Pancreatic fluid collections prior to intervention: evaluation with MR imaging compared with CT and US

Imaging of acute pancreatitis and its complications

Patients with acute pancreatitis may present with mild or severe disease, the latter comprising a minority of cases but accounting for most of the morbidity and mortality associated with this disease. Contrast-enhanced computed tomography is the mainstay of imaging patients with acute pancreatitis and is widely used in both the community and academic settings. A variety of retroperitoneal morphologic changes are readily depicted, and the correct assessment of these abnormalities is imperative for management. The purpose of this review is to describe the imaging evaluation of patients with acute pancreatitis by using the 1992 Atlanta Symposium classification and definitions to describe local complications depicted on contrast-enhanced computed tomography. Correlation with the proposed revision of Atlanta Symposium definitions set forth by the Acute Pancreatitis Working Group will be discussed.

CT findings of walled-off pancreatic necrosis (WOPN): differentiation from pseudocyst and prediction of outcome after endoscopic therapy

Computed tomography (CT) findings that may differentiate walled-off pancreatic necrosis (WOPN) from pancreatic pseudocyst were investigated. CT examinations performed before endoscopic therapy of pancreatic fluid collection (PFC) in 73 patients (45 WOPN, 28 pseudocysts) were evaluated retrospectively by two radiologists. PFC was evaluated for size, extension to paracolic space, characteristics of wall and internal structure. The pancreas was evaluated for deformity or discontinuity, and pancreatic duct dilation. CT findings that were associated with WOPN or pseudocyst were identified. CT score (number of CT findings associated with WOPN minus number of findings associated with pseudocyst) was calculated for each PFC. PFC was categorized as WOPN or pseudocyst using a CT score threshold. Larger size, extension to paracolic space, irregular wall definition, presence of fat attenuation debris in PFC, pancreatic deformity or discontinuity (P < 0.05-0.0001) were findings associated with WOPN. Presence of pancreatic duct dilation was associated with pseudocyst. Using a CT score of 2 or higher as a threshold, CT differentiated WOPN from pseudocyst with an accuracy of 79.5-83.6%. Thus, CT can differentiate WOPN from pseudocysts.

Debridement and drainage of walled-off pancreatic necrosis by a novel laparoendoscopic rendezvous maneuver: experience with 6 cases

BACKGROUND

Walled-off pancreatic necrosis (WOPN) is a known complication of acute and chronic pancreatitis. Indications for treatment of WOPN are infection, a rapid increase in size, pain, or biliary or duodenal obstruction. Endoscopic transgastric treatment of pseudocysts with liquid content is successful in approximately 90% of patients; however, the treatment of WOPN is less satisfactory.

OBJECTIVE

A demonstration of a novel minimally invasive approach to adequately remove and drain pancreatic necrosis.

DESIGN

Between June 2004 and June 2006, a nonrandomized observational study was conducted with 6 consecutive patients. WOPN was treated by a minimally invasive laparoendoscopic rendezvous technique.

SETTING

All patients were examined at the university hospital in Freiburg, Germany.

PATIENTS

Six patients were treated for WOPN of an average diameter of 13 cm (range 9-20 cm). In 5 cases, the WOPN was a consequence of acute pancreatitis; there was 1 case of chronic pancreatitis. The average interval between diagnosis and initial treatment was 14 weeks (range 6-20 weeks).

RESULTS

Conventional surgery was avoided in 5 patients (83%) over a median follow-up of 14 months (range 1.5-27 months). Six endoscopic sessions (range 4-11) were performed during the entire treatment period. One patient needed emergency surgery on day 4 after the intervention for a perforation because of gastric-wall separation from the necrotic cavity. There was 1 lethal gastric variceal bleeding, which occurred when a gastrostomy tube was removed 46 days after the initial treatment.

LIMITATION

The small number of patients.

CONCLUSIONS

In selected cases, minimally invasive laparoendoscopic treatment of WOPN is possible without the need of laparotomy or laparoscopy.

Endoscopic drainage of pancreatic pseudocysts

Pancreatic pseudocysts arise as a complication of acute and chronic pancreatitis, pancreatic trauma, or after surgery. Endoscopic treatment of pancreatic pseudocysts can be achieved using transpapillary and/or transmural (transgastric or transduodenal) approaches with acceptable success rates, complication rates, and recurrence rates. Advantages of endoscopic drainage is the avoidance of external pancreatic fistula.

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.

Update on acute pancreatitis: ultrasound, computed tomography, and magnetic resonance imaging features

Imaging of patients with acute pancreatitis requires an understanding of the subtypes and complications that were defined at the Atlanta symposium in 1992. In the last decade, several new entities have been recognized with important clinical implications. In this article, the radiological aspects of the terminology and classification of acute pancreatitis are reviewed and new entities are clarified. The roles of ultrasound, computed tomography, and magnetic resonance imaging in the diagnosis and evaluation of acute pancreatitis and its complications are discussed and the limitations of each imaging technique, when interpreting pancreatic and peripancreatic inflammatory disease, are addressed.

Prospective evaluation of nonenhanced MR imaging in acute pancreatitis

PURPOSE

To compare the value of nonenhanced (NE) magnetic resonance imaging (MRI) (NE-MRI) with contrast-enhanced (CE) computed tomography (CT) (CE-CT) scan in assessing acute pancreatitis (AP) and in evaluating the severity index (SI) with clinical outcome.

