Comparison of Eastern and Western patients undergoing bariatric surgery at two US and Korean institutions: a retrospective analysis of differing bariatric patient populations.

BACKGROUND: Currently, there are differences in both demographics and indications for bariatric surgery between Eastern and Western countries. We compared postoperative outcomes between Korean and American bariatric programs in order to assess how bariatric surgery differently affects these populations. METHODS: We enrolled 540 patients who underwent bariatric surgery at University of California, Los Angeles (UCLA) and 85 patients who underwent surgery at Kosin University Gospel Hospital (KUGH) between January 2019 and December 2020. We compared demographics, complications, weight loss, and metabolic parameters between these groups. RESULTS: There was a difference in age between the UCLA and KUGH patient groups (44.3 years vs 37.6 years, P < 0.01). Frequencies of T2DM and OSA were also different (4.2% vs 50.6%, 34.1% vs 85.9% P < 0.01. Length of hospital stay varied (1.55 days vs 6.68 days, P < 0.01), but there was no difference in operating time and complications. There was no difference in percent of excess weight loss between the two groups at 6 months (29.7 vs 33.8, P = 0.13). Hepatic steatosis index (HSI) was higher in the UCLA group both before (54.2 vs 51.5, P < 0.01) and after (44.4 vs 40.0, P = 0.02) surgery. LSG was the most frequently performed operation, and robotic surgery and revisions were performed only in the UCLA program. CONCLUSION: There were differences in age, BMI, length of stay, and choice of operation between Korean and American bariatric patients. Also, there were differences in the degree of fatty liver disease using HSI and liver enzymes before and after surgery. There was no significant differences in operation time and complications. These findings suggest differences in bariatric practices and reactions to bariatric surgery in Eastern and Western settings.

Solitary osteolytic skull metastasis as the only recurrence of advanced gastric cancer: a case report and literature review.

Bone metastases from gastric cancer are very rare, and skull metastases develop in only 11.2% among patients who develop bone metastases from gastric cancer. We report a case of solitary osteolytic skull metastasis as the only recurrence of advanced gastric cancer. A 67-year-old man was referred to us with a two-month history of headache and progressive scalp swelling in the left parietal region. A right hemiparesis developed a week before admission. Thirteen months previously, he had undergone radical total gastrectomy with Roux-en-Y reconstruction. Pathological analysis indicated well-differentiated adenocarcinoma of the gastric cardia (stage IIIA: pT3N2M0). Brain magnetic resonance imaging showed a large skull metastasis in the left parietal region (approximately 65 × 54 mm). An extensive search did not reveal any other tumors. Gross total tumor resection was performed, and the biopsy revealed an adenocarcinoma, suggesting metastasis of the gastric cancer.

Appropriate Number of Adjuvant Chemotherapy Cycles for Patients with Stage 2 or 3 Gastric Cancer After Curative Gastrectomy: A Multicenter Cohort Study.

BACKGROUND: Few studies have presented evidence pertaining to the adequate minimum number of adjuvant chemotherapy (AC) cycles required to achieve an oncologic benefit for gastric cancer. METHODS: From January 2012 to December 2013, data from patients who underwent curative radical gastrectomy and consequently received AC for pathologic stage 2 or 3 gastric cancer at 27 institutions in South Korea were analyzed. RESULTS: The study enrolled 925 patients, 661 patients (71.5%) who completed 8 cycles of AC and 264 patients (28.5%) who did not. Compared with the mean disease-free survival (DFS) of the patients who completed 8 AC cycles (69.3 months), the mean DFS of patients who completed 6 AC cycles (72.4 months; p = 0.531) and those who completed 7 AC cycles (63.7 months; p = 0.184) did not differ significantly. However, the mean DFS of the patients who completed 5 AC cycles (48.2 months; p = 0.016) and those who completed 1-4 AC cycles (62.9 months; p = 0.036) was significantly lower than the DFS of those who completed 8 AC cycles. In the multivariate Cox proportional hazards analysis, the mean DFS was significantly affected by advanced stage, large tumor size, positive vascular invasion, and number of completed AC cycles (1-5 cycles: hazard ratio 1.45; 95% confidence interval 1.01-2.08; p = 0.041). CONCLUSION: The current multicenter observational cohort study showed that the mean DFS for 6 or 7 AC cycles was similar to that for 8 AC cycles as an adjuvant treatment for gastric cancer.

