The radiologic diagnosis of idiopathic myointimal hyperplasia of mesenteric veins with a novel presentation: case report and literature review.

Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare condition of the rectosigmoid colon that primarily affects middle-aged men. IMHMV typically presents as proctosigmoiditis and often requires surgical resection due to complications throughout the protracted clinical course. It can be differentiated from idiopathic chronic inflammatory bowel disease by histopathologic examination of surgically resected colon specimens. This report describes a rare case of IMHMV presenting as left hemicolitis in a 64-year-old male. We also describe potentially distinguishing computed tomographic and angiographic findings that may aid in the diagnosis of IMHMV.

Discriminating renal nutcracker syndrome from asymptomatic nutcracker phenomenon using multidetector computed tomography.

PURPOSE: To retrospectively evaluate the ability of computed tomographic (CT) findings to discriminate nutcracker syndrome (NCS) from asymptomatic nutcracker phenomenon (NCP) and to investigate the diagnostic value of CT findings in diagnosis of NCS. METHODS: From January 2014 to April 2015, 216 patients who underwent initial urographic CT were included. Initially, 216 patients were categorized as "nutcracker" or "normal," based on the following CT criteria: (1) the presence of beak sign and (2) hilar-aortomesenteric left renal vein diameter ratio >4. Patients who satisfied both of these criteria were diagnosed with nutcracker. The nutcracker was then divided into "NCS" and "asymptomatic NCP" based on the presence of characteristic symptoms. CT findings in sagittal and axial scans of corticomedullary phase were evaluated. Multivariate analysis was used to identify significant factors among 30 NCS, 51 asymptomatic NCP, and 135 normal patients. Diagnostic performance and threshold using receiver operating characteristic (ROC) curve were calculated. RESULTS: A total of 131 males and 85 females, with mean age of 38.6 years (range 18-89 years), were included. Multivariate analysis demonstrated superior mesenteric artery (SMA)-aortic angle (p < 0.001) and visualization of a dilated collateral vein with reflux (p = 0.001) were independent factors for distinguishing NCS from asymptomatic NCP. The combination of SMA-aortic angle <25° and visualization of a dilated collateral vein with reflux provided the greatest diagnostic accuracy (area under the ROC curve, 0.841). CONCLUSIONS: The combination of SMA-aortic angle and visualization of a dilated collateral vein with reflux in multidetector CT can be useful to differentiate NCS from asymptomatic NCP.

Fluoroscopically guided large balloon dilatation for treating congenital esophageal stenosis in children.

PURPOSE: We aimed to evaluate the safety and clinical effectiveness of fluoroscopically guided large balloon dilatation for treating congenital esophageal stenosis in children. METHODS: Our study included seven children (mean age 4.0 years) who underwent a total of ten balloon dilatation sessions. The initial balloon diameters were 10-15 mm. The technical success, clinical success (improved food intake and reduced dysphagia within 1 month following the first balloon dilatation), dysphagia recurrence, and complications were retrospectively evaluated. RESULTS: Technical and clinical success rates were 100 %. During the mean 38-month follow-up period after the first balloon dilatation, 3 (43 %) patients underwent only one additional balloon dilatation 4-5 months after the first balloon dilatation for dysphagia recurrence. Two of them showed improvement without further recurrence, while the remaining one underwent partial esophagectomy. Well-contained transmural esophageal rupture (type 2) occurred in two (29 %, 2/7) patients and during two (20 %, 2/10) balloon dilatation sessions. All ruptures were successfully treated conservatively. CONCLUSIONS: Our study showed that fluoroscopically guided large balloon dilatation seems to be a simple and effective primary treatment technique for congenital esophageal stenosis in children. Esophageal ruptures were not uncommon although they were not fatal.

Femoral artery access using the US-determined inguinal ligament and femoral head as reliable landmarks: prospective study of usefulness and safety.

