Abnormal Imaging Features

The continuity of the subperitoneal space and its interconnections is vividly demonstrated by CT in Figures 13-9 and 13-10. Subperitoneal gas is seen diffusing

Abnormal Mri Abdomen

Fig. 13—9. Gas originating in the mediastinum diffusing inferiorly via the subperitoneal space through the abdomen and pelvis.

(a) CT scan at lower thorax. Pneumomediastinum is seen anteriorly (arrow 1)

(b) Scan through upper abdomen at esophagogastric junction. E = esophagus; Ao = aorta. Note gas (arrow 2) as it courses through the diaphragmatic hiatus and on both sides of the diaphragmatic crura.

(c) Scan at level of origin of superior mesenteric artery (arrowheads). Gas has dissected along the celiac axis and is demonstrated in the peripancreatic region (arrow 3). Note air coursing into the transverse mesocolon (anterior to arrow).

(d) Scan at level of renal hila. Gas traversing in the subperitoneal space from right to left (double-headed arrow 4). Air is seen at the renal hila in the region of the ureteropelvic junctions (arrowheads). Continued on following page

Fig. 13—9. Gas originating in the mediastinum diffusing inferiorly via the subperitoneal space through the abdomen and pelvis.

(a) CT scan at lower thorax. Pneumomediastinum is seen anteriorly (arrow 1)

(b) Scan through upper abdomen at esophagogastric junction. E = esophagus; Ao = aorta. Note gas (arrow 2) as it courses through the diaphragmatic hiatus and on both sides of the diaphragmatic crura.

(c) Scan at level of origin of superior mesenteric artery (arrowheads). Gas has dissected along the celiac axis and is demonstrated in the peripancreatic region (arrow 3). Note air coursing into the transverse mesocolon (anterior to arrow).

(d) Scan at level of renal hila. Gas traversing in the subperitoneal space from right to left (double-headed arrow 4). Air is seen at the renal hila in the region of the ureteropelvic junctions (arrowheads). Continued on following page

Subperitoneal Space

Fig. 13—9. Gas originating in the mediastinum diffusing inferiorly via the subperitoneal space through the abdomen and pelvis. (Continued)

(e) Scan through lower abdomen below kidneys. Gas has diffused caudally in the left lateral abdomen in the subperitoneal space (arrow 5). DC = descending colon. Intramural air in transverse colon (arrowheads). Note air also coursing anterior to aorta and inferior vena cava.

(f) Scan at level of upper pelvis. Gas courses in left lateral pelvis (arrow 6) and diffuses into the sigmoid mesocokm (arrow 7a). Note intramural air within the sigmoid colon (SC).

(g) Section through upper rectum. Perirectal gas is present (arrow 7b). R = rectum. (Reproduced from Oliphant et al.27)

Fig. 13—9. Gas originating in the mediastinum diffusing inferiorly via the subperitoneal space through the abdomen and pelvis. (Continued)

(e) Scan through lower abdomen below kidneys. Gas has diffused caudally in the left lateral abdomen in the subperitoneal space (arrow 5). DC = descending colon. Intramural air in transverse colon (arrowheads). Note air also coursing anterior to aorta and inferior vena cava.

(f) Scan at level of upper pelvis. Gas courses in left lateral pelvis (arrow 6) and diffuses into the sigmoid mesocokm (arrow 7a). Note intramural air within the sigmoid colon (SC).

(g) Section through upper rectum. Perirectal gas is present (arrow 7b). R = rectum. (Reproduced from Oliphant et al.27)

throughout a major portion of the space. The gas originates from the mediastinum in the first case and from the rectum in the second instance. These cases demonstrate the mediastinum's continuity with the subper-itoneal space. The gas accompanies the celiac artery and its branches into the interconnecting peritoneal folds of the upper abdomen. Gas extends to and partially surrounds the stomach and spleen since the peritoneal folds envelop these organs (Figs. 13-9c and 13-10f). The gas dissects along the renal vasculature to the right and left kidneys and outlines an anterior communication across the midline (Figs. 13-9d and 13-10e). Central diffusion of gas can be traced along the lower abdominal aorta to its bifurcation. There is central-to-lateral continuity in the subperitoneal space at the level of the iliac vessels bilaterally and also along the inferior mesenteric artery on the left side. Gas on the left is seen in continuity with the left lateral pelvis as well as in the subperitoneal space

Subperitoneal Space

Fig. 13—10. Gas originating from a rectal perforation diffusing within the subperitoneal space superiorly to the mediastinum.

