Hyun Woong Park

Rotational Vertebral Artery Compression : Bow Hunter's Syndrome

Bow hunters syndrome (BHS) is rare cause of vertebrobasilar insufficiency that arises from mechanical compression of the vertebral artery by head rotation. There is no standardized diagnostic regimen or treatment of BHS. Recently, we experienced 2 cases resisted continues medication and treated by surgical approach. In both cases, there were no complications after surgery and there were improvements in clinical symptoms. Thus, we describe our cases with surgical decompression with a review of the relevant medical literature.

Body mass index, carotid plaque, and clinical outcomes in patients with coronary artery disease

Objectives We evaluated the relationship among BMI, carotid sonographic findings, and long-term (5 years) cardiovascular events in Asian patients with coronary artery disease (CAD). Patients and methods The study population consisted of 1342 consecutive patients with CAD, who were stratified into four groups according to weight status, as defined by the WHO for the Asian population: underweight (group I: BMI<18.5 kg/m2, n=38); normal weight (group II: 18.5⩽BMI<23.5 kg/m2, n=352); overweight (group III: 23.5⩽BMI<27.5 kg/m2, n=700); and obese (group IV: BMI≥27.5 kg/m2, n=252). All patients underwent carotid ultrasonography. Multivariate analysis was performed to identify predictors of long-term mortality, and the results were expressed in terms of hazard ratio (HR) with 95% confidence interval (95% CI). Results Compared with the other groups, groups I and II included older patients and had a higher incidence of multivessel CAD, carotid plaque (group I: 42.1%; group II: 42.3%; group III: 27.9%; group IV: 24.6%; P=0.003), and major cardiovascular events including cardiac death, acute myocardial infarction, and stroke. In multivariate analysis, old age, lower ejection fraction, high carotid intima-media thickness, and presence of carotid plaque were positive independent predictors for mortality, whereas BMI was a negative independent predictor (group II: HR=0.28, 95% CI=0.14–0.57, P<0.001; group III: HR=0.26, 95% CI=0.13–0.51, P<0.001; group IV: HR=0.08, 95% CI=0.03–0.22, P<0.001). Conclusion In patients with CAD, underweight and normal-weight status was associated with higher long-term mortality rates and incidence of major cardiovascular events, suggesting that the obesity paradox is also manifested in Asian patients with CAD.

Tophaceous Gout of the Spine Causing Neural Compression

Gout is a common metabolic disease in which monosodium urate crystals called tophi develop. Spinal involvement in gout resulting in neural compression is unusual. We describe a case of a 64-year-old man with a history of gouty arthritis of the knee. The patient presented with thoracic myelopathy and radiculopathy. Imaging of the spine revealed an extradural mass lesion with bony erosion of the thoracic spine. A decompressive operation was performed, and a chalky white material was found. Histopathological examination confirmed a gouty tophus. The symptoms of spinal gout vary and its radiological features are not sufficiently specific to provide a definite diagnosis. Therefore, in patients with a history of gouty arthritis who present with neural compressive symptoms of the spine, spinal gout should be strongly suspected.

Novel role of platelet reactivity in adverse left ventricular remodelling after ST-segment elevation myocardial infarction: The REMODELING Trial

The role of platelet-leukocyte interaction in the infarct myocardium still remains unveiled. We aimed to determine the linkage of platelet activation to post-infarct left ventricular remodelling (LVR) process. REMODELING was a prospective, observational, cohort trial including patients (n = 150) with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention. Patients were given aspirin plus clopidogrel therapy (600 mg loading and 75 mg daily). Platelet reactivity (PRU: P2Y12 Reaction Units) was assessed with VerifyNow P2Y12 assay on admission. Transthoracic echocardiography was performed on admission and at one-month follow-up. The primary endpoint was the incidence of LVR according to PRU-based quartile distribution. LVR was defined as a relative ≥ 20 % increase in LV end-diastolic volume (LVEDV) between measurements. Adverse LVR was observed in 36 patients (24.0 %). According to PRU quartile, LVR rate was 10.8 % in the first, 23.1 % in the second, 27.0 % in the third, and 35.1 % in the fourth (p = 0.015): the optimal cut-off of PRU was ≥ 248 (area under curve: 0.643; 95 % confidence interval: 0.543 to 0.744; p = 0.010). LVR rate also increased proportionally according to the level of high sensitivity-C reactive protein (hs-CRP) (p = 0.012). In multivariate analysis, the combination of PRU (≥ 248) and hs-CRP (≥ 1.4 mg/l) significantly increased the predictive value for LVR occurrence by about 21-fold. In conclusion, enhanced levels of platelet activation and inflammation determined the incidence of adverse LVR after STEMI. Combining the measurements of these risk factors increased risk discrimination of LVR. The role of intensified antiplatelet or anti-inflammatory therapy in post-infarct LVR process deserves further study.

