Performance Evaluation of a Miniature and Disposable Endovascular Robotic Device.

PURPOSE: The LIBERTY® Robotic System is a miniature, single-use device designed to facilitate remote-controlled navigation to intravascular targets. We aim to evaluate the robot's performance to manipulate a range of microguidewires and microcatheters during percutaneous endovascular procedures. MATERIALS AND METHODS: Six interventional radiologists performed selective robotic-assisted catheterization of eight pre-determined vascular targets in a pig model. The navigation time from the guiding catheter tip to the target vessel was recorded. Each physician with a clinical experience of 20 years completed a questionnaire to evaluate the ease of use, accuracy, and safety of the robotic operation. RESULTS: Most of the physicians reached the vascular targets in less than one minute. There was no angiographic evidence of vascular injury such as artery laceration or contusion. All physicians reported consensus about the high performance of the robot. CONCLUSION: The miniature disposable robot is effective at reaching a range of vessels in a porcine model. Physicians found the device intuitive and easy to operate remotely.

Joint UK societies' 2019 consensus statement on renal denervation.

Improved and durable control of hypertension is a global priority for healthcare providers and policymakers. There are several lifestyle measures that are proven to result in improved blood pressure (BP) control. Moreover, there is incontrovertible evidence from large scale randomised controlled trials (RCTs) that antihypertensive drugs lower BP safely and effectively in the long-term resulting in substantial reduction in cardiovascular morbidity and mortality. Importantly, however, evidence is accumulating to suggest that patients neither sustain long-term healthy behaviours nor adhere to lifelong drug treatment regimens and thus alternative measures to control hypertension warrant further investigation. Endovascular renal denervation (RDN) appears to hold some promise as a non-pharmacological approach to lowering BP and achieves renal sympathectomy using either radiofrequency energy or ultrasound-based approaches. This treatment modality has been evaluated in clinical trials in humans since 2009 but initial studies were compromised by being non-randomised, without sham control and small in size. Subsequently, clinical trial design and rigour of execution has been greatly improved resulting in recent sham-controlled RCTs that demonstrate short-term reduction in ambulatory BP without any significant safety concerns in both medication-naïve and medication-treated hypertensive patients. Despite this, the joint UK societies still feel that further evaluation of this therapy is warranted and that RDN should not be offered to patients outside of the context of clinical trials. This document reviews the updated evidence since our last consensus statement from 2014 and provides a research agenda for future clinical studies.

Renal artery sympathetic denervation: observations from the UK experience.

BACKGROUND: Renal denervation (RDN) may lower blood pressure (BP); however, it is unclear whether medication changes may be confounding results. Furthermore, limited data exist on pattern of ambulatory blood pressure (ABP) response-particularly in those prescribed aldosterone antagonists at the time of RDN. METHODS: We examined all patients treated with RDN for treatment-resistant hypertension in 18 UK centres. RESULTS: Results from 253 patients treated with five technologies are shown. Pre-procedural mean office BP (OBP) was 185/102 mmHg (SD 26/19; n = 253) and mean daytime ABP was 170/98 mmHg (SD 22/16; n = 186). Median number of antihypertensive drugs was 5.0: 96 % ACEi/ARB; 86 % thiazide/loop diuretic and 55 % aldosterone antagonist. OBP, available in 90 % at 11 months follow-up, was 163/93 mmHg (reduction of 22/9 mmHg). ABP, available in 70 % at 8.5 months follow-up, was 158/91 mmHg (fall of 12/7 mmHg). Mean drug changes post RDN were: 0.36 drugs added, 0.91 withdrawn. Dose changes appeared neutral. Quartile analysis by starting ABP showed mean reductions in systolic ABP after RDN of: 0.4; 6.5; 14.5 and 22.1 mmHg, respectively (p < 0.001 for trend). Use of aldosterone antagonist did not predict response (p > 0.2). CONCLUSION: In 253 patients treated with RDN, office BP fell by 22/9 mmHg. Ambulatory BP fell by 12/7 mmHg, though little response was seen in the lowermost quartile of starting blood pressure. Fall in BP was not explained by medication changes and aldosterone antagonist use did not affect response.

Do emergency physicians and radiologists reliably interpret pelvic radiographs obtained as part of a trauma series?