PURPOSE: To evaluate ultrasound (US)-guided femoral artery access using the US-determined inguinal ligament (IL; US-IL) and femoral head as anatomic landmarks to prevent "high stick" (ie, cannulation above the IL) of the common femoral artery (CFA). MATERIALS AND METHODS: Fifty consecutive US-guided femoral artery accesses for embolization of hepatocellular carcinoma (n = 49) or renal angiography (n = 1) between December 2008 and August 2009 were prospectively analyzed. Primary endpoints were evaluation of technical success and major/minor complications during the procedure and follow-up visits. Secondary endpoints were the relative locations of the US-IL, fluoroscopically determined IL (FL-IL), and origin site of the inferior epigastric artery (IEA) on completion angiography. Relationships were evaluated between CFA types and lengths on US, between CFA types on US, and between frequencies of low-lying US-IL on fluoroscopy. Spearman correlation, Student t test, and Fisher exact test were used for statistical analysis. RESULTS: Technical success of CFA access was achieved in all patients (100%), with no high stick of the CFA noted. No complications were noted. On fluoroscopy, US-IL was located significantly lower than FL-IL (P = .002). On fluoroscopy and completion angiography, US-IL was more strongly correlated (ρ = 0.823, P < .001) with the IEA origin site than with the FL-IL (ρ = 0.287, P = .043). Finally, a "slope-type" CFA was shorter than a "horizontal-type" CFA on US and was more common in patients with low-lying US-IL on fluoroscopy (P = .001). CONCLUSIONS: US-guided CFA access with US-IL and femoral head guidance is safe and useful and can be helpful in preventing high stick.

The roles of the liver and pancreas in renal nutcracker syndrome.

INTRODUCTION: To assess the frequency and significance of presence of the liver and pancreas at the left renal vein (LRV) level in patients with suspected renal nutcracker syndrome (NCS). MATERIALS AND METHODS: We included 101 patients with hematuria who underwent urography three-dimensional CT between April 2009 and November 2013. These patients were divided into NCS (n=25) and non-NCS (n=76) patients according to the following CT criteria: (1) the presence of beak sign and (2) hilar-aortomesenteric left renal vein diameter ratio >4. Patients were grouped according to the presence of the liver and pancreas at the LRV: group LP (both liver and pancreas), group L (only liver), group P (only pancreas), and group O (neither liver nor pancreas). The difference in the frequencies of groups was analyzed between NCS and non-NCS patients. Multivariate analysis was used to determine the independent factors between NCS and non-NCS patients. RESULTS: The frequencies of group LP, group L, group P, and group O in NCS vs. non-NCS were 88% vs. 5.3% (p<0.001), 4.0% vs. 2.6% (p=0.75), 4.0% vs. 11.8% (p=0.45), 4.0% vs. 80.3% (p<0.001), respectively. Multivariate analysis demonstrated that group was a predictor for differential diagnosis between NCS and non-NCS (p=0.022), and group LP was an independent factor for the presence of NCS (odds ratio, 43.8; 95% confidence interval, 3.8-500.3; p<0.002; reference, group O). CONCLUSION: The presence of the liver and pancreas at the level of the LRV was frequently found in NCS and was the independent factor for NCS.

Mmp-9 expression after metallic stent placement in patients with colorectal cancer: association with in-stent restenosis.

PURPOSE: To verify the expression of matrix metalloproteinase (MMP)-9 in stent-induced hyperplastic tissue from patients with colorectal cancer who received colorectal stents as a bridge to surgery. MATERIALS AND METHODS: This prospective study was institutional review board-approved, and informed consent was obtained from all patients. Eleven patients (nine men, two women; mean age, 67 years; age range, 53-82 years) with malignant colorectal obstructions who received a colorectal stent between May and December 2010 were included. Tissue specimens were analyzed for MMP-9 and MMP-2 expression. After resection, the tissue was segmented into three parts: tumor tissue, stent-induced tissue hyperplasia, and normal colon tissue. MMP-9 and MMP-2 expression were determined by using zymography, Western blot analysis, and real-time reverse-transcription (qRT) polymerase chain reaction (PCR). Significance of differences between groups was evaluated with Friedman analysis of variance test. Signed-rank test was used to determine differences between malignant tumor tissue and stent-induced hyperplastic tissue groups. RESULTS: Stent placement was technically successful in all 11 patients. Stent-induced hyperplastic tissues were found in all patients. Zymography (P = .003) and Western blot analysis (P = .008) showed that expression of MMP-9 was higher in malignant tumor tissue and stent-induced hyperplastic tissue groups compared with normal colorectal tissue group, demonstrating significant differences between groups but no significant differences between malignant tumor and stent-induced hyperplastic tissues. As for results of qRT PCR analysis, the stent-induced hyperplastic tissue group showed increases in messenger RNA expression level of MMP-9 compared with the malignant tumor tissue group (50.42-fold ± 66.30 higher). CONCLUSION: High expression of MMP-9 is closely associated with stent-induced colorectal tissue hyperplasia in patients with colorectal cancer.

