• Archives of Pharmacal Research
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• v.26 no.9
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• pp.747-755
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• 2003

The aim of the present study was to clarify whether cotinine affects the release of catecholamines (CA) from the isolated perfused rat adrenal gland, and to establish the mechanism of its action, in comparison with the response of nicotine. Cotinine (0.3∼3 mM), when perfused into an adrenal vein for 60 min, inhibited CA secretory responses evoked by ACh (5.32 mM), DMPP (a selective neuronal nicotinic agonist, 100 $\mu$M for 2 min) and McN-A-343 (a selective muscarinic $M_1 -agonist, 100 \mu$ M for 2 min) in dose- and time-dependent manners. However, cotinine did not affect CA secretion by high $K^+$ (56 mM). Cotinine itself also failed to affect basal CA output. Furthermore, in the presence of cotinine (1 mM), CA secretory responses evoked by Bay-K-8644 (an activator of L-type $Ca^{2+}$ channels, 10 $\mu$ M) and cyclopiazonic acid (an inhibitor of cytoplasmic $Ca^{2+}-ATPase, 10 \mu$ M) were relative time-dependently attenuated. However, nicotine (30$\mu$ M), given into the adrenal gland for 60 min, initially rather enhanced CA secretory responses evoked by ACh and high $K^+$, followed by the inhibition later, while it time-dependently depressed the CA release evoked by McN-A-343 and DMPP. Taken together, these results suggest that cotinine inhibits greatly CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors, but does fail to affect that by the direct membrane-depolarization. It seems that this inhibitory effect of cotinine may be exerted by the cholinergic blockade, which is associated with blocking both the calcium influx into the rat adrenal medullary chromaffin cells and $Ca^{2+}$ release from the cytoplasmic calcium store. It also seems that there is a big difference in the mode of action between cotinine and nicotine in the rat adrenomedullary CA secretion.

• Journal of Yeungnam Medical Science
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• v.40 no.2
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• pp.146-155
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• 2023

Background: Despite the recent increasing trend in the prevalence of type 2 diabetes among older individuals, the relationship between diabetic retinopathy (DR) and chronic kidney disease (CKD) in these patients remains unclear. This study investigated the severity of renal dysfunction according to the degree of DR in older patients with type 2 diabetes. Methods: A total of 116 patients with diabetes and CKD stage ≥3 who visited both the nephrology and ophthalmology outpatient departments between July 2021 and January 2022 were screened. There were 53 patients in the no DR group, 20 in the nonproliferative DR (NPDR) group, and 43 in the proliferative DR (PDR) group. Results: DR severity was related to the deterioration of renal function. The proportion of patients with advanced CKD significantly increased with DR severity (p for trend <0.001). In the multivariate regression model adjusted for age of ≥80 years, male sex, poorly controlled diabetes, macroalbuminuria, insulin use, diabetes duration of ≥10 years, cerebrovascular accident, hypertension, hyperlipidemia, and cardiovascular disease history, the odds ratio compared with the no DR group was approximately 4.6 for the NPDR group and approximately 11.8 for the PDR group, which were both statistically significant (p=0.025 and p<0.001, respectively). Conclusion: DR severity in older patients with diabetes may be associated with deterioration of renal function and high prevalence of advanced CKD. Therefore, periodic examination for DR in older patients with diabetes is important for predicting renal function deterioration and CKD progression.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.2
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• pp.150-159
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• 2023

Objective: The aim of this study was to investigate the efficacy of intraoperative indocyanine green videoangiography (ICG-VA) and intraoperative neuromonitoring (IONM) to prevent postoperative ischemic complications during microsurgical clipping of unruptured anterior choroidal artery (AChA) aneurysms. Methods: We retrospectively reviewed the clinical and radiological records of all patients who had undergone microsurgical clipping for unruptured AChA aneurysms at our institution between April 2001 and December 2019. We compared the postoperative complication rate of the group for which intraoperative ICG-VA and IONM were utilized (group B; n=324) with that of the group for which intraoperative ICG-VA and IONM were not utilized (group A; n=72). Results: There were no statistically significant differences in demographic data between the two groups. Statistically significant differences were observed in the rate of overall complications (p=0.014) and postoperative ischemic complications related to AChA territory (p=0.039). All the cases (n=4) in group B who had postoperative infarctions related to AChA territory showed false-negative results of intraoperative ICG-VA and IONM. Conclusions: Preserving the patency of the AChA is essential to minimize postoperative complications. Intraoperative monitoring tools including ICG-VA and IONM can greatly contribute to lowering complication rates. However, their pitfalls and false-negative results should always be considered.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.4
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• pp.373-379
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• 2023