(a) CT scan at level of rectum. Perirectal gas (arrow 1) and perivesical air are demonstrated. R = rectum; Bl = bladder.

(b) Scan at level of greater sciatic notch. Gas courses cephalad and anterior (arrow 2) to left lateral pelvis (arrow 3). Air-fluid level caused by the rectal perforation is seen intimately related to the sigmoid colon (SC).

(c) Scan at level of upper pelvis junction with lower abdomen shows gas coursing along left lateral pathway (arrow 4).

(d) Scan of lower abdomen below kidneys demonstrates gas diffuses cephalad in the left lateral subperitoneal space (arrow 5). Continued on following page

Fig. 13—10. Gas originating from a rectal perforation diffusing within the subperitoneal space superiorly to the mediastinum.

(a) CT scan at level of rectum. Perirectal gas (arrow 1) and perivesical air are demonstrated. R = rectum; Bl = bladder.

(b) Scan at level of greater sciatic notch. Gas courses cephalad and anterior (arrow 2) to left lateral pelvis (arrow 3). Air-fluid level caused by the rectal perforation is seen intimately related to the sigmoid colon (SC).

(c) Scan at level of upper pelvis junction with lower abdomen shows gas coursing along left lateral pathway (arrow 4).

(d) Scan of lower abdomen below kidneys demonstrates gas diffuses cephalad in the left lateral subperitoneal space (arrow 5). Continued on following page extending within the sigmoid mesocolon (Fig. 13—9f). Intramural gas in the transverse colon (Fig. 13-9e) and sigmoid colon (Fig. 13-9f) has resulted from the dissection along their mesocolons. A third case of gas diffusion (Fig. 13-11) graphically displays the subperitoneal continuum. Subperitoneal gas originating from a perforated sigmoid diverticulum diffused from the pelvis through the abdomen, predominately along the central pathway. Further cephalad spread of the gas occurred through the thoracoabdominal continuum to the mediastinum.

These three striking cases clearly indicate potential for bidirectional spread of disease processes throughout the abdomen and pelvis and the continuity of the abdomen with the mediastinum.

Abdominal neuroblastoma notoriously presents beyond the confines of its site of origin in 60-70% of patients.17 This is due to its propensity to infiltrate the adjacent areolar tissue and thus gain access to the subperitoneal space. The permeative nature of this malignancy allows it to grow along the vascular scaffold and

Fig. 13—10. Gas originating from a rectal perforation diffusing within the subperitoneal space superiorly to the mediastinum. (Continued)

(e) Scan at level of lower pole of kidneys. Gas is coursing along midline anterior to aorta and inferior vena cava (double-headed arrow 6). Also note gas extending from pericolic area on left toward midline (arrowheads). DC = descending colon.

(f) Scan at level of pancreatic body. Gas has diffused along celiac axis and is seen in the peripancreatic area (arrow 7) and in the splenic hilum and perisplenic area. S = spleen.

(g) Scan at upper abdomen shows gas in right retrocrural region courses through aortic hiatus to mediastinum (arrow 8) and anterior (white arrowhead) and posterior (black arrowheads) to stomach (St).

(Reproduced from Oliphant et al.27)

Fig. 13—10. Gas originating from a rectal perforation diffusing within the subperitoneal space superiorly to the mediastinum. (Continued)

(e) Scan at level of lower pole of kidneys. Gas is coursing along midline anterior to aorta and inferior vena cava (double-headed arrow 6). Also note gas extending from pericolic area on left toward midline (arrowheads). DC = descending colon.

(f) Scan at level of pancreatic body. Gas has diffused along celiac axis and is seen in the peripancreatic area (arrow 7) and in the splenic hilum and perisplenic area. S = spleen.

(g) Scan at upper abdomen shows gas in right retrocrural region courses through aortic hiatus to mediastinum (arrow 8) and anterior (white arrowhead) and posterior (black arrowheads) to stomach (St).

