Woocheol Kwon

A Randomized, Open-Label, Multicenter Trial for the Safety and Efficacy of Adult Mesenchymal Stem Cells after Acute Myocardial Infarction

Recent studies suggest that the intracoronary administration of bone marrow (BM)-derived mesenchymal stem cells (MSCs) may improve left ventricular function in patients with acute myocardial infarction (AMI). However, there is still argumentative for the safety and efficacy of MSCs in the AMI setting. We thus performed a randomized pilot study to investigate the safety and efficacy of MSCs in patients with AMI. Eighty patients with AMI after successful reperfusion therapy were randomly assigned and received an intracoronary administration of autologous BM-derived MSCs into the infarct related artery at 1 month. During follow-up period, 58 patients completed the trial. The primary endpoint was changes in left ventricular ejection fraction (LVEF) by single-photon emission computed tomography (SPECT) at 6 month. We also evaluated treatment-related adverse events. The absolute improvement in the LVEF by SPECT at 6 month was greater in the BM-derived MSCs group than in the control group (5.9%±8.5% vs 1.6%±7.0%; P=0.037). There was no treatment-related toxicity during intracoronary administration of MSCs. No significant adverse cardiovascular events occurred during follow-up. In conclusion, the intracoronary infusion of human BM-derived MSCs at 1 month is tolerable and safe with modest improvement in LVEF at 6-month follow-up by SPECT. (ClinicalTrials.gov registration number: NCT01392105)

Optimal position for external chest compression during cardiopulmonary resuscitation: an analysis based on chest CT in patients resuscitated from cardiac arrest

Objectives This study was conducted to determine the proper hand position on the sternum for external chest compression to generate a maximal haemodynamic effect during cardiopulmonary resuscitation (CPR). Methods 114 patients with cardiac arrest who underwent chest CT after successful resuscitation from January 2006 to August 2009 were included in the study. To evaluate the area of the cardiac chambers subjected to external chest compression, the area of each cardiac chamber under the sternum was measured using cross-sectional CT at three different locations: the internipple line on the sternum (point A), halfway between point A and the sternoxiphoid junction (point B) and at the sternoxiphoid junction (point C). Results The widest total heart area, total ventricular area and left ventricular area (LVA) were observed most frequently at point C (58%, 85% and 78% of all cases, respectively). Few cases (six in total heart area, one in total ventricular area and one in LVA) were observed as the widest at point A. Predicted compressed areas of the right and left ventricle were wider at point C than at points A or B (right ventricular area: 366±536 mm2 at point A, 961±653 mm2 at point B and 1383±689 mm2 at point C, p<0.001; LVA: 65±236 mm2 at point A, 365±506 mm2 at point B and 1099±817 mm2 at point C, p<0.001). Conclusions Only a small proportion of the ventricle is subjected to external chest compression when CPR is performed according to the current guidelines. Compression of the sternum at the sternoxiphoid junction might be more effective to compress the ventricles.

Comparison of the Effectiveness of Embolic Agents for Bronchial Artery Embolization: Gelfoam versus Polyvinyl Alcohol

Objective The purpose of this study was to compare the results of different agents for bronchial artery embolization of hemoptysis. Materials and Methods From March 1992 to December 2006, a bronchial artery embolization was performed on 430 patients with hemoptysis. The patients were divided into three groups. Group 1 included 74 patients treated with a gelfoam particle (1×1×1 mm), while group 2 comprised of 205 patients treated with polyvinyl alcohol (PVA) at 355-500 µm, and group 3 included 151 patients treated with PVA at 500-710 µm. We categorized the results as technical and clinical successes, and also included the mid-term results. Retrospectively, the technical success was compared immediately after the procedure. The clinical success and mid-term results (percentage of patients who were free of hemoptysis) were compared at 1 and 12 months after the procedure, respectively. Results Neither the technical successes (group 1; 85%, 2; 85%, 3; 90%) nor the clinical successes (group 1; 72%, 2; 74%, 3; 71%) showed a significant difference among the 3 groups (p > 0.05). However, the mid-term results (group 1; 45%, 2; 63%, 3; 62%) and mid-term results excluding the recurrence from collateral vessels in each of the groups (group 1; 1 patient, 2; 4 patients, 3; 2 patients) showed that group 1 was lower than the other two groups (p < 0.05). No significant difference was discovered for the mid-term results between groups 2 and 3. Moreover, the same results not including incidences of recurrence from collateral vessels also showed no statistical significance between the two groups (p > 0.05). Conclusion Polyvinyl alcohol appears to be the more optimal modality compared to gelfoam particle for bronchial artery embolization in order to improve the mid-term results. The material size of PVA needs to be selected to match with the vascular diameter.

