Talk:Paper - The genesis of Jackson's membrane (1914)

From Embryology

THE GENESIS OF JACKSON’S MEMBRANE: NOTES ON THE GENITO-MESENTERIC FOLD OF PERITONEUM. AND THE SUPRA-ADHESION FORAMEN. By Dovuauas G. Rep, M.B., Ch.B. Edin., M.A. Trin. Coll. Camb., Anatomical Department, University of Cambridge.


WHILST supervising the dissection of an adult I observed a strong membrane (see fig. 1) lying in front of the ascending colon. The cecum lay in its normal position and was free from adhesions except at the upper part of its posterior wall, where it was fixed to the parietal peritoneum of the iliac fossa. Here it covered the short appendix (35 em. long), which was almost completely buried in the adhesions. The terminal portion of the ileum was also “ free.”?

The transverse colon, in the first part of its course, was bound directly to the ascending colon, in the last 5 cm. of its course, by the great omentum as it passed to the right lateral abdominal wall to form a “right colic ligament.”

The connexion was rendered still more secure by adhesions binding the transverse colon directly to the anterior surface of this part of the ascending ‘colon. In this way a permanently acute kink of the bowel was produced at the hepatic flexure. Immediately below this adhesion the transverse colon became horizontal in direction; and so closely were the two portions of the colon bound together that at first there appeared to be an abnormal cecum-like outgrowth of the bowel.”

Crossing in front of the ascending colon and covering the whole of its anterior surface, with the exception of the part which was bound to the transverse colon, was a strong opaque membrane, coated by endothelium. It contained a considerable amount of fat, distributed uniformly throughout, and many blood-vessels, which coursed parallel to one another and at

1 Apart from its mesentery the terminal part of the ileum may be connected to the abdominal wall by (1) the genito-mesenteric fold of peritoneum ; (2) the bloodless fold of

Treves; (3) adhesions which bind the ileum directly to the parietal peritoneum (in 50

per cent. of adults). 2 For skiagrams showing conditions resembling this, see Pilcher’s paper, “Surgical Aspects of Membranous Pericolitis,” Annals of Surgery, January 1912, vol. lv. p. 1. - The Genesis of Jackson's Membrane 433

right angles to the long axis of the bowel. They were visible macroscopically ; and the arteries, ultimate branches of the right colic and ileo-colic vessels, crossed the bowel to reach the lateral parietal peritoneum. They gave rise to a transversely striated appearance, seen to some extent in the photograph (see fig. 1). The membrane completely obscured the anterior teenia coli of the ascending colon.

It passed directly from the colon to the lateral abdominal wall without giving rise to any peritoneal fold. Below it faded away upon the cecum.

Fie. 1.—Case I. Jackson’s membrane in an adult, ¢. A knife has been passed between the membrane and the ascending colon, and its blade rests upon the cecum (also indicated b: a hook). A hook has been stuck into the terminal part of the ileum, and another holds forwards the upper part of the membrane which was dissected up from the bowel.

Here it formed a number of strands passing downwards and to the right from the ileo-ceecal junction. It did not pass from the cw#cum to the parietal peritoneum, and did not end below in a free edge.

It was a Jackson’s membrane.

Above it was continuous with the right colic ligament. It did not bound a pre-colic fossa such as I have described (Journal of Anatomy and Physiology, vol. xlvi. p. 401); but the handle of a knife could easily be passed between the membrane and the connective element of the penton coat of the bowel. ~ LSS 434 Mr Douglas G. Reid

As pointed out by Eastman (Surgery, Gynecology, and Obstetrics, April 1913), “this would hardly be the case were it a product of membranous pericolitis alone, as suggested by Jackson, or of mechanical irritation alone, as indicated by Martin.”

Jackson also draws special attention to its “apparently distinctly detachable nature.”

This is illustrated by the fact that before I secured the photograph the dissectors, who were unconscious of the existence of the membrane, had dissected a part of it up from the bowel (see fig. 1). .

The ascending colon was not kinked in any way, but was constricted to a remarkable degree, and flattened from before backwards. At its narrowest part it measured 32 mm. from border to border. Above it expanded quite abruptly ; and the part which was bound to the transverse colon, as well as the transverse colon itself, had a width of 5 cm. —

Traced downwards, the colon, after retaining a uniform diameter for some distance, gradually widened, and the cecum was 7 cm. broad.

The colic constriction was obviously due to the membrane.

Pieces of bowel between two teenie coli were examined microscopically.