(Reproduced from Oliphant et al.27)

thereby invade the various subperitoneal space pathways for its direct spread. The observation that adrenal neuroblastoma that originates in the perirenal space readily and commonly crosses the midline to invade the contralateral perirenal space (Figs. 13-12 and 13-13) is explained by direct extension along the vascular scaffold. The perirenal spaces are naturally separated by the aorta and inferior vena cava. Whereas this subdivision may prevent fluids (blood, exudate, extravasated urine) from crossing the midline, a permeative tumor such as neu-roblastoma may spread between the perirenal spaces by growing aggressively along the renal vascular struc-tures.17

Neuroblastoma initially spreads medially to the para-caval and paraaortic areas, where it encases these vessels. The tumor can then grow along the renal vessels to dis

Digitale Radiographie Werkstoffpr Fung

Fig. 13—11. Gas originating from a perforated sigmoid diverticulum diffusing through the pelvis and abdomen via the subperitoneal space and into the mediastinum.

(a) CT scan coronal reconstruction. The gas within the pelvis diffuses through the abdomen to the esophageal hiatus. Arrow = gas within the esophageal hiatus; St = stomach.

(b) CT scan midline sagittal reconstruction. Gas within the subperitoneal continuum diffuses along the central pathway. Small amount of gas is traversing the aortic hiatus (arrows). Ao = aorta.

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

Fig. 13—11. Gas originating from a perforated sigmoid diverticulum diffusing through the pelvis and abdomen via the subperitoneal space and into the mediastinum.

(a) CT scan coronal reconstruction. The gas within the pelvis diffuses through the abdomen to the esophageal hiatus. Arrow = gas within the esophageal hiatus; St = stomach.

(b) CT scan midline sagittal reconstruction. Gas within the subperitoneal continuum diffuses along the central pathway. Small amount of gas is traversing the aortic hiatus (arrows). Ao = aorta.

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

place and invade the kidneys (Figs. 13-12a and 13-13b) and obstruct the collecting system. This presentation can mimic primary intrarenal masses.28

Once a permeative tumor has advanced to the aorta and vena cava it can spread cephalad and/or caudad, with direct access then via the celiac axis and its branches to the gastrohepatic ligament, where pressure on the esophagogastric junction may cause dysphagia,17 and to the hepatoduodenal ligament with invasion of the liver across Glisson's capsule (Fig. 13-12b).

Neuroblastoma can also permeate the root of the small bowel mesentery to grow within its fanlike extensions following the superior mesenteric artery and its branches, occupying a major portion of the abdominal cavity (Fig. 13-13b).

In the upper abdomen, the avenues of spread provided by the major peritoneal ligaments and mesenteries and their characteristic clinical features have been clearly established.1,6 Their critical role in the dissemination of inflammatory and neoplastic processes is detailed in Chapters 3, 4, 10, and 11. Extension through the sub-peritoneal stratum within ligaments in the left upper quadrant is further illustrated in Figures 13-14 and 13-15.

The mesenteric root of the small bowel interconnects the left upper abdomen to the right lateral abdomen1,6,20 (Fig. 13-16). Opacification of the mesenteric root throughout its length provides a striking in vivo model of this portion of the subperitoneal continuum (Fig. 1316). In acute pancreatitis, extravasated enzymes may encapsulate to form a pancreatic pseudocyst. This may progress down the mesenteric root and often down its entire length to the right lower quadrant (Fig. 13-17).

As in neuroblastoma, the development of lympho-matous masses within the mesenteric root is often based on the anatomic continuity of the subperitoneal space

Hepatoduodenal Ligament

Fig. 13-12. Neuroblastoma in a neonate with subperitoneal spread along the vascular scaffold from the right adrenal area to the kidneys, the hepatoduodenal ligament, and into the liver.

(a) Right adrenal mass (M) that infiltrates the right perirenal space extends to the right renal hilum, where it displaces and obstructs the right kidney (RK), encases the aorta (Ao), and extends along the left renal vasculature (arrowheads) toward the left kidney (LK). L = liver.

(b) Scan 2 cm cephalad. Direct spread of mass (M) along the celiac axis to the hepatoduodenal ligament and extending into the liver (L).

(Reproduced from Oliphant and Berne.17)

Fig. 13-12. Neuroblastoma in a neonate with subperitoneal spread along the vascular scaffold from the right adrenal area to the kidneys, the hepatoduodenal ligament, and into the liver.

