divided nephrectomy is the better course, but if incompletely an attempt should be made to repair the rent, using the finest round needles and the finest silk boiled in vaseline, and taking care that the media and adventitia are not turned in between the two layers of intima. A large rubber drainage-tube is conducted from the kidney to the surface, and the remainder of the wound stitched up in layers and dressed with dry gauze.

The bullet of the modern rifle leaves the muzzle with such a high velocity that, not only is it sterilised in the process, but does not carry in particles of clothing with it, as was found by experience in the late wars. If death from primary hæmorrhage did not occur far better results were obtained by dressing the external wound or wounds with a sterilised pad and keeping the wounded soldier at rest on his back after reaching the hospital, and awaiting natural healing, than by attempts to explore the wound under the necessarily defective conditions for operation that obtain in war. Recoveries in such cases were surprisingly high (70-75 per cent.).

In civil practice bullets cannot be considered as sterile, and, owing to their lower velocity, carry in portions of clothing with them. Bullet-wounds in civil practice should therefore be treated in the way first described. The prognosis is good if asepsis can be obtained, and in the absence of other complications, such as aneurysm and wounds of other organs.

Aneurysm of the Renal Artery.

Henry Morris1 could only collect nineteen cases from the literature up to 1900, so that the disease is very rare. Renal aneurysms are:

1. Traumatic or false.

2. Spontaneous or true.

The traumatic are caused by the rupture or puncture of the wall of the renal artery, a sacculated aneurysm, or a diffuse aneurysmal hæmatoma resulting.

The spontaneous arise from diseases of the vessel-wall combined with a heightened blood-pressure, the causes being syphilis, infective emboli, and senile degeneration.

The cavity of the aneurysm contains laminated layers of blood-clot and communicates with the renal artery by an opening of varying shapes and sizes, the wall being formed by condensed layers of fibrillar tissue closely adherent to the 1 'Surgical Diseases of the Kidney and Ureter,' vol. i.

surrounding tissues. As the tumour increases in size it presses upon the surrounding organs, and either displaces them or causes pressure atrophy, finally bursting into some neighbouring cavity.

Clinically a traumatic aneurysm is ushered in by some injury to the kidney, which clears up for the time being, but a few months, or even years later an abdominal tumour is noticed, which may be painless and of slow growth, or may cause pressure symptoms on the nerves, blood-vessels, and organs in its neighbourhood. Hæmaturia may appear, either in small amounts frequently repeated, or so profuse as to fill the bladder with clots and rapidly cause death. Death may also occur from internal hæmorrhage into the peritoneum. The tumour is of large size, and lies just to one side of the middle line in the upper part of the abdomen, is firm, elastic, rounded, and painless, and is absolutely fixed to the posterior belly-wall. Pulsation is seldom felt, but when present it is expansile, and persists even when the patient lies prone. A systolic bruit has been heard over such a tumour, and the percussion note yields a dull tympany.

The diagnosis may be suggested by the history of a recent kidney injury, but it is impossible to be certain that the tumour is not a neoplasm. A neoplasm may come on after an injury, may pulsate and present a bruit, may lead to profuse painless hæmaturia, and, in fact, may simulate an aneurysm in every way. The diagnosis can only be made by open exploration, which should always be undertaken early in cases of injury when a loin-tumour persists for more than a month, or in cases where attacks of painless hæmaturia cannot be assigned to a general cause. On exposure of the tumour, if the diagnosis is not evident, incision will reveal laminated blood-clot. Henry Morris advises immediate plugging of this incision rather than further turning out of the clot, followed by nephrectomy by the lumbar, transperitoneal or combined routes.

The disease is inevitably fatal in from a few months up to five years, apart from operation.

CHAPTER IV.

NEPHROPTOSIS.

MOVABLE KIDNEY.1

Definitions.

The

The kidney in health has a wide range of up-and-down movement during expiration and inspiration of at least one to one and a half inches, so that all kidneys are strictly "movable," the lower pole descending at the end of full inspiration to within one inch of the umbilical line on the right side, one and a half inches on the left side.2 Many kidneys are placed lower in the abdomen, and have a wider range of movement without causing any symptoms; but undue mobility is a very common cause of symptoms. difficulty of drawing a distinction clinically between normal mobility and undue mobility has led to wide variations in the figures given by different authors. Nephroptosis" is the most correct name for pathological mobility, but the term "Movable kidney" can hardly be avoided, and has the merit of common use and convenience. "Floating kidney" is a term applied to those rare cases of congenital defect where the kidney has a mesonephron and floats freely in a complete double fold of peritoneum.

