Pipeline™ embolization device for the treatment of complex intracranial aneurysms: a NICE Medical Technology Guidance

Evaluation of disease severity and treatment intensity as cost drivers for ruptured intracranial aneurysms

BACKGROUND

Previous studies have not evaluated the impact of illness severity and postrupture procedures in the cost of care for intracranial aneurysms. We hypothesize that the severity of aneurysm rupture and the aggressiveness of postrupture interventions play a role in cost.

METHODS

The Value Driven Outcomes database was used to assess direct patient cost during the treatment of ruptured intracranial aneurysm with clipping, coiling, and Pipeline flow diverters.

RESULTS

One hundred ninety-eight patients (mean age 52.8 ± 14.1 years; 40.0% male) underwent craniotomy (64.6%), coiling (26.7%), or flow diversion (8.6%). Coiling was 1.4× more expensive than clipping (p = .005) and flow diversion was 1.7× more expensive than clipping (p < .001). More severe illness as measured by American Society of Anesthesia, Hunt/Hess, and Fisher scales incurred higher costs than less severe illness (p < .05). Use of a lumbar drain protocol to reduce subarachnoid hemorrhage and use of an external ventricular drain to manage intracranial pressure were associated with reduced (p = .05) and increased (p < .001) total costs, respectively. Patients with severe vasospasm (p < .005), those that received shunts (p < .001), and those who had complications (p < .001) had higher costs. Multivariate analysis showed that procedure type, length of stay, number of angiograms, vasospasm severity, disposition, and year of treatment were independent predictors of cost.

CONCLUSIONS

These results show for the first time that disease and vasospasm severity and intensity of treatment directly impact the cost of care for patients with aneurysms in the USA. Strategies to alter these variables may prove important for cost reduction.

Construction of Aneurysmal Models on a Curved Vascular Segment of a Carotid Siphon Model for Testing Endovascular Devices

OBJECTIVE

To investigate construction of an aneurysm on a curved vascular segment of a carotid siphon model for testing endovascular devices.

METHODS

Preshaped carotid siphon models of polytetrafluoroethylene were constructed from a human cadaver for confining canine common carotid artery (CCA). The canine right external jugular vein was isolated and harvested to make a venous pouch by suturing 1 end. The right CCA was isolated, and the venous pouch was sutured onto the right CCA to make an aneurysm. The right CCA segment containing the aneurysm was excised and guided through the preshaped polytetrafluoroethylene carotid siphon model using a guidewire with the aneurysm adjusted to protrude out of the round window of the siphon model. The siphon model together with the aneurysm was sutured end-to-end onto the left CCA to form a carotid siphon model in vivo.

RESULTS

Five canine models were successfully constructed; the average construction time was 120 minutes. All aneurysms and siphon models remained patent 7 days and 2 weeks later. Five covered stents for intracranial use were tested for flexibility and apposition to the vascular wall in the curved segment of the carotid siphon model in vivo. All the covered stents passed the tortuous siphon model without much difficulty and were deployed successfully to cover the aneurysm orifice without endoleak.

CONCLUSIONS

The carotid siphon model in vivo can simulate well the geometry of the human carotid siphon segment and can be used to test endovascular devices for interventions.

Parent vessel occlusion for treatment of cerebral aneurysms: Is there still an indication? A series of 17 patients

INTRODUCTION/PURPOSE

Flow diversion has allowed cerebrovascular neurosurgeons and neurointerventionalists to treat complex, large aneurysms, previously treated with trapping, bypass, and/or parent vessel sacrifice. However, a minority of aneurysms remain that cannot be treated endovascularly, and microsurgical treatment is too dangerous. However, balloon test occlusion (macro and micro), micro WADA testing, ICG, intra-angiography and intra-operative monitoring are all available to clinically test the hypothesis that vessel sacrifice is safe. We describe a dual-institution series of aneurysms successfully treated with parent vessel occlusion (PVO).

MATERIALS/METHODS

Prospectively collected databases of all endovascular and open cerebrovascular cases performed at Maine Medical Center and Vanderbilt University Medical Center from 2011 to 2013 were screened for patients treated with primary vessel sacrifice. A total of 817 patients were screened and 17 patients were identified who underwent parent vessel sacrifice as primary treatment.

RESULTS

All 17 patients primarily treated with PVO are described below. Nine patients presented with SAH, and 3/17 involved anterior circulation. Complete occlusion was achieved in 15/17 patients. In the remaining 2 patients, significant reduction in the aneurysm occurred. Modified Rankin Score (mRS) of 0, signifying complete independence, was achieved for 16/17 patients. One patient died due to an extracranial process.

CONCLUSIONS

Parent vessel sacrifice remains a viable and durable solution in select ruptured and unruptured intracranial aneurysms. Many adjuncts are available to aid in the decision making. In this small series, patients naturally divided into vertebral dissecting aneurysms, giant aneurysms and small distal aneurysms. Outcomes were favorable in this highly selected group.

