Dear Editor,
we read with great interest the paper by Durst at al. [1], aimed to define
the anatomy of cerebral dural sinus system in the generalized population,
evaluating the prevalence of sinus venous stenosis and hypoplasia. This
condition is considered of pathogenetic relevance in idiopathic
intracranial hypertension (IIH) [2-4] and has been also associated to
chronic and, mostly, to refractory headaches [5-7].
We a...
Dear Editor,
we read with great interest the paper by Durst at al. [1], aimed to define
the anatomy of cerebral dural sinus system in the generalized population,
evaluating the prevalence of sinus venous stenosis and hypoplasia. This
condition is considered of pathogenetic relevance in idiopathic
intracranial hypertension (IIH) [2-4] and has been also associated to
chronic and, mostly, to refractory headaches [5-7].
We appreciate the Authors' efforts in reconstructing the venous system
anatomy by using as source the CT Angiography (CTA) of a large sample of
selected patients. However, we would point that their sample cannot be
easily considered representative of the "generalized population" and that
study results might be appreciably overestimated.
The study has been performed on a large series of cases selected among
patients that, on the basis of their own clinical presentation, underwent
a CTA. At the Author's institution, a CTA was routinely performed in "all
suspected strokes, many trauma patients, and anyone suspected of having a
vascular disorder". In order to make their sample representative of the
general population, out of 600 screened examinations, 245 have been
excluded for technical reasons or because of clinic presentations or
pathologic findings that could "conceivably alter venous outflow".
However, according to the exclusion criteria list, posterior fossa lesions
were excluded, but anterior focal ischemia and head trauma - both
conditions usually running with at least a mild brain edema and consequent
raised intracranial pressure (ICP) - were presumably included. There is
evidence that raised ICP is associated with focal or diffuse narrowing of
sinus venous tree [8].
Moreover, a number of other clinical presentations that could prompt
neurovascular investigations but might result from a cerebral venous
outflow derangement despite a negative CTA, are not listed within the
exclusion criteria. These include: responsive chronic migraine [9-10]
(only refractory chronic headaches were excluded but there is evidence of
> 50% sinus stenosis prevalence in chronic migraine); acute vertigo
(often comorbid with episodic or chronic migraine); cough, exertional and
sexual activity-associated headaches [11], and idiopathic stabbing
headache [12]. Finally, Transient global amnesia may result from a
deranged cerebral venous outflow with jugular valve incompetence [13].
Based on the above considerations, we believe that the design of this
otherwise excellent study implies a not negligible overestimation of the
prevalence of sinus stenosis and hypoplasia in the general population. The
true prevalence of sinus stenosis in healthy subjects remains unknown.
1. Durst CR, Ornan DA, Reardon MA, et al.. Prevalence of dural venous
sinus stenosis and hypoplasia in a generalized population. J Neurointerv
Surg. 2016. [Epub ahead of print]. doi: 10.1136/neurintsurg-2015-012147
2.Farb RI, Vanek I, Scott JN, et al. Idiopathic intracranial
hypertension: the prevalence and morphology of sinovenous stenosis.
Neurology. 2003 May 13; 60(9):1418-24.
3. De Simone R, Ranieri A, Montella S, et al. The role of dural sinus
stenosis in idiopathic intracranial hypertension pathogenesis: the self-
limiting venous collapse feedback-loop model. Panminerva Med. 2014 Sep;
56(3):201-9
4. Puffer RC, Mustafa W, Lanzino G. Venous sinus stenting for
idiopathic intracranial hypertension: a review of the literature. J
Neurointerv Surg. 2013;5(5):483-486
5. Bono F, Salvino D, Tallarico T, et al. Abnormal pressure waves in
headache sufferers with bilateral transverse sinus stenosis. Cephalalgia
2010; 30: 1419-1425
6. De Simone R, Ranieri A, Montella S, et al. Sinus venous stenosis-
associated idiopathic intracranial hypertension without papilledema as a
powerful risk factor for progression and refractoriness of headache. Curr
Pain Headache Rep. 2012 Jun;16(3):261-9.
7. De Simone R, Ranieri A, Montella S, et al. Intracranial pressure
in unresponsive chronic migraine. J Neurol. 2014 Jul;261(7):1365-73.
8. Rohr A, Bindeballe J, Riedel C, et al. The entire dural sinus tree
is compressed in patients with idiopathic intracranial hypertension: a
longitudinal, volumetric magnetic resonance imaging study. Neuroradiology.
2012 Jan;54(1):25-33
9. Bono F, Cristiano D, Mastrandrea C, et al. The upper limit of
normal CSF opening pressure is related to bilateral transverse sinus
stenosis in headache sufferers. Cephalalgia 2010; 30: 145-151.
10. Fofi L, Giugni E, Vadal? R, et al. Cerebral transverse sinus
morphology as detected by MR venography in patients with chronic migraine.
Headache. 2012 Sep;52(8):1254-61.