INTRODUCTION: Interpretation of pelvic radiography is an important component of the primary survey and is commonly performed by emergency physicians. Radiologists bring unique skills to trauma care, including choice of imaging modality and image interpretation. It is not clear if this limited resource is most efficiently used in the resuscitation room. No studies have compared radiologists and trauma clinicians in their ability to interpret pelvic radiographs following trauma. OBJECTIVE: To determine the sensitivity and specificity of trauma experienced and trauma inexperienced emergency physicians in detecting pelvic fractures compared with radiologists, the latter subgroup combined report being used as the gold standard. SETTING AND METHODS: Prospective cohort study conducted in two large teaching hospitals in central London. All participants reviewed 144 consecutive pelvic radiographs performed each as part of a 'trauma series' and known to have undergone concomitant pelvic CT imaging. RESULTS: No statistically significant difference was found between radiologists and emergency physicians from a trauma centre in pelvic radiograph interpretation. Radiologist reporting was associated with an improved specificity compared with emergency physicians working in a non-trauma hospital (p=0.049). The study population missed 30% of fractures on plain radiography against the gold standard of CT. DISCUSSION: The ability to interpret trauma series pelvic radiographs is comparable between emergency physicians and radiologists. If this were also true of trauma chest radiographs, then the most valuable use of the radiologist may not be the resuscitation room but in rapid reporting of more complex imaging techniques. However, plain radiography is insensitive for pelvic fracture detection compared with CT, even in expert hands.

Portal vein embolisation for extended hepatectomy: single-centre experience.

BACKGROUND: Portal vein embolisation (PVE) induces contra-lateral liver hypertrophy to facilitate an extended hepatectomy. AIM: This paper aims to analyse our data on PVE and extended hepatectomy. Outcome measures included success of PVE, feasibility of resections, operative morbidity and survival. METHODS: A retrospective analysis of data collected prospectively on 33 patients (2004-2008) was performed. Survival curves were estimated by the Kaplan-Meier (Breslow) method. Significance was defined as p < 0.05. RESULTS: A total of 31 patients had successful PVE. There were 24 patients who underwent surgery. Significant hypertrophy of residual liver was noted from 230.15 (pre-embolisation) to 428.50 ml (post-embolisation) (median, p < 0.0001). A total of 16 patients had hepatectomy (14: R0; 2: R1) with a single mortality (6.25%) and 56.25% morbidity, and a median length of stay of 17 days. Median overall survival was 14 (95% CI 7.8-20.2) months. Patients who underwent resection had a median disease-specific survival of 33 (95% CI 4-62) months compared with 8.6 (95% CI 0-19.9) months for patients without resection (p = 0.14). For patients with primary hepato-biliary tumours, the median disease-specific survival was 7.9 (95% CI 4.5-11.3) months compared with a median survival of 19.7 (95% CI 0-42.2) months for patients with metastases (p = 0.07). CONCLUSIONS: PVE is safe, facilitates R0 resection and offers the best chance of cure, especially for liver metastases.

Effectiveness of stent-graft placement for salvage of dysfunctional arteriovenous hemodialysis fistulas.

PURPOSE: To determine the clinical effectiveness of stent-graft placement in dysfunctional autogenous hemodialysis fistulas. MATERIALS AND METHODS: Between September 2006 and June 2008, 24 Fluency Plus stent-grafts were inserted in 17 patients with failing autogenous hemodialysis fistulas (two radiocephalic, 12 brachiocephalic, and three brachiobasilic). Six fistulas were thrombosed at presentation. Indications for stent-graft insertion included 10 residual stenoses, six pseudoaneurysms, and one fistuloplasty-induced rupture. Fistula function before and after intervention was assessed with ultrasound dilution technique. RESULTS: The technical success rate was 100%, as were the anatomic and clinical success rates. Via Kaplan-Meier method, the primary access patency rates were 94.1% at 3 months (95% CI, 0.461-0.995) and 88.2% at 6 and 12 months (95% CI, 0.468-0.980). The primary lesion patency rate was 94.1% (95% CI, 0.650-0.992) at 3, 6, and 12 months. The secondary access patency rate had a point estimate of 100% at 3 months, and was 93.8% (95% CI, 0.632-0.991) at 6 and 12 months. Univariate analysis suggested that male sex and left-sided accesses were associated with a longer primary access patency rate (P = .02). The binary restenosis rate at 6 months was 5.9%. Mean transonic flow rates were 667.5 mL/min before intervention and 2,076.0 mL/min after intervention (P = .03, Wilcoxon signed-rank test). No patients were lost to follow-up. CONCLUSIONS: Stent-graft placement in dysfunctional autogenous hemodialysis fistulas is technically feasible and effective in preserving function and preventing access abandonment, with patency rates that exceed historical patency rates with angioplasty and/or uncovered stents.

