Vaso-Lock for sutureless anastomosis in a pig arteriovenous loop model

A vascular anastomosis is a critical surgical skill that involves connecting blood vessels. Traditional handsewn techniques can be challenging and resource intensive. To address these issues, we have developed a unique sutureless anastomotic device called Vaso-Lock. This intraluminal device connects free vascular ends using anchors to maintain traction and enable a rapid anastomosis. We tested the anastomotic capability of Vaso-Locks in a pig common carotid-internal jugular arteriovenous model. The use of Vaso-Lock allowed us to accomplish this procedure in less than 10 min, in contrast to the approximately 40 min required for a handsewn anastomosis. The Vaso-Lock effectively maintained patency for at least 6 weeks without causing significant tissue damage. Histological analysis revealed that the device was successfully incorporated into the arterial wall, promoting a natural healing process. Additionally, organ evaluations indicated no adverse effects from using the Vaso-Lock. Our findings support the safety and effectiveness of the Vaso-Lock for arteriovenous anastomosis in pigs, with potential applicability for translation to humans. Our novel sutureless device has the potential to advance surgical practice and improve patient outcomes.

Susac syndrome in a patient with chronic myelocytic leukemia: Consequence or coincidence?

Purpose

In this study, we report a patient who presented with both chronic myelocytic leukemia (CML) and Susac syndrome (SS).

Observations

A 45-year-old male diagnosed with CML in the blast phase sought consultation due to a deterioration in vision in his right eye. He also had hearing loss and severe migraneous headaches. Best corrected visual acuity was light perception and 20/20 in the right and left eyes, respectively. The slit lamp examination and intraocular pressure were within normal ranges for both eyes. Upon dilated fundoscopy, organized vitreous hemorrhage was observed in the right eye, while the left eye exhibited extensive sclerotic vessels with retinal neovascularization in the periphery. Ultrasound of the right eye showed tractional retinal detachment. Optical coherence tomography of the left retina showed thinning of the retina in temporal macula. Fluorescein angiography revealed a substantial nonperfused region in the peripheral left retina, accompanied by arterioarterial and arteriovenous collaterals, along with microaneurysms. MRI showed scattered foci of hyperintensity within the supratentorial white matter, mostly subcortical on T2-weighted and fluid-attenuated inversion-recovery. The patient received a diagnosis of SS and was subsequently referred to the neurology service for further assessment and potential treatment.

Conclusion and importance

SS may manifest as a presentation of CML. It is advisable to conduct investigations for SS in CML patients experiencing neurological, ophthalmological, or otological symptoms.

Pelvic arteriovenous malformation causing per rectal haemorrhage - A case report

INTRODUCTION AND IMPORTANCE

We present the case of a 17 years old girl with per rectal haemorrhage secondary to pelvic arteriovenous malformations (AVM) and potentially haemorrhoids. Pelvic AVMs are rare and extremely variable in their clinical presentation, size and location and pose a therapeutic challenge. Focus has turned towards interventional radiological procedures with angioembolisation as the main treatment form for pelvic AVMs.

CASE PRESENTATION

A 17 years old girl presented to a rural hospital with significant per rectal bleeding requiring transfer to a tertiary centre with interventional radiology capabilities. Diagnostic imaging determined the presence of a pelvic AVM as well as haemorrhoid. She had no prior history of haemorrhoids, per rectal bleeding or per vaginal bleeding. Further diagnostic imaging including a digital subtraction angiography and MRI pelvis was performed and her case was discussed at a multidisciplinary meeting where the decision was made for angioembolisation of a large right rectal AVM as well as precautionary banding of haemorrhoids that had developed secondary to outflow obstruction. A repeat CT mesenteric angiogram a month later demonstrated diminished appearances of the rectal AVM.

CLINICAL DISCUSSION

Pelvic AVMs are a rare entity and are not a common cause for per rectal bleeding. There is currently no direct consensus on the optimum management of complex pelvic AVMs particularly those that present with a second pathology such as haemorrhoids. Surgical management often results in recurrence or rapid progression of the AVM lesion and recruitment of new blood supply further complicates the problem. Selective embolisation allows for control of haemorrhage and utilises chemical agents as well as detachable coils and balloons. However, postoperative pain and swelling can still be expected and multiple transcatheter embolisations may be required.

CONCLUSION

The treatment of symptomatic pelvic AVMs is complex and requires a multidisciplinary approach with careful radiological planning prior to embolisation. Angioembolisation is becoming increasingly prevalent and multiple embolisation procedures may be required to reach the desired therapeutic effect.

Balloon-assisted U-turn Technique to Access Cortical Vein for Transvenous Embolization of Mixed Dural-pial Arteriovenous Malformation

Cerebral arteriovenous malformations can be classified into pure pial, mixed dural-pial, and pure dural types. Mixed pial-dural AVMs (DPAVM) are rare and often receive blood supply from dural meningeal arteries, including branches of the internal carotid, external carotid, and vertebral arteries.1- 6 DPAVMs, which are usually large and complex, require delicate endovascular and surgical treatment methods. The cure rate is low, and recurrence is very common, leading to high morbidity and mortality. In this case video, we present a case of PDAVM that recurred after initial endovascular onyx embolization, requiring additional endovascular coiling which resulted in obliteration of the DPAVM.

Retained foreign body misdiagnosed as a low flow vascular malformation: A case report

A 21-year-old woman presented with 1 year history of progressive dorsal right foot pain with no recollection of trauma. The physical exam did not reveal any unusual appearance to the plantar or dorsal skin surfaces. Specifically, no scars were seen. Foot radiographs were unremarkable. The presumed etiology after Doppler ultrasound (US) and MRI was a likely venous or venolymphatic malformation. She received 2 rounds of sclerotherapy 12 months apart with transient symptomatic clinical improvement. After the second sclerotherapy treatment, repeat MRI revealed dorsal extension of the lesion with skin involvement, prompting referral for surgical intervention. At surgery, a 3 cm wood splinter was found surrounded by granulation tissue. After showing the patient the resected splinter, she recalled stepping on a wooden broomstick that punctured the bottom of her foot in her childhood. She stated she also remembered pulling a splinter out of her foot. This case demonstrates the unusual and rare appearance of a chronic retained foreign body creating a cystic lesion in the foot presumed to be a low-flow vascular malformation on US and MRI.

Recent evaluation by nephrologists is associated with decreased incidence of tunneled dialysis catheter being used at the time of first arteriovenous access creation

OBJECTIVE

Late primary care provider (PCP) or nephrologist evaluation of patients with progressive kidney disease may be associated with increased morbidity and mortality. Among patients undergoing initial arteriovenous (AV) access creation, we aimed to study the relationship of recent PCP and nephrologist evaluations with perioperative morbidity and mortality.

METHODS

We performed a retrospective review of patients from 2014 to 2022 who underwent initial AV access creation at an urban, safety-net hospital. Univariable and multivariable analyses identified associations of PCP and nephrologist evaluations <1 year and <3 months before surgery, respectively, with hemodialysis initiation via tunneled dialysis catheters (TDCs), 90-day readmission, and 90-day mortality.

