Treatment for pancreatic abscesses via omentalization with abdominal closure versus open peritoneal drainage in dogs: 15 cases (1994–2004)

The Omentum-A Forgotten Structure in Veterinary Surgery in Small Animals' Surgery

The greater and lesser omentum are derived from embryonic mesogastrium. The expansive greater omentum in dogs covers intestinal coils, while in cats, it is smaller. Comprising distinct portions, the greater omentum is rich in lymphatics and blood vessels. Conversely, the lesser omentum spans the liver, stomach, and duodenum. Studies on canine omentum reveal unique immune cell composition and regenerative potential attributed to adipose tissue-derived stromal cells (ADSCs). These cells hold promise in regenerative medicine, showing enhanced abilities compared with ADSCs from other sources. The omentum is critical in tissue repair and pathology, making it invaluable in veterinary surgery across various medical fields. The aim of this article was to research current knowledge about the applications of the omentum in veterinary surgery and the possibilities of using this structure in the future.

Computed tomography of suppurative and neoplastic diseases involving the canine omenta and omental bursa

The greater and lesser omenta are fused peritoneal folds that largely delimit the omental bursa (lesser peritoneal cavity). The omental bursa is a potential space within the abdominal cavity that communicates with the greater peritoneal cavity via the omental (epiploic) foramen: it is subdivided into the omental vestibule, caudal omental recess, and splenic recess. Aims of this retrospective case series study were to describe the frequencies of CT findings of dogs with confirmed inflammatory or neoplastic disease of the omenta, omental bursa, or both. The sample included seven adult, medium-to-large breed dogs. All had fluid in the greater peritoneal cavity and 5/7 (71%) dogs also had fluid in the omental bursa. Primary suppurative inflammatory disease was present in three dogs, each dog had a large abscess with central gas in either the omental vestibule (two dogs) or caudal omental recess (one dog). Both abscesses in the omental vestibule arose from the papillary process of the caudate liver lobe and were surgically removed without complication. Neoplasia was present in four dogs and either arose from omentum (hemangiosarcoma, carcinoma) or infiltrated the omentum from an adjacent organ (splenic leiomyosarcoma, gastric adenocarcinoma). Neoplasms created mass-like tumors, infiltrative tumors, or both and had variable distribution (focal, multifocal, or locally extensive). All dogs with neoplasia were euthanized. CT signs of inflammatory and neoplastic disease overlapped, but the presence of gas might prioritize abscessation. CT signs helped decide feasibility of surgery based on extent of local invasion, especially involvement of structures passing through the porta hepatis.

Perioperative outcomes in dogs and cats undergoing pancreatic surgery: 81 cases (2008-2019)

OBJECTIVES

To identify and describe the type and frequency of perioperative factors in dogs and cats undergoing pancreatic surgery under referral care.

METHODS

Medical records from a small animal surgical referral practice were retrospectively reviewed to identify dogs and cats that underwent pancreatic surgery between 2008 and 2019. Inclusion criteria included complete medical record, histopathology results and follow-up of at least 14 days postoperatively or until death. Variables collected included signalment, history, presenting complaint, preoperative diagnostic results, intraoperative complications, surgical findings/procedures, postoperative complications and histopathology results. Cases were excluded if pertinent information or a histopathology report was missing from the medical record. The frequency of these variables was reported.

RESULTS

There were 81 client-owned animals identified that met the inclusion criteria (57 dogs and 24 cats). The most common pancreatic procedure performed in dogs was partial pancreatectomy 63.2% (36/57) and in cats was pancreatic biopsy 62.5% (15/24). The most common histologic diagnosis in dogs was pancreatic islet cell carcinoma 50.9% (29/57) and in cats was pancreatitis 41.7% (10/24). The overall mortality rate was 13.6% (11/81), with a 10.5% (6/57) mortality rate in dogs and a 20.8% (5/24) mortality rate in cats.

CLINICAL SIGNIFICANCE

In this series of dogs and cats, pancreatic surgery under referral care carried a low to moderate mortality rate.

Medical and surgical management of pancreatic fluid accumulations in dogs: A retrospective study of 15 cases

BACKGROUND

Limited data exist on the diagnosis and successful medical management of suspected pancreatic abscessation, and the appropriate terminology of this condition.

HYPOTHESIS/OBJECTIVES

To describe the diagnosis and management of pancreatic fluid accumulations in dogs where pancreatic fluid cytology results were available, to describe those medically and surgically managed at the same institution, and reconsider the terminology describing acute pancreatitis with pancreatic fluid accumulation.

ANIMALS

Fifteen dogs treated for suspected pancreatic abscessation at a university teaching hospital between January 2010 and March 2020.

METHODS

Retrospective descriptive study.

