DIAPHRAGMATOCELE. DIAPHRAGMATIC HERNIA. PHRENIC HERNIA.
Definition. Susceptibility by genera, horse, dog, ox. Enterocele, epiplocele, gastrocele, hepatocele. Congenital, arrest of development and of closure of foramen or elsewhere, diaphragm absent. Traumatic, blows on false ribs by pole, shaft, buffer, gate, bars, beams, kicks, blows with horns, tusks, clubs, fractured rib perforating diaphragm, falls on projecting bodies, muscular strains in draught, plunging, falling, slipping, casting, parturition; trotting or galloping down hill, jumping to lower level, slipping to knees, dystokia, colic, tympany. Symptoms: extreme dyspnœa and asphyxia; or difficult breathing slowly increasing, colics, dilated nostrils, retracted angle of mouth, projecting eyeballs, shallow, rapid catching respirations, gurgling in chest, drumlike percussion sounds, with perhaps flat areas; in slight cases, listlessness, colics, double lift of flank, tender intercostals; in chronic cases, short wind on exertion, sluggishness, colics after meals. Hernia through intercostal space. Lesions: unduly large foramen sinistrum or dextrum, lacerations of all forms and sizes, edges ragged, thickened, bloody, broken rib, inflated stomach causes shreddy tear; post mortem lacerations show no inflammatory products; chronic cases have edges devoid of inflammation and often smooth, serosæ usually perforated, nature of hernial mass, omentum, intestine, colon, cæcum, stomach, spleen, liver, congestion of viscera involved. Prognosis: slight cases may survive, to be fattened or to breed, but are useless for work. Treatment: quiet, sedatives, antiferments, cathartic, concentrated food, lift by fore limbs, incline stall backward and downward, laparotomy in cattle, dogs, and swine.
As this lesion is shown by symptoms referable to internal organs only, and as it is considered irremediable by surgical measures, it may be properly considered in the class of medical affections.
Definition. A displacement of one or more of the abdominal organs into the cavity of the thorax.
Frequency in different animals. It has been found most frequently in the horse, and less so in the dog and ox. Severe exertions conduce to it in horse and dog, while in the ruminant the great bulk of the gastric cavities, covering the whole posterior surface of the diaphragm, tends to prevent protrusion even if a slight rupture has taken place. On the other hand, the weight of the gastric cavities in the ox and the tension upon the œsophagus, when the animals ride each other, sometimes cause laceration of the foramen sinistrum and hernia of the reticulum.
Hernial mass in different animals. In the horse the protruding organ is most commonly the small intestine (enterocele), omentum (epiplocele), colon, or less frequently the cæcum, stomach (gastrocele), or liver (hepatocele). In the ox the reticulum most commonly protrudes, and after that the liver, abomasum, the omentum or the small intestine. In the dog the mass is usually formed by the stomach or liver, or less frequently by the small intestine or omentum.
Causes and mode of formation. The hernia is either congenital or acquired after birth. Again, it may result from imperfect development or from a trauma. Congenital cases usually depend on an arrest of development, the foramen sinistrum fails to close and the abdominal organ passes through by the side of the œsophagus into the chest; or the diaphragm is left imperfect at some other point, and the two cavities, abdominal and thoracic, communicate. In some instances there is left not a distinct opening but a mere relaxation of the parts and under traction, as, for example, by the gullet, an orifice is torn and a hernia protrudes. Such cases are very rare. Other lacerations may be almost all referred to external injuries on the posterior ribs, violent muscular exertions, sudden shocks in connection with falls, or throwing for operations, and overdistension of the abdominal viscera.
1st. External Violence. In the larger animals this may come from blows on the last ribs, by poles or shafts of carriages, the buffers of cars, the end of a gate and the gatepost, projecting ends of bars or beams against which they run, kicks by horse or ox, blows by the horns of cattle or tusks of boars. In the smaller animals in addition to the above, blows with heavy clubs and kicks with heavy boots. In all such cases there is usually a fracture of one or more ribs, the sharp broken ends of which are forced into the diaphragm, which they tear when they again spring outward. The same occurs as the result of falls on hard projecting bodies of any kind.