The muscular coat of the caecum was normal in thickness, and all its coats were healthy. The longitudinal and circular layers of the muscular coat? of the ascending colon were both much thicker than usual, and on an average were four times as thick as those of the transverse colon.

The connective tissue of the membrane did not “seem to penetrate in increased amount between the muscle bundles” (Hall).

The walls of some of the arteries in the submucous coat were rather thicker, and some of the veins rather larger than normal.”

It will be seen that my description differs in some points from that of a membrane given by Hall in Jackson’s article, “Membranous Pericolitis ” (Surgery, Gynecology, and Obstetrics, September 1909).

The fact remains that a sheet was present such as Jackson was the first to point out might become of considerable clinical interest.

It is noteworthy that there was an acute kink of the bowel at the hepatic flexure; and the cecum lay in its normal position and was neither hypertrophied nor dilated*

1 It is a mistake to think, as some still seem to do, that in man there is no longitudinal muscular layer between the teniz coli.

2 The body was that of a man aged (?) who died partly as the result of a compound fracture got whilst in a state of alcoholic intoxication.

3 Compare this with some of the remarks made by Gray and Anderson, University Press, Aberdeen, 1912. It is noteworthy that in none of the adults in which I found a well-marked Jackson’s membrane was there “prolapse” of the cecum such as some say is common ; and in none were there angulations of the ascending colon such as are sometimes The Genesis of Jackson’s Membrane 435

The Genesis of Jackson’s Membrane.

If we include Case II. (see fig. 2), a well-marked membrane was present in front of the ascending colon in three out of six adults (50 per cent.) whose abdomens were dissected at Cambridge this term (Lent, 1914). In two out of twenty foetuses I found the parieto-colic fold of Jonnesco formed by a large appendix epiploica. In one it arose from the front of the ascending colon; in the other it crossed in front of the bowel, bounded a pre-colic fossa, and contained arteries, visible macroscopically, which crossed

Fic, 2.—Case II. Adult male. The fold of peritoneum referred to has been lifted up from the colon. The upper and lower parts of this appendix epiploica are not shown. It really extends downwards as far as the knife.

the colon, at right angles to its long axis, to reach the lateral parietal peritoneum. A Jackson’s membrane is really nothing but a parieto-colic fold of Jonnesco in cases in which this forms an investment for a definite part of the ascending colon.!

found in association with the membrane (Jackson). ‘“ Recently I have operated on a great many cases of dilated and prolapsed czeca associated with a Jackson’s membrane” (H. J. Stiles, personal communication). “«

1 Eastman first drew attention to my pre-colic folds in relation to Jackson’s “membranous pericolitis” about which I was ignorant at the time my papers were published. 436 Mr Douglas G. Reid

In another adult male I found a fold of peritoneum (see fig. 2), 12 cm. long, and attaining a height of 3°8 cm., lying in front of the ascending colon. Its posterior surface and right border were quite free from any union with the bowel. It contained fat, distributed uniformly throughout, and blood-vessels. It was a large appendix epiploica. It extended from a point just above and internal to the ileo-cecal junction upwards to the hepatic flexure, and had no connexion whatsoever with the right colic ligament. Below, it arose from the parietal peritoneum (formerly ascending mesocolon) immediately to the left of the colon. Above, it was attached for a distance of 5 em. to the colon to the left of the anterior tenia coli. Just before passing on to the colon it gained some attachment to the duodenum, which in the descending part of its course was closely bound, as is not uncommon, to the left side of the ascending colon. It covered a number of smaller appendices epiploice.

The blood-vessels in this fold were visible macroscopically and lay parallel to one another and at right angles to the long axis of the bowel. The arteries were ultimate branches of right colic and ileo-colic vessels,

I have no doubt as to how the Jackson’s membrane in Case I. (see fig. 1) arose. Had the fold in Case II. become fused down to the bowel (and apparently this had occurred to a slight extent over the upper and inner part of the ascending colon), and adherent at its free the parietal peritoneum, as in the two foetuses referred to, a membrane, similar in every respect, would have been produced ;! and the smaller appendices epiploice buried beneath it would have given rise to special “spots and tags of fat” (Hall).

I am not inclined to lay any stress upon the continuity of the membrane in Case I. with the right colic ligament.

In the foetus the great omentum may adhere to the ascending colon and cecum (completely descended), and may pass from these to the parietal peritoneum, coating the right surface of the genito-mesenteric fold, and carrying on to it blood and lymph-vessels (Journal of Anatomy and Physiology, January 1911).

