Chun-Ku Chen

Reintervention for distal stent graft-induced new entry after endovascular repair with a stainless steel-based device in aortic dissection.

OBJECTIVE Stent graft-induced new entry (SINE) has been increasingly observed after thoracic endovascular aortic repair (TEVAR) for aortic dissection. We investigated the mechanism of late distal SINE, prevention strategies, proper size selection of the stent graft, and implantation sequence. METHODS From November 2006 to May 2011, 99 patients with aortic dissection underwent TEVAR with Zenith TX2 stent grafts (Cook, Bloomington, Ind) at our center. Among them, 27 distal SINEs were recognized. Eight of these patients with complicated distal SINE required intervention with new distal endografts, and all were enrolled for further analysis. RESULTS Eight of the 27 patients with distal SINE underwent a secondary endograft procedure from February 2011 to July 2011. All were successfully treated without any complications or deaths. A high taper ratio (35%±11%) and excessive oversizing of the true lumen area at the distal stent level (293%±76%) were noted among these patients. CONCLUSIONS The incidence of distal SINE seemed to be high; however, there were also low rates of death and complications after TEVAR for aortic dissection using stainless steel-based stent grafts. Complicated distal SINE can successfully be resolved by distal endograft implantation. Excessive oversizing of the distal stent graft, as measured by the true lumen area, may be a significant factor causing delayed distal SINE. Precise size selection is crucial for the distal end of the stent, especially for high taper ratio dissection pathology in which the implantation sequence of a distal small-sized stent graft first might be considered to prevent future distal SINE.

The impact of bird-beak configuration on aortic remodeling of distal arch pathology after thoracic endovascular aortic repair with the Zenith Pro-Form TX2 thoracic endograft

OBJECTIVE Structural changes and incomplete endograft apposition to the aortic arch (bird-beak configuration) after thoracic endovascular aortic repair are poorly understood. The aim of this study was to analyze the morphologic changes, conformability, and angulation factors in patients who underwent stainless steel-based stent graft repair of thoracic aortic pathology. METHODS From March 2011 to March 2012, the study enrolled 19 patients with aortic pathology requiring proximal fixation in zones 2 and 3 who underwent stent graft repair using Zenith Pro-Form TX2 stent grafts (Cook Medical, Bloomington, Ind). For comparison, another 19 patients who received Zenith Z-Trak stent grafts were selected from December 2009 to February 2011. Chest computed tomography scans were analyzed at baseline, and then at 1, 6, and 12 months postoperatively. Arch angulation and bird-beak configuration were evaluated according to sealing zones of attachment by Aquarius iNtuition software (TeraRecon, San Mateo, Calif). RESULTS The treated diseases included chronic type B aortic dissection in 17 patients and degenerative aneurysms in 21. Significant arch angle transformation was noted at the zone 2 level between the Pro-Form and Z-Trak treated groups (150° ± 11° vs 158° ± 6°; P = .033) and left subclavian artery level (152° ± 12° vs 160° ± 8°; P = .031) during 1 year of follow-up. The bird-beak configuration was detected in six patients (32%) in the Pro-Form group and in 11 (58%) in the Z-Trak group (P = .096) at 1 month, and in six (32%) in the Pro-Form group and in 14 (74%) in the Z-Trak group (P = .022) at 12 months. The mean bird-beak angle was significantly less in Pro-Form-treated patients at 1 month (5° ± 9° vs 15° ± 13°; P = .019) and at 1 year (6° ± 10° vs 18° ± 15°; P = .033). In the Pro-Form platform, a preoperative zone 2 angle <151.1° was a better estimation of the presence of a postoperative bird-beak configuration, with a sensitivity of 86% and specificity of 83%. CONCLUSIONS Aortic remodeling after stainless steel stent graft repair of thoracic aortic pathology is a continuous process. Significant arch angle transformation was discovered over the zone 2 and left subclavian artery levels. TX2 Pro-Form stent grafts improved arch conformation after 1 year of follow-up. Furthermore, in the patients with dissection, a preoperative distal arch angle of zone 2 was predictive of postoperative bird-beak configuration, regardless of whether they were treated with a Pro-Form stent graft.

