Endovascular management of renal transplant dysfunction secondary to hemodynamic effects related to ipsilateral femoral arteriovenous graft

Hemodialysis access options become complex in long-term treatment for patients with renal disease, while awaiting renal transplantation (RT). Once upper extremity sites are exhausted, lower extremities are used. RT is preferably in the contralateral iliac fossa, rarely ipsilateral. In current literature, RT dysfunction secondary to the hemodynamic effects of an ipsilateral femoral arteriovenous graft (AVG) has been rarely described. To our knowledge, AVG ligation is the only published technique for hemodynamic correction of an ipsilateral AVG. We present a simple, potentially reversible endovascular approach to manage the hemodynamic effects of an AVG, without potentially permanently losing future AVG access

In vitro and in vivo evaluation of intraluminal ultrasound in normal and atherosclerotic arteries

This study evaluated the dimensional and morphologic precision of arterial images obtained using intraluminal rotating A-scan ultrasound catheters [5.0F (30 mHz) and 8.0F (20 mHz)]. Dimensions of in vitro ultrasound images from human arteries (eight normal and nine arteriosclerotic) were compared with those from histologic sections of the vessels. In addition, in vivo ultrasound studies (23 normal and 22 arteriosclerotic) of canine femoral arteries were compared with luminal dimensions obtained from angiograms of the vessels. The correlation of in vitro ultrasound images to luminal diameters (n=22, r=0.96), adventitial diameters (n=19, r=0.83), and wall thickness (n=19, r=0.68) in normal human vessels was significant (p<0.05). In vitro measurements of images and histologic specimens from human atherosclerotic arteries also correlated significantly (p<0.05) with luminal diameters (n=27, r=0.91), adventitial diameters (n=24, r=0.60), and wall thickness (n=24, r=0.62). Morphologically, in vitro images of the wall of normal human arteries had a concentric laminated appearance and atherosclerotic vessels had patchy echodense and echolucent areas. In vivo studies showed significant correlation of diameters for both normal (n=16, r=0.91, p<0.05) and arteriosclerotic (n=16, r=0.57, p<0.05) canine arteries compared with luminal dimensions measured from uniplanar angiograms. We conclude that rotating A-scan intraluminal ultrasound accurately defines both normal and atherosclerotic arterial wall morphology and dimensions. This technology may be valuable for intravascular guidance of angioplasty devices by identifying the location and consistency of lesions

Analysis of 855 Upper Extremity Fistulas Created Using a Standard Protocol: The Role of Graft Extension to Achieve Functional Status

The Fistula First Breakthrough Initiative (FFBI) has been one of the most important national programs to help achieve considerable improvements in the care of patients on chronic hemodialysis. FFBI has helped place guidelines to push practitioners to reduce the use of tunneled central venous catheters and to increase the rate of arteriovenous fistula use in patients requiring chronic hemodialysis access. However, despite current guidelines, no specific protocols exist for the creation and management of autogenous arteriovenous fistulas and outcomes at most centers are below national benchmarks. In this study, we examine the effectiveness of a standard protocol used at our institution for the creation of autogenous upper extremity fistulas for hemodialysis access in achieving early cannulation and early removal of tunneled dialysis catheters. Our review encompasses 855 consecutive autogenous fistulas created over a 10-year period. Our findings suggest that the use of a standard protocol for creation and management of autogenous fistulas can help increase the rate of functional accesses over national benchmarks. Additionally, extension/conversion of malfunctioning fistulas to grafts appears to be an excellent method to expedite removal of a tunneled dialysis catheter with concomitant preservation of a fistula

Steal syndrome of the hand with a strong palpable radial pulse at the wrist after creation of a basilic-vein-transposition fistula in the arm above the elbow

