Su Bum Park

Cone-beam computed tomography evaluation of short- and long-term airway change and stability after orthognathic surgery in patients with Class III skeletal deformities: bimaxillary surgery and mandibular setback surgery

The purpose of this study was to evaluate the volumetric change of the upper airway space in 36 Class III patients who had undergone bimaxillary surgery or isolated mandibular setback, and, further, to analyse the relation between post-surgical stability and airway change using cone-beam computed tomography (CBCT). A three-dimensional (3D) CBCT examination was performed at three stages: T0 (before surgery), T1 (an average of 4.6 months after surgery), and T2 (an average of 1.4 years after surgery). The results showed that the volumes of the oropharyngeal and hypopharyngeal airways decreased significantly 4.6 months post-surgery in the mandibular setback group (p<0.05), and these diminished airways had not recovered 1.4 years post-surgery. In the bimaxillary surgery group, the volume of the oropharyngeal airway also decreased. A Spearman correlation analysis showed that the anteroposterior length of the hypopharyngeal area had a correlation with post-surgical stability in the isolated mandibular surgery group, and that the cross-sectional area of the nasopharynx was correlated with maxillary relapse only in the bimaxillary surgery group (p<0.05).

Endoscopic papillary large balloon dilation in Billroth II gastrectomy patients with bile duct stones

Background and Aims:  Patients with Billroth II (B‐II) gastrectomy present technical difficulties during endoscopic stone removal due to altered anatomy. Although endoscopic sphincterotomy alone or endoscopic balloon dilation alone has been used for removal of bile duct stones in patients with B‐II gastrectomy, the results are not satisfactory. The aim of this study was to evaluate the efficacy and safety of endoscopic papillary large balloon dilation (EPLBD) for removal of bile duct stones in patients with B‐II gastrectomy.

A Double-Layered (Comvi) Self-Expandable Metal Stent for Malignant Gastroduodenal Obstruction: A Prospective Multicenter Study

BackgroundA self-expandable metal stent (SEMS) has emerged as an effective palliative treatment for malignant gastroduodenal obstruction resulting from gastric or periampullary malignancy. Despite the stent’s effectiveness, tumor ingrowth and stent migration remain complications requiring reintervention. The purpose of this study was to evaluate the efficacy and safety of a double-layered SEMS (Comvi).MethodsWe performed a prospective multicenter study in two university hospitals and two referral hospitals. In fifty consecutive patients with malignant gastroduodenal obstructions, placement of double-layered SEMS, comprising an outer uncovered stent and an inner covered stent that overlap each other, was performed. Palliation, efficacy, and incidence of complications were evaluated.ResultsTechnical and clinical success was achieved in 100 and 88% of patients, respectively. There were no procedure-related complications. Five patients experienced stent migration (10%). For four of five patients’ stent migration occurred within two weeks of stent placement. Stent collapse occurred in five patients after one month. Reintervention for stent migration, collapse, or tumor overgrowth was required for 14 (28%) patients.ConclusionsEndoscopic placement of a double-layered stent is a safe and effective modality for the palliation of malignant gastroduodenal obstruction. However, considering reintervention, this stent does not seem to add any clear advantage compared with preexisting uncovered stents. Migration, especially within the first two weeks, and stent collapse are still unresolved problems. The device should be fixed or the design modified to reduce these problems.

Endoscopic Treatment of Dieulafoy Lesions and Risk Factors for Rebleeding

Background/Aims Dieulafoy lesions are an important cause of upper gastrointestinal bleeding. The purpose of this study was to assess the efficacy of endoscopic treatment for these lesions and to identify the possible predictive factors for rebleeding associated with clinical and endoscopic characteristics. Methods Records from 44 patients admitted with Dieulafoy bleeding between January 2006 and December 2007 were reviewed. We retrospectively analyzed the clinical and endoscopic findings and then correlated the rebleeding risk factors with Dieulafoy lesions. Results Primary hemostasis was achieved by endoscopic treatment in 39 patients (88.6%). There were no significant differences between the rebleeding and non-rebleeding groups with respect to age, gender, initial hemoglobin levels, presence of shock, concurrent disease, location of bleeding, or initial hemostatic treatment methods. However, the use of non-steroidal anti-inflammatory drugs or anticoagulants (p=0.02) and active stages in the Forrest classification (p<0.01) were risk factors for rebleeding after endoscopic therapy. Conclusions Endoscopic therapy is effective and safe for treating Dieulafoy lesions, and it has both short- and long-term benefits. Early identification of risk factors such as the use of non-steroidal anti-inflammatory drugs or anticoagulants and the Forrest classification of bleeding predict the outcome of Dieulafoy lesions.

