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The primary objective was to compare the accuracy of dynamic computed tomography (CT) angiography (d-CTA) with standardized triphasic contrast enhanced CT angiography (t-CTA) in diagnosing endoleak type after endovascular aortic repair (EVAR) using digital subtraction angiography (DSA) as reference standard. The secondary objective was to study the impact of d-CTA on image fusion-guided endoleak embolization.A retrospective review of patients who underwent d-CTA imaging after EVAR between March 2019 and July 2021 was performed. Deidentified images were independently reviewed by two-two blinded readers to document endoleak type and target vessels. An impact of d-CTA-guided embolization was evaluated by a number of planning angiograms, radiation exposure, and accuracy of target vessel overlay.During the study period, 52 patients underwent d-CTA and 19 had all 3 modalities available for analysis. DSA imaging confirmed 4 (21.0%) type-I, 14 (73.7%) type-II, and 1 (5.3%) type-III endoleak. Findings from d-CTA matched with DSA in 19/19 cases (100%), whereas t-CTA matched in 14/19 cases (73.7%). In type-II endoleaks, the number of target vessels identified by d-CTA, t-CTA, and DSA were 23, 17, and 16, respectively. Mean dose-length product from d-CTA and t-CTA was 1,445 ± 551 and 1,612 ± 530 mGy × cm (P = 0.26). Nine patients underwent d-CTA-guided type-II endoleak embolization, using a median of 1 (range: 1-4) planning angiogram before embolization using 21.6 (± 8.7)% of total procedural radiation dose. Target vessel overlay was accurate in 9/9 (100%) cases.Dynamic, time-resolved CTA is more accurate compared to standardized triphasic contrast enhanced CTA in diagnosing endoleak type after EVAR. In type-II endoleak, d-CTA better identified target vessels and enabled safe, targeted embolization.

Purpose: Our purpose was to study the accuracy of dynamic computed tomography angiography (d-CTA) in characterizing endoleak type, inflow vessels as compared with digital subtraction angiography (DSA) using qualitative and quantitative analysis. Methods: Between March 2019 and January 2021, all patients who underwent d-CTA imaging after EVAR were retrospectively reviewed. Two blinded independent reviewers qualitatively reviewed d-CTA and DSA images. Quantitative region of interest (ROI) analysis was performed by measuring time-resolved contrast enhancement within the aorta and endoleak lesion(s) in the aneurysm sac. Differences between time-to-peak enhancement (Δ TTP) across different ROIs were quantified. Results: A total of 48 patients underwent d-CTA during the study period, of whom 24 patients had abdominal EVAR and DSA imaging for comparison. Qualitative review of DSA imaging showed type I (n=4), type II (n=16), and type III (n=2) and no endoleak (n=2). In 23 of 24 patients (95.8%), d-CTA findings correlated with DSA findings for endoleak type. One patient had a type III endoleak that was demonstrated only in d-CTA (arising from defect in polymer sealing ring of Ovation stent graft) imaging. In type II endoleak cases, d-CTA identified more inflow vessels than DSA imaging (33 vs 21 vessels, p=0.010). Quantitative analysis showed mean (±SD) Δ TTP values for type I endoleak as 1.8 (±1.8) seconds, type II as 9.6 (±3.5) seconds, and for type III endoleak as 5.6 (±1.3) seconds. Conclusion: Dynamic CTA can accurately characterize aortic endoleak type, inflow vessels as compared with DSA imaging. Quantitative parameters such as Δ TTP enhancement can help better differentiate endoleak types and provide an objective approach to endoleak diagnosis.

Central venous obstruction in the symptomatic patient is often treated with endovascular stenting. A rare, but serious, complication of this treatment is migration of the stent from the original site of deployment. Treatment of this complication requires either open or endovascular retrieval of the displaced stent. To treat a rare, but potentially devastating, complication, we have presented an effective endovascular method for migrated stent retrieval using a combination of a large bore sheath, balloon, and snare.

Although venous aneurysms are rare, typically asymptomatic, and most commonly found incidentally on imaging studies, patients with this pathology can develop pulmonary emboli owing to these aneurysms acting as a nidus for thrombus formation. There is no clear consensus regarding conservative management with anticoagulation vs operative intervention as the best treatment of deep venous aneurysms. We report the clinical course and surgical treatment of a patient presenting with both bilateral common femoral vein and bilateral popliteal venous aneurysms who had a known history of prior symptomatic pulmonary emboli.

Purpose: Thoracic central venous obstruction is commonly associated with the use of central venous catheters. The Surfacer System to Facilitate Access in Venous Occlusions Study was an Food and Drug Administration–approved US Investigational Device Exemption study designed to evaluate the performance and safety of the Surfacer System when used to facilitate central venous access in patients with thoracic central venous obstruction. Methods: Thirty patients were enrolled in this prospective, multicenter, single-arm study between December 2017 and May 2019. Device performance and adverse events were collected peri-procedurally and at discharge. Enrollment included 15 female and 15 male subjects with a mean age of 55.5 ± 12.9 (range: 30–79) years. Twenty-eight patients (93.3%) required central venous access for hemodialysis access. Locations of thoracic central venous obstruction were graded from 1 to 4 based on severity and extension of venous occlusions. Seven patients (23.3%) had type 1, 6 (20.0%) type 2, 16 (53.3%) type 3, and 1 (3.3%) type 4 obstruction. Results: Successful central venous catheter placement was achieved in 27 of 30 patients (90.0%). The procedure was discontinued in three (10.0%) due to tortuous anatomy discovered intraprocedurally. All 27 patients with successful CVC placement achieved adequate catheter patency and tip positioning with a mean overall procedural time and time to achieve central venous access with the Surfacer System being 44.1 ± 30.6 and 19.1 ± 25.1 min, respectively. There were no device-related adverse events or catheter malposition. Conclusion: The results of the SAVEUS Study confirm the safety and efficacy of the Surfacer System and the Inside-Out procedure when used for the placement of right-sided central venous access in patients with thoracic central venous obstruction.

