Surgical management of pancreatic necrosis: towards lesser and later

Asian consensus statements on endoscopic management of walled-off necrosis Part 1: Epidemiology, diagnosis, and treatment

Walled-off necrosis (WON) is a relatively new term for encapsulated necrotic tissue after severe acute pancreatitis. Various terminologies such as pseudocyst, necroma, pancreatic abscess, and infected necrosis were previously used in the literature, resulting in confusion. The current and past terminologies must be reconciled to meaningfully interpret past data. Recently, endoscopic necrosectomy was introduced as a treatment option and is now preferred over surgical necrosectomy when the expertise is available. However, high-quality evidence is still lacking, and there is no standard management strategy for WON. The consensus meeting aimed to clarify the diagnostic criteria for WON and the role of endoscopic interventions in its management. In the Consensus Conference, 27 experts from eight Asian countries took an active role and examined key clinical aspects of WON diagnosis and endoscopic management. Statements were crafted based on literature review and expert opinion, employing the modified Delphi method. All statements were substantiated by the level of evidence and the strength of the recommendation. We created 27 consensus statements for WON diagnosis and management, including details of endoscopic procedures. When there was not enough solid evidence to support the statements, this was clearly acknowledged to facilitate future research. Proposed management strategies were formulated and are illustrated using flow charts. These recommendations, which are based on the best current scientific evidence and expert opinion, will be useful for guiding endoscopic management of WON. Part 1 of this statement focused on the epidemiology, diagnosis, and timing of intervention.

Management of acute pancreatitis in Japan: Analysis of nationwide epidemiological survey

Acute pancreatitis (AP) is an acute inflammatory disease of the exocrine pancreas. In Japan, nationwide epidemiological surveys have been conducted every 4 to 5 years by the Research Committee of Intractable Pancreatic Diseases, under the support of the Ministry of Health, Labour, and Welfare of Japan. We reviewed the results of the nationwide surveys focusing on the severity assessment and changes in the therapeutic strategy for walled-off necrosis. The severity assessment system currently used in Japan consists of 9 prognostic factors and the imaging grade on contrast-enhanced computed tomography. By univariate analysis, all of the 9 prognostic factors were associated with AP-related death. A multivariate analysis identified 4 out of the 9 prognostic factors (base excess or shock, renal failure, systemic inflammatory response syndrome criteria, and age) that were associated with AP-related death. Receiver-operating characteristics curve analysis showed that the area under the curve was 0.82 for these 4 prognostic factors and 0.84 for the 9 prognostic factors, suggesting the comparable utility of these 4 factors in the severity assessment. We also examined the temporal changes in treatment strategy for walled-off necrosis in Japan according to the 2003, 2007, and 2011 surveys. Step-up approaches and less-invasive endoscopic therapies were uncommon in 2003 and 2007, but became popular in 2011. Mortality has been decreasing in patients who require intervention for walled-off necrosis. In conclusion, the nationwide survey revealed the comparable utility of 4 prognostic factors in the severity assessment and the increased use of less-invasive, step-up approaches with improved clinical outcomes in the management of walled-off necrosis.

Consensus guidelines on severe acute pancreatitis

This Position Paper contains clinically oriented guidelines by the Italian Association for the Study of the Pancreas (AISP) for the diagnosis and treatment of severe acute pancreatitis. The statements were formulated by three working groups of experts who searched and analysed the most recent literature; a consensus process was then performed using a modified Delphi procedure. The statements provide recommendations on the most appropriate definition of the complications of severe acute pancreatitis, the diagnostic approach and the timing of conservative as well as interventional endoscopic, radiological and surgical treatments.

Early-phase peritoneal drainage and lavage in a rat model of severe acute pancreatitis

PURPOSE

To evaluate the effects of early-phase drainage on the survival rates and pancreatic pathological changes associated with severe acute pancreatitis (SAP) in a rat model.

METHODS

Sprague-Dawley rats were divided into the following groups: SAP model (control), early drainage and delayed drainage. The 24-h survival rates were compared among the groups. In addition, the serum and ascites concentrations of interleukin (IL)-1β, IL-6, IL-8, IL-10 and tumor necrosis factor (TNF)-α were measured, and pancreatic pathological changes were observed.

