Duct In Dogs Research Articles

Experimental microsurgery of salivary ducts in dogs

The results achieved by experimental microsurgical suturing of salivary ducts in dogs are presented. Nine partial lesions and one complete transection of the ducts were made on parotid and submandibular ducts. Four to seven interrupted microsutures were used for each lesion. The operations were successful in seven out of 10 cases, as observed by sialography. Histologically, granulation tissue compressing the ducts was observed after suturing the lesions. Four venous graft transplantations were performed and none were successful. After venous graft transplantation, the transplant was not apparent histologically, raising doubt as to the potential success of this technique. The use of stenting is discussed based on a summary of the published literature. Those reports indicate that long-term stenting can benefit the outcome of salivary duct repair. The use of dogs as a model for experimental salivary duct operations has been shown to be valuable in assessing various surgical techniques.

Microsurgical repair of Stensen's & Wharton's ducts with autogenous venous grafts: An experimental study on dogs

This study presents the results of microsurgical repair of Stensen's and Warton's ducts in dogs. A method is presented which involves a special technique making use of a catheter and an adventitial cuff. The histological, clinical and sialographic results show the feasibility of this technique.

Does hyperamylasemia in choledochal cyst indicate true pancreatitis? An experimental study.

Patients with choledochal cyst often have repeated attacks of abdominal pain accompanied by hyperamylasemia, and they may be diagnosed as having acute pancreatitis. However, the attacks generally tend to subside in a short period by conservative treatment, and evidence of pancreatitis is rarely observed at the time of surgery. Choledochal cyst is commonly associated with pancreatobiliary maljunction, and high concentrations of pancreatic enzymes in bile are usually observed. When the bile duct pressure increases due to obstructive cholangitis, pancreatic enzymes in bile may regurgitate into the blood stream. Cholangiovenous reflux of amylase might cause hyperamylasemia. In order to investigate the mechanism of hyperamylasemia by cholangiovenous reflux, canine pancreatic juice or bile from a patient with choledochal cyst was injected into the obstructed common bile duct in dogs. The pancreatic enzymes in bile could readily enter into the blood stream at the pressure level of 15 mmHg or more in the bile duct. The peak amylase level in the thoracic lymph was observed to be more than 4 times higher than that in the blood serum, and the lymph flow during 30 minutes increased significantly from 8.1 to 20.4 ml at the bile duct pressure level of 20 mmHg. The reflux of amylase in bile into the blood stream via both the hepatic vein and thoracic duct might result in hyperamylasemia in the patients with choledochal cyst.

Longitudinal changes of plasma pancreatic enzymes and hormones in experimental pancreatolithiasis in dogs.

Plasma pancreatic enzymes and hormones were longitudinally observed after producing partial obstruction of the major pancreatic duct in dogs to study an initial state of chronic pancreatitis or pancreatolithiasis. Fasting plasma immunoreactive cationic trypsin was elevated during the first six months and then decreased in a subgroup with pancreatic calculi, marked fibrosis, or duct dilatation when compared with the corresponding opposite at the end of the 12-month period. Similar but less prominent changes were found in fasting plasma immunoreactive pancreatic polypeptide (IRPP). Plasma amylase, glucose, or immunoreactive insulin or glucagon (IRG) show no significant variation. Plasma IRG and IRPP responses to intravenous insulin were reduced in the subgroups with marked pancreatic changes towards the end of the 12-month period. These results suggest that plasma pancreatic enzymes and hormones remain elevated as long as pancreatic damage is mild and then start to decline as the damage progresses in chronic pancreatitis or pancreatolithiasis.

Acute pancreatitis is not a cause of chronic pancreatitis in the absence of residual duct strictures.