The use of dynamic volumetric CT angiography (DV-CTA) for the characterization of endoleaks following fenestrated endovascular aortic aneurysm repair (f-EVAR).

Accurate endoleak classification is essential following fenestrated endovascular aneurysm repair (f-EVAR). Both endoleak type and exact source of endoleak have implications upon the urgency and complexity of future management strategies. Herein we report on a patient with a documented endoleak post-f-EVAR, in which the source of blood flow into the aneurysm sac could not be determined using conventional computed tomographic angiography. Consequently, dynamic volumetric computed tomographic angiography (DV-CTA) was employed, which clearly illustrated the site of origin of the endoleak. DV-CTA enables accurate endoleak characterization following f-EVAR, with excellent conspicuity of the source of blood flow into the aneurysm sac.

Total percutaneous aortic repair: midterm outcomes.

The purpose of this study was to examine the immediate and midterm outcomes of percutaneous endovascular repair of thoracic and abdominal aortic pathology. Between December 2003 and June 2005, 21 patients (mean age: 60.4 +/- 17.1 years; 15 males, 6 females) underwent endovascular stent-graft insertion for thoracic (n = 13) or abdominal aortic (n = 8) pathology. Preprocedural computed tomographic angiography (CTA) was performed to assess the suitability of aorto-iliac and common femoral artery (CFA) anatomy, including the degree of CFA calcification, for total percutaneous aortic stent-graft repair. Percutaneous access was used for the introduction of 18- to 26-Fr delivery devices. A 'preclose' closure technique using two Perclose suture devices (Perclose A-T; Abbott Vascular) was used in all cases. Data were prospectively collected. Each CFA puncture site was assessed via clinical examination and CTA at 1, 6, and 12 months, followed by annual review thereafter. Minimum follow-up was 36 months. Outcome measures evaluated were rates of technical success, conversion to open surgical repair, complications, and late incidence of arterial stenosis at the site of Perclose suture deployment. A total of 58 Perclose devices were used to close 29 femoral arteriotomies. Outer diameters of stent-graft delivery devices used were 18 Fr (n = 5), 20 Fr (n = 3), 22 Fr (n = 4), 24 Fr (n = 15), and 26 Fr (n = 2). Percutaneous closure was successful in 96.6% (28/29) of arteriotomies. Conversion to surgical repair was required at one access site (3.4%). Mean follow-up was 50 +/- 8 months. No late complications were observed. By CT criteria, no patient developed a >50% reduction in CFA caliber at the site of Perclose deployment during the study period. In conclusion, percutaneous aortic stent-graft insertion can be safely performed, with a low risk of both immediate and midterm access-related complications.

Portal vein embolization using a nitinol plug (Amplatzer vascular plug) in combination with histoacryl glue and iodinized oil: adequate hypertrophy with a reduced risk of nontarget embolization.

The purpose of this study was to assess whether portal vein embolization (PVE) using a nitinol vascular plug in combination with histoacryl glue and iodinized oil minimizes the risk of nontarget embolization while obtaining good levels of future liver remnant (FLR) hypertrophy. Between November 2005 and August 2008, 16 patients (8 females, 8 males; mean age, 63 +/- 3.6 years), each with a small FLR, underwent right ipsilateral transhepatic PVE prior to major hepatectomy. Proximal PVE was initially performed by placement of a nitinol vascular plug, followed by distal embolization using a mixture of histoacryl glue and iodinized oil. Pre- and 6 weeks postprocedural FLR volumes were calculated using computed tomographic imaging. Selection for surgery required an FLR of 0.5% of the patient's body mass. Clinical course and outcome of surgical resection for all patients were recorded. At surgery, the ease of hepatectomy was subjectively assessed in comparison to previous experience following PVE with alternative embolic agents. PVE was successful in all patients. Mean procedure time was 30.4 +/- 2.5 min. Mean absolute increase in FLR volume was 68.9% +/- 12.0% (p = 0.00005). There was no evidence of nontarget embolization during the procedure or on subsequent imaging. Nine patients proceeded to extended hepatectomy. Six patients demonstrated disease progression. One patient did not achieve sufficient hypertrophy in relation to body mass to undergo hepatic resection. At surgery, the hepatobiliary surgeons observed less periportal inflammation compared to previous experience with alternative embolic agents, facilitating dissection at extended hepatectomy. In conclusion, ipsilateral transhepatic PVE using a single nitinol plug in combination with histoacryl glue and iodinized oil simplifies the procedure, offering short procedural times with minimal risk of nontarget embolization. Excellent levels of FLR hypertrophy are achieved enabling safe extended hepatectomy.

