The Project Gutenberg e-Book of A System of Practical Medicine, Edited by William Pepper (2025)

Cancer of the Pericardium.

Cancer of the pericardium is one of the rarest of all cancerous affections, never occurring as a primary disease, but consequent on cancer in some other part of the body, generally on cancer adjacent to the heart. It may be the result of direct extension of cancer or of secondary formations. In cancer of the pericardium the parietal layer of the sac is the one always attacked. The extension of the disease from the bronchi and mediastinal glands, from the lungs, pleura, oesophagus, and stomach, is the common cause. Cancer will under certain conditions produce lymphous exudation and adhesions and serous, hemorrhagic, and even purulent effusions. When lymph is thrown out friction sound exists and adhesions may follow. Serous effusion with little or no inflammation is generally present in cancer of the pericardium, and results from the obstruction in the vessels caused by pressure or by direct extension of the disease to the vessels. If the effusion be hemorrhagic, it can be attributed to the same cause. Pus is generally the result of erosion of vessels and membrane.

The DIAGNOSIS of cancer of the pericardium is practically impossible, for the physical signs are essentially the same as in pericarditis from other causes, the darting, lancinating pain excepted; yet even the pain may not be sufficiently typical to lead us to a correct conclusion. Therefore, as a rule, the existence of the disease can only be suspected, or regarded as very probable in consequence of the general features of the malady.

The rarity of this affection is seen in the summary given in Ziemssen's Cyclopædia. Köhler noted 6 cases of cancer of the pericardium in 9118 autopsies; Günsburg found 1 case of cancer in 1700 autopsies; and Willigk, 7 cases in 477 autopsies of persons dying of cancer.

Death, which is the result in all cases, is generally by exhaustion. Other diseases of a nature allied to cancer also attack or involve the pericardium, such as lymphadenoma or lymphosarcoma in the mediastinum; the pathology is practically the same as that of cancer, and the general symptoms and the termination are alike.

Hydatids⁴¹ give rise to growths which occasion a surmise of cancer; so do those white calcified bodies formed in concentric layers known as cardiliths. Neither has any diagnostic signs by which it can be distinguished.

⁴¹ See Rokitansky's Pathological Anatomy, and Klob, "Zeitschrift der K. K.," Gesellschaft der Aertze zu Wien, 1860.

Tubercular Pericarditis.

Tubercular pericarditis is an exceedingly uncommon affection. Laennec only met with 2 instances of it, Louis with but 1 case. It is never primary, being always associated with tubercle in some other part of the body. Among the earlier records we find the case of Baillie,⁴² who mentions "a case of two or three scrofulous tumors growing within the cavity of the pericardium." The case had tubercles in the lungs, and died with all the symptoms of phthisis, nothing indicating the presence of tumors in the pericardium prior to death.

⁴² Morbid Anatomy, 5th ed., London, 1818, pp. 11, 17.

Tubercle in the pericardium may remain latent or excite inflammation which gives rise to the same physical signs and local phenomena as when the pericarditis is of idiopathic origin. The tubercle is mostly found beneath the serous layer of the pericardium, either cardiac or parietal, and sometimes in the adhesions, and bears a close resemblance to tubercular disease of the meninges, the peritoneum, and pleura. It must be understood, however, that pericarditis may happen in a tubercular person without being due to a deposit of tubercle in the pericardium; and a deposit may occur in the adhesions in a case of pericarditis in a tubercular person brought on by other causes than a tubercular development in the pericardium, as the instances reported by Burrows show.⁴³ Tubercular disease of the pericardium may be due, as Weigert has proved, to infection by contiguity from the lymphatic glands of the thorax. The pericardium may be free from tubercle, yet the purulent fluid in it be filled with tubercle bacilli.⁴⁴ Vaillard⁴⁵ declares the pericarditis to be dry in the majority of cases. The disease generally happens under forty years of age, but in Mickle's⁴⁶ case the patient died at the age of fifty-four.

⁴³ Med.-Chir. Trans., vol. xxx. p. 77.

⁴⁴ Kast, Virchow's Archiv, June, 1884; see also Medical News, Aug., 1884.

⁴⁵ Journ. de Méd. de Bordeaux, 1880, l. x.

⁴⁶ London Lancet, May 26, 1883.

The differential DIAGNOSIS of tubercular pericarditis cannot be made, as there is no positive physical sign distinguishing this form from any other. If pericarditis either in its acute or advanced stage occur in a tubercular person, and if there be neither rheumatism, Bright's disease, nor pleuro-pneumonia, and if the person have not been subjected to any injury in the præcordial region, the pericardial affection may be presumed to be due to tubercle, but only an autopsy would afford certain proof.

The PROGNOSIS is always unfavorable.

The TREATMENT is that of chronic pericarditis, sustaining the failing nutrition as well as we can by cod-liver oil and other nutrients.

THE OPERATIVE TREATMENT OF PERICARDIAL EFFUSIONS.

BY JOHN B. ROBERTS, A.M., M.D.

The operative treatment of pericardial exudations and transudations has received a new impetus within the last fifteen or twenty years from the investigations of Trousseau,¹ Roberts,² Hindenlang,³ Fiedler,⁴ West,⁵ and others. Reference to the works of these writers will furnish the reader with the history and statistics of such operations, and with those details that I have not deemed necessary to incorporate in the present article.

¹ Clinical Medicine.

² New York Med. Journ., Dec., 1876, with analysis of 41 cases; also Paracentesis of the Pericardium, Philada., 1880; Trans. Am. Med. Ass'n, 1880; and elsewhere.

³ Deutsches Archiv für klinische Medicin, 1879.

⁴ Samml. klin. Vortr., No. 215, Leipzig, 1882.

⁵ Medico-Chirurgical Transactions, 1883.

In all cases of bloody, serous, purulent, or aërial effusions into the pericardium, that present dangerous symptoms of heart failure, operative interference should be undertaken as soon as it is evident that medication is not lessening the embarrassment of the central organ of circulation. It is bad practice to delay the operation, which will generally be aspiration, until exhaustion, pulmonary engorgement, pericardial changes, and degeneration of the cardiac muscle render permanent relief impossible. The tendency is to wait, instead of affording immediate relief of the distressing symptoms by prompt resort to pericardicentesis. Clinical experience has abundantly shown that when the pericardial fluid is evacuated, dyspnoea, cyanosis, irregularity of the pulse, and the other threatening symptoms are lessened; and usually at once.

The time for aspiration depends less on the amount of fluid than would at first be supposed, because the sudden effusion of a moderate amount of serum will exert more pressure upon the heart than a much larger quantity poured out in so gradual a manner as to allow the pericardium to become stretched. Aspiration should therefore be performed in all cases of pericardial effusion, in which dangerous symptoms of heart embarrassment occur, as soon as medication fails, and without regard to the supposed quantity of fluid. This should be the practice without regard to any other visceral lesion that may be present as a complication, except in the case of pleural effusion.

