Pancreatitis Falciform Ligament

Fig. 8—57. Extraperitoneal perforation of the descending duodenum following blunt trauma with anterior pararenal space infection.

(a) Gastrografin GI series shows extravasation from the duodenum. Mottled gaseous lucencies extend inferiorly and laterally. Below the level of the cone of the renal fascia and the lateroconal fascia, the infection reaches and then ascends the flank fat (arrows).

(b) Pathway of spread inferior to the lateroconal fascia to communicate with the flank fat. (Reproduced from Meyers.8)

Survived Melanoma

Fig. 8-58. Retroduodenal anterior pararenal hemorrhage.

(a) Lateral excretory urogram shows a mass separating the right kidney from the anteriorly displaced descending duodenum (D). C = colon.

(b) Upper GI series shows spiculation of mucosal folds along the posterior aspect of the descending duodenum.

(Reproduced from Meyers et al.12)

Fig. 8-58. Retroduodenal anterior pararenal hemorrhage.

(a) Lateral excretory urogram shows a mass separating the right kidney from the anteriorly displaced descending duodenum (D). C = colon.

(b) Upper GI series shows spiculation of mucosal folds along the posterior aspect of the descending duodenum.

(Reproduced from Meyers et al.12)

Fascial Plane

Fig. 8—59. Anterior renal fascial reactions in pancreatitis in three different patients.

(a) A thickened left anterior renal fascia converges behind the pancreas (arrows), which is swollen with intrapancreatic fluid. SV = splenic vein.

(b) Intrapancreatic fluid collection (F) with thickened left anterior renal fascia blending into posterior pancreatic tissue (arrows). LRV = left renal vein.

(c) Inflammatory pancreatic mass (M) with very thickened anterior renal fascial planes bilaterally (black-and-white arrows). DU = duodenum; SMA = superior mesenteric artery; sp = spleen; VC = vena cava.

(Reproduced from Feldberg.17)

Fascial Planes

Fig. 8—59. Anterior renal fascial reactions in pancreatitis in three different patients.

(a) A thickened left anterior renal fascia converges behind the pancreas (arrows), which is swollen with intrapancreatic fluid. SV = splenic vein.

(b) Intrapancreatic fluid collection (F) with thickened left anterior renal fascia blending into posterior pancreatic tissue (arrows). LRV = left renal vein.

(c) Inflammatory pancreatic mass (M) with very thickened anterior renal fascial planes bilaterally (black-and-white arrows). DU = duodenum; SMA = superior mesenteric artery; sp = spleen; VC = vena cava.

(Reproduced from Feldberg.17)

Anterior Pararenal Space

Fig. 8—60. Pancreatitis extending through anterior pararenal space.

CT scan shows fluid collection (C) extending from tail of pancreas through the anterior pararenal space on the left. Note its continuation to the bare area posteriorly of the descending colon (curved arrow), where it is bounded laterally by the lateroconal fascia. There is fluid interposition within the posterior renal fascia, tapering posteriorly. The perirenal space and flank fat remain uninvolved.

Fig. 8—60. Pancreatitis extending through anterior pararenal space.

CT scan shows fluid collection (C) extending from tail of pancreas through the anterior pararenal space on the left. Note its continuation to the bare area posteriorly of the descending colon (curved arrow), where it is bounded laterally by the lateroconal fascia. There is fluid interposition within the posterior renal fascia, tapering posteriorly. The perirenal space and flank fat remain uninvolved.

On plain films, in the presence of an exudate in the left anterior pararenal space, a radiolucent halo about the left kidney may rarely be evident, secondary to enhanced visualization of the peripheral margin of the uninvolved perirenal fat.87,88

Solitary or predominant involvement of the anterior pararenal space on the right is seen in pancreatitis involving the head, typically severe in nature (Figs. 8-62 and 8-63). Bilateral involvement of the anterior pararenal spaces reflects advanced or fulminating pancreatitis (Figs. 8-64 through 8-66). The extrapancreatic collection may readily extend within the posterior renal fascia on either or both side as well as along mesenteric pathways.

Extraperitoneal spread of a pancreatic abscess may be extensive but usually follows recognizable planes. Drainage from the head of the pancreas tends to be downward and to the right. Figure 8-67 illustrates the typical localization found at surgery in cases of extensive pancreatic infections within the anterior pararenal compartment. The large abscess pictured has come into contact with the ascending colon and has not crossed the mid-line. Figure 8-68 demonstrates identical character

Fig. 8-61. Thickened renal fascia (arrows).

This is identified on plain film as a curvilinear soft-tissue band separated by lucent perirenal fat from the lateral contour of the kidney. This finding persisted after resolution of acute pancreatitis.

Fig. 8-61. Thickened renal fascia (arrows).

