The role of surgical disconnection for posterior fossa pial arteriovenous fistulas and dural fistulas with pial supply: an illustrative case series.

BACKGROUND: Pial arteriovenous fistulas (pAVFs) are rare vascular malformations characterized by high-flow arteriovenous shunting involving a cortical arterial supply directly connecting to venous drainage without an intermediate nidus. Dural arteriovenous fistulas (dAVFs) can infrequently involve additional pial feeders which can introduce higher flow shunting and increase the associated treatment risk. In the posterior fossa, arteriovenous fistula (AVF) angioarchitecture tends to be particularly complex, involving either multiple arterial feeders-sometimes from both dural and pial origins-or small caliber vessels that are difficult to catheterize and tend to be intimately involved with functionally critical brainstem or upper cervical cord structures. Given their rarity, published experience on microsurgical or endovascular treatment strategies for posterior fossa pAVFs and dAVFs with pial supply remains limited. METHODS: Retrospective chart review from 2019-2023 at a high-volume center identified six adult patients with posterior fossa pAVFs that were unable to be fully treated endovascularly and required microsurgical disconnection. These cases are individually presented with a technical emphasis and supported by comprehensive angiographic and intraoperative images. RESULTS: One vermian (Case 1), three cerebellopontine angle (Cases 2-4) and two craniovertebral junction (Cases 5-6) posterior fossa pAVFs or dAVFs with pial supply are presented. Three cases involved mixed dural and pial arterial supply (Cases 1, 4, and 6), and one case involved a concomitant microAVM (Case 2). Endovascular embolization was attempted in four cases (Cases 1-4): The small caliber and tortuosity of the main arterial feeder prevented catheterization in two cases (Cases 1 and 3). Partial embolization was achieved in Cases 2 and 4. In Cases 5 and 6, involvement of the lateral spinal artery or anterior spinal artery created a prohibitive risk for endovascular embolization, and surgical clip ligation was pursued as primary management. In all cases, microsurgical disconnection resulted in complete fistula obliteration without evidence of recurrence on follow-up imaging (mean follow-up 27.1 months). Two patients experienced persistent post-treatment sensory deficits without significant functional limitation. CONCLUSIONS: This illustrative case series highlights the technical difficulties and anatomical limitations of endovascular management for posterior fossa pAVFs and dAVFs with pial supply and emphasizes the relative safety and utility of microsurgical disconnection in this context. A combined approach involving partial preoperative embolization-when the angioarchitecture is permissive-can potentially decrease surgical morbidity. Larger studies are warranted to better define the role for multimodal intervention and to assess associated long-term AVF obliteration rates in the setting of pial arterial involvement.

Surgical management of multiple coronary artery to coronary sinus fistulas with giant left circumflex artery and multivalvular infective endocarditis.

Coronary artery fistula (CAF) is characterized as a congenital or acquired abnormal communication between a coronary artery and any of the four chambers of the heart (coronary-cameral fistula) or great vessels (coronary arteriovenous fistula) bypassing the capillaries within myocardium. CAF is a rare disease, challenging to diagnose and treat depending on the anatomical location and type of the fistula and accompanying diseases. This study aims to report a case with multiple coronary artery to coronary sinus (CS) fistulas with giant left circumflex artery and multivalvular infective endocarditis.

Embolization of a Non-Galenic Pial Arteriovenous Fistula with Assistance of a SolitaireTM Stent: Case Report.

This study aimed to describe a novel endovascular strategy to help control blood flow used successfully to treat an infant with highflow pial arteriovenous fistula (AVF). Here, a single-hole high-flow nongalenic pial AVF was diagnosed in a 2.5 year-old infant is presented. After coil packing failure despite temporal balloon occlusion, we deployed a SolitaireTM stent in the fistula. By twisting with detachable coils, we achieved satisfactory blood flow control, and obliteration of the fistula was achieved with Onyx injection. In conclusion, SolitaireTM stent deployment in the high-flow pial AVF can help stabilize the coils in the fistula, leading to satisfactory blood control. This strategy may be a valuable addition to currently available options.

