Pancreatic abscess and infected pancreatic necrosis. Different local septic complications in acute pancreatitis

Diffusion-Weighted Magnetic Resonance Imaging Is an Ideal Imaging Method to Detect Infection in Pancreatic Collections: A Brief Primer for the Gastroenterologists

Background: The development of infection in pancreatitis significantly increases the mortality rate up to 100% in the absence of any intervention. Therefore, it is extremely important to diagnose these cases at an early stage. The objectives of this study were to assess the diagnostic performance of computed tomography (CT) and diffusion-weighted MR imaging (DW-MRI) in the diagnosis of infection in pancreatic collections.

Materials and methods: Prospective observational study of abdominal collections due to pancreatitis that underwent both CT and DW-MRI from August 2018 to July 2020 were enrolled in the study. The collections were analysed for infections - air foci in CT and diffusion restriction on DW-MRI.

Results: Of the 39 patients recruited in the study, infected collections were present in 17, and 22 cases had sterile collections. On CT, air foci within the collection were present only in seven of the cases in our study (sensitivity 35%, specificity 95.4%, PPV 85.7%, NPV 65.6%). DW-MRI detected infection in all 17 cases (sensitivity 100%, specificity 72.7%, PPV 74%, NPV 100%).

Discussion: Thirteen out of 17 collections suspicious for infection on DW-MR showed microbiological growth on culture examination. We believe that this is likely due to the patient's prior antibiotic use, which might have altered the micro-environment or inflammatory cell and bacterial content of the collection.

Conclusion: DW-MRI is complementary and superior to CT in detecting infection in pancreatic collections. CT may be used to detect disease burden, extent and vascular complication.

Reporting of acute pancreatitis by radiologists-time for a systematic change with structured reporting template

Acute pancreatitis has a wide array of imaging presentations. Various classifications have been used in the past to standardize the terminology and reduce confusing and redundant terms. We aim to review the historical and current classifications of acute pancreatitis and propose a new reporting template which can improve communication between various medical teams by use of appropriate terminology and structured radiology template. The standardized reporting template not only conveys the most important imaging findings in a simplified yet comprehensive way but also allows structured data collection for future research and teaching purposes.

Clinical practice guideline: management of acute pancreatitis

ABSTRACT

There has been an increase in the incidence of acute pancreatitis reported worldwide. Despite improvements in access to care, imaging and interventional techniques, acute pancreatitis continues to be associated with significant morbidity and mortality. Despite the availability of clinical practice guidelines for the management of acute pancreatitis, recent studies auditing the clinical management of the condition have shown important areas of noncompliance with evidence-based recommendations. This underscores the importance of creating understandable and implementable recommendations for the diagnosis and management of acute pancreatitis. The purpose of the present guideline is to provide evidence-based recommendations for the management of both mild and severe acute pancreatitis as well as the management of complications of acute pancreatitis and of gall stone-induced pancreatitis.

Acute Pancreatitis: Work-up and Management

Acute pancreatitis is still a common clinical entity that causes significant morbidity and mortality. The most common etiological associations include chronic al coholism, biliary tract disease, iatrogenic (e.g., endo scopic retrograde cholangiopancreatography-induced), hypertriglyceridemia, and idiopathic varieties. New radiological techniques such as dynamic pancreatog raphy appear to be useful in diagnosing and determin ing the extent of necrotizing pancreatitis. Biochem ical variables such as the C-reactive protein and the trypsinogen-activated peptide seem promising in de tecting severe disease within the first few days of hospi talization. Computed tomographic-guided percutane ous aspiration of phlegmonous pancreatitis may be helpful in differentiating infected from noninfected masses. Although current studies have not identified any pharmacological agent as efficacious in improving sur vival, emergency sphincterotomy and removal of im pacted gallstones in severe gallstone pancreatitis may be beneficial in this regard. Prolonged (i.e., 7 day) perito neal dialysis may reduce the severity of pancreatic sep sis. Surgical drainage of infected fluid collections such as abscesses is a well-accepted adjunct to medical therapy. Surgical necrosectomy for necrotizing pancreatitis, however, which is advocated in some aggressive surgi cal units, is not yet commonplace and its role needs to be determined in controlled studies.

Severe acute pancreatitis: Clinical course and management

Severe acute pancreatitis (SAP) develops in about 25% of patients with acute pancreatitis (AP). Severity of AP is linked to the presence of systemic organ dysfunctions and/or necrotizing pancreatitis pathomorphologically. Risk factors determining independently the outcome of SAP are early multi-organ failure, infection of necrosis and extended necrosis (>50%). Up to one third of patients with necrotizing pancreatitis develop in the late course infection of necroses. Morbidity of SAP is biphasic, in the first week strongly related to early and persistence of organ or multi-organ dysfunction. Clinical sepsis caused by infected necrosis leading to multi-organ failure syndrome (MOFS) occurs in the later course after the first week. To predict sepsis, MOFS or deaths in the first 48-72 h, the highest predictive accuracy has been objectified for procalcitonin and IL-8; the Sepsis-Related Organ Failure Assessment (SOFA)-score predicts the outcome in the first 48 h, and provides a daily assessment of treatment response with a high positive predictive value. Contrast-enhanced CT provides the highest diagnostic accuracy for necrotizing pancreatitis when performed after the first week of disease. Patients who suffer early organ dysfunctions or at risk of developing a severe disease require early intensive care treatment. Early vigorous intravenous fluid replacement is of foremost importance. The goal is to decrease the hematocrit or restore normal cardiocirculatory functions. Antibiotic prophylaxis has not been shown as an effective preventive treatment. Early enteral feeding is based on a high level of evidence, resulting in a reduction of local and systemic infection. Patients suffering infected necrosis causing clinical sepsis, pancreatic abscess or surgical acute abdomen are candidates for early intervention. Hospital mortality of SAP after interventional or surgical debridement has decreased in high volume centers to below 20%.

Severe acute pancreatitis: Clinical course and management

Severe acute pancreatitis (SAP) develops in about 25% of patients with acute pancreatitis (AP). Severity of AP is linked to the presence of systemic organ dysfunctions and/or necrotizing pancreatitis pathomorphologically. Risk factors determining independently the outcome of SAP are early multi-organ failure, infection of necrosis and extended necrosis (> 50%). Up to one third of patients with necrotizing pancreatitis develop in the late course infection of necroses. Morbidity of SAP is biphasic, in the first week strongly related to early and persistence of organ or multi-organ dysfunction. Clinical sepsis caused by infected necrosis leading to multi-organ failure syndrome (MOFS) occurs in the later course after the first week. To predict sepsis, MOFS or deaths in the first 48-72 h, the highest predictive accuracy has been objectified for procalcitonin and IL-8; the Sepsis-Related Organ Failure Assessment (SOFA)-score predicts the outcome in the first 48 h, and provides a daily assessment of treatment response with a high positive predictive value. Contrast-enhanced CT provides the highest diagnostic accuracy for necrotizing pancreatitis when performed after the first week of disease. Patients who suffer early organ dysfunctions or at risk of developing a severe disease require early intensive care treatment. Early vigorous intravenous fluid replacement is of foremost importance. The goal is to decrease the hematocrit or restore normal cardiocirculatory functions. Antibiotic prophylaxis has not been shown as an effective preventive treatment. Early enteral feeding is based on a high level of evidence, resulting in a reduction of local and systemic infection. Patients suffering infected necrosis causing clinical sepsis, pancreatic abscess or surgical acute abdomen are candidates for early intervention. Hospital mortality of SAP after interventional or surgical debridement has decreased in high volume centers to below 20%.

