Prospective Evaluation of Laparoscopic Pancreatic Biopsies in 11 Healthy Cats

Surgical Anatomy of the Gastrointestinal Tract in Cats

In cats, the gastrointestinal tract is one of the regions in which surgical procedures are most frequently performed by veterinary surgeons; therefore, knowledge of the surgical anatomy of the feline gastrointestinal tract is of high importance. The main surgical procedures performed include gastrotomy, gastrectomy, enterotomy, and enterectomy, as well as procedures in the liver and pancreas. There are also anatomical differences between dogs and cats, increasing the need for deep knowledge of the anatomy treated in the different surgical approaches. The aim of the present review is to describe in detail the anatomy of the gastrointestinal tract in cats highlighting the anatomical regions of significant importance in different surgical procedures.

Retrospective comparison of open vs minimally invasive cystotomy in 28 cats using a composite outcome score

OBJECTIVES

The aim of this study was to compare the outcomes of cats undergoing open cystotomy with those undergoing minimally invasive surgery (MIS) for removal of cystic calculi by use of a composite outcome score.

METHODS

Twenty-eight cats were retrospectively enrolled and divided into two groups: open cystotomy (n = 14) and MIS (n = 14). The primary outcome measure was a composite outcome score, including three variables: pain scores ⩾2 at either 6 or 12 h postoperatively; failure to remove all stones as determined by postoperative radiographs; and postoperative complications requiring a visit to the hospital separate from the planned suture removal appointment. Other data collected included signalment, history, other procedures performed during anesthesia, willingness to eat the day after surgery and the financial cost of the procedures.

RESULTS

There was no significant difference in age, weight, sex or breed between the two groups. The risk of experiencing the composite outcome was 3/14 (21.4%) in the MIS group and 10/14 (71%) in the open procedure group (P = 0.02). The cats in the open surgery group had 8.3 times greater odds of developing the composite outcome than cats in the MIS group (odds ratio 8.3, 95% confidence interval 1.3-74.4; P = 0.02). In the MIS group, 10/14 cats were eating the day after surgery vs 3/14 in the open procedure group (P = 0.02). The procedural cost was higher in the MIS group, with a median cost of US$945 (interquartile range [IQR] US$872-1021) vs US$623 (IQR US$595-679) in the open group (P <0.01).

CONCLUSIONS AND RELEVANCE

In this study the composite outcome score provided evidence to support the use of MIS techniques in cats with cystic calculi. The composite outcome score should be considered in future veterinary studies as a promising method of assessing clinically relevant outcomes.

ACVIM consensus statement on pancreatitis in cats

Background

Pancreatitis in cats, although commonly diagnosed, still presents many diagnostic and management challenges.

Objective

To summarize the current literature as it relates to etiology, pathogenesis, diagnosis, and management of pancreatitis in cats and to arrive at clinically relevant suggestions for veterinary clinicians that are based on evidence, and where such evidence is lacking, based on consensus of experts in the field.

Animals

None.

Methods

A panel of 8 experts in the field (5 internists, 1 radiologist, 1 clinical pathologist, and 1 anatomic pathologist), with support from a librarian, was formed to assess and summarize evidence in the peer reviewed literature and complement it with consensus clinical recommendations.

Results

There was little literature on the etiology and pathogenesis of spontaneous pancreatitis in cats, but there was much in the literature about the disease in humans, along with some experimental evidence in cats and nonfeline species. Most evidence was in the area of diagnosis of pancreatitis in cats, which was summarized carefully. In contrast, there was little evidence on the management of pancreatitis in cats.

Conclusions and Clinical Importance

Pancreatitis is amenable to antemortem diagnosis by integrating all clinical and diagnostic information available, and recognizing that acute pancreatitis is far easier to diagnose than chronic pancreatitis. Although both forms of pancreatitis can be managed successfully in many cats, management measures are far less clearly defined for chronic pancreatitis.

Feline comorbidities: What do we really know about feline triaditis?

PRACTICAL RELEVANCE

Feline triaditis describes concurrent pancreatitis, cholangitis and inflammatory bowel disease (IBD). The reported prevalence is 17-39% in ill referral patients. While the aetiology is poorly understood, it is known to include infectious, autoimmune and physical components. What is not known is whether different organs are affected by different diseases, or the same process; indeed, triaditis may be part of a multiorgan inflammatory disease. Feline gastrointestinal tract anatomy plays its role too. Specifically, the short small intestine, high bacterial load and anatomic feature whereby the pancreatic duct joins the common bile duct before entering the duodenal papilla all increase the risk of bacterial reflux and parenchymal inflammation. Inflammation may also be a sequela of bowel bacterial translocation and systemic bacteraemia.