This is identified on plain film as a curvilinear soft-tissue band separated by lucent perirenal fat from the lateral contour of the kidney. This finding persisted after resolution of acute pancreatitis.

istic features in vivo. Figure 8-69 shows the operative findings when the process has continued inferiorly to the level of the iliac crest. The drainage here has led to a discrete collection external to the peritoneum. Although this pathway has not been previously explained in the surgical literature, it is clearly the result of the process extending below the level of the lateroconal fascia and then gaining immediate access to the properi-toneal flank fat. This is basically the same pathway as outlined in Figure 8-57.

Emphysematous or fulminating pancreatitis is a principal exception to unilateral confinement within the anterior pararenal space from a process arising in the upper abdomen. Figure 8-70 illustrates a gas-producing infection of the pancreas with spread downward within both sides of the compartment. The gaseous lucencies overlie the psoas muscles, but there is no evidence of direct continuity across the midline. This indicates that the in

Necrotizing Pancreatitis

Fig. 8-62. Right anterior pararenal space fluid secondary to necrotizing pancreatitis.

(a) While there is enhancement of the body and tail of the pancreas, high-resolution bolus CT shows there is lack of enhancement of the area of the head, which is surrounded by fluid. These changes indicate necrosis.

(b) There is extension of fluid loculating predominantly within the anterior pararenal space on the right as well as within the transverse mesocolon.

(Courtesy of Emil Balthazar, M.D., Bellevue Hospital, New York University School of Medicine, New York, NY.)

Fig. 8-62. Right anterior pararenal space fluid secondary to necrotizing pancreatitis.

(a) While there is enhancement of the body and tail of the pancreas, high-resolution bolus CT shows there is lack of enhancement of the area of the head, which is surrounded by fluid. These changes indicate necrosis.

(b) There is extension of fluid loculating predominantly within the anterior pararenal space on the right as well as within the transverse mesocolon.

(Courtesy of Emil Balthazar, M.D., Bellevue Hospital, New York University School of Medicine, New York, NY.)

fection has dissected separately down both sides from the pancreas. Figure 8-71 shows similar bilateral changes of large infected pseudocysts of the pancreas in an alcoholic male. Yet, the anatomic planes of the anterior pararenal space may allow direct extension across the midline, particularly in cases of liberated pancreatic enzymes (Fig. 8-72).

A potential space into which fluid collections from the anterior pararenal space can extend is created by the division of the posterior renal fascia into two laminae (Figs. 8-73 and 8-74). In moderate to severe cases of pancreatitis, retrorenal extension of pancreatic effusion

20 34 35

or phlegmon into this potential space is common (Figs. 8-64 through 8-66). Raptopoulos and colleagues have emphasized the typical appearance of this posterior extension of pancreatitis as a widening of the posterior renal fascia that tapers posteriorly20 (Fig. 8-60). However, I have observed that variability in the origin of the division into two leaves in the horizontal plane as well as apparently in the vertical dimensions of the cleavage account for the varied appearances of fluid accumulation in this plane (Figs. 8-75 and 8-76).

Posteriorly, these collections at some axial level generally become contiguous with the lateral edge of the quadratus lumborum muscle. Instances of extension of severe pancreatitis toward the structures of the posterior wall without cutaneous signs are not uncommonly observed by CT.12,34,90,91 Sites of anatomic weakness in the flank wall may contribute to more ready passage in some

Anterior Pararenal Space

Fig. 8-63. Pancreatitis with anterior pararenal space fluid collections.

A huge fluid collection (C) is encapsulated on the right, and a smaller one has localized on the left lateral to the transverse duodenum (D).

(Courtesy of Jay P. Heiken, M.D., Mallinckrodt Institute of Radiology, St. Louis, MO.)

Fig. 8-63. Pancreatitis with anterior pararenal space fluid collections.

A huge fluid collection (C) is encapsulated on the right, and a smaller one has localized on the left lateral to the transverse duodenum (D).

(Courtesy of Jay P. Heiken, M.D., Mallinckrodt Institute of Radiology, St. Louis, MO.)

individuals. The lumbar region is an area defined superiorly by the 12th rib, inferiorly by the iliac crest, medially by erector spinae muscle group, and laterally by the posterior border of the external oblique muscle as it extends from the 12th rib to the iliac crest.92 Defects

Fig. 8-64. Pancreatitis extending through the anterior pararenal spaces bilaterally.

Fluid collection (C) extends to both anterior pararenal spaces and between the lamellae of the posterior renal fasciae (open arrows). On the left, the process involves the extraperitoneal fat of the bare area of the descending colon (white arrow). A mesocolic phlegmon is also present. (Courtesy of David H. Stephens, M.D., Mayo Clinic, Rochester, MN.)

Extraperitoneal Fluid

Fig. 8-65. Bilateral spread of fulminating acute pancreatitis.