2nd. Muscular Strain. In heavy draught the fixing of the glottis, ribs and diaphragm and the extreme contraction of the abdominal muscles often lead to extraordinary tension of the muscular septum by the mere violence of which, or when there is superadded a sudden shock, (in plunging in harness, or displacement of the feet or slipping and falling,) the diaphragm is torn, usually in its tendinous portion, and the abdominal viscus protrudes into the chest. If the diaphragm is momentarily relaxed the lesion may take place in the peripheral muscular portion. In still other cases the lesion is at one of the natural openings. The same accident occurs in animals thrown for operation, the abdominal viscera being full, the hind limbs drawn forward so as to further compress the belly, and the muscles being subjected to violent contraction in the efforts to get loose. Violent straining in dystokia is another cause which, however, usually partakes of a sudden shock on the diaphragm when a violent pain sets in.
3rd. Sudden Shocks on the diaphragm, and pressure by the abdominal organs. In the horse especially the weight of the abdominal viscera is very great and the floor of the abdomen inclines downward and forward so that the whole mass presses with great force against the concave diaphragm. In cattle the great weight of the stomach and liver is especially important and in dog and pig of the liver mainly. In trotting or galloping down hill or jumping from a higher to a lower level, or in slipping back on the fore feet so that the horse falls on the knees or shoulders, this pressure is suddenly greatly enhanced and the tense diaphragm may give way in its tendinous portion or the relaxed organ through its muscular tissue. A similar danger attends on the violent straining which attends on difficult cases of parturition, and even in cases of overloaded stomach and tympany and especially when the tortured animal throws itself suddenly and recklessly on the ground. In cattle and sheep this is usually the result of tympany of the rumen, and in solipeds of stomach and intestines.
Rupture by simple overloading or overdistention is, however, a rare occurrence, and many cases attributed to this are in reality instances of post mortem lesions, to be identified by the seat of the laceration in the muscular portion, and by the absence of blood clots, exudate, thickening or other sign of inflammation on the torn border.
Symptoms. These bear a direct relation to the size of the laceration and the mass of abdominal organs that protrude into the chest.
In very grave, recent cases, with a great phrenic rupture and a most extensive protrusion of abdominal organs into the chest, there may be simply the indications of extreme dyspnœa, nostrils and chest widely and persistently distended, nasal mucosa darkly congested, countenance pinched, eyes protruding and fixed, pupils dilated, breathing rapid, shallow and oppressed, and in a few minutes the animal staggers and falls in the death agony.
In cases which are less rapidly fatal, the patient lasting for hours or even days, there occurs, after the accident, deep, difficult and oppressed breathing, but not so violent as to threaten instant suffocation, or more commonly, these symptoms increase slowly as more and more of the hernial mass protrudes through the narrow opening into the chest. This form is usually seen only in animals of a specially quiet disposition, and which have not been subjected to active exertion or excitement after the accident and the hernia has increased by slow degrees only. The patient becomes listless, or very restless, paws, looks at his flanks, shifts from one hind foot to the other or even kicks at the abdomen, lies down carefully, rolls, sits on his haunches (though no more than in other forms of colic), and manifests the anxious, pinched, colic-countenance. The advance of the pain is constant but slow, and usually it is not characterized by that intensity which drives the animal to throw himself down recklessly and to roll and kick with violence. There is also usually an absence of the weak running down pulse of hemorrhagic congestion (thrombosis) and of the pallor of the surface mucosæ which usually attend on the extensive blood extravasations of that disease. An exception may be made in those cases in which the hernial mass is strangulated, as these may closely resemble spasmodic colic or hemorrhagic congestion.