Postoperative groin complication is a common cause of morbidity in vascular surgery. Prophylactic wound adjuncts addressing this issue have been shown to reduce complications in high-risk patients, but their widespread implementation is limited by their high cost. This study introduces a risk prediction model for patients at a high risk for groin complication which can be accessed through the iPhone application, Vasculink.A literature search identified risk prediction models for groin complication in vascular surgery. Odds ratios of risk factors that were present in at least 2 published models were calculated with a pooled effect size. The weighted risk for each factor was used to create our model and a cutoff point defining high risk patients was chosen. The initial model was assessed and validated using a split-sample methodology on a cohort identified via a retrospective chart review of all patients undergoing open vascular surgery at our institution between 2017 and 2020. Model performance was assessed using the C-statistic.Risk factors included in our model were female gender, body mass index ≥28 kg/mBy using risk factors identified in the literature we have been able to establish a highly sensitive risk prediction model for groin complication following open vascular surgery. By incorporating our model into an iPhone application, Vasculink, we hope to facilitate preoperative decision making regarding the use of prophylactic wound adjuncts.

The novel Surfacer Inside-Out recanalization technique facilitates right-sided central venous access in occluded vessels but carries a risk of arterial and pleural injuries. This article demonstrates how an advanced intraoperative imaging protocol can help to avoid these potential complications.This retrospective review included patients undergoing the Surfacer Inside-Out central venous recanalization procedure between December 2017 and October 2021. The study sample comprised patients included in the SAVE-US trial at our site as well as patients treated after US Food and Drug Administration approval of the device. All procedures were performed using intraoperative cone-beam computed tomography (CBCT) angiography to map out the trajectory of the device through the mediastinum and supraclavicular space with fusion imaging for guidance. Procedures were aborted if CBCT findings predicted injury to arterial or respiratory structures. The intraoperative coronal and sagittal orientation of the device was compared to preoperatively predicted trajectory.A total of 17 procedures were performed in 16 patients with end-stage renal disease and a mean age of 61 ± 11 years. Most patients presented a type 3 central venous occlusion (9/15). Successful recanalization was achieved in 14 of the 17 cases (82.4%) with no intraoperative complications. The procedure had to be aborted in 3 of the 17 cases based on intraoperative CBCT findings, which projected the device to perforate the right pleural space in one patient, the trachea and right subclavian artery in another, and the innominate artery in the third patient. The total radiation dose per procedure was 753 ± 346 mGy and the mean procedural time was 101.6 ± 29.7 minutes. A median of 2 (range, 1-5) intraoperative CBCT scans were performed per patient and accounted for 70% of the total radiation dose. Statistical analysis showed intraoperative CBCT findings to differ significantly from preoperative predicted values.The nonsteerable and penetrating nature of the Surfacer device may lead to serious complications when performed under fluoroscopic guidance alone. Intraoperative CBCT with fusion overlay enhances the safety and effective use of this device and inside out crossing technique.

Because of the fear of obliterating the collateral outflow path and thus worsening venous hypertension, many physicians believe that deep venous obstruction (DVO) is a contraindication for the treatment of superficial venous reflux (SVR). In the present review, we have described the available clinical data for this important group of patients.A literature search was performed of PubMed, Web of Science, and Google Scholar to identify clinical research studies reported between 1991 and 2021 that had evaluated the concomitant management of SVR and DVO. Studies were excluded if they had included fewer than five patients, had not specified the interventions used to treat SVR, or had no follow-up data available. All the studies included were observational, and their quality was assessed using the Newcastle-Ottawa scale.Ten retrospective cohort studies were included, with a total of 2476 limbs in 2428 patients, with concurrent SVR and DVO or a known history of deep vein thrombosis treated in 944 limbs. Of the 10 studies, 8 were comparative. The level of DVO was suprainguinal, when specified, in most cases. The mean age range was 42 to 65 years, 1432 patients (59%) were women, and advanced chronic venous disease (ie, CEAP [clinical, etiologic, anatomic, pathophysiologic] class 4-6) was present in 614 limbs (70%), with two studies reporting uniquely on C6 patients. Of the 944 limbs treated for concomitant SVR and DVO, a combination of saphenous vein ablative procedures and deep venous stenting was performed in 483 limbs (51.2%), saphenous vein ablative procedures alone in 293 limbs (31%), and deep venous stenting alone in 168 (17.8%). Of the five studies comparing the different treatment strategies to treat concurrent SVR and DVO, four reported better outcomes after a combination of deep venous stenting and saphenous vein ablation compared with ablation alone. Studies comparing the outcomes of saphenous ablation for patients with reflux alone vs patients with concurrent reflux and DVO did not find any significant differences in clinical improvement and postoperative complication rates.The current evidence is weak owing to the limited number of studies and small sample size but suggests that ablation of SVR is safe for patients with concurrent DVO. Patients with advanced venous disease and iliac vein obstruction had better results when SVR ablation was combined with treatment of iliac vein obstruction. Additional contemporary studies are needed to confirm the safety and specifically investigate the efficacy of SVR ablation in relieving the symptoms of patients with concurrent infrainguinal obstruction.