The extrapancreatic fluid collections (C) in both anterior pararenal spaces dissect between the two layers of the posterior renal fascia bilaterally (arrowheads). No direct communication across the midline is evident. The process extends into the transverse mesocolon (TM) on the right and to the extraperitoneal fat of the bare area of the descending colon.

(Courtesy of Jay P. Heiken, M.D., Mallinckrodt Institute of Radiology, St. Louis, MO.)

Fig. 8-64. Pancreatitis extending through the anterior pararenal spaces bilaterally.

Fluid collection (C) extends to both anterior pararenal spaces and between the lamellae of the posterior renal fasciae (open arrows). On the left, the process involves the extraperitoneal fat of the bare area of the descending colon (white arrow). A mesocolic phlegmon is also present. (Courtesy of David H. Stephens, M.D., Mayo Clinic, Rochester, MN.)

Fig. 8-65. Bilateral spread of fulminating acute pancreatitis.

The extrapancreatic fluid collections (C) in both anterior pararenal spaces dissect between the two layers of the posterior renal fascia bilaterally (arrowheads). No direct communication across the midline is evident. The process extends into the transverse mesocolon (TM) on the right and to the extraperitoneal fat of the bare area of the descending colon.

(Courtesy of Jay P. Heiken, M.D., Mallinckrodt Institute of Radiology, St. Louis, MO.)

Fig. 8-66. Pancreatitis involving both anterior pararenal spaces.

Fluid collections (C) are evident bilaterally. It is difficult to ascertain whether this has occurred simultaneously on each side or is the result of midline communication. The process has reached both the ascending and descending colon and, on the left, has interposed within the posterior renal fascia (arrow).

Renal Fascia RadiologyPancreatic Abscess Drainage
Fig. 8-67. Inferior drainage of infection from pancreatic abscess within anterior pararenal space secondary to penetration of a posterior duodenal ulcer, as depicted in the surgical literature. (Reproduced from Wulsin.89)
Soap Bubble Sign Pancreatitis

Fig. 8-68. Inferior extension of abscess from head of pancreas within right anterior pararenal space (arrows) shown in a coronal CT section. (Courtesy of Michiel Feldberg, M.D., University of Utrecht, The Netherlands.)

Posterior Penetrating Duodenal Ulcer

Fig. 8-69. Pancreatitis secondary to duodenal ulcer, as depicted in the surgical literature.

The anterior pararenal extension reaches the flank fat external to the peritoneum below the level of the cone of renal fascia. (Reproduced from Wulsin.89)

Fig. 8-69. Pancreatitis secondary to duodenal ulcer, as depicted in the surgical literature.

The anterior pararenal extension reaches the flank fat external to the peritoneum below the level of the cone of renal fascia. (Reproduced from Wulsin.89)

in the lumbar musculature or aponeurosis in this region result in two sites known as the larger and more constant superior triangle of Grynfeltt-Lesshaft inferior to the 12th rib93,94 and the smaller inferior lumbar triangle of Petit just cephalad to the iliac crest95 (Fig. 8-77). Figure 8-78 clearly depicts the relationship of the superior lumbar triangle to the extraperitoneal structures and fascial planes of the flank. The floor of Petit's triangle is composed of the underlying internal oblique and transversus abdominis muscles. While these triangles have been recognized as anatomic areas of weakness that may lead to unusual lumbar hernias,96-98 it is also apparent that these structural defects may predispose to the ready transmission of extravasated pancreatic enzymes or blood-stained fluid to the subcutaneous tissues of the flanks. Thus, fluid in the retrorenal plane that lies behind the perirenal fat often tracks along the lumbar triangle pathway through a cleft between the medial border of the posterior pararenal space and the lateral border of the quad-ratus lumborum fat pad lying just anterior to the quad-ratus lumborum muscle (Figs. 8-79 through 8-81). Hemorrhage (Figs. 8-82) and infection (Fig. 8-83) may also course along this pathway.

I have shown12,91 that these pathways provide an anatomic-radiologic explanation for the classic clinical sign of subcutaneous discoloration in the costovertebral text continues on page 377

Fatty Cleft Pancreas

Fig. 8—70. Gas-producing infection of the pancreas.

Mottled lucencies are present diffusely throughout the pancreas and progress down both sides within the anterior pararenal spaces (arrows), overlying the psoas muscle. The flank stripes are maintained. (Reproduced from Meyers.9)

Fig. 8—70. Gas-producing infection of the pancreas.

Mottled lucencies are present diffusely throughout the pancreas and progress down both sides within the anterior pararenal spaces (arrows), overlying the psoas muscle. The flank stripes are maintained. (Reproduced from Meyers.9)

Psoas And Flank StripesInfected Pancreatic PseudocystInfected Pancreatic Pseudocyst

Fig. 8—71. Bilateral infected pancreatic pseudocysts within the anterior pararenal compartments.

