Obstruction of the Pancreatic Duct

Obstruction of the excretory duct is a frequent occurrence in pancreatic disease, and is due to two classes of causes—namely, 1st, pressure from without; and, 2d, closure of the canal by catarrhal swelling of its mucous membrane or by calculi.

In the first class may be placed obstruction depending upon contraction occurring in sclerosis of the gland, upon carcinoma of the head of the gland, upon peripancreatic adhesions and indurations, upon the presence of large gall-stones in the ductus choledochus, and upon carcinoma of the pylorus and duodenum and enlargement of the neighboring lymphatic glands.

In catarrh of the canal of Wirsung the obstruction results either from simple swelling of the mucous membrane or from the presence of a plug of tough mucus.

The formation of pancreatic concretions is by no means a rare event, though these calculi are met with far less frequently than either gall-stones or salivary concretions. They result from precipitation of the inorganic ingredients of the pancreatic juice, and are usually seated in the main duct, although they may be situated in the smaller branches. They may be single or multiple, as many as twenty having been counted in one gland. In shape they are spherical, oval, or branched, with sometimes a smooth, at others a spiculated, surface; their size varies from that of a minute granule to a small walnut; they are usually white or grayish-white in color, but may be black; and are composed of the carbonate of lime or of a combination of the carbonate and phosphate with oxalate of lime. Coincidently with these calculi it is common to find concretions in the kidneys and gall-bladder.

Concretions composed of insoluble protein substances have also been found in the pancreatic ducts (Virchow).

The most probable causes of the formation of pancreatic calculi seem to be catarrhal conditions of the mucous membrane of the ducts and an alteration in the chemical composition of the secretion.

Whatever the cause, the obstruction, when complete, leads to retention of the secretion and the formation of retention cysts.

When the obstruction is situated at the duodenal extremity of the duct, the canal and its secondary branches are either uniformly dilated or sacculi are formed. These sacculi are round or oval, vary greatly in size, sometimes reaching the dimensions of the fist or of a child's head; they may be single, or several of them may be present, differing in size and causing irregular projections of the outer surface of the gland. When the obstruction occurs at some point in the course of the duct, the dilatations and sacculi are found only behind the point of occlusion. The small cysts contain a fluid resembling the pancreatic juice; the larger, a whitish, chalky fluid, which in old cases may contain white friable concretions composed of carbonate and phosphate of lime, and become purulent, or be stained bright red or chocolate-colored from the occurrence of hemorrhage. In such instances hæmatoidin crystals can be discovered by the microscope. The interior of the dilated ducts and of the retention cysts is lined by a single layer of thin flat cells, with irregular edges and with oval flat nuclei. The walls are thickened, and composed of superimposed layers of laminated connective tissue separated from one another by flat nucleated cells. The secreting structure of the gland undergoes atrophy from pressure, or fatty metamorphosis takes place, and, although the gland is increased in size from the presence of the cysts, its functional power is lost.

In addition to causing obstruction of the duct of Wirsung and the changes mentioned, pancreatic calculi may produce induration, atrophy, acute inflammation, or even suppuration of the surrounding glandular tissue.

SYMPTOMS AND COURSE.—The main feature is the presence in the epigastrium of a rounded, smooth, fluctuating, painless tumor. There are also indications of the absence of the pancreatic secretion from the digestive tract—notably, emaciation, general debility, and the appearance of fat in the stools. Jaundice resulting from a coincident obstruction of the bile-duct is a frequent symptom, and melituria has been noted in some cases. It is probable, too, that the passage of a calculus along the duct may give rise to pain resembling in character and distribution the pain of hepatic colic.

The duration is indefinite. Sometimes the termination is sudden from the rupture of a cyst into the peritoneal cavity or into the stomach or duodenum, with hemorrhage.

DIAGNOSIS.—The absence of pain, of tenderness, and of cachexia, together with the physical characters of the tumor, distinguishes it from carcinoma of the gland.

Though not likely to be confounded with this disease, both hydatid tumor of the liver and distension of the gall-bladder must be borne in mind in making the diagnosis of a fluctuating tumor situated in the upper third of the abdomen.

TREATMENT must be entirely symptomatic. Attention to the general health, proper regulation of the diet, and the employment of pancreatin or an infusion of calf's pancreas to supply the place of the deficient pancreatic juice, are the important steps. Attacks of pancreatic colic indicate the use of anodynes.

In two reported cases in which the cysts were very large paracentesis for the removal of the fluid contents was resorted to, and there are two cases on record in which the cysts were extirpated after abdominal section. Kulenhampff of Bremen records a case of a man, thirty-nine years of age, in whom, after a succession of severe blows upon the abdomen, a tumor appeared in the epigastrium. An exploratory incision was made, and a few ounces of pancreatic fluid evacuated by aspiration. Six days afterward the abdomen was opened, the peritoneum united to the incision, and antiseptic gauze inserted to produce adhesive inflammation between the sac and the abdominal wall. Adhesion taking place after four days, the cyst was opened, a liter of fluid evacuated, a tent inserted, and an antiseptic dressing applied. For sixteen days fluid constantly escaped in slowly diminishing quantities, and the tumor disappeared, a fistulous tract remaining. This completely closed under the use of tincture of iodine and nitrate of silver at the end of the seventh week. Thiersch opened a pancreatic cyst and evacuated three liters of chocolate-colored fluid; recovery with a fistula followed.

From a patient supposed to be suffering from ovarian dropsy Rokitansky partially extirpated a cyst connected with the tail of the pancreas; death from suppurative peritonitis occurred on the tenth day.

N. Bozeman on December 2, 1880, successfully removed from a woman forty-one years old a pancreatic cyst weighing, with its contents, twenty and a half pounds. In this instance also the operation was undertaken for the removal of a supposed ovarian tumor, the diagnosis not being established until after the abdomen was opened.

New York Medical Record, Jan. 14, 1882.