RESULTS

Among 558 patients receiving initial AV access, mean age was 59.7 ± 14 years, 59% were female gender, and 60.6% were Black race. Recent PCP and nephrology evaluations occurred in 386 (69%) and 362 (65%) patients, respectively. On multivariable analysis, unemployed and uninsured statuses were associated with decreased likelihood of PCP evaluation (unemployment: odds ratio [OR], 0.51; 95% confidence interval [CI], 0.34-0.77; uninsured status: OR, 0.05; 95% CI, 0.01-0.45) and nephrologist evaluation (unemployment: OR, 0.63; 95% CI, 0.43-0.91; uninsured status: OR, 0.22; 95% CI, 0.06-0.83) (all P < .05). Social support was associated with increased likelihood of PCP evaluation (OR, 1.81; 95% CI, 1.07-3.08) (all P < .05). Hemodialysis was initiated with TDCs in 304 patients (55%). Older age (OR, 0.98; 95% CI, 0.96-0.99), obesity (OR, 0.38; 95% CI, 0.25-0.58), and nephrologist evaluation (OR, 0.12; 95% CI, 0.08-0.19) were independently associated with decreased hemodialysis initiation with TDCs in patients receiving an initial AV access (all P < .05). Ninety-day readmission occurred in 270 cases (48%). Cirrhosis (OR, 2.5; 95% CI, 1.03-6.03; P = .04), coronary artery disease (OR, 2.31; 95% CI, 1.5-3.57), prosthetic AV access (OR, 1.84; 95% CI, 1.04-3.26), and impaired ambulation (OR, 1.75; 95% CI, 1.15-2.66) were independently associated with increased readmission (all P < .05). Older age (OR, 0.98; 95% CI, 0.97-0.99), prior TDC (OR, 0.65; 95% CI, 0.45-0.94), and unemployment (OR, 0.58; 95% CI, 0.39-0.86) were associated with decreased readmission (all P < .05). Ninety-day mortality occurred in 1.6% of patients. Neither PCP nor nephrologist evaluation was associated with readmission or mortality.

CONCLUSIONS

Recent nephrology evaluation was associated with reduced hemodialysis initiation with TDCs among patients undergoing initial AV access creation. Unemployed and uninsured statuses posed barriers to accessing nephrology care.

Systematic review and meta-analysis: Efficacy and safety of balloon angioplasty in salvaging non-matured arteriovenous fistulas

This study aimed to evaluate the clinical and technical success rates achieved after performing balloon-assisted maturation (BAM) for non-matured arteriovenous fistula (AVF). For this, a systematic review and meta-analysis were conducted by searching PubMed and Scopus databases. Studies regarding AVFs not suitable for use based on clinical examination or ultrasound criteria and BAM use for correcting the underlying stenotic lesion were eligible for inclusion in the meta-analysis. Accordingly, 13 studies with 1427 patients with non-matured AVF who underwent BAM were included. The pooled random effect for the clinical success rate was 90% (95% CI, 86%-93%), and that for the technical success rate was 97% (95% CI, 94%-99%). Complications after BAM were reported in 1.7%-41% of the patients. Complications included venous ruptures, wall hematomas, and puncture site hematomas. Early-BAM group had better clinical success rates. BAM is an effective intervention for salvaging non-matured AVF. The procedure is safe and feasible, and high clinical and technical success rates can be achieved. The complications were also manageable without serious sequelae.

Maintenance and Salvage of Hemodialysis Access

Many end-stage kidney failure patients require hemodialysis as a life-sustaining treatment. Hemodialysis access via arteriovenous fistula or graft creation is preferred over long-term dialysis catheters, but intervention to maintain patency and prevent access failure is common. Endovascular and open surgical techniques are both utilized to address the underlying etiology of failure. Endovascular options include balloon angioplasty, angioplasty with stenting, and drug-eluting stents. Open revision is commonly needed for recurrent stenosis, aneurysmal or pseudoaneurysmal change, hemodialysis access-induced distal ischemia, and infection. Treatment plans should be guided by patient's individualized goals of care and require a multidisciplinary approach to the management of this complex disease.

A cadaveric study of arteriovenous trigone of heart: the triangle of Brocq and Mouchet

Left coronary artery divides into anterior interventricular branch and circumflex branch. As both the arteries run in their corresponding grooves, an arteriovenous trigone is formed between conus arteriosus and left auricle called triangle of Brocq and Mouchet. The triangle base is formed by great cardiac vein. This study aims to describe the frequency of triangle and its type and relationship between various boundaries and content of triangle and to supplement the existing knowledge of clinicians. This observational and descriptive study was conducted on 40 formalin fixed cadaveric hearts in department of anatomy, Kalpana chawla government medical college. The triangle was found in 92.5% of specimen with most common type being closed (51.3%) which is followed by inferiorly open in 35.1%, superiorly open in 8.1% and completely open in 5.4% hearts. Most frequent content of triangle was median artery followed by diagonal branches of anterior interventricular and circumflex branches. The mean area of the triangle was 246.3 mm². Relationship of vein with two arterial branches was either superficial or deep. The knowledge of different patterns of existence will be required for angiographic procedures. Further the triangle is a potential epicardial access route to left fibrous ring. Thus detailed knowledge of variations will help cardiologist to achieve better outcome in interventional procedures with minimal complications.

Inpatient re-rupture of a middle meningeal arteriovenous fistula after traumatic brain injury

We present a case of a spontaneous second intraparenchymal hemorrhage (IPH) following patient admission for a traumatic brain injury with an initial traumatic IPH. After a subsequent review of all imaging, it was concluded that the patient had a traumatic middle meningeal associated dural arterial venous fistula (MMAVF) which re-ruptured during admission, and the MMAVF was overlooked as a potential contributor to the initial traumatic IPH for which the patient was admitted. A 49-year old man presented with right temporal IPH following an ATV accident and was found to have a right MMAVF on cerebral angiography. The MMAVF appeared on angiography to be unruptured, and therefore was not immediately treated. Later in admission, the patient suffered a new spontaneous IPH ipsilateral to the MMAVF, suggesting a re-rupture. Endovascular transarterial embolization with ethyl vinyl alcohol resulted in complete obliteration of the MMAVF. The patient tolerated treatment well and went on to make a good recovery as of last post-operative imaging at 8 months. Hence, MMAVFs may be present in the setting of IPH following a traumatic brain injury which warrants maintaining a high level of suspicion and low threshold for intervention as they can cause secondary spontaneous intracranial hemorrhage. The absence of notable subdural or extradural hemorrhage on imaging should not exclude rupture. Transarterial embolization with an ethylene vinyl alcohol copolymer is an effective treatment modality.

Results of endovascular treatment of venous anastomotic stenosis in prosthetic arteriovenous for hemodialysis PTFE grafts. Comparative analysis between patent and occluded grafts

OBJECTIVE

To analyze the results of endovascular treatment of venous anastomotic stenosis (VAS) in humero-axillary arteriovenous grafts (HAG), comparing outcomes between patent and thrombosed HAG.

MATERIAL AND METHODS

A retrospective cohort study was made of endovascular treated patients because of a VAS in a HAG between January 2009 and December 2019. Group A: Thrombosed HAG secondary to a VAS. Group B: Patent HAG with a VAS detected during follow-up. Technical success was defined as residual stenosis after treatment <30%, and clinical success as satisfactory immediate dialysis after surgery. After ET a biannual clinical and ultrasound follow-up was performed.

STATISTICAL ANALYSIS

Survival analysis was performed for time-to-event data to assess patency.

RESULTS

Group A: 55 patients. Group B: 22. There were no significative differences in demographic and anatomical factors between groups. Technical and clinical success were 100% in group B and 94.5% and 91% respectively in group A. Primary patency at 1, 6 and 12 months was: Group A: 81.8%, 22.4% y 15.7% respectively. Group B: 100%, 85.9%, 76,4% (p < 0.001). Secondary patency at 1, 6 and 12 months was: Group A: 85.2%, 45.8% y 31.3% respectively. Group B 100%, 95.3%, 95.2% (p < 0.001). Use of non-covered stents was associated with an increased risk of occlusion (HR 2.669 IC 95% 1.146-6.216, p = 0.010).

CONCLUSION

A higher patency of EV performed on a patent HAG is expected. It is therefore advisable to develop surveillance programs that are capable to detect VAS before its occlusion.

Hemorrhagic cerebral proliferative angiopathy in two pediatric patients: case reports

Cerebral proliferative angiopathy (CPA) is an infrequent vascular malformation. It is composed of a nidus, arterial feeders, and venous drainage. Some special features differentiate it from the common arteriovenous malformations (AVM). The nidus has normal cerebral tissue intermingled and occupies a large portion of the brain. There is a frequent transdural arterial supply. Arterial feeders and draining veins are of small caliber concerning the nidus size. Ischemic strokes are the most common clinical event. Intracranial bleeding when occurs has a worse prognosis due to its high recurrence rate. We have presented two cases of CPA in pediatric patients who required surgical resolution of their acute episode.