11. Donnet A, Valade D, Houdart E. Primary cough headache, primary
exertional headache, and primary headache associated with sexual activity:
a clinical and radiological study. Neuroradiology 2013; 55:297-305
12. Montella S, Ranieri A, Marchese M, De Simone R. Primary stabbing
headache: a new dural sinus stenosis-associated primary headache? Neurol
Sci. 2013 May;34 Suppl 1:S157-9.
13. Chung CP, Hsu HY, Chao AC, et al. Transient global amnesia:
cerebral venous outflow impairment-insight from the abnormal flow patterns
of the internal jugular vein. Ultrasound Med Biol. 2007 Nov;33(11):1727-
35. Epub 2007 Jul 16.
Letter by Parthasarathy et al. regarding article, "Unwanted
detachment of the Solitaire device during mechanical thrombectomy in acute
ischemic stroke ".
Letter by Parthasarathy et al. regarding article, "Unwanted
detachment of the Solitaire device during mechanical thrombectomy in acute
ischemic stroke ".
Department of Neurointerventional surgery, Institute of Neuroscience,
Medanta, the Medicity, Gurgaon, India.
Title word count: 14
Word Count: Abstract: 157; Manuscript count excluding references: 554
References: 4
Key words:Stentriever, mechanical thrombectomy, detachment, stent
based retrieval
Corresponding Author
Dr Vipul Gupta MD,
Additional Director and Head, Neurointerventional Surgery,
Medanta Institute of Neurosciences
Medanta - the Medicity,
Gurgaon 122001
Tel: 00919810542372
drvipulgupta25@gmail.com
Abstract:
Stent detachment is a dreaded device complication in the setting of
acute stroke management and may result in poor outcome. The principal
objective in the event of stent detachment is to establish flow in the
occluded territory. Techniques including balloon angioplasty, local
infusion of antiplatelet or thrombolytic agent and suction have been
described with variable success in achieving meaningful reperfusion. Stent
retrieval can potentially restore flow to the occluded territory and
negate the need for administering dual antiplatelet. We read with interest
the article by Castano et al (2016) on unwanted detachment of the
Solitaire device during mechanical thrombectomy in acute ischemic
stroke.Stents with type 'A' detachment were retrievable; whereas, attempts
at retrieving stents with type B detachment were invariably unsuccessful.
Therefore, a rescue strategy, 'stent based retrieval',may prove to be
useful when snare retrieval fails. Stent based retrieval could be
considered in both type A and type B detachments when snare retrieval is
unsuccessful.
Letter to the Editor
We read with great interest the article by Casta?o et al (2016) on
unwanted detachment of the Solitaire device(Medtronic/Covidien/ev3,
Dublin, Ireland) during mechanical thrombectomy in acute ischemic stroke.1
Stent detachment in their series was invariably associated with a poor
outcome, higher rates of symptomatic intracranial hemorrhage and higher
mortality.
They had classified stent detachment as either type A or type B based
on if the separation occurred before or after the proximal radiopaque
stent marker. They attempted stent retrieval with an Amplatz GooseNeck
snare (Medtronic/Covidien/ev3, Dublin, Ireland) in all irrespective of the
type of detachment.A rescue strategy in case of failure of snare retrieval
was not described.Stents were retrievable with 'type A' detachments;
however, attempts to retrieve stents with 'type B' detachmentwere
invariably unsuccessful. The likely explanation is that with type B
detachment the 'stent legs' either open or stay together making a
'spearhead' that digs into the wall of the artery making snare retrieval
not possible.
The primary aim in such a situation is to re-establish flow in the
occluded territory. A number of techniques including balloon angioplasty,
local infusion of antiplatelet/ thrombolytic agent, and suction have been
described with variable success in achieving meaningful reperfusion.(2,3)
Furthermore, leaving a stent in situ necessitates administration of dual
antiplateletto a patient in whom the infarct core can increase either due
to delayed occlusion or failure to recanalise. Therefore, an attempt to
restore flow by retrieving the detached stent is likely to be crucial to
achieving a good outcome. Castano et al (2016) were able to achieve
meaningful reperfusion in 50% of patients; however, the outcomes were poor
despite device retrieval.(1) This further reiterates the importance of
time and the need to establish perfusion early. Therefore, a second
strategy may be beneficial when snare retrieval fails.
Snare retrieval may not be successful in type A detachments and not likely
to be the appropriate strategy in type B stent detachments. Therefore, an
alternate strategy, 'Solitaire stentectomy' may prove to be effective
under these circumstances. (4) 'Stent based retrieval' using a Solitaire
device can be performed as a '4 step' process in a patient with stent
detachment. Step 1: Partial deployment of an appropriately sized solitaire
device proximal to the detached stent [the distal end of microcatheter is
positioned proximal to the proximal radiopaque marker/ proximal legs
(struts) of the detached stent and then the stent is partly unsheathed to
allow for its expansion]. Step 2: Engaging the proximal end of the
detached stent by the distal end of the second stent by advancing the
microcatheter and the stent together. Step 3: re-sheathing the device in
an attempt to capture the proximal legs/ struts of the detached stent.