DIAGNOSTIC CHALLENGES

Cholangitis, pancreatitis and IBD manifest with overlapping, vague and non-specific clinical signs. Cholangitis may be accompanied by increased serum liver enzymes, total bilirubin and bile acid concentrations, and variable ultrasonographic changes. A presumptive diagnosis of pancreatitis is based on increased serum pancreatic lipase immunoreactivity or feline pancreas-specific lipase, and/or abnormal pancreatic changes on ultrasonography, though these tests have low sensitivity. Diagnosis of IBD is challenging without histopathology; ultrasound findings vary from normal to mucosal thickening or loss of layering. Triaditis may cause decreased serum folate or cobalamin (B12) concentrations due to intestinal disease and/or pancreatitis. Triaditis can only be confirmed with histopathology; hence, it remains a presumptive diagnosis in most cases.

EVIDENCE BASE

The literature on feline triaditis, pancreatitis, cholangitis and IBD is reviewed, focusing on histopathology, clinical significance and diagnostic challenges. Current management recommendations are provided. Further studies are needed to understand the complex pathophysiology, and in turn improve diagnosis and treatment.

Prevalence and Clinicopathological Features of Triaditis in a Prospective Case Series of Symptomatic and Asymptomatic Cats

Background

The term triaditis designates the concurrent presence of idiopathic inflammatory bowel disease (IBD), cholangitis, and pancreatitis in cats.

Hypothesis/Objectives

The histopathology of concurrent, but often subclinical, inflammatory processes in the small intestine, liver, and pancreas of cats is poorly described. We aimed to investigate the frequency of enteritis, cholangitis, pancreatitis, or some combination of these in symptomatic and asymptomatic cats, compare clinicopathological features, and correlate histopathological with laboratory findings.

Animals

Domestic cats (27 symptomatic, 20 asymptomatic, and 8 normal).

Methods

Prospective study. Physical examination, laboratory variables (CBC, serum biochemistry profile, serum thyroxine concentration, serum feline trypsin‐like immunoreactivity [fTLI], feline lipase immunoreactivity [fPLI, as measured by Spec fPL^®], urinalysis, and fecal analysis), imaging, and histopathological examinations were conducted. Feline liver, pancreas, and small intestine were biopsied during laparotomy.

Results

Inflammatory lesions were detected in 47 cats (27 symptomatic, 20 asymptomatic). In total, 20 cats had histopathologic lesions of IBD (13/47, 27.7%), cholangitis (6/47, 12.8%), or pancreatitis (1/47, 2.1%) alone, or inflammation involving >1 organ (27/47, 57.4%). More specifically, 16/47 cats (34.0%) had concurrent lesions of IBD and cholangitis, 3/47 (6.4%) of IBD and pancreatitis, and 8/47 cats (17%) of triaditis. Triaditis was identified only in symptomatic cats (8/27, 29.6%). A mild, positive correlation was detected between the severity (score) of IBD lesions and the number of comorbidities (rho = +0.367, P = .022).

Conclusions and Clinical Importance

Histopathological evidence of IBD or IBD with comorbidities was detected in both symptomatic and asymptomatic cats. The possibility of triaditis should be considered in symptomatic cats with severe IBD.

Can clinical signs, clinicopathological findings and abdominal ultrasonography predict the site of histopathological abnormalities of the alimentary tract in cats?

OBJECTIVES

Many cats with gastrointestinal signs have coexisting abnormalities in the intestine, liver and pancreas. Investigations typically involve clinicopathological tests, diagnostic imaging and biopsy, either at coeliotomy or by non-invasive means. While exploratory coeliotomy enables all organs to be sampled simultaneously, it is invasive and might not be necessary. The aim of the current study was to assess the performance of preliminary clinical information in predicting the histopathological presence of abnormalities in alimentary tract organs in cats.

METHODS

The records of 38 cats with alimentary tract signs, which had ultimately undergone exploratory coeliotomy and surgical biopsy, were reviewed. The clinical signs, clinicopathological findings, diagnostic imaging findings and histopathology results were reviewed.