(a) On the right, a large mass with a vertical axis displaces bowel toward the midline. The flank stripe is intact (arrow). Another extraperitoneal abscess is present on the left, draping small bowel loops.

(b) Steep oblique projection shows bowel displaced anteriorly and intact perirenal fat on right (arrows).

(c) Contrast injections of the huge pseudocysts verify their bilateral anterior pararenal compartmentalization.

Pancreatic Phlegmon

Fig. 8-72. Bilateral spread of emphysematous pancreatitis within anterior pararenal spaces.

(a) CT displays a gas-producing pancreatic phlegmon extending across the midline throughout both anterior pararenal spaces. AC = ascending colon; DC = descending colon.

(b) More inferiorly, the collection has fused into the anterior and posterior pararenal spaces.

(c) At the level of the iliac crests, CT shows the apex of the renal fascial cones (arrows), where anterior and posterior pararenal spaces communicate, just in front of and slightly lateral to the psoas muscles (PM) and immediately behind the ascending (AC) and descending colon (DC). (Courtesy of Roger Parienty, M.D., Neuilly, France.)

Quadratus Lumborum Muscle Images

Fig. 8—73. Fluid in the anterior pararenal space may extend posteriorly between the two lamellae of the posterior renal fascia.

K = kidney; C = descending colon; PM = psoas muscle; QL = quadratus lumborum muscle; APS = anterior pararenal space; PRF = posterior renal fascia; LCF = lateroconal fascia.

Fig. 8—73. Fluid in the anterior pararenal space may extend posteriorly between the two lamellae of the posterior renal fascia.

K = kidney; C = descending colon; PM = psoas muscle; QL = quadratus lumborum muscle; APS = anterior pararenal space; PRF = posterior renal fascia; LCF = lateroconal fascia.

angle (Grey Turner's sign) that may be associated with acute pancreatitis99,100 (Figs. 8-84 and 8-85). The characteristic radiologic changes are readily distinguished from the subcutaneous soft tissue densities occasionally seen in the flanks and gluteal region by CT in severe pancreatitis secondary to the extravascular movement of fluid.101 Three days to a week after the onset of symptoms, hemorrhagic changes (characteristically slate blue to yellow-brown discoloration) may be apparent in the flank, more frequently on the left.99,100,102,103 The discoloration indicates extravasation of blood in the subcutaneous tissue and further resembles ecchymosis in that the color is typically at first a bluish black, fading through greenish and finally yellowish tints before dis-appearing.102 The fat deep to the subcutaneous fascial plane103a,103b is predominantly involved. Grey Turner's sign has been observed in about 2% of patients with acute pancreatitis.100,104

Grey Turner's sign is frequently accompanied by peri-umbilical discoloration (Cullen's sign).100,104,105 Cullen's sign is secondary to the tracking of liberated pancreatic enzymes to the anterior abdominal wall from the inflamed hepatoduodenal ligament and across the falciform ligament.24,91 The subperitoneal tissue within the falciform ligament and ligamentum teres communicates with the properitoneal fatty tissue106 in the abdominal

Posterior Pararenal Fascia Collection

Fig. 8-74. Extrapancreatic fluid collection (F) in the left anterior pararenal space between the posterior parietal peritoneum (curved arrow) and the anterior renal fascia cleaves into the space between the two lamellae of the posterior renal fascia and extends behind the kidney toward the quadratus lumborum muscle. It can be seen that the inner layer of the posterior renal fascia is continuous with the anterior renal fascia (white arrows) and the outer layer is continuous with the lateroconal fascia (open arrows). The perirenal and posterior pararenal spaces are preserved. C = descending colon.

(Reprinted with permission from Pistolesi GF, Procacci C, Tonegutti, N, et al.: Analyses des différents espaces des régions extra-péritonéales. Radiologie J CEPUR 1990; 10: 195-204.)

Fig. 8-74. Extrapancreatic fluid collection (F) in the left anterior pararenal space between the posterior parietal peritoneum (curved arrow) and the anterior renal fascia cleaves into the space between the two lamellae of the posterior renal fascia and extends behind the kidney toward the quadratus lumborum muscle. It can be seen that the inner layer of the posterior renal fascia is continuous with the anterior renal fascia (white arrows) and the outer layer is continuous with the lateroconal fascia (open arrows). The perirenal and posterior pararenal spaces are preserved. C = descending colon.