Step 4: retrieval of microcatheter, device and detached stent. This
strategy may be useful in both type A and type B detachments when snare
retrieval fails.
Clearly, stent detachment is a dreaded device complication for the
neurointerventionist in the setting of acute stroke management and may
result in poor outcome. Development of methods and techniques is crucial
to dealing with stent detachments in a timely and effective manner. "Stent
based retrieval" can be a useful alternate technique when snare retrieval
fails and may be employed as the primary technique in type B detachments.
References:
1. Castano C, Dorado L, Remollo S, et al. Unwanted detachment of the
Solitaire device during mechanical thrombectomy in acute ischemic stroke.
J Neurointerv Surg. 2016 Jan 27. [Epub ahead of print]
2. Kim ST, Jin SC, Jeong HW, et al. Unexpected detachment of
solitaire stents during
mechanical thrombectomy. J Korean Neurosurg Soc 2014;56:463-8.
3. Yub Lee S, Won Youn S, Kyun Kim H, et al. Inadvertent detachment
of a retrievable intracranial stent: review of manufacturer and user
facility device experience. Neuroradiol J 2015;28:172-6.
4. Chapot R, Stracke P, Nordmeyer H, Heddier M. Stentectomy:
Retrieval of stents after stent assisted coiling. Interventional
Neuroradiology 2015; 21(1S):160
We read with great interest the article by Fargen et al(1), which
reports the Journal of Neurointerventional Surgery (JNIS) experience in
social media. The journal recently implemented a three-pronged social
media strategy, along with the hiring of dedicated social media staffing,
to enhance their online viewership. Since implementing this marketing
approach, JNIS has had significantly more website accessions to their pe...
We read with great interest the article by Fargen et al(1), which
reports the Journal of Neurointerventional Surgery (JNIS) experience in
social media. The journal recently implemented a three-pronged social
media strategy, along with the hiring of dedicated social media staffing,
to enhance their online viewership. Since implementing this marketing
approach, JNIS has had significantly more website accessions to their peer
reviewed articles, and gained more insight into their Twitter analytics.
The information presented provide a road-map to guide social media
marketing strategies for journals in neurosurgery, neurology, and
radiology.
While not studied in this manuscript directly, the authors discuss
the potential for social media metrics to predict subsequent article
citations. In Toronto, our group studied the association between social
media metrics and traditional indices of scientific impact among
neurosurgical journals as well as departments.(2) We found that
neurosurgical journals and departments with active social media presences
had significantly higher H-indices as well as overall citation counts. As
a journal not limited purely to neurosurgery, JNIS was outside the scope
of our study; however, a repeat analysis with JNIS' social media metrics
included did not alter our findings. Of particular note, our data did not
meet the criteria for parametric analysis because of many outliers.
Interestingly, JNIS' primary outcome data, the number of clicks per
article, showed similar distributional skew (Figure 3, in Fargen et al.).
The authors made significant efforts to identify associated covariates,
identifying the day of the week of tweet posting as a significant
predictor. With significant outlying data however, there may certainly be
other unidentified covariates which may influence social media
dissemination. The complexity of established and emerging social media
analytics requires careful conceptualization for future studies.
In conclusion, we commend the authors' efforts to advance JNIS's
social media presence. This is another study that contradicts
Circulation's randomized trial results which failed to show any benefits
for social media on readership numbers and article downloads.(3) Without a
doubt, there are many unanswered questions for the use of social media in
neurosurgery and neurointerventional surgery. Are there independent
predictors for citations in all specialties, or this is specialty/audience
dependent effect? While difficult to assess given the relative anonymity
online, it would be interesting to note the demographics of clicks and
followers, whether they be faculty, residents, local or international
fellows, etc.. We look forward to future analyses from the JNIS team, and
the wider medical community.
Naif M Alotaibi, Daipayan Guha, Andres M Lozano (Division of
Neurosurgery, Department of Surgery, University of Toronto, Toronto,
Ontario, Canada)
References
1. Fargen KM, Ducruet AF, Hyer M, Hirsch JA, Tarr RW. Expanding the
social media presence of the Journal of Neurointerventional Surgery:
editor's report. J Neurointerv Surg. Feb 29 2016.
2. Alotaibi NM, Guha D, Fallah A, et al. Social Media Metrics and
Bibliometric Profiles of Neurosurgical Departments and Journals: Is There
a Relationship? World Neurosurg. Feb 5 2016.
3. Fox CS, Bonaca MA, Ryan JJ, Massaro JM, Barry K, Loscalzo J. A
randomized trial of social media from Circulation. Circulation. Jan 6
2015;131(1):28-33.
Optimal outcome of intra-arterial treatment for Acute ischemic stroke
(AIS) requires the involvement of appropriately trained and qualified
providers from diverse specialties working together in synchrony under
tight time line, communicating effectively to provide evidence-based
clinical care. Hence, we welcome the international multi-society consensus
document on training guidelines for the interventionalists involved in...