Objective: Arteriovenous fistulas created for hemodialysis often fail to become usable and are frequently abandoned. This prospective trial evaluated the efficacy of vonapanitase, a recombinant human elastase, in increasing radiocephalic fistula use for hemodialysis and secondary patency. Methods: PATENCY-2 was a randomized, double-blind, placebo-controlled trial in patients on or approaching the need for hemodialysis undergoing radiocephalic arteriovenous fistula creation. Of 696 screened, 613 were randomized, and 603 were treated (vonapanitase n = 405, placebo n = 208). The study drug solution was applied topically to the artery and vein for 10 min immediately after fistula creation. The primary endpoints were fistula use for hemodialysis and secondary patency (fistula survival without abandonment). Other efficacy endpoints included unassisted fistula use for hemodialysis, primary unassisted patency, fistula maturation and unassisted maturation by ultrasound criteria, and fistula procedure rates. Results: The proportions of patients with fistula use for hemodialysis was similar between groups, 70% vonapanitase and 65% placebo, ( p = 0.33). The Kaplan–Meier estimates of 12-month secondary patency were 78% (95% confidence interval [CI], 73–82) for vonapanitase and 76% (95% CI, 70–82) for placebo ( p = 0.93). The proportions with unassisted fistula use for hemodialysis were 46% vonapanitase and 37% placebo ( p = 0.054). The Kaplan–Meier estimates of 12-month primary unassisted patency were 50% (95% CI, 44–55) for vonapanitase and 43% (95% CI, 35–50) for placebo ( p = 0.18). There were no differences in the proportion of patients with fistula maturation or in fistula procedure rates. Adverse events were similar between groups. Vonapanitase was not immunogenic. Conclusions: Vonapanitase treatment did not achieve clinical or statistical significance to meaningfully improve radiocephalic fistula surgical outcomes. Outcome in the placebo group were better than in historical controls. Vonapanitase was well-tolerated and safe. TRIAL REGISTRATION: clinicaltrials.gov: NCT02414841 ( https://clinicaltrials.gov/ct2/show/NCT02414841 )

Medial claviculectomy is an alternative option for thoracic outlet decompression. Claviculectomy provides exceptional exposure of the subclavian vein resulting in excellent reported outcomes for decompression and resolution of symptoms related to symptomatic venous thoracic outlet (VTOS) and dialysis associated VTOS. Therefore, medial claviculectomy is a very viable surgical alternative for this particular patient population. Cosmetic results may not be quite as satisfactory as the transaxillary first rib resection, but functional outcomes remains good and there are minimal reported post-operative deficits.

Venous Thoracic Outlet Syndrome in dialysis patients (AVF- VTOS) is a poorly recognized entity. Symptomatic central venous stenosis in dialysis patients is a vexing problem with no unified treatment approach. Careful consideration of the dialysis shunt is required for thorough evaluation. Existing literature for treatment options focuses primarily on endovascular treatments, but lumps together all central venous lesions, making it challenging to tease out the subclavian venous stenoses that are likely related to thoracic outlet compression. Thoracic outlet stenosis in dialysis patients clearly does exist as evidenced by recurrence at that location and fractured stents. We propose evaluation and treatment considerations.

Jumonji domain-containing protein-3 (JMJD3), a histone H3 lysine 27 (H3K27) demethylase, promotes endothelial regeneration, but its function in neointimal hyperplasia (NIH) of arteriovenous fistulas (AVFs) has not been explored. In this study, we examined the contribution of endothelial JMJD3 to NIH of AVFs and the mechanisms underlying JMJD3 expression during kidney failure. We found that endothelial JMJD3 expression was negatively associated with NIH of AVFs in patients with kidney failure. JMJD3 expression in endothelial cells (ECs) was also downregulated in the vasculature of chronic kidney disease (CKD) mice. In addition, specific knockout of endothelial JMJD3 delayed EC regeneration, enhanced endothelial mesenchymal transition, impaired endothelial barrier function as determined by increased Evans blue staining and inflammatory cell infiltration, and accelerated neointima formation in AVFs created by venous end to arterial side anastomosis in CKD mice. Mechanistically, JMJD3 expression was downregulated via binding of transforming growth factor beta 1-mediated Hes family transcription factor Hes1 to its gene promoter. Knockdown of JMJD3 enhanced H3K27 methylation, thereby inhibiting transcriptional activity at promoters of EC markers and reducing migration and proliferation of ECs. Furthermore, knockdown of endothelial JMJD3 decreased endothelial nitric oxide synthase expression and nitric oxide production, leading to the proliferation of vascular smooth muscle cells. In conclusion, we demonstrate that decreased expression of endothelial JMJD3 impairs EC regeneration and function and accelerates neointima formation in AVFs. We propose increasing the expression of endothelial JMJD3 could represent a new strategy for preventing endothelial dysfunction, attenuating NIH, and improving AVF patency in patients with kidney disease.

