽  
Janie Yang ◽  
Maria Köllnberger ◽  
Anil K. Chauhan ◽  
...  
Keyword(s):  
Blood Flow ◽  
Deep Vein Thrombosis ◽  
Vessel Wall ◽  
Conflicts Of Interest ◽  
Blood Stasis ◽  
Vena Cava ◽  
Oxygen Mixture ◽  
Vein Thrombosis ◽  
Flow Restriction ◽  
Deep Vein

Abstract Abstract 473 Deep vein thrombosis (DVT) and its life-threatening complication, pulmonary embolism, are wide-spread in the Western world. Disturbance of blood flow without substantial endothelial denudation is a leading pathogenic factor for non-cancer related DVT. Von Willebrand Factor (VWF), a large multimeric protein, facilitates hemostasis via two separate pathways by stabilizing coagulation Factor VIII (FVIII) and by recruiting platelets to injured vessel wall or thrombi through the interaction with GPIb-alpha. Whereas the role of FVIII in DVT has been suggested by clinical studies (Koster T et al., Lancet, 345(8943):152-5,1995), whether VWF-platelet interaction is implicated in venous thrombosis remains unclear. We utilized murine models of partial and complete flow restriction in the inferior vena cava (IVC) in mice to mimic clinical conditions in which thrombus develops in deep veins. In 8-10 week old C57BL/6 male mice anesthetized by isoflurane-oxygen mixture, IVC and two side branches were ligated by a polypropylene suture immediately below the renal veins to obtain complete blood stasis. For partial flow restriction (stenosis), IVC ligation was performed over a 30G needle and then the needle was removed. Mice were euthanized after 48 h and thrombi from the IVC were taken for analysis. Results were evaluated using the chi-square test. The VWF-/- mice were completely protected from thrombosis in the stenosis model: none of the 14 VWF-/- mice developed a thrombus compared to 6/6 wild-type (WT) mice (p<0.001). In the stasis model, a similar albeit less pronounced phenotype was observed (33% of VWF-/- mice with thrombus, n=9, versus 82% in WT mice, n=11; p<0.03). Stenosis-induced thrombi in WT mice contained abundant amounts of VWF, as was shown by immunostaining. To delineate the involvement of VWF-platelet interactions, we infused WT mice with GPG-290, a recombinant GPIb-alpha N-terminal domain conjugated with human IgG1 Fc fragment. This compound has been shown to inhibit VWF-GPIb-alpha interaction (Hennan JK et al., Thromb Haemost, 95(3):469-75, 2006), but does not interfere with FVIII binding and turnover. Infusion of GPG-290 markedly reduced thrombus development in the stenosis model (3/9 GPG-290-treated WT mice developed DVT versus 9/9 vehicle-treated control mice; p=0.003). Notably, in the absence of blood flow (stasis model), GPG-290 was less effective (83% thrombosis development in vehicle-treated WT, n=6, versus 55.6% thrombosis in GPG-290-treated WT group, n=9; p=0.26). We next addressed the events preceding thrombus formation in the DVT stenosis model using intravital microscopy on living mice. We observed accumulation of fluorescently labeled platelets and leukocytes in the IVC in the area below the suture 6 h after stenosis induction. The amount of both adhering platelets and leukocytes was substantially reduced in VWF-/- mice compared to WT (approx. 20-fold, p<0.005 and 11-fold, p<0.001, respectively). In conclusion, VWF mediates platelet and leukocyte recruitment to the vessel wall. This initiates thrombus development in the absence of major endothelial injury. Interference with the VWF-GPIb-alpha axis may be a potential target for prophylaxis of deep vein thrombosis. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Open and endovascular treatment of spinal dural arteriovenous fistulas: a 10-year experience

2017 ◽  
Vol 26 (4) ◽  
pp. 519-523 ◽  
Author(s):  
Matthew J. Koch ◽  
Christopher J. Stapleton ◽  
Pankaj K. Agarwalla ◽  
Collin Torok ◽  
John H. Shin ◽  
...  
Keyword(s):  
Vascular Malformations ◽  
Management Strategies ◽  
Case Series ◽  
Endovascular Embolization ◽  
Definitive Treatment ◽  
Type I ◽  
Arteriovenous Fistulas ◽  
Presenting Symptoms ◽  
Dural Arteriovenous Fistulas ◽  
Spinal Dural Arteriovenous Fistulas

OBJECTIVE Vascular malformations of the spine represent rare clinical entities with profound neurological implications. Previously reported studies on management strategies for spinal dural arteriovenous fistulas (sDAVFs) appeared before the advent of modern liquid embolic agents. Authors of the present study review their institutional experience with endovascularly and surgically treated sDAVFs. METHODS The authors performed a retrospective, observational, single-center case series on sDAVFs treated with endovascular embolization, microsurgical occlusion, or both between 2004 and 2013. The mode, efficacy, and clinical effect of treatment were evaluated. RESULTS Forty-seven patients with spinal arteriovenous malformations were evaluated using spinal angiography, which demonstrated 34 Type I sDAVFs (thoracic 20, lumbar 12, and cervical 2). Twenty-nine of the patients (85%) were male, and the median patient age was 63.3 years. Twenty patients underwent primary endovascular embolization (16 Onyx, 4 N-butyl cyanoacrylate [NBCA]), and 14 underwent primary surgical clipping. At a mean follow-up of 36 weeks, according to angiography or MR angiography, 5 patients treated with endovascular embolization demonstrated persistent arteriovenous shunting, whereas none of the surgically treated patients showed lesion persistence (p = 0.0237). Thirty patients (88%) experienced some resolution of their presenting symptoms (embolization 17 [85%], surgery 13 [93%], p = 1.00). CONCLUSIONS Microsurgical occlusion remains the most definitive treatment modality for sDAVFs, though modern endovascular techniques remain a viable option for the initial treatment of anatomically amenable lesions. Treatment of these lesions usually results in some clinical improvement.

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