Johannes Meier

Oral chronic graft-versus-host disease: report from the International Consensus Conference on clinical practice in cGVHD.

Chronic graft-versus-host disease (cGVHD) is a multi-organ disease that occurs post-hematopoietic stem cell transplantation, with the mouth being one of the most frequently affected organs. In 2009, the German–Austrian–Swiss working party on bone marrow and blood stem cell transplantation held a consensus conference to define clinical management of cGVHD. The consensus conference aimed to summarize the literature on diagnosis and topical treatment options for oral cGVHD and to provide recommendations for clinical practice, including routine dental and oral care as well as monitoring for secondary malignancies and bisphophonate-induced osteonecrosis of the jaw.

Specific differences in migratory function of myofibroblasts isolated from Crohn's disease fistulae and strictures.

Background: Recently we found that migration of colonic lamina propria fibroblasts in Crohns disease patients (CD‐CLPF) from inflamed mucosa is significantly reduced as compared to control‐CLPF. The behavior of CD‐CLPFs isolated from fistulae and strictures was now investigated in detail. Methods: Initially migration assays for all CLPF cultures (CD‐CLPF, fibrosis‐CLPF, and fistula‐CLPF) were performed in the modified 48‐well Boyden chamber. Subsequently, for a migration assay more resembling the in vivo situation a 3D matrix model was developed. After seeding of cells into the 3D matrix the CLPF layer was wounded by an ERBIUM:YAG laser leading to circular cell rupture without effect on the extracellular matrix. Results: In the modified Boyden chamber migration of fistula‐CLPF was significantly reduced compared to CD‐CLPF. This was correlated with a decrease in FAK‐protein expression, whereas in migrating fibrosis‐CLPF an increase in FAK‐protein expression, ‐autophosphorylation and migratory potential was found. This was confirmed in the 3D matrix wounding assay: Fistula‐CLPF migrated less than CD‐CLPF, whereas fibrosis‐CLPF migrated significantly more in the 3D matrix wounding assay. Between 1 to 36 hours incubation time fibrosis‐CLPF always displayed increased migration ability as compared to CD‐CLPF. In contrast, fistula‐CLPF migratory potential was always below that of CD‐CLPF. Conclusions: Myofibroblasts isolated from inflamed, fibrostenotic, or fistulized CD mucosa differ in their migratory potential both in the modified Boyden chamber as well as in a 3D matrix model. These different migratory behaviors could be an explanation for impaired or excess wound healing and subsequently for fistula and fibrosis formation. (Inflamm Bowel Dis 2011;)

High resolution contrast-enhanced ultrasound and 3-tesla dynamic contrast-enhanced magnetic resonance imaging for the preoperative characterization of cervical lymph nodes: First results

The reliable detection of cervical lymph node (LN) metastases is the planning basis of a selective neck dissection for patients with oral squamous cell carcinoma (OSCC). The aim of this study was to evaluate whether contrast-enhanced ultrasound (CEUS) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) together are able to improve the preoperative characterisation of LNs. A time intensity curve analysis has been performed using CEUS and DCE-MRI for ten LNs, where one LN has been examined per patient. The studied LNs consist of five with and five without metastases. In CEUS the mean time to peak (TTP) was 18 s (range 13-29 s, standard deviation (SD) ± 7 s) for benign and 12 s (range 9-16 s, SD ± 4 s) for malignant LNs. In DCE-MRI the mean TTP was 27 s (range 18-36 s, SD ± 9 s) for benign and 21 s (range 18-27 s, SD ± 5 s) for malignant LNs. Moreover, the relative signal change with respect to reference tissue was significantly higher for LNs with than for those without metastases in both CEUS and DCE-MRI. A combination of imaging morphology, CEUS and DCE-MRI might be a promising method for a reliable differentiation of benign and malignant LNs.