Evolution of lesions of the pancreatic duct following acute pancreatitis associated with a pseudocyst

AIMS

After an episode of acute pancreatitis, there is usually no sequelae; nevertheless cases of ductal stenosis have been reported. The aim of our study was to evaluate the frequency of pancreatic duct lesions after acute pancreatitis complicated by pseudocyst.

PATIENTS AND METHODS

Between 1983 and 2004, 67 patients were admitted for severe acute pancreatitis. Out of these 67 patients, 36 patients were excluded because of chronic pancreatitis (N=12), intraductal papillary mucinous tumors of the pancreas (N=3), carcinoma (N=2), cystadenoma (N=3), alcohol consumption > 40 g/d (N=6), post-traumatic acute pancreatitis (N=3), and a follow-up less than 12 months (N=7).

RESULTS

A stenosis of the main pancreatic duct was observed in 52% (16/31) of patients. This stenosis was isolated in 100% of cases, complete for 69% of them (11/16) and associated with upstream dilatation in 69% of cases (11/16). Although the pseudocyst was located in the body of the pancreas in 7/31 cases (48%), the stenosis was located in the head in 9/16 cases (56%). The predictive criteria of pancreatic duct lesions were complications associated with pseudocyst: extra-luminal compression (P=0.01), and vascular thrombosis (P=0.02).

CONCLUSION

After an episode of acute pancreatitis complicated by pseudocyst, pancreatic duct stenosis is observed in 52% of the cases. These results show that complete resolution of pancreatic abnormalities after acute pancreatitis is not achieved systematically.

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.

The management of suspected pancreatic sepsis

The management of infected pancreatic necrosis is centered on image-guided fine needle aspiration followed by antibiotic therapy that is based on microbiologic culture results. The authors favor targeted antibiotic therapy rather than routine prophylactic antibiotic coverage. Prompt surgical debridement is recommended for patients who have infected necrosis who are suitable operative candidates. Newer surgical, percutaneous, and endoscopic techniques, as well as prolonged antibiotic therapy without intervention, are being evaluated as alternatives to operative debridement. Well-designed prospective trials will help to determine optimal treatment for patients who have infected pancreatic necrosis.

Roles of endotoxin-related signaling molecules in the progression of acute necrotizing pancreatitis in mice

OBJECTIVE

To study the potential roles of lipopolysaccharide (LPS) signaling molecules, LPS-binding protein (LBP), CD14, and Toll-like receptor 4 (TLR4) in mice with acute necrotizing pancreatitis (ANP).

METHODS

The ANP model was made by 7 intraperitoneal injections of cerulein (50 mug/kg) at hourly intervals, challenged by LPS administration of a dose of 5 mg/kg intraperitoneally 5 hours after the first injection of cerulein. Fifty-nine Balb/C mice were divided into 4 groups: group A, ANP control group, n = 18, received physiological saline; group B, anti-LBP group, n = 18, received 200 mug anti-LBP antibody; group C, anti-CD14 group, n = 18, received 20 microg anti-CD14 antibody; group D, anti-TLR4 group, n = 5, received 20 mug anti-TLR4 antibody. All treatments were given at 15 minutes before LPS injection. Serum amylase and lactic dehydrogenase (LDH) were measured. Histologic alteration of the pancreas was evaluated. Expressions of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and intercellular adhesion molecular (ICAM-1) mRNA were determined using reverse transcription polymerase chain reaction (RT-PCR). Myeloperoxidase (MPO) activity in pancreas was also analyzed. Nuclear factor-kappaB (NF-kappaB) p65 subunit was measured by immunohistochemistry and Western blotting.

RESULTS

Pretreatment of animals with anti-CD14 antibody resulted in a significant decrease in serum amylase and LDH levels, reduction of the severity of pancreatic injury, down-regulation of TNF-alpha, IL-1beta, and ICAM-1 mRNA expression, decrease in pancreatic MPO activity, and decrease in NF-kappaB expression compared with ANP control mice. In contrast, mice pretreated with anti-LBP antibody or anti-TLR4 antibody resulted in increasing of serum amylase and LDH levels, aggravation of the severity of necrosis and inflammation in pancreas, up-regulation of TNF-alpha, IL-1beta, and ICAM-1 mRNA expression, increasing of pancreatic MPO activity, and up-regulation of NF-kappaB expression compared with ANP control mice.

CONCLUSIONS

(1) LBP per se possesses a protective effect on ANP. It could facilitate clearance of endotoxin. (2) CD14 plays a crucial intermediate role in the progression of ANP. (3) TLR4, the essential transducer of LPS responses, may act independently of LPS. The antibody against TLR4 may mimic endotoxin and induce activation of downstream cytokines. For implication, recombinant LBP, anti-CD14 antibody, or silent TLR4 might alleviate the progression of ANP.

Factors influencing mortality in acute pancreatitis: can we alter them?

Severe acture pancreatitis (SAP), a multisystem disease, is characterized by multiple organ system failure and additionally by local pancreatic complications such as necrosis, abscess, or pseudocyst. The rate of mortality in SAP, which is about 20% of all cases of acute pancreatitis (AP), may be as high as 25%, as in infected pancreatic necrosis. The factors that influence mortality in different degrees are various. Etiology for the episode, age, sex, race, ethnicity, genetic makeup, severity on admission, and the extent and nature of pancreatic necrosis (sterile vs. infected) influence the mortality. Other factors include treatment modalities such as administration of prophylactic antibiotics, the mode of feeding (TPN vs. enteral), ERCP with sphincterotomy, and surgery in selected cases. Epidemiological studies indicate that the incidence of AP is increasing along with an increase in obesity, a bad prognostic factor. Many studies have indicated a worse prognosis in idiopathic AP compared to pancreatitis induced by alcoholism or biliary stone. The risk for SAP after ERCP is the subject of extensive study. AP after trauma, organ transplant, or coronary artery bypass surgery is rare but may be serious. Since Ranson reported early prognostic criteria, a number of attempts have been made to simplify or add new clinical or laboratory studies in the early assessment of severity. Obesity, hemoconcentration on admission, presence of pleural effusion, increased fasting blood sugar, as well as creatinine, elevated CRP in serum, and urinary trypsinogen levels are some of the well-documented factors in the literature. The role of appropriate prophylactic antibiotic therapy although still is highly controversial, in properly chosen cases appears to be beneficial and well accepted in clinical practice. Early enteral nutrition has gained much support and jejunal feeding bypassing the pancreatic stimulatory effect of it in the duodenum is desirable in selected cases. The limited role for endoscopic sphincterotomy in patients with demonstrated dilated CBD with impacted stone and evidence of impending cholangitis is well documented. Surgery in AP other than for removal of the gallbladder is often limited to infected pancreatic necrosis, pseudocysts, and pancreatic abscess and in some cases of traumatic pancreatitis with a ruptured duct system. The progress in the understanding of the role of cytokines will over us opportunities to use immunomodulatory therapies to improve the outcome in SAP.

