Comparison of vascular access patency and patient survival between native arteriovenous fistula and synthetic arteriovenous graft according to age group.

INTRODUCTION: Arteriovenous fistula (AVF) is historically known to be the ideal option for vascular access (VA) for hemodialysis compared with arteriovenous graft (AVG). However, this approach has been recently questioned in the aging population because of their poor vessel quality and multiple comorbidities. METHODS: Data from a total of 2200 patients from the VA category of The Catholic Medical Center nephrology registry from March 2009 to February 2017 were analyzed. We compared VA patency and patient survival between two groups, AVF and AVG, according to age. FINDINGS: Compared with the AVG group, survival benefit in the AVF group continued even in patients ≥80 years. In the whole population, all the primary patency (PP), primary-assisted patency (PAP), and secondary patency (SP) measures were superior in the AVF group. With regard to subgroups, PP was comparable between the two groups in patients ≥65 years, whereas PAP and SP were superior in the AVF group even in septuagenarian patients who are from 70 to 79 years old. In patients ≥80 years, all the patency measures were comparable between the two groups. When the separate comparison of lower-arm AVF (or upper-arm AVF) and AVG, lower-arm AVF failed to demonstrate its superiority in any kind of patency in septuagenarian patients compared with AVG, whereas upper-arm AVF demonstrated its superiority in PAP and SP in septuagenarian patients. However, even upper-arm AVF failed to demonstrate its superiority in any kind of patency in patients ≥80 years. DISCUSSION: Arteriovenous fistula if using upper-arm vessel showed the superior VA patency up to septuagenarian patients, whereas, in HD patients ≥80 years, AVF and AVG were comparable in VA patency.

Central venous disease in hemodialysis patients.

Central venous disease (CVD) is difficult to treat and often resistant to treatment. In CVD, hemodialysis vascular access should sometimes be abandoned, or in serious cases, the patient's life may be threatened. Therefore, prevention is ideal. However, as the prevalence of chronic kidney disease (CKD) has increased steadily with population aging, CKD patients with a peripherally inserted central catheter (PICC) are encountered frequently. PICCs can cause CVD, and the basilic vein, which is regarded as the important last option for native arteriovenous fistula (AVF) creation in end-stage renal disease (ESRD) patients, is destroyed frequently after its use as the entry site of PICC. The most well-established risk factors for CVD are a history of central venous catheter (CVC) insertion and its duration of use. Therefore, to reduce the incidence of CVD, catheterization in the central vein (CV) should be minimized, along with its duration of use. In this review, we will first explain the basic territories of the CV and introduce its pathophysiology, clinical features, and advanced treatment options. Finally, we will emphasize prevention of CVD.

The effect of vascular access type on intra-access flow volume during hemodialysis.

INTRODUCTION: Previous studies have revealed that vascular access resistance is constant during hemodialysis, but differs according to vascular access type. It is possible that intra-access flow volume (Qac) variation during hemodialysis may also differ according to vascular access type. We conducted this study to investigate whether there are differences in Qac according to vascular access type during hemodialysis. METHODS: A total of 58 lower-arm arteriovenous fistula, 14 lower-arm arteriovenous graft, 27 upper-arm arteriovenous fistula, and 45 upper-arm arteriovenous graft cases were studied. Three consecutive Qac values (at 30, 120, and 240 min after the start of hemodialysis) were measured in each patient by the ultrasound dilution technique. Variations in Qac over time were analyzed using repeated measures analysis of variance and multivariate regression analyses, to assess the impact of different factors on Qac variation. RESULTS: The repeated measures analysis of variance revealed that a significant interaction exists between time and vascular access type (p < 0.001). This suggests that vascular access type affects Qac change (%) variation over time during hemodialysis. In a multivariate analysis, mean arterial pressure change during hemodialysis (p = 0.009), access type (p < 0.001), and access location (p < 0.001) were independent variables causing Qac change variation. CONCLUSION: This study showed that there is a significant difference in Qac variation according to vascular access type during hemodialysis and that arteriovenous graft (vs arteriovenous fistula) and the lower-arm location (vs upper arm) were associated with a decrease in Qac during hemodialysis. This suggests that consideration of vascular access type is required to minimize Qac variation during hemodialysis.