RESULTS

On histopathological analysis, lesions were detected in 29/37 (78%) liver biopsies, in 29/35 (83%) gastrointestinal biopsies and in 17/37 (46%) pancreatic samples, the majority of which were inflammatory in nature. Clinical signs were generally poor markers of the presence of lesions in the alimentary tract. Further, while liver enzyme activity was relatively specific (88-100%) for detecting histopathological abnormalities in the liver, sensitivity was poor (11-50%). Pancreatic histopathological abnormalities were present in 1/3 of the cats with a positive pancreas-specific lipase result, and in 6/8 cats with a negative result. While relatively specific (57-100%) for both intestinal (57-100%) and hepatic (71-80%) histopathological abnormalities, abdominal ultrasonography lacked sensitivity for both organs (intestine 50-80%; liver 20-25%). In contrast, ultrasonography was relatively sensitive (50-80%), but not specific (17-22%) for detecting pancreatic lesions.

CONCLUSIONS AND RELEVANCE

Clinical signs, and clinicopathological and ultrasonographic abnormalities lack precision for hepatic and pancreatic histopathological lesions in cats with alimentary tract signs, and cannot reliably predict from which organs biopsies should be collected. Arguably, therefore, exploratory coeliotomy is necessary to determine the site of histopathological abnormalities in feline alimentary tract disorders.

Laparoscopic-Assisted Surgical Procedures

Laparoscopic-assisted procedures allow a balance between the improved patient recoveries often associated with smaller incisions and the need for appropriate visualization of visceral organs/identification of lesions. The organ systems of small animal veterinary patients that are highly amenable to laparoscopic-assisted procedures include the urinary bladder, the gastrointestinal tract, and the reproductive tracts. Laparoscopic-assisted procedures are especially beneficial in the approach to luminal organs, allowing the organ incision to be exteriorized through the body wall, protecting the peritoneal cavity from contamination from luminal contents. Procedure-specific morbidities and patient selection should be considered when choosing between assisted laparoscopic and open approaches.

Diagnosis of pancreatitis in dogs and cats

Pancreatitis is the most common disorder of the exocrine pancreas in both dogs and cats. Ante-mortem diagnosis of canine and feline pancreatitis can be challenging. The clinical picture of dogs and cats with pancreatitis varies greatly (from very mild to severe or even fatal) and is characterised by non-specific findings. Complete blood count, serum biochemistry profile and urinalysis should always be performed in dogs and cats suspected of having pancreatitis, although findings are not-specific for pancreatitis. Serum amylase and lipase activities and trypsin-like immunoreactivity (TLI) concentrations have no or only limited clinical value for the diagnosis of pancreatitis in either dogs or cats. Conversely, serum pancreatic lipase immunoreactivity (PLI) concentration is currently considered to be the clinicopathological test of choice for the diagnosis of canine and feline pancreatitis. Abdominal radiography is a useful diagnostic tool for the exclusion of other diseases that may cause similar clinical signs to those of pancreatitis. Abdominal ultrasonography can be very useful for the diagnosis of pancreatitis, but this depends largely on the clinician's experience. Histopathological examination of the pancreas is considered the gold standard for the diagnosis and classification of pancreatitis, but it is not without limitations. In clinical practice, a combination of careful evaluation of the animal's history, serum PLI concentration and abdominal ultrasonography, together with pancreatic cytology or histopathology when indicated or possible, is considered to be the most practical and reliable means for an accurate diagnosis or exclusion of pancreatitis compared with other diagnostic modalities.

Prospective evaluation of access incision position for minimally invasive surgical organ exposure in cats

OBJECTIVE

To evaluate the exposure obtained for minimally invasive abdominal organ biopsy (MIOB) from 3 access incisions in cats.

DESIGN

Prospective experimental study and clinical case series.

ANIMALS

6 purpose-bred research cats and 6 feline clinical patients with indications for abdominal organ biopsy.

PROCEDURES

Three 3-cm incisions into the peritoneal cavity were created at different locations along the linea alba in research cats in randomized order. A wound retraction device was inserted in each incision. Ability to exteriorize various abdominal organs to the extent required to reasonably perform a surgical biopsy was recorded, and results were compared among incision sites. On the basis of results obtained, the access incision that provided exposure of the most frequently biopsied abdominal organs was used to perform MIOB in 6 feline clinical patients with various underlying pathological conditions.

RESULTS

On the basis of experiments with research cats, a 3-cm access incision centered midway between the caudal margin of the xiphoid cartilage and the umbilicus was found to provide access for MIOB for most organs. In 5 of 6 clinical patients, all of the organs of interest were biopsied successfully via this incision location, although access to all hepatic lobes and all parts of the pancreas was inconsistent. In 1 cat, conversion to an open approach was performed because a palpable mass was detected in the area of the duodenocolic ligament.

