Silicone-based simulation models for peripheral nerve microsurgery

Background

There is a need for a peripheral nerve model on which surgeons-in-training can simulate the repair of nerve injuries at their own pace. Although practicing on animal models/cadavers is considered the “gold standard” of microsurgical training, the proposed model aims to provide a platform for improving the technical skills of surgical trainees prior to their practice on cadaver/animal models. In addition, this model has the potential to serve as a standardized test medium for assessing the skill sets of surgeons.

Granuloma annulare possibly triggered by antitetanus vaccination

We report the case of a 6-year-old girl with granuloma annulare (GA) possibly related to antitetanus vaccinations. The first episode occurred 2 months after the girl had been vaccinated but the lesions were not located at the vaccination site. After 1 year of being free of lesions, she had a second episode unrelated to vaccination. After another 6-month lesion-free period, the girl was administered another antitetanus vaccination and a solitary lesion developed at the vaccination site within 3 days. A few lesions developed on her legs in the 2 months following the appearance of the initial plaque. The literature includes two reports of cases with papular lesions limited to the hepatitis B vaccination site, both histopathologically consistent with necrobiotic granuloma, but clinically not suggestive of GA. To the best of our knowledge, GA following antitetanus vaccination and occurring at the vaccination site has not been reported before. Either the trauma alone from the injection or a vaccine-induced immunological reaction might have triggered the necrobiosis of collagen through some unexplained mechanisms.     

Nosocomial infections and risk factors in intensive care unit of a university hospital in Turkey

The aim of this study was to determine the types nosocomial infections (NIs) and the risk factors for NIs in the central intensive care unit (ICU) of Trakya University Hospital. The patients admitted to the ICU were observed prospectively by the unit-directed active surveillance method based on patient and the laboratory over a 9-month-period. The samples of urine, blood, sputum or tracheal aspirate were taken from the patients on the first and the third days of their hospitalization in ICU; the patients were cultured routinely. Other samples were taken and cultured if there was suspicion of an infection. Infections were considered as ICU-associated if they developed after 48 hours of hospitalization in the unit and 5 days after discharge from the unit if the patients had been sent to a different ward in the hospital. The rate of NIs in 135 patients assigned was found to be 68%. The most common infection sites were lower respiratory tract, urinary tract, bloodstream, catheter site and surgical wound. Hospitalization in ICU for more than 6 days and colonization was found to be the main risk factor for NIs. Prolonged mechanical ventilation and tracheostomy, as well as frequently changed nasogastric catheterization, were found to be risk factors for lower respiratory tract infections. For bloodstream infections, both prolonged insertion of and frequent change of arterial catheters, and for urinary tract infections, female gender, period and repeating of urinary catheterization were risk factors. A high prevalence rate of nosocomial infections was found in this study. Invasive device use and duration of use continue to greatly influence the development of nosocomial infection in ICU. Important factors to prevent nosocomial infections are to avoid long hospitalization and unnecessary device application. Control and prevention strategies based on continuing education of healthcare workers will decrease the nosocomial infections in the intensive care unit.     

Differentiating clinical and echocardiographic characteristics of chordal rupture detected in patients with rheumatic mitral valve disease and floppy mitral valve: impact of the infective endocarditis on chordal rupture.

AIMS: We aimed to compare the clinical and echocardiographic correlates of chordal rupture in patients with rheumatic mitral valve disease and floppy mitral valve. METHODS AND RESULTS: The study group comprised of 224 patients who underwent transthoracic and transesophageal echocardiography because of the severe mitral regurgitation. Chordal rupture was detected in 58 (25.9%) out of the 224 patients, in 33 out of the 83 (39.7%) patients with floppy mitral valve, and in 25 out of the 141 (17.7%) patients with rheumatic mitral valve disease. Chordal rupture was more frequently associated with anterior leaflet (80%) in patients with rheumatic mitral valve disease, and posterior leaflet (72.7%) in patients with floppy mitral valve (p<0.05). Univariate correlates of chordal rupture were age, male sex, posterior mitral leaflet thickening and chordal elongation in patients with floppy mitral valve (p<0.05), and chordal shortening (p<0.0001) and infective endocarditis involving mitral anterior leaflet (p<0.05) in rheumatic group. Independent predictors of chordal rupture were age (>50 years), posterior mitral leaflet thickness (> or =0.45cm), and male sex (p<0.05) in patients with floppy mitral valve while infective endocarditis involving mitral anterior leaflet (p<0.05) in patients with rheumatic mitral valve disease. Patients with chordal rupture due to floppy mitral valve had an older age (p<0.0001), a male dominance, longer mitral leaflets and chordae, and a larger mitral annulus circumference (p<0.05) as compared to those with rheumatic chordal rupture. Despite the comparable severity of mitral regurgitation and left atrial diameters between the two groups of chordal rupture (p>0.05), functional class and pulmonary artery systolic pressure were higher, and atrial fibrillation, acute deterioration, infective endocarditis, mitral leaflet rupture and need for mitral valve surgery in the 3 months were more frequent in rheumatic chordal rupture subgroup (p<0.05). CONCLUSION: Chordal rupture seems to be more frequently associated with anterior mitral leaflet in rheumatic mitral valve disease, whereas it was the posterior leaflet in floppy mitral valve. Chordal rupture was related to male sex, older age, posterior leaflet thickening, and chordal elongation in patients with floppy mitral valve. However, infective endocarditis, acute deterioration, and need for early mitral surgery were more frequent in patients with rheumatic chordal rupture.     

PD-L1 – inhibitors in neuroendocrine neoplasia: Results from a real-life study

Immune check-point inhibitors (ICIs) have changed our view on how to treat cancer. Despite their approval in treatment of many different cancers, efficacy of immune check-point inhibitors (ICI) in neuroendocrine neoplasia is limited and poorly understood. Established treatment options of neuroendocrine tumors (NET) and neuroendocrine carcinomas (NECs) are based on surgery, tumor-targeted medical treatments, Peptide Receptor Radionuclide Therapy (PRRT), and locoregional therapies. However, in many patients these treatments lose efficacy over time, and novel therapies are urgently needed. We report on 8 patients diagnosed with neuroendocrine neoplasms (NEN) that were treated with ICI (pembrolizumab, avelumab, nivolumab plus ipilimumab) as salvage therapy. In this cohort, we observed tumor response with partial remission in 3 patients and stable disease in 1 patient. Four patients showed progressive disease. Of note, responses were observed both in PD-L1 positive and PD-L1 negative patients. Here, we discuss clinical courses of these patients in the context of available literature to highlight limitations and drawbacks currently preventing the use of ICI in routine management of patients with NEN.     

Retinal vessel diameters and their correlation with retinal nerve fiber layer thickness in patients with pseudoexfoliation syndrome

AIM: To compare retinal artery-vein diameters (RAVDs) of patients with pseudoexfoliation (PSX) syndrome with healthy controls and investigate the correlations between retinal nerve fiber layer (RNFL) thickness parameters and RAVDs. METHODS: Seventeen eyes with PSX and 17 eyes of age-matched controls were included in the study. All participants underwent routine ophthalmological examination, Humphrey visual field and RNFL examination by using Stratus OCT. Retinal images were obtained by using a retinal camera (Topcon 501X). RAVDs were measured from inferior nasal, inferior temporal, superior nasal and superior temporal arcuates by using IMAGEnet software. Superior, inferior, nasal, temporal and average RNFL thicknesses were recorded. RAVDs and RNFL parameters in groups and correlations were analyzed by Mann-Whitney U and Spearmann correlation tests. RESULTS: Only inferior quadrant and average RNFL thickness were detected thinner in the PSX group compared with control group (P=0.009, P=0.038, respectively). No statistically significant difference regarding RAVDs was found between two groups. CONCLUSION: RAVDs seems to be comparable in the PSX and control group. RNFL is thinner in the inferior quadrant in the PSX group. RNFL thickness and RAVDs show significant correlations in both groups. This correlation doesn’t seem to be specific to PSX.     

Severe mitral regurgitation may prevent mural thrombus formation within the left ventricle with systolic dysfunction

The protective effect of severe mitral regurgitation (MR) against left atrial thrombus formation has been well documented. It was also proposed that severe MR may prevent thrombus formation within the left ventricle (LV) with systolic dysfunction. Therefore, we investigated whether ischemic MR prevents thrombus formation within the LV in patients with systolic dysfunction. The study population was comprised of 1313 patients (1133 males, 180 females, age 56+/-18) with ischaemic LV dysfunction documented by coronary angiography and left ventriculography. None of the patients had a history of chronic anticoagulation. Epicardial coronary arteries were normal in 91 patients, and single-vessel, two-vessel, and triple-vessel disease were detected in 328, 330, and 564 patients, respectively. Left ventricular thrombus and severe MR were detected in 191 (14.5%) and 125 (9.5%) patients, respectively. Overall incidence of LV thrombus was lower in patients with severe MR than in patients without severe MR (4% vs 15.6%, OR: 0.2, P<0.001). Severe MR compared with absence of severe MR was associated with a lower incidence of LV thrombus both in patients with ischemic dilated cardiomyopathy (6.8% vs 34.2%, OR: 0.19, P<0.001), and in patients with aneurysm (3% vs 18%, OR: 0.14, P<0.0001) involving anterolateral, septal and/or apical LV segments. A similar trend without statistical significance was also observed in patients with dyskinesia (4.7% vs 16%, OR: 0.26, P=0.1) related to anterolateral, septal and/or apical LV segments. However, MR had no impact on the incidence of LV thrombus in patients with aneurysm or dyskinesia related to posterior and/or inferior segments (3.7% vs 3%, OR: 1.2, P>0.05). In conclusion, severe MR seems to prevent LV mural thrombus formation in patients with ischemic dilated cardiomyopathy, and in patients with aneurysm related to anterolateral, septal, and/or apical LV segments. This relative risk reduction may be associated with diastolic volume overloading due to severe MR which may overcome stagnation and a procoagulant state within the LV with severe systolic dysfunction.