The role of imaging in acute pancreatitis

The Atlanta Classification of acute pancreatitis revisited

BACKGROUND

In a complex disease such as acute pancreatitis, correct terminology and clear definitions are important. The clinically based Atlanta Classification was formulated in 1992, but in recent years it has been increasingly criticized. No formal evaluation of the use of the Atlanta definitions in the literature has ever been performed.

METHODS

A Medline literature search sought studies published after 1993. Guidelines, review articles and their cross-references were reviewed to assess whether the Atlanta or alternative definitions were used.

RESULTS

A total of 447 articles was assessed, including 12 guidelines and 82 reviews. Alternative definitions of predicted severity of acute pancreatitis, actual severity and organ failure were used in more than half of the studies. There was a large variation in the interpretation of the Atlanta definitions of local complications, especially relating to the content of peripancreatic collections.

CONCLUSION

The Atlanta definitions for acute pancreatitis are often used inappropriately, and alternative definitions are frequently applied. Such lack of consensus illustrates the need for a revision of the Atlanta Classification.

The role of percutaneous external drainage in the treatment of fluid collections associated with severe acute pancreatitis. What, when and how to drain?

A súlyos akut pancreatitist kísérő folyadékgyülem-képződéssel járó lokális szövődmények perkután drenázskezelése, főleg steril esetekben, nem széles körben alkalmazott eljárás. Jelen közlemény célja a perkután drenázs indikációjának, technikájának, korlátjainak és eredményének elemzése az irodalom alapján. A perkután drenázskezelés a súlyos akut pancreatitist kísérő akut folyadékgyülem, az akut pseudocysta és a hasnyálmirigytályog, valamint az elfolyósodott nekrózis kezelésében jelentős szerepet játszik. A fertőzött folyadékgyülemek kezelésére a perkután drenázs mint első kezelés ajánlható. A steril akut folyadékgyülem és pseudocysta kezelésében a drenázskezelés, a sterilitás szabályainak fokozott betartása mellett, a iatrogén fertőzés relatív gyakorisága miatt csak komoly panaszokat okozó esetekben ajánlott. Az elfolyósodott steril és szeptikus nekrózis kezelésében a legjobb eredménnyel a 20–30F vastagságú katéterekkel végzett drenázskezelés, a „sinus tract endoscopy” és a laparoszkóppal asszisztált necrectomia kecsegtet. Az esetek több mint 25%-ában a drenázs a konzervatív kezelés mellett a beteg végleges gyógyulásához vezet. Más esetekben a műtét időpontjának prolongálására, a „korai” műtét elkerülésére hasznos eljárás.

Peripancreatic vascular abnormalities complicating acute pancreatitis: contrast-enhanced helical CT findings

OBJECTIVE

To determine the prevalence and morphologic helical computed tomography (CT) features of peripancreatic vascular abnormalities in patients with acute pancreatic inflammatory disease in correlation with the severity of the pancreatitis.

MATERIALS AND METHODS

One hundred and fifty-nine contrast-enhanced helical CT scans of 100 consecutive patients with acute pancreatitis were retrospectively and independently reviewed by three observers. CT scans were scored using the CT severity index (CTSI): pancreatitis was graded as mild (0-2 points), moderate (3-6 points), and severe (7-10 points). Interobserver agreement for both the CT severity index and the presence of peripancreatic vascular abnormalities was calculated (K-statistic). Correlation between the prevalence of complications and the degree of pancreatitis was estimated using Fisher's exact test.

RESULTS

The severity of pancreatitis was graded as mild (n = 59 scans), moderate (n = 82 scans), and severe (n = 18 scans). Venous abnormalities detected included splenic vein (SV) thrombosis (31 scans, 19 patients), superior mesenteric vein (SMV) thrombosis (20 scans, 14 patients), and portal vein (PV) thrombosis (17 scans, 13 patients). Arterial hemorrhage occurred in five patients (6 scans). In our series, no cases of arterial pseudoaneurysm formation were detected. The interobserver agreement range for scoring the degree of pancreatitis and the overall presence of major vascular abnormalities was 75.5-79.2 and 86.2-98.8%, respectively. The presence of the vascular abnormalities in correlation with the severity of pancreatitis was variable.

CONCLUSION

Vascular abnormalities are relatively common CT findings in association with acute pancreatitis. The CT severity index is insufficiently accurate in predicting some of these complications since no statistically significant correlation between their prevalence and the severity of pancreatitis could be established.

The role of ultrasound in biliary and pancreatic diseases

The possibilities and the limits of transabdominal ultrasonography (US) in the diagnosis of bilio-pancreatic diseases are reviewed here in the light of the last 10 years' research. US remains the method of choice for the diagnosis of gallstones and is generally accepted as an initial imaging technique in gallstone complications, such as acute cholecystitis. Moreover the method can be useful for the detection of the biliary complications after laparoscopic cholecystectomy and after liver transplantation. US is still considered the first diagnostic procedure when stones are suspected in the common bile duct. The use of color Doppler can provide a differential diagnosis of gallbladder cancer with respect to other benign inflammatory or polypoid lesions. Color Doppler US allows to detect vascular complications of acute pancreatitis such as pseudoaneurysms. US is still considered useful for the initial screening of the pancreatic cancer. However, for staging other imaging techniques must be employed. With US useful informations are obtained in the diagnosis of cystic tumors of the pancreas and of pancreatic metastases. US is generally of little use for the diagnosis of endocrine tumors.

MR imaging of the pancreas

Current MR imaging technology offers the surgeon diagnostic information about pancreatic diseases. This article reviews the basics of MR imaging formation and the rationale for the different types of imaging sequences that comprise a comprehensive pancreaticobiliary examination. Clinical examples include evaluation of pancreatic neoplasms, acute and chronic pancreatitis, and congenital abnormalities.

Vascular complications in acute pancreatitis assessed by color duplex ultrasonography

We determined the sensitivity of computed tomography and color duplex ultrasonography in the detection and characterization of vascular complications in acute pancreatitis. The relationship of these complications with the etiology and activity of the disease was assessed. In a prospective study, 189 patients with acute pancreatitis seen in the Department of Gastroenterology. Charité Hospital in Berlin over a period of 38 months underwent color duplex ultrasonography every second day for 3 weeks and thereafter at least once a week for 2 months. Dynamic computed tomography was performed within 72 hours after admission, and follow-up computed tomography scans were obtained. In 45 patients (23%), at least temporary thromboses of portal venous vessels were demonstrated by color duplex ultrasonography. The incidence of venous thromboses was 30% in severe acute pancreatitis with fluid collections without necroses and 57% in necrotizing pancreatitis. In 27 of those 45 patients, a formation of collaterals was documented. In 13 patients, arterial pseudoaneurysms were demonstrated. Vascular complications were significantly more frequent in alcohol-induced than in gallstone-induced pancreatitis. Only 62% of all sonographically diagnosed thromboses and only 32% of all collaterals were demonstrated by computed tomography. The prevalence of vascular complications in acute pancreatitis was much higher as suspected. The risk of gastrointestinal bleeding was lower than previously reported. Color duplex sonography is the method of choice for the detection of vascular complications in acute pancreatitis.