The Left Side

On the left side, there may be striking posteromedial malposition of the distal transverse colon. Normally, the highest portion of the large intestine in the left upper quadrant ("roentgenographic" splenic flexure) retains the mesenteric attachment of the transverse colon. Distal to this, it courses inferiorly between the medial surface of the spleen and the anterolateral aspect of the left kidney to the anatomic splenic flexure in relation to the splenic angle. The anatomic splenic flexure is normally not only the most posterior but also the most fixed portion ofthe large intestine, being restrained by the phren-icocolic ligament.36 Distal to this point, the colon continues as the extraperitoneal descending colon.

With agenesis or ectopia of the left kidney, the mes-enteric distal transverse colon may be deflected posteriorly and medially into the "empty" renal fossa area. Similarly, the anatomic splenic flexure of the colon may be deflected toward the same site (Figs. 9-45, 9-51 through 9-53). The colonic malposition may be evident as a finding on plain films (Fig. 9-54).

Figure 9-55 illustrates colonic herniation through a large foramen of Bochdalek. Associated left renal agenesis is indicated by the medial malposition of the sub-diaphragmatic distal transverse colon and anatomic splenic flexure at the level of the phrenicocolic ligament.

The most common condition from which these characteristic changes must be distinguished is a congenital anomaly of fixation of the left colon.37 Here, the splenic flexure may be medially situated, but it is in association with a freely mobile and medially located descending colon.

In left renal agenesis or ectopia, the posteromedial deflection of the distal transverse colon and anatomic splenic flexure into the renal bed should also not be confused for displacement by an enlarged spleen. Splenomegaly may depress the anatomic splenic flexure of the colon but does not displace it medially. In the entity known as wandering spleen,38-40laxity or absence of its supporting structures, including the phrenicocolic ligament, allows the organ to migrate from the left upper quadrant. The anatomic splenic flexure may then be sharply angulated medially (Figs. 9-56 and 9-57), a consequence of traction by the splenic pedicle.

These changes in intestinal position have not been seen with renal dysplasia, after flank nephrectomies, or with acquired atrophy of the kidney. In the latter, adipose replacement between the intact perirenal fascial layers contributes to this. However, colonic malposition may be noted after anterior nephrectomies (Figs. 9-58 through 9-62), because of the operative mobilization of the colon and violation of the anterior renal fascia. Occasionally, after left nephrectomy, the tail of the pancreas falls posteriorly and occupies the medial aspect of the renal bed, adjacent to the aorta and the left psoas muscle (Figs. 9-60 and 9-61).42,43

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Hernia Paraduodenal Agenesis PancreasPsoas Atrophy

Fig. 9—47. Right renal agenesis with intestinal malposition.

(a and b) Upper gastrointestinal series demonstrates striking posterior malposition of the descending duodenum and proximal jejunal loops in the right flank region, simulating some of the features of a right paraduodenal hernia. (continued on opposite page)

Fig. 9—47. Right renal agenesis with intestinal malposition.

(a and b) Upper gastrointestinal series demonstrates striking posterior malposition of the descending duodenum and proximal jejunal loops in the right flank region, simulating some of the features of a right paraduodenal hernia. (continued on opposite page)

Paradudenum And Picture

Fig. 9—47. Right renal agenesis with intestinal malposition. (Continued)

(c and d) Selective superior mesenteric arteriogram. The arterial phase demonstrates the jejunal arteries arising normally on the left, but then curving to the right midabdomen. The capillary blush of the jejunal loops assumes a general reniform contour.

(e and f) Flush aortogram and delayed film reveal absence of the right kidney and renal artery, with compensatory hypertrophy on the left. (Reproduced from Meyers et al. )

Fig. 9—47. Right renal agenesis with intestinal malposition. (Continued)

(c and d) Selective superior mesenteric arteriogram. The arterial phase demonstrates the jejunal arteries arising normally on the left, but then curving to the right midabdomen. The capillary blush of the jejunal loops assumes a general reniform contour.

(e and f) Flush aortogram and delayed film reveal absence of the right kidney and renal artery, with compensatory hypertrophy on the left. (Reproduced from Meyers et al. )

Location Hepatic Flexure

Fig. 9—48. Crossed renal ectopia with intestinal malposition.

(a and b) Upper GI series demonstrates posterior malposition of descending duodenum and abnormal location of jejunal loops in area of right renal bed. There is also a suggestion of separation of small bowel loops in the left lower quadrant.

(c) Intravenous urogram reveals crossed renal ectopia to the left side.