Cerebrofacial vascular metameric syndrome associated with Moyamoya syndrome: a rare case report

INTRODUCTION

Neural crest and mesoderm cell dysfunction of certain metameric level result in vascular malformations, i.e., cerebrofacial arteriovenous metameric syndrome (CAMS) and cerebrofacial venous metameric syndrome (CVMS). Moyamoya disease is a progressive steno-occlusive disease in the terminal portions of the bilateral internal carotid artery. The patient in this case report was a child with cerebrofacial vascular metameric syndrome, associated with moyamoya syndrome.

CASE REPORT

Child, 7 months old, female, admitted to the emergency department with seizures, hemangioma on the right half of the face (forehead, upper eyelid, and upper lip), and left hemiparesis. The magnetic resonance imaging of the skull indicated increased myelination in the right hemisphere (T2) and atrophy compatible with Sturge-Weber syndrome. Cerebral angiography indicated vasculopathy with bilateral moyamoya pattern, associated with other arteriovenous malformations compatible with cerebrofacial vascular metameric syndrome. Moyamoya syndrome was treated with indirect revascularization (pial synangiosis) achieving good outcomes.

DISCUSSION

Vascular malformations can involve the orbits, face, and brain simultaneously. CAMS with forebrain or hindbrain involvement can be classified into subgroups: I, II, and III. On the other hand, venous malformations in Sturge-Weber syndrome or encephalotrigeminal angiomatosis can be considered CVMS. Moyamoya disease is called syndrome when related to another clinical condition, such as the present case, i.e., neurocutaneous Sturge-Weber syndrome. The association of chronic moyamoya vasculopathy with cerebrofacial vascular metameric syndrome is rare. Further studies are required to establish the best treatment approach.

Microsurgical Management of a Marginal Sinus Dural Arteriovenous Fistula: 2-Dimensional Operative Video

Dural arteriovenous fistulas (DAVFs) are benign but may present with life-threatening hemorrhage or symptoms of venous hypertension (eg, progressive myelopathy).1-3 DAVFs follow well-described anatomic patterns.4 The marginal sinus is located between the layers of the dura, circumferentially around the foramen magnum. It communicates with the basal venous plexus of the clivus anteriorly and the occipital sinus posteriorly.5,6 Arterial supply to the dura in this region that fistulizes into the sinus arises from meningeal branches from the V3 or V4 segments.  A man in his early 70s presented with chronic neck pain and new onset of left arm and face paresthesias. He had brisk patellar reflexes bilaterally and a marginal sinus DAVF, with numerous dilated veins around the cisterna magna, causing dorsal cervicomedullary compression. Angiography confirmed the diagnosis of DAVF rather than arteriovenous malformation. Endovascular embolization was considered, but surgery was preferable because of poor transarterial access.  The patient underwent left far lateral craniotomy and C1 laminectomy with exposure of the condylar fossa. The dura was carefully elevated laterally, revealing a network of dilated tortuous veins, with multiple points of fistulous connection within the dura emanating in a large venous varix. Indocyanine green videoangiography showed the aberrant flow dynamics. The fistulous point was occluded with aneurysm clips on the venous side, then cauterized and interrupted. The patient was discharged within 3 d of surgery and had full resolution of symptoms at 6 wk. Angiography confirmed complete obliteration of the DAVF. The patient provided written informed consent for treatment. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Results of endovascular treatment of venous anastomotic stenosis in prosthetic arteriovenous for hemodialysis PTFE grafts. Comparative analysis between patent and occluded grafts

OBJECTIVE

To analyze the results of endovascular treatment of venous anastomotic stenosis (VAS) in humero-axillary arteriovenous grafts (HAG), comparing outcomes between patent and thrombosed HAG.

MATERIAL AND METHODS

A retrospective cohort study was made of endovascular treated patients because of a VAS in a HAG between January 2009 and December 2019. Group A: Thrombosed HAG secondary to a VAS. Group B: Patent HAG with a VAS detected during follow-up. Technical success was defined as residual stenosis after treatment <30%, and clinical success as satisfactory immediate dialysis after surgery. After ET a biannual clinical and ultrasound follow-up was performed.

STATISTICAL ANALYSIS

Survival analysis was performed for time-to-event data to assess patency.

RESULTS

Group A: 55 patients. Group B: 22. There were no significative differences in demographic and anatomical factors between groups. Technical and clinical success were 100% in Group B and 94.5% and 91% respectively in Group A. Primary patency at 1, 6 and 12 months was: Group A: 81.8%, 22.4% and 15.7% respectively. Group B: 100%, 85.9%, 76.4% (p<0.001). Secondary patency at 1, 6 and 12 months was: Group A: 85.2%, 45.8% and 31.3% respectively. Group B 100%, 95.3%, 95.2% (p<0.001). Use of non-covered stents was associated with an increased risk of occlusion (HR 2.669 95% CI 1.146-6.216, p=0.010).

CONCLUSION

A higher patency of EV performed on a patent HAG is expected. It is therefore advisable to develop surveillance programs that are capable to detect VAS before its occlusion.

Vascular anomalies of the head and neck: diagnosis and treatment

Vascular malformations and vascular tumors comprise the two specific subsets of vascular anomalies that arise as a result of disorganized angiogenesis and neoplasm, respectively. Malformations are separate entities from vascular tumors (e.g., hemangiomas) and are recognized by the International Society for the Study of Vascular Anomalies (ISSVA) as such. Vascular malformations are classified into four main groups: simple, combined, anomalies of major vessels, and those associated with other vascular anomalies. Vascular tumors are neoplastic growths of blood vessels and are morphologically and molecularly distinct from malformations but can arise in the head and neck and have syndromic association. Head and neck vascular anomalies are not uncommon in the pediatric population and require special care in the workup, diagnostic imaging and clinical care. The purpose of this manuscript is to discuss the diagnosis and management of the most common intracranial and extracranial vascular malformations and tumors in the head and neck in children and adolescents.

Characteristics and outcome in prenatally diagnosed vascular aorta-umbilical vein malformation

Congenital arteriovenous fistulas involving the abdominal aorta are very rare. We report an unusual presentation involving the umbilical vein and characterized by the occurrence of a postnatal thrombosis and a favorable outcome.Synopsis: Fetal abdominal arteriovenous fistulas are rare involve branches from the aorta and can lead to umbilical vein thrombosis.

Clinical features and treatment strategy of paraspinal arteriovenous shunt (PAVS): a systematic review with individual participants data meta-analysis

BACKGROUND

Because of the rarity of the disease, paraspinal arteriovenous shunt (PAVS) is not well recognized, and therapeutic options remain controversial. To introduce a rare disease of PAVS and demonstrate its etiology, clinical features, treatment options, and outcomes, we presented a case report and conducted a systematic review and individual participants data (IPD) meta-analysis.

METHODS

Studies regarding on PAVS were integrated and IPD were obtained including patients' demographics, disease etiology, clinical and radiologic features, clinical courses and outcomes. Clinical manifestation and treatment outcomes were reviewed, and comparison analysis (cervical versus thoracolumbar) were performed. Further, logistic regression analyses were conducted to identify the poor prognostic factors (incomplete obliteration).

RESULTS

Fifty-two articles were selected, and 88 patients enrolled. General and location-specific characteristics of PAVSs were identified: '3/4 of the isolated and 1/4 of the associated etiology', 'bruit, thrill, or murmur (cervical) and weakness (thoracolumbar) as common symptoms', '40% multiple feeders', and '22% intradural venous involvement'. Endovascular treatment was usually preferred (75%). Of 88 enrolled patients, 18 patients showed incomplete obliteration (20.5%). In multivariate analysis, 'etiologies of systematic genetic dysplasia (P = 0.031) and trauma (negatively, 0.038)' were significantly associated with incomplete obliteration. The parameters of 'multiple feeders (0.066)' and 'combined approach (negatively, 0.065)' are verified only in univariate analysis.