RESULTS

Ultrasonographic findings described pancreatic fluid accumulations as hypoechoic in 10/15 and anechoic in 2/15 cases, ranging between 1.6 and 7 cm in diameter (median, 3.5 cm). No complications were documented after ultrasound guided fine-needle aspiration. Cytologically, all samples revealed a predominantly neutrophilic inflammation. 11/15 samples yielded a negative culture (9/11 received antimicrobials before sampling) and in 4 cases culture was positive. 7/15 were initially managed surgically including all 4 infected cases. 4/7 surgically managed cases were discharged, including 2 infected cases. The remaining 3/7 surgically managed cases were euthanized due poor quality of life. 8/15 cases were managed medically; 7/8 were discharged, 1 died. 3/7 then represented, and underwent successful surgical intervention after recrudescence of clinical signs, and all were discharged. The remaining 4 medically managed cases did not require further therapeutic intervention, with no clinical deterioration on reassessment.

CONCLUSIONS AND CLINICAL IMPORTANCE

Medical management is a viable treatment option for some dogs with pancreatic fluid accumulation, or as a prequel to surgical management. Subclassifications of pancreatic fluid accumulations using diagnostic findings could enable more tailored management approaches and accurate prognostication.

Pancreatic Abscess in a cat due to Staphylococcus aureus infection

A 16-year-old spayed female American Shorthair cat was presented with lethargy, anorexia, and wamble. Physical and blood examination did not reveal any remarkable findings. Abdominal ultrasonography identified the presence of a localized anechoic structure with a thick wall in contact with the small intestine and adjacent to the liver. Ultrasound-guided fine-needle aspiration of the structure revealed fluid containing numerous cocci and neutrophils. Two days after antibiotic treatment, exploratory laparotomy was performed and the content of the structure was removed before multiple lavages. The pathological and bacteriological examination results supported a confirmatory diagnosis of pancreatic abscess due to Staphylococcus aureus infection, making this the first such report in a cat. The cat remained healthy thereafter with no disease recurrence.

Management of acute pancreatitis in dogs: a critical appraisal with focus on feeding and analgesia

Knowledge about acute pancreatitis has increased recently in both the medical and veterinary fields. Despite this expansion of knowledge, there are very few studies on treatment interventions in naturally occurring disease in dogs. As a result, treatment recommendations are largely extrapolated from experimental rodent models or general critical care principles. General treatment principles involve replacing fluid losses, maintaining hydrostatic pressure, controlling nausea and providing pain relief. Specific interventions recently advocated in human medicine include the use of neurokinin-1 antagonists for analgesia and early interventional feeding. The premise for early feeding is to improve the health of the intestinal tract, as unhealthy enterocytes are thought to perpetuate systemic inflammation. The evidence for early interventional feeding is not supported by robust clinical trials to date, but in humans there is evidence that it reduces hospitalisation time and in dogs it is well tolerated. This article summarises the major areas of management of acute pancreatitis in dogs and examines the level of evidence for each recommendation.

Pancreatic Abscess in a Cat with Diabetes Mellitus

An 11 yr old spayed female Maine coon cat was referred with uncontrolled diabetes mellitus. The cat had a 2 mo history of weight loss and intermittent vomiting. An abdominal ultrasound identified the presence of a large cavity measuring a maximum of 4.6 cm in the pancreas that was filled with a homogeneous echogenic fluid. Cytological analysis and culture of the fluid obtained from the pancreatic mass indicated the presence of a bacterial abscess. The application of nonsurgical drainage and the administration of glargine insulin and antibiotics resolved the clinical signs. The size of the pancreatic abscess was reduced after 5 mo, and the cat achieved diabetic remission and remained healthy at the time this report was prepared. This case report describes the successful treatment of a pancreatic bacterial abscess concurrent with diabetes mellitus in a Maine coon cat.

Barium peritonitis in small animals

Barium peritonitis is extremely rare, but is difficult to treat and may be life-threatening. Barium suspension leakage from the gastrointestinal tract into the abdominal cavity has a time-dependent and synergistically deleterious effect in patients who have generalized bacterial peritonitis. The severity of barium peritonitis is dependent on the quantity of barium in the abdominal cavity. Barium sulfate leakage results in hypovolemia and hypoproteinemia by worsening the exudation of extracellular fluid and albumin. Abdominal fluid analysis is a useful and efficient method to diagnose barium peritonitis. Serial radiographs may not be a reliable or timely diagnostic technique. Initial aggressive fluid resuscitation and empirical broad-spectrum antibiotic treatment should be instituted promptly, followed quickly by celiotomy. During exploratory surgical intervention, copious irrigation and direct wiping with gauze are employed to remove as much barium as possible. Omentectomy should be considered when needed to expedite barium removal. Despite aggressive medical and surgical treatments, postoperative prognosis is guarded to poor due to complications, such as acute vascular shock, sepsis, diffuse peritonitis, hypoproteninemia, electrolyte imbalance, cardiac arrest, small bowel obstruction related to progression of granulomas and adhesions in the abdominal cavity. Therefore, intensive postoperative monitoring and prompt intervention are necessary to maximize chances for a positive outcome. For those that do survive, small bowel obstruction is a potential consequence due to progression of abdominal adhesions.

