Dissolution of pancreatic stones by oral trimethadione in a dog experimental model

Successful treatment of feline pancreatolithiasis associated with an ascending Providencia rettgeri infection using a novel surgical technique

A 12-year-old female spayed Domestic Shorthair cat presented with a 4-day history of lethargy, inappetence and vomiting. Physical findings included a grade 2/6 heart murmur and cranial abdominal pain on palpation. Serum biochemistry revealed elevated total bilirubin and liver enzymes activities. Abdominal ultrasound revealed multiple pancreatoliths, cholelithiasis and dilation of the pancreatic duct. During exploratory laparotomy, catheterisation of the pancreatic duct with retrograde and orthograde flushing to remove the pancreatoliths was performed via a distal enterotomy and proximal left apical partial pancreatectomy respectively. Catheterisation and flushing of the common bile duct were performed to confirm patency prior to cholecystectomy. Bacterial culture of pancreatoliths, pancreatic tissue and bile grew a heavy, pure growth of Providencia rettgeri. Fluorescent immunostaining histopathology revealed clusters of rod-shaped bacteria within the pancreatic parenchyma and gall bladder mucosa. The cat received pradofloxacin for two weeks. She made a complete recovery and remained well at a six-month follow-up.

Obstructive pancreatolithiasis in a cat with triaditis and concurrent hypercalcaemia

Case summary

A 7-year-old neutered female domestic longhair cat was presented for further investigation of suspected hepatobiliary disease. Increases in serum 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6'-methylresorufin) ester lipase and hepatobiliary enzymes, with concurrent hypoalbuminaemia, were documented on blood biochemistry. Abdominal ultrasonography findings were consistent with acute pancreatitis with multiple pancreatoliths visualised within the pancreatic duct. Treatment for suspected triaditis was initiated with a hydrolysed protein diet, amoxicillin-clavulanate, hepatoprotectants and buprenorphine. Fifty-three days later, the patient presented with hypercalcaemia and obstructive pancreatolithiasis, and was euthanased. Post-mortem examination revealed severe chronic active pancreatitis with moderate chronic lymphocytic, plasmacytic cholangiohepatitis and mild chronic lymphocytic-plasmacytic duodenal enteritis (triaditis). Multiple calcium carbonate pancreatoliths present within the pancreatic ducts had resulted in pancreatic duct obstruction.

Relevance and novel information

Pancreatolithiasis is a very rare condition in cats, with only five reports to date. In human medicine, pancreatolithiasis is often a sequala to chronic pancreatitis, seen in up to 50-90% of patients. However, in cats the aetiology of pancreatolithiasis, and indeed chronic pancreatitis, is poorly understood. This report describes a case of obstructive pancreatolithiasis in a cat with histopathological confirmation of triaditis and is the first report of hypercalcaemia in a cat with obstructive pancreatolithiasis. This further adds to the evidence base that pancreatolithiasis may have a similar pathogenesis to humans and can develop secondarily to chronic pancreatitis in cats.

Effectiveness of oral litholysis therapy for improving glucose intolerance and malnutrition in patients with poor results following endoscopic therapy and extracorporeal shock wave lithotripsy for calcified pancreatic stones

We report a case of pancreatolithiasis in which glucose intolerance and malnutrition were significantly improved after starting oral litholysis therapy (OLT) with use of trimethadione. A 43-year-old female with multiple calcified stones in the main and peripheral pancreatic ducts had experienced recurrent and severe attacks of pain for 7 years (from 21 to28 years of age). Impaired glucose tolerance was first noted at the age of 32 years. We started OLT after interventional endoscopic therapy combined with extracorporeal shock wave lithotripsy failed because of kink and stenosis of the main pancreatic duct (MPD). Over the next 9 years, a significant decrease in total pancreatic calcified stone volume was shown by computer analysis of follow-up computed tomography images. Larger stones completely disappeared without attacks of pain. In addition, both glucose intolerance and insulin secretion were significantly ameliorated, followed by improvement of malnutrition. OLT may induce intraductal decompression by dissolving stones in the peripheral ducts as well as the MPD, with resulting preservation of endocrine function and improvement of malnutrition. Since the present results were obtained in a single case, further clinical trials are necessary to evaluate the value of performing OLT under various conditions to eliminate stones.

