Sabina Siddiqui
James D. Geiger
Presentation
A 9-month-old previously healthy male infant is brought to the emergency department with a 12-hour history of severe intermittent abdominal pain during which he would draw his knees up into his abdomen and become inconsolable. His mother tried various home remedies for colic, as he was playful and normal between episodes. She became concerned when he became more lethargic, had an episode of vomiting, and passed stool resembling currant jelly. On your evaluation of the child, he appears lethargic but is not in any acute distress. Initially, his abdomen is soft and mildly distended and not obviously tender. However, during the examination, his abdomen becomes distended and tender with a palpable, sausage-like mass in the right upper quadrant.
Differential Diagnosis
The differential diagnosis for this patient includes intussusception, incarcerated hernia, ruptured appendicitis, gastroenteritis, Meckel’s diverticulitis, volvulus, and blunt abdominal trauma associated with abuse.
Workup
Presentation Continued
You order a CBC that shows a white blood cell count of 14.0 and a hematocrit of 45%. A chemistry panel shows a sodium of 150, potassium of 3.2, chloride of 120, bicarbonate of 20, a BUN of 18, and creatinine of 0.7. A plain abdominal film documents mild dilated loops of small bowel with a few air fluid levels with a paucity of gas in the right lower quadrant. You decide to order an abdominal ultrasound that shows concentric alternating echogenic and hypoechogenic bands (target sign) in the bowel in the right upper quadrant.
Routine laboratory tests are nonspecific in these patients, but the CBC and electrolytes can show evidence of dehydration or infection.
Plain abdominal radiograph may be normal, or show distal obstructive pattern with paucity of gas in the right lower quadrant related to a soft tissue mass in the right lower quadrant (Dance’s sign), or, rarely, free air associated with perforation. Abdominal ultrasound will show coencentric echogenic and hypoechogenic bands (target or doughnut sign) on transverse view or a “ pseudokidney” sign on oblique view of the intussuscepted bowel (Figure 1).
FIGURE 1 • Abdominal ultrasound illustrates a “target sign” with hypoechoic rim (edematous bowel wall) surrounding hyperechoic central area (intussusceptum and mesenteric fat).
The diagnosis is confirmed with an abdominal ultrasound or an air-contrast enema. If the patient develops or presents with a surgical abdomen or is unstable, the contrast enema is contraindicated and the patient should be resuscitated and taken straight to the operating room.
Diagnosis and Treatment
Intussusception is the telescoping of one portion of the bowel (known as the intussusceptum) into an immediately adjacent segment (known as the intussuscipiens) (Figure 2). Edema and venous congestion lead to mucosal ischemia, which causes the “currant jelly” stools. While some cases may spontaneously reduce, without successful reduction, the ischemia may progress to full-thickness necrosis and rarely perforation.
FIGURE 2 • Intraoperative photograph shows intussuscepted ileum into the ascending colon. (Photo courtesy of Dr. Marcus Jarboe, with many thanks.)
Presentation Continued
While awaiting surgical consultation and an aircontrast enema, you order IV placement, a fluid bolus at 20 mL/kg, and a second-generation cephalosporin antibiotic.
The treatment algorithm for intussusception is dependent on the patient’s clinical status. If the patient shows signs of advanced bowel obstruction, antibiotics and nasogastric tube decompression may be indicated. In the absence of hemodynamic instability, frank peritonitis or radiographic evidence of perforation with free air, air-contrast enemas are both diagnostic and therapeutic. Enemas should be performed in consultation with a surgeon and a radiologist. A rectal tube is inserted and an adequate seal must be maintained to ensure success. Air is introduced with a manometer and pressure insufflation is carefully monitored not to exceed 120 mm Hg. Contrast enemas are sometimes utilized with barium or water-soluble contrast instilled up to a column of 100 cm above the patient. Enemas can be repeated up to three times before considered a failed maneuver (Figure 3).
