Left hepatic vein attenuation for treatment of patent ductus venosus in a dog

Patent ductus venosus was identified in a young dog. Surgical attenuation of the anomalous vessel was performed by partial ligation of the left hepatic vein. Clinical signs resolved after surgery, and laboratory values returned to normal. Jejunal venous portography, performed 8 weeks after surgery, revealed complete occlusion of the patent ductus venosus, with normal portal vasculature to the right and central divisions of the liver. Atrophy of the left hepatic division resulted.     

Transportal Approach for Attenuating Intrahepatic Portosystemic Shunts in Dogs

A novel surgical approach, using portal venotomy during total hepatic vascular occlusion, was used to locate and attenuate congenital intrahepatic portosystemic shunts in nine dogs. Shunt location was consistent with a persistent ductus venosus in only two dogs. In the remaining seven dogs the shunts were window-like orifices arising from either the left (two dogs) or right portal vein branch (five dogs) and communicating with the ipsilateral hepatic vein or caudal vena cava. The transportal approach using total hepatic vascular occlusion consistently provided good access to the portosystemic shunts, including those with window-like communications. A 7 to 16 minute period of total vascular occlusion was well-tolerated hemodynamically, with few intraoperative complications. Intrahepatic shunts were successfully attenuated in eight dogs, while one dog with portal atresia was euthanatized. The postoperative course was complicated by high protein pulmonary edema (one dog), an encapsulated biliary pseudocyst (one dog) and uncontrollable hemorrhage caused by an uncharacterized coagulopathy (one dog). Three dogs required a second operation to further attenuate their shunts. The clinical condition of all seven surviving dogs was improved after surgery.     

Cellophane banding of congenital intrahepatic portosystemic shunts in two Irish wolfhounds

Two three-month-old, male Irish wolfhound siblings were diagnosed with breed-typical left divisional congenital intrahepatic portosystemic shunts consistent with patent ductus venosus. The shunts were amenable to surgical dissection at a posthepatic location. Both dogs had cellophane banding for shunt attenuation. One dog was euthanased after developing post-ligation neurological dysfunction, which was refractory to treatment. The other dog survived and demonstrated shunt attenuation. Successful surgical management using cellophane banding of a patent ductus venosus has not been previously described in a large-breed dog.     

Hepatoencephalopathy associated with situs inversus of abdominal organs and vascular anomalies in a dog.

Throughout its life, a 1-year-old Doberman Pinscher dog had had gastrointestinal disorders and episodes of circling. It was less active than its littermates, and it usually seemed lethargic. When 3 months old, the pup had been anesthetized for ear cropping and it had remained anesthetized for 32 hours. Behavioral problems were apparent when the dog was 11 months old. Two weeks later the behavioral problems accentuated to the point that the dog developed "temper tantrums" and became aggressive toward its owner. On the basis of clinicopathologic and contrast radiographic findings, hepatoencephalopathy due to persistent patent ductus venosus was diagnosed and the dog was euthanatized. Situs inversus abdominalis and multiple vascular anomalies were found at necropsy. Gross and microscopic studies of the viscera were correlated with corrosion casts of the vasculature. In addition to changes in organ position, 3 spleens and malformation of the pancreas were observed. Vascular anomalies were: (1) The portal vein was contiguous with the common hepatic vein by way of a patent ductus venosus; branches of the portal vein were not given off to the liver; (2) the caudal vena cava was continued by the azygos vein, and a cranial segment of the caudal vena cava was absent; (3) the hepatic artery was larger than normal; (4) the left gastric artery arose anomalously from the cranial mesenteric artery; and (5) histologic and radiographic study of the liver did not reveal any interlobular branches of the portal vein; however, hypoplastic branches of the gastroduodenal vein did enter the liver and were demonstrated on a corrosion cast.     

Medical management of a patent ductus venosus in a dog

A 2.5-year-old dog with signs of weight loss, vomiting, and hepatic encephalopathy was diagnosed with a patent ductus venosus, based on serum biochemical analysis, jejunal portography, and biopsies, and treated with lactulose, antibiotics, and a reduced protein diet. Two years after initial presentation, the dog is still being managed medically.     

Anatomy of the Ductus Venosus in Neonatal Dogs (Canis familiaris)

Anatomical features of the ductus venosus in 84 neonatal dogs are described. The ductus venosus was a straight conduit 1–3 mm wide and 4–12 mm long in pups with a crown-rump length of 80–200 mm. It arose from the left main portal vein branch opposite the umbilical vein, passed between the left lateral liver lobe and the papillary process of the caudate lobe, and terminated in the dorsal aspect of the proximal part of the left hepatic vein. The left hepatic vein was dilated at this point. There was no variation in the location of the ductus venosus in the animals studied.     