Ultrasound-guided high-intensity focused ultrasound ablation for uterine arteriovenous fistula: a case series.

PURPOSE: To evaluate the efficacy and safety of high-intensity focused ultrasound (HIFU) ablation in the treatment of uterine arteriovenous fistula (UAVF). MATERIALS AND METHODS: This case series included three patients diagnosed with acquired UAVF. All patients underwent routine laboratory tests, electrocardiography (ECG), chest X-ray, ultrasound, and pelvic contrast-enhanced magnetic resonance imaging (MRI). HIFU treatment was performed under sedation and analgesia using a Model JC Focused Ultrasound Tumor Therapeutic System (made by Chongqing Haifu Medical Technology Co. Ltd., China) with a B mode ultrasound device for treatment guidance. The treatment time, sonication power, sonication time, and complications were recorded. Follow-up evaluations were scheduled at 1-, 3-, 6-, and 12-month to assess symptom improvement and evaluate the post-treatment imaging. RESULTS: All patients completed HIFU treatment in a single session without any major complication. All patients complained of mild lower abdominal and sacrococcygeal pain. Typically, no special treatment is required. Following HIFU treatment, there was a significant relief in clinical symptoms, particularly abnormal uterine bleeding. Ultrasound examinations conducted one month after the treatment revealed a notable reduction in the volume of the lesion, ranging from 57% to 100%. Moreover, the efficacy and safety of HIFU treatment remained consistent during the 12-month follow-up period. CONCLUSION: HIFU ablation appears to be an effective and safe treatment modality for UAVF. It provides a noninvasive approach with favorable clinical outcomes.

Arteriovenous Fistula Closure Using a Simple Ligation Technique After Kidney Transplantation.

BACKGROUNDS: There are advantages and disadvantages with closure of an arteriovenous fistula (AVF) after kidney transplantation, but some cases require closure. The general procedure for closure is angioplasty with exposure of the anastomotic site, but this is often time-consuming and complicated. We have developed a simpler, less invasive, and shorter procedure for AVF closure, in which the anastomotic site itself is not peeled off and the outflow vein close to this site is ligated using 1-0 silk. In this study, we examined the utility of this procedure. METHODS: A retrospective case series study was conducted by review of electronic medical records of patients and surgeries. All patients (n = 52) who underwent AVF closure after kidney transplantation at our hospital between January 2008 and April 2021 were reviewed. Perioperative and long-term postoperative results were examined. This study was carried out following the ethical standards of the Declaration of Helsinki and Istanbul. Donors were not from prisoners, or from those individuals who are coerced of paid. RESULTS: Simple ligation was performed for 46 patients (88.5%). The median time after renal transplantation was 40 (24.5-66.5) months. Median operative time and blood loss were 20 (12.2-30) minutes and 10 (5-15) mL, respectively. Two patients (4.3%) developed the aneurysm after the AVF closure using the simple ligation. CONCLUSION: The simple ligation technique had a relatively shorter operative time and only 2 cases had aneurysm formation. These results suggest that this technique is an option for closure of an AVF after kidney transplantation.

Effect of two different techniques of arteriovenous fistula puncture on wound infection in haemodialysis patients.

