The role of vagal innervation on the early development of postoperative ileus in mice.

BACKGROUND: Postoperative ileus (POI) involves an intestinal inflammatory response that is modulated by afferent and efferent vagal activation. We aimed to identify the potential influence of the vagus nerve on POI by tracking central vagal activation and its role for peripheral inflammatory changes during the early hours after surgery. METHODS: C57BL6 mice were vagotomized (V) 3-4 days prior to experiments, while control animals received sham vagotomy (SV). Subgroups underwent either laparotomy (sham operation; S-POI) or laparotomy followed by standardized small bowel manipulation to induce postoperative ileus (POI). Three hours and 9 h later, respectively, a jejunal segment was harvested and infiltration of inflammatory cells in intestinal muscularis was evaluated by fluorescein isothiocyanate (FITC) avidin and myeloperoxidase (MPO) staining. Moreover, the brain stem was harvested, and central nervous activation was investigated by Fos immunochemistry in both the nucleus of the solitary tract (NTS) and the area postrema (AP). Data are presented as mean ± SEM, and a p < 0.05 was considered statistically significant. KEY RESULTS: Three hour experiments revealed no significant differences between all experimental groups, except MPO staining: 3 h after abdominal surgery, there were significantly more MPO-positive cells in vagotomized S-POI animals compared to sham-vagotomized S-POI animals (26.7 ± 7.1 vs. 5.1 ± 2.4, p < 0.01). Nine hour postoperatively intramuscular mast cells (IMMC) were significantly decreased in the intestinal muscularis of V/POI animals compared to SV/POI animals (1.5 ± 0.3 vs. 5.9 ± 0.2, p < 0.05), while MPO-positive cells were increased in V/POI animals compared to SV/POI animals (713.2 ± 99.4 vs. 46.9 ± 5.8, p < 0.05). There were less Fos-positive cells in the NTS of V/POI animals compared to SV/POI animals (64.7 ± 7.8 vs. 132.8 ± 23.9, p < 0.05) and more Fos-positive cells in the AP of V/POI animals compared to SV/POI animals 9 h postoperatively (38.0 ± 2.0 vs. 13.7 ± 0.9, p < 0.001). CONCLUSIONS AND INTERFERENCES: Afferent nerve signaling to the central nervous system during the development of early POI seems to be mediated mainly via the vagus nerve and to a lesser degree via systemic circulation. During the early hours of POI, the intestinal immune response may be attenuated by vagal modulation, suggesting interactions between the central nervous system and the intestine.

Is the EOS imaging system as accurate as conventional radiography in grading osteoarthritis of the knee?

OBJECTIVES: The EOS imaging system allows for the acquirement of long-leg radiographic images in a standing position without stitching artifacts or projection bias and at a comparatively low-radiation-dose exposure. The aim of our study was to compare the accuracy of EOS images of the lower limb to conventional radiographs (CR) of the knee in a.p. view for the grading of osteoarthritis (OA). METHODS: One hundred forty-two patients who had undergone EOS of the lower limb and radiography of the knee on the same day were included. For the grading of OA, the Kellgren and Lawrence score (KL) score and the Osteoarthritis Research Society International (OARSI) system were used. Additionally, the joint space was measured and compared between the two techniques. EOS images were compared to conventional anteroposterior radiographs of the knee which constitute the gold standard. RESULTS: Measurements of the joint space showed very good intra-class correlation. The calculated weighted kappa for the KL score of EOS versus CR was excellent. The comparison of the different parameters of the OARSI score showed superb weighted kappa scores between 0.9 and 0.96 (α < 0.001) for the parameters osteophytes and joint space narrowing. The parameter deformity showed a good agreement between EOS and radiographs (sensitivity 93.6%; specificity 100%). For the sclerosis parameter, an overall sensitivity of 71.3% and a specificity of 99.3% were calculated. CONCLUSIONS: The grading of OA using the KL score as well as the quantitative assessment of joint space width can be performed on EOS images in a.p. view as reliably as on CR. Subchondral sclerosis of the lateral and medial femur condyle or tibia is sometimes not as evident on EOS images. KEY POINTS: • Grading of OA may be performed as reliably with EOS images in a.p. view as with conventional radiographs in a.p. view. • EOS can be safely used for primary assessment of osteoarthritis of the knee. • In the preoperative setting for knee replacement surgery, conventional radiographs in two or three planes of the knee should still be acquired in addition to long-leg EOS images.

Improved detection of a tumorous involvement of the mesorectal fascia and locoregional lymph nodes in locally advanced rectal cancer using DCE-MRI.

