A Multinational, Single-Arm Pivotal Study Assessing the Performance of the SoundBite Crossing System for Peripheral Chronic Total Occlusions (The PROSPECTOR Study).

PURPOSE: This study aimed to demonstrate the efficacy and safety of the SoundBite Crossing System‒Peripheral (SCS-P) to facilitate crossing chronic total occlusions (CTOs) of infrainguinal arteries. MATERIALS AND METHODS: This clinical trial was approved by the Ethics Committees of all 4 participating centers and enrolled 52 patients with symptomatic de novo infrainguinal CTOs. Technical device success, the primary efficacy endpoint, was defined as the ability to facilitate the treatment of the target lesion by crossing a portion or the whole length of the CTO. Freedom from SCS-P-related major adverse events (MAEs) at 30 days after the procedure was the primary safety endpoint. RESULTS: The SCS-P met the primary efficacy and safety endpoints in 92.3% (48/52) and 100% (52/52) of subjects, respectively. Technical device success with postprocedural patency and freedom from SCS-P-related MAEs was achieved in 88.5% (46/52) of subjects. The mean CTO crossing time was 20.0 minutes ± 30.8, and the SCS-P was able to traverse the whole CTO and enter the distal true lumen without the need of any other device in 59.6% (31/52) of subjects. The mean Rutherford category and ankle-brachial index improvement at the 30-day follow-up was 2.4 ± 1.17 and 0.23 ± 0.22, respectively. CONCLUSIONS: The SCS-P demonstrated a satisfactory safety and performance profile to cross peripheral CTOs and enter the distal true lumen of infrainguinal CTOs.

Page kidney: Rare cause of acute kidney injury after complicated renal artery angioplasty.

The authors present a case of a patient who experienced a rare complication after attempted renal angioplasty and stenting, Page kidney. This patient presented with new onset hypertension secondary to bilateral renal artery stenosis and was referred for revascularization given hypertension refractory to medical management. The right renal artery underwent successful angioplasty and stenting; however, the left renal artery experienced recoil stenosis. Post-procedure the patient developed acute kidney injury secondary to Page kidney from subcapsular and extracapsular hematoma. This was managed conservatively with transfusions and the hematoma and acute kidney injury self-resolved over the next 4 months. This case highlights the importance of revascularization for refractory hypertension secondary to hemodynamically significant bilateral renal artery stenosis, the rare complication of Page kidney with attempted revascularization of renal artery stenosis and the involvement of a hypertension specialist in the decision of revascularization of renal artery stenosis.

Embolotherapy in Bronchial Hemorrhage.

Hemoptysis, defined as bleeding into the tracheobronchial tree, is a serious symptom that can cause asphyxiation if inadequately treated. Massive hemoptysis carries a very high mortality risk, and therefore, a prompt multidisciplinary approach to hemoptysis is highly encouraged. Bronchial artery embolization has evolved as the mainstay of treatment in control of hemoptysis. It is a low-risk procedure that carries high initial clinical success rates. Despite relatively high recurrence rates, it can be repeated until the underlying disease process can be definitively treated.

Acute Severe Renal Artery Stenosis Presenting as Acute Kidney Injury With Severe Hypertension and Active Urine Sediment.

We present a case of severe renal artery stenosis that mimicked rapidly progressive glomerulonephritis with acute kidney injury, active urine sediments, and severe hypertension. Simultaneous presence of secondary hyperaldosteronism and hypokalemia prompted renal angiography and subsequent renal artery angioplasty and stenting, leading to rapid resolution of acute kidney injury, proteinuria, and hypertension. This case emphasises the importance and benefits of prompt diagnosis and revascularisation of acute severe renal artery stenosis in a patient with history of atherosclerotic renovascular disease presenting with sudden onset of severe hypertension and acute kidney injury with active urine sediment mimicking rapidly progressive glomerulonephritis.

Renovascular hypertension from the BCR-ABL tyrosine kinase inhibitor ponatinib.

Drug-induced hypertension is one of the commonest causes of secondary hypertension. In the last few years, secondary hypertension due to tyrosine kinase inhibitors, from the vascular endothelial growth factor class, has been recognized to be an important cause of hypertension, as well as proteinuria, and occasionally kidney dysfunction in some cases. Less well-recognized is that BCR-ABL tyrosine kinase inhibitors also have adverse vascular effects. These manifest as vascular stenoses in large vessels, which may sometimes cause renal artery stenosis and subsequent hypertension. We describe a case report which presented as classical bilateral renal artery stenosis, and responded to revascularization. Increased awareness of these effects, as well as research into the pathogenesis, may provide more insight into vascular biology.

