Intraabdominal Complications Secondary to Ventriculoperitoneal Shunts: CT Findings and Review of the Literature

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1 Gastrointestinal Imaging Original Research Chung et al. CT of Ventriculoperitoneal Shunts Gastrointestinal Imaging Original Research Jae-Joon Chung 1 Jeong-Sik Yu 1 Joo Hee Kim 1 Se Jin Nam 1 Myeong-Jin Kim 2 Chung JJ, Yu JS, Kim JH, Nam SJ, Kim MJ Keywords: abdominopelvic CT, cerebrospinal fluid, hydrocephalus, peritonitis, pseudocyst, ventriculoperitoneal shunt DOI: /JR Received January 27, 2009; accepted after revision pril 12, Supported by a research grant from Yonsei University College of Medicine for Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, 612, Eunjuro, Gangnam-gu, Seoul, Korea. ddress correspondence to J. J. Chung (jjchung@yuhs.ac). 2 Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea. JR 2009; 193: X/09/ merican Roentgen Ray Society Intraabdominal Complications Secondary to Ventriculoperitoneal Shunts: CT Findings and Review of the Literature OJECTIVE. The purpose of our study was to evaluate the abdominopelvic CT findings of various intraabdominal complications secondary to ventriculoperitoneal shunts for hydrocephalus and to review the literature. MTERILS ND METHODS. The CT images of 70 patients (33 men and 37 women; mean age, 48.5 years) who underwent ventriculoperitoneal shunt placement and abdominopelvic CT because of shunt-related abdominal symptoms were reviewed retrospectively. CT images were analyzed with regard to the location of the shunting catheter tip; site, size, wall, and septa of localized fluid collection; peritoneal thickening; omentomesentery infiltration; abscess; bowel perforation; abdominal wall infiltration; and thickening of the catheter track wall. RESULTS. The mean period between the last ventriculoperitoneal shunting operation and CT was 11 months (range, 1 week to 115 months), and the mean number of ventriculoperitoneal shunting operations undergone was 1.4 (range, 1 6). total of 76 ventriculoperitoneal shunting catheters were introduced in 70 patients: 64 patients had a unilateral catheter inserted and six patients had bilateral catheters inserted. Sixteen patients (22.9%) were pathologically diagnosed with ventriculoperitoneal shunt related complications: 11 cases (15.7%) of shunt infection, six cases (8.6%) of CSF pseudocyst, four cases (5.7%) of abdominal abscess, three cases (4.3%) of infected fluid collection, and one case (1.4%) of bowel perforation. Microorganisms were cultured from the tip of the shunting catheter or peritoneal fluid in 11 patients (15.7%). CONCLUSION. On abdominopelvic CT, various intraabdominal complications secondary to ventriculoperitoneal shunt were shown, of which, shunt infection was the most common, followed by CSF pseudocyst, abscess, and infected fluid collection. P lacement of a ventriculoperitoneal shunt is the most common operation performed in the treatment of hydrocephalus. Intraabdominal complications after ventriculoperitoneal shunt placement are most commonly located near the peritoneal end of the shunt catheter; more than 50% of patients require shunt revision [1, 2]. The most common complications have been infection of the shunt, malfunction due to blockage, disconnection, migration, and equipment failure, which are related to extraperitoneal retraction of the catheter, development of an incisional hernia, subcutaneous collection of CSF, and peritoneal pseudocyst formation due to lowgrade infection followed by wrapping by the omentum [2 4]. Other complications reported in the literature include intestinal perforation, CSF ascites, inguinal hernia, and intestinal volvulus [5 7]. These complications may manifest as either local abdominal signs or increased intracranial pressure. Shunt infection remains a frequent and potentially fatal complication of CSF diversion. Therefore, a key issue in the treatment of these complications is early and correct diagnosis of intraabdominal complications by CT, MRI, sonography, or abdominal radiography. There have been several case reports about various abdominal complications that can occur after ventriculoperitoneal shunting operations [8 11]. The purpose of this study was to evaluate the CT findings of various intraabdominal complications secondary to ventriculoperitoneal shunt placement for hydrocephalus and to review the literature. Materials and Methods This retrospective study was approved by our institutional review board, and the requirement for JR:193, November