Optimal outcome of intra-arterial treatment for Acute ischemic stroke
(AIS) requires the involvement of appropriately trained and qualified
providers from diverse specialties working together in synchrony under
tight time line, communicating effectively to provide evidence-based
clinical care. Hence, we welcome the international multi-society consensus
document on training guidelines for the interventionalists involved in
intra-arterial treatment of AIS.(1) However, we wish to point out the
critical missing link in the consensus document - the role of
anesthesiologists.
We wish to offer a brief outline of the importance of anesthesiology
inputs in stroke care. Given the emergent and complex nature of the
interventional procedures for AIS, frequent association of multiple co-
morbidities, the need for strict hemodynamic management and ensuring
homeostasis, it is recommended to have a qualified and experienced
anesthesiologist to provide monitored anesthesia care (MAC) or general
anesthesia (GA), as deemed suitable based on the patient
characteristics.(2) Providing an optimal milieu for the procedure while
poised to quickly manage complications and concurrently maintaining the
blood pressure in a tight range in patients who often have associated
cardiovascular diseases is challenging. Optimal hemodynamic management of
these patients requires judicious fluid, vasopressor / inotrope selection.
Moreover, oxygenation and ventilation patterns during intra-arterial
therapy can impact cerebral blood flow and contribute to outcome.
Additionally, glycemic management in accordance with current guidelines is
critical. These skill sets are uniquely possessed by anesthesiologists
experienced in the care of stroke patients. Further underscoring the
complexity mandating this expertise is the fact that type of GA including
the choice of anesthetic/sedative agents may impact the ischemic brain and
can affect the outcome of AIS.(3) Not surprisingly, it has been
recommended that acute stroke interventions, even when performed on awake
patients, should be carried out in the presence of experienced anesthesia
providers who can rapidly manage untoward events.(2) Essentially, the
involvement of a qualified and experienced anesthesiologist can have
significant bearing on the outcome. The anesthetic management should
follow the evidence based recommendations made by the Society for
Neuroscience in Anesthesiology and Critical Care (SNACC) consensus
statement.(2)
Although some studies reported that GA, as a generic and
uncharacterized therapy, is associated with poor outcome in patients
undergoing intra-arterial treatment of AIS, these investigators did not
recognize that GA constitutes a continuum of central nervous system
depression, wherein effects on the brain are dose-related, disparate, and
protean in terms of neurochemistry, perfusion, neuroprotection, and
neurotoxicity.(4) This has led to the initiation of clinical trials
randomizing the patients with AIS to GA or MAC. However, these trials
suffer from significant limitations due to lack of anesthetic insight /
involvement and do not reflect the relevant clinical and protean
neuropharmacology of GA.(4) We offer the similar criticism for the
Training Guidelines for Endovascular Ischemic Stroke Intervention.(1)
While this document provides crucial recommendations for not only
physician training and qualification but also essential hospital
requirements like 24/7 access to all relevant expertise such as vascular
neurology, neurosurgery and neurocritical care; it fails to address the
fundamental need of the 24/7 availability of a qualified anesthesiologist.
We encourage the various disciplines involved in stroke care to work
together and we urge the community of stroke providers to actively engage
SNACC and the anesthesiology community in order to effectively enhance the
care of patients with AIS.
References
1. Lavine SD, Cockroft K, Hoh B, et al. Training Guidelines for
Endovascular Ischemic Stroke Intervention: An International Multi-Society
Consensus Document. AJNR Am J Neuroradiol. 2016 Feb 18. [Epub ahead of
print]
2. Talke PO, Sharma D, Heyer EJ, et al. Society for Neuroscience in
Anesthesiology and Critical Care Expert consensus statement: anesthetic
management of endovascular treatment for acute ischemic stroke: endorsed
by the Society of NeuroInterventional Surgery and the Neurocritical Care
Society. J Neurosurg Anesthesiol. 2014 Apr;26(2):95-108.
3. Sivasankar C, Stiefel M, Miano TA, et al. Anesthetic variation and
potential impact of anesthetics used during endovascular management of
acute ischemic stroke. J Neurointerv Surg. 2015 Nov 27. [Epub ahead of
print]
4. Kofke WA, Sharma D. SIESTA trial: Is GA a drug you get from the
hospital pharmacy? International Journal of Stroke. (In Press)
Dear Editor:
The study by Smith et al. is a valuable effort to look at outcomes in
elderly patients with intracranial aneurysms.(1) However, we would like to
raise a few questions about the study.
The follow-up periods among the included studies are highly variable,
which is a limitation that the authors acknowledged. The authors described
in the Method section that a meta-regression was performed to measure the
effects of...
Dear Editor:
The study by Smith et al. is a valuable effort to look at outcomes in
elderly patients with intracranial aneurysms.(1) However, we would like to
raise a few questions about the study.