A new "angle" on aortic neck angulation measurement.

OBJECTIVE: Infrarenal aortic neck angulation is one of the most powerful predictors of endovascular aneurysm repair failure. Whereas the "gold standard" to measure this angle is three-dimensional (3D) reconstruction and centerline measurement, many surgeons rely on estimations of angulation based on two-dimensional (2D) views of computed tomography imaging. Unfortunately, these views do not accurately represent the true angle, particularly if aortic angulation is oblique to the standard views. In response to this issue, our group has developed a novel trigonometric formula that uses coronal and sagittal measured angles to calculate the true angle. The purpose of this study was to compare the paired angle formula with 3D centerline measurements for estimating true aortic neck angulation. METHODS: Fifty randomly selected patients treated by endovascular aneurysm repair at The Ottawa Hospital between 2010 and 2015 were studied. The 3D centerline aortic neck angle measurements were made by a radiology staff physician. The paired angle formula was applied by a vascular surgeon, resident, and student using 2D coronal and sagittal angles from computed tomography imaging to estimate the true angle. RESULTS: The average age was 78 years; 74% of patients were male, and average preoperative aneurysm diameter was 5.7 cm. The mean neck length was 1.9 cm (1.1-3.2 cm), and mean neck angulation calculated by the gold standard measurements was 39 degrees (2-84 degrees). Linear regression demonstrated strong association between 3D measurements and the paired angle formula, with correlations comparable to the intraobserver variability (intraclass correlation coefficient values range, 0.74-0.87). The average user estimates deviated minimally from the gold standard (absolute difference, 6 degrees; 95% confidence interval, 4-8 degrees) without systemic bias. The paired angle formula accurately ruled out severe angulation >60 degrees with an overall negative predictive value of >99%. Compared with isolated 2D measurements, application of the paired angle formula significantly decreased the false-negative rate of unappreciated severe angulation >60 degrees from 4.8% to 0.7% (P = .032). CONCLUSIONS: The paired angle formula detects significantly more severe angles than isolated 2D measurements and can accurately rule out severe angulation >60 degrees compared with the 3D measurements. The implementation of this angle estimation method is a useful adjunct in the measurement of aortic neck angulation, especially if 3D reconstruction software is not readily available. Furthermore, the importance of accurate angle measurement is not limited to vascular surgery and has direct relevance to any procedural specialty that relies on preoperative angle measurements.

Implanted vascular access device related deep vein thrombosis in oncology patients: A prospective cohort study.

BACKGROUND: Implanted vascular access devices (IVADs) have significantly improved the management of cancer patients. These patients are at an increased risk of venous thromboembolism and IVADs are a known risk factor. We sought to assess the incidence of IVAD-related upper extremity deep vein thrombosis (IVAD-related UEDVT) associated with BioFlo® IVADs (Angiodynamics, Inc.). METHODS: A total of 394 cancer patients were enrolled over 12 months. The primary outcome was the incidence of IVAD-related UEDVT confirmed by diagnostic imaging. IVAD-related UEDVT was defined as symptomatic ipsilateral upper extremity (axillary vein or proximal) deep vein thrombosis and symptomatic pulmonary embolism (PE). Patients were followed until initiation of therapeutic anticoagulation, catheter removal, death, or up to 12 months. RESULTS: 389 patients were included in the analysis. The median age of the cohort was 58.2 years; 68% (n = 273) were females. Sixty-six percent had gastrointestional cancer (including pancreatic cancer) and 68% had metastases. Eighty four percent of IVADs were right sided insertions. Ninety eight percent of catheter tip placements were distal superior vena cava (n = 237), cavo-atrial junction (n = 67) or atrium (n = 90). Overall, 5 patients had symptomatic IVAD-related UEDVT (1.29%, 95% CI 0.2 to 2.4%). CONCLUSION: IVAD-related UEDVT is an infrequent complication in cancer patients with BioFlo® IVADs.

Modified Inside-Out Technique for Continued Use of Chronically Occluded Upper Central Veins.