BACKGROUND Percutaneous devices for creation of native arteriovenous fistulae offer an alternative to traditional open surgical techniques. The 4 Fr WavelinQ EndoAVF System was developed as a lower profile alternative to facilitate access through smaller vessels and minimize access site complications; The current report is the original first experience of this device, assessing outcome in 120 patients followed for 6 months. METHODS The use of the 4 Fr WavelinQ system in three studies, EASE (32 patients), EASE-2 (24 patients), and the EU post-market clinical follow-up study (64 patients) was aggregated and analyzed. Patients were followed with duplex ultrasound at discharge and follow-up visits at 1, 3, and 6 months. Primary, assisted primary, and secondary patency rates were evaluated as Kaplan-Meier (KM) estimates and standard errors. Time to maturity and time to successful cannulation were defined as the mean ± SD days from the procedure in patients enrolled on dialysis. RESULTS Procedural success was achieved in 116 patients (96.7%). Primary, assisted-primary, and secondary 6-month patency rates were 71.9%±4.5%, 80.7%±4.1%, and 87.8%±3.3%, respectively. Time to maturity averaged 41±17 days. Time to successful cannulation averaged 68±51 days. Device-related serious adverse events were reported in 3/120 patients (2.5%) and procedure-related serious adverse events occurred in 7/120 patients (5.8%). Arterial or venous access complications were not reported in any of the patients. Access circuit reinterventions were performed in 23 patients (19.2%), split between those performed for EndoAVF maturation (13/120, 10.8%) and maintenance (11/120. 9.2%). CONCLUSIONS Percutaneous creation of native dialysis fistulae with the 4 Fr WavelinQ EndoAVF System is safe and effective, with favorable durability and a low rate of serious complications and reinterventions through 6-month follow-up. Utilization of the 4F device allows for percutaneous fistula creation between the radial artery and radial vein or the ulnar artery and ulnar vein. These findings suggest that the 4 Fr device is a useful percutaneous alternative to open surgical AVF or endovascular AVF with larger-bore devices.

Chronic kidney disease (CKD) induces the failure of arteriovenous fistulas (AVFs) and promotes the differentiation of vascular adventitial GLI1-positive mesenchymal stem cells (GMCs). However, the roles of GMCs in forming neointima in AVFs remain unknown. GMCs isolated from CKD mice showed increased potential capacity of differentiation into myofibroblast-like cells. Increased activation of expression of PDGFRA and hedgehog (HH) signaling were detected in adventitial cells of AVFs from patients with end-stage kidney disease and CKD mice. PDGFRA was translocated and accumulated in early endosome when sonic hedgehog was overexpressed. In endosome, PDGFRA-mediated activation of TGFB1/SMAD signaling promoted the differentiation of GMCs into myofibroblasts, extracellular matrix deposition, and vascular fibrosis. These responses resulted in neointima formation and AVF failure. KO of Pdgfra or inhibition of HH signaling in GMCs suppressed the differentiation of GMCs into myofibroblasts. In vivo, specific KO of Pdgfra inhibited GMC activation and vascular fibrosis, resulting in suppression of neointima formation and improvement of AVF patency despite CKD. Our findings could yield strategies for maintaining AVF functions., Hedgehog signaling regulates PDGFRA in vascular adventitial mesenchymal stem cells to promote neointima formation in arteriovenous fistula in chronic kidney disease.

Even in the best of circumstances, a significant number of patients will require adjunctive endovascular and/or surgical revision prior to achieving functional patency after endovascular or percutaneous AVF creation, at least within the United States. This rate appears to be higher after percutaneous AVF than after endovascular AVF, although because published reports of the former are mostly derived from American experience and those of the latter derived from experience outside the United States, it is unclear whether these differences are due to the technique itself or cultural and/or anatomic differences in dialysis access practices and patient populations. If arterial inflow is poor, this should be corrected first. When flow is adequate (perhaps 900 cc/min) but no single vein is cannulatable, a dominant suitable vein can be superficialized or transposed. If no suitable vein is dominant (most accurately assessed by using an intraoperative flowmeter), the best vein can be used, with or without occlusion of the other veins or reimplantation into the brachial artery. Finally, if the original anastomosis remains the sole supply to the cannulated vein, the original fistula has achieved assisted primary maturation (and assisted primary patency continues), while if a new arteriovenous anastomosis has been constructed, the original fistula has failed. We point out that for this reason as well as to best utilize the upper arm for later access, endovascular and percutaneous AVFs should be constructed and maintained within an atmosphere where both surgeons and non-surgeons work together on the overall access plan.

Purpose: Thoracic central venous obstruction is commonly associated with the use of central venous catheters. The Surfacer System to Facilitate Access in Venous Occlusions Study was an Food and Drug Administration–approved US Investigational Device Exemption study designed to evaluate the performance and safety of the Surfacer System when used to facilitate central venous access in patients with thoracic central venous obstruction. Methods: Thirty patients were enrolled in this prospective, multicenter, single-arm study between December 2017 and May 2019. Device performance and adverse events were collected peri-procedurally and at discharge. Enrollment included 15 female and 15 male subjects with a mean age of 55.5 ± 12.9 (range: 30–79) years. Twenty-eight patients (93.3%) required central venous access for hemodialysis access. Locations of thoracic central venous obstruction were graded from 1 to 4 based on severity and extension of venous occlusions. Seven patients (23.3%) had type 1, 6 (20.0%) type 2, 16 (53.3%) type 3, and 1 (3.3%) type 4 obstruction. Results: Successful central venous catheter placement was achieved in 27 of 30 patients (90.0%). The procedure was discontinued in three (10.0%) due to tortuous anatomy discovered intraprocedurally. All 27 patients with successful CVC placement achieved adequate catheter patency and tip positioning with a mean overall procedural time and time to achieve central venous access with the Surfacer System being 44.1 ± 30.6 and 19.1 ± 25.1 min, respectively. There were no device-related adverse events or catheter malposition. Conclusion: The results of the SAVEUS Study confirm the safety and efficacy of the Surfacer System and the Inside-Out procedure when used for the placement of right-sided central venous access in patients with thoracic central venous obstruction.