When pleural effusion of considerable amount coexists, the pleural sac should be aspirated first, because of the difficulty of discriminating between respiratory distress due to pulmonary pressure and that resulting secondarily from interference with cardiac action, and because the evacuation of the pleural effusion seems at times to lead to absorption of the fluid in the pericardium without resort to operation. This rule applies to pleurisy of the right side as well as of the left.

In dropsy of the pericardium from renal disease I admit that the transudation is at times absorbed with great rapidity, and that aspiration does not directly affect the primary disease; but still, tapping should be done if the failure of circulation and respiration seems to be dependent on the effusion. Pepper's case⁶ of recovery after pericardicentesis affords corroborative evidence of the propriety of this advice. Before operation the urine was albuminous and contained tube-casts, but these symptoms entirely disappeared in the course of a few weeks.

⁶ Medical News and Library, Philada., March, 1878; and Am. Journ. Med. Sciences, April, 1879.

When the amelioration of symptoms following the operation is not permanent because reaccumulation takes place, repetition of the operative procedure is demanded. It is better, in my opinion, to vary somewhat the point of puncture, lest the heart be wounded at the second tapping because of adhesion of the parietal to the visceral pericardium at the original point of puncture. Should repeated tapping be required in serous effusions, I should at the time of the third operation inject into the sac, after removing the serum, a solution containing tincture of iodine, alcohol, or carbolic acid, with the purpose of modifying the secreting surface and producing pericardial adhesion. Universal pericardial adhesion has been found by examination subsequent to cure by aspiration; and in a number of cases intra-pericardial injections have been made without preventing, or apparently interfering with, recovery.

The fluid injected ought probably to be concentrated, as the object to be obtained is pericarditis of a grade that will furnish plastic exudation instead of serum. Undiluted but liquefied carbolic acid, such as is used in treating hydrocele of the vaginal tunic of the testicle, would be the proper agent were it not for the possibility that its contact with the heart-walls might induce dangerous cardiac spasm. The strength of the fluid to be injected, as well as its utility, will have to be determined by future observation. Aran used fifteen grammes of tincture of iodine (French), one gramme of iodide of potassium, and fifty grammes of distilled water, and his patient recovered. Malle injected a solution of tincture of iodine "five times weaker than that recommended for hydrocele operations," but suspended the operation quickly because of the excessive pain in the cardiac region produced by the injection. Violent inflammatory symptoms arose. The patient died of diarrhoea before the exact result of the injection could be determined, though the indications were that cure by pericardial adhesion was about to take place. The autopsy seemed to confirm this belief.⁷ It must be remembered also that his operation was done by trephining the sternum, which may have had something to do with the inflammatory reaction, though the injection was not made until the sixteenth day after the original operation.

⁷ De la Paracentèse du Péricarde, par Michel Labrousse, Thèse No. 107, 1871, pp. 22, 27.

When aspiration has shown the pericarditis to be purulent, a free incision should be made, an antiseptic drainage-tube of good size introduced, and the cavity washed out daily with antiseptic solutions of carbolic acid (1 to 40) or corrosive sublimate (1 to 2000). In fact, pericardial effusions should be managed exactly as pleural effusions by tapping, injection, or drainage, according to the character of the contents of the sac. I have advocated this course since 1876, and it has been justified by the cases of Villeneuve, Jürgensen, Viry, Rosenstein, West, Partzevsky,⁸ and Savory. Although these operators did not all practise free incision, yet the study of their cases shows the absence from danger and the propriety of such incision. As far as I know, no cases of purulent pericarditis have recovered after simple aspiration. The case of Rosenstein and that of West, however, did recover after incision and drainage; and in that of Villeneuve, which was originally serous, there remained a fistulous track discharging pus for nearly six months, when spontaneous closure and cure resulted. Gussenbauer has successfully treated pyopericardium following acute osteo-myelitis at the shoulder by resection of five ribs and washing out the sac with a thymol solution.⁹

⁸ See Lond. Med. Rec., Feb. 15, 1883.

⁹ Wien. med. Wochenschr., Nov. 21, 1884, quoted in Medical News, Philada., Jan. 17, 1885.

Pericardial fistules, due to spontaneous or operative evacuation, should be managed by dilatation, with compressed sponge, and irrigation of the cavity with astringent or disinfectant solutions. Some supposed pericardial fistules may be pleural fistules, or sinuses opening into small pockets between the parietal and visceral layers of an adherent pericardium, or entirely external to the pericardium in new tissue occupying the mediastinum. Such sinuses should be laid open with the scalpel, and compelled to granulate from the bottom. Sinuses dependent upon diseased rib, sternum, or cartilage should be laid open, and the necrotic or carious structure removed by burr or chisel.

Incision of the pericardium under antiseptic precautions may be useful, and is justifiable as a diagnostic procedure in grave cases when doubt exists between a large pericardial effusion and a dilated heart. The wound will scarcely increase the danger if the pathological condition be cardiac dilatation, and may save life if effusion be the cause of the threatening symptoms. The case of Vigla upon which Roux operated shows the value of such procedures.¹⁰

¹⁰ Trousseau's Clinical Medicine.

Aspiration is the method to be employed at first in all instances of pericardicentesis. Incision is to be reserved for the second step in purulent pericarditis, for diagnostic purposes, and for the extraction of foreign bodies, and similar operative designs. The best point for aspiration is usually in the fifth interspace, just above the sixth rib, and about five or six centimeters (2–2¼ inches) to the left of the median line of the sternum. In a child it should be a little nearer the sternum. The point advised is outside of the line of the internal mammary artery, is in a wide portion of the intercostal space, corresponds with the notch in the border of the left lung, is low enough to preclude wounding the auricle, high enough to avoid the diaphragm, and does not approach the point where a cartilaginous band often joins the fifth and sixth costal cartilages. Both layers of the pleura will probably be pierced by the aspirating-needle at this point, but this is not an important complication, and can only be avoided with anything like certainty by going close to the sternum, which is objectionable on other grounds.