The angiographic anatomy of the portal venous system in the neonatal dog

The angiographic anatomy of the portal venous system in 50 dead, neonatal Labrador/Retriever type puppies is described. Angiography was performed by the injection of radioopaque contrast media through a catheter placed within the umbilical vein. In 49 pups the ductus venosus was a straight vessel arising from the left main portal vein and terminating in an ampulla into which the left hepatic and left phrenic veins entered prior to the ampulla entering the caudal vena cava. The diameter of the ductus venosus was significantly narrower (P<0.001) in pups born alive (n=10) when compared to stillborn individuals (n=39). No discreet narrowing of the ductus venosus indicating a sphincter was found, with closure appearing to be uniform along the vessel's length. A well-developed, patent portal venous system was present in the majority of individuals. One pup showed variation from the others studied having a vascular connection between the portal sinus and the vena cava within the liver. This may represent a normal variant of the ductus venosus, or may be an anatomical abnormality leading to the development of an intrahepatic portosystemic shunt. If this was an intrahepatic shunt, no concurrent ductus venosus was present.     

Doppler ultrasonographic assessment of closure of the ductus venosus in neonatal Irish wolfhounds

The normal appearance and closure time of the ductus venosus of 22 neonatal Irish wolfhounds from three unrelated litters were determined by repeated two-dimensional, grey-scale and colour-flow Doppler ultrasound examinations. A left intercostal approach was used to identify the ductus venosus, which appeared as a parallel-sided or cone-shaped vessel connecting a left-sided intrahepatic branch of the portal vein with a confluence of veins on the cranial aspect of the liver. Doppler signals indicative of patent ductus venosus were obtained in nine of nine puppies on day 2, 11 of 17 on day 4, five of 22 on day 6, none of nine on day 9 and none of eight on day 10.     

Anatomy of the patent ductus venosus in the dog

The biplanar umbilical vein portovenograms of 49 newborn puppies and the biplanar mesenteric vein portovenograms, obtained during surgery, of 42 adult dogs with left divisional intrahepatic portosystemic shunts consistent with a patent ductus venosus (PDV) were reviewed. On the basis of the combined surgical, postmortem and imaging data, the left divisional intrahepatic portosystemic shunts were consistent, each having a straight vessel which drained into a venous ampulla before draining into the caudal vena cava at the level of the diaphragm. The left phrenic vein and the left hepatic vein both entered the ampulla independently of the shunting vessel. The morphology of the ductus venosus in the pups was similar and consistent with the morphology of the left divisional intrahepatic PDV shunt of the adult dogs. It is concluded that this form of left divisional shunt is correctly named a PDV and is the result of the persistence of the fetal ductus venosus. From the surgical records it is concluded that all the shunts described as a PDV were attenuated by the direct manipulation of the ductus venosus before its entry into the ampulla.     

Ultrastructural Studies of the Goose Embryo Liver

Development of the liver in goose embryo was studied ultrastructurally. The structural changes of the liver in the 14, 21, 24 and 28 days old embryos were investigated.
The liver primordium of endodermal origin localized around the ductus venosus. The hepatocyte trabeculae proliferating into the ductus venosus, first divide the lumen into wide sinusoids then with the number of trabeculae increasing the sinusoids become narrow on the 15th day. The hepatocytes in 11–14 days old embryos are less differentiated and poor in cell organelles. There are many fat drops in multi vacuolic form at the hepatocytes in 21 days old but specially in 27 days old embryos. The liver contain little connective tissue, it is formed between days 17 and 21. The endothelial cells comprise well developed endoplasmic reticulum. The Kupffer-cells contain lipid drops after the 22th day.     

Medial insertion of the patent ductus arteriosus characterized by computed tomography angiography in a cat and dog

Surgical ligation of a left-to-right shunting patent ductus arteriosus was attempted in two animals. In both cases, a young cat and dog, ligation was complicated by poor visualization of the ductus resulting in unsuccessful ligation. Post-operatively, both the cat and dog underwent computed tomography angiography to characterize the location and morphology of the patent ductus arteriosus. In both cases, computed tomography angiography revealed a left-to-right shunting patent ductus arteriosus with an insertion location medial to the left pulmonary artery branch compared to the typical location. We hypothesize that this atypical location resulted in a difficult surgical visualization from the left thoracotomy approach. Transvenous coil embolization of the duct from the external jugular vein was performed in both cases and resulted in successful occlusion. Variations in the medial-lateral insertion of the ductus arteriosus may have consequences for surgical intervention. If an atypical location of a patent ductus arteriosus is suspected on transthoracic echocardiography, computed tomography angiography prior to ligation may be useful to further define ductal location and help guide the surgical approach.     

