VOLVULUS (TWISTING) OF THE INTESTINE IN SOLIPEDS.
Definition: rolling of a loop on its mesenteric axis, bending in a vicious direction, rolling of one loop round another. Causes: laxity of mesentery in hernia, relaxation or rupture of linea alba, pot belly in old breeding mares, sudden movements in falls, leaps, draught, galop, slipping, mounting, warm weather, casting, rolling, rising, sudden filling of a loop, heavy feeding and fermentescible food, cold drinks, chills. Lesions, most in double colon, next in jejunum, cæcum wrapped in small intestine, floating colon, tympany and pallor of obstructed loops, later congestion, infiltration, extravasation, adhesions, necrosis, sloughs, infective peritonitis. Symptoms: sudden severe attack, violent, reckless colicy movements, pain constant with exacerbations, fever, prostration, collapse. Diagnosis: only by rectal exploration and exceptionally. Treatment: by rectal manipulation, eserine, castor oil, laparotomy.
Strictly speaking this lesion consists in the twisting of a loop of intestine upon its mesenteric axis, so that the portion which is drawn spirally over the mesentery of the other is more or less completely obstructed. The term has, however, been applied as well to the turning of a viscus at a sharp angle from its normal direction so as to interfere more or less with the passage of its contents and with its circulation. This has been especially seen in a vicious direction given to the cæcum, but also at times to the double colon. The simple twisting on the mesenteric axis is common to the floating portion of the small intestines, the double colon, floating colon and rectum. A third form of twisting which is, however, rather a strangulation, consists in the rolling of one loop of intestine round the loop of another, the mesentery of which has become unduly long.
Causes. The predisposing cause is a certain laxity or undue lengthening of the mesenteric attachment of the intestine. This is sometimes formed in connection with the existence of hernia, into which the bowel protrudes, or short of this a relaxation or rupture of the linea alba so that the whole of the intestinal mass hangs down unduly, or finally in unthrifty pot-bellied animals and in breeding mares in which the abdomen is unduly pendent.
Next comes the question of sudden movement as in falls, in leaping, in violent exertions of draught, or galop, in sudden slipping upon wet or icy ground, and of stallions in mounting mares. In the Omnibus Company’s (Paris) horses Palat found 35 cases in entire horses, 23 in mares, and 11 in geldings. The stallions in the stables were fewer than the mares and geldings put together, but it does not appear that the difference was sufficient to make the above figures very significant. These stallions it should be added, are not used for breeding, so that the statistics have no bearing on the effect of mounting.
Palat’s figures show a greater number of cases in summer, than in winter. There were 58 cases from April to October and but 21 from November to March. It would seem as if the relaxation of the system and mesentery in summer more than counterbalanced the combined effect of slipping on ice and sudden chills.
A large proportion of the cases have been found in horses that have died of colic, or which have been cast for operation, and the recent character of the lesions has often shown that we must look upon them as the result of the tumultuous peristalsis, and the lying, rolling, sitting and other sudden and unwonted movements performed. A heavily loaded portion of bowel, occupying a position slightly lower than a lighter portion or parallel to it, suddenly moves by gravitation when their relative positions are altered as in rolling, decubitus, or rising, and it thereby becomes twisted upon itself. Or a portion of intestine filled with liquid or gaseous contents is suddenly emptied by the passage of these onward into another and the latter portion of intestine or some other lodged alongside it, in moving to fill the place, rotates upon itself and establishes a volvulus.
Hard worked horses which are subjected to stimulating feeding are much more frequently attacked than those which have light work and feeding. In the same way newly harvested hay or oats, spoiled or otherwise indigestible food have apparently been productive causes. Cold drinks, and exposure to cold draughts have been similarly charged. Indeed any cause of indigestion and colic may be held to predispose to volvulus.
Lesions. Seat. Twisting of the small intestine is impossible in the duodenum, and for the floating portion it is far more common in the ileum and terminal portion of the jejunum where the mesentery is long than in the anterior jejunum where it is short.
The double colon from the sternal portion to the pelvic flexure being free from any restraint by omental or mesenteric bands is especially liable to torsion. Palat found four cases of torsion of the colon to one of the small intestine, and Schutze gives the ratio as 56 of the first to 13 of the second.
The cæcum has been frequently found twisted upon itself with a portion of the small intestine rolled round it.
The floating colon like the small intestine is rolled around its mesenteric axis, but cases are much more rare than in the case of the small intestine.
In a recent and complete twisting with obstruction of the bowel, the loop of intestine is distended with gas the result of fermentation of its contents, and its walls may be thin and pale. Much more commonly and when the lesion is of longer standing there is hyperæmia, and infiltration and thickening with inflammatory products, and blood extravasations. At the seat of torsion the compressed intestine is congested, covered with petechiæ, and its peritoneal surface with fibrinous exudate tending to bind the parts together. Later there may be seen spots of necrosis and perforating sores and semi-detached sloughs, or the whole mass of twisted bowel may be gangrenous. The patient usually dies before this last stage has been reached. If the animal survives long enough the lesions of infective peritonitis are constantly present.
Symptoms. The disease usually sets in suddenly with intense severity. In exceptional cases there is an insidious onset, the twist being at first but partial and gradually increasing and for a time the contents pass on in a restricted but still physiological manner. Colics at first slight become by degrees more and more intense until all the symptoms of obstruction and acute inflammation are developed.
More commonly symptoms of extreme gravity appear at once, the patient stops, paws, kicks at his belly, tries to lie down, strains to defecate or urinate, lies down, rolls, sits, gets up and moves round uneasily trying to lie down again. He looks at the flank with anxious eye and countenance and has all indications of the most violent colic. Pain is constant, but worse at one time than another, the pulse is from 50 to 90 and becomes weak and even imperceptible as the case advances, and hyperthermia, at first slight or absent rises with the onset of inflammation. Finally great prostration, depression and stupor, sunken, glazed eye with dilated pupil, and cold sweats and extremities bespeak collapse or general infection.
Diagnosis is rarely certain. The sudden onset, extreme violence of the symptoms, and rapidly fatal progress are significant and in exceptional cases rectal exploration will detect obstruction in the rectum or floating colon, or a tympanitic condition of the pelvic flexure.
Treatment. A rational treatment is only possible in those rare cases in which the diagnosis is certain. When the lesion can be reached in the rectum or adjacent part of the floating colon, the oiled hand may be made to drag on the interior of the viscus so as to restore it to its normal position.
Cadiot has had recoveries from supposed volvulus by the use of eserine hypodermically, and Trasbot by the use of castor oil and it is just possible that active peristalsis, and plenitude of the bowel running into the volvulus, may serve to unwind slight cases. When the diagnosis is certain and the case, as usual, intractable the resort of laparotomy and the attempt at untwisting is fully warranted. The case is a fatal one if unrelieved.