Duplex gall bladder associated with choledocholithiasis, cholecystitis, gall bladder rupture and septic peritonitis in a cat

Double cholecystectomy of duplex gallbladder associated with chronic cholecystitis in a cat

A 6-year-old female neutered Persian cat presented with hyporexia and gradual weight loss over 6 months. Physical examination revealed cranial abdominal pain. Haematology and serum biochemistry were within normal limits. Abdominal ultrasonography and a computed tomography scan suggested a non-neoplastic mass compressing the gallbladder. During an exploratory laparotomy, a duplex gallbladder with two separate cystic ducts was diagnosed intraoperatively. The mass identified using the imaging techniques was an abnormal right gallbladder which was distended with immobile mucoid bile and a thickened wall. The left gallbladder and cystic duct were grossly normal. A cholecystectomy of both gallbladders was performed. Histopathology of the right gallbladder identified chronic cholecystitis. The cat made a good recovery from surgery and reported complete resolution of its hyporexia and a return to normal body weight. This is the first report of a successful cholecystectomy of a duplex gallbladder with chronic cholecystitis of a single gallbladder.

Surgical Management Of Feline Biliary Tract Disease: Decision-making and techniques

PRACTICAL RELEVANCE

Diseases of the hepatobiliary system are not uncommon in first-opinion practice. The anatomy of the feline hepatobiliary tract differs from that of dogs and may predispose cats to inflammatory hepatobiliary disease. Case management can be challenging, and the prognosis is variable and dependent on the underlying disease process.

CLINICAL CHALLENGES

Biliary tract disease in the cat has non-specific clinical signs that overlap with those of diseases of other body systems. Diagnostic tests of the hepatobiliary system are widely available, but interpretation of results can be challenging. Deciding on medical or surgical management can also be challenging; for example, various degrees of cholestasis may be seen with different diseases and disease severities, and will influence the decision to manage the patient medically or surgically. Surgery is indicated in cases of bile peritonitis, severe cholestasis, focal neoplasia or disease that is refractory to medical management. Intensive perioperative and postoperative management, with 24 h hospitalisation facilities, is essential.

AUDIENCE

This review article is written for the small animal general/primary care practitioner, with an emphasis on decision-making in the surgical management of feline hepatobiliary disease.

EVIDENCE BASE

Evidence available in the published literature is reviewed and presented, and the inherent limitations are discussed.

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.

Common bile duct perforation due to choledocholithiasis in a cat with gallbladder agenesis

Case summary

An 8-year-old neutered male domestic shorthair cat was presented for further investigation of anorexia, vomiting and lethargy. Abdominal ultrasonography and contrast-enhanced CT revealed choledocholithiasis with suspected bacterial peritonitis and non-visualisation of the gallbladder. During surgery, the common bile duct was noted to be perforated, and a cholelith was found in the abdominal cavity. No gallbladder was confirmed during surgery. Three months postoperatively, the cat underwent CT cholangiography and absence of the gallbladder with a vestigial duplicated gallbladder was diagnosed.

Relevance and novel information

Gallbladder agenesis is extremely rare in cats, with only one previous report, but several dogs have been diagnosed based on CT cholangiography and laparoscopy. This report describes gallbladder agenesis concurrent with choledocholithiasis in an adult cat and represents the first report of CT cholangiography in a cat with gallbladder agenesis.

Ultrasonographic prevalence and proposed morphologic classification of bilobed gallbladder in cats

OBJECTIVES

Morphologic anomalies of the feline gallbladder (GB) have been previously reported in the literature. These morphologic variants are frequently encountered on routine abdominal ultrasound examination. The aim of this study was to provide an ultrasonographic classification system of these variants and document the overall incidence in the feline population.

METHODS

A prospective, descriptive study was undertaken; cats that had an abdominal ultrasound examination that included at least one sagittal and transverse plane image of the GB were included. GB shape was evaluated and categorized based on a classification scheme of morphologic variants modified from the human literature. Septated (S), bilobed (B1, B2, B3), duplex (D) and complex (C) categories were described.

RESULTS

Of 516 cats included in the study, 389 had normal GB morphology, while 127 had anomalous GB morphology. The overall incidence rate of anomalous GB morphology was 24.61%. When examined by morphologic type, the septated (S) morphology had an incidence of 9.69%. A bilobed (B) morphology was the most commonly observed classification; incidence was 14.35% within our population; incidence of B1, B2 and B3 subtypes were 2.91%, 6.98% and 4.46%, respectively. Duplex GBs only made up 0.39% of the total population. The incidence of complex (C) morphologies was 0.19%.

CONCLUSIONS AND RELEVANCE

The incidence of GB morphologic anomalies was higher in our population than previously reported. Identification of these anomalies on routine ultrasound evaluation is common; numerous different morphologies can be identified and a standardized classification scheme is proposed. Complete evaluation of morphology can be challenging, particularly with regard to cystic duct anatomy. Clinical significance is uncertain and future studies are warranted to determine the relationship between morphologic variants and hepatobiliary disease.

Feline cholangitis/cholangiohepatitis complex - what have we learned?

Cholangitis/cholangiohepatitis complex in cats is commonly encountered in clinical practice worldwide. Diagnosis and management of cats with this complex is difficult because of the ambiguity of clinical signs, diagnostic test results and commonality of comorbid disorders. These impediments can delay disease identification and treatment, which can increase morbidity and mortality. ​In this narrative review, we aimed to provide a thorough review of the unique physioanatomic features of the biliary system as well as clinically relevant updates on cholangitis/cholangiohepatitis complex in cats.