In two adults I have seen a quite extensive pre-colic membrane formed by the laminge of the great omentum which had fused together (as may

1 Although the main blood-vessels in these appendices epiploice lay at right angles to the long axis of the bowel, it is possible, should an oe ei ix epiploica Shere to the abdominal wall before the caecum had completed its descent, that the blood-vessels in it might become oblique. They might then extend from “ the inner lower portion of the it” to its “outer upper peritoneal attachment” (Hall). In cases where the membrane is ormed by the great omentum, the blood-vessels in it tend to take a distinctly descending course. The Genesis of Jackson’s Membrane 437

occur extensively in foetuses from five to nine months old) and become adherent to the ascending colon from which they passed to the right lateral abdominal wall. In both the cecum was in its normal position. In one the right part of the transverse colon was closely bound to the upper part of the ascending colon simply by this membrane.1

In several adults I have noted bands of variable width lying across the front of the ascending colon. These, doubtless, were formed by appendices epiploiczs which had become adherent to the bowel and to the parietal peritoneum.”


This fold was present in seven out of ten (70 per cent. of) full-time foetuses recently examined by me.

It must be fairly common in children.*

In foetus No. I. (a full-time male) there was a very interesting fold (see figs. 3 and 4).4 Its mesenteric border (3 cm. long) was related, as normally, to the ileac branch of the ileo-colic artery. Its posterior (parietal) border descended, for a distance of 3 cm., upon the right spermatic vessels. At a

! Jackson (Surgery, Gynecology, and Obstetrics, 1909) notes that “in some instances it appears as though the membrane came on to the colon from the lateral parietal wall just above the cecum, and courses directly upwards to disappear beneath the liver on the superior layer of the transverse mesocolon.” The transverse colon may also be “drawn down” to the ascending colon by the “membrane.”

2 In some cases a membrane which invests the cecum, appendix, or indeed the ascending colon, may be formed in other ways. Should the bloodless fold of Treves adhere to the abdominal wall, or should some other adhesion be formed between the bowel and the parietal peritoneum, it is possible that during cecal descent and torsion, the bowel may gain an unusual peritoneal investment. Eastman has indicated this especially in relation to Treves’s fold. In this connexion he gives another interpretation of C. H. Mayo’s view regarding the congenital origin of Jackson’s membrane. These are the various ways in which such a membrane may be formed apart from pathological causes. I have an interesting specimen showing the genito-mesenteric fold forming a partial investment for the ascending colon.

By the term “adhesion” I mean a union which was not different from those which occur elsewhere during the fusions together of peritoneal sheets in the foetus. Moreover, I have shown that there is no “general shifting of the endothelial layers in such a manner that what was once free peritoneal surface remains free”; and have demonstrated the mechanical causes which operate in producing adhesions in different situations.

3 In children ‘‘numerous instances of acute and chronic salpingitis, sometimes accompanied with ovaritis and pelvic peritonitis, have been recorded ” (Kelly, Operative Gynecology, 1906, vol. ii. p. 566). ,

“Appendicitis occurs su frequently that it should be formally designated as a disease of childhood (Sonnenberg, Karewski, Selter)” (Pfaundler and Schlossmann, The Diseases of Children, vol. iii.).

4 For other photographs of the genito-mesenteric and other folds of peritoneum, etc., see my paper in the Proceedings of the Royal Society of Medicine, February 1914, and Professor Eastman’s paper, “ Foetal Peritoneal Folds” (Journal of the American Medical Association, 30th August 1913). 438 Mr Douglas G. Reid

point 2 cm. from the internal abdominal ring (annulus inguinalis abdominalis) it deviated from this line and passed horizontally outwards for 1:2 cm. The fold thus formed a shelf (I have seen it forming a deep pocket), slightly concave upwards, upon which the appendix rested at the. lowest point of its acute curve convex downwards (see fig. 3). :

There was no doubt that this alteration in the line of attachment was brought about through the pressure which had been exerted upon the left

Fic. 3.—Full-time foatus No. I, The specimen is viewed from the right side, An opening (above which lies the ileo-cecal orifice) has been made into the cecum. The ileum is simply steadied by the hook, and the natural form of the loop is. in no way distorted (of. fig. 4). Note. the large loop of pelvic colon to the left of the genito-mesenteric fold. :

surface of the fold by the large intra-abdominal meconium-distended pelvic

colon. I have now noted, in a number of foetuses, that the pelvic colon may

obliterate in this way part of the genito-mesenteric fold, and thus interrupt a track by which inflammation may spread from the bowel to the ovary and Fallopian tube, or in the opposite direction. The appendix at first descended for a distance of nearly 2 cm.; and in this part of its course skirted the posterior border of the genito-mesenteric fold, and adhered firmly to the posterior abdominal wall, as did the cecum higher up. __ ee The Genesis of Jackson’s Membrane 439

Below, where it became bent upon itself to form an acute flexure, it was bound directly to the right surface of the fold.