(Reprinted with permission from Pistolesi GF, Procacci C, Tonegutti, N, et al.: Analyses des différents espaces des régions extra-péritonéales. Radiologie J CEPUR 1990; 10: 195-204.)

wall, with the left periportal space, with the hepatic hi-lum, and with the hepatoduodenal ligament and gastro-hepatic ligament107 (Figs. 8-86 and 8-87). Therefore, a continuous pathway is established between the pancrea-toduodenal area in the retroperitoneum and the anterior abdominal wall. Early investigations explored this route. Podlaha noted that gas formed from subserous injections of hydrogen peroxide at the pylorus in dogs and human cadavers diffused into the hepatoduodenal ligament, fat of porta hepatis, ligamentum teres, and subsequently to the subcutaneous tissues in the region of the umbili-cus.110 This pathway of gas from the pancreatoduodenal area to the porta hepatis can be documented clinically text continues on page 385

Renal Fascia Radiology

Fig. 8-75. Pancreatitis extending from anterior pararenal space to within the leaves of the posterior renal fascia.

(a-c) Three axial CT levels demonstrate pancreatic fluid collection (F) spreading from the left anterior pararenal space to the potential space between the bilaminated posterior renal fascia. Inferiorly the collection tapers to remain as a small loculated intrafascial collection. Dissection through the posterior renal fascia thus appears most prominent in the portion related to the upper renal pole.

(d) Reconstructed CT image demonstrates in the coronal plane the size, position, and relationships of the fluid collection within the posterior renal fascia. K = left kidney; Sp = spleen.

Fig. 8-75. Pancreatitis extending from anterior pararenal space to within the leaves of the posterior renal fascia.

(a-c) Three axial CT levels demonstrate pancreatic fluid collection (F) spreading from the left anterior pararenal space to the potential space between the bilaminated posterior renal fascia. Inferiorly the collection tapers to remain as a small loculated intrafascial collection. Dissection through the posterior renal fascia thus appears most prominent in the portion related to the upper renal pole.

(d) Reconstructed CT image demonstrates in the coronal plane the size, position, and relationships of the fluid collection within the posterior renal fascia. K = left kidney; Sp = spleen.

Renal Fascia Radiology

Fig. 8—76. Extension of pancreatitis to posterior pararenal space.

(a) Extensive phlegmonous infiltrate in anterior pararenal space (black-and-white arrows) surrounds pancreas whose preserved contours are identifiable after bolus contrast injection (white arrows). A = ascitic fluid; Sp = spleen.

(b) The extrapancreatic inflammatory process with fluid has extended from the anterior pararenal space (1) to the posterior pararenal space (3). At this particular level, the lateroconal fascia remains visible (small arrows). The perirenal space (2) is preserved. On the right, renal fasciae are also thickened (large arrows). Pancreatic abscess extends into small bowel mesentery (MT).

(Reproduced from Feldberg. )

Fig. 8—76. Extension of pancreatitis to posterior pararenal space.

(a) Extensive phlegmonous infiltrate in anterior pararenal space (black-and-white arrows) surrounds pancreas whose preserved contours are identifiable after bolus contrast injection (white arrows). A = ascitic fluid; Sp = spleen.

(b) The extrapancreatic inflammatory process with fluid has extended from the anterior pararenal space (1) to the posterior pararenal space (3). At this particular level, the lateroconal fascia remains visible (small arrows). The perirenal space (2) is preserved. On the right, renal fasciae are also thickened (large arrows). Pancreatic abscess extends into small bowel mesentery (MT).

(Reproduced from Feldberg. )

Superior Lumbar Triangle

Fig. 8—77. Superior lumbar triangle (a) and inferior lumbar triangle (b).

1 = psoas muscle

2 = quadratus lumborum muscle

3 = sacrospinalis muscle

4 = serratus posterior inferior muscle

5 = latissimus dorsi muscle

6 = transverse abdominis muscle

7 = internal oblique muscle

8 = external oblique muscle P = peritoneum

TF = transversalis fascia LDF = lumbodorsal fascia

Fig. 8—77. Superior lumbar triangle (a) and inferior lumbar triangle (b).

1 = psoas muscle

2 = quadratus lumborum muscle

3 = sacrospinalis muscle

4 = serratus posterior inferior muscle

5 = latissimus dorsi muscle

6 = transverse abdominis muscle

7 = internal oblique muscle

8 = external oblique muscle P = peritoneum

TF = transversalis fascia LDF = lumbodorsal fascia

Quadratus Lumborum Muscle Images

Fig. 8-78. The lumbar triangle.

Anatomic section of the left flank through the base of the superior lumbar triangle. Note the anatomic defect of the flank wall lateral to the quadratus lumborum muscle. K = kidney; C = descending colon.

Fig. 8-78. The lumbar triangle.

Anatomic section of the left flank through the base of the superior lumbar triangle. Note the anatomic defect of the flank wall lateral to the quadratus lumborum muscle. K = kidney; C = descending colon.

Quad Lumborum Muscle Kidney

Fig. 8-79. Opacification of lumbar triangle pathway.