Aggressive endoscopic therapy for pancreatic necrosis and pancreatic abscess: a new safe and effective treatment algorithm (videos)

BACKGROUND

Pancreatic necrosis and pancreatic abscess are severe complications of acute pancreatitis. Surgery is associated with significant morbidity and mortality in these critically ill patients. Endoscopic therapy has the potential to offer a safer and more effective alternative treatment modality. However, its role needs to be further investigated.

METHODS

This is a retrospective study of the outcome of consecutive patients with pancreatic necrosis and pancreatic abscess, all unfit to undergo surgery, who underwent a new aggressive endoscopic approach. The treatment includes (1) synchronous EUS-guided multiple transmural and/or transpapillary drainage procedures followed by balloon dilation of the cystogastrostoma or cystoduodenostoma, (2) daily endoscopic necrosectomy and saline solution lavage, and (3) sealing of pancreatic fistula by N-butyl-2-cyanoacrylate.

RESULTS

Pancreatic necrosis and pancreatic abscesses were successfully drained in 13 patients, thus avoiding emergency surgery as an initial treatment. Surgery was completely avoided in 9 patients over a median follow-up of 8.3 months (range 3-81 months). Surgery was combined with endoscopic therapy in one patient because of abscess extension into the right paracolic gutter, which was not manageable by endoscopic drainage. Because of the "disconnected-duct syndrome," two patients later developed recurrent pseudocysts and underwent elective surgery. Complications included minor bleeding after balloon dilation and necrosectomy in 4 cases, which were self limiting or controlled endoscopically.

CONCLUSIONS

This aggressive endoscopic approach shows promising results. It expands the potential for endoscopic treatment in patients with pancreatic necrosis and/or pancreatic abscess.

Antibiotic prophylaxis in severe acute pancreatitis

Severe acute pancreatitis is considered to be a subgroup of acute pancreatitis with the development of local and/or systemic complications. A significant correlation exists between the development of pancreatic necrosis, the frequency of bacterial contamination of necrosis and the evolution of systemic complications. Bacterial infection and the extent of necrosis are determinants for the outcome of severe acute pancreatitis. The late course of necrotizing pancreatitis is determined by bacterial infection of pancreatic and peripancreatic necroses. Mortality increases from 5-25% in patients with sterile necrosis to 15-28% when infection has occurred. The use of prophylactic antibiotics has been recommended in patients with necrotizing pancreatitis. Several controlled clinical trials demonstrated a significant reduction in pancreatic infections or a significant reduction of hospital mortality. However, the results of these clinical trials are controversial and not convincing. Recently, the largest randomized placebo-controlled, double-blind trial has been able to demonstrate that antibiotic prophylaxis with ciprofloxacin and metronidazole has no beneficial effects with regard to the reduction of pancreatic infection and the decrease of hospital mortality. The clinical data from this placebo-controlled trial do not support antibiotic prophylaxis in all patients with necrotizing pancreatitis, but in specific subgroups of patients with pancreatic necrosis and a complicated course.

[Percutaneous ultrasound-guided drainage in the surgical treatment of acute severe pancreatitis]

AIM OF THE STUDY

To report results of percutaneous ultrasound-guided drainage, performed by a surgeon, in the treatment of complications of acute pancreatitis (AP), and to determine the role of this technique in the therapeutic armamentarium of severe AP.

PATIENTS AND METHODS

From 1986 to 2001, 59 patients were included in this retrospective study. All patients initially had severe necrotizing AP (mean Ranson score = 4.1 ; range : 2-7). Anatomical lesions included pancreatic abscess in 6 patients and necrosis in 53 (17 stage D and 36 stage E according to Balthazar's classification). Necrosis was infected in 42 and sterile in 11 respectively. Drainage was performed under ultrasound guidance and local anaesthesia using small-diameter drains (7-14 French).

RESULTS

Drainage was performed on average 23 days after onset of AP. Infection was proven by fine-needle aspiration in 47 (80 %) patients (41 infected necrosis and 6 localized abscess). In one patient, culture of aspirated fluid was negative but necrosis was infected (one false negative). Culture of aspirated fluid was negative and necrosis was sterile in 11 patients. Nineteen (32%) patients healed without subsequent surgery: 7 (16%) in the infected necrosis group, 6(55%) in the sterile necrosis group, and 6 (100%) in the abscess group. Forty (68%) patients had subsequent necrosectomy including 8 (14%) who died. Twenty (34 %) digestive fistulas healed spontaneously, except one treated by diversion stomia. Of the 16 (27 %) pancreatic fistulas, 6 needed subsequent interventional treatment.

CONCLUSION

In selected patients, percutaneous drainage can represent an alternative to surgery with a 14% mortality rate. The high rate of subsequent necrosectomy suggests that drains with larger diameter, possibly associated with continuous irrigation, should be used.

Imaging and Percutaneous Management of Acute Complicated Pancreatitis

Acute pancreatitis varies from a mild, self-limited disease to one with significant morbidity and mortality in its most severe forms. While clinical criteria abound, imaging has become indispensable to diagnose the extent of the disease and its complications, as well as to guide and monitor therapy. Percutaneous interventional techniques offer options that can be life-saving, surgery-sparing or important adjuncts to operation. Close cooperation and communication between the surgeon, gastroenterologist and interventional radiologist enhance the likelihood of successful patient care.

Infectious complications of acute pancreatitis

Disease severity in patients with acute pancreatitis varies from mild disease with minimal morbidity, to severe disease in which a whole spectrum of local and systemic complications may occur. Infectious complications frequently arise, and especially infection of pancreatic necrosis is an important risk factor for mortality. Several strategies have been devised to reduce this risk, and the use of prophylactic therapy, e.g. selective digestive decontamination, can be considered in patients with documented necrosis fo the pancreas. Pancreatic abscesses and infected pseudocysts arise later in the course of disease, and should be considered as separate entities, due to differences in therapy and outcome of these patients. When infection occurs, source control using either surgical or percutaneous drainage techniques, is essential to avoid systemic complications.

The effect of antibiotic and probiotic combination therapy on secondary pancreatic infections and oxidative stress parameters in experimental acute necrotizing pancreatitis

INTRODUCTION

Ciprofloxacin and meropenem have effects on intestinal bacteria that are responsible for pancreatic infection, and on the basis of recent data it has been argued that probiotics, especially those used in the food industry, could improve efforts to prevent and treat secondary pancreatic infections by inhibiting bacterial translocation.