(a) Right adrenal mass (M) that infiltrates the right perirenal space extends to the right renal hilum, where it displaces and obstructs the right kidney (RK), encases the aorta (Ao), and extends along the left renal vasculature (arrowheads) toward the left kidney (LK). L = liver.

(b) Scan 2 cm cephalad. Direct spread of mass (M) along the celiac axis to the hepatoduodenal ligament and extending into the liver (L).

(Reproduced from Oliphant and Berne.17)

Fig. 13-13. Neuroblastoma extending along the vascular scaffold to the left kidney and into the small bowel mesentery.

(a) Scan of the upper abdomen shows distinct left adrenal mass (M). LK = left kidney; (S) = stomach; L = liver.

(b) Scan at the origin of the superior mesenteric artery (arrow). The mass infiltrates the left perirenal space and displaces, invades, and obstructs the left kidney (LK). Tumor also encases and elevates the aorta (Ao). It crosses to encase the inferior vena cava and invade the right perirenal space. The mass spreads along the aorta to the superior mesenteric artery and infiltrates the small intestine mesentery (M). gb = gallbladder; L = liver.

(Reproduced from Oliphant and Berne.17)

Fig. 13-13. Neuroblastoma extending along the vascular scaffold to the left kidney and into the small bowel mesentery.

(a) Scan of the upper abdomen shows distinct left adrenal mass (M). LK = left kidney; (S) = stomach; L = liver.

(b) Scan at the origin of the superior mesenteric artery (arrow). The mass infiltrates the left perirenal space and displaces, invades, and obstructs the left kidney (LK). Tumor also encases and elevates the aorta (Ao). It crosses to encase the inferior vena cava and invade the right perirenal space. The mass spreads along the aorta to the superior mesenteric artery and infiltrates the small intestine mesentery (M). gb = gallbladder; L = liver.

(Reproduced from Oliphant and Berne.17)

Abnormal Abdominal Mri Pictures

Fig. 13—14. Direct spread of pancreatic tumor to interconnecting ligaments of the left upper abdomen.

(a) Pancreatic mass (M) invades the base of the transverse mesocolon (arrowhead) and extends toward the spleen (S). Mass is also seen in the perirenal space (m). P = pancreas; LK = left kidney.

(b) Mass (M) with direct extension to the transverse mesocolon to the splenic flexure (long arrow) and to the splenorenal ligament to the perirenal space (short arrow). S = spleen; LK = left kidney.

(c) Scan subjacent to spleen. Mass (M) extends to the phrenicocolic ligament (arrowhead). Note perirenal mass (m) anterior to the left kidney (LK); arrow points to ureter.

Kidney Dynamic Imaging

Fig. 13-15. Direct spread of pancreatic tumor to obstruct the left ureter at the ureteropelvic junction.

(a) Mass (M) arising in the tail of the pancreas invades the perirenal space via the splenorenal ligament and spreads to the ureteropelvic junction (m) to obstruct the left ureter. Arrow points to opaque catheter at site of obstruction.

(b) Injection of contrast material through catheter that traverses the site of obstruction (arrow).

Fig. 13-15. Direct spread of pancreatic tumor to obstruct the left ureter at the ureteropelvic junction.

(a) Mass (M) arising in the tail of the pancreas invades the perirenal space via the splenorenal ligament and spreads to the ureteropelvic junction (m) to obstruct the left ureter. Arrow points to opaque catheter at site of obstruction.

(b) Injection of contrast material through catheter that traverses the site of obstruction (arrow).

(Figs. 13-18 and 13-19). Indeed, we have observed that many of the characteristic growth patterns ofmesenteric lymphoma are secondary to spread in the small bowel mesentery. Lymphoma may present or originate in the mesenteric root, and extension may be as multiple or conglomerate densities or stellate infiltration of the mesentery.20 Spread through the subserous connective tissue of the subperitoneal space accompanying the superior mesenteric artery and its branches brings the process into relationship with the small bowel and colon. Lymphoma can involve the wall of the small bowel, specifically its mesenteric border.26 When mesenteric lymphoma coexists with paraaortic and/or paracaval adenopathy, a differential imaging feature is the plane of demarcation detectable between the lymphomatous mass infiltrating the mesenteric leaves and the extraper-itoneal adenopathy (Fig. 13-18b).