It has been shown that intraductal injections of bile salts into the bile-pancreatic ducts of dogs or rats were immediately followed by acute hemorrhagic pancreatitis and, some months later, by persisting chronic pancreatitis. The study described in this article was designed to test the assumption that these chronic lesions were due to ductal strictures secondary to the toxic effect of bile salts. The bile-pancreatic ducts of 100 rats were injected with 0.2 ml of a solution containing 4 microM Na taurodeoxycholate and 0.2 microM trypsin. The 66 survivors were killed at intervals from 1 day to 2 months following the induction of acute pancreatitis. Four to six sections were done in the first series, and serial 15-micron sections of the entire pancreas were taken from rats surviving 2 months. These showed that from the sixth day on, the largest ducts draining pathological areas were obstructed by fibrosis. Distal to this obstruction, intralobular ducts were dilated and their epithelia flattened or atrophied. Acini were atrophied and replaced by peri- and intralobular fibrosis. Lesions were limited to areas drained by obstructed ducts, with the rest of the parenchyma being normal. We conclude that in experimental animals, as in human beings, chronic lesions that persist after acute pancreatitis are due to duct obstruction, not to acinar necrosis.

Experimental study on the association between bacterial infecton and chronic proliferative cholangitis of the intrahepatic bile ducts in dogs

Experimental study on the association between bacterial infecton and chronic proliferative cholangitis of the intrahepatic bile ducts in dogs

Survival of venous patches autografted into the common bile duct in dogs

The aim of this investigation was to study the possibility of using an autologous vein to replace defects in the anterior wall of CBD. Attempts of this kind were undertaken as long ago as in 1909 by A. F. Bashkirov [1], and later by many other workers [2, 3, 7, i0], but all were unsuccessful. Patches of this kind did not survive in experiments on dogs. Either peritonitis developed after the operation or, if the animal survived, the venous graft underwent severe fibrosis which led to stenosis in the zone of the operation. In clinical practice autologous venous patches (AVP) have been used extremely rarely, and in all cases a rigid internal support was used for drainage [2]. The use of an AVP without drainage tube to close a defect in CBD temporarily is not satisfactory, because fibrous degeneration of the AVP always caused shrinking followed by stenosis of the duct. The authors cited above, who performed these operations, used ordinary surgical techniques. On theoretical grounds, the present writers concluded that ordinary operative techniques adversely affect survival of the AVP in the wall of CBD. In particular, compression of the AVP by the ordinary forceps and clips usually used in surgery is detrimental. These manipulations are extremely traumatic, and this must of course be reflected in the subsequent course of repair processes. The use of quite thick suture material~ in our opinion, also is disadvantageous. The workers who performed these experiments [4-6, Ii] used atraumatic No. i-0 or No. 2-0 suture material. For operations of this kind, as our experience has shown, puncture of the AVP and the wall of CBD by such needles is quite traumatic and rough. Formation of sutures by threads of this thickness also is very traumatic. Bile leaks through the puncture wounds and microfissures thus formed. This may have two results. First, if leakage of bile is slight, foci of infiltration form, complicated in some cases by infection, or even by the formation of microabscesses. Later this leads to progressive cicatrization. Second, in more severe cases the leaking bile and local activation of infection cause lysis of the patch either at its junction with the wall or totally, with subsequent development oflocal peritonitis. To avoid these complications, when performing operations of this kind the present writers have used microsurgical techniques.

Percutaneous cholecystostomy for entry into the canine gallbladder and common bile duct.

Interventional postoperative manipulation of the common bile duct is usually performed for removal of retained calculi via T-tube or surgical cholecystostomy tracks. The removal of foreign bodies from the gallbladder and common bile duct in dogs via cholecystostomy tracks using interventional radiology techniques is described as an alternative to surgery.

Dynamic insufficiency of lung lymph flow from the right lymph duct in dogs with acute filtration edema.