The aspiration may be performed by using the pump and the ordinary needle or trocar which is furnished by instrument-makers in the aspirator-case. In cases of emergency or for mere exploratory puncture the common hypodermic syringe and needle will answer the purpose. The puncturing instrument should be clean and anointed with carbolized oil, and in all cases the vacuum-chamber should be attached to the needle or trocar as soon as its point is buried beneath the skin, in order that a flow of fluid may indicate the moment at which the pericardial sac is entered. Abrasion of the heart, which may occur from contact with the needle-point when the fluid is almost entirely evacuated, is not very important, but should be avoided if possible by deflecting or partially withdrawing the needle, or by using Roberts's improved pericardial trocar or that suggested by Pepper. The instrument figured in my monograph on Paracentesis of the Pericardium was too large for use. The improved instrument here figured is no larger than a moderate-size aspirating-needle. It consists of such a needle, flattened at its upper extremity to give the surgeon a firm hold, within which slides a canula. The distal end of the canula, made flexible by a spiral, when thrust beyond the point of the needle curves downward, and thus prevents the point of the puncturing instrument injuring the heart when the sac is nearly emptied. During penetration of the thoracic wall the canula is retracted, so that the flexible end is contained within the needle, and the perforation at the end of the canula allows the fluid to escape as soon as the sac itself is punctured. The canula is then thrust forward until the sharp point of the needle is guarded. This movement brings a lateral fenestra in the canula opposite a similar opening in the needle, and thus provides a second orifice for the escape of fluid in case the terminal one becomes occluded. The external end of the canula has a square shoulder to prevent rotation within the needle, and should be tight enough at that point to preclude entrance of air. The canula finally terminates in a ground end for attachment to the aspirator-tube. The needle—or outer canula as it may be called—is marked on the surface to show the number of centimeters concealed in the tissues. If the inner canula is suspected to be clogged with shreds of lymph or with thick pus, it can be withdrawn without disturbing the needle. The attachment may then be made to the latter as if it were an ordinary aspirating-needle, or the inner tube being cleaned may be reinserted. This is an important element, gained by using a double aspirating-trocar; for plugging is not uncommon in pericardicentesis done for chronic inflammation of the sac.

FIG. 49.

Roberts's Pericardial Aspirating Trocar.

Beverley Robinson of New York has still further modified¹¹ my trocar. His additions may have improved the instrument if they do not unduly complicate it. Pepper, after operating upon his case, had made a delicate double canula, the inner tube of which was furnished with a fine needle-point. After introduction the inner tube was withdrawn until its point was sheathed.¹²

¹¹ New York Med. Record, March 29, 1884.

¹² Medical News and Library, Philada., March, 1878.

It is said that at the meeting of the Italian Medical Association at Pisa in 1878, Baccelli proposed a new method of puncture; but the account given by Severi¹³ in speaking of Baccelli's cases indicates that his proposal referred not to a method of operating, but to a method of selecting the point of puncture.

¹³ Lo Sperimentale, Aprile, 1881, p. 392.

It must also be remembered that failure to obtain fluid when pericardial effusion existed has occurred because the needle had been passed through a costal cartilage, and was thus plugged by a disk of cartilage. The manner in which the intercostal spaces are narrowed and changed in direction by the curving upward of the anterior portion of the ribs and by the curvature of the cartilages should be impressed upon the operator.

If failure to obtain fluid occurs, and the diagnosis remains quite certain from the symptoms, withdrawal of the needle and puncture in another position should be done or an incision of an exploratory kind made.

In pericardicentesis care must be taken not to thrust the needle or trocar into the heart. This may happen even in quite careful hands. If the right ventricle is entered, venous blood will escape through the canula; if the needle is buried in the cardiac muscle, no fluid or blood can escape. The violent movements communicated to the needle will usually indicate that the needle is either in contact with the heart or thrust into its tissue. Of course such movements will occur from cardiac contact when most of the fluid has been withdrawn; but are not to be expected immediately after the introduction of the puncturing instrument unless the fluid is very small in amount, the needle deeply inserted, the pericardium adherent at the point of puncture, or the diagnosis of fluid an error.

Puncture of the heart has occurred accidentally during pericardial tapping without doing any harm, and has been suggested as a proper surgical procedure in certain cardiac conditions. Still, it is an accident to be avoided by the use of proper trocars and pumps, by the selection of a proper site of operation, by the adaptation of the suction power as soon as the point of the trocar or needle is buried beneath the skin, and by other precautions that will suggest themselves. In thick, oedematous, or fatty chest-walls no fluid will be reached perhaps until a depth of four or five centimeters (about two inches) has been attained by the point of the puncturing apparatus.

I must call attention to the fact that West¹⁴ records a case of pericardial tapping occurring at St. Bartholomew's Hospital in 1874 where a trocar and a canula were introduced through the fourth left space near the edge of the sternum, and caused death in five minutes from hemorrhage into the pericardium, due to tearing of the right ventricle. The position chosen and the form of instrument may have had to do with this unfortunate result, of which the details are not given.

¹⁴ Med.-Chir. Trans., 1883, pp. 259, 275.

A few words on cardicentesis, or intentional heart-puncture, may here be appropriate. It has been suggested as a means for rapid abstraction of blood from the right heart in intense pulmonary and cardiac engorgement, and for the abstraction of air after air-embolism has occurred from wounds of the large venous trunks. It has been known for years that aspiration and similar punctures of the heart are comparatively harmless. Roger accidentally withdrew 200 grammes of blood from the right ventricle of a boy of five years without doing harm. Hulke seemed to benefit a case of pleuro-pneumonia by accidentally aspirating the right heart. Cloquet, Bouchut, Steiner, and Legros and Onimus have made similar observations on the absence of danger from such wounds. Westbrook of Brooklyn, Corwin,¹⁵ Dana,¹⁶ and apparently Janeway of New York, have performed intentional cardiac aspiration in moribund patients without causing any noticeable harm. The contributions of Westbrook,¹⁷ Roberts,¹⁸ and Leuf¹⁹ on this topic, as well as that of Senn²⁰ on air-embolism and its treatment, will interest those who wish further information.

¹⁵ N.Y. Med. Record, March 10, 1883, p. 263.

¹⁶ Ibid., Feb. 3, 1883, p. 140.

¹⁷ Ibid., Dec. 23, 1882.

¹⁸ Philada. Med. News, Jan. 13, 1883.

¹⁹ Amer. Journ. Med. Sci., Jan., 1885, p. 79.

²⁰ Trans. Amer. Surg. Ass., 1885, and Annals of Surgery, St. Louis, 1885.

The results of operations for pericardial aspiration or incision are exceedingly good when the frequent postponement of the operation till the patient is almost moribund is recollected. Elaborate statistical tables would be out of place in this volume; and, besides, it seems almost impossible to get a complete collection of the cases. Hindenlang, West, and I have published and analyzed long lists of cases collected from various sources, and I have now references to more, but this tabulation seems unnecessary, as the practical points to be derived from their study are well proved by the previous work done. In addition to the bibliographical notes already given, I add for the use of inquirers in this field two recent monographs—one by a German,²¹ the other by a French writer.²²

²¹ Ueber Paracentese des Herzbeutels, Gerhard Beck, Würzb., 1882, p. 33 (Thesis).

²² Contribution à l'Étude de la Paracentèse du Péricarde, H. Ferraud, Bordeaux, 1883.

DISEASES OF THE AORTA.

BY G. M. GARLAND, M.D.

Acute Aortitis.

