Hyemoon Chung

Parapharyngeal space surgery via a transoral approach using a robotic surgical system: transoral robotic surgery.

OBJECTIVE In transoral robotic surgery (TORS), if an endoscopic arm equipped with two integrated cameras is placed close to a lesion, a three-dimensionally magnified view of the operative field can be obtained. More important is that the operation can be performed precisely and bimanually using two instrument arms that can move freely within a limited working space. We performed TORS to treat several diseases that occur in the parapharyngeal space (PPS) and subsequently analyzed the treatment outcomes to confirm the validity of this procedure. PATIENTS AND METHODS Between February 2009 and February 2012, 11 patients who required surgical treatment for the removal of a parapharyngeal lesion were enrolled in this prospective study. Nine patients received TORS for parapharyngeal tumor resection, and 2 patients with stylohyoid syndrome underwent TORS for resection of an elongated styloid process. The average age of the patients included in this study was 42 years. Five patients were male, and 6 patients were female. RESULTS TORS was successfully performed in all 11 patients. The average robotic system docking and operation times were 9.9 minutes (range, 5-24 minutes) and 54.2 minutes (range, 26-150 minutes), respectively. Patients were able to swallow normally the day after the operation. The average blood loss during the robotic operation was minimal (11.8 mL). The average hospital stay was 2.6 days. There were no significant complications in the perioperative or postoperative period. All patients were extremely satisfied with their cosmetic outcomes. CONCLUSIONS PPS surgery via a transoral approach using a robotic surgical system is technically feasible and secures a better cosmetic outcome than the transcervical, transparotid, or transmandibular approach. This new surgical method is safe and effective for benign diseases of the PPS.

Comparison of treatment outcomes after transoral robotic surgery and supraglottic partial laryngectomy: Our experience with seventeen and seventeen patients respectively

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Correction with blood T1 is essential when measuring post-contrast myocardial T1 value in patients with acute myocardial infarction

BackgroundPost-contrast T1 mapping by modified Look-Locker inversion recovery (MOLLI) sequence has been introduced as a promising means to assess an expansion of the extra-cellular space. However, T1 value in the myocardium can be affected by scanning time after bolus contrast injection. In this study, we investigated the changes of the T1 values according to multiple slicing over scanning time at 15 minutes after contrast injection and usefulness of blood T1 correction.MethodsEighteen reperfused acute myocardial infarction (AMI) patients, 13 cardiomyopathy patients and 8 healthy volunteers underwent cardiovascular magnetic resonance with 15 minute-post contrast MOLLI to generate T1 maps. In 10 cardiomyopathy cases, pre- and post-contrast MOLLI techniques were performed to generate extracellular volume fraction (Ve). Six slices of T1 maps according to the left ventricular (LV) short axis, from apex to base, were consecutively obtained. Each T1 value was measured in the whole myocardium, infarcted myocardium, non-infarcted myocardium and LV blood cavity.ResultsThe mean T1 value of infarcted myocardium was significantly lower than that of non-infarcted myocardium (425.4±68.1 ms vs. 540.5±88.0 ms, respectively, p< 0.001). T1 values of non-infarcted myocardium increased significantly from apex to base (from 523.1±99.5 ms to 561.1±81.1 ms, p=0.001), and were accompanied by a similar increase in blood T1 value in LV cavity (from 442.1±120.7 ms to 456.8±97.5 ms, p<0.001) over time. This phenomenon was applied to both left anterior descending (LAD) territory (from 545.1±74.5 ms to 575.7±84.0 ms, p<0.001) and non-LAD territory AMI cases (from 501.2±124.5 ms to 549.5±81.3 ms, p<0.001). It was similarly applied to cardiomyopathy patients and healthy volunteers. After the myocardial T1 values, however, were adjusted by the blood T1 values, they were consistent throughout the slices from apex to base (from 1.17±0.18 to 1.25±0.13, p>0.05). The Ve did not show significant differences from apical to basal slices.ConclusionPost-contrast myocardial T1 corrected by blood T1 or Ve, provide more stable measurement of degree of fibrosis in non-infarcted myocardium in short- axis multiple slicing.

