Endoscopic versus histological characterisation of polyps during screening colonoscopy.

BACKGROUND: As screening colonoscopy becomes more widespread, the costs for histopathological assessment of resected polyps are rising correspondingly. Reference centres have published highly accurate results for endoscopic polyp classification. Therefore, it has been proposed that, for smaller polyps, the differential diagnosis that guides follow-up recommendations could be based on endoscopy alone. OBJECTIVE: The aim was to prospectively assess whether the high accuracy for endoscopic polyp diagnosis as reported by reference centres can be reproduced in routine screening colonoscopy. DESIGN: Ten experienced private practice endoscopists had initial training in pit patterns. Then they assessed all polyps detected during 1069 screening colonoscopies. Patients (46% men; mean age 63 years) were randomly assigned to colonoscopy with conventional or latest generation HDTV instruments. The main outcome measure was diagnostic accuracy of in vivo polyp assessment (adenomatous vs hyperplastic). Secondary outcome measures were differences between endoscopes and reliability of image-based follow-up recommendations; a blinded post hoc analysis of polyp photographs was also performed. RESULTS: 675 polyps were assessed (461 adenomatous, 214 hyperplastic). Accuracy, sensitivity and specificity of in vivo diagnoses were 76.6%, 78.1% and 73.4%; size of adenomas and endoscope withdrawal time significantly influenced accuracy. Image-based recommendations for post-polypectomy surveillance were correct in only 69.5% of cases. Post hoc analysis of polyp photographs did not improve accuracy. CONCLUSIONS: In everyday practice, endoscopic classification of polyp type is not accurate enough to abandon histopathological assessment and use of latest generation colonoscopes does not improve this. Image-based surveillance recommendations after polypectomy would consequently not meet guideline requirements. TRIALREGNO: NCT01297712.

Molecular characterization of peripheral arterial disease in proximal extremity arteries.

PURPOSE: Although risk factors for atherosclerosis in peripheral arterial disease (PAD) are well defined, the underlying mechanisms are poorly understood and no medication exists for causal therapy. Molecular pathways that could be targeted have not been identified so far. To address this issue, we compared the molecular profiles of healthy versus PAD proximal femoral arteries. METHODS: Gene expression profiles from proximal femoral arteries of patients with PAD (Fontaine stage IIb-IV; n = 20) and femoral arteries from healthy controls (CO) (n = 3) were compared by microarray technology. We evaluated all samples by histopathology and performed microdissection on the CO tissue before molecular analysis. We analyzed genes regarding their cellular localization, molecular function, and risk factors such as hypercholesterolemia, smoking, and diabetes. We used a selected panel of genes for polymerase chain reaction validation of microarray results and compared the data with previously published studies. RESULTS: Most genes overexpressed in PAD versus CO were located in the cytoplasm, membrane, and nucleus. Functionally, they had binding activity to nucleotides, cytoskeletal proteins, and transcription factors. They were mainly involved in immune regulation (e.g., interleukin-8, chemokine ligand 18, and allograft-inflammatory factor-1) (P < 0.01). Down-regulated genes in PAD versus CO were located in the extracellular region. They had transporter and G-protein receptor activity. They were associated with signaling, cell growth, and tissue formation (e.g., myosin VB, marker for differentiated aortic smooth muscle, myosin 11) (P < 0.01). Polymerase chain reaction successfully validated the expression of the differences among 10 selected genes (e.g., chemokine ligand 18, common leukocyte antigen, killer cell lectin-like receptor subfamily B, member 1, and interleukin-8). CONCLUSIONS: Genes enrolled in immune regulation and inflammatory response were identified as key players in PAD. Various membrane-bound molecules with binding activity are hereunder. Identification of such molecules may elucidate relevant players that act as candidates for therapeutic targets or prognostic markers in the future.

Relative value of normalized sonographic in vitro analysis of arteriosclerotic plaques of internal carotid artery.