Pancreatic enzyme activity in the bile of healthy cats and its association with biliary morphology

Background

In human medicine, congenital maljunction of the common bile duct (CBD) and main pancreatic duct (MPD), or pancreatobiliary maljunction (PBM), is a known cause of cholecystitis.

Objective

Pancreatic enzyme activity in the bile (a diagnostic marker for PBM) of healthy cats was measured to determine normal values and evaluate its relationship with biliary morphology.

Animals

Fifty‐two healthy cats.

Methods

Cross‐sectional study of the biliary tracts of healthy cats during laparoscopic ovariohysterectomy and measurement of pancreatic enzyme activity in bile. The cats were divided into groups A and B based on the ratio of the diameter of the cystic duct (CD) to the CBD. The normal ratio was 3.4. Pancreatic enzyme activity in bile was compared between the groups.

Results

The CBDs were straight in all cases, whereas the CDs were variably tortuous or dilated. Amylase activity in the bile (median, <100 U/L; range, <100‐591 U/L) was lower than in serum in all cases, and group B, which had a CD/CBD ratio >3.4, had significantly higher amylase activity (median, 109 U/L; range, <100‐591 U/L) in the bile than did group A (median, <100 U/L; range, <100‐238 U/L), which had a CD/CBD ratio <3.4 (P = .0009).

Conclusions and Clinical Importance

The results suggest that a dilated CD is associated with reflux of pancreatic juice. In the future, it will be necessary to examine the clinical usefulness of these findings by measuring pancreatic enzyme activity in the bile of cats with cholangitis.

Surgical Management of Feline Extrahepatic Biliary Tract Diseases

Extrahepatic biliary obstruction occurs infrequently in cats. Pathophysiology of biliary obstruction is characterized by cholestasis, obstruction, inflammation, and exudation. Clinical signs and laboratory examination findings are nonspecific. Ultrasonographic examination of the biliary tract aids significantly in diagnosis. The aims of feline biliary surgery are to determine the underlying cause and extent of the obstruction, restore bile flow to the gastrointestinal tract, and prevent bile leakage and subsequent peritonitis. Surgical techniques to restore bile flow and decompress the biliary distension include cholecystostomy tube placement and choledochal stenting, cholecystectomy, choledochotomy, and biliary diversion procedures. Surgical management of extrahepatic biliary obstruction carries a fair to guarded prognosis. Cats undergoing biliary diversion procedures have poorer outcomes than those undergoing nondiversion procedures. Cats with neoplastic involvement have significantly shorter lives than those with inflammatory involvement.

Feline abdominal ultrasonography: what's normal? what's abnormal? The biliary tree

PRACTICAL RELEVANCE

Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. The biliary tree encompasses the liver, gall bladder and bile ducts, although only diseases affecting the latter two are discussed here. Diseases of the bile ducts and gall bladder are more common than those of the liver parenchyma and ultrasound plays an important role in their diagnosis.

CLINICAL CHALLENGES

Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even differentiating between normal variation and pathological changes can be challenging for all but the most experienced. In addition, a lack of pathological change does not necessarily rule out disease; for example, absence of gall bladder and/or extrahepatic biliary distension is not sufficient to exclude the possibility of biliary obstruction, and in many cases of cholangitis the liver and biliary tree are unremarkable on ultrasound examination.

EQUIPMENT

Ultrasound facilities are readily available to most practitioners, although use of ultrasonography as a diagnostic tool is highly dependent on operator experience.

AIM

This review, part of an occasional series on feline abdominal ultrasonography, discusses the appearance of the normal and diseased biliary system. It is aimed at general practitioners who wish to improve their knowledge and confidence in feline abdominal ultrasound and is accompanied by high-resolution images. Percutaneous ultrasound-guided cholecystocentesis is also covered. Ultrasound examination of the liver was discussed in an article published in January 2019 and an upcoming article will cover hepatic vascular anomalies.

EVIDENCE BASE

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

Feline biliary tree and gallbladder disease: Aetiology, diagnosis and treatment

Practical relevance Diseases of the biliary tree and gallbladder are more common in cats than diseases of the liver parenchyma. The parenchyma is usually affected secondarily to systemic illnesses, while the biliary system is the prime target for infectious agents (eg, bacteria and flukes) and non-infectious conditions (eg, neoplasia and cysts). Clinical approaches Cats with biliary disease are evaluated because of common feline clinical signs such as anorexia, nausea, vomiting and lethargy. Icterus may or may not be obvious. Biopsies for histological evaluation, and bile aspirates for culture and cytological evaluation are helpful diagnostically. Antibiotics and immunosuppressive drugs have been used successfully. Hepatosupportive drugs may help in liquefying thick bile and protecting hepatic tissue from damage. Ultrasound is a noninvasive diagnostic tool that may help in identifying dilated bile ducts, liver cysts and choleliths. It is also used to guide percutaneous bile aspiration. Audience This review, written for all veterinarians who treat cats, describes the various conditions that can affect the feline biliary tree and gallbladder. Treatment options are discussed, and brief summaries provided of surgical techniques and diagnostic approaches. Evidence base The veterinary literature pertaining to feline biliary disease is comprehensively reviewed. When appropriate, data on dogs and humans has been included to provide background information. Based on the available literature, more research into feline biliary diseases is needed.