Paper - Chiefly concerning the genito-mesenteric fold of peritoneum
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Reid DG. Chiefly concerning the genito-mesenteric fold of peritoneum. (1914) Proc R Soc Med. 7(Obstet Gynaecol Sect): 158-176. PMID 19978001
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Chiefly concerning the Genito-Mesenteric Fold of Peritoneum
By Douglas G. Reid, M.B., Ch.B. Edin., B.A. Trin. Coll. Camb.,
Demonstrator of Anatomy in the University of Cambridge.
(1) .P6?"it0'n6Cl/Z Comzezrions of the Terrmlnal Part of the Ileum;
Intestinal flexures.——Apart from the Inesentery, the terminal part of
the ileum may be connected to the abdominal wall by two different
folds of peritoneum. One is the ileo-appendicular fold of Jonnesco
(the “bloodless” fold of Treves), the other is the fold which I have
described in the foetus and named genito-mesenteric.‘ In such cases
these folds must be carefully distinguished from one another. The fold
of Treves may actually adhere to the genito-mesenteric fold. When it
adheres to the abdominal wall the bloodless fold of Treves may help,
along with the terminal part of the ileum, to bound a Very definite
fossa.2 This was present in the foetus shown in fig. 11 ; and I have now
seen it well marked in a number of adult bodies. “ In pericaecal hernia
the bowel is thrust into one or other of the pouches met with in the
region of the ileo-caecal junction ” ; 3 and without wishing to exaggerate
the possibilities of such a fossa, I think it should be kept in mind as
the possible seat of an internal hernia. Through the genito-mesenteric
fold the ileum may be very closely bound to the right ovary and
Fallopian tube, even closer than is shown in fig. 1. This connexion
is not to be mistaken for a pathological adhesion; but the genitomesenteric fold as a track along which infection, or inflammation, may
spread to or from the ovary and Fallopian tube is to be kept specially
in mind. In the third place, the terminal part of the ileum may be
- See Jozmz. of Anat. and Phys., 1908-9, xliii, p. 308; 1910-11, xlv, pp. 73, 406 ; 1911-12,
xlvi, p. 239. This fold occurred in 55 per cent.‘ of twenty 12 to 22 cm. (vertex to coccyx) foetuses. I have found it in a great number of full-time foetuses.
- For a photograph of this fossa, as seen in an adult, and for other photographs showing
the genito-mesenteric, bloodless and root folds of peritoneum, &c., I must refer the reader to Professor Joseph Rilus Eastman’s recent papers, “ The Foetal Peritoneal Folds of J onnesco, Treves and Reid,” and “ Foetal Peritoneal Folds.” See S’urg., Gyn. and 0bstet., April, 1913, and Journ. Amer. Med. Assoc., 1913, lxi, p. 635. I hope shortly to have published in the Journal of Anatomy some more photographs of the genito-mesenteric fold. One shows the ileum and appendix both adhering to the fold, and forming flexures rendered permanent in this remarkable manner. Their lymph vessels were also thrown into immediate con nexion.
- 3 H. Alexis Thomson and A. Miles, “ Manual of Surgery,” Edinb., ii, 1911.
connected to the abdominal wall, not by a fold,‘ but by adhesions which
bind it directly to the parietal peritoneum (see fig. 2). This is extremely
common both in the foetus and in the adult. In the adult the terminal
part of the ileum almost always ascends from the pelvic cavity,” and the part of the ileum involved in adhesions generally extends from the
pelvic brim to the caecum, and usually takes a straight course (see
fig. 2, A). But in one adult it presented a flexure which was rendered
permanent by these adhesions (see fig. 2, B). In another adult the ileum,
instead of ascending, descended to form an acute flexure with the part
that Was bound to the parietal peritoneum. But such a flexure (see
fig. 2, 0) could scarcely be regarded as being permanent, since the ileum was simply held up by coils of small intestine which had doubtless
pushed it upwards out of the pelvic cavity. Therefore, we must carefully distinguish between flexures which are permanent and those which
are most probably only temporary in nature. In the same Way the
ascending colon may be bent upon itself if its lower part remain “free”
and be pushed upwards by coils of small intestine. It is in such cases that the surgeon may fail to find the caecum in the right iliac fossa,
although it can be pulled downwards into this various bends on the colon (sec fig. 3), at first quite gentle curves,
.may become acute by movements which approximate the limbs of the
loops. Thus a V-shaped loop may be formed on the transverse colon;
and the pelvic colon (Which in the foetus often forms a large intraabdominal loop whose summit ascends to the duodenum) may have its
limbs squeezed together, as it Were, and become “compressed” (sec
figs. 8 and 9). The transverse colon may then adhere to its own mesentery, and the pelvic colon, throughout its whole extent, to the
parietal peritoneum. The latter may even adhere to the duodenum and
to the mesentery of the small intestine. Such adhesions may cause
these bends to become permanent, and many, as we are aware, seriously
interfere with the functional activity of the bowel.