MATERIALS AND METHODS

Patients with AP were prospectively investigated by CE-CT scan and NE-MRI on admission. MRI was performed with fat-saturated T1-weighted imaging, T2-weighted imaging, and MR cholangiopancreatography (MRCP). Balthazar's grading system was used to evaluate the NE-MRI severity index (CTSI, MRISI) and it was compared to the clinical outcome.

RESULTS

A total of 90 patients (median age = 55 years) were included in the study. AP was of biliary etiology in 37 patients (41%). On admission, AP was assessed as grade III by CTSI in four patients (4%), whereas 19 patients were classified grade III by MRISI. The coefficient correlation between CTSI and MRISI was good, with r = 0.6 (P < 0.001). Considering CE-CT scan as the gold standard, sensitivity (Sn), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) of NE-MRI for detecting severe AP based on imaging criteria were 100%, 82.6%, 100%, and 21%, respectively. NE-MRI discriminates normal pancreatic parenchyma from edema and necrosis with a correlation between morbidity (P < 0.008).

CONCLUSION

NE-MRI seems to be a reliable method of staging AP severity in comparison to CE-CT scan.

Toward an update of the atlanta classification on acute pancreatitis: review of new and abandoned terms

OBJECTIVES

The 1992 Atlanta classification is a clinically based classification system that defines the severity and complications of acute pancreatitis. The purpose of this review was to assess whether the terms abandoned by the Atlanta classification are really discarded in the literature. The second objective was to review what new terms have appeared in the literature since the Atlanta symposium.

METHODS

We followed a Medline search strategy in review and guideline articles after the publication of the Atlanta classification. This search included the abandoned terms: "phlegmon," "infected pseudocyst," "hemorrhagic pancreatitis," and "persistent pancreatitis."

RESULTS

A total of 239 publications were reviewed, including 10 guideline articles and 42 reviews. The abandoned terms "hemorrhagic pancreatitis" and "persistent pancreatitis" are hardly encountered, in contrast, both "infected pseudocyst" and "phlegmon" are frequently used, and several authors question their abandonment. New terminology in acute pancreatitis consists of "organized pancreatic necrosis," "necroma," "extrapancreatic necrosis," and "central gland necrosis."

CONCLUSIONS

This review demonstrates that the Atlanta classification is still not universally accepted. Several abandoned terms are frequently used, and new terms have emerged that describe manifestations in acute pancreatitis that were not specifically addressed during the Atlanta symposium.

Peroral endoscopic drainage/debridement of walled-off pancreatic necrosis

BACKGROUND

Experience with minimal access, transoral/transmural endoscopic drainage/debridement of walled-off pancreatic necrosis (WOPN) after necrotizing pancreatitis is limited. We sought to determine outcome using this technique.

METHODS

Retrospective analysis.

RESULTS

From 1998 to 2006, 53 patients underwent transoral/transmural endoscopic drainage/debridement of sterile (27, 51%) and infected (26, 49%) WOPN. Intervention was performed a median of 49 days (range, 20-300 days) after onset of acute necrotizing pancreatitis. A median of 3 endoscopic procedures/patient (range, 1-12) were performed. Twenty-one patients (40%) required concurrent radiologic-guided catheter drainage of associated or subsequent areas of peripancreatic fluid and/or WOPN. Twelve patients (23%) required open operative intervention a median of 47 days (range, 5-540) after initial endoscopic drainage/debridement, due to persistence of WOPN (n = 3), recurrence of a fluid collection (n = 2), cutaneous fistula formation (n = 2), or technical failure, persistence of pancreatic pain, colonic obstruction, perforation, and flank abscess (n = 1 each). Final outcome after initial endoscopic intervention (median, 178 days) revealed successful endoscopic therapy in 43 (81%) and persistence of WOPN in 10 (19%). Preexistent diabetes mellitus, size of WOPN, and extension of WOPN into paracolic gutter were significant predictive factors for need of subsequent open operative therapy.

CONCLUSIONS

Successful resolution of symptomatic, sterile, and infected WOPN can be achieved using a minimal access endoscopic approach. Adjuvant percutaneous drainage is necessary in up to 40% of patients, especially when WOPN extends to paracolic gutters or pelvis. Operative intervention for failed endoscopic treatment is required in about 20% of patients.

Treatment of pancreatic pseudocysts, pancreatic necrosis, and pancreatic duct leaks

Pancreatic pseudocysts arise as a complication of acute and chronic pancreatitis or pancreatic trauma (including postsurgical). Pancreatic necrosis occurs following severe pancreatitis and may evolve into an entity termed organized pancreatic necrosis that is endoscopically treatable. Pancreatic duct leaks are frequently seen in relation to pseudocysts and necrosis. Alternatively, pancreatic duct leaks may present with pleural effusions, ascites, or after pancreatic surgery or percutaneous drainage. Endoscopic treatment of pancreatic fluid collections and pancreatic duct leaks can be achieved using transpapillary and/or transmural stent placement.