CONCLUSION

General as well as location-specific characteristics of PAVS is successfully demonstrated. Approximately 20% of the incomplete obliteration is noted, and three potential poor prognostic factors are identified, namely, 'etiology of systematic genetic dysplasia (positive) and trauma (negative)', 'combined approach (negative), and 'multiple feeders'.

Microsurgical Resection of Brainstem Arteriovenous Malformation: 2-Dimensional Operative Video

Brainstem arteriovenous malformations (AVMs) are rare lesions (2%-6% of all intracranial AVMs) that are surgically challenging because of the high eloquence of the brainstem, including dense fiber tracts, cranial nerves, and multiple vital cerebrovascular structures. All these lesions possess eloquence and deep venous drainage, making them innately Spetlzer-Martin grade III or above. This patient had a large midbrain AVM with a complex clinical course beginning with ventriculoperitoneal shunting due to mass effect; the patient experienced 4 hemorrhages, underwent radiation treatment, and finally underwent surgical resection. The surgical approach involved a large torcular craniotomy exposing all posterior sinuses at the confluence. The vein of Galen was exposed and carried deeply to permit ambient cistern opening and relaxation of the cerebellum. Because of earlier radiation therapy, the vessels had undergone hyalinosis, which resulted in difficult manipulation of the nidus but did permit excellent coagulation of the vessels. The complete nidus was removed, as confirmed on postoperative angiography. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

A systematic review of brachial artery ligation as a safe and feasible option in the management of arteriovenous dialysis access infection

OBJECTIVE

Creation of good long-term arteriovenous access is essential in patients requiring hemodialysis for end-stage renal failure. However, arteriovenous grafts or fistulae can be complicated by infection that may require emergency surgery. For infections that involve the brachial artery anastomosis, or if total graft explantation is indicated, brachial artery repair or reconstruction is often required. An alternative management strategy would be brachial artery ligation (BAL). We performed a systematic review to evaluate the outcomes of BAL that has been performed for infected arteriovenous grafts or fistulae.

METHODS

A thorough literature search was conducted using various electronic databases. We included articles that reported outcomes of BAL performed for infected arteriovenous grafts or fistulae. The primary outcome was the incidence of upper limb ischemia after BAL. Secondary outcomes were the need for urgent revascularization, need for upper limb amputation, and incidence of postoperative neurological deficit after BAL.

RESULTS

A total of five studies with a total of 125 patients were included in our systematic review. BAL was performed for infected arteriovenous grafts or fistulae for all studies. Follow-up period ranged from 1 to 27 months. The incidence of upper limb ischemia after BAL was low. Only a single study reported three patients who developed upper limb ischemia. Two patients required urgent revascularization, and one patient required forearm amputation after proximal ligation. All studies reported clearance of infection with no recurrence.

CONCLUSIONS

Distal BAL may be performed safely for patients with infected arteriovenous fistulae or grafts with low risk of upper limb ischemia, postoperative neurological deficit, and recurrent infection.

Silent and dangerous: catheter-associated right atrial thrombus (CRAT) in children on chronic haemodialysis

BACKGROUND

Catheter-associated right atrial thrombus (CRAT) is a recognised complication of central venous catheter (CVC) use for haemodialysis (HD) patients.

METHODS

This was a single-centre retrospective longitudinal observational study of consecutive children aged 6 months-18 years over a 7-year period receiving in-centre chronic HD. Echocardiograms as per routine cardiac surveillance were performed 6 months or earlier given clinical concerns.

RESULTS

Sixty-five children, 36 boys (55.4%), median (IQR) age 11.8 (5.3, 14.7) years, received HD for kidney failure with replacement therapy (KFRT). Initial modality was HD in 45 (69.2%), with CVC as initial access in 42 (93.3%) and AVF in 3 (6.7%); in the remaining 20 (30.8%) patients PD was the initial modality before switching to HD. Seven of 65 (10.8%) developed CRAT at median 2 (0.8, 8.4) months from CVC insertion, with one CRAT detected 3 days following insertion. One child had 2 episodes of CRAT and one additionally thrombosed their AVF. No patient had an underlying primary kidney disease associated with a pro-thrombotic state. Those with CRAT were younger, had more frequent CVC change and received dialysis for longer duration compared to those with no CRAT. Six episodes of CRAT (75%) received anticoagulation therapy. Infective complications were observed in 25% and catheter malfunction in 50%. Five CRAT episodes (62.5%) resulted in CVC loss. One patient died after a haemorrhagic complication of anticoagulation and sepsis, and another developed life-threatening superior vena cava obstruction syndrome. Overall mortality 14% (1/7).

CONCLUSIONS

This is the first report of CRAT in a paediatric HD population. There was ~ 11% incidence of CRAT in patients receiving chronic HD detected by surveillance echocardiography. Although frequently asymptomatic, CRAT is associated with serious sequelae. Anticoagulation and surveillance with expert echocardiography remain mainstays of management. Graphical abstract.

Update on extracranial arteriovenous malformations: A staged multidisciplinary approach

Arteriovenous malformations (AVMs) are vascular lesions that are thought to arise from congenital errors during development of vessels resulting in abnormal connections between arteries and veins. Though most AVMs develop in the brain or spinal cord, they can occur anywhere in the body. These extracranial or peripheral AVMs have a predilection for the head, neck, and limbs. Since these malformations infiltrate normal soft tissue, management requires selective treatment with preservation of normal surrounding architecture. Therefore, they are best addressed through a staged multimodal and multidisciplinary approach, using a combination of different laser, interstitial, intravascular and surgical techniques to specifically target anomalous vessels. The goal of treatment is overall disease improvement and symptom control with interventions that do not result in outcomes worse than the disease itself. Recently, the discovery of somatic and germline mutations in peripheral AVMs have contributed to a better understanding of the pathophysiology, resulting in promising new pharmacologic treatments. Recent evidence suggests that adjuvant medical therapy can enhance and sustain interventional and/or surgical outcomes. Herein we describe how a new understanding of the etiology and physiology of extracranial AVM provides guidance to current treatment approaches.

Efficacy and safety of secondary procedures for maintaining arteriovenous hemodialysis access patency: protocol for a systematic review and network meta-analysis

BACKGROUND

Arteriovenous (AV) hemodialysis access creation is recommended by international guidelines as the preferred method of hemodialysis access. However, most AV access sites will require revision to maintain patency. Although several treatment options exist, many have not been directly compared. We intend to compare the relative effectiveness of methods to maintain post-intervention primary patency of failing AV access.

METHODS

We will search EMBASE, MEDLINE, CENTRAL, trial registries, the grey literature, and ancestry and citation search from January 1977 to present, for randomized controlled trials comparing interventions to maintain primary patency of AV access. Two investigators will independently and blindly review all identified citations and extract data from included studies. The primary outcome is the primary patency 6 months after intervention. Secondary outcomes include immediate technical and functional success, reinterventions, patency, and mortality. Risk of bias, subgroup analyses, and sensitivity analyses are planned.

DISCUSSION

There are a number of treatment modalities for the management of failing AV access. However, most modalities have only been directly compared with plain old balloon angioplasty, and currently synthesized evidence focuses on individual pairwise comparisons. In light of the lack of comprehensively synthesized evidence and clinical equipoise, our study intends to synthesize currently available evidence though it is unclear which treatment modality is most effective.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO ID CRD42020148224.

