Improvement of MRI-functional measurement with automatic movement correction in native and transplanted kidneys

PURPOSE: To improve 2D software for motion correction of renal dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and to evaluate its effect using the Patlak-Rutland model. MATERIALS AND METHODS: A subpixel-accurate method to correct for kidney motion during DCE-MRI was evaluated on native and transplanted kidneys using data from two different institutions with different magnets and protocols. The Patlak-Rutland model was used to calculate glomerular filtration rate (GFR) on a voxel-by-voxel basis providing mean (Kp) and uncertainty (sigma(K(p))) values for GFR. RESULTS: In transplanted kidneys, average absolute variation of Kp was 6.4% +/- 4.8% (max = 16.6%). In native kidneys average absolute variation of Kp was 12.11% +/- 6.88% (max = 25.6%) for the right and 11.6% +/- 6% (max = 20.8%) for the left. Movement correction showed an average reduction of sigma(K(p)) of 6.9% +/- 6.6% (max = 21.4%) in transplanted kidneys, 30.9% +/- 17.6% (max = 60.8%) for the right native kidney, and 31.8% +/- 14% (max = 55.3%) for the left kidney. CONCLUSION: The movement correction algorithm showed improved uncertainty on GFR computation for both native and transplanted kidneys despite different spatial resolution from the different MRI systems and different levels of signal-to-noise ratios on DCE-MRI.     

Successful use of continuous ambulatory peritoneal dialysis in octogenarians

This paper reports experience with 18 patients who started CAPD at an age≥80 years at our centre, with emphasis on results, complications and outcome. There were 12 male and 6 female patients whose mean age was 85 years (range 82–91 years); the median duration on CAPD was 31.5 months (range 2 to 58 months). End-stage renal diseases (ESRD) was caused by nephrosclerosis in 9, diabetes mellitus (DM) and light chain disease in 2 each, chronic glomerulonephritis, membranous nephropathy and IgA nephropathy in 1 each, the cause was unknown in yet another two. Seven patients performed their own dialysis while 11 required assistance. The most common co-morbid conditions were hypertension and angina. Peritonitis, that occurred at a rate of 1 episode per 10.8 patient months was responsible for most of the hospitalizations. Peritonitis necessitated catheter removal in 7 patients, reinsertion was done in 6 of them. Fourteen episodes of exit site infection were encountered in 8 patients, 2 developed pericatheter leak and 1 had a tunnel infection. Of the hernias observed in 4 patients, none were inguinal-2 patients each had umbilical and incisional hernias. Nine patients are still continuing CAPD successfully with a median duration of 29 months (range 11–57 months). One patient was transferred to hemodialysis because of congestive heart failure and eight patients died. The causes of death were peritonitis (3/8), CVA (2/8), pneumonia (1/8) and septicemia (1/8). In one patient, the cause of death was not clearly established. Our survival rate of 80% at 3 years is encouraging and hence we advocate CAPD as an acceptable mode of treatment in octogenarians with ESRD.     

Challenges associated with treatment of left internal mammary artery graft thrombosis

Acute occlusion of the left internal mammary artery (LIMA) graft late after coronary artery bypass grafting surgery is a rare and potentially life‐threatening complication. We describe a case of acute myocardial infarction 19 years after coronary artery bypass graft surgery due to acute occlusion of the distal anastomosis of a LIMA graft to the left anterior descending artery. Aspiration thrombectomy failed to remove the thrombus. Laser thrombectomy caused perforation. After drug‐eluting and covered stent implantation, antegrade TIMI 3 flow was restored with an uneventful postprocedural course.     

Selection of Patients for Treatment of Brain Arteriovenous Malformations by the Transvenous Approach: Relationship with Venous Anatomy and Risk of Hemorrhagic Complications