Ultrasound-guided interventional radiology in critical care

Ultrasound-guided intervention is becoming an increasingly popular and valuable tool in the critical care setting. In general, image-guided procedures can expedite wait times and increase the accuracy, safety, and efficacy of many procedures commonly performed within intensive care units. In the intensive care unit setting, ultrasound has particular advantages over other imaging modalities such as computed tomography and fluoroscopy, including real-time visualization, portability permitting bedside procedures, and reduced exposure to nephrotoxic contrast agents. We review the technical and procedural aspects of a number of ultrasound-guided interventions appropriate for critical care patients. These include central venous catheter deployment, thoracentesis, paracentesis, and drainage of a wide variety of abscesses, and percutaneous nephrostomy, percutaneous cholecystectomy, and inferior vena cava filter placement. Although we believe ultrasound is significantly underutilized in critical care today, we anticipate that with the improvement of ultrasound technology and the innovation of new ultrasound-guided procedures, the role of ultrasound in the intensive care unit will continue to expand, with bedside ultrasound-guided interventions increasingly becoming the norm.

Cross-Sectional Imaging in Acute Pancreatitis

Acute pancreatitis is a common disease with potentially serious outcomes. Multiple imaging modalities can be used to evaluate the disease process and its associated complications. Familiarity with the pathogenesis of this disease, indications for imaging, imaging protocols, staging systems, and the strengths and weaknesses of various modalities will help the radiologist optimize patient care.

Pancreatic-fluid collections: a randomized controlled trial regarding stent removal after endoscopic transmural drainage

BACKGROUND

Endoscopic transmural drainage is obtained by creating a communication between the intestinal tract and the pancreatic-fluid collection, and then inserting 1 or more stents. Collection recurrence after therapy is noted in 10% to 30% of cases. It is not known whether leaving the stents in position reduces recurrence rates.

OBJECTIVE

To test the hypothesis that patients who have undergone previous successful pancreatic-collection drainage and whose stents are retrieved have higher recurrence rates.

DESIGN

Randomized controlled trial.

SETTING

Tertiary referral center.

PATIENTS

During a period of 27 months, 46 of 77 patients who had undergone endoscopic transmural drainage for pancreatic collections met inclusion or exclusion criteria, and 28 of these patients were randomized.

INTERVENTIONS

Fifteen patients were assigned to group A, whose stents were left in place, and 13 were assigned to group B, whose stents were removed after collection resolution. The remaining 18 patients, who were not randomized, also had their stents left in place. All 46 patients were similarly followed.

MAIN OUTCOME MEASUREMENT

Recurrence of the same pancreatic collection that required therapy.

RESULTS

All patients were followed for a median period of 14 months (interquartile range, 8.2-22 months) after treatment. The primary end point was reached in 5 patients in group B (stent retrieval), as opposed to none in group A (P = .013). Moreover, no recurrence was observed in the remaining 18 nonrandomized patients.

LIMITATIONS

Small sample size.

CONCLUSIONS

In patients who underwent successful transmural drainage of pancreatic collections, stent retrieval was associated with higher recurrence rates.

Feasibility of minimally invasive approaches in patients with infected necrotizing pancreatitis

Background

Minimally invasive procedures to treat infected necrotizing pancreatitis (INP) are gaining popularity. The proportion of patients suitable for this approach remains unknown.

Methods

Preoperative computed tomography (CT) scans were reviewed from 106 consecutive patients who had surgery for INP between 2000 and 2003 in 11 Dutch hospitals. Collections related to the pancreas were classified according to their distance from the left abdominal wall. Five radiologists judged ‘accessibility’ for drain placement and the likelihood that there was a fluid component that would drain (‘drainability’). Agreement between radiologists was determined.

Results

CT scans of 80 (75 per cent) patients were available (59 men; age range 29–80 years). The median interval between hospital admission and preoperative CT scan was 20 days. In 55 (69 per cent) patients, the lateral border of the collection was less than 5 cm from the left abdominal wall. Placement of a drain was deemed feasible in 67 (84 (range 77–89) per cent) patients; mean(s.d.) kappa 0·428(0·096). In 45 (56 per cent) patients, a drain could be placed through the left retroperitoneum. In 43 (54 (range 49–82) per cent) patients, collections were judged to contain a drainable fluid component. Interobserver agreement on ‘drainability’ was poor, mean(s.d.) kappa 0·289(0·101).

Conclusion

Most peripancreatic collections in INP were considered accessible to a minimally invasive approach.

IRM et maladies pancréatiques

Magnetic resonance (MR) imaging of the pancreas has undergone a major change because it can provide noninvasive images of the pancreatic ducts and the parenchyma. MR cholangiopancreatography (MRCP) enables detection of anatomic variants such as pancreas divisum. Although contrast material-enhanced CT is still considered the gold standard in acute pancreatitis and for the detection of calcifications in chronic pancreatitis, MR imaging and secretin-enhanced MRCP are useful in evaluating pseudocysts and pancreatic disruption. The role of MR is still debated in pancreatic neoplasms except the cystic lesions where MR imaging provides critical information regarding the lesion's content and a possible communication with the pancreatic ducts. MRCP and MR of the pancreas are also useful in identifying other pancreatic diseases such as lymphoplasmocytic pancreatitis and groove pancreatitis.