The existence of inflammation of the membranes of the aorta was mentioned by Galen and other early writers, but it was not until 1824 that a systematic treatise on this subject was published. Since that time the subject has received more attention, but the results obtained are unsatisfactory. There is grave doubt, according to many writers, as to the existence of acute aortitis independent of other lesions, although it is recognized that the aorta may participate in inflammation of the neighboring organs. Even then, as Powell says, "the aorta is very slow to share in such processes, and when it does so the inflammation is very chronic and limited, giving rise to no special symptoms." Peter treats the subject at length, and after enumerating certain so-called symptoms of acute aortitis, confesses that these symptoms are merely the ordinary phenomena of angina pectoris, and these two affections cannot be distinguished from each other. It must be concluded for the present, therefore, that acute aortitis is rare, and that we know of no symptoms which are characteristic of it.

Atheroma of the Aorta.

Atheroma of the aorta is the result of chronic endarteritis, and is always of slow development. The process may be limited to the intima or it may extend to the middle and outer tunics. Beginning with a thickening and softening of the wall, it finally develops plates of calcareous deposit. These plates are most numerous in the region of the aortic valves, and diminish in number as the artery proceeds from that point. The descending portion of the aorta is relatively free from these patches, but they reappear again near or at the bifurcation.

ETIOLOGY.—Atheroma is one of the ordinary products of old age, and is therefore one expression of senility. Heredity probably exerts some influence, and certain cachexias predispose to an early occurrence of the process. Gout and syphilis render one especially prone to it. High pressure and strain are also important factors. Continuous hard toil is more productive of atheroma, according to Allbutt, than intermittent work. The pre-albuminuric stage of Bright's disease, which is characterized by high arterial pressure, is frequently productive of atheroma.

SYMPTOMS.—When the inner coat alone is affected, there are no symptoms of this disease. According as the degeneration extends deeper and involves the middle and outer tunics, the aorta begins to dilate, and the symptoms may vary from the slightest feelings of discomfort upon exertion to the most violent attacks of palpitation and pain.

Usually, at the beginning the symptoms are very obscure. A slight dyspnoea on exertion, or palpitation, or dyspeptic troubles are the chief complaint. The presence of these troubles in a man of fifty years or over, whose heart and kidneys present nothing abnormal, and in whom the smaller arteries of the extremities feel hard and calcareous, may excite the suspicion of atheroma of the aorta. There are no distinctive physical signs. Some writers speak of a short post-systolic murmur over the aorta beyond the valves, which may be audible only when the heart is acting strongly.

The aorta is almost invariably dilated, and Peter says that this dilatation may be traced by percussion. According to him, the normal aortic dull area measures from two to five centimeters transversely in the male, and from two to four centimeters in the female. He says that he has seen cases of atheroma where he was able to determine a dull aortic area of eight centimeters in diameter. If the inflammation extend from the aorta to the neighboring nerves, the patient may suffer from the ordinary symptoms of angina pectoris.

TREATMENT.—This disease cannot be cured by drugs. The physician's task is to regulate the habits of the patient, to remove so far as possible all conditions which tend to aggravate and increase the trouble, and to alleviate incidental symptoms of distress.

Thoracic Aneurism.

DEFINITION.—The origin of the term aneurism is buried in obscurity, and the theories which have been advanced regarding it are not very satisfactory. Montanus thought it was derived from a privative, and neuron, a nerve. Oetius declares it is from aneurisma, an enlargement, from eurumo, I dilate. Coale thinks a ready origin is offered in the words aneu, without, rusmos, a series, course, or succession, from ruo, I flow.

Aneurism of the aorta is a local dilatation of that vessel. When all the arterial tunics persist unruptured in the tumor, it is a true aneurism. When one or more of the tunics are torn in the process of expansion, it becomes a false aneurism. When all the tunics of the artery rupture and the blood escapes into the neighboring cellular tissue, it becomes a diffuse false aneurism. The internal and middle coats of an artery may burst, and the blood escape into and coagulate in the space between the middle and external tunics, and this is termed a dissecting aneurism. In rare instances of this type of aneurism the blood finds a second opening, and returns into the artery again, thus forming a double tube for a short distance.

In former times great stress was laid upon the distinction of aneurism according to the number and combination of persistent tunics, and we read of the mixed internal and the mixed external type. These points have less clinical importance, however, than a proper appreciation of the size and shape of a tumor, because all aneurisms are false after they exceed a certain size. When an aneurism involves the entire periphery of the aorta, it may be cylindrical, fusiform, or globular in shape, and receive names accordingly. When it is a mere bulging on one side of the artery it is saccular in shape. Obviously, the opening into the fusiform aneurism is quite or nearly the entire length of the tumor, whereas in the false saccular type the orifice may be reduced to a mere puncture of the arterial wall. The size of the orifice is a matter of great importance, particularly in connection with the question of operative interference, and therefore it will be referred to later. The sacciform and fusiform aneurisms are often combined together, or, in other words, it is quite common to find a lateral bulging superimposed upon a local dilatation of the artery; but such grouping is not necessary, as either form appears without the other. It is not uncommon also to find one bulbous aneurism superimposed upon another, the dependent aneurism in this case being of the false or diffuse type. The second aneurism often lies outside the chest-wall, and it is connected with the mother aneurism by a narrow opening or channel.

Varicose aneurism is a false aneurism formed by communication between the aorta and the vena cava, the pulmonary artery, the right auricle, or the right ventricle. It is almost without exception rapidly fatal and not amenable to treatment.

Occasionally the aorta will present alternate bulgings upon one side and the other, so that the vessel appears to wind in its course. This condition is called cirsoid aneurism, but it has nothing in common with external aneurism of the same name.

The size of an aneurism is variable, like its shape, but in general the true aneurism rarely exceeds the size of an egg (Jaccoud). Beyond this size one or more of the coats give way, and the aneurism becomes false, in which condition it may grow as large as an adult's head if the patient lives long enough to allow such development. Balfour refers to two rare forms of aneurism—the intravalvular, which is situated within the aortic valves and above the ventricle, and the intervalvular, which is still more rare, and is situated between the valves themselves. The symptoms of these aneurisms are merely those of valvular lesion, and therefore present no differential points for diagnosis.

ETIOLOGY.—Local weakness of the aorta submitted to sudden strain is unquestionably the most frequent cause of aneurism. It is rare to find an aneurism in an otherwise healthy aorta, and some authors go so far as to assert that aneurism never occurs without preceding degenerative changes in the arterial wall. Naturally, strain is the physiological burden of the aorta, and this strain tends sooner or later to degeneration of the arterial tunics. Then, given a weakened spot, the ordinary occurrences of every-day life are sufficient to precipitate disaster. A sneeze, a cough, some sudden exertion of the body in lifting or moving, have been the starting-points of aneurism. All accumulated testimony indicates that sudden strain is more dangerous than prolonged uniform strain, and therefore some occupations are more productive of aneurism than others. Inasmuch as age, sex, occupation, and personal habits influence the development and nutrition of the aorta, it is obvious that they must exert an important influence upon the occurrence of aneurism.

