Laparoscopic portosystemic shunt attenuation in 20 dogs (2018-2021)

Serum Amino Acid Profiles in Dogs with a Congenital Portosystemic Shunt

Background/Objectives: A functional liver is vital for normal protein metabolism. Alterations of circulating amino acid (AA) concentrations have previously been reported in dogs with hepatocellular carcinoma, chronic hepatitis, and hepatocutaneous syndrome. The purpose of this study was to compare serum AA profiles between dogs with a congenital portosystemic shunt (CPSS) and healthy control dogs. Methods: Serum samples were collected from 50 dogs with an extrahepatic congenital portosystemic shunt (eCPSS) and 10 dogs with an intrahepatic congenital portosystemic shunt (iCPSS) at time of surgical intervention and from 21 healthy control dogs. Serum AA and other nitrogenous compounds were measured with a dedicated amino acid analyzer. The concentration of each AA was compared between groups using a Kruskal-Wallis test followed by Dunn's multiple comparisons tests, as appropriate. The Benjamini-Hochberg procedure was used to control for false discovery. Significance was set at q < 0.05. Results: Compared to healthy controls, dogs with a CPSS had significantly increased serum concentrations of ammonia, asparagine, glutamic acid, histidine, phenylalanine, serine, and tyrosine and had significantly decreased concentrations of isoleucine, leucine, threonine, urea, and valine. There were no significant differences in serum AA concentrations between dogs with an eCPSS and dogs with an iCPSS. Conclusions: Dogs with a CPSS had altered serum AA concentrations compared to healthy control dogs, including decreased branched-chain amino acids (BCAAs) and increased aromatic amino acids (AAAs). In summary, serum AA profiles can differentiate dogs with a CPSS from healthy dogs but not dogs with an eCPSS from dogs with an iCPSS.

A Window Opens and a Shunt Closes: A New Laparoscopic Approach for the Attenuation of the Gastrophrenic Shunt

The portosystemic shunt is characterized by the presence of an anomalous vessel, whether congenital or acquired, that connects the portal circulation to the systemic circulation. Surgical treatment is indicated in congenital cases and involves the progressive occlusion of the anomalous vessel. The objective of this study is to report the use of an innovative and fully laparoscopic technique for the attenuation of a gastrophrenic shunt. The procedure was performed on a two-year-old female German Spitz dog with a history of frequent vomiting and diarrhea. The diagnosis was established through computed tomography. For the procedure, three portals were placed in the left lateral region, employing an ameroid constrictor. This device featured a specific perforation for the passage of a pre-mounted suture, which was subsequently occluded intracorporeally, facilitating the closure of the ring defect. The absence of flow in the anomalous vessel was confirmed five weeks after the procedure. It is concluded that the reported implantation technique represents a new modality for the treatment of this type of shunt using a minimally invasive approach.

Advances in Minimally Invasive Procedures of the Thoracic Cavity

Significant advances in veterinary minimally invasive surgeries and procedures have occurred in the past 10 years. These advances have been allowed due to continual research into optimizing working space through one-lung ventilation techniques and carbon dioxide insufflation. Additionally, minimally invasive surgery enthusiasts have joined forces with interventionalists and, in many cases, physicians to push the boundaries, minimize pain, suffering, and time away from owners with advances in a variety of procedures. Several larger multi-institutional retrospective studies on various disease processes allow veterinarians and owners to understand that minimally invasive approaches allow for outcomes comparable to traditional open surgery and, in some cases, may now be considered the standard of care in canine and feline patients.

Clinical outcomes for 20 cats with congenital extrahepatic portosystemic shunts treated with ameroid constrictor ring attenuation (2002-2020)

OBJECTIVE

To report the clinical perioperative, short-term, and long-term outcomes for cats undergoing ameroid ring constrictor (ARC) attenuation of a congenital extrahepatic portosystemic shunt (EHPSS).

STUDY DESIGN

Retrospective case series from a single veterinary teaching hospital (2002-2020).

ANIMALS

Twenty client-owned cats with EHPSS.

METHODS

Data collected from medical records included signalment, history, physical examination, clinicopathologic testing, medications, diagnostic imaging, intraoperative findings, perioperative complications, and postoperative clinical outcomes. Long-term clinical outcome was obtained from a standardized owner interview or medical records.