CT Imaging of a Pancreatic Pseudocyst: Clinical and Anatomic Implications

We report the case of a 42-year-old man with a large pancreatic pseudocyst, the presence of which was not suspected upon initial presentation. This case provides an example of when imaging may be useful for the detection of pancreatitis and its complications. It also demonstrates classic pseudocyst localization to the lesser sac and left anterior pararenal space. The unusually large size of this pseudocyst provides a clear delineation of retroperitoneal fascial planes and an illustration of possible clinical consequences of mechanical obstruction by pseudocyst.

Describing computed tomography findings in acute necrotizing pancreatitis with the Atlanta classification: an interobserver agreement study

OBJECTIVES

The 1992 Atlanta classification is a clinically based classification system that defines the severity and complications of acute pancreatitis. A study was undertaken to assess the interobserver agreement of categorizing peripancreatic collections on computed tomography (CT) using the Atlanta classification.

METHODS

Preoperative contrast-enhanced CTs from 70 consecutive patients (49 men; median age, 59 years; range, 29-79 years) operated for acute necrotizing pancreatitis (2000-2003) in 11 hospitals were reviewed. Five abdominal radiologists independently categorized the peripancreatic collections according to the Atlanta classification. Radiologists were aware of the timing of the CT and the clinical condition of the patient. Interobserver agreement was determined.

RESULTS

Interobserver agreement among the radiologists was poor (kappa, 0.144; SD, 0.095). In 3 (4%) of 70 cases, the same Atlanta definition was chosen. In 13 (19%) of 70 cases, 4 radiologists agreed, and in 42 (60%) of 70 cases, 3 radiologists agreed on the definition. In 21 cases (30%), 1 or more of the radiologists classified a collection as "pancreatic abscess," whereas 1 or more radiologist used another Atlanta definition.

CONCLUSION

The interobserver agreement of the Atlanta classification for categorizing peripancreatic collections in acute pancreatitis on CT is poor. The Atlanta classification should not be used to describe complications of acute pancreatitis on CT.

Acute interstitial edematous pancreatitis: Findings on non-enhanced MR imaging

AIM: To study the appearances of acute interstitial edematous pancreatitis (IEP) on non-enhanced MR imaging.

METHODS: A total of 53 patients with IEP diagnosed by clinical features and laboratory findings were underwent MR imaging. MR imaging sequences included fast spoiled gradient echo (FSPGR) fat saturation axial T1-weighted imaging, gradient echo T1-weighted (in phase), single shot fast spin echo (SSFSE) T2-weighted, respiratory triggered (R-T) T2-weighted with fat saturation, and MR cholangiopancreatography. Using the MR severity score index, pancreatitis was graded as mild (0-2 points), moderate (3-6 points) and severe (7-10 points).

RESULTS: Among the 53 patients, IEP was graded as mild in 37 patients and as moderate in 16 patients. Forty-seven of 53 (89%) patients had at least one abnormality on MR images. Pancreas was hypointense relative to liver on FSPGR T1-weighted images in 18.9% of patients, and hyperintense in 25% and 30% on SSFSE T2-weighted and R-T T2-weighted images, respectively. The prevalences of the findings of IEP on R-T T2-weighted images were, respectively, 85% for pancreatic fascial plane, 77% for left renal fascial plane, 55% for peripancreatic fat stranding, 42% for right renal fascial plane, 45% for perivascular fluid, 40% for thickened pancreatic lobular septum and 25% for peripancreatic fluid, which were markedly higher than those on in-phase or SSFSE T2-weighted images (P < 0.001).

CONCLUSION: IEP primarily manifests on non-enhanced MR images as thickened pancreatic fascial plane, left renal fascial plane, peripancreatic fat stranding, and peripancreatic fluid. R-T T2-weighted imaging is more sensitive than in-phase and SSFSE T2-weighted imaging for depicting IEP.

Laparoscopic Debridement of Recurrent Pancreatic Abscesses in the Hostile Abdomen

Recurrent necrotizing pancreatitis in the frozen or hostile abdomen remains a challenge. Percutaneous drainage is useful in these cases but often fails if there is significant pancreatic necrosis. We describe a technique for laparoscopic drainage of necrotic pancreas. The preexisting percutaneous drainage tract was sequentially dilated and a working thoracoscope was placed via a Hasson cannula. A pulsatile irrigation system was used to open the cavity for visualization and to wash away obvious necrotic debris. Working sequentially using the irrigation jet flow for debridement and visualization, we opened the entire tract and debrided a majority of the necrotic tissue. A large drainage tube was placed to allow the egress of any residual infection. Three patients to date have been treated with the above technique with no intraoperative complications. All three patients did well initially postoperatively and had adequate drainage. One patient developed a delayed pancreatic pseudocyst. Laparoscopic debridement via percutaneous drainage tract is a useful technique in the hostile abdomen.

Magnetic resonance imaging in the detection of pancreatitis and pancreatic neoplasms

This article presents current magnetic resonance imaging techniques for the diagnosis of acute and chronic pancreatitis and pancreatic neoplasms. It emphasises the need for a comprehensive protocol combining imaging sequences of the pancreatic parenchyma with magnetic resonance angiography and secretin-enhanced magnetic resonance cholangiopancreatography in order to evaluate the full range of pancreatic inflammatory and neoplastic conditions. Imaging characteristics that may indicate a specific diagnosis are discussed.