The follow-up periods among the included studies are highly variable,
which is a limitation that the authors acknowledged. The authors described
in the Method section that a meta-regression was performed to measure the
effects of follow-up lengths and dates of publication. However, we were
unable to find any mention of the meta-regression results in the
subsequent text. The presentation of between study variance, regression
coefficients, and residual errors along with other relevant information
would be essential for the readers to understand the effects of these two
key variables. Sensitivity analysis is also mentioned in the methods
sections, but its results are not discussed.
The authors use mRS and GOS scores to derive utility values. It would be
helpful to elaborate on at what time frame after treatment these values
were obtained, as short term assessment after clipping would be misleading
to derive long term utility values compared to coiling. There was no
specification of the time horizon of the decision-tree model. It was not
clear whether the final outcome in terms of QoL was measured over the
remaining years of the patient's life or just one year post-procedure. In
the first case, a Markov model should be performed, with the probability
of late death being accounted in each year. In the latter case, the
probability of late death should be accounted in the model.
A recent meta-analysis by Hong et al. showed a recurrence rate after
coiling as high as 34.4% and high rates of retreatment including multiple
retreatments are being reported in long term follow-ups of patients with
intracranial aneurysms.(2,3) The structure of the decision tree appears
highly simplistic, without considering incidence of recurrence with
coiling or clipping. Elderly patients with a shorter life expectancy might
be at lower risk for recurrence, but the impact of this with a Markov
analysis would be worth considering.
For this reason, and as per the convention of decision-analysis, it might
be prudent to consider a "do nothing" strategy as the control.
Conservative treatment of elderly patients with cerebral aneurysms,
especially unruptured aneurysms, should be included in the model for
comparison. Given the characteristics of the patient population in this
study (relatively shorter life expectancy and higher risks of
perioperative complications), conservative option might yield better
quality of life than both coiling and clipping. The absence of this
control option renders the conclusion biased.
As per Table 2 (Clinical characteristics of patients analyzed), 165/ 165
clipped unruptured and 113/136 coiled unruptured aneurysms were in the
posterior circulation. Similarly, 1187/1236 ruptured clipped and 519/604
ruptured coiled aneurysms were in the posterior circulation. Such a high
proportion of posterior circulation aneurysms is likely incorrect,
especially since posterior circulation aneurysms are infrequently clipped,
have an unfavorable anatomy, and have an inherent higher rate of
reopening.(3)
Table 3 lists the number of cases considered in periprocedural death in
ruptured clipped patients as 1357 and the number considered in late death
as 1231. It is unclear what these numbers mean as Table 2 lists the total
number of ruptured clipped aneurysms as 1236. Same applies to other
variables in Table 3.
There is a lack of detailed explanation about how the probability of late
death was defined and calculated. Since the follow-up period for most of
the included studies was very short, further elaboration on how the
authors measured the late death rate would be helpful.
References:
1. Smith MJ, Sanborn MR, Lewis DJ, et al. Elderly patients with
intracranial aneurysms have higher quality of life after coil
embolization: a decision analysis. J Neurointerv Surg 2015;7(12):898-904.
2. Hong Y, Wang Y-J, Deng Z, et al. Stent-Assisted Coiling versus Coiling
in Treatment of Intracranial Aneurysm: A Systematic Review and Meta-
Analysis. PloS one 2014;9(1):e82311.
3. van Eijck M, Bechan RS, Sluzewski M, et al. Clinical and Imaging Follow
-Up of Patients with Coiled Basilar Tip Aneurysms Up to 20 Years.
2015;36(11):2108-13.
I read with interest the article "Onyx extrusion through the scalp
after embolization of dural arteriovenous fistula" by SIngla et al. The
objective of the article is mainly to reinforce in our pre-treatment
discussions the need to include as much as possible the outcomes arising
from the use of Onyx that include, but are not exclusively related to,
micro catheter retention or rupture, unintended ves...
I read with interest the article "Onyx extrusion through the scalp
after embolization of dural arteriovenous fistula" by SIngla et al. The
objective of the article is mainly to reinforce in our pre-treatment
discussions the need to include as much as possible the outcomes arising
from the use of Onyx that include, but are not exclusively related to,
micro catheter retention or rupture, unintended vessel occlusion and the
possibility of stroke.
The use of the occipital artery is a valid means of occluding
fistulas of the transverse sinus and on occasion the torcula however there
is the risk of skin necrosis especially if reflux is obtained to the
degree seen here in this case, filling the contralateral occipital artery.
We have used the middle meningeal artery to occlude such superior
sagittal sinus, other transverse sinus and higher grade dural fistulas
with detachable tip micro catheters such as Apollo (eV3) and Sonic (BALT)
and dual lumen remodelling balloons (Sceptre C, Microvention)1.
Perhaps use of the middle meningeal artery feeders would have pre-
empted surgery and completed the treatment endovascularly as well as
avoiding possible skin necrosis from use of the occipital arteries and
potential skin extrusion of the embolic agent. We understand that a
complete endovascular cure may not be achievable without venous balloon
remodelling using the Copernic balloon ( BALT) but the same
clinical/angiographic result can be obtained with careful monitoring of
the sinus lumen on an anteroposterior view. It may be that both middle
meningeal arteries arose from the ophthalmic arteries, thus precluding
their use. This would be very unusual however.