RESULTS

Perioperative complications were reported in five cats out of 20, including blindness (two cats), ascites (one cat), head pressing (one cat), and seizures and death (one cat). Short-term clinical outcome was excellent in 14/18 cats, good in 2/18 cats, and poor in 2/18 cats that were available for follow up, and long term clinical outcome was excellent in 15/18, good in 1/18 cats, and poor in 2/18 cats that were available for follow up.

CONCLUSION

Long-term clinical outcome was good or excellent in 16/18 of cats available for follow up. Perioperative complications were reported in five cats.

CLINICAL SIGNIFICANCE

Surgical attenuation of EHPSS with an ARC can result in resolution of clinical signs and biochemical abnormalities in the majority of cats. The perioperative complication rate for feline patients with EHPSS attenuated with an ARC was lower than reported historically. Seizures may persist in the long term despite normal bile acid stimulation test results, complete blood count, and biochemistry analysis.

Percutaneous shunt vessel embolisation with Amplatzer vascular plugs II and IV in the treatment of dogs with splenophrenic shunts: four cases (2019-2022)

OBJECTIVES

To describe the treatment of four dogs with splenophrenic shunts using percutaneous shunting vessel embolisation with Amplatzer vascular plugs II and IV and provide information on their clinical outcomes.

MATERIALS AND METHODS

Dogs with splenophrenic shunts treated at a veterinary hospital from January 2019 to December 2022 were identified through a medical record search.

RESULTS

Six dogs with splenophrenic shunts were identified. Two dogs were excluded because they were treated with laparoscopic surgery. Four underwent percutaneous shunting vessel embolization with Amplatzer vascular plugs and were included in the case series. A sheath was placed in the left external jugular vein and a balloon catheter was advanced to the shunting vessel under fluoroscopy. Portal vein pressure was confirmed to be within an acceptable range during temporary balloon occlusion. Based on preoperative CT angiography and intraoperative contrast examination, Amplatzer vascular plugs II were selected for two dogs and IV were selected for two dogs. Under fluoroscopy, the plug was deployed into the shunting vessel, and angiography confirmed occlusion. In all cases, the increase in portal pressure after temporary occlusion was within the acceptable range, and complete occlusion of blood flow was possible with a single plug. There were no major procedure-related complications. No dogs developed post-ligation seizures or signs of portal hypertension. In addition, improvements in ammonia values were observed in all cases.

CLINICAL SIGNIFICANCE

Percutaneous splenophrenic shunt embolisation using Amplatzer vascular plugs II and IV is technically feasible in dogs, and assessed by intra-procedure angiography, a single plug completely obstructed blood flow in all dogs. Based on the literature search, this is the first report describing Amplatzer vascular plugs for the treatment of splenophrenic shunts.

Laparoscopic attenuation of a congenital extrahepatic portosystemic shunt in a dog—a thin-film banding for splenophrenic shunt: A case report

A 6-year-old castrated male Shih-Tzu dog weighing 6. 5 kg presented with chief complaints of pollakiuria and urine dribbling. He had a history of urolithiasis for 3 years, which was confirmed by the presence of ammonium urate in the urinary stone analysis, performed 2 years prior to the presentation. Blood examination showed high values of fasting ammonia, post-prandial bile acid, and low blood urea nitrogen. Microhepatica and urolithiasis were identified on plain radiography and ultrasonography. A computed tomography angiography demonstrated a shunting vessel, diameter up to 9.6 mm, originated from the splenic vein, and linked with the phrenic vein. A surgical attenuation with a thin-film banding was performed under laparoscopic visualization. Left triangular ligament was incised, and one stay suture was placed to the stomach to expose the vessel. The shunting vessel was dissected before it entered the diaphragm, and a thin-film band was applied around the vessel. The patient recovered uneventfully without post-attenuation neurologic signs. Portal vein diameter increased with time, and complete closure of the shunting vessel was identified on computed tomography angiography performed at 14 months after attenuation. The patient was doing well for 31 months after surgery without protein restriction. This is a report of laparoscopic attenuation for splenophrenic type of canine congenital extrahepatic portosystemic shunt with a favorable outcome using thin-film banding.