Pancreatic abscess

Pancreatic abscess. It is a rare but highly lethal local complication of a severe episode of pancreatitis. It manifests late and is characterized by high fever, increasing abdominal pain, leukocytosis, and a palpable mass in 1/3 of patients.

Imaging methods can detect the lesion, but the only way to determine the presence of infection is by analyzing the secretion obtained by percutaneous aspiration or surgery .

The germs involved are those belonging to the intestinal flora , especially coliforms. The only effective treatment is drainage, be it percutaneous or surgical, accompanied by good antibiotic coverage.

Summary

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  • 1 Form of presentation
  • 2 Diagnosis
  • 3 Causes
  • 4 Symptoms
  • 5 Signs and tests
  • 6 Treatment
  • 7 Expectations (prognosis)
  • 8 Complications
  • 9 Prevention
  • 10 See also
  • 11 Source

Form of presentation

Pancreatic abscess is usually a very serious local complication that occurs after a severe episode of pancreatitis . In particular, patients with postoperative pancreatitis are at high risk of developing pancreatic abscesses.

The incidence of abscess formation varies from 3 – 22%, depending on the patient population. Most patients present 2 to 4 weeks after the onset of symptoms, deterioration of the general condition, high fever, pain, palpable mass and leukocytosis. Late death is generally the result of sepsis. 85% of patients present with fever greater than 38 ° C, 80% suffer from increasing pain, up to 33% present a palpable lesion and in almost 100% of cases a leukocytosis greater than 10,000 cel / mm3 is observed. Patients appear toxic, with tachycardia, chills, and hypotension. However, these findings can also be seen in an episode of severe pancreatitis without infection, therefore, they are not always reliable and it is necessary to resort to other methods to arrive at an accurate diagnosis. Abscesses not only,

Diagnosis

The presence of a pancreatic abscess left to its free evolution progresses rapidly to sepsis with a high mortality rate bordering 100%, hence an accurate and timely diagnosis, at the beginning of the picture, is especially important.

Hematological tests are not of great diagnostic help because they are very nonspecific. In practically all cases, leukocytosis greater than 10,000 cel / mm3 with marked left deviation is observed. Blood cultures are not always positive and they are not specific to the site of infection. Serum amylase levels often do not increase after the initial decline, they tend to maintain and even continue to decrease. Other biochemical tests such as serum ribonuclease, phospholipase A2, C-reactive protein, Alpha1 antitrypsin or Alpha2 macroglobulin have not provided further information that decisively contributes to a diagnosis.

Diagnostic imaging methods play a very important role in the diagnosis of this pathology, since they not only detect the lesion, requiring characteristics of location, size and relationship with other organs, but through direct observation they allow a percutaneous aspiration to be carried out to document the presence of PA infection.

Imaging studies such as Ultrasonography (US), CrQ Computed Tomography and Magnetic Resonance Imaging (MRI) are of great diagnostic value due to their remarkable progress and success rates, however the advantages and disadvantages of each of them are not fully defined. and my studies are still required; Comparatives to evaluate which of these methods is more effective.

Computed Tomography is the diagnostic procedure that has been most used and continues to be used, having managed to improve the morbidity and mortality of patients with pancreatic abscess by allowing early diagnosis and showing anatomical details that optimize surgical treatment.

CT shows the abscess as a low-density fluid collection and may reveal pancreatic edema, fluid within the pancreas, or gas bubbles in the pancreatic bed. The presence of gas in the pancreatic and / or peripancreatic region in a patient with acute necrotizing pancreatitis should be considered as evidence of abscess until proven otherwise.

CT with fast contrast injection bolus is widely accepted as it gives information considering the extent of necrotic tissue that appears as hypoperfused areas. It is important to keep in mind the presence of sub-acute necrotic collections, in these cases the MRI surpasses CT and US as it has a sensitivity and specificity that borders 100% (10). However, none of these procedures helps us to differentiate an abscess from an uninfected liquid collection or an old bleeding area, so when a abscess is suspected, a percutaneous fine-needle aspiration should be performed under ultrasound or tomographic control. and subjecting said sample to a smear, Gram and cultures in aerobic and anaerobic media, which will allow an early diagnosis.