Update on endoscopic management of main pancreatic duct stones in chronic calcific pancreatitis

Pancreatic duct stones are a common complication during the natural course of chronic pancreatitis and often contribute to additional pain and pancreatitis. Abdominal pain, one of the major symptoms of chronic pancreatitis, is believed to be caused in part by obstruction of the pancreatic duct system (by stones or strictures) resulting in increasing intraductal pressure and parenchymal ischemia. Pancreatic stones can be managed by surgery, endoscopy, or extracorporeal shock wave lithotripsy. In this review, updated management of pancreatic duct stones is discussed.

Analysis of occluded pancreatic stents and juices in patients with chronic pancreatitis

BACKGROUND

Pancreatic stents may occlude with time, and there is little information available on the nature of the clogging process.

METHODS

We analyzed the contents of occluded pancreatic polyethylene stents in nine patients with chronic pancreatitis. In the same patients, the protein patterns in the corresponding pancreatic juices were analyzed. The stents had been in place for a mean of 9 weeks (range 2 to 17).

RESULTS

All stents were occluded at both ends, especially around side holes, with thick creamy-white precipitate. The average dry weight of occluding debris was 3 mg per 3.25 cm 10F stent. Total protein content was 50% (SD 16.3) and total calcium 0.8% of dry weight (SD 0.6). Light microscopy showed that proteinaceous material completely filled the stent lumen. Yeasts and plant material were seen in two stents. A variable number of bacteria of mixed species, sometimes in clumps, were patchily scattered in the protein matrix. Cultures of stent contents grew several species of Gram-positive and negative bacteria. Scanning and transmission electron microscopy showed an amorphous protein matrix in all stents, arranged as a network in some areas, but in layers in other areas. Sodium dodecylsulfate polyacrimide gel electrophoresis showed that protein patterns of stent contents were remarkably different from the protein patterns of the juice samples of the same patient. A 66 kD band, identified as albumin, appeared in the protein patterns of stent content, whereas it was lacking in most juice samples.

CONCLUSIONS

Adherence of protein, especially albumin, plays an important role in the process of pancreatic stent clogging. Other factors, such as bacteria, refluxed duodenal contents, and calcium seem to be of less importance.

Chronic pancreatitis: diagnosis and treatment

Three-dimensional magnetic resonance cholangiopancreatography is currently the most exciting new imaging technique for chronic pancreatitis. Endoscopy-assisted duodenal intubation during the secretin-cholecystokinin test reduces intubation time in difficult cases. The NBT-para-amino benzoic acid test has been refined to enhance its discriminant power. The cholesteryl-[C13]octanoate breath test and the faecal elastase test are newer highly sensitive and specific tubeless tests. Pain in chronic pancreatitis continues to be a vexing therapeutic issue. Enzyme treatment continues despite criticism. Neurotensin is the new suspected mediator of the feedback mechanism, which is downregulated by enzyme therapy. Steroid ganglion block is an exciting therapeutic tool for pain relief. Endoscopic pancreatic sphincterotomy, Dormia basketing and pancreatic stenting in conjunction with extracorporeal shock wave lithotripsy should be performed early in chronic pancreatitis to prevent parenchymal atrophy with ensuing exocrine and endocrine pancreatic dysfunction. The modified Puestow's procedure preserves endocrine and exocrine pancreatic functions besides relieving pain. Closed loop insulin infusion allows superior management of pancreatic diabetes following near total pancreatectomy. The standardised incidence rate of pancreatic cancer is 16.5 in patients with alcoholic chronic pancreatitis and 100 for tropical chronic pancreatitis. Aggressive treatment protocols combining neo-adjuvant chemoradiation and intra-operative radiation with surgery are being used to improve the prognosis in this dismal complication of chronic pancreatitis.

Pancreatic calculi superimposed upon slow growing pancreatic cancer

We report on a 59 year old male patient with cancer of the head of the pancreas, upon which pancreatic calculi were superimposed during the 3 year clinical course. Pancreatic calculi were noted in the main pancreatic duct (MPD) on both computed tomographic scans and ultrasonographs of the abdomen approximately 10 months after the recognizable dilatation of the MPD. Existence of the calculi was confirmed by autopsy. Elemental analysis and infrared spectrophotometry of the calculi demonstrated that the main constituent of the calculi was calcium carbonate. Histopathological examination showed that the pancreatic cancer was moderately differentiated adenocarcinoma. Immunohistochemical studies revealed that pancreatic stone protein (lithostathine) was present in the cytoplasm of tumour cells. In this case, pancreatic cancer progressed to obstruct the MPD unusually slowly, resulting in stagnation of pancreatic secretion and subsequent formation of the calculi.

