Correction to: The unexplained success of stentplasty vasospasm treatment : Insights using Mechanistic Mathematical Modeling.

Correction to: Clin Neuroradiol 2019 https://doi.org/10.1007/s00062-019-00776-2 The original version of this article unfortunately contained a mistake. The Acknowledgements were missing. The correct information is given ….

The unexplained success of stentplasty vasospasm treatment : Insights using Mechanistic Mathematical Modeling.

BACKGROUND: Cerebral vasospasm (CVS) following subarachnoid hemorrhage occurs in up to 70% of patients. Recently, stents have been used to successfully treat CVS. This implies that the force required to expand spastic vessels and resolve vasospasm is lower than previously thought. OBJECTIVE: We develop a mechanistic model of the spastic arterial wall to provide insight into CVS and predict the forces required to treat it. MATERIAL AND METHODS: The arterial wall is modelled as a cylindrical membrane using a constrained mixture theory that accounts for the mechanical roles of elastin, collagen and vascular smooth muscle cells (VSMC). We model the pressure diameter curve prior to CVS and predict how it changes following CVS. We propose a stretch-based damage criterion for VSMC and evaluate if several commercially available stents are able to resolve vasospasm. RESULTS: The model predicts that dilatation of VSMCs beyond a threshold of mechanical failure is sufficient to resolve CVS without damage to the underlying extracellular matrix. Consistent with recent clinical observations, our model predicts that existing stents have the potential to provide sufficient outward force to successfully treat CVS and that success will be dependent on an appropriate match between stent and vessel. CONCLUSION: Mathematical models of CVS can provide insights into biological mechanisms and explore treatment approaches. Improved understanding of the underlying mechanistic processes governing CVS and its mechanical treatment may assist in the development of dedicated stents.

The Medina Embolic Device: Karolinska experience.

Background The aim of this study was to report our single centre experience with the Medina Embolic Device (MED). Methods We performed a retrospective analysis of prospectively collected data to identify all patients treated with the MED. A total of 14 aneurysms (non-consecutive), in 13 patients, were treated including one ruptured and one partially thrombosed aneurysm. Fundus diameter was ≥5 mm in all cases. We evaluated the angiographic appearances, the clinical status, complications, and the need for adjunctive devices or repeat treatments. Results Aneurysm location was cavernous internal carotid artery (ICA; n = 1), supraclinoid ICA ( n = 1), terminal ICA ( n = 2), anterior communicating artery (AComA; n = 4), A2-3 ( n = 1), M1-2 junction ( n = 1), posterior communicating artery (PComA; n = 1), superior cerebellar artery (SCA; n = 1), and basilar tip ( n = 2). The average aneurysm fundus size was 8.6 mm (range 7-10 mm) and average neck size 3.75 mm (range 1.9-6.9 mm). Immediate angiographic results were modified Raymond-Roy occlusion classification (mRRC) I n = 2, mRRC II n = 1, mRRC IIIa n = 2, mRRC IIIb n = 2, the remaining 7 aneurysms showed complete opacification. At follow-up angiography (mean 5 months) mRRC I n = 5, mRRC II n = 5, mRRC IIIa n = 3, and persistent filling was seen in 1 aneurysm. Overall, four patients had repeat treatment and one is pending further treatment. Of the aneurysms treated with more than one MED, 75% showed complete occlusion at 6-month follow up whereas only one aneurysm treated with a single device showed complete occlusion. Overall, three patients had temporary complications and there were no deaths. Conclusions The MED is an intra-saccular flow-diverting device with satisfactory angiographic results and an acceptable safety profile. Use of a single MED cannot be recommended and further longer term studies are needed prior to widespread clinical use.

Intracranial vessel wall MRI.

There are many different methods of imaging the intracranial arteries; however, the vast majority of currently used techniques are based on luminal imaging. Although this is useful, it does have limitations as many different pathological processes can produce the same appearance. Therefore, directly imaging the site of the pathology - the vessel wall itself - offers the hope of discriminating between different disease processes. In this review, we will discuss the current status of vessel wall magnetic resonance imaging alongside its potential usefulness in differentiating between various disease entities.

Cilostazol: an antiplatelet agent for the neurointerventionist?

Antiplatelet agents are essential for the successful management of patients undergoing a variety of neurointerventional procedures. The most commonly used anti-platelet agents are aspirin, clopidogrel and prasugrel. However, there exist an alternative class of anti-platelet agent that may prove useful for neurointerventionists. In particular a drug called cilostazol may have numerous added advantages above and beyond its antiplatelet effect that may be valuable for our patients. In this short review we aim to highlight some of these potential advantages.

Management considerations in ruptured isolated radiculopial artery aneurysms. A report of two cases and literature review.