The respiration furnishes more distinctive symptoms. The breathing which may be hurried and almost panting in colic and acute congestion, is changed in this lesion to a condition of extreme oppression, the nostrils remain widely dilated in expiration as well as inspiration, the angle of the mouth is retracted so as to show the teeth and gums, all the facial muscles stand out, the eyes are protruding and fixed, with dilated pupils, the head is held extended on the neck, and the ribs are not allowed to fall in freely, as after ordinary inspiration, but like the nostrils they remain permanently drawn out. The efforts at inspiration are violent though shallow and marked by lifting of the flanks. There are usually one or two nervous catches in each expiration and sometimes in inspiration as well. This is partly due to the impotence of the deeply lacerated diaphragm as an organ of respiration, but also to the pressure of the displaced and overdistended abdominal organs on the lungs, and to the profound nervous shock. The whole work has been suddenly thrown on the costal muscles, and the depressed nervous system proves unequal to sustaining them in the unwonted toil.
Still clearer indications may be obtained from auscultation and percussion. These are gurgling, rumbling and clucking, or a coarse mucous râle which seem abnormally close to the ear, and a drumlike resonance, much greater than that of emphysematous lung and enormously in excess of what is given out by the sound lung tissue. These may be heard at points where only pulmonary murmurs naturally occur or where abdominal sounds, if heard at all, are distant in health. There may also be areas of abnormal flatness on percussion by reason of the protrusion of a solid viscus like the liver or spleen or one with solid contents. These symptoms are only clear when there is a large intrusion of abdominal organs into the thorax, and they increase rapidly until asphyxia supervenes.
In cases which do not immediately threaten life the extent of the phrenic laceration is usually small and the orifice may be blocked by a bulky organ like the rumen, double colon, stomach or liver, so that any protrusion takes place only to a limited amount and the function of the diaphragm can still be carried on to a reasonable extent. In these cases there may be no very marked symptom at the outset, though the animal is dull, listless and without appetite, or, if he eats or drinks, it is liable to be followed by slight colics and a double action of the flank in expiration as in pulmonary emphysema (heaves). Pressure or percussion in the posterior intercostal spaces is painful. Cough when roused by pinching the larynx is broken and abortive. These symptoms are not distinctive, however, and unless there is a protrusion of a loop of small intestine, to give gurgling and drumlike sounds the diagnosis of the case is liable to fail. The fact of a recent injury may however assist in the recognition of the lesion.
The chronic cases are even more difficult to recognize as there is no record of recent injury and no fever. There may be short wind, the animal breathing hurriedly on slight exertion, and showing a double lift of the flank in expiration (Girard). In place, however, of the tympanitic bowels and frequent passage of flatus which characterize heaves, there is a tendency to colic, especially after meals, and in a certain number of cases there are all the symptoms of fatal strangulation, due to the contraction of the diaphragmatic wound. When the hernia is made by a loop of intestine there are the characteristic symptoms of thoracic gurgling and drumlike resonance.
Cases are on record in which the intestine protrudes through one of the last intercostal spaces or between the ends of the broken rib as a hernia and diagnosis becomes easy by auscultation, palpation and percussion. But in a large proportion of cases the lesion escapes recognition and is only found on post mortem examination.
Lesions. The lacerated orifice in the diaphragm varies much as regards situation, extent, form and the nature of its border. In congenital cases due to an imperfect closure of the natural openings there may be simply a round or ovoid opening, too spacious to be filled by the gullet, vena cava or aorta as the case may be, and capable in the different cases, of containing an organ of any size from the omentum to the liver or stomach. Its margins may be perfectly smooth and even, without any thickening, irregularity, fringe, clot or exudate. In traumatic cases on the other hand the orifice may be of almost any form, size or situation. It may be round, elliptical, triangular, or irregular in many ways. It may be so small as to admit nothing more than a small fold of the omentum, or it may be large enough to open the two cavities, thoracic and abdominal into one common space, and to practically abolish the function of the diaphragm. If the lesion is a recent one the torn margin is irregularly indented or fimbriated and marked by small black blood clots, and somewhat later by exudate and irregular thickening or swelling. When due to a broken rib, the existence of the fracture is patent and the laceration extends along two lines often radiating from point of perforation by the rib. When the laceration has resulted from tympany of the stomach or intestines or from other overdistension of the abdominal organs, the general and comparatively equable pressure has determined the independent laceration of numerous tendinous or muscular bundles all over the diaphragm, so that the divided ends stand out at intervals each bearing its little clot of dark blood, but without actual perforation. The actual orifice in such cases is confined to one point where the tension has been greater or the resistance less. Post mortem lacerations, from tympany or other cause, are easily distinguished from those occurring during life, in that the edges of the wound are pale and bloodless, without clot or exudate.