All records agree that aneurism is pre-eminently a casualty of middle life, and a glance at the accompanying table, which I have prepared from an analysis of 69 reported cases, shows that the disease is most common between thirty and fifty years of age:

Crisp analyzed 551 cases, and reports 398 between the ages of thirty and fifty.

Beneke has found in his records of arterial measurements that the pulmonary artery greatly exceeds the aorta in circumference up to the age of thirty. After that period the aorta begins to increase with relatively greater rapidity, until in the forties it exceeds the pulmonary artery in size, and it maintains its superiority from that time forward. The aorta continues to increase in circumference throughout life, but after the age of fifty this increase is considered a senile dilatation rather than an actual growth. It is interesting to note that the era of greatest liability to aneurism coincides with that of most rapid aortic development.

Sex furnishes a distinction in the frequency of aneurism. In 82 cases I found that only a seventh were females; Crisp registers less than an eighth. The radically different occupations and habits of women may contribute somewhat to their relative immunity from aneurism, and their physiological development also seems in their favor. Beneke states that the blood-pressure during childhood is about the same for both sexes. From puberty onward it is greater in the male. This is due to the fact that after puberty the volume of the heart relative to the length of the body is less in the female than in the male, and at the same time the main arteries of the body relative to the length of the body are only a trifle narrower in women than in men. The pulmonary artery, indeed, is relatively a trifle wider in women than in men. It follows from this that the blood-tension in both the large vessels emerging from the heart is less in the female than in the male.

In general terms, it may be said that those people who are exposed to heavy labor, as mechanics, laborers, soldiers, porters, cabmen, etc., are more liable to aneurism than those who are less exposed to such straining efforts. Fixture of the chest during effort brings greater strain upon the heart and aorta, and therefore men who wield heavy hammers and sledges are especially liable to aortic disease. Constriction of the neck or forcible extension of the same during exertion is dangerous, because it thus happens that the arteries are stretched in their long diameter at the same instant that the blood-wave is expanding them laterally, and they are thereby subjected to double strain. I knew of a trotting horse which was killed by this very combination of strain upon the aorta. At the end of a trial of speed the animal refused to stop; whereupon a groom sprang forward, seized him by the bit, and threw his head strongly upward and backward. His carotids and aorta were thus stretched to full length at the moment when his heart was acting with great force. The horse dropped dead, and the autopsy revealed a rupture of the aorta.

The frequency of aneurism among the soldiers of the English army was long the subject of anxiety and thought to English surgeons. Finally, some bright man recognized one cause in the dress of the soldiers. They were obliged to wear a high stock, which constricted the neck and kept it stretched, and their trappings were adjusted so as to keep the body in a stiff and unnatural position. These objectionable details of the dress have been removed, and it is now claimed that aneurism is much less common in the army.

Syphilis and gout undoubtedly contribute to the formation of aneurism, because they both dispose to degenerative processes in the arterial tunics. Some writers, however, have laid too much stress upon syphilis. It was claimed that this disease was the cause of the great frequency of aneurism in the English army. Barwell, however, calls attention to the fact that aneurism has been 13½ times more frequent per 1000 men in the army than in the navy, and yet no one maintains that syphilis is more common in the army than in the navy.

SYMPTOMS.—The diagnosis of aneurism of the aorta may be one of the easiest problems of clinical medicine, or it may present difficulties which defeat the most skilful diagnosticians. A large number of aneurisms utter no sign of their existence, and are only revealed by the manner of death or by an autopsy. Again, the so-called signs of aneurism are so indefinite in character, and so associated with other pathological conditions, that the greatest confusion often befogs their interpretation. Mistakes therefore arise in two ways: either aneurism is diagnosed as present when it is absent, or it is declared absent when present. Robin reports the case of a vigorous young man upon whom several of the most eminent clinicians of Paris diagnosed aneurism of the aorta, and yet a rest of a few days sufficed to remove all symptoms of that disease. Three candidates for the diploma of the Royal College of Physicians and Surgeons in England recently declared a case of loculated pleurisy to be aneurism of the aorta, and B. W. Richardson says he has "seen at least seven persons suffering severe mental anxiety from the belief that they were fatally struck with aneurism," and yet they were free of such disease. Balfour says: "There is only one phenomenon positively characteristic of thoracic aneurism, and that is the existence in some part of the thorax of a pulsating tumor other than the heart, which beats isochronously with it, and at least as forcibly, and which at each pulsation expands in every direction." And yet simple dilatation of the aorta, combined with mental excitement, will so increase the thoracic pulsations as to simulate aneurism. It is necessary, therefore, that a patient during an examination should be as quiet as possible, both in mind and body, and if any doubt exist regarding the significance of the symptoms present, the patient should be kept in bed for a few days in order to allay the arterial excitement.

The phenomena produced by an aneurism are naturally divided into two groups: 1. The direct symptoms, which are confined to the limits of the tumor itself, and which are termed the physical signs. 2. The indirect symptoms, which are due to the influence of the tumor upon neighboring organs, and which present themselves often at remote points as signals of distress within. This influence of the tumor upon its environment is purely mechanical and due to pressure, and the resulting symptoms vary according to the particular organ or function involved. These symptoms are therefore classified as the physiological signs.

Pain is one of the earliest and most troublesome of the pressure symptoms of aneurism. It is due to a stretching of the nerve-filaments in the aortic wall and to the pressure of the tumor upon neighboring organs, especially the vertebral column and sternum. When due to nerve-stretching, the pain is neuralgic in character, and is not necessarily confined to the chest. It may appear in the back, and is intensified by coughing or sneezing. It may be rheumatic in type, and affect the arm and shoulders for several months before other aneurismal signs develop. In such cases the right arm and shoulder appear to be most often affected. Sometimes the pain cannot be located, but is referred indefinitely to the chest, or it may accompany acts of deglutition. As a rule—and this point is important—this form of pain from an aneurism exhibits wide variations of intensity and is usually intermittent. Exercise, coughing and sneezing, mental excitement, or anything which increases the activity of the circulation or raises the blood-tension, increases the pain. It may resemble angina pectoris in location and radiation, but it differs essentially otherwise. It is more continuous, and is associated with less anxiety, which is such a conspicuous element of angina.

When the pain is due to erosion of the vertebræ or sternum, it is more steady and gnawing. It is still liable to violent exacerbations, and excitement of all kinds increases it. Oftentimes the pain is so excessive that the sufferer cannot lie down or obtain relief in any position. This is especially the case with aneurism of the abdominal aorta. Bennet reports the case of a patient who poisoned himself to be free from the terrible pain, and deaths by exhaustion from pain and distress are not uncommon.