Use of Reversed Iliac Leg Stent-Graft for the Treatment of Isolated Aneurysm of Internal Iliac Artery.

This is to report the technique of reversed iliac leg stent-graft in endovascular treatment for isolated internal iliac artery (IIA) aneurysm, which had significant size discrepancy between the common iliac artery (CIA) and external iliac artery (EIA) in 3 patients from different hospitals. Three patients were a 85- and two 82-year-old men. Treated were right IIA aneurysms, sized 6.5×6.2 cm, 5.0×4.0 cm, and 4.1 cm in longest diameter, respectively. The diameters of the right CIA and right EIA measured 21 mm/11 mm, 15 mm/11 mm, and 20 mm/10 mm, respectively. In all cases, reversed iliac leg stent-grafts were prepared on-site; unsheathed and mounted upside-down manually, and deployed in each right CIA. Post-stent-graft angiograms showed complete exclusion of the aneurysms, except for minimal type 1 endoleak in one case. This technique is a useful treatment option in patients with isolated IIA aneurysm.

Bleeding after expandable nitinol stent placement in patients with esophageal and upper gastrointestinal obstruction: incidence, management, and predictors.

BACKGROUND: Placement of self-expandable nitinol stents is useful for the treatment of esophageal and upper gastrointestinal (GI) obstruction. However, complications such as stent migration, tumor overgrowth, and bleeding occur. Although stent migration and tumor overgrowth are well documented in previous studies, the occurrence of bleeding has not been fully evaluated. PURPOSE: To evaluate the incidence, management strategies, and predictors of bleeding after placement of self-expandable nitinol stents in patients with esophageal and upper GI obstruction. MATERIAL AND METHODS: We retrospectively reviewed the medical records and results of computed tomography and endoscopy of 1485 consecutive patients with esophageal and upper GI obstructions who underwent fluoroscopically guided stent placement. RESULTS: Bleeding occurred in 25 of 1485 (1.7%) patients 0 to 348 days after stent placement. Early stent-related bleeding occurred in 10 patients (40%) and angiographic embolization was used for 5/10. Late bleeding occurred in 15 patients (60%) and endoscopic hemostasis was used for 7/15. Twenty-two of 25 (88%) patients with bleeding had received prior radiotherapy and/or chemotherapy. CONCLUSION: Bleeding is a rare complication after placement of expandable nitinol stents in patients with esophageal and upper GI obstruction, but patients with early bleeding may require embolization for control. Care must be exercised on placing stents in patients who have received prior radiotherapy or chemotherapy.

Usefulness of a guiding sheath for fluoroscopic stent placement in patients with malignant gastroduodenal obstruction.

BACKGROUND: Self-expandable metallic stent placement is widely used to manage malignant gastroduodenal obstructions. However, there are difficulties in negotiating a guidewire (GW) and a stent delivery system (SDS). PURPOSE: To investigate feasibility, usefulness, and safety of a guiding sheath for fluoroscopic stent placement in patients with malignant gastroduodenal obstructions. MATERIAL AND METHODS: In July 2001 to August 2011, 726 patients with malignant gastroduodenal obstructions underwent stent placement. Guiding sheath was used in patients in whom a GW could not be passed through the obstruction and a SDS failed to reach the obstruction. Sheath usefulness was evaluated based on the ability of the sheath to successfully assist. The technical success rate and the most frequent reasons for the use of a sheath were evaluated. RESULTS: The guiding sheath was needed in 148 of 726 patients (20%). The overall technical success rate was 98% with the guiding sheath. In two of 148 patients, stent placement failed because, the GW could not be passed through the obstruction, in the other, the SDS could not be passed. A minority of patients reported mild discomfort. Patients with pancreatic cancer and duodenal obstruction were significantly more likely to require the use of guiding sheaths (P = 0.002, P < 0.001, respectively). CONCLUSION: Using a guiding sheath for fluoroscopic stent placement appears to be feasible, useful and safe in patients with malignant gastroduodenal obstructions.