Exchange over the guidewire from non-tunneled to tunneled hemodialysis catheters can be performed without patency loss.

PURPOSE: The exchange from a non-tunneled hemodialysis catheter to a tunneled one over a guidewire using a previous venotomy has been reported to be safe. However, some concerns that it may increase infection risk prevent its clinical application. This approach seems particularly useful for acute kidney injury patients requiring initial renal replacement therapy, in whom we frequently worry about the choice of non-tunneled versus tunneled catheters. MATERIALS AND METHODS: From March 2012 to February 2016, 88 cases to receive the over-the-guidewire exchange method from a non-tunneled to a tunneled catheter and 521 cases to receive de novo tunneled catheter placement from the hemodialysis vascular access cohort were compared retrospectively. RESULTS: The immediate complication, later catheter dysfunction requiring replacement, and infection rates were comparable between the two groups. Newly placed tunneled catheter survival in the over-the-guidewire exchange group was comparable with survival in the de novo tunneled catheter group (p = 0.24). In addition, when we compared the same two methods among only intensive care unit patients; they remained similar (p = 0.19). CONCLUSION: An exchange with the over-the-guidewire method from a non-tunneled to a tunneled catheter was comparable to a de novo catheter placement technique. Therefore, this method should be viewed more favorably and should especially be considered for acute kidney injury patients.

Long-term outcomes and prognostic factors in patients with mild hemoptysis.

OBJECTIVE: The aim of this retrospective study was to observe the long-term outcomes of conservative treatment and bronchial artery embolization (BAE) in patients with mild hemoptysis and to analyze the risk factors associated with hemoptysis recurrence. METHODS: Patients with mild hemoptysis from January 2005 to January 2016 were enrolled in this study. The patients' medical records, including smoking history, etiologic diseases, bronchoscopic findings, mortality, BAE information, and follow-up data of recurrent hemoptysis, were reviewed and analyzed. RESULTS: A total of 288 patients with mild hemoptysis were included in this study. Of them, 71 patients (24.7%) underwent BAE and 217 patients (75.3%) were treated conservatively. The clinical success rate of BAE was 98.6%, with a low minor complication rate of 5.6%. Bronchoscopy before treatments was performed in 237 patients (82.3%). Fifty-five patients (19.1%) experienced recurrent hemoptysis during a median follow-up period of 2.4years (interquartile range: 1.0-4.4years). Patients who showed active bleeding or blood clots on bronchoscopy had a significantly lower recurrence-free survival rate than patients with no bronchoscopic evidence of bleeding or blood clots (p=0.012). The risk factors affecting recurrence were heavy smoking (p=0.002, hazard ratio [HR]: 3.57), aspergillosis (p=0.035, HR: 6.01), and bronchoscopic findings of active bleeding (p=0.016, HR: 3.29) or blood clots (p=0.012, HR: 2.77). CONCLUSIONS: The recurrence rate of hemoptysis was not negligible in patients with mild hemoptysis. BAE can be considered in patients with a high risk of recurrence.

Usefulness of assisted procedures for arteriovenous fistula maturation without compromising access patency.

