Perfusion Rate Assessment by Near-infrared Fluorescence in Gastrointestinal Anastomoses

Inclusion Criteria: * Age ≥ 18 * capability of signing informed consent * diagnosis of malignancies of the upper gastrointestinal tract (GI), or malignancies of the lower GI, or malignancies of the hepatobiliary system, refractory ulcerative colitis, or Crohn's disease, or acute, inflammatory, degenerative functional or anatomical disorders * Surgery possible and medically indicated to the diagnosis (esophageal resection, or subtotal or total gastrectomy, or Y-Roux reconstruction, or right or left colonic interposition, or small bowel segment resection, or ileocecal resection, or colectomy, or proctectomy with restorative ileoanal pouch (one or two-stage), or left or right hemicolectomy, or sigmoid resection, or rectal resection (deep anterior resection (TAR)), or proctectomy with colo-anal anastomosis, or abdominoperineal resection, or stoma closure, or pancreaticoduodenectomy Exclusion Criteria: * liver disfunction (MELD score \> 10) * ICG (indocyanine green) specific exclusion criteria as per literature (intolerance to indocyanine green or sodium iodide, iodine allergy, hyperthyroidism, autonomous thyroid adenoma, focal or diffuse autonomies of the thyroid, previously badly tolerated injection of ICG) * pregnancy or breastfeeding