Evaluation of Pipeline Flex delivery system for the treatment of unruptured aneurysms

INTRODUCTION

Refinements in endovascular technology have revolutionized the treatment of intracranial aneurysms (IAs) with the development of flow-diversion technology. The first generation of the Pipelin Embolization Device (PED) has demonstrated its safety and efficacy. However, the deployment technique was a difficult task that often led to complex maneuvers. The Pipeline Flex Embolization Device (PED Flex) is the second generation and its introduction has arrived with high expectations due to a completely redesigned delivery system that intends to overcome deployment difficulties seen in the previous generation. Areas covered: Preclinical studies, mechanism of action of flow-diverters, technical aspects and deployment system of the PED Flex, and clinical outcomes with both PED generations. Expert commentary: Flow diversion has allowed us to treat lesions that would be otherwise challenging for surgical clipping or unsuitable for other endosaccular strategies. Although the experience with PED Flex is limited, initial results suggest its safety and short-term efficacy.

The Debrisoft(®) Monofilament Debridement Pad for Use in Acute or Chronic Wounds: A NICE Medical Technology Guidance

As part of its Medical Technology Evaluation Programme, the National Institute for Health and Care Excellence (NICE) invited a manufacturer to provide clinical and economic evidence for the evaluation of the Debrisoft(®) monofilament debridement pad for use in acute or chronic wounds. The University of Birmingham and Brunel University, acting as a consortium, was commissioned to act as an External Assessment Centre (EAC) for NICE, independently appraising the submission. This article is an overview of the original evidence submitted, the EAC's findings and the final NICE guidance issued. The sponsor submitted a simple cost analysis to estimate the costs of using Debrisoft(®) to debride wounds compared with saline and gauze, hydrogel and larvae. Separate analyses were conducted for applications in home and applications in a clinic setting. The analysis took an UK National Health Service (NHS) perspective. It incorporated the costs of the technologies and supplementary technologies (such as dressings) and the costs of their application by a district nurse. The sponsor concluded that Debrisoft(®) was cost saving relative to the comparators. The EAC made amendments to the sponsor analysis to correct for errors and to reflect alternative assumptions. Debrisoft(®) remained cost saving in most analyses and savings ranged from £77 to £222 per patient compared with hydrogel, from £97 to £347 compared with saline and gauze, and from £180 to £484 compared with larvae depending on the assumptions included in the analysis and whether debridement took place in a home or clinic setting. All analyses were severely limited by the available data on effectiveness, in particular a lack of comparative studies and that the effectiveness data for the comparators came from studies reporting different clinical endpoints compared with Debrisoft(®). The Medical Technologies Advisory Committee made a positive recommendation for adoption of Debrisoft(®) and this has been published as a NICE medical technology guidance (MTG17).

Comparison of the flow diverter and stent-assisted coiling in large and giant aneurysms: safety and efficacy based on a propensity score-matched analysis

OBJECTIVES

The flow diverter (FD) is a device aimed at reconstructing the parent artery and occluding an aneurysm. We performed a propensity score-matched analysis to compare safety and efficacy between the FD and stent-assisted coiling.

METHODS

A database review was conducted to identify patients with large and giant unruptured aneurysms (aneurysms located in the ACA, MCA, or PCA were excluded) treated with the FD or stent-assisted coiling. A propensity score, representing the probability of using the FD, was generated for each aneurysm using the relevant patient and aneurysmal variables. Angiographic results, complications, and clinical outcomes were compared.

RESULTS

Forty-five aneurysms treated with the FD (FD alone: 32; FD+Coils: 13) and 45 treated with stent-assisted coiling were matched. The rate of complete occlusion was significantly (P = 0.0002) higher in the FD cohort than the conventional stent cohort at the 6-month follow-up. The FD cohort achieved greater improvement (P < 0.0001) and a lower rate of recurrence (P = 0.0001). The rate of periprocedural complications was similar, as was the proportion of patients who attained mRS ≤ 2 at discharge and at the 6-month follow-up.

CONCLUSIONS

Our findings provide reliable evidence demonstrating that the FD may be a preferred treatment option for large and giant unruptured aneurysms.

KEY POINTS

• Flow Diverter provided a higher complete occlusion rate at 6-month follow-up. • Flow Diverter achieved more progress occlusion and less recurrence. • Compared with the conventional stents, procedure-related morbidity of Flow Diverter was similar. • Flow Diverter is a preferred treatment for large and giant unruptured aneurysms.