INTRODUCTION: To increase the rate of arteriovenous fistula (AVF) use, assisted procedures for immature AVF have been strenuously performed. However, this is controversial in that an AVF matured by these assisted procedures may require more frequent intervention to maintain its patency, and have decreased long-term patency. METHODS: Eighty four AVFs that were matured with assisted maturation procedures and 266 AVFs that matured spontaneously without intervention, created between November 2009 and March 2013 from the hemodialysis (HD) vascular access (VA) cohort, were compared retrospectively and we also investigated the factors that may influence AVF long-term patency. Median follow-up was 26.8 months (interquartile range, 6.6-45.0 months). FINDINGS: Access survival did not differ between AVFs matured by assisted procedures and spontaneously mature AVFs (P = 0.29). In multivariate Cox regression analysis of AVF survival, age (HR, 1.029; 95% CI, 1.004-1.056; P = 0.024), maturation without assisted procedures 4-6 weeks after AVF creation (HR, 0.233; 95% CI, 0.107-0.506; P < 0.001), and AVF thrombosis (HR, 26.511; 95% CI, 10.986-63.978; P < 0.001) were significantly associated with AVF survival. Performance of assisted procedures to induce AVF maturation did not influence AVF survival (HR, 0.437; 95% CI, 0.191-1.002; P = 0.05). DISCUSSION: Our results support that idea that assisted maturation procedures can ensure the success of immature AVF without compromising long-term patency. These procedures can be considered more positively for increasing AVF use for VA placement in HD patients.

Pitfalls in Radiographic Interpretation of Emphysema Patients.

Emphysema commonly accompanies various complications such as pneumonia. Sometimes, these comorbidities look so strange on images, because destroyed airspaces could change the usual disease progression. So, we demonstrated various cases of common comorbidities with unusual radiographic findings in emphysema patients. Awareness of various findings of emphysema with commonly coexistent diseases may aid in the proper diagnosis and management of emphysema patients.

Conversion of percutaneous endoscopic gastrostomy to gastrojejunostomy under fluoroscopic guidance for treatment of gastrocutaneous fistula.

Persistent enterocutaneous fistula after the removal of a gastrostomy tube is an unusual complication of percutaneous endoscopic gastrostomy (PEG). The following case report describes an 81-year-old man diagnosed with stroke and dysphagia in May 2008. The patient had been using a PEG since 2008, and PEG site infection occurred in June 2013. The PEG tube was removed and a new PEG tube was inserted. Thereafter, formation of gastrocutaneous fistula around the previous infected PEG site was observed. The fistula was refractory to medical management, accompanied by long duration of fasting and peripheral alimentation. Therefore, gastrojejunostomy tube insertion via the previously inserted PEG tube was performed, under fluoroscopic guidance; this mode of management was successful. For patients who have a gastrocutaneous fistula, gastrojejunostomy tube insertion via the pre-existing PEG tube is a safe and effective alternative management for enteral feeding.

MR-guided high-intensity focused ultrasound treatment for symptomatic uterine leiomyomata: long-term outcomes.

RATIONALE AND OBJECTIVES: To evaluate the long-term clinical outcomes of magnetic resonance--guided high-intensity focused ultrasound (MR-g HIFU) treatments for symptomatic uterine leiomyomata. MATERIALS AND METHODS: Patients were recruited for a prospective study for MR-g HIFU treatments of symptomatic leiomyomata, with up to 3-year follow-up. The study was approved by the institutional review board and was Health Insurance Portability and Accountability Act--compliant. Clinical assessments were obtained at 3 months, 6 months, and 1, 2, and 3 years after MR-g HIFU, as well as uterine fibroid symptom severity scores (SSS) and health-related quality of life questionnaires (UFS-QOL). MR imaging was performed at each follow-up to assess the efficacy of the treatment at 6 months, 1 year, 2 years, and 3 years. RESULTS: Fifty-one leiomyomata in 40 patients were treated. All patients were treated within the US Food and Drug Administration guidelines with leiomyomata localized on MR and treated with sonication. The mean baseline volume of treated leiomyomata was 336.9 cm(3). The mean improvement scores for transformed SSS was 47.8 (P < .001) and for tUFS-QOL was 39.8 (P < .001) at 3 years. The mean volume decrease in treated leiomyomata was 32.0% (P < .001), and, in the uterus, the volume decrease was 27.7% (P < .001) at 3 years. There were no long-term complications. CONCLUSIONS: Long-term follow-up data from MR-g HIFU treatments show sustained symptomatic relief among enrolled patients. Although the results are preliminary, MR-g HIFU for the treatment of uterine leiomyomata may result in acceptable long-term outcomes at 3 years.