Surgical site infection (SSIs) in lower extremity vascular procedures is a major contributor to patient morbidity and mortality. Despite previous advancements in preoperative and postoperative care, the surgical infection rate in vascular surgery remains high, particularly when groin incisions are involved. However, successfully targeting modifiable risk factors reduces the surgical site infection incidence in vascular surgery patients. We conducted an extensive literature review to evaluate the efficacy of various preventive strategies for groin surgical site infections. We discuss the role of preoperative showers, preoperative and postoperative antibiotics, collagen gentamicin implants, iodine impregnated drapes, types of skin incisions, negative pressure wound therapy, and prophylactic muscle flap transposition in preventing surgical site infection in the groin after vascular surgical procedures.

Objective: In complex dialysis patients, central venous stenosis may preclude additional upper extremity access options. The Hemodialysis Reliable Outflow graft (Merit Medical Systems, Inc.) can bypass this stenosis providing patients with an additional upper extremity long-term access option. We report our experience with early-cannulation Hemodialysis Reliable Outflow grafts and compare them to traditional Hemodialysis Reliable Outflow grafts. Methods: We retrospectively reviewed all patients undergoing Hemodialysis Reliable Outflow graft placement from 1 January 2013 through 15 August 2017 at our institution and compared those undergoing placement of traditional Hemodialysis Reliable Outflow grafts and simultaneous tunneled dialysis catheter insertion to those undergoing Hemodialysis Reliable Outflow graft placement using an early-cannulation Hemodialysis Reliable Outflow graft without a tunneled dialysis catheter. Results: A total of 88 patients had 98 Hemodialysis Reliable Outflow grafts inserted throughout this time period. Of these, 61 (62%) were early-cannulation Hemodialysis Reliable Outflow grafts, while 37 (38%) were traditional Hemodialysis Reliable Outflow grafts. Primary, primary-assisted, and secondary patency rates at 1 year were higher for the traditional Hemodialysis Reliable Outflow graft cohort (53.1% vs 25.2%, p < 0.01; 70.1% vs 30.5%, p < 0.01; and 80.4% vs 55.4%, p = 0.07, respectively). There was no difference in the rate of postoperative hematoma, seroma, pseudoaneurysm formation, steal syndrome, or overall graft thrombosis between the two cohorts. Early-cannulation Hemodialysis Reliable Outflow grafts required earlier reintervention for thrombosis and earlier reintervention for any cause when compared to traditional Hemodialysis Reliable Outflow grafts (146 ± 184 days vs 417 ± 272 days, p < 0.01, and 123 ± 169 days vs 401 ± 311 days, p < 0.01, respectively). Conclusion: In complex dialysis patients, early-cannulation Hemodialysis Reliable Outflow grafts have significantly lower 1-year primary and primary-assisted patency rates and require earlier reintervention to maintain this patency compared to traditional Hemodialysis Reliable Outflow grafts.

A woman in her mid-forties with a history of cervical cancer requiring chemoradiation presented with bilateral ureteral strictures secondary to radiation therapy. The ureteral obstruction was initially relieved with bilateral percutaneous nephrostomy tubes, and subsequently, bilateral ureteral stents. Over the course of 8 months, she presented with multiple episodes of severe gross haematuria. This persisted even after stent removal and conversion back to percutaneous nephrostomy tubes. The initial evaluation, done with concern for an uretero-iliac artery fistula, which included bilateral retrograde pyelograms and CT angiography was non-diagnostic. Given continued haematuria, repeat endoscopic evaluation was undertaken; on retrograde pyelogram, brisk contrast was seen to pass into the arterial system, consistent with a left ureteroarterial fistula. The patient underwent endovascular iliac artery stent placement. Subsequently, the patient underwent resection of the iliac artery with endovascular graft in situ, left distal ureterectomy with proximal ureteral ligation following femoral-to-femoral bypass. This allowed for complete resolution of the patient’s gross haematuria episodes.

Objective Outflow tract stenosis is the leading cause of hemodialysis access loss. Many lesions are highly resistant to endovascular treatment, necessitating open surgical intervention. We present our experience using medial claviculectomy for treatment of recalcitrant lesions at the thoracic outlet. Methods We retrospectively reviewed patients who underwent medial claviculectomy for dialysis-associated venous thoracic outlet syndrome at our institution between February 2013 and February 2018. Data collection included demographics, past medical history, access history, subsequent procedures, preoperative and postoperative brachial volume flows, and access use. Results We performed 25 medial claviculectomies in 25 patients with central venous stenosis. Four patients underwent concomitant central venous bypass and were excluded from this study. Twelve accesses were created at our institution; of these, the average access age was 41.6 months (±26.7 months). All patients previously underwent multiple angioplasty attempts to treat outflow stenosis and continued to have residual symptoms and poor fistula function. Medial claviculectomy with venolysis and angioplasty were performed to treat residual outflow stenosis at the level of the subclavian vein. Twenty-one patients had residual stenosis requiring angioplasty. Six patients had subclavian rupture requiring stent graft placement. All patients reported symptom improvement and immediate use of the fistula after medial claviculectomy. Nineteen (76%) patients reported complete resolution of symptoms after the procedure. Ultimately, eight (32%) ipsilateral arteriovenous accesses were lost, and six (24%) patients died in follow-up with patent, functional fistulas. Median length of follow-up was 17 months (interquartile range, 5-28 months). The 18-month primary patency and secondary patency with regard to subclavian vein interventions were 28% (95% confidence interval, 13.8%-56.1%) and 84% (95% confidence interval, 69.7%-100%), respectively. One patient required ligation for high-output cardiac failure. One patient had contralateral brachiocephalic jailing, which was corrected with kissing brachiocephalic stents. Conclusions Medial claviculectomy is an effective treatment of recalcitrant central venous stenosis of the thoracic outlet. Balloon angioplasty or stent or stent graft placement is often necessary after extrinsic compression is alleviated and demonstrates acceptable secondary patency rates.