Retroperitoneal Abscesses in Seven Dogs

Retroperitoneal abscesses, although uncommon, are clinically important. Medical records of seven dogs with naturally occurring retroperitoneal infections from 1999 to 2011 were reviewed to document historical, examination, clinicopathologic, imaging, and surgical findings; etiologic agents; and outcome. Middle-aged sporting dogs were most commonly affected. Dogs were febrile with evidence of either abdominal or lumbar pain. Although traditional radiography can aid in diagnosis, ultrasound appeared to be a more sensitive indicator of disease within the retroperitoneal space. Numerous bacteria were isolated from the abscesses, with anaerobic and facultative anaerobic bacteria being the most commonly isolated. Etiology was largely unknown, but migrating plant material was often suspected. Resolution of the infection required surgical intervention as well as prolonged antibiotic therapy. Although recurrence is possible, outcome can be favorable with no long-term sequela.

Pathophysiology of acute pancreatitis: potential application from experimental models and human medicine to dogs

The cellular events leading to pancreatitis have been studied extensively in experimental models. Understanding the cellular events and inciting causes of the multisystem inflammatory cascades that are activated with this disease is of vital importance to advance diagnosis and treatment of this condition. Unfortunately, the pathophysiology of pancreatitis in dogs is not well understood, and extrapolation from experimental and human medicine is necessary. The interplay of the inflammatory cascades (kinin, complement, cytokine) is extremely complex in both initiating leukocyte migration and perpetuating disease. Recently, nitric oxide (NO) and altered microcirculation of the pancreas have been proposed as major initiators of inflammation. In addition, the role of the gut is becoming increasingly explored as a cause of oxidative stress and potentiation of systemic inflammation in pancreatitis.

Characteristics and outcomes in surgical management of severe acute pancreatitis: 37 dogs (2001-2007)

OBJECTIVE

Describe clinical characteristics and outcomes associated with canine patients undergoing surgical intervention for treatment of acute pancreatitis.

DESIGN

Retrospective outcome study from 2001 to 2007.

ANIMALS

Thirty-seven dogs.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The following data were collected for dogs who underwent surgical intervention in the course of treatment for severe acute pancreatitis: preoperative clinicopathologic and physical data, ultrasonographic findings, surgical procedure detail, histopathologic findings, and transfusion requirements. The survival rate was 80.8% in dogs with extrahepatic biliary obstruction, 64.3% in dogs undergoing necrosectomy, and 40.6% with pancreatic abscess. Overall survival was 63.6%. Surgical complications included intraoperative and postoperative hemorrhage in 12 dogs, postoperative development of diabetes mellitus in 3 dogs, exocrine pancreatic insufficiency in 1 dog, and bacterial peritonitis in 2 dogs.

CONCLUSION

Surgical intervention and aggressive postoperative care may be pursued in select dogs with severe acute pancreatitis. In dogs with extrahepatic biliary obstruction secondary to acute pancreatitis, surgical intervention may be associated with a good prognosis whereas dogs with pancreatic abscess formation may have a more guarded prognosis.

Treatment of a retroperitoneal abscess by omentalization in an orangutan (Pongo pygmaeus pygmaeus)

A 38-yr-old orangutan (Pongo pygmaeus pygmaeus) presented with chronic lethargy and difficulty in locomotion that progressed to weakness, anorexia, and permanent dorsal and/or lateral recumbency. The orangutan was immobilized with ketamine. Abdominal ultrasonography revealed a mass in the caudal portion of the abdomen. Exploratory surgery was performed, but the mass could not be resected. Instead, the mass was drained and omentalized in an attempt to establish continuous drainage after surgery. The only complication was a wound infection that was treated locally with a disinfectant and installation of a drain that was changed every 2 days under anesthesia. Omentalization was successful in providing continuous fluid drainage for this retroperitoneal abscess and required minimal postoperative handling of the animal.

Primary Omental Abscessation or Omental Infarction in Four Dogs

Primary omental abscessation was diagnosed in three dogs after laparotomy. Laparotomy was performed to explore an abdominal mass of unknown origin and chronic fat necrosis diagnosed in one dog as an incidental finding during ovariohysterectomy. Primarily hypoechoic masses not connected to any abdominal structures were visualized with abdominal ultrasound in three dogs. Suppurative inflammation was diagnosed from fine-needle aspirate evaluation in two dogs. Bacteria were cultured from two abscesses despite the absence of organisms on Gram stain, cytology, and histopathology. Foreign material was found in one abscess. All four dogs experienced weight loss and/or an episode of gastrointestinal signs. Primary omental abscessation may be preceded by omental vascular compromise and/or interaction of the omentum with foreign material.

Pancreatic abscess in 36 dogs: a retrospective analysis of prognostic indicators

Thirty-six dogs were diagnosed with pancreatic abscess by the presence of purulent exudate within the parenchyma of the pancreas during exploratory laparotomy. Data regarding history, physical examination findings, clinicopathological data, diagnostic imaging findings, bacteriological culture results, abdominal drainage technique, and perioperative treatment were evaluated for factors predictive of survival. Elevated blood urea nitrogen, serum alkaline phosphatase activity, and rising bicarbonate ion concentration were each found to have statistically significant (P<0.05) influences on survival to discharge. Twenty-two (71%) of 36 dogs died or were euthanized prior to discharge from the hospital.