The ileum, as traced from the ileo-cecal junction, also descended for 2 cm. and then ascended for the same distance. It thus formed a loop (see fig. 3). This was firmly bound, throughout its entire extent, to the right surface of the genito-mesenteric fold.

Fic. 4.—Another view of the genito-mesenteric fold in full-time foetus No. I. Whilst this photograph was being taken, a slight traction, in an outward direction, was exerted upon the ascending limb of the loop of ileum (indicated by the thread and the strip of white paper). The exact position of the posterior (parietal) border of the fold is indicated by the end of another strip of paper.

Not only this, the mesentery of the loop also adhered to the right side of the fold, as did the whole of the meso-appendix. Therefore the appendix was connected to the terminal part of the ileum not only by the bloodless fold of Treves, also fused down, but by the meso-appendix and genitomesenteric fold. Its lymph-vessels were thus thrown into immediate connexion with those of the ileum and genito-mesenteric fold—a connexion which is not uncommon, however, as the ileum quite frequently adheres to

VOL. XLVIII. (THIRD SER. VOL. IX.)—JULY 1914. 440 Mr Douglas G. Reid

the fold and is then often connected with the meso-appendix, over which the ileum also frequently fuses down to the abdominal wall.

I have pointed out (Proceedings of the Royal Society of Medicine, February 1914) that it is necessary to distinguish between flexures of the terminal part of the ileum which are permanent and those which have no real claim to be regarded as other than temporary, and also (Jowrnal of Anatomy and Physiology, 1909-13) that the ileum, appendix, cecum, etc., may adhere to the genito-mesenteric fold. But foetus I. (see figs. 3 and 4) was especially interesting in that the ileum and appendix both adhered to the fold and formed flecwres which were rendered permanent in this remarkable manner. In another full-time foetus there was an almost exactly similar condition.

In several foetuses I have observed that the appendix may lie completely below the cecum; and when retained in this position by a genitomesenteric fold, it is noteworthy that it may become retro-colic if the cecum is able to complete its descent.

In two full-time foetuses the appendix, besides adhering to the right surface of the genito-mesenteric sheet, was bent backwards over its sharp free edge to come into contact with the left surface of the fold. The appendix and its mesentery may be acutely kinked in this way; and if kept thus for any length of time, or should the kink become permanent, inflammation, or even strangulation, may follow upon interference with the blood supply. I have pointed out that the genito-mesenteric fold may in some cases determine strangulation of the-ileum.

In foetus II. (see fig. 5) the genito-mesenteric fold passed downwards from the mesentery, and ileac branch of the ileo-colic artery, to the Fallopian tube and ovary. Lying in the fold, some in its central part, others close to its mesenteric border, were a number of small lymph-nodes —an important point. It contained many blood-vessels, especially veins —some of these could be traced to the ovarian vein. Apart from these vessels, no muscular fibres were present in the part removed for microscopic examination.” ‘The meso-appendix adhered to the right side of the fold (to a much greater extent than would appear from the photograph).

This important connexion is very common. Indeed, when there are no adhesions binding the ileum, meso-appendix, ete. to the abdominal wall, the two folds are rarely seen completely separate from one another.

The ileo-appendicular fold of Jonnesco (“ bloodless” fold of Treves) was

' For photographs showing variations in the position and relations of the appendix at different stages of cecal torsion, see my paper in the Proceedings of the Royal Society of Medicine, February 1914. Such variations must of course be interesting to the surgeon.

2 It might be well to make further microscopic examinations of folds in foetuses at various ages. The Genesis of Jackson’s Membrane 441

quite distinct from the genito-mesenteric fold, with which it should not be confused (see fig. 5).

The genito-mesenteric fold may remain well marked in the adult; but even if obliterated, through fusion with adjacent peritoneum, it must “leave behind,” in the form of adhesions, many permanent results of its presence.

A remnant of the fold was present this term (Lent, 1914) in two out of six adults (33 per cent.).

In both it was attached to the peritoneum over the external iliac artery.