MR imaging of the pancreas

MR imaging is a valuable tool in the assessment of the full spectrum of pancreatic diseases. MR imaging techniques are sensitive for the evaluation of pancreatic disorders in the following settings: (1) TI-weighted fat-suppressed and dynamic gadolinium-enhanced SGE imaging for the detection of chronic pancreatitis, ductal adeno-carcinoma, and islet-cell tumors; (2) T2-weighted fat-suppressed imaging and T2-weighted breath-hold imaging for the detection of islet-cell tumors;and (3) precontrast breath-hold SGE imaging for the detection of acute pancreatitis. Relatively specific morphologic and signal intensity features permit characterization of acute pancreatitis,chronic pancreatitis, ductal adenocarcinoma, insulinoma, gastrinoma, glucagonoma, microcystic cystadenoma, macrocystic cystadenoma, and solid and papillary epithelial neoplasm. MR imaging is effective as a problem-solving modality because it distinguishes chronic pancreatitis from normal pancreas and chronic pancreatitis with focal enlargement from pancreatic cancer in the majority of cases.MR imaging studies should be considered in the following settings: (1) in patients with elevated serum creatinine, allergy to iodine contrast, or other contraindications for iodine contrast administration; (2) in patients with prior CT imaging who have focal enlargement of the pancreas with no definable mass; (3) in patients in whom clinical history is worrisome for malignancy and in whom findings on CT imaging are equivocal or difficult to interpret; and (4) in situations requiring distinction between chronic pancreatitis with focal enlargement and pancreatic cancer. Patients with biochemical evidence of islet-cell tumors should be examined by MR imaging as the first-line imaging modality because of the high sensitivity of MR imaging for detecting the presence of islet-cell tumors and determining the presence of metastatic disease.

Magnetic Resonance Imaging of the Pancreas: The Future Is Now

MR imaging has made significant advances in recent years, with an increasingly important role in the detection, characterization, and staging of pancreatic diseases. MRI is appealing as a noninvasive imaging modality as it can evaluate the pancreas, the vasculature, and the pancreaticobiliary ducts in a single examination. Advantages of MRI include its excellent soft tissue contrast resolution and anatomic detail and absence of ionizing radiation. This article reviews the utility of MRI and its use not only as a problem-solving tool but its potential use as a primary examination (similar to CT) in a wide variety of pancreatic diseases.

Percutaneous video-assisted necrosectomy for infected pancreatic necrosis

AIMS OF THE STUDY

Percutaneous drainage of infected pancreatic necrosis is not always efficient and morbidity is high with open necrosectomy techniques. Minimally-invasive procedures have been developed to reduce this morbidity. We report our early experience with percutaneous video-assisted necrosectomy.

METHODS

Among 61 patients with acute pancreatitis treated between January 2001 and February 2003, seven developed infected pancreatic necrosis. Six of these seven patients underwent percutaneous video-assisted necrosectomy after failure of radio-guided percutaneous drainage.

RESULTS

One to four sessions of percutaneous video-assisted necrosectomy were required. There was no death. Sepsis control was achieved in all patients. One patient developed postoperative peritonitis due to intraoperative contamination of the peritoneal cavity. Eighteen months after the last necrosectomy, one patient developed a pseudocyst which was successfully cured by percutaneous drainage. One patient developed diabetes mellitus.

CONCLUSION

Early experience in six patients has shown that percutaneous video-assisted necrosectomy is feasible, safe and efficient, in accordance with reports in the literature. Further evaluation is necessary.

Endoscopic management of pancreatic fistula after pancreatic and other abdominal surgery

Post-operative pancreatic fistulae represent a challenge for all the actors in gastroenterology: for surgeons, because they want to prevent and treat conservatively this complication since re-operation is associated with high morbidity and mortality rates; for radiologists, because they have to provide the best staging and informations without any additional risk; and for endoscopists, because endoluminal treatment is emerging as a safe and effective procedure provided it is performed in highly experienced tertiary centres in the setting of a multidisciplinary approach. Herein, we review the definitions, the causes, the staging and the possible options to prevent or treat post-operative pancreatic fistulae. Special attention is paid to the endoscopic management of this complication: including the relief of ductal obstructions, the stenting of leakages and the drainage of bulging or non-bulging fluid collections. Practical problems and issues are clearly outlined as well as the need for future improvements in staging and management of the patients having such complications.

Intra-abdominal infections

Intra-abdominal infections in the hospitalized patient differ from those arising in the community in their clinical presentation, sites of involvement, and characteristic microbiology. They are also associated with greater morbidity and mortality. New onset organ dysfunction, more than acute abdominal pain and tenderness, is the predominant clinical manifestation. Successful management depends on aggressive resuscitation and hemodynamic support, administration of adequate antimicrobial therapy, and the timely use of source control measures appropriate to the clinical situation.