fiG. 1. Sagittal-section of a foetus. The terminal part of the ileum is seen to be
closely connected to the ovary (and Fallopian tube) by the genito-mesenteric
fold (indicated by the needle) of peritoneum. The pelvic colon, which lay in
contact with the fold, has been removed.
- Provided the adhesions be not too difiuse, traction (as through the movements of the
ileum) upon the connective tissue elements, where they have become continuous, tends to elongate them into a fold. In this way it is possible that, secondarily, a fold may be produced at the periphery of the adhesions.
- 2 This must be remembered. For example, I have an almost exactly similar photograph
to that given by Gray and Anderson as representing Lane's kink (see “Developmental Adhesions affecting the lower end of the Ileum and Colon,” The University Press, Aberd., 1912, pl. iii); but the similarity in the cases could only be obtained by pulling the ileum upwards out of the pelvic cavity.
fiG. 2.
The stippling indicates the parts involved in adhesions.
fiG. 3.
The stippling indicates the parts involved in adhesions. The splenic process is normally present in the adult as well as in the foetus. Sometimes it adheres to the diaphragm so that the spleen lies in a very definite compartment closed in front, and sometimes below, by this fold.
- In one such case the transverse colon occupied the right iliac fossa in place of the
caecum which it had doubtless helped to push upwards into contact with the liver and gall-bladder.
(2) The Gemlto-mesentevrvic Fold appears after the fourth month of
foetal life. Its surfaces, which are right and left, are at first free as
regards adhesions. It is not attached along indefinite lines. Primitively
it is attached to the mesentery along the line of the ileac branch of the
ileo-colic artery. Behind it is attached to the abdominal wall over the
right spermatic or ovarian vessels, and sometimes over the right
external iliac artery. Along its posterior border lie the spermatic
plexus of nerves, or the ovarian nerves, and the right external spermatic
nerve (genital branch of the genito-crural) and lymphatic vessels. I
have been able to demonstrate the presence of lymphatic nodes in the
genito-mesenteric fold ; and this is doubtless an important point in view
of its usual connexion below with the ovary and Fallopian tube, through
the suspensory ligament (plica vascularis) of the ovary, and the possible
spread of infection. In the male it is sometimes, but not usually,
continuous with the suspensory ligament (plica vascularis) of the testis.
I have noted that the great omentum may adhere to the ascending
colon and caecum,2 and may pass from these to the parietal peritoneum ;
and in cases where the ascending colon remains “free,” it is noteworthy
that it might coat the right surface of the genito-mesenteric fold and
carry on to it blood-vessels and lymphatic vessels. The connexion with
the suspensory ligament of the genital gland explains how the genitomesenteric fold may gain attachment to the peritoneum at the interval
abdominal ring in full-time foetuses and in the adult.
Permit me to draw your special attention to the fact that there is one main fold of peritoneum lying in the right half of the abdomen below the mesentery. It is the genito-mesenteric fold; and to it the ileum, the appendix, the meso-appendix, the caecum and the “ bloodless ” fold of Treves may become adherent. In some cases it is probable that these secondary connexions may explain the presence of these parts in the sac of a right-sided congenital inguinal hernia. In an adult the free, sharp border of the genito-mesenteric fold was tightly stretched. Had small intestine crossed this edge to enter the patent processus vaginalis, or the tubular retrocolic fossa which was present, strangulation might readily have been produced. There are various ways in which the genito-mesenteric fold may complicate operations for removal of appendix.