Trends in laparoscopic anti-reflux surgery: a Korea nationwide study.

BACKGROUND: In 2014, the results derived from the nationwide data of the Korean Anti-reflux Surgery Study (KARS) demonstrated short-term feasibility and safety of anti-reflux surgery. This study aimed to update the longer-term safety and feasibility of laparoscopic anti-reflux surgery up to 1-year follow-up with the KARS nationwide cohort. METHODS: The data of 310 patients with GERD who received anti-reflux surgery up to 2018 were analyzed. Baseline patient characteristics, postoperative symptom resolution, and postoperative complications were evaluated at postoperative 3 months and 1 year using the questionnaire designed by KARS. We divided the patients into two groups according to the operation period (up to and after 2014) to identify changes in the trends of the characteristics of surgical patients and operative qualities. RESULTS: The typical preoperative symptoms were present in 275 patients (91.7%), and atypical symptoms were present in 208 patients (71.0%). Ninety-seven (35.5%) and 124 patients (46.1%) had inadequate PPI responses and hiatal hernia, respectively. At postoperative 1 year, typical and atypical symptoms were either completely or partially controlled in 90.3% and 73.5.0% of patients, respectively. Moderate-to-severe dysphagia, inability to belch, gas bloating, and flatulence at postoperative 1 year were identified in 23.5%, 29.4%, 23.2%, and 22.0% of patients, respectively. The number of surgical patients continuously increased from 2011 to 2018 in Korea. The proportion of patients with hiatal hernia and comorbidities increased (p < 0.01, p = 0.053), and the operation time decreased significantly (p < 0.01) in the late period (2015-2018) as compared with the early period (2011-2014). Symptom control and complication rate were equivalent between the two periods. CONCLUSIONS: Anti-reflux surgery was effective with > 90% of typical symptom resolution and posed a comparable postoperative complication rate with those in Western studies with mid-term to long-term follow-up. This result supports the feasibility and safety of anti-reflux surgery as a treatment for GERD in the Korean population.

A comparison of postoperative outcomes after open and laparoscopic reduction of Petersen's Hernia: a multicenter observational cohort study.

BACKGROUND: The aim of this multicenter cohort study was to compare the clinical courses between open and laparoscopic Petersen's hernia (PH) reduction. METHOD: We retrospectively collected the clinical data of patients who underwent PH repair surgery after gastrectomy for gastric cancer from 2015-2018. Forty patients underwent PH reduction operations that were performed by six surgeons at four hospitals. Among the 40 patients, 15 underwent laparoscopic PH reduction (LPH), and 25 underwent open PH reduction (OPH), including 4 patients who underwent LPH but required conversion to OPH. RESULTS: We compared the clinical factors between the LPH and OPH groups. In the clinical course, we found no differences in operation times or intraoperative bowel injury, morbidity, or mortality rates between the two groups (p > 0.05). However, the number of days on a soft fluid diet (OPH vs. LPH; 5.8 vs. 3.7 days, p = 0.03) and length of hospital stay (12.6 vs. 8.2 days, p = 0.04) were significantly less in the LPH group than the OPH group. Regarding postoperative complications, the OPH group had a case of pneumonia and sepsis with multi-organ failure, which resulted in mortality. In the LPH group, one patient experienced recurrence and required reoperation for PH. CONCLUSION: Laparoscopic PH reduction was associated with a faster postoperative recovery period than open PH reduction, with a similar incidence of complications. The laparoscopic approach should be considered an appropriate strategy for PH reduction in selected cases.

Miniplate With a Bendable C-Tube Head Allows the Clinician to Alter Biomechanical Advantage in Extremely Complicated Anatomic Structure.

