Background and objective The Atlanta classification of acute pancreatitis enabled standardised reporting of research and aided communication between clinicians. Deficiencies identified and improved understanding of the disease make a revision necessary. Methods A web-based consultation was undertaken in 2007 to ensure wide participation of pancreatologists. After an initial meeting, the Working Group sent a draft document to 11 national and international pancreatic associations. This working draft was forwarded to all members. Revisions were made in response to comments, and the web-based consultation was repeated three times. The final consensus was reviewed, and only statements based on published evidence were retained. Results The revised classification of acute pancreatitis identified two phases of the disease: early and late. Severity is classified as mild, moderate or severe. Mild acute pancreatitis, the most common form, has no organ failure, local or systemic complications and usually resolves in the first week. Moderately severe acute pancreatitis is defined by the presence of transient organ failure, local complications or exacerbation of co-morbid disease. Severe acute pancreatitis is defined by persistent organ failure, that is, organ failure >48 h. Local complications are peripancreatic fluid collections, pancreatic and peripancreatic necrosis (sterile or infected), pseudocyst and walled-off necrosis (sterile or infected). We present a standardised template for reporting CT images. Conclusions This international, web-based consensus provides clear definitions to classify acute pancreatitis using easily identified clinical and radiologic criteria. The wide consultation among pancreatologists to reach this consensus should encourage widespread adoption.

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Classification of acute pancreatitis—2012: revision of the Atlanta classification and definitions by international consensus

• Acute pancreatitis is a protean disease capable of wide clinical variation, ranging from mild discomfort to apocalyptic prostration. Moreover, the inflammatory process may remain localized in the pancreas, spread to regional tissues, or even involve remote organ systems. This variability in presentation and clinical course has plagued the study and management of acute pancreatitis since its original clinical description. In the absence of accepted definitions for acute pancreatitis and its complications, it has not been possible to devise a clinical classification system useful for case management. Following 3 days of group meetings and open discussions, unanimous consensus on a series of definitions and a clinically based classification system for acute pancreatitis was achieved by a diverse group of 40 international authorities from six medical disciplines and 15 countries. The proposed classification system will be of value to practicing clinicians in the care of individual patients and to academicians seeking to compare interinstitutional data. (Arch Surg.1993;128:586-590)

https://jamanetwork.com/journals/SURG/articlepdf/595684/archsurg_128_5_019.pdf

A Clinically Based Classification System for Acute Pancreatitis: Summary of the International Symposium on Acute Pancreatitis, Atlanta, Ga, September 11 Through 13, 1992

https://www.spg.pt/wp-content/uploads/2015/11/2013-ACG_Guideline_AcutePancreatitis_September_2013.pdf

American College of Gastroenterology guideline: management of acute pancreatitis.

Background Necrotizing pancreatitis with infected necrotic tissue is associated with a high rate of complications and death. Standard treatment is open necrosectomy. The outcome may be improved by a minimally invasive step-up approach. Methods In this multicenter study, we randomly assigned 88 patients with necrotizing pancreatitis and suspected or confirmed infected necrotic tissue to undergo primary open necrosectomy or a step-up approach to treatment. The step-up approach consisted of percutaneous drainage followed, if necessary, by minimally invasive retroperitoneal necrosectomy. The primary end point was a composite of major complications (new-onset multiple-organ failure or multiple systemic complications, perforation of a visceral organ or enterocutaneous fistula, or bleeding) or death. Results The primary end point occurred in 31 of 45 patients (69%) assigned to open necrosectomy and in 17 of 43 patients (40%) assigned to the step-up approach (risk ratio with the step-up approach, 0.57; 95% confidence interval, 0.38 to 0.87; P = 0.006). Of the patients assigned to the step-up approach, 35% were treated with percutaneous drainage only. New-onset multiple-organ failure occurred less often in patients assigned to the step-up approach than in those assigned to open necrosectomy (12% vs. 40%, P = 0.002). The rate of death did not differ significantly between groups (19% vs. 16%, P = 0.70). Patients assigned to the step-up approach had a lower rate of incisional hernias (7% vs. 24%, P = 0.03) and new-onset diabetes (16% vs. 38%, P = 0.02). Conclusions A minimally invasive step-up approach, as compared with open necrosectomy, reduced the rate of the composite end point of major complications or death among patients with necrotizing pancreatitis and infected necrotic tissue. (Current Controlled Trials number, ISRCTN13975868.)

/pdf/a-step-up-approach-or-open-necrosectomy-for-necrotizing-4fontie42x.pdf

A step-up approach or open necrosectomy for necrotizing pancreatitis

Objective
To determine benefits of conservative versus surgical treatment in patients with necrotizing pancreatitis.

Acute Necrotizing Pancreatitis: Treatment Strategy According to the Status of Infection

https://www.gastrojournal.org/article/0016-5085(86)90579-2/pdf

Bacterial contamination of pancreatic necrosis. A prospective clinical study.