2 Chung et al. informed consent was waived. We reviewed the medical records of all patients who underwent abdominopelvic CT after ventriculoperitoneal shunt placement from January 2001 to June The medical records of 100 consecutive patients were reviewed. n attending abdominal radiologist retrieved the images from a hospital archiving system and conducted a preliminary review of the CT images of the 100 patients. mong the patients reviewed, a total of 30 were excluded for the following reasons: seven patients had no specific abdominal symptoms (staging workup for underlying cancer [n = 4], evaluation of hypertension [n = 2], and falling injury [n = 1]); five patients had no recorded clinical information for an abdominopelvic CT scan; five patients underwent ventriculoperitoneal shunt removal just before the CT for shunt malfunction; four patients underwent CT for evaluation of percutaneous endoscopic gastrostomy tube placement; three patients underwent CT for renal or ureteral stones; three patients underwent CT for urinary tract infection; two patients underwent CT for gallstones; and one patient underwent CT for voiding difficulty. Inclusion criteria for the study included abdominopelvic CT with previous ventriculoperitoneal shunt placement and abdominal symptoms such as diffuse or localized abdominal pain, fever with abdominal symptoms, advanced hydrocephalus because of shunt malfunction, ventriculitis because of shunt infection, prolonged diarrhea, abdominal wall mass, pus discharge from the operation site, and hematochezia. fter exclusion of the aforementioned 30 patients, a total of 70 patients (33 male and 37 female; age range, 2 75 years; mean age, 48.5 years) were enrolled in this study. The causes of hydrocephalus in the 70 patients were 14 cases of primary or secondary brain tumors, 12 cases of subarachnoid hemorrhage and intraventricular hemorrhage (IVH), 11 cases of traumatic intracerebral hemorrhage (ICH) and IVH, six cases of postoperative ischemic change, six cases of postoperative hemorrhage, five cases of hypertensive ICH and IVH, four cases of IVH, three cases of tumor seeding, two cases of vascular ICH and IVH, two cases of ICH after infarct, two cases of congenital disease, two cases of meningitis, and one case of subdural hematoma. Two cases of vascular ICH and IVH were from a case of moyamoya disease and a case of arteriovenous malformation (VM). Two cases of congenital diseases were from a case of congenital hydrocephalus and a case of rnold- Chiari malformation. The window for abdominopelvic CT was from 2 cm above the right hemidiaphragm to 2 cm below the symphysis pubis, with a 7-mm collimation and a 7-mm reconstruction interval. fter IV administration of ml of nonionic iodinated contrast medium (iopromide, Ultravist 300, Schering), given by an automatic injector at 3 4 ml/s, 3-minute delayed equilibrium phase images were obtained. ll scanned images were sent to the PCS for interpretation. The locations of intraperitoneal fluid collections were divided into right upper quadrant (RUQ), right lower quadrant (RLQ), left upper quadrant (LUQ), left lower quadrant (LLQ), right paracolic gutter (RPG), left paracolic gutter (LPG), midabdomen (paraumbilical area), pelvic cavity (below acetabular roof), and abdominal wall. One abdominal radiologist with 14 years of experience reviewed all the abdominopelvic CT images, focusing on the site and size of localized fluid collection, the presence of walls or septa in the localized fluid collections, peritoneal thickening, peritoneal contrast enhancement, omentomesentery infiltration, abscess, bowel perforation, bowel-wall thickening and contrast enhancement, abdominal wall infiltration, thickening of the catheter track wall, and intraperitoneal free air. Results bdominopelvic CT was performed in 70 patients for complaints of varying abdominal symptoms, such as diffuse abdominal pain (n = 25), localized abdominal pain (n = 17), aggravated hydrocephalus due to shunt malfunction (n = 9), fever with vague abdominal symptoms (n = 6), ventriculitis with suspected shunt infection (n = 5), prolonged diarrhea (n = 3), palpable abdominal mass (n = 2), subphrenic free air (n = 1), pus discharge from the operation site (n = 1), and hematochezia (n = 1). Twelve (70.6%) of the 17 patients with localized abdominal pain complained of lower abdominal pain. mong the 12 patients with lower abdominal pain, six had RLQ pain that was initially diagnosed as acute appendicitis, two (2.9% of all patients) of whom were finally diagnosed with acute appendicitis. Fig year-old woman with large pseudocyst in abdominal wall., Contrast-enhanced abdominopelvic CT scan shows about cm pseudocyst in subcutaneous layer of right anterior abdominal wall with internal ventriculoperitoneal shunt catheter. Smoothly compressed abdominal wall muscle is noted. Causes of hydrocephalus were subarachnoid hemorrhage and intraventricular hemorrhage., More caudal CT image shows pericystic irregular fluid collections (arrows) in abdominal wall. This patient complained of aggravated headache because of advanced hydrocephalus from shunt malfunction. Subsequently, shunt revision was performed, and there was no growth of microorganism from catheter tip JR:193, November 2009