Self-Assembled Polymeric Micelles Based on Hyaluronic Acid-g-Poly(d,l-lactide-co-glycolide) Copolymer for Tumor Targeting

Graft copolymer composed hyaluronic acid (HA) and poly(d,l-lactide-co-glycolide) (PLGA) (HAgLG) was synthesized for antitumor targeting via CD44 receptor of tumor cells. The carboxylic end of PLGA was conjugated with hexamethylenediamine (HMDA) to have amine end group in the end of chain (PLGA-amine). PLGA-amine was coupled with carboxylic acid of HA. Self-assembled polymeric micelles of HAgLG have spherical morphologies and their sizes were around 50–200 nm. Doxorubicin (DOX)-incorporated polymeric micelles were prepared by dialysis procedure. DOX was released over 4 days and its release rate was accelerated by the tumoric enzyme hyaluronidase. To assess targetability of polymeric micelles, CD44-positive HepG2 cells were employed treated with fluorescein isothiocyanate (FITC)-labeled polymeric micelles. HepG2 cells strongly expressed green fluorescence at the cell membrane and cytosol. However, internalization of polymeric micelles were significantly decreased when free HA was pretreated to block the CD44 receptor. Furthermore, the CD44-specific anticancer activity of HAgLG polymeric micelles was confirmed using CD44-negative CT26 cells and CD44-positive HepG2 cells. These results indicated that polymeric micelles of HaLG polymeric micelles have targetability against CD44 receptor of tumor cells. We suggest HAgLG polymeric micelles as a promising candidate for specific drug targeting.

Effect of setback Le Fort I osteotomy on midfacial soft-tissue changes as evaluated by cone-beam computed tomography superimposition for cases of skeletal Class III malocclusion

This study employed the cone-beam computed tomography (CBCT) superimposition method to evaluate postoperative midfacial soft-tissue changes in cases of skeletal Class III malocclusion after double-jaw surgery with setback and vertical reduction Le Fort I osteotomy. A retrospective study was carried out on 15 patients who had undergone maxillary setback Le Fort I osteotomy and mandibular setback sagittal split ramus osteotomy with alar cinch suturing and V-Y soft-tissue closure. Three dimensional CBCT volume scans were recorded preoperatively (T0) and 6 months postoperatively (T1) to measure soft-tissue changes of the upper lip and midface. Post-surgery, soft-tissue landmarks in the cheek and paranasal areas had moved forward; the soft-tissue thickness at the A-point had markedly increased (P<0.05); there was no significant change in the subnasale, and the midline of the soft-tissue of the upper-lip area had moved backward. The extent of the mean soft-tissue change at the labrale superius was greater than that at the other soft-tissue landmarks of the upper lip. The results suggest that maxillary setback movement of the maxilla by alar cinch suturing has a beneficial effect on paranasal soft-tissue and lip contours for patients with protrusive lip and acute nasolabial angle.

Double layered self-expanding metal stents for malignant esophageal obstruction, especially across the gastroesophageal junction

AIM To evaluate the clinical outcomes of double-layered self-expanding metal stents (SEMS) for treatment of malignant esophageal obstruction according to whether SEMS crosses the gastroesophageal junction (GEJ). METHODS Forty eight patients who underwent the SEMS insertion for malignant esophageal obstruction were enrolled. Patients were classified as GEJ group (SEMS across GEJ, 18 patients) and non-GEJ group (SEMS above GEJ, 30 patients) according to SEMS position. Double layered (outer uncovered and inner covered stent) esophageal stents were placed. RESULTS The SEMS insertion and the clinical improvement were achieved in all patients in both groups. Stent malfunction occurred in seven patients in the GEJ group and nine patients in the non-GEJ group. Tumor overgrowth occurred in five and eight patients, respectively, food impaction occurred in one patient in each group, and stent migration occurred in one and no patient, respectively. There were no significant differences between the two groups. Reflux esophagitis occurred more frequently in the GEJ group (eight vs five patients, P = 0.036) and was controlled by proton pump inhibitor. Aspiration pneumonia occurred in zero and five patients, respectively, and tracheoesophageal fistula occurred in zero and two patients, respectively. CONCLUSION Double-layered SEMS are a feasible and effective treatment when placed across the GEJ for malignant esophageal obstruction. Double-layered SEMS provide acceptable complications, especially migration, although reflux esophagitis is more common in the GEJ group.