Necrosectomy with postoperative continuous local lavage was performed in a prospective study involving 95 patients with necrotizing pancreatitis. In the same period 567 patients with oedematous-interstitial pancreatitis were treated non-operatively with a hospital mortality rate of 0.7 per cent. In patients with necrotizing pancreatitis the median Ranson criteria score was 4.5 points; operation was required at a median of 7 days after the onset of symptoms because of non-response to conservative treatment. In all, 59 per cent of the patients (56 out of 95) developed extended intrapancreatic parenchymal necrosis, 70 per cent had ascites, and 66 per cent had intra- and extrapancreatic necrosis; 42 per cent of the patients had bacterial infection of the necrotic tissue. For lavage a median of 8 l/24 h of fluid were instilled postoperatively for 25 days (median). The lavage fluid showed high levels of immunoreactive trypsin, phospholipase A2, and endotoxin in the early postoperative period. Hospital mortality rate was 8.4 per cent. Necrosectomy and continuous postoperative lavage can achieve high survival rates in patients with necrotizing pancreatitis. Postoperative local lavage allows the continuous non-operative evacuation of biologically active compounds and devitalized tissue, and avoids damage to remaining vital exocrine and endocrine pancreatic tissue.

Necrosectomy and postoperative local lavage in necrotizing pancreatitis.

One hundred and five of 395 patients with acute pancreatitis were surgically treated in our clinic from 1981 to 1984. Ninety three of these patients were examined with contrast enhanced computed tomography and/or ultrasound and were clinically assessed according to Ranson's objective criteria before operation. At operation, 77 patients showed necrotising pancreatitis and 16 showed biliary acute interstitial pancreatitis. Ninety per cent of the cases with extensive and 79% of those with minor necroses of the pancreas had been demonstrated with contrast enhanced computed tomography. Ultrasound failed to be diagnostic in 24% of the patients due to meteorism; the sensitivity of the diagnostic studies for pancreatic necrosis was 73% regardless of the extent of the process. Using the early objective signs, seven patients with acute interstitial pancreatitis were classified as having a severe attack, whereas 30 patients with necrotising pancreatitis were categorised as mild attacks. We conclude that the contrast enhanced computed tomography is an aid in deciding on conservative or surgical treatment in a case of acute pancreatitis. Ultrasound does not appear to be an adequate method for determining pancreatic necrosis. The early objective signs fail to sufficiently identify the necrotising form of acute pancreatitis.

https://gut.bmj.com/content/gutjnl/27/9/1035.full.pdf

Identification of pancreas necrosis in severe acute pancreatitis: imaging procedures versus clinical staging.

Most publications consider pancreatic abscess a rare complication in acute pancreatitis, occurring with a frequency of only 1%–4% [1–7] Only 103 cases are described in the literature up to 1967 [8] Today, however, pancreatic abscess is gaining increasing importance Although many authors still underestimate its significance, it is now acknowledged to be one of the most dangerous complications [9] and the commonest cause of death in acute pancreatitis [10] It is therefore necessary to develop better methods for the prevention, early diagnosis and therapeutic management of this complication This in turn raises the problem that no generally accepted definition of pancreatic abscess exists to date [11] Where some authors think that only localized collection of pus in the pancreatic or peripancreatic region constitutes an abscess, others define it as any kind of local septic complication in acute pancreatitis, including even bacterially contaminated necrosis without any significant pus formation [10, 12]

Pancreatic Abscess and Infected Pancreatic Necrosis: Different Local Septic Complications in Acute Pancreatitis

In 205 patients with necrotizing pancreatitis, surgery was carried out following failure of medical treatment. Intraoperatively, according to the size of the necrotic area and the weight of the surgically removed necrotic tissue, 79 patients showed a limited pancreatic necrosis, and 126 patients an extended necrotizing process. In 40.4% of 138 patients with bacteriological reports, a bacterial contamination of the pancreatic necrosis was found. The main objective of surgical management was the removal of the necrotic tissue. This was performed with 2-way drainage and postoperative continuous peritoneal and/or local lavage, in a smaller group of patients with inner drainage of the necrosis cavity, and in a few patients with drainage alone. The overall hospital mortality rate was 24.4%. The lowest mortality was achieved in patients treated with necrosectomy and postoperative continuous local lavage (6.0%). In patients with necrosis of approximately 30% of the pancreas, mortality was lower (7.6%) than in patients with a 50% necrosis (24.0%) or in patients with a subtotal/total necrosis (51.0%) (p<0.0001). Formation of extrapancreatic necrosis resulted in a significantly increased mortality rate (p<0.02). In patients with bacterially contaminated necrosis, a mortality rate of 32.1% was found, whereas in patients with a sterile necrosis, mortality was down to 9.8% (p<0.01). Based on the results of this study, we conclude that the clinical course of necrotizing pancreatitis depends essentially on the extent of the necrosis in the pancreas itself, the development of extrapancreatic necrosis, and the bacteriological status of the necrotic area. Adequate surgical management leads to a considerably increased survival rate of patients with necrotizing pancreatitis.

S. Block

Papers

Bacterial contamination of pancreatic necrosis. A prospective clinical study.

Necrosectomy and postoperative local lavage in necrotizing pancreatitis.

Identification of pancreas necrosis in severe acute pancreatitis: imaging procedures versus clinical staging.

Pancreatic Abscess and Infected Pancreatic Necrosis: Different Local Septic Complications in Acute Pancreatitis

Results of surgical treatment of necrotizing pancreatitis.