RESUMO
Introduction: Kidney dysfunction is common in patients with aortic stenosis (AS) and correction of the aortic valve by transcatheter aortic valve implantation (TAVI) often affects kidney function. This may be due to microcirculatory changes. Methods: We evaluated skin microcirculation with a hyperspectral imaging (HSI) system, and compared tissue oxygenation (StO2), near-infrared perfusion index (NIR), tissue hemoglobin index (THI) and tissue water index (TWI) in 40 patients undergoing TAVI versus 20 control patients. HSI parameters were measured before TAVI (t1), directly after TAVI (t2), and on postinterventional day 3 (t3). The primary outcome was the correlation of tissue oxygenation (StO2) to the creatinine level after TAVI. Results: We performed 116 HSI image recordings in patients undergoing TAVI for the treatment of severe aortic stenosis and 20 HSI image recordings in control patients. Patients with AS had a lower THI at the palm (p = 0.034) and a higher TWI at the fingertips (p = 0.003) in comparison to control patients. TAVI led to an increase of TWI, but had no uniform enduring effect on StO2 and THI. Tissue oxygenation StO2 at both measurement sites correlated negatively with creatinine levels after TAVI at t2 (palm: ρ = -0.415; p = 0.009; fingertip: ρ = -0.519; p < 0.001) and t3 (palm: ρ = -0.427; p = 0.008; fingertip: ρ = -0.398; p = 0.013). Patients with higher THI at t3 reported higher physical capacity and general health scores 120 days after TAVI. Conclusion: HSI is a promising technique for periinterventional monitoring of tissue oxygenation and microcirculatory perfusion quality, which are related to kidney function, physical capacity, and clinical outcomes after TAVI. Clinical trial registration: https://drks.de/search/de/trial, identifier DRKS00024765.
RESUMO
BACKGROUND: Tumor regression grading (TRG) based on histopathology is the main tool to assess therapy effects after neoadjuvant therapy (NAT) of pancreatic ductal adenocarcinoma (PDAC). However, reliable markers to distinguish therapy effects from pre-existing tumor features are lacking. The aim of this study was the characterization of PDAC after NAT, focusing on the stroma. MATERIAL AND METHODS: Tissue samples from patients resected for PDAC after NAT (n=27) were analyzed. TRG was assessed using the Royal North Shore (RNS) system. Stromal composition was evaluated by Movat's stain. Immunohistochemistry (IH) for Ki-67 and five previously established stroma markers (alpha-Crystallin B, alpha-Smooth muscle actin (alpha-SMA), Neurotrophin-3 (NT-3), SPARC and Tenascin C) was also performed. Results were compared with therapy-naïve PDACs (n=10). RESULTS: Most cases showed a moderate response (RNS 2; 74%), while 15% displayed a poor response (RNS 3), and 11% a good response (RNS 1). No complete response was observed. Poor regression was associated with mucin-rich stroma, while good regression was associated with collagen-rich stroma. Cases with poorer therapy response had significantly higher proliferation. Higher peritumoral staining intensity for alpha-SMA and Tenascin C also showed a trend towards an association with poor regression. CONCLUSIONS: Similar to the stroma in therapy-naïve PDAC, the stroma of PDAC after NAT is heterogeneous. Distinguishing between desmoplastic stroma and therapy-induced fibrosis by single markers is not possible. Movat's pentachrome stain, IH for Ki-67, and to some extent for Tenascin C and alpha-SMA, can help detect poor histopathological response to NAT.