Primary Thymic Mucinous Adenocarcinoma: A Case Report

Primary thymic mucinous adenocarcinoma is an extremely rare aggressive subtype of thymic carcinoma. With a review of literatures, only nine cases have been reported up to present. A 36-year-old woman was admitted for further evaluation and treatment of a mediastinal mass. The patient had no medical history of cancer. The clinicoradiological examination disclosed no tumor elsewhere. After the surgical excision of mediastinal mass, it was grossly a round semi-solid mass with mucin-filled cystic areas. Microscopically solid areas showed cords, small nests and dilated glands infiltrating the fibrotic parenchyma, while the cystic areas were lined by mucinous epithelium with tumor cells floating in extracellular-mucin pools. Some cystic walls underwent malignant transformation of the benign thymic epithelium. Immunohistochemically, the tumor cells were positive for cytokeratin (CK) 7, CK20, CD5, and CDX-2, and negative for thyroid transcription factor-1. In conclusion, the mucinous thymic adenocarcinoma should be recognized as a separate histopathological entity and considered in the differential diagnosis of mediastinal carcinomas.

Placental Transmogrification of the Lung

Placental transmogrification is a very rare lung disease, where the alveoli resemble the chorionic villi of placenta, and this change is a characteristic finding. A 31-year-old female patient presented with cough and dyspnea that had begun 2 weeks prior to admission. Along with giant bulla found in the left upper lung field, subsegmental consolidation was also identified in the lingular segment on plain chest radiograph and CT scan. Wedge resection was performed to remove the bulla. Pathologic examination of the resected bulla revealed destruction of the normal structures and characteristic villous and papillary changes. These changes led to a diagnosis of placental transmogrification. We made an encounter of an unusual placental transmogrification which had different image findings from other reported transmogrification cases. Thus, we report an atypical placental transmogrification case where both consolidation and giant bulla coexist.

Lung perfusion CT: The differentiation of cavitary mass

PURPOSE To assess the findings of perfusion maps and to evaluate the usefulness of perfusion computed tomography (CT) in the differentiation of cavitary mass. MATERIALS AND METHODS Fifty-three patients with cavitary lung masses were analyzed. Dynamic chest CT was performed after contrast injection. The volume map, washout map, peak map, and time-to-peak (TTP) map were reformatted using Interactive Data Language (IDL). The perfusion patterns were classified into three scoring groups, and these scorings were repeated after 2-week intervals. Diagnostic confidence levels were assigned by consensus. The kappa statistics was used to determine intraobserver agreement, and Fishers exact test was used to analyze statistical differences in perfusion scores. Receiver operating characteristic (ROC) analysis was performed to evaluate the usefulness of the perfusion maps. RESULTS Perfusion maps were reformatted pixel-by-pixel from the time-to-density curve analyses. Pyogenic cavities showed weak washout and slow TTP (69.6%). Conversely, malignant cavities showed strong washout (73.3%). Tuberculous cavities showed low perfusions in the volume and peak maps (66.7%). Intraobserver agreement was excellent. The performance of the combination of CT and perfusion maps was better than that of CT alone. CONCLUSION Lung perfusion CT could be a promising and feasible method for differentiation of cavitary mass.

The effectiveness of embolotherapy for treatment of hemoptysis in patients with varying severity of tuberculosis by assessment of chest radiography.