Simple, fast and reliable perfusion monitoring of microvascular flaps

BACKGROUND Free tissue transfer in head and neck reconstructions has a very high success rate, but thrombotic vessel occlusion is still a serious complication occurring in up to 10% of all cases. Thus, a simple, fast and reliable monitoring system for free flaps would be of advantage. OBJECTIVE The aim of this study was to investigate whether free flap monitoring by measuring perfusion-dependent parameters is a suitable method for discovering vessel thrombosis in free flaps. METHODS 10 patients requiring tissue reconstruction after tumour surgery or because of chronic wounds were included in this study. 10 microvascular flaps were harvested and transplanted. Perfusion was determined by measuring a fluorescent oxygen sensor foil covering the flaps skin surface by means of a USB-handheld fluorescence microscope prototype. The sensor contained an oxygen reservoir which was consumed by the tissue corresponding to the perfusion status of the flap. Measurements were done before explantation, after successful anastomosis and 1 day after surgery. RESULTS Clinically well-perfused grafts showed slope values between 0.07 and 0.27 (mean: 0.18 ± 0.07), and clinically poorly perfused grafts showed slope values between 0.35 and 0.75 (mean: 0.52 ± 0.19). In the present study, we used a threshold slope value of 0.3 for differentiating between well-perfused and poorly perfused flaps. CONCLUSION Flap monitoring via oxygen imaging by means of fluorescent sensor foils appears to be a fast, non-invasive, cost-effective and thus suitable method for analyzing flap perfusion with the additional advantage of aiding decision making on flap revision.

Fatal course of tonsillar squamous cell carcinoma associated with Fanconi anaemia: A mini review

Fanconi anaemia (FA) is a rare genetic syndrome characterized by progressive pancytopenia, variably expressed congenital abnormalities and susceptibility, amongst others, to solid tumours. Early detection by oral health professionals of a pathological process can have a critical impact on the clinical course of that condition. In this paper we report the case of a 27-year-old male patient with tonsillar squamous cell carcinoma (cT4 cN2b cM0 G3) associated with FA. Due to the locally advanced growth of the tumour and the poor systemic condition we ruled out primary surgery and settled for primary radio- and chemotherapy. Given the poor clinical course a focus on the aspect of secondary prevention is reasonable, given that it is known that patients with FA are at higher risk of developing malignancy than the general population. A multi-disciplinary approach is necessary in which the prevention of, surveillance for and the treatment of malignancies are important aspects of management and may improve disease-free survival.

Diffusion-weighted imaging in oral squamous cell carcinoma using 3 Tesla MRI: is there a chance for preoperative discrimination between benign and malignant lymph nodes in daily clinical routine?

Background Preoperative staging of cervical lymph nodes is important to determine the extent of neck dissection in patients with oral squamous cell carcinoma (OSCC). Purpose To evaluate whether a preoperative discrimination of benign and malignant cervical lymph nodes with diffusion-weighted imaging (DWI) (3T) is feasible for clinical application. Material and Methods Forty-five patients with histological proven OSCC underwent preoperative 3T-MRI. DWI (b = 0, 500, and 1000 s/mm2) was added to the standard magnetic resonance imaging (MRI) protocol. Mean apparent diffusion coefficients (ADCmean) were measured for lymph nodes with 3 mm or more in short axis by two independent readers. Finally, these results were matched with histology. Results Mean ADC was significantly higher for malignant than for benign nodes (1.143 ± 0.188 * 10−3 mm2/s vs. 0.987 ± 0.215 * 10−3 mm2/s). Using an ADC value of 0.994 * 10−3 mm2/s as threshold results in a sensitivity of 80%, specificity of 65%, positive predictive value of 31%, and negative predictive value of 93%. Conclusion Due to a limited sensitivity and specificity DWI alone is not suitable to reliably discriminate benign from malignant cervical lymph nodes in daily clinical routine. Hence, the preoperative determination of the extent of neck dissection on the basis of ADC measurements is not meaningful.

Mandibular reconstruction with microvascular re-anastomosed fibular free flaps – Two complementary methods of postoperative transplant monitoring

