Deok Ho Nam

Malignant esophageal-tracheobronchial strictures: parallel placement of covered retrievable expandable nitinol stents.

Purpose: To assess the safety and clinical effectiveness of the parallel placement of covered retrievable expandable metallic stents in the palliative treatment of malignant esophageal and tracheobronchial strictures. Material and Methods: Under fluoroscopic guidance, parallel stents were placed in 12 symptomatic patients with both malignant esophageal and tracheobronchial strictures. Seven of these 12 patients also had an esophagorespiratory fistula (ERF) and one patient had an esophagocutaneous fistula. Technical success, clinical improvement, complications, and survival rates were evaluated. Results: A total of 28 esophageal and airway stents were successfully placed. The grade of dysphagia and dyspnea score significantly decreased after stent placement (P = 0.002 and 0.003, respectively). ERF and esophagocutaneous fistula were sealed off in all eight patients after esophageal stent placement; however, the esophagocutaneous fistula reopened 1 month later. Complications included stent migration or expectoration (n = 3), tracheal compression by the esophageal stent (n = 3), new fistula development due to covering membrane degradation of the esophageal stent (n = 1), and symptomatic sputum retention (n = 1). Stent removal was easily performed for two stents; one migrated stent and the other with covering membrane degradation. All 12 patients died within the mean survival period of 72.50 days (range 7–375 days). Conclusion: Parallel placement of covered retrievable expandable metallic stents is safe and effective for the palliative treatment of malignant esophageal and tracheobronchial strictures.

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.

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 patients 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.

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.

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.

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.

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.

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.

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.