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.     

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.     

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.     

Intracaval Repair of a Persistent Ductus Venosus in a Dog

A persistent ductus venosus was diagnosed in a 4-month-old Old English sheepdog. Total occlusion of blood flow to the liver was achieved through heparinization, hepatic artery occlusion, and placement of bypass cannulas from the portal vein and caudal vena cava to the right atrium. Intracaval closure of the ductus venosus then was accomplished. Despite postoperative complications of continued hemorrhage and acute renal uremia, the animal recovered. The neurologic abnormalities exhibited before surgery resolved, and the dog became more active and gained weight. The dog died due to undetermined causes three months after surgery. The ductus venosus was found to be closed, and the liver was markedly increased in size at necropsy.     

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.     

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.     

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.     

Anatomy of the patent ductus venosus in the cat

The biplanar mesenteric vein portovenograms of 10 cats with left divisional intrahepatic portosystemic shunts consistent with a patent ductus venosus (PDV) were reviewed. A corrosion cast of the hepatic portal vasculature was made post mortem from one individual that died post operatively following surgical attenuation of the shunting vessel. On the basis of the combined surgical, post mortem and imaging data, these left divisional shunts were found to have consistent anatomy, 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 left hepatic vein both entered the ampulla independently of the shunting vessel. The anatomical similarity between these findings in the cat and the PDV in the dog suggest that it is appropriate to describe this particular portosystemic shunt as a PDV.     

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.     

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.     

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.     

PORTAL VEIN ANOMALY AND HEPATIC ENCEPHALOPATHY IN THREE DOGS

SUMMARY Portal vein anomaly and associated hepatic encephalopathy was diagnosed in three dogs; a 2-year-old Old English Sheep Dog, a 14-week-old Old English Sheep Dog and a 20-week-old Corgi. The common clinical changes were anorexia, vomiting, depression, weakness and ataxia. The major laboratory findings were an elevated serum alanine amino transferase activity, hypoproteinaemia, hypoalbuminaemia, prolonged retention of sulphobromophthalein, fasting and postprandial hypeoammonaemia and ammonium biurate crystalluria. Angiographic studies demonstrated the presence of a patent ductus venosus in each case. The 2 Old English Sheep Dogs were destroyed at the owners' request and the necropsy findings in each case verified the presence of a portacaval shunt and hepatic encephalopathy. The Corgi is still alive, with conservative medical management, 28 months after the onset of signs. The dog is stunted and has mild, intermittent neurological disturbances. Clinical biochemistry indicates severe hepatic insufficiency and suggests a poor long term prognosis.     

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.     

Azoospermia associated with bilateral segmental aplasia of the ductus deferens in a stallion

A 3-year-old Quarter Horse halter stallion was referred for routine semen evaluation. Physically, the stallion's reproductive organs appeared normal. Repeated semen evaluations did not reveal any spermatozoa. Because high activities of alkaline phosphatase are detected in the epididymal fluid and indicative of complete ejaculation, alkaline phosphatase activities were analyzed in several samples, which yielded activities far less than reference values and suggested a blockage of the reproductive tract. Endoscopic evaluation of the urethra and the bulbourethral, prostate, and urethral gland ducts did not reveal abnormalities. The left ductus deferens was exposed surgically, and attempts to pass a catheter through it in a normograde direction met resistance after 20 cm. Laparoscopic abdominal surgery revealed the ductus deferens tapered to a thin structure just cranial to the entrance in the urogenital fold, cranial and lateral to the bladder. Both ductus deferentia were similarly affected. The symmetry and bilateral nature of the abnormalities were strong indications of a possible congenital defect.     

Effect of left hepatic vein ligation on hepatic circulation, function, and microanatomy in dogs.

Eighteen healthy dogs were allotted to 3 groups (n = 6 dogs each). All dogs were evaluated at the beginning of the study by complete physical examination; total and differential WBC counts; serum biochemical analysis (alanine transaminase and alkaline phosphatase activities and bilirubin and albumin concentrations); sulfobromophthalein excretion, ammonia tolerance, and glucagon response testing; portal and intraparenchymal pressure determinations; operative mesenteric portography; and histologic assessment of hepatic biopsy specimens. The left hepatic vein was ligated completely in dogs of groups 1 and 2. Group-3 (control) dogs had a ligature placed loosely around the left hepatic vein. Dogs of groups 1 and 3 were reevaluated 24 hours after surgery by use of the aforementioned hematologic and biochemical tests. Group-1 dogs were reevaluated by use of portal and intraparenchymal pressure determinations, jejunal vein portography, and complete necropsy at 48 hours after surgery. At 4 weeks after surgery, dogs of groups 2 and 3 were reevaluated by use of all aforementioned tests. Results indicated transient hepatic congestion, which resolved by the fourth postoperative week. Longstanding effect on hepatic structure, circulation, or function was not found. We concluded that left hepatic vein ligation in clinically normal dogs does not cause severe or permanent liver damage.     