AIMS

To evaluate the effects of probiotic treatment alone or in combination with early administration of two different antibiotics on serum amylase, pancreatic histopathology, bacterial translocation, and oxidative markers.

METHODOLOGY

Acute pancreatitis was induced in rats with 3% sodium taurocholate (1 mL/kg intraductally), except in group VI (sham group). After the stabilization period, the rats were divided into seven groups (n = 20) randomly. At hour 6 after injection, group I rats received probiotic Saccharomyces boulardii (25 mg/d orally q.d.), group II received meropenem (60 mg/kg intraperitoneally b.i.d.), group III received ciprofloxacin (40 mg/kg intraperitoneally b.i.d.), group IV received the same dose of probiotic plus meropenem, and group V received probiotic plus ciprofloxacin. Treatment was not given to group VI (sham group) and group VII (pancreatitis group). At hour 48 after induction, specimens were collected.

RESULTS AND CONCLUSION

Although histopathologic scores in treatment groups were found to be lower than in group VII, the difference was statistically significant only in group V (p < 0.001). In evaluation of oxidative stress, we found that MDA levels decreased and SOD levels increased in treatment groups in comparison with levels in group VII. Probiotic treatment alone reduced bacterial translocation. Probiotic-antibiotic combination therapy was shown to improve histopathologic scores and oxidative parameters.

Diagnosis and treatment of intra-abdominal abscesses

Despite recent advances in the diagnosis and management of intra-abdominal abscesses, these infections still cause substantial morbidity and mortality. Low pH, large bacterial inocula, poor perfusion, the presence of hemoglobin, and large amounts of fibrin (which impedes antibiotic penetration) make the abscess a cloistered environment that is penetrated poorly by many antimicrobial therapies. Therefore, management of these infections requires prompt recognition, early localization, and effective drainage, as well as appropriate antimicrobial use. Although various imaging techniques, such as ultrasonography, gallium scans, and indium-labeled white-blood-cell scans, can be used for the diagnosis and localization of intra-abdominal abscesses, computer-assisted tomography is the most useful study. Once the diagnosis is made and the abscess is localized, treatment should begin promptly. Percutaneous or open surgical drainage should be used. Broad-spectrum antibiotics should be given until culture and sensitivity data are obtained. Once these data are obtained, a therapy with appropriate coverage that is likely to work in the abscess environment should be chosen. Percutaneous drainage is inappropriate for abscesses in the posterior subphrenic space or in the porta hepatis, for those among loops of small bowel, for suspected echinococcal cysts, and for abscesses containing necrotic or neoplastic tissues. Finally, surgeons need to be cognizant of risk factors, such as advanced age, obesity, complex abscesses, and high Acute Physiology and Chronic Health Evaluation (APACHE) II or APACHE III scores, which correlate with poor outcomes for these patients.

Role of the gut in the course of severe acute pancreatitis

INTRODUCTION

The pathogenesis of acute pancreatitis remains elusive. Sepsis and multiple organ failure continue to cause death (overall mortality rate, approximately 10%) despite immense improvements in supportive, radiologic, and surgical therapy. The gut appears to play a key role in the development of these complications.

AIM

To critically review the evidence implicating the gut in the pathogenesis of acute pancreatitis.

METHODS

Relevant English-language literature or abstracts cited in the MEDLINE database were reviewed.

RESULTS AND CONCLUSION

Gram-negative enteric organisms account for most infections of pancreatic necrosis and subsequent sepsis, which suggests the gut as a source. Intestinal permeability is increased early in patients with severe acute pancreatitis and correlates with endotoxemia, which suggests translocation as a possible mechanism. The pathogenesis of the deranged function of the gut mucosal barrier and the possible sites of increase in intestinal permeability are discussed. The gut also plays a role in priming neutrophils and the release of inflammatory cytokines, which initiate and propagate nearly all the detrimental consequences of severe inflammation and sepsis. Future research avenues and potential therapeutic measures that may restore and preserve gut barrier function are explored.

The early increase in intestinal permeability and systemic endotoxin exposure in patients with severe acute pancreatitis is not associated with systemic bacterial translocation: molecular investigation of microbial DNA in the blood

INTRODUCTION

Sepsis is the main cause of late mortality in patients with severe acute pancreatitis and is largely attributed to secondary infection of pancreatic necrosis with gram-negative enteric organisms. This is commonly preceded by a significant increase in intestinal colonization with such microbes and with early increases in intestinal permeability, thus suggesting a mechanism of bacterial translocation. Whilst cultures of blood specimens from these patients often remain sterile, it is conceivable that bacteria might translocate in small volumes with detrimental effects but elude detection by standard microbial culture techniques.

AIMS

To investigate the incidence and frequency with which bacterial DNA may exist in the systemic circulation of patients with acute pancreatitis and to relate that to disease severity, changes in intestinal permeability, and systemic endotoxin exposure.

METHODOLOGY

Blood samples were obtained at admission and on days 3 and 7 from 26 patients with acute pancreatitis (seven with severe cases) and from 10 healthy controls for DNA extraction and standard microbial cultures. Polymerase chain reaction techniques were used to amplify a gene region (16S ribosomal RNA) found in all bacteria. Levels of serum endotoxin and antibodies to endotoxin core (EndoCAb) were measured at admission, and intestinal permeability to the macromolecule polyethylene glycol 3350 was determined within 72 hours of the onset of symptoms.

RESULTS

Blood cultures yielded and enterococci for one patient with a severe attack and coagulase-negative staphylococci for another patient with a mild attack. No bacterial DNA was found in any of the samples. Endotoxemia was detected in 20 patients (five with severe cases), and levels of serum IgM EndoCAb were depleted in patients with severe attacks but remained relatively unchanged during mild attacks (p = 0.033). Intestinal permeability was significantly increased in patients with severe attacks of acute pancreatitis but remained unchanged during mild attacks (p < 0.05).

CONCLUSIONS

Whilst severe attacks of acute pancreatitis are associated with early derangement in gut barrier function and systemic endotoxin translocation, there is no molecular evidence for associated bacterial "translocation."

Complications of acute pancreatitis: clinical and CT evaluation

Mortality of acute pancreatitis is dependent on the development of potentially lethal complications that can coexist and occur at any time following an acute attack. The nature and clinical relevance of these complications differ, contingent on the time of occurrence following a severe episode of pancreatitis. They can be divided into (1), early complications that manifest at the onset or within the first 2 to 3 days, (2) intermediate complications that occur predominantly during the second to fifth week, and (3) late complications that usually manifest months or years following the resolution of an acute attack. Early complications are systemic in nature with diverse clinical manifestations of the cardiovascular, pulmonary, renal, and/or metabolic systems. Intermediate complications are abdominal, pancreatic, and retroperitoneal, and are mostly septic in nature, associated with pancreatic or peripancreatic fat necrosis and pseudocysts. Late, life-threatening complications are mainly vascular or hemorrhagic in nature or involve the development of chronic pancreatic ascites. The early detection and objective evaluation of these complications by clinical and imaging methods leads to specific treatment options in the continuous attempt to decrease mortality rates in acute pancreatitis.