Endoscopic Mucosal Resection with Circumferential Incision for the Treatment of Large Sessile Polyps and Laterally Spreading Tumors of the Colorectum

Background/Aims Endoscopic mucosal resection (EMR) is the standard treatment for colorectal polyps such as adenomas and early cancers with no risk of lymph node metastasis. However, endoscopic resection of large colorectal polyps (≥20 mm diameter) is difficult to perform. We evaluated the clinical outcomes of EMR with circumferential incision (EMR-CI) for the resection of large sessile polyps (Is) and laterally spreading tumors (LSTs) in the colorectum. Methods Between February 2009 and March 2011, we resected 80 large colorectal polyps by EMR-CI. We retrospectively investigated the en bloc resection rate, histologic complete resection rate, recurrence rate, and complications. Results The median polyp size was approximately 25 mm (range, 20 to 50), and the morphologic types included Is (13 cases), LST-granular (37 cases), and LST-nongranular (30 cases). The en bloc and complete histologic resection rates were 66.3% and 45.0%, respectively. The recurrence rate was 0% (median follow-up duration, 23 months), and perforation occurred in five cases (6.3%). Conclusions EMR-CI is an effective treatment modality for 20 to 30 mm-sized colorectal polyps, and may be considered as a second line therapeutic option if ESD is difficult.

Usefulness of Percutaneous Transhepatic Cholangioscopic Lithotomy for Removal of Difficult Common Bile Duct Stones

Background/Aims Approximately 5% to 10% of common bile duct (CBD) stones are difficult to remove by conventional endoscopic methods. Percutaneous transhepatic cholangioscopic lithotomy (PTCSL) can be an alternative method for this condition, but is not well established yet. The aim of this study was to evaluate the clinical efficacy and safety of PTCSL for removal of difficult CBD stones. Methods This study is a retrospective review of 34 consecutive patients who underwent unsuccessful removal of CBD stones using conventional endoscopic methods between December 2008 and July 2010 and were subsequently treated using PTCSL. Results Among 443 patients with CBD stones, 34 patients (7.8%) failed to achieve stone removal using conventional endoscopic methods. Of these 34 patients, 33 were treated using PTCSL. In all 33 cases (100%), complete stone removal was achieved using PTCSL. Most complications (15/17, 88.2%) were mild and transient. Major complications occurred in two patients (6.1%) who experienced hemobilia, and percutaneous transhepatic biliary drainage tract disruption, respectively; which were fully recovered without mortality. Conclusions Despite prolonged hospital stay and temporary decline of quality of life, PTCSL is an effective and safe method in the management of difficult CBD stones, especially in patients with difficulty in approaching the affected bile duct.

Efficacy of cap-assisted colonoscopy according to lesion location and endoscopist training level

AIM To evaluate the efficacy of cap-assisted colonoscopy (CAC) for detection of colorectal polyps and adenomas according to the lesion location and endoscopist training level. METHODS Patients 20 years or older, who underwent their first screening colonoscopy in a single tertiary center from May 2011 to December 2012 were enrolled in this study. All patients underwent either CAC or standard colonoscopy (SC), and all of the procedures were performed by 11 endoscopists (8 trainees and 3 experts). All procedures were performed with high-definition colonoscopes and narrow band imaging. The eight trainees had experiences of performing 150 to 500 colonoscopies, and the three experts had experiences of performing more than 3000 colonoscopies. A 4-mm-long transparent cap was attached to the end of a colonoscope in the CAC group. We retrospectively evaluated the number of polyps and adenomas, polyp detection rate (PDR), and the number of adenomas and adenoma detection rate (ADR) according to the lesion location and endoscopist training level between CAC and SC. We also evaluated the number of polyps and adenomas according to their size between CAC and SC. RESULTS Overall, PDR and ADR using CAC were significantly higher than those using SC for both whole colon (48.5% vs 40.7%, P = 0.012; 35.7% vs 28.3%, P = 0.012) and right-side colon (35.3% vs 26.6%, P = 0.002; 27.0% vs 16.9%, P < 0.001). The number of polyps and adenomas per patient using CAC was significantly higher than that using SC for both the whole colon (1.07 ± 1.59 vs 0.82 ± 1.31, P = 0.008; 0.72 ± 1.32 vs 0.50 ± 1.01, P = 0.003) and right-side colon (0.66 ± 1.18 vs 0.41 ± 0.83, P < 0.001; 0.46 ± 0.97 vs 0.25 ± 0.67, P < 0.001). In the trainee group, the PDR and ADR using CAC were significantly higher than those using SC for both the whole colon (46.7% vs 39.7%, P = 0.040; 33.9% vs 26.0%, P =0.012) and right-side colon (34.2% vs 26.5%, P = 0.015; 25.3% vs 15.9%, P = 0.001). In the expert group, the PDR and ADR using CAC were significantly higher than those using SC only for the right-side colon (42.1% vs 27.0%, P =0.035; 36.8% vs 21.0%, P = 0.020). CONCLUSION CAC is more effective than SC for detection of colorectal polyps and adenomas, especially when performed by trainees and when the lesions are located in the right-side colon.