Safe and effective arteriovenous fistula (AVF) puncture is very important to reduce the wound complications of haemodialysis (HD). For AVF puncture in dialysis patients, there is a lack of clarity and consistency regarding the relative advantage of buttonhole (BH) over rope-ladder (RL) cannulae in terms of wound complications. The study was published in several scientific databases including Cochrane Library, PubMed and Embase by October 2023. Data from all controlled trials looking at the effect of BH and RL on wound complications in haemodialysis patients were included. The articles were written in English, and they were about adult who had AVF while on dialysis. Studies with or without BH or RL treatment were excluded from the analysis. The data was analysed with RevMan5.3 software. Out of 215 trials, 9 were chosen for the final analysis. The study publication dates were between 2000 and 2023. Of these, 17 326 patients received AVF therapy. Among them, there were 3070 BH and 14 256 RL. In 9 studies, RL had a lower risk of postoperative wound infection compared to BH (OR, 3.38; 95% CI, 3.06, 3.73 p < 0.0001); In all 3 studies, there were no statistically significant differences in the risk of post operative bleeding in RL versus BH(OR, 0.76; 95% CI, 0.25, 2.33 p = 0.63). Our studies have demonstrated that RL trocars are superior to BH trocars in the prevention of wound infection.

[Spontaneous femoral arterio-venous fistula in an 80-year-old female patient as an incidental finding]. / Spontane femorale arterio-venöse Fistel bei einer 80-jährigen Patientin als Zufallsbefund.

INTRODUCTION: Spontaneous arteriovenous fistulas (AVF), in contrast to iatrogenic or post-traumatic ones, are extremely rare and only sporadically published in the literature. In the absence of exposure risk, the diagnosis of AVF can be challenging, especially if it is an incidental finding. CASE HISTORY: An 80-year-old female patient presented to our vascular consultation because of swelling of the left leg due to varicosis. For years, she had also noticed that the right foot seemed to be cooler. Percutaneous catheter examinations via the groin had not been performed, and she could not remember any groin injuries. EXAMINATION AND FINDINGS: Truncal varicosis of the great saphenous vein confirmed clinically and sonographically. In addition, with peripheral pulses obtained, the right foot appeared slightly cooler but not discolored. On auscultation, a systolic-diastolic murmur accompanied by palpable buzzing was heard in the right groin. Color duplex sonography showed a coarse color mosaic pattern between the common femoral artery (AFC) and the anterior saphenous vein (VSAA) in the sense of aliasing ("confetti phenomenon"). A fistula channel between the AFC and VSAA could be visualized, in which very high systolic-diastolic flow velocities prevailed; pulsatile and turbulent flow was present in the region of the crosse-near femoral vein. THERAPY AND COURSE: Endovenous laser ablation was performed for symptomatic truncal varicosis of the left leg. Under ultrasound-guided compression of the afferent artery and fistula at the right groin, the fistula flow did not stop. The patient was reluctant to undergo a proposed interventional closure of the AVF. In follow-up over 4 years, no signs of cardiac insufficiency or critical limb ischemia developed. DISCUSSION: Spontaneous femoral AVF is a rarity. Characteristic clinical findings lead to a targeted use of color duplex sonography with correct interpretation of artifacts that can otherwise be easily missed.

Evaluating patient perspectives of endovascular created arteriovenous fistulas for dialysis access (EndoAVF).

BACKGROUND: Patient reported experience measures are contemporary quality indicators that focus on evaluation of healthcare delivery processes. While surgical arteriovenous fistulas (otherAVF) are preferred for haemodialysis vascular access, fears about surgery and complications often result in refusal/delays. A new technique of endovascular arteriovenous fistula creation (EndoAVF) has been developed and as part of it's ongoing introduction into our unit, the patient perspective was felt critical to its evaluation. The Vascular Access Questionnaire (VAQ) provides a mechanism for identifying and scoring perceptions in this setting. METHOD: Patients who had previously undergone EndoAVF formation were approached to undertake the VAQ as part of a service evaluation of their experience. In addition to the components of the VAQ, data questions relating to the patient's perception of their access were gathered. Results were compared with a matched historical cohort of surgically created fistulas (otherAVF) patients. RESULTS: Patient satisfaction and self-reported ease of use with EndoAVF were high. Overall VAQ scores were similar between the EndoAVF and the surgically created cohort. Functionally, there was no significant difference in perception of their fistula by patients, irrespective of them being created surgically or radiologically. CONCLUSION: Although numbers in this report are small limiting exploration of preserved inherent heterogeneity, we provide a useful initial patient reported experience and perspectives on comparative functional use of radiologically and surgically created AVFs. As real world experience gathers, future larger cohorts with adequate sampling may allow exploration of patient reported experiences and outcome measures.

