Small Bowel

7

Small Bowel


Small Bowel Obstruction


Overview


Most commonly due to adhesions (70%) or incarceration of bowel within a hernia


Other etiologies include small bowel tumor, volvulus, intussusception, and strictures


Obstruction may be partial or complete


Signs and Symptoms


Colicky periumbilical pain that may be relieved with bilious emesis


Abdominal distention, tenderness, and occasional high-pitched bowel sounds


Severe tenderness at the site of incarcerated hernia with possible overlying skin changes


Patients with complete bowel obstruction will have absence of flatus or bowel movement, patients with partial bowel obstruction will present with abdominal distention with decreased passage of flatus


Diagnosis


Abdominal x-rays will show multiple air–fluid levels with distended loops of small bowel


CT scan with IV contrast may be obtained to assess for a transition point


Treatment/Management


NPO for bowel rest, IV fluids, NG decompression; correct any underlying electrolyte abnormalities


Attempt to perform bedside reduction of any incarcerated hernia


Patients with diffuse peritonitis or complete bowel obstruction should warrant surgical exploration


Patients with partial bowel obstruction who do not improve with conservative management will require exploration and adhesiolysis with possible bowel resection


Patients without signs of incarcerated hernia and who have no previous abdominal surgeries should also be surgically explored


RADIOLOGY


Plain film findings (Fig. 7.1)


• Dilated small bowel loops with air fluid levels


CT findings (Fig. 7.1)


• Fluid-filled, dilated small bowel loops


• Closed-loop obstruction manifests as a C-shaped configuration of dilated bowel loops with mesenteric vessels converging toward the point of torsion


• Strangulation is characterized by bowel wall thickening, little or no contrast enhancement of the bowel wall, engorgement of mesenteric vasculature, and mesenteric edema


• Small bowel loops are dilated proximal to the obstruction, and decompressed distal to the obstruction


FIGURE 7.1 A–H



FIGURE 7.1 A



FIGURE 7.1 B



FIGURE 7.1 C



FIGURE 7.1 D



FIGURE 7.1 E



FIGURE 7.1 F



FIGURE 7.1 G



FIGURE 7.1 H


Ileus


Overview


Lack of peristalsis or bowel function without a structural obstruction


Most commonly secondary to abdominal surgery


Other causes are electrolyte abnormalities, intra-abdominal abscess, systemic infection, hypothyroidism, or other medications such as anticholinergics


Signs and Symptoms


Abdominal distension without flatus or bowel movements


Bilious or feculent emesis


Generalized abdominal distension associated with discomfort without diffuse peritonitis


Diagnosis


Same as small bowel obstruction


Treatment/Management


Same as small bowel obstruction


May consider initiation of total parenteral nutrition (TPN) for patients who have prolonged ileus with underlying malnutrition


RADIOLOGY


Plain film findings (Fig. 7.2)


• Distended small bowel loops with air fluid levels


• May be indistinguishable from SBO


• Distal air in the rectum may help differentiate ileus from SBO


FIGURE 7.2 A,B



FIGURE 7.2 A



FIGURE 7.2 B


Small Bowel Enterocutaneous Fistula


Overview


A fistula is defined as an abnormal connection between two epithelized organs


Small bowel enterocutaneous fistula is usually caused by unrecognized iatrogenic injury to the bowel, anastomotic leak, inflammatory bowel disease, or malignancy


Signs and Symptoms


Fever, leukocytosis, ileus, abdominal tenderness followed by drainage of enteric contents via the wound or skin


Factors that prevent fistula closure—(FRIEND)


Foreign body


Radiation


Inflammation/infection


Epithelialization of the tract


Neoplasm


Distal obstruction


Diagnosis


CT scan with enteric contrast will help identify any undrained abscess. It might help identify the origin of the fistula


Fistulogram or sinogram consists of contrast injection into the cutaneous end of the fistula to evaluate the tract and origin of the fistula


Treatment/Management


Usually treatment consists of making patient NPO, parenteral nutrition, possible octreotide to decrease the output from the fistula for easier wound management


Definitive treatment is surgery if spontaneous closure does not occur within 4 to 5 weeks’ time


RADIOLOGY


Plain film findings


• Contrast injection through the fistula can diagnose the tract between the skin and the small bowel lumen


CT findings (Fig. 7.3)


• CT can be performed in addition to a fistulogram to distinguish fluid collections from bowel loops, and also to guide percutaneous drainage of any abscesses


• A fistula between the small bowel and skin can sometimes be directly seen on CT


• Fat stranding and abscess formation may be seen around the fistula tract


FIGURE 7.3 A–C


A. Stomach


B. Descending colon


C. Portal vein


D. Liver


E. Mesenteric vessels


F. Psoas muscle


G. IVC


H. Common iliac artery


I. Small bowel loops


J. Vertebra


K. Kidney



FIGURE 7.3 A

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Dec 27, 2016 | Posted by in ULTRASONOGRAPHY | Comments Off on Small Bowel
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