Differentiating Benign and Malignant Soft Tissue Masses by Magnetic Resonance Imaging: Role of Tissue Component Analysis

Background: There is a variable degree of accuracy in discriminating benign from malignant soft tissue masses based on signal intensity and morphologic characteristics by magnetic resonance imaging (MRI). The aim of this study was to determine the utility of detailed component pattern assessment, in addition to morphologic study, for differentiating benign from malignant soft tissue masses by MRI. Methods: The imaging features of 118 histologically proven soft tissue masses were analyzed according to: (1) signal characteristics: (a) high T1 matrix; (b) low T2 matrix; (c) fibrous tissue signal; (d) calcification; (e) myxoid signal tissue; (f) fatty signal tissue; (g) cystic signal; (h) necrotic signal; (i) septations; (j) vascular signal void signal; (k) fat rim; and (l) hemorrhage; and according to (2) morphologic assessment: (a) lesion size (maximal diameter) in centimeters (cm); (b) lesion depth in cm; (c) margins; (d) peritumoral edema; (e) bone involvement; (f) marginal capsule or pseudocapsule; and (g) neurovascular bundle involvement. Univariate and multivariate analyses followed by stepwise logistic regression of combination of imaging features were performed. The predictive value of each imaging feature and various combinations of imaging features were determined. Results: In univariate analysis, T2 low signal matrix, fibrous tissue, calcification, necrosis, septum, fat rim sign, peritumoral edema, and hemorrhage showed statistically significant differences between benign and malignant masses (p < 0.05). The positive predictive value of necrosis for malignancy was 84.8%, and its specificity was 90.9%. In multivariate analysis, the best model for predicting malignant masses was the combination of necrosis, maximal mass diameter, peritumoral edema, and absent fibrosis, absent calcification, and lack of fat rim. The combination of these parameters resulted in the most correct diagnoses of malignancy, with a sensitivity of 84.2%, specificity of 64.0%, and accuracy of 74.8%, whereas the accuracy of models consisting of component character and morphologic feature were 74.3% and 70.9%, respectively. Conclusion: MRI is useful in determining whether a soft tissue mass is malignant or not. Traditional morphologic assessment was reinforced by detailed component characterization analysis. The parameters favoring malignancy were large lesion size, peritumoral edema, necrosis, and absent calcification, absent fibrosis, and lack of fat rim.

Sonographic findings in skeletal muscle metastasis from renal cell carcinoma.

The skeletal muscle is an unusual site of metastasis for renal cell carcinoma (RCC). In large autopsy series, only 0.4% of patients with RCC had skeletal metastases. Renal cell carcinoma metastasis can occur late in the course of the disease, creating a diagnostic challenge. In this report, we describe a patient with skeletal muscle metastasis from RCC that appeared 14 years after nephrectomy. We describe the sonographic findings, which, to our knowledge, have not been previously reported.

Percutaneous cryoablation for inoperable malignant lung tumors: midterm results.

OBJECTIVE To retrospectively analyze the efficacy and short- to mid-term survival rate of cryoablation for malignant lung tumors. METHODS Percutaneous CT-guided cryoablation for 45 malignant lung tumors in 26 patients during 41 sessions from 2009 to 2013 were performed. Follow up CT-scan were used to determine local tumor progression. Survival rate, local tumor control rate and associated risk factors were analyzed. RESULTS The immediate during and short-term complications with CTCAE grade 2 or upper include pneumothorax (15%), pleural effusion (20%), pulmonary hemorrhage (24%), pneumonitis (15%), hemothorax (15%), hemoptysis (10%), pain (20%), bronchopleural fistula (n=1), and empyema (n=2). Life-threatening bleeding or hemodynamic instability was not observed. There was no procedural-related mortality. Overall survival rate of 1, 2, 3 years are 96%, 88%, 88%. For curative intent, local tumor control (LTC) rate of 1, 2, 3 years are 75%, 72%, 72%. CONCLUSION Cryoablation for malignant lung tumors is effective and feasible in local control of tumor growth, with good short- to mid-term survival rate, as an alternative option for inoperable patients.

