Raman fiber-optical method for colon cancer detection: Cross-validation and outlier identification approach.

Endoscopy plays a major role in early recognition of cancer which is not externally accessible and therewith in increasing the survival rate. Raman spectroscopic fiber-optical approaches can help to decrease the impact on the patient, increase objectivity in tissue characterization, reduce expenses and provide a significant time advantage in endoscopy. In gastroenterology an early recognition of malign and precursor lesions is relevant. Instantaneous and precise differentiation between adenomas as precursor lesions for cancer and hyperplastic polyps on the one hand and between high and low-risk alterations on the other hand is important. Raman fiber-optical measurements of colon biopsy samples taken during colonoscopy were carried out during a clinical study, and samples of adenocarcinoma (22), tubular adenomas (141), hyperplastic polyps (79) and normal tissue (101) from 151 patients were analyzed. This allows us to focus on the bioinformatic analysis and to set stage for Raman endoscopic measurements. Since spectral differences between normal and cancerous biopsy samples are small, special care has to be taken in data analysis. Using a leave-one-patient-out cross-validation scheme, three different outlier identification methods were investigated to decrease the influence of systematic errors, like a residual risk in misplacement of the sample and spectral dilution of marker bands (esp. cancerous tissue) and therewith optimize the experimental design. Furthermore other validations methods like leave-one-sample-out and leave-one-spectrum-out cross-validation schemes were compared with leave-one-patient-out cross-validation. High-risk lesions were differentiated from low-risk lesions with a sensitivity of 79%, specificity of 74% and an accuracy of 77%, cancer and normal tissue with a sensitivity of 79%, specificity of 83% and an accuracy of 81%. Additionally applied outlier identification enabled us to improve the recognition of neoplastic biopsy samples.

Feasibility of a colon capsule overnight procedure followed by colonoscopy.

BACKGROUND AND AIM: Due to limited acceptance of colonoscopy as diagnostic and screening test alternatives are warranted. Colon capsule endoscopy (CCE) has been shown to be a possible filter test, but because of logistical issues a second bowel preparation is usually required, if consecutive colonoscopy is needed. We therefore evaluated the feasibility of a single bowel preparation for both overnight CCE and (therapeutical) colonoscopy thereafter. METHODS: Patients from two university hospitals referred to undergo colonoscopy were prospectively included in a dual centre feasibility study. A polyethylene glycol (PEG) based bowel preparation-schedule with ingestion of a colon capsule endoscopy (CCE) at 10pm and subsequent colonoscopy at about 12am on the next day was investigated. The first generation PillCam colon capsule was used with 4 different preparation protocols containing several prokinetics in different compositions (i. e. metoclopramide, erythromycin, sennosoides). The main endpoint was the proportion of patients who completed both CCE and colonoscopy; secondary endpoints were capsule transit times, amount of colon seen on CCE, bowel cleanliness, sensitivity and specifity of CCE and patients' acceptance. RESULTS: 50 patients between 18 and 75 years were included. The sequence of overnight colon capsule endoscopy and colonoscopy was successfully completed in all but one (one refused colonoscopy). The capsule was excreted during recording time in 86 % of examinations, visualization of the complete colon was possible in 60 %, but adequate colon preparation was achieved in only 45 % irrespective of the regimen used. The preparation regimen consisting of a PEG-solution, erythromycin as prokinetic drug followed by PEG-solution as boost showed the largest proportion of adequate preparations. Overall sensitivity and specificity of CCE for polyps of any size were 65 % and 76 %, respectively. 26 of 30 patients (86.7 %) returned the subjective assessment questionnaire. 23 patients (88 %) reported mild to no discomfort or embarrassment during CCE, whereas 15 patients (58 %) did during the preparation procedure. Drinking the purgative solution was the most inconvenient step in 84 % of cases, drinking the boosts during CCE the second inconvenient step (60 %). CONCLUSION: Overnight CCE-procedure followed by direct capsule-reading is feasible and safe and might avoid repetitive bowel preparation for subsequent colonoscopy. The bowel preparation needs to be improved.

Equal detection rate of cervical heterotopic gastric mucosa in standard white light, high definition and narrow band imaging endoscopy.

BACKGROUND AND AIM: The prevalence of cervical heterotopic gastric mucosa (HGM) of the proximal oesophagus differs widely between studies, perhaps due to examination conditions during endoscopy. In this study we aimed to determine whether narrow band imaging (NBI) or high definition (HD) imaging improves detection of HGM. Possible factors of influence for HGM detection, in particular setting (position, timing, in-/out-patient), examination time and sedation parameters, were analysed. METHODS: Retrospective analysis of 641 consecutive patients who underwent an oesophagogastroduodenoscopy (EGD) by the same, substantially experienced endoscopist between June 2011 and August 2013. The type of endoscope was randomly assigned to patients. RESULTS: A total of 85 patients showed HGM with an overall prevalence of 13.3 %. The detection rate in the HD-NBI group was 18/127 (14.2 %) and in the HD white light (HDWL) group, 15/104 (14.4 %, p = 0.957). The detection rate between standard definition white light (SDWL) endoscopy (52/410, 12.7 %) and HD endoscopy did not differ significantly (33/231, 14.3 %, p = 0.566). Setting, sedation dosage and examination times were equally distributed between study groups. The indication of dysphagia (11.8 % vs. 2.4 % with p = 0.000, respectively) and dyspepsia (19.1 % vs. 10.8 %, p = 0.047, respectively) occurred significantly more often in HGM patients than in the control group. There was no difference in the detection rate depending on HGM size. CONCLUSIONS: The prevalence of HGM in the upper EGD is high and does not differ significantly between the study groups of SDWL, HDWL and HD-NBI under equivalent conditions.