L'activité sérique de L'ornithine transcarbamylase (OCT) lors d'hépatopathies canines expérimentales

Serum ornithine carbamyl transferase (OCT) was evaluated on eighteen dogs. Three groups were used, the first and second ones were treated with carbon tetrachloride (CCI₄) to produce acute hepatic necrosis and cirrhosis. To the third group a ductus choledochus ligation was performed to simulate extrahepatic cholestasis. Ornithine carbamyl transferase has proven its use in all phases of hepatic necrosis, but only after the fourth day in the extrahepatic cholestasis. Finally in cirrhosis, it was sometimes difficult to interpret the results.     

Hepaticojejunostomy for Treatment of Common Hepatic Duct Obstructions Associated with Duodenal Stenosis in Two Foals

Two female Standardbred foals 2 and 3 months of age were presented with signs of gastroduodenal obstruction that was confirmed with contrast radiography and exploratory surgery. Ventral midline celiotomy was performed, showing stenosis of the duodenum proximal and distal to the hepatopancreatic ampulla. The common hepatic duct, the pancreatic duct, and the sigmoid section of the duodenum proximal to the stenosis were greatly dilated. To bypass the intestinal obstruction, a side-to-side duodenojejunostomy was performed. Obstruction of the common hepatic duct was relieved by side-to-side hepaticojejunostomy. In addition, jejunojejunostomy was performed distal to the other anastomoses. Both foals recovered. On admission, the foals' total bilirubin, aspartate aminotransferase, and gamma glutamyl transferase levels were greatly elevated. During the subsequent 6 to 8 months, they returned to normal. Six months after the first surgery, one foal was readmitted with an acute abdominal crisis. At surgery, there was greater than 360 degrees clockwise rotation of the mesenteric root involving most of the jejunum. At necropsy, the previously created stomas were patent. The liver and bile duct were grossly and histologically normal. The second foal continues to progress normally 12 months after surgery.     

Use of a free cortical ulnar autograft following en bloc resection of a mandibular tumor

A dog was presented for the en bloc resection of a previously irradiated mandibular ossifying epulis. A central hemimandibulectomy was performed, and the mandibular defect was stabilized by the use of a free cortical ulnar autograft and rigid internal fixation. The dog had normal mastication and left forelimb function two weeks after surgery. Radiographic evaluation of the surgical site at three and 10 months after surgery showed normal bony healing.     

Complications from a testicular prosthesis in a stallion

A testicular prosthesis was removed from the scrotum of a 3-year-old Quarter Horse stallion. The prosthesis had been placed in the left side of the scrotum 10 months earlier, after an unsuccessful attempt to reposition the retained left testis. Because of a persistent draining fistula on the scrotum, first noted 5 months after placement of the prosthesis, surgery was performed to remove the prosthesis. At surgery, the left testis was found in a fibrous mass surrounding the prosthesis. The left testis had descended after placement of the prosthesis, and its involvement in the fibrous tissue surrounding the infected prosthesis necessitated its removal. Had the prosthesis not been placed, descent of the left testis probably would have resulted in an essentially normal stallion.     

Results of ligation of patent ductus arteriosus in dogs: 201 cases (1969-1988)

Surgical treatment of 201 dogs with patent ductus arteriosus at the College of Veterinary Medicine, The Ohio State University was evaluated retrospectively to determine risk factors for development of surgical complications. During surgery, 15 dogs (7%) died because of hemorrhage associated with ductus dissection (n = 8), pulmonary edema (n = 4), ventricular fibrillation (n = 1), hemorrhage not associated with ductus dissection (n = 1), and cardiac arrest immediately after ductus ligation (n = 1). An additional 8 dogs (4%) died less than 1 month after surgery (total mortality before, during, and immediately after surgery, 11%). Nineteen dogs (9.5%) developed hemorrhage during surgery. Sixteen dogs developed complications other than hemorrhage (pulmonary edema [n = 4], cardiac arrest [n = 4], iatrogenic lung trauma [n = 3], ventricular fibrillation [n = 2], septicemia [n = 2], and recanalized ductus [n = 2]). Correlation was not found between age, sex, body weight, surgical technique (Jackson method vs standard method of dissection), or surgeon level of training and development of hemorrhage during surgery, other complications, or survival less than 5 days. Positive correlation (P less than 0.05) was found between hemorrhage and death within 5 days after surgery. Positive correlation (P less than 0.05) was also found between other complications and death within 5 days after surgery. Nineteen dogs survived surgery, but later died of unrelated causes (mean life span, 57 months); 63 of the dogs were still alive and doing well as of January 1990 (mean life span, 47 months after surgery). Contrary to previous reports, age, body weight, and surgical technique did not affect results.(ABSTRACT TRUNCATED AT 250 WORDS)