- I can well understand how such adhesions, as seen by me, might also cause considerable
trouble in such operations as excision of the rectum by the sacral route and sigmoidostomy. Several years ago I dissected an adult in which the mesentery, at its root, had no attachment to the abdominal wall. It had fused down over the pelvic colon from which it took origin.
- 2 Journ. Anat. and Physz'ol., 1910-11, xlv, pp. 73-84.
It is very common for the meso-appendix to adhere to the genitomesenteric fold (sec fig. 4). This may occur in such a Way that the
fiG. 4. Full-term foetus. The meso-appendix (the thin strip of white paper lies behind the vermiform appendix) adheres to the genito-mesenteric fold.
appendicular artery comes to lie along the free border of the genitomesenteric fold in which it appears to lie. The artery to the appendix may also be bound to the right surface of the genito-mesenteric fold. The appendix may also adhere, in a very firm manner, to the right surface of this peritoneal fold (see fig. 5), and through this be connected to the ovary and Fallopian tube. The genito-mesenteric fold can be exposed by pulling the small intestine forward. It may bound a retrocolic fossa. Should the appendix lie in this and be bound to the genito-mesenteric fold, either directly or through the meso-appendix, any attempt to drag the appendix from the fossa would result in considerable laceration and tearing of peritoneum. In some cases free access to the appendix may be obtained by dividing the genitomesenteric fold. If in an operation this be done for any reason, the relations of the fold to the appendix, and to blood-vessels (including the appendicular artery) and nerves; should be kept in mind.
fiG. 5. Foetus, 155 cm. long, 9 . The appendix adheres very firmly to the
genito-mesenteric fold.
In a foetus 24 cm. long (see fig. 6) the right ovary and Fallopian tube were held in a vertical plane (on the left side the ovary and tube lay in a practically transverse plane, the plane both ovaries usually occupy in foetuses of this length), and were bound, almost directly, to the under surface of the mesentery by an extremely short genitomesenteric fold. This presented all its normal vascular relations. In addition to this, the appendix adhered very firmly to theright surface of the genito-mesenteric fold, and through this was bound, almost directly, to the ovary and Fallopian tube. This is not a pathological adhesion, but a connexion which, I think, must be of considerable interest, in view of the occurrence of appendicitis, or salpingo-ovaritis, and the spread of infection, or inflammation, from the appendix to the ovary or tube, or in the opposite direction.
(3) The Action of the Gemlto-mesenteric Fold in producing Adheslons and in a'7°1'esting the C'o77q9letz'0~n of Oaecal Tors1Ion.——Primitively the mesentery is attached at its root to the posterior peritoneum along the line of the root-folds of peritoneum (see fig. 7).1 The left or superior root-fold contains the ileo-colic, vessels. The right or inferior root-fold is also known as the mesenterico-caecal fold of Jonnesco. But the genito-mesenteric fold when it develops anchors, and indeed appears to exert a traction upon, the mesentery. I have shown that Whenever a sheet or fold of peritoneum is rendered relatively immobile it tends to become still more immovable through the formation of adhesions. Thus in quite small foetuses, Where the parts were absolutely healthy,
fiG. 6.
Sagittal section of a foetus, 24 cm. long (vertex-coccygeal measurement). The right ovary and Fallopian tube lie in a vertical plane and are bound almost directly to the mesentery and to the appendix (this lies ‘between the needle and the strip of white paper) by an extremely short genito-mesenteric fold (the needle indicates the anterior border of this fold).
- For a photograph of these see Professor J. R. Eastman’s paper in Jomm. Amer. Med. Assoc., Chicago, lxi, p. 635.