Frontal Ethmoidal Dural Arteriovenous Fistula: 2-Dimensional Operative Video

Anterior cranial fossa dural arteriovenous fistulas (DAVFs) are an infrequent subtype of cranial DAVFs. These lesions are most commonly derived from the ophthalmic artery. These lesions are often best treated utilizing endovascular embolization; however, this modality can be challenging because of the difficulty in catheterizing the ophthalmic or ethmoidal arteries. Surgical intervention is therefore indicated and requires approaching the proximal portion of the drainage vein to appropriately obliterate the fistulous point. For ethmoidal DAVFs, this is frequently along the dura of the cranial base adjacent to the cribriform plate. This patient had a right frontal hematoma with a typical ethmoidal DAVF. The fistula was exposed through a frontal craniotomy, and the ethmoidal branch was identified at the fistulous point. Intraoperative angiography was used to test for obliteration, which revealed a contralateral DAVF. The contralateral fistula was then obliterated in a similar manner, demonstrated on a second intraoperative angiogram. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

The current clinical picture of cerebral proliferative angiopathy: systematic review

BACKGROUND

Cerebral proliferative angiopathy (CPA) is a rare subset of arteriovenous malformations (AVM). It has unique clinical presentation, angiographic characteristics, and pathophysiology which often brings challenges for the treatment. We aimed to define its epidemiology, pathophysiology are unknown, and best management strategies.

METHODS

A systematic review was conducted according to the PRISMA guidelines. MEDLINE was searched for articles regarding CPA. Extracted data included epidemiological, clinical, and angiographical characteristics, treatment, and outcomes. Treatment was classified as conservative, radiosurgery, endovascular, decompression, and indirect vascularization. A meta-analytical approach was employed for description of the data as study-size adjusted percentages or weighted means, as appropriate.

RESULTS

Thirty-three studies were analyzed, rendering a total 95 cases-half of which came from a single study. Patients were predominantly young (mean 23 years old) and female (60.0%) presenting with headaches (44.9%), seizures (37.1%), or transient ischemic attacks (33.7%). Hemorrhage was present in 18.0%, but rebleeding rates were as high as 67%. The majority of nidus were > 6 cm (52.5%) with hemispheric extension (73.0%). Capillary angioectatic appearance (85.7%), transdural supply (62.5%), and deep venous drainage (73.0%) were also frequent features. Most patients were treated conservatively (54.4%), followed by endovascular (34.2%). Indirect vascularization and radiosurgery were attempted in five and two patients, respectively. Mean follow-up was 110.8 patient-years. Neurological status improved in 50.7%, remained stable in 40.2%, and worsened in 9.0%.

CONCLUSIONS

Conservative and endovascular treatments seem adequate interventions, despite limited evidence. Complementary techniques can be used in patients throughout disease history, according to symptom-based, individualized approach. More studies are required for choosing interventions based on reliable long-term results.

Imaging of Vascular Malformations

Recent advances in imaging have allowed a better understanding of imaging features and classification of vascular anomalies. This article focuses on imaging of vascular malformations; describes the updated classification system and clinical and imaging characteristics of the different subtypes; and discusses the associated syndromes, differential diagnosis, and available treatment options, including the role of imaging in management.

Same day embolisation followed by microsurgical resection of brain arteriovenous malformations: a single centre early experience

INTRODUCTION

The purpose of this paper is to report our experience of treating cerebral arteriovenous malformations (AVM) in adults with pre-operative embolisation and microsurgical resection on the same day during a single anaesthetic at a single centre between April 2016 and December 2018. We included both elective AVM and AVM that had bled acutely.

METHODS

We retrospectively analysed data from patients with cerebral AVMs who underwent embolisation followed by microsurgical resection on the same day at a single neurosurgical centre.

PRIMARY ENDPOINTS INCLUDED

Total procedure time (embolisation and microsurgical resection), procedure finish time, intra-operative blood loss, degree of nidus obliteration on postoperative angiography, intensive care unit (ICU) stay, total stay at the neurosurgical centre and modified Rankin Score (pre- and post-procedure).

RESULTS

•Nineteen patients underwent same-day pre-operative embolisation and microsurgical resection over the 32-month period. The average patient age was 40 years (range 19-66 years). One patient had undergone a prior attempt at embolisation and one patient previously had sterotactic radiosurgery (STRS). •Thirteen of the AVM were in the dominant hemisphere and six in the non-dominant hemisphere. Sixteen AVM were located supratentorially and three were in the posterior fossa. Spetzler-Martin grades included 4 grade 1, 10 grade 2, 4 grade 3 and 1 grade 4. •The average blood loss intra-operatively was 289 mls. •The average list finish time was 19:56 (range 15:10-00:00). •Seventeen patients had 100% nidus obliteration on post-operative digital subtraction angiography, one patient had a small remnant and was referred to STRS and one patient died in the ICU post operatively.

CONCLUSION

Overall, the authors believe same-day embolisation and microsurgical resection represents a safe treatment strategy. The technique minimises hemorrhagic complications from delayed venous occlusion and avoids multiple anaesthetics and hospital admissions.

The Clinical Relevance and Management of High-Flow Arteriovenous Access

Obtaining an arteriovenous (AV) access for initiation of hemodialysis is considered the gold standard as it reduces risks of infections, hospitalizations, and need for interventions. It is well documented that creation of AV access can cause or aggravate heart failure. Once AV access is created, blood volume, cardiac contractility, and left ventricular end-diastolic volume increase in a nonphysiologic fashion resulting in an overall increase in cardiac output. Left ventricular hypertrophy, diastolic dysfunction, pulmonary hypertension, and high-output cardiac failure can occur. AV accesses that have blood flows greater than 1.5 L per minute are of high risk. When access flow exceeds 25% to 30% of cardiac output, the risk of developing high-output heart failure increases. Studies suggest that a blood flow (Qa)/cardiac output (CO) ratio of greater than 0.30 should be used as a screening tool to perform further cardiac testing. Depending on the severity of symptoms, management can range from banding procedure (flow reduction) or need for total abandonment of the AV access. The complications associated with high-flow AV accesses are often overlooked. Nephrologists and vascular access experts should work in tandem to mitigate potential harm to patients on dialysis who are afflicted by this condition.

Refining our knowledge of macrovascular arteriovenous shunts (MAS): Anatomical and pathological studies

BACKGROUND

The macrovascular arteriovenous shunt (MAS) connecting the deep inferior epigastric artery (DIEA) and superficial inferior epigastric vein (SIEV) in the abdominal wall has already been identified as an important structure, and further study has been deemed necessary to establish its role and function.

METHODS

Review of CT angiograms (CTA) of 38 female patients was undertaken, by means of analysis of fine-cut axial images and three-dimensional image reconstructions of the cutaneous vasculature of the deep and superficial vasculature. In vivo dissection of the structure was also performed to establish its communications. Lastly, a histopathological analysis was carried out to investigate its intrinsic structure and function.

RESULTS

The MAS was identified in both sides of the abdomen in all subjects and the diameter ranges from 0.72 to 2.81 mm with a median diameter of 1.28 mm. In vivo dissection revealed it as a distinct structure connecting the DIEA and SIEV. Pathological analysis showed that it has characteristics of both elastic and muscular arteries, which constitutes a new vessel.

CONCLUSION

These further investigations have yielded a better understanding of the MAS shunt, its position, structure and function. This can be of crucial importance to reconstructive surgeons when raising the DIEP flap.

Left Parietal Craniotomy for Resection of Grade IV Arteriovenous Malformation: 2-Dimensional Operative Video

Parieto-occipital arteriovenous malformations (AVMs) are the second most common site for cranial AVMs. These lesions are defined as eloquent when the nidus involves either the postcentral gyrus or the occipital pole. If located on the dominant hemisphere, these lesions can also involve the arcuate fasciculus ventrally. This patient had a large unruptured Spetzler-Martin grade IV AVM within the parieto-occipital region extending deeply to the ventricle, following presentation with a seizure. The digital subtraction angiography demonstrated feeding vessels from both the middle cerebral artery and posterior cerebral artery distributions. Despite the high Spetzler-Martin grade, the lesion demonstrated favorable features such as a compact nidus, convexity presence, and lack of involvement of the precentral and postcentral gyrus. Preoperative embolization was utilized. The AVM was successfully resected both superficially and deeply to the level of the atrium of the lateral ventricle. Postoperative angiography demonstrated complete removal of the AVM, and the patient made a complete recovery from the procedure. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Left Occipital Craniotomy for Resection of Arteriovenous Malformation: 2-Dimensional Operative Video

Medial parieto-occipital arteriovenous malformations (AVMs) are fed by distal cortical posterior cerebral artery branches and are generally considered eloquent given the proximity to the calcarine fissure and paracentral lobule. This patient was a neurologically intact 12-yr-old girl with an incidentally discovered left occipital AVM. The patient underwent preoperative angiographic evaluation with embolization of a dominant posterior cerebral artery feeding vessel. The AVM was removed in the standard manner using circumdissection. Indocyanine green angiography was utilized to demonstrate disconnection of the AVM before sacrificing the draining veins. The AVM was removed entirely, as evidenced on postoperative angiography. The patient had a partial right hemianopsia after the operation but was otherwise neurologically intact. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Complications of arteriovenous fistula in dialysis patients: Incidence and risk factors in Taif city, KSA

AIM

The aim of this study was to measure the prevalence of arteriovenous fistula (AVF) and its complications in patients undergoing hemodialysis (HD) in Taif Region, Saudi Arabia.

