Evaluation of gallbladder and common bile duct size and appearance by computed tomography in dogs

Computed tomographic features of exocrine pancreatic carcinomas in dogs and cats

Exocrine pancreatic carcinomas are uncommon in dogs and cats, and diagnosis with diagnostic imaging can be challenging. This retrospective, multi-institutional, descriptive study was performed to evaluate the CT features of exocrine pancreatic carcinomas. The CT examinations of 18 dogs and 12 cats with exocrine pancreatic carcinomas diagnosed by cytology or histopathology were reviewed. The CT features of exocrine pancreatic carcinomas included a well-defined mass in 28/30 (93%) with contrast enhancement in 27/30 (90%), commonly heterogeneous 22/30 (73%); often with a nonenhancing fluid to soft tissue attenuating center 12/30 (40%). The right lobe of the pancreas was the most common location, 14/30 (47%), then the left lobe, 10/30 (33%), and the body, 6/30 (20%). Extrahepatic biliary duct dilation was present in six animals; 5/6 (83%) of the masses were located in the right pancreatic lobe. Additional findings included peripancreatic fat-stranding 17/30 (57%), lymphadenopathy 16/30 (57%), peripancreatic soft tissue nodules 12/30 (40%), and free fluid 10/30 (33%). When comparing the imaging features of dogs and cats, there was a large overlap in imaging characteristics. There was a significant difference between the height of the masses, with dogs having larger masses (P-value.0028). Lymphadenopathy was more likely in larger masses [increased height (P-value.029)]. Cats were significantly older than dogs (P-value.0355). Pancreatic carcinomas were commonly identified as masses with heterogeneous contrast enhancement and a nonenhancing fluid to soft tissue attenuating center with concurrent peripancreatic changes (fat-stranding and/or soft tissue nodules) and lymphadenopathy.

Computed tomographic quantitative evaluation of common bile duct size in normal dogs: A reference range study considering body weight

Introduction

Common bile duct (CBD) measurements are important for the evaluation of biliary systemic disorders. However, in veterinary medicine, reference ranges for specific body weights (BW) and correlation between CBD diameter and BW have not been studied. This study aimed to establish normal reference ranges of CBD diameter for different BW groups and to analyse correlation between CBD diameter and BW in dogs without hepatobiliary disease. Additionally, normal reference ranges of CBD to aorta ratio (CBD: Ao ratio) were established which is not affected by BW.

Methods

CBD diameter was measured at three different sites: porta hepatis (PH), duodenal papilla (DP) level and mid-portion (Mid) between these points using computed tomography (CT) in 283 dogs without hepatobiliary disease.

Results

The reference range of CBD diameter at PH level: 1.69 ± 0.29 mm (Class 1; 1 kg ≤ BW < 5 kg), 1.92 ± 0.35 mm (Class 2; 5 kg ≤ BW < 10 kg), 2.20 ± 0.43 mm (Class 3; 10 kg ≤ BW < 15 kg), 2.79 ± 0.49 mm (Class 4; 15 kg ≤ BW < 30 kg); Mid-level: 2.06 ± 0.25 mm (Class 1), 2.43 ± 0.37 mm (Class 2), 2.74 ± 0.52 mm (Class 3), 3.14 ± 0.44 mm (Class 4); DP level: 2.33 ± 0.34 mm (Class 1), 2.90 ± 0.36 mm (Class 2), 3.35 ± 0.49 mm (Class 3), and 3.83 ± 0.50 mm (Class 4). There was a significant difference in CBD diameter at each level among all BW groups. Furthermore, BW and CBD diameter showed positive linear correlation at each level. We devised CBD: Ao ratio at each level that showed no significant difference between the different BW groups; PH level: 0.34 ± 0.05; Mid-level: 0.42 ± 0.06; DP level: 0.47 ± 0.06.

Conclusion

In conclusion, since the CBD diameter for each BW is significantly different, different normal reference ranges of CBD diameter should be applied for each BW, and the CBD: Ao ratio can be used regardless of the BW.

CT features of divisional bile ducts in healthy Labrador Retrievers

Computed tomography (CT) is increasingly being used for the study of gallbladder and bile duct diseases. The first step in interpreting CT findings is understanding the cross-sectional anatomy of the structures involved, but there are no published studies describing the CT features of the divisional bile ducts. In dogs, anatomic studies report two common patterns including three or four divisional bile ducts. The aim of this retrospective, descriptive, anatomical study was to describe the size and pattern of the visible divisional bile ducts, based on their location and extension, using contrast-enhanced CT in a group of Labrador Retrievers without evidence of hepatobiliary diseases. The correlation between the biliary duct number and dimensions, and the visceral fat area percentage (VFA%) was also evaluated. The right lateral divisional duct (RLD) was visualized in four of 40 dogs, the left lateral divisional duct (LLD) in nine of 40 dogs, and in 17 of 40 dogs, both were simultaneously visualized. In 10 of 40 dogs, the RLD and LLD were not highlighted. When visible, the RLD has a median diameter of 0.23 cm and a median length of 0.82 cm. The LLD has a median diameter of 0.23 cm and a median length of 2.72 cm. The median diameter of the common bile duct before and after the insertion of divisional bile ducts was 0.23 and 0.25 cm, respectively. No correlation with the VFA% was found. At least one of the divisional bile ducts could be visualized using contrast-enhanced CT in the majority of sampled dogs (75%) .