Contrast-enhanced CT shows extravasation from the left kidney after stone extraction.

(a) Gross extravasation localizes adjacent to the psoas major (pm) and quadratus lumborum (ql) muscles. Extravasated contrast has also dissected along perirenal bridging septa to the interlaminar plane of the posterior renal fascia (open arrow).

(b) At a lower level, fluid tracks through the lumbar triangle (curved arrow) through a defect between the posterior pararenal space (p) and the quadratus lumborum fat pad. k = kidney.

(Courtesy of Michiel Feldberg, M.D., University of Utrecht, The Netherlands.)

Fig. 8-79. Opacification of lumbar triangle pathway.

Contrast-enhanced CT shows extravasation from the left kidney after stone extraction.

(a) Gross extravasation localizes adjacent to the psoas major (pm) and quadratus lumborum (ql) muscles. Extravasated contrast has also dissected along perirenal bridging septa to the interlaminar plane of the posterior renal fascia (open arrow).

(b) At a lower level, fluid tracks through the lumbar triangle (curved arrow) through a defect between the posterior pararenal space (p) and the quadratus lumborum fat pad. k = kidney.

(Courtesy of Michiel Feldberg, M.D., University of Utrecht, The Netherlands.)

Lumbar Triangle

Fig. 8-80. Extension of pancreatitis to posterior abdominal wall in two different patients.

(a) Fluid collection ( F) progressing through the posterior renal fascia intrudes upon the flank wall lateral to the quadratus lumborum muscle.

(b) In another patient, pancreatitis is manifested at this level by inflammatory tumefaction of the uncinate process (U). Secondary fluid collection (F) has dissected in relationship with the posterior abdominal wall lateral to the quadratus lumborum muscle.

Note that in both instances, the extravasated pancreatic enzymes are approaching the lumbar triangle and subcutaneous fat.

(Courtesy of Richard Gore, M.D., Evanston Hospital, Evanston, IL.)

Fig. 8-80. Extension of pancreatitis to posterior abdominal wall in two different patients.

(a) Fluid collection ( F) progressing through the posterior renal fascia intrudes upon the flank wall lateral to the quadratus lumborum muscle.

(b) In another patient, pancreatitis is manifested at this level by inflammatory tumefaction of the uncinate process (U). Secondary fluid collection (F) has dissected in relationship with the posterior abdominal wall lateral to the quadratus lumborum muscle.

Note that in both instances, the extravasated pancreatic enzymes are approaching the lumbar triangle and subcutaneous fat.

(Courtesy of Richard Gore, M.D., Evanston Hospital, Evanston, IL.)

Anterior Extension Pancreas

Fig. 8-81. Extension of pancreatitis to lumbar triangle pathway.

(a) Contrast-enhanced CT shows that the pancreas is largely liquified with voluminous fluid (F). A small amount of viable pancreas remains in the uncinate process (U).

(b) Pancreatic fluid (F) dissects along the posterior interfascial plane through the lumbar triangle (arrows) between the posterior pararenal fat (p) and the fat anterior to the quadratus lumborum muscle (ql) to contact the transversalis fascia. k = kidney.

(Courtesy of James Brink, M.D., Yale University School of Medicine, New Haven, CT.)

Fig. 8-81. Extension of pancreatitis to lumbar triangle pathway.

(a) Contrast-enhanced CT shows that the pancreas is largely liquified with voluminous fluid (F). A small amount of viable pancreas remains in the uncinate process (U).

(b) Pancreatic fluid (F) dissects along the posterior interfascial plane through the lumbar triangle (arrows) between the posterior pararenal fat (p) and the fat anterior to the quadratus lumborum muscle (ql) to contact the transversalis fascia. k = kidney.

(Courtesy of James Brink, M.D., Yale University School of Medicine, New Haven, CT.)

Interfascial Pathway

Fig. 8-82. Extension of retrorenal blood to lumbar triangle pathway.

After aortic prosthesis for aneurysmal rupture, contrast-enhanced CT demonstrates blood in the anterior pararenal space progressing through the retrorenal interfascial pathway (F) to the lumbar triangle (arrows). This is the site of a defect between the posteromedial boundary of the posterior pararenal space (p) and the anterolateral margin of the fat pad adjacent to the quadratus lumborum muscle (ql). K = kidney; pm = psoas muscle.

(Courtesy of Michiel Feldberg, M.D., University of Utrecht, The Netherlands.)

Erector Spinae Muscle Abscess

Fig. 8—83. Extension of psoas and posterior pararenal abscess to lumbar triangle pathway.

Contrast-enhanced CT demonstrates abscesses with rim enhancement in the psoas muscle and posterior pararenal space directly extending through the lumbar triangle. (Courtesy of Michiel Feldberg, M.D., University of Utrecht, The Netherlands.)