METHODS

This was a prospective hospital-based study conducted on 196 patients aged above 18 years who were undergoing dialysis in two hospital Taif City. Data collected and documented using a pretested questionnaire, which included sociodemographic details and also information about fistula-related complications. Hospital records were also reviewed to match the complication and related risk factors. Appropriate statistical tests were used and analyzed with SPSS software ver. 23.

RESULTS

Majority of the study patients were in the age group of 41-60 years and the prevalence in male and female were 49.5% and 50.5%, respectively. The most prevalent chronic illness in the patients was hypertension (41.7%) and more than 30.6% had multiple chronic illness. The most common type of AVF was radiocephalic fistula (RCF). The most common complication associated with the patients with AVF was ischemic neuropathy (29.6%). Smokers had significant history of myocardial infarction than non smokers.

CONCLUSION

Early and timely detection of complications in AVF is essential for proper management. Health professional should have thorough knowledge regarding the complications related to AVF. Early diagnosis and appropriate treatment are essential to improve the quality of life in patients on HD.

Relationship of arteriovenous fistula stenosis and thrombosis with the platelet-lymphocyte ratio in hemodialysis patients

BACKGROUND

The platelet-lymphocyte ratio, which was reported to have a strong relationship with chronic inflammation and thrombosis, is a useful biomarker. The purpose of this study was to evaluate the relationship between the platelet-lymphocyte ratio, arteriovenous stenosis, and thrombosis in patients with chronic renal failure.

METHODS

Patients who were referred to our interventional radiology department due to arteriovenous fistula dysfunction from dialysis units between August 2015 and December 2018 were retrospectively reviewed. In the study, 95 patients with arteriovenous fistula access problems were included. Patients were divided into two groups: stenosis (n = 52) and thrombosis (n = 43). Thirty-six subjects with a patent left radiocephalic arteriovenous fistula proven by both color Doppler ultrasonography and clinically were added to the control group. Blood samples were obtained on the same day before the fistulography.

RESULTS

Platelet counts, lymphocyte counts, and platelet-lymphocyte ratio were found to be significantly different between the three groups. After the Bonferroni post hoc analysis, there was a significant difference between the stenosis and control group (p = 0.017), and the thrombosis and control group (p < 0.001) in terms of the platelet-lymphocyte ratio. No significant difference for any parameter was found between stenosis and thrombosis group.

CONCLUSION

High levels of the platelet-lymphocyte ratio may be a supportive finding of arteriovenous fistula stenosis and thrombosis and can be taken into consideration during hemodialysis-dependent patients' follow-up.

Sphenoid dural arteriovenous fistulas

Sphenoid wing dural AVFs represent a rare clinical entity. These lesions may be asymptomatic or present with focal neurologic deficits, intracranial venous hypertension, or intracranial hemorrhage. Diagnosis is based on clinical findings and diagnostic imaging. They are alternatively classified as lesions of either the greater or lesser wings of the sphenoid bone. We performed a search of the PubMed database of studies evaluating the clinical behavior and surgical and endovascular therapies of these lesions. Dural AVFs draining into the superficial middle cerebral vein and/or laterocavernous sinus, or rather, lesions of the greater wing of the sphenoid, exhibit a greater likelihood of developing an aggressive clinical course, with higher probability of cortical venous reflux and consequent intracranial venous hypertension, intracranial hemorrhage, and symptomatic presentation. Dural AVFs of the sphenoparietal sinus, that is, lesions of the lesser wing of the sphenoid, typically exhibit a more benign clinical course, as there is a prominent epidural venous drainage into the cavernous sinus, reducing the risk of cortical venous reflux, and consequently, the probability of intracranial venous hypertension, hemorrhage, and floridly symptomatic presentation. These lesions may be treated via surgical clipping of the fistulous point, transarterial or transvenous embolization, and/or stereotactic radiosurgery. Though surgical intervention was the principal therapy due to facility of craniotomy access to the fistulous point, embolization has become standard of care permitted by innovation in endovascular technology. The natural history, clinical presentation, angioarchitecture, diagnosis, and management of these lesions are reviewed and discussed.

Quantitative color-coded digital subtraction neuroangiography for pediatric arteriovenous shunting lesions

BACKGROUND

Several complex pediatric neurovascular conditions are amenable to endovascular treatment. Given the unique anatomical and physiological challenges in children, there is an ongoing need for tools and techniques that provide accurate information for treatment planning, while minimizing exposure to ionizing radiation and contrast. This is more so for neonates and infants with high-flow arteriovenous (AV) shunts that are challenging to assess using conventional techniques.

OBJECTIVE

In this brief report, we describe, through representative cases, the potential role of quantitative color-coded digital subtraction angiography (qDSA) in neuroendovascular procedures in children with high-flow AV shunting lesions.

METHODS

Images were obtained using an ArtisQ biplane system (Siemens Healthineers, Erlangen, Germany). Post-processing was performed at a dedicated workstation (Syngo, Siemens) using the iFlow module to generate color-coded maps of individual digital subtraction angiography runs.

CONCLUSION

Color-coded qDSA provides real-time quantitative information in high-flow AV shunting neurovascular lesions. This can potentially help direct treatment choices, optimize endovascular treatment protocols, monitor outcomes, and determine treatment end points.

Reduced patency in left-sided arteriovenous grafts in a porcine model

OBJECTIVE

The porcine arteriovenous graft model is commonly used to study hemodialysis vascular access failure, with most studies using a bilateral, paired-site approach in either the neck or femoral vessels. In humans, left- and right-sided central veins have different anatomy and diameters, and left-sided central vein catheters have worse outcomes. We assessed the effect of laterality on arteriovenous prosthetic graft patency and hypothesized that left-sided carotid-jugular arteriovenous prosthetic grafts have reduced patency in the porcine model.

METHODS

Arteriovenous polytetrafluoroethylene grafts were placed ipsilaterally or bilaterally in 10 Yorkshire male pigs from the common carotid artery to the internal jugular vein. Ultrasound measurements of blood flow velocities and diameters were assessed before graft placement. Animals were sacrificed at 1 week, 2 weeks, or 3 weeks. Patency was determined clinically; grafts and perianastomotic vessels were excised and analyzed with histology and immunostaining.

RESULTS

At baseline, left- and right-sided veins and arteries had similar blood flow velocities. Although internal jugular veins had similar diameters at baseline, left-sided carotid arteries had 11% smaller outer diameters (P = .0354). There were 10 left-sided and 8 right-sided polytetrafluoroethylene grafts placed; only 4 of 10 (40%) grafts were patent on the left compared with 7 of 8 (88%) grafts patent on the right (P = .04). Left-sided grafts had increased macrophages at the arterial anastomosis (P = .0007). Left-sided perianastomotic arteries had thicker walls (0.74 vs 0.60 mm; P = .0211) with increased intima-media area (1.14 vs 0.77 mm²; P = .0169) as well as a trend toward 38% smaller luminal diameter (1.6 vs 2.5 mm; P = .0668) and 20% smaller outer diameter (3.0 vs 3.7 mm; P = .0861). Left- and right-sided perianastomotic veins were similar histologically, but left-sided veins had decreased expression of phosphorylated endothelial nitric oxide synthase (P = .0032) and increased numbers of α-actin-positive smooth muscle cells (P = .0022).