3 CT of Ventriculoperitoneal Shunts Ventriculitis was suspected in five patients because of findings on brain CT or MRI examinations that were performed for acute and persistent headache or increased intracranial pressure. The mean period between the last ventriculoperitoneal shunting operation and abdominopelvic CT was 11 months (range, 1 week to 115 months), and the mean number of ventriculoperitoneal shunting operations undergone was 1.4 (range, 1 6). In the 70 patients, 76 ventriculoperitoneal shunting catheters were introduced: 64 patients with a unilateral catheter and six patients with bilateral catheters. There were 46 right ventricle origin shunting catheters and 30 left ventricle origin shunting catheters; six patients had bilateral ventriculoperitoneal shunting catheters placed. In the 70 patients, 87 localized fluid collection sites, of which 47 patients (67.1%) had one fluid collecting site, 17 (24.3%) had two fluid collecting sites, and two (2.9%) had three fluid collecting sites, as well as six CSF pseudocysts were found. The locations of the 87 localized fluid collection sites were the pelvic cavity (n = 55), RPG (n = 16), midabdomen (n = 5), LPG (n = 4), RLQ (n = 3), abdominal wall (n = 1), RUQ (n = 1), LUQ (n = 1), and LLQ (n = 1). mong them, one patient had fluid collections in both paracolic gutters. The locations of the six CSF pseudocysts were the RLQ (n = 3), pelvis (n = 2), and abdominal wall (n = 1) (Fig. 1). Fig year-old man with localized omentomesentery infiltration. Contrast-enhanced abdominopelvic CT scan shows localized dirty infiltration in omento mesentery of abdominal left lower quadrant (LLQ) with adjacent peritoneal thickening and minimal fluid collection. Ventriculoperitoneal shunt catheter (arrows) is noted within localized infection area. Cause of hydrocephalus was postoperative intraventricular hemorrhage for arteriovenous malformation and patient complained of localized abdominal pain in abdominal LLQ. Shunt revision was performed and Staphylococcus aureus grew from tip of shunt catheter. Of the 70 patients, 16 (22.9%) were histopathologically diagnosed with shunt-related complications, which included 11 cases (15.7%) of shunt infection (Fig. 2), six cases (8.6%) of CSF pseudocyst formation (Fig. 3), four cases (5.7%) of abdominal abscess (Fig. 4), three cases (4.3%) of infected localized fluid collection (Fig. 5), and one case (1.4%) of bowel perforation. mong these, all four cases of abscess, three cases of pseudocyst, and two cases of infected localized fluid collection coexisted in the patients with shunt infection. Of the six cases (8.6%) of CSF pseudocysts, five were located in the peritoneal space and one was located in the abdominal wall. One case (Fig. 6) of pseudocyst caused small-bowel obstruction secondary to wrapped mesentery at the catheter tip within 5 days of ventriculoperitoneal shunt placement. Three cases of infected fluid collection were diagnosed by sonographically guided aspiration of fluid. One patient with subphrenic free air was diagnosed with peritonitis secondary to a 5-mm bowel perforation in the transverse colon due to the shunting catheter. Eighteen patients (25.7%) showed a wall of fluid collection, 12 (17.1%) of which showed contrast enhancement of the wall. Seven cases (10.0%) showed internal septa within the fluid collection. There were 30 cases (42.9%) of peritoneal thickening, 19 cases (27.1%) of peritoneal enhancement, 34 cases (48.6%) of omentomesentery infiltration (Figs. 2 and 5), Fig year-old man with intraperitoneal pseudocyst and inflammatory infiltration in abdominal wall., Contrast-enhanced abdominopelvic CT scan shows 11 6 cm pseudocyst in abdominal right lower quadrant with enhanced wall and internal shunt catheters (arrows). Small amount of fluid collection is also seen in both paracolic gutters. Causes of hydrocephalus were traumatic hemorrhage and postoperative ischemic change. CT was performed because of abdominal pain., More cephalic CT image shows inflammatory fatty infiltration in subcutaneous layer of right midabdominal wall with adjacent skin thickening. djacent small-bowel loops show mild wall thickening with mesenteric haziness and fluid collections in both paracolic gutters. There was no growth of microorganisms from catheter tip and shunt externalization was performed. JR:193, November