Vision Amniotic Leak Detector (ALD) to Eliminate Amniotic Fluid Leakage as a Cause of Vaginal Wetness in Pregnancy: A NICE Medical Technology Guidance

In prelabour rupture of membranes (PROM) or preterm PROM the amniotic membranes rupture prior to labour. Where this is not overt a speculum examination is undertaken to confirm diagnosis. The Vision Amniotic Leak Detector (ALD) is a panty liner that can diagnose amniotic fluid as a cause of vaginal wetness. It was evaluated by the UK National Institute for Health and Care Excellence (NICE) as part of the Medical Technologies Evaluation Programme. The sponsor (CommonSense Ltd) identified five studies, of which three were deemed within scope by the External Assessment Centre (EAC). Two of these three used an inappropriate comparator. The EAC recalculated the diagnostic accuracy of Vision ALD using speculum examination as the comparator: sensitivity of 97% (95% CI 93-99%), negative predictive value of 96% (95% CI 92-98%). A negative result would therefore allow patients to be discharged with confidence. In the sponsor's cost-consequence model only patients with a positive Vision ALD result would have a speculum examination, producing a cost saving of around £10 per patient. The EAC felt that some costs were unjustified and the model did not include infection outcomes or use in a community setting. The EAC revised the sponsor's model and found the results were most sensitive to clinician costs. Vision ALD was associated with savings of around £15-£25 per patient when administration in lower-cost community healthcare avoided a referral to a higher-cost secondary-care centre. NICE published guidance MTG15 in July 2013 recommending that the case for adopting Vision ALD was supported by the evidence.

The geko™ electro-stimulation device for venous thromboembolism prophylaxis: a NICE medical technology guidance

The geko™ device is a single-use, battery-powered, neuromuscular electrostimulation device that aims to reduce the risk of venous thromboembolism (VTE). The National Institute for Health and Care Excellence (NICE) selected the geko™ device for evaluation, and invited the manufacturer, Firstkind Ltd, to submit clinical and economic evidence. King's Technology Evaluation Centre, an External Assessment Centre (EAC) commissioned by the NICE, independently assessed the evidence submitted. The sponsor submitted evidence related to the geko™ device and, in addition, included studies of other related devices as further clinical evidence to support a link between increased blood flow and VTE prophylaxis. The EAC assessed this evidence, conducted its own systematic review and concluded that there is currently limited direct evidence that geko™ prevents VTE. The sponsor's cost model is based on the assumption that patients with an underlying VTE risk and subsequently treated with geko™ will experience a reduction in their baseline risk. The EAC assessed this cost model but questioned the validity of some model assumptions. Using the EACs revised cost model, the cost savings for geko™ prophylaxis against a 'no prophylaxis' strategy were estimated as £197 per patient. Following a second public consultation, taking into account a change in the original draft recommendations, the NICE medical technologies guidance MTG19 was issued in June 2014. This recommended the adoption of the geko™ for use in people with a high risk of VTE and when other mechanical/pharmacological methods of prophylaxis are impractical or contraindicated in selected patients within the National Health Service in England.

EXOGEN ultrasound bone healing system for long bone fractures with non-union or delayed healing: a NICE medical technology guidance

A routine part of the process for developing National Institute for Health and Care Excellence (NICE) medical technologies guidance is a submission of clinical and economic evidence by the technology manufacturer. The Birmingham and Brunel Consortium External Assessment Centre (EAC; a consortium of the University of Birmingham and Brunel University) independently appraised the submission on the EXOGEN bone healing system for long bone fractures with non-union or delayed healing. This article is an overview of the original evidence submitted, the EAC's findings, and the final NICE guidance issued.

E-vita open plus for treating complex aneurysms and dissections of the thoracic aorta: a NICE medical technology guidance

The E-vita open plus is a one-stage endoluminal stent graft system used for treating complex aneurysms and dissections of the thoracic aorta. The National Institute for Health and Care Excellence (NICE), as a part of its Medical Technologies Evaluation Programme (MTEP), selected this device for evaluation and invited the manufacturer, JOTEC GmbH, to submit clinical and economic evidence. King's Technology Evaluation Centre (KiTEC), an External Assessment Centre (EAC) commissioned by the NICE, independently critiqued the manufacturer's submissions. The EAC considered that the manufacturer had included most of the relevant evidence for the E-vita open plus, based on international E-vita open registry data for 274 patients, but had provided only limited evidence for the comparators. The EAC therefore conducted a systematic review and meta-analysis of all comparators to supplement the information, and found ten additional studies providing outcome data for the three two-stage comparators. The EAC noted that the cost model submitted by the manufacturer did not include key complications during the procedures. The EAC developed a new economic model incorporating data on complications along with their long-term costs. The revised model indicated that the E-vita open plus might not provide cost savings when compared with some of the comparators in the short-term (1 year), but would have high cost savings in the long-term, from the second year onwards. The NICE Medical Technologies Guidance MTG 16, issued in December 2013, recommended the adoption of the E-vita open plus in selected patients within the National Health Service in England.