Thus in summary, use of the middle meningeal arteries in this case
may have precluded the surgery and having to expose the occipital artery
territories and scalp to the liquid embolic agent. Thus possible skin
necrosis and the observed material extrusion could be avoided.
Reference:
1. Preliminary experience with the liquid embolic material agent PHIL
(Precipitating Hydrophobic Injectable Liquid) in treating cranial and
spinal dural arteriovenous fistulas: technical note
Joe J Leyon, Swarupsinh Chavda, Allan Thomas and Saleh Lamin
J NeuroIntervent Surg published online May 20, 2015
Dr. Chen's article is an interesting change of format in Medical
Journal articles. It is a "letter" presenting a unique perspective by
addressing a young woman on the topic of philosophical and experiential
aspects of his work as a neurosurgeon.
This is a welcome addition to standard medical information. As a
patient, intelligence and humanity are attributes I seek in a
physician/surgeon. Dr. Chen's capacity...
Dr. Chen's article is an interesting change of format in Medical
Journal articles. It is a "letter" presenting a unique perspective by
addressing a young woman on the topic of philosophical and experiential
aspects of his work as a neurosurgeon.
This is a welcome addition to standard medical information. As a
patient, intelligence and humanity are attributes I seek in a
physician/surgeon. Dr. Chen's capacity for varying his perspective in
order to better grasp nuance in complex situations is a essential aspect
of his excellence in medical practices.
J. J. (Buddy) Connors MD, Interventional Neuroradiology, Vanderbilt
University Medical Center, Nashville, TN.
Re: Understanding IMS III: old data shed new light on a futile trial
I read this article with great interest. The issue of tPA and its
risk/benefit ratio for intra-arterial treatment of acute ischemic stroke
is essential to understanding the results of IMS III. While possible
toxic effects of...
J. J. (Buddy) Connors MD, Interventional Neuroradiology, Vanderbilt
University Medical Center, Nashville, TN.
Re: Understanding IMS III: old data shed new light on a futile trial
I read this article with great interest. The issue of tPA and its
risk/benefit ratio for intra-arterial treatment of acute ischemic stroke
is essential to understanding the results of IMS III. While possible
toxic effects of tPA might be a concern, other characteristics of intra-
arterial lysis are perhaps of greater importance.
It has long been known that evidence points to an inverse
relationship of speed of lysis to the dose/concentration of alteplase.
Bookstein and others have demonstrated that too much lytic agent actually
slows the speed of lysis considerably (1,2,3,4,5). An additional concern
is the insolubility of alteplase in saline (L-arginine is the diluent)(6)
and associated altered bioactivity. Conversely, reteplase (EKR
Therapeutics Inc.) is water-soluble with possibly faster lytic ability
than alteplase and penetrates thrombus more like urokinase (7). These
issues were summarized in 2004 (8) and at SNIS annual meetings and
dedicated stroke training courses (9). Determining the best lytic agent to
use (alteplase or reteplase) and the optimal concentration and dosing was
the primary purpose of the original INSTOR registry (10). INSTOR tested
alteplase vs. reteplase in high-dose vs. low-dose regimens knowing that
there would eventually be a randomized trial that very much needed this
information. To this day, we still do not know the correct dose of intra-
arterial alteplase, optimal duration of infusion, or whether alteplase is
better than reteplase for intra-arterial use. However, IMS III did prove
that the specified alteplase regimen used for unknown durations did not
open more than half the vessels even half the time, a result worse than
that obtained with urokinase in PROACT II (11).
REFERENCES:
1) Bookstein JJ, Bookstein FL. Augmented experimental pulse-spray
thrombolysis with tissue plasminogen activator, enabling dose reduction by
one or more orders of magnitude. J Vasc Interv Radiol 2000; 11:299-303.
2) Bookstein JJ, Bookstein FL. Pulsespray thrombolysis with reteplase:
optimization and comparison with tPA in a rabbit model. J Vasc Interv
Radiol 2001; 12:1319-1324.
3) Wu JH, Diamond SL. Tissue plasminogen activator (tPA) inhibits plasmin
degradation of fibrin: a mechanism that slows tPA-mediated fibrinolysis
but does not require alpha 2-antiplasmin or leakage of intrinsic
plasminogen. J Clin Invest 1995; 95:2483-2490.
4) Torr SR, Nachowiak DA, Fujii S, Sobel BE. "Plasminogen steal" and clot
lysis. J Am Coll Cardiol 1992; 19:1085-1090.
5) Onundarson PT, Francis CW, Marder VJ. Depletion of plasminogen in vitro
or during thrombolytic therapy limits fibrinolytic potential. J Lab Clin
Med 1992; 120:120-128.