Prophylactic antibiotics alter the bacteriology of infected necrosis in severe acute pancreatitis

BACKGROUND

Use of appropriate prophylactic antibiotics has been shown to decrease infectious complications and mortality rate in patients with severe acute pancreatitis, but its influence on the bacteriology of secondary pancreatic infection is poorly defined.

STUDY DESIGN

Operative cultures from 61 consecutive patients with pancreatic necrosis treated during routine prophylactic antibiotic use (1993-2001) were compared with 34 consecutive patients with necrosis treated before routine antibiotic use (1977-1992).

RESULTS

The two groups of patients were similar in demographics, etiology of pancreatitis, and severity of illness. All patients in the antibiotic group received prophylactic antibiotics compared with only 38% (13 of 34) in the control group. Routine broad-spectrum prophylactic antibiotics altered the bacteriology of secondary pancreatic infection in severe acute pancreatitis from predominantly gram-negative coliforms (56% versus 26%, p = 0.005) to predominately gram-positive organisms (23% versus 52%, p = 0.009) without a significant increase in either the rate of beta-lactam resistance or fungal infections. The overall hospital stay in patients treated with prophylactic antibiotics was significantly reduced (61 +/- 24 days versus 41 +/- 28 days, p = 0.002), and there was a trend toward a decline in mortality rate in the antibiotic treatment group.

CONCLUSION

Routine broad-spectrum prophylactic antibiotic use has altered the bacteriology of secondary pancreatic infection in severe acute pancreatitis from predominantly gram-negative coliforms to predominantly gram-positive organisms without altering the rate of beta-lactam resistance or fungal superinfection.

Pancreatic sepsis: prevention and therapy

Except for a minority of early fatalities, most deaths in acute pancreatitis occur after the first 7 to 10 days due to infective complications, particularly infected necrosis. Hence, preventing this risk factor seems to represent a major step forward in the clinical management of severe pancreatitis. Consequently, antibiotics emerged as a cornerstone of the treatment of severe acute pancreatitis. The duration of such treatment, the route of administration and the substance(s) of choice need to be carefully selected. Surgical debridement is the treatment of choice of infected necrosis, while percutaneous drainage is successful in some patients.

Definitive treatment of pancreatic abscess by endoscopic transmural drainage

BACKGROUND

Experience with endoscopic transmural drainage of pancreatic pseudocysts prompted the use of a similar technique for the primary treatment of pancreatic abscess. The aim of this study was to assess the feasibility, safety, and effectiveness of endoscopic transmural drainage for the treatment of pancreatic abscesses compressing the gut lumen.

METHODS

In 9 patients, a total of 11 pancreatic abscesses compressing the stomach, duodenum, or both organs were drained endoscopically by means of endoscopic fistulization followed by saline solution irrigation and subsequent stent(s) placement. Complete resolution of the pancreatic abscess was defined as the absence of symptoms and no residual collection on follow-up CT.

OBSERVATIONS

Endoscopic transmural drainage was technically successful in all cases. Ten abscess cavities (91%) resolved completely after stent placement for a mean duration of 32 days. In 2 patients, insertion of a nasopancreatic catheter was required to irrigate thick pus or necrotic debris. Bleeding occurred in 1 case (11%) but there was no mortality. The relapse rate was 13% over a mean follow-up of 18 months.

CONCLUSION

Endoscopic transmural drainage is an effective therapy with minimal morbidity for pancreatic abscess compressing the gut lumen and is a valuable alternative to surgical drainage.

IAP Guidelines for the Surgical Management of Acute Pancreatitis

During 2002 the International Association of Pancreatology developed evidenced-based guidelines on the surgical management of acute pancreatitis. There were 11 guidelines, 10 of which were recommendations grade B and one (the second) grade A. (1) Mild acute pancreatitis is not an indication for pancreatic surgery. (2) The use of prophylactic broad-spectrum antibiotics reduces infection rates in computed tomography-proven necrotizing pancreatitis but may not improve survival. (3) Fine-needle aspiration for bacteriology should be performed to differentiate between sterile and infected pancreatic necrosis in patients with sepsis syndrome. (4) Infected pancreatic necrosis in patients with clinical signs and symptoms of sepsis is an indication for intervention including surgery and radiological drainage. (5) Patients with sterile pancreatic necrosis (with negative fine-needle aspiration for bacteriology) should be managed conservatively and only undergo intervention in selected cases. (6) Early surgery within 14 days after onset of the disease is not recommended in patients with necrotizing pancreatitis unless there are specific indications. (7) Surgical and other forms of interventional management should favor an organ-preserving approach, which involves debridement or necrosectomy combined with a postoperative management concept that maximizes postoperative evacuation of retroperitoneal debris and exudate. (8) Cholecystectomy should be performed to avoid recurrence of gallstone-associated acute pancreatitis. (9) In mild gallstone-associated acute pancreatitis, cholecystectomy should be performed as soon as the patient has recovered and ideally during the same hospital admission. (10) In severe gallstone-associated acute pancreatitis, cholecystectomy should be delayed until there is sufficient resolution of the inflammatory response and clinical recovery. (11) Endoscopic sphincterotomy is an alternative to cholecystectomy in those who are not fit to undergo surgery in order to lower the risk of recurrence of gallstone-associated acute pancreatitis. There is however a theoretical risk of introducing infection into sterile pancreatic necrosis. These guidelines should now form the basis for audit studies in order to determine the quality of patient care delivery.

Incidence, spectrum and antibiotic sensitivity pattern of bacterial infections among patients with acute pancreatitis

BACKGROUND AND AIM

Secondary infection of pancreatic necrotic tissue and peripancreatic fluid is a serious complication of acute pancreatitis resulting in significant morbidity and mortality. The aim of this study was to find out the spectrum of bacterial infections, and their antibiotic sensitivity pattern in patients with acute pancreatitis.

METHODS

All consecutive patients with acute pancreatitis were studied prospectively. Detailed investigations were carried out to identify bacterial infections and their antibiotic sensitivities in patients with suspected infection. These investigations included cultures of various body fluids, throat swabs, indwelling cannula and catheter tips. Pancreatic tissue was obtained by using needle aspiration or at surgery for Gram's stain, culture and sensitivity. All cultures were repeated until the presence of infection was confirmed or excluded.

