Part 6

If it be the function of the normal rectal valve to beneficently retard the descent of the feces it is obviously true that it may be the especial property of the valve in certain other than normal conditions to maliciously obstruct the descent of the feces.

There are three forms of valvular obstruction:

1. _Anatomic coarctation of the valves_ may afford an exaggerated physiologic resistance to the descent of the feces (Fig. 54).

2. _Congenital hyperplasia of the rectal valve_ is a condition classically described as diaphragmatic stricture or membranous septum in the abdominal rectum.

3. _Hypertrophy of the rectal valve_ constitutes the classic annular stricture of the abdominal rectum.

THE SYMPTOMS.

The patient is the subject of more or less chronic obstipation, he sometimes makes frequent partially successful attempts daily at defecation, but may experience an unrequited desire for stool. The patient acquires the reprehensible physic-habit. In time the periods of obstipation are interrupted by diarrhea. There is an ineffectual straining at stool except for fluid feces. Later the diarrhea occurs with greater frequency, and ultimately long periods of diarrhea may ensue which are interrupted by a transitory constipation and obstipation. All these symptoms may be accompanied by increasing degrees of flatulence and borborygmus, and from time to time the patient is subjected to attacks of intestinal autointoxication, and finally he becomes neurasthenic. On account of the especial nonsensitiveness of the rectal valve the patient’s sufferings are not uniformly referred to this region by himself, but in many instances, however, the intelligent patient is prepared to present his physician with a ready-made diagnosis of rectal obstruction. Finally, the symptoms of intestinal obstruction become pronounced, and if the patient be unrelieved the disease proceeds to a fatal termination. Symptoms of pain, aching in the sacral and iliac regions, hemorrhage, proctorrhea, prolapse, hemorrhoids, fistulas, etc., are usually the signs of concomitant sequels of the hypertrophied valve, and these may embrace the entire proctica. For a classic graphic description of the symptoms of rectal stricture, which has never been excelled, the reader is referred to the paper by Dr. Sherwin published in the Transactions of the London County Medical Society in 1787.

PATHOGENESIS.

1. _Obstructive anatomic coarctation_ of the normal rectal valves is a fortuitous embryonic affair, and admits of no amplification in this section.

2. _Prenatal hyperplasia_: The fibrous and muscular laminas of the rectal valve are developed from the mesoblastic layer of the blastoderm and the mucous membrane is derived from the hypoblast; this latter layer consists of columnar epithelium, and epithelium of this character may be found covering both superior and inferior surfaces of congenital diaphragmatic strictures or membranous septums. When there exists an aperture in this character of stricture it is seldom or never situated centrally. Another distinguishing feature of this obstruction is that it constitutes a cephalad boundary to a rectal chamber. If the lowermost valve be deformed, and if it be situated unusually low down, the lower rectal chamber may be noninflatable. In such an instance the anal or fixed rectum may seem to be of an extraordinary length, but that such is not really the fact may be determined by digitally ascertaining the situation of the anal borders of the levatores ani muscles. Such a stricture has its origin, probably, in the embryonic hyperplasia of the rectal valve. Another form of diaphragmatic stricture is sometimes observed at the anus. It has its origin in an imperfect anorectal coalescence. The salient structures of this septum are hypoblastic enteron and epiblastic proctodeum, and a microscopic inspection of a portion of membrane taken from its inferior surface reveals its epiblastic origin. This anorectal septum is of variable thickness, if there be a perforation it is located centrally. This character of stricture is always situated caudal to the rectal chamber. It is due to an arrest of fetal development.

3. _Postnatal hypertrophy_: Inflammation of the normally formed rectal valve, infiltration of lymph through its structures and organization of the plastic exudate contract and fix in a state of contraction this normal projection across the lumen of the rectum and constitute the nonmalignant annular stricture of this organ. Abnormal increase of fibrous tissue from any cause may, without contracting the valve-strait, render the valve sufficiently inelastic as to constitute it an obstruction. Extension of the inflammatory processes to an adjacent valve or a general hypertrophic rectitis involving an area occupied by several valves, consequent contraction of the longitudinal muscular bands in the area involved, together with contraction of the circular muscular bands, the infolding of masses of the lax mucous membrane, and the infiltration of plastic lymph into all these tissues between the valves as well as into the valve structure itself, organization of the exudate, degeneration of the muscular elements and increase of fibrous tissue, is the probable sequence of morbid processes which establish the nonmalignant tubular stricture of the rectum. The great thickness of the gut-wall at the situation of the tubular stricture is ordinarily not a new product of the disease. It is the consequence of the infolding of the mucous membrane, fixed in longitudinal corrugations by the organization of the plastic exudate.