6) Semba CP, Weck S, Patapoff T. Alteplase: Stability and Bioactivity
after Dilution in Normal Saline Solution. J Vasc Interv Radiol 2003;14:99-
102
7) Fischer S, Kohnert U. Major mechanistic differences explain the higher
clot lysis potency of reteplase over alteplase: lack of fibrin binding is
an advantage for bolus application of fibrin-specific thrombolytics.
Fibrinolysis & Proteolysis (1997) 11(3), 129-135.
8) Connors JJ. Pharmacologic Agents in Stroke Prevention, Acute Stroke
Therapy, and Interventional Procedures. J Vasc Interv Radiol 2004; 15:S87-
S101.
9) Catheter Lysis of Thromboembiolic Stroke (CLOTS). Dallas TX. Oct 2010-
2013.
10) www.strokeregistry.org. accessed May 19, 2014.
11) Furlan A, Higashida R, Weschler L, et al. Intra-arterial prourokinase
for acute ischemic stroke: the PROACT II study--a randomized controlled
trial JAMA 1999; 282:2003-2011.
Conflict of Interest:
Medical Director, INSTOR, Interventional Stroke Therapy Outcomes Registry
We read with interest the study published ADAPT FAST study article
(Turk AS, et al.) as published first online in the Journal of
NeuroInterventional Surgery on 25Feb2014. We would like to congratulate
the authors for their work in improving aspiration technique for acute
stroke treatment that have been quite disappointing on demonstrating
improvement on clinical outcomes on previous publications (1, 2). The
advent on th...
We read with interest the study published ADAPT FAST study article
(Turk AS, et al.) as published first online in the Journal of
NeuroInterventional Surgery on 25Feb2014. We would like to congratulate
the authors for their work in improving aspiration technique for acute
stroke treatment that have been quite disappointing on demonstrating
improvement on clinical outcomes on previous publications (1, 2). The
advent on the new generation devices, the stent retrievers, pushed forward
the whole acute stroke treatment field towards fast, efficient and
consistent interventional treatments and the standards are much higher
than first generation devices (3, 4). Other or additional being able to
demonstrate high recanalization rates in clinical studies are needed to
establish a multimodal technical armamentarium, adjustable to different
anatomical settings. However, as the principle investigators of the STAR
study we would also like to point out some incorrect values that were
reported by the colleagues on table 4 of this publication. The outcome
data for the STAR study is listed incorrectly. In particular, the
percentages for the following outcomes were listed incorrectly in Table 4
of the article: TICI 2a/2b/3, Final TICI 2b/3, mRS 0-2, mortality, device-
related complications, and symptomatic ICH (5). We would kindly ask that
the correct numbers should be stated in the original publication.
The incorrect values displayed in table 4 were TICI 2a/2b/3 (%), Final
TICI 2b/3 (%), mRS 0-2 (%), Mortality (%), Device related complications
(%) and Symptomatic ICH (%).
The correct values and correct context as reported in the STAR study
publication (Pereira VM, Stroke 2013) are indicated below:
1. The penumbra pivotal stroke trial: safety and effectiveness of a
new generation of mechanical devices for clot removal in intracranial
large vessel occlusive disease. Stroke; a journal of cerebral circulation
2009;40:2761-2768
2. Tarr R, Hsu D, Kulcsar Z, et al. The POST trial: initial post-market
experience of the Penumbra system: revascularization of large vessel
occlusion in acute ischemic stroke in the United States and Europe.
Journal of neurointerventional surgery 2010;2:341-344
3. Nogueira RG, Lutsep HL, Gupta R, et al. Trevo versus Merci retrievers
for thrombectomy revascularisation of large vessel occlusions in acute
ischaemic stroke (TREVO 2): a randomised trial. Lancet 2012;380:1231-1240
4. Saver JL, Jahan R, Levy EI, et al. Solitaire flow restoration device
versus the Merci Retriever in patients with acute ischaemic stroke
(SWIFT): a randomised, parallel-group, non-inferiority trial. Lancet
2012;380:1241-1249
5. Pereira VM, Gralla J, Davalos A, et al. Prospective, multicenter,
single-arm study of mechanical thrombectomy using Solitaire Flow
Restoration in acute ischemic stroke. Stroke; a journal of cerebral
circulation 2013;44:2802-2807
Re: Ogata A et al. Carotid artery stenting without post-stenting
balloon dilatation. J NeuroIntervent Surg 2013; Dec 6: (Epub ahead of
print)
We read with interest this article regarding carotid stenting (CAS)
without post-stent balloon angioplasty. The authors believe that this
method reduces the risk of embolic complications. They point out that
every passage of a device across a carotid stenosis can generate...
Re: Ogata A et al. Carotid artery stenting without post-stenting
balloon dilatation. J NeuroIntervent Surg 2013; Dec 6: (Epub ahead of
print)
We read with interest this article regarding carotid stenting (CAS)
without post-stent balloon angioplasty. The authors believe that this
method reduces the risk of embolic complications. They point out that
every passage of a device across a carotid stenosis can generate emboli,
and that the post-stent angioplasty is the most embologenic part of
standard CAS techniques.