Diagnosis and surgical outcomes of intraparotid facial nerve schwannoma showing normal facial nerve function

The findings of intraparotid facial nerve schwannoma (FNS) using preoperative diagnostic tools, including ultrasonography (US)-guided fine needle aspiration biopsy, computed tomography (CT) scan, and magnetic resonance imaging (MRI), were analyzed to determine if there are any useful findings that might suggest the presence of a lesion. Treatment guidelines are suggested. The medical records of 15 patients who were diagnosed with an intraparotid FNS were retrospectively analyzed. US and CT scans provide clinicians with only limited information; gadolinium enhanced T1-weighted images from MRI provide more specific findings. Tumors could be removed successfully with surgical exploration, preserving facial nerve function at the same time. Gadolinium-enhanced T1-weighted MRI showed more characteristic findings for the diagnosis of intraparotid FNS. Intraparotid FNS without facial palsy can be diagnosed with MRI preoperatively, and surgical exploration is a suitable treatment modality which can remove the tumor and preserve facial nerve function.

Prognostic significance of elevated lipoprotein(a) in coronary artery revascularization patients

BACKGROUND Although lipoprotein(a) [Lp(a)] has been considered a cardiovascular risk factor for many years, there is a paucity of data in regard to the potential risk of elevated Lp(a) in symptomatic patients with CAD. Therefore, we sought to evaluate whether elevated Lp(a) is associated with worse outcome in symptomatic patients with coronary artery disease (CAD), and to clarify the prognostic value of Lp(a) in the era of coronary artery revascularization. METHODS 6252 consecutive subjects (59.2% male, mean age 61.2 ± 11.2 years) suspected of having CAD underwent coronary angiography. Laboratory values for lipid parameters including Lp(a) were obtained on the day of coronary angiography. Baseline risk factors, coronary angiographic findings, length of follow-up, and major adverse cardiovascular events (MACE), including cardiac death and non-fatal myocardial infarction were recorded. RESULTS Over a mean follow-up period of 3.1 ± 2.2 years, there were 100 MACE (56 cardiac deaths and 44 non-fatal myocardial infarctions), with an event rate of 1.6%. In multivariate Cox regression analysis, elevated Lp(a) was a significant predictor of MACE [hazard ratio 1.773 (95% confidence interval 1.194-2.634, p=0.005)], and the addition of this factor to the model significantly increased the global х(2) value over traditional risk factors and CAD (from 79.1 to 88.7, p=0.003). CONCLUSIONS Elevated Lp(a) is an independent prognostic risk factor for cardiovascular events, and moreover, has incremental prognostic value in symptomatic patients with coronary artery revascularization.

Outcomes of Cardiac Involvement in Patients with Late-Stage Duchenne Muscular Dystrophy under Management in the Pulmonary Rehabilitation Center of a Tertiary Referral Hospital

Objectives: The purpose of this study was to investigate the clinical outcome as well as the sequential changes of cardiac function in late-stage Duchenne muscular dystrophy (DMD) patients by 2-dimensional echocardiography. Methods: A total of 31 individuals (initial age: 21.6 ± 5.0 years, range: 15–35 years) with late-stage DMD (Swinyard-Deaver’s stage 7 or 8) were enrolled. All of these patients had respiratory insufficiency and were on ventilator support. Sequential echocardiographic data were collected over at least 3 years. Repeated measures analysis of variance was used to compare changes in left ventricular ejection fraction (LVEF) over time. Results: The sequential change in the mean LVEF showed no significant differences with initial, 1-, 2-, and 3-year follow-up LVEFs which were 42.2, 42.9, 43.8 and 42.6%, respectively (p = 0.320). In terms of the clinical outcome, all but 1 patient survived during the follow-up period of 46.5 ± 9.1 months. Conclusions: The cardiac function in late-stage DMD patients showed a stabilization of LVEF on adequate ventilatory support and optimal cardiac medication therapy until their mid-30s. In addition, considering the favorable clinical outcome in our study, the process of cardiac involvement in late-stage DMD may demonstrate that in some patients it is nonprogressive.

Different contribution of extent of myocardial injury to left ventricular systolic and diastolic function in early reperfused acute myocardial infarction

BackgroundWe sought to investigate the influence of the extent of myocardial injury on left ventricular (LV) systolic and diastolic function in patients after reperfused acute myocardial infarction (AMI).MethodsThirty-eight reperfused AMI patients underwent cardiac magnetic resonance (CMR) imaging after percutaneous coronary revascularization. The extent of myocardial edema and scarring were assessed by T2 weighted imaging and late gadolinium enhancement (LGE) imaging, respectively. Within a day of CMR, echocardiography was done. Using 2D speckle tracking analysis, LV longitudinal, circumferential strain, and twist were measured.ResultsExtent of LGE were significantly correlated with LV systolic functional indices such as ejection fraction (r = -0.57, p < 0.001), regional wall motion score index (r = 0.52, p = 0.001), and global longitudinal strain (r = 0.56, p < 0.001). The diastolic functional indices significantly correlated with age (r = -0.64, p < 0.001), LV twist (r = -0.39, p = 0.02), average non-infarcted myocardial circumferential strain (r = -0.52, p = 0.001), and LV end-diastolic wall stress index (r = -0.47, p = 0.003 with e’) but not or weakly with extent of LGE. In multivariate analysis, age and non-infarcted myocardial circumferential strain independently correlated with diastolic functional indices rather than extent of injury.ConclusionsIn patients with timely reperfused AMI, not only extent of myocardial injury but also age and non-infarcted myocardial function were more significantly related to LV chamber diastolic function.