The caudal termination of disease in the mesenteric root is in the right lower quadrant. Tumor involving the ileal portion of the small bowel mesentery may infiltrate the right lateral abdominal wall.14 It is evident that the mesentery is the conduit through which disease can spread from the upper abdomen to the right lower quadrant and/or encroach upon the coelomic cavity.

In a similar manner, the continuity of the subperi-toneal space provides an avenue of spread that may result in a mesenteric hematoma from blood of renal origin that may track medially along the renal artery to the aorta and subsequently along the superior mesenteric artery and its branches (Fig. 13-20). Fulminating pelvic bleeding may track laterally and then spread cephalad within the subperitoneal space to dissect into the mes-enteric root to produce significant mesenteric hematoma (Fig. 13-21).

Dissection by means of the central pathway is illustrated in Figure 13-22. In this instance, hemorrhage from a lower abdominal aortic aneurysm spreads along the plane of the inferior mesenteric artery into the sigmoid mesocolon to present a hematoma at this site. Pancreatitis, with direct spread laterally and caudally to the pelvis and sigmoid colon (Fig. 13-23), and diverticulitis, with direct spread from the sigmoid mesocolon to the left lateral pelvis and abdomen (Fig. 13-24), illustrate text continues on page 630

Opacification The Abdominal Aorta

Fig. 13—16. Opacification of mesenteric root in vivo secondary to communication from a gastric ulcer.

(a) Upper GI series demonstrates striking continuity across the subperitoneal space from a penetrating posterior ulcer of the greater curvature of the stomach through the length of the root of the small bowel mesentery (arrows) to the bare area of the ascending colon. Note its typically oblique course toward the right lower quadrant relating to duodenum, jejunum, ileum, and cecum. (b and c) Following intraoperative drainage, CT demonstrates the catheter (c) precisely placed within the mesenteric root.

(d) Sinography via the catheter confirms continued communication between the root of the small intestine mesentery and the stomach (Reproduced from Oliphant et al.20)

Fig. 13—16. Opacification of mesenteric root in vivo secondary to communication from a gastric ulcer.

(a) Upper GI series demonstrates striking continuity across the subperitoneal space from a penetrating posterior ulcer of the greater curvature of the stomach through the length of the root of the small bowel mesentery (arrows) to the bare area of the ascending colon. Note its typically oblique course toward the right lower quadrant relating to duodenum, jejunum, ileum, and cecum. (b and c) Following intraoperative drainage, CT demonstrates the catheter (c) precisely placed within the mesenteric root.

(d) Sinography via the catheter confirms continued communication between the root of the small intestine mesentery and the stomach (Reproduced from Oliphant et al.20)

Continuation The Mesentery

Fig. 13—17. Continuity of the subperitoneal space from the upper abdomen to the right lower abdomen: spread of pancreatic pseudocyst within the root of the small intestine mesentery.

(a) A large pancreatic pseudocyst (PS1) occupies the lesser sac. Another pseudocyst (PS2) occupies the root of the small intestine mesentery, originating in the region of the uncinate process of pancreas (UP).

(b) This pseudocyst (PS2) dissects inferiorly within the root of the small intestine mesentery.

(c) Its course can be followed down the length of the mesenteric root into the right lower quadrant, where it lies in relation to a distal ileal loop.

(Reproduced from Oliphant and Berne.3)

Fig. 13—17. Continuity of the subperitoneal space from the upper abdomen to the right lower abdomen: spread of pancreatic pseudocyst within the root of the small intestine mesentery.

(a) A large pancreatic pseudocyst (PS1) occupies the lesser sac. Another pseudocyst (PS2) occupies the root of the small intestine mesentery, originating in the region of the uncinate process of pancreas (UP).

(b) This pseudocyst (PS2) dissects inferiorly within the root of the small intestine mesentery.

(c) Its course can be followed down the length of the mesenteric root into the right lower quadrant, where it lies in relation to a distal ileal loop.

(Reproduced from Oliphant and Berne.3)

Subperitoneal Space

Fig. 13—18. Continuity of lymphoma with paraaortic and paracaval adenopathy and small intestine mesenteric tumor via the subperitoneal space.

(a) MRI' T1-weighted axial image' demonstrates mass surrounding the aorta and extending along the superior mesenteric artery (arrow) into the mesentery.