FIGURE 3 • Air-contrast enema demonstrates a long ileocolic intussusception with intussusceptum encountered in sigmoid colon (left) and reduced now to the splenic flexure (right).
Presentation Continued
You achieve successful reduction on the first attempt and admit the child for observation and further resuscitation.
Successful reduction is determined both radiographically and clinically. On imaging, there is easy reflux of air into the small bowel and symptom improvement. Clinically, the child’s abdominal pain resolves. Enemas are successful in up to 90% of cases. Upon successful reduction, the patient is admitted to the hospital for observation as 5% to 10% of cases will recur.
Presentation Continued
You are recalled to the patient’s bedside 4 hours later for recurrent symptoms with intermittent pain. You attempt radiographic reduction, however without success this time. You reassure the mother and plan to take the child to the operating room.
Surgical Approach
Surgery is the initial therapy for the unstable patient or the patient who presents with frank peritonitis. Surgery is also indicated for patients who are unable to achieve reduction with enema therapy, have an identified lead point, or have had multiple recurrences.
Two surgical approaches are common: open and laparoscopic. In an open procedure, a transverse incision is made in the right upper quadrant and the intussuscepted mass is delivered into the wound. Reduction is performed with gentle finger pressure on the apex of the intussuscepted intestine in the descending or the transverse colon to “milk” out the intussusceptum. Care is taken not to pull the bowel out as the inflamed and edematous bowel is friable and may be damaged. Appendectomy is sometimes performed, but there is no clear data supporting this additional procedure. If the bowel shows evidence of frank necrosis or cannot be manually reduced, resection is performed with primary anastomosis. The bowel is run to ensure there is not a mechanical lead point.
In the laparoscopic approach, three ports are placed: one at the umbilicus, one in the right upper quadrant at the midclavicular line and one in the left lower quadrant at the midclavicular line. The bowel is inspected, reduction is performed by placing a grasper into the folded over intussusceptiens and ‘unfolding’ the tissue of the cecum while applying gentle counter-traction on the intussuscepted ileum. The bowel is run to identify a possible mechanical lead point or a perforation and necrosis. Appendectomy and resection are performed as indicated above (Table 1).
TABLE 1. Key Technical Steps and Potential Pitfalls in the Surgical Reduction of Intussusception
Special Intraoperative Considerations: (1) Necrotic bowel. After successful reduction, it is common for the bowel to appear nonviable at first. Warm saline and time may allow the appearance of the bowel to improve. It is important to be aware that lymphoid hypertrophy and mucosal edema may cause “thumbprinting” of the bowel, also making it appear nonviable. These lesions do not require resection. If the bowel continues to appear nonviable, a standard small bowel resection is performed including the cecum in some cases. (2) Irreducible lesion. Rarely, the intussusception is irreducible in the operating room. Rather than use excessive force and create a perforation with subsequent peritoneal contamination, an ileocolic resection can be performed. (3) The unidentified lead point—Most cases of intussusception are idiopathic, with no identifiable lesion in up to 85% of cases. Mechanical lead points can include Meckel diverticulum, intestinal polyp, enteric duplication cysts, intestinal tumor, or hemangioma. If a lead point is identified, resection is performed to prevent recurrence.
Case Conclusion
You successfully perform a laparoscopic reduction of the intussusception. The patient is returned to the floor in stable condition. The patient has a return of bowel and is started on clear liquids and advanced over the next day. He is discharged home postoperative day 3 tolerating a regular diet.
TAKE HOME POINTS
· Intussusception is the predominate cause of intestinal obstruction in children between 3 months and 2 years old.
· Patients with intussusception may present with the classic triad of colicky abdominal pain, vomiting, and red currant jelly stools.
· Air-contrast enema is diagnostic and therapeutic: 90% of cases are resolved nonoperatively.
· Operative indications include sepsis, peritonitis, recurrent intussusception, or failure of nonoperative reduction.
· During operative reduction, the technique is to apply pressure distally and “milk” the intussusceptum (distal bowel) from the intussusceptiens (proximal bowel).
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