Australas Radio1 1992;36: 332-333
Organo-axial volvulus of the sigmoid colon DENNIS L. JANZEN, M.D. Department of Radiology University of British Columbia and Vancouver General Hospital 8.55 West 12th Avenue, Vancouver,BC, Canada, VZZ I M 9 STUART W.HEAP,M.B.B.S., F.R.A.C.R. Department of Radiology Auckland Hospital, Private Bag, Grafon Road, Auckland, New Zealand
ABSTRACT A 59 year old man presented with subacute abdominal distension.and diarrhea. Plain radiographs and barium enema demonstrated organo-axial volvulus of the sigmoid colon. The radiologic, surgical, and pathologic findings are presented. The radiologic dif‘ferences between organo-axial volvulus and the common mesentemaxial vdvulus of the &owid d o n are discussed. CASE REFQRT A 59 year old man presented with a 10 day history of abdominal distension, and a 3 day history of watery diarrhea. He denied abdominal pain, vomiting, and melena. Similar episodes had o c c d 14 days prior to admission and 11 months prior to admission. These episodes resolved following colonoscopic insertion of a rectal tube. On examination, the patient was afebrile with no abdominal tenderness. The abdomen was massively distended and tympanitic with high pitched bowel sounds. Laboratory examination revealed the following: Hemoglobin: 141, WBC: 6.5, Na: 140. K: 2.7. The hypokalemia had occurred with the previous episodes, and was due to the watery
FIGURE 1 - Barium enema demonstrates massively distended segment of sigmoid colon extending from mid-pelvis to left upper quadrant of abdomen. Note the absence of a “U-shaped”loop and the absence of a medial summation line.
twisted segment in the midpelvis near the rectosigmoid junction.
Plain radiographs of the abdomen demonstrated marked distension of the colon, with a large air-filled segment measuring 22cm in diameter present in the central abdomen. The proximal colon was mildly distended. N o mucosal thickening, mural emphysema, or pneumoperitoneum was present. A single constrast barium enema was performed (Figure 1). A massively distended segment of sigmoid colon was demonstrated, with twisted segments in the left upper quadrant (Figure 2) and in the pelvis (Figure 3). Partial obstruction was present at both sites. The distended segment had rotated 180 in a counter-clockwise direction (viewed from below), as demonstrated by the mucosal folds at the site of twisting. A diagnosis of organo-axial volvulus of the sigmoid colon was made.
diarrhea.
Address for unrespondence: Dennis L. Janzen, M.D. Department of Radiology University of British Columbia and Vancouver General Hospital 855 West 12th Avenue Vancouver BCCanadaVSZIM9 Telephone: (604)875 4355
332
FIGURE 3 - Barium enema demonstrates the
Submittedfor publication on: 17th December. 1991
FIGURE 2 -Barium enema demonstrates the twisted segment in the left upper quandrant.
Resubmitted for publicationon: 6th April, 1992 Accepted for publication on: 21st May, 1992 Austrulusian Rudiology, Vol. 36. No.4 . November, 1992
ORGANO-AXIAL VOLVULUS OF THE SIGMOID COLON (“bird’s beak”), and if the obstruction is incomplete, the proximal twisted segment can also be opacified. In mesentero-axial volvulus. the two twisted segments will be immediately adjacent to one another (5).
FIGURE 4 - A schematic drawing of the distal colon illusbating the mechanism of mesentenaxial volvulus (left side of drawing) and organo-axial volvulus (right side of drawing). The arrows indicate the direction of torsion.