BACKGROUND AND PURPOSE: A close correlation between B-mode sonography and the histopathology and surface structure of plaque is rarely seen in vivo with high-grade stenoses of the extracranial carotid artery. The goal of this study was to determine whether normalized gray scale analysis and surface analysis of the plaque are capable of characterizing the attributes correctly. METHODS: Optimized B-mode images of 107 carotid endarterectomy specimens were captured, and the gray scale median (GSM) was calculated. The specimens were classified histologically into 3 groups: (1) calcium-rich hard plaques, (2) lipid-rich soft plaques, and (3) combined plaques. The surfaces of the plaques were classified as smooth or rough on the basis of standardized reference samples. The endoluminal surface was digitally documented in vitro by videoendoscopy and again classified into the same categories. All stages of the investigation were performed by 2 observers at 2 different times. RESULTS: Evaluation of the GSM showed close interobserver and intraobserver correlation (P<0.01, R>0.8). However, there was only 46% agreement between the GSM and the histopathological findings. In both in vitro angioscopy (kappa=0.936, P<0.001) and sonographic evaluation (kappa=0.842, P<0.001), there was a high correlation between the observers with regard to the evaluable specimens. In 73%, agreement was observed between the sonographic image and angioscopy. CONCLUSIONS: Normalized gray scale analysis and evaluation of the plaque surface in an in vitro study make possible observer-independent evaluation. The composition of the plaque cannot be visualized with sufficient accuracy by sonographic GSM analysis. This also applies to the correlation between sonography and actual surface composition of the plaque.

[Treatment of carotid stenosis: carotid surgery or stent? In favor of operation]. / PTA oder Operation bei der Therapie von Karotisstenosen? Pro Operation.

BACKGROUND: According to international studies (ACAS, NASCET, ECST, ACST) the discussion concerning the indication for an operative treatment of carotid artery stenosis which lasted over years, may be regarded as completed. The impressive results showed that the operative treatment is of less risk for the patient than the natural history. But is this conclusion also true for carotid artery stenting? Comparative studies are running, but are not completed yet. The treatment of carotid stenosis by operative or interventional means is controversial, since conflicting conclusions have been drawn from the correlation between plaque morphology and the patients' embolic risk. We clearly recommend treatment by carotid endarterectomy and discourage angioplasty and stenting except in controlled and randomized studies. METHODS AND RESULTS: In a prospective study of patients with carotid artery stenoses, we compared plaque morphology, as examined by ultrasound, with the histological diagnosis. We found that plaque morphology (soft vs. hard plaques) cannot adequately predicted, since in only 80% of cases the noninvasively suspected plaque morphology could be confirmed. In contrast, the accuracy for the estimation of the degree of stenosis was excellent with 98%. In the case of stroke in progression and completed stroke, histological examination found ulcerations in 72% of patients, whereas ultrasound had detected these ulcerations in only 53%. A significantly higher number of transient ischemic attacks and strokes occurred in patients with soft plaques as compared to asymptomatic patients, who tend to present with hard plaques. Patients with soft plaques seem to have a higher risk of postoperative permanent neurological deficit. Dangerous plaque formation with thrombotic or ulcerous material was not accurately detected by ultrasound. Therefore the risk of embolisation cannot be predicted efficiently by means of duplex scanning, which, however, is especially important for carotid stenting. High intensity transient signals (HITS) were detected by transcranial Doppler during carotid endarterectomy and carotid stenting. A significant higher number of HITS was found in dangerous plaque formations like ulcerations or thrombotic formations. The number of HITS during carotid angioplasty and stenting was eight to ten times higher than in the worst group during operation. CONCLUSION: Due to the insufficient knowledge about the benefit of carotid stenting, these observations are indicating that surgery on the carotid artery is not comparable to interventional treatment and remains the gold standard, until the results of prospective randomized trials will demonstrate an equivalent outcome.