(b) Axial T1-weighted image at level of the kidneys shows conglomerate mesenteric lymphoma (M) and nodal masses (N) encasing the aorta and inferior vena cava. Note cleft between M and N.

(c) T1-weighted sagittal image shows aorta with superior mesenteric artery (arrow). The aorta is encased in tumor (N) that extends along the superior mesenteric artery and into the small bowel mesentery (M).

(Reproduced from Oliphant et al.20)

Fig. 13—18. Continuity of lymphoma with paraaortic and paracaval adenopathy and small intestine mesenteric tumor via the subperitoneal space.

(a) MRI' T1-weighted axial image' demonstrates mass surrounding the aorta and extending along the superior mesenteric artery (arrow) into the mesentery.

(b) Axial T1-weighted image at level of the kidneys shows conglomerate mesenteric lymphoma (M) and nodal masses (N) encasing the aorta and inferior vena cava. Note cleft between M and N.

(c) T1-weighted sagittal image shows aorta with superior mesenteric artery (arrow). The aorta is encased in tumor (N) that extends along the superior mesenteric artery and into the small bowel mesentery (M).

(Reproduced from Oliphant et al.20)

Fig. 13—19. Widespread subperitoneal continuity of Burkitt's lymphoma.

CT scan at level of the renal hila shows large mass encasing and displacing the aorta (AO) anteriorly and spreading bidirectionally along the faintly visualized renal arteries (double-headed arrow). The tumor invades and obstructs the right kidney at the ureteropelvic junction (large arrowhead) and invades the left kidney at the hilum (arrowheads). M = mass in small intestine mesentery. (Reproduced from Oliphant et al.20)

Mesenteric Bleeding From Trauma

Fig. 13-20. Spread to small bowel mesentery of hemorrhage from trauma to left kidney.

(a) CT at level of left renal artery. This 26-year-old male was in a motor vehicle accident and suffered a fractured left kidney (LK). The left renal artery was severed (curved arrow) and was subsequently documented by angiography. Hyperdensities represent extravasated contrast medium (arrowheads). Blood is present in the small bowel mesentery (B). Free peritoneal blood (P) from fractured spleen.

(b) CT caudad to renal artery. Blood in mesenteric root extends through the small bowel mesentery (arrow). LK = fractured left kidney.

(Reproduced from Oliphant et al.20)

Fig. 13-20. Spread to small bowel mesentery of hemorrhage from trauma to left kidney.

(a) CT at level of left renal artery. This 26-year-old male was in a motor vehicle accident and suffered a fractured left kidney (LK). The left renal artery was severed (curved arrow) and was subsequently documented by angiography. Hyperdensities represent extravasated contrast medium (arrowheads). Blood is present in the small bowel mesentery (B). Free peritoneal blood (P) from fractured spleen.

(b) CT caudad to renal artery. Blood in mesenteric root extends through the small bowel mesentery (arrow). LK = fractured left kidney.

(Reproduced from Oliphant et al.20)

Left Lateral Abdominal Hematoma

Fig. 13-21. Direct spread of hemorrhage from the pelvis cephalad to the right lateral abdomen and into the small intestine mesentery via the subperitoneal space.

This 31-year-old female, receiving anticoagulants for disorders of multiple heart valves, underwent a total hysterectomy and bilateral salpingo-oophorectomy for a bleeding ovarian cyst. Postoperatively, she developed (a) massive pelvic bleeding (1) that extended to the right lateral pelvic wall and (b) to the right posterior abdominal wall (2) and dissected through the abdominal subperitoneal space on the right to the ileal portion of the small intestine mesentery (3). (Reproduced from Oliphant et al.20)

Fig. 13-21. Direct spread of hemorrhage from the pelvis cephalad to the right lateral abdomen and into the small intestine mesentery via the subperitoneal space.

This 31-year-old female, receiving anticoagulants for disorders of multiple heart valves, underwent a total hysterectomy and bilateral salpingo-oophorectomy for a bleeding ovarian cyst. Postoperatively, she developed (a) massive pelvic bleeding (1) that extended to the right lateral pelvic wall and (b) to the right posterior abdominal wall (2) and dissected through the abdominal subperitoneal space on the right to the ileal portion of the small intestine mesentery (3). (Reproduced from Oliphant et al.20)

Fig. 13—22. Continuity of subperitoneal space from the lower central abdomen to the left pelvis: direct spread of hemorrhage from a ruptured aortic aneurysm along the inferior mesenteric artery distribution to the sigmoid mesocolon.

