rectal instruments

BRIEF SURGICAL ANATOMY OF THE COLON


By • Дек 26th, 2010 • Category: For surgery

The mucous and submucous membranes of the rec­tum and anal canal are provided with a dense network of lymphatics which extensively anastomose with each other. From the anus and the perineal rectum, lymph passes to the inguinal and, partly, to the femoral nodes, and goes upwards through the inguinal fold (Fig. 13). The lymphatic pathways, which accompany branches of predominantly the middle and superior rectal arteries, start from the lymphatic network of the rectal ampula (Fig 14), fuse into the lymph nodes of the pelvic side wall and sacral promontory, and run upwards along the superior rectal artery to enter the lymph nodes of the common iliac artery and aorta (Fig. 14).

Innervation of the rectum is effected by sympathetic and spinal nerves. From the branches of the 2nd, 3d and 4th lumbar sympathetic ganglia, the superior rectal ple­xus is formed which descends to the pelvis in the course of the superior rectal artery and penetrates the rectal wall. Here the hypogastric nerve can be seen (Fig. 15) which passes to the pelvic parallel with the middle sac­ral artery where it gives off numerous branches. To­gether with the roots of the 2nd, 3d and 4th sacral ner­ves it forms a dense nervous plexus (Fig. 15). The skin of the perineum and the anus are innervated by the free perforating terminal branches of several nerves listed in Fig. 17.

Brief surgical anatomy of the colon. Situated in the right iliac fossa, the caecum continues as the ascending colon (Fig. 18) which has no mesentery. At the inferior surface of the liver, it bends around at a right angle (hepatic flexure) to continue as the transverse colon which is provided with a mesentery. Anteriorly, the omentutn is attached to it. In the left hypochondriac re­gion the transverse colon bends sharply (splenic flexu­re) to become the descending colon which has no me­sentery. Descending to the left iliac fossa, the des­cending colon gradually passes into the sigmoid colon. This is completely invested with peritoneum and has a rather wide mesentery (mesosigmoid). The sigmoid length varies from 14 to 24 cm. As it approaches the sacral promontory the sigmoid colon gradually loses its mesentery and passes into the rectum on the level of the 3d sacral vertebra.

Blood supply of the colon is shown in Fig. 18 and 21. It is seen in Fig. 21 that at operation, when the main trunk of the inferior mesenteric artery is ligated, the blood supply to the descending colon and a part of the sigmoid colon can be preserved due to the blood coming through the branches of the middle colic artery. For practical purposes, in the Quenu-Miles operation, in an­terior resection, and in some pull-through operations it might be quite sufficient to ligate the inferior mesente-ric artery immediately distal to the branching of the left colic artery, since we believe that the last-named artery should be preserved. Blood supply to the wall of the colon itself is effected from the marginal arteriesor ar­teries running within the mesentery body parallel to the mesocolic taenia. The distance between the marginal ar­teries (arcades) and the rectal wall varies from 1.5 to 5 cm. The closer the arcades are situated to the rectal wall, the easier it is to free a sufficiently long portion of the sigmoid for pulling it through the pelvis on to the perin

Lymphatic pathways running from the distal rectum to the femoral and inguinal lymph nodes

Fig. 13 Lymphatic pathways running from the distal rectum to the femoral and inguinal lymph nodes. (After V. R. Braitsev)

 Lymph nodes of the rectum and pelvis. (After Bacon)

Fig. 14. Lymph nodes of the rectum and pelvis. (After Bacon)

l.Levator ani muscle. 2. Superior inguinal lymph nodes. 3. Periaortal lymph nodes. 4. Inferior mesenteric artery. 5. Superior rectal artery. 6. Lymph nodes of the pelvic promontory. 7. Rectum. 8. Gerotas lymph nodes.

Fig. 15. Lymphogram of the perineal, pelvic, and periaor-tal lymph nodes

Fig. 15. Lymphogram of the perineal, pelvic, and periaor-tal lymph nodes

Fig. 16. Innervation of the rectum. (Schematic). Sympathetic nerves are shaded lightly, and parasympathetic nerves are coloured black:

Fig. 16. Innervation of the rectum. (Sche­matic). Sympathetic nerves are shaded lightly, and parasympathetic nerves are coloured black:

1. Inferior mesenteric ganglion. 2. Gang­lia of the sympathetic trunk. 3. Superior rectal plexus. 4. Hypogastric nerve runn­ing into the lesser pelvis next to the middle, sacral artery. 5. Roots of sacral nerves. 6. Pudendal nerves. 7. Inferior rectal nerve

Fig. 17 Sensitive nerves of the perineum: /. Ratnus perineus n. cutaneus femoris posterioris. 2. Inferior rectal nerves. 3. Anococcygeal nerves. 4. Perineal nerve&. 5. Posterior scrotal nerves

Fig. 17 Sensitive nerves of the perineum:

1. Ratnus perineus n. cutaneus femoris posterioris. 2. Inferior rectal nerves. 3. Anococcygeal nerves. 4. Perineal nerve&. 5. Posterior scrotal nerves

Fig. 18 Vasogram of large intestine arteries

Fig. 18 Vasogram of large intestine arteries

Topography of the colon. (From Rauber's Atlas)

Fig. 19 Topography of the colon. (From Rauber’s Atlas):

1. Caecum. 2. Ascending colon. 3. Hepatic flexure of the colon. 4. Transverse colon. 5. Splenic flexure of the colon. 6. Descending colon. 7. Sigmoid colon

Fig. 20. Section of the colonic wall. (After Bacon)

Fig. 20. Section of the colonic wall. (After Bacon):

1. Appendices epiploicae. 2. Omental taenia. 3. Mesocolic taenia. 4. Free taenia. 5. Circular mus­cular layer. 6. Submucous layer. 7. Mucous mem­brane

Fig. 21 Blood supply of the colon and rectum. (Schematic)

Fig. 21 Blood supply of the colon and rectum. (Schematic):

I. Ileocolic artery. 2. Right colic arte­ry. 3. Middle colic artery. 4. Superior mesenteric artery. 5. Marginal colic ar­tery. 6, Inferior mesenteric artery. 7. Left colic artery. 8. Trunk of the in­ferior mesenteric artery. 9. Sigmoid arteries. 10. Superior rectal artery.

II. Middle rectal artery. 12. Inferior rectal artery

Fig. 22. Blood supply to the colonic wall (after Bacon).

Fig. 22. Blood supply to the colonic wall (after Bacon).

1. Straight intestinal artery. 2. Short branch of the straight intestinal artery. 3. Artery of the omental process.



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