Cecal Volvulus: Case Presentation and Review of CT Findings

Transcription

1 August 2011 Cecal Volvulus: Case Presentation and Review of CT Findings Omar Pardesi, Harvard Medical School Year III

2 Our Patient LD: History & Physical HPI: 28 y.o. female presents with diffuse abdominal pain; began suddenly this AM, worst in LLQ. Began menses yesterday Had normal BM without relief Denies fever, chills, vaginal discharge, hematuria, dysuria, diarrhea, melena, or hematochezia. 2

3 Patient LD: History & Physical (cont.) PMH: Ruptured ovarian cyst Meds: Oral contraceptives Social: Not currently sexually active Pertinent exam findings: abdomen soft and mildly distended, moderately tender in all quadrants without rebound or guarding; normal bowel sounds. 3

4 Initial Differential: Broad Categories Gynecologic (ovarian torsion, ectopic pregnancy, menstrual, etc.) Infection (gastroenteritis, pyelonephritis, etc.) Primary abdominal pathology (diverticulitis, ischemic bowel, intussusception, etc.) 4

5 Patient LD: Initial Labs CBC: WBC 5.2, Hct 39.9, Plt 223 HCG negative AST 26, ALT 16, Alk Phos 78, Tbili 0.2, Lipase 32 UA negative 5

6 Patient LD: Initial Imaging LD had an abdominal + pelvic ultrasound Showed normal ovaries, but large amount of free fluid in the right pelvis Next imaging test to work up abdominal pain and free fluid: CT of the abdomen. We will briefly view images from this CT now, but will revisit the findings in more detail later in this presentation. 6

7 Patient LD: Abdominal CT Scan 1 Dilated cecum, located in LUQ Blue Box: Transition point C CT abdomen, axial view PACS, BIDMC 7

8 LD: Abdominal CT Scan 2 Whirl Sign C CT abdomen, sagittal view PACS, BIDMC 8

9 These findings on CT are diagnostic of cecal volvulus; we will now proceed to briefly review the anatomy of cecal volvulus. We will then revisit these images in order to review important CT findings of cecal volvulus. 9

10 Cecal Volvulus: Definition and Illustration Defined as torsion of the bowel around its own mesentery This image shows cecum twisting and inverting upward, tangling with ileum. Moore CJ et al. CT of Cecal Volvulus: Unraveling the Image. AJR. 2001; 177:

11 Sites of Volvulus in the Bowel Cecum accounts for 11 40% of intestinal volvulus Cecal volvulus usually only occurs in patients with a developmental failure of fixation of proximal right colon to peritoneum More common in younger patients Sigmoid colon is most common site of volvulus Caplan, Geralyn M. Digestive System Study Guide. Owensboro Community & Technical College: Anatomy & Physiology II. 11

12 Prior to reviewing CT findings of cecal volvulus, we will view an abdominal plain film from a companion patient and discuss the diagnostic utility of the plain film for cecal volvulus. 12

13 Companion Pt 1: Abdominal Plain Film Major findings: Focal loop of air distended bowel Prominent small bowel ( cm) Supine Abdominal Plain Film PACS, BIDMC 13

14 Plain Films: Diagnostic Utility In one large series, plain film suggested diagnosis of cecal volvulus <50% of the time. 1/3 of cases were thought to be small bowel obstruction. Why might this be? Let us briefly consider a differential diagnosis based on these plain film findings. 14

15 Partial Differential Diagnosis Suggested by Plain Film Findings Massively dilated loop of (large) bowel: Distal obstruction Functional obstruction Paralytic ileus (nonobstructive distention) Scleroderma, dermatomyositis Toxic megacolon Congenital / pediatric For distended small bowel, add: Drug effect Mesenteric ischemia Postvagotomy Celiac sprue Other malabsorptive syndromes In part because of this broad differential, plain films are of limited utility in diagnosing volvulus, and CT is preferable. 15

16 Important CT Findings of Volvulus Severe cecal distention (> 10 cm) Whirl sign, transition point(s) Dilation and fecalization of small bowel Decompression of colon Split wall sign 16