Steal syndrome is a major complication after creation of an arteriovenous fistula (AVF) and may lead to ischemic symptoms in the hand. A strong palpable radial pulse at the wrist typically excludes the diagnosis of steal syndrome in patients with brachial-artery-based AVF. We present a patient with steal syndrome and a palpable radial pulse after creation of an above-the-elbow AVF using the basilic vein transposition approach. The patient had a brachial artery with high bifurcation and the vein was mistakenly anastomosed to the dominant aberrant ulnar artery. The steal syndrome was treated by proximalization of arterial flow to the proximal brachial artery

In vivo human comparison of intravascular ultrasonography and angiography

This study evaluates the in vivo correlation of intravascular ultrasonography and uniplanar angiography in determining the luminal dimensions of normal and moderately atherosclerotic human arteries. Five French and 8F rotating A scan intravascular ultrasound catheters were used to obtain 48 images in four superficial femoral arteries, five iliac arteries, and one aorta in eight patients undergoing vascular surgery. Cross-sectional areas measured by intravascular ultrasonography were compared to cross-sectional areas calculated by uniplanar angiography of the same location in the vessel. Maximum and minimum luminal diameters were also measured from intravascular ultrasound images. An ellipticity index was defined as the maximum/minimum diameter ratio (max/min) and ranged from 1.0 to 1.8 (mean, 1.2). Comparison of the cross-sectional areas measured from intravascular ultrasound images and those calculated from uniplanar angiography showed no significant difference at any level of ellipticity studied. However, when the values of cross-sectional areas were analyzed in groups corresponding to the diameter of the vessel, that is, aortic, iliac, and femoral, the values for the iliac arteries calculated from uniplanar angiography were significantly greater by 9.8% ± 0.7% (n = 29, p = 0.03) when compared to those measured by intravascular ultrasonography. In addition to providing accurate luminal determinations, intravascular ultrasound images displayed transmural morphology, the location and character of the atherosclerotic lesions, and the thickness of the vessel wall. We conclude that intravascular ultrasound imaging provides accurate, novel information regarding human vessels and that this technology may play a significant role in future diagnostic and interventional therapies

Clinical results of argon laser tissue fusion

Tissue fusion by laser energy is an intriguing arxi very promising new application for laser technology. In coniparison to using high laser energy to ablate tissue as in the aricplasty application, laser tissue fusion is possible in any soft tissue by deliverir appropriate lc levels of energy to the cppose tissue surfaces. This technology is particularly appealing for vascular applications in inakir sutureless blood vessel anastornosis and for securir the endpOints of erxarterect:amies ani dissection planes. Although there have been limitel evaluations of this technology the preliminary experimental ar1 clinical data is very promisir for continu development arid application

Potential of intraluminal ultrasound for angioplasty guidance

The manifestation of atherosclerotic lesions in arteries can vary from asymptomatic thickening in the vessel wall to complete occlusion. Experimental studies on non-human primates and on human subjects indicate that atherosclerotic lesions may progress without a reduction in luminal diameter because of dilatation of the arterial wall . Although angiography has been considered the "gold standard" for visualization of the arterial tree ar1 detection of luminal narrowing, it does not demonstrate arterial wall thickening or morphology. Moreover, the measurement of luminal diameter of the sane lesion can vary considerably depending on the plane of projection of the x-ray beam. This is attributed to the eccentric nature of the residual lumen in an atherosclerotic vessel . Extraluminal B-mode real time imaging has the feasibility of demonstrating arterial lumen and arterial wall thickness. However, it is still in some instances limited by inadequate resolution and image quality. Intraluminal ultrasound using a phased array or rotating transducer gives better definition of the vessel wall and luminal diameter as it is not limited by the tissue interposed between the vessel and the probe in transcutaneous devices. This paper demonstrates further experience with intravascular ultrasound as a diagnostic tool using B-mode real time imaging

A Technique for Prolonged Arterial Infusions of Fibrinolytic Agents in the Immediate Postoperative Period through a Cutaneous Venostomy