(Reproduced from Meyers et al.16)

Compensatory Hyperplasia LiverRenal Agenesis

Fig. 9—49. Colonic malposition in right renal agenesis.

(a) Upper GI series, delayed film, demonstrates distal ascending colon and posterior hepatic flexure occupy area of right renal fossa.

(Reproduced from Curtis et al.)21

(b) Excretory urography reveals absence of the right kidney and compensatory hypertrophy on the left.

Fig. 9—49. Colonic malposition in right renal agenesis.

(a) Upper GI series, delayed film, demonstrates distal ascending colon and posterior hepatic flexure occupy area of right renal fossa.

(Reproduced from Curtis et al.)21

(b) Excretory urography reveals absence of the right kidney and compensatory hypertrophy on the left.

Radiography The 50s

Fig. 9—50. Colonic malposition in right renal ectopia.

(a) Barium enema demonstrates angulated posteromedial deflection of posterior hepatic flexure.

(b) Intravenous urogram reveals right ectopic kidney overlying the lumbosacral junction. (Surgical clips are from a previous hysterectomy.)

Kidney Left Side

Fig. 9—51. Colonic malposition in left renal agenesis.

(a and b) Barium enema demonstrates marked medial and posterior malposition of the distal transverse colon and anatomic splenic flexure into the area of the left renal bed. (c) Intravenous urogram reveals absence of the left kidney. (Reproduced from Meyers et al. )

Crossed Kidney Ectopia UrogramEnema Left Side Malposition Bowel

Fig. 9—52. Colonic malposition in left renal agenesis.

(a and b) The anatomic splenic flexure (SF) is deflected medially and posteriorly, occupying the position of the "empty" renal fossa. (Reproduced from Meyers.2)

Fig. 9—52. Colonic malposition in left renal agenesis.

(a and b) The anatomic splenic flexure (SF) is deflected medially and posteriorly, occupying the position of the "empty" renal fossa. (Reproduced from Meyers.2)

Fig. 9—53. Crossed renal ectopia with intestinal malposition.

CT demonstrates crossed fused renal ectopia on the right with colon and small bowel loops occupying the "empty" renal fossa on the left. Renal fascia is identifiable on the right (arrowheads) but not on the left.

Bochdalek Fossa

Fig. 9—54. Colonic malposition in left renal agenesis.

Excretory urogram. In this child, the anatomic splenic flexure (SF) occupies the "empty" renal fossa. There is compensatory hypertrophy of the right kidney. (Reproduced from Meyers. )

Fig. 9—54. Colonic malposition in left renal agenesis.

Excretory urogram. In this child, the anatomic splenic flexure (SF) occupies the "empty" renal fossa. There is compensatory hypertrophy of the right kidney. (Reproduced from Meyers. )

Herniated Colon

Fig. 9—55. Intrathoracic colonic herniation.

(a) Lateral view of barium enema study shows large intrathoracic herniation of the transverse colon through the foramen of Bochdalek.

(b) There is also marked medial malposition of the distal transverse colon and anatomic splenic flexure into the area of the left renal bed. These changes are secondary to associated agenesis of the left kidney. (Reproduced from Meyers et al.16)

Picture Soft Tissure Colon

Fig. 9—56. Torsion of wandering spleen.

(a) Plain film shows a large central soft-tissue mass displacing bowel loops (arrows).

(b) Barium enema study demonstrates marked medial angulation and malposition of the anatomic splenic flexure (SF). This is produced by traction from the twisted splenic pedicle.

Picture Soft Tissure Colon

Fig. 9—57. Torsion of wandering spleen.

Barium enema study demonstrates sharply angulated medial malposition of the anatomic splenic flexure (SF), produced by traction from an elongated and twisted splenic pedicle. The enlarged congested spleen is indicated by the soft-tissue mass in the lower abdomen displacing the descending and sigmoid colon.

Picture Soft Tissure Colon

Fig. 9—58. Malposition of the colon following right nephrectomy.

The hepatic flexure is deviated into the "empty" renal fossa.

Fig. 9—58. Malposition of the colon following right nephrectomy.

The hepatic flexure is deviated into the "empty" renal fossa.

Wondering Spleen

Fig. 9—59. Malposition of the colon following left nephrectomy.

In two different cases, the angulated splenic flexure occupies the area of the renal fossa.

Fig. 9—59. Malposition of the colon following left nephrectomy.

In two different cases, the angulated splenic flexure occupies the area of the renal fossa.

4

Bowel may be a conspicuous component of lumbar hernias secondary to postoperative flank incisions.41 (Fig. 9-63).

Essentials of Human Physiology

Essentials of Human Physiology

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