Intussusceptions can be classified into three types based on location: (i) enteroenteric, when confined to the small bowel; (ii) colo-colonic, when involving the large bowel; and (iii) enterocolonic, which can be ileocecal or ileocecocolonic. Colo-colonic intussusceptions are the least common type [2, 3, 7]. We achieved successful surgical reduction laparoscopically because of an accurate preoperative diagnosis based on characteristic CT features and surgical technique.
Several imaging modalities can assist in the diagnosis of intussusception, such as abdominal plain radiography, ultrasonography, and CT . Of these, CT is the most accurate, with a reported diagnostic accuracy of 78–100% [8,9,10]. The characteristic CT features of intussusception include an inhomogeneous “target”- or “sausage”-shaped soft tissue mass with layering effect . Idiopathic intussusception does not generally cause proximal bowel obstruction and possesses distinct anatomic features that can be clearly seen on CT, such as the entering wall, mesenteric fat and vessels, returning wall, and intraluminal space [12, 13]. In this case, because bowel obstruction, tumor, or bowel wall edema was not observed on CT, it was possible to diagnose idiopathic intussusception. More than half of large bowel intussusceptions are associated with malignant lesions . Therefore, confirming the specific features mentioned above on CT is important when deciding the surgical strategy for treatment of adult colo-colonic intussusception.
Laparoscopic surgical reduction for adult idiopathic intussusception was useful and effective. The earliest description of laparoscopic-assisted resection of intussusception due to Meckel’s diverticulum was reported in 1993 . Since then, the number of reports of laparoscopic approach for intussusception had gradually increased. According to previous reports, laparoscopic approach for adult intussusception was more useful than open in the following points: the diagnostic point of view and the short-term clinical outcomes, e.g., earlier oral intake and a lower comprehensive complication index , while there might be more serious complications, such as bowel perforation and major vessel injury, in laparoscopic approach . Although patients with intussusception normally present with chronic symptoms and do not usually present with acute intestinal obstruction with significant abdominal distension, early conversion to the open procedure should be considered when necessary.
Surgical reduction of intussusception before resection is not recommended in adults due to the risk of bowel perforation. In addition, if the intussusception is associated with a malignant tumor, reduction may cause tumor cell dissemination . In contrast, the usefulness of laparoscopic surgical reduction in children with intussusception is widely recognized, as most pediatric cases are idiopathic [17,18,19]. Since not all cases of adult intussusception are associated with tumor, laparoscopic surgical reduction is feasible if idiopathic intussusception is confirmed on preoperative imaging, as illustrated by this case.
We identified relevant studies by searching the PubMed database using the terms “adult idiopathic intussusception” and “colonic”. Only three cases, including this case, were found as true idiopathic intussusception cases with no apparent cause [20, 21]. In two out of three cases, surgery was selected because of strong abdominal symptoms. Cases with few symptoms were treated using non-invasive treatment like endoscopic reduction . Endoscopic approach was very useful because diagnosis and treatment could be performed at the same time. Thus, it is considered to be important to decide the treatment strategy according to the degree of symptoms; in cases with few symptoms, non-invasive reduction, such as endoscopy and barium examination, was a first choice and incases with strong symptoms, surgery was performed with careful consideration for bowel ischemia. Moreover, it is considered necessary to evaluate the mucosal surface for distinguishing the condition from special intussusception, such as parasites [22, 23]. We believe that minimal bowel resection or early endoscopic observation after surgery was desirable.
The reduction success rate by laparoscopy was ≥ 70%, and the success rate was particularly high in ileo-colonic intussusception . The reduction enables avoiding the excessive length of the bowel resection. Surgical reduction methods for adult intussusception are not definitive. These methods involving a combination of delicate direct pressure on the anal side of transverse colon and gentle pulling on the oral side, which is often used for children, may be applicable to adults as in the present case. But, surgical reduction should not be attempted if there are signs of inflammation or ischemia of the bowel wall.
Laparoscopic approach for adult intussusception still has many challenges. When they are limited to adult intussusception without a tumor, laparoscopic approach and surgical reduction can be performed safely. Going forward, as the laparoscopic approach is used more frequently for all types of intussusceptions, its use for acute abdominal conditions will continue to expand.