RESULTS

The survival rate significantly improved in the early drainage group. Compared with that observed in the control group, the serum TNF-α and IL-8 concentrations in the early drainage group decreased, while the serum IL-10 levels increased, and the ascites concentrations of IL-1β, IL-6, IL-8 and TNF-α decreased, while that of IL-10 increased significantly. In the delayed drainage group, only the ascites concentrations of TNF-α decreased. Meanwhile, the pancreatic pathological changes at 3, 6 and 24 h worsened in the early drainage group; however, the pancreatic lesions in the early drainage group were less mild than those seen in the control group.

CONCLUSIONS

Rebalancing the cytokine levels in ascites after early drainage may be a key factor for enhancing the survival rate in rats.

Study on acute recent stage pancreatitis

Acute pancreatitis (AP) is an inflammatory disease of the pancreas which involves the pancreas and surrounding tissue, and systemic inflammation with a characteristic systemic increase of vascular permeability and increased risk of multiple organ dysfunction. Currently, the pathogenesis of AP is fuzzy, and the diagnosis and treatment need to be standardized. Nevertheless, increased knowledge of AP may achieve more thorough understanding of the pathogenesis. The use of further advanced diagnostic tools and superior treatment, potentially will help clinicians to manage AP at an appropriate stage. However, in view of the multi factorial disease and the complex clinical manifestations, the management of patients with AP is also remaining areas for improvement.

Percutaneous minimally invasive necrosectomy following endoscopic transgastric drainage in acute necrotising pancreatitis

A patient who had undergone failed transgastric placement of two cystgastrostomy stents referred to the regional pancreatic unit with ongoing sepsis for further management. Following stabilisation, percutaneous minimally invasive necrosectomy (MIN) was performed. MIN resulted in sustained clinical resolution of the sepsis and normalisation of serum C reactive protein levels. The transgastric drains were removed by MIN and, importantly, the patient did not develop a gastric fistula. To our knowledge, this is the first report of MIN following endoscopic cystgastrostomy stent placement. Pancreatic necrosis progresses from solid to semisolid to liquid states over a period of several months. Transgastric drainage should be reserved for subjects with either a pancreatic abscess or predominantly liquid necrosis reserving MIN for patients with systemic sepsis and those with semisolid necrosis. As increasing strategies to treat pancreatic necrosis become available clinicians must be alert to the development of new complications of these treatments.

Minimally invasive operations for acute necrotizing pancreatitis: comparison of minimally invasive retroperitoneal necrosectomy with endoscopic transgastric necrosectomy

BACKGROUND

A "step-up" approach is currently the treatment of choice for acute necrotizing pancreatitis. Our aim was to evaluate the outcome of minimally invasive retroperitoneal necrosectomy (MINE) and endoscopic transgastric necrosectomy (ETG) and to compare it to open necrosectomy (ONE).

METHODS

Patients with acute pancreatitis admitted to our institution from 1998 to 2010 (n = 334) were identified. From these, patients who underwent either ONE, MINE, or ETG were selected for further analysis. Statistical analysis employed 2-sided Fisher's exact test and Mann-Whitney U-test.

RESULTS

From 2002 to 2010, 32 patients with acute necrotizing pancreatitis were treated by minimally invasive procedures including MINE (n = 14) and ETG (n = 18) or with the classic technique of ONE (n = 30). Time from onset of symptoms to intervention was less for ONE than for MINE or ETG (median, 11 vs 39 vs 54 days; P < .05). The rate of critically ill patients with sepsis or septic shock was greatest in ONE (93%) and MINE (71%) compared with ETG (17%; P < .05). Problems after ONE and MINE were ongoing sepsis (ONE 73% vs MINE 29% vs ETG 11%) and bleeding requiring intervention (ONE 26% vs MINE 21% vs ETG 17%). A specific complication of ETG was gastric perforation into the peritoneal cavity during the procedure (28%), requiring immediate open pseudocystogastrostomy. Laparotomy was necessary in 21% after MINE and 28% after ETG owing to specific complications or persistent infected necrosis. Overall mortality was greatest after ONE (ONE 63% vs MINE 21% vs ETG 6%; P < .05).

CONCLUSION

Morbidity and mortality remains high in acute necrotizing pancreatitis. Operative procedures should be delayed as long as possible to decrease morbidity and mortality. Minimally invasive procedures can avoid laparotomy, but also introduce specific complications requiring immediate or secondary open operative treatment. Minimally invasive procedures require unique expertise and therefore should only be performed at specialized centers.