Endovascular abdominal aortic aneurysm repair in patients with renal transplant.

The repair of abdominal aortic aneurysm (AAA) in patients with functioning renal transplant is critical because it is important to avoid ischemic and reperfusion injury to the transplanted kidney. Endovascular aneurysm repair (EVAR) avoids aortic cross clamping and can prevent renal graft ischemia. Here we report the endovascular management and outcome of AAA in two renal transplant patients using a bifurcated aortic stent graft. One patient underwent EVAR using a small amount of contrast (30 mL) due to decreased renal function resulting from chronic rejection. Another patient had EVAR performed with iliac conduit because of the heavily calcified, stenotic lesion of external iliac artery. EVAR in patients with a renal transplant is a feasible option without impairing renal arterial flow.

Placement of retrievable self-expandable metallic stents with barbs into patients with obstructive prostate cancer.

OBJECTIVES: To evaluate the technical feasibility and clinical effectiveness of retrievable self-expandable metallic stents with barbs in patients with obstructive prostate cancer. METHODS: Retrievable self-expandable metallic stents with eight barbs each were inserted into eight consecutive patients with obstructive prostate cancer. Patient ages ranged from 55 to 76 years (mean, 69 years). All eight patients had previously received hormone therapy, and three had undergone palliative transurethral prostatectomy. Stents were removed using a 21-F stent removal set if they caused complications. RESULTS: Stent placement was technically successful and well tolerated in all patients. One had severe incontinence, which improved spontaneously, and two had gross haematuria, which disappeared spontaneously within 4 days. Peak urine flow rates and post-void residual urine volumes 1 month after stent placement were 5.6-10.2 ml/s (mean, 8.3 ml/s), and 5-45 ml (mean, 27 ml), respectively. During a mean follow-up of 192 days (range, 39-632 days), one patient required stent removal after 232 days because of stone formation within the stent. No further intervention was required because the mass improved after stent removal. CONCLUSIONS: These preliminary results suggest that retrievable stents with eight barbs are both feasible to place and effective in patients with obstructive prostate cancer.

Evaluation of the anti-migration effect of barbed prostatic stents: in vitro study in urethra-mimicking bovine pericardium phantoms.

PURPOSE: This study was designed to compare the migration rates of covered stents with eight, four, and zero barbs in urethra-mimicking bovine pericardium models. METHODS: Three types of polytetrafluoroethylene-covered retrievable self-expandable prostatic stents, with eight, four, and zero barbs, were tested in bovine pericardium models, consisting of normal saline-filled acrylic containers with tubes at both ends and a replica of the human urethra. The barbs were 2 mm in length and projected 60° toward the urinary bladder. The anti-migration force (AMF) and resistance force against stent removal (RFSR) were measured by an automatic push-pull gauge system at a fixed rate (2 mm/s). RESULTS: Significant differences in AMF among the three stent types were detected (P < 0.001). Median AMF was far greater for eight-barbed than for four-barbed stents (11.96 vs. 7.55 N, P = 0.003). For stent removal, the difference between 4- and 8-barbed stents were not significant in median static (5.54 vs. 6.08 N, P = 0.15) or sliding (prostatic urethra, 5.32 vs. 5.59 N, P = 0.65; membranous urethra, 7.78 vs. 8.57 N, P = 0.364) RFSR. No perforations or scratched traces were observed during removal of these stents. CONCLUSIONS: The inclusion of eight barbs projecting 60° toward the urinary bladder were not only effective against stent migration in this model but suggests that these stents may be suitable for the treatment of prostatic urethral strictures without severely irritating the tissue. However, whether these results translate into living urethral tissue is unclear, necessitating further studies.

Afferent loop syndrome: treatment by means of the placement of dual stents.