Colon Ischemia Associated with Buerger's Disease: Case Report and Review of the Literature.

Buerger's disease, or thromboangiitis obliterans, is a nonatherosclerotic inflammatory disease affecting the small- and medium-sized arteries and veins of the extremities (arms, hands, legs, and feet). It is most common in the Orient, Southeast Asia, India, and the Middle East, and usually affects men aged between 20 and 40 years, although it is becoming more common in women. It is well established that most such patients smoke heavily and experience an improvement in symptoms following smoking cessation. Mesenteric involvement in Buerger's disease is extremely rare; however, we describe herein two cases of colon ischemia in patients who were previously diagnosed with lower-extremity Buerger's disease. In one case, the patient developed colonic obstruction, and surgical resection was performed. Histopathologic findings were compatible with the chronic stage of Buerger's disease. In the other case, angiography revealed abrupt occlusion of the inferior mesenteric artery with numerous collateral vessels, just like the corkscrew appearance found in the extremities. If patients with established Buerger's disease of the extremities complain of gastrointestinal symptoms, early interventional diagnosis should be performed to prevent intestinal obstruction and gangrene.

High-resolution CT findings of re-expansion pulmonary edema.

OBJECTIVE: To describe the high-resolution CT (HRCT) findings of re-expansion pulmonary edema (REPE) following a thoracentesis for a spontaneous pneumothorax. MATERIALS AND METHODS: HRCT scans from 43 patients who developed REPE immediately after a thoracentesis for treatment of pneumothorax were retrospectively analyzed. The study group consisted of 41 men and two women with a mean age of 34 years. The average time interval between insertion of the drainage tube and HRCT was 8.5 hours (range, 1-24 hours). The patterns and distribution of the lung lesions were analyzed and were assigned one of the following classifications: consolidation, ground-glass opacity (GGO), intralobular interstitial thickening, interlobular septal thickening, thickening of bronchovascular bundles, and nodules. The presence of pleural effusion and contralateral lung involvement was also assessed. RESULTS: Patchy areas of GGO were observed in all 43 patients examined. Consolidation was noted in 22 patients (51%). The geographic distribution of GGO and consolidation was noted in 25 patients (58%). Interlobular septal thickening and intralobular interstitial thickening was noted in 28 patients (65%), respectively. Bronchovascular bundle thickening was seen in 13 patients (30%), whereas ill-defined centrilobular GGO nodules were observed in five patients (12%). The lesions were predominantly peripheral in 38 patients (88%). Of these lesions, gravity-dependent distribution was noted in 23 cases (53%). Bilateral lung involvement was noted in four patients (9%), and a small amount of pleural effusion was seen in seven patients (16%). CONCLUSION: The HRCT findings of REPE were peripheral patchy areas of GGO that were frequently combined with consolidation as well as interlobular septal and intralobular interstitial thickening.

[Isolated spontaneous dissection of superior mesenteric artery: treated by percutaneous endovascular stent placement].

Isolated spontaneous dissection of the superior mesenteric artery (SMA) without aortic dissection is a rare cause of acute mesenteric ischemia. A sudden decrease of intestinal blood flow can lead to fatal complications such as ischemic necrosis, shock, and death. Therefore, early diagnosis and therapeutic approach before the occurrence of intestinal infarction are the most important factor to determine the patients prognosis. A 52-year-old male presented with postprandial periumbilical pain, and isolated spontaneous dissection of the superior mesenteric artery with mural thrombus was detected by abdominal computed tomography with contrast enhancement. By the percutaneous implantation of vascular metallic stent via femoral artery, he was treated successfully. We report a case of isolated spontaneous dissection of the SMA treated by a percutaneous endovascular stent replacement with a review of literature.

Typical and atypical manifestations of intrathoracic sarcoidosis.