Fic. 5.—Full-time foetus No. II., 9. The genito-mesenteric fold is viewed from the right side. One strip of white paper crosses the appendix, and the others indicate the posterior border of the fold and the upper end of the Fallopian tube. Note the ileo-appendicular fold of Jonnesco (‘‘ bloodless” fold of Treves).

In one it passed from the terminal part of the ileum, at the lower limit of the adhesions (present in 50 per cent. of adults), binding this to the peritoneum of the iliac fossa. These adhesions were absent in the other case, the fold passed from the mesentery, and the meso-appendix adhered to its right surface. The root of the mesentery formed an angle the vertex of which lay at the genito-mesenteric fold, and considerably below and to the left of the ileo-colie artery (which primitively lies along the line of the root). The root descended, much more vertically than usual, to reach the fold. It then passed to-the right and slightly downwards to a 442 Mr Douglas G. Reid

normally placed cecum. Obviously the genito-mesenteric fold had caused an abnormal displacement of the root of the mesentery downwards and to the left.

In accounting for the adhesions in the ileo-cecal region, not only the genito-mesenteric fold, but the large intra-abdominal pelvic colon, so often seen in the foetus, and the relatively unyielding posterior and right lateral abdominal walls must be kept in mind.

Thus, confined between the abdominal wall:and the genito-mesenteric fold, and rendered relatively immobile through the anchoring of the mesentery and connexion with the large intestine, the terminal part of the ileum, as well as the mesentery on each side of the fold, may readily become adherent to adjoining peritoneum against which it is pressed.

The pressure exerted by the pelvic colon is important in determining adhesions.? Special attention is directed to this mechanical cause of peritoneal adhesions. The cecum and appendix may be bound directly to the abdominal wall or, in the case of the appendix, to the under surface of the mesentery, as a result of this pressure. This gives us an explanation, apart from pathological causes, of the direct adhesion, sometimes seen in adults, of the appendix and meso-appendix, to the left (under) surface of the mesentery. The whole appendix may become “sessile” in this way and may be kinked acutely and permanently. Adhesions involving the pelvic mesocolon itself may thus be produced (see the Journal of Anatomy and Physiology, 1911, vol. xlv.).

I have now shown that we are further justified in believing that the genito-mesenteric fold must be of interest to the surgeon and gynecologist, not only as a track by which infection or inflammation may spread, but in relation to the formation of adhesions—adhesions which may act as readymade barriers resisting the spread of inflammation, adhesions which the surgeon may encounter, and should carefully deal with, in operations in the ileo-ceecal region.


I have already published figures and a photograph of this foramen (see the Journal of Anatomy and Physiology, July 1911 and 1912, April 1918, and the Proceedings of the Royal Society of Medicine, February 1914) as

' In association with the fold in the foetus, whilst the caecum still lies high up in the abdomen, I have shown that the root of the mesentery may acquire the direction it normally has in the adult.

2 It is noteworthy that if in the foetus a large unyielding meconium-distended pelvic colon remain with its summit at the level of the duodenum, the mesentery may fuse down over this part of the colon. I have noted this in several adults. I have a photograph showing some remarkable effects of the pressure exerted upon adjacent parts by the pelvic colon. The Genesis of Jackson’s Membrane 443

Fic, 6.—The supra-adhesion foramen in an adult, ?. The liver has been pulled upwards and the gastro-hepatic omentum reflected downwards. The handle of the knife rests upon the stomach at its pyloric end, and the blade lies in the foramen. Photo by Mr Walter J. Calcott, Anatomical Museums, Cambridge.

Fic. 7.--The supra-adhesion foramen in a foetus (¢) 19 cm. long. A large portion of the liver, and the left part of the great omentum have been removed and the greater curvature of the stomach has been pulled upwards into contact with the heart. Note how the transverse mesocolon passes from the stomach below the small foramen. Behind the foramen the

‘*deep gastric ligament” is seen. Photo by Mr W. J. Calcott. 44,4, The Genesis of Jackson’s Membrane

seen in foetuses. Fig. 6 shows the. foramen as I have frequently seen it in adults.

The coronary vein lay at some distance from the free margin of the coronary (left gastric) portion of the septum bursarum omentalium (deep gastric ligament of Jonnesco, plica gastro-pancreatica).

Primitively it lies along this border. Fig. 7 shows how the foramen is determined, viz. by adhesions (appearing relatively late in intra-uterine life) which bind the postero-inferior surface of the stomach to the transverse mesocolon. These and other adhesions must be of importance both in anatomy and surgery in helping to fix and support the viscera.