Challenges in treatment and diagnosis of forgotten/encrusted double-J ureteral stents: the largest single-center experience

Purpose: We aimed to evaluate the effectiveness of the endourologic management of forgotten and/or encrusted ureteral stents together with our single-center experience.

Materials and methods: Fifty-four patients with forgotten double-J ureteral stents were treated in our center between January 2008 and March 2014. Encrustation and the related stone burdens were estimated by using computerized tomography and kidney–ureter–bladder radiography. The management method was chosen based on the stone burden or clinical and radiological findings.

Results: Fifty-four patients, 39 males and 15 females, were included in the study. The average age of the patients was 38.2?±?25.06 (2–86) years. The average indwelling time of the ureteral stents was 22.6?±?30.3 (6–144) months. Six of the patients with forgotten stents had solitary kidneys. The double-J stent (DJS) was fragmented in four (7.4%) patients. A urinary system infection was present in 15 (27.7%) of the patients. The ureteral stents and related stones were successfully removed without any complications by combined endourologic techniques to achieve a stone-free state in all patients except for patient with 110 months of forgotten stent time in whom nephrectomy was performed for a nonfunctioning kidney related to the forgotten stent.

Conclusions: Forgotten/encrusted DJS may lead to complications in a range of urinary system infections, up to a loss of renal function. They can be safely and successfully removed, and the renal function can be preserved by endourologic techniques, starting with the least invasive procedures in centers highly experienced.     

Effect of Mucin and Bicarbonate Ion on Corrosion Behavior of AZ31 Magnesium Alloy for Airway Stents

The biodegradable ability of magnesium alloys is an attractive feature for tracheal stents since they can be absorbed by the body through gradual degradation after healing of the airway structure, which can reduce the risk of inflammation caused by long-term implantation and prevent the repetitive surgery for removal of existing stent. In this study, the effects of bicarbonate ion (HCO₃⁻) and mucin in Gamble’s solution on the corrosion behavior of AZ31 magnesium alloy were investigated, using immersion and electrochemical tests to systematically identify the biodegradation kinetics of magnesium alloy under in vitro environment, mimicking the epithelial mucus surfaces in a trachea for development of biodegradable airway stents. Analysis of corrosion products after immersion test was performed using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). Electrochemical impedance spectroscopy (EIS) was used to identify the effects of bicarbonate ions and mucin on the corrosion behavior of AZ31 magnesium alloys with the temporal change of corrosion resistance. The results show that the increase of the bicarbonate ions in Gamble’s solution accelerates the dissolution of AZ31 magnesium alloy, while the addition of mucin retards the corrosion. The experimental data in this work is intended to be used as foundational knowledge to predict the corrosion behavior of AZ31 magnesium alloy in the airway environment while providing degradation information for future in vivo studies.     

Double waffle-cone technique using twin Solitaire detachable stents for treatment of an ultra-wide necked aneurysm

Several stent-supported coiling techniques have been devised for treating wide-necked bifurcation aneurysms including the Y-stent and waffle-cone constructs. The Y-stent technique is not technically possible with obtusely oriented daughter vessels, and the waffle-cone method is inadequate for aneurysms with necks exceeding the stent’s maximal expansion diameter. We describe here the novel use of the Solitaire electrolytically detachable slotted stent (Solitaire, ev3, Irvine, CA, USA) featuring large-sized cells to fashion a concentric “double waffle-cone” construct. This method enabled the doubling of the neck coverage to treat an ultra-wide necked middle cerebral aneurysm with obtusely oriented daughter branches. The technique relies on the intra-cell crossing of the first stent using the second stent delivery microcatheter and fine tuning the relative position with the aid of cross-sectional cone-beam computed tomographic angiography to achieve optimal coverage of the neck prior to detachment of the stents in position. A retrievable stent with large cells such as the Solitaire device is optimal for this application given the need for relative adjustment of the deployment before final stent release to avoid under- or over-penetration of the distal stent struts into the aneurysm dome. An additional advantage of this approach over the kissing-stent technique is the absence of intraluminal stent struts, which was confirmed here by down-the-barrel cross-sectional imaging. The double waffle-cone construct enabled the successful coiling of the aneurysm with no post-procedural ischemic events detected on diffusion-weighted MRI and with stable complete embolization and no residual filling or in-stent stenosis at 6 month follow-up.     

Advances in Percutaneous Coronary Interventions for Elderly Patients

Coronary heart disease (CHD) is one of the leading causes of morbidity and the most common cause of death in older adults. Paradoxically, elderly patients tend to be systematically excluded from randomized-controlled cardiovascular trials, which complicates decision-making in this population. Management of CHD in the elderly is frequently more difficult in virtue of chronic comorbid conditions and aging-intrinsic dynamics. Despite these challenges, the number of elderly and very elderly patients undergoing percutaneous coronary interventions (PCI) is increasing. Elderly patients in many registries and large clinical series exhibit even a greater benefit from interventional procedures than younger patients, but they have a higher rate of overall complications. We present an overview of the current available evidence of PCI in older adults with stable and unstable CHD, including comparisons between drug-eluting and bare-metal stents, transfemoral and transradial access, and methods of revascularization. Adjuvant antiplatelet and antithrombotic therapies are also discussed.     

Current management of acute malignant large bowel obstruction: a systematic review

BackgroundThe management of colonic obstruction has changed in recent years. In distal obstruction, optimal treatment remains controversial, particularly after the appearance and use of colonic endoluminal stents. The purpose of this study was to review the current treatment of acute malignant large bowel obstruction according to the level of evidence of the available literature.MethodsA systematic search was conducted in PubMed, MEDLINE, Embase, and Google Scholar for articles published through January 2013 to identify studies of large bowel obstruction and colorectal cancer. Included studies were randomized and nonrandomized controlled trials, reviews, systematic reviews, and meta-analysis.ResultsAfter a literature search of 1,768 titles and abstracts, 218 were selected for full-text assessment; 59 studies were ultimately included. Twenty-five studies of the diagnosis and treatment of obstruction and 34 studies of the use of stents were assessed.ConclusionsIn view of the various alternatives and the lack of high-grade evidence, the treatment of distal colonic obstruction should be individually tailored to each patient.