PRACTICAL CONSIDERATIONS : ABDOMINAL HERNIA. 1779 



Internal (intra-abdominal, retroperitoneal) hernise are those which 

 arise within the abdominal cavity, whether they develop in normal peritoneal recesses 

 or in abnormal peritoneal recesses arising in a physiological manner (Brosike). 

 The classification adopted by Su.kan is sufficiently comprehensive to include all 

 herniae coming under the above definition. Five varieties can be differentiated : 

 (i) hernia of the foramen of Winslow, (2) hernia of the duodeno-jejunal recess, 

 (3) hernia of the retrocaecal and ileo-caecal recesses, (4) hernia of the intersigmoid 

 recess, (5) retrovesical hernia. 



1. The hernia of the foramen of Winslow (Fig. 1475) into the lesser peritoneal 

 cavity, which may be regarded as a pre-existing hernial sac is rare on account of 

 the narrowness of the opening (page 1746), and Merkel believes that either an abnor- 

 mally long mesentery or a retardation of the normal process of fixation of the colon 

 must exist if portions of the intestine are present in the lesser peritoneal cavity. The 

 part of the bowel involved is usually the colon. 



2. The duodeno-jejunal fossa, the orifice of which looks upward (Fig. 1501), 

 is formed by a peritoneal fold and is usually to the left of the spine at the duodeno- 

 jejunal junction. It may, in marked cases, receive the whole of the small intestine 



FIG. 1501. 



Transverse tnesocolon 

 Jejunum Duodenum 



Superior duodeno-jejunal 

 fossa 



2L_Branch of left 

 colic artery 



Inferior duodeno- 

 jejunal fossa 

 Descending colon 



Mesentery ot small 

 intestine 



Duodeno-jejunal junction, showing duodenal fossee; jejunum turned to the right. 



which is then placed behind the posterior parietal peritoneum. The duodenum can 

 be seen to enter the sac and the end of the ileum to leave it. The renal artery is 

 behind the sac and the inferior mesenteric artery in front of it (Treves). The inferior 

 mesenteric vein and sometimes the colica sinistra artery run in the upper margin of 

 the orifice. 



3. The more important peritoneal fossae about the caecum are shown in Fig. 1502. 

 They contain hernise with great rarity ; the retrocaecal pocket extending upward 

 behind the caecum and ascending colon has received coils of the lower ileum. 



4. By raising the sigmoid flexure and drawing it to the left, the intersigmoid 

 fossa may be seen opening towards the left between the root of the sigmoid meso- 

 colon and the parietal peritoneum. It is caused by the sigmoid artery, and is about 

 over the bifurcation of the iliac vessels. It has been occupied by coils of small 

 intestine. 



5. The plica hypogastrica (ligamentum umbilicalis lateralis} (Fig. 1487) may be 

 so exceptionally salient as to form a deep peritoneal pocket becoming a retrovesical 

 hernial pouch. 



All these internal hernias have in common the essentials of abdominal herniae of 

 all varieties, viz., an orifice through which, by intra-abdominal pressure or by 