Using 14 anesthetized dogs with lymph flowing through right lymph duct, we observed dynamic insufficiency of lung lymph flow during acute left atrial pressure loading. Net pulmonary microvascular fluid filtration pressure (sigma p) was defined as the difference between pulmonary microvascular pressure (Pmv) and oncotic gradient through the capillaries (pi mv - pi pmv). Pulmonary extravascular water content (PEVW) was well correlated with sigma p in either mild edema or gross edema (PEVW = 0.19 sigma p + 2.15, r = 0.813, 0.001 less than p less than 0.002). Percent increase in lymph flow (% Qlym) was well correlated with both PEVW (% Qlym = 130.8 PEVW - 376.5, r = 0.886, 0.005 less than p less than 0.01) and sigma p (% Qlym = 11.0 sigma p + 34.7, r = 0.853, 0.02 less than p less than 0.05) in mild edema. However, in gross edema compared with mild edema, % Qlym as a function of PEVW or sigma p was significantly low. We concluded that in gross edema with PEVW, over 6 g/g of bloodless dry lung and sigma p over 20 mmHg, lymph flow from right lymph duct becomes dynamically insufficient and can neither transport enough fluid from the pulmonary interstitium nor tracheobronchial trees to relieve the edema process.

A study on the dissolution and disintegration of calcium bilirubinate stones, with special reference to effects of litholytic agents in human bile and to irrigation of bile duct in dogs.

1) Slices of calcium bilirubinate stones were readily soluble in bile added with tetrasodium salt of ethylene-diaminetetraacetic acid (EDTA.4Na). 2) Bile added with 3 agents, EDTA.4Na, ursodeoxycholate (Urso), and heparin could dissolve calcium bilirubinate stones more easily than, or comparably to, the bile added only with EDTA.4Na. 3) The pH of the bile added with the combination of EDTA.4Na-Urso-heparin was 8.72 +/- 0.15, which was slightly more neutral than the bile added with EDTA.4Na alone. 4) In dogs, the bile duct was dilated and irrigated with an EDTA solution for 4 weeks. This irrigation resulted in no abnormalities in hepatic function, the serum calcium level, or the histology of the gallbladder or the common bile duct. In conclusion, the combined solution of EDTA.4Na-Urso-heparin is effective for the dissolution and disintegration of calcium bilirubinate stones with little disturbance of human bodies.

Natriuretic effect of propranolol on dogs with chronic bile-duct ligation.

1. Chronic ligation of the bile duct in dogs is associated with salt retention and a blunted natriuretic response to extracellular volume expansion. The mechanism of this phenomenon has not been clarified. 2. We have examined the influence of chronic beta-adrenergic blockade on sodium excretion in dogs with bile-duct ligation during extracellular hypotonic volume expansion. 3. Urinary excretion of sodium and fractional excretion of sodium rose significantly after 5 days of oral DL-propranolol administration to dogs with bile-duct ligation. 4. The antinatriuresis after bile-duct ligation was not followed by a significant alteration in the mean peripheral plasma renin activity as compared with control values. 5. It is suggested that propranolol can partially reverse the antinatriuresis of chronic bile-duct ligation, and that this is mediated by an extrarenal effect of the beta-adrenergic blockade.

Effect of ligation of the pacreatic ducts on distribution of endogenous serotonin in organs of the gastrointestinal tract

During the 12 months after ligation of the pancreatic ducts in dogs the concentration of endogenous serotonin (5-HT) was studied in the mucous membrane of different parts of the stomach and small intestine, and also in homogenates of pancreatic tissue and in peripheral blood. Considerable and prolonged disturbances of the deposition of endogenous 5-HT were found. The disturbances were characterized by definite patterns for each tissue studied and were connected with changes in the relative constancy of the enteral medium as a result of absence of the pancreatic secretion in the lumen of the alimentary canal.

Sphincteric mechanism of the main pancreatic duct in the dog. An experimental model of the isolated sphincteric preparation.

This study describes an in vitro experimental model of the sphincter at the lower end of the main pancreatic duct in the dog. This model, employing a drop counter to measure the drop rate, monitors the perfusion rate of Tyrode through the sphincter. Acetylcholine (ACh), employed to establish the sensitivity and viability of the isolated sphincter, produced a contraction of the sphincter which was concentration-response related. Saline, as a control, atropine and hexamethonium did not affect the drop rate. Atropine (20 microgram) partially abolished the contraction produced by 50 microgram of ACh; hexamethonium (50 microgram) did not have an effect. Caerulein 50 microgram produced a relaxation of the sphincter; adrenaline 50 microgram a contraction. Both sympathetic and parasympathetic mechanisms seem to play a role in the regulation of sphincteric activity of the main pancreatic duct in dogs.