Dissolution of pancreatic stones by oral trimethadione in patients with chronic calcific pancreatitis

The effect of oral dissolution therapy for pancreatic stones was evaluated in patients with chronic calcific pancreatitis. The anti-epileptic agent trimethadione was given orally to 30 outpatients at a dose of 0.9-1.5 g daily. On plain X-ray films and CT scans of the abdomen, pancreatic stones began to be dissolved around 8 months of treatment, and diminished in size and number or disappeared in 21 patients (70%) during the mean follow-up period of 32 months. The effect of trimethadione treatment on dissolution of stones was not closely related to the aetiology of the disease, distribution and size of stones, previous history of surgical interventions, or the degree of pancreatic dysfunctions. In three patients who stopped this medication of their own accord, pancreatic stones re-increased or reappeared about 6 months later. During trimethadione treatment, impaired exocrine pancreatic function returned to normal in four of nine patients examined, and diabetes mellitus was well controlled by either diet therapy alone or oral hypoglycaemic agents in eight of 10 patients who did not need insulin before trimethadione treatment. Complete relief of pain was noted in 73% of patients during the treatment. Overall gains and no change in bodyweight were observed in 83% of patients. Mild photophobia was the most common side effect, but could be easily overcome by wearing sunglasses. No severe side effects were observed in the liver, kidney, blood or the eyeground. Pancreatic stones in 30 patients not treated with trimethadione neither disappeared nor diminished spontaneously. Trimethadione treatment may be a useful tool for chemical dissolution of pancreatic stones.

Effect of dimethadione administered intravenously on pancreatic secretion in dogs

In order to detect both pancreatic excretion of dimethadione (DMO), a weak organic acid, and the effect of pancreatic DMO on secretin-stimulated pancreatic secretion, DMO was given intravenously to dogs with pancreatic fistulae at a dose of 50, 100 and 200 mg/kg. DMO was promptly excreted into pancreatic juice; the concentration decreased exponentially as it did in plasma at the highest dose of the compound. At equilibrium of DMO between pancreatic juice and plasma, the DMO concentration in the juice depended directly on that in plasma; the juice/plasma concentration ratios for DMO exceeded 1.0, ranging from 1.7 to 2.1. Pancreatic DMO caused a small but significant decrease in the water, bicarbonate and sodium secretion at non-equilibrium, and in the bicarbonate secretion at equilibrium. A decrease in the bicarbonate secretion may result largely from the buffer action of bicarbonate on protons provided by the undissociated form of DMO. The sum of both bicarbonate and chloride concentrations in pancreatic juice decreased with the increased DMO concentration in the juice, implying that DMO may compete with the secretion of bicarbonate and/or chloride across the apical membrane of the duct cell. Pancreatic DMO can act as a non-specific inhibitor of pancreatic water and electrolyte secretions.

Extracorporeal shock-wave lithotripsy of pancreatic calculi

Extracorporeal shock-wave lithotripsy (ESWL) has been used to disintegrate pancreatic stones located in the main pancreatic duct for 123 patients with severe chronic pancreatitis. Endoscopic management following ESWL is aimed at restoring the pancreatic flow to the duodenum. Stone disintegration was achieved in 122 patients, whereas a decrease in the main pancreatic duct diameter resulted in 111, and complete clearance of the main pancreatic duct was obtained in 72. Pain relief, complete (40/88) or partial (35/88), correlated significantly with the results of the endoscopic drainage of the main pancreatic duct (e.g., decrease in main pancreatic duct diameter). Relapsing pain was most often related to recurrent pancreatic duct obstruction. Of 76 patients whose body weight had decreased before ESWL, 54 gained weight. Improvement of the exocrine function, evaluated by the [14C]triolein breath test before and 11 months, on the average, after ESWL, was observed in 12 patients among 22 for whom this test was performed before and after treatment. Improvement of the endocrine function after relief of obstruction of the main pancreatic duct was less frequently recorded (4/41). ESWL of pancreatic stones is a new, safe, and highly effective method of facilitating the endoscopic procedures for relief of pancreatic duct obstruction in severe chronic pancreatitis.