4 Chung et al. four cases (5.7%) of abscess, one case (1.4%) of bowel perforation, nine cases (12.9%) of bowel-wall thickening, 38 cases (54.3%) of abdominal wall infiltration (Fig. 3), and seven cases (10.0%) of thickening of the catheter track wall in the abdominal wall. Specimen cultures from the peritoneal tips of the shunt catheter or intraperitoneal fluid were obtained in 21 patients (30.0%). The following microorganisms grew in 11 patients (15.7%): five cases of Staphylococcus aureus, one case of Pseudomonas aeruginosa, one case of vancomycin-resistant enterococci, one case of cinetobacter baumannii, one case of Micrococcus species, one case of gram-positive cocci, and one case of gram-negative cocci. In 10 patients, there was no growth. Fig year-old boy with intraperitoneal abscess. Contrastenhanced abdominopelvic CT scan shows 3 1 cm lentiform-shaped low-density lesion (arrows) with rimlike enhancement noted in left anterior peritoneal cavity with adjacent peritoneal thickening. Cause of hydrocephalus was congenital rnold-chiari malformation. CT was performed because of suspicion of shunt malfunction. Two shunt catheters are noted in both sides of abdominal wall with distal catheter near descending colon. This lesion was confirmed as abscess by percutaneous needle aspiration, and Pseudomonas aeruginosa grew from aspirated abscess fluid. Shunt catheter was removed. For the treatment of ventriculoperitoneal shunt related abdominal complications in the 16 patients (22.9%), the following were used: antibiotic therapy only (n = 4), shunt externalization and antibiotic therapy (n = 2), exploratory laparotomy (n = 2), shunt revision (n = 2), sonographically guided percutaneous drain tube insertion (n = 2), removal of the catheter (n = 2), laparotomy and drainage (n = 1), and conservative treatment (n = 1). Discussion The use of the peritoneal cavity for CSF absorption in ventriculoperitoneal shunting was first introduced in 1908 by Kausch [12]. Other shunting techniques have since been used and include a ventriculoatrial shunt, a lumboperitoneal shunt, and a third ventriculostomy [13]. The peritoneal cavity is preferable to the pleural cavity for insertion or reinsertion of the shunt [6]. The most common causes of shunt malfunction are catheter obstruction and infection. The incidence of ventriculoperitoneal shunt related abdominal complications has been reported to be from 5% to 47% [14, 15]. In our study, 16 patients (22.9%) were histopathologically diagnosed with shunt-related complications. The most common distal ventriculoperitoneal shunt complications include shunt infection, subcutaneous collection of CSF, peritoneal pseudocyst, bowel perforation, intestinal volvulus [6], mesenteric pseudotumor, migration of the catheter into the pleural cavity and heart, and development of an incision hernia [8 11, 16 20]. Other less-common abdominal complications [21, 22] include bowel obstruction secondary to adhesion; subphrenic abscess, cerebrospinal enteric fistula; untreatable CSF ascites; catheter disconnection; and extraperitoneal retraction of the catheter through the mouth [10], umbilicus [4], bladder, vagina, anus [11], or scrotum. Nonenteric viscus perforations also can occur and can involve multiple organs, such as the gallbladder, stomach, liver, uterus, or urethra. Obstruction of the distal catheter must be treated as an emergency because it can lead to a significant increase in intracranial pressure, resulting in associated complications that can cause considerable morbidity and possibly death [5]. Fig year-old woman with intraperitoneal infected fluid collection., Contrast-enhanced abdominopelvic CT scan shows large amount of ascites with thickened and enhanced peritoneum (arrows) with ventriculoperitoneal shunt catheter in left lower abdomen. Causes of hydrocephalus were subarachnoid hemorrhage and intraventricular hemorrhage. CT was performed because of abdominal pain, nausea, and vomiting., More cephalic CT image shows loculated fluid collections with thin wall in both sides of midabdomen. Dirty fatty infiltration is also seen in omentomesentery of right midabdomen, with fluid collections in right paracolic gutter and mesentery. Micrococcus species grew from tip of shunt catheter. External drainage tube was inserted for treatment JR:193, November 2009

5 CT of Ventriculoperitoneal Shunts Malfunction of the ventriculoperitoneal shunt after initial placement occurs in approximately 25 35% of patients at 1 year [23], and 70 80% of patients require at least one revision at some point in their lives [16]. Cochrane and Kestle [24] reported the initial shunt failure rate to be 31% at 6 months for experienced surgeons, with an infection rate of 7% over the same period. In our study, the mean period between the last ventriculoperitoneal shunting operation and abdominopelvic CT was 11 months; 52 patients (74.3%) had an interval of less than 11 months. mong these 52 patients, eight underwent abdominopelvic CT within 1 week because of abdominal symptoms. One of these eight patients underwent laparotomy because of small-bowel obstruction caused by smallbowel mesentery wrapping around the catheter tip and pseudocyst. Shunt infection remains a frequent and