The causation of hypertrophy of the rectal valve may be direct infection; a rectitis, dysentery, chancre, chancroid, gonorrhea; or traumatism, irritation or injury by a foreign body; the irritation of scybalums; or, it may be the local expression of some constitutional dyscrasia; syphilis or tuberculosis. The influence of age or of emaciation, through atrophy of the cellular tissues and the hypertrophy of the fibrous, may contribute a relative increase to the tendinous feature of the rectal valve.

_Because of the absence of the rectal valve in the rabbit, cat, dog and monkey_ it was found impossible to do vivisection work for the production of an experimental stricture.

There are many specimens of hypertrophied rectal valves to be seen in the metropolitan museums in Europe, none of which, of course, are classified as such. The cases quoted below were copied by me from the catalog of the Pathological Museum of the Royal College of Surgeons, London, and the specimens which are pictured here may be found on their shelves. These cases are chosen for illustration because their accessibility affords the reader an opportunity for their verification. The pictures were drawn under my direction by Mr. Godart with the aim of illustrating this essay. The specimens immersed in preservative are sealed in cylindric glass jars of the usual laboratory type. Each of these we set into rectangular vessels of water to overcome refraction-errors and afford accurate appearances.

The first case quoted is one of traumatic injury to the rectal valve, and, I believe, affords a close imitation of what might have been expected from an effort at the production of an experimental stricture by simple inflammation of the rectal valve.

The method used for the preparation and preservation of these specimens accounts for the nonappearance of the normal valves. From the time of the preparation of Hunter’s first specimen to the present time more than a century and a quarter has about elapsed.

Fig. 55. “Specimen 2569. Presented by William Coulson, Esq. A rectum and part of a colon, the blood-vessels of which have been minutely injected. Six inches above the margin of the anus there is a very close and narrow annular stricture of the rectum, produced by thickening and contraction of its coats and of the tissues immediately surrounding them. The inner surface of the stricture is ulcerated, and a small thin piece of fish bone is sticking in it. Above the stricture the intestine is dilated to a diameter of nearly four inches, but its coats are not much thickened.” The following is the history of the case:

“‘I was requested to see a woman, aged 34, between four and five months advanced in pregnancy, who, three days before, had been seized with sickness, constipation, pain, and distention of the abdomen. These symptoms increased in severity, fecal matter was rejected from the stomach, the abdomen became more distended, no evacuation could be obtained from the bowels, and the injections which were attempted to be thrown up the rectum were immediately expelled. Her powers gradually sank, and on the third day from the commencement of the attack she died.

“‘On examination after death, the colon was seen to be exceedingly distended, especially its descending portion, and about six inches from the anus a foreign body, believed to be a small portion of fish bone, was found adherent to the lining membrane of the rectum.... Immediately below this body the bowel was completely closed, to the extent of half an inch, by the effusion of lymph caused by the presence of the foreign substance. There was no other morbid appearance.

“‘Prior to the attack which destroyed this patient, she was in her usual state of health and had no ailment whatever.’”

Fig. 56.--“Specimen 2568. Presented by Sir William Blizard: Portion of a rectum, of which the canal is at one part suddenly reduced to less than a quarter of an inch in diameter by the thickening, induration, and uniform contraction of its walls. The stricture is half an inch in length, and terminates as suddenly as it commences. The intestine above the stricture is very much distended, and its muscular coat is hypertrophied; the part below it is small and atrophied.”

Fig. 57.--“Specimen 2571a. Presented by Dr. David Lawson (see _Lancet_, Vol. I, p. 512, 1879): A portion of a rectum, the seat of a stricture, which was excised. The bowel is much narrowed, and its walls are thickened.

“From a woman, aged 34, who had suffered from symptoms of stricture of the rectum for 8 years. Dilatation by bougies proved of no permanent benefit. The stricture was hard, annular, admitted the tip of the finger, and was situated 2 inches above the anus. It was excised through an incision between the anus and coccyx, and the divided edges of the bowel above and below were united by sutures. The patient recovered from and was much relieved by the operation.”

The cases just quoted illustrate the typic advanced hypertrophy limited to the rectal valve. The 2 cases following next are cases of tubular stricture of the rectum. The definite boundary between the diseased and normal tissues suggests the idea that the rectal valves are both starting and limiting boundaries, and the tortuous course of the stricture’s canal in Case 2571 seems also to support this idea, as will be pointed out in the section on diagnosis.