Contrast-enhanced magnetic resonance angiography of patent ductus arteriosus in a dog

Gadolinium-enhanced three-dimensional magnetic resonance angiography is a relatively new technique in the veterinary field. A mature dog with suspected patent ductus arteriosus underwent contrast-enhanced magnetic resonance angiography at 1·0 T with a three-dimensional fast low-angle shot (FLASH) gradient-echo technique. Qualitatively, three-dimensional images of the ductus were particularly clear with surface reconstructions, and ductus diameters were easy to assess in native images. Contrast-enhanced magnetic resonance angiography is a fast, relatively non-invasive procedure that could be particularly useful when non-surgical interventional procedures are anticipated for ductus occlusion.     

Minimally invasive patent ductus arteriosus occlusion in 5 dogs

OBJECTIVE: To report a technique for minimally invasive occlusion of patent ductus arteriosus (PDA) and outcome in 5 dogs. STUDY DESIGN: Clinical cases. Animals: Five, 4-6-month-old, dogs with PDA. MATERIALS AND METHODS: Titanium ligating clips were used for PDA closure in all dogs. Three dogs had video-enhanced mini-thoracotomy PDA occlusion. Two other dogs had thoracoscopic PDA occlusion using a custom-designed thoracoscopy clip applicator. RESULTS: Thoracoscopic PDA occlusion was successful in both dogs in which it was attempted. Complete PDA closure was achieved in 4 dogs. Three months after surgery, the largest dog had residual ductal flow that hemodynamically was insignificant. CONCLUSIONS: Although technically demanding, minimally invasive PDA occlusion is a safe and reliable technique in dogs. Preoperative measurement of the diameter of the PDA is crucial to determine if complete closure with metal clips can be achieved. CLINICAL RELEVANCE: Minimally invasive PDA occlusion should be considered as an alternative to occlusion via conventional thoracotomy.     

Supplemental embolization coil implantation for closure of patent ductus arteriosus in a beagle dog.

Embolization coil for the occlusion of patent ductus arteriosus (PDA) was inserted in a beagle dog diagnosed as PDA with systolic murmur. Residual shunt was observed three months postoperatively and then supplemental coil was inserted. In the past only one coil was required for the closure of PDA in our cases with good post-operative results. In this case, however, the largest coil presently available (8 mm in diameter with 5 loops) was inadequate to make sufficient closure within 3 months postoperatively and supplemental coil insertion was necessary to produce a successful occlusion.     

Transvenous detachable coiling of patent ductus arteriosus in small dogs

ObjectiveTo report on transvenous detachable coiling in small dogs deemed ineligible for traditional transarterial patent ductus arteriosus occlusion and compare transthoracic echocardiographic and angiographic measurements to determine their equivalence.Materials and methodsA retrospective study of 35 dogs that underwent transvenous coiling of a patent ductus arteriosus. Demographic information, echocardiographic and angiographic studies, surgery reports, and follow-up evaluation of residual flow were obtained. A Bland-Altman analysis was used to compare echocardiographic and angiographic measurements of the minimal ductal diameter (Echo-MDD, Ang-MDD) and ampulla diameter (Echo-A, Ang-A).ResultsThirty-four of 35 dogs had successful deployment of a coil, with one dog undergoing occlusion with a different device after the exteriorized coil pulled through the ductus. Complete occlusion was achieved in 18 dogs within 24 h; four dogs were lost to follow-up, and the remaining 12 dogs had no residual flow or a significant reduction in shunting with normalization in cardiac chamber dimensions by a median of 99 days. Thirty percent of dogs (11/35) experienced perioperative complications of which 10 were minor complications. The analysis of 26 dogs with both echocardiographic and angiographic ductal measurements showed a −0.14 mm mean difference (95% limits of agreement −1.08 to 0.8 mm) in minimal ductal diameter and −0.68 mm mean difference (95% limits of agreement −2.73 to 1.37 mm) in ampulla diameter.ConclusionsDogs less than 3 kg deemed too small for transarterial occlusion can successfully undergo transvenous coil embolization of patent ductus arteriosus.     