Frequency and risk factors associated with atherosclerotic plaques in patients with a zero coronary artery calcium score.

Background: Analysis of the coronary artery calcium levels usually provides important information that can be used in patient prognosis and stratification of treatment when coronary artery disease is suspected. However, plaques, with or without significant stenosis, have been reported in patients without coronary artery calcium. The aim of this study was to determine the frequency and risk factors of the development of coronary artery plaques in individuals with a zero calcium score. Methods: Analysis of coronary artery calcium levels and coronary computed tomography angiography (CTA) were performed using 64‐slice computed tomography (CT). The demographic data, clinical risk factors, and imaging features of 519 consecutive patients (54 ± 10 years, male:female ratio of 56:44) were retrospectively analyzed. The presence of plaques and the degree of the resulting stenosis were recorded. Descriptive, univariate, and multivariate analyses were carried out to identify the frequency and risk factors associated with the presence of coronary artery plaques. Results: Among 66 patients, 82 coronary arteries were found to have plaques, and six coronary arteries showed significant stenosis. Univariate analysis showed that an age greater than 55 years, male gender, a body mass index (BMI) of more than 27, hypertension, and diabetes mellitus are significant factors associated with the development of coronary artery plaques. Multivariate logistic regression analysis showed that an age over 55 years (p = 0.012, OR = 2.13, 95% C.I. = 1.18–3.84) and BMI greater than 27 (p = 0.026, OR = 2.01, 95% C.I. = 1.09–3.72) are independent factors associated with the presence of plaques in patients with a zero calcium score. Conclusion: The results of this study show that plaques are present in a significant proportion of individuals with a zero coronary artery calcium score. In addition, advanced age and obesity are risk factors associated with the development of plaques.

Outcome comparison between thoracic endovascular and open repair for type B aortic dissection: A population-based longitudinal study

Background Management of diseases of the descending thoracic aorta is trending from open surgery toward thoracic endovascular aortic repair (TEVAR), because TEVAR is reportedly associated with less perioperative mortality. However, comparisons between TEVAR and open surgery, adjusting for patient comorbidities, have not been well studied. In this nationwide population‐based study, we compared the outcomes between TEVAR and open surgery in type B aortic dissection. Methods From 2003 to 2009, data on patients with type B aortic dissection who underwent either open surgery or TEVAR were obtained from the National Health Insurance Research Database. Survival, length of stay, and complications were compared between TEVAR and open repair. To minimize possible bias, we performed an additional analysis after matching patients by age, sex, and propensity score. Results A total of 1661 patients were identified, of whom 1542 underwent open repair and 119 TEVAR. Patients in the TEVAR group were older (63.0 ± 15.4 years vs. 58.1 ± 13.1 years; p = 0.001), included more males, and had more preoperative comorbidities. Thirty‐day mortality in the TEVAR group was significantly lower than that in the open repair group (4.2% vs. 17.8%; p < 0.001). The midterm survival rates in the unmatched cohort between the open surgery and TEVAR groups at 1 year, 2 years, 3 years, and 4 years were 76%, 73%, 71%, and 68% vs. 92%, 86%, 82%, and 79%, respectively. The length of stay in the TEVAR group was shorter than that in the open repair group (p = 0.001). The TEVAR group had less respiratory failure (p = 0.022) and fewer wound complications than the open repair group (p = 0.008). The matched cohort showed similar results. Conclusion TEVAR for type B aortic dissection repair has less perioperative mortality, a shorter length of hospitalization, a higher midterm survival rate, less postoperative respiratory failure, and fewer wound complications than open surgery.