BACKGROUNDS: This article reports C-tube miniplates as a practical temporary anchorage device choice to treat open bite patients with maxillary sinus pneumatization. METHODS: The C-tube components are titanium anchor plates and monocortical screws that are basically similar to any other miniplate systems, but it has the unique characteristic of the tube head to be malleable. The manipulation of the head part is easy due to the composition of pure titanium. The I-shaped C-tube with 3 holes and T-shaped C-tube miniplates were placed above the apices of maxillary molars as an absolute anchorage system to intrude the posterior maxilla. The bending of the tube heads assisted in reduction of severe open bite patient with maxillary sinus pneumatization. RESULTS: Sinus perforation during placement of skeletal anchorage system weakens stability of the anchorage and further cause complications. Placement of titanium C-tube miniplates allowed reliable skeletal anchorage and avoided maxillary sinus perforation in patients with extreme pneumatizations. Simple bending of C-tube miniplates ensured increased orthodontic intrusion force without having to replace them, and eliminated consequences such as perforation of maxillary sinus, sinusitis, soft tissue irritation, or infection. CONCLUSIONS: Anatomic difficulties in the placement of temporary anchorage device can be easily managed by using the bendable C-tube miniplate. It can serve as a great alternative over miniscrews or regular miniplates with reduced risk of sinus perforation and ability to bend the head portion to control orthodontic vectors and forces.

Single-Tooth Osteotomy Combined Wide Linear Corticotomy Under Local Anesthesia for Correcting Anterior Protrusion With Ectopically Erupted Canine.

BACKGROUNDS: This article presents the alternative surgical treatments of both anterior protrusion by carrying out retraction on mandibular anterior fragment, meanwhile applying retraction force on maxilla anterior teeth and ectopically erupted canine with using platelet-rich fibrin (PRF). METHODS: Anterior segmental osteotomy was combined with linear corticotomy under local anesthesia. The correction of right ectopic canine was achieved through 2 stages. First, dento-osseous osteotomy on palatal side was performed. Then second osteotomy with immediate manual repositioning of the canine with concomitant first premolar extraction was enhanced with PRF, which was prepared by centrifuging patient's blood, applied into buccal side of high canine during osteotomy. Mandibular retraction was accomplished by anterior segmental osteotomy. RESULTS: Single-tooth osteotomy is a more effective surgical method for ankylosed or ectopically erupted tooth in orthodontic treatment. It can reduce the total orthodontic treatment time and root resorption, 1 common complication. Significant improved bone formation was seen with the addition of PRF on noncritical size defects in the animal model. It is reasonable to think that PRF can promote bone regeneration. So early bone formation also can reduce the complication such as postoperative infection. CONCLUSIONS: As an alternative to anterior protrusion and ectopically erupted canine treatment, segmental osteotomy and corticotomy combined platelet-rich plasma can enhance orthodontic treatment outcome.

A New Designed Expander Supported by Spike Miniscrews With Enhanced Stability.

INTRODUCTION: This article represents a new design of expander-spike expander-to correct transverse maxillary deficiency. This new type appliance is easy to fabricate, more hygienic, and less soft-tissue irritation because of elimination of acrylic plate. In addition, because of the position of mini-implant, it can provide a relatively parallel alveolar expansion, compared with other types of expander. MATERIALS AND METHODS: The spike expander consists of 2 parts: 4 spike screws and an expansion screw. Four spike screws were placed on the palatal slope. After installation of the spike screws, based on the position of spike screw, the extension arms of expansion screw were bended on the cast model, and connected to the spike screws by adding resin. The expansion screw was turned once a day (0.25 mm/d), and the process was terminated at 6 weeks. RESULTS: The stability and design of the spike screw enable widening of maxilla easier. Compared with other expander, spike expander reduces the forces being placed directly on teeth, which can maximize skeletal expansion, minimize dental tipping, produce a relatively parallel expansion, and reduce soft-tissue irritation caused by acrylic pads. Furthermore, the teeth can be aligned and leveled simultaneously using the fixed appliance because teeth are free of contact by the expander. And the best point for spike expander is that it is simply fabricated and removed. CONCLUSIONS: The design of spike expander is combining spike screws and an expansion screw, which can provide a good and easy treatment method for transverse maxillary deficiency.

Study on the deformation of endothelial cells using a bio-inspired in vitro disease model.