The effectiveness of percutaneous embolotherapy in cases of hemoptysis due to pulmonary tuberculosis from increasing severity of lung parenchymal injury was compared. The pattern of pleural involvement, as seen on chest radiography and angiography, were comparatively analyzed in 230 patients who were available for follow-ups from March 1992 to December 2003. Chest radiography findings were classified into 4 types based on levels of complicated lesions and pleural involvement. Angiography findings were divided into 4 groups based on the level of blood supply to lesions. Early hemostasis with respect to radiographic group were as follows: Type I- 92% (73/79), Type II- 80% (52/65), Type III- 70% (42/60), and Type IV- 56% (52/92); there was an average success rate of 73% (219/296), and continued hemostasis was found in 80% of Type I patients (62/77), 77% of Type II patients (41/53), 62% of Type III patients (25/40), and 45% of Type IV patients (27/60), with an average long-term hemostatic rate of 67% (155/230). Increasing severity of pleural involvement and associated complications correlated with increasing development of systemic collateral arteries other than the bronchial artery. The severely increased circulation in systemic collateral arteries makes it difficult to predict good hemostatic results following embolization. Therefore, we recommend aggressive treatment, such as surgical intervention, after embolization in such instances.

Occlusion of Traumatic Carotid Cavernous Fistula by Incidentally Formed Thrombus During the Interventional Procedure: A Case Report

In this report, we present a rare case of traumatic carotid cavernous fistula that was occluded during the interventional procedure by incidentally formed blood clot. Sudden occlusion of the fistula and the resolution process of the precarious blood clot can be clearly seen on the serial angiogram.

Pneumoperitoneum caused by transhepatic air leak after metallic biliary stent placement

A self-expanding metallic biliary stent was placed for palliation of a common bile duct obstruction in a 68-year-old male with unresectable pancreatic head cancer 3 days after initial percutaneous right transhepatic catheter decompression. The stent crossed the ampulla of Vater. Three days later, the stent was balloon-dilated and the percutaneous access was removed. At removal, a small contrast leak from the transhepatic tract was seen. Three days later, pneumoperitoneum was found with symptoms of peritoneal irritation and fever. A widely open sphincter of Oddi caused by the metallic stent, accompanied by delayed sealing of the transhepatic tract, may have caused the air and bile leakage into the peritoneal space. This case shows that pneumoperitoneum may occur without ductal tear or bowel injury, with a biliary stent crossing the ampulla of Vater.

Evaluation of relationship between coronary artery status evaluated by coronary computed tomography angiography and development of cardiomyopathy in carbon monoxide poisoned patients with myocardial injury: a prospective observational study

Abstract Objectives: Whether coronary artery changes are a main mechanism in the development of carbon monoxide (CO)-induced cardiomyopathy remains unknown. We investigated the effects of coronary artery stenosis on the presence or patterns of cardiomyopathy in CO-poisoned patients with myocardial injury defined as elevation of troponin I. Materials and methods: This prospective observational study collected data from consecutive patients who were diagnosed with CO poisoning and myocardial injury during the 24-month study period. Transthoracic echocardiography (TTE) and coronary computed tomography angiography (CCTA) were performed to evaluate cardiac function and coronary artery status. Results: TTE and CCTA were performed in 32 consecutive patients. The observed echocardiographic patterns included non-cardiomyopathy (59.4%), left ventricular global dysfunction (25%), Takotsubo cardiomyopathy (6.3%), and cardiomyopathy matching the distribution of the left anterior descending (LAD) artery (9.4%). Four patients had more than moderate stenosis, while stenoses of the LAD, left circumflex, and right coronary arteries were observed in two (6.3%), three (9.4%), and zero patients, respectively. Patients with coronary artery stenosis did not develop cardiomyopathy except for one patient; this patient also did not have regional wall motion abnormalities (RWMA) matched with the stenosis territory. Conclusions: Because there was no difference in coronary artery stenosis according to the presence or patterns of CO-induced cardiomyopathy, coronary artery stenosis is not the main mechanism for the development of CO-induced cardiomyopathy. Thus, the evaluation of coronary arteries is not necessary in all patients with CO-induced cardiomyopathy unless there is RWMA consistent with ischemic changes in electrocardiograms and elevated troponin I levels.