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subdivision may be established through the left loin, or by a tube introduced down to the bottom of the pelvis, namely, into the recto-vesical pouch in the male, and into or through the recto-vaginal pouch (pouch of Douglas) in the female.
On account of the oblique manner in which the mesentery proper is attached to the posterior abdominal wall, it follows that in order to examine the organs related to the right infra-colic subdivision of the abdomen, the coils of small intestine should be displaced downwards and to the left, while to investigate the left infra-colic subdivision they should be carried upwards and to the right.
Liver. The anterior margin of the liver, as it crosses the costal angle, can readily be determined by palpation and light percussion; it passes from the eighth left to the tip of the tenth right costal cartilage, and crosses the median plane at the level of the transpyloric line. In the mid-clavicular line it reaches down to a point a little below the most inferior part of the tenth right costal cartilage. Above the left costal margin the anterior margin passes upwards and to the left to join the left border of the liver at the fifth interspace in the mammary line. The highest part of the liver, which corresponds also to the highest part of the right arch of the diaphragm, reaches, during expiration, to the level of the fourth intercostal space in the mammary line. To the right of the median plane the superior surface of the liver is too far removed from the anterior wall of the chest, and overlapped by too thick a layer of lung substance, to be accurately determined by percussion. Behind the sternum the superior surface reaches to the level of the sixth chondrosternal junctions. To the left of the median plane the superior limit of the liver cannot be determined by percussion since it merges into the cardiac dulness. The base or right lateral surface extends from the level of the seventh to the level of the eleventh rib in the mid-axillary line and is separated by the diaphragm from the lower part of the right lung and pleura.
The falciform ligament of the liver lies, as a rule, a little to the right of the median plane.
The anterior surface of the liver may be reached through a median incision, extending downwards from the xiphoid process, or by an oblique incision, a finger's breadth below and parallel to the right costal margin. To obtain free access to the superior surface the eighth and ninth costal cartilages must be resected; the seventh cartilage should, if possible, be avoided; otherwise the pleural cavity may be opened into. Division of the round and falciform ligaments allows of greater downward displacement of the liver. To reach the upper part of the lateral surface of the right lobe, portions of the seventh and eighth ribs should be resected in the midaxillary line, and both the pleural and peritoneal cavities must be traversed.
Gall-Bladder.-The relation of the fundus of the gall-bladder to the surface of the body is subject to considerable variation. Normally it is situated behind the angle between the ninth costal cartilage and the lateral border of the right rectus; exceptionally, it is pendulous and suspended from the liver by a more or less distinct mesentery; or it may be elongated and drawn downwards by adhesion to the duodenum or colon. When displaced downwards it is liable to be mistaken for a movable kidney, but may be distinguished from that by the fact that although it may be pushed backwards into the lumbar region it returns at once to its habitual position, immediately behind the anterior abdominal wall, as soon as it ceases to be manipulated.
The cystic duct is enclosed in the right extremity of the superior border of the gastro-hepatic ligament. It is about an inch and a half in length, is sharply bent. upon itself close to its origin at the neck of the gall-bladder. It joins the hepatic duct at a very acute angle. The passage of a probe along the normal duct is rendered difficult by the marked flexure at its commencement, as well as by the folded condition of its mucous membrane; hence also the frequency with which calculi become impacted at the neck of the gall-bladder. In excising the gall-bladder, it is an advantage to ligature and divide the cystic artery and duct before proceeding to detach the organ from the inferior surface of the liver.
