ADULT BOWEL INTUSSUSCEPTIONS: RADIOLOGYAPPEARANCE AND IDENTIFICATION OF A CAUSATIVE LEAD POINT N. MEKKI, R. KHARRAT, S. BOURKHIS, R. BEN NACEUR, F. BEN AMARA, N. MNIF. CHARLE NICOLLE’S HOSPITAL, TUNIS, TUNISIA
Introduction: • Intussusception in adults is an unusual cause of bowel obstruction: • 1% of all bowel obstructions. • 5 % of all intussusceptions. • 80-90 %: due to an underlying pathology. • The growing use of computed tomography (CT) and magnetic resonance imaging (MRI) has led to increased detection of intussusceptions as mostly unsuspected clinically, presented with non-specific abdominal pain.
Objectives : • To describe the characteristic radiologic features of intussusception according to location. • To illustrate pathologies which cause intussusceptions. • To correlate the different features with the pathologic findings.
Materials and methods : • We made a retrospective study, over 1-year period (2011). • 6 cases of adult bowel intussusceptions: • Sex ratio: 4 men/ 2 women. • Age : vary from 21 to 60 years, mean age: 38 years. • Explorations: • 5 patients was explored by abdominal enhanced CT examination General Electric (GE) 16 slices. • One patient was explored by MRI GE 1.5 Tesla .
RESULTS: • Clinicalpresentationwas non specific for all patients: abdominal pain+++ • Radiologydetect: • 4 ileoilealintessusception in 3 patients: 2 were in the same one. • 1 ileocoecalintessusception. • 1 colo colicintessusception in the transverse colon. • 1 colo rectal intessuscetion.
RESULTS: • Case N° 1: A.H. is a 36 yearold man whoconsult for gastro intestinal bleeding and anemia, contrastenhanced abdominal CT scan was made to identify the cause of hemorrhagia and to search if thereis an active bleeding. 2 1 2 • Axial slices of CT scan without (1) and with contrast enhancement (2). • They demonstrate the typical multilayered appearance of a small bowel intussusception in the left hypochondrium .
Coro RESULTS: Sag • Contrast-enhanced CT scan showed invaginated mesenteric fat and vessels . Sag Sag • Multiplanar reconstructions: sagittal and coronal help a lot to see the sausage of the ileoilealintessusception. Sag
Coro RESULTS: Sag • At laparotomy, the small bowel intussusception was confirmed and histology showed the lead point to be a stromal tumor. Ax • At the top of the intessusception, we notice a round lesionthatenhancesheterogeneouslyaftercontrast injection • ( ), these one wasconfirmed by peroperative constatation .
RESULTS: • Case N°2: R.S. is a 27 Yearold men whowasadmitted in the emergency for abdominal stabwounds, hewasexplored by surgery for peritoneal effusion. He wascontrolledafter 10 days by CT withoutcontrastenhancement. • CT showed the target aspect of loops in 2 differnt sites in relation with 2 smallbowelintessusceptions: the first existunder the liver and the second ispelvic .
RESULTS: • Notice in thisrecontructed images the sausage aspect • Intessusceptions in this cases weretaken as transientbecause the patient wasasymptomatic. Another control after 2 weeksshowedtheir persistance, surgerydid not found a lead point. • The final diagnosiswaspost operativeintessusceptions.
RESULTS: • Case N°3: M.A. is a 30 yearsoldwomanoperated for bilateralkidneyadenocarcinoma (radical right nephrectomy and leftlumpectomy) consulting for non specific abdominal pain. Enhanced CT examination shows ileoilealintessusception in the right iliacfossa.
RESULTS: • We notice the presenceat the distal portion of the intessuceptum , of an ovallesion ( ) thatisenhanced by the contrast, itmaybe the causative lead point. • The surgery and the histologyfind the underlyingpathology to be a bowelmetastasis of a renaladenocarcinoma in the last ilealloop.