OBJECTIVE: The purpose of this article is to assess the technical feasibility and clinical effectiveness of the placement of partially covered self-expandable dual stents in patients with afferent loop syndrome. MATERIALS AND METHODS: Data from 13 consecutive patients who had undergone partially covered dual stent placement for afferent loop syndrome after various types of surgery were retrospectively analyzed. Nine patients underwent stent placement via the percutaneous transhepatic biliary drainage tract, and four patients underwent placement via the peroral route. A total of 16 stents were used in this study (i.e., 15 dual stents and one fully covered esophageal stent). RESULTS: The route of stent insertion was determined on the basis of each patient's general condition, the site of obstruction, anatomic variations, and associated symptoms. Stent placement was technically successful in all patients. After stent placement, 12 of 13 patients experienced normalization of their abnormal biliary laboratory findings and decompression of the dilated bowel loop, whereas the remaining patient showed no change. This patient had to undergo the additional treatment of surgical jejunojejunostomy. No procedure-related complications occurred in any patients enrolled in this study. CONCLUSION: Placement of partially covered dual stents appears to be a promising technique that may offer successful palliation for patients who develop afferent loop syndrome after various types of surgery.

Usefulness of a guiding sheath for fluoroscopic colorectal stent placement.

OBJECTIVE: To investigate the technical feasibility, clinical usefulness, and safety of a guiding sheath in fluoroscopic stent placement for patients with malignant colorectal obstructions. MATERIALS AND METHODS: Between June 2007 and January 2011, fluoroscopic placement of a dual colorectal stent was attempted in a total of 97 patients with malignant colorectal obstructions. A polytetrafluoroethylene guiding sheath was used in patients in whom a stent delivery system failed to reach the obstruction. Usefulness of the sheath was evaluated depending on whether the sheath could successfully assist the stent delivery system reach its area of interest. RESULTS: The guiding sheath was needed in 22 patients (15 men, 7 women; age range, 33-77 years; mean age, 59 years). The overall success rate for passing the sheath to the area of interest was 100%. There were no procedure-related deaths or major complications. The majority of the patients reported mild discomfort. In 2 of 22 patients with successful passing of the sheath to the area of interest, stent placement failed because of failure in the negotiation of a guide wire through the obstruction. CONCLUSION: Using a guiding sheath seems to be easy, safe and useful in fluoroscopic stent placement for patients with malignant colorectal obstructions.

Placement of a covered expandable metallic stent to treat nonanastomotic malignant jejunal obstructions after total gastrectomy with esophagojejunostomy.

OBJECTIVE: The objective of our study was to assess the technical feasibility and clinical effectiveness of expandable metallic stent placement in patients with nonanastomotic malignant jejunal obstruction after total gastrectomy with esophagojejunostomy. MATERIALS AND METHODS: We retrospectively analyzed data from 21 patients with malignant jejunal obstruction after total gastrectomy with esophagojejunostomy who received one of two types of expandable metallic stent. Clinical effectiveness was assessed using the following variables: technical and clinical outcomes, complications, dysphagia scores before and after stent placement, patient survival, and stent patency. Complications with related interventions were evaluated and compared between the two stent types. RESULTS: Stent placement was technically successful in 20 of the 21 patients (95%) with 19 of 20 patients (95%) showing symptomatic improvement. Type A stents were used in 10 patients and type B stents in the remaining 10 patients. Complications occurred with seven of 20 stents (35%) and involved stent migration (n = 3), tumor overgrowth (n = 3), or pain (n = 1). The dysphagia score before stent placement (mean ± SD, 3.2 ± 0.5) had improved by 3 days after stent placement (1.3 ± 0.9, p < 0.001) and was maintained compared with the initial score up to 1 month (1.7 ± 1.1, p < 0.001) and 3 months (2.1 ± 1.5, p = 0.021) after stent placement. The median patient survival and stent patency were 114 and 46 days, respectively. The type of stent was not significantly related to complications (p = 0.350). CONCLUSION: Placement of expandable metallic stents to treat nonanastomotic malignant jejunal obstruction in patients who have undergone total gastrectomy with esophagojejunostomy is feasible and clinically effective.

Auxiliary partial orthotopic liver transplantation for adult onset type II citrullinemia.