The bile-duct, about three and a half inches in length, lies, in its superiore third, close to the right free border of the gastro-hepatic ligament. When cutting into this, the most accessible part of the duct, it should be drawn forwards by the finger introduced behind it, through the epiploic foramen; the portal vein, which take must be avoided, lies posterior and a little to the left of the duct. The middle third of the duct lies a little to the right of the commencement of the gastroduodenal artery behind the superior part of the duodenum about a finger's breadth from the pyloro-duodenal junction. The inferior third of the duct, which passes downwards and to the right, is intimately related to the pancreas; in about two out of three instances it is so embedded in the posterior aspect of its head that it cannot be freed by blunt dissection. Close to its termination the duct is joined by the main pancreatic duct of Wirsung, the two opening separately, but close together, at the bottom of a diverticulum, which pierces the wall of the duodenum obliquely, and opens at the summit of a small papilla situated at the inferior part of the medial wall of the descending part of the duodenum, about four inches from the pylorus. When a calculus becomes impacted in the ampulla there is retention of the pancreatic as well as of the biliary secretion. Frequently, however, the gland possesses an accessory pancreatic duct (duct of Santorini) which opens into the duodenum at a higher level than the main duct, with which it also communicates. A calculus in the ampulla may be reached either by opening the duodenum from the front (trans-duodenal route), or by freeing the duodenum and gaining access to the duodenum from behind (retro-duodenal route). In the latter instance an incision is made, lateral to the right border of the descending part of the duodenum, through that portion of the peritoneum which passes upwards and to the right from the superior layer of the transverse mesocolon, over the superior part of the pars descendens of the duodenum on to the anterior surface of the right kidney. By blunt dissection, directed medially, behind the duodenum, that organ, along with the adjacent part of the head of the pancreas, can be separated from the kidney and vena cava, and folded over towards the left like a door on its hinges. It freeing the bile-duct from the posterior aspect of the head of the pancreas a vein of considerable size will be encountered; this vein, which returns the blood from the pancreatic-duodenal system of arteries, lies close to the bile-duct as it ascends behind the head of the pancreas to open into the commencement of the vena porta. Of the lymph glands related to the bile passages it is to be remembered that one lies at the neck of the gall-bladder, another at the junction of the cystic and hepatic ducts, while a third lies close to the termination o the bile-duct. When these glands are enlarged and indurated, care must be taken not to mistake them for impacted gall-stones.
Stomach. The stomach lies almost entirely within the left half of the epigastric region and in the left hypochondriac region. The cardiac orifice, which lies 1 in. below and to the left of the oesophageal opening in the diaphragm, is about 4 in. from the surface, and corresponds, on the anterior surface of the body, to a point over the seventh left costal cartilage 1 in. from the median plane. The pylorus, which is generally partly overlapped by the anterior margin o the liver, lies in, or a little to the right of the median plane; when the stomach is empty it generally lies in the median plane, when distended it may reach two. or even three inches to the right of the median plane. Passing from the superior to the inferior border of the pylorus opposite its junction with the duodenum is the anterior pyloric vein of Mayo. This vein affords a useful visible guide to the position of the pylorus. Another guide is furnished by the ring-like thickening of the pyloric sphincter which projects into the commencement of the duodenum (like the cervix uteri into the vagina), and can be readily palpated through its thir wall. The pyloric portion of the stomach is practically bisected by a horizontal plane which passes through the abdomen at the level of a point midway between the jugular notch of the sternum and pubic symphysis (Addison); it lies, there fore, three to four inches below the infra-sternal notch, midway between it an the umbilicus, opposite the first lumbar vertebra. The highest part of th fundus of the stomach corresponds to the left vault of the diaphragm, and he at the level of the fifth rib in the mammary line, a little above and behind the
apex of the heart. The greater curvature crosses behind the left costal margin opposite the tip of the ninth costal cartilage, that is to say, where the transpyloric line intersects the left lateral line. The lowest part of the great curvature, situated generally in the median plane, extends down to, or a little above, the infracostal plane, about two inches above the umbilicus. The lesser curvature and the adjacent part of the anterior wall of the stomach are overlapped by the anterior margin of the liver.
Radiography of Stomach.-Radiograms of the stomach, taken after a "bismuth meal," show that the form and position of the stomach in the living subject differ considerably from that which it presents in the cadaver.
In the cadaver, owing to loss of muscular tone, it presents itself as a more or less empty pear-shaped bag with collapsed and flaccid walls. The same applies to a large extent to the stomach as seen in the operating room, its normal tonicity being almost entirely held in abeyance by the anesthetic.
In the living subject, the form and position of the stomach are found to vary not only according to the amount of food it contains, but also according to whether the patient occupies the erect or the recumbent posture. The most reliable as well as the most useful, information regarding the form, the position, and the motor activity of the stomach is obtained by "screen" examinations and radiograms taken with the patient in the erect posture. When examined in this way, after partly filling the stomach with a "bismuth meal," the organ is seen to possess a distinctly J-shaped form. The stem of the J, which is represented by the body of the stomach, lies immediately and entirely to the left of the vertebral column. The fundus, which is slightly more expanded than the body, reaches up to the left cupola of the diaphragm; it is represented in the skiagram as a light semilunar shadow, the horizontal inferior margin of which corresponds to the superior limit of the bismuth. This clear semilunar area is due to the rising up of the gaseous contents of the stomach to the highest part of the cavity. The cardiac orifice is seen to lie opposite the left side of the fibro-cartilage between the tenth and eleventh thoracic vertebræ. The shadow of the curved pyloric portion of the stomach, after crossing the left side of the vertebral column opposite the third and fourth lumbar vertebræ, ascends as the pyloric canal to join the duodenum at or a little to the right of the median plane, opposite the second (not infrequently the third) lumbar vertebra. The pylorus itself is represented by a light disc due to a break in the continuity of the bismuth, caused by contraction of the pyloric sphincter. The lowest portion of the greater curvature, which generally lies at or a little to the left of the median plane, reaches, in the erect posture, down to the level of the middle or inferior border of the fourth lumbar vertebra, or, in other words, to the umbilicus and the highest part of the iliac crest.