When the hernia is chronic there is an absence of exposed fringes, and of indications of inflammation, the margins of the orifice being in some cases smooth, even and fibrous, and in others irregularly notched or indented with nodular, fibroid swellings of various sizes at intervals. In such cases the orifice is always relatively small and the hernial mass inconsiderable.
As a rule the peritoneum and pleura, being firmly adherent to the diaphragm, are involved in the laceration so that the hernial mass is not retained in a special sac, but simply protrudes into the pleural cavity, after the manner of an eventration. In exceptional cases they become detached from the muscle, and becoming distended, envelope the hernial mass in a distinct sac.
In hernia with a very small orifice the omentum alone may pass through, even the small intestine proving too large for admission. In such cases it is usual to find the band of omentum adherent to the callus formed by the repair of a fractured rib. When the orifice is somewhat larger a portion of small intestine or of the double colon or cæcum may be engaged, while with a still larger opening the stomach, spleen, or liver may form the hernia. In cattle the reticulum is most likely to be the hernial mass, as noted in an article below. In rare cases the small intestines, omentum or liver protrude (Youatt, Lafosse). The protruding organ is liable to be constricted and strangulated sooner or later by increase in its bulk in connection with its vermicular movements, the accumulation of its contents or the extrication of gas in its lumen, or by the gradual contraction of the orifice in process of healing. Then there may be dark red venous congestion, blood extravasation and effusion, friability and even rupture of the intestinal walls, and adhesions to the wound or the lungs. Once started this congestion and extravasation may extend backward into the abdominal cavity involving a great part of the contiguous intestinal canal.
Prognosis. The worst cases are promptly fatal, while others destroy life in one or two days and such are always to be recognized by the extreme dyspnœa which appears soon after the accident. The slight cases with small orifice and little protrusion may merge into the chronic form, and the animal may even be fit for work, notwithstanding existing dyspnœa, which closely resembles that of chronic emphysema (heaves), but is not benefited by the same treatment. In the ruminants even considerable lacerations and protrusions may not be incompatible with fattening provided the animal is kept from all causes of excitement or over-exertion.
Treatment. Surgical treatment has not proved successful. Expectant and medicinal treatment are the only available resorts and then only in the slighter cases. Quiet and the absence of all excitement is the first consideration to allow of an arrest of any increase of the hernia and the establishing of a healing process in the torn margins. Bouley strongly advises bleeding to allay abdominal pain. Chloral hydrate (1 ounce for the larger animals) will often meet the same end, with the additional advantage that it counteracts fermentation and tympany. The unloading of stomach and bowels by a cathartic, and the use of flaxseed meal or other concentrated food of a laxative nature are indicated. Small animals may be lifted by their fore limbs, and the abdomen may be meanwhile manipulated to favor the return of the hernial mass by gravitation. Large animals should be placed in a stall having an inclination downward and backward for the same reason. When it can be ascertained that the hernia consists of a loop of small intestine only, it is permissible, especially in cattle, carnivora and omnivora, to make an incision in the flank and with the disinfected hand to attempt the reduction of the hernia and the placing of a bulky viscus, like the rumen, stomach or liver in the way of its return. In case of violent abdominal pain Bouley advises active counter-irritation over the abdomen, but as strangulation is usually present in such cases, this measure may be held to be inferior in value to gravitation, anodynes, antiseptics, unloading of the gastro-intestinal organs and absolute rest or surgical interference.