potentially fatal complication of CSF diversion, with a reported incidence of 5 47% [14, 15], and approximately 70% of shunt infections occur within 2 months after shunt placement [13, 25]. In our study, shunt infection was confirmed by bacterial culture in 11 patients (15.7%). The most common organism was S. aureus. However, it has been reported that 7% of ventriculoperitoneal shunt infections are caused by Escherichia coli [17]. Peritoneal fluid is either absent or present in only a small amount in patients with normally functioning ventriculoperitoneal Fig year-old man with intraperitoneal pseudocyst causing small-bowel obstruction., Contrast-enhanced abdominopelvic CT scan shows approximately 6 5 cm pseudocyst in abdominal right lower quadrant with adherent and distended neighboring small-bowel loops. Shunt catheter (arrow) is seen just below peritoneum. Cause of hydrocephalus in this patient was chondrosarcoma in skull base, and CT was performed because of abdominal pain., More cephalic CT image shows considerably more distended small-bowel loops with internal bowel contents and air fluid level, suggesting mechanical bowel obstruction. Laparoscopy confirmed small-bowel obstruction caused by adherent pseudocyst secondary to wrapped mesentery at catheter tip. Ventriculoperitoneal shunt catheter was removed and reintroduced into another site. No microorganism grew from pseudocyst fluid. shunts. CSF loculation may present as recurrent ascites, a peritoneal cyst, an omental cyst, or subphrenic or lesser sac loculation [8]. Peritoneal CSF pseudocyst formation is an unusual complication, with a reported incidence of less than % [8, 26]. The wall of the pseudocyst is composed of fibrous tissue or an inflamed serosal surface without an epithelial lining and is filled with CSF and debris [8, 27]. The most common presentation of an abdominal CSF pseudocyst in children is elevated intracranial pressure and abdominal pain, whereas local abdominal signs, such as abdominal pain, distention, nausea, or vomiting, predominate in adults [8]. n abdominal CSF pseudocyst was first described by Harsh [28] in Hahn et al. [29] reported that infection was the most prominent cause of pseudocyst formation (80%) and emphasized that all cases of abdominal pseudocysts should be considered to be caused by infection until proven otherwise. The most common intraabdominal response to infection is sheathing of the peritoneal catheter. The CSF draining into these sheaths may produce large intraabdominal fluid-filled cysts [8]. The infection and subsequent high levels of CSF protein, allergic reactions to immunization [30], liver dysfunction [19], and tissue reaction against tubing material and CSF protein [20] have been known to impair the absorption of CSF and to have a role in pseudocyst formation. The time from the last shunting procedure to the development of an abdominal pseudocyst ranges from 3 weeks to 5 years [16]. There has been a reported case of pseudocyst formation 10 years after ventriculoperitoneal shunt placement. In our study, six cases (8.6%) of pseudocyst were detected, and the time interval between the last shunting operation and abdominopelvic CT ranged from 5 days to 25 months. The CSF pseudocyst can either move freely within the peritoneal cavity or adhere to loops of small bowel, the serosal surface of solid organs, or the parietal peritoneum [8]. CSF pseudocysts can be differentiated from ascites by their characteristic displacement of the bowel gas pattern on abdominal films and by the absence of shifting dullness [8]. lthough sonography and CT can accurately localize abdominal fluid collections, differentiation of ascites from the aforementioned cystic lesions may not be possible. Therefore, fine-needle aspiration of the localized CSF collections under sonographic or CT guidance should be performed to increase the diagnostic yield. Coley et al. [31] reported that although the sonographically guided percutaneous aspiration of CSF pseudocyst was not curative, performance of this procedure to alleviate the acute symptoms followed by elective shunt revision is a feasible alternative to the traditional treatment approach and could be helpful to limit radiation exposure to patients who were likely JR:193, November