RESULTS: CT shows alsootherlesions suggestive of metastasis : : corticomedullaryhypodense range in the upper pole of the leftkidney suggestive of tumorrecurrence. : Osteolysis of the left iliac wing suggestive of to metastases. Intra peritoneal effusion
RESULTS: CORO T1 GADO • Case N°4: G.K. is a 21 yearold men followed for crhon’sdiseasesince 6 months, heconsult for abdominal pain, hewasexplored by MRI: Small bowel opacification showed a masse in the ileocecal junction AX T1 GADO CORO SSFSE CORO SSFSE • MRI showed an important inflammatory thickening of the distal ileum heaving a look like tumor with intense heterogeneous enhancement after contrast injection
RESULTS: • The sagittal and coronal sections showed intussusception of the ileocecal valve into the caecum ( ) . SAG T1 GADO SAG T1 GADO • Notice the intestinal expansion upstream of the thickening. CORO T1 GADO • Endoscopy showed an inflammatory ileocecal valve which is prolapsed in the caecum, it showed also ulcerated terminal ileitis. • The diagnosis was intessusception on an acute episode of crhon’s disease.
RESULTS: • Case N°5: M.H. is a 60 yearold men whoconsult in the emergency for abdominal pain with acute bowel obstruction. • CT scan showed the image of bowel-within-bowel in the pelvis clearly visible on the axial and sagittal, relevant to a colo rectal intessusception ( ).
sag Coro RESULTS: Coro Ax • At the top of the sausage, we notice an irregularstenosing mass withspontaneousisoattenuating relative to rectal wallwhichenhancesheterogeneouslyaftercontrast injection . • we notice also a densification of the mesenteric fat surrouding the rectum withlymphadenopathies . • The surgeryconfirm CT findings and histolo!gyshowed the lead point to be an infiltratingadenocarcinoma of the rectum.
RESULTS: • Case N°6: M.H. is a 50 yearsoldwomanwhowastreated for degeneratedcolicpolyp, CT was made to control because of non specific abdominal pain: • Contrastenhanced CT scan showed a colo colicintessusception ( ) in the transverse colon occuping the epigastrium and thelefthypochondrium.
RESULTS: • CT showed in the tip of the intussusception an oval hypodense mass heaving spontaneously an homogeneous fat density without contrast enhancement, it is characteristic of a lipoma. • Surgeryconfirmed the large bowelintessusception • Histologyconfirmed the lead point to be a lipoma.
Discussion: Definition: • Intussusception is a progressive invagination of a bowel loop with its mesentery and mesentericvesselsM(intussusceptum) into the lumen of a contiguous portion of bowel (intussuscipiens). • It is the results of abnormalperistalsisproducingunequal longitudinal forces in the intestinal wall. M • It maybecaused by a mass pulled forward by normal peristalsis or by functionaldisturbances.
Discussion: ClinicalPresentation: • Symptoms are often chronic: several weeks to months, may be occasionally acute, it mayberelated to the lead point. • Unlike children, the most common symptoms of intussusception in adult are non specific: • Abdominal pain, nausea and vomiting +++ • Less frequently: constipation, fever, weight loss, diarrhea; • It is often asymptomatic, especially in chronic invaginations or without leadpoint. • Physicalexaminationis often unremarkable, sometimes note palpable mass.