Neointima formation is a major contributor to arteriovenous fistula (AVF) failure. We have previously shown that activation of the Notch signaling pathway contributes to neointima formation by promoting the migration of vascular smooth muscle cells (VSMCs) into the venous anastomosis. In the current study we investigated the mechanisms underlying the dedifferentiation and migration of VSMCs, and in particular the role of bone marrow-derived fibroblast specific protein 1 (FSP-1)(+) cells, another cell type found in models of vascular injury. Using VSMC-specific reporter mice, we found that most of the VSMCs participating in AVF neointima formation originated from dedifferentiated VSMCs. We also observed infiltration of bone marrow-derived FSP-1+ cells into the arterial anastomosis where they could interact with VSMCs. In vitro, conditioned media from FSP-1+ cells stimulated VSMC proliferation and phenotype switching. Activated Notch signaling transformed FSP-1(+) cells into type I macrophages and stimulated secretion of cytokines and growth factors. Pretreatment with a Notch inhibitor or knockout of the canonical downstream factor RBP-Jκ in bone marrow-derived FSP1(+) cells decreased FSP1(+) cell infiltration into murine AVFs, attenuating VSMC dedifferentiation and neointima formation. Our results suggest that targeting Notch signaling could provide a new therapeutic strategy to improve AVF patency.

Objective Arteriovenous fistulas created in patients with chronic kidney disease often lose patency and fail to become usable. This prospective trial evaluated the efficacy of vonapanitase, a recombinant human elastase, in promoting radiocephalic fistula patency and use for hemodialysis. Methods PATENCY-1 was a double-blind, placebo-controlled trial that enrolled 349 patients on or approaching hemodialysis and being evaluated for radiocephalic arteriovenous fistula creation. Of these, 313 were randomized and 311 treated. Patients were assigned to vonapanitase (n = 210) or placebo (n = 103). The study drug solution was applied topically to the artery and vein for 10 minutes immediately after fistula creation. The primary and secondary end points were primary patency (time to first thrombosis or corrective procedure) and secondary patency (time to abandonment). Tertiary end points included use of the fistula for hemodialysis, fistula maturation by ultrasound, and procedure rates. Results The Kaplan-Meier estimates of 12-month primary patency were 42% (95% confidence interval [CI], 35-49) and 31% (95% CI, 21-42) for vonapanitase and placebo (P = .25). The Kaplan-Meier estimates of 12-month secondary patency were 74% (95% CI, 68-80) and 61% (95% CI, 51-71) for vonapanitase and placebo (P = .048). The proportions of vonapanitase and placebo patients were 39% and 25% (P = .035) with unassisted use for hemodialysis and 64% and 44% (P = .006) with unassisted plus assisted use. Conclusions Vonapanitase treatment did not significantly improve primary patency but was associated with increased secondary patency and use for hemodialysis. Further research is needed to evaluate these end points.

Purpose: To describe the use of the Hybrid vascular graft in disadvantaged anatomy for hemodialysis access creation and compare outcomes to standard-wall polytetrafluoroethylene (PTFE) grafts. Methods: In a retrospective analysis, 25 patients (mean age 65±14 years; 13 men) who received the Hybrid graft were compared with 35 contemporaneous patients (mean age 63±12 years; 20 men) who received a standard PTFE graft for hemodialysis access over a 2-year period. Criteria for Hybrid graft placement were (1) exhausted or inadequate peripheral veins for arteriovenous fistula (AVF) creation and concomitant small target veins that precluded conventional PTFE graft placement, (2) previous graft anastomosis or a stent in the venous target at the level of the axilla, or (3) failed brachial-basilic or brachial-brachial upper arm transposition AVF with a small target vein at the axilla. Efficacy, anatomic and clinical considerations, and technique were reviewed; patency rates, complications, and reinterventions were examined. Results: Technical success was achieved in all cases, and all grafts were usable for hemodialysis. Seven of 25 Hybrid patients required stent-graft extensions and 3 patients required angioplasty to improve venous outflow at the time of Hybrid graft insertion. Three of 35 standard PTFE graft patients required angioplasty to improve venous outflow at the time of graft insertion. There was no perioperative mortality or procedure-related morbidity in either group. Median follow-up was 21 months. The patient survival estimate was 66% at 2 years. Estimated primary patency (24% vs 18%, p>0.05), assisted primary patency (34% vs 28%; p>0.05), and secondary patency rates (40% vs 38%, p≥0.05) at 24 months were equivalent for Hybrid vs PTFE grafts, respectively. Venous hypertension was not a complication following Hybrid graft implantation but was seen in 2 patients with the standard PTFE graft. Conclusion: The Hybrid graft offers a safe, technically effective alternative for patients with disadvantaged anatomy requiring hemodialysis access and has comparable outcomes to standard PTFE grafts. Further clinical experience and long-term data are required for determining the proper utility of this device in chronic dialysis-dependent patients.