At surgery, a 60cm segment of sigmoid colon was found to be distended to a maximum diameter of 22cm. The twisted segments were found in the pelvis and in the left upper quadrant. The twisted segments were widely separated from one another, and there was no rotation about the mesenteric axis. The venous structures in the distended segment of colon were markedly engorged, however there was no evidence of infarction. The entire descending colon was found to be on a mesentery. A sigmoid colectomy was performed, and the patient recovered uneventfully. Pathologic examination demonstrated dilatation and congestion of the subserosal and submucosal blood vessels, indicating chromic venous obstruction. No ischemic changes were present. Venous congestion was also present in the mesenteric lymph nodes. DISCUSSION Volvulus of the colon accounts for 4% of intestinal obstructions and 18%
of colonic obstructions in Western countries (1,2). The incidence of colonic volvulus is increased in patients with neuropsychiatric disorders, advanced age, debility, constipation, and high-fibre diets. These factors tend to produce a redundant mobile colon (3). Volvulus
is most common in the sigmoid (47%) and caecal (42%) portions of the colon, due to their freely mobile mesenteric attachments (4). Less common sites of volvulus include the transverse colon ( I 1%) and rarely the splenic or hepatic flexures. The common type of sigmoid volvulus is due to a mesentero-axial rotation of a redundant loop of sigmoid colon (Figure 4). The direction of twisting is usually such that the afferent limb passes anterior to the efferent limb. The rotation is usually 360 degrees (50% of cases) or 180 degrees (35% of cases) (5). Once the mesentero-axial rotation has occurred, localized axial torsion occurs at the site of volvulus, which contributes to the luminal narrowing and vascular compromise. This mechanism is responsible for the well-known radiologic signs of mesentero-axial sigmoid volvulus: a distended ahaustral loop of bowel arises from the left iliac fossa and extends superiorly towards the right upper quadrant, a central soft tissue density summation line is present which represents the apposed medial walls of the “U-shaped loop (6). This has been termed the “coffeebean sign” (3). Plain radiographs are able to establish the diagnosis of sigmoid volvulus in 30%of cases, and are supportive of the diagnosis in 60% of cases (4). Contrast enema will show the distal twisted segment
Australasian Radioloipy. Vol.36. No.4. November. I992
In organo-axial volvulus of the sigmoid colon, a segment of colon rotates around its longitudinal axis (Figure 4). The two twisted segments of colon lie at opposite ends of a distended segment. The distended portion of colon is not a “U-shaped” loop, therefore there is no central summation line, and the distended loop does not have a “coffee-bean”configuration. If the obstruction is incomplete, contrast enema will show that the two twisted segments are not adjacent to one another. This mechanism of sigmoid volvulus has not previously been described. Reported series of sigmoid volvulus totalling 127 patients describe only mesentero-axial volvulus (1, 2. 7). In the case presented, the presence of a mesentery along the descending colon may have contributed to the hypermobility necessary to allow volvulus to occur. A mesentery of the descending colon is found in 36% of normal patients (8). This case demonstrates bowel obstruction and venous engorgement secondary to organo-axial volvulus of the sigmoid colon. It is likely that this condition carries a significant risk of bowel infarction and perforation. Organo-axial sigmoid volvulus has radiologic features which allow it to be differentiated from the more common mesentero-axial sigmoid volvulus.
REFERENCES 1.
2.
3. 4.
5.
6. 7.
8.
Kerry RL, Lee F, Ransom HK. Rantgenologic examination in the diagnosis and treatmmt of sigmoid volvulus. AJR 1971; 113: 343-348. Kerry RL, Ransom HK. Volvulus of the colon: etiology, diagnosis, and treatment. Arch S U ~I%% . 99: 215-221. Skucas J, Spatam RF. Radiology of the acute abdomen. New York, ChurchillLivingstone, 1988: 226-228. Shackleford RT, Zuidema GD. Surgery of the alimentary tract. Philadelphia. WB Saunders, 1982: 95-59. Frimann-Lhhl 1. Roentgen examinations in acute abdominal diseases. Springfield. Charles C. Thomas. 1974: 279-315. Young WS. Engelbrecht HE, Stoker A. Plain fdm analysis in sigmoid volvulus. Clin Radiol. 1978; 29: 553-560. Drapanas T. Stewart JD. Acute sigmoid volvulus: concepts in surgical treatment. Am J Surg 1961: 101: 70-77. Kazam E. Rubenstein WA, Markisz JA, Whalen JP. Zirinsky K. Anatomy in alimentary tract radiology. Margulis AR. Burhenne HI.4th Edition, vol 1. St Louis. CV Mosby Company, 1988: 226.