Fig. 8-82. Extension of retrorenal blood to lumbar triangle pathway.

After aortic prosthesis for aneurysmal rupture, contrast-enhanced CT demonstrates blood in the anterior pararenal space progressing through the retrorenal interfascial pathway (F) to the lumbar triangle (arrows). This is the site of a defect between the posteromedial boundary of the posterior pararenal space (p) and the anterolateral margin of the fat pad adjacent to the quadratus lumborum muscle (ql). K = kidney; pm = psoas muscle.

(Courtesy of Michiel Feldberg, M.D., University of Utrecht, The Netherlands.)

Fig. 8—83. Extension of psoas and posterior pararenal abscess to lumbar triangle pathway.

Contrast-enhanced CT demonstrates abscesses with rim enhancement in the psoas muscle and posterior pararenal space directly extending through the lumbar triangle. (Courtesy of Michiel Feldberg, M.D., University of Utrecht, The Netherlands.)

Dorsal Cervical Fat Pad

Fig. 8-84. Extension of pancreatitis to posterior abdominal wall presenting with Grey Turner's sign.

(a) Accompanying thickening of the renal fasciae and of the lateroconal fascia (arrows), there is a loculadon of fluid (F) between the leaves of the posterior renal fascia immediately behind the descending colon (C).

(b) At a lower level, the fluid collection has dissected more posteriorly and comes into relationship with the posterior abdominal wall, presumably effacing the intervening segment of the posterior pararenal space.

(c) More inferiorly, while some fluid distention of the posterior renal fascia remains evident, a loculated fluid collection intrudes upon the flank lateral to the quadratus lumborum muscle at the site of cutaneous discoloration that is clinically evident.

Fig. 8-84. Extension of pancreatitis to posterior abdominal wall presenting with Grey Turner's sign.

(a) Accompanying thickening of the renal fasciae and of the lateroconal fascia (arrows), there is a loculadon of fluid (F) between the leaves of the posterior renal fascia immediately behind the descending colon (C).

(b) At a lower level, the fluid collection has dissected more posteriorly and comes into relationship with the posterior abdominal wall, presumably effacing the intervening segment of the posterior pararenal space.

(c) More inferiorly, while some fluid distention of the posterior renal fascia remains evident, a loculated fluid collection intrudes upon the flank lateral to the quadratus lumborum muscle at the site of cutaneous discoloration that is clinically evident.

Fig. 8-85. The Grey Turner sign secondary to pancreatitis.

Extravasated pancreatic fluid in the left anterior partrenal space (1) dissects between the leaves of the posterior renal fascia with a loculated fluid collection f) near the descending colon (c). The perirenal space (2) is maintained.

Inflammatory changes have reached an adjacent portion of the posterior pararenal space (3) and the subcutaneous tissues in the left flank (arrows) at the clinical site of discoloration.

Fig. 8—86. Ligamentum teres and falciform ligament with vascular relationships.

Illustration depicts the paraumbilical veins running in the falciform ligament with the obliterated umbilical vein. The relationship to the left portal vein is also demonstrated. (Reproduced from Horton and Fishman.108)

Falciform ligament

Paraumbilical v.

Ligamentum Teres

Falciform ligament

Paraumbilical Vein

Left portal v.

Umbilical vein recess

Left portal v.

Umbilical vein recess

Portal vein

Ligamentum Venosum Falciform Ligament

Fig. 8-87. Falciform ligament and ligamentum venosum in a patient with ascites.

(a) Fat-containing falciform ligament (arrows) extends from the anterior abdominal wall to the ligamentum teres (arrowheads). The falciform ligament is uneven in thickness, and the ligamentum teres contains small vessels.

(b) Sagittal MRI in a patient with liver cirrhosis shows entire extent of the ligamentum teres (arrowheads). Falciform ligament may be too thin to be visualized. The greater omentum (arrows) floats underneath the anterior abdominal wall.

(Reproduced from Auh et al.109)

Fig. 8-87. Falciform ligament and ligamentum venosum in a patient with ascites.

(a) Fat-containing falciform ligament (arrows) extends from the anterior abdominal wall to the ligamentum teres (arrowheads). The falciform ligament is uneven in thickness, and the ligamentum teres contains small vessels.

(b) Sagittal MRI in a patient with liver cirrhosis shows entire extent of the ligamentum teres (arrowheads). Falciform ligament may be too thin to be visualized. The greater omentum (arrows) floats underneath the anterior abdominal wall.