(a) CT at level of bifurcation of abdominal aorta shows blood (1) dissecting within the subperitoneal space in the region of the inferior mesenteric artery. A = aneurysm.

(b) In the upper pelvis, hematoma is present within the lateral wall of the pelvis (arrow 2) and the sigmoid mesocolon (arrow 3).

(c) Inferiorly, blood is clearly identifiable within the sigmoid mesocolon (arrow 5), displacing the sigmoid colon (SC) to the right. Blood in the lateral wall of the left pelvis remains evident (arrow 4). (Reproduced from Oliphant et al.21)

Sigmoid MesocolonMesocolon HematomasSubperitoneal Space

Fig. 13—23. Continuity of the subperitoneal space along the left lateral abdomen into the pelvis: direct spread of inflammation from pancreatitis to the pelvis and sigmoid mesocolon.

(a) Inflammation in the anterior pararenal spaces extends laterally to the left (1) and to the right (1). There is extension to the left posterior abdominal wall (2). P = pancreas.

(b) Below the level of the kidneys, the process extends down the left (arrow 3) and the right (2) posterior abdomen.

(c) Inferiorly, the inflammation on the left extends to the lateral pelvis (4) and the sigmoid mesocolon (5), and on the right to the lateral pelvis (3'). The process also extends into the posterior pelvic sub-peritoneal space

(Reproduced from Oliphant et al.27)

Subperitoneal

Fig. 13-24. Continuity of the subperitoneal space from the left pelvis to the abdomen: direct spread of pelvic inflammation from a sigmoid diverticular abscess to the left lateral abdomen.

(a) An abscess with an air-fluid level has developed in the sigmoid mesocolon (1). The inflammation spreads to other segments of the mesocolon (2) and the left lateral wall (3) at the junction of the abdomen and pelvis.

(b) In the lower abdomen, the abscess has localized in the subperitoneal space laterally (4). (Reproduced from Oliphant et al.27)

Fig. 13-24. Continuity of the subperitoneal space from the left pelvis to the abdomen: direct spread of pelvic inflammation from a sigmoid diverticular abscess to the left lateral abdomen.

(a) An abscess with an air-fluid level has developed in the sigmoid mesocolon (1). The inflammation spreads to other segments of the mesocolon (2) and the left lateral wall (3) at the junction of the abdomen and pelvis.

(b) In the lower abdomen, the abscess has localized in the subperitoneal space laterally (4). (Reproduced from Oliphant et al.27)

bidirectional spread of inflammatory disease along these pathways.

The lateral continuity of the subperitoneal space is unique in that no major blood vessels course in this portion; yet, this anatomic continuity is the basis for understanding the direct spread of disease between the abdomen and female pelvis.14 Figures 13-25 and 13-26 document bidirectional spread of tumor between the abdomen and the female pelvis. These cases illustrate massive disease extending along the right lateral pelvic wall and the broad ligament simultaneously. Distinction between these two areas of involvement can be appreciated by noting a "cleft" of normal tissue lying between the areas of tumefaction (Fig. 13-25c-e). This is analogous to the plane of demarcation between the ade-nopathy and small bowel mesenteric tumefaction described previously (Fig. 13-18). In a similar manner, inflammatory processes can spread through this same pathway of the subperitoneal space, at times over a considerable distance (Fig. 13-27).

Fig. 13-25. Continuity of subperitoneal spread from the right adnexa to the mesentery of the small bowel.

A 72-year-old female with ovarian carcinoma demonstrates direct spread to the broad ligament, right lateral pelvic wall, right posterior abdomen, cecum, and mesentery of the terminal ileum.

(a) Gross pathology specimen. Large mass is present in the broad ligament (Mu). The cecum (C) is bulged forward by tumor lying posteriorly. Tumor extends along the serosa (arrow) of the tenninal ileum (T).

(b) Anterolateral portion of the cecum and terminal ileum (T) have been removed, exposing mass (M,). This mass is in direct continuity with the broad ligament (Mu). Continued on opposite page

Fig. 13-25. Continuity of subperitoneal spread from the right adnexa to the mesentery of the small bowel.