To systematically review the reported outcomes and complications of different treatment options for choroid plexus arteriovenous malformations (AVMs), specifically focusing on surgical resection and endovascular embolization. A systematic literature review was performed using a PubMed query for studies published between January 1975 and July 2021. All studies describing the clinical presentation, management, and outcome of confirmed choroid plexus AVM cases were included. A total of 20 studies were included in the final analysis. Of these, 18 were single-patient case reports, one article contained two patients, and a single study was a cohort of 24 patients. Patient age ranged from one day to 61 years, with a mean of 31.8±20.4 years. Most choroid plexus AVMs were located in the lateral ventricles (14 patients, 70.0%), while there were four (20.0%) located in the third ventricle, and two in the fourth ventricle (10.0%). Almost all patients were treated with surgical resection (18 patients, 90%). In 14 patients (77.8%), complete resection of the AVM was achieved. A residual AVM was reported in one case (5.6%). Most patients were reported to have improved from their presentation status over time (14 patients, 70.0%). Presence or absence of long-term sequelae (e.g., neurologic deficits) were reported for 14 patients (70%). Eleven of these patients (78.6%) were reported to have no neurological sequelae. While data on choroid plexus AVMs remains limited, the available evidence suggests gross total resection of lesions in this location can be safely achieved with subsequent reduction in preoperative symptoms.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.26 no.1
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• pp.46-50
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• 2024

Objective: Diagnostic cerebral angiograms (DCAs) are widely used in neurosurgery due to their high sensitivity and specificity to diagnose and characterize pathology using ionizing radiation. Eliminating unnecessary radiation is critical to reduce risk to patients, providers, and health care staff. We investigated if reducing pulse and frame rates during routine DCAs would decrease radiation burden without compromising image quality. Methods: We performed a retrospective review of prospectively acquired data after implementing a quality improvement protocol in which pulse rate and frame rate were reduced from 15 p/s to 7.5 p/s and 7.5 f/s to 4.0 f/s respectively. Radiation doses and exposures were calculated. Two endovascular neurosurgeons reviewed randomly selected angiograms of both doses and blindly assessed their quality. Results: A total of 40 consecutive angiograms were retrospectively analyzed, 20 prior to the protocol change and 20 after. After the intervention, radiation dose, radiation per run, total exposure, and exposure per run were all significantly decreased even after adjustment for BMI (all p<0.05). On multivariable analysis, we identified a 46% decrease in total radiation dose and 39% decrease in exposure without compromising image quality or procedure time. Conclusions: We demonstrated that for routine DCAs, pulse rate of 7.5 with a frame rate of 4.0 is sufficient to obtain diagnostic information without compromising image quality or elongating procedure time. In the interest of patient, provider, and health care staff safety, we strongly encourage all interventionalists to be cognizant of radiation usage to avoid unnecessary radiation exposure and consequential health risks.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.26 no.1
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• pp.23-29
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• 2024

Objective: Flow diverting stents (FDS) are increasingly used for the treatment of intracranial aneurysms. While FDS can provide flow diversion of parent vessels, their high metal surface coverage can cause thromboembolism. Transcranial Doppler (TCD) emboli monitoring can be used to identify subclinical embolic phenomena after neurovascular procedures. Limited data exists regarding the use of TCDs for emboli monitoring in the periprocedural period after FDS placement. We evaluated the rate of positive TCDs microembolic signals and stroke after FDS deployment at our institution. Methods: We retrospectively evaluated 105 patients who underwent FDS treatment between 2012 and 2016 using the Pipeline stent (Medtronic, Minneapolis, MN, USA). Patients were pretreated with aspirin and clopidogrel. All patients were therapeutic on clopidogrel pre-operatively. TCD emboli monitoring was performed immediately after the procedure. Microembolic signals (mES) were classified as "positive" (<15 mES/hour) and "strongly positive" (>15 mES/hour). Clinical stroke rates were determined at 2-week and 6-month post-operatively. Results: A total of 132 intracranial aneurysms were treated in 105 patients. TCD emboli monitoring was "positive" in 11.4% (n=12) post-operatively and "strongly positive" in 4.8% (n=5). These positive cases were treated with heparin drips or modification of the antiplatelet regimen, and TCDs were repeated. Following medical management modifications, normalization of mES was achieved in 92% of cases. The overall stroke rates at 2-week and 6-months were 3.8% and 4.8%, respectively. Conclusions: TCD emboli monitoring may help early in the identification of thromboembolic events after flow diversion stenting. This allows for modification of medical therapy and, potentially, preventionf of escalation into post-operative strokes.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.26 no.1
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• pp.51-57
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• 2024

Since the first description of the possible utilization of the internal maxillary artery for bypass surgery, there are some reports of its use in aneurysm cases; however, there is no information about the possible advantages of this type of bypass for cerebral ischemic disease. We present a 77-year-old man with a history of diabetes, hypertension, systemic atherosclerosis, and two acute myocardial infarctions with left hemiparesis. Imaging studies reported total occlusion of the right internal carotid artery and 75% occlusion on the left side, with an old opercular infarction and repeated transient ischemic attacks in the right middle cerebral artery territory despite medical treatment. After a consensus, we decided to perform a bypass from the internal maxillary artery to the M2 segment of the middle cerebral artery using a radial artery graft. After performing the proximal anastomosis, the calculated graft's free flow was 216 ml/min. Subsequently, after completing the bypass, the patency was confirmed with fluorescein videoangiography and intraoperative Doppler. Postoperatively, imaging studies showed improvement in the perfusion values and the hemiparesis from 3/5 to 4+/5. The patient was discharged one week after the operation, with a modified Rankin scale of 1, without added deficits. The use of revascularization techniques in steno-occlusive disease indicates a select group of patients that may benefit from this procedure. In addition, internal maxillary artery bypass has provided a safe option for large areas of ischemia that cannot be supplied with a superficial temporal artery - middle cerebral artery bypass.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.1
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• pp.36-49
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• 2023