RESULTS

A total of 169 patients with acute pancreatitis were studied during the period between January 1997 and June 2000 (mean age 41.3 years; 116 males and 53 females). Of the 169 patients, 63 had infections at various sites. A total of 80 cultures were positive, and 12 different bacterial isolates were cultured from samples taken from these 63 patients. Polymicrobial infection was seen in 32% of patients. Twenty-four patients had a confirmed pancreatic infection. Blood cultures had a growth of organisms in 19 patients, with evidence of ongoing or worsening pancreatitis, thus raising a strong suspicion of infected necrosis in them. The commonest organisms were Escherichia coli from 20 cultures and Pseudomonas aeruginosa from 18 cultures. The antibiotic sensitivity pattern showed that most bacteria were sensitive to third generation cephalosporins and quinolones; notably among them were cefotaxime, ceftazidime, and ciprofloxacin.

CONCLUSION

Bacterial infections were seen in 37% of patients with acute pancreatitis. The commonest organisms were Pseudomonas aeruginosa and Escherichia coli. Most bacterial isolates were sensitive to third generation cephalosporins and quinolones.

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.

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.

Does an infected peripancreatic fluid collection or abscess mandate operation?

OBJECTIVE

To assess the treatment of peripancreatic fluid collections or abscess with percutaneous catheter drainage (PCD).

SUMMARY BACKGROUND DATA

Surgical intervention has been the mainstay of treatment for infected peripancreatic fluid collections and abscesses. Increasingly, PCD has been used, with mixed results reported in the literature.

METHODS

A retrospective chart review of 1993 to 1997 was performed on 82 patients at a tertiary care public teaching hospital who had computed tomography-guided aspiration for suspected infected pancreatic fluid collection or abscess. Culture results, need for subsequent surgical intervention, length of stay, and death rate were assessed.

RESULTS

One hundred thirty-five aspirations were performed in 82 patients (57 male patients, 25 female patients) with a mean age of 40 years (range 17-68). The etiologies were alcohol (41), gallstones (32), and other (9). The mean number of Ranson's criteria was four (range 0-9). All patients received antibiotics. Forty-eight patients had evidence of pancreatic necrosis on computed tomography scan. Cultures were negative in 40 patients and positive in 42. Twenty-five of the 42 culture-positive patients had PCD as primary therapy, and 6 required subsequent surgery. Eleven patients had primary surgical therapy, and five required subsequent surgery. Six patients were treated with only antibiotics. The death rates were 12% for culture-positive patients and 8% for the entire 82 patients.

CONCLUSIONS

Historically, patients with positive peripancreatic aspirate culture have required operation. This series reports an evolving strategy of reliance on catheter drainage. PCD should be considered as the initial therapy for culture-positive patients, with surgical intervention reserved for patients in whom treatment fails.

Discriminant power and information content of Ranson's prognostic signs in acute pancreatitis: a meta-analytic study

OBJECTIVE

To determine a meta-analytical definition of the discriminant power of Ranson's signs in the prediction of acute pancreatitis severity and outcome, and of their information content, also compared with clinical judgment.

DATA SOURCES

Two hundred eleven studies since 1974, reporting any predictive system for acute pancreatitis (MEDLINE by various Medical Subject Headings in MEDLARS, Current Contents, Medscape, Virtual Hospital, and other on-line medical services).

STUDY SELECTION

One hundred ten studies reporting clinical use of Ranson's signs were retained. A quality index was calculated for each study. A selection was made according to inclusion criteria, separately for prediction of severity (19 studies; group S) and prognosis (10 studies; group P). Six other studies reporting clinical judgment results were also selected (group C).

DATA EXTRACTION

Sensitivity and specificity values were extracted. Effect sizes were calculated and summarized by the inverse variance-weighted method. Categorical models were studied by analysis of variance. Publication bias was sought by correlation test and analysis of variance. Summary receiver operating characteristic curves were drawn, and the corresponding false-positive rate (FPR) and true-positive rate were calculated for each group. From the total true-positive rate and FPRs, the probabilities of illness for positive and negative results were calculated, for severe pancreatitis prevalence from 0 to 1. Last, the area below the curve and the ratio between this and that of the "perfect test" were calculated as a measurement of information content.

DATA SYNTHESIS

Ranson's signs demonstrated poor discriminant power in both predictions: "d" values were 1.200 (95% confidence interval, 1.083-1.318) and 1.302 (95% confidence interval, 1.046-1.559), respectively. The lack of homogeneity in group S (Q = 58.737; p = .0000032) can be explained by the presence of three outliers. The summary curves showed, for low FPRs, a higher sensitivity of clinical judgment; Ranson's signs reached useful sensitivity only for high FPRs. No differences between groups in the area below the information content curves were found.

CONCLUSIONS

Ranson's signs showed a poor predictive power. The information content did not differ from that of clinical judgment.

Surgical approach in patients with acute pancreatitis. Is infected or sterile necrosis an indication--in whom should this be done, when, and why?

The morbidity and mortality rates of severe acute pancreatitis are related to the degree of pancreatic necrosis that accompanies the attack and to the presence of infection. The decision about whether and when to operate on these patients is often difficult, and it requires mature clinical judgment. Proven infection of pancreatic necrosis is an absolute indication for surgical intervention, at which time surgical doffebridement and drainage should be performed. Most patients with sterile necrosis eventually respond to conservative nonsurgical medical management. In patients who remain critically ill for weeks or whose clinical course deteriorates despite maximal intensive care, surgery may be appropriate. Even when these guidelines are followed, the mortality (15% to 40%) and morbidity (approximately 80%) rates remain high.

The role of antibiotic prophylaxis in the treatment of acute pancreatitis

Infected necrosis in acute pancreatitis is one of the most dreaded complications of acute pancreatitis. Whereas selection of an appropriate antibiotic treatment of the infection poses no problem, prophylactic application of antibiotic remains controversial in the absence of symptoms of infection, but where contrast-enhanced CT scan clearly proves necrosis. This article discusses the present state of the art of the role of antibiotic prophylaxis in the treatment of acute pancreatitis and provides clinical guidelines.

Surgical management of necrotizing pancreatitis

In necrotizing pancreatitis, surgical treatment is indicated in patients with infected necrosis. Conservative management should be favored if necrosis remains sterile and the patient responds to intensive care therapy. Different surgical techniques have been established during the past years, including conventional drainage, open and semiopen drainage, and closed management with postoperative continuous lavage of the lesser sac. For experienced physicians, these techniques provide comparable results, and none has been proved to be superior to the others.

Case report: inappropriate use of percutaneous drainage in the management of pancreatic necrosis

We describe three cases of severe necrotizing pancreatitis, with Apache II scores of 11, 17 and 22, respectively. There was no significant pancreatic parenchymal perfusion in any of the three patients on contrast-enhanced computed tomography. All three patients were primarily treated with percutaneous drains and all three subsequently required open laparotomies. We do not recommend percutaneous drainage as a definitive therapy for severe necrotizing pancreatitis.

[Percutaneous drainage of infected pancreatic necrosis: an alternative to surgery]

AIM OF THE STUDY

To describe a technique of percutaneous CT guided catheter drainage of infected pancreatic necrosis and to report the results of this technique compared with those of the conventional surgical treatment and of other percutaneous drainage series.