This report describes a 2-step, inside-out procedure for upper body central venous access in patients with chronic central venous occlusions. Blunt cephalad dissection through the mediastinum was achieved with a curved metal cannula and guide wire followed by percutaneous puncture of an open snare from a right supraclavicular approach and dilation of the tract for a tunneled central venous catheter insertion. Of 9 patients, all had a successful placement of a tunneled central venous catheter using this method. Although this 2-step, inside-out technique is effective for creating access in the presence of central venous occlusion, further clinical evaluation is warranted.

Endoluminal dilatation for embedded hemodialysis catheters: A case-control study of factors associated with embedding and clinical outcomes.

BACKGROUND: With the increasing frequency of tunneled hemodialysis catheter use there is a parallel increase in the need for removal and/or exchange. A small but significant minority of catheters become embedded or 'stuck' and cannot be removed by traditional means. Management of embedded catheters involves cutting the catheter, burying the retained fragment with a subsequent increased risk of infections and thrombosis. Endoluminal dilatation may provide a potential safe and effective technique for removing embedded catheters, however, to date, there is a paucity of data. OBJECTIVES: 1) To determine factors associated with catheters becoming embedded and 2) to determine outcomes associated with endoluminal dilatation. METHODS: All patients with endoluminal dilatation for embedded catheters at our institution since Jan. 2010 were included. Patients who had an embedded catheter were matched 1:3 with patients with uncomplicated catheter removal. Baseline patient and catheter characteristics were compared. Outcomes included procedural success and procedure-related infection. Logistic regression models were used to determine factors associated with embedded catheters. RESULTS: We matched 15 cases of embedded tunneled catheters with 45 controls. Among patients with embedded catheters, there were no complications with endoluminal dilatation. Factors independently associated with embedded catheters included catheter dwell time (> 2 years) and history of central venous stenosis. CONCLUSION: Embedded catheters can be successfully managed by endoluminal dilatation with minimal complications and factors associated with embedding include dwell times > 2 years and/or with a history of central venous stenosis.

Infolding of fenestrated endovascular stent graft.

We report a case of infolding of a fenestrated stent graft involving the visceral vessel segment after a juxtarenal abdominal aorta aneurysm repair. The patient remains free of any significant endoleak, and the aortic sac has shown regression. The patient remains asymptomatic, with no abdominal pain, with normal renal function, and without ischemic limb complications. We hypothesize that significant graft oversizing (20%-30%) with asymmetric engineering of the diameter-reducing ties may have contributed to the infolding. Because of the patient's asymptomatic nature and general medical comorbidities, further intervention was deemed inappropriate as the aneurysmal sac is regressing despite the infolding.

Randomized Trial Comparing the Primary Patency following Cutting Versus High-Pressure Balloon Angioplasty for Treatment of de Novo Venous Stenoses in Hemodialysis Arteriovenous Fistulae.

PURPOSE: A single-center randomized clinical trial was performed to compare postinterventional primary patency rates achieved by cutting balloon angioplasty and high-pressure balloon angioplasty in the treatment of de novo stenoses within autogenous arteriovenous (AV) fistulae for hemodialysis. MATERIALS AND METHODS: Forty-eight patients undergoing their first angioplasty were prospectively randomized to undergo angioplasty with a cutting balloon or high-pressure balloon 4-8 mm in diameter because cutting balloons larger than 8 mm are not available. Nine patients were excluded after angiography, with seven requiring balloons larger than 8 mm. In the remaining 39 patients, there were 42 stenoses in the following regions: juxtaanastomotic (38%), perianstomotic (38%), midcephalic (9%), and cephalic arch (14%). Patients in the cutting balloon group were younger (mean age difference, 9 y; P = .04), but other demographic variables were comparable (range, P = .08-.89). The mean follow-up period was 8.5 mo (range, 24 d to 32 mo). Kaplan-Meier analysis was used to compare duration of patency. Mann-Whitney rank-sum t test and χ2/Fisher exact tests were used to compare continuous and categoric variables, respectively. RESULTS: Technical success was achieved in all 39 patients. At 3, 6, and 12 months, the postinterventional primary patency rates for the cutting balloon group were 61.1% (95% confidence interval [CI], 35.75%-82.70%), 27.7% (95% CI, 9.69%-53.48%), and 11.1% (95% CI, 1.38%-34.71%), respectively, compared with 70.0% (95% CI, 45.72%-88.11%), 42.1% (95% CI, 20.25%-66.50%), and 26.3% (95% CI, 9.15%-51.20%), respectively, for the high-pressure balloon group (P < .3 at each interval). CONCLUSIONS: Compared with high-pressure balloon angioplasty, cutting balloon angioplasty does not improve postinterventional primary patency of de novo stenotic lesions in autogenous arteriovenous fistulae.

