[Intraoperative multidimensional visualization]. / Intraoperative mehrdimensionale Visualisierung.

Modern intraoperative techniques of visualization are increasingly being applied in general and visceral surgery. The combination of diverse techniques provides the possibility of multidimensional intraoperative visualization of specific anatomical structures. Thus, it is possible to differentiate between normal tissue and tumor tissue and therefore exactly define tumor margins. The aim of intraoperative visualization of tissue that is to be resected and tissue that should be spared is to lead to a rational balance between oncological and functional results. Moreover, these techniques help to analyze the physiology and integrity of tissues. Using these methods surgeons are able to analyze tissue perfusion and oxygenation. However, to date it is not clear to what extent these imaging techniques are relevant in the clinical routine. The present manuscript reviews the relevant modern visualization techniques focusing on intraoperative computed tomography and magnetic resonance imaging as well as augmented reality, fluorescence imaging and optoacoustic imaging.

[Lymph node metastases in ypT1/2 rectal cancer after neoadjuvant chemoradiotherapy : The Achilles heel of organ-preserving operative procedures?]. / Lymphknotenmetastasen beim ypT1/2-Rektumkarzinom nach neoadjuvanter Radiochemotherapie : Die Achillesferse organerhaltender Operationsverfahren?

BACKGROUND: For patients with rectal cancer and complete remission (ypT0) or with good response and residual tumor restricted only to the bowel wall (ypT1-2) after neoadjuvant chemoradiotherapy (CRT), local excision has been suggested as an alternative to avoid the significant morbidity and functional deficits associated with total mesorectal excision (TME). The aim of this investigation was to investigate the incidence, distribution and tumor-related localization of mesorectal lymph node (LN) metastases in TME specimens with complete remission (ypT0), intramural (ypT1-2) and extramural (ypT3-4) residual tumor tissue. PATIENTS AND METHODS: Specimens of TME from 81 patients with locally advanced rectal cancer (UICC II-III) undergoing neoadjuvant CRT within the phase III German rectal cancer trial CAO/ARO/AIO-04 were prospectively evaluated. The entire mesorectal compartment was microscopically screened after complete paraffin embedding. The number and localization of all detectable LN metastases were documented in relation to the primary tumor. RESULTS: Whereas 50 patients (62 %) had ypT3-4 rectal cancer after neoadjuvant CRT, 20 patients (25 %) presented with residual tumor within the bowel wall (ypT1-2), 11 patients (14 %) had pathological complete remission (ypT0), an average of 28 ± 13.7 LN were detected per specimen and 25 patients (31 %) had residual LN metastases after CRT. Although the incidence of LN metastases was higher in the ypT3-4 group (40 %), 25 % of patients in the ypT1-2 group with intramural residual tumor had a mean number of 2.2 residual LN metastases of which 55 % were located far from the primary lesion in the proximal mesorectum. None of the patients with ypT0 status (complete response) had residual LN metastases. CONCLUSION: Even in patients with good response and post-CRT tumor tissue restricted only to the bowel wall (ypT1-2), there is still a considerable risk for residual LN metastases. Local excision of residual rectal cancer was accompanied by a higher rate of local failure and radical surgery with TME should remain the standard treatment in these patients. To date, valid selection criteria for patients eligible for organ-sparing surgery are still lacking.

Proangiogenic potency of MUC18 in arteriosclerotic disease.

AIM: Stenotic peripheral and dilatative arteriosclerotic diseases have different pathomechanism although associations between both diseases are well known. The adhesion molecule MUC18 is a cell membrane glycoprotein also known as the melanoma cell adhesion molecule. As MUC18 has proangiogenic potency in melanoma and prostate cancer this study investigated the role of MUC18 in patients with stenotic or dilatative arteriosclerotic disease as a putative biochemical marker. METHODS: Using qRT-PCR, Western Blot and immunohistochemistry techniques, the expression of MUC18 in arteriosclerotic arteries from major lower limb amputates (AP, N.=15) as well as specimen from femoral endarterectomies (TEA, N.=20) and in dilatative aortic diseases using abdominal aortic aneurysms (AAA, N.=13) was evaluated. Human visceral arteries without macroscopic arteriosclerosis from liver transplants served as controls (AN, N.=19). RESULTS: MUC18 mRNA and protein expression could be found in AN, AP, TEA and AAA tissues. Immunohistochemical analysis showed that a complete and intact intima was the predominant location of MUC18 expression. Although in stenotic arteriosclerotic disease (AP and TEA) the intima was widely calcified, qRT-PCR analysis showed overexpression compared to normal tissue. Interestingly, MUC18 expression was significantly down-regulated in dilatative compared to stenotic arteriosclerotic disease and normal arteries. CONCLUSION: In peripheral stenotic arteriosclerotic disease the proangiogenic potency of MUC18 may play a role in angiogenesis of collaterals, whereas in dilatative aortic diseases the induction of collaterals is typically not evident. The results support the hypothesis of a role in angiogenesis of MUC18 in stenotic arteriosclerotic disease.