I have frequently found the most extensive adhesions associated with the genito-mesenteric fold. These are accurately represented in fig. 7. The ileum adheres to the right surface of the genito-mesenteric sheet. To the right of this it adheres, as does its mesentery, to the abdominal Wall. The caecum, appendix, meso—appendix, and fold of Treves all adhere to the parietal peritoneum. The appendix may be buried behind the ascending colon and caecum fixed down by the most firm adhesions. Theseare not due to pathological causes, although they may become useful as ready-made barriers resisting the spread of inflammation, especially from the appendix. Even the most extensive adhesions, which the surgeon tries so carefully to deal with in operations, as for appendicitis, may be due to the operation during foetal life of this genito-mesenteric fold. Furthermore, as a result of this anchoring or traction, the adhesions of the mesentery may extend to the left of the line of the genito-mesenteric fold (see fig. 7). In short, this fold may lower the root of the mesentery, Whilst the caecum is still placed high up in front of the right kidney, and Whilst the root—folds are still practically transverse in direction.
fiG. 7.
The parts involved in adhesions are indicated by the stippling.
The foetus shown in fig. 8 presents some of these adhesions. The
ileum adheres to the abdominal wall as does the caecum, part of the
appendix, the meso-appendix, and the bloodless fold of Treves. The
adhesions which involve the ileum always involve it to the right, and
never to the left, of the genito-mesenteric fold (see fig. 8). Apart from
enlargement or prolapse of the liver or stomach, it is possible that in
some cases this fold may be a -cause of -a downward displacement of the
duodenum. It is noteworthy that it is always to the lowest part of
the duodenum that this fold is attached; and it is thispart which may
sometimes be found lying definitely in the right iliac fossa.
fiG. 8. Foetus, 17 cm. long. The perforated _end of the needle rests on the left surface of the genito-mesenteric fold. There are strong adhesions in the i1eo caecal region.
The genito-mesenteric fold may not be the onlycause of adhesions in theeileo-caecal region and fixation of the caecum and appendix. firm pressure upon these parts by a meconium-distended pelvic colon may cause them to adhere to the abdominal wall over an area which in extent equals the surface upon which the pressure was exerted. In this way the appendix may also become bound directly to the under (left) surface of the mesentery.
The statement that two normal endothelial surfaces can adhere to
one another does not express a theory but a truth.‘ Similarly the pelvic
colon, by pressing on the genito-mesenteric fold may cause it to adhere to the abdominal Wall (see fig. 9). This partly explains how this fold
is not so common in the adult as in the foetus. The continuity of
the fold with the plica vascularis may be broken in this way. This is what had occurred in the foetus shown in‘ fig. 10.1 It was, of course,
impossible to tell if there had been any obliteration of the lymphatic
vessels. But, at all events, a track along which inflammation itself may
possibly spread has been interrupted.
In II there is a compressed omega-shaped intra-abdominal loop of pelvic colon.
In this case it has been formed through the descent of a portion of the left limb ’
of the primitive omega-shaped loop of pelvic colon seen in I. In III a compressed
and incompletely inverted omega loop has been formed through the summit of
the compressed omega gliding downwards through an arc of a circle. In this
movement it has pressed upon the genito-mesenteric fold and caused it to adhere
to the parietal peritoneum.
- I have found evidences for this in almost every foetus I have examined.
Variations in the position and relations of the appendix, which are
brought about through the arrest of caecal torsion at various stages, must be of interest to the surgeon. fig. 11 shows a very early stage
of caecal torsion, for the concavity of the caecum is directed to the right
as well as upwards. A rotation of the caecum “through an arc of 180°” is necessary before the completion of caecal torsion.‘
fiG. 10.
The two upper strips of White paper lie, one above and the other below the appendix. They indicate the remains of the genito-mesenteric fold. The lower strip of paper rests on the head of the epididymis and points to the free edge of the plica vascularis. To expose this the incompletely inverted omega has been pulled a little forwards.
The large appendix
of the foetus lies in front of the short ascending colon, and the caecum
is placed in front of the right kidney. But the bloodless fold of Treves
adheres to the abdominal Wall. This adhesion may resist, prevent,
or at all events assist in preventing, the completion of caecal torsion.