Fig. 58.--“Specimen 2571. Presented by John Hunter, Hunterian MS., Cases and Dissections, No. 59. A rectum, with the urinary bladder and other adjacent parts. About 2 inches above the anus the canal of the rectum is gradually reduced to less than half its usual size by extensive thickening, induration, and contraction of the walls and of the tissues around them. They are all converted into a uniform pale, brawny, hard substance, like that of a cicatrix. This change, and the stricture due to it, extend for about 3 inches up the intestine. The mucous membrane lining the diseased part is superficially ulcerated; above it the intestine is greatly dilated, and its coats are thickened; below it is deeply wrinkled, but apparently not of unhealthy texture. The following is most probably the history of the case:

“‘About the spring, 1785, General G. consulted me. He complained of a sensation in the rectum, attended with a kind of difficulty in going to stool when costive, and often a desire to go when there was nothing to pass. I examined the rectum, and found, so far as I could reach with my finger, a hard contracted ring surrounding the gut. I then pronounced what the case was, and what would be the event.

“‘This hardness and thickening of the gut gradually increased, so as to make it difficult at times to pass the feces, especially when costive. At last, it occasionally became so difficult as to require the passing of bougies and hollow catheters, which one could always pass the lower stricture, but with difficulty passed the upper, which appeared to be 3 or 4 inches further up the gut.

“‘Clysters, purgatives, sedative and diluting, were occasionally thrown up, which sometimes had their intended uses. In this way he went on--sometimes better, other times worse--but upon the whole becoming worse. At last, it became difficult to pass a bougie, catheter, or even to throw up an injection, and which was attended with very disagreeable symptoms for the time, as acidity in the stomach, fulness, oppression, kind of hiccough, a vast rumbling in his bowels, and want of rest; but he got occasionally a passage which gave him relief for a time.

“‘He was, of course, put on a very low diet, and such as was thought best to answer the purposes of diet, while producing the least quantity of excrements, as also such as tended as little to acidity as possible. This was animal food in all the forms he liked best.

“‘All this art probably kept him alive for a twelve-month longer than he otherwise could have lived, for without this attention one or two costive days would have almost killed him, which I think I have often seen.

“‘What appeared to be very singular, the constitution did not, till the very last, seem to feel the disease or its consequences, for his pulse kept slow and regular, never in the least hard; and when signs of dissolution had taken place, the pulse was only weaker, but not irritable. At last nothing passed through the strictures, either downwards by stool, or upwards by way of clyster. The belly became gradually fuller and fuller, which was principally air, as towards the last he took but little food, and which was easily known by the sound in patting on the belly. He became in some degree insensible to his own situation, and in some degree less sensible of pain, which increasing, he died in that kind of easy and insensible manner.

“‘On opening the body the colon was found very much distended with air through its whole length; its transverse arch made a quick turn down to near the pelvis, then up upon itself to the left side, and then down the left, forming the sigmoid flexion; from all which turns, viz., making four, and being considerably distended, it appeared to fill almost the whole belly.

“‘There was a good deal of feces in the colon, but not in the least distending it.

“‘On putting the hand into the bottom of the pelvis was found a considerable tumor, which, with the bladder and rectum, was removed; but in this operation it was found that the tumor adhered closely to the hollow of the lower part of the sacrum, so as to be obliged to lay that bone bare in the removal of it.

“‘On slitting down the rectum, which was very large, it was found to be very much thickened in its coats, and of a hardish, gristly texture, a good deal like the turtle’s intestines. This increase of thickness was to give it power to expel its contents.

“‘At the tumor the intestine contracted almost at once; and at its entrance into the tumor its inner coats were thrown into loose folds, so as to obliterate almost any appearance of a passage there; however, I could readily pass the end of my finger into it, those folds easily giving way. The tumor was next slit through, which showed a firm increase of the gut, near an inch thick all round, and for three inches in length. At the lower part it terminated all at once into the sound gut, which we had often felt when alive. The inner surface had lost entirely its natural appearance; was slightly rugged so as to appear like villi.

“‘On introducing the pipe by the anus it was found to come butt against the side of the upper part of the cavity of the tumor, where there was a bend in the passage; but why a crooked pipe did not pass when attempted to be passed by turning it to all sides, I cannot conceive. Or why a bougie which was slightly bent, did not hit the hole, is not easily accounted for; but what is more extraordinary than either, why a clyster did not pass freely up; or why did not the wind or soft excrements, that did yet lay, pass pretty readily down, while I could pretty readily pass the end of my finger down from the gut above into the tumor. The folds of the contracted part did not appear after death to have been sufficient for an entire stoppage of this kind.”