PATIENTS AND METHODS

Between 1992 and 1997, the series included 32 patients who had a severe acute necrotizing pancreatitis with a mean Ranson score of 4.6, scored into grade D (n = 10), and grade E (n = 22), according to the Balthazar radiological staging. Modified Van Sonnenberg 24 F double lumen catheters were used for continuous irrigation and aspiration.

RESULTS

Forty-nine drains were inserted for 41 infected necroses and eight abscesses. Among the 32 patients, the proof of infected necrosis was obtained in 26 patients by fine needle aspiration and culture (enterococcus, staphylococcus, pseudomonas). The average delay of catheter insertion was 23 days after onset of pancreatitis; the mean duration of drainage was 43 days, and an average of three catheters per patient was required. Five patients (15%) died, and among the survivors, 16 (59%) presented 21 complications including 14 enterocutaneous or pancreatic fistulas. A subsequent surgical procedure including two necrosectomies was necessary in six patients.

CONCLUSION

This study demonstrates that percutaneous drainage of infected pancreatic necrosis with a 15% mortality and 70% success rate, represents an interesting alternative to conventional surgery.

Difference in microbes contaminating pancreatic necrosis in biliary and alcoholic pancreatitis

CONCLUSION

There are differences in the microbiology of infected pancreatic necrosis in alcoholic and biliary pancreatitis. One possible explanation may be different routes of contamination.

BACKGROUND

Infection is a severe complication in acute pancreatitis. Bacteria are found in 40-70% of all patients suffering from necrotizing pancreatitis. We investigated whether there were any differences in microbes isolated from pancreatic necrosis in biliary and alcoholic pancreatitis.

METHODS

Microbiological tests were conducted on necrosis taken at the operation for pancreatitis with the etiology of (group A) alcoholic pancreatitis (n = 47) and (group B) biliary pancreatitis (n = 23). Patients with simultaneous cholecystitis were excluded. The time from the first symptoms to the operation or the extent of necrosis did not differ between the groups.

RESULTS

Microbes were isolated more often in the cultures from group B than group A (17/23 = 74% vs 15/47 = 32%, p = 0.001). The most common were Gram-positive bacteria in group A and Gram-negative bacteria in group B. From the first week, from the onset of symptoms to the operation. Gram-negative bacteria were isolated significantly more often in the cultures from group B patients than from group A patients (8/10 = 80% vs 1/5 = 20%, p = 0.04). In multivariate analysis, we found that biliary pancreatitis was an independent risk factor (adds ratio 5.5, 95% confidence interval [CI] 0.59-52.10) of contamination of necrosis with Gram-negative bacteria.

Infected bile-induced acute pancreatitis in rabbits. The role of bacteria

CONCLUSIONS

Bacteria species commonly found in bile of patients with choledocholithiasis render human bile toxic to the pancreas. The severity of infected bile-induced acute pancreatitis depends on the bacterial species. Infected bile-induced acute pancreatitis turns into a sterile inflammation within 10 d.

BACKGROUND

Flow of bile into the pancreatic duct was proposed to cause some forms of gallstone pancreatitis. The development of bile-induced acute pancreatitis at physiologic ductal pressure is known to depend on the bacterial infection of bile. In this study, we investigated the effect of a variety of bacteria species commonly found in bile of patients with choledocholithiasis upon the pancreatic toxicity of human bile. The time-course of pancreatic infection in infected bile-induced acute pancreatitis was also analyzed.

METHODS

In rabbits, the pancreatic duct was kept obstructed throughout the experiment. After 24 h, 50 microL of pancreatic juice was obtained from the congested pancreatic duct and replaced with the same quantity of infected human bile. Bile contained bacteria (10(7) microorganisms/microL) of species frequently found in choledochal secretions of patients with gallstone disease. Effects on pancreatic morphology were studied after 48 h. In another experiment, the number of Escherichia coli/mg of pancreatic tissue was determined in a time sequence study following exposure of the rabbit pancreatic duct to 50 microL E. coli-infected bile (10(7) microorganisms/mL) and temporary (12 h) or permanent duct obstruction.

RESULTS

Sterile bile was not harmful to the pancreas. Infected bile caused an interstitial-edematous pancreatitis with occasional acinar necrosis. The severity of acute pancreatitis depended on the bacterial species. Following pancreatic duct exposure to E. coli-infected bile, there was complete clearance of the bacteria from the gland with a concomitant interstitial leukocyte infiltration within a period of 2-10 d.

Antibiotic prophylaxis in the initial management of severe acute pancreatitis

BACKGROUND

The role of antibiotic prophylaxis in the initial management of patients with acute pancreatitis is an area of major controversy. Contrary to earlier clinical trials, recent experimental and clinical studies have accrued evidence that warrants reappraisal of current clinical practice. This article reviews these recent advances in knowledge.

METHODS

All papers derived from a Medline search for the years 1990-1997 inclusive using the text words 'acute', 'pancreatitis', 'antibiotic' and 'antibiotics' were studied. Additional papers were derived from reference lists within papers identified by the Medline search. Only experimental and clinical papers relevant to the issue of prophylactic antibiotic therapy in acute pancreatitis are included in the review.

RESULTS AND CONCLUSION

Current experimental evidence favours the use of prophylactic antibiotics in severe acute pancreatitis. The results of contemporary randomized clinical trials restricted to patients with prognostically severe acute pancreatitis have demonstrated improvement in outcome associated with antibiotic treatment.

Value of early blood Th-1 cytokine determination in predicting severity of acute pancreatitis

BACKGROUND

Early evaluation of the severity of acute pancreatitis (AP) requires measurement of many variables within 48 h after admission. Septic complications (SC) are frequent, and preliminary studies have highlighted the value of prophylactic antibiotherapy; however, single and reliable predictive markers of sepsis are not yet available. The aim of this study was to assess the value of determining early blood Th-1 cytokines and their natural antagonists (interleukin-6 (IL-6), IL-1, IL-1ra, and the soluble form of tumor necrosis factor (sTNF) receptors RI and RII) to predict the severity and SC during AP.

METHODS

Thirty-seven patients with AP were prospectively included; 25 of them had severe AP, including 8 with SC. Serum cytokines were measured 48 h and 72 h after the onset of AP with an enzyme-linked immunosorbent assay. The optimal severity or SC diagnostic thresholds was determined using receiver operative curves.