Numerous other accidents besides pain arise from pressure upon the neighboring veins. Balfour says that severe dyspnoea, vomiting, and flatulency are frequently caused by pressure of an aneurism upon the pneumogastric nerves, and that these symptoms may be relieved by gently rubbing the tumor. Hiccough and paralysis of one-half the diaphragm are caused by pressure upon the phrenic nerve. Occasionally destructive inflammations of the lung and pleura occur with aneurism, and these have been attributed to pressure upon the pneumogastric nerves and the pulmonary plexus. Palpitation of the heart is likewise often produced in a similar manner. Sometimes the patient is conscious of a pulsation in the tumor itself. Pressure upon the intercostal nerves will produce herpes zoster, and cicatricial records of such attacks are found upon patients with aneurism. Implication of the sympathetic nerves produces modifications of the pupils according as the nerves are merely irritated or paralyzed. In the first case the radial muscles of the iris become permanently contracted and the pupil is dilated. In the second case the radial muscle becomes paralyzed and the pupil is contracted. Jaccoud says that this succession of changes is not rare, and he has watched cases progress through both pupillary stages. The nerves affected are those which emerge from the cilio-spinal region, which extends, according to Budge and Waller, from the sixth cervical to the sixth dorsal, or, according to Brown-Séquard, as low as the tenth dorsal vertebra. From the anterior roots of this region nerve-filaments pass through the cervical sympathetic to the iris. The difference in the pupils is often so slight that it requires very careful measurement to detect it. The application of atropia will assist in the examination, because that drug has very incomplete influence upon the affected pupil. The pupil is also much less sensitive to light, but it contracts more strongly than the normal eyes in its accommodation for near objects. Robertson cautions against conclusions based upon mere casual observance of the eyes, because 1 person in every 14 has one pupil naturally smaller than the other.

Myosis is not pathognomonic of aneurism. It denotes merely some trouble with the cilio-spinal nerves. The nature of that trouble must of course be determined by the other associated symptoms of the case. The contraction of the pupil is sometimes accompanied by paleness of the corresponding side of the face and neck, while at other times the same region may be swollen, oedematous, and perspiring. These symptoms are due to local vascular changes from interference with, and disorganization of, the vaso-motor nerves which govern these regions. Remote local paralysis sometimes utters the first warning of aneurism, and such cases are usually very striking. Paralysis of the recurrent laryngeal is the most frequent of this group of signs. Urquhart reports a case where for some months the chief symptom was a falling of the head on the breast, as if it had been forcibly drawn down by the sterno-cleido-mastoids. Another patient was supposed to have rheumatism, but he soon became paralyzed on the right side and lost his speech. He recovered somewhat, but died subsequently from bursting of the tumor into a pulmonary cavity. Tufnell says if an amaurosis occur suddenly look for valvular disease of the heart or for aneurism of the aorta.

Dyspnoea.—The dyspnoea produced by an aneurism may vary from a slight difficulty of breathing on exertion to the most marked orthopnoea. It is produced by—a, direct pressure upon the trachea or bronchi; b, pressure upon the recurrent laryngeal or the vagus. The two forms of trouble are easily discriminated by physical examination. In cases of pressure upon the respiratory tubes auscultation reveals very characteristic signs. The constriction of the tube causes a peculiar harsh sound, which, heard only in inspiration at first, becomes audible later in expiration as well. If the pressure is upon the trachea, the sounds will be heard equally in both lungs; whereas if only one bronchus is involved, the sounds will be confined to the corresponding side. If a bronchus be completely occluded by pressure, then the peculiar breath-signs will disappear, and complete respiratory silence reign instead. The dyspnoea of this origin is greatly relieved by motion and by certain positions of the body. In capillary bronchitis, pneumonia, asthma, etc. the patient sits with the head thrown back and the shoulders raised, whereas a patient with tracheal compression finds greater relief in leaning across the back of a chair, with his head resting upon his arms folded on a table, and the nights are passed in this position. Again, the pressure dyspnoea is subject to sudden and excessive variations. Any excitement which increases the cardiac activity and the blood-tension will excite dyspnoea, whereas rest and repose diminish it. This form of dyspnoea is likewise accompanied by loud stridulous breathing, and by harshness and a metallic quality of the voice. The stridor and dyspnoea bear no direct relation to the size of the tumor, because a small tumor pressing upon the side of the trachea, where the cartilaginous rings are thinner and less resistant, will produce more discomfort than a larger tumor directly in front. Where the compression of an air-tube is considerable, it usually provokes inflammation of the mucous membrane, and the secretions thereby engendered are liable to collect behind the obstruction and increase the distress for breath. Cases are reported where, tracheotomy having been performed, a catheter was pushed by the obstruction and the backed-up secretion allowed to escape, to the great relief of the sufferer. One case is recorded where the examining physician was able to see by the aid of a laryngoscope an inward projection of the wall of the trachea, which pulsated with each heart-beat.

The dyspnoea arising from pressure upon the recurrent laryngeal and vagus may begin in two ways—either by a sudden paralysis of both vocal cords, or by a preliminary spasm of the cords due to nerve-irritation. When both cords are paralyzed, which is very rare, the voice is entirely obliterated and the dyspnoea is intense and continuous. The complete paralysis may be associated with choking at meals. When only one cord is paralyzed, the breathing is not materially affected, though the voice is altered in a characteristic manner.

If the compression of the nerves mentioned simply irritates them, then the phenomenon of laryngeal spasm occurs. The voice becomes high, squeaking, and false or whispering, with a muffled falsetto. Jaccoud describes a condition where the nerves of the two sides are not uniformly affected, and therefore the cords are not equally tense in their spasm. The result of this difference of tension and vibration is a peculiar commingling of high and low tones, which produces a very discordant and unpleasant sound to the ear. Jaccoud terms this la voix bitonale. The dyspnoea from spasm persists through both inspiration and expiration, whereas with paralysis of the cords the inspiration is alone or mainly affected. The cough in these cases is phenomenal in its character, being very loud and metallic, often barking, and it is very distressing to the patient and to all who hear it.

When a bronchus is compressed the percussion note on the corresponding lung is higher in pitch and tympanitic. The inspiratory murmur is ordinarily diminished, but bronchial breathing may (rarely) occur. The coincidence of bronchial breathing with tympanitic resonance is an eccentric combination of a very paradoxical character. The cough is almost pathognomonic, with a loud barking, distressing metallic clang. Such a cough is still more suggestive when combined with the high, shrill, whistling vox anserina. The amount of expectoration is at first small, consisting of glairy, frothy mucus. Later it becomes more copious and muco-purulent, and may even be rusty and red. The presence of bloody sputa with an aneurism is always grave, because it raises suspicion of a so-called weeping aneurism which is approaching rupture.

Dysphagia.—This is a common symptom with aneurism, but it is not so constant in appearance as it is with other mediastinal tumors. It appears more often when the aneurism is situated upon the transverse portion of the aorta. It is frequently painful, but always variable in severity, and may disappear for long intervals at a time. Lying upon the face usually relieves the difficulty, while it is aggravated by reclining upon the back. Fluids are usually swallowed more easily than solids. Hayden says that a feeling of sharp pain in a particular part of the gullet in swallowing when aneurism is present indicates erosion of the mucous membrane and early perforation.

