Gastrointestinal stromal tumors:a multidisciplinary challenge

Gastrointestinal stromal tumors(GISTs) are the most common mesenchymal tumors located in the alimentary tract. Its usual manifestation is gastrointestinal bleeding. However, small asymptomatic lesions are frequently detected as incidental finding. Characteristically, most GISTs(> 95%) are positive for the KIT protein(CD117) by IHC staining and approximately 80%-90% of GISTs carry a mutation in the c-KIT or PDGFRA genes. Mutational analysis should be performed when planning adjuvant and neoadjuvant therapy, due to its possible resistance to conventional treatment. The arise of tyrosine kinase inhibitor has supposed a revolution in GISTs treatment being useful as adjuvant, neoadjuvant or recurrence disease treatment. That is why a multidisciplinary approach to this disease is required. The correct characterization of the tumor at diagnosis(the diagnosis of recurrences and the evaluation of the response to treatment with tyrosine kinase inhibitors) is fundamental for facing these tumors and requires specialized Endoscopist, Radiologists and Nuclear Medicine Physician. Surgery is the only potentially curative treatment for suspected resectable GIST. In the case of high risk GISTs, surgery plus adjuvantImatinib-Mesylate for 3 years is the standard treatment. Neoadjuvant imatinib-mesylate should be considered to shrink the tumor in case of locally advanced primary or recurrence disease, unresectable or potentially resectable metastasic tumors, and potentially resectable disease in complex anatomic locations to decrease the related morbidity. In the case of Metastatic GIST under Neoadjuvant treatment, when there are complete response, stable disease or limited disease progression, complete cytoreductive surgery could be a therapeutic option if feasible.

Back-table surgery pancreas allograft for transplantation:Implications in complications

To describe the main aspects of back-table surgery in pancreatic graft and the problems arising from poor technique.Back-table surgery for pancreatic graft is a complex,meticulous and laborious technique on which the success of implant surgery and perioperative results depends.The technique can be described in the following steps:Preparation of the sterile table,ex-situ inspection of the pancreasspleen block,management of the duodenum,identification of the bile duct,preparation of the portal vein,preparation of the own graft arteries and anastomosis to the arterial graft,spleen management and graft preservation prior to implantation in the recipient.A careful inspection of the pancreas-spleen block should be performed.It is important to identify the stump of the main bile duct,the portal vein cuff,and the arrangement of the superior mesenteric artery and splenic artery.The redundant duodenum must be removed.The availability of a good venous cuff facilitates the portal vein anastomosis and the positioning of the graft,two key points to prevent thrombosis.The section line of the arteries must be clean,without atherosclerosis,to prevent arterial thrombosis.The superior and splenic mesenteric arteries are generally separated by dense fibrolymphatic tissue.The artery can be reconstructed by interposing a"Y"graft from the donor iliac artery;or with an end-to-end anastomosis between the splenic artery and the superior mesenteric artery.An exquisite technique of bench work helps to prevent the most feared complications of pancreas transplantation:Thrombosis and graft pancreatitis.