333
Organo-axial volvulus of the sigmoid colon DENNIS L. JANZEN, M.D. Department of Radiology University of British Columbia and Vancouver General Hospital 8.55 West 12th Avenue, Vancouver,BC, Canada, VZZ I M 9 STUART W.HEAP,M.B.B.S., F.R.A.C.R. Department of Radiology Auckland Hospital, Private Bag, Grafon Road, Auckland, New Zealand
ABSTRACT A 59 year old man presented with subacute abdominal distension.and diarrhea. Plain radiographs and barium enema demonstrated organo-axial volvulus of the sigmoid colon. The radiologic, surgical, and pathologic findings are presented. The radiologic dif‘ferences between organo-axial volvulus and the common mesentemaxial vdvulus of the &owid d o n are discussed. CASE REFQRT A 59 year old man presented with a 10 day history of abdominal distension, and a 3 day history of watery diarrhea. He denied abdominal pain, vomiting, and melena. Similar episodes had o c c d 14 days prior to admission and 11 months prior to admission. These episodes resolved following colonoscopic insertion of a rectal tube. On examination, the patient was afebrile with no abdominal tenderness. The abdomen was massively distended and tympanitic with high pitched bowel sounds. Laboratory examination revealed the following: Hemoglobin: 141, WBC: 6.5, Na: 140. K: 2.7. The hypokalemia had occurred with the previous episodes, and was due to the watery
FIGURE 1 - Barium enema demonstrates massively distended segment of sigmoid colon extending from mid-pelvis to left upper quadrant of abdomen. Note the absence of a “U-shaped”loop and the absence of a medial summation line.
twisted segment in the midpelvis near the rectosigmoid junction.
Plain radiographs of the abdomen demonstrated marked distension of the colon, with a large air-filled segment measuring 22cm in diameter present in the central abdomen. The proximal colon was mildly distended. N o mucosal thickening, mural emphysema, or pneumoperitoneum was present. A single constrast barium enema was performed (Figure 1). A massively distended segment of sigmoid colon was demonstrated, with twisted segments in the left upper quadrant (Figure 2) and in the pelvis (Figure 3). Partial obstruction was present at both sites. The distended segment had rotated 180 in a counter-clockwise direction (viewed from below), as demonstrated by the mucosal folds at the site of twisting. A diagnosis of organo-axial volvulus of the sigmoid colon was made.
diarrhea.
Address for unrespondence: Dennis L. Janzen, M.D. Department of Radiology University of British Columbia and Vancouver General Hospital 855 West 12th Avenue Vancouver BCCanadaVSZIM9 Telephone: (604)875 4355
332
FIGURE 3 - Barium enema demonstrates the
Submittedfor publication on: 17th December. 1991
FIGURE 2 -Barium enema demonstrates the twisted segment in the left upper quandrant.
Resubmitted for publicationon: 6th April, 1992 Accepted for publication on: 21st May, 1992 Austrulusian Rudiology, Vol. 36. No.4 . November, 1992
ORGANO-AXIAL VOLVULUS OF THE SIGMOID COLON (“bird’s beak”), and if the obstruction is incomplete, the proximal twisted segment can also be opacified. In mesentero-axial volvulus. the two twisted segments will be immediately adjacent to one another (5).
FIGURE 4 - A schematic drawing of the distal colon illusbating the mechanism of mesentenaxial volvulus (left side of drawing) and organo-axial volvulus (right side of drawing). The arrows indicate the direction of torsion.
