Intraoperative ultrasound imaging in the surgical treatment of congenital hyperinsulinism: prospective, blinded study.

BACKGROUND: In congenital hyperinsulinism (CHI), preoperative prediction of the histological subtype (focal, diffuse, or atypical) relies on genetics and 6-[18F]fluoro-l-3,4-dihydroxyphenylalanine (18F-DOPA) PET-CT. The scan also guides the localization of a potential focal lesion along with perioperative frozen sections. Intraoperative decision-making is still challenging. This study aimed to describe the characteristics and potential clinical impact of intraoperative ultrasound imaging (IOUS) during CHI surgery. METHODS: This was a prospective, observational study undertaken at an expert centre over a 2-year interval. IOUS was performed blinded to preoperative diagnostic test results (genetics and 18F-DOPA PET-CT), followed by unblinding and continued IOUS during pancreatic resection. Characteristics and clinical impact were assessed using predefined criteria. RESULTS: Eighteen consecutive, surgically treated patients with CHI, with a median age of 5.5 months, were included (focal 12, diffuse 3, atypical 3). Focal lesions presented as predominantly hypoechoic, oval lesions with demarcated or blurred margins. Patients with diffuse and atypical disease had varying echogenicity featuring stranding and non-shadowing hyperechoic foci in three of six, whereas these characteristics were absent from those with focal lesions. The blinded IOUS-based subclassification was correct in 17 of 18 patients; one diffuse lesion was misclassified as focal. IOUS had an impact on the surgical approach in most patients with focal lesions (9 of 12), and in those with diffuse (2 of 3) and atypical (2 of 3) disease when the resection site was close to the bile or pancreatic duct. CONCLUSION: Uniform IOUS characteristics made all focal lesions identifiable. IOUS had a clinical impact in 13 of 18 patients by being a useful real-time supplementary modality in terms of localizing focal lesions, reducing the need for frozen sections, and preserving healthy tissue and delicate structures.

[Challenges and opportunities for endoscopic ultrasound in the preoperative diagnosis of topical insulin the pancreas].

Insulinoma in most cases is monohormonal orthoendocrine tumor. This fact limits its searching area by a pancreas. However the insulinoma's clinical picture can be caused by other pathology. Therefore the main task of visual the tumor but also to use all the possibilities of each method for defining type of surgery and avoiding such errors and complications, as pancreatorrhage, damage of bile or pancreatic duct, necrosis of duodenal wall, etc. On the basis of our own experience of endoscopic ultrasound for 61 patients with 66 insulinomas, we have allocated the basic variants of insulinoma ultrasound pictures: hypoechoic, heteroechoic, isoechoic tumor, and also foci without a trustworthy contour. On the basis of the analysis of our own errors we have essentially added the technique, having used multiplane pancreas scanning and biplane tumor scanning. Important points in EUS algorithm are also the following items: detecting tumor relationship to pancreatic surface, distance from the tumor to the ducts, gastrointestinal wall and vessels--for definition of possibility of the tumor enucleation; careful scanning of pancreas even after detecting one tumor--for an exception of multiple tumors, especially at MEN-I; careful scanning of a contour of the gland for an exception of parapancreatic insulinomas; estimation of vascularization not only of the detected tumor and suspicious foci, but also of all the gland--for detection of hypervascularized isoechoic tumors; revealing and the description of focal changes, especially more homoechogeneous in comparison with surrounding parenchyma-- for selection patients for examination by other methods; scanning of zones of possible metastasis. Examination of patients with organic hyperinsulinism demands combined application of two or more techniques. Use of all modern possibilities of endosonography can put this technique on one of the first places in the diagnosis of insulinomas.