The Supports of the Kidney.

The weight of the kidney is supported in health by the general abdominal pressure. The abdominal viscera are contained in a closed bag surrounded by elastic muscular walls which by their tone maintain a condition of intra-abdominal pressure considerably above that of the outside air. As the

1 For ideas and help in preparation of this chapter we are deeply indebted to Professor Keith. See Allbutt, System of Medicine,' new edition, vol. iii, 1907, p. 860. Keith, article on Splanchnoptosis," bibliography.

66

2 "The average height of the kidney above the umbilical line is 30 mm. on the right side, 35 mm. on the left."-Keith.

diaphragm descends during inspiration, the supra-umbilical viscera are forced downwards and forwards, the thrust being resisted by the active tonic contraction of the muscles of the belly wall obliques, transversales, and recti, which do not completely relax during inspiration. During expiration the diaphragm relaxes, and is driven upwards through and with the viscera by means of the active contractions of the muscles of the belly wall, movements which at the same time drive the venous blood on into the heart and prevent stagnation of blood in the abdominal viscera. The peritoneal attachments and ligaments do not support the weight of the viscera in health, but their function is to carry the blood-vessels and nerves to the different organs, and to restrain and anchor the viscera if exposed to unusual and excessive dislocating forces, so that they keep their relative positions. The peritoneum and its attachments are very elastic, and can be stretched as much as 2-4 inches in health (Keith).

If from any cause the muscles of the belly wall fail to support the weight of the viscera the peritoneal ligaments have to take on a supporting function, but they become gently stretched in the process, the viscera prolapse, and their vessels and nerves are pulled upon and interfered with. peritoneal attachments therefore only support the weight of the viscera in disease.

The

The kidney is restrained from moving inwards and forwards by the attachments of the peritoneum as it sweeps over the kidney and colon, and by the perinephric fascia. The perinephric fascia is fixed to the back of the belly wall above and does not move during respiration. It splits into two layers which enclose the supra-renal completely above and below, so that this body does not move down within it. Extremely delicate elastic bands of connective tissue run from its inner surface to be attached to the true fibrous kidney capsule. In health these do not take the weight of the kidney, though they may do so in disease and after operations on the kidney, when they are turned into tough scar-tissue. The perinephric fat lies interspersed amongst these bundles between the perinephric fascia and the kidney, and serves to transmit the abdominal pressure to the walls of the kidneys, prevents jarring, lubricates the kidney movements, and adapts the perinephric space to the movements of the kidney within the perinephric fascia. It is said to be absent in children before the age of ten, but this statement is founded on the examination of wasted children in the post-mortem room.

LANE LIBRARY

Summary:

In health the moving kidney is supported by the general abdominal pressure, and is restrained from any excessive dislocating forces by the attachments of the perinephric fascia and peritoneum.

In disease, if the support of the abdominal muscles is removed the moving kidney has to fall back upon the attachments of the perinephric fibrillæ, the perinephric fascia and peritoneum, and upon its pedicle, which soon become stretched to an excessive degree, the result being excessive mobility.

If the abdominal muscles are healthy and retain their tone, dislocation of the kidney may still be produced either by sudden rupture of the perinephric fascia and peritoneum, or by the kidney being crowded out or squeezed out of the supra-umbilical space. When none of these causes are at work the movable kidney must be considered as ectopic or mal-developed. Either it has never ascended to its proper level during foetal life, or has descended again during the development of the trunk from the infantile to the adult type.

Thus there are two distinct groups of cases which present movable kidneys. In one the kidney is ectopic, just like an undescended testicle, and has failed to ascend or maintain its proper position in the loin in the course of development. In the other the kidney is prolapsed. It has developed normally and reached its proper position in the loin, but from certain acquired causes it has dropped again. The two conditions

may be distinguished as Ectopia and Nephroptosis. congenital or germinal, the other is acquired.

The Congenital Group. Ectopic Kidney.

One is

Man, in evolution from the quadruped, has assumed the upright position, and to maintain this without visceroptosis, and without a fatal fall in systemic and cerebral bloodpressure from stagnation of blood in the splanchnic vessels he has had to develop two important muscle-nerve systems. In the first place a vaso-motor apparatus which responds to a rise into the upright position by vaso-constriction of the splanchnic arteries, in the second place a viscero-motor apparatus controlled by sympathetic impulses from the viscera, which produces a tonic contraction of the abdominal musculature, so as not only to prevent the viscera from pro