BACKGROUND AND PURPOSE:Intracranial hemorrhage represents a severe complication of brain arteriovenous malformation treatment. The aim of this cohort was to report the rate of hemorrhagic complications after transvenous endovascular embolization and analyze the potential angioarchitectural risk factors as well as clinical outcomes.MATERIALS AND METHODS:During an 11-year period, 57 patients underwent transvenous endovascular embolization. All cases of hemorrhagic complications were identified. We analyzed the following variables: sex, age, hemorrhagic presentation, Spetzler-Martin grade, size of the AVM before the transvenous treatment, number of venous collectors, pattern of drainage, presence of dilated veins, and technical aspects. Univariate and multivariate multiple regression analyses were performed to evaluate the potential risk factors for procedure-related hemorrhagic complications.RESULTS:Hemorrhagic complications (either intraprocedural or periprocedural) unrelated to a perforation due to micronavigation occurred in 8 (14.0%) procedures. Significant (mRS > 2) and persistent neurologic deficits were present in 2 (3.5%) patients at 6-month control. Larger nidi, especially >3 cm (P = .03), and a larger number of venous collectors have shown a statistically significant correlation with hemorrhagic complications. Only the number of venous collectors was identified as an independent predictor of hemorrhagic complications in the multivariate analysis (OR, 8.7; 95% confidence interval, 2.2–58.2) (P = .006).CONCLUSIONS:Larger nidus sizes and an increased number of venous collectors may increase the risk of hemorrhagic complications when implementing transvenous endovascular treatment of AVMs. The technique is effective and promising, especially with small nidi and single venous collectors.

Endovascular treatment for brain arteriovenous malformations (bAVMs) was traditionally focused on targeting the nidus through an intra-arterial approach, whether as a means of curative treatment or targeted embolization as an adjunctive or emergency treatment. In an attempt to target parts of the nidus that lie in the deep brain areas or that are supplied by very thin or perforating arterial branches, transvenous endovascular embolization (TVE) has emerged and is becoming a new tool to target otherwise incurable brain AVMs.^1-3Even though TVE has several advantages, including a very high rate of angiographic cure up to 92.6%³ and a means of curing otherwise incurable bAVMs,^4,5 it still needs to be used very selectively, to reduce hemorrhagic complications (HC).Nevertheless, the technique is not exempt from intraprocedural or periprocedural complications. Hemorrhagic complications represent the most important and challenging procedure-related issues with this technique, which may lead to poor clinical outcomes.^6-9A greater understanding of the frequency and risk factors for HC may optimize patient selection for TVE. The aim of this study was to estimate the rates of intraprocedural and periprocedural hemorrhage after TVE for bAVMs, to assess the morbidity and mortality associated with bleeding, and to analyze the angioarchitectural risk factors linked with such complications.     

Primary adrenal lymphoma presenting as Addison’s disease: case report and review of the literature

Primary adrenal lymphoma (PAL) is an extremely rare entity and adrenal insufficiency is a common complication. Bilateral enlargement of adrenal glands should raise the suspicion of lymphoma, especially in patients with clinical or laboratory features of adrenal insufficiency. Most of these cases are highly aggressive tumors and should be treated with multiagent chemotherapy. The role of bilateral adrenalectomy and/or radiotherapy cannot be estimated. Our patient with PAL was an 80-year-old man who presented with clinical and laboratory features of adrenal insufficiency. Combination chemotherapy plus rituximab was unsuccessful and our patient died from progressive disease.     

The safety of polymyxin antibiotics

Introduction: The emergence of multidrug-resistant gram-negative bacteria has led to the increasing use of polymyxins. Nephrotoxicity and, to a lesser degree, neurotoxicity occur often during systemic polymyxin therapy. Scientific evidence regarding safety associated with polymyxins remains limited.

Areas covered: Case reports/case series, observational studies and clinical trials assessing safety and toxicity of polymyxins were critically reviewed.

Expert opinion: Polymyxins are drugs with a narrow therapeutic range. Nephrotoxicity is associated with both host factors and polymyxin exposure, and recent studies suggest that the relative risk of nephrotoxicity is similar for colistin and polymyxin B. Studies that have examined the safety of polymyxins have several limitations. Considering the available evidence, toxicities that may develop while on polymyxin therapy most often are mild to moderate in magnitude and reversible in nature. Strategies to minimize toxicity associated with polymyxins have evolved and include avoidance of toxic medications, careful dosing, use of critical care, therapeutic drug monitoring and development of polymyxin derivatives. However, given that polymyxin use has re-emerged in an era of increased antimicrobial resistance, the presence of other treatment modalities may be limited. Therefore, clinicians must consider overall risk to benefit ratio of continuing versus stopping polymyxin treatment and optimize minimization strategies to reduce polymyxin-induced toxicities.