RESULTS

Severe AP in accordance with the Atlanta criteria were better predicted by C-reactive protein and IL-6 serum determination, albeit these levels could not predict absolutely the death of two patients. In severe AP cases (n = 25) the IL-1 to IL-1-ra ratio was lower in cases further complicated by sepsis ((6+/-4) 10(-3) versus (34+/-13) 10(-3), P < 0.05); moreover, sTNF RI (2497+/-270 pg/ml versus 2133+/-611 pg/ml, P < 0.05) and RII (3751+/-400 pg/ml versus 3045+/-509 pg/ml, P < 0.05) were higher in AP characterized by further SC. The IL-1 to IL-1-ra ratio and IL-1 concentration were dramatically decreased within the first 48 h ((0.4+/-0.4) 10(-3) versus (30+/-11) 10(-3), P < 0.05, and 0.3+/-0.3 versus 15+/-3 ng/l, P < 0.05) in patients with further infection of the pancreatic necrosis (n = 3). The SC diagnosis was better anticipated by an IL-1 to IL-1-ra ratio lower than 5 x 10(-3) or by an sTNF RI higher than 1750 pg/ml and sTNF RII higher than 2750 pg/ml, and the infection of the pancreatic necrosis by an IL-1 concentration <2 ng/l or an IL-1 to IL-1-ra ratio <2 x 10(-3).

CONCLUSION

Besides severity markers, IL-1, IL-1-ra, and sTNF RI and RII should be considered in base-line AP assays and, if confirmed by larger studies, could help to screen patients at risk for SC and candidates for prophylactic antibiotherapy with a good negative predictive value.

Acute pancreatitis after orthotopic liver transplantation in children: incidence, contributing factors, and outcome

BACKGROUND

Acute pancreatitis after orthotopic liver transplantation is a well-known complication in adults that has never been described in children. In adults, end-stage liver disease related to hepatitis B, intraoperative pancreatic injury caused by extensive peripancreatic dissection, the type of biliary anastomosis performed, and numerous drugs, have all been described as predisposing factors in acute pancreatitis after liver transplantation. The current retrospective review was undertaken to identify the incidence, the contributing factors, and the outcome of acute pancreatitis after liver transplantation in children.

METHODS

During a 10-year period, 375 children underwent 434 liver transplantations in the authors' institution. In seven patients (1.9%), clinical acute pancreatitis developed after orthotopic liver transplantation. Indication for initial liver transplantation was biliary atresia (n = 3), acute liver failure (n = 3), and type 1 Crigler-Najjar syndrome. In all seven patients, liver graft function was initially adequate. The diagnosis of acute pancreatitis was based on clinical, biochemical, ultrasonographic, and surgical signs.

RESULTS

In six patients, acute pancreatitis appeared within the first week after transplantation. The diagnosis was confirmed by abdominal laparotomy in five children. In the current series, emergency liver transplantation (p < 0.001), retransplantations (p < 0.001), and infectious peritonitis (p < 0.001) were contributing factors. Despite supportive measures, three patients died (43%) because of multiple organ dysfunction syndrome.

CONCLUSIONS

Acute pancreatitis is an uncommon but life-threatening complication after liver transplantation in children. Early diagnosis and aggressive treatment of infectious complications are major elements in the management of acute pancreatitis after liver transplantation.

Role of ultrasonographically guided fine-needle aspiration cytology in the diagnosis of infected pancreatic necrosis

BACKGROUND

Early detection of infected pancreatic necrosis has a major impact on further management and outcome in acute pancreatitis. The aim of this study was to evaluate the clinical value of ultrasonographically guided fine-needle aspiration cytology (FNAC) in patients with necrotizing pancreatitis over an 8-year period.

METHODS

From January 1988 to September 1996 193 (mean 2.0 (range 1-9) aspirations per patient) prospectively assessed FNACs guided ultrasonographically were performed in 98 patients with necrotizing pancreatitis proven by contrast-enhanced computed tomography. Aspirates were considered infected if either Gram stain and/or culture revealed micro-organisms.

RESULTS

Ultrasonographically guided FNAC correctly diagnosed infection in 29 of 33 patients with infected necrosis a median of 13 days after onset of symptoms. Of 61 patients with sterile necrosis 55 were identified correctly as sterile by FNAC. There were six false-positive and four false-negative aspirates of which nine occurred during the first week of the disease. In four patients who did not undergo operation FNAC revealed Gram-negative organisms; however, in the absence of repeated aspirations, the positive results remained unconfirmed. An overall sensitivity of 88 per cent and a specificity of 90 per cent was obtained. No difference was found in biochemical and clinical parameters indicating systemic inflammatory response syndrome before each FNAC between patients with proven sterile or infected necrosis. All patients tolerated the procedure well and no major complications were observed.

CONCLUSION

Ultrasonographically guided FNAC is a fast and reliable technique for the diagnosis of infected necrosis. As complication rates are very low, the procedure can be repeated at short intervals to improve the diagnostic accuracy. Ultrasonographically guided FNAC is recommended for all patients with necrotizing pancreatitis in whom systemic inflammatory response syndrome persists beyond the first week after onset of symptoms.

Management of necrotizing pancreatitis by repeated operative necrosectomy using a zipper technique

METHODS

From 1983 to 1995, 72 patients with necrotizing pancreatitis were treated with a general approach involving planned reoperative necrosectomies and interval abdominal wound closure using a zipper.

RESULTS

Hospital mortality was 25%. Multiple organ failure without sepsis caused early mortality in 3 of 4 patients and sepsis caused late mortality in 11 of the remaining 14. The mean number of reoperative necrosectomies/debridements was 2 (0 to 7). Fistulae developed in 25 patients (35%); 64% were treated conservatively. Recurrent intraabdominal abscesses developed in 9 patients (13%) but were drained percutaneously in 5. Hemorrhage required intervention in 13 patients (18%). Prognostic factors included APACHE-II score on admission < 13 (P = 0.005), absence of postoperative hemorrhage (P = 0.01), and peripancreatic tissue necrosis alone (P < 0.05).

CONCLUSIONS

The zipper approach effectively maximizes the necrosectomy and decreases the incidence of recurrent intraabdominal infection requiring reoperation. APACHE-II score > or = 13, extensive parenchymal necrosis, and postoperative hemorrhage signify worse outcome.

Natural course of acute pancreatitis

Acute pancreatitis comprises, in terms of clinical, pathologic, biochemical, and bacteriologic data, four entities. Interstitial edematous pancreatitis and necrotizing pancreatitis are the most frequent clinical manifestations; pancreatic pseudocyst and pancreatic abscess are late complications after necrotizing pancreatitis, developing after 3 to 5 weeks. Determinants of the natural course of acute pancreatitis are pancreatic parenchymal necrosis, extrapancreatic retroperitoneal fatty tissue necrosis, biologically active compounds in pancreatic ascites, and infection of necrosis. Early in the course of acute pancreatitis multiple organ failure is the consequence of various inflammatory mediators that are released from the inflammatory process and from activated leukocytes attracted by pancreatic injury. During the late course, starting the second week, local and systemic septic complications are dominant. Around 80% of deaths in acute pancreatitis are caused by septic complications. The infection of pancreatic necrosis occurs in 8% to 12% of acute pancreatitis and in 30% to 40% of patients with necrotizing pancreatitis. Bacteriologic analysis of intraoperative smears and aspirates reveals predominantly gram-negative germs deriving from the intestine, most frequently Escherichia coli. It has been confirmed that after necrotizing pancreatitis a considerable large group of patients suffer long-lasting exocrine and endocrine insufficiency.