Pressure upon Veins.—Localized oedema and cyanosis are two common symptoms of aneurism of the aorta. The sudden eruption, the limited distribution, and the terrifying effect of these symptoms render them especially interesting. They are due to pressure of the tumor upon the veins near the heart, and particularly upon the superior vena cava. Dujardin-Beaumetz says that, thanks to the vena azygos, compression of the superior vena cava produces simply a varicosity of the neck and upper part of trunk. Should the vena azygos be simultaneously blocked, then the oedema and cyanosis will spread over the entire head, neck, arms, shoulders, and upper trunk—i.e. over all parts drained by the superior vena cava. Only two such cases have been reported, however. One case was seen by Piorry and one by Dujardin-Beaumetz. In the latter case the oedema and cyanosis of parts named above came on suddenly without apparent cause. The face was swollen, blue, and covered with red patches, and the eyes were injected. The ears were cold; the abdomen and lower limbs retained their normal color. The contrast between the upper and lower portions of the body under these conditions is very striking.

Balfour says that "a thick oedematous collar covered with large veins surrounding the root of the neck" is indicative of compression of the superior vena cava.

Pressure upon the brachio-cephalic veins produces oedema and cyanosis of the head and upper extremities; oedema of the glottis has occurred under such conditions. Sudden swelling of one arm, unaccompanied by inflammation, is suspicious of aneurismal compression of the corresponding vein, especially if it comes on suddenly after exertion. Compression of the descending vena cava or right auricle may give rise to congestion and dropsy of the lower part of the body, but these are later symptoms.

Pressure upon the thoracic duct is relatively rare. It may cause emaciation, but loss of flesh with aneurism is more often due to obstruction of the oesophagus or to dyspepsia and the exhaustion from pain and sleeplessness.

Pressure upon Bones.—Pressure of a tumor on neighboring bones causes absorption and dislocation of the same. The clavicles, sternum, and ribs are rapidly eroded by the aneurism, and are pushed forward and disarticulated. Pressure upon the spinal column causes absorption of the vertebræ and of the cartilages, until oftentimes the cord is laid bare and even subjected to direct pressure.

Inspection.—Inspecting a person suspected of aneurism, one should examine the pupils, the color of the skin, the condition of the veins of the head, neck, and arms, all movements of the neck and chest, and especially the contour of the front part of the chest.

The conditions of the pupils, skin, and veins have all been described, but the movements of the neck and chest require notice here. Any area of pulsation apart from the normal apex-impulse should be critically marked and examined. Fulness or beating in the episternal notch is significant. Cheesman reports a case where a curious pulsation was occasionally communicated to the larynx and the tongue by an aneurism situated beneath the manubrium. Every now and then the thyroid cartilage would rise and fall, and the tongue would pulsate backward and forward with each beat of the aneurism.

Inspection of the larynx quickly determines the presence or absence of paralysis of the cord, and may sometimes reveal pulsating tumors pressing upon the trachea. While inspecting the shape of the chest it is best to stand upon one side of the patient and look across the surface of the thorax. In this way slight deviations from the symmetrical become most readily apparent. If any abnormal point seems to pulsate, the fact can be rendered more obvious by pasting bits of paper upon the suspected spot and around its immediate neighborhood. Viewed thus in an oblique light, the relative movements of these pieces may be easily discerned. If a tumor be present and the diagnosis established, one should carefully note the color and condition of the skin over the prominence. As the tumor develops pressure the skin becomes tense and glossy. Then it turns red, and may be covered with livid spots and even ecchymoses. In later stages a black dried scale of flesh may be all that seems to restrain the heaving blood. Weeping of blood may take place for some time before the final break.

Palpation.—Given a prominence of the chest-wall or a localized pulsation in the abdomen, the next step is to examine the suspected part with the hands. Any tumor lying across an artery will move forward and backward with each pulsation of the artery, and conditions of this kind have been repeatedly diagnosed as aneurism. An aneurismal tumor, however, is distensile as well as pulsatile. Every tumor, therefore, should be grasped as far as possible between the two hands, to determine if it distends with each beat.

When one cannot reach the sides of the tumors in front, one can resort to Stokes's plan. Place the flat of one hand upon the front of the chest, and the other hand upon the back. By this means the expansile character of the pulsation may sometimes be determined.

Many intra-thoracic aneurisms present a double impulse or two distinct blows to the hand during the cardiac systole; and when these blows are too faint to be felt, they may still be registered by the sphygmograph. This double impulse is not characteristic of aneurism of the aorta, because it may also be felt in aneurisms of the large branches of the arch. Bellingham thought that the second blow was due to a reflex wave from the aortic valves, and was therefore diastolic in rhythm. Jaccoud, however, showed that it occurs even with great insufficiency of the aortic valves, thus excluding reflex waves. François Frank also proved that both blows were systolic in rhythm. He thinks they are due to the fact that the blood enters the aneurism en deux temps. The blood, rushing in at the beginning of the systole, gives a sudden distension of the partially relaxed sac-walls, and thus causes the first impulse. Then the bulk of the blood-waves, following more slowly on account of greater resistance, produces a second elevation more or less pronounced.

Balfour states that aneurismal pulsations are usually more forcible than those of the heart, and that this point has not received the attention which it merits. If the sac contains much fibrin the impulse is feebler than that of the heart.

W. S. Oliver describes a new sign of aneurism and the method for detecting it. Place the patient in the erect position and direct him to close his mouth and elevate his chin to the fullest extent. Grasp the cricoid cartilage between the fingers and the thumb, and push it gently upward. If an aneurism of the arch of the aorta be present, its pulsation will be plainly transmitted up the trachea to the hand. The act of examining will also increase the laryngeal distress if such be present.

The frémissement cataire, or thrill imparted to the hand by an aneurism, has been frequently described. It is very characteristic when felt, but Powers says it is not of frequent occurrence. He has felt it in eight cases of aneurism, but four of them were complicated by regurgitant disease of rheumatic origin, and all were probably of the fusiform kind.

Pulse.—Partial or total obliteration of a large vessel, dilatation of the aorta, compression of an artery by a tumor, may produce a radial pulse similar to that of aneurism. Moreover, we may find the radials differing from each other in persons who are perfectly healthy. It follows, therefore, that, taken by itself, the pulse does not contribute very decisive evidence of an aneurism. When the diagnosis of an aneurism is established or confirmed by other signs, then the added evidence of the pulse does possess some value. The finger will often detect the following characteristics of an aneurismal pulse:

1. Delay.—The pulse at the wrist is normally from ¹¹/100 to ¹⁴/100 of a second later than the cardiac impulse. With aneurism this interval may be prolonged in one or both radials, and the additional delay may amount to ⁴/100 of a second. This sign of delay is of most value when the pulse in one wrist loiters behind its mate. The relative delay of the impulse of the aneurism itself and of the carotid artery may give useful information. If the beat of the tumor precedes that of the left carotid, then the tumor is nearer the heart, whereas the aneurism is evidently beyond the left carotid when the beat of the latter precedes.

