A clinicopathologic study of intussusception in Nepalese adults

Introduction: was designed to review adult intussusception, including presentation, diagnosis, and pathology. Methods: A retrospective study of 18 cases of intussusception in individuals older than 18 years of age visiting the department of surgery of Civil Service Hospital from 2010 to 2018 was done. Results: There were 18 cases of adult intussusception. The mean age was 49.2 years (range 19-84 years). Abdominal pain and vomiting were the commonest symptoms. The median duration of presentation was 5 days (range 20 hours to 10 months). Three patients (16.6%) presented with generalized peritonitis. There were eight ileocolic, seven ileoileal, and three colocolic intussusceptions. Two patients (11.1%) settled spontaneously. Twelve out of the 18 patients (66.6%) had leading lesions. Benign pathologies were seen Conclusions: Adult intussusception is a rare entity, nearly one-third of their causes are malignant. Surgery is the best recommended treatment, with or without a primary reduction of the intussusception; the latter can result in more limited bowel resection.


Introduction
of the gastrointestinal tract into a distal one. 1 Intestinal intussusception is a common disorder in children, however, it is a rare clinical entity in adult patients. 2 Adult intussusception represents 5-8.2% of all cases of intussusceptions and only 1-5% of intestinal obstructions. 1,2 Most of the cases (70-90%) of adult intussusceptions are 3,4 Adult intussusception is always treated by surgery. However, reduction before resection has always remained controversial. [1][2][3][4] The present study reviews our experience of this rare clinical entity, attempting to summarize the clinical features, presentation, and its causes.

Methods
It is a retrospective study of case records of all patients aged 18 years or older admitted to the Civil Service Hospital of Nepal, Kathmandu from 2010 January to December 2018, who were diagnosed with intussusception. We reviewed the demographic data, together with clinical signs, diagnostic tests, diagnosis, treatment, etiology, and location of the intussusception, follow-up, and complications. The preoperative, operative, and pathologic records were reviewed to determine the location of the involved segment, conservative or surgical management, and the nature of the lesion, and the clinical course of the patient. Intussusception was preoperatively diagnosed with ultrasonography with the target and doughnut signs on transverse view and the pseudo-kidney sign in the longitudinal view, and/or contrast-enhanced computed tomography of the abdomen with the characteristic sausage or target sign, bowel-within-bowel appearance in more than one image with or without a lead point and bowel obstruction, inclusion of mesenteric fat or vessels, bowel wall edema, and fat stranding, and mesentery in the lumen. 4,5 to the location and pathological lead-points into three (2) ileocolic (prolapse of the terminal ileum through the ileocecal valve within the caecum/ascending colon) and (3) colo-colic (involving the large bowel); and according to the etiology into benign, malignant or idiopathic. 7

Results
There were 18 patients in our study. There was a slight female predominance: 11 females (62 %) and seven males (38 %). The youngest patient in this series was aged 19 years and the oldest was aged 84 years (mean 49.2 years). Sixteen patients out of the 18 in our series underwent laparotomy. Two patients, one with ileocolic and another with ileoileal intussusception were planned for surgical intervention but they improved over a few hours, with the disappearance of the symptoms and lump. They underwent a colonoscopy and a barium meal follow-through later to identify the lesion, but they revealed a normal study, and on follow-up, they did not have any symptoms. They have been included in the conservative group and labeled as idiopathic intussusception.
Intraoperatively, out of the 16 patients, reduction was tried in 13 patients. Three patients had colocolic intussusception and they underwent primary resections without initial reduction. Reduction was successful in 11 (84.67%) patients out of the 13. In the rest three, resection was done after reduction and assessment of the lesion. In the three patients operated for peritonitis, necrosis and perforation of the bowel were found at the neck of the intussusceptum. Ileostomy was performed in one such patient with peritonitis. In two patients, after reduction, no organic lesion was found; one had a very mobile cecum for which was done. In the other patient, the ileocecal junction was the lead point, without any obvious pathology. The case with postoperative intussusception underwent reduction hospital mortality or within 30 days.
Of the 18 patients, eight of the intussusceptions were in the ileocecal region (44.4%). There were seven (38.8%) cases of ileoileal intussusception and three (16.6%) cases of colonic intussusceptions. One patient had double invagination creating an ileoileocolic intussusception; it has been grouped under ileoileal because the primary pathologic junction was in the ileum.
Two patients (11.1%) improved without surgical intervention. They were normal on later examinations, so the exact cause the intussusception was not known. They were categorised under the idiopathic group, along with three other in which only ischemia, congestion, or gangrene were found on histopathological examination without a lead point and one in which just the ileocolic junction was the lead point without any pathology. Regarding the nature, 12 patients (66.6%) had proven leading lesions. Benign pathologies were seen in seven cases (38.8%) and malignant causes, which were all in the colon, four were secondary to adenocarcinoma of the colon, and one was secondary to a large B-cell Non-Hodgkin's lymphoma (NHL). Two cases of adenocarcinoma of the caecum and one NHL of the caecum caused the intussusception of the ileocolic junction. Hence they were grouped under the ileocolic intussusception although the aetiology were in the caecum.

Discussion
Adult intussusception is said to be rare. Recent reviews have shown that over a time span, presentation of adult intussusception to a single institution or multiple institutions in a country is extremely less. [7][8][9][10][11][12][13][14] Here in our institution, 18 patients over eight years are comparable in volume to these reports as well.
There was a slight female preponderance in our study and a mean age of around 50 years. The classic presentation of intussusception like abdominal pain, lump, and currant-jelly stools is rare and this triad has been found in only two of our patients (11.11%). Abdominal pain was the presenting symptom in all patients. There were three patients with intussusception who presented with peritonitis, the reason being delay in presentation to our hospital. Such a presentation has been reported in very few reports. 4 There have been various results of studies regarding pathologies in adult intussusceptions. In our review, 12 patients (66.66%) had pathologic lead points. Six out of the 18 patients (33.33%) were idiopathic and did could be seen in the caecum and the ileum without other obvious pathologies. Whether these were the cause or et al's study, only 7% were idiopathic, with other studies 1,[7][8][9][13][14][15][16] In our study, out malignancies were in the large bowel, and their frequency was comparable to other series with reported malignancy rate between 27% and 43%. [15][16][17][18] However, unlike these other series, small bowel malignant lesions were not found in our review.
The optimal treatment for adult intussusception has always been a matter of controversy. [1][2][3][4][7][8][9][10][11][12][13][14] The standard treatment is laparotomy and evaluation. However, in our series, two of our patients experienced spontaneous reduction and improvement without surgical intervention. The decision not to operate may have been detrimental, but we were careful to exclude any possible pathology by colonoscopy and barium meal follow-through leading to the conclusion that they were cases of benign transient intussusceptions.
Authors consider performing a laparotomy and resection of the segment of bowel with the intussusception because of the possibility of malignancy. [16][17][18] There are controversies associated with the option of preliminary reduction of the intussusception before resection versus primary resection without reduction. The theoretic objections to the reduction of bowel are: 1) intraluminal seeding and venous embolization of malignant cells in the region of ulcerated mucosa, 2) possible perforation during manipulation, 3) increased risk of anastomotic complications in the face of an edematous 15,16 Based on the high incidence of underlying malignancy in adult intussusception, which authors have recommended primary resection whenever possible without reduction. 1 But many other authors have also challenged this view, opting for resection without a reduction in selective cases only. [7][8][9][10][11][12][13][14]19,20 An aspect not discussed in any of the till-dated articles is the possibility of an ileoileocolic intussusception, which is inadvertently thought to be an ileocolic intussusception and which We had one patient with ileoileocolic intussusception, which if resected without reduction would have resulted in an unnecessary extensive resection for an otherwise series, we adopted a selective approach to resection, with resection straightaway in colocolic intussusceptions due to a high chance of malignancy and reduction in others so as to minimize the physiologic alterations which are so apt to occur in patients presenting with obstruction and peritonitis and to preserve the maximum length of the bowel. This maneuver may have been the key to decreasing the morbidity and mortality in our patients, meanwhile also decreasing the possibility of dissemination of malignant cells during the reduction of colocolic intussusception. This is also supported by the only systematic review and meta-analysis of adult intussusception by Hong et al. 19 Conclusion Adult intussusception is a rare entity, and nearly onethird of their causes are malignant. Surgery is the best recommended treatment, with or without a primary reduction of the intussusception; the latter can result in more limited bowel resection.