Little is known on the natural history of ruptured isolated aneurysms of the posterior spinal artery (PSA). To date, only a few of such cases have been described in the literature. This paper aims to assess the most appropriate management strategy, based on the available literature and two new cases. In one of these, treatment was postponed until day 33, when angiography showed slight growth of the aneurysm. In the other, conservative treatment, requested by the patient, was successful. From these data, we conclude that treatment strategies for ruptured PSA aneurysms may vary. Aside from the recommendation by others to perform prompt surgical treatment, we suggest an alternative clinical paradigm allowing for the evaluation of the early clinical course. This may preclude the unnecessary treatment of spontaneously regressing lesions and still allows for appropriate treatment for persistent lesions.

Detection and classification of cranial dural arteriovenous fistulas using 4D-CT angiography: initial experience.

BACKGROUND AND PURPOSE: The criterion standard to diagnose and classify cranial DAVFs is DSA. Since this is invasive, relatively expensive and time-consuming, a noninvasive alternative is of interest. We aimed to evaluate the capabilities and pitfalls of 4D-CTA in a consecutive series of patients who presented with a newly diagnosed cranial DAVF, as demonstrated by conventional DSA. MATERIALS AND METHODS: Eleven patients were included in this study after biplane DSA demonstrated a cranial DAVF. They subsequently underwent 4D-CTA imaging by using a 320-detector CT scanner. DSA and 4D-CTA studies were independently read by 2 blinded observers, by using a standardized scoring sheet. 4D-CTA results were analyzed with DSA as the criterion standard. RESULTS: In 10 cases, there was full agreement between DSA and 4D-CTA regarding the Borden classification. However, in the remaining patient, a slow-filling DAVF with a low shunt volume was missed by both readers on 4D-CTA. In all 10 detected cases, ≥ 1 of the major contributing arteries could be identified with 4D-CTA. Although, by using DSA, the 2 observers identified additional arterial feeders in 7 and 8 cases, respectively, these discrepancies did not influence clinical decision making. CONCLUSIONS: Although novel 4D-CTA imaging may not rule out a small slow-flow DAVF, it appears to be a valuable new adjunct in the noninvasive diagnostic work-up, treatment planning, and follow-up of patients with cranial DAVFs.

Endovascular treatment of a ruptured blood blister-like aneurysm with a flow-diverting stent.

Treatment of BBAs is currently challenging and remains difficult despite improvement of microsurgical technique and advancement in endovascular technologies. Therapeutic options are reconstructive and deconstructive open surgeries or endovascular procedures. However, there is a lack of consensus about optimal treatment. We report a case of 38-year old woman with subarachnoid hemorrhage due to a ruptured BBA successfully treated with placement of an endovascular flow-diverting stent.

Bilateral frontal sinus pericranii with an intratabular course. A case report.

Sinus pericranii is a rare venous anomaly, representing a transosseous connection between the intracranial venous system and the epicranial venous system. We present an unusual case of bilateral frontal sinus pericranii in a 12-year-old boy, with associated lacrimation. Instead of the usual short bridging vein between the intra- and extracranial venous circulation, in our case the veins connecting the superior sagittal sinus and the left superior ophthalmic/orbital vein coursed intratabularly over a distance of several centimeters. To our knowledge, such a course has not previously been reported in literature.

Dynamic 320-section CT angiography in cranial arteriovenous shunting lesions.

Novel 320-section CT scanning equipment enables dynamic noninvasive angiographic imaging of the entire cranial vasculature (4D-CTA). We describe this technique and demonstrate its potential in arteriovenous shunting lesions. 4D-CTA imaging resulted in a correct diagnosis, lesion classification, and treatment-strategy selection in 3 patients, compared with CA. We think that 4D-CTA can further reduce the need for CA, sparing the patient the discomfort and risk associated with an invasive procedure.

Giant intracranial aneurysm in a ten-year-old boy with parry romberg syndrome. A case report and literature review.

SUMMARY: Parry-Romberg syndrome (PRS) is a rare acquired syndrome consisting of progressive hemiatrophy of the face.We present a child with PRS and progressive neurological deficit caused by a giant intracranial aneurysm and reviewed the literature concerning all intracranial abnormalities in patients with PRS.A literature search identified 27 articles reporting on 88 patients ith PRS and intracranial abnormalities. Ipsilateral brain calcification and hemiatrophy are the most prominent features on CT scan and hyperintense white matter lesions are most frequently seen on T2-weighted MRI. Although lacking precise prevalence data, intracranial abnormalities are not uncommon in patients with PRS. We found three other PRS patients with intracranial aneurysms. Our case and literature search suggests a possible association between PRS and intracranial aneurysms. We consider this association important for clinical practice and recommend including intracranial vascular diseases in the differential diagnosis when dealing with a PRS patient with neurological symptoms.