A bio-inspired in vitro disease model was developed to investigate the basic biophysics of atherosclerotic diseases. In vivo study was conducted in advance using zebrafish fed with a normal diet and a cholesterol-enriched diet. The endothelial cells (ECs) of the zebrafishes fed with a normal diet are tightly attached and aligned. Their collagen has a fiber-like structure. By contrast, the endothelial cells of the zebrafish on high cholesterol diet are disorganized and their collagen has broken structures. In vitro models of human umbilical vein endothelial cells (HUVECs) were established on collagen films to mimic such in vivo experimental results. The normal collagen film simulates the extracellular matrix (ECM) in the blood vessels of a normal zebrafish, and the collagenase-treated collagen film mimics the ECM in blood vessels of an abnormal zebrafish. The HUVECs cultured on the normal collagen film are tightly attached, similar to those of a normal zebrafish. However, the cells cultured on the collagenase-treated collagen film are aggregated and biomarkers of endothelial dysfunction are expressed on the surface of the abnormal endothelial cells established on the denatured collagen film. The present in vitro model using a bio-inspired collagen film has a great potential for the design of novel therapies for clinical treatments of atherosclerosis through better understanding on the outbreak mechanism of atherosclerosis.

Precise measurement of three-dimensional positions of transparent ellipsoidal particles using digital holographic microscopy.

The dynamic motions of various particles suspended in microscale flows are essential phenomena in the scientific and engineering fields. These motions can be precisely measured by using 3D quantitative flow visualization techniques. Moreover, most cells and particles in nature possess a nonspherical shape. Digital holographic microscopy (DHM) is employed to measure the 3D positional information of transparent ellipsoidal particles. Both in-plane and out-of-plane positional information are obtained by analyzing the distinctive light scattering from the microsized ellipsoidal particles. The performance of the 3D position measurement method is experimentally verified for ellipsoidal particles seeded in a planar surface and a microtube. This DHM technique exhibits promising potential in the dynamic analysis of ellipsoidal particles and cells suspended in various microscale fluid flows.

Versatile Clinical Application of the Spike Screw: Direct Anchorage Versus Indirect Anchorage.

OBJECTIVES/INTRODUCTION: This article represents clinical application of spike screw, novel design of miniscrew, for direct anchorage and indirect anchorage in orthodontic treatment. Accompanied by easy placement and removal, the spike screw provides good stability for the orthodontic anchorage. MATERIALS AND METHODS: The spike screw consists of 6 spikes attached to a washer with laser welded stainless-steel hook that is placed by self-drilling fixation miniscrew. The spike screws were applied to correct malocclusions in patients as follows: traction of impacted canines and protraction of posterior teeth as a direct anchorage and correction of midline discrepancy as an indirect anchorage. For orthodontic traction of impacted canines, spike screws were placed in the mandibular labial mucosal area to create extrusive forces. Afterward, it was utilized for the protraction of posterior teeth. In the second case of the indirect anchorage, spike screw was applied on the midpalatal area to correct midline discrepancy that occurred during orthodontic treatment. The extended hook of a washer was prebended along the curvature of the palate and then secured with a mini screw. The extended hook was bonded to maxillary left first molar. RESULTS: In the first case, the spike screw provided adequate anchorage for the vertical traction of horizontally impacted canine. Since the spike screws were placed in the mandibular anterior lesion, the vertical traction force was applied simply with orthodontic elastics. Also, enough distance was achieved for up-down elastics to work by placing the spike screw in the opposite arch. The force of vertical traction was adjusted with selection of size and force of up-down elastics. Later, it was used to provide anchorage for protraction of mandibular molars without changing orientation of the spike screws. In the second case, the spike screw placed in the midpalatal area was attached to the left first molar and worked as an indirect anchorage. The midline discrepancy was resolved by consolidating the spaces to the left with securing the left first molar location. CONCLUSION: The novel design of the spike screw permits clinicians to have minimum invasive and easy placement and removal of the appliance while maintaining a good control over tooth movement with improved stability in various clinical cases.

Biophysiochemical properties of endothelial cells cultured on bio-inspired collagen films.