PURPOSE: The prediction of an infiltration of the mesorectal fascia (MRF) and malignant lymph nodes is essential for treatment planning and prognosis of patients with rectal cancer. The aim of this study was to assess the additional diagnostic value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for the detection of a malignant involvement of the MRF and of mesorectal lymph nodes in patients with locally advanced rectal cancer. METHODS: In this prospective study, 22 patients with locally advanced rectal cancer were examined with 1.5-T MRI between September 2012 and April 2015. Histopathological assessment of tumor size, tumor infiltration to the MRF, and malignant involvement of locoregional lymph nodes served as standard of reference. Sensitivity and specificity of detecting MRF infiltration and malignant nodes (nodal cut-off size [NCO] ≥ 5 and ≥ 10 mm, respectively) was determined by conventional MRI (cMRI; precontrast and postcontrast T1-weighted, T2-weighted, and diffusion-weighted images) and by additional semi-quantitative DCE-MRI maps (cMRI+DCE-MRI). RESULTS: Compared to cMRI, additional semi-quantitative DCE-MRI maps significantly increased sensitivity (86 vs. 71% [NCO ≥ 5 mm]/29% [NCO ≥ 10 mm]) and specificity (90 vs. 70% [NCO ≥ 5 mm]) of detecting malignant lymph nodes (p < 0.05). Moreover, DCE-MRI significantly augmented specificity (91 vs. 82%) of discovering a MRF infiltration (p < 0.05), while there was no change in sensitivity (83%; p > 0.05). CONCLUSION: DCE-MRI considerably increases both sensitivity and specificity for the detection of small mesorectal lymph node metastases (≥ 5 mm but < 10 mm) and sufficiently improves specificity of a suspected MRF infiltration in patients with locally advanced rectal cancer.

Long-term quality of life after conservative treatment versus surgery for different stages of acute sigmoid diverticulitis.

PURPOSE: It is controversial whether patients fare better with conservative or surgical treatment in certain stages of acute diverticulitis (AD), in particular when phlegmonous inflammation or covered micro- or macro-perforation are present. The aim of this study was to determine long-term quality of life (QoL) for AD patients who received either surgery or conservative treatment in different stages. METHODS: We included patients treated for AD at the University Hospital Grosshadern, Munich, Germany, between January 1, 2000, and December 31, 2010. Patients were classified by the Hansen and Stock (HS) classification, the modified Hinchey classification, and the German classification of diverticular disease (CDD). Pre-therapeutic staging was based on multidetector computed tomography. Long-term QoL was assessed by the Cleveland Global Quality of Life (CGQL) questionnaire, the Short Form 36 (SF-36), and the Gastrointestinal Quality of Life Index (GIQLI). Data are mean ± SEM. RESULTS: Patients with phlegmonous AD (HS type 2a, Hinchey Ia and CDD 1b, respectively) had a better long-term QoL on the GIQLI when they were operated (78.5 ± 2.5 vs. 70.7 ± 2.1; p < 0.05). Patients with micro-abscess (CDD 2a) had a better long-term QoL on the GIQLI, CGQL, and the "Role Physical" scale of the SF-36 when they were not operated (GIQLI 86.9 ± 2.1 vs. 76.8 ± 1.0; p = 0.10; CGQL 82.8 ± 5.1 vs. 65.3 ± 11.0; p = 0.08; SF-36/Role Physical 100 ± 0.0 vs. 41.7 ± 13.9; p < 0.001). Patients with macro-abscess (CDD 2b) had a better long-term QoL when they were operated (GIQLI 89.3 ± 1.4 vs. 69.5 ± 4.5; p < 0.01; CGQL 80.3 ± 7.6 vs. 60.5 ± 5.8; p < 0.05; SF-36/Role Physical 95.8 ± 4.2 vs. 47.9 ± 13.6; p < 0.001). CONCLUSION: Considering long-term QoL, phlegmonous AD (HS type 2a, Hinchey Ia and CDD 1b, respectively) should be treated conservatively. In patients with covered perforation, abscess size should guide the decision on whether to perform surgery later on or not. In the light of long-term quality of life, patients fare better after elective sigmoid colectomy when abscess size exceeds 1 cm.

Improved assessment of mediastinal and pulmonary pathologies in combined staging CT examinations using a fast-speed acquisition dual-source CT protocol.