Endovascular coil embolization after clipping: endovascular treatment of incompletely clipped or recurred cerebral aneurysms.

Objective The presence of a cerebral aneurysm remnant after surgical clipping is associated with a risk of regrowth or rupture. For these recurred aneurysms, coil embolization can be considered as a treatment option. We retrospectively reviewed cases of ruptured or regrown aneurysms after clipping treated by endovascular coil embolization. Materials and Methods We conducted a retrospective review of patients with ruptured or recurred aneurysm after clipping, who underwent coil embolization between January 1995 and December 2013. We evaluated clinical information and the outcomes of these cases. Results Eight patients were treated by endovascular coil embolization after surgical clipping. Six aneurysms were located in the anterior communicating artery, one in the posterior communicating artery, and one in the middle cerebral artery bifurcation. All patients were initially treated by surgical clipping because of a ruptured aneurysm. Aneurysm recurrence at the initial clipping site was detected in all cases. The median interval from initial to second presentation was 42 months. In four patients, aneurysms were detected before rupture and the four remaining patients presented with recurrent subarachnoid hemorrhage. All patients were treated by coil embolization and showed successful occlusion of aneurysms without complications. Conclusion Endovascular coil embolization can be a safe and successful treatment option for recurred aneurysms after clipping.

The Outcomes of Spontaneous Intracerebral Hemorrhage in Young Adults - A Clinical Study

Objective Spontaneous intracerebral hemorrhage (ICH) in young adults is rare. The purpose of this study was to investigate causes, sites and other factors affecting the prognosis of ICH in young adults aged ≤ 40 years. Methods We reviewed 39 consecutive patients diagnosed with spontaneous ICH between January 2001 and June 2012. Patients with primary subarachnoid hemorrhage, previously diagnosed brain tumor bleeding, or vascular malformation were excluded. We analyzed the differences in prognostic factors such as hemorrhage location and vascular structural etiology. The outcome was measured using the Glasgow outcome scale (GOS), and a good outcome was defined as a score of 4 or more. Results We retrospectively evaluated 39 patients (mean age, 33 years; SD = 6.4, range 17 to 40 years). The most common structural etiology was arteriovenous malformation. A statistically significantly higher proportion of patients with good outcomes had a lower initial systolic blood pressure (SBP ≤ 160 mmHg, p = 0.036), a higher initial Glasgow coma scale (GCS) (9 or more, p = 0.034), lower cholesterol levels (< 200 mg/dl, p = 0.036), and smoking history (at discharge, p = 0.008; 6 months after discharge, p = 0.019). Conclusion In this study, cryptogenic ICH was the leading cause of spontaneous ICH. A GCS score of 9 or more on admission, a lower serum cholesterol level (< 200 mg/dl), and a lower SBP (< 160 mmHg) predicted a good outcome.

Long-term Prognosis and Clinical Characteristics of Patients with Newly Diagnosed Diabetes Mellitus Detected after First Acute Myocardial Infarction: from KAMIR-NIH Registry

Background and Objectives After the first acute myocardial infarction (AMI), a considerable proportion of patients are newly diagnosed with diabetes mellitus (DM). However, in AMI, controversy remains regarding the disparity in prognosis between previously diagnosed DM (known-DM) and newly diagnosed DM (new-DM). Methods The study included 10,455 patients with AMI (non-DM, 6,236; new-DM, 659; known-DM, 3,560) admitted to one of 15 participating centers in Korea between November 2011 and January 2016 (average follow-up, 523 days). We compared the characteristics and clinical course of patients with known-DM and those with new- or non-DM. Results Compared to patients with known-DM, those with new-DM or non-DM were younger, more likely to be male, and less likely to have hypertension, dyslipidemia, prior stroke, angina, or myocardial infarction. Compared to patients with new-DM or non-DM (reference), those with known-DM had higher risks of major adverse cardiac events (hazard ratio [HR], 1.20; 95% confidence interval [CI], 1.06–1.35; p=0.004), cardiac death (HR, 1.26; 95% CI, 1.01–1.57; p=0.042), and congestive heart failure (HR, 1.58; 95% CI, 1.20–2.08). Unlike known-DM, new-DM did not increase the risk of cardiac events (including death). Conclusions Known-DM was associated with a significantly higher risk of cardiovascular events after AMI, while new-DM had a similar risk of cardiac events as that noted for non-DM. There were different cardiovascular outcomes according to diabetes status in patients with AMI.