PURPOSE Evaluation of two complementary methods, i.e. luminescence ratiometric oxygen imaging (LROI) and contrast-enhanced ultrasound (CEUS) for postoperative evaluation of the perfusion of osseocutaneous fibular free flaps used for mandibular reconstructions. PATIENTS AND METHODS 15 patients with microvascular re-anastomosed osseocutaneous fibular flaps were included in this trial. Perfusion of the cutaneous part of the flap was determined by measuring a fluorescent oxygen sensor foil covering the flaps skin surface with a handheld fluorescence-microscope. The sensor contains a reservoir of oxygen that is consumed by the tissue, which corresponds to the perfusion status of a flap. Measurements were done before explantation, after successful anastomosis and 1 day after surgery. Additionally, flap perfusion was qualitatively evaluated by contrast-enhanced ultrasound (CEUS) in 13 out of 15 patients. Ultrasound examinations were carried out with a high resolution linear probe after an intravenous bolus injection of 2.4 ml SonoVue® within the first 14 days after surgery. RESULTS Out of the 15 harvested and transplanted flaps, 3 showed microcirculatory problems on the first postoperative day. All complications were detected by LROI prior to clinical signs. For LROI, we were able to confirm the threshold slope value of 0.3 for differentiating between well perfused and compromised flaps as suggested in our previous study. CEUS showed qualitatively detectable bone perfusion in the 13 measured flaps. 2 flaps that were lost on the second and third postoperative day were also lost for CEUS control. The flap survival rate was 87%, and the complication rate was 33%. CONCLUSION LROI has been proven to deliver reproducible objective results for monitoring cutaneous flaps. In addition, CEUS is a promising method for evaluating the microcirculation of the deeper parts (such as bone) of osseocutaneous flaps. Both methods supplement each other, thus allowing the monitoring of all levels of osseocutaneous flaps.

Luminescence ratiometric oxygen imaging (LROI) in microvascular anastomosed fibular and radial forearm flaps

BACKGROUND In a preliminary trial, we were able to show first promising results in the analysis of perioperative and postoperative perfusion of free flaps by means of a new monitoring system for detecting thrombotic vessel occlusion before clinical signs become evident. OBJECTIVE We investigated whether flap monitoring by measuring perfusion-dependent parameters differs between radial forearm and fibular free flaps and whether a threshold value requiring anastomosis revision could be determined. METHODS 37 radial forearm flaps (RF) and 15 fibular flaps (FF) were harvested and transplanted. Perfusion was determined by measuring a fluorescent oxygen sensor foil covering a flaps skin surface with a handheld fluorescence microscope. The sensor contained an oxygen reservoir, which was consumed by the tissue corresponding to the perfusion status of the flap. Measurements were done before explantation, after successful anastomosis and one day after surgery. RESULTS We found a significant difference (p < 0.005) in the relative transdermal oxygen consumption (RTOC) between clinically well-perfused grafts (RF: mean: 0.13 ± 0.08; FF: mean: 0.15 ± 0.07) and clinically poorly perfused grafts (RF: mean: 0.40 ± 0.09; FF: mean: 0.55 ± 0.28). A threshold RTOC value of 0.3 for differentiating between well-perfused and poorly perfused flaps was confirmed for both RF and FF.

Accuracy in orthognathic surgery─comparison of preoperative plan and postoperative outcome using computer-assisted two-dimensional cephalometry by the Onyx Ceph® system

PURPOSE This retrospective study analyzes deviations between preoperative planning and postoperative outcome in orthognathic surgery using 2D Onyx Ceph®-cephalometric analyzing and planning system. MATERIALS AND METHODS A total of 100 patients with a mean age 25.1 of years were included in this study. In 33 patients a bilateral sagittal split osteotomy and in seven patients a Le Fort I osteotomy was performed. A total of 60 patients were treated by a bimaxillary approach. Onyx Ceph® was used as cephalometric planning software (Onyx Ceph®), followed by mock operations. Postoperative cephalograms were obtained after 3.3 days and compared to preoperative planning cephalograms for sagittal (SNA, SNB, ANB) and vertical (ArGoMe, ML-NSL, NL-NSL) angle measurements. Real and absolute mean deviation were documented. RESULTS Absolute mean deviation (degrees) between postoperative and planned jaw movement was lower for the sagittal parameters SNA (0.58), SNB (1.15) and ANB (1.05) compared to the vertical parameters NL-NSL (1.47), ML-NSL (1.96) and ArGoMe (3.20). SNA, SNB and ANB showed constant deviations independent from the extent of jaw movement. With regard to the vertical parameters ML-NSL, ArGoMe and NL-NSL the extent of the postoperative rotational jaw movement was not as much as planned, particularly for vertical shifts of more than 4°. CONCLUSION By using the 2D Onyx Ceph® cephalometric software for orthognathic surgery, the deviations between planned and actual movements are within an acceptable and predictable range. Planning of extensive vertical alterations may result in greater deviations after surgery.