Externalization of tunneled hemodialysis catheter in patients with tunnel or exit-site infections and limited access options.

PURPOSE: To evaluate the viability and effectiveness of temporary externalization of a tunneled hemodialysis (HD) catheter in catheter-dependent HD patients presenting with catheter-related tunnel or exit-site infection, documented central venous stenosis, and limited alternative venous access. MATERIALS AND METHODS: All catheter-dependent HD patients with known central venous stenosis presenting with exit-site or tunnel infection and who subsequently underwent catheter externalization between February 2008 and May 2012 were reviewed. After catheter externalization, patients were concurrently treated with antibiotics for approximately 3 weeks before reinsertion of a new tunneled catheter. Treatment outcomes were collected, with treatment failures defined as reinfection with the same organism within 45 days of tunneled catheter reinsertion. RESULTS: There were 42 catheter externalization procedures performed in 26 patients for 42 exit-site or tunnel infections. Technical success rate for catheter externalization was 100%, with no complications during the externalization procedure and preservation of all original access sites. Treatment failure occurred in 9.8% (4 of 41) of cases. Median infection-free survival after treatment and retunneling of a new dialysis catheter was 80 days. One major periprocedural complication of death occurred before reinsertion of a new tunneled catheter. Minor complications after the procedure occurred in four patients and included three cases of a small persistent wound at the temporary supraclavicular access site and one initially nonfunctioning externalized catheter. CONCLUSIONS: Temporary dialysis catheter externalization appears both technically feasible and effective for the treatment of exit-site and tunnel infections, while allowing preservation of the venous access site in catheter-dependent HD patients with central venous stenosis and limited alternative venous access.

Percutaneous renal sympathetic denervation: 2013 and beyond.

Systemic hypertension affects almost a quarter of Canadian adults. Although most can achieve adequate blood pressure control using a combination of medical and lifestyle interventions, many have resistant hypertension and are unable to reach their target. Percutaneous renal sympathetic denervation has been developed to address a crucial mechanism in the pathophysiology of hypertension: renal sympathetic overactivity. In 2009, the first-in-man experience with renal denervation was published. Several studies followed, including the randomized Symplicity HTN-2 trial of 106 patients: 6-month mean blood pressure reduction was 32/12 mm Hg in those who underwent renal denervation, vs a change of +1/0 Hg in those who did not. However, all the evidence to date suffers from the same drawbacks: studies are small, and follow-up is short and largely incomplete. The future of renal denervation will be determined by 3 factors. First, there will be more and better evidence. Symplicity HTN-3 has randomized 530 patients to renal denervation vs a sham procedure; 24-hour ambulatory blood pressure monitoring will be assessed in all participants. Other quality trials will follow, including ones that will assess clinical end points. Second, other indications for this treatment will be investigated. Sympathetic overactivity is implicated in many other conditions, including heart failure and arrhythmia; sympathetic denervation might benefit these patients as well. Third, myriad devices, using different methods to achieve renal denervation, are being developed. The first renal denervation system was approved for clinical use in Canada in March 2012. Until more data are available, patients undergoing this procedure should be carefully screened and, ideally, enrolled in research protocols.

Chronic total occlusion of the iliac artery: endoluminal reentry using a metal stiffening cannula.

When chronic total occlusion of the iliac artery cannot be crossed with traditional guide wires and catheters, the metal stiffener from a universal drainage catheter kit can be shaped and used to direct a guide wire from a subintimal tract into the true lumen. In the present report, reentry was achieved in 12 of 12 patients with the use of the cannula. This technique provides a useful alternative for treatment of chronic total iliac occlusions.

Renal sympathetic denervation for resistant hypertension.