Stenosis to stented: decrease in flow disturbances following stent implantation of a diseased arteriovenous fistula.

The arteriovenous fistula (AVF) is commonly faced with stenosis at the juxta-anastomotic (JXA) region of the vein. Implantation of a flexible nitinol stent across the stenosed JXA has led to the retention of functioning AVFs leading to the resulting AVF geometry being distinctly altered, thereby affecting the haemodynamic environment within it. In this study, large eddy simulations of the flow field within a patient-specific AVF geometry before and after stent implantation were conducted to detail the change in flow features. Although the diseased AVF had much lower flow rates, adverse flow features, such as recirculation zones and swirling flow at the anastomosis, and jet flow at the stenosis site were present. Larger velocity fluctuations (leading to higher turbulent kinetic energy) stemming from these flow features were apparent in the diseased AVF compared to the stented AVF. The unsteadiness at the stenosis created large regions of wall shear stress (WSS) fluctuations downstream of the stenosis site that were not as apparent in the stented AVF geometry. The larger pressure drop across the diseased vein, compared to the stented vein, was primarily caused by the constriction at the stenosis, potentially causing the lower flow rate. Furthermore, the WSS fluctuations in the diseased AVF could lead to further disease progression downstream of the stenosis. The change in bulk flow unsteadiness, pressure drop, and WSS behaviour confirms that the haemodynamic environment of the diseased AVF has substantially improved following the flexible stent implantation.

High flow priapism following the insertion of an inflatable penile prosthesis mimicking autoinflation: a case report.

Penile prosthesis implantation is a surgical option for erectile dysfunction when other treatments fail or the patient prefers implantation. Although penile prosthesis is generally considered safe and effective, various complications have been reported in the literature. High-flow priapism, resulting from an arteriovenous fistula between the cavernosal artery and the corpora cavernosa, is a rare complication after penile prosthesis implantation. Managing the condition as autoinflation may lead to unfortunate complications. A 54-year-old male patient underwent a penile prosthesis implantation due to erectile dysfunction lasting for 5 years. Doppler ultrasound revealed arterial insufficiency that was refractory to oral and intracavernosal treatments. A 3-piece inflatable penile prosthesis (Coloplast - Titan) was implanted through a midline penoscrotal incision without any complications. The patient reported uncontrolled tumescence after activating the device, which led us to suspect autoinflation. The final diagnosis was high-flow priapism due to an arteriovenous fistula in the cavernosal artery. The patient was given an antiandrogenic medication and the prosthesis was deflated for 3 months. The fistula closed without any additional intervention. High-flow priapism is a rare but potential complication of penile prosthesis implantation. Careful evaluation and management of patients' symptoms are necessary for diagnosing and treating this condition. This case highlights the importance of considering high-flow priapism as a potential cause of uncontrolled tumescence after penile prosthesis implantation and the possibility of successful non-surgical management.

Stereotactic-guided direct orbital puncture for treatment of orbital arteriovenous fistula.

The patient presented with left-sided chemosis, exophthalmos, and progressive visual loss. Cerebral angiography ed a left orbital arteriovenous malformation and an associated hematoma, with the point of fistulation between the left ophthalmic artery and the anterior section of the inferior ophthalmic vein, with retrograde flow through the superior ophthalmic vein. Transvenous embolization through the anterior facial and angular veins was unsuccessful, with residual shunting. Stereotactic-guided direct venous puncture and Onyx embolization was subsequently performed in the hybrid operating room (OR) to cure the fistula. A subciliary incision allowed for retraction of the orbital contents, creating an optimal trajectory. An endonasal endoscopic approach was performed after the embolization to decompress the orbit. This procedure is shown in video 11-11 neurintsurg;16/4/429/V1F1V1Video 1 .

