Procedure and Clinical Success of Drug-Coated Balloon Fistuloplasty of the Drainage Vein in Dysfunctional Native Arteriovenous Fistulas

Purpose. Native arteriovenous fistulas (AVFs) are the most effective vascular access (VA) for haemodialysis. We aimed to evaluate the results of balloon angioplasty (fistuloplasty) from drainage vein performed for the treatment of AVF dysfunction in haemodialysis patients and examine potential patient and AVF-associated factors that might affect such results. Methods. This is a nonrandomized, retrospective, and single-centred study. A total of 105 balloon fistuloplasties were performed for dysfunctional AVFs of 82 haemodialysis patients. Patients were treated with a drug-coated balloon according to standard procedures. Evaluations were performed by physical examinations and if needed by color Doppler imaging in every 6 months. The primary endpoint was patency by balloon fistuloplasty. Patency was evaluated clinically by detecting the thrill in AVF and by the adequacy of the dialysis. Multidimensional scaling (MDS) technique was used as a method for the statistical analysis. Results. The success of the procedure after the first attempt was 85.3% with 70 patients. Patency in the 6th, 12th, 18th, and 24th months were 63 (76.8%), 60 (73.1%), 53 (64.6%), and 44 (54%), respectively. The procedure was considered successful when the thrill was detected in AVF and when dialysis was adequate. The statistical analysis by MDS revealed that patients’ age was the most effective factor acting on the procedure success followed by the age of AVF. Other patient-associated and AVF-associated factors were not found as effective statistical evaluation. Conclusions. Haemodialysis through native AVFs with restored functionality contributes positively to the life span and the quality of life of the patient. Probably, advanced age and high fistula age are unfavourable factors leading to the development of neointimal hyperplasia and venous stenosis. Balloon fistuloplasty of the draining vein is an effective and safe method regardless of patient age and the age of AVF.

Interhemispheric Contralateral Transfalcine Approach for Subparacentral Arteriovenous Malformation: 3-Dimensional Operative Video

Neurovascular procedures along the interhemispheric fissure harbor unique features differentiating them from those arteriovenous malformations (AVMs) located at the lateral surface of the brain.1-4 The aim of this 3-dimensional operative video is to present a microsurgical resection of an AVM in a subparacentral location, operated through an interhemispheric contralateral transfalcine approach.1,3,5 This is a case of a 29-yr-old female, with headaches and history of seizures. The patient presented an interhemispheric bleeding 6 mo before the surgery. The magnetic resonance imaging (MRI) showed a vascular lesion located on the medial surface of the right hemisphere at the confluence between the cingulate sulcus and its ascending sulcus. In the cerebral angiography, a right medial AVM was observed, receiving afference from the right anterior cerebral artery and draining to the superior longitudinal sinus. The patient signed an informed consent for the procedure and agreed with the use of her images and surgical video for research and academic purposes. The patient was in a supine position, and a left interhemispheric contralateral transfalcine approach was performed,1-3 a circumferential dissection of the nidus, and, finally, the AVM was resected in one piece. The patient evolved without neurological deficits after the surgery. The postoperative MRI and angiography showed a complete resection of the AVM. In the case presented, to avoid exposing the drainage vein first and to use the gravity of the exposure, the contralateral transfalcine interhemispheric approach was used,1,2 which finally accomplished the proposed objectives.

Evaluation of Role of Arterialization of Venous Flaps in Abdomen in Rats

Introduction Reconstruction forms the primary tenet in plastic surgery. Venous flaps are a known option but the survival is limited. Arterialization of venous flap can enhance its survival. While various techniques of arterialization of venous flaps are described, there are very few studies comparing them. Material and methods The current study was conducted among 34 rats weighing 160 to 200 grams. The rats were divided into four groups. Group I—islanded epigastric flap was raised with superficial caudal epigastric vessels as pedicle. Group II—arterialized flow through venous flap was raised with superficial caudal epigastric vein (SCEV) as afferent and lateral thoracic vein as drainage vein. Side-to-side anastomosis was done between femoral artery and vein, lateral to the origin of superficial caudal epigastric artery. Group III—after raising the flap, as in group II, femoral vein was ligated proximal to superficial caudal epigastric vessels. Group IV—an arterialized flow through venous flap was raised with superficial caudal epigastric vein as afferent and lateral thoracic vein as drainage vein. End-to-side anastomosis was done between femoral artery and superficial caudal epigastric vein. Animals that died before completion of the study were excluded. The color changes of flaps were noted. Flap survival was expressed as a percentage of the total flap surface area. The patency of anastomosis was seen on postoperative day 5. Results There was no total flap failure. On statical analysis, the flap survival area on day 5 between Group I and Group IV was not significant (p value 0.431). The survival area in Group I (78.85 ± 10.54%) was comparable to Group IV (65.71 ± 20.70%). Group II and III had poor results as compared with Group I. In four rats, thrombosis of arteriovenous anastomosis was noted with flap survival area of 30 to 33%. Conclusion It was noted that epigastric venous flaps with end-to-side anastomosis between femoral artery and superficial caudal epigastric vein (group IV) have survival area comparable to islanded flaps.