Computed Tomography-guided Drainage of Intra-abdominal Infections

Image-guided percutaneous abscess drainage has become a standard method of treatment of most abdominal abscesses. In most cases, it should be considered the treatment of choice, but there are selected areas and circumstances that require specific approaches and methods. Typical abscesses within solid parenchyma organs or those in the peritoneal spaces can be reliably detected and efficiently drained. Abscesses that are multiple or long and circuitous require careful placement of catheters. Management of the drainage catheters includes irrigation with fluid to minimize accumulations of material that may impair egress of fluid. In selected cases, fibrinolytic agents have proved effective in shortening the drainage times and shortening hospital stays. Some controversial areas such as splenic abscesses, pancreatic abscesses, echinococcal abscesses, and fungal abscesses should only be attempted with careful selection and meticulous technique. Successful treatment is most likely with candid consultation among the various clinical services.

Endoscopic technique for the management of pancreatitis and its complications

Therapeutic endoscopy is now increasingly used to treat gallstone pancreatitis, acute pancreatitis of other aetiologies, chronic pancreatitis and complications associated with acute or chronic pancreatitis. This chapter is a brief review of the endoscopic interventions currently performed in patients with acute or chronic pancreatitis. These interventions include biliary and pancreatic endoscopic sphincterotomy at the major or minor papilla, stricture dilatation on the common bile duct or main pancreatic duct, stent placement in the biliary or pancreatic ducts, stone extraction with or without extracorporeal shock wave lithotripsy, and transmural or transpapillary drainage of pancreatic fluid collections. As most of the studies reported were uncontrolled and retrospective, uncertainties persist with regard to the best approaches for treating the patients concerned. Appropriate patient selection, adequate expertise, and a supporting multidisciplinary infrastructure are essential prerequisites of a high success rate in improving the clinical condition of these patients.

Endoscopic drainage of pancreatic fluid collections and pancreatic necrosis

PFCs are heterogeneous, with different underlying pathology and pathophysiology. Each type of PFC is amenable to drainage, although not in every patient. Collections with only a fluid component that have either apposition to the gastric or duodenal wall demonstrated by CT or communication with the main pancreatic duct demonstrated by pancreatography can be drained endoscopically using transmural or transpapillary approaches, respectively. Collections containing significant amounts of solid debris that are treated endoscopically require placement of an irrigation system to evacuate solid debris. Endoscopists considering endoscopic therapy of a pancreatic collection must identify the type of collection being drained and exclude masqueraders of PFCs such as cystic neoplasms. EUS-guided drainage, if available, may decrease the complications of bleeding and perforation during transmural entry of PFCs. Refinement in endoscopic techniques to improve the safety and studies comparing the efficacy of endoscopic therapy with that of other drainage methods are needed.

Impact on patient outcomes of experience in the performance of endoscopic pancreatic fluid collection drainage

BACKGROUND

Much attention has been focused on the competence to perform endoscopic procedures. The aim of this study was to determine the impact of procedure experience on patient outcomes after endoscopic pancreatic fluid collection drainage.

METHODS

Outcomes for consecutive patients with symptoms from pancreatic fluid collections who were referred for endoscopic transmural and/or transpapillary drainage were analyzed retrospectively. Collections were classified as acute pseudocyst, chronic pseudocyst, and pancreatic necrosis. To assess the impact of endoscopist experience, outcomes for patients who underwent the first 20 procedures were compared with those for patients who had subsequent procedures.

RESULTS

In total, 175 patients underwent pancreatic fluid collection drainage; 40 (23%) acute pseudocyst, 78 (44%) chronic pseudocyst, and 57 (33%) pancreatic necrosis. Procedure complication rates, collection recurrence rates, and patient outcomes after acute pseudocyst drainage were independent of endoscopist experience. There was a dramatic improvement in chronic pseudocyst resolution rates after the first 20 procedures versus subsequent procedures (45% vs. 93%; p = 0.0002) and a reduction in days to resolution (50 days, initial 20 procedures vs. 33.5 days, subsequent procedures; p = 0.05). In patients with pancreatic necrosis, there was a decrease in median hospital stay with greater experience (23 days to 15 days; p = 0.04).

CONCLUSIONS

Resolution of chronic pseudocyst after endoscopic drainage improves markedly with increasing endoscopist experience. Future prospective studies assessing skill acquisition are required to define the minimum number of collection drainage procedures at which competence can be achieved.

Magnetic resonance imaging and magnetic resonance cholangiopancreaticography for diagnosis and pre-interventional evaluation of a fluid thoracic mass

Differential diagnoses of various types of thoracic cystic masses are a prerequisite for appropriate management strategies. Mediastinal pancreatic pseudocysts are rare but life-threatening complications of pancreatitis. They may appear as a thoracic mass on X-rays and need to be differentiated from other lesions. This report demonstrates that magnetic resonance cholangiopancreaticography, which is not included in current algorithms, is a valuable diagnostic tool in such cases. We summarize the advantages and disadvantages of magnetic resonance cholangiopancreaticography and show how pre-interventional identification of pancreatic origin and exclusion of necrotic debris guided the therapeutic management of the patient. However, after 3 weeks of successful percutaneous drainage, infectious complications necessitated surgical intervention.