Effect of dimethadione derived from repeated oral administration of trimethadione on pancreatic secretion in dogs

The effect of the weak organic acid of dimethadione (DMO) on secretin-stimulated pancreatic secretion was studied with repeated oral administration of trimethadione (TMO), the precursor of DMO, to dogs at a dose of 10 to 160mg/kg/day for a period of 14 days. The bicarbonate concentration in pancreatic juice at a steady state decreased significantly, reflecting a close correlation with the dose of TMO and DMO concentrations in plasma and pancreatic juice. The maximal decrement from the control of cases of no TMO administration was 18.8 mEq/l (12.1% of the control level). The chloride concentration in pancreatic juice showed a reciprocal relation to the bicarbonate concentration. The sum of both anion concentration was constant, irrespective of the dose of TMO. The average carbon dioxide tension of pancreatic juice in all doses of TMO was lower than that of the control, but differences were not statistically significant. The pH, flow rate, sodium and potassium concentrations in pancreatic juice at a steady state did not differ significantly in relation to the dose of TMO. These findings suggest that repeated oral administration of TMO cause a significant decrease in bicarbonate concentration in pancreatic juice, resulting probably from the buffer action of bicarbonate on protons provided from the undissociated form of DMO.

Evolution and regression of pancreatic calcification in chronic pancreatitis. A prospective long-term study of 107 patients

Pancreatic calcifications are virtually pathognomonic of chronic pancreatitis and develop in up to 90% of patients with alcoholic chronic pancreatitis in series with long-term results. We investigated the natural course of pancreatic calcification in a prospective longitudinal study over the past 23 yr. All patients were studied at regular intervals with particular regard to etiology, clinical findings, surgery, pancreatic function, and pancreatic calcification visible by x-ray (e.g., film series in three projections centered on the pancreas). We evaluated the findings of 107 patients with x-ray documentation of pancreatic calcification in at least three film series over a period of 4 yr or longer. Eighty-four patients had alcoholic chronic pancreatitis (group A) and 23 patients had nonalcoholic chronic pancreatitis (group B). Four hundred seventy-two film series of group A and one hundred forty-two film series of group B were reviewed independently by two expert teams. Both series were graded according to a score system in terms of intensity and distribution of pancreatic calcification (correlation of grading r = 0.91). The duration of calcification averaged 10 yr in group A and 12.6 yr in group B. Similar dynamic changes of pancreatic calcification were noted in groups A and B. Chronologically, three phases of evolution could be distinguished. After an initial increase (phase 1), greater than 50% of cases reached a plateau of stationary calcification (phase 2). Approximately one-third of cases showed a marked decrease of calcification in late phases of chronic pancreatitis (phase 3). Dissolution of pancreatic stones was related primarily to duration of chronic pancreatitis (duration of calcification and marked pancreatic dysfunction), and occurred frequently (but not exclusively) in patients after ductal drainage procedures. These results indicate that spontaneous dissolution of pancreatic stones is a rather common biologic phenomenon. The factors responsible for dissolution of stones remain to be elucidated.

Macroautoradiographic and densitometric studies of [14C]dimethadione in rats: accumulation of the compound in the pancreas

Whole-body autoradiographic and densitometric distribution studies were performed on rats to investigate the accumulation of [14C]dimethadione (DMO) in the pancreas. [14C]DMO was intravenously administered at a dose of 167 microCi/0.5 mg/kg. Animals were sacrificed 1, 15, 30, 60 and 180 min after administration of the radioactive compound. The compound was found to rapidly distribute in all body tissues. The distribution pattern of the compound in the pancreas was spotty or linear due to the presence of the radioactive compound in blood of intrapancreatic vessels and in pancreatic ducts at higher levels than parenchyma. The radioactivity of pancreatic ducts became more evident with time, indicating the gradual accumulation of the compound in the ducts. These findings provide morphological evidence that DMO is accumulated in the pancreas and possibly eliminated from pancreatic juice. Densitometry revealed that the levels of radioactive compound in the pancreas were virtually as high as those in the liver and kidney.