Our group and others (1,2) have shown that primary carotid stenting
(PCS), in which a self-expanding stent alone, without the use of an
embolic protection device or balloon angioplasty, can safely and
effectively treat the majority of carotid stenoses. PCS is particularly
effective in patients with moderate amounts of "soft" plaque and minimal
plaque calcification. PCS minimizes the potential for embolus generation,
results in less hemodynamic depression, is faster and cheaper and may be
safer than standard techniques. Although re-stenosis rates are higher,
these patients are rarely symptomatic and re-angioplasty of recurrent
lesions with neointimal formation is usually straightforward.
Ogata et al are on the right path towards making CAS safer, but in
appropriate patients, PCS may be an even better option.
1. Bussiere M, Pelz DM, Kalapos P et al. Results using a self-
expanding stent alone in the treatment of severe, symptomatic carotid
bifurcation stenosis. J Neurosurg 2008; 109: 454-460
2. Baldi S, Zander T, Rabellino M, Gonzalez G, Maynar M. Carotid artery
stenting without angioplasty and carotid protection: a single center
experience with up to 7 years follow-up. AJNR Am J Neuroradiol 2011; 32
(4): 759-763
David M. Pelz, MD, FRCPC
Department of Medical Imaging
Stephen P. Lownie, MD, FRCSC
Department of Clinical Neurological Sciences
Division of Neurosurgery
Schulich School of Medicine and Dentistry
Western University, London, Ontario
Canada
Dear Editor, we read with great interest the paper by Durst at al. [1], aimed to define the anatomy of cerebral dural sinus system in the generalized population, evaluating the prevalence of sinus venous stenosis and hypoplasia. This condition is considered of pathogenetic relevance in idiopathic intracranial hypertension (IIH) [2-4] and has been also associated to chronic and, mostly, to refractory headaches [5-7]. We a...
Letter by Parthasarathy et al. regarding article, "Unwanted detachment of the Solitaire device during mechanical thrombectomy in acute ischemic stroke ".
Rajsrinivas Parthasarathy MRCP (UK) Neurology, Vipul Gupta MD, Gaurav Goel MD DM
Department of Neurointerventional surgery, Institute of Neuroscience, Medanta, the Medicity, Gurgaon, India.
Title word count: 14
Word Count: Abstract: 1...
We read with great interest the article by Fargen et al(1), which reports the Journal of Neurointerventional Surgery (JNIS) experience in social media. The journal recently implemented a three-pronged social media strategy, along with the hiring of dedicated social media staffing, to enhance their online viewership. Since implementing this marketing approach, JNIS has had significantly more website accessions to their pe...
Optimal outcome of intra-arterial treatment for Acute ischemic stroke (AIS) requires the involvement of appropriately trained and qualified providers from diverse specialties working together in synchrony under tight time line, communicating effectively to provide evidence-based clinical care. Hence, we welcome the international multi-society consensus document on training guidelines for the interventionalists involved in...
Dear Editor: The study by Smith et al. is a valuable effort to look at outcomes in elderly patients with intracranial aneurysms.(1) However, we would like to raise a few questions about the study. The follow-up periods among the included studies are highly variable, which is a limitation that the authors acknowledged. The authors described in the Method section that a meta-regression was performed to measure the effects of...
Dear Sirs,
I read with interest the article "Onyx extrusion through the scalp after embolization of dural arteriovenous fistula" by SIngla et al. The objective of the article is mainly to reinforce in our pre-treatment discussions the need to include as much as possible the outcomes arising from the use of Onyx that include, but are not exclusively related to, micro catheter retention or rupture, unintended ves...
Dr. Chen's article is an interesting change of format in Medical Journal articles. It is a "letter" presenting a unique perspective by addressing a young woman on the topic of philosophical and experiential aspects of his work as a neurosurgeon.
This is a welcome addition to standard medical information. As a patient, intelligence and humanity are attributes I seek in a physician/surgeon. Dr. Chen's capacity...
J. J. (Buddy) Connors MD, Interventional Neuroradiology, Vanderbilt University Medical Center, Nashville, TN.
Re: Understanding IMS III: old data shed new light on a futile trial
I read this article with great interest. The issue of tPA and its risk/benefit ratio for intra-arterial treatment of acute ischemic stroke is essential to understanding the results of IMS III. While possible toxic effects of...
We read with interest the study published ADAPT FAST study article (Turk AS, et al.) as published first online in the Journal of NeuroInterventional Surgery on 25Feb2014. We would like to congratulate the authors for their work in improving aspiration technique for acute stroke treatment that have been quite disappointing on demonstrating improvement on clinical outcomes on previous publications (1, 2). The advent on th...
Re: Ogata A et al. Carotid artery stenting without post-stenting balloon dilatation. J NeuroIntervent Surg 2013; Dec 6: (Epub ahead of print)
We read with interest this article regarding carotid stenting (CAS) without post-stent balloon angioplasty. The authors believe that this method reduces the risk of embolic complications. They point out that every passage of a device across a carotid stenosis can generate...
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