Are the UK systems of innovation and evaluation of medical devices compatible? The role of NICE's Medical Technologies Evaluation Programme (MTEP)

The economic evaluation of medical products and services is increasingly prioritised by healthcare decision makers and plays a key role in informing funding allocation decisions. It is well known that there are a number of methodological difficulties in the health technology assessment of medical devices, particularly in the provision of efficacy evidence. By contrasting devices with pharmaceuticals, the way in which the differing systems of innovation mould the UK's industry landscape is described and substantiated with market statistics. In recognition of the challenges faced by industry, as well as the growing need for cost-effective allocation of National Health Service (NHS) resources, the National Institute for Health and Care Excellence (NICE) led the development of the Medical Technologies Evaluation Programme (MTEP), which launched in 2009/2010. The review of the UK's medical devices market supports the programme's three principal aims: to simplify access to evaluation, speed up the process, and increase evaluative capacity for devices within NICE. However, an analysis of the output of MTEP's first 3 years suggests that it has some way to go to meet each of these aims.

Use of pipeline flow diverting stents for wide neck intracranial aneurysms: A retrospective institutional review

BACKGROUND

Intracranial aneurysms (ICA) if inadequately treated may result in serious morbidity and mortality. Wide-neck; large/giant, fusiform, and dissecting aneurysms are not well treated using the conventional coil embolization technique. Recent advance in endovascular treatment and technology has introduced flow diverter devices including pipeline embolization devices (PED) and Silk stents that have been shown to be more effective in treating these more complicated aneurysms. Flow Diverter devices offer a more physiologic approach to ICA treatment.

METHODS

We conducted a retrospective chart review of 23 adult patients who underwent aneurysm treatment utilizing the pipeline stent at Duke University Medical Center from July 2011 to March 2013.

RESULTS

Majority of patients (19, 82.7%) showed angiographic evidence of complete obliteration of aneurysm at 6 months follow-up, with sustained clinical improvement on modified Rankin scale score. All of the patients tolerated the procedure well with no intra-operative hemorrhage or intra-operative thromboembolic complications.

CONCLUSIONS

Our experience shows that use of PED offers a safe and effective strategy for treatment of complex ICA. Larger prospective studies are needed to confirm these observations.

WatchBP Home A for opportunistically detecting atrial fibrillation during diagnosis and monitoring of hypertension: a NICE Medical Technology Guidance

The Microlife(®) 'WatchBP Home A' oscillometric blood pressure monitor detects irregular pulse, suggestive of atrial fibrillation (AF). Early detection of AF can prevent thromboembolic stroke via anticoagulation therapy. The device was considered by the Medical Technologies Evaluation Programme of the UK National Institute for Health and Care Excellence (NICE). The sponsor (Microlife) identified 10 studies. These were reviewed by an External Assessment Centre (EAC) which considered three relevant to the decision problem, including one which found the device detected AF more accurately (sensitivity 96.8%, specificity 88.8%) than pulse palpation (87.2, 81.3%). The EAC concluded the technology had potential to improve detection of AF, but the three studies had uncertain external validity. From a cost-consequence model with a 1-year timeframe, the sponsor calculated the device would reduce electrocardiogram (ECG) referrals and prevent strokes, but incur anticoagulation therapy costs, with net NHS savings of £11.6 million and prevention of 221 strokes, annually. The EAC criticised the model for its limited time horizon, and its consideration of symptomatic AF patients who were outside the scope issued by NICE. The EAC applied a de novo Markov model, with a 10-year timeframe. The per use saving was calculated as £2.98 for asymptomatic patients aged 65-74 years and £4.26 for those aged 75-84 years, with the prevention of 53-117 nonfatal and 28-65 fatal strokes per 100,000 people screened. Following consideration by the NICE Medical Technologies Advisory Committee, NICE judged that the case for adoption was supported by the evidence (Medical Technologies Guidance 13; MTG13).

Current state of medical device nomenclature and taxonomy systems in the UK: spotlight on GMDN and SNOMED CT

A standardised terminology for describing medical devices can enable safe and unambiguous exchange of information. Proposed changes to EU-wide medical devices regulations mandate the use of such a system. This article reviews two important classification systems for medical devices in the UK. The Global Medical Device Nomenclature (GMDN) provides a classification system specifically for medical devices and diagnostics, and facilitates data exchange between manufacturers and regulators. SNOMED CT is the terminology of choice in the NHS for communicating, sharing and storing information about patients’ healthcare episodes. Harmonisation of GMDN and SNOMED CT will encourage use of single terminology throughout the lifetime of a device; from regulatory approval through clinical use and post-marketing surveillance. Manufacturers will be required to register medical devices with a European device database (Eudamed) and to fit certain devices with a Unique Device Identifier; both are efforts to improve transparency and traceability of medical devices. Successful implementation of these elements depends on having a consistent nomenclature for medical devices.