Radiofrequency ablation of lung lesions: practical applications and tips.

Radiofrequency ablation (RFA) therapy is a minimally invasive technique that can be used in the management of inoperable non-small-cell lung cancer and for palliation in selected patients with pulmonary metastases. Surgical resection remains the gold standard of treatment; however, many patients are ineligible due to comorbidities or poor cardiopulmonary reserve. Others may simply decline radical surgical intervention. Alternative treatment options are limited mainly to chemotherapy and external beam radiation. With the development of RFA, a new promising technique has evolved that can be offered to many, as an alternative choice or as part of combination therapy. The published results of RFA for the treatment of primary and secondary lung malignancies are encouraging. This article aims to minimize the learning curve for performing RFA of lung lesions by examining the technical difficulties more commonly encountered and offering practical tips and applications.

Femoral artery stenosis following percutaneous closure using a starclose closure device.

Starclose (Abbott Vascular Devices, Redwood City, CA) is a new arterial closure device that seals a femoral puncture site with an extravascular star-shaped nitinol clip. The clip projects small tines into the arterial wall which fold inward, causing the arterial wall to pucker, producing a purse-string-like seal closing the puncture site. The case history is that of a 76-year-old female patient who underwent day-case percutaneous diagnostic coronary angiography. A Starclose femoral artery closure device was used to achieve hemostasis with subsequent femoral artery stenosis.

Endovascular management of acute blunt traumatic thoracic aortic injury: a single center experience.

BACKGROUND: Traumatic injury of the thoracic aorta is a life-threatening complication in patients who sustain deceleration or crush injuries. The magnitude of force necessary to cause blunt thoracic aortic injury results in a high proportion of concomitant injuries, posing a significant challenge for prioritizing management. Open surgical mortality is increased in the presence of coexisting head, lung, and abdominal injuries. Spinal cord ischemia may occur following aortic cross-clamping and operative hypotension. Endovascular stent-graft placement offers a safe, effective, and timely treatment option. The aim of this study was to assess our single center experience of endovascular repair following acute blunt traumatic aortic injury. METHODS: Data from thirteen consecutive patients (mean age, 43.2 years; range, 16 to 84 years) with acute blunt traumatic aortic injury treated by endovascular stent-graft insertion between October 2001 and March 2007 was prospectively collected. Demographics, injury characteristics, technique, and complications were recorded. Follow-up data consisted of computed tomographic angiography and plain chest radiography at regular intervals. Mean and median follow-up after stent-graft implantation were 28.9 and 29 months, respectively. RESULTS: All patients underwent endovascular repair within a median of 9 hours from hospital presentation. Two patients underwent carotico-carotid bypass immediately prior to endovascular stenting during a single anesthetic. Stent-graft implantation was technically successful in all patients. No patient required conversion to open surgical repair of the acute blunt traumatic aortic injury. Procedure-related paraplegia was zero. Complications included proximal migration of initial stent-graft in one patient and iliac artery avulsion in another patient with consequent ilio-femoral bypass. The median hospital stay was 17 days. There were no in-hospital deaths. CONCLUSION: Endovascular repair is evolving as the procedure of choice for acute blunt traumatic aortic injury. Treatment of lesions that extend into the aortic arch is feasible with extra-anatomical bypass. In our study, endovascular repair of blunt traumatic aortic injury is a safe procedure with low morbidity and a mortality rate of zero.