CONCLUSIONS AND CLINICAL RELEVANCE

Optimization of access incision location for MIOB allowed biopsy specimen collection from organs of interest to be performed in a minimally invasive manner in cats.

Diagnostic laparoscopy in the cat: 2. Common procedures

PRACTICAL RELEVANCE

Minimally invasive techniques are becoming increasingly available in both first opinion and referral veterinary surgeries. Clients may be reluctant to pursue open surgery for the collection of biopsy samples in a sick cat but may be more open to a laparoscopic approach. Furthermore, a laparoscopic approach provides excellent visualization of the abdominal organs and enables high quality biopsies to be taken that are invariably more diagnostic than percutaneous needle biopsies. Although the feline patient is small in size, its distensible abdomen allows more room for surgical manipulation than afforded by a similar sized canine patient.

CLINICAL CHALLENGES

Clinical challenges for the most part relate to mastering laparoscopic technique. Familiarity with the use of long instrumentation viewed on a two-dimensional screen is essential. Hemostasis is an important consideration and suitable instrumentation for achieving hemostasis should be available at all times. Insufflation of the abdomen carries its own challenges with regard to anesthesia and this is covered in an accompanying article in this Special Issue series.

AIM

This article introduces the feline practitioner to basic techniques required to effectively utilize diagnostic laparoscopy within feline medical investigations. It focuses on the common procedures of liver biopsy, cholecystocentesis, pancreatic biopsy, kidney biopsy and laparoscopic-assisted intestinal biopsy.

EVIDENCE BASE

Information provided in this article is drawn from the published literature and the authors' own clinical experience.

Diagnostic laparoscopy in the cat: 1. Rationale and equipment

PRACTICAL RELEVANCE

The integration of minimally invasive techniques into feline practice seems to be an intuitive step forward, especially for those cases where the owner may be reluctant to subject their cat to major surgery 'just for a biopsy'. Although ultrasound is frequently employed as a diagnostic tool in similar cases, this modality can only provide information on gross abnormalities in organ size and shape, echogenicity and internal architecture; even with ultrasound-guided fine-needle aspiration a definitive diagnosis is rarely achieved. So the clinician and owner are left with unanswered questions that are central to the diagnosis, the most appropriate treatment to pursue and the prognosis for the cat. Laparoscopy does require anesthesia and is more expensive than ultrasound; however, when performed correctly, it is only marginally more invasive and vastly more informative, with a proven track record of minimal morbidity.

AUDIENCE

This article is aimed at all feline practitioners, from first opinion through to the referral setting. It is intended to encourage practitioners untrained in minimally invasive procedures to seek formalized training, especially those who want to expand their diagnostic capabilities. For those already performing minimally invasive surgery, it describes how laparoscopic techniques can be applied to many feline gastrointestinal cases.

EVIDENCE BASE

Information provided in this article is based on published literature, comprising original studies, case review series and textbook chapters, and the authors' own clinical experience.

Pancreatic surgical biopsy in 24 dogs and 19 cats: postoperative complications and clinical relevance of histological findings

OBJECTIVE

To assess the immediate postoperative complications associated with pancreatic biopsy in dogs and cats and review the clinical relevance of biopsy findings.

METHODS

Retrospective review of clinical records from two referral institutions for cases undergoing pancreatic biopsy between 2000 and 2013.

RESULTS

Twenty‐four dogs and 19 cats that had surgical pancreatic biopsy had sufficient detail in their clinical records and fulfilled the inclusion criteria. Postoperative complications were seen in 10 cases of which 5 were suggestive of post‐surgical pancreatitis. Two patients were euthanased within 10 days of surgery because of the underlying disease; neither suffered postoperative complications. Pancreatic pathology was found in 19 cases, 7 cases showed no change other than benign pancreatic nodular hyperplasia, and no abnormalities were seen in 18 cases.

CLINICAL SIGNIFICANCE

Complications may be encountered following surgical pancreatic biopsy, although the risk should be minimal with good surgical technique. Pancreatic biopsy may provide a useful contribution to case management but it is not clear whether a negative pancreatic biopsy should be used to rule out pancreatic disease. Dogs were more likely to have no significant pathology found on pancreatic biopsy than cats, where chronic pancreatitis was the most common finding.