BACKGROUND: In this study, we investigated the effect of the extracellular matrix on endothelial dysfunction by careful observation of human umbilical vein endothelial cells (HUVECs) cultured on denatured collagen film. RESULTS: HUVECs on denatured collagen film showed relatively high surface roughness compared with normal HUVECs. The expression levels of MMP-1, MMP-2 and CD146 increased in the ECs on denatured collagen film. In addition, we examined the accumulation of fluorescent beads on HUVEC layers subjected to circulatory flow. The number of accumulated fluorescent beads increased on the disorganized HUVEC layers. CONCLUSIONS: The proposed in vitro study using bio-inspired collagen films could potentially be used in the size- and ligand-based design of drugs to treat endothelial dysfunction caused by circulatory vascular diseases.

High-accuracy measurement of depth-displacement using a focus function and its cross- correlation in holographic PTV.

We propose a method using a focus function and its cross-correlation to measure depth-position and precise depth-displacement. The focus function provides acceptable results in the determination of depth-position of a transparent particle, an opaque particle, and a red blood cell. However, positional errors and a short time interval can cause unreliable results in identifying depth-displacement (Δz) and depth-directional velocity in digital holographic particle tracking velocimetry (DHPTV). To minimize the errors in Δz, we propose a method that directly obtains depth displacement from the cross-correlation of focus values between consecutive holograms. The feasibility of this method is demonstrated by quantitatively visualizing a 3D flow using HPTV.

Measuring the light scattering and orientation of a spheroidal particle using in-line holography.

The light scattering properties of a horizontally and vertically oriented spheroidal particle under laser illumination are experimentally investigated using digital in-line holography. The reconstructed wave field shows the bright singular points as a result of the condensed beam formed by a transparent spheroidal particle acting as a lens. The in-plane (θ) and out-of-plane (ϕ) rotating angles of an arbitrarily oriented spheroidal particle are measured by using these scattering properties. As a feasibility test, the 3D orientation of a transparent spheroidal particle suspended in a microscale pipe flow is successfully reconstructed by adapting the proposed method.

Miniplate with a bendable C-tube head allows the clinician to alter biomechanical advantage without physically moving the skeletal anchorage device.

BACKGROUNDS: This article introduces a binary function of a miniplate with a bendable C-tube head used in corticotomy-assisted segment intrusion. The advantage of the device is that the point of force application can be altered without having to move the miniplate or place an additional anchorage device. METHODS: Cases for this study were selected from patients who received perisegmental corticotomy with compression osteogenesis (Speedy Surgical Orthodontics) for segmental intrusion. For the skeletal anchorage on patients who received Speedy Surgical Orthodontics for posterior segment intrusion to improve on severe open bite correction, the C-tube was placed on the buccal wall of the maxilla for traction of orthopedic force as a temporary skeletal anchorage. The C-tube head portion is made with titanium grade II, which makes bending easy with a Weingart plier. This adjustment regains distance and range needed to continue intrusion of posterior segment. RESULTS: As an alternative to orthognathic surgery to correct a severe open bite, perisegmental corticotomy combined with orthopedic force application from a temporary skeletal anchorage device can be used. The corticotomy-assisted segment intrusion is a 2-stage procedure: first, the corticotomy is performed in the palate and 2 weeks later in the buccal alveolus. A C-plate was placed in the midpalatal area, and a C-tube was placed apical to the buccal corticotomy site. Elastics were used with orthopedic forces to induce compression osteogenesis. As the intrusion took place, the elastic stretched, and resultant force and range in the buccal segment decreased. The C-tube head was adjusted by bending to gain more distance, reviving the elastic force on the posterior segment until desired intrusion was accomplished. CONCLUSIONS: The miniplate with a bendable C-tube head serves for temporary skeletal anchorage of orthopedic traction force to achieve segmental intrusion and has the advantage that the bendable head can be adjusted to improve the force application for intrusion without having to move or place another temporary skeletal anchorage device.

Modification protocol for an early class III treatment using 3 miniplates for bone-anchored maxillary orthopedic traction.