Gastroscopic-assisted laparoscopic cystogastrostomy in the management of pseudocysts of the pancreas

Once pancreatic pseudocysts become persistent, unresolving, and symptomatic, surgical drainage is mandatory. Between January 1998 and December 2001, we performed five laparoscopic cystogastrostomies for such pseudocysts with the simultaneous use of the gastroendoscope. The mean cyst diameter was 20 cm (range, 18.5-24). In the first four cases, the anterior wall of the stomach was entered through two 10-mm balloon cannulae under gastroscopic guidance. By introducing the laparoscope through one port and a harmonic scalpel through the other, a wide cystogastrostomy was performed. In the fifth case, a modification of the above technique was carried out. A single 10-mm cannula was used to enter the stomach and, with the use of a side-viewing gastroduodenoscope as the camera source, the harmonic scalpel was used to create the cystogastrostomy. The punctures in the wall of the stomach were repaired with endosutures. The gallbladder was removed in all cases. The mean operating time was 110 minutes (range, 92-128) for the combined procedure. There were no postoperative complications, and the mean hospital stay was 4 days. Postoperative follow-up with ultrasonography over a period of 1 year in each case revealed complete resolution of the cyst. Laparoscopic cystogastrostomy using harmonic scalpel under gastroscopic control is an effective and rapid method of surgically managing such lesions.

MR imaging of the pancreas: a practical approach

This article reviews the current practical MRI techniques in assessment of the pancreas. With the comprehensive "one-stop-shopping" approach, the great majority of pancreatic diseases can be detected and characterized by the use of a combination of T1, T2-weighted, MRCP, and fat-suppressed T1-weighted dynamic post-gadolinium SGE sequences. This approach may provide the clinician with information regarding the site, nature, and staging of pancreatic tumor in a single setting. In many institutions worldwide, however, including our own, CT remains the main imaging method for the assessment of acute pancreatic diseases, due largely to its wide availability. MR imaging is reserved for the indications listed above, most importantly, the detection of small and non-organ-deforming pancreatic ductal adenocarcinoma, islet cell tumors, choledocholithiasis and pancreatic duct calculi, cholangiocarcinomas, and in cases of pancreatic head enlargement with no mass discernable on CT.

Current status of imaging in pancreatic diseases

Recent technological developments in multidetector CT allow pancreatic imaging in a single breath-hold, which is especially valuable in obtaining isotropic three-dimensional reformations that improve our ability to provide accurate preoperative vascular mapping. Advanced MR technology allows faster imaging of pancreas, thus facilitating MR cholangiopancreatography. Use of tissue-specific MR contrast agents, endoscopic ultrasound, and positron emission tomography (PET) in pancreatic imaging has evolved considerably. This review article discusses the roles of CT, MR, endoscopic ultrasound, and PET imaging in the pancreas.

Outcome differences after endoscopic drainage of pancreatic necrosis, acute pancreatic pseudocysts, and chronic pancreatic pseudocysts

BACKGROUND

Comparative outcomes after endoscopic drainage of specific types of symptomatic pancreatic fluid collections, defined by using standardized nomenclature, have not been described. This study sought to determine outcome differences after attempted endoscopic drainage of pancreatic fluid collections classified as pancreatic necrosis, acute pseudocyst, and chronic pseudocyst.

METHODS

Outcomes were retrospectively analyzed for consecutive patients with symptoms caused by pancreatic fluid collections referred for endoscopic transmural and/or transpapillary drainage.

RESULTS

Complete endoscopic resolution was achieved in 113 of 138 patients (82%). Resolution was significantly more frequent in patients with chronic pseudocysts (59/64, 92%) than acute pseudocysts (23/31, 74%, p = 0.02) or necrosis (31/43, 72%, p = 0.006). Complications were more common in patients with necrosis (16/43, 37%) than chronic (11/64, 17%, p = 0.02) or acute pseudocysts (6/31, 19%, p = NS). At a median follow-up of 2.1 years after successful endoscopic treatment (resolution), pancreatic fluid collections had recurred in 18 of 113 patients (16%). Recurrences developed more commonly in patients with necrosis (9/31, 29%) than acute pseudocysts (2/23, 9%, p = 0.07) or chronic pseudocysts (7/59, 12%, p = 0.047).

CONCLUSIONS

Successful resolution of pancreatic fluid collections may be achieved endoscopically by an experienced therapeutic endoscopist. Outcomes differ depending on the type of pancreatic fluid collection drained. Further studies of endoscopic drainage of pancreatic fluid collections must use defined terminology to allow meaningful comparisons.

Acute pancreatitis: assessment of severity with clinical and CT evaluation

Treatment of patients with acute pancreatitis is based on the initial assessment of disease severity. Severe pancreatitis occurs in 20%-30% of all patients with acute pancreatitis and is characterized by a protracted clinical course, multiorgan failure, and pancreatic necrosis. Early staging is based on the presence and degree of systemic failure (cardiovascular, pulmonary, renal) and on the presence and extent of pancreatic necrosis. Individual laboratory indexes (markers of pancreatic injury, markers of inflammatory response), while promising, have not yet gained clinical acceptance. Numeric grading systems with sensitivities of about 70% are commonly used today as indicators of organ failure and disease severity. Contrast material-enhanced computed tomography is used in addition to help evaluate local pancreatic morphology and the presence and extent of pancreatic necrosis. Advantages and limitations of the clinical, laboratory, and imaging prognostic indexes are analyzed and discussed.