As more food enters the stomach its capacity is increased by lateral expansion rather than by any elevation of its fundus or downward expansion of its greater curvature. The normal tonic action of the gastric muscle is able to hold up the meal against the action of gravity to the level of the cardiac orifice.
When, as not infrequently happens, the normal muscular tonicity of the stomach is lost, the bismuth meal is no longer held up against the action of gravity, but at once sinks to the most dependent part of the stomach where it lies as in a flaccid sac, and gives rise to a crescentic shadow which may reach down almost, or even quite, to the level of the pubes.
In gastroptosis, and in general visceroptosis, the whole stomach may be displaced downwards without any great loss of its tonicity.
During a "screen" examination after a bismuth meal, the peristaltic movements of the stomach can be seen to pass in distinct wave-like indentations from left to right along the greater curvature, and to increase in force as they approach the pylorus.
When the stomach is hypertrophied and dilated, as a result of pyloric obstruction, the peristaltic waves are more pronounced, and the bismuth shadow extends well over to the right of the median plane, owing to the dilated pyloric antrum and pyloric canal being carried over to the right, in front of the superior part of the duodenum. The stomach tends, therefore, to lose its somewhat J-shaped
tubular form, and the axis of its body becomes more oblique. In the infant and young child the stomach is flask-shaped rather than J-shaped, and its axis is less vertical than in the adult. The elongated form of the adult stomach is acquired as a result of the erect posture.
It must be remembered that the only really fixed part of the stomach is the region of the cardia, so that the form and position of the organ may be considerably ac influenced by the condition of the neighbouring organs. For example, it may be displaced downwards and to the left by enlargement of the liver, upwards by distension of the intestines, and to the right by distension of the left colic flexure.
Overlying the stomach is an important surface area known to clinicians as the semilunar space of Traube. This space, which yields a deeply tympanitic note on percussion, is bounded, above, by the inferior margin of the left lung; below, by the left costal margin; to the right, by the anterior margin of the left lobe of the liver; behind and to the left, by the anterior border and anterior basal angle of the spleen. The line of the costo-diaphragmatic pleural reflection crosses the space about midway between its superior and inferior limits. The tympanitic area of the space is diminished superiorly by pleuritic effusion, towards the right by enlargement of the liver, and towards the left by enlargement of the spleen.
Perforation of an ulcer on the anterior wall of the stomach leads to extravasation into the greater sac of the peritoneum, while if the perforated ulcer is on the posterior wall, extravasation takes place into the omental bursa. The close relation of the splenic artery and its branches to the posterior wall of the stomach explains the severe hæmorrhage which is sometimes caused by a posterior gastric ulcer. The surgeon may reach the posterior wall of the stomach through the gastro-colic ligament, or, after throwing upwards the greater omentum and transverse colon, by traversing the transverse mesocolon; by the former route the posterior wall of the stomach is reached through the anterior wall of the omental bursa, in the latter through its posterior wall.
When a partial resection of the stomach, for malignant disease, is performed, the bleeding is controlled by ligaturing the main vessels at an early stage of the operation. These are the right and left gastrics at the lesser curvature, the gastroduodenal behind the first part of the duodenum, and the right and left gastroepiploics at the greater curvature. The left gastric should be ligatured as near the cardia as possible, so that the whole chain of lymph glands along the lesser curvature may be removed. Care is taken to remove also all the glands which lie behind the first part of the duodenum in relation to the gastro-duodenal artery and head of the pancreas, as well as those along the right half of the greater curvature in relation to the right gastro-epiploic artery. If the disease has spread to the retro-peritoneal lymph glands, surrounding the coeliac artery, above the pancreas, the chances of a permanent recovery are very remote.