CONCLUSIONS

Left-sided arteriovenous grafts are associated with reduced short-term patency compared with right-sided grafts in the Yorkshire pig preclinical model of arteriovenous prosthetic grafts. Laterality must be considered in planning and interpreting surgical preclinical models.

Unilateral Venous Approach to Contralateral or Bilateral Carotid Cavernous Shunts

BACKGROUND

Cavernous carotid fistulas (CCF) are anatomically complex vascular lesions. Treatment via the venous approach has been previously described and is highly dependent on the patency of the drainage pathways. The use of a unilateral approach to contralateral or bilateral shunts is technically challenging and not commonly described. We present our experience with the unilateral across-the-midline approach to both cavernous sinuses to treat shunts according to anatomic compartments to achieve anatomic cure.

METHODS

Patients included in this study presented with either bilateral or unilateral shunts with unilateral venous drainage. We used a transarterial guiding catheter for road mapping and control angiography. A venous triaxial system was used to achieve support for distal navigation across the midline via the coronary sinus to the contralateral cavernous sinus. Coils were favored for embolization, with occasional complementary liquid embolic material.

RESULTS

Five patients underwent complete occlusion in a single session. One patient required additional complementary transarterial embolization. Despite a successful unilateral approach to bilateral cavernous sinuses, 1 patient needed an additional ipsilateral transophthalmic venous approach to obliterate the anterior compartment of the cavernous sinus. No complications were encountered. Complete angiographic cure was observed in all patients by the end of the final procedures, with persistent occlusion in their follow-up imaging.

CONCLUSIONS

Careful inspection of the venous anatomy and fistulization sites is critical when treating unilateral or bilateral carotid cavernous shunts. The contralateral venous route can serve as a safe approach when visualized. Crossing the midline via the anterior or posterior coronary sinuses is feasible and efficacious.

Cranial dural arteriovenous shunts: selection of the ideal lesion for surgical occlusion according to the classification system

BACKGROUND

The types of cranial dural arteriovenous fistulae (cDAVFs) that constitute good surgical candidates are unclear despite the use of classifications. We aimed to compare the DES classification with other classification schemes in identifying "ideal lesions for surgery." The DES scheme is based on two features: the level of the shunt (BVS, bridging vein shunt; DSS, dural sinus shunt; ISS, isolated sinus shunt; EVS, emissary vein shunt) and the type of leptomeningeal venous reflux (LVR) (direct, exclusive, strained).

METHODS

In this observational cohort study, the angiographies of 20 consecutive patients treated over 1 year were analyzed retrospectively. We defined cDAVFs as ideal for surgery, if cure may be achieved by disconnecting the arterialized draining vein through a single craniotomy. To evaluate the performance of each classification scheme in identifying the "ideal lesion for surgery," we carried out a sensitivity analysis of the Borden, Cognard, and DES schemes.

RESULTS

Eight lesions were Borden type 3 and 1 type 2, and 11 type 1. According to Cognard, 2 lesions were type IV, 2 type III, 1 type IIa+b, 11 type I, and 4 lesions could not be clearly classified. According to the DES scheme, 8 lesions were DSS, 4 BVS, 3 ISS, and 5 EVS. All 4 lesions classified as BVS in the DES were ideal lesions for surgery (sensitivity, specificity, PPV, NPV 100%). Not all high-grade lesions according to Borden were good surgical candidates.

CONCLUSION

The DES scheme, as opposed to other classifications, facilitates the therapeutic decision-making especially for selecting candidates for surgery.

A Propensity Score-Matched Cohort Analysis of Outcomes After Stereotactic Radiosurgery in Older versus Younger Patients with Dural Arteriovenous Fistula: An International Multicenter Study

OBJECTIVE

This study aims to evaluate the outcomes of Gamma Knife stereotactic radiosurgery (SRS) for dural arteriovenous fistulas (dAVFs) in older patients (≥65 years) compared with younger patients (age <65 years).

METHODS

Two groups with a total of 96 patients were selected from a database of 133 patients with dAVF from 9 international medical centers with a minimum 6 months follow-up. A 1:2 propensity matching was performed by nearest-neighbor matching criteria based on sex, Borden grade, maximum radiation dose given, and location. The older cohort consisted of 32 patients and the younger cohort consisted of 64 patients. The mean overall follow-up in the combined cohort was 42.4 months (range, 6-210 months).

RESULTS

In the older cohort, a transverse sinus location was found to significantly predict dAVF obliteration (P = 0.01). The post-SRS actuarial 3-year and 5-year obliteration rates were 47.7% and 78%, respectively. There were no cases of post-SRS hemorrhage. In the younger cohort, the cavernous sinus location was found to significantly predict obliteration (P = 0.005). The 3-year and 5-year actuarial obliteration rates were 56% and 70%, respectively. Five patients (7.8%) hemorrhaged after SRS. Margin dose ≥25 Gy was predictive of unfavorable outcome. The obliteration rate (P = 0.3), post-SRS hemorrhage rate (P = 0.16), and persistent symptoms after SRS (P = 0.83) were not statistically different between the 2 groups.

CONCLUSIONS

SRS achieves obliteration in most older patients with dAVF, with an acceptable rate of complication. There was no increased risk of postradiosurgery complications in the older cohort compared with the younger patients.

Comparison of Endovascular Embolization and Surgery in the Treatment of Spinal Intradural Dorsal Arteriovenous Fistulas

BACKGROUND

We compared the outcomes of endovascular embolization and surgery and investigated the factors affecting the clinical outcomes of spinal intradural dorsal arteriovenous fistulas (SIDAVFs).

METHODS

The medical records of 26 patients who had undergone endovascular embolization or surgery for SIDAVFs from 2004 to 2014 were retrospectively reviewed. The recurrence rate and clinical outcomes for each treatment modality were compared. Multivariate analysis was used to identify significant factors influencing the clinical outcomes using the Aminoff and Logue (AL) score.

RESULTS

Of the 26 patients, 14 (56%) had undergone endovascular embolization and 11 (44%) had undergone surgery as the initial treatment. Embolization was applied as the primary treatment for most patients. Surgery was chosen for patients with difficult superselection (n = 5), multiple feeders (n = 2), or easy surgical accessibility (n = 4). Of the 14 patients who had undergone embolization as initial treatment, 5 (36%) had developed a recurrence within an average of 29.6 months (range, 2-87). One patient with recurrent SIDAVF was treated with repeat embolization and four with surgery. None of patients in the surgical group developed recurrence. Embolization as the initial treatment resulted in significantly greater recurrence compared with surgery (odds ratio, 2.222; 95% confidence interval, 1.369-3.608; P = 0.046). Surgery resulted in better clinical outcomes than embolization (P = 0.021). The final AL score was also strongly affected by the preoperative AL score, micturition score, and recurrence (P = 0.000, P = 0.000, and P = 0.011, respectively).

CONCLUSIONS

Our results have shown that surgery results in a low recurrence rate and superior clinical outcomes. A multidisciplinary and ordered decision is crucial for the treatment choice to ensure better outcomes, especially for patients with a definite neurologic deficit at diagnosis.

Type I Spinal Arteriovenous Fistula with Ventral Intradural Venous Drainage: A Proposal of a Modified Classification

Objectives:

Spinal arteriovenous fistula (AVF) is the most common spinal vascular lesion and constitutes an abnormal communication between a feeder artery and a draining vein. Arterialization of the venous plexus leads to venous hypertension; consequent edema and congestion of the spinal cord are associated with progressive neurological decline.

Patients and Methods:

In this report, we describe two unique cases of type I cervical spinal AVF, in which a radiculomeningeal artery forms an intradural fistula that drains into the ventral venous plexus.