The role of critical shear stress on acute coronary syndrome

Increased aggregation of RBC is associated with many vascular diseases, including acute coronary syndrome (ACS). Critical shear-stress (CSS) as in index of red cell aggregation is defined as either the minimum shear-stress required dispersing the aggregates. The objective of this study is to access the role of CSS in ACS comparing to SA, and to evaluate the correlation with usual biomarkers for atherosclerosis such as fibrinogen, hs-CRP. 169 SA and 223 ACS patients were finally enrolled. A detailed medical history and laboratory data were obtained for each participant from clinical records. CSS is measured by simultaneous measurement of shear stress and light backscattering using a small disposable kit with a microfluidic hemorheometer. We hypothesized that higher value of CSS might be associated increased thrombosis in ACS. As results, relatively younger age was shown and more male in ACS patients, and inflammatory markers (WBC, hs-CRP) were higher in ACS. Whole blood viscosities were significantly higher in ACS than SA along at all shear rates. CSS was 25.7% higher in ACS (333.8 ± 147.8) than in SA (265.4 ± 149.9 mPa) (p < 0.001). CSS was highly correlated white blood cell counts, hs-CRP, fibrinogen, and erythrocyte sedimentation rate (ESR). Among those variables, fibrinogen, and ESR were strongly correlated with CSS. We may suggest that CSS could be used as a novel risk marker for ACS.

Lipoprotein-Associated Phospholipase A2 Is Related to Plaque Stability and Is a Potential Biomarker for Acute Coronary Syndrome

Purpose Plasma lipoprotein-associated phospholipase A2 (Lp-PLA2) binds to low-density lipoprotein. The levels of Lp-PLA2 reflect the plaque burden, and are upregulated in acute coronary syndrome (ACS). We investigated the diagnostic value of Lp-PLA2 levels and found that it might be a potential biomarker for ACS. Materials and Methods We classified 226 study participants into three groups: patients without significant stenosis (control group), patients with significant stenosis with stable angina (SA group), and patients with ACS (ACS group). Results Lp-PLA2 and high-sensitivity C-reactive protein (hs-CRP) levels were significantly greater in the ACS group than in the SA group (p=0.044 and p=0.029, respectively). Multivariate logistic regression analysis revealed that Lp-PLA2 levels are significantly associated with ACS (odds ratio=1.047, p=0.013). The addition of Lp-PLA2 to the ACS model significantly increased the global χ2 value over traditional risk factors (28.14 to 35.602, p=0.006). The area under the receiver operating characteristic curve for Lp-PLA2 was 0.624 (p=0.004). The addition of Lp-PLA2 level to serum hs-CRP concentration yielded an integrated discrimination improvement of 0.0368 (p=0.0093, standard error: 0.0142) and improved the ability to diagnose ACS. Conclusion Lp-PLA2 levels are related to plaque stability and might be a diagnostic biomarker for ACS.

Spontaneous Coronary Artery Dissection Mimicking Coronary Spasm Diagnosed by Intravascular Ultrasonography

Spontaneous coronary artery dissection (SCAD) is a rare and occasionally life-threatening cause of acute coronary syndrome. Patients may present with clinical scenarios ranging from angina pectoris to cardiogenic shock to sudden cardiac death, and it may be a potentially life-threatening condition if not recognized. However, its etiology, pathophysiology and optimal therapeutic strategies have not been well understood. SCAD is diagnosed on the basis of coronary angiography, but complementary techniques as such intravascular ultrasound (IVUS) and optical coherence tomography should be considered for diagnostic clarification where appropriate. Likewise, the selection of treatment strategy depends upon the clinical manifestation, location and the extent of dissection and amount of ischemic myocardium at risk. Herein, we present the case of a 35-year-old woman who presented with acute myocardial infarction. She was diagnosed by IVUS with spontaneous diffuse dissection of the left anterior descending artery without atheroma, treated with percutaneous coronary stenting, and had a favorable clinical course and was discharged on medical therapy.