Background Arteriovenous fistula (AVF) aneurysms (AVFAs) can lead to skin erosion, bleeding, difficult access while on hemodialysis, and poor cosmetic appearance. We reviewed our experience in treating patients with aneurysmal dilatation of their AVF. Methods We reviewed clinical data of 48 patients (37 men; overall mean age, 55 years; range, 28-85 years) with an AVFA who underwent treatment during a 30-month period. Relevant clinical variables and treatment outcomes were analyzed. Results All patients underwent a fistulogram, and 90% required percutaneous angioplasty to improve outflow. Fifty-six percent of patients had one stenotic outflow lesion, and 44% had at least two tandem outflow stenoses that required treatment. Open repair with aneurysmorrhaphy was performed in one stage in 64% of patients and in two stages in 36%. A tunneled hemodialysis catheter was required in 11 patients (23%) until the surgically repaired AVF was ready for use again, comprising 10 patients treated with single-stage surgery and only one patient in the staged group. All AVFAs were effectively treated, and patients were able to maintain functional use of their access when healed. Conclusions There is a high association of venous outflow stenoses and AVFA. Comprehensive therapy should encompass treatment of any venous outflow stenoses before open AVFA repair. A two-stage repair may decrease tunneled hemodialysis catheter use in patients with multiple aneurysms.

Despite the lower cost, improved early survival, and preservation of the remaining kidney function, peritoneal dialysis is used by only 8.8% of the dialysis population in the USA. Intraabdominal adhesions reported in 70-90% of patients with prior abdominal surgery (PAS) reduce the peritoneal surface area and may increase the intraoperative and postoperative morbidity. The objective of this study is to evaluate the outcomes of laparoscopic peritoneal dialysis (LPD) catheter placement in patients with and without PAS.Patients who had LPD catheters placed between January 2014 and August 2016 were retrospectively reviewed. A Kaplan-Meier analysis was performed to assess the revision-free catheter survival (RFCS) and revision-assisted catheter survival (RACS) between the 2 groups.One hundred forty-two patients had had LPD catheter placed during the study time, 82 (58%) with PAS. Lysis of adhesions (LOA) was required in 26 patients (28%) with PAS. Demographics and comorbidities were similar, but more women had PAS (65% vs. 35%, P 0.001). Seventeen patients (12%) required revision, with no difference between the 2 groups. Both RFCS and RACS were similar in patients without and with PAS (P = 0.38 and 0.98, respectively). RFCS was 73% vs. 64% at 1 year (no PAS versus PAS) and 62% vs. 51% at 2 years, whereas RACS was 84% vs. 77% at 1 year (no PAS versus PAS) and 69% vs. 68% at 2 years. Only 2 intraoperative complications occurred, namely a superficial liver injury and pelvic hematoma. Three complications (0.02%) occurred within 30 days, namely 1 peritonitis and 2 catheter malfunctions. Overall complication rate was 25%, predominantly poor drainage (17% and 22% for PAS and no PAS, respectively), and there were no differences between the subgroups. No deaths occurred within a year of surgery during the study follow-up.LPD and LOA can be performed safely in patients with multiple PAS. When possible, LPD catheters should be part of the vascular surgery training armamentarium and offered to patients with PAS.

Introduction: Central venous occlusive (CVO) disease involving the superior vena cava (SVC) and inferior vena cava (IVC) can occur frequently in patients with end-stage renal disease (ESRD) on chronic dialysis. Dialysis access is essential for the survival of these patients. Case description: We report a case of a chest wall graft creation using bovine carotid artery conduit in a patient who was experiencing life-threatening loss of dialysis access secondary to her SVC and IVC occlusion along with a hypercoagulable state. We did a subcutaneous anterior chest wall graft from the left axillary artery to the right atrium (RA) using a mini thoracotomy incision. Conclusions: ESRD patients with CVO pose a unique challenge. We believe our approach can provide an excellent option for dialysis access in patients with exhausted conventional access options.

Introduction: Not all newly created arteriovenous fistulas (AVF) successfully mature and develop into a functioning access for hemodialysis. Percutaneous transluminal angioplasty (PTA) and balloon-assisted maturation (BAM) have been utilized to either treat flow-limiting stenoses or to promote and accelerate maturation. We hypothesized that unusable upper arm AVFs can be rescued by conversion to a functional access using the percutaneous placement of a stent graft (SG). Methods: Clinical data on 12 patients with an early non-usable upper arm AVF underwent percutaneous revision using stent grafts. There were 6 brachial-cephalic, 3 brachial-basilic, and 3 brachial-brachial vein transposition AVFs. Results: All patients had either at least 2 or more stenoses (> 2 cm) within the fistula conduit, or a long segment stenosis (> 4 cm) in combination with shorter segment stenoses. Nine patients had failed PTA. Three patients had failed BAM at outside access centers. All patients were referred for failure to achieve access cannulation and concomitant hemodialysis through the AVF. Stent grafts were placed retrograde towards the arterial anastomoses and ranged in diameter (6 mm, 7 mm, and 8 mm in 4, 7 and 1 patients, respectively). The average length of the stent graft was 10 cm (range 5-15 cm). All stent grafts were post balloon dilated at the time of placement. All AVFs were salvaged and patients were able to maintain functional use of their access with cannulation occurring through the stent graft. The primary patency (PP) rate at 6 and 12 months was 91% (95% confidence interval (CI), 56% to 98%) and 65% (95% confidence interval (CI), 32% to 87%), respectively (n= 11 and 5 at risk, respectively). The secondary patency (SP) rate at 6 and 12 months was 100 % and 72% (95% confidence interval (CI), 46% to 93%), respectively ( n=11 and 7 at risk, respectively ). Conclusions: This report outlines a successful initial experience using stent grafts to rescue, preserve and convert an unusable upper arm AVF into a functioning hemodialysis access.