Improved method for cannulation of the right lymph duct in dogs.

We have developed a relatively simple technique for cannulating the right lymph duct in the dog. We have successfully cannulated 19 of 20 dogs and have obtained stable lymph flows for up to 6 h. We make a skin incision over the origin of the pectoralis superficialis muscle and extend it laterally and cephalically until it is parallel and lateral to the external jugular vein. Using the cephalic vein as a landmark, we identify the cervical lymphatic which lies deep to the external jugular vein. We trace the cervical lymphatic posteriorly to the lymphatic ampulla, which is located at the external jugular and axillary venous junction. The ampulla receives the cervical, axillary, and right lymph ducts. We place a ligature around the ampulla and tie it off, forming a lymphatic pouch and obstruction lymph flow into the vein. We then cannulate the cervical lymphatic and advance the catheter into the ampulla and tie it in place. All lymphatic branches draining into the ampulla, except the right lymph duct, are ligated, enabling us to collect lymph form only the right duct. The high success rate is due, we believe, to the fact that we approach the right duct high in the neck and cannulate via the cervical lymphatic. We avoid direct dissection over the right lymph duct, and usually we do not have to cannulate the right duct directly.

Ein neues Verfahren zur zuverlässigen Dauerkanülierung des Ductus Choledochus am Hund

A new method for long term cannulation of the common bile duct in dogs is reported. The procedure is carried out with a T-tube, which is brought out through the abdominal wall. There it is rolled up in the hole of an implanted Thomas cannula. - A reliable protection from removal by the animal. The result in 9 dogs was very good, the longest duration of cannulation was 9 months.

Surgical techniques for long-term study of thoracic duct lymph circulation in dogs

Two new surgical techniques for cannulation of the thoracic duct in dogs are presented. Both allow the study of the thoracic duct circulation under physiological conditions in awake and unrestrained animals.

ETHACRYNIC ACID-Reply

Reply We are very grateful to Dr. Cohn for his comments on our article. According to Cohn et al ( Science 171: 910, 1971) and Brusilow ( Fed Proc 31: 298, 1972) low doses (1 to 5 mg/kg) of ethacrynic acid produce an increase of Na+ concentration and a drop of K+ concentration inside the cochlear duct in dogs; however, Silverstein and Yules ( Laryngoscope 81:873-888, 1971), after 30 mg/kg of ethacrynic acid, described an increase of Na+ concentration and no change of K+ concentration inside the cochlear duct in cats. Wilson and Juhn ( Fed Proc 29:805, 1970) reported an increase in the concentration of K+ in perilymph from guinea pigs after very large doses of ethacrynic acid. Recently, we have found that after local application of 1 × 10 −3 M solution of ethacrynic acid into the scala tympani, there were no significant changes of K+ concentration inside the cochlear duct. Our results

Controlled ductal infusion and absorption from the interstitium of canine pancreas.

Infusion of 0.1M ammonium bicarbonate buffer solution into the pancreatic duct in dogs with and without obstruction of the pancreatic veins or portal vein and with or without obstruction or collection of lymph from the thoracic duct revealed that, in the normal canine pancreas, ductal pressures above 40 cm resulted in passage of fluid into the interstitium of the gland. Large volumes of innocuous fluid, such as ammonium bicarbonate buffer, were absorbed by the pancreatic microcirculation, which appears to have extensive collateral outflow pathways. The portal venous bed appeared to be a major route for absorption of fluid from the pancreatic interstitium, while the lymphatic system played a secondary role, and increased in importance when flow in the venous outflow was compromised.

Restoration of cell function and structure of the liver after obstruction of the bile duct in dogs

Restoration of cell function and structure of the liver after obstruction of the bile duct in dogs

Comparative study of flow and protein composition of lymph in the right and common thoracic ducts of dogs

Comparative study of flow and protein composition of lymph in the right and common thoracic ducts of dogs