MR imaging of the pancreas: a pictorial tour

Magnetic resonance (MR) imaging of the pancreas has undergone a major change because of its capability of providing noninvasive images of the pancreatic ducts, cross-sectional images of the parenchyma analogous to computed tomography (CT) images, and angiographic depiction of blood vessels. Recent technical issues include the use of half-Fourier T2-weighted pulse sequences and the administration of secretin for MR cholangiopancreatography (MRCP). Secretin improves pancreatic duct and side-branch delineation and the detection of anatomic variants such as pancreas divisum. It allows monitoring of pancreatic flow dynamics and evaluation of pancreatic exocrine function. Although contrast material--enhanced CT is still considered the standard of reference in severe acute pancreatitis and for the detection of calcifications in chronic pancreatitis, in patients referred for suspicion of pancreatic disease or with recurrent acute pancreatitis, MR imaging and secretin-enhanced MRCP are useful after unenhanced CT suggests the cause of disease. In advanced inflammatory disease, MR imaging and secretin-enhanced MRCP are useful for planning surgery or therapeutic endoscopy and for follow-up studies after therapy. MR imaging in combination with secretin-enhanced MRCP and MR angiography is useful in identifying pancreatic malignancies and in establishing resectability.

Cystic focal liver lesions in the adult: differential CT and MR imaging features

Cystic lesions of the liver in the adult can be classified as developmental, neoplastic, inflammatory, or miscellaneous. Although in some cases it is difficult to distinguish these entities with imaging criteria alone, certain cystic focal liver lesions have classic computed tomographic (CT) and magnetic resonance (MR) imaging features, which are important for the radiologist to understand and recognize. Lesions with such features include simple (bile duct) cyst, autosomal dominant polycystic liver disease, biliary hamartoma, Caroli disease, undifferentiated (embryonal) sarcoma, biliary cystadenoma and cystadenocarcinoma, cystic subtypes of primary liver neoplasms, cystic metastases, pyogenic and amebic abscesses, intrahepatic hydatid cyst, extrapancreatic pseudocyst, and intrahepatic hematoma and biloma. Specific CT and MR imaging findings that are important to recognize are the size of the lesion; the presence and thickness of a wall; the presence of septa, calcifications, or internal nodules; the enhancement pattern; the MR cholangiographic appearance; and the signal intensity spectrum. In addition, access to critical clinical information remains extremely important. The most important clinical parameters defined include age and gender, clinical history, and symptoms. An understanding of the classic CT and MR imaging appearances of cystic focal liver lesions will allow more definitive diagnosis and shorten the diagnostic work-up.

The role of diagnostic radiology in pancreatitis

Acute pancreatitis is a frequent inflammatory and necrotic process of pancreas and peripancreatic field. To detect the presence of infected or sterile necrotic components and hemorrhage of the pancreatic paranchyma is important for therapeutic approach. Chronic pancreatitis is characterized by irreversible exocrine dysfunction, progressive loss of pancreatic tissue and morphological changes of the pancreatic canal. Imaging modalities play a primary role in the management of both acute and cronic pancreatitis. CT and MR imaging confirm the diagnosis and detect the severity of disease. In chronic pancreatitis, MRCP after Secretin administration, Spiral CT and endoscopic US seems to replace diagnostic ERCP. However differentiation of pseudotumor of chronic pancreatitis from the pancreatic carcinoma is difficult with either imaging modalities.

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.

Percutaneous necrosectomy and sinus tract endoscopy in the management of infected pancreatic necrosis: an initial experience

OBJECTIVE

To describe the development of a minimally invasive technique aimed at surgical debridement in addition to simple drainage of the abscess cavity.

SUMMARY BACKGROUND DATA

Surgical intervention for secondary infection of pancreatic necrosis is associated with a death rate of 25% to 40%. Although percutaneous approaches may drain the abscess, they have often failed in the long term as a result of inability to remove the necrotic material adequately.

METHODS

Fourteen consecutive patients with infected necrosis secondary to acute pancreatitis were studied. The initial four patients underwent sinus tract endoscopy along a drainage tract for secondary sepsis after prior open necrosectomy. This technique was then modified to allow primary debridement for proven sepsis to be carried out percutaneously in a further 10 patients. The techniques and initial results are described.

RESULTS

Additional surgery for sepsis was successfully avoided in the initial four patients managed by sinus tract endoscopy, and none died. Of the following 10 patients managed by percutaneous necrosectomy, 2 died. The median inpatient stay was 42 days. There was one conversion for intraoperative bleeding. Eight patients recovered and were discharged from the hospital after a median of three percutaneous explorations. Only 40% of patients required intensive care management after surgery.

CONCLUSIONS

These initial results in an unselected group of patients are encouraging and show that unlike with percutaneous or endoscopic techniques, both resolution of sepsis and adequate necrosectomy can be achieved. The authors' initial impression of a reduction in postoperative organ dysfunction is particularly interesting; however, the technique requires further evaluation in a larger prospective series.

Updates in interventional ultrasonography

Interventional ultrasonography, including diagnostic, therapeutic, and intraoperative interventions, is a rapidly developing field in both human and veterinary medicine. Growing expertise and significant improvements in the technology have contributed to the innovation of numerous ultrasound-assisted procedures. Ultrasound-guided biopsy and fine-needle aspiration are now commonly performed. New techniques and the indications for other procedures such as cavity drainage, indwelling catheter placement, and intraoperative procedures are presented.