The preceding case seems to illustrate that form of stricture which is built upon two or more rectal valves and in which the walls of the rectal chambers are involved and thickened. The mucous membrane is longitudinally folded upon itself and incorporated in the organized plastic exudate. The following case exhibits a tubercular tubular stricture and is characterized by a destruction of the mucous membrane:

Fig. 59.--“Specimen 2571c. Presented by Dr. H. Handford (see _Trans. Path. Soc._, London, 1888, page 117). From a lad, aged 17, who, four months before death, began to suffer from wasting, irregular attacks of diarrhea, and passed blood by the anus. Death resulted from purulent peritonitis, the result of perforation of a rectal stricture by a bougie. There were tubercle deposits in the upper lobes of both lungs and in the head of the pancreas.

“Microscopic sections of the lungs, the nodules in the pancreas, and all the lumbar and mesenteric glands showed masses of caseous material with a few giant cells.

“The rectum exhibits a tubercular stricture which commences 3½ inches above the anus. The stricture is 2 inches in length, moderately narrow, and the mucous membrane covering it is superficially ulcerated. The intestinal wall is somewhat thickened. Near the upper part of the stricture is a small perforation, produced in an attempt to pass a bougie through it.”

The following case is that of a stricture not builded on the rectal valve. It is situated at the levator ani level, it is probably a cicatricial product of disease which is not uncommon at this situation, but it may have had its origin in an imperfect anorectal coalescence.

Fig. 60.--“Specimen 2570. Presented by John Hunter: The lower part of a rectum, with the anus. On the margin of the anus are several large hemorrhoids, and the skin for a considerable distance around it is excoriated. At the right side of the anus is an appearance of a narrow granulating wound, as if a fistula had been there operated on. Immediately above the anus the canal of the rectum is suddenly and irregularly contracted to half an inch in diameter, but without any apparent change in the structure of its mucous membrane. Above the contraction it is unnaturally dilated, its coats are thickened, and the tissues around it appear rather indurated and confused.”

Case 2567 belongs to the same class as the preceding.

Fig. 61.--“Specimen 2567. From the Museum of Sir Astley Cooper: The lower part of a rectum, the canal of which, about an inch from the margin of the anus, is suddenly reduced to half an inch in diameter by the deep annular fold of its mucous membrane. Above the fold the mucous membrane appears healthy; below it is excoriated; and in one place there is a narrow bridge of it, as if there had been an abscess external to it, or as if a bougie had pierced it. The tissues around the contracted part of the rectum are not manifestly diseased. There are several external hemorrhoids at the margin of the anus.”

DIAGNOSIS.

_Fallacious Sounding._--Sounding the rectum with the patient in the horizontal posture, supinated or semipronated, has been a feature of the conventional method employed for the diagnosis of stricture of the rectum for more than a century, and as a great array of fatalities has not yet persuaded the profession to abandon the practice I feel that at this moment an analytic study of the procedure would not be unprofitable.

Sounding as a method of diagnosis requires three conditions: (1) that the tube to be sounded have a recognized limit of distensibility; (2) that its mobility in the direction of its axis be inappreciable, and (3) that there be not at irregular intervals normal anatomic obstructions in its channel sufficient to arrest the progress of a sound.

These conditions obtain in the urethra which is fixed from extremity to extremity within a mass of tissue which firmly supports it when the organ is in a situation for the practice of this diagnostic maneuver. The rectum on the contrary answers negatively to each of these three propositions.

Seven or eight inches (17.78 or 20.32 cm.) of the rectum’s length are not fixed; the lowermost inch (2.54 cm.) is the only portion muscle bound (Fig. 21) and as this part is easily accessible to digital exploration, to it, therefore, the method of diagnosis by sounding is not applied. A little way above the upper border of the prostate, or the pelvic floor in the female, the rectum is invested by a loop of peritoneum which does not yoke the gut fixedly but anchors it loosely in the abdominal cavity.

1. The distensibility of the abdominal rectum is governed by the elasticity of the gut’s inherent coats and is not limited by a comparatively unyielding musculofibrous wall supplied by the contiguity of other parts twentyfold its own strength and several times its own density and bulk, as is the case with the male urethra. The normal range of distensibility of the rectum then may be said to be from zero to three and a half inches (0 to 8.89 cm.) and consequently a definite calibration for sounding is impossible. (Fig. 21). The sound of a size which may enter the anus is not to be considered appropriate for sounding the rectum in accordance with the principle governing urethral catheterization which may be formulated in the aphorism; the sound which fits the mouth should discover contractions in the tube.

The average diameter of rectal sounds is about one inch (2.54 cm.). Two-thirds or three-fourths of the rectum’s expansibility, which may be greater than three inches (7.62 cm.), must then of necessity be sacrificed before rectal sounding will uniformly produce any definite evidence of stricture, provided all other things are equal and comparable to conditions obtaining in urethral catheterization.