BACKGROUND : Revascularization alternatives for patients with critical limb ischemia and without adequate autogenous vein remain challenging. We reviewed our experience with the use of arterial homograft as a conduit for limb salvage in patients with limb ischemia and active lower extremity infections. METHODS : A retrospective review of patients who underwent open arterial revascularization of the lower extremity with cryopreserved femoral artery homograft for the treatment of symptomatic critical limb ischemia (i.e., foot ulceration, infection, or gangrene) during an 18-month period was performed. Relevant clinical variables and treatment outcomes were analyzed. Clinical success was defined as limb salvage for one year, patency of the reconstruction, and wound healing. RESULTS : Thirteen patients (5 men; average age 71 ± 8.3 years, range 51-87 years) were treated during this study period. Treatment indications included 10 (77%) foot ulcerations, 2 (15%) critically ischemic limbs without ulceration, and 1 (8%) infected polytetrafluoroethylene bypass graft with acute occlusion and limb ischemia. A femoral below-the-knee popliteal bypass was performed in 4 (1%), femoral to anterior tibial artery in 4 (31%), femoral to posterior tibial artery in 3 (23%), and femoral to peroneal artery in 2 (15%). All 13 limbs were preserved. Minor amputations were performed in 6 patients, 2 underwent toe amputations and 4 patients had a trans-metatarsal amputation. The cumulative patency rate at 6, 9, and 18 months was 92.3%, 70.3%, and 58.6%, respectively. CONCLUSION : Open arterial revascularization with arterial femoral homograft is an acceptable treatment method in patients with critical limb ischemia and active infection in whom autogenous vein is not available or the use of a synthetic conduit is not possible.

Background. Hypercoagulable disorders can lead to deep vein thrombosis (DVT), arterial thrombosis or embolization, and early or recurrent bypass graft failure. The purpose of this study was to identify whether diabetes increased the likelihood of heparin-induced platelet factor 4 antibodies in at risk vascular patients. Methods. We reviewed clinical data on 300 consecutive patients. A hypercoagulable workup was performed if patients presented with (1) early bypass/graft thrombosis (Results. 85 patients (47 women; age 53 ± 16 years, range 16–82 years) had one of the defined conditions and underwent a hypercoagulable evaluation. Screening was done in 4.7% of patients with early bypass graft thrombosis, 60% of patients were screened because of multiple bypass or graft thrombosis, and 35.3% had a previous history of DVT, PE, or native vessel thrombosis. Of the 43 patients with DM and 42 nDM evaluated, 59 patients (69%) had an abnormal hypercoagulable profile. An elevated heparin antibody level was present in 30% of DM and 12% of nDM patients (chi-squared test P<0.04). Additionally, DM was associated with a higher likelihood of arterial complications while nDM was associated with a higher rate of venous adverse events (chi-squared test P<0.003). Conclusions. Diabetes is associated with a higher likelihood of developing heparin-induced antibodies and an increased combined incidence of arterial complications that include early or multiple bypass/graft thrombosis. This finding may influence the choice of anticoagulation in diabetic patients at risk with vascular disease.

Venous stenosis and occlusion are a major cause of vascular access dysfunction and failure. The HeRO Graft bypasses occlusion and traverses stenosis with outflow directly into the central venous circulation. A randomized, multicenter study was conducted to evaluate the efficacy and safety of the HeRO Graft relative to conventional AV grafts. The design was to enroll 143 patients in a 2:1 randomization ratio between HeRO and conventional AV control groups. Data on 72 subjects (52 HeRO Graft and 20 AV graft controls) were obtained. The HeRO Graft and control cohorts were comparable in baseline characteristics. Adequacy of dialysis, bacteremia rates, and adverse events were consistent between groups. Twelve month Kaplan-Meier estimates for primary and secondary patency rates were 34.8% and 67.6% in the HeRO Graft cohort, and 30.6% and 58.4% in the control cohort. There was no statistical difference in terms of patency between groups. The rates of intervention were 2.2/year for HeRO Graft and 1.6/year for the control (p = 0.100). Median days to loss of secondary patency was 238 for HeRO Graft versus 102 for the control (p = 0.032). The HeRO Graft appears to provide similar patency, adequacy of dialysis, and bacteremia rates to those of conventional AV grafts.

Introduction In this article, we will review the clinical symptoms of dialysis access steal syndrome (DASS), evaluation, treatment options, and our approach and treatment algorithm. Methods We reviewed the literature discussing different aspects of DASS including its epidemiology, pathogenesis, clinical presentation, evaluation and management options. Results DASS is the most dreaded complication of access surgery. Although the incidence is low, all providers caring for dialysis patients should be aware of this problem. Symptoms can range from mild to limb threatening. Although various tests are available, the diagnosis of DASS remains a clinical one and requires thoughtful management to have the best outcomes. Conclusions Multiple treatment options exist for steal. We present diagnostic evaluation and management algorithm.