Hybrid technique for ventricular septal defect closure in a dog using an Amplatzer® Duct Occluder II

A left-to-right shunting muscular ventricular septal defect (VSD) was diagnosed in a 4-month-old, female, 1.8 kg Bichon Frise – poodle mix dog. Echocardiographic evidence of cardiac remodeling, calculated pulmonary blood flow (Qp) to systemic blood flow (Qs) ratio of 2.8, and radiographic evidence of pulmonary edema supported the diagnosis of a hemodynamically important VSD. Using a combination of surgery and interventional catheter-based techniques to approach the VSD through the right ventricle, the VSD was occluded with an Amplatzer^® Duct Occluder (ADO) II device. The ADO II is a low profile, flexible device originally developed for patent ductus arteriosus closure in humans that has been used to close muscular and perimembranous VSD in children. This report describes the hybrid procedure and imaging that was essential for successful occlusion of the VSD in this dog.     

The use of Amplatzer vascular plug II in 32 consecutive dogs for transvenous occlusion of patent ductus arteriosus

ObjectivesTo describe the use of the Amplatzer vascular plug II (AVPII) for transvenous occlusion of patent ductus arteriosus in a non-selective population of dogs, with a focus on the surgical technique, short term outcome and associated complications.Animals, materials and methodsRetrospective study. Records of thirty-two consecutive dogs treated for a left-to-right shunting patent ductus arteriosus with the AVPII were reviewed.ResultsDuctal occlusion with an AVPII occlusion device was attempted in 32 dogs weighing 1.1–53.8 kg. Transvenous occlusion was successful in 30 dogs. One dog required a transarterial approach for occlusion. One dog died during catheterisation of the right heart but prior to transductal catheterisation. Mean ductal ampulla diameter was 7.9 mm (range, 4.1–15.4 mm) and median size of deployed devices was 10 mm (range 4–20 mm). Mean device to ampulla ratio was 1.34 ± 0.15. Device was positioned in situ with no residual flow on follow-up echocardiographic assessment (> one month) in all dogs where deployment was attempted. Occlusion success rate was 96.9% and mortality rate was 3.1%. Four dogs (13.3%) demonstrated minor complications, with none having long-term significance.ConclusionsThe use of AVPII device via a transvenous approach is a feasible and effective method for occlusion of a left-to-right shunting patent ductus arteriosus in dogs of a wide range of weight. The method described may complement existing catheter-based occlusion methods.     

Closure of a persistent ductus arteriosus of Botallo in two dogs using transarterial coil embolization

Non-surgical occlusion of persistent ductus arteriosus (PDA) by catheter guided coil embolisation was performed in two dogs. In both dogs the procedure was performed through the femoral artery. The exact location and the narrowest diameter of the PDA were evaluated angiographically after contrast medium injection into the ascending aorta. Based on shunt diameter measurements of 4 mm in dog no. 1 and 2.4 mm in dog no. 2, a coil of 8 mm diameter was chosen for dog no. 1, and of 5 mm diameter for dog no. 2. The coils were placed within the shunt vessel under fluoroscopic guidance using the Cook delivery-system for detachable PDA coil. The success of the intervention was documented angiographically 10 minutes after coil release. The shunt vessel was completely occluded in dog no. 1, while minimal blood flow was detected in dog no. 2 at that time. The technique of transvascular PDA closure compares favorably with the traditional surgical technique due to minimal invasiveness and hence excellent postinterventional comfort to the patient.     

Intracardiac echocardiography: use during transcatheter device closure of a patent ductus arteriosus in a dog

Intracardiac echocardiography (ICE) is used in humans for percutaneous interventional procedures, such as transcatheter device closures. Intracardiac echocardiography provides high-resolution imaging of cardiac structures with two-dimensional, M-mode, Doppler, and also three-dimensional modalities. The present report describes application of ICE during transcatheter occlusion of patent ductus arteriosus using a canine ductal occluder in a dog for which transesophageal echocardiography could not provide an optimal acoustic window.     

Congenital feline portosystemic shunts

Five young cats with portosystemic communications, 2 with single intrahepatic and 3 with single extrahepatic portosystemic communications, were managed surgically. One cat with a ductus venosus was treated successfully by surgery. Ptyalism and behavioral changes were similar in all 5 cats. Biochemical abnormalities included low BUN values, increased blood ammonia values, and increased sulfobromophthalein retention. None of the cats had portal hypertension at the time of surgery. Seemingly, single portosystemic shunts should be considered a surgical disease in the cat.