At surgery, a 60cm segment of sigmoid colon was found to be distended to a maximum diameter of 22cm. The twisted segments were found in the pelvis and in the left upper quadrant. The twisted segments were widely separated from one another, and there was no rotation about the mesenteric axis. The venous structures in the distended segment of colon were markedly engorged, however there was no evidence of infarction. The entire descending colon was found to be on a mesentery. A sigmoid colectomy was performed, and the patient recovered uneventfully. Pathologic examination demonstrated dilatation and congestion of the subserosal and submucosal blood vessels, indicating chromic venous obstruction. No ischemic changes were present. Venous congestion was also present in the mesenteric lymph nodes. DISCUSSION Volvulus of the colon accounts for 4% of intestinal obstructions and 18%
of colonic obstructions in Western countries (1,2). The incidence of colonic volvulus is increased in patients with neuropsychiatric disorders, advanced age, debility, constipation, and high-fibre diets. These factors tend to produce a redundant mobile colon (3). Volvulus
is most common in the sigmoid (47%) and caecal (42%) portions of the colon, due to their freely mobile mesenteric attachments (4). Less common sites of volvulus include the transverse colon ( I 1%) and rarely the splenic or hepatic flexures. The common type of sigmoid volvulus is due to a mesentero-axial rotation of a redundant loop of sigmoid colon (Figure 4). The direction of twisting is usually such that the afferent limb passes anterior to the efferent limb. The rotation is usually 360 degrees (50% of cases) or 180 degrees (35% of cases) (5). Once the mesentero-axial rotation has occurred, localized axial torsion occurs at the site of volvulus, which contributes to the luminal narrowing and vascular compromise. This mechanism is responsible for the well-known radiologic signs of mesentero-axial sigmoid volvulus: a distended ahaustral loop of bowel arises from the left iliac fossa and extends superiorly towards the right upper quadrant, a central soft tissue density summation line is present which represents the apposed medial walls of the “U-shaped loop (6). This has been termed the “coffeebean sign” (3). Plain radiographs are able to establish the diagnosis of sigmoid volvulus in 30%of cases, and are supportive of the diagnosis in 60% of cases (4). Contrast enema will show the distal twisted segment
Australasian Radioloipy. Vol.36. No.4. November. I992
In organo-axial volvulus of the sigmoid colon, a segment of colon rotates around its longitudinal axis (Figure 4). The two twisted segments of colon lie at opposite ends of a distended segment. The distended portion of colon is not a “U-shaped” loop, therefore there is no central summation line, and the distended loop does not have a “coffee-bean”configuration. If the obstruction is incomplete, contrast enema will show that the two twisted segments are not adjacent to one another. This mechanism of sigmoid volvulus has not previously been described. Reported series of sigmoid volvulus totalling 127 patients describe only mesentero-axial volvulus (1, 2. 7). In the case presented, the presence of a mesentery along the descending colon may have contributed to the hypermobility necessary to allow volvulus to occur. A mesentery of the descending colon is found in 36% of normal patients (8). This case demonstrates bowel obstruction and venous engorgement secondary to organo-axial volvulus of the sigmoid colon. It is likely that this condition carries a significant risk of bowel infarction and perforation. Organo-axial sigmoid volvulus has radiologic features which allow it to be differentiated from the more common mesentero-axial sigmoid volvulus.
REFERENCES 1.
2.
3. 4.
5.
6. 7.
8.
Kerry RL, Lee F, Ransom HK. Rantgenologic examination in the diagnosis and treatmmt of sigmoid volvulus. AJR 1971; 113: 343-348. Kerry RL, Ransom HK. Volvulus of the colon: etiology, diagnosis, and treatment. Arch S U ~I%% . 99: 215-221. Skucas J, Spatam RF. Radiology of the acute abdomen. New York, ChurchillLivingstone, 1988: 226-228. Shackleford RT, Zuidema GD. Surgery of the alimentary tract. Philadelphia. WB Saunders, 1982: 95-59. Frimann-Lhhl 1. Roentgen examinations in acute abdominal diseases. Springfield. Charles C. Thomas. 1974: 279-315. Young WS. Engelbrecht HE, Stoker A. Plain fdm analysis in sigmoid volvulus. Clin Radiol. 1978; 29: 553-560. Drapanas T. Stewart JD. Acute sigmoid volvulus: concepts in surgical treatment. Am J Surg 1961: 101: 70-77. Kazam E. Rubenstein WA, Markisz JA, Whalen JP. Zirinsky K. Anatomy in alimentary tract radiology. Margulis AR. Burhenne HI.4th Edition, vol 1. St Louis. CV Mosby Company, 1988: 226.
333