6 Chung et al. to have significant exposure during their lives, especially children. If infection is present, the pseudocyst wall should be excised and the peritoneal shunting catheter removed [8]. In our study, 18 cases (25.7%) showed a wall of fluid collection, of which 12 cases (17.1%) showed wall enhancement and seven (10.0%) showed internal septa; however, histopathologic diagnoses via fluid aspiration were available in only a few cases. Once the shunt tip is removed, the pseudocyst gradually collapses because there is no secretory epithelium present in the cyst [3]. The formation of a CSF pseudocyst is a poor prognostic sign for the usefulness of the peritoneal cavity for shunting [32]. lthough previous abdominal pseudocyst formation and peritonitis are not contraindications to subsequent peritoneal shunting in some reports [19, 29], the CSF had to be diverted to other cavities because of either recurrence of the cysts or failure of the peritoneum to absorb fluid [27]. Culture of the tip of the peritoneal catheter was reported to be more sensitive than culture of the CSF [8]. owel perforation is a rare complication of ventriculoperitoneal shunt placement, occurring in less than % of cases [9], among which nearly half are diagnosed after removal of the catheter. Possible causes of bowel perforation include the sharp tip of the shunting catheter, subclinical shunt infection, and increased protein content in the CSF [11]. Recently, silicon allergy, which may result in a foreign body like reaction, has been implicated in the breakdown and perforation of the bowel wall [18]. This complication can lead to fatal meningeal infection when not recognized early. The overall mortality rate of bowel perforation is nearly 15% in shunted patients [26]. In our study, one case (1.4%) of bowel perforation initially presented with subphrenic free air, and a subsequent abdominopelvic CT and exploratory laparotomy were performed, showing transverse colon perforation by the catheter tip. Patients with myelomeningocele or congenital hydrocephalus may be more prone to bowel perforation because of neurogenic weakness of the bowel wall from deficient innervations [7]. owel perforation can occur immediately after shunt placement or months or years later. Clinicians must be vigilant in their assessment for the presence of the following clinical conditions in shunted patients: meningitis or ventriculitis caused by an enteric microorganism (e.g., E. coli) and abdominal symptoms, such as prolonged unexplained diarrhea and fever [10]. owel perforation should be suspected in cases of shunt infection by gram-negative bacilli, pneumocephalus, prolonged unexpected diarrhea with sterile cultures, or abdominal pain [22]. The risk of ventriculoperitoneal shunt related complications varies with the use of prophylactic antibiotics, size and condition of the patient, and experience of the operating surgeon. Recognition of these facts and consequent changes in treatment have resulted in a steady improvement in the outcomes of patients undergoing ventriculoperitoneal shunt placement [33]. The imaging techniques for early detection of intraabdominal complications secondary to ventriculoperitoneal shunt include radiography, sonography, CT, and MRI. On radiography, the location of the shunt tip, displaced bowel gases, soft-tissue mass of pseudocyst, and intraperitoneal free air can be seen. On sonography, the internal content, septa, and wall thickness of pseudocysts can be observed well. On contrast-enhanced CT or MRI, the peritoneal thickening, bowel-wall thickening and contrast enhancement, omentomesentery infiltration, abscess, axial location of shunt tip and adjacent abnormal findings, and localized extraluminal air densities because of bowel perforation can be well evaluated. mong these techniques, however, CT may be more useful for the exact diagnosis of complicated intraabdominal abnormalities. There are a few limitations to this study. The study is retrospective; therefore, 30 cases were excluded for various reasons. The number of pathologically confirmed cases was small, with only 15.7% of microorganisms being cultured. Infiltration or infection of the abdominal wall, catheter track, or omentomesentery was diagnosed only according to the findings on CT images of fatty infiltration or a thick and enhanced catheter track wall and were not proven histologically. The localized peritoneal fluid collections with contrast-enhanced walls or internal septa were not analyzed for possible infection or localized peritonitis. Nevertheless, we believe that familiarity with the broad spectrum of ventriculoperitoneal shunt complications will enhance the role of radiologists in the management of intraabdominal complications [7]. high degree of suspicion and careful clinical and radiologic examinations could help diagnose and treat ventriculoperitoneal shunt related complications before they progress to more serious conditions. References 1. orgbjerg M, Gjerris F, lbeck MJ, Hauerberg J, orgesen SE. Frequency and causes of shunt revisions in different cerebrospinal fluid shunt types. cta Neurochir (Wien) 1995; 136: Sells CJ, Shurtleff D, Loeser JD. Gram-negative CSF shunt associated infections. Pediatrics 1977; 59: charya R, Ramachandran CS, Singh S. Laparoscopic management of abdominal complications in ventriculoperitoneal shunt surgery. 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