The terminal part of the ileum, for example, also adheres to the
abdominal wall in this specimen; and this adhesion would also resist
the completion of caecal torsion.
- It is noteworthy that in this foetus, as in many other specimens, the appendix is
connected to the mesentery by a fold of peritoneum formed by the fusion together of the meso-appendix and the genito-mesenteric fold. For -this reason the appendicular artery projects from the right surface of the fold. '
fiG. 11. Foetus, 22 cm. long. Early stage of caecal torsion. Note that the bloodless fold
of Treves adheres to the abdominal Wall.
I have already referred to the genito-mesenteric fold as a cause of adhesions involving the ileum and other parts in the ileo-caecal region. The fold of Treves may be enormously stretched consequent upon this adhesion and the descent of the caecum. At the more advanced stage of torsion shown in fig. 12 the appendix forms a loop which lies quite on the right side of the colon and caecum and intervenes between these and the lateral abdominal wall; and at the stage shown in fig. 13 the appendix lies in a plane behind the ascending colon. This is the position it usually occupies in foetuses in which the caecum has descended to below the right kidney. The appendix ascends to the kidney and is then bent downwards. It thus accomodates itself to the space available below the prominent foetal kidney. Now, or after only a little more torsion, the appendix is brought into. contact with the right surface of the genito-mesenteric fold, or into contact with the adhesions produced in association with this (see fig. 8). It is obstructed in its passage inwards and may always remain in a retrocolic position. It may also now adhere to the genito-ymesenteric fold and through it be connected to the genital gland. The genito-mesenterie fold is the commonest cause of a retrocolic position of the appendix.
- This stage of cmcal torsion has been well described by Huntington in his book on the
peritoneum.
fiG. 12. Foetus, 20 cm. long. More advanced stage of caecal torsion. The genito-mesenteric fold is present.
(4) Jackson’s Membrane.+—I have shown that the parieto-colic fold of J onnesco may be formed in ‘the foetus by a fold of peritoneum which crosses in front of the ascending colon and may contain blood-vessels, which are visible macroscopically, and course towards the parietal peritoneum. It may also be formed by a fold (appendix epiploica) which arises from the front of the ascending colon and becomes adherent to the lateral abdominal wall. We have already noted that the great omentum may adhere to the ascending colon and caecum and pass from these to the abdominal wall. I have seen such a sheet, formed by the points in relation to the origin of J ackson’s veil apart from pathological fusion of the laminae of the great omentum, in two adults. In one the right part of the transverse colon was closely bound to the ascending colon by the great omentum which crossed between them. It was Professor Eastman, of Indianapolis, who drew special attention to these causes. In reference to this membrane he also points out, that following upon the adhesion of the bloodless fold of Treves to which I have drawn attention, the caecum, during its descent and during caecal torsion,
fiG. 13.
Foetus, 17 cm. long. Still more advanced stage of caecal torsion.
(6
may wrap itself up in this fold. At all events, this fold may form a sconce from which in adults the caput coli must occasionally be shelled out.”
(5) There are many other remarkable adhesions. Many are, doubtless, of importance in helping to fix and support the viscera, and some
may become of interest to the surgeon. I found that adhesions had
begun to be formed even in an embryo 25 mm. long. fig. 14 shows
that the duodenum and head of the pancreas can adhere completely to
the abdominal wall only after the caudate lobe (process) of the liver
has retracted from a recess in which it lies behind these viscera. Note how the posterior surface of the head of the pancreas is left exposed. I
have traced the development of this recess, and have found it present in
full-time foetuses. A persistent recess would be an interesting condition
to find in an adult. It is noteworthy that in adult bodies one can
readily get one’s fingers behind the head of the pancreas and separate
it up from the abdominal wall. The postero-inferior surface of the
foetal stomach forms adhesions with the parts behind it. These
adhesions may subdivide the lesser sac of peritoneum into two parts
fiG. 14.
