Although the kidneys lie in a protected position they are not infrequently injured, both by contusions and by penetrating wounds. From the latter blood will escape externally. In the former it can only extravasate when the cortex and capsule are torn, or escape through the ureter into the bladder, when it will be seen in the urine, which, however, may have to be drawn by the catheter on account of retention. Blood in the urine after a local injury denotes serious mischief inside the kidney or along the urinary tract. If continuing for several hours, but especially if accompanied by local indications, swelling or other evidences of extravasation, by muscle rigidity or by severe pain, with general symptoms, it should be assumed that these fluids are escaping into the perirenal tissues, perhaps into the peritoneal cavity, and that an immediate exploratory operation should be urged. When once this indication is clearly recognized the condition brooks no delay. The same is true of penetrating wounds. On general principles, with a patient in such a condition and showing no improvement, or especially if the reverse, exploration offers the safer course in by far the greater number of cases. The surgeon need only convince himself that such blood as the urine contains does not come from the lower tract, but rather from the kidney or ureter. Exploratory nephrotomy is by itself so harmless that one need never hesitate to urge it. A kidney found slightly lacerated may be repaired with sutures, while one found seriously disorganized should either be sutured and drained or totally removed, as the case may require. There is little room for doubt that it is better to institute such a measure early rather than to permit the dangers and even ravages of infiltration of blood and urine. In fact it may almost be laid down as a precept that every patient who has received an injury in the loin or flank and who repeatedly passes blood in the urine should be explored.
PAIN IN THE KIDNEY; NEPHRALGIA.
This is a vague term, implying pain or neuralgia in the kidney, and can refer only to symptoms, not to any particular disease. Yet it must be confessed that for certain cases of so-called nephralgia no physical cause is easily discovered. Pain in the kidneys—or, as patients will often say, in the back—may be associated with excess of oxalic and uric acids and salts in the urine, and is then relieved by a steady course of alkaline diuretic treatment, with plenty of fluid, the severe pain being combated with aspirin. Nephralgia may be expected in connection with many renal disorders, but the term should ordinarily be confined to cases of pain without known cause.
When such pain is uncontrollable and intolerable the indication is to make an exploratory operation, by which the kidney should be at least exposed, perhaps delivered upon the external surface of the body, and carefully examined. Its capsule should be split (capsulotomy), as Harrison and others have suggested, and if on palpation or needling (using a needle as a probe) there be any good reason for opening it this may be done, so that with the finger its pelvic cavity may be carefully explored, in order to find any previously unrecognized calculus or other surgical lesion. The mere operation of capsulotomy or capsule splitting has proved of such great value that I always practise this measure upon any kidney which for any reason it may seem wise to expose.
INFLAMMATIONS AND INFECTIONS OF THE KIDNEYS.
Under this head it is intended to consider (1) acute or subacute specific infections of the upper urinary passages, due to bacteria, with the effects of which we are familiar, i. e., septic, gonorrheal, and tuberculous lesions, and (2) chronic nephrites of irregular or uncertain type, for which operative treatment has been recently proposed.
Septic Nephritis; Pyelitis; Pyelonephritis; Surgical Kidney.
—Septic infection of the kidney is usually the result of a process ascending from the lower urinary passages, particularly when these are obstructed by calculus, tumor, prostatic enlargement, or ureteral stricture. It may follow catheterism either once or prolonged, especially when done without strict precaution; or the infection may come from the other direction via the blood stream, as in typhoid and various other fevers, the exanthems, and diphtheria. Gonorrhea is a frequent cause, acting insidiously and by a creeping invasion, with the intervention of a rather more abrupt cystitis. Nevertheless when gonorrhea is followed by pyemia and metastatic abscess these form early in both kidneys, and disaster quickly follows. These types of infection spreading upward along the ureters do not spare the pelvis of the kidney, but expend their first violence there. Beyond this they may extend to the renal tissue proper, where they set up a true nephritis, which may prove fatal.
Symptoms.
—Clinical symptoms do not vary greatly except in detail. They include fever, chills, and similar expressions of toxemia, with more or less pain in the kidney, down the ureter, and even referred to the ultimate distribution of the nerves sympathetically or anatomically involved, e. g., to the testicle on the same side, often with retraction of the scrotum, and down the thigh. There is a tendency to thamuria (frequency of urination) when the bladder is involved, as it always is sooner or later. Pus and mucus are recognizable in the urine by the naked eye, while a microscopic study of this fluid will reveal, from the character of the cells, the extent and type of the invasion. The tuberculous type will be considered separately. Suffice it to say that in this form, however pure may have been its original type, it becomes sooner or later converted into a mixed septic infection, with which renal abscess is often connected. The gonorrheal type is nowise clinically distinct, so far as the kidneys are concerned, but is to be recognized either by the microscope or by other clinical evidence.