(Reproduced from Auh et al.109)

by CT (Fig. 8-88). Similarly, intrahepatic pancreatitis107 (Figs. 8-89 and 8-90) even with pseudocyst formation111 extending to localize in the falciform ligament (Fig. 8-91) and involve the properitoneal fat of the periumbilical region (Fig. 8-92) can be observed. By way of the same anatomic continuity, a cutaneous discoloration of the medial upper abdominal wall after infusion of chemotherapeutics in the hepatic artery can occur because the falciform ligament artery originating from the left or middle hepatic artery may bring the drugs to the properitoneal fat.112,112a Another, more direct pathway may be extension from inflammatory changes of the small bowel mesentery or greater omentum to the round ligament and then to properitoneal fat deep to the umbilicus.

The liberated digestive enzymes of severe pancreatitis may dissect within fascial planes to result in an interesting extension to the posterior pararenal space from the anterior pararenal space without the contamination of the intervening perirenal compartment. This may be a consequence either of violation of the lateroconal fas cia7,18 or the process spreading from the pancreas down the anterior pararenal space and then rising posterior to the cone of renal fascia within the posterior pararenal space,8,12 (Fig. 8-93). The kidney and colon are pushed forward, and the psoas muscle and flank stripe are obliterated.

Despite the digestive effects of pancreatic fluid, the renal fascia almost invariably is not transgressed so that the perirenal fat and kidney retain their integrity. Indeed, in acute pancreatitis, CT documentation of ex-

trapancreatic fluid collections with perirenal spread and

113_120

without renal involvement is rare , (Figs. 8-94 through 8-96).

Ranson has defined a set of laboratory and clinical criteria that are commonly used to judge the severity of an attack of acute pancreatitis and have some prognostic significance in predicting complications, including abscess development and hemorrhage.121,122 Several investigators, most notably Balthazar, have recently reported the use of CT early in the course of pancreatitis as a predictor of outcome. In most reports, the presence and

Periportal Tracking

Fig. 8-88. Intrahepatic extension via the hepatoduodenal ligament.

ERCP with sphincterotomy resulted in duodenal rupture.

(a) Digital scout film shows periductal/periportal gas tracking cephalad within the hepatoduodenal ligament

(arrowheads).

(b) CT demonstrates gas (arrows) deep to the portal vein (PV), anterior to the caudate lobe.

(c) At a higher level, gas is in the upper hilum near the falciform ligament.

Fig. 8-88. Intrahepatic extension via the hepatoduodenal ligament.

ERCP with sphincterotomy resulted in duodenal rupture.

(a) Digital scout film shows periductal/periportal gas tracking cephalad within the hepatoduodenal ligament

(arrowheads).

(b) CT demonstrates gas (arrows) deep to the portal vein (PV), anterior to the caudate lobe.

(c) At a higher level, gas is in the upper hilum near the falciform ligament.

Fig. 8-89. Tracking of pancreatic pseudocysts along hepatoduodenal ligament.

Multiple extrapancreatic locula-tions course along the hepatoduodenal ligament toward the li-gamentum teres fissure, from which the potential pathway may further extend along this edge of the falciform ligament to the umbilical region to present as Cullen's sign. (Courtesy of Yong Ho Auh, M.D., Asan Medical Center, Seoul.)

Hepatoduodenal Hepatic HilumCullen Lobe

Fig. 8-90. Direct extension of pancreatitis into the liver.

Fluid collection secondary to pancreatitis has extended along the hepatoduodenal ligament.

(a) Contrast-enhanced CT shows pancreatic fluid (arrows) around the portal vein (PV). The pancreatic duct (PD) is dilated. CHA = common hepatic artery.

(b) At a higher level, the fluid collection extends upward along the portal vein at the hepatic hilum. (Courtesy of Toshio Fukuda, M.D., Nagasaki University School of Medicine, Japan.)

Free Fluid Falciform Ligament

Fig. 8-91. Pancreatic fluid in falciform ligament.

This patient presented with a palpable epigastric mass after an episode of acute pancreatitis.

(a and b) CT images show a fluid collection (F) between the left hepatic lobe and the abdominal wall, within the falciform ligament (arrow). There is inflammatory thickening of the intrahepatic portion of the ligament

(arrowheads), which communicates with the hepatic hilum and the hepatoduodenal ligament, through the left periportal space. Fine-needle aspiration yielded dark fluid with high amylase content.

(Reproduced from Arenas et al.66)

Fig. 8-91. Pancreatic fluid in falciform ligament.

This patient presented with a palpable epigastric mass after an episode of acute pancreatitis.

(a and b) CT images show a fluid collection (F) between the left hepatic lobe and the abdominal wall, within the falciform ligament (arrow). There is inflammatory thickening of the intrahepatic portion of the ligament

(arrowheads), which communicates with the hepatic hilum and the hepatoduodenal ligament, through the left periportal space. Fine-needle aspiration yielded dark fluid with high amylase content.

(Reproduced from Arenas et al.66)

extent of extrapancreatic abnormalities as detected by CT have correlated with Ranson's criteria and the sub-

sequent development of complications.

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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