Adult-onset type II citrullinemia (CTLN2) is a disorder caused by an inborn error of metabolism affecting the liver. CTLN2 is an autosomal recessive disorder characterized by recurrent encephalopathy with hyperammonemia due to highly elevated plasma levels of citrulline and ammonia, caused by a deficiency of argininosuccinate synthetase in the liver. A small number of patients have undergone liver transplantation with favorable results. In Korea, the limitations of the deceased donor pool have made living donor liver transplantation a common alternative treatment option. We report the case of a patient with type II citrullinemia who was treated successfully with auxiliary partial orthotopic liver transplantation (APOLT) from a living donor. This is the first description of an APOLT for a patient with adult onset type II citrullinemia in Korea.

Ultrasound-guided biopsy of focal lesions using three-dimensional ultrasound with a matrix array transducer: comparison with 2-dimensional ultrasound in a phantom study.

OBJECTIVES: To investigate the feasibility of biopsy-guided 3-dimensional (3D) ultrasound (US) with a matrix array transducer (3D US-MAT), using the lateral and/or elevation tilt modes. MATERIALS AND METHODS: Both inexperienced and experienced examiners performed biopsy experiments using a freehand technique on agar-based phantoms with 2-dimensional (2D) US guidance and 3D US-MAT guidance allowing real-time biplane imaging, using the lateral tilt mode and/or elevation tilt mode. Each phantom contained 4 targets of different sizes, and there were 3 different types of phantom, each having a different distance between the target and the surface. In every session, each target was aimed at 3 times, with 3 different distances between the transducer and puncture site, which resulted in 36 biopsies (3 biopsies per target × 4 targets × 3 phantoms, each of which was uniquely identified by size, depth, and angle). This procedure was carried out by each of 2 examiner twice by 2D US and twice by 3D US-MAT, resulting in paired data for each biopsy and each examiner. Target variables were target specimen length (TSL), procedure time, and agreement between the TSL of the first and second procedure by each examiner with identical biopsy parameters as a reliability measure. RESULTS: The intraexaminer agreements between the TSLs with the 3D US-MAT in both inexperienced (r = 0.84) and experienced (r = 0.93) examiners were higher than with the 2D US (r = 0.59 with P = 0.0066, and r = 0.87 with P = 0.06, respectively). However, the procedure time with the 3D US-MAT was significantly longer than with the 2D US. The TSL were significantly longer with 3D US-MAT than with 2D US for both the examiners; the inexperienced examiner (P < 0.001) benefited more than his experienced colleague (P = 0.024). In addition, the 3D US-MAT had significant benefits for the acquisition of TSL with small target diameters and for targets with shallow locations; with more acute puncture angles for both the examiners (all P < 0.05). CONCLUSIONS: Using a 3D US-MAT guidance improves the reliability and precision of biopsies, particularly under difficult conditions and for inexperienced examiners.

The spectrum of vascularized superficial soft-tissue tumors on sonography with a histopathologic correlation: Part 1, benign tumors.

OBJECTIVE: The objective of this article is to illustrate the sonographic findings of benign, vascularized superficial soft-tissue tumors. CONCLUSION: Sonography can play an important role in the diagnosis of benign, vascularized superficial soft-tissue tumors. Awareness of these findings is important in establishing the correct diagnosis and determining the optimal treatment.

Use of guiding sheaths in peroral fluoroscopic gastroduodenal stent placement.

Our purpose was to assess the safety and usefulness of guiding sheaths in peroral fluoroscopic gastroduodenal stent placement. Two types of guiding sheath were made from straight polytetrafluoroethylene tubes. Type A was 80 cm in length, 4 mm in outer diameter and 3 mm in inner diameter. Type B was 70 cm in length, 6 mm in outer diameter and 5 mm in inner diameter. The type A sheath was used in 18 patients in whom a catheter-guide wire combination failed to pass through a stricture. The type B sheath was used in 22 patients in whom a stent delivery system failed to pass through the stricture due to loop formation within the gastric lumen. The overall success rate for guiding a catheter-guide wire through a stricture after using the type A sheath was 89%. The overall success rate for passing a stent delivery system through a stricture after using the type B sheath was 100%. All procedures were tolerated by the patients without any significant complications. The guiding sheaths were safe and useful in peroral fluoroscopic gastroduodenal stent placement.