Pseudomonas 8-10% of cases. Enterococci and other streptococcal species are isolated in the same percentage . Anaerobic isolation is infrequent and the incidence of negative cultures is relatively low (2-10%). On the other hand, there is a high incidence of polymicrobial infection (30-55%), which suggests that contaminated bile, rather than the hematogenous route, is what causes bacterial seeding in the pancreas.

Other studies indicate that E.coli is present in 51% of cases, enterococci in 19%, Proteus species, Klebsiella and Pseudomonas in 10% for each of them, staphylococci in 18%, Streptococcus fecalis in 7% and Bacteroides species at 6%. These bacteria are thought to come from the colon by filtering through the intestinal wall, which is more patent due to the adjacent inflammatory process, followed by local spread through lymphatics (and not blood vessels) to necrotic tissues. The triggering mechanism for this bacterial migration is unknown.

Causes

Pancreatic abscesses develop in patients with pancreatic pseudocysts that become infected.

Symptoms

  • Abdominal mass
  • Abdominal pain
  • Shaking chills
  • Fever
  • Inability to eat
  • Nausea andvomiting

Signs and tests

Patients with pancreatic abscesses have generally had pancreatitis. However, the complication takes 7 or more days to appear. Symptoms usually include:

  • Abdominal pain
  • Fever

The signs of an abscess can be seen in:

  • Computed tomography
  • MRI of the abdomen
  • Ultrasound

Treatment

Since most deaths in the late phase of acute pancreatitis are due to abscess formation, diagnosis and treatment must be aggressive. Once the diagnosis of abscess has been specified, the treatment, in addition to broad antibiotic coverage and effective treatment of complications associated with bleeding , kidney and liver failure , etc., should be aimed at draining the abscess, either through external drainage or a surgical debridement with removal of purulent material and construction of adequate drainage.

There are various studies that show the benefits and indications of each of these methods. A group of authors agree that the most appropriate treatment is surgical debridement with a good posterior drainage system and that external drainage would be reserved for critically ill patients or prior to definitive surgical treatment (12,14,15). However, at present, most authors propose the placement of a percutaneous drainage catheter as initial treatment for pancreatic abscess, which is effective in around 50% (4). In the rest of the patients, an adequate surgical debridement will be performed with early reoperation if there is a septic state.

A study by Freeny and Col (19) showed success with percutaneous drainage in 15 of 23 patients (65%), the rest required surgery. Van Sonnenberg and Col reported success in 51 of 59 patients (86%) with a mortality 30 days after completing the drainage of 8%. They recommend that in order to be successful with this method, it is important to have a good selection of patients, to use catheters of adequate size and number, and to follow them carefully with proper manipulation of the catheters.

Mithofer and Col performed drainage in 39 patients, obtaining success in 3.1% of cases in the first attempt, the; others required surgery, with residual abscess occurring in 14 patients who were successfully treated with percutaneous drainage. However, despite these and others; Similar reports, there are studies like those of Snape and Schoelf (2,20) that refer that although there are very promising results in the percutaneous drainage of pseudocysts, this is not applicable to an abscess whose content is denser and frequently causes obstruction of drainage catheters and, on the other hand, the abscess may be partitioned, not allowing adequate drainage.

They state that in most cases a timely and well-indicated surgical intervention is superior to any percutaneous drainage and that this should only be performed when the surgery is limited by some circumstance. Internal drainage is not indicated in abscess treatment, this should only be attempted in case of uncomplicated pancreatic pseudocyst.

The prophylactic value of antibiotics is uncertain. In 2 recent studies of imipenem , ofloxacin and metronidazole , high levels of these drugs were observed in the blood of the pancreatic tissue, which were reflected in an apparent clinical improvement and in an unclear improvement in the survival averages, however further studies will be required to determine the actual role of prophylactic antibiotic therapy.

Expectations (prognosis)

The person’s prognosis depends on the severity of the infection . The mortality rate of pancreatic abscesses that have not been drained is very high.

Complications

  • Multiple abscesses
  • Sepsis

Prevention

Proper drainage of a pancreatic pseudocyst can help prevent some cases of pancreatic abscess; however, in many cases, this disorder cannot be prevented.

 

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