Use of laparoscopy for diagnosing experimentally induced acute pancreatitis in dogs

Diagnosis of acute pancreatitis in dogs remains a significant challenge despite the development of advanced diagnostic methodologies. Visual inspection and pancreas biopsy using laparoscopy are generally considered to be procedures free of complications when conducted on healthy animals. However, the usefulness of laparoscopy for diagnosing acute pancreatitis has not been assessed. In the present study, the efficacy of laparoscopy for diagnosing acute pancreatitis in dogs was evaluated in animals with experimentally induced acute pancreatitis. Gross appearance of the pancreatic area was examined by laparoscopy to survey for the presence of edema, adhesions, effusion, pseudocysts, hemorrhage, and fat necrosis. Laparoscopic biopsy was performed and the histopathologic results were compared to those of pancreatic samples obtained during necropsy. The correlation between laparoscopy and histopathologic findings of the pancreas was evaluated. The presence of adhesions, effusion, and hemorrhage in the pancreatic area observed by laparoscopy significantly correlated with the histopathologic results (p < 0.05). There was no significant relationship between the histopathologic and laparoscopic biopsy findings. Results of this study suggested that laparoscopic evaluation of gross lesions has clinical significance although the laparoscopic biopsy technique has some limitations. This method combined with additional diagnostic tools can be effective for diagnosing acute pancreatitis in dogs.

Investigation of Parenchymal Abdominal Organ Disease in Cats

Practical relevance:

Definitive diagnosis of disease involving the parenchymal abdominal viscera often requires a representative specimen of affected tissue. Methods used to obtain tissue samples range from those that are minimally invasive, such as fine-needle aspiration (FNA), to more invasive techniques such as surgical biopsy.

Clinical challenges:

FNA and cytological examination can be a useful diagnostic tool and is commonly used for hepatic, splenic and lymph node specimens. FNA is an easy and cheap procedure that is best suited to diffuse disease and can be performed at low risk to the patient. However, its accuracy and agreement with the histopathological findings vary depending on the underlying disease and it often fails to provide information on parenchymal architecture. Importantly, FNA for cytological examination of the liver has serious limitations when used to identify the primary disease process due to the small sample size obtained.

Audience:

This review is aimed at clinicians undertaking more detailed and specialist investigation of diseases of feline parenchymal abdominal organs and provides practical guidance on the different methods used to obtain hepatic, renal, pancreatic and splenic specimens in cats.

Evidence base:

The information presented is based on peer-reviewed publications and the clinical experience of the author.

Laparoscopic splenectomy: operative technique and outcome in three cats

CLINICAL SUMMARY: The clinical findings, treatment and outcome for three cats that underwent laparoscopic splenectomy using bipolar vessel-sealing devices for resection of diffuse splenic disease are described. In each case, a three-portal laparoscopic technique was used. The spleen was manipulated and its mesentery and associated vessels sequentially cauterized and ligated to enable removal through a portal incision with minimal hemorrhage. Each of the three patients recovered from anesthesia without incident and was able to be discharged to the owner the next day. PRACTICAL SIGNIFICANCE: Laparoscopic splenectomy may be a safe and effective alternative to celiotomy in a select group of cats requiring splenectomy.

Laboratory tests for diagnosis of gastrointestinal and pancreatic diseases

The panel of laboratory tests available for diagnosis of gastrointestinal (GI) diseases in dogs and cats is wide, and, recently, several new tests have been developed. This article will focus on advances in laboratory tests that are available for the general practitioner for diagnosis of GI diseases. Laboratory tests for diagnosis of gastric and intestinal infectious diseases include fecal parasite screening tests, enzyme-linked immunosorbent assays for parvoviral enteritis, and some specific bacterial tests like fluorescent in situ hybridization for identification of specific bacteria attached to the intestinal epithelial cells. Serum concentrations of folate and cobalamin are markers of intestinal absorption, but are also changed in exocrine pancreatic insufficiency and intestinal bacterial overgrowth. Hypocobalaminemia is common in GI and pancreatic disease. Decreased serum trypsin-like immunoreactivity is a very sensitive and specific test for the diagnosis of exocrine pancreatic insufficiency in dogs and cats. Serum pancreatic lipase is currently the most sensitive and specific test to identify pancreatic cell damage and acute pancreatitis. However, serum canine pancreas-specific lipase is less sensitive in canine chronic pancreatitis. Increased serum trypsin-like immunoreactivity is also specific for pancreatic damage but is less sensitive. It is very likely that further studies will help to better specify the role of these new tests in the diagnosis of canine and feline pancreatic diseases.