Prolonged use of fibrinolytic agents post thrombectomy is limited by present techniques that require arterial puncture and indwelling arterial catheters. This limitation can be avoided by attaching a short segment of saphenous vein to the arteriotomy used for the thrombectomy and bringing this out to the skin as a “venostomy”; thus providing ready access to the vascular tree for arteriography, prolonged infusion of thrombolytic agents, or selective catheter placement. In delayed thrombectomies (Categories 2 & 3 as described by the Ad Hoc Committee on Reporting Standards, J Vasc Surg 1986;4:80-94), extending the use of these agents may represent the only hope for limb salvage. (Ann Vasc Surg 1997;11:546–549.

Abstract 632: Cell Populations In Pre-access Veins And Arteriovenous Fistulas: A Single Cell Perspective

Abstract only Objective: A comprehensive picture of the cellular events dictating the transformation of the vein after arteriovenous fistula (AVF) creation has remained elusive so far. This study generated the first granular cellular atlas of pre-access veins and AVF from patients with end-stage kidney disease (ESKD). Methods: Veins (n=5) and AVF (n=7) were obtained from a total of 12 ESKD patients undergoing fistula creation in two stages. 41,000 enzymatically dissociated cells were single cell sequenced using the 10x Chromium system. Monocle3 inferred the trajectory leading to neointimal cells and signaling interactome in the AVF. Results: Cells populated 16 clusters containing canonical and non-canonical vascular markers after integrating the single cell transcriptomic profiles in Seurat v4. The majority of cells in both veins and AVF were smooth muscle cells (6.6 vs. 9.4%), fibroblasts (12.4 vs. 26.7%), neointimal-like cells (11.5% vs, 17.0, endothelial cells (10.5 vs. 10.5%), macrophages (26.1 vs. 19.5%), lymphocytes (16.4 vs.10.3), and neutrophils (0.7vs. 3.8 %). CENPF+ dividing cells were abundant in the AVF (0.2 to 1.2%). For the first time, we have detected a potential transcriptomic neointimal signature defined by the expression of BGN and PRELP genes that was increased in AVFs, but not absent in the pre-access veins, confirming previous histological findings. Neutrophilic infiltration (S100A8/9+ and CSF3R+) was increased in the AVF. Interestingly, lymphocytes and macrophages were decreased in the AVF with respect to the vein. These changes in cell populations in the AVF wall correlated with up-regulation of GO terms such as ECM deposition, neutrophil activation, and blood vessel remodeling in the AVF. Finally, we established a pseudotime cellular trajectory from contractile SMCs to neointimal-like cells, defined by COL8A1, PRELP, and BGN by Cohen’s I. Conclusions: We present a comprehensive single-cell atlas of the AVF transformation and assign identity to the cellular sources and cell trajectories in this remarkable vascular transformation

In-vivo intravascular ultrasound in human ileo-femoral vessels

This study evaluates the ability of intravascular ultrasound (IUS) to image normal and mildly diseased human ileo-femoral vessels during angioplasty or vascular bypass procedures. Five Fr. and 8Fr. rotating A scan IUS catheters were used to obtain 43 images in 4 superficial femoral arteries, and 5 iliac arteries in 8 vascular surgery patients. Luminal cross sectional (LCS) areas measured by IUS were compared to LCS areas calculated by uniplanar angiography (ANGIO) at the same location in the vessel. The correlation between the areas (IUS vs ANGIO) for all images was significant (n = 43, r = 0.90, P<0.05). Mean LCS area calculated from ANGIO (33.7 +/- 21 mm ) was greater than LCS area measured by IUS (30.6 +/- 19.5 mm ) with n = 43; P = 0.02. In addition to providing accurate luminal determinations, IUS images displayed transmural morphology, the location of the atherosclerotic lesions and the thickness of the vessel wall. We conclude that IUS imaging provides accurate, novel information regarding human vessel wall anatomy and luminal dimensions. This technology may play a significant role in future diagnostic and interventional therapies