Multi-phase MULTIDETECTOR-row computed tomographic features and laboratory findings in dogs with gallbladder rupture

Gallbladder rupture is a life-treating condition in dogs. In human medicine, multidetector-row computed tomography (MDCT) is considered the best modality for the diagnosis of gallbladder rupture. The aims of the study were to describe MDCT features of gallbladder rupture in dogs and to determine the CT findings and laboratory data that differ between dogs with ruptured biliary tree and dogs with biliary disease with no rupture. For this single-center, cross-sectional study were considered for inclusion dogs presented from May 2010 to September 2020, with surgical diagnosis of gallbladder rupture or integrity, who underwent MDCT examination and with CBC and biochemistry results available for review. Forty-seven dogs with different diseases of the biliary tract were included. Seventeen dogs with confirmed gallbladder rupture and 30 dogs with intact gallbladder were included. Multiple MDCT findings showed statistical significance in distinguish dogs with gallbladder rupture: irregular contours of the gallbladder (p < 0.0001), discontinuation of the gallbladder wall (p = 0.0005), adhesions with adjacent organs (p = 0.005), heterogeneous enhancement of the gallbladder wall (p = 0.01), pericholecystic effusion (p = 0.001) and pericholecystic peritonitis (p = 0.001). The presence of three or more of these findings was highly indicative for gallbladder rupture (AUC = 0.921). In this study, MDCT proved to be useful in differentiating dogs with gallbladder rupture from dogs with biliary disease without rupture.

Long-Term Outcome after Cholecystectomy without Common Bile Duct Catheterization and Flushing in Dogs

The aim of this study is to report outcomes of dogs undergoing cholecystectomy for gall bladder mucocele (GBM) without flushing and catheterization of the common bile duct (CBD). This is a retrospective multicentric study from three veterinary referral hospitals and included 82 dogs diagnosed with GBM. Medical records were reviewed for clinical and histopathological findings. Long-term outcome was assessed with an owner questionnaire. The common bile duct was considered normal (<4 mm), mildly dilated (5−6 mm) and moderately dilated (>7 mm) in 88%, 10% and 2.4% of dogs, respectively. Surgery was uncomplicated in 83% of dogs. Intraoperative complications were recorded in 21% of dogs, with hypotension being the most common, whereas postoperative complications were documented in 20% of dogs, with vomiting/regurgitation being the most common. Ninety-six percent of dogs that underwent cholecystectomy in this study survived to discharge. Follow-up ranged from 142 to 3930 days (median: 549 days). Eighty-five percent of dogs were alive at the time of follow-up. Dogs undergoing cholecystectomy for GBM without catheterization and flushing of the CBD have a favourable prognosis for recovery and quality of life.

Diagnostic value of endoscopic retrograde cholangiopancreatography and therapeutic value of endoscopic sphincterotomy in dogs with suspected hepatobiliary disorders

Background

Conventional diagnostic methods have some limitations in diagnosing specific causes of canine hepatobiliary disorders. In the evaluation of the hepatobiliary system in dogs, ultrasonography (US) is the first imaging method of choice. Nonetheless, endoscopic retrograde cholangiopancreatography (ERCP) has also been proven to be a practicable technique for evaluating canine hepatobiliary (endoscopic retrograde cholangiography, ERC) and pancreatic duct (endoscopic retrograde pancreatography, ERP) disorders, providing additional therapeutic options by sphincterotomy (EST). To date, the efficacy and safety of diagnostic and therapeutic ERCP has not been evaluated in veterinary medicine literature. The present study sought to report complications and outcomes of dogs undergoing ERCP and EST, and to assess the usefulness of diagnostic ERCP by comparing the findings of US, ERCP and histopathological findings in liver and pancreas.

Results

This retrospective case series comprises data collected from 15 dogs that underwent successful ERC/ERCP. Nine dogs underwent EST following ERC. US and ERC were best in agreement when assessing the common bile duct. In case of disagreement between the modalities, the ERC findings of the ductal structures were in line with the available pathology findings more often than the US findings, whereas the opposite was noted for the gallbladder. The technical success rates were 88.2% for ERC, 66.7% for ERP, and 81.8% for EST, with no major complications during or immediately after the procedure. Immediate bile flow after EST was recorded in 7/9 dogs but only four showed coinciding clinical and laboratory improvement and four dogs were euthanized within 1-6 days after EST.