The challenges of extrapulmonary presentations of sarcoidosis: A case report and review of diagnostic strategies.

A patient presenting with overweight, amenorrhea, diabetes insipidus, and oral, nasal, and pharyngeal inflammation was admitted to our hospital. Using a non-invasive approach, we were able to narrow the differential diagnosis down to a systemic lymphoproliferative or granulomatous disease, most likely sarcoidosis. This diagnosis was eventually confirmed by a biopsy of an enlarged tonsil. To our knowledge, tonsil biopsies have not been reported to be of help in the diagnostic strategy for systemic sarcoidosis. In this report, we review the possible diagnostic approaches and point out that the pharyngeal tonsils, if enlarged or inflamed, can be targeted to obtain tissue for histological confirmation.

Pituitary magnetic resonance imaging is not required in the postoperative follow-up of acromegalic patients with long-term biochemical cure after transsphenoidal surgery.

After successful transsphenoidal surgery for acromegaly, life-long follow-up is required, because 10-15% of patients develop recurrence of disease. We assessed whether it is safe to perform postoperative follow-up with only biochemical evaluation in acromegalic patients initially cured by transsphenoidal surgery. We studied 32 patients cured after transsphenoidal surgery for acromegaly during a follow-up of 8.7 +/- 6.4 yr (mean +/- sd). Serial measurements of serum GH during glucose tolerance test and magnetic resonance imaging (MRI) scans were performed. Serial MRI scans were reevaluated by three independent neuroradiologists, who were blinded for the clinical and biochemical data, for growth of suspected tumor tissue. Twenty-three patients remained biochemically cured in the long term, whereas nine of the 32 patients developed recurrence of disease, indicated by elevated serum GH concentrations during glucose tolerance test and clinical symptoms/signs. None of the 23 patients with long-term biochemical cure showed growth of tumor tissue according to two neuroradiologists, whereas the third neuroradiologist assessed three of 23 patients as having tumor growth despite continuing biochemical cure. In the nine patients with biochemical recurrence, no tumor growth was found in the series of postoperative MRI scans, according to two of the three independent radiologists, whereas the third radiologist found tumor growth in four patients with recurrent disease. In conclusion, in patients with acromegaly, initially cured by transsphenoidal surgery, it appears safe to check for recurrent disease during long-term follow-up of these patients by biochemical markers only.

A five-vessel aortic arch with an anomalous origin of both vertebral arteries and an aberrant right subclavian artery.

SUMMARY: In this case presentation we describe a patient with an anomalous origin of the right vertebral artery arising from the right common carotid artery in combination with an aberrant right subclavian artery and a left vertebral artery originating from the arch between the left common carotid artery and left subclavian artery. Hence there were five vessels originating from the aortic arch. The possible embryological mechanism as well as a postulation on the importance of the level of entrance of the vertebral artery in the cervical transverse foramen is discussed.

Effect of photodynamic therapy on the mechanical strength of healed rodent skin incisions.

A factor that might complicate the use of intraoperative photodynamic therapy (PDT) is a possible adverse effect on normal tissue recovery. In this study, rats with experimental skin incisions received intraoperative PDT (10 mg/kg haematoporphyrin derivative, 180 J/cm(2) laser light), immediately followed by closure. Healing was evaluated by tensile strength assessment of the incisions 21 days after PDT. No significant differences between the PDT-treated group and control groups were found. We therefore concluded that with respect to healing of skin incisions in rats, intraoperative PDT is not contraindicated.

Photodynamic therapy in AIDS-related cutaneous Kaposi's sarcoma.

For evaluating the role of photodynamic therapy (PDT) in the local treatment of acquired immune deficiency syndrome (AIDS)-related cutaneous Kaposi's sarcoma (KS), nine treatments were performed in eight human immunodeficiency virus-positive homosexual men. The patients received 2 mg Photofrin/kg and either 120 J/cm2 (n = 5) or 70 J/cm2 (n = 4) laser light (630 nm). A total of 83 lesions were evaluable for response with a follow-up of 3-8 months. The overall response rates by patient for all treated lesions were 50-100% (120 J/cm2) and 83.3-90.3% (70 J/cm2), with a median duration of 3 months (range, 2-6 months). Tumors located at the head had higher response rates than those at the trunk or extremities (p = 0.005 and p - 0.015 respectively). The size of the KS showed a negative relationship with the probability of complete response (p = 0.047). Local and general side effects occurred, including pain, blisters, temperature increase, muscle stiffness, and severe edema. The cosmetic result was unsatisfactory because of a high prevalence of scars and long-lasting hyperpigmentation. Although the response rates of PDT are high, light dose of 70-120 J/cm2 cannot be recommended in the treatment of cutaneous KS in combination with 2 mg/kg Photofrin because of severe side effects and unsatisfactory cosmetic result.