[Improvement of cost allocation in gastroenterology by introduction of a novel service catalogue covering the complete spectrum of endoscopic procedures]. / Verbesserung der Kostenkalkulation in der Gastroenterologie durch Einführung eines neuen Leistungskatalogs für alle endoskopischen Prozeduren.

BACKGROUND: The German hospital reimbursement system (G-DRG) is incomplete for endoscopic interventions and fails to differentiate between complex and simple procedures. This is caused by outdated methods of personnel-cost allocation. METHODS: To establish an up-to-date service catalogue 50 hospitals made their anonymized expense-budget data available to the German-Society-of-Gastroenterology (DGVS). 2.499.900 patient-datasets (2011-2013) were used to classify operation-and-procedure codes (OPS) into procedure-tiers (e.g. colonoscopy with biopsy/colonoscopy with stent-insertion). An expert panel ranked these tiers according to complexity and assigned estimates of physician time. From June to November 2014 exact time tracking data for a total 38.288 individual procedures were collected in 119 hospitals to validate this service catalogue. RESULTS: In this three-step process a catalogue of 97 procedure-tiers was established that covers 99% of endoscopic interventions performed in German hospitals and assigned validated mean personnel-costs using gastroscopy as standard. Previously, diagnostic colonoscopy had a relative personnel-cost value of 1.13 (compared to gastroscopy 1.0) and rose to 2.16, whereas diagnostic ERCP increased from 1.7 to 3.62, more appropriately reflecting complexity. Complex procedures previously not catalogued were now included (e.g. gastric endoscopic submucosal dissection: 16.74). DISCUSSION: This novel service catalogue for GI-endoscopy almost completely covers all endoscopic procedures performed in German hospitals and assigns relative personnel-cost values based on actual physician time logs. It is to be included in the national coding recommendation and should replace all prior inventories for cost distribution. The catalogue will contribute to a more objective cost allocation and hospital reimbursement - at least until time tracking for endoscopy becomes mandatory.

[Hepatitis B associated polyarteriitis nodosa with cerebral vasculitis]. / Hepatitis-B-assoziierte Panarteriitis nodosa mit zerebraler Vaskulitis.

HISTORY AND ADMISSION FINDINGS: A 53-year-old male was admitted with an acute brainstem syndrome. He developed a severe fluctuating psychosis. Because of the worsening neurological symptoms he was admitted to our neurological clinic five months after onset of the disease. On admission he showed signs of a productive psychosis in addition to akinetic-rigid parkinsonism and cerebellar symptoms. INVESTIGATIONS: Laboratory tests revealed a HBeAg-negative hepatitis B. The initial neuroradiolgical studies showed multiple supratentorial and periventricular ischemic and hemorrhagic lesions. MR-angiography and conventional cerebral angiography demonstrated multiple irregularities of the intracranial vessels and vascular occlusions, findings which were compatible with cerebral vasculitis. DIAGNOSIS, THERAPY AND COURSE: The laboratory and neuroradiological studies indicated a hepatitis B-associated polyarteriitis nodosa and cerebral vasculitis. He was given oral immunsuppressive therapy (prednisolone 60 mg daily) and virostatic drug (lamivudine 100 mg daily). When the steroid dosis was reduced to 40 mg prednisolon a severe relapse of the encephalopathy occurred which was treated with the atypical antipsychotic drug risperidon, 3 mg daily, and intravenous methylprednisolone plus plasmaphereses. Later he was given prednisolone (60 mg daily) and lamivudine (100 mg daily) again which has so far stabilized the clinical course. CONCLUSION: The main treatment of the rare hepatitis B-associated polyarteriitis nodosa with cerebral vasculitis consists of oral steroids in combination with antiviral drugs. Depending on the course of the disease an escalating steroid pulse administration and plasmaphereses should be considered.

[Methotrexate-induced pneumonitis in a woman with Crohn's disease]. / Methotrexat-induzierte Pneumonitis bei Morbus Crohn.

HISTORY AND ADMISSION FINDINGS: A 36-year-old woman (BMI 37,2 kg m (-2)) with steroid-dependent Crohn's disease presented with stomatitis (aphthous ulcers), retrosternal pain and dry cough after 10 weeks of methotrexate treatment. INVESTIGATIONS: Initially the C-reactive protein (CRP) was elevated, the blood gas analysis was normal, as were computed tomography (CT) and gastroscopy. Lung function tests showed restrictive partial respiratory failure. As pneumonia was suspected antibiotic treatment with ceftriaxone was started as well as topical antimycotic therapy with amphotericin B. However, within a few days the patient developed severe partial respiratory insufficiency. DIAGNOSIS, TREATMENT AND COURSE: The CT-scan showed extensive ground-glass infiltrates, bronchoalveolar lavage revealed CD3 (+) and CD8 (+) lymphocytosis. Methotrexate-induced pneumonitis was diagnosed. Methotrexate administration was discontinued, high dose steroid application was started and ventilatory support given. These measures achieved full recovery. CONCLUSION: Methotrexate-induced pneumonitis can be a relevant complication in Crohn's disease. Abnormal ventilation is an early sign and should lead to further investigation.