Resistant hypertension is an increasingly prevalent health problem associated with important adverse cardiovascular outcomes. The pathophysiology that underlies this condition involves increased function of both the sympathetic nervous system and the renin-angiotensin II-aldosterone system. A crucial link between these 2 systems is the web of sympathetic fibres that course within the adventitia of the renal arteries. These nerves can be targeted by applying radiofrequency energy from the lumen of the renal arteries to renal artery walls (percutaneous renal sympathetic denervation [RSD]), an approach that has attracted great interest. This paper critically reviews the evidence supporting the use of RSD. Small studies suggest that RSD can produce dramatic blood pressure reductions: In the randomized Symplicity HTN-2 trial of 106 patients, the mean fall in blood pressure at 6 months in patients who received the treatment was 32/12 mm Hg. However, there are limitations to the evidence for RSD in the treatment of resistant hypertension. These include the small number of patients studied; the lack of any placebo-controlled evidence; the fact that blood pressure outcomes were based on office assessments, as opposed to 24-hour ambulatory monitoring; the lack of longer-term efficacy data; and the lack of long-term safety data. Some of these concerns are being addressed in the ongoing Renal Denervation in Patients With Uncontrolled Hypertension (Symplicity HTN-3) trial. The first percutaneous RSD system was approved by Health Canada in the spring of 2012. But until more and better-quality data are available, this procedure should generally be reserved for those patients whose resistant hypertension is truly uncontrolled.

Endoluminal dilation technique to remove "stuck" tunneled hemodialysis catheters.

Most tunneled catheters can be easily removed after the retention cuff is dissected. Occasionally, these catheters can become resistant to removal even after application of potentially hazardous forceful traction. In addition, an infected catheter may cause life-threatening septicemia. Several methods have been described for their extraction, some of which may be available only in tertiary-care facilities. The present report describes the successful extraction of five such "stuck" catheters by using a recently described technique of endoluminal dilation. The technique appears safe and straightforward and can be performed in any interventional suite while allowing preservation of venous access.

Spherical versus conventional polyvinyl alcohol particles for uterine artery embolization.

PURPOSE: To compare the efficacy of spherical polyvinyl alcohol (PVA) particles versus conventional PVA particles for uterine artery embolization (UAE). MATERIALS AND METHODS: Of 149 patients with 1-year follow-up after UAE, 96 received conventional PVA particles and 53 received spherical PVA particles. Severity of symptoms was ranked on an 11-point numeric rating scale (0-10). The changes in severity of symptoms after embolization, blood hemoglobin level, and the size of the dominant tumor depicted by ultrasonography were used to assess the efficacy of the two types of particles. The number of hysterectomies and myomectomies in each group was also recorded as evidence of UAE failure. RESULTS: On 1-year follow-up, patients treated with conventional PVA showed average numeric rating scale score improvements of 4.6 in menorrhagia, 2.9 in dysmenorrhea, 3.7 in pressure sensation, and 3.4 in urinary frequency. With spherical PVA, the average improvements were 3.0 in menorrhagia, 2.4 in dysmenorrhea, 3.1 in pressure sensation, and 2.0 in urinary frequency. Except in dysmenorrhea, all differences were significant (P < .001). With conventional PVA, there was an 8-mg/mL increase in blood hemoglobin level versus a 3-mg/mL increase with spherical PVA (P < .05). With conventional PVA, there was a 28-mm (34%) average reduction in diameter of the dominant tumor versus a 15.7-mm (19%) reduction with spherical PVA (P = .01). Eight of 96 patients (8%) treated with conventional PVA underwent hysterectomy or myomectomy during the entire length of the study, versus six of 53 patients (11%) treated with spherical PVA (P = .6). No patient underwent multiple embolizations. CONCLUSIONS: In comparison with conventional PVA particles, UAE with the use of spherical PVA particles resulted in less fibroid tumor shrinkage and less improvement in clinical symptoms.

Significant caval penetration by the celect inferior vena cava filter: attributable to filter design?

This report describes transmural penetration of the inferior vena cava (IVC) by a newly introduced IVC filter within 9 days of its placement. A computed tomographic study demonstrated filter penetration with one of the primary struts lodging in the uncinate process of the pancreas. Because of the close resemblance of this new filter to another filter that has not been associated with penetration injuries, the key differences between the two designs were examined and the determination was made that the new filter, unlike the older one, has unprotected primary struts. Only filters with an unprotected primary strut design have been associated with penetration injuries such as the one described in this case.