OBJECTIVES: To demonstrate the feasibility of fast Dual-Source CT (DSCT) and to evaluate the clinical utility in chest/abdomen/pelvis staging CT studies. METHODS: 45 cancer patients with two follow-up combined chest/abdomen/pelvis staging CT examinations (maximally ±10 kV difference in tube potential) were included. The first scan had to be performed with our standard protocol (fixed pitch 0.6), the second one using a novel fast-speed DSCT protocol (fixed pitch 1.55). Effective doses (ED) were calculated, noise measurements performed. Scan times were compared, motion artefacts and the diagnostic confidence rated in consensus reading. RESULTS: ED for the standard and fast-speed scans was 9.1 (7.0-11.1) mSv and 9.2 (7.4-12.8) mSv, respectively (P = 0.075). Image noise was comparable (abdomen; all P > 0.05) or reduced for fast-speed CTs (trachea, P = 0.001; ascending aorta, P < 0.001). Motion artefacts of the heart/the ascending aorta (all P < 0.001) and breathing artefacts (P < 0.031) were reduced in fast DSCT. The diagnostic confidence for the evaluation of mediastinal (P < 0.001) and pulmonary (P = 0.008) pathologies was improved for fast DSCT. CONCLUSIONS: Fast DSCT for chest/abdomen/pelvis staging CT examinations is performed within 2 seconds scan time and eliminates relevant intrathoracic motion/breathing artefacts. Mediastinal/pulmonary pathologies can thus be assessed with high diagnostic confidence. Abdominal image quality remains excellent. KEY POINTS: • Fast dual-source CT provides chest/abdomen/pelvis staging examinations within 2 seconds scan time. • The sevenfold scan time reduction eliminates relevant intrathoracic motion/breathing artefacts. • Mediastinal/pulmonary pathologies can now be assessed with high diagnostic confidence. • The coverage of the peripheral soft tissues is comparable to single-source CT. • Fast and large-volume oncologic DSCT can be performed with 9 mSv effective dose.

A Novel and Sensitive Approach for the Evaluation of Liver Ischemia-Reperfusion Injury After Liver Transplantation.

OBJECTIVES: The purpose of our study was to evaluate the potential of x-ray propagation-based phase-contrast imaging (PCI) computed tomography (CT) for the detection and characterization of early changes after ischemia-reperfusion (IR) in a standardized rat liver transplantation (LTx) model. MATERIALS AND METHODS: Syngeneic orthotopic liver transplantation was performed in male Lewis rats. Ischemia-reperfusion injury (IRI)-induced changes of liver parenchyma were investigated in a time-dependent manner (2, 16, 24, and 32 hours). X-ray phase-contrast images of formalin-fixated liver specimens were acquired in CT mode by using a voxel size of 8 × 8 × 8 µm. Necrapoptotic cell death was visualized with the TdT-mediated dUTP-biotin nick end labeling technique, and alterations of liver graft microhemodynamics, that is, acinar and sinusoidal perfusion failure, were evaluated by in vivo fluorescence microscopy. RESULTS: Acquired and reconstructed PCI-CT images showed an increase in necrotic liver parenchyma dependent on cold storage time, measuring 5.7% ± 1.6% after 2 hours (comparable to 2.6% ± 0.4% for sham livers), 11.5% ± 2.1% (16 hours; P < 0.05 vs control), 23.0% ± 0.5% (24 hours; P < 0.001 vs control), and 31.3% ± 2.2% (32 hours; P < 0.001 vs control). There were a significant lower number of perfused acini in dependence on increasing cold storage time. The acinar perfusion index reached 0.970 ± 0.006 after 2 hours of cold ischemia (comparable to 0.960 ± 0.009 for sham livers) and declined continuously after 16, 24, and 32 hours cold ischemia (0.58 ± 0.03, 0.49 ± 0.02, 0.41 ± 0.03, each P < 0.0001 vs controls). Comparable results were found for sinusoidal perfusion, reaching 1.8% ± 0.4% of nonperfused sinusoids for 2 hours of cold ischemia and 8.2% ± 0.8% after 16 hours, 18.8% ± 1.4% after 24 hours, and 39.0% ± 2.4% after 32 hours (each P < 0.0001 vs controls). Prolonged cold ischemia was associated with an increasing number of TdT-mediated dUTP-biotin nick end labeling-positive cells (hepatocytes and sinusoidal lining cells), reaching 0.4 ± 0.1 (sham), 0.7 ± 0.4 (2 hours), 6.4 ± 1.1 (16 hours), 2.1 ± 0.3 (24 hours), and 14.7 ± 3.5 (32 hours; P = 0.002) for hepatocytes. CONCLUSIONS: X-ray PCI of histological liver specimens can detect IR-induced tissue necrosis and can provide detailed complementary 3-dimensional information to standard histopathologic findings.