A 72-year-old female with ovarian carcinoma demonstrates direct spread to the broad ligament, right lateral pelvic wall, right posterior abdomen, cecum, and mesentery of the terminal ileum.

(a) Gross pathology specimen. Large mass is present in the broad ligament (Mu). The cecum (C) is bulged forward by tumor lying posteriorly. Tumor extends along the serosa (arrow) of the tenninal ileum (T).

(b) Anterolateral portion of the cecum and terminal ileum (T) have been removed, exposing mass (M,). This mass is in direct continuity with the broad ligament (Mu). Continued on opposite page

Fig. 13-25. Continuity of subperitoneal spread from the right adnexa to the mesentery of the small bowel.

(Continued)

(c) CT at level of greater sciatic notch shows mass in broad ligament (Mt,) and mass in lateral pelvic wall (MJ. Arrow points to cleft between the two sites.

(d) Inferiorly, tumor is seen in the broad ligament and the lateral pelvic wall The tumor extends to the posterior abdominal wall and then to the root of the small intestine mesentery, shown subjacent to the terminal ileum (T). Arrows indicate the cleft between tumor in the broad ligament and the lateral pelvic wall.

(e) Scan at junction of right lower abdomen and pelvis reveals confluence of tumor in the broad ligament (Mhl) and the lateral pelvic wall Arrow lies within this confluence and also points to cleft, which represents the iliac vessels within the adipose tissue of the lateral pelvic wall, displaced medially.

(Reproduced from Oliphant et al.14)

Fig. 13-25. Continuity of subperitoneal spread from the right adnexa to the mesentery of the small bowel.

(Continued)

(c) CT at level of greater sciatic notch shows mass in broad ligament (Mt,) and mass in lateral pelvic wall (MJ. Arrow points to cleft between the two sites.

(d) Inferiorly, tumor is seen in the broad ligament and the lateral pelvic wall The tumor extends to the posterior abdominal wall and then to the root of the small intestine mesentery, shown subjacent to the terminal ileum (T). Arrows indicate the cleft between tumor in the broad ligament and the lateral pelvic wall.

(e) Scan at junction of right lower abdomen and pelvis reveals confluence of tumor in the broad ligament (Mhl) and the lateral pelvic wall Arrow lies within this confluence and also points to cleft, which represents the iliac vessels within the adipose tissue of the lateral pelvic wall, displaced medially.

(Reproduced from Oliphant et al.14)

Subjacent EndometriumSubjacent Endometrium Subjacent EndometriumSubjacent Endometrium

Fig. 13—26. Cecal carcinoma with direct spread via the subperitoneal space to the right lateral wall of the uterus.

(a) Scan at junction of lower abdomen and pelvis. Cecal mass (M) extends to the posterior abdominal wall.

(b) The tumor spreads along the right lateral pelvic wall (arrow M,j.

(c) At a lower level, there is direct extension of tumor from the lateral wall into the broad ligament (arrow Mm).

(d) Scan at greater sciatic notch. Mass in the broad ligament is contiguous with the right lateral wall of uterus (arrowheads). (Reproduced from Oliphant et al.14)

Fig. 13—26. Cecal carcinoma with direct spread via the subperitoneal space to the right lateral wall of the uterus.

(a) Scan at junction of lower abdomen and pelvis. Cecal mass (M) extends to the posterior abdominal wall.

(b) The tumor spreads along the right lateral pelvic wall (arrow M,j.

(c) At a lower level, there is direct extension of tumor from the lateral wall into the broad ligament (arrow Mm).

(d) Scan at greater sciatic notch. Mass in the broad ligament is contiguous with the right lateral wall of uterus (arrowheads). (Reproduced from Oliphant et al.14)

Fig. 13—27. Subperitoneal spread of inflammation from pancreatitis to the broad ligament and into the lateral flank.

(a) CT at level ofpancreas (P). Inflammation courses from the anterior pararenal space to the right posterior abdomen (arrow 1).

(b) The inflammation extends down the right posterior abdomen (2) and through Petit's triangle to the right flank (arrow).

(c) In the upper pelvis, the inflammatory process extends to the right lateral pelvis (3) and into the broad ligament (4). Note "cleft" (arrow) between 3 and 4.

(d) Inferiorly, inflammation within the broad ligament (5) extends to the uterus (Ut).

Subperitoneal Space
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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