The retro-pancreatico-duodenal recess in a. 17-cm. foetus. In front of the right suprarenal body the caudate lobe (process) of the liver is seen lying in the recess which may fail to communicate with one another, or may only communicate through a small foramen (see fig. 15). This may be termed the supm-adhesion fommen since it lies above, and is determined by the normally developed adhesions binding thestomach to the transverse meso-colon. I have frequently found small supra-adhesion foramina in adults. Owing to these adhesions,‘and the associated fusion together of the laminae of the great omentum, the surgeon, should he desire to open through the gastrocolic omentum‘ into that portion of the lesser sac that lies behind the stomach, should make his incision in the neighbourhood of the spleen even in a young child. ‘These adhesions, together with others, subdivide the abdomen into compartments or recesses. These in some cases may form, as it Were, definite readymade “ abscess cavities.” I have found the great omentum very useful in forming these abscess cavities.” It might be interesting to consider the ways in which the genito-mesenteric fold may assist or prevent the spread of inflammation from one part to another. We have seen that it determines adhesions Which may “bury” the appendix behind the colon. Apart from creating these barriers resisting the spread of inflammation, it may also act as a track along which infection, or inflammation, can spread to or from the ovary and Fallopian tube. The lymphatics in the fold may in some cases be of considerable importance in association with this spread.
fiG. 15.
Foetus, 19 cm. long, viewed somewhat from the right side. In relation to the stomach the supra-adhesion fommen is seen. To expose it a large part of the liver and the gastro-hepatic omentum have been removed.
- In operations for gastric ulcer Treves (“ A Manual of Operative Surgery,” 1909, i, p. 220)
has advised the gastro-hepatic route.
- See fig. 11 of my paper in Joum. of Anat. and Physiol., 1913, xlvii, p. 506.
Obstetrical cmd Gynaecological -Section 175
Recent papers, especially by Dr. Macnaughton-Jones,‘ have dealt
with this subject; and the special purpose of this paper is to ‘lay before
you some of the anatomical truths of the ileo-caecal region as I know
them.
Discussion
Dr. MACNAUGHTON-JONES said that as the President had stated, he had included in his address to the Section in 1911 Dr. Reid's description of the genito-mesenteric fold and its relations to the ovary as Well as to the appendix. The relations of this fold to the appendix, and also to the mesentery, ileum, and caecum, have a most important bearing on the spread or arrest of inflammation from the appendix to the pelvic structures, or from the latter to the appendix. Since then Dr. Reid had made many further important investigations into the relations of the peritoneal folds and bands to the intestines in the foetus, as also to the appendix and the pelvic structures. The permanency of such folds or hands explains many of the pathological conditions found in adult life, as, for'instance, retrocaecal abscess, the presence of the appendix in hernial sacs, and the appendical complications in affections of the adnexa. No one had thrown so much light on these foetal peritoneal relations as Dr. Reid. The Section was much indebted to him for the extremely interesting demonstration which he had just given.
Professor WATERSTON considered that Dr. Reid had given satisfactory
evidence of the existence, in a certain proportion of cases, of the genitomesenteric fold. He suggested that further information as to its significance
might be obtained by microscopical examination, as it seemed possible that the
fold might be due to a band of muscular tissue resembling the gubernaculum
testis. He appealed to the members of the Section for specimens of embryosat all stages of development, and promised that good use would be made of
any material sent to him, either fresh or immersed in 5 per cent. formalin
solution.
- See Proc. Roy. Soc. Med., 1911, iv (Obstet. Sect.), p. 346, and Med. Press and C"irc., 1912, n.s., xciv, p. 601, and 1913, n.s., xcv, p. 196.
Dr. Reid stated that he had explained the origin of certain folds of
peritoneum as the result of adhesion and traction. Professor Eastman
seemed to have given a somewhat similar explanation of the origin of the
genito-mesenteric fold. Its origin Was extremely difficult to explain, and
especially its relation to the ileac branch of the ileo-colic artery. Any View
expressed must take this into consideration as Well as the late origin of the
fold (after _the fourth month), otherwise it might be discounted. He implied
that he might undertake a further research into the fold. It was dificult to
obtain embryos, and for the study of the lymphatics especially it was necessary
to have “fresh” material. At present it was impossible to give them any
more information regarding the genito-mesenteric fold.
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