Objective: Arteriovenous malformations (AVMs) are benign congenital lesions. The estimated prevalence is 10-18 per 100,000 individuals, with an incidence rate of 1.1-1.4 per 100,000 person-year; only 12% of AVMs present symptoms during life. It is important to study different characteristics associated with AVMs because these patients require multidisciplinary treatment. Methods: A descriptive, observational, longitudinal, and retrospective study was carried out from January 15, 2016 to October 19, 2021. Convenience sampling was used on patients diagnosed with arteriovenous malformation. Sociodemographic data was obtained, such as: sex, age, site, predominant symptoms, clinical debut, type of malformation, data associated with post therapy evolution, type of embolizing agent used, associated complications, Rankin scale, and death. Results: Data from 535 procedures was collected, we calculated an incidence of 4.4 cases per million inhabitants. Ninety procedures in 56 patients that used endovascular therapy were obtained with a female-male ratio of 0.75 and an age distribution of 35±14 (SD). A 36.3±11.5 (SD) mm diameter was registered. There was a 33% success rate for endovascular surgery. Conclusions: The multidisciplinary treatment of AVMs is made up of three pillar techniques: microsurgical resection, embolization, and radio-neurosurgery. It is extremely important to make an appropriate decision, with an emphasis on achieving better functional outcomes for the patient. Although neurological endovascular therapy was initially used as an adjuvant treatment for neurosurgery and radio-neurosurgery, it has been used more and more frequently as the first line of treatment.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.1
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• pp.1-12
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• 2023

Objective: Although chronic carotid artery occlusion seems to be associated with significant risk of ischemic stroke, revascularization techniques are neither well established nor widespread. In contrast, extracranial-intracranial bypass is common despite the lack of evidence regarding neurological improvement or prevention of ischemic events. The aim of current review is to evaluate the effectiveness of various methods of recanalization of chronic carotid artery occlusion. Methods: Comprehensive literature search through PubMed, Scopus, Cochrane and Web of Science databases performed. Various parameters were assessed among patients underwent surgical, endovascular and hybrid recanalization for chronic carotid artery occlusion. Results: 40 publications from 2005 to 2021 with total of more than 1300 cases of revascularization of chronic carotid artery occlusion have been reviewed. Further parameters were assessed among patients underwent surgical, endovascular and hybrid recanalization for chronic carotid artery occlusion: mean age, male to female ratio, mean duration of occlusion before treatment, rate of successful recanalization, frequency of restenosis and reocclusion, prevalence of ischemic stroke postoperatively, neurological or other symptoms improvement and complications. Based on proposed through reviewed literature indications for revascularization and predictive factors of various recanalizing procedures, an algorithm for clinical decision making have been formulated. Conclusions: Although treatment of chronic carotid artery occlusion remains challenging, current literature suggests revascularization as single option for verified neurological improvement and prevention of ischemic events. Surgical and endovascular procedures should be taken into account when treating patients with symptomatic chronic carotid artery occlusion.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.1
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• pp.19-27
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• 2023

Objective: The purpose of this study was to determine the efficacy of a 3D-printed aneurysm simulation model (3DPM) in educating patients and improving physicians' comprehension and performance. Methods: This prospective study involved 40 patients who were diagnosed with unruptured intracranial aneurysms (UIAs) and scheduled for surgical clipping or endovascular coiling and randomly divided into two groups (the 3DPM group and the non-3DPM group). The 3DPM was used in preoperative consultation with patients and intraoperatively referenced by surgeons. The patients, 7 neurosurgical residents, and 10 surgeons completed questionnaires (5-point Likert scale) to determine the usefulness of the 3DPM. Results: Patients in the 3DPM group had significantly higher scores in terms of their understanding of the disease (mean 4.85 vs. 3.95, p<0.001) and the treatment plan (mean 4.85 vs. 4.20, p=0.005) and reported higher satisfaction during consultation (5.0 vs. 4.60, p=0.036) than patients in the non-3DPM group. During patient consultation, 3DPMs were most useful in improving doctor-patient communication (mean 4.57, range 4-5). During clipping surgery, the models were most useful in assessing adjacent arteries (mean 4.9, range 4-5); during endovascular coiling, they were especially helpful in microcatheter shaping (mean 4.7, range 4-5). Conclusions: In general, 3DPMs are beneficial in educating patients and improving the physician's performance in terms of surgical clipping and endovascular coiling of UIAs.