INTRODUCTION: This article introduces the modification of 4-miniplate-assisted orthopedic protocol for class III correction. Instead of bilateral mandibular miniplates between lateral incisors and canine, the single modified Y-type C-tube with extension arms can replace 2 miniplates for temporary skeletal anchorage with advantages. METHODS: Y-type C-tube was modified to have 2 extension arms for the application of class III elastics to replace 2 separate miniplates on either side of the mandible. A patient who declined a facemask therapy was selected to receive the modified protocol using only 3 C-tubes for bone-anchored maxillary orthopedic traction. The modified Y-type C-tube was inserted at the mandibular symphysis, and the bifurcation of the extension arms exited the tissue near the mucogingival junction. RESULTS: The modified Y-type C-tube was placed on the mandibular symphysis, and this provided 3 advantages compared with conventional miniplates: (1) 1 C-tube placement warrants less surgical sites than 2-miniplate installation, (2) placing the C-tube in between mandibular incisors prevents damage to developing or erupting permanent canines and allows early treatment start, and (3) the characteristic bendability of extension arms permits easy alteration on position and results in the vertical and sagittal vector controls of class III elastics. When the treatment is finished, it can be also simply removed like any other C-tubes with simple detachment of extension arms. CONCLUSIONS: The modification of 4-miniplate-assisted orthopedic protocol for class III correction provides easier surgical placement of miniplates by minimizing complications, early initiation of treatment, and more vector control with bendable extension arms of the modified Y-type C-tube.

A novel designed screw with enhanced stability introduces new way of intermaxillary fixation.

INTRODUCTION: This article represents new design of a fixation screw-spike screw-for the intermaxillary elastic fixation application after the first surgery in orthognathic surgery. This new type called spike screw is easily placed and provides enough rigidity for the intermaxillary fixation (IMF) with increased stability that was a common problem using screw-type fixation. MATERIALS AND METHODS: Spike screw has a unique design: a washer with soldered stainless hook that adds stability and fixation to the screw done by a miniscrew. It increases stability by reducing the high peak stress-often occurs in miniscrew-and obtaining the advantage of miniplate system with miniscrew fixation. It allows noninvasive screw placement unlike miniplate. The 8 spike screws were placed on the posterior lesion to provide secure IMF, and 2 I-type C-tubes were placed on the anterior lesion. RESULTS: By modifying the length of the hook attached to a washer can accommodate each patient's IMF length variation like a custom-made screw. The stability of the screw was kept well for 6 weeks even with minor gingival irritation in some of the area. This proved that spike screw could be one of the methods for IMF. The closeness of the hook to the teeth eliminated further gingival irritation around the elastic attachment site. Finally, it provided easy manipulation of the hook to change vectors of the elastic force application. CONCLUSIONS: The novel design of the screw permits easy placement and removal for the IMF. In addition, its advantages include increased stability with unique design, less gingival irritation, and simple vector modification of the IMF elastics by adjusting the hook length and shape.

A Comparative Study of Postoperative Complications Associated with Distal Gastrectomy and Pylorus-Preserving Gastrectomy among Gastric Cancer Patients Based on Nationwide Survey Data and Propensity Score Weighting.

BACKGROUND/OBJECTIVE: This study aimed to compare complication rates between pylorus-preserving gastrectomy (PPG) and distal gastrectomy (DG) using Korean nationwide survey data and propensity score weighting (PSW). PPG preserves gastric function but may lead to more postoperative complications than DG. METHODS AND RESULTS: We analyzed 9424 gastric cancer patients who underwent either DG (n = 9183) or PPG (n = 241). PSW balanced variables such as age, sex, TNM stage, comorbidities, ASA score, and surgical approach. Before PSW, 87.8% of DG patients and 87.1% of PPG patients had no complications (p = 0.053). Severe complications (Clavien-Dindo IIIa or higher) were more frequent in PPG (6.6%) than in DG (3.8%) (p = 0.039). After PSW, overall complication rates (p = 0.960) and severe complication rates (p = 0.574) were similar between groups. Incidence rates of anastomotic stricture and leakage were higher in PPG (2.9% and 1.7%) compared to DG (0.6% and 0.5%) (p = 0.001 and 0.036) before PSW, but these differences were not significant after PSW (p = 0.999 and 0.123). CONCLUSION: The PSW-adjusted analysis indicates no significant difference in overall and severe complication rates between PPG and DG in gastric cancer patients.