on behalf of the guideline group "Functional Somatic Symptoms"* T he German clinical practice guideline on the management of patients with unspecific, functional, and somatoform physical symptoms (1, 2) expired in March 2017. Between November 2016 and July 2018, the guideline was updated and thoroughly revised by a group under the coordination of the German College of Psychosomatic Medicine (Deutsches Kollegium für Psychosomatische Medizin, DKPM) and the German Society of Psychosomatic Medicine and Medical Psychotherapy (Deutsche Gesellschaft für Psychosomatische Medizin und Ärztliche Psychotherapie, DGPM) and in accordance with the requirements of the Association of the Scientific Medical Societies in Germany (Arbeitsgemeinschaft wissenschaftlicher medizinischer Fachgesellschaften, AWMF). Particular attention was paid to userfriendly language and relevance to daily practice. The long version of the guideline and the guideline methods report are available (in German) on the AWMF website (3). The patient guideline is currently undergoing revision. Characterization of the clinical pictureThe term "functional somatic symptoms" refers to a broad spectrum of symptom patterns of greatly varying severity (4-6):• Persistent unspecific symptoms that are burdensome enough for the patient to consult a doctor but are not classified as disease ("medically unexplained symptoms" or "persistent physical symptoms"). These can nevertheless discernibly impair the patient's everyday functioning.• Defined symptom clusters present over an extended period in the form of functional somatic syndromes (such as fibromyalgia syndrome or irritable bowel syndrome). These are mostly associated with a significant limitation of everyday functioning.• Conditions that fulfill the criteria of pronounced (multi)somatoform disorders and the newly defined somatic stress disorders. These presuppose considerable impairment of everyday functioning and are also associated with psychobehavioral symptoms. Functional somatic symptoms as outlined above are to be distinguished from the commonly occurring transitory indispositions that rarely prompt a visit to the doctor and affect everyday functioning only slightly for a limited time, if at all. These are of no medical significance.

Indocyanine green fluorescence angiography allows a perfusion analysis of amputation stumps and therefore a prediction of the expected tissue necrosis. This tool may allow reliable prediction of amputation level.

Purpose: Indocyanine green (ICG) fluorescence angiography is used to evaluate tissue perfusion in many different medical fields. This study aims to evaluate the value of ICG angiography in the determination of tissue perfusion in the PAD lower extremities.Material and methods: In a prospective clinical study, ICG angiography was used to evaluate tissue perfusion and collateralization in 30 PAD patients. The perfusion index and maximum fluorescence intensity (MPI) were calculated as arterial perfusion parameters.Results: Significant differences in the perfusion index were found for the different PAD stages (p < 0.001). Poor collateralization was associated with a significantly lower perfusion index than good collateralization (p = 0.003). A ROC analysis for the perfusion index showed a positive likelihood ratio of 6.00 and a negative likelihood ratio of 0.00 with an area under the curve of 0.949 to discriminate critical and non-critical PAD.Conclusion: ICG angiography is a promising diagnostic tool to quantify tissue perfusion and demonstrate critical limb ischemia and collateralization in lower extremities affected by PAD.