17 Pt LD: Whirl Sign on CT Whirl Sign / Hurricane Sign An important defining sign of volvulus Twisted loops of bowel and branching mesenteric vessels create swirling strands of soft tissue attenuation within a background of mesenteric fat attenuation. Khurana B, Radiology (2003); 226: C CT abdomen, sagittal view PACS, BIDMC 17

18 PACS, BIDMC Pt LD: Transition Points PACS, BIDMC Sequential axial C CT images showing transition points in small and large bowel. Left (arrow): proximal dilated cecum transitioning to narrowed, collapsed distal colon. Right: proximal small bowel (arrow) entering into twist (box) with large bowel. 18

19 Companion Pt 1: Whirl Sign (Axial View) Dilated cecum, seen here closer to midline Blue Box: Whirl Sign Our companion patient provides another example of the whirl sign. C CT abdomen, axial view PACS, BIDMC 19

20 Companion Pt 1: Whirl Sign (Coronal View) This coronal view of our companion patient clearly demonstrates the whirl sign, with distended large bowel entering into the twist. C CT abdomen, coronal view PACS, BIDMC 20

21 Important CT Findings of Volvulus: Progress Severe cecal distention (> 10 cm) Whirl sign, transition point(s) Dilation and fecalization of small bowel Decompression of colon Split wall sign 21

22 Companion Pt 1: Fecalized Small Bowel Fecalized Small Bowel, suggesting distal obstruction C CT abdomen, coronal view PACS, BIDMC 22

23 Companion Pt 2: Decompressed Colon Here, we see decompressed right colon distal to the point of volvulus. Oral contrast has not reached this loop, and it appears collapsed. Rosenblat JM, AM Rozenblit, EL Wolf, et al. Findings of Cecal Volvulus at CT. Radiology. 2010; 256:

24 Companion Pt 3: Split Wall Sign Split Wall Sign: Apparent splitting of colon wall by mesenteric fat. Caused by adjacent mesenteric fat invagination in a twisted loop of bowel. Rosenblat JM, AM Rozenblit, EL Wolf, et al. Findings of Cecal Volvulus at CT. Radiology. 2010; 256:

25 Important CT Findings of Volvulus: Complete Severe cecal distention (> 10 cm) Whirl sign, transition point(s) Dilation and fecalization of small bowel Decompression of colon Split wall sign 25

26 Our Patient LD: Clinical Outcome LD had an emergent exploratory laparotomy, with no signs of bowel ischemia Ileocolectomy was performed without complication LD recovered well and was discharged on postoperative day 4. Companion patient s surgical specimen Habre J, N Sautot Vial, C Marcotte et al. Caecal Volvulus. Am J Surg. 2008; 196:e48 e49. 26

27 References Caplan, Geralyn M. Digestive System Study Guide. Owensboro Community & Technical College: Anatomy & Physiology II. uide%20k%20digestive%20anatomy.htm. Accessed 8/20/11. Habre J, N Sautot Vial, C Marcotte et al. Caecal Volvulus. Am J Surg. 2008; 196:e48 e49. Katz DS, B Yam, JJ Hines et al. Uncommon and Unusual Gastrointestinal Causes of the Acute Abdomen: Computed Tomographic Diagnosis. Seminars in Ultrasound CT and MRI. 2008; 29: Khurana B. The Whirl Sign. Radiology. 2003; 226: Moore CJ, F Corl, E Fishman. CT of Cecal Volvulus: Unraveling the Image. AJR. 2001; 177: Peterson C, J Anderson, AK Hara et al. Volvulus of the Gastrointestinal Tract: Appearance at Multi modality Imaging. RadioGraphics. 2009; 29: Reeder, Maurice M. Reeder and Felson s Gamuts in Radiology: Comprehensive Lists of Imaging Differential Diagnoses. Fourth edition. New York: Springer; Accessed 8/20/11. Rosenblat JM, AM Rozenblit, EL Wolf, et al. Findings of Cecal Volvulus at CT. Radiology. 2010; 256:

28 Acknowledgements Samir Shah, MD Emily Hanson 28