In the classical "no-loop" gastro-enterostomy operation a longitudinal opening in the commencement of the jejunum is anastomosed by suturing it to an opening in the posterior wall of the stomach, near the greater curvature. The jejunum is applied to the stomach in such a way that it maintains its normal direction, namely, obliquely upwards and to the left. To bring the surfaces of the two organs contact, surgeons are in the habit of protruding the posterior wall of the stomach through an opening made in the transverse mesocolon, on the proximal side of the arch formed by the middle and left colic arteries. A better plan, however, is to make an opening also into the omental bursa through the gastro-colic ligament a little below the gastro-epiploic vessels, and then to bring the jejunum into contact with the posterior wall of the stomach by pushing it (the jejunum) upwards through the opening in the transverse mesocolon. By this plan the posterior wall of the stomach along with the jejunum can be protruded through an opening in the gastro-colic ligament, and can be more easily delivered out of the abdominal cavity.
When the posterior wall of the stomach and transverse colon are held down by adhesions, a long loop of jejunum is brought up in front of the greater omentum and transverse colon and anastomosed to the anterior wall of the stomach.
The Duodenum.-The duodenum is the widest, thickest, and most fixed part
of the small intestine. For descriptive purposes it is divided by anatomists into three parts. From the surgical standpoint it may with advantage be subdivided into a supra-colic and an infra-colic portion, the former, comprising the superior and the upper half of the descending part, being situated above the attachment of the transverse mesocolon; while the latter, comprising the lower half of the descending part along with both subdivisions of the third part, being situated below this attachment. To expose the supra-colic portion the greater omentum and the transverse colon must be pulled downwards, while to expose the infra-colic portion they are thrown upwards along with the transverse mesocolon.
The first portion proper (pars superior) lies in the right part of the epigastric region, medial to the gall-bladder, where it is overlapped by the quadrate lobe of the liver. As regards its blood-supply, it occupies the frontier zone between the coeliac and superior mesenteric vascular areas, and the vessels which supply it vary considerably in their size and mode of origin.
This peculiarity of its blood-supply may partly account for the relative frequency with which this portion of the intestine is found to be the seat of ulceration. The first inch or so the duodenum possesses some degree of mobility, being surrounded by the same two layers of peritoneum which invest the stomach. Beyond this it is in direct contact posteriorly and inferiorly with the pancreas, while descending behind it are the common bile-duct and the gastro-duodenal artery. The relations must be borne in mind in performing the operation of pylorectomy. When an ulcer of the superior part perforates, extravasation takes place, in the first instance, into the supra-colic compartment of the peritoneum, thence into its hepato-renal pouch, and subsequently down along the ascending colon into the right iliac fossa,-hence the possibility of mistaking the condition for an acute appendicitis. Perforation of the ulcer, however, is often prevented by the duodenum becoming adherent especially to the gall-bladder, to the omentum, or to the transverse colon.
If the finger is passed upwards, backwards, and to the left, immediately above the first part of the duodenum and behind the right free border of the lesser omentum, it will pass through the foramen epiploicum into the omental bursa of the peritoneum.
The second portion of the duodenum (pars descendens) descends in the epigastric and umbilical regions a little medial to the right lateral plane. The attachment of the transverse mesocolon crosses it about its middle, while posteriorly it lies in front of the hilum and medial border of the right kidney, from which it is separated by loose areolar tissue. The procedure necessary to mobilise this portion of the duodenum has been referred to already.
The horizontal portion of the inferior part of the duodenum occupies the superior part of the umbilical region, and crosses the median plane about one inch above a line joining the highest part of the iliac crests; behind its commencement is the superior part of the right ureter.
The ascending portion of the inferior part of the duodenum crosses the infracostal plane, and ascends upon the left side of the vertebral column opposite the second and third lumbar vertebra.
The duodeno-jejunal flexure, which lies in the transpyloric plane one inch to the left of the median plane, is the landmark which the surgeon makes for when he wishes to identify the commencement of the jejunum (Fig. 946, p. 1204). To find the flexure the greater omentum and transverse colon should be thrown upwards and the finger passed along the inferior layer of the transverse mesocolon to the left side of the vertebral column. The flexure lies in the angle or recess formed by the left side of the second lumbar vertebra and the inferior surface of the body of the pancreas. With the finger in this recess the commencement of the jejunum may be hooked forward a little to the left of the superior mesenteric vessels at the root of the mesentery. In connexion with the duodeno-jejunal junction is the inferior duodenal fossa of Jonnesco, formed by a fold of peritoneum which stretches from the left side of the fourth or ascending part of the duodenum upwards to become attached to the peritoneum of the posterior abdominal wall close to the medial border of the left kidney. The free edge of the fold and the mouth of the