Conclusions

US remains a valuable initial diagnostic imaging method for hepatobiliary disorders and allows good assessment of the gallbladder. ERC can serve as a complementary procedure for diagnostic assessment of the hepatobiliary duct disorders. However, in order to improve the outcomes of EST, careful selection of patients for the procedure would require more advanced diagnostic imaging of the hepatobiliary area.

Intravenous dexmedetomidine, morphine, or a combination can result in gallbladder wall thickening; with no significant association with plasma histamine concentrations

The gallbladder is routinely evaluated during ultrasonographic examinations in dogs. However, published studies describing the effects of sedative agents on gallbladder wall thickness are currently lacking. The aims of this prospective, blinded, randomized crossover pilot study were to test hypotheses that IV morphine would result in gallbladder wall thickening, that morphine administration would increase plasma histamine concentrations, and that combining IV morphine with dexmedetomidine would potentiate gallbladder wall thickening. Six healthy Beagle dogs were sedated with intravenous (IV) morphine 0.4 mg/kg (group M), dexmedetomidine 7 μg/kg (group D), or a combination of the two (group MD). Physiologic parameters were measured at baseline and at regular intervals until the last ultrasonographic scan. Ultrasonographic scans were performed at baseline, 90 s, and at 5, 15, 30, 45, 60, 90, and 120 min. Plasma histamine samples were taken at baseline, 90 s, and 5 and 60 min. Cochran's Q-test was used to compare gallbladder wall thickening between groups, while the association between histamine plasma concentration and gallbladder wall thickness was compared with a mixed-effects model. Baseline gallbladder wall thickness was not significantly different between groups. Six of 18 treatments/dogs (33%) developed gallbladder thickening, with no difference between groups. There was no significant difference in baseline plasma histamine concentrations between groups, and no association between plasma histamine concentration and gallbladder wall thickness. Gallbladder wall thickening was observed in at least one dog in each group, therefore caution is recommended for gallbladder wall thickness ultrasonographic interpretation in dogs when these drugs have been administered.

Clinical findings for dogs undergoing elective and nonelective cholecystectomies for gall bladder mucoceles

OBJECTIVES

The purpose of this study was to describe elective and nonelective post-cholecystectomy complications and mortality rates in dogs with a gall bladder mucocele. The secondary purpose was to report complications and mortality rates for different methods of common bile duct catheterisation.

MATERIALS AND METHODS

A multi-institutional retrospective case series was performed to identify dogs with a gall bladder mucocele between 2004 and 2018 that underwent a cholecystectomy. Dogs were classified into nonelective or elective based on the presence or absence, respectively, of gall bladder rupture, biliary duct distension, clinical signs or hyperbilirubinemia. Each cholecystectomy was classified into three groups: duodenotomy and retrograde catheterisation, normograde catheterisation or no catheterisation. Complications were divided into four grades based on increasing severity and mortality rates were assessed for each.

RESULTS

The mortality rate was 2 (6%) out of 31 for dogs undergoing an elective cholecystectomy and 21 (23%) out of 90 for dogs undergoing a nonelective cholecystectomy. The complication rate was 52% for the elective cholecystectomy and 50% for nonelective cholecystectomy. The majority of the complications in the elective category were grade 1 (mild). Post-operative hyperthermia developed in 35% of dogs that had a duodenotomy and retrograde common bile duct catheterisation, in 4% of dogs with a normograde common bile duct catheterisation and in 7% of dogs that did not have the common bile duct catheterised.

CLINICAL SIGNIFICANCE

Elective cholecystectomy in dogs with a gall bladder mucocele in this study carried a low mortality rate and a relatively high frequency of minor complications.

Computed tomographic features of confirmed gallbladder pathology in 34 dogs

Gallbladder pathology is common in dogs, but published studies describing the computed tomographic (CT) appearance of many gallbladder pathologies are currently lacking. This retrospective, multicenter, cases series, descriptive study evaluated the CT features of confirmed gallbladder pathology in 34 dogs. In this subset of dogs, the most common pathologies included cystic mucosal hyperplasia (15/34, 44.1%), gallbladder wall edema (9/34, 26.5%), gallbladder mucocele (8/34, 23.5%), bactibilia (7/34, 20.6%), cholecystitis (6/34, 17.6%), white bile (6/34, 17.6%), and cholelithiasis (4/34, 11.8%). The presence of intraluminal nodules, gallbladder wall thickening, hyperattenuating material (35-100 HU), and mineral attenuating material (>100 HU) were the most common abnormalities detected. However, overlap of each of these findings with a variety of gallbladder pathologies showed that none of the findings were pathognomonic for any of these pathologies. The presence of any of these CT abnormalities should increase the suspicion of gallbladder pathology and prompt further evaluation of the gallbladder for definitive diagnosis.