Two pediatric observations of spinal extradural arteriovenous fistulas presenting with epidural hemorrhages and cord compression.

We report two cases of acute spinal cord compression in children with low-flow spinal epidural arteriovenous fistulas (SEAVFs) and discuss the clinical presentation and management of these vascular anomalies. While most low-flow SEAVFs without radiculomedullary drainage are benign lesions typically diagnosed incidentally, we suggest that asymptomatic lesions may warrant aggressive management in specific circumstances, including lesions diagnosed at an early age or in patients under anticoagulation therapy. Our observations also emphasize that patients with a "spontaneous" epidural hemorrhage should undergo dedicated preoperative or postoperative vascular imaging to identify a possible underlying vascular anomaly.

Comparison of Open and Endovascular Aneurysm Repair in Native Arteriovenous Fistulas.

BACKGROUND: Arteriovenous accesses develop aneurysms (FA) during their active use, resulting in pain, erosion, bleeding, and difficulty in cannulation. This study aims to evaluate the outcomes of open and endovascular management of single FA in arteriovenous fistulas (AVF). METHODS: A retrospective review of all upper extremity primary AVFs over 12 years was undertaken at a single center. Patients undergoing elective open and endovascular repair of a single FA were identified. Thirty-day outcomes, cannulation failure, line placement, re-intervention, and functional dialysis (continuous hemodialysis) for 3 consecutive months were examined. RESULTS: Three hundred and seventy nine patients presented with a single FA that met the requirements for intervention: 126 (33%) underwent endovascular repair, and the remainder 253 (67%) underwent open repair. Preoperative fistulogram identified anatomically significant issues in 91% of the cases, and these were treated by balloon angioplasty: 10% within the fistula tract, 44% within the outflow tract, and 47% in the central veins. In open repair, 57% underwent plication, 35% underwent resection and re-anastomosis, and the remainder (8%) underwent interposition grafting. In endovascular repair, successful placement of a stent was achieved in all cases with 1 ± 2 (mean ± standard deviation [SD]) covered stents (diameter: 6 -8 mm) placed, achieving successful exclusion of the FA. The combination of early thrombosis and cannulation failures led to the greater need for a tunneled central line in endovascular repair (6.5% vs. 2.4%; endovascular versus open repair; P = 0.04). As a result, the mean time for establishing renewed access in the index AVF was significantly higher in endovascular repair (2 ± 3 vs. 2 ± 2 weeks, mean ± SD; endovascular open repair versus open repair; P = 0.001). In follow-up, there were more secondary interventions per year in the endovascular compared to open repair groups (3.1 vs. 1.4 secondary interventions per year; endovascular versus open repair; P = 0.04). Median functional dialysis durations were superior in the open repair (48 ± 6%, mean + standard error) compared to the endovascular repair at 5 years. (26 ± 7%; P = 0.03). CONCLUSIONS: Open repair results in a more rapid return to access use, lower need for a tunneled central line, lower secondary re-intervention rates, and superior functional dialysis durations compared to endovascular repair. Open FA repair should be considered for symptomatic single FA repairs before endovascular FA repair.

Traumatic Iliac Arteriovenous Fistula Treated With the Amplatzer Vascular Plug II: A Case Report and Literature Review.

Traumatic iliac arteriovenous fistula is a rare complication of vascular injury. Open surgical repair has an incidence of postoperative complications. In recent years, endovascular treatment has shown better efficacy. We report a 62-year-old female AVF patient with a stab injury history of more than 16 years. Computed tomography angiography (CTA) revealed a large arteriovenous fistula between the right internal iliac artery and the common iliac vein. After considering the patient's relevant conditions, an endovascular approach was satisfactorily performed with the implantation of an Amplatzer Vascular Plug II to interrupt the abnormal vascular communication and maintain arterial and venous patency. The final control images showed closure of the arteriovenous communication.