2. Diminution in Volume.—The pulse in one radial may be much smaller than in the other or altogether absent.

3. Diminution in Force.—The pulse of one side may convey a less sudden and less forcible blow to the finger. This diminished suddenness of the sensation imparted to the finger corresponds to the sloping up-stroke of the sphygmographic tracing.

4. Thrill.—Under certain rare and not very clearly defined circumstances the pulse imparts a sensation of thrill to the finger. Mahomed says this probably occurs when the entrance to the aneurismal sac is very narrow and the aneurism is directly in the course of the vessel. It may also be occasionally produced by the rigidity of the wall of the vessel or by a partially-dilated clot vibrating in the blood-stream.

Under the enthusiastic and elaborate study of Mahomed the sphygmograph has attained a certain degree of usefulness. Though difficult in its application and limited in its results, yet many of the points demonstrated by it are of sufficient importance to justify their consideration. The sphygmographic tracing of the normal pulse is shown in Fig. 50.

FIG. 50.

AB. The Up-stroke. ABC. Percussion Wave. E. Aortic Notch. D. Dicrotic Wave.

Now, the points which distinguish an aneurismal tracing from the normal are—1, a sloping up-stroke; 2, impairment or loss of the percussion wave; 3, obliteration of the secondary waves; 4, diminished volume of the curve; 5, vibratile waves; 6, a different blood-tension.

FIG. 51.

Right and Left Radial Pulse in Aneurism of Aorta.

In comparing the curves shown in Fig. 51, taken from Powell's article upon aneurism, it will be noticed that the up-stroke AB is more sloping in the curve of the right wrist than in that of the left. The percussion and dicrotic waves are entirely smoothed out into an almost uniform wavy slope. As one writer has expressed it, an aneurism acts like an air-chamber in an engine, and tends to break up the intermittent pulse into a steady stream. The relative difference of the blood-tension of two arteries is determined by the relative amount of pressure required of the instrument to develop the tracing. This amount of pressure is sometimes greater and sometimes less on the affected side.

In comparing the tracings from the radials the following points are to be noted: 1. Is there any difference in the percussion waves?—i.e. is the up-stroke more sloping or the apex less pointed in the one than in the other? 2. Is the tidal wave equally high and sustained in both? 3. Is the dicrotic wave equally developed?

If a difference exist in the tidal wave alone, it need not, and probably will not, be due to aneurism. It is the loss of the percussion wave and of the dicrotism which characterizes aneurism.

It must be conceded here that the use of the sphygmograph and the interpretation of its tracings are beset by the greatest difficulties. Mahomed, to whom I am chiefly indebted for these sphygmographic details, declares that the use of the instrument requires great care and skill, and it may easily lead to error. "No one should attempt to use it who cannot readily obtain similar tracings from the two radials of a healthy person." Great care in the application of the instrument should be exerted, and we must guard against all causes of transient excitement. It is well to let the patient see the instrument applied to others before attempting it on him, in order that he may not fear it. The patient must be placed in a comfortable position, with both arms alike, and the points of application of the instrument must be alike on the two sides. The amount of pressure on the two sides must be equal, or the difference carefully noted. Moreover, one should never be contented with one tracing, but a number on each wrist should be taken. If, then, the two radials appear to differ, the precautions must be redoubled, and the pulse tested again on another day. Inequalities of the tracings may be produced by abnormal distribution of the radials, and an old fracture or other injury of one arm may affect the flow of blood in the arm.

Paralysis of the arm, by interfering with the vaso-motor nerves, and thereby with the venous return of the blood, may alter the character of the pulse. A tumor external to the artery, either intra-thoracic or extra-thoracic, will produce aneurismal pulse and endarteritis, or congenital contraction of the aorta may so block the artery as to produce diminished pulse-waves. It may be said that the sphygmograph is incapable of distinguishing between an endarteritis and an aneurism.

On the other hand, the instrument is very useful in distinguishing between an aneurism and a tumor compressing an artery, because in the latter case the up-stroke and percussion wave remain normal, whereas in the former they are strongly modified, as described above. With aneurism of the ascending aorta both radials must be similarly affected, if at all, and in these cases the sphygmograph teaches very little. If the right radial is alone or mainly affected, then the aneurism involves the innominate and arch together. When an aneurism of the innominate includes the aorta, then the whole sac forms virtually a dilated aorta, and no difference in the radials will appear. Hence it follows as a corollary: Given an innominate aneurism, if the radials remain equal the aorta is certainly involved. When the left radial pulse is alone affected, the aneurism lies beyond the brachio-cephalic branch, and may or may not involve the left subclavian.

The sphygmograph is of less avail in aneurisms of the descending portion of the thoracic aorta or of the abdominal aorta. It may be of service in affording information regarding the condition of the aorta itself with reference to an operation, and it may also be of service in determining the upper limits of an aneurism under the following conditions: A case is reported which presented all the physical signs of aneurism of the descending aorta, but the sphygmograph showed that the left radial was affected, and thereby proved that the aneurism extended as high as the left subclavian at least.

While the foregoing facts prove that the sphygmograph by itself affords very inconclusive and untrustworthy evidence, yet when the presence of a tumor and other physical signs prove the existence of an aneurism, the written pulse-record will often be the guide to the accurate placement of the tumor, and thereby will often furnish decisive indications in the selection of the method of treatment.

Auscultation.—The typical aneurismal bruit is not an ordinary souffle, but it is an accentuated booming sound of a very peculiar character. Many writers describe it as a systolic jog or shock. Occasionally this bruit de battement is double—i.e. one hears two shocks, so to speak, just as one feels a double impulse. No satisfactory explanation for this reduplication of murmur has yet been given. The aneurismal murmur is almost invariably systolic. Balfour reports two cases of a diastolic murmur heard with abdominal aneurism. One of these cases was observed by himself and the other by Wickham Legg.

When this peculiar booming sound is heard over a circumscribed dull patch, it is very distinctive of aneurism, but its absence possesses no eliminative value. Many aneurismal tumors are absolutely quiet, and some of them give only a soft murmur like an ordinary cardiac souffle.

Associated with the aneurismal sound one also hears the normal heart sounds much intensified. This is peculiarly noticeable of the second cardiac sound, which acquires a ringing, booming, accentuated character when heard over an aneurism. Johnson thinks that this intensification of the heart sounds is due to the sudden tension of the walls of the sac. Balfour in referring to the same phenomenon considers it of greatest diagnostic value, and thinks that proper emphasis is not ordinarily given it.