Post-Operative Acute Pancreatitis After Pancreaticoduodenectomy

Overview

The occurrence of post-pancreatectomy acute pancreatitis (PPAP) can critically impact outcomes after pancreaticoduodenectomy. Although diagnosing a PPAP can be challenging, its identification appears crucial as it can trigger additional morbidity. However, due to the early onset in the perioperative period, the actual spectrum of its early phases has not been systematically explored yet. For this reason, the present study will compare some early biochemical evidence of pancreatic stump damage to morphological changes evident at postoperative imaging. The postoperative evaluation of serum and/or urine pancreatic enzymes and the radiologic assessment are included in everyday clinical practice. However, the timing and the clinical relevance of such findings mostly rely on the single-institution experience. This study aims to characterize PPAP by investigating its early radiologic, biochemical, and clinical spectrum of either local or systemic changes associated.

The occurrence of an acute inflammatory process of the pancreatic parenchyma after pancreatic resections has been reported in the literature, but the actual existence of a clinically evident post-pancreatectomy acute pancreatitis (PPAP), defined as a distinct postoperative complication, has been traditionally challenged or, at least, considered to be a rare event. Emerging evidence, however, defines PPAP as an acute inflammatory/ischemic condition of the pancreatic remnant, able to trigger further postoperative morbidity. The assessment of ischemic damage of the organ subjected to surgery was also evaluated in other scenarios, such as for the post-cardiac surgery myocardial infarction (MI) and the post-neurosurgery stroke. These ischemic complications, besides having well-defined biochemical features, maybe detected early on post-operative magnetic resonance imaging (MRI). The decrease of pancreatic perfusion may, in some instances, lead to an altered signal in diffusion-weighted images (DWI) and apparent diffusion coefficient (ADC) maps. DWI MRI with Intravoxel incoherent motion (IVIM) sequences have also recently emerged as a key tool to provide quantitative estimates of physiological parameters associated with perfusion and permeability in vivo and can provide information on alterations of tissue cellularity, membrane-cell integrity, and the extracellular space. The recent PPAP definition has left some unsolved issues, including the need to investigate the role of lipases as a diagnostic criterion, the actual spectrum of PPAP complications, the proper timing for postoperative radiological evaluation, and the preferred imaging modality for PPAP assessment.