Effects of analgesics and antidepressants on TREK-2 and TRESK currents

TWIK-related K+ channel-2 (TREK-2) and TWIK-related spinal cord K+ (TRESK) channel are members of two-pore domain K+ channel family. They are well expressed and help to set the resting membrane potential in sensory neurons. Modulation of TREK-2 and TRESK channels are involved in the pathogenesis of pain, and specifi c activators of TREK-2 and TRESK may be benefi cial for the treatment of pain symptoms. However, the effect of commonly used analgesics on TREK-2 and TRESK channels are not known. Here, we investigated the effect of analgesics on TREK-2 and TRESK channels. The effects of analgesics were examined in HEK cells transfected with TREK-2 or TRESK. Amitriptyline, citalopram, escitalopram, and fluoxetine significantly inhibited TREK-2 and TRESK currents in HEK cells (p<0.05, n=10). Acetaminophen, ibuprofen, nabumetone, and bupropion inhibited TRESK, but had no effect on TREK-2. These results show that all analgesics tested in this study inhibit TRESK activity. Further study is needed to identify the mechanisms by which the analgesics modulate TREK-2 and TRESK differently.

Analysis of the Risk Factors Affecting the Surgical Site Infection after Cranioplasty Following Decompressive Craniectomy

Objective The risk factors for surgical site infections (SSIs) after cranioplasty following decompressive craniectomy remain unclear. The goal of this study was to analyze the risk factors related to developing SSIs after cranioplasty and to suggest valuable predictors. Methods A retrospective review was conducted of patients who underwent cranioplasty following decompressive craniectomy at our institution from January 2011 to December 2014, a total of 78 patients who underwent 78 cranioplasties. Univariate and multivariate logistic regression analyses were carried out to determine possible risk factors related to developing SSIs. We analyzed both patient-specific and surgery-specific factors. Results The overall rate of SSIs was 9.0% (7/78). SSIs after cranioplasty were significantly related to being female, having the primary etiology of traumatic brain injury (TBI) and having had a bilateral cranioplasty in the univariate analysis. Multivariate logistic regression analysis showed that being female [odds ratio (OR) 5.98, p=0.000] and having had a bilateral cranioplasty (OR 4.00, p=0.001) significantly increased the risk of SSIs. Conclusion Based on our data, cranioplasty following decompressive craniectomy is associated with a high incidence of SSI. Being female, having a primary etiology of TBI and having had a bilateral cranioplasty may be risk factors for surgical site infections after cranioplasty.

A Suction Thrombectomy Technique: A Rapid and Effective Method for Intra-Arterial Thrombolysis

Objective During mechanical thrombolysis, to reduce procedure-related complications and time, the authors have performed a simple suction thrombectomy technique. In this article, the authors describe the technical details and clinical outcomes of this technique. Materials and Methods From January 2013 to December 2013, 14 consecutive acute ischemic stroke (AIS) patients with large cerebral arterial occlusions in the middle cerebral artery (MCA; n = 7), internal cerebral artery (ICA; n = 5), basilar artery (BA; n = 1), and a tandem lesion (ICA and MCA; n = 1) were treated using this technique. The proximal part of the occluding clot was aspirated or captured and retrieved as one piece using a large bored microcatheter by applying negative suction pressure using a 50 mL syringe. Results Overall recanalization rate was 85.7% (12 patients). In the 8 patients in whom this technique was used alone, the recanalization rate was 87.5% (7 patients). The median procedural duration was 30 minutes (range 17-112) in these 7 patients. Distal embolism did not occur. Two patients developed post-procedural intracerebral hemorrhages and one was symptomatic. His modified Rankin Scale (mRS) score at 90 days was 4. Conclusion This technique is a feasible, fast, and safe method for treatment of AIS.