Image-guided lung tumor ablation: Principle, technique, and current status

&NA; Image‐guided tumor ablation for lung malignancies has emerged as a treatment modality for medically inoperable patients. Overall, image‐guided lung tumor ablation is a minimally invasive procedure that has an acceptable safety profile and less impact on lung function. This is important for patients with poor pulmonary and/or cardiac functions or with multiple comorbidities, which prevent them from undergoing surgery, chemotherapy, and radiation therapy. Herein, we review the principle, techniques, clinical application, and patient outcomes of image‐guided lung tumor ablation.

Hospice palliative care article publications: An analysis of the Web of Science database from 1993 to 2013

Background Academic publications are important for developing a medical specialty or discipline and improvements of quality of care. As hospice palliative care medicine is a rapidly growing medical specialty in Taiwan, this study aimed to analyze the hospice palliative care‐related publications from 1993 through 2013 both worldwide and in Taiwan, by using the Web of Science database. Methods Academic articles published with topics including “hospice”, “palliative care”, “end of life care”, and “terminal care” were retrieved and analyzed from the Web of Science database, which includes documents published in Science Citation Index‐Expanded and Social Science Citation Indexed journals from 1993 to 2013. Compound annual growth rates (CAGRs) were calculated to evaluate the trends of publications. Results There were a total of 27,788 documents published worldwide during the years 1993 to 2013. The top five most prolific countries/areas with published documents were the United States (11,419 documents, 41.09%), England (3620 documents, 13.03%), Canada (2428 documents, 8.74%), Germany (1598 documents, 5.75%), and Australia (1580 documents, 5.69%). Three hundred and ten documents (1.12%) were published from Taiwan, which ranks second among Asian countries (after Japan, with 594 documents, 2.14%) and 16th in the world. During this 21‐year period, the number of hospice palliative care‐related article publications increased rapidly. The worldwide CAGR for hospice palliative care publications during 1993 through 2013 was 12.9%. As for Taiwan, the CAGR for publications during 1999 through 2013 was 19.4%. The majority of these documents were submitted from universities or hospitals affiliated to universities. Conclusion The number of hospice palliative care‐related publications increased rapidly from 1993 to 2013 in the world and in Taiwan; however, the number of publications from Taiwan is still far below those published in several other countries. Further research is needed to identify and try to reduce the barriers to hospice palliative care research and publication in Taiwan.

Utilization and patterns of community healthcare services for senior residents in long-term care facilities in Taiwan: A nationwide study

Background: Community healthcare is one of the many important services used to care for the disabled elderly in aging societies. The aim of this study was to evaluate the utilization and patterns of community healthcare services used by senior residents in long‐term care facilities (LTCFs) in Taiwan. Methods: Secondary data analyses were conducted of the Taiwan National Health Insurance Research Database for 9338 LTCF senior residents receiving community healthcare services throughout the 2004 calendar year. The community healthcare services used by male and female LTCF senior residents were also compared by Chi‐square testing. Descriptive statistics are used to present the patterns of professional visits and services by contracted healthcare facilities. Results: About one‐third of those senior residents living in LTCFs in Taiwan in 2004 received community healthcare services. Female residents received a higher percentage of community healthcare services than males in all age groups (p < 0.001). Community home nursing care institutions provided 67% of healthcare visits and professional visits. Of those services provided to patients, the majority of the skilled nursing services were attributable to replacement of nasogastric tube (55%) and urinary catheter (38%). Conclusion: Whether or not the replacement of nasogastric tubes and urinary catheters among the LTCF senior resident population is an appropriate use of time and targeted medical resources needs further investigation. When addressing concerns about the community healthcare needs of senior residents of LTCFs, policymakers should carefully consider the current shortage of professional healthcare workers as they assess strategies to best meet the needs of the elderly in Taiwan.