Sarcoidosis is a systemic disorder of unknown cause that is characterized by the presence of noncaseating granulomas. The radiological findings associated with sarcoidosis have been well described. The findings include symmetric, bilateral hilar and paratracheal lymphadenopathy, with or without concomitant parenchymal abnormalities (multiple small nodules in a peribronchovascular distribution along with irregular thickening of the interstitium). However, in 25% to 30% of cases, the radiological findings are atypical and unfamiliar to most radiologists, which cause difficulty for making a correct diagnosis. Many atypical forms of intrathoracic sarcoidosis have been described sporadically. We have collected cases with unusual radiological findings associated with pulmonary sarcoidosis (unilateral or asymmetric lymphadenopathy, necrosis or cavitation, large opacity, ground glass opacity, an airway abnormality and pleural involvement) and describe the typical forms of the disorder as well. The understanding of a wide range of the radiological manifestations of sarcoidosis will be very helpful for making a proper diagnosis.

Incidental thyroid uptake on F-18 FDG PET/CT: correlation with ultrasonography and pathology.

PURPOSE: To evaluate the usefulness of maximum standard uptake value (max SUV) calculated from F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) examination and findings from ultrasonographic (US) examination on incidentally detected thyroid FDG uptake on FDG PET/CT. MATERIALS AND METHODS: We collected and reviewed FDG PET/CT images performed at our institution from March 2005 to March 2008. This study included 190 subjects with increased FDG uptake of thyroid gland who later underwent thyroid US and histological examinations. Of these subjects, the uptake pattern on FDG PET/CT was classified as either diffuse or focal. The FDG uptake pattern, max SUV, and US findings were evaluated and correlated with the histological results. RESULTS: In the focal FDG uptake pattern cases (n = 148), the mean max SUV of malignant cases was higher than that of benign cases (5.93 +/- 5.35 vs. 3.47 +/- 2.89). Of the diffuse FDG uptake cases (n = 42), nodules were detected in 25 subjects (59.5%) by US examination. Thyroid nodules were well characterized on US studies, and combined findings of suspicious US features or high max SUV of focal FDG uptake lesion increased sensitivity, PPV, NPV, and accuracy. CONCLUSIONS: Focal uptake pattern and high max SUV may be helpful in differentiating benign and malignant nodules on FDG PET/CT. However, US examination provides further information, and for lesions with increased FDG uptake of thyroid, US examination should be recommended.

The role of diffusion-weighted imaging and the apparent diffusion coefficient (ADC) values for breast tumors.

OBJECTIVE: We wanted to evaluate the role of diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) for detecting breast tumors, as compared with the T1- and T2-weighted images. MATERIALS AND METHODS: Forty-one female patients underwent breast MRI, and this included the T1-, T2-, DWI and dynamic contrast-enhanced images. Sixty-five enhancing lesions were detected on the dynamic contrast-enhanced images and we used this as a reference image for detecting tumor. Fifty-six breast lesions were detected on DWI and the histological diagnoses were as follows: 43 invasive ductal carcinomas, one mucinous carcinoma, one mixed infiltrative and mucinous carcinoma, seven ductal carcinomas in situ (DCIS), and four benign tumors. First, we compared the detectability of breast lesions on DWI with that of the T1- and T2-weighted images. We then compared the ADCs of the malignant and benign breast lesions to the ADCs of the normal fibroglandular tissue. RESULTS: Fifty-six lesions were detected via DWI (detectability of 86.2%). The detectabilities of breast lesions on the T1- and T2-weighted imaging were 61.5% (40/65) and 75.4% (49/65), respectively. The mean ADCs of the invasive ductal carcinoma (0.89+/-0.18 x 10(-3)mm(2)/second) and DCIS (1.17+/-0.18 x 10(-3)mm(2)/ second) are significantly lower than those of the benign lesions (1.41+/-0.56 x 10(-3)mm(2)/second) and the normal fibroglandular tissue (1.51+/-0.29 x 10(-3)mm(2)/ second). CONCLUSION: DWI has a high sensitivity for detecting breast tumors, and especially for detecting malignant breast tumors. DWI was an effective imaging technique for detecting breast lesions, as compared to using the T1- and T2-weighted images.