Stasis index from hemodynamic analysis using quantitative DSA correlates with hemorrhage of supratentorial arteriovenous malformation: a cross-sectional study

OBJECTIVEAssessments of hemorrhage risk based on angioarchitecture have yielded inconsistent results, and quantitative hemodynamic studies have been limited to small numbers of patients. The authors examined whether cerebral hemodynamic analysis using quantitative digital subtraction angiography (QDSA) can outperform conventional DSA angioarchitecture analysis in evaluating the risk of hemorrhage associated with supratentorial arteriovenous malformations (AVMs).METHODSA cross-sectional study was performed by retrospectively reviewing adult supratentorial AVM patients who had undergone both DSA and MRI studies between 2011 and 2017. Angioarchitecture characteristics, DSA parameters, age, sex, and nidus volume were analyzed using univariate and multivariate logistic regression, and QDSA software analysis was performed on DSA images. Based on the QDSA analysis, a stasis index, defined as the inflow gradient divided by the absolute value of the outflow gradient, was determined. The receiver operating characteristic (ROC) curve was used to compare diagnostic performances of conventional DSA angioarchitecture analysis and analysis using hemodynamic parameters based on QDSA.RESULTSA total of 119 supratentorial AVM patients were included. After adjustment for age at diagnosis, sex, and nidus volume, the exclusive deep venous drainage (p < 0.01), observed through conventional angioarchitecture examination using DSA, and the stasis index of the most dominant drainage vein (p = 0.02), measured with QDSA hemodynamic analysis, were independent risk factors for hemorrhage. The areas under the ROC curves for the conventional DSA method (0.75) and QDSA hemodynamics analysis (0.73) were similar. A venous stasis index greater than 2.18 discriminated the hemorrhage group with a sensitivity of 52.6% and a specificity of 81.5%.CONCLUSIONSIn QDSA, a higher stasis index of the most dominant drainage vein is an objective warning sign associated with supratentorial AVM rupture. Risk assessments of AVMs using QDSA and conventional DSA angioarchitecture were equivalent. Because QDSA is a complementary noninvasive approach without extra radiation or contrast media, comprehensive hemorrhagic risk assessment of cerebral AVMs should include both DSA angioarchitecture and QDSA analyses.

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.

Microsurgical Resection of Spinal Cord Hemangioblastoma: 2-Dimensional Operative Video

This video demonstrates microsurgical resection of spinal cord hemangioblastoma. Hemangioblastomas are rare, benign, highly vascularized tumors classified as grade I according to World Health Organization classification systems. About 3% of all intramedullary tumors are hemangioblastomas.1,2 Spinal cord hemangioblastomas are either sporadic3,4 or manifestations of von Hippel-Lindau (VHL) disease in 20% to 45% of patients.5,6 A 30-year-old male presented with sudden onset urinary incontinence. Magnetic resonance imaging showed contrast enhancing intramedullary tumor with adjacent cyst in T11, and syringomyelia extending to C1. Surgical resection followed rules that apply to resection of arteriovascular malformations: coagulation of arterial feeders precedes the coagulation of the draining vein, which is preserved until the end of surgery.2,4,5,7,8 First, posterior midline myelotomy was performed and the tumor cyst was drained in order to develop a dissection plane. Following this, we continuously separated dorsal nerve roots from the tumor nodule using microsurgical technique. The key step in tumor resection is devascularization of the tumor, achievable in 2 ways.2,7,9-13 The circumferential detachment of the normal pia from the tumor pia is crucial in developing a plane of dissection. The coagulation and division of arterial feeders while preserving the drainage vein further devascularizes the tumor. Once the tumor mural nodule was detached from the spinal cord, the drainage vein was coagulated last and the tumor was removed. The patient fully recovered from his incontinence and was neurologically intact. Screening for VHL disease was negative. Written consent was obtained directly from the patient.

Quantitative evaluation of arteriovenous malformation hemodynamic changes after endovascular treatment using parametric color coding: A case series study

Background Brain arteriovenous malformations (AVMs) are complex vascular lesions. Endovascular treatment results are usually measured by calculating the volume reduction of the lesions. Nevertheless, vascular flow quantification seems a more physiologically accurate way of measuring endovascular results. We evaluated the use of parametric color coding (PCC) with digital subtraction angiography (DSA), in order to determine the feasibility of PCC to detect and measure the impact of AVM endovascular treatment-induced changes using real-time hemodynamic parameters. Methods and results Supratentorial brain AVM treatment was evaluated in 29 patients over the course of 38 sessions. Using regions of interest (ROIs) at the carotid siphon, arterial feeder, drainage vein and venous sinus, we found significant increase in time to peak (TTP) values at the arterial feeder, drainage vein and venous sinus. We compared TTP in four different embolization volume groups: I (0–25%), II (26–50%), III (51–75%) and IV (76–100%). We found significant differences between groups and a moderate correlation between embolization percentages, as well as an increase in TTP at the main vein ROI; but not in the arterial side or sinus. Conclusions Brain AVM endovascular treatment results can be quantified in vivo with PCC. PCC is capable of detecting hemodynamic changes after brain AVM endovascular treatment, that may reflect flow drop, and it is correlated with volume embolization.

Transvenous embolization: a report of 4 pediatric cases

The treatment of brain arteriovenous malformations (AVMs) in children has always been a challenge for interventionalists, neurosurgeons, and radiosurgeons. Endovascular embolization is usually performed through transarterial access, but in selected cases the transvenous approach can be considered. The authors of this report aimed to evaluate the efficacy of transvenous embolization in very selected pediatric cases. They describe 4 children treated using transvenous embolization for AVMs that were small, had a single drainage vein, and were deeply located or had a difficult arterial access. The 6-month angiographic and clinical follow-ups are reported as well. In all cases, complete occlusion of the AVM was achieved with no side effects for the patient. Transvenous embolization may represent a promising alternative therapeutic option in very selected cases.