Results:

Both patients underwent surgical obliteration of the fistula with complete occlusion confirmed on postoperative angiography.

Conclusion:

Both cases do not fit into the current classification scheme. A modified classification is proposed.

High-Flow Vascular Malformation of Ear: A Case Report

Vascular anomalies are categorized into vascular tumours or vascular malformations on the basis of clinical features and histopathology. The literature regarding high flow arteriovenous malformations of the auricle is rare. A case of a patient clinically diagnosed with an arteriovenous malformation of the external ear and was managed with preoperative embolization, surgical excision and reconstruction of ear with split thickness skin graft, is presented. The pathogenesis, clinical presentation, diagnostic work up, radiological intervention and management options regarding arteriovenous malformations are discussed. Total cure is an illusion and rarely achieved in high flow high grade vascular malformation with nearly 98% recurrence reported in 5 years. Patient followed for next 3 months with no evidence of recurrence.

Dangerous Headache: A Case of Dural Venous Sinus Thrombosis with Protein S Deficiency

Dural Venous Sinus Thrombosis (DVST) is a sporadic cause of headache. DVST is a recherché complication of maxillary sinus infection. Maxillary sinusitis infection may spread directly to orbit via lamina papyracea and it is expedited by the presence veins of breschet. The authors present a clinical case of dural sinus thrombosis with protein S deficiency and also describe an effective management approach for DVST.

Contrast-Enhanced Chest Computed Tomography Reveals Treatable Causes of Cerebral Abscesses in Patients without Antecedent Surgery or Trauma

OBJECTIVE

Brain abscesses cause substantial morbidity and mortality even after appropriate therapy, and no underlying cause is found in 25% of cases. We investigated the added utility of contrast-enhanced chest computed tomography (CT) in the diagnostic work-up of patients presenting with cerebral abscesses and no history or prior trauma or cranial surgery.

METHODS

All patients presenting to a single institution with a surgically proven brain abscess were reviewed. Concurrent contrast-enhanced chest CT imaging results were reviewed when available to identify treatable predisposing causes of intracranial suppuration.

RESULTS

This study included 31 patients with biopsy-proven abscesses. Multiple abscesses were present in 8 patients (26%). Contrast-enhanced CT was performed in 15 patients (48%). Of these 15 patients, 2 had pulmonary arteriovenous malformations, 1 had an intrapulmonary shunt, and 3 had empyemas. Definitive therapy for the chest findings was provided to 6 of the 15 patients (40%). In the remaining 9 patients, 3 had pulmonary abscesses, for which diagnostic aspiration was requested. Another patient had an incidental pulmonary embolism, resulting in same-day placement of an inferior vena caval filter (not included in chest analysis, given that the finding was incidental).

CONCLUSIONS

Contrast-enhanced chest CT is useful for identifying treatable causes of cerebral abscesses in patients with a cerebral abscess and no history of surgery or trauma.

Open liver trauma causing hepatico caval fistula successfully treated by embolization

Introduction

Traumatic arteriovenous fistula results from a breach of vascular integrity between a vein and an adjacent artery. Hepato caval fistula is a rare entity. Open surgical approaches have increasingly given way to radiological embolization techniques in the treatment of these arteriovenous fistulae, especially in intrahepatic locations.

Case report

We report the case of a patient diagnosed with a fistula, from the right branch of the liver artery to the right hepatic vein, developed following an open liver trauma. Successful embolization through the transarterial route was achieved with simple outcomes.

Conclusion

The interventional radiology for endovascular management has revolutionized the treatment of hepatic liver traumas. The conservative treatment is henceforth the common approach even if hepatic artery or hepatic veins are involved in case of arteriovenous fistula.

Surgical management of cerebral dural arteriovenous fistulae

Dural arteriovenous fistulae are high flow, low resistance intracranial vascular malformations defined by an aberrant connection between an artery and dural vein or sinus. Symptomatology and presentation are highly dependent on location, generally categorized as supratentorial, tentorial, or infratentorial, and consist primarily of sequelae secondary to local venous hypertension, insufficiency, and cortical venous reflux. Surgery is generally reserved for high risk or persistently symptomatic lesions that are unamenable or unresponsive to endovascular therapy. For surgical lesions, familiarity with skull base approaches, specific fistula anatomy, and technical nuances based on fistula location offer patients the best chance of a favorable outcome.

Middle meningeal arteriovenous fistulas: A rare and potentially high-risk dural arteriovenous fistula

Background:

Middle meningeal arteriovenous fistulas (MMAVFs) are rare lesions with a poorly established natural history. We report our experience with patients with MMAVFs who presented with intracranial hemorrhage.

Methods:

We reviewed our prospectively maintained endovascular database for patients with MMAVFs, who were treated by embolization during a 15-year period. Hospital and outpatient medical records and imaging studies were reviewed.

Results:

Nine patients with MMAVFs, who presented with intracranial hemorrhage, underwent embolization (mean age 60.3 years, range 21–76; four male and five female). Four patients presented after trauma and five after spontaneous hemorrhage. All nine patients were angiographically cured after embolization of the fistula with liquid embolic agents (n = 8) or coils (n = 1). There were no procedure-related complications.

Conclusion:

MMAVFs represent a rarely reported class of vascular lesions. They are typically associated with trauma, but also develop spontaneously, and may be associated with intracranial hemorrhage, which warrants classification of these lesions as high risk. Endovascular treatment is safe and effective and should be considered for these patients, particularly for those who have lesions with intracranial venous drainage.

The Use of Arteriovenous Fistulae as an Adjunct to Peripheral Arterial Bypass: A Systematic Review and Meta-analysis

BACKGROUND

Peripheral arterial bypass is an effective procedure for the management of patients with critical limb ischaemia. However, it is commonly associated with high rates of graft occlusion and subsequent limb loss. This is particularly apparent when the distal anastomosis is to the below-knee arterial segment. A number of studies have suggested that an arteriovenous fistula (AVF) sited at the distal anastomosis may reduce afterload, improve graft patency, and boost subsequent limb salvage. The aim of this study was to assess the effects of adjuvant AVF on the outcomes of peripheral arterial bypass.

METHODS

The following databases were searched up to May 2015: Medline through Pubmed; the Cochrane Library; EMBASE; and reference lists of articles.

STUDY ELIGIBILITY

All randomised controlled and observational studies that assessed the role of AVF as an adjunct to peripheral arterial bypass were included. Studies were required to include at least one pre-defined outcome. Data were extracted and assessed by two reviewers with any disagreements adjudicated on by the senior author. Pooled risk ratios were calculated using a random effects model. Additional subgroup analyses were performed.

RESULTS

Two randomised controlled trials and seven retrospective cohort studies comprising 966 participants were included. Pooled standardized data showed no difference in primary graft patency (pooled RR = 1.25, 95% CI 0.73-2.16), secondary patency (pooled RR = 1.16, 95% CI 0.82-1.66), or limb salvage at 12-months (pooled RR = 1.13, 95% CI 0.80-1.60) for the peripheral bypass with AVF group compared with peripheral bypass alone. Subgroup analysis indicated a reduction in reintervention rates associated with AVF when performed in conjunction with a synthetic graft (pooled RR = 0.55, 95% CI 0.30-0.98).

CONCLUSION

Although adjuvant AVF is not associated with additional operative complication there is little evidence to support its use. The evidence assessing its merits is weakened by small, retrospective studies with heterogeneous cohorts.

Arteriovenous malformation of the iris. Two cases

CASE REPORT

A 50-year-old patient was seen during a regular follow up. The main complaint was decreased near-sight vision. Biomicroscopy showed a vascular malformation on the temporal sector of the iris in the left eye, diagnosed as an arteriovenous malformation. A second case of similar features is also presented.

DISCUSSION

The vascular malformations of the iris may be asymptomatic and go unnoticed or cause recurrent spontaneous hyphemas. Treatment must be individualised and may range from observation to photocoagulation with laser, or even surgery.