Discussion: Classification: • Intussusceptions are classified according to : • Causes • Location: • Small or large bowel: more frequent in the small bowel (2/3)than in the colon(1/3). • 4 different locations: • Entero enteric: confined to the smallBowel. • Colo colic:linvolving the large bowel only. • Ileo colic: defined as the prolapse of the terminal ileum within the ascending colon. • Ileo cecal: the ileo-cecal valve is the leading point of the Intussusception. • Idiopathic:10%: • -It tends to be allmosttransient. • Withunderlyingpathology: 80-90%: • Neoplastic: 65% • Benign • Malignant • Non-neoplastic: 15-25%
Discussion: Etiologies: in the colon: • Intussusception in the large bowel is more likely to have a malignant etiology :50–60% • the most common underlying malignant lesions in the colon: are primarymalignanttumors: adenocarcinomaand lymphoma. • Benign lesions : 30% • lipoma, leiomyoma, adenomatouspolyp, endometriosis and previous anastomosis. • Idiopathic intussusception occursless often than in the small bowel: 10%
Discussion: Etiologies: in the small bowel • Benign lesions: 65% • benignneoplasms: lipoma, leiomyoma, haemangioma, neurofibroma, • following abdominal surgery: adhesions,anastomosis, • Meckel’sdiverticulum, • lymphoid hyperplasia and adenitis, • Traumatism, • coeliacdisease, • intestinal duplication • Crohn’sdisease • Malignantlesions: 15% : most often metastatic: • Melanoma+++ • Idiopathic intussusception: 20%
Discussion: Radiologicalfindings: • CT constitute the main imaging modality because of its virtually pathognomonic appearance: bowel-within-bowel: • It appears as a complex soft tissue mass, consisting of the outer intussuscipiens and the central intussusceptum. • There is often an eccentric area of fat density within the mass representing the intussuscepted mesenteric fat. • the mesenteric vessels are often visible within it.
Discussion: Radiologicalfindings: • When the CT beam is parallel to its longitudinal axis of the intussusception, itappears as a sausage-shaped mass. • Sometimes as reniformor “pseudokidney” mass: it is due to edema, mural thickening, and vascular compromise. • When the beam is perpendicular to the longitudinal axis, itappear as a ‘‘target’’ mass.
Discussion: Radiologicalfindings: • CT examination allow to: • Detect and confirm the diagnosis of intessusception. • Show the exact location: small or large bowel. • Appreciate the viability of invaginated loops. • Distinguish between • Intussusception without a lead point: no signs of proximal bowel obstruction, target-like or sausage-shaped mass, layering effect. • Intussusception with a lead point: signs of bowel obstruction, bowel wall edema with loss of the classic three-layer appearance due to impaired mesenteric circulation and demonstration of the lead mass. CT help reducing the number of unnecessarysurgical interventions.
Discussion: Radiologicalfindings:Intessusceptionwith an underlyinglead point • Suspected by the epidemiological data( age+++, medicalhistory) and the clinicalpresentation. • Ct scan find a mass in addition to the intussusception outlined distal to the tapered lumen of the intussusceptum.
Discussion: Radiologicalfindings:Intessusceptionwith an underlyinglead point • The mass’s type is established by the study of its spontanous density and enhancement: for example: • Lipoma: fat density wihoutcontainingbloodvessels to bedistinguishedfrommesenteric fat and withoutenhancement. • Othermalignanttumors (primary or metastatic): tissulardensitywithheterogenousenhancement. • Neoplastic lead point VS Non-neoplastic one: • significantly longer • significantly larger diameter • significantly more proximal dilatation of small boweldownstream.
Discussion: Radiologicalfindings: Transcientintessusception: • More frequent in the smallbowelthan in the colon • It is most frequently detected incidentally and is presumed to be innocuous. • Reported in adults with: • Celiac disease • Crohn disease
Discussion: Radiologicalfindings:MagneticResonance Imaging (MRI) • Recent developments in MRI with ultrafast multiplanar techniques now allow for rapid evaluation of bowel obstruction. • The multiplanar HASTE (half-fourier single shot turbo spin echo): SSFSE is particularly useful in the diagnosis of intussusception. • The high contrast resolution between the increased signal of the trapped intraluminal fluid and the intermediate to low signal of the bowel wall can clearly demonstrate the pathology.
Discussion: Treatment • There is no universal agreement upon the correct treatment of adult intussusception, • The surgery decision is based on: • The epidemiological data: age, medical history .. • The clinicalpresentation: acute abdominal pain, bowel obstruction, digestive hemorrhagia... • The imaging findings: • if a lead point is found or not, • If there is ischemic bowel signs: • The type of intervention depends essentially on the intraoperativefindings.
Conclusion: • Intussusception in adults is an infrequent cause of intestinal obstruction. • Preoperative diagnosis is difficult as symptoms can be intermittent and long standing. • More frequent use of computed tomography in undiagnosed abdominal pain increases the pick up rates.