Air suctioning during colon biopsy forceps removal reduces bacterial air contamination in the endoscopy suite

Bacterial contamination of endoscopy suites is of concern; however studies evaluating bacterial aerosols are lacking. We aimed to determine the effectiveness of air suctioning during removal of biopsy forceps in reducing bacterial air contamination.

Eosinophilic vasculitis: an inhabitual and resistant manifestation of a vasculitis

A 55-year-old woman was referred because of diffuse pruritic erythematous lesions and an ischemic process of the third finger of her right hand. She was known to have anaemia secondary to hypermenorrhea. She presented six months before admission with a cutaneous infiltration on the left cubital cavity after a paravenous leakage of intravenous iron substitution. She then reported a progressive pruritic erythematous swelling of her left arm and lower extremities and trunk. Skin biopsy of a lesion on the right leg revealed a fibrillar, small-vessel vasculitis containing many eosinophils.Two months later she reported Raynaud symptoms in both hands, with a persistent violaceous coloration of the skin and cold sensation of her third digit of the right hand. A round 1.5 cm well-delimited swelling on the medial site of the left elbow was noted. The third digit of her right hand was cold and of violet colour. Eosinophilia (19 % of total leucocytes) was present. Doppler-duplex arterial examination of the upper extremities showed an occlusion of the cubital artery down to the palmar arcade on the right arm. Selective angiography of the right subclavian and brachial arteries showed diffuse alteration of the blood flow in the cubital artery and hand, with fine collateral circulation in the carpal region. Neither secondary causes of hypereosinophilia nor a myeloproliferative process was found. Considering the skin biopsy results and having excluded other causes of eosinophilia, we assumed the diagnosis of an eosinophilic vasculitis. Treatment with tacrolimus and high dose steroids was started, the latter tapered within 12 months and then stopped, but a dramatic flare-up of the vasculitis with Raynaud phenomenon occurred. A new immunosuppressive approach with steroids and methotrexate was then introduced. This case of aggressive eosinophilic vasculitis is difficult to classify into the usual forms of vasculitis and constitutes a therapeutic challenge given the resistance to current immunosuppressive regimens.

Poor performance of microbiological sampling in the prediction of recurrent arthroplasty infection

During a two-stage revision for prosthetic joint infections (PJI), joint aspirations, open tissue sampling and serum inflammatory markers are performed before re-implantation to exclude ongoing silent infection. We investigated the performance of these diagnostic procedures on the risk of recurrence of PJI among asymptomatic patients undergoing a two-stage revision. A total of 62 PJI were found in 58 patients. All patients had intra-operative surgical exploration during re-implantation, and 48 of them had intra-operative microbiological swabs. Additionally, 18 joint aspirations and one open biopsy were performed before second-stage reimplantation. Recurrence or persistence of PJI occurred in 12 cases with a mean delay of 218 days after re-implantation, but only four pre- or intraoperative invasive joint samples had grown a pathogen in cultures. In at least seven recurrent PJIs (58%), patients had a normal C-reactive protein (CRP, < 10 mg/l) level before re-implantation. The sensitivity, specificity, positive predictive and negative predictive values of pre-operative invasive joint aspiration and CRP for the prediction of PJI recurrence was 0.58, 0.88, 0.5, 0.84 and 0.17, 0.81, 0.13, 0.86, respectively. As a conclusion, pre-operative joint aspiration, intraoperative bacterial sampling, surgical exploration and serum inflammatory markers are poor predictors of PJI recurrence. The onset of reinfection usually occurs far later than reimplantation.

Multimodal target correction by local bone registration: a PET/CT evaluation

PET/CT guidance for percutaneous interventions allows biopsy of suspicious metabolically active bone lesions even when no morphological correlation is delineable in the CT images. Clinical use of PET/CT guidance with conventional step-by-step technique is time consuming and complicated especially in cases in which the target lesion is not shown in the CT image. Our recently developed multimodal instrument guidance system (IGS) for PET/CT improved this situation. Nevertheless, bone biopsies even with IGS have a trade-off between precision and intervention duration which is proportional to patient and personnel exposure to radiation. As image acquisition and reconstruction of PET may take up to 10 minutes, preferably only one time consuming combined PET/CT acquisition should be needed during an intervention. In case of required additional control images in order to check for possible patient movements/deformations, or to verify the final needle position in the target, only fast CT acquisitions should be performed. However, for precise instrument guidance accounting for patient movement and/or deformation without having a control PET image, it is essential to be able to transfer the position of the target as identified in the original PET/CT to a changed situation as shown in the control CT.

Reproducibility of sensory nerve conduction studies of the sural nerve using ultrasound-guided needle positioning

In this study we sought to evaluate the reproducibility of sensory nerve conduction studies (NCS) using ultrasound-guided needle positioning (USNP).

Evaluation of a novel needle guide for ultrasound-guided phantom vessel cannulation

We evaluated a novel, sled-mounted needle guide for ultrasound-guided vessel cannulation. Fifty medical students were randomly assigned to use ultrasound with the sled (sled group, n = 23) or ultrasound without the sled (control group, n = 27) for vessel cannulation in a phantom. For each of 15 attempts we recorded cannulation time and designated a successful cannulation as 1 and a failure as 0. Our primary outcome was the mean overall success rate. The median (IQR [range]) number of successes in the sled group and control group were 15.0 (13.0-15.0 [11.0-15.0]) and 11.0 (9.0-13.0 [6.0-15.0]), respectively (p < 0.001). Cannulation time decreased from the first to the last attempt in the sled group from 7.0 s (6.0-10.0 [4.0-16]) s to 4.0 s (3.0-4.0 [1.0-6.0]) s and in the control group from 35.0 s (27.0-35.0 [11.0-35.0]) s to 7.0 s (5.0-10.0 [3.0-25.0]) s. The sled group demonstrated a shorter cannulation time at each attempt (p < 0.001). The novel sled improved the success rate and efficiency of ultrasound-guided phantom vessel cannulation.

Indocyanine green fluorescence-guided sentinel lymph node biopsy in dermato-oncology

Sentinel lymph node biopsy (SLNB) for cutaneous malignancies usually carried out with radioactive nanocolloids (Tc-99m). The SLNE is controversially discussed internationally. This is especially given to the high false-negative rate up to 44 %. An alternative could be the fluorescent dye indocyanine green (ICG).

A navigation system for percutaneous needle interventions based on PET/CT images: design, workflow and error analysis of soft tissue and bone punctures

Percutaneous needle intervention based on PET/CT images is effective, but exposes the patient to unnecessary radiation due to the increased number of CT scans required. Computer assisted intervention can reduce the number of scans, but requires handling, matching and visualization of two different datasets. While one dataset is used for target definition according to metabolism, the other is used for instrument guidance according to anatomical structures. No navigation systems capable of handling such data and performing PET/CT image-based procedures while following clinically approved protocols for oncologic percutaneous interventions are available. The need for such systems is emphasized in scenarios where the target can be located in different types of tissue such as bone and soft tissue. These two tissues require different clinical protocols for puncturing and may therefore give rise to different problems during the navigated intervention. Studies comparing the performance of navigated needle interventions targeting lesions located in these two types of tissue are not often found in the literature. Hence, this paper presents an optical navigation system for percutaneous needle interventions based on PET/CT images. The system provides viewers for guiding the physician to the target with real-time visualization of PET/CT datasets, and is able to handle targets located in both bone and soft tissue. The navigation system and the required clinical workflow were designed taking into consideration clinical protocols and requirements, and the system is thus operable by a single person, even during transition to the sterile phase. Both the system and the workflow were evaluated in an initial set of experiments simulating 41 lesions (23 located in bone tissue and 18 in soft tissue) in swine cadavers. We also measured and decomposed the overall system error into distinct error sources, which allowed for the identification of particularities involved in the process as well as highlighting the differences between bone and soft tissue punctures. An overall average error of 4.23 mm and 3.07 mm for bone and soft tissue punctures, respectively, demonstrated the feasibility of using this system for such interventions. The proposed system workflow was shown to be effective in separating the preparation from the sterile phase, as well as in keeping the system manageable by a single operator. Among the distinct sources of error, the user error based on the system accuracy (defined as the distance from the planned target to the actual needle tip) appeared to be the most significant. Bone punctures showed higher user error, whereas soft tissue punctures showed higher tissue deformation error.

Massive Systemic Fat Embolism Detected by Postmortem Imaging and Biopsy

Postmortem computed tomography (pmCT) and pmCT angiography (pmCTA) provide a minimally invasive method to determine the cause of death. Postmortem image-guided biopsy allows for precise sampling of histological specimens. This case study describes the findings of lethal systemic fat embolism (FE) on whole-body unenhanced pmCT, pmCTA, and image-guided biopsy, with autopsy and histopathologic correlation. Unenhanced pmCT revealed a distinct fat level on top of sedimented layers of corpuscular blood particles and serum in the arterial system and pulmonary trunk. Subsequent pmCTA showed reproducible results, and image-guided biopsy confirmed fatal FE. pm CT/pmCTA combined with image-guided biopsy established the cause of death as right heart failure as a result of systemic fatal FE prior to autopsy. All imaging findings were consistent with traditional autopsy and histological specimens. This unique case demonstrates new imaging findings in massive, fatal FE and highlights that postmortem imaging, supplemented by image-guided biopsy, may detect the cause of death prior to traditional autopsy.

A Minimally Invasive Technique for the Detection and Analysis of Pulmonary Fat Embolism: A Feasibility Study*

We investigated the feasibility of postmortem percutaneous needle biopsy (PNB) for obtaining pulmonary samples adequate for the study of pulmonary fat embolism (PFE). Samples of both lungs were obtained from 26 cadavers via two different methods: (i) PNB and (ii) the double-edged knife technique, the gold standard at our institute. After water storage and Sudan III staining, six forensic pathologists independently examined all samples for the presence and severity of PFE. The results were compared and analyzed in each case regarding the vitality of the PFE and its relationship to the cause of death. The results showed that PFE was almost identically diagnosed and graded on the samples obtained via both methods. The discrepancies between the two techniques did not affect the diagnoses of vitality or cause of death related to PFE. This study demonstrates the feasibility of the PNB sampling method for the diagnosis and interpretation of PFE in the postmortem setting.

Fine-tuning of substrate architecture and surface chemistry promotes muscle tissue development

Tissue engineering has been increasingly brought to the scientific spotlight in response to the tremendous demand for regeneration, restoration or substitution of skeletal or cardiac muscle after traumatic injury, tumour ablation or myocardial infarction. In vitro generation of a highly organized and contractile muscle tissue, however, crucially depends on an appropriate design of the cell culture substrate. The present work evaluated the impact of substrate properties, in particular morphology, chemical surface composition and mechanical properties, on muscle cell fate. To this end, aligned and randomly oriented micron (3.3±0.8 μm) or nano (237±98 nm) scaled fibrous poly(ε-caprolactone) non-wovens were processed by electrospinning. A nanometer-thick oxygen functional hydrocarbon coating was deposited by a radio frequency plasma process. C2C12 muscle cells were grown on pure and as-functionalized substrates and analysed for viability, proliferation, spatial orientation, differentiation and contractility. Cell orientation has been shown to depend strongly on substrate architecture, being most pronounced on micron-scaled parallel-oriented fibres. Oxygen functional hydrocarbons, representing stable, non-immunogenic surface groups, were identified as strong triggers for myotube differentiation. Accordingly, the highest myotube density (28±15% of total substrate area), sarcomeric striation and contractility were found on plasma-coated substrates. The current study highlights the manifold material characteristics to be addressed during the substrate design process and provides insight into processes to improve bio-interfaces.

Sudden Death after Chest Pain: Feasibility of Virtual Autopsy with Postmortem CT Angiography and Biopsy

Purpose:To determine the potential of minimally invasive postmortem computed tomographic (CT) angiography combined with image-guided tissue biopsy of the myocardium and lungs in decedents who were thought to have died of acute chest disease and to compare this method with conventional autopsy as the reference standard.Materials and Methods:The responsible justice department and ethics committee approved this study. Twenty corpses (four female corpses and 16 male corpses; age range, 15-80 years), all of whom were reported to have had antemortem acute chest pain, were imaged with postmortem whole-body CT angiography and underwent standardized image-guided biopsy. The standard included three biopsies of the myocardium and a single biopsy of bilateral central lung tissue. Additional biopsies of pulmonary clots for differentiation of pulmonary embolism and postmortem organized thrombus were performed after initial analysis of the cross-sectional images. Subsequent traditional autopsy with sampling of histologic specimens was performed in all cases. Thereafter, conventional histologic and autopsy reports were compared with postmortem CT angiography and CT-guided biopsy findings. A Cohen k coefficient analysis was performed to explore the effect of the clustered nature of the data.Results:In 19 of the 20 cadavers, findings at postmortem CT angiography in combination with CT-guided biopsy validated the cause of death found at traditional autopsy. In one cadaver, early myocardial infarction of the papillary muscles had been missed. The Cohen κ coefficient was 0.94. There were four instances of pulmonary embolism, three aortic dissections (Stanford type A), three myocardial infarctions, three instances of fresh coronary thrombosis, three cases of obstructive coronary artery disease, one ruptured ulcer of the ascending aorta, one ruptured aneurysm of the right subclavian artery, one case of myocarditis, and one pulmonary malignancy with pulmonary artery erosion. In seven of 20 cadavers, CT-guided biopsy provided additional histopathologic information that substantiated the final diagnosis of the cause of death.Conclusion:Postmortem CT angiography combined